Abstract:
A basic device for an image sensor includes a photodiode consisting of a doped area having a first type of conductivity and formed at the surface of a semiconductor substrate having a second type of conductivity, adapted to be biased at a first reference voltage, wherein the photodiode is combined with a device for the transfer, multiplication and insulation of charges, the photodiode being a fully depleted one and including, at the surface of the doped area having a first type of conductivity, a strongly doped region having the second type of conductivity and adapted to be biased at a second reference voltage.
Abstract:
A basic device for an image sensor includes a photogeneration and charge-collecting region formed at the surface of a semiconductor substrate having a first type of conductivity, adapted to be biased at a reference voltage, the photogeneration region being associated with a device for the transfer, multiplication, and insulation of charges. The photogeneration region has an insulated gate mounted thereon, which is adapted to be alternately biased at a first voltage and at a second voltage, the insulated gate being made of a low-absorption material.
Abstract:
An image sensor formed of an array of pixels, each pixel including a photodiode coupled between a first reference voltage and a first switch, the first switch being operable to connect the photodiode to a first node; a capacitor arranged to store a charge accumulated by the photodiode, the capacitor being coupled between a second reference voltage and a second node; a second switch coupled between the first and second nodes, the second switch being operable to connect the capacitor to the first node; and read circuitry coupled for reading the voltage at the second node.
Abstract:
A near infrared/color photodetector made in a monolithic form in a lightly-doped substrate of a first conductivity type covering a holder and comprising a face on the side opposed to the holder. The photodetector includes at least first and second photodiodes for the storage of electric charges photogenerated in the substrate, the second photodiode being adjacent to said face; and a first region extending at least between the second photodiode and the holder, preventing the passage of said charges between a first substrate portion being located between said region and the holder and a second substrate portion extending between said face and the first region, the first photodiode being adapted to store at least charges photogenerated in the first substrate portion and the second photodiode being adapted to store charges photogenerated in the second substrate portion.
Abstract:
In a CCD type photosensitive device, the charges produced in two consecutive columns of pixels are transferred into different reading registers: the charges from the first column are loaded into the first register and the charges from the second column travel through the first register to be loaded into the second register. The two reading registers are controlled by independent potentials during the step for the loading of these registers. The device makes it possible to increase the efficiency of the transfer between the two reading registers, especially when the registers are of the type working in a two-phase mode.
Abstract:
A method of detecting electromagnetic radiation imparted onto a matrix of photosensitive photomos networks in which pixels of each photomos network are simultaneously exposed to electromagnetic radiation source for a predetermined period of time. Thereafter, transfer signals are applied to each photomos pixel and accumulated charges corresponding to the strength of the radiation imparted onto the pixels are transferred in a columnwise fashion to the end of each column of the photomos networks. The charges are summed at the end of the columns and placed in a reading register. The charges in the reading register of each photomos network are summed and a signal is output corresponding to the strength of the electromagnetic radiation imparted onto the photomos network.
Abstract:
A photosensitive sensor including multilinear arrays of n lines of cells which operate by charge integration and time delay by successive observations of the same image line by the n lines in the array, and by accumulation of the corresponding n observations in the cells of the sensor.To avoid the risk of saturation inherent in the fact that the electrical charges resulting from n observations accumulate in the same cell, the number of lines between which the charge integration and delays are preformed is programmed to be between 1 and n. This programming is performed as a function of the average illumination of the image analysed. To do so, the electrodes (ES1, ES2) of certain lines of cells are used, and potentials are applied to them; either the normal charge transfer potentials or a blocking potential which isolates the lines beyond this blocking electrode from a reading stage (RL, CL).
Abstract:
In a photosensor with a frame transfer structure, each pixel constituting the matrix of photosensitive points is provided with a pulse-controlled MOS transistor. At the end of the frame transfer the TMOS is controlled through the electrodes, V.sub.DA and V.sub.GA, to eliminate residual charges which are present in the photosensitive zone and which are due to the transfer of empty stages corresponding to the dark zones of the image in the stages under the illuminated zones.
Abstract:
An improved line-transfer photosensitive device and particularly a device which operates with a double drive charge comprises on at least one semiconductor substrate a photosensitive region made up of M lines of N photosensitive points. The photosensitive points of the different lines are connected in parallel by means of conductive columns to a line memory which carries out at least the transfer of the signal charges integrated on any one line of the phtosensitive region to a read register consisting of a charge-coupled shift register of the volume transfer type. The line memory is formed on a semiconductor substrate region having an impurity implantation of opposite type with respect to the substrate in order to produce a volume charge transfer. The region in which the line memory is formed has a dopant concentration which is lower than or equal to that of the region in which the shift register is formed.
Abstract:
The storage capacity of the photosensitive points is increased during the time interval starting after the evacuation of the parasitic charges from the conductive columns to the memory and finishing by the transfer of signal charges from a row of the columns to the memory. Thus, even the overilluminated photosensitive points do not overflow onto the columns.