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Video magnifiers / CCTV

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According to the American Foundation for the Blind, a video magnifier, or closed-circuit television (CCTV) system uses a stand-mounted or handheld video camera to project a magnified image onto a video monitor, a television (TV) screen, or a computer monitor. [1]

Contents

Stand Mounted Systems

A stand mounted video magnifier.  http://www.lowvision.us/products.php?cat=19
A stand mounted video magnifier. http://www.lowvision.us/products.php?cat=19

Stand mounted systems are typically mounted in one location. The material for viewing is then placed underneath the camera and the signal is then relayed to a computer screen above the camera. A movable “xy table” sometimes called a “reading table” is frequently placed underneath the camera for the material to be placed on. The table is then moved around to capture the appropriate portion of the viewing material. Stand mounted systems are also helpful for writing because they have enough room underneath the camera to accommodate a hand. [1] This video offers more information about stand mounted systems.

Handheld Systems

Handheld cameras are more portable and have a variety of uses. There are a few different styles of handheld portable cameras.

TV linked Cameras

These cameras allow the individual to take their camera to a different location. As long as the individual has access to a television or similar screen, they can use this type of device. The need to have a screen available does limit the locations that this device can be used, but it does allow the individual to have more autonomy to use a device outside of their own home. [2]

Single-Unit

These devices can be small enough to fit inside a person’s purse or pocket. They consist of a camera mounted on one side of the device and an LCD screen on the opposite side of the device. The are powered by rechargeable batteries and can be useful for scanning small objects such as labels, price tags or brochures. The viewable area is limited by the smaller size of the LCD screen, but these can be useful for viewing objects while away from home. [2]

Head Mounted

Head mounted systems use display goggles that can be worn like eyeglasses that utilize LCD screens. These goggles also have built in video magnifiers that transmit the information to the LCD screens on the goggles. These devices can be bulky, but they are useful for viewing information while stationary. They should not be used while walking because of the narrow field of vision generated by the goggles. [2] It is important to note that a 1999 study found here showed that head mounted systems can help during reading, but that individuals with severe vision impairment may not be helped sufficiently by these devices. [3] More information about video magnifiers is available by watching this video.

References

  1. 1.0 1.1 http://www.afb.org/Section.asp?SectionID=4&TopicID=31&DocumentID=221
  2. 2.0 2.1 2.2 http://www.abledata.com/abledata_docs/video_magnifiers.htm
  3. http://www.ncbi.nlm.nih.gov/pubmed/10566860