Teledyne E2v Semiconductors Sas

E2v Semiconductors

Bruno Diasparra

Thierry Ligozat

Pierre Fereyre

Gareth Powell

Vincent Prevost

Frédéric Mayer

Frédéric Barbier

Stéphane Gesset

Romain Guiguet

Vincent Richard

Pascal Douine

Arnaud Foucher

Jérôme Vanrumbeke

A CMOS image sensor for a code reader in an optical code recognition system incorporates a digital processing circuit that applies a calculation process to the capture image data as said data acquired by the sequential readout circuit of the sensor, in order to calculate a macro-image from the capture image data, which corresponds to location information of code(s) in the capture image, and transmit this macro-image in the image frame following the capture image data, in the footer of the frame.

Image sensor for optical code recognition

An image sensor includes a pixel structure which pair-wise vertically shares at least one read node, and further comprises a memory node for storing charges. A vertical transfer control line commands charge transfer from the photodiode to the memory node of a given column. The vertical transfer control rows apply two different exposure times, a first to the even columns and a second to the odd columns. The pixels and the read circuit perform one read operation per vertical pair of pixels over the exposure time associated with the column of the pair. A processing block is configured to calculate, for each vertical pair of pixels, an interpolated digital value. A periodic pattern of colored filters creates an HDR-mode color image sensor.

High-dynamic image sensor

The invention provides a method for acquiring an image of a target code, which allows the CMOS sensor, after the reader has been triggered to acquire a target code, to rapidly determine, and internally, a desirable exposure-time value Topt for the image capture of this code. When it is triggered, the sensor activates a measuring mode Mode_MES with a rapid acquisition of image data for k different exposure-time values Ti, i=1 to k, k being at least equal to 2, and this acquisition is employed only by the sensor and to rapidly define a desirable exposure-time value on the basis of histograms H(Ti) calculated with the image data acquired with the various exposure times; this value is stored in the register of image-capture parameters, and the sensor then activates a nominal image-acquiring mode Mode_ACQ, which applies this desirable exposure-time value delivered by the registered to all the pixels of the matrix array, and the obtained image DATA-OUT is the image delivered as output by the sensor, for recognition/decoding of the code by an external system.

Method of image acquisition by an image sensor of CMOS type for the recognition of optically readable code

The invention relates to the processing operation of interpolating the colours of a Bayer mosaic image sensor. A first elementary matrix filter, which is a bilinear interpolation filter, of size m&#xd7;m, m being an odd number larger than or equal to 3, a low-pass matrix filter of size n&#xd7;n, n being an odd number larger than or equal to 3, and a high-pass matrix filter, complementary to the low-pass filter, of size n&#xd7;n, are defined. The first matrix filter is convoluted with the low-pass filter, resulting in a low-frequency interpolation filter of size (m+n&#x2212;1)&#xd7;(m+n&#x2212;1), and the first matrix filter is convoluted with the high-pass filter, resulting in a high-frequency interpolation filter of size (m+n&#x2212;1)&#xd7;(m+n&#x2212;1). The matrix of digital signals arising from the pixels is filtered separately, using the pixels of each colour, by the low-frequency interpolation filter. The complete matrix of signals is filtered using the high-frequency interpolation filter. The result of the low-frequency filtering operation and the result of the high-frequency filtering operation are added together, for each pixel, in order to obtain a numerical value of a given colour of that pixel.

Method for processing signals from a matrix for taking colour images, and corresponding sensor

The invention relates to color-image sensors. To benefit both from a good luminance resolution and a color accuracy that is not excessively degraded by the sensitivity of silicon to near-infrared radiation, the invention proposes to produce a mosaic of pixels comprising colored pixels (R), (G), (B), coated with color filters, which are distributed in the matrix, with white pixels (T) not coated with color filters and which are distributed in the matrix. The colored pixels include photodiodes constructed differently from the photodiodes of the white pixels, the different construction being such that the photodiodes of the colored pixels have a lower sensitivity to infrared radiation than the photodiodes of the white pixels.

Colour image sensor with white pixels and colour pixels

The invention proposes a method for distributing a signal to each block Bof a series of N adjacent blocks of identical design in an electronic circuit. It proposes, in an identical fashion for each of the N blocks, placing a timing delay circuit MUX-DELon the path for conveying a signal Sfrom the input INcof the block to an internal electrical node Ndof the block for this signal S; providing for the timing delay circuit to supply N delayed signals corresponding to N different timing delays &#x394;f, . . . &#x394;f, . . . &#x394;fseparated by an increment of elementary duration &#x394;t that corresponds to the elementary delay &#x394;t for transit of a block introduced into a conductive line; and selecting the delayed signal corresponding to the applicable timing delay according to the block in question, by means of an index signal propagated through the N blocks, and which is incremented or decremented on passage through each block.

Method for synchronously distributing a digital signal over N identical adjacent blocks of an integrated circuit

The invention relates to image sensors and more specifically the generation of control signals for pixels and readout circuits. The sequencing circuit which produces these signals comprises: a programmable memory (MEM) containing binary words (M, M, M, etc.) in which each word comprises a group of several bits of position 1 to N, and in which the position i of a bit in a word corresponds to the position i of a respective control signal; a memory controller (CTRL_MEM) for extracting from the memory at a determined rate the words located at successive addresses of the memory from a start address to an end address; and a control signal generation circuit (GEN_TIMING) establishing each control signal of position i from the succession of bits of respective position i that are extracted from the memory by the controller, the control signal reproducing the successive values taken by the bit of position i at the clock rate.

Image sensor with control signal sequence generation

The invention relates to the production of images associating with each point of the image a depth, i.e. a distance between the observed point and the camera that produced the image. A light source emits N trains of light pulses. For each train of rank I=1 to N, charge is integrated in a short time slot of length Tthat starts with a temporal offset trelative to the pulse, this temporal offset representing a journey time of the light pulse between the light source and the sensor after reflection from a point placed a distance dfrom the sensor. The temporal offset tis the same for all the light pulses of the ipulse train but the temporal offsets tof the N trains are different from one another in order to correspond to various distances relative to the sensor. The charge photogenerated by the pulses of a given train is accumulated; then the accumulated charge is read in order to produce an image of rank i representing the pixels located at the distance d. The observation of a scene comprises producing N different images by virtue of which it is possible to associate a distance with each pixel.

Method for producing images with depth information and image sensor

The invention relates to image sensors, and more particularly to matrix sensors having active pixels in CMOS technology. According to the invention, a method for imaging a scene with a very short integration time, by using a standard image sensor comprising a matrix of pixels, comprising photodiodes, and charge storage nodes, is provided. Two images of the same scene are produced under identical light conditions, one of the images corresponding to integration of charges during a first time interval with a duration Tand the other image corresponding to a second time interval with a duration T'longer than T, and a difference between these two images is established, representing an image integrated during a time interval T&#x2032;&#x2212;T. The light may be provided by a light pulse (IMP). This method may be used for observing points in a scene that lie at a well-determined distance, the brevity of the integration time allowing good precision of the observation distance.

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Seyssins, France

Bruno Diasparra