JP2008040130A - Optical modulation device and image display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for detecting intensity of light directly related to the display of an image. <P>SOLUTION: An optical modulation device includes a display area to be used for the display of the image and modulates light made incident on the display area in order to display the image. The optical modulation device is provided with: a plurality of modulation parts which are disposed inside the display area and modulate the light made incident on the display area in accordance with a plurality of pixel data included in image data; and an optical sensor which is disposed inside the display area and detects light made incident on the display area. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light modulation device for modulating incident light.

  The image display device usually includes a light source device and a light modulation device that modulates light emitted from the light source device in accordance with image data.

  When the intensity of light emitted from the light source device is not stable, the brightness and color tone of the displayed image change. In order to display a stable image, it is necessary to emit light having a stable intensity to the light source device.

  For this reason, conventionally, the intensity of light emitted from the light source device is detected by an optical sensor, and the intensity of light emitted from the light source device is adjusted according to the detection result.

  For example, Patent Document 1 discloses a technique in which a photoelectric conversion element is provided outside a display area of a liquid crystal device and the output of a light source is controlled according to the detection result of the photoelectric conversion element.

JP 2004-317800 A

  However, in the prior art, the intensity of light that is not incident on the display area of the light modulation device, in other words, the intensity of light that is not directly related to the display of the image is detected, and is directly related to the display of the image. There was a problem that the intensity of the light to be detected was not detected.

  The present invention has been made to solve the above-described problems in the prior art, and an object thereof is to detect the intensity of light directly related to image display.

In order to solve at least a part of the above-described problems, a first apparatus of the present invention includes a display area used for displaying an image, and modulates light incident on the display area to display an image. A modulation device,
A plurality of modulation units that are provided inside the display region and modulate light incident on the display region according to a plurality of pixel data included in image data;
An optical sensor provided inside the display area for detecting light incident on the display area;
It is characterized by providing.

  In this device, since the optical sensor is provided inside the display area of the light modulation device, it is directly related to the intensity of light actually incident on the display region of the light modulation device, in other words, the image display. The intensity of light can be detected. If the detection result of this optical sensor is used, the light source device can be controlled so that light having a stable intensity is incident on the light modulation device.

In the above apparatus,
Each of the modulation units is
A modulation region for modulating light;
A control region for controlling light modulation in the modulation region in accordance with the corresponding pixel data;
Including
It is preferable that the optical sensor is provided in the control region included in at least one modulation unit among the plurality of modulation units.

  As described above, if the optical sensor is provided in the control region of the modulation unit, pixels in the image are not lost. For example, when one modulation unit among a plurality of modulation units in the display area is replaced with an optical sensor, pixels in an image corresponding to the one modulation unit are lost. However, if the above configuration is adopted, pixels in the image are not lost due to the presence of the optical sensor.

In the above apparatus,
The plurality of modulation units are:
A first substrate utilized by the plurality of modulators;
A second substrate utilized by the plurality of modulators;
A liquid crystal layer used by the plurality of modulators and provided between the first substrate and the second substrate;
A first electrode layer used by the plurality of modulators and provided between the first substrate and the liquid crystal layer;
A plurality of second electrode layers provided between the second substrate and the liquid crystal layer and corresponding to the plurality of modulators;
With
The optical sensor may be provided between the second substrate and the liquid crystal layer.

In the above apparatus,
The optical sensor may detect light incident from the first substrate.

Alternatively, in the above device,
The optical sensor may detect light incident from the second substrate.

  By doing so, the optical sensor can detect the light that has not passed through the liquid crystal layer, so that the intensity of the light incident on the display area of the light modulation device can be detected more accurately.

In the above apparatus,
A lens array provided on the light incident surface side of the plurality of modulators;
The lens array is
A plurality of lenses for guiding light incident on the lens array to the plurality of modulation regions included in the plurality of modulation units;
A light guiding unit for guiding light incident on the lens array to the photosensor provided in the control region included in the at least one modulation unit;
It is preferable to provide.

  In this way, even when a lens array is used, sufficient light can be incident on the optical sensor.

In the above apparatus,
It is preferable that the optical sensor is provided in the center of the display area.

  In this way, it is possible to detect the intensity of light incident on a position corresponding to the center of the image that is most important for image display.

In the above apparatus,
Two or more optical sensors may be provided inside the display area.

  By doing this, it is possible to know the average intensity and intensity distribution of light incident on the display area of the light modulation device.

In the above apparatus,
It is preferable that a temperature sensor is provided inside the display area and detects the temperature of the optical sensor.

  Since the optical sensor has temperature dependency, the detection result of the optical sensor changes according to the temperature. However, if the above configuration is adopted, the temperature of the optical sensor can be detected. If the detection result of the optical sensor and the detection result of the temperature sensor are used, the light source device can be controlled so that light having a more stable intensity enters the light modulation device.

A second device of the present invention is an image display device,
The light modulation device described above;
A light source device that emits light toward the light modulation device;
A control circuit for controlling the intensity of light emitted from the light source device;
With
The control circuit includes:
A correction unit for obtaining corrected light intensity by correcting the detection result of the optical sensor using the detection result of the temperature sensor;
An adjustment unit that adjusts the intensity of light emitted from the light source device so that the corrected light intensity is equal to the target light intensity;
It is preferable to provide.

  In this apparatus, since the corrected light intensity is obtained by correcting the detection result of the optical sensor using the detection result of the temperature sensor, the light emitted from the light source device can be obtained by using the corrected light intensity. As a result, light having a stable intensity can be incident on the light modulation device.

  The present invention relates to a light modulation device and a control method thereof, an image display device including the light modulation device and a control method thereof, a computer program for realizing the functions of these methods or devices, and a recording in which the computer program is recorded The present invention can be realized in various forms such as a medium, a data signal including the computer program and embodied in a carrier wave.

Next, embodiments of the present invention will be described in the following order based on examples.
A. First embodiment:
A-1. Projector configuration:
A-2. LCD panel configuration:
A-3. Configuration and operation of light emission controller:
B. Second embodiment:
C. Third embodiment:
D. Fourth embodiment:
D-1. Modification of the fourth embodiment:

A. First embodiment:
A-1. Projector configuration:
FIG. 1 is an explanatory diagram showing a schematic configuration of a projector PJ in the first embodiment. The projector PJ includes three illumination optical systems 110R, G, B, three liquid crystal panels 120R, G, B, a cross dichroic prism 130, and a projection optical system 140. The projector PJ includes a control circuit 170 including an image data processing unit 180 and a light emission control unit 190, and three sets of optical sensors 192R, G, B and temperature sensors 194R, G, B. In FIG. 1, the illustration of the optical system is considerably simplified.

  The image data processing unit 180 supplies analog image data to the liquid crystal panels 120R, 120G, and 120B. The analog image data includes three color data of red, green, and blue, and the three color data are supplied to the three liquid crystal panels 120R, G, and B, respectively. The three color data are generated using synchronization signals suitable for the liquid crystal panels 120R, 120G, 120B, and have a resolution (number of pixels) suitable for the liquid crystal panels 120R, 120G, 120B. The image data processing unit 180 supplies various timing signals including a synchronization signal to the three liquid crystal panels 120R, 120G, and 120B.

  Of the three illumination optical systems 110R, G, and B, the illumination optical system 110R is a red light illumination optical system for emitting red light. The illumination optical system 110G is a green light illumination optical system for emitting green light, and the illumination optical system 110B is a blue light illumination optical system for emitting blue light. The three illumination optical systems 110R, G, and B include light emitting units 102R, G, and B, respectively. The three light emitting units 102R, 102G, and 102B are light emitting units that emit light of different colors, and in this embodiment, emit red light, green light, and blue light, respectively. Each light emitting unit 102R, G, B includes, for example, a light emitting diode (LED).

  Of the three liquid crystal panels 120R, G, and B, the liquid crystal panel 120R is a red light liquid crystal panel for modulating red light emitted from the illumination optical system 110R. The liquid crystal panel 120G is a green light liquid crystal panel for modulating the green light emitted from the illumination optical system 110G, and the liquid crystal panel 120B is a blue light for modulating the blue light emitted from the illumination optical system 110B. Liquid crystal panel. The three liquid crystal panels 120R, G, and B modulate the three color lights emitted from the three illumination optical systems 110R, G, and B using the three color data supplied from the image data processing unit 180. Thereby, light (image light) representing an image of each color is emitted from each of the liquid crystal panels 120R, G, and B. In practice, polarizing plates are provided on the light incident surface side and the light exit surface side of each liquid crystal panel.

  The cross dichroic prism 130 combines the three color image lights emitted from the three liquid crystal panels 120R, 120G, and 120B. The projection optical system 140 projects the combined image light on the screen and forms a color image (combined image) on the screen.

  Each optical sensor 192R, G, B is provided inside the liquid crystal panel 120R, G, B, and detects light emitted from each light emitting unit 102R, G, B. In this embodiment, a photodiode is used as the optical sensor.

  Each temperature sensor 194R, G, B is provided inside the liquid crystal panel 120R, G, B, and detects the temperature of each optical sensor 192R, G, B. Each temperature sensor 194R, G, B is arranged in the vicinity of the corresponding optical sensor 192R, G, B. In this embodiment, a thermal diode is used as the temperature sensor.

  The light emission control unit 190 controls the three light emitting units 102R, G, and B included in the three illumination optical systems 110R, G, and B to emit three color lights.

  In particular, in the present embodiment, the light emission control unit 190 acquires the light detection value from the optical sensors 192R, G, and B, and acquires the temperature detection value from the temperature sensors 194R, G, and B. And the light emission control part 190 adjusts the intensity | strength of the light inject | emitted from each light emission part 102R, G, B using a light detection value and a temperature detection value.

  In FIG. 1, only the exchange of signals among the light emitting unit 102R, the optical sensor 192R, the temperature sensor 194R, the liquid crystal panel 120R, and the control circuit 170 is shown for convenience, but the other light emitting units 102G, Similarly, signals are exchanged between B and the like and the control circuit 170.

  The liquid crystal panels 120R, G, and B in this embodiment correspond to the light modulation device in the present invention. Further, the light emitting units 102R, G, and B in this embodiment correspond to the light source device in the present invention, and the light emission control unit 190 corresponds to the control circuit in the present invention.

A-2. LCD panel configuration:
FIG. 2 is an explanatory diagram showing the configuration of the liquid crystal panel 120R. The same applies to the other liquid crystal panels 120G and 120B.

  As shown in the figure, the liquid crystal panel 120R includes a cell array 310, a scanning line driver 320, and a data driver 330. The cell array 310 includes M × N cells 302 arranged in a matrix.

  The scanning line driver 320 receives a timing signal from the image data processing unit 180. The scanning line driver 320 sequentially selects each of the M scanning lines SL according to the timing signal. When one scanning line SL is selected, the N cells 302 connected to the one scanning line SL are in a state where data can be acquired via the data line DL.

  The data driver 330 receives a timing signal and one color data (red data) composed of a plurality of pixel data from the image data processing unit 180. The data driver 330 sequentially selects each of the N cells 302 connected to the one scanning line SL selected by the scanning line driver 320 according to the timing signal, and selects the data line in the selected one cell 302. Pixel data is supplied via DL.

  Each cell 302 includes a liquid crystal element, and controls the operation state of the liquid crystal element in accordance with the supplied pixel data. As a result, light incident on the liquid crystal element is modulated, and modulated light is emitted from the liquid crystal element.

  In the present embodiment, the configuration of one cell arranged in the center of the cell array 310 is different from the configuration of other (M × N−1) cells. Specifically, only the cell 302 arranged in the center includes the above-described optical sensor 192R and temperature sensor 194R. Hereinafter, the cell 302 arranged in the center is also referred to as a “specific cell 302s”, and the other cell 302 is also referred to as a “normal cell 302o”.

  FIG. 3 is an explanatory diagram showing the specific cell 302s of FIG. 2 in an enlarged manner. As illustrated, the specific cell 302s includes a modulation region W1 for modulating light and a control region W2 for controlling light modulation in the modulation region W1. A semiconductor device group including a transistor Tr, an optical sensor 192R, and a temperature sensor 194R is formed in the control region W2. On the other hand, no semiconductor device is formed in the modulation region W1.

  Note that the normal cell 302o includes two regions W1 and W2, similarly to the specific cell 302s. However, the optical sensor 192R and the temperature sensor 194R are not provided in the control region W2 of the normal cell 302o.

  As shown in FIG. 2, the liquid crystal panel 120R further includes a light intensity detection circuit 360 connected to the optical sensor 192R in the specific cell 302s, and a temperature detection circuit 370 connected to the temperature sensor 194R in the specific cell 302s. It is equipped with.

  The light intensity detection circuit 360 includes, for example, an amplification circuit that amplifies a light detection signal acquired from the optical sensor (more specifically, a photodiode) 192R, and supplies the amplified light detection signal to the light emission control unit 190. To do. The temperature detection circuit 370 includes, for example, a circuit for applying a voltage to a temperature sensor (more specifically, a thermal diode) 194R and an amplification circuit for amplifying a temperature detection signal acquired from the temperature sensor 194R. The amplified temperature detection signal is supplied to the light emission control unit 190.

  In the present embodiment, the cell array 310 includes M × N cells 302, and all the cells are used for image display. Therefore, the formation region of the cell array 310 in this embodiment, in other words, the region circumscribing the M × N cells 302 corresponds to the display region in the present invention. However, the cell array may include (M + α) × (N + β) cells, and only M × N cells may be used for image display. In this case, an area circumscribing M × N cells used for displaying an image among all the cells corresponds to a display area in the present invention. The display area is also called an effective display area. As can be seen from this description, M × N cells 302 in this embodiment correspond to a plurality of modulation units in the present invention.

  FIG. 4 is a circuit diagram showing a specific configuration of the specific cell 302s. In FIG. 4, a circuit diagram of the normal cell 302o provided in the vicinity of the specific cell 302s is shown together with a circuit diagram of the specific cell 302s.

  The specific cell 302s includes a transistor Tr, a capacitor (retention capacitor) Cp, a liquid crystal element LC, an optical sensor 192R, and a temperature sensor 194R. The liquid crystal element LC is provided in the modulation region W1 shown in FIG. 3, and the transistor Tr, the capacitor Cp, the optical sensor 192R, and the temperature sensor 194R are provided in the control region W2 shown in FIG.

  The gate terminal G of the transistor Tr is connected to the scanning line SL, the source terminal S is connected to the data line DL, and the drain terminal D is connected to one terminal of the liquid crystal element LC and the capacitor Cp. The other terminals of the liquid crystal element LC and the capacitor Cp are set to a predetermined potential (for example, ground).

  When the scanning line SL to which the specific cell 302s is connected is selected by the scanning line driver 320, the transistor Tr in the specific cell 302s is turned on. When the data driver 330 supplies pixel data to the specific cell 302s through the data line DL, the pixel data is supplied to the liquid crystal element LC and the capacitor Cp through the transistor Tr. As a result, the liquid crystal element LC is set to an operation state corresponding to the pixel data, and as a result, light incident on the liquid crystal element LC is modulated.

  As described above, in this embodiment, a photodiode is used as the optical sensor 192R. The anode terminal and the cathode terminal of the photodiode are connected to the light intensity detection circuit 360 via signal lines Lpa and Lpc, respectively. In this embodiment, a thermal diode is used as the temperature sensor 194R. The anode terminal and cathode terminal of the thermal diode are connected to the temperature detection circuit 370 via signal lines Lta and Ltc, respectively.

  The normal cell 302o has substantially the same configuration as the specific cell 302s. However, as described above, the normal cell 302o is not provided with the optical sensor 192R and the temperature sensor 194R.

  FIG. 5 is an explanatory diagram schematically showing the structure of the liquid crystal panel 120R. In FIG. 5, the specific cell 302s is drawn with attention. Further, FIG. 5 shows the modulation area W1 and the control area W2 of the specific cell 302s shown in FIG.

  The liquid crystal panel 120 </ b> R includes a first transparent substrate 410, a second transparent substrate 420, and a liquid crystal layer 430. A plurality of pixel electrodes 411 and a first alignment film 412 are formed in this order on the first transparent substrate 410, and the common electrode 421 and the second alignment film are formed on the second transparent substrate 420. 422 are formed in this order. The liquid crystal layer 430 is provided between the two substrates 410 and 420, more specifically, between the two alignment films 412 and 422. As the transparent substrates 410 and 420, for example, a quartz substrate or a glass substrate can be used. As the pixel electrode 411 and the common electrode 421, a transparent electrode such as ITO (Indium Tin Oxide) can be used.

  Note that the two transparent substrates 410 and 420, the common electrode 421, the two alignment films 412 and 422, and the liquid crystal layer 430 are commonly used by the plurality of cells 302, and the plurality of pixel electrodes 411 are formed by a plurality of cells. 302 is provided correspondingly.

  The first transparent substrate 410 is provided with a recess C1. Note that the region where the recess C1 is not provided is the modulation region W1, and the region where the recess C1 is provided is the control region W2. In the recess C1, a device group included in the specific cell 302s is formed by a known semiconductor process. In FIG. 5, only the structure of the transistor Tr and the optical sensor 192R provided in the recess C1 is shown, and the structure of the temperature sensor 194R and the capacitor Cp provided in the recess C1 is omitted. . Note that the temperature sensor 194R and the capacitor Cp exist on the back side of the drawing sheet of FIG.

  A transistor Tr is formed on the right side of the recess C1 in the drawing. In FIG. 5, the gate electrode G, the drain region D, and the source region S of the transistor Tr are shown. A gate insulating film GI is shown below the gate electrode G, and a channel forming region Ch where a channel is formed is shown below the gate insulating film GI. The gate electrode G is connected to a conductor wiring (not shown) that constitutes the scanning line SL. The source region S is connected to the conductor wiring E1 that constitutes the data line DL. The drain region D is connected to the conductor wiring E <b> 2 that constitutes the pixel electrode 411.

  An optical sensor 192R (more specifically, a photodiode) is formed on the left side of the recess C1 in the drawing. FIG. 5 shows a p-type semiconductor region pS on the anode side and an n-type semiconductor region nS on the cathode side of the photodiode. Further, an anode electrode EA connected to the p-type semiconductor region pS and a cathode electrode EC connected to the n-type semiconductor region nS are shown. The anode electrode EA is connected to the conductor wiring E3 constituting the signal line Lpa, and the cathode electrode EC is connected to a conductor wiring (not shown) constituting the signal line Lpc.

  In other portions of the recess C1, insulating layers IL1 and IL2 that insulate between the conductor wirings are shown.

  In this embodiment, the light emitted from the light emitting unit 102R is incident from the second transparent substrate 420, modulated by the liquid crystal layer 430, and then emitted from the first transparent substrate 410, as shown in FIG. The

  However, when light is incident on a device such as the transistor Tr, the device may malfunction. Therefore, more specifically, the second transparent substrate 420 is provided with a light shielding film 440 between the second transparent substrate 420 and the common electrode 421. In this embodiment, the light shielding film 440 is provided in a region corresponding to the transistor Tr, the capacitor Cp, and the temperature sensor 194R in the recess C1, and is not provided in a region corresponding to the optical sensor 192R. That is, in the present embodiment, the incidence of light on the three devices Tr, Cp, 194R is prohibited and the incidence of light on the optical sensor 192R is allowed.

  The normal cell 302o has the same structure as that of the specific cell 302s. However, as described above, the optical sensor 192R and the temperature sensor 194R are not provided in the recess C1.

  Further, the scanning line driver 320, the data driver 330, the light intensity detection circuit 360, and the temperature detection circuit 370 shown in FIG. 2 are formed on the second transparent substrate 420 as in the device group in each cell 302. Yes.

  Note that the common electrode 421 in this embodiment corresponds to the first electrode layer in the present invention, and the plurality of pixel electrodes 411 correspond to the plurality of second electrode layers in the present invention. In addition, the second transparent substrate 420 in this embodiment corresponds to the first substrate in the present invention, and the first transparent substrate 410 corresponds to the second substrate in the present invention.

A-3. Configuration and operation of light emission controller:
FIG. 6 is an explanatory diagram showing an example of the configuration of the light emission control unit 190 (FIG. 1). As shown in the figure, the light emission control unit 190 includes three processing units 202R, G, and B corresponding to the three light emitting units 102R, G, and B, and one target light intensity setting unit 230.

  The first processing unit 202R corresponding to the first light emitting unit 102R includes two analog-digital (AD) converters 212 and 214, a correction unit 220, a comparison unit 240, and a pulse width modulation (PWM) signal generation. A circuit 250, a switching element 260, and a smoothing circuit 270 are provided. In FIG. 6, only the configuration of the first processing unit 202R is shown, but the configurations of the other processing units 202G and B are the same. Hereinafter, the description will be given focusing on the first processing unit 202R and the target light intensity setting unit 230.

  In this embodiment, the functions of the correction unit 220 and the comparison unit 240 and the function of the target light intensity setting unit 230 included in each processing unit 202R, G, B are stored in a memory (not shown) by a CPU (not shown). This is realized by executing a computer program.

  The first AD converter 212 acquires an optical detection value in the analog format from the optical sensor 192R via the optical intensity detection circuit 360, and converts the optical detection value in the analog format into a optical detection value in the digital format. The second AD converter 214 acquires an analog temperature detection value from the temperature sensor 194R via the temperature detection circuit 370, and converts the analog temperature detection value into a digital temperature detection value.

  In this embodiment, each AD converter 212, 214 acquires each detection value in the analog format at a predetermined cycle and converts it into each detection value in the digital format. The predetermined cycle is set to a time of 1 μs (corresponding to 1 MHz) to 20 μs (corresponding to 50 KHz), for example. In this way, if the light emission control unit 190 acquires each detection value at a relatively short period, the intensity of light emitted from the light emission unit 102R can be controlled in real time.

  Note that the second and third processing units 202G and B each include two detection circuits 360 and 370 provided in the second and third liquid crystal panels 120G and B, respectively, similarly to the first processing unit 202R. To obtain two detection values.

  The correction unit 220 corrects the light detection value (digital format) acquired from the first AD converter 212 by using the temperature detection value (digital format) acquired from the second AD converter 214. Find the light intensity value (digital format).

  Specifically, the correction unit 220 includes a plurality of lookup tables (LUT) prepared in advance. The plurality of LUTs correspond to a plurality of types of temperature values, and each LUT stores a plurality of corrected light intensity values corresponding to a plurality of light detection values. The correction unit 220 selects one of the plurality of LUTs according to the temperature detection value, and obtains a corrected light intensity value corresponding to the light detection value with reference to the selected one LUT.

  When there is no LUT corresponding to the temperature detection value, a corrected light intensity value is obtained by interpolation calculation. Specifically, first, the first LUT corresponding to the first temperature value T1 slightly higher than the temperature detection value T, and the second LUT corresponding to the second temperature value T2 slightly lower than the temperature detection value T. LUT is selected. Next, the first reference value (corrected light intensity value) L1 corresponding to the light detection value L is obtained by referring to the first LUT, and the light detection value L by referring to the second LUT. Is obtained as a second reference value (corrected light intensity value) L2. Then, the corrected light intensity value is obtained by multiplying each reference value L1, L2 by a weighting coefficient determined according to the temperature detection value T and each temperature value T1, T2, and adding the two obtained values. Is determined. That is, the corrected light intensity value is obtained by, for example, (T−T2) / (T1−T2) × L1 + (T1−T) / (T1−T2) × L2.

  By the way, the reason why the light detection value is corrected using the temperature detection value is to consider the temperature dependence of the optical sensor 192R. Note that the temperature of the optical sensor 192R rises as the optical sensor operates, and changes according to the ambient temperature of the optical sensor.

  FIG. 7 is a graph showing the temperature dependence of the optical sensor. The graph in FIG. 7 shows the relationship between the temperature (° C.) and the output (%) of the optical sensor when the optical sensor detects light having a predetermined intensity. In FIG. 7, the output (detection value) when the temperature of the optical sensor is 25 ° C. is shown as 100%. As shown in FIG. 7, when the temperature of the photosensor is relatively high, the detection value of the photosensor becomes relatively large. When the temperature of the photosensor is relatively low, the detection value of the photosensor is relatively low. Get smaller.

  In consideration of the characteristics of FIG. 7, in this embodiment, as described above, a plurality of LUTs corresponding to a plurality of types of temperature values are prepared. That is, in the first LUT corresponding to a relatively high temperature, a relatively small value is set as the corrected light intensity value corresponding to the specific light detection value. In the second LUT corresponding to a relatively low temperature, a relatively large value is set as the corrected light intensity value corresponding to the specific light detection value.

  The correction unit 220 (FIG. 6) supplies the corrected light intensity value (digital format) obtained as described above to the comparison unit 240.

  The target light intensity setting unit 230 supplies three preset target light intensity values to the three processing units 202R, G, and B. The three target light intensity values are values related to the intensity of the three lights to be emitted from the three light emitting units 102R, G, B, in other words, the three target light intensity values obtained by the three processing units 202R, G, B. It shows the target value of the corrected light intensity value.

  In particular, in this embodiment, the target light intensity setting unit 230 can change three target light intensity values in accordance with an instruction from the user. Specifically, the target light intensity setting unit 230 supplies the user interface screen to the liquid crystal panels 120R, 120G, and 120B via the image data processing unit 180, and causes the projector PJ to display the screen. Then, when the normal mode is selected by the user via the user interface screen, the target light intensity setting unit 230 sets the three target light intensity values to relatively high values, and the power saving mode is set by the user. When selected, the target light intensity setting unit 230 sets the three target light intensity values to relatively low values. When a specific color tone mode (for example, a color tone with a strong red color) is selected by the user, the target light intensity setting unit 230 compares a specific target light intensity value corresponding to a specific light emitting unit (for example, 102R). Set to a higher value. In the present embodiment, three target light intensity values are prepared in advance for each mode. Instead, the three target light intensity values may be arbitrarily set by the user.

  The comparison unit 240 compares the corrected light intensity value given from the correction unit 220 with the target light intensity value corresponding to the light emitting unit 102R given from the target light intensity setting unit 230, and outputs the comparison result. . The comparison result indicates which one of the corrected light intensity value and the target light intensity value is higher, and indicates the difference between the corrected light intensity value and the target light intensity value.

  The PWM signal generation circuit 250 is a circuit that generates a pulse width modulation (PWM) signal S1, and changes the duty ratio of the PWM signal according to the comparison result given from the comparison unit 240. Specifically, when the corrected light intensity value is lower than the target light intensity value, the PWM signal generation circuit 250 increases the duty ratio according to the difference between the corrected light intensity value and the target light intensity value. . On the other hand, when the corrected light intensity value is higher than the target light intensity value, the PWM signal generation circuit reduces the duty ratio according to the difference between the corrected light intensity value and the target light intensity value. The change amount of the duty ratio is set to be larger as the difference is larger.

The switching element 260 includes a transistor. A PWM signal S1 is applied to the gate terminal G of the transistor, a predetermined voltage V ₀ is applied to the drain terminal D, and a smoothing circuit 270 is connected to the source terminal S. The predetermined voltage V ₀ is determined according to the electrical characteristics (for example, forward voltage) of the light emitting unit 102R. The switching element 260 is switched between an on state and an off state according to the PWM signal S1, and as a result, the PWM signal S2 is output.

  Smoothing circuit 270 includes a diode 272, an inductor 274, and a capacitor 276. The cathode terminal of the diode 272 is connected to the source terminal S of the switching element 260 and one terminal of the inductor 274, and the anode terminal is set to a predetermined potential (for example, ground). The other terminal of the inductor 274 is connected to one terminal of the capacitor 276 and the light emitting unit 102R. The other terminal of the capacitor 276 is connected to a predetermined potential (for example, ground). The diode 272 is a so-called free wheel diode, and has a function of causing the inductor 274 to return a current when the switching element 260 is set to an off state. The smoothing circuit 270 smoothes the PWM signal S2 and outputs a smoothed voltage V. As a result, the light emitting unit 102R emits light having an intensity corresponding to the voltage V.

FIG. 8 is an explanatory diagram showing an outline of a signal generated by the light emission control unit 190. FIG. 8A shows the PWM signal S 1 output from the PWM signal generation circuit 250. FIG. 8B shows the PWM signal S <b> 2 output from the switching element 260. FIG. 8C shows the voltage V output from the smoothing circuit 270 and applied to the light emitting unit 102R. As can be seen from FIGS. 8A and 8B, the PWM signal S2 is a signal having substantially the same pulse width as the PWM signal S1, and the maximum value of the PWM signal S2 is approximately V ₀ .

In the period Ta, the duty ratio of the two signals S1 and S2 is about 50%. For this reason, in the period Ta, the voltage V is set to about ½ × V ₀ . Similarly, in the period Tb, since the duty ratio of the two signals S1 and S2 is about 75%, the voltage V is set to about 3/4 × V ₀ . In the period Tc, since the duty ratio of the two signals S1 and S2 is about 25%, the voltage V is set to about 1/4 × V ₀ .

  As can be seen from FIGS. 8A to 8C, the voltage V applied to the light emitting unit 102R is set to a relatively high value when the signals S1 and S2 have a relatively high duty ratio. A relatively low value is set when S2 has a relatively low duty ratio.

  Thus, if the voltage V applied to the light emitting unit 102R is adjusted according to the relationship between the corrected light intensity value and the target light intensity value, the light emitting unit 102R has an intensity corresponding to the target light intensity value. It is possible to stably emit the red light. Each of the light emitting units 102R, G, and B stably emits color light having an intensity corresponding to the corresponding target light intensity value, so that the projector PJ displays an image having stable brightness and color tone. be able to.

  Specifically, the intensity of the light emitted from each light emitting unit 102R, G, B can vary according to the temperature of each light emitting unit. When the intensity of the light emitted from each light emitting unit 102R, G, B changes, the brightness and color tone of the image displayed by the projector PJ will change.

  However, in this embodiment, since each of the light sensors 192R, G, B detects a part of the light emitted from the corresponding light emitting units 102R, G, B, the intensity of the light emitted from each light emitting unit. Each light emitting unit can be controlled so that is substantially constant.

  However, the detection values of the respective optical sensors 192R, G, and B can change according to the temperature of each optical sensor, as described with reference to FIG. Therefore, in this embodiment, temperature sensors 194R, G, and B that detect the temperatures of the optical sensors 192R, G, and B are provided. Then, by correcting the detection results of the optical sensors 192R, G, B using the detection results of the temperature sensors 194R, G, B, it is related to the intensity of light actually emitted from the light emitting units 102R, G, B. Value (corrected light intensity value) can be obtained. And the intensity | strength of the light inject | emitted from light emission part 102R, G, B can be adjusted appropriately by using the corrected light intensity value. In other words, the three light emitting units 102R, G, and B can stably emit three colored lights having intensities corresponding to the three target light intensity values preset by the target light intensity setting unit 230. . Thereby, the projector PJ can display an image having stable brightness and color tone.

  In addition, since the intensity | strength of the light inject | emitted from LED changes according to the electric current supplied to LED, the intensity | strength of the light inject | emitted from LED is normally adjusted by controlling an electric current. However, when the LED is controlled by current, the control circuit has a relatively complicated configuration and the current consumption of the control circuit becomes relatively large. On the other hand, in the present embodiment, the intensity of light emitted from each of the light emitting units 102R, G, and B including the LEDs is adjusted by controlling the voltage. For this reason, in the present embodiment, the control circuit 170 (more specifically, the light emission control unit 190) can be made relatively simple, and the current consumption of the control circuit 170 can be made relatively small. There are advantages.

  As can be seen from the above description, the comparison unit 240, the target light intensity setting unit 230, the PWM signal generation circuit 250, the switching element 260, and the smoothing circuit 270 in this embodiment correspond to the adjustment unit in the present invention. .

  As described above, in this embodiment, the optical sensors 192R, G, B are provided inside the display area of the liquid crystal panels 120R, G, B. For this reason, it is possible to detect the intensity of light actually incident on the display area of the liquid crystal panel, in other words, the intensity of light directly related to image display. Then, by using the detection result of the optical sensor as described above, the light emitting units 102R, G, and B can be controlled so that light having a stable intensity is incident on the liquid crystal panel.

  In particular, in the present embodiment, the optical sensors 192R, G, and B are provided at the center of the display area of the liquid crystal panels 120R, G, and B. Therefore, the optical sensors 192R, G, and B are located at positions corresponding to the center of the image that is most important for image display. The intensity of incident light can be detected.

  Further, in the present embodiment, since the temperature sensors 194R, G, B for detecting the temperatures of the optical sensors 192R, G, B are provided, the detection results of the optical sensors and the detection results of the temperature sensors are obtained as described above. By using this, the light emitting units 102R, 102G, and 102B can be controlled so that light having a more stable intensity is incident on each liquid crystal panel.

  In this embodiment, the optical sensor 192R detects the intensity of light that has passed through the liquid crystal layer 430. Instead, the optical sensor 192R detects the intensity of light that has not passed through the liquid crystal layer 430. Also good. In this case, for example, the optical sensor 192R (and the temperature sensor 194R) may be provided on the second transparent substrate 420. Alternatively, a light-transmitting member formed of glass or the like may be disposed on the liquid crystal layer 430 so that light that has passed through the light-transmitting member enters the optical sensor 192R.

B. Second embodiment:
FIG. 9 is an explanatory view schematically showing the structure of the liquid crystal panel 120Rb in the second embodiment, and corresponds to FIG.

  FIG. 9 is substantially the same as FIG. 5, but the position of the light shielding film 440b is changed. Along with this, the shapes of the common electrode 421b and the second alignment film 422b are changed. Further, the shape of the first transparent substrate 410b is changed. As can be seen by comparing FIG. 9 and FIG. 5, in this embodiment, the first transparent substrate 410b is formed with the recess C1 as in FIG. 5, but the recess C2 is further formed inside the recess C1. Is formed. The light shielding film 440b is formed in the recess C2. As in the first embodiment, the light shielding film 440b prohibits light from entering the transistor Tr, the capacitor Cp, and the temperature sensor 194R provided in the recess C1, and prevents light from entering the light sensor 192R. It is provided to allow. An insulating layer IL4 is formed on the light shielding film 440b so as to fill the recess C2.

  In this embodiment, the light emitted from the light emitting unit 102R is incident from the first transparent substrate 410b, modulated by the liquid crystal layer 430, and then emitted from the second transparent substrate 420, as shown in FIG. The

  When the configuration of the present embodiment is employed, the optical sensor detects the intensity of light incident on the display area of the liquid crystal panel more accurately than when the configuration of the first embodiment is employed. Can do. That is, in the first embodiment, the optical sensor detects the intensity of light incident from the second transparent substrate 420 and passed through the liquid crystal layer 430. In this embodiment, the optical sensor It is possible to detect the intensity of light incident from one transparent substrate 410b and not passing through the liquid crystal layer 430. For this reason, if this embodiment is adopted, the intensity of light incident on the display area of the liquid crystal panel can be detected more accurately.

C. Third embodiment:
A microlens array may be provided on the light incident surface side of the liquid crystal panel. The microlens array includes a plurality of microlenses (microlenses) arranged in a matrix, and the plurality of microlenses are provided corresponding to the plurality of cells 302 of the liquid crystal panel. Each microlens has a function of guiding light incident on the microlens to the modulation region W1 of the corresponding cell 302. Thereby, the amount of light incident on the modulation region W1 can be increased, and the light use efficiency can be improved.

  By the way, when a microlens array is used, it is difficult for light to enter the control region W2 of each cell 302. For this reason, when a microlens array is used, it becomes difficult to make light sufficiently incident on the optical sensor 192R in the specific cell 302s. Therefore, in this embodiment, the shape of the microlens array is devised.

  FIG. 10 is an explanatory diagram showing a first example of a microlens array. In FIG. 10, the liquid crystal panel 120Rb of the second embodiment (FIG. 9) is used.

  As shown in FIG. 10, a microlens array 150 and a dustproof glass 129 are provided on the light incident surface side of the liquid crystal panel 120Rb, that is, on the first transparent substrate 410b side. The microlens array 150 includes a transparent member 151 and an adhesive layer 156 made of an adhesive that adheres the transparent member 151 to the first transparent substrate 410b. The transparent member 151 includes a plurality of convex portions 152 and a light guide portion 153. The adhesive layer 156 includes a plurality of concave portions 157 corresponding to the plurality of convex portions 152 of the transparent member 151. The plurality of convex portions 152 of the transparent member 151 are provided in a region corresponding to the modulation region W1 of each cell 302o, 302s, and the light guide unit 153 is a region corresponding to the control region W2 of the specific cell 302s (more specifically, Specifically, it is provided in a region corresponding to the optical sensor 192R).

  In this example, the refractive index of the adhesive layer 156 is set lower than the refractive index of the transparent member 151. For this reason, each convex part 152 of the transparent member 151 functions as a convex lens. Specifically, each convex portion 152 of the transparent member 151 has a substantially planar incident surface and a substantially spherical exit surface, and condenses light incident on the microlens array 150 to collect each cell 302o. , 302s to the modulation region W1. On the other hand, the light guide portion 153 of the transparent member 151 has a substantially columnar shape having a substantially planar incident surface and a substantially planar exit surface, and light incident along the normal direction of the incident surface. Is ejected along the normal direction of the exit surface.

  By adopting the microlens array 150 shown in FIG. 10, even when the microlens array is used, sufficient light can be incident on the optical sensor 192R in the specific cell 302s. The liquid crystal panel 120Rb and the microlens array 150 in FIG. 10 correspond to the light modulation device in the present invention.

  FIG. 11 is an explanatory diagram showing a second example of the microlens array. FIG. 11 is substantially the same as FIG. 10 except that the microlens array 160 is modified. The microlens array 160 includes a transparent member 161 and an adhesive layer 166 made of an adhesive that adheres the transparent member 161 to the first transparent substrate 410b. The transparent member 161 includes a plurality of concave portions 162 and a light guide portion 163. The adhesive layer 166 includes a plurality of convex portions 167 corresponding to the plurality of concave portions 162 of the transparent member 161. The plurality of recesses 162 of the transparent member 161 are provided in a region corresponding to the modulation region W1 of each cell 302o, 302s, and the light guide unit 163 is a region corresponding to the control region W2 of the specific cell 302s (more specifically, Is provided in a region corresponding to the optical sensor 192R.

  In this example, the refractive index of the adhesive layer 166 is set higher than the refractive index of the transparent member 161. For this reason, each convex part 167 of the adhesive layer 166 corresponding to each concave part 162 of the transparent member 161 functions as a convex lens. Specifically, each convex portion 167 of the adhesive layer 166 has a substantially spherical incident surface and a substantially planar exit surface, and condenses light incident on the microlens array 160 to each cell 302o. , 302s to the modulation region W1. On the other hand, the light guide part 163 of the transparent member 161 has a substantially planar incident surface and a substantially planar exit surface, and the light incident along the normal direction of the entrance surface is normal to the exit surface. Inject along the direction.

  Even when the microlens array 160 shown in FIG. 11 is employed, sufficient light can be incident on the optical sensor 192R in the specific cell 302s. The liquid crystal panel 120Rb and the microlens array 160 in FIG. 11 correspond to the light modulation device in the present invention.

  Note that the transparent members 151 and 161 shown in FIGS. 10 and 11 can be manufactured, for example, by performing dry etching on a glass substrate. This manufacturing method is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-329906.

  In this embodiment, the microlens arrays 150 and 160 are applied to the liquid crystal panel 120Rb of the second embodiment (FIG. 9), but can be similarly applied to the liquid crystal panel 120R of the first embodiment (FIG. 5). It is. Also in this case, the microlens array is provided on the light incident surface side of the liquid crystal panel 120R, that is, on the second transparent substrate 420 side.

D. Fourth embodiment:
In the first to third embodiments, only one set of the optical sensor 192R and the temperature sensor 194R is provided in one liquid crystal panel. Instead, a plurality of sets of optical sensors and temperatures are provided in one liquid crystal panel. A sensor may be provided.

  FIG. 12 is an explanatory diagram showing the arrangement of a plurality of sets of optical sensors and temperature sensors in the fourth embodiment. In FIG. 12, nine sets of sensors 192R and 194R are provided in one liquid crystal panel 120Rd1. Nine sets of sensors 192R and 194R are provided in nine partial areas obtained by equally dividing the display area of the liquid crystal panel 120Rd1, and each set of sensors 192R and 194R is provided at the center of each partial area. Is provided.

  As described above, if a plurality of sets of light sensors and temperature sensors are provided, the average intensity and intensity distribution of light incident on the display area of the liquid crystal panel can be known. The light emitting unit can be controlled.

  Specifically, in this embodiment, the light emission control unit 190 acquires nine light detection values from the nine light sensors 192R via the light intensity detection circuit 360, and also via the temperature detection circuit 370. , Nine temperature detection values are acquired from the nine temperature sensors 194R. Then, the light emission control unit 190 controls the light emitting unit 102R using nine sets of light detection values and temperature detection values.

  For example, the light emission control unit 190 controls the light emitting unit 102R so that an average value of nine corrected light intensity values obtained from nine sets of light detection values and temperature detection values is equal to the target light intensity value. be able to.

  Alternatively, the light emission control unit 190 changes the light emitting unit 102R so that the minimum value among the nine corrected light intensity values obtained from the nine sets of light detection values and temperature detection values is equal to the target light intensity value. Can be controlled. In this case, the image data processing unit 180 changes the gradation value of the pixel data included in the red data for each partial area according to the nine corrected light intensity values corresponding to the nine partial areas. can do. Specifically, the red data is divided into nine blocks corresponding to the nine partial areas, and the image data processing unit 180 calculates the corrected light intensity value and the target light intensity value corresponding to each partial area. The gradation value of the pixel data included in the corresponding block is reduced according to the difference between the two. In this way, among the nine partial areas, in the partial area where the incident light intensity is relatively high, the incident light is modulated using the pixel data whose gradation value is relatively reduced, and the intensity of the incident light is compared. In a relatively low partial area, incident light is modulated using pixel data whose gradation value is relatively small and reduced. As a result, it is possible to correct image brightness and color tone unevenness caused by the intensity distribution of light incident on the display area. In this case, in order to mitigate the change in the brightness of the image in steps near the boundary between two adjacent partial areas, the pixel data between the two blocks corresponding to the two partial areas It is preferable that the gradation value of the pixel data is corrected so that the gradation value changes smoothly.

  Alternatively, when the light emitting unit 102R includes nine LEDs corresponding to the nine partial regions, the light emission control unit 190 uses the nine corrected light intensities obtained from the nine sets of light detection values and temperature detection values. The nine LEDs can be individually controlled so that each of the values is equal to the target light intensity value.

  In FIG. 12, the display area is divided into nine partial areas. However, m × n (m and n are natural numbers of 1 or more and m × n is a natural number of 2 or more). Even when it is divided into partial areas, the same processing as in the present embodiment can be executed.

D-1. Modification of the fourth embodiment:
FIG. 13 is an explanatory diagram showing the arrangement of a plurality of sets of optical sensors and temperature sensors in a modification of the fourth embodiment. In FIG. 12, the liquid crystal panel 120Rd2 is provided with 13 sets of sensors 192R and 194R. Nine of the 13 sets of sensors 192R and 194R are arranged at the same positions as in FIG. The other four sensors 192R and 194R are provided near the four corners of the display area of the liquid crystal panel 120Rd2. Specifically, each pair of sensors 192R and 194R is provided at a predetermined position on the diagonal line of the display area, and the predetermined position is 1/10 times the length L of the diagonal line from the end point of the diagonal line. It is a position closer to the center by the distance.

  Even when this example is adopted, the same processing as in the fourth embodiment can be executed. In particular, in this example, since the intensity of light incident on the peripheral portion of the display area can be detected, the brightness and color tone in the peripheral portion of the image can be changed by changing the gradation value of the pixel data included in the red data. There is an advantage that non-uniformity can be corrected.

  The positions at which the pairs of optical sensors and temperature sensors shown in FIGS. 12 and 13 are provided correspond to measurement points for measuring predetermined characteristics (for example, brightness and contrast of displayed images) of the projector. Yes. Therefore, if the light emitting unit is controlled using the detection results of the plurality of sets of optical sensors and temperature sensors, an image that satisfies the predetermined characteristics of the projector can always be displayed.

  The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

(1) In the above embodiment, the light emission control unit 190 acquires the detection result of the optical sensor and the detection result of the temperature sensor in a relatively short cycle. The two detection results may be acquired with a relatively long period. In this case, for example, one scanning line may be connected to the two detection circuits 360 and 370, and a voltage may be applied to the two sensors each time the scanning line is selected. Such a configuration is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-317800.

(2) In the above embodiment, the light intensity detection circuit 360 and the temperature detection circuit 370 are provided outside the cell array 310, but are instead provided in the control region W2 of the specific cell 302s. Also good.

(3) In the above embodiment, the optical sensor and the temperature sensor are provided in the control region W2 of the specific cell 302s, but are provided in place of one cell 302 of the M × N cells 302. May be. In this case, the cell array does not include a specific cell, but includes (M × N−1) cells 302. However, if the configuration of the above embodiment is employed, pixels in the displayed image need not be lost. Specifically, as described above, when one of the plurality of cells 302 in the display area is replaced with an optical sensor, pixels in the image corresponding to the one cell are lost. However, if the configuration of the above embodiment is employed, the display area includes a plurality of cells corresponding to a plurality of pixels in the image, and therefore the pixels in the image are lost due to the presence of the photosensor. You do n’t have to.

  In the above embodiment, the optical sensor and the temperature sensor are provided in the control region W2 of the specific cell 302s. Instead, they are provided in a wiring region where the scanning line SL and the data line DL are formed. It may be.

  In general, the optical sensor may be provided inside the display area.

(4) In the above embodiment, the liquid crystal panel is provided with both the optical sensor and the temperature sensor, but instead of this, only the optical sensor may be provided. However, if both the optical sensor and the temperature sensor are provided as in the above embodiment, light having a more stable intensity can be incident on the liquid crystal panel.

  In general, the light modulation device only needs to include at least an optical sensor.

(5) In the above-described embodiment, three liquid crystal panels 120R, G, and B are used. However, instead of this, one liquid crystal panel may be used. In this case, the three color lights emitted from the three light emitting units may be sequentially incident on one liquid crystal panel. In this case, the one liquid crystal panel may be provided with three sets of optical sensors and temperature sensors corresponding to the three light emitting units. In this case, the emission of two colored lights from the other two light emitting units is prohibited during the period in which one colored light is emitted from one light emitting unit. The emission of light from the light emitting unit can be prohibited by setting the voltage V applied to the light emitting unit to zero. The voltage V applied to the light emitting unit is set, for example, when the PWM signal generation circuit 250 corresponding to the light emitting unit sets the PWM signal S1 to zero, or the target light intensity setting unit 230 corresponds to the light emitting unit. By setting the target light intensity value given to the comparison unit 240 to zero, it can be set to zero.

(6) In the said Example, although the light emission part was equipped with LED, it may replace with this and may be provided with other solid light sources, such as a semiconductor laser.

  In the above-described embodiment, the projector includes three light emitting units that emit three color lights. Instead, one light emitting unit that emits light including three color lights (for example, a mercury lamp or a halogen lamp). Lamp) and a separating unit (for example, a filter) that separates the light emitted from the light emitting unit into three color lights.

(7) In the above embodiment, the projector displays a color image, but instead, a monochrome image may be displayed.

(8) In the above embodiment, the present invention is applied to a transmissive liquid crystal panel, but the present invention may be applied to a reflective liquid crystal panel instead. In this case, the first transparent substrate 410 is changed to a semiconductor substrate.

  In the above-described embodiment, the present invention is applied to the projector PJ including the liquid crystal panels 120R, G, and B. Instead, a DMD (digital micromirror device) (trademark of TI) or the like is used instead. The present invention may be applied to a projector including a micromirror light modulation device.

(9) In the above embodiment, the light modulation device of the present invention is applied to a projector. However, instead of this, it may be applied to a direct-view display.

(10) In the above embodiment, a part of the configuration realized by hardware may be replaced with software, and conversely, a part of the configuration realized by software may be replaced with hardware. Also good.

It is explanatory drawing which shows schematic structure of the projector PJ in 1st Example. It is explanatory drawing which shows the structure of liquid crystal panel 120R. It is explanatory drawing which expands and shows the specific cell 302s of FIG. It is a circuit diagram which shows the specific structure of specific cell 302s. It is explanatory drawing which shows the structure of liquid crystal panel 120R typically. It is explanatory drawing which shows an example of a structure of the light emission control part 190 (FIG. 1). It is a graph which shows the temperature dependence of an optical sensor. It is explanatory drawing which shows the outline | summary of the signal produced | generated by the light emission control part 190. FIG. It is explanatory drawing which shows typically the structure of liquid crystal panel 120Rb in 2nd Example. It is explanatory drawing which shows the 1st example of a micro lens array. It is explanatory drawing which shows the 2nd example of a micro lens array. It is explanatory drawing which shows arrangement | positioning of the multiple sets of optical sensor and temperature sensor in 4th Example. It is explanatory drawing which shows arrangement | positioning of the multiple sets of optical sensor and temperature sensor in the modification of 4th Example.

Explanation of symbols

102R, G, B: Light emitting section 110R, G, B ... Illumination optical system 120R, G, B, Rb, Rd1, Rd2 ... Liquid crystal panel 129 ... Dust-proof glass 130 ... Cross dichroic prism 140 ... Projection optical system 150 ... Micro lens array DESCRIPTION OF SYMBOLS 151 ... Transparent member 152 ... Convex part 153 ... Light guide part 156 ... Adhesive layer 157 ... Concave part 160 ... Micro lens array 161 ... Transparent member 162 ... Concave part 163 ... Light guide part 166 ... Adhesive layer 167 ... Convex part 170 ... Control circuit 180 ... image data processing unit 190 ... light emission control unit 192R, G, B ... optical sensor 194R, G, B ... temperature sensor 202R, G, B ... processing unit 212, 214 ... analog-digital converter 220 ... correction unit 230 ... target Light intensity setting unit 240 ... comparison unit 250 ... pulse width modulation signal generation circuit 260 ... switching Child 270: Smoothing circuit 272 ... Diode 274 ... Inductor 276 ... Capacitor 302 ... Cell 302o ... Normal cell 302s ... Specific cell 310 ... Cell array 320 ... Scan line driver 330 ... Data driver 360 ... Light intensity detection circuit 370 ... Temperature detection circuit 410 , 410b ... Transparent substrate 411 ... Pixel electrode 412 ... Alignment film 420 ... Transparent substrate 421, 421b ... Common electrode 422, 422b ... Alignment film 430 ... Liquid crystal layer 440, 440b ... Light shielding film Cp ... Capacitor SL ... Scanning line DL ... Data line LC ... Liquid crystal element Tr ... Transistor W1 ... Modulation area W2 ... Control area PJ ... Projector

Claims (10)

A light modulation device that includes a display area used for displaying an image and modulates light incident on the display area to display an image,
A plurality of modulation units that are provided inside the display region and modulate light incident on the display region according to a plurality of pixel data included in image data;
An optical sensor provided inside the display area for detecting light incident on the display area;
An optical modulation device comprising: The light modulation device according to claim 1,
Each of the modulation units is
A modulation region for modulating light;
A control region for controlling light modulation in the modulation region in accordance with the corresponding pixel data;
Including
The optical sensor is an optical modulation device provided in the control region included in at least one of the plurality of modulation units. The light modulation device according to claim 2,
The plurality of modulation units are:
A first substrate utilized by the plurality of modulators;
A second substrate utilized by the plurality of modulators;
A liquid crystal layer used by the plurality of modulators and provided between the first substrate and the second substrate;
A first electrode layer used by the plurality of modulators and provided between the first substrate and the liquid crystal layer;
A plurality of second electrode layers provided between the second substrate and the liquid crystal layer and corresponding to the plurality of modulators;
With
The light sensor is a light modulation device provided between the second substrate and the liquid crystal layer. The light modulation device according to claim 3,
The light sensor is a light modulation device that detects light incident from the first substrate. The light modulation device according to claim 3,
The light sensor is a light modulation device that detects light incident from the second substrate. The light modulation device according to any one of claims 2 to 5, further comprising:
A lens array provided on the light incident surface side of the plurality of modulators;
The lens array is
A plurality of lenses for guiding light incident on the lens array to the plurality of modulation regions included in the plurality of modulation units;
A light guiding unit for guiding light incident on the lens array to the photosensor provided in the control region included in the at least one modulation unit;
A light modulation device. The light modulation device according to any one of claims 1 to 6,
The light sensor is a light modulation device provided in the center of the display area. The light modulation device according to any one of claims 1 to 6,
An optical modulation device, wherein two or more optical sensors are provided inside the display area. The light modulation device according to claim 1, further comprising:
A light modulation device provided with a temperature sensor provided inside the display area for detecting the temperature of the light sensor. An image display device,
The light modulation device according to claim 9,
A light source device that emits light toward the light modulation device;
A control circuit for controlling the intensity of light emitted from the light source device;
With
The control circuit includes:
A correction unit for obtaining corrected light intensity by correcting the detection result of the optical sensor using the detection result of the temperature sensor;
An adjustment unit that adjusts the intensity of light emitted from the light source device so that the corrected light intensity is equal to the target light intensity;
An image display device comprising:

Images