Abstract: In a CMOS-based photosensor chip, the area between the last photosensor in a linear array of photosensors and the edge of the chip can be a source of unintended charge generation affecting the last photosensor. A guardring, in the form of a biased diffusion area, prevents the unwanted leakage of charge from the edge area to the end photosensor.

Abstract: An image sensor array includes a plurality of photosensor chips, which are butted end-to-end to form a single linear array of photosensors. Each individual chip in the array is provided with an independently-addressable output enable line and video output line. This configuration allows individual chips to be addressed to output image data at specific times and in a specific manner suitable for any kind of downstream circuitry.

Abstract: A depleted-gate photosensor, or photogate, structure includes a polysilicon layer disposed over a silicon substrate. The polysilicon layer occupies only a portion of each exposure area of the substrate, and is preferably in the form of a ring around the exposure area. By having a portion of the exposure area not covered by the polysilicon, the blue-light-attenuation effects of a polysilicon layer are reduced.

Abstract: In a photosenstive device wherein video voltage signals are output from a plurality of photosensors, the photosensors are divided into odd and even subsets. Odd photosensors output video into an odd video channel, and even photosensors output video into an even video channel. The two video signals are time-staggered from each other by one-half cycle. The signals on the odd and even video channels are then multiplexed into a single high-speed channel.

Abstract: An input scanner for converting original hard-copy images into digital signals is adapted for efficient scanning of simple "business color" documents. Three linear arrays of photosensors, each linear array corresponding to one primary color, are moved relative to the original image. One linear array of photosensors operates on a full cycle and converts every single scan line of the original image into digital signals. Simultaneously, the other primary-color-sensitive linear arrays operate on half cycles and record only signals corresponding to an evenly-distributed subset of small areas of the original image.

Abstract: In a color input scanner for deriving digital signals from a full-color original image, a sensor bar having three parallel arrays of photosensors, each array being sensitive to a different primary color, is moved relative to the original image in a scan direction. With each scan cycle, the exposure of the photosensors in each array is precisely timed so that the optical "center of gravity" for each exposed area in the original image is superimposed for all of the primary color photosensors.

Abstract: A test system for a photosensitive array includes an on-board test circuit with a single input terminal, wherein the output of the test circuit directly affects the value of a bias charge placed on a selected photodiode. The test circuit enables a quick test for the presence of a desired bias charge when a digital-high voltage is entered on the single input terminal, and also enables a more precise test of photodiode response linearity by application of a predetermined analog voltage to the single input terminal.

Abstract: A raster input scanner comprises a linear array of photosensors arranged on a plurality of butted chips. The analog video signal from the first photosensor on each chip is read out for an extended period relative to the readout of the other photosensors on the chip, to provide extra settling time for the signal.

Abstract: Sensor array architectures for both analog and digital sensor arrays adapted for single chip applications or abutment with other like arrays to form a composite scanning array, the architecture providing a sensor array in which the array video signal processing circuits, clock circuits, etc. are integrated onto the same chip as the sensor array itself and dark reference sensors are located in-line or apart from the image scanning sensors to avoid gaps in the scan line when several sensor arrays are assembled together.

Abstract: A color image sensor array for both synchronous and asynchronous operation, especially adapted for using fabricated full width arrays, in which the chip has three photosites per pixel. The control circuit for charge transfer uses several components in common and requires no memory buffers to obtain full color information for each pixel on a page being scanned.