Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/74—Projection arrangements for image reproduction, e.g. using eidophor
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N9/00—Details of colour television systems
  • H04N9/12—Picture reproducers
  • H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
  • H04N9/3102—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators
  • H04N9/3111—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators for displaying the colours sequentially, e.g. by using sequentially activated light sources
  • H04N9/3117—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators for displaying the colours sequentially, e.g. by using sequentially activated light sources by using a sequential colour filter producing two or more colours simultaneously, e.g. by creating scrolling colour bands
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N9/00—Details of colour television systems
  • H04N9/12—Picture reproducers
  • H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
  • H04N9/3102—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators
  • H04N9/312—Driving therefor
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N9/00—Details of colour television systems
  • H04N9/12—Picture reproducers
  • H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
  • H04N9/3179—Video signal processing therefor
  • H04N9/3182—Colour adjustment, e.g. white balance, shading or gamut
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N9/00—Details of colour television systems
  • H04N9/12—Picture reproducers
  • H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
  • H04N9/3191—Testing thereof
  • H04N9/3194—Testing thereof including sensor feedback
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
  • H10F39/00—Integrated devices, or assemblies of multiple devices, comprising at least one element covered by group H10F30/00, e.g. radiation detectors comprising photodiode arrays
  • H10F39/10—Integrated devices
  • H10F39/12—Image sensors
  • H10F39/18—Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors
  • H10F39/182—Colour image sensors
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
  • G02F1/1362—Active matrix addressed cells
  • G02F1/136277—Active matrix addressed cells formed on a semiconductor substrate, e.g. of silicon
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F2201/00—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00
  • G02F2201/58—Arrangements comprising a monitoring photodetector

Definitions

• the invention relates to image projection and / or image viewing systems comprising an imager or SPL “Spatial Light Modulator” in English, comprising a matrix array of pixels, for example liquid crystal on silicon substrate. or LCOS “Liquid Cristal On Silicon” in English, with micro-mirrors or DMD “Digital Micro-mirror Device / Display” in English, or with HTPS “High Temperature Poly Silicon” liquid crystal in English, arranged in lines and in columns on a substrate forming an active matrix, in particular in silicon, an illumination system of this imager for moving bands of lights of different colors, "color scrolling" in English, on the imager perpendicular to said lines , means for identifying the illumination color on each line or on each group of pixel lines of the imager, video data management means of the so-called image s for controlling the writing of the pixels of the imager, means for synchronizing the video data sent to each line of the imager as a function of the illumination color of said line identified by said identification means.
• Image projection systems commonly called projectors or overhead projectors depending on whether the projection is from the front of the screen for projectors, or whether the projection is from the rear for overhead projectors, operate on the same principle.
• An illumination system uniformly illuminates one or more imagers, the light is modulated after passing through the imager (s) in the case of transmissive imagers or after reflection on the imager (s) in the case of reflective imagers. The light thus modulated is then projected onto a screen.
• projection systems of this type sequentially display images of different colors on the screen, usually the three primary RGB colors (red, green and blue), fast enough for the human eye to perceive no color changes on the screen.
• These image projection systems generally include illumination devices for illuminating the single imager with alternately red, green and blue light by using colored wheels, for example in English, or partially red. , green and blue at the same time in the form of light bands "color scrolling" in English and scrolling perpendicular to the lines of the pixel array of the imager, by the use of systems which we will briefly describe below.
• the video data controlling the writing of the pixels must therefore be synchronized as a function of the color that each pixel receives in order to form an image free of defects for the viewer such as for example an improper mixture of colors or a reduction in image contasts. on the screen.
• the synchronization between the illumination system and the video data controlling the writing of the pixels of the imager is carried out by synchronization means which will on the one hand measure a position signal of the element of the system of illumination at the origin of the scrolling of the bands of light of different colors on the imager to inform said means of synchronization of the color of illumination of the light sent on each pixel of the imager by the colored wheel or the system of illumination, and on the other hand controlling the writing of the pixels as a function of said measured signal.
• This synchronization is relatively easy if the imager is illuminated alternately by a red green and blue light, by the use of the colored wheel for example, but it becomes more complex when the illumination of the imager or more precisely the color of the light incident on the imager, is composed of said bands of lights of different colors and varies according to the pixel lines of the imager.
• the synchronization means are generally programmed with safety margins in the generation of video data.
• Document US5416514 describes a system for projecting to a transmissive imager comprising an illumination system (references 10, 12, 14, 16 in FIG. 1 of the document) separating the white light coming from a light source into light bands of different colors by the use of a dichroic mirror device (reference 12 in Figure 1 of the document). After passing through an assembly of rotating prisms driven by a motor (reference 14 in FIG. 1 of the document) and lenses (reference 16 in FIG. 1 of the document), rectangular bands of different colors pass over the imager (reference 18 in FIG. 1 of the document) alternatively.
• an illumination system references 10, 12, 14, 16 in FIG. 1 of the document
• a dichroic mirror device reference 12 in Figure 1 of the document
• the video data (reference 112) coming from a video source (reference 110) are sent to a video memory (reference 114), and controlled by a control circuit (reference 140 ) which receives a SYNC synchronization signal (reference 118) from the video source (reference 112).
• the video data leaving the video memory (reference 114) are then sent for writing to the imager (reference 122).
• a second control circuit (reference 142) connected to the first control circuit (reference 140) to receive in particular the synchronization signal SYNC (reference 118), controls the reading (reference 130) of the video memory (reference 114) and the writing (reference 132) of the pixels of the imager (reference 122).
• the motor (reference 125), actuating the rotation of the prisms rotating in the illumination system (reference 124), is controlled by the second control circuit (reference 142) to produce the rotation of the prisms rotating in accordance with the synchronization signal SYNC (reference 118), thereby causing a scrolling of the light bands of different colors on the imager in synchronization with the video data which controls the writing of the optical valves.
• the control circuit also receives real-time signals from the position, or phase, of the assembly of rotating prisms from a position "encoder" (reference 127) integrated into the illumination system.
• a position, or phase, of the rotating prism assembly corresponds to a single position on the imager of the bands of light of different colors, and the position encoder (reference 127), which provides this position signal, or phase, constitutes here a means of identifying the illumination color of each line of the imager.
• the means of identifying the illumination color of each line of pixels comprising the device for measuring the instantaneous position of the assembly of rotating prisms has the disadvantage of relying on the measurement of an assembly of mechanical elements.
• the prisms susceptible, with time and the rotational stresses which it undergoes, to be out of adjustment and to introduce a shift, even slight, between the measurement of the position of the assembly of rotating prisms supposed to inform the means for synchronizing the color of illumination of the light sent to each pixel of the imager, and the actual position of the bands of light of different colors on the array of pixels of the imager. This shift then leads to synchronization, color mixing, and lowering of the contrasts mentioned above.
• One of the critical points is the mechanical assembly of the device of the rotating prisms.
• a slit in the shape of a rectangle, located in front of each rotating prism, is generally imaged on the screen. Its position, particularly in the vertical plane of the imager, is critical, and its rotation can induce errors that the prism synchronization system cannot detect.
• An object of the invention is to avoid the aforementioned drawbacks.
• the invention relates to an image projection system comprising an imager comprising an array of pixels arranged in rows and columns on a substrate forming an active matrix, an illumination system for moving bands of colored light different on the imager, perpendicular to said lines, means for identifying the illumination color of each line of pixels of the imager, means for managing video data of said images to control the writing of said lines pixels of the imager, means for synchronizing the video data sent to each line of pixels of the imager as a function of the illumination color of said line identified by said means of identification characterized in that the means d 'identification include at least one photosensitive sensor disposed at said pixels of the imager.
• each sensor is arranged at the level of a line of pixels of the imager, the number of sensors is less than that of the lines of pixels, and the projection system comprises calculation means suitable for deduce the illumination color of the lines of pixels which are not provided with a sensor as a function of data delivered by said sensors.
• this unique sensor is for example positioned on the imager at a specific line of pixels; this unique sensor is suitable for identifying the illumination color of the pixels of this line.
• the projection system comprises calculation means adapted to deduce, from the illumination color of the pixels of this specific line of pixels, the illumination color of each line of pixels of the imager.
• These calculation means integrate data relating to the width of the color bands illuminating the imager, the case where appropriate, the width of black bands interposed between the colored bands, and / or the speed of movement of bands perpendicular to the lines.
• the identification of the illumination color of each line of pixels of the imager can then be done as follows: - during the displacement of the color bands, the photosensitive sensor locates the instant of each change or transition of color band at the specific line of pixels; this data is transmitted to the calculation means, which deduces therefrom in a known manner a given position of the colored bands on the imager at this instant, - from the time interval which elapses between two successive changes, the means of calculation deduce the speed of movement of the colored bands,
• the calculation means calculate the position of the color bands at each instant and deduce the illumination color therefrom of each line of pixels in the imager at all times.
• each sensor makes it possible to identify directly the illumination color of the line of pixels with which it is associated and makes it possible to identify indirectly, using the means of calculation described above, the illumination color of the lines of pixels which are not provided with sensors .
• the identification means comprise at least one photosensitive sensor at the level of each line of pixels of the imager (12) and each sensor of a line is adapted to identify the illumination color of this line.
• each sensor of a line is adapted to identify the illumination color of this line.
• the photosensitive sensor of each line of pixels of the imager thus identifies directly or "a posteriori", in real time and in a reliable manner, the color of the light actually received by each pixel of the same line, and not indirectly as in the case of a single sensor for the whole of the imager, or "a priori" as described in the prior art.
• the photosensitive sensor positioned at the level of the pixels of the imager or of each line of pixels of the imager is integrated into the substrate, generally made of silicon of the imager.
• the photosensitive sensor (s) should be illuminated where the light beam still has the same characteristics as the useful light beam illuminating the active area of the imager. Since the logic circuits for controlling the rows and columns of pixels of the imager are generally etched on the substrate, each photosensitive sensor thus advantageously has a circuit etched on the same substrate as that which supports the pixels of the imager. Furthermore, the integration of the photosensitive sensors into the substrate is advantageously carried out during the imager manufacturing process without significantly increasing either the size of the component or the production costs, since there is sufficient space on the substrate of the imager to integrate the photosensitive sensors and their connection with the other circuits of the imager, and since the control circuits and these sensors can be formed by similar technologies.
• said photosensitive sensor is adapted to measure the intensity of illumination received by the line of pixels of the imager at the level of which it is positioned.
• the modulation of light by the imager to form images is generally carried out according to three principles.
• a first principle is the attenuation of the light during a fixed duration
• the second is the modulation of the duration without the light being attenuated
• the third is the generation of pulses of variable durations approaching a binary coding.
• Knowledge of the intensity of the illumination light allows the value of the attenuation, the pulse duration or the generated code to be adjusted as best as possible, and the colors to be rendered more precisely.
• Flickering phenomena of light or "flicker” in English are generally induced by the light source and produce parasitic variations in the light intensity on the imager.
• the photosensitive sensors perceive these phenomena of low frequency beat and send the corresponding signals to the video data management means which then advantageously correct the writing of the pixels of the imager so as to compensate for these phenomena.
• the wear of the light source contributes to increasing the flicker phenomena over time
• the presence of photosensitive sensors at the level of the imager advantageously makes it possible to preserve quality images throughout the lifetime of the source.
• the said at least one photosensitive sensor positioned at the level of each line of optical valves of the imager is associated with a colored filter.
• the color filter associated with the photosensitive sensor allows on the one hand a precise identification of the color of the light received, in this case the same color as that of the color filter, and on the other hand to measure the light intensity of said color. colored light illuminating the line of pixels at which the photosensitive sensor is positioned.
• a configuration comprising three photosensitive sensors at least at each line of pixels of the imager, each associated with a different color filter, for example RGB, advantageously makes it possible to precisely identify the three primary RGB colors of the light bands received by each line of pixels and measure their light intensity in real time. As a result, the time variation and the level of each of the three RGB signals are used to adjust and synchronize the video data for the three colors.
• said color filter associated with the photosensitive sensor of each line of pixels of the imager forms a continuous band associated with all of the photosensitive sensor (s) of each line of pixels of the imager responsible for identifying a particular color, for example red, green or blue.
• the color filter thus forms a simple colored band to be produced, which is available for example by depositing multilayers or absorbent layers etched on the glass plate covering the imager, opposite the row of sensor (s). photosensitive (s) located at each line of pixels of the imager.
• FIG. 1 schematically represents the main elements of an image projection system with a single imager or “single valve” in English;
• FIG. 2 shows an imager, for example of the LCOS type, comprising, according to a preferred embodiment of the invention, at least one photosensitive sensor per line of pixels;
• FIG. 3 presents a diagram describing the means for synchronizing the video data to synchronize the video data with the illumination color on the imager according to the invention
• - Figure 4 describes the cross section along a line of pixels on one side of an LCOS imager 12 comprising, according to the preferred embodiment of the invention, at least one photosensitive sensor 121 at each line pixels 120 according to the invention
• - Figure 5 shows an imager, for example of LCOS type, comprising three photosensitive sensors per line of pixels according to a variant of the preferred embodiment of the invention.
• a projection system with an imager or mono-imager or “single valve” in English is shown schematically in Figure 1.
• the system comprises an illumination system 1 comprising in particular a light source 2 which sends the light to a device 10 responsible for separating the light into light beams of different colors, for example into bands of light of different colors, through an intermediate optical device 3 generally for collimation.
• a device 10 responsible for separating the light into light beams of different colors, for example into bands of light of different colors, through an intermediate optical device 3 generally for collimation.
• there are different devices for forming on the single imager bands of colored scrolling red, green and blue for example, in particular by the use of colored wheels with helical filters "Color Wheel” in English, described in patent EP1098536 from Texas Instruments, or by the use of rotating prism devices described for example in the article by Matthew S.
• the light from the illumination system 1 illuminates a transmissive or reflective imager 12 comprising a network of pixels whose writing is managed by a video data generator, not shown here, associated in particular with synchronization means 11 for synchronizing the light from the pixel illumination system with the video data coming from the video data generator or vice versa to synchronize the video data controlling the writing of the pixels of the imager 12 to modulate the incident light, as a function of the illumination color light on these valves.
• the light thus modulated is projected onto a screen 5 via an optical device 4.
• the devices 3 and 4, as well as the light source 2 are known in themselves and will not be described further below.
• an imager 12 comprising, according to a preferred embodiment of the invention, at least one photosensitive sensor 121 at each line of pixels 120.
• the imager 12 comprises a matrix array of pixels 120 for example of LCOS type “Liquid Cristal On Silicon” in English or of DMD type “Digital Micro- Mirror Device ”in English, the writing of which is controlled by the generator of the video data and the synchronization means not shown in FIG. 2.
• the photosensitive sensor (s) 121 is (are) integrated (s) to the substrate of the imager 12, for example on the silicon substrate in the case of an LCOS type imager.
• a single photosensitive sensor 121 without color filter is integrated into the substrate 100 at each line of pixels 120 of the imager 12, all of these sensors 121 then forming for example a column of sensors 121
• one of these photosensitive sensors 121 is illuminated, like the line of pixels with which it is associated, by a band of colored light, it transmits a signal corresponding to the color of illumination perceived.
• the signal will be different if the illumination color changes. This signal difference is sufficient to identify, in the video data generator, the illumination color on each line of pixels 120 of the imager 12.
• a substrate of the imager is integrated photosensitive sensor 121 on either side of each line of the pixel array of the imager 12, in order to have a more reliable and symmetrical measurement of the illumination received.
• three photosensitive sensors 121 ′ are integrated at the level of each line of pixels 120.
• the photosensitive sensors 121 are integrated on the substrate of the imager 12 within the array of pixels 120 of the imager 12, or on the substrate of the transparent plate, generally made of glass, receiving the counter-electrode.
• the synchronization means 11 of a projection system comprising an illumination system of the rotating prism type.
• a video source 13 providing in particular a video stream and a SYNC synchronization signal is connected to a controller 14 responsible on the one hand for transmitting video data 131 to a video data generator 15 and on the other hand for controlling the mechanical part of the device for forming colored bands 10.
• the device for forming colored bands 10 comprises for example an assembly with rotating prisms 17 and, in particular in its mechanical part, a servo motor 16 for rotating the rotating prisms.
• the controller 14 is also in charge of synchronizing "A priori", in particular thanks to the SYNC synchronization signal, the generation of the video data 131 'in the generator 15, before writing the pixels 120 of the imager 12, and the angular position of the assembly of the rotating prisms 17 via a servo motor drive device 161.
• a priori in particular thanks to the SYNC synchronization signal
• Such synchronization is known in the prior art, in particular in document US5416514 from Philips (columns 7 and 8).
• each photosensitive sensor 121 at the level of the imager 12 is, like the line of pixels 120 with which it is associated, illuminated by the moving bands of colored lights, which are projected onto the imager via the 'assembly of rotating prisms 17, and transmits in real time a signal 18 corresponding to the perceived illumination color to a signal processing device 151 in the video data generator 15 for identification.
• the illumination color is determined, for example in the video data generator 15, by analysis of the level of signal received, knowing a priori the spectral composition of the light for each of the red, green or blue states, as well as the response spectral of the photosensitive sensor 121.
• the video data generator 15 processes the information on the color with the video data which correspond to it in order to control in real time the writing of the pixels 120 of each line of the imager 12 including the color of illumination is thus directly identified.
• This "a posteriori" synchronization results from the direct identification of the illumination color at the level of each line of pixels 120: it is performed in real time and is very precise.
• the identification of the illumination color at the level of each line of pixels by the presence of the photosensitive sensors 121 according to the invention, and the “a posteriori” synchronization 11 ′ which is associated with it, allows in particular, in the case of systems for projecting images using a synchronization of the “a priori” type described above, for correcting for example the offsets or misadjustments which may appear at the level of the mechanical part 16 of the illumination system 10.
• the “a posteriori” synchronization means 11 ′ according to the invention are sufficient by themselves to synchronize the video data 131 with the illumination color on the imager 12; in the absence of synchronization a priori, the use of an inexpensive and non-slave drive motor 161 then becomes possible, thus simplifying the illumination system 10.
• an LCOS type imager 12 comprising, according to the preferred embodiment of the invention, at least one photosensitive sensor 121 at the level of each line of pixels. 120 according to the invention.
• an aluminum layer 101 is deposited as well as dielectric layers 102 to maximize the reflectivity and isolate the circuits from incident radiation.
• a sealing joint 122 seals the substrate 100 and the transparent plate 106 in order to ensure good sealing.
• the at least one photosensitive sensor 121 at each line of pixels 120 is integrated into the substrate 100 of the imager by reserving on the substrate 100 a silicon area 110 without the metallization layer 101 and the other treatments. specific to the imager which were briefly described above.
• the set of silicon areas 110 reserved on the substrate forms a strip, for example vertical, within which are integrated the photosensitive sensors 121 correctly aligned with the useful lines of pixels 120 of the imager 12.
• the substrate 100 of the imager here, of LCOS type, is made of silicon, however the invention relates more generally to the integration of all of the photosensitive sensors 121 in substrates forming an active matrix.
• the invention also applies to DMD type imagers.
• FIG. 4 also describes a photosensitive sensor 121, for example of the broad spectrum silicon type, at the level of a line of pixels 120. This type of sensor makes it possible to detect an important signal, the junction being carried out by boxes. P 107 in N 108 or vice versa.
• the sensor situated on the periphery of the array of pixels 120 should be illuminated by rays of the light beam which have the same characteristics as the useful beam illuminating the active area of LCOS 12, in other words the array of pixels 120.
• This beam of light passes through the glass slide 106 covering the imager ie LCOS 12, the liquid crystal 104 as well as any transparent layers, for example layers 102 improving the reflectivity.
• An embodiment in which a transistor is associated with the photosensitive sensor (s) constitutes an active “memory” device for saving, for example, the information on the color of illumination perceived and sending a signal to the signal processing device 151 in the video data generator 15 only when the illumination changes.
• each photosensitive sensor 121 is associated with a colored filter 109, for example red or green or blue.
• the simple configuration according to which a single photosensitive sensor 121 is integrated, associated with a color filter 109, at the level of each line of pixels 120 of the imager 12 allows the precise identification of a color, that of the color filter 109 for example , and / or the measurement of the light intensity of the light strip.
• the precise identification, in real time, of a single illumination color is sufficient, in the case where the running speed and the illumination surface of each of the bands of light of different colors are known or fixed, to determine, in the video data generator, the illumination color at each line of pixels 120 of the imager 12.
• a variant of the invention which consists in integrating into the substrate 100 three photosensitive sensors 121 at each line of pixels 120, each of the sensors being associated with a colored filter 109 of different color, for example red, green and blue.
• the time variation and the level of each of the three signals, red green and blue are used in the video data generator to synchronize and adjust the video data for the three colors.
• a particular case of application to maximize the use of the luminous flux for unsaturated images consists in replacing one or more of the three colors R, G, B of illumination by a secondary color, yellow, magenta or cyan for example, or by a combination of primary and secondary colors.
• the video data generator, with the signal of the photosensitive sensors will best define the writing of the pixels to correctly restore the original colors of the image.
• All the colored filters of the same color associated with the photosensitive sensors form, according to a variant of the invention, a colored band, for example vertical.
• These filters or colored bands associated with the photosensitive sensors are, with reference to FIG. 4, arranged in contact with the sensors (filter 109 in FIG. 4) or according to a variant of the invention, written on or in the transparent plate 106, opposite the sensors with which they are associated (filter 109 ′ in FIG. 4).
• the photosensitive sensor (s) 121 are integrated into the substrate of the imager on either side of each line of the pixel array of the imager 12, in order to to have a more reliable and symmetrical measurement of the illumination received.
• any other type of photosensitive sensor can be used.
• the invention also applies to cases where the imager has only one photosensitive sensor which is used, as described above, for the indirect identification of the illumination color of each line of pixels of the imager.
• the invention also applies to intermediate cases where the imager is provided with a plurality of photosensitive sensors, in a number less than that of the lines of pixels, each associated with a line of pixels of the imager, which are used not only for the direct identification of the illumination color of the pixel lines with which they are associated, but also for the indirect identification of the illumination color of the other pixel lines.

Landscapes

• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Physics & Mathematics (AREA)
• Nonlinear Science (AREA)
• Mathematical Physics (AREA)
• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Microelectronics & Electronic Packaging (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Liquid Crystal (AREA)
• Color Television Image Signal Generators (AREA)
• Control Of Indicators Other Than Cathode Ray Tubes (AREA)
• Video Image Reproduction Devices For Color Tv Systems (AREA)
• Liquid Crystal Display Device Control (AREA)
• Projection Apparatus (AREA)
• Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=32524809

Family Applications (1)

Country Status (8)

Families Citing this family (1)

Citations (2)

Family Cites Families (7)

• 2003
  • 2003-01-07 FR FR0300228A patent/FR2849737B1/fr not_active Expired - Fee Related
• 2004
  • 2004-01-05 WO PCT/EP2004/050003 patent/WO2004062294A2/fr not_active Ceased
  • 2004-01-05 KR KR1020057012563A patent/KR20050090071A/ko not_active Withdrawn
  • 2004-01-05 CN CNB2004800018230A patent/CN100463529C/zh not_active Expired - Fee Related
  • 2004-01-05 US US10/541,634 patent/US7612771B2/en not_active Expired - Fee Related
  • 2004-01-05 EP EP04700131A patent/EP1582073A2/de not_active Withdrawn
  • 2004-01-05 MX MXPA05007336A patent/MXPA05007336A/es active IP Right Grant
  • 2004-01-05 JP JP2006500108A patent/JP2007527018A/ja active Pending

Patent Citations (2)

Also Published As

Similar Documents

Legal Events