An optical mouse uses a light-emitting diode and photodiodes to detect movement relative to the underlying surface, unlike wheeled mice which use a set of one rolling ball and two chopper wheels for motion detection.

Early optical Mice

Early optical mice, first demonstrated by two independent inventors in 1980, came in two different varieties:

Some, such as those invented by Steve Kirsch of MIT and Mouse Systems Corporation, used an infrared LED and a four-quadrant infrared sensor to detect grid lines printed with infrared absorbing ink on a special metallic surface. Predictive algorithms in the CPU of the mouse calculated the speed and direction over the grid.

Others, invented by Richard F. Lyon and sold by Xerox, used a 16-pixel visible-light image sensor with integrated motion detection on the same chip and tracked the motion of light dots in a dark field of a printed paper or similar mouse pad.

These two mouse types had very different behaviors, as the Kirsch mouse used an x-y coordinate system embedded in the pad, and would not work correctly when the pad was rotated, while the Lyon mouse used the x-y coordinate system of the mouse body, as mechanical mice do.
Modern Optical Mice

Modern surface-independent optical mice work by using an optoelectronic sensor (essentially, a tiny low-resolution video camera) to take successive images of the surface on which the mouse operates. As computing power grew cheaper, it became possible to embed more powerful special-purpose image-processing chips in the mouse itself. This advance enabled the mouse to detect relative motion on a wide variety of surfaces, translating the movement of the mouse into the movement of the cursor and eliminating the need for a special mouse-pad.

The first commercially successful optical computer mouse was the Microsoft IntelliMouse® with IntelliEye™, introduced in 1999 using technology developed by Hewlett-Packard. It worked on almost any surface, and represented a welcome improvement over mechanical mice, which would pick up dirt, track capriciously, invite rough handling, and need to be taken apart and cleaned. Instead the reliable performance of the IntelliMouse® allowed relaxed grips which also were less likely to cause repetitive strain injury. Other manufacturers soon followed Microsoft’s lead using components manufactured by the HP spin-off Agilent Technologies, and over the next several years mechanical mice became obsolete.

The technology underlying the modern optical computer mouse is known as digital image correlation, a technology pioneered by the defense industry for tracking military targets. Optical mice use image sensors to image naturally occurring texture in materials such as wood, cloth, mouse pads and Formica. These surfaces, when lit at a grazing angle by a light emitting diode, cast distinct shadows that resemble a hilly terrain lit at sunset. Images of these surfaces are captured in continuous succession and compared with each other to determine how far the mouse has moved.

To understand how optical mice work, imagine two photographs of the same object except slightly offset from each other. Place both photographs on a light table to make them transparent, and slide one across the other until their images line up. The amount that the edges of one photograph overhang the other represents the offset between the images, and in the case of an optical computer mouse the distance it has moved.

Optical mice capture one thousand successive images or more per second. Depending on how fast the mouse is moving, each image will be offset from the previous one by a fraction of a pixel or as many as several pixels. Optical mice mathematically process these images using cross correlation to calculate how much each successive image is offset from the previous one.

An optical mouse might use an image sensor having an 18 x 18 pixel array of monochromatic pixels. Its sensor would normally share the same ASIC as that used for storing and processing the images. One refinement would be accelerating the correlation process by using information from previous motions, and another refinement would be preventing deadbands when moving slowly by adding interpolation or frame-skipping.

The invention of the modern optical mouse at HP was made more likely by a succession of related projects during the 1990s at its central research laboratory. In 1992 John Ertel, William Holland, Kent Vincent, Rueiming Jamp and Richard Baldwin were awarded US Patent 5,149,980 for measuring paper advance in a printer by correlating images of paper fibers. In 1998 Travis N. Blalock, Richard A. Baumgartner, Thomas Hornak, and Mark T. Smith were awarded US Patent 5,729,008 for tracking motion in a hand-held scanner by correlating images of paper fibers and document features, a technology commercialized in 1998 with the HP 920 Capshare handheld scanner. In 2002 Gary Gordon, Derek Knee, Rajeev Badyal and Jason Hartlove were awarded US Patent 6,433,780 for the modern optical computer mouse using image correlation.
Laser Mice

The laser mouse uses an infrared laser diode instead of a LED to illuminate the surface beneath their sensor. As early as 1998, Sun Microsystems provided a laser mouse with their Sun SPARCstation servers and workstations. However, laser mice did not enter the mainstream market until 2004, when Paul Machin at Logitech, in partnership with Agilent Technologies, introduced its MX 1000 laser mouse. This mouse uses a small infrared laser instead of an LED and has significantly increased the resolution of the image taken by the mouse. The laser enables around 20 times more surface tracking power to the surface features used for navigation compared to conventional optical mice, via interference effects.

Glass laser (or glaser) mice have the same capability of a laser mouse but can also be used on top of mirror or transparent glass with few problems.

In August 2009, Logitech introduced mice with two lasers, to track on glass and glossy surfaces better; they dubbed them “dark field” mice.
LED Color

The color of the optical mouse’s light-emitting diodes can vary, but red is most common, as red diodes are inexpensive and silicon is very sensitive to red light. Other colors are sometimes used, such as the blue LED of the V-Mouse VM-101 illustrated at right.
Power

Manufacturers often engineer their optical mice—especially battery-powered wireless models—to save power when possible. In order to do this, the mouse dims or blinks the laser or LED when in standby mode (each mouse has a different standby time). This function may also increase the laser / LED life. Mice designed specifically for gamers, such as the Logitech G5 or the Razer Copperhead, often lack this feature in an attempt to reduce latency and to improve responsiveness.

A typical implementation in Logitech mice has four power states, where the sensor is pulsed at different rates per second:
- 1500: full on condition for accurate response while moving, illumination appears bright.
- 100: fallback active condition while not moving, illumination appears dull.
- 10: standby
- 2: sleep state

Some other mice turn the sensor fully off in the sleep state, requiring a button click to wake.

Optical mice utilizing infrared elements (LEDs or lasers) offer substantial increases in battery life. Some Logitech mice, such as the V450 848 nm laser mouse, are capable of functioning on two AA batteries for a full year, due to the low power requirements of the infrared laser.
Optical Versus Mechanical Mice

Unlike mechanical mice, which can become clogged with lint, optical mice have no rolling parts; therefore, they do not require maintenance other than removing debris that might collect under the light emitter. However, they generally cannot track on glossy and transparent surfaces, including some mouse-pads, sometimes causing the cursor to drift unpredictably during operation. Mice with less image-processing power also have problems tracking fast movement, though high-end mice can track at 2 m/s (80 inches per second) and faster.

Some models of laser mice can track on glossy and transparent surfaces, and have a much higher sensitivity than either their mechanical or optical counterparts but are more expensive than their LED based or mechanical counterparts.

As of 2006, mechanical mice have lower average power demands than their optical counterparts. In practice this is only significant when the mouse is either used with a battery-powered computer, such as a notebook model, or is a battery-powered wireless mouse.

Optical models will outperform mechanical mice on uneven, slick, soft, sticky, or loose surfaces, and generally in mobile situations lacking mouse pads. Because optical mice render movement based on an image which the LED (or infrared diode) illuminates, use with multicolored mouse pads may result in unreliable performance; however, laser mice do not suffer these problems and will track on such surfaces. The advent of affordable high-speed, low-resolution cameras and the integrated logic in optical mice provides an ideal laboratory for experimentation on next-generation input-devices. Experimenters can obtain low-cost components simply by taking apart a working mouse and changing the optics or by writing new software.

The Basic Idea

Webcams, like most things, range from simple to complex. If you understand the essence of a simple Webcam setup, increasing the complexity is only a matter of adding functionality through software, custom code and/or equipment connections.
A simple Webcam setup consists of a digital camera attached to your computer, typically through the USB port. The camera part of the Webcam setup is just a digital camera — there’s really nothing special going on there. The “Webcam” nature of the camera comes with the software. Webcam software “grabs a frame” from the digital camera at a preset interval (for example, the software might grab a still image from the camera once every 30 seconds) and transfers it to another location for viewing. If you’re interested in using your Webcam for streaming video, you’ll want a Webcam system with a high frame rate. Frame rate indicates the number of pictures the software can grab and transfer in one second. For streaming video, you need a minimum rate of at least 15 frames per second (fps), and 30 fps is ideal. To achieve high frame rates, you need a high-speed Internet connection.

Once it captures a frame, the software broadcasts the image over your Internet connection. There are several broadcast methods. Using the most common method, the software turns that image into a JPEG file and uploads it to a Web server using File Transfer Protocol (FTP). You can easily place a JPEG image on any Web page (for information on creating Web pages and adding JPEG images, see How Web Pages Work).

If you don’t have your own Web server, lots of companies offer you a free place to upload your images, saving you the trouble of having to set up and maintain a Web server or a hosted Web site.

This is the simplest possible Webcam. Let’s see what you need to make it happen.

What You Need

In order to create a simple Webcam, you need three things:

•A camera of some sort connected to your computer
•A piece of software that can grab a frame from the camera periodically
•A way to broadcast your images on the Web

If you have your own Web server and Web site, you already have a way to post your Webcam images on the Web. At its most basic, a Web server is simply a piece of hardware that has the ability to deliver Web-based content to a Web browser. For some people, their home computer serves as their Web server. If that’s the case, a camera, a piece of software and your PC are all that you need. If you want to use a Web server that’s hosted elsewhere (for example, if you’re paying an ASP to host your Web server), you also need:
•The ability to move frames from your computer to the Web server, typically by File Transfer Protocol (FTP). For most Web servers, this is no problem; but occasionally, a hosting company will have policies in place that make this difficult.

•A relatively consistent connection between your computer and the Internet. A modem connection to an ISP is fine if it is something that you keep connected most of the time, which implies that you have a dedicated phone line for your computer. If you have something like a cable modem that is connected all the time, that’s perfect.
If you don’t have a Web server or a Web site, and you don’t want one, you can simply have someone else maintain your Webcam images. Lots of Webcam software comes complete with Web-based image access. They usually offer different access options, including remote access, which utilizes UDP protocol to transfer your Webcam images directly from your computer to another computer. This can be done:

•via Web browser, in which case the software itself establishes its own HTTP server so anyone using a Web browser can access the Webcam images on your PC
•via traditional FTP upload to a remote Web server
By using this type of service, you avoid having to host and/or maintain your own Web site. If you are using one of these services and you want the image to refresh itself constantly, you need a relatively consistent connection between your computer and the Internet. If your connection is not consistent, it won’t hurt anything. It just means that the image won’t always be up to date.

Setting It Up

In order to experiment with Webcams and go through the process of setting one up, HowStuffWorks got itself a Webcam. To set it up, here is what we did:

1.We went down to the local computer warehouse and bought the Intel Pro Video PC Camera.

2.We installed the software for the camera on a Windows XP machine.
3.We went to the Web site www.webcam32.com and downloaded a program called Webcam32. This is a popular software package for Webcams. You can get a free demo version or pay $39.95 for the full version. We went ahead and paid for a registered copy. (The complete user’s manual for this product is available on the Web site. Check it out to see the wide array of features available on today’s Webcam software.)

4.We installed Webcam32. It was a very easy installation.
5.After entering the address of the FTP site and a couple of other pieces of information, the Webcam showed its first signs of life!

6.We pointed the camera out the window.
7.We then tuned the software a bit to reduce the file size of the images and to enable the temporary-file copying feature.

There are many different features you can experiment with in Webcam32: streaming video, chat, captions, AVI files and different resolutions and compression ratios, to name a few. Webcam32 also supports the AutoCam feature, which allows you to create a Web page for your Webcam for free on the company’s server. The software makes it simple.
As you can see, setting up a basic Webcam is extremely easy. If nothing else, the setup described here is a fun, inexpensive and simple way to experiment with a Webcam and see what you can do with one of your own!

Advanced Features

Once you manage the simple system, you can look into other Webcam features and settings like:

•Motion sensing – The Webcam takes a new picture when it detects motion.
•Image archiving – You can create an archive that saves all of your Webcam images or only certain images at pre-set intervals.
•Video messaging – Some instant messenger programs support Webcam video.
•Advanced connections – Use wired or wireless methods to connect your home-theater A/V equipment to your Webcam.
•Automation – Robotic cameras let you set a series of pan/tilt positions and program frame-capture settings based on the position of the camera.
•Streaming media – For professional applications, a Webcam setup can use MPEG4 compression to achieve true streaming audio and video (this is the compression system used in most of the popular PC-based media players).
•Custom coding – Import your own computer code to tell the Webcam what to do.

One example of custom coding is a set of commands that makes a Webcam image automatically refresh. The simple Webcam system we’ve set up in this article produces a static image. Users have to refresh the image manually (by pushing the Refresh button in the browser) if they want to see any changes. There are three different techniques you can use to create automatic refreshing:

•You can add a meta tag to the HTML for the page so that the page refreshes at some frequency. The tag to add is:

<meta http-equiv=”refresh” content=”30″>

The “30″ is the number of seconds between each refresh and can be set to anything you like. The entire page will reload every 30 seconds, so it is beneficial to keep the page short.

•You can add a Java applet to your site. The Webcam32 and Java Applets page explains how to obtain and install the free applet. The applet is a program that automatically fetches the image periodically. The advantage is that only the image refreshes, not the entire page. Most browsers support Java applets, so most of your viewers will have no problem.

•You can use JavaScript, as demonstrated on The JavaScript Source: Refresh (look at the source code on this page). You can also check out How Java Works for a detailed look at Java programming.

Webcam Networking

One problem with using a camera hooked to a computer via a USB cable is the limited cable length. What if the room you want to capture is at the other end of the house, or outside? In that case, you need to purchase a camera with external connections. You have a few options:

•You can place a standard camera anywhere in the house and run a video cable with RCA jacks on it from the camera to the computer. There are all sorts of places on the Web that sell small pinhole video cameras, either on their own or embedded in things like clocks and smoke detectors. You can find small security cameras for less than $100. (Click here to use the HowStuffWorks search engine to search for security cameras.)

•You can avoid the cable by using a radio link (X10: XRay Vision is one example of this type of product), an Ethernet connection or a WiFi setup. If you already have a home network, connecting an external Webcam to your computer probably won’t require any additional networking.

Monitoring your home and sharing images via the Web are only a couple of the things you can do with your Webcam. There are any number of ways to make use of a camera that’s connected to your computer. You can get software that will let you make video phone calls with a friend who also has a Webcam. You can hold a video-conferencing session with business associates on the other side of the world. You can conduct a video interview and broadcast it live on your blog. Some Webcam software will even deliver images directly to your Web-enabled PDA or smartphone. Other products let you connect your camcorder to your Webcam setup so you can let everybody watch your vacation footage via the Internet. The possibilities are endless.

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LED TV’s and monitors are part of the new High Definition generation. Quite simply, LED (Light Emitting Diode) technology uses individual backlights which in many cases can be tuned on or off in areas to allow for precision control of the lighting emitted from the TV screen or monitor. This differs from traditional backlighting which uses a CCFL (Cathode Fluorescent Lamp) that involves several fluorescent tubes placed horizontally across the screen. The enhanced benefits of LED technology allow for a sleeker screen design plus improved brightness potential, colour reproduction and viewing contrast.

The following guide will help you get to grips with LED technology so you can decide for yourself whether it deserves the must-have hype.

Types of LED Lighting

The first thing to understand is that there are two distinct types of LED TV screens or monitors based on how the LED backlighting is arranged:

Edge-lit screens

This type of TV screen or monitor has a row of LED backlights placed around the edges of the screen panel, which shine into a multi-layered diffuser panel creating a uniform view. Because the lights surround the perimeter of the screen instead of being behind it, edge-lit models allow for an ultra sleek design.

Full-matrix screens

These models have their LED lights arranged across the back of the display, which then feed through a diffuser panel to make the backlighting even. The most effective LED TV’s or monitors of this range have a feature called ‘local dimming’ or ‘smart dimming’ – this allows you to dim or switch off particular sections of the lighting elements while leaving other areas at full brightness. The result is enhanced picture contrast of black levels and other colours. It must be said that without this ability to fine tune the LED lighting to your tastes, LED TV’s are generally very similar to traditional LCD TV’s.

LED Viewing Quality

Colours

For on-point colour accuracy, LED TV’s and monitors with coloured backlighting are the best option. The display is still impressive however with the other type of LED lights which are white.

Definition & Contrast

As explained above, LED TV and monitors with the ‘local dimming’ feature gives you the power to control the backlighting arrangement for an improved picture quality in terms of definition and colour contrast. The result of being able to dim or switch off certain sections of the LED lights allows for darker blacks and enhanced definition while viewing dark-lit images. The other models that don’t have this feature are still high in viewing quality to the eye of the average person, but a true visual connoisseur will notice that uniform LED backlighting causes some areas of the screen to be better lit than others.

Angle of View

Because of the flat screen used by LED technology, it must be noted that this design suffers slightly from contrast degradation when the screen or monitor is viewed at angles of more than approximately 30 degrees from the centre. This issue has been significantly improved on over the past few years and has now advanced sufficiently to offer better viewing quality than plasma screens.

Size and Cost of LED TV’s

Televisions with LED backlights are currently on offer in sizes that range from 46 to 70 inches. While they generally cost a fair amount more than their traditional LCD television counterparts, many people are happy to pay the extra cost to have the best picture quality possible.

Life Expectation

As a general rule of thumb, TV manufacturers say their products have the longevity of approximately 100 000 hours. Since LED TV’s are quite new to the marketplace, this life expectation has not been fully confirmed as yet, however LED lights are known to last for a reasonably long period of time. LED backlighting technology is also said to suffer less degradation in colour over time than LCD models.

Power Usage

LED backlights offer better energy efficiency than CCFL-based backlights. It must be said however that a LED TV with the local dimming feature will use more electrical power than a traditional or edge-lit LCD TV that has the same screen size.
Whether you’re looking to buy a LED TV or LED monitor, the above information gives you the key facts about this new technology so you can make the right choice when shopping around for your viewing needs. As there are now an increasing amount of models available from different manufacturers, it’s crucial to do your research so you can be sure of finding the manufacturer and model that offers the best quality for your money.

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USB 1.1, USB 2.0, and USB 3.0

History

USB stands for Universal Serial Bus. USB is a plug-and-play interface used between computers and add-on devices (such as audio players, joysticks, keyboards, scanners, mass storage devices, and printers). With USB, a new device can be installed into your computer without having to add an adapter card, or even having to turn the computer off. USB CD-RW drives can be installed by simply plugging them into the computer at any time during operation. The USB peripheral bus standard was jointly developed by Compaq, IBM, DEC, Intel, Microsoft, NEC, and Northern Telecom (though it is in small-part based upon a similar Serial Interface was developed for Atari Home Computers in 1980). The first computers that began shipping with USB capability, began showing up in late 1996. Today, the technology is now openly available for all computer and device vendors. Currently, USB is available on over 90% of computers manufactured today.

Why USB?

The purpose for USB was to provide a universal interface that would eventually replace different types of peripheral interfaces (parallel ports, serial ports, PS/2, etc.), while maintaining wide compatibly with current and future Windows operating systems. Since late 1996, Windows operating systems have been equipped with USB drivers or special software designed to work with specific USB I/O devices complying with the USB 1.0 Standard. With the introduction of Windows 98, a newer USB 1.1 standard was, for the first time, completely integrated within the operating system. The newer USB 1.1 Standard provided for tighter integration with Microsoft’s Plug and Play standard (PnP), making installation of external devices and peripherals virtually hassle-free, while still maintaining backward-compatibility with existing USB 1.0 devices. USB has since been integrated into every Windows operating system, with the exception of Windows NT.  While we tend not to think much about this technology, it was not so long ago that almost every device involved complex installation processes, and unique adaptor cards.

USB Today

Today, most new computers and peripheral devices are equipped with USB capability. The USB 1.1 Standard’s integration into the Windows 98 operating system was the catalyst that allowed countless USB devices to be created and sold for use with personal computers. USB has slowly become the interface of choice for connecting such devices as keyboards, mice, scanners, printers, external hard drives, thumbprint scanners, and even thumbdrives! However, newer and more-bandwidth-demanding devices such as digital cameras and external mass storage devices began to demonstrate the limitations of the USB 1.1 Standard. In late 2001, the USB 2.0 Standard was introduced to bridge the performance gap between the USB 1.1 Standard and the demand of high-bandwidth devices, while still maintaining wide compatibility with the current USB 1.1 Standard.

USB 2.0 is over 40 times faster than USB 1.1, with data throughput speeds reaching up to 480Mbits/s. The chart below compares USB 2.0 performance with existing USB 1.1 performance, as well as other interface standards.

 Compatibility

If you have an older PC, you may very well have a USB 1.1 interface.  USB is backwards compatible (as long as the cable connector fits).  A 1.1 port means devices will work at 1.1 speeds, etc.

Newer USB Standards

SuperSpeed USB from the USB-IF
 As technology innovation marches forward, new kinds of devices, media formats, and large inexpensive storage are converging. They require significantly more bus bandwidth to maintain the interactive experience users have come to expect. In addition, user applications demand a higher performance connection between the PC and these increasingly sophisticated peripherals. USB 3.0 addresses this need by adding an even higher transfer rate to match these new usage and devices.

USB continues to be the answer to connectivity for PC, Consumer Electronics, and Mobile architectures. It is a fast, bidirectional, low-cost, dynamically attachable interface that is consistent with the requirements of the PC platforms of today and tomorrow.

SuperSpeed USB brings significant performance enhancements to the ubiquitous USB standard, while remaining compatible with the billions of USB enabled devices currently deployed in the market. SuperSpeed USB will deliver 10x the data transfer rate of Hi-Speed USB, as well as improved power efficiency. 

•  
  • SuperSpeed USB has a 5 Gbps signaling rate offering 10x performance increase over Hi-Speed USB.
  • SuperSpeed USB is a Sync-N-Go technology that minimizes user wait-time.
  • SuperSpeed USB will provide Optimized Power Efficiency.No device polling and lower active and idle power requirements.
  • SuperSpeed USB is backwards compatible with USB 2.0. Devices interoperate with USB 2.0 platforms. Hosts support USB 2.0 legacy devices.

Wireless USB from the USB-IF
With more than 2 billion legacy wired USB connections in the world today, USB is the de facto standard in the personal computing industry. Soon, these same, fast, interoperable connections will become available in the wireless world, with the introduction of Wireless USB from the USB-IF.  Wireless USB is the new wireless extension to USB that combines the speed and security of wired technology with the ease-of-use of wireless technology. Wireless connectivity has enabled a mobile lifestyle filled with conveniences for mobile computing users. Wireless USB will support robust high-speed wireless connectivity by utilizing the common WiMedia MB-OFDM Ultra-wideband (UWB) radio platform as developed by the WiMedia Alliance.

UWB technology offers a solution for high bandwidth, low cost, low power consumption, and physical size requirements of next-generation consumer electronic devices. 

•  
  • Wireless USB is the first high-speed wireless personal interconnect technology to meet the needs of multimedia consumer electronics, PC peripherals, and mobile devices.
  • Wireless USB will preserve the functionality of wired USB while also unwiring the cable connection and providing enhanced support for streaming media CE devices and peripherals.
  • Wireless USB performance is targeted at 480Mbps at 3 meters and 110Mbps at 10 meters.

USB On-The-Go and Embedded Host
Virtually every portable device now uses USB for PC connectivity. As these products increase in popularity, there is a growing need for them to communicate both with USB peripherals and directly with each other when a PC is not available.  There is also an increase in the number of other, non-PC hosts (Embedded Hosts) which support USB in order to connect to USB peripherals.

The newly published Revision 2.0 of the USB On-The-Go and Embedded Host Supplement addresses these scenarios by allowing portable devices and non-PC hosts to have the following enhancements: 

•  
  • Targeted host capability to communicate with selected other USB peripherals
  • Support for direct connections between OTG devices
  • A small USB connector to fit the mobile form factor
  • Power saving features to preserve battery life

Firmware refers to read-only memory (ROM) chips that store permanent instructions. Firmware boots up computerized or digital devices, as ROM chips are non-volatile, meaning they do not require a power source to hold their contents. This differentiates firmware from random access memory (RAM), for example, which loses stored data at shutdown. Perhaps the most familiar firmware is the basic input output system (BIOS) chip. The BIOS chip on a computer motherboard holds instructions that, upon powering up, initialize the hardware, ensure components are working, and finally roll out the operating system to take over.

In the past, firmware chips could not be rewritten. When the BIOS became outdated, the only option was to buy a new motherboard. New firmware would understand the latest hardware so that the user would not be limited to older drives and other legacy technologies when facing inevitable upgrades.

It became clear that a new type of firmware chip that could be updated would be extremely beneficial. This became possible with flash memory chips. With the BIOS written to this type of chip, a user could connect to the manufacturer’s website, download a firmware upgrade to diskette and flash the BIOS chip during boot-up to install a new set of instructions. All quality motherboards today feature a flash BIOS, or upgradeable firmware.

Firmware is at the heart of virtually every popular digital device. Portable audio players, cell phones, personal digital assistants, digital cameras and gaming consoles are just some of the devices that use firmware. When shopping for electronic items, take note that if the firmware can be flashed, the product is usually advertised as being ‘upgradeable.’ This is accomplished online by connecting the device to a universal serial bus (USB) or FireWire port on your computer system and following instructions from the manufacturer’s website.

Upgradeable firmware has extended the life of countless electronic devices, adding new functionality. However, flashing firmware is also risky, as the device will not boot if the flashing process is interrupted or becomes corrupted. When upgrading firmware, be sure to follow instructions carefully and back up any important data beforehand.

source: http://www.wisegeek.com/what-is-firmware.htm

A Guide To How To Choose The Right Type Of Camera

Choosing the right camera can be an extremely difficult task. There are literally hundreds of cameras to choose from, and making the wrong choice is the last thing you would want to do. Choosing the right type of camera for your needs would probably be the most important decision you will have to make before completing that purchase.
Digital cameras are generally categorized into three types; the digital point & shoot camera, the digital bridge camera, and the digital SLR camera. Each camera type has its advantages and disadvantages. It is now up to you to determine which type of camera fits your photography needs and budget.

Digital Point & Shoot Cameras

The digital point & shoot camera is the smallest of the three types and is usually the simplest to use. They are designed to be very handy. They can be easily placed in a purse or a briefcase, and some are even small enough to fit into a shirt pocket. Today’s digital point & shoot cameras feature bright LCD screens which also double as digital viewfinders which allow the user to frame their pictures perfectly without the fear of cutting off someone’s head in the photo. Most digital point & shoot cameras also feature multiple program modes that tackle specific situations or lighting conditions adding creativity and fun to photography.

Although digital point & shoot cameras are basically easy-to-use cameras that don’t require the user to have any formal training in photography, choosing the right camera for the right needs may call for a little more thought. Things to look out for when choosing a digital point & shoot camera are its maximum resolution, its optical and digital zoom range, and the type of battery it uses.

The megapixel rating in the form “MP” usually denotes the maximum resolution of each digital point & shoot camera. The higher the “MP” rating, the higher the resolution gets which allows you to print larger photos without sacrificing sharpness or quality. Choosing a camera with a good mix of optical and digital zoom may also be a good idea. Be reminded though that images taken with an optical zoom lens will always be better in quality when compared to those taken with the digital zoom feature of a digital point & shoot camera.

Most digital point & shoot cameras today are powered by proprietary rechargeable batteries that require a special AC charger. If you intend to do a lot of traveling where an AC outlet may be hard to find, look for a digital point & shoot camera that is powered by AA batteries. This type of battery can be found almost anywhere around the world.

If you intend to use the camera for shooting people in parties or small gatherings, look for a camera with a zoom lens that has it widest setting at no more than 36mm (equivalent focal length in 35mm film).

If you shoot a lot of sports and portraits, you will find that digital point & shoot cameras that offer lenses that have a zoom setting of 85mm (equivalent focal length in 35mm film) and above can give you flattering photos. At this focal length though, camera shake may occur resulting in blurred photos. To avoid camera shake, look for a digital point & shoot camera equipped with an image-stabilizing feature.

Zoom lenses are labeled from its widest setting to its longest setting in terms of focal length. An example would be 4.5-17.3mm f/2.8-4.9 (35mm film equivalent: 35-105mm). Some digital point & shoot cameras state the 35mm equivalent on the lens itself while others state it only in the technical specifications of the users’ manual.

Another feature found on many point and shoot cameras is Face Detection, which finds individual or multiple faces in the frame and sets the most suitable focus point, when the shutter button is pressed halfway. And an additional feature, Face Detection on some models adjusts the flash, based on a person’s face on the screen. Exposure and flash are controlled to ensure proper illumination of both the faces and the overall scene, eliminating the common problem of darkened or overexposed faces.

Digital Bridge Cameras

The digital bridge camera, as its term implies, bridges the gap between the digital point & shoot camera and the digital SLR camera. Built larger than the digital point & shoot camera, it usually comes equipped with a larger lens that looks almost like those found on digital SLR cameras. It also uses a larger imaging sensor, which means it can produce better quality images when compared to digital point & shoot cameras. The controls and functions of the digital bridge camera are very similar to those found on digital SLR cameras making them ideal for advanced users and for those who are looking for the best all around performance in an all-in-one camera. Most digital bridge cameras also come with an accessory shoe, also referred to as a hot shoe, for attaching auxiliary flash units or triggering devices that can be used to control studio flash systems.

Some digital bridge cameras are equipped with superzoom lenses in the 12X range. An example is the Canon PowerShot S5 IS, which has a 6.0-72.0mm f/2.7-3.5 (36-432mm equivalent focal length in 35mm film) zoom lens that offers a versatile 12X wide angle to super telephoto coverage. Other digital bridge cameras utilize a moderate 3.5X zoom lens but can be supplemented with add-on wide angle or telephoto converter lenses to extend its zoom range.

Digital SLR Cameras

Digital SLR cameras are system cameras that offer a wide selection of lenses. They feature the most advanced focusing and metering systems and are the most versatile of the three types of digital cameras. Another advantage of digital SLR cameras is that it offers reflex viewing where you see exactly what the lens sees real-time. This leaves no mistake of missing that important shot.

Lenses for digital SLR cameras can range from special fish-eye lenses that cover a 180° picture angle, to super-telephoto lenses with a focal length of 1200mm. A 1200mm super-telephoto lens is powerful enough to fill up the frame of a digital SLR camera with the image of the moon. Digital SLR cameras can also be fitted with special application lenses such as those used for architectural photography called perspective control lenses or those used for macrophotography called macro lenses.

A good moderate zoom can be a handy choice as an all around lens for a digital SLR camera. Some digital SLR cameras even come bundled with a moderate zoom lens commonly referred to as a kit lens. But if more versatility is needed, a lens having a 10X zoom range may be a better choice.

Weatherproof Cameras

If you spend a lot of time in the weather outdoors, especially rain, then another option for you is a Weatherproof or Waterproof submergable camera.

Digital Weather/Waterproof Cameras Are Available In Point And Shoot And SLR

Digital Still/Video Camcorders

Yet another category of digital cameras are Digital Camcorders, that offer the ability to take both still photos and digital video.

This class of cameras come with a huge range of features and capabilities. However, it the Digital Camcorders flexibility that sets them apart. The offer storage on Hard Drives, DVDs, and DV tapes.

In Summary

If you are looking for a camera that offers the best image quality, the versatility of handling different shooting situations, and the ability to use interchangeable lenses and accessories, then the SLR is the best camera for you.

If you are looking for an all-in-one camera which offers digital SLR-like performance with the ease of use of a point-and-shoot, then a digital bridge camera may suit your needs better. But, if ease of use is most important to you and the ability to bring your camera anywhere without weighing you down, then get a digital point & shoot camera.

Camera Selection Check List

• Buy the camera with the highest resolution you can afford, at least 4 to 6 megapixels (4 million to 6 million pixels), if possible.
• Look for a 100 percent glass lens as opposed to a plastic one – With the exception of Fluorite lenses which have been used in pro-quality equipment. Fluorite is technically not glass but a crystal.
• Buy a camera with as much built in memory as you can afford. More built-in memory means the camera can store more pictures so you won’t need to download or erase them as often. But also look at the removable memory technology supported by the camera, so that you have the maximum capacity you will need.
• Expect zoom to be the feature you will use most. Compare optical, as opposed to digital, zoom capabilities.
• Compare flash modes, if any. Other than the basic flash modes, some cameras have slow-sync flash, and some go even further by adding rear curtain sync flash.
• Recognition modes, such as Face Recognition.
• Investigate viewfinders: Look for an optical (through-the-lens) viewfinder as well as an LCD display. Through-the-lens(TTL) is a term associated with SLR cameras. No point & shoot camera features a Through-the-lens optical viewfinder. Some may offer optical viewfinders but are not free from paralax errors. Bridge cameras may feature TTL electronic viewfinders.
• Consider autofocus and macro features, shutter-release lag times, camera start-up time, and bundled software.
• Compare additional features you might want: interchangeable lenses, steady-shot, burst mode, auto and manual exposure modes, automatic white balance, voice memo, variable shutter speeds, manual focus and self-timer.
• Compare removable media of various types (if you need more storage space for your photos).
• Investigate batteries, chargers and battery-saving features. For DSLRs and Bridge cameras, other power accessories are frequently available, these include AC power supplies to power the unit indefinitely
• Look for additional features you might need, such as USB or IEEE 1394 (FireWire) connectivity (to connect the camera to the appropriate port on your computer), a battery-time-remaining indicator, an AC adapter or video-out connections for outputting to a television, and WiFi.

Exactly what are these new technologies?

OLED TVs and Laser TVs offer two versions of television technology. These two types of televisions have multiple similarities to consider. They also have individual benefits to consider before you make your final purchase.

First, there are concerns over both technologies and they are:

* Laser: Some techies have raised questions of the effect of prolonged exposure to the lasers that project the image onto the screen. Manufactures say it is fine, but research is in progress.
* OLED: The organic material will deteriorate and this affects the picture quality. We would like to add that this is after thousands of hours use. They are looking into prolonging its lifetime.

We are sure they will be improve and addressed over time, giving us all confidence in future developments.

OLED TV
Sony 11″ OLED TVThe Technology Behind OLED
OLED television (Organic Light Emitting Diode television) features LEDs that have a luminescent layer that is made of organic compounds. This technology allows a matrix of pixels to be created. This matrix of pixels allows the LEDs to emit light of multiple different colors and intensity.

Benefits of OLEDs
OLED televisions allow for a wide range of colors. The matrix that is created, along with the organic compound, allows for amazing brightness and contrast. The OLED television allow for a deeper black on the screen, which offers greater contrast with each screen. OLED TVs are also known for their low power consumption. They do not use as much power as many of the TV types on the market today, including Laser TV.

Laser TV
The Technology Behind Laser Televisions

Panasonic Laser TVLaser TVs use multiple waves to create the colors that are needed for the television picture. The use of lasers allows for an accurate projection.

The waves follow the idea of the old projection TVs. Laser TVs are large, utilizing the laser technology to give a clear, sharp, stable picture over a large area with great color depth, contrast and strong blacks.

Benefits of Laser TVs
Laser TVs are known for having a wider range of colors than OLED TVs. These televisions are also known for being lightweight, and for being relatively thin. Laser TVs are known for having a long life, and for keeping the picture quality throughout their lives.

Choosing Between the Two

OLED TVs are perfect for people who want a smaller TV. The current technology only allows for smaller TVs at present. If you are looking for a larger TV, you will want to look towards Laser TVs. OLED TVs rarely tip the 11 inch for commercial production. Laser TVs, on the other hand, have been created, commercially, over 60 inches.

Laser TVs have come to the market at a lower price than OLED TVs. Eventually, the price of the OLED TV will drop. The technology is still new, and is still expensive. As technology progresses and the sizes get larger, prices will lower.

Laser TVs have progressed further than OLED TVs. Eventually, the technology behind the OLED TV will catch up. Until then, Laser TVs meet the needs of the consumer more than the OLED TV. Each TV serves a different market, as the projection technology behind the laser TV caters to a larger screen.

source:
http://www.hdtvinfoport.com/oled-laser-comparison.html

Enabling crisp full-motion video

With the recent widespread use of PC and online games, and PCs equipped with DVD drives give users more opportunities to see moving images such as those in 3D games or action movies on screen. This increase in motion picture content means computer monitors must be able to display not only still images, but moving ones as well.

Manufacturers and IT publications often cite a fast response time as an indication that a display can play videos or games with little or no blurring. Hence, we would like to share with you what response time is, and how helpful it is in determining how well an individual LCD display can portray moving images.

Response time:
Why is it increasingly important for LCD applications?

If response time is slow, the transition from one picture (or frame) to another can produce an afterimage or blurring effect. This problem occurs not only when looking at motion pictures, but also during scrolling. For this reason, panels with faster response times are typically recommended for displaying moving images. Listed below are calculations for the liquid crystal response times that LCD displays meet, with consistent reliability, for various application standards. Response time is measured in milliseconds (ms, 1/1000 second). The shorter the time frame, the better the display quality.

 
Crisp Low Response Rate at Left and High Response Rate at Right.
Notice the blurring that occurs (right image) with High Response Rates.

LCD RESPONSE RATES
30 ms:1/0.030 = 33 fps meets specs of NTSC (30 fps), PAL (25 fps) or movie (24 fps) standards
16 ms:1/0.016 = 63 fps meets the spec of HDTV (60 fps) standards
12 ms:1/0.012 = 83 fps meets VESA flicker-free display with CRT of 72 fps and human-eye perception
8 ms:1/0.008 = 125 fps 3D PC games requirement
4 ms:1/0.004 = 250 fps Professional 3D PC games requirement
fps = frame (picture) per second

What is response time?

The transition time when LC materials are rotating on each of the required white/black or gray levels is called “rise time” and “fall time,” respectively. Normally, the transition time of 256 x 256 LC rotation levels needs to be measured. However, some companies don’t measure degree levels due to limitations of equipment capability.

Liquid crystals are rarely completely turned on or off. Instead, they cycle in between gray states. The following are two common methods some manufacturers use to measure response time:

On-Off response time Refers to the change time for screen pixels to turn from white to black (Tr) and from black to white (Tf) when the screen receives the signal. However, it does not indicate the transit time between gray levels.

Gray-to-Gray response time:

Since virtually all moving images include gray levels, and the frequency of gray-to-gray transitions is typically far greater than black-and-white transitions, we use the Gray-to-Gray response time definition to address the gray-to-gray transition time, allowing us to make an accurate assessment of a displays’ suitability to portray moving images.

At present, there is no accepted standard for the computation of Gray-to-Gray response time. However, as a company that emphasizes product reliability, most manufacturers insist on using the average to gauge performance, delivering better value to the end user.

How some manufacturers accelerate response times and guarantees reliable products:

Lower rotational viscosity liquid crystal materials and reduced cell gap thickness enhance “On-Off Response Time” performance.

To rapidly improve liquid crystal on-off response time, some manufacturers have developed products with lower rotational viscosity liquid crystal materials and reduced cell gap thickness during the first stage.

Many manufacturers overcome technical challenges such as non-uniformity and side effects caused by new LC materials in the LC-cell manufacturing process. Furthermore, new products undergo strict testing before launch.

Higher voltage with overdriving technology reduces the moving image’s “Gray-to-Gray response time.”

These quick response times modeled with new LC materials and a thick cell gap have earned such products much praise in the market in terms of capability and reliability, encouraging their makers to keep seeking new technologies for product upgrades. Models with overdriving technology have been integrated into many LCD displays, from manufacturers such as Acer, accelerating response times, especially for gray-to-gray.

Faster gray-to-gray response time via overdrive (OD) technology

The key benefit of OD technology is the clear improvement of the gray-to-gray level, which is the most important factor in the moving-picture viewing experience. Liquid crystal molecules respond faster to the high voltage that’s needed for black-white transitions than to the low voltage that’s needed for transitions between gray areas. Therefore, even though going from one grayscale level to another is less of a jump than going from black to white, the gray-to-gray transition time can actually take longer. Two LCD panels with the same black-white response times but with different gray-to-gray response times will have different moving picture playback capabilities.

As the figures below show, using an overdriving algorithm, LCD displays can reduce the deviation in the transition time and approach ideal performance. This significant improvement allows LCDs to deliver high-quality moving pictures for 3D games and videos.

A liquid crystal display (LCD) is a thin, electronic flat panel used to display information and images. It includes monitors for computers, televisions, instrument panels, and other devices ranging from aircraft cockpit displays, to every-day consumer devices such as video players, gaming devices, clocks, watches, calculators, and telephones. LCDs are simply everywhere now.

Its major features and benefits are: lightweight construction (compared to Plasma displays); portability (in the case of smaller displays); the ability to be produced in much larger screen sizes than were practical for older Tube (CRT) displays; and perhaps most important, its much lower power consumption.

Technically, an LCD display is an “electronically-modulated optical device” made up of any number of tiny pixels filled with liquid crystals and arrayed in front of a light source (backlight) or reflector to produce images in color.  The earliest discoveries leading to the development of LCD technology date from 1888. Today, tube CRT displays are almost a thing of the past!

Unfortunately, from time to time, a new LCD TV or Monitor will have a problem pixel.  This is where the physical crystal actually is stuck or frozen in place.  However, don’t panic, since these can frequently be fixed.

There are three basic types of problem pixels:

• a hot pixel (always on, usually white)
• a dead pixel (always off, black)
• a stuck pixel (one or more sub-pixels (red, blue or green) are always on or always off)

To solve a problem pixel, it is recommended to let the display fully warm up (leave on for at least a full day) – this alone can fix many problems, as the display expands due to warming and can free the pixel.  Always try this before calling for help.  Next, call the manufacturer’s technical support for other techniques that they might recommend – each manufacturer may have different solutions for their products.  There are also other techniques that you might try, but always be careful not to damage your display, as this might void your warranty. 

LCD Problem Pixel Policy
In the event that warranty service or an exchange is required, it is important to understand that every manufacturer has their own dead pixel policies, and that they should be contacted about solutions before requesting any exchange.  We want you to experience the best possible image on your LCD, so typically, an LCD TV or Monitor with 5 hot, dead, or stuck pixels would qualify for an exchange within the first 30 days of ownership after support efforts have been exhausted.  See the product warranty below for more information.

LCD Technology

How LCD’s Work

The twisted nematic (TN) is the most common type liquid crystal used in display applications such as LCD televisions, monitors and projectors. It is so named because it has a naturally twisted crystalline structure. This crystal reacts to electric currents in predictable ways, such as untwisting to varying degrees depending on the voltage of the current to which it is exposed. The main difference between plasma and LCD technology is that LCD pixels don’t emit light. As with plasma technology, an LCD pixel is comprised of three sub-pixels in the elementary colors. Because they don’t emit light, LCD displays need white backlighting. The light emitted by the backlighting passes through the liquid crystal and is then colored by a filter. Each subpixel has the same characteristics; only the color of the filter changes depending on the pixel. The liquid crystal of each subpixel can be controlled electrically like a valve; the amount of light allowed to pass through the crystal governs how much red, green and blue is emitted for each pixel. Active matrix LCDs employ thin film transistors (TFTs),m or tiny switching transistors and capacitors arranged in a matrix on a glass substrate, to direct electric charges down columns to reach a particular pixel. In turn, this causes the liquid crystals to untwist and display a predetermined amount of light generated by the light source – usually a fluorescent bulb located in back of them. By exploiting a combination of red, green, and blue subpixels of various intensities (or gray scales), a single pixel triad can reproduce approximately 16.8 million colors.

LCD Pluses

LCDs offer higher resolutions than plasmas of the same size. They also have excellent image stability. In other words, you can sit close without experiencing eye fatigue. Additionally, LCDs boast a longer lifetime than plasma televisions – on average about 50,000 hours versus 30,000 hours. Also, If you’re contemplating a home entertainment setup involving a PC–perhaps running Windows XP Media center Edition – or other activities involving text as well as graphics, you’ll get a crisper, brighter image from an LCD. LCDs are also space-efficient and because they operate at much cooler temperatures cost less per hour than plasma televisions. The smaller and better transistors found in LCDs give them another advantage over plasma – higher resolution.

LCD Minuses

LCD viewing angles cannot match those of plasma displays. You tend to see some brightness and color shift when you’re sitting at too far an angle from your LCD, while a plasma’s picture remains fairly solid. LCDs also have lower contrast ratios than plasmas and are not as good at rendering deep blacks. Additionally, they are not as good as plasmas in tracking motion and fast-moving objects may exhibit what is called, lag artifacts.

LCD Uses

The area where LCD reigns supreme over any other flat-panel displays is, of course, computers. LCD monitors can now be used for most applications including games, office applications, and photo retouching. But it’s another story for television. LCD is lagging behind plasma, but it’s available in more reasonable display sizes. In terms of absolute video quality, plasma is still tops, because it offers blacks as good as what CRTs can display, exceptional viewing angles, and unmatched color. However, LCDs are closing the gap little by little with technologies that are constantly being refined.