E2v Semiconductors

Teledyne E2v Semiconductors Sas

Atmel Grenoble

Thierry Ligozat

Bruno Diasparra

Pierre Fereyre

Bruno Gili

Romain Guiguet

Gareth Powell

Frédéric Mayer

Stéphane Gesset

Grégoire Chenebaux

Vincent Prevost

Marie Guillon

Gérard Beal

Jean-Marie Caupain

Norman Mangeret

Arnaud Foucher

Jérôme Vanrumbeke

Pascal Douine

Andy Noiret

Franck Tellier

Nicolas Lebouleux

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

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 provides a linear sensor including a rowof N regularly spaced pixels that are formed in a semiconductor substrate, and a circuit for reading out the N pixels, which delivers an output signal for each of the N pixels of the row, characterized in that the N pixels comprise image-capturing pixels that have a useful photosensitive area in the shape of a rectangle R that is higher than it is wide, where the width is in the direction of the row and the height is in the perpendicular direction, and at least two spaced-apart pairs of alignment-detecting pixels PP, PP, wherein the detecting pixels of each pair are pixels P, Pthat are adjacent in the rowof pixels and the useful photosensitive area DT, DTof the detecting pixels has a width that varies monotonically in the height direction, but in opposite directions for the two detecting pixels of a given pair.

Linear sensor for a spectroscopic optical coherence tomography imaging apparatus

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 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.

Image-sensing method having a very short integration time

The invention relates to image sensors of scanner type observing one image line at a time. According to the invention, only two lines of pixels are used, operating in TDI mode (summation of the charge of two pixels seeing the same image point successively) but using active pixels with a charge-voltage conversion within the pixel. The pixels of like rank of the two lines each use a photodiode and a charge storage node with a transfer gate adjacent to the photodiode and to the storage node for transferring the charge accumulated in the photodiode to the charge storage node. The storage node is shared between the two pixels of like rank, and the charge of the two photodiodes is transferred successively into this node before the reading of the potential taken by the node. The time interval which separates the two charge transfers corresponds substantially to the time which separates the transit of an image line past the first line of pixels and then past the second.

Two-line, shared pixel linear image sensor

An image sensor for gathering images at one and the same time at low illumination level and at high illumination level is described. The sensor operates with a double integration time at each frame. Two successive charge transfers from a photodiode to a storage node are performed, the first after a first duration, the second after a second duration different from the first. The potential of the storage node after the first transfer of charge is sampled in a first capacitor of the reading circuit. The potential after a reinitialization of the storage node is sampled in a second capacitor. A level of potential taken after the second transfer is conditionally resampled in the first capacitor. The condition of the resampling is a condition of signal level after the first transfer. This level is applied to the differential amplifier of a ramp-type converter for a short duration of ramp.

Image sensor with double integration time and conditional selection

The invention relates to matrix-array image sensors with MOS-technology active pixels, comprising a matrix-array of pixels arranged in rows and columns. To read the signal from a pixel, the reset potential present on a column conductor is sampled in two capacitors. The first capacitor is linked to an input of a comparator; the other input receives, through the second capacitor, a linear voltage ramp varying in a first direction for a first duration, then a linear voltage ramp in the reverse direction; a digital value N of the time between the start of this second ramp and the switching over of the comparator is counted; the useful potential present on the column conductor and representing the lighting of the pixel is sampled again, but in the first capacitor only; two ramps identical to the preceding ones are applied to the second input, through the second capacitor; a digital value N' of the time between the start of the second reverse ramp and the switching over of the comparator is counted, the difference between the two counts N and N&#x2032; representing a measurement of the lighting of the pixel.

Method of reading an image sensor signal and image sensor

The invention relates to image sensors using a chip with cut corners. The sensor comprises a chip with cut corners comprising a matrix () of horizontal lines and vertical columns of photosensitive members, the matrix having a generally rectangular shape of horizontal width W and having four bevels, the sensor comprising as many current or voltage read blocks as there are matrix columns, in order to read the image signals detected by the photosensitive members, characterized in that the current or voltage read blocks are placed in a row () along a horizontal edge of the matrix of width W' and are all housed within a vertical strip, the width Wof which is substantially less than the maximum width W of the matrix. There are two superposed rows of current read blocks with blocks distributed at the same pitch as the pixel columns, or there is a single row with read blocks distributed with a pitch less than that of the pixel columns. The invention can be applied to CMOS technology intraoral radiological sensors.

Image sensor with corner cuts

The invention relates to large-dimension linear image sensors operating by relative translation between the image and the sensor and consisting of a plurality of linear arrays abutting in a staggered fashion. In order to improve the design of the sensor, according to the invention the arrays are mounted on packages whose upper surface has an elongate rectangular shape provided on two opposite sides of the rectangle with two extensions substantially covered by the ends of the array, two adjacent packages bearing against each other along a respective extension of each of them. The staggered arrangement prevents the blind zones, photosensitive points being present in the extensions, and the offset between the two rows of staggered chips is practically no greater than the width of the chips.

Image sensor having linear abutting bars

The invention proposes an image sensor comprising a picture capture matrix having N rows and K columns of image dots, a read register at the free end of the K columns. In order to improve the read speed of the matrix, the invention proposes that the horizontal transfer into the read register be continued even while the vertical signals for shifting from one row to the other are operative, without however continuing the horizontal transfer while the transfer gate between columns and horizontal register is open. The unloading time of the horizontal read register therefore overlaps the time reserved for each vertical transfer step, instead of these times being added together. The gain in time, being repeated for each row, will be all the more significant the higher the number of rows. Means are provided for limiting the effect of the column transfer switching operations on the reading of the charges at the output of the read register.

Image sensor with rapid read cycle

The invention relates to small dimension image recorders, such as an image recorder, comprising a matrix of rows and columns of photosensitive points, arranged on a chip of a generally square or rectangular form with believed corners, characterised in comprising a reading register arranged at the base of the matrix. The register is bent to follow the bevelled corners of the chip and thus comprises a horizontal piece and two oblique pieces. The sensor further comprises means (ZI) to direct the photosensitive charges form the columns terminating opposite the beveled corners towards the stage of the reister situated in the oblique part along the beveled corners. The above is of application to intraoral dental radiological sensors.

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Grenoble, France

Thierry Ligozat