摘要:
CMOS pixel sensors have been of interest as replacements for CCD's in imaging applications. Such devices promise lower power and simpler system level design through fewer power supply voltages and higher functional integration. It is difficult and cost ineffective to utilize images to test active pixel sensors. Here, a method and apparatus for electrical testing of CMOS pixel sensors is described which involves electrically writing a pattern into the CMOS pixel sensors for the detection of adjacent cell shorts or stuck at faults as well as verification of read-channel circuit functionality and performance. The invention provides for an electrical testing of CMOS pixel array that is simple, time efficient and cost effective for use in, for example, production.
摘要:
An image sensor having a well-to-substrate diode as the photodetector. In a preferred embodiment, a modern salicided (CMOS) process is utilized to manufacture the image sensor. The field oxide region above the diode junction is transparent to visible light, thus allowing the photodiode competitive quantum efficiency as compared to devices having source/drain diffusion-to-substrate photodiodes fabricated on a non-salicided process. The photodiode can be integrated as part of a sensor array with digital circuitry using a relatively unmodified digital CMOS process. Furthermore, the structure allows the optical properties of the photodiode to be engineered by modifying the well without deleterious effects, to approximate a first order, on the characteristics of a FET built in another identical well.
摘要:
In a pixel having an electronic shutter, a method of increasing the retention time of the electronic shutter is disclosed. A reset signal is employed to drive a diode node to a predetermined voltage immediately after integration is completed. A sample signal is employed to control a pass gate. The sample signal includes a state where the sample signal is a negative voltage.
摘要:
An architecture for self-calibration and fixed-pattern noise removal in imager chips. The column-to-column fixed pattern noise and/or pixel-to-pixel fixed pattern noise is determined through a self-calibration operation. During operation of the imager chip, when a value of a pixel is read, the read value is compensated with the fixed-pattern noise corresponding to either the column fixed pattern noise corresponding to the column having the pixel from which the value was read or to the pixel fixed pattern noise corresponding to the pixel from which the value was read.
摘要:
A method for providing an improved active pixel sensor cell having a soft-saturation circuit. The method includes providing a pixel node and a photodiode coupled to the pixel node. The photodiode receives light and converts the light into an electrical signal representative of light. A soft-saturation circuit for selectively affecting the electrical signal at the pixel node based on the electrical signal at the pixel node based on the electrical signal at the pixel node is also provided.
摘要:
A circuit that includes at least two driver circuits. Each driver circuit receives analog information and drives a value related to the analog information to an analog bus. Each driver circuit also includes a select transistor to pass the value related to the analog information to the analog bus when the driver circuit is selected. The select transistor includes a source and a bulk. Each driver circuit further includes a bulk potential control circuit (BPCC) to couple the bulk to the source when the driver circuit is selected and to couple the bulk to a voltage supply when the driver circuit is not selected.
摘要:
A method and apparatus for employing a light shield to modulate pixel color responsivity. The improved pixel includes a substrate having a photodiode with a light receiving area. A color filter array material of a first color is disposed above the substrate. The pixel has a first relative responsivity. A light shield is disposed above the substrate to modulate the pixel color responsivity. The light shield forms an aperture whose area is substantially equal to the light receiving area adjusted by a reduction factor. The reduction factor is the result of an arithmetic operation between the first relative responsivity and a second relative responsivity, associated with a second pixel of a second color.
摘要:
A photodiode is provided. The photodiode includes an insulative region (IR) that permits passage of light therethrough. The photodiode also includes a substrate region of a first conductivity type and a well region of a second conductivity type. The well is formed within the substrate, beneath the IR. The well is demarcated from the substrate by a first surface. The photodiode further includes a heavily doped region (HDR) of the second conductivity type. The HDR is formed within the IR at a first position. The first surface meets the HDR at substantially the first position.
摘要:
A method and apparatus for employing a light shield to modulate pixel color responsivity. The improved pixel includes a substrate having a photodiode with a light receiving area. A color filter array material of a first color is disposed above the substrate. The pixel has a first relative responsivity. A light shield is disposed above the substrate to modulate the pixel color responsivity. The light shield forms an aperture whose area is substantially equal to the light receiving area adjusted by a reduction factor. The reduction factor is the result of an arithmetic operation between the first relative responsivity and a second relative responsivity, associated with a second pixel of a second color.
摘要:
A method and apparatus for employing a light shield to modulate pixel color responsivity. The improved pixel includes a substrate having a photodiode with a light receiving area. A color filter array material of a first color is disposed above the substrate. The pixel has a first relative responsivity. A light shield is disposed above the substrate to modulate the pixel color responsivity. The light shield forms an aperture whose area is substantially equal to the light receiving area adjusted by a reduction factor. The reduction factor is the result of an arithmetic operation between the first relative responsivity and a second relative responsivity, associated with a second pixel of a second color.