|
Camcorder Accessories
The Fisher-Price PXL-2000 (also known as the PixelVision by Fisher-Price, and the KiddieCorder by some of its fans) was a toy black-and-white camcorder produced in 1987 that used an ordinary compact audio cassette as its recording medium. more...
 Home
Bags, Cases & Straps
Binoculars & Telescopes
Camcorder Accessories
 Accessories
Batteries & Chargers
Blank Tapes & Memory
Cables, Cords & Connectors
Lenses & Accessories
Camcorders
Digital Camera Accessories
Digital Cameras
Film
Film Camera Accessories
Film Cameras
Film Processing & Darkroom
Flashes & Accessories
Lenses & Filters
Lighting & Studio Equipment
Manuals, Guides & Books
Photo Albums & Archive Items
Printers, Scanners &...
Professional Video Equipment
Projection Equipment
Stock Photography & Footage
Tripods, Monopods
Vintage
Wholesale Lots
When the PXL-2000 was available in retail outlets, it came in two versions—one with just the camera and necessary accessories (power supply, blank tape, etc.), and another which came packaged with a portable black and white television with a 4.5 in (114.3 mm) diagonal screen, for use as a monitor. There were also extra accessories sold separately, such as a carrying case.
Technical information
The PXL-2000 consisted of a simple aspherical lens, an infrared filter, a CCD image sensor, a custom ASIC (the Sanyo LA 7306M), and an audio cassette mechanism. This was mounted in a plastic housing with a bay for consumable batteries and a simple RF video modulator. A plastic viewfinder and some control buttons completed the makeup of the device itself.
The fixed-focus, aspherical lens was actually of quite reasonable quality, and does not significantly differ from that found on many modern low-end digital cameras.
An ordinary cassette transport was used for storage of both audio and video. The PXL-2000 could store 11 minutes of shooting by moving the tape at a high speed, roughly 16 7/8 in/s (429 mm/s) as opposed to cassette's standard speed of 1 7/8 in/s (48 mm/s) on a C90 CrO2 (chromium dioxide) cassette. The high speed is necessary because video requires a wider bandwidth than standard audio recording (In magnetic tape recording, the faster the recording speed, the more bandwidth can be recorded on the tape). The PXL-2000 records the video information on the left audio channel of the cassette, and the audio on the right.
In order to reduce the amount of information recorded on the tape to fit within the narrow confines of even a revved up audio cassette, it used an ASIC to generate slower video timings than conventional TVs use. It scanned the 90 by 120 pixel CCD fifteen times a second, feeding the results through a filtering network, and then to both a frequency modulation circuit driving the left channel of the cassette head and to an ADC, which fed the framestore.
The ASIC connected the digital output of the ADC to a block containing a digital framestore capable of storing two frames of video at the resolution of the image sensor. While one frame was being gradually read out of the CCD into the first framestore section, a previous frame would be scanned out of the second framestore section at full TV frequency. The ASIC was also responsible for generating control signals for the CCD image sensor, and for generating automatic gain control (AGC) signals.
The PXL scanned its 120 by 90 CCD fifteen times a second, meaning that it processed 162000 pixels per second ignoring recovery time; the CCD clocks actually ran at approximately 180kHz. It ran its tape approximately nine times faster than an audio cassette, giving approximately 160kHz of useful bandwidth. This meant that, assuming the tape behaved at specification, it would record only half of the information scanned out of the CCD. With this in mind, the PXL ASIC applied fairly heavy analogue filtering to the video signal to smooth it on exit from the CCD, then pre-emphasize it, offsetting the disproportionate loss of higher frequencies.
Read more at Wikipedia.org
|
|
