JP2007011163A - Liquid crystal display device, liquid crystal display system, and liquid crystal projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide more stable video output by detecting and feeding back the luminance of a light source that is irradiated to a liquid crystal display device. <P>SOLUTION: The liquid crystal display device is equipped with a pair of substrates which are made to overlap the other, across a specified gap so that liquid crystal is charged in the gap and an optical sensor 15, which detects the quantity of light from the light source irradiating the liquid crystal on one of the pair of substrates (e.g. driving-side substrate 10). Furthermore, disclosed is a liquid crystal display system, constituted of equipping the liquid crystal display device 1 with the light source and a control section, which controls the light source in response to the detection signal from the optical sensor 15. Furthermore, disclosed is a liquid crystal projector which projects video produced by the liquid crystal display device 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, a liquid crystal display system, and a liquid crystal projector that generate images using liquid crystal, and more particularly to a liquid crystal display device and a liquid crystal display system that perform control according to the amount of light emitted from a light source toward the liquid crystal. And a liquid crystal projector.

  In recent years, with the advancement of high definition, miniaturization, and high brightness of projection systems, a reflective liquid crystal display device that can be miniaturized and high definition as a display device and that can be expected to have high light utilization efficiency has attracted attention and has been put to practical use. Has been. This is an active reflective liquid crystal display in which a glass substrate on which a transparent electrode is formed on one side and a silicon substrate made of, for example, a CMOS semiconductor circuit on the other side is used as a drive element substrate, and liquid crystal is injected between the pair of substrates. Device (see, for example, Patent Document 1).

  A pixel electrode for reflecting light and applying a voltage to the liquid crystal is disposed on the silicon drive substrate. This pixel electrode is a metal material mainly composed of aluminum used in LSI processes. Consists of.

  In these elements, a voltage is applied to the liquid crystal by applying a voltage to the transparent electrode provided on the glass substrate and the pixel electrode provided on the silicon substrate. At this time, the liquid crystal changes the refractive index of the liquid crystal according to the potential difference between the electrodes, causes an optical characteristic change, and performs gradation display by modulating the incident light.

  A silicon reflective liquid crystal display device using this silicon driving substrate and a projection system using this display device are required to have high brightness, high definition and high image quality year by year.

JP 2005-156717 A

  Here, the projector irradiates the liquid crystal display device with light from a light source such as a lamp and projects the reflected light onto a screen to form an image, as can be seen from the optical system. At this time, the intensity of the light applied to the liquid crystal display device surface generally changes over time due to deterioration of the lamp light source, and also changes due to temperature changes in the projector set. Therefore, it is desired to keep the brightness constant by detecting it and feeding it back to the power source of the light source.

  In order to monitor the change in luminance in a light source such as a lamp, a method of taking out light in the middle of the optical system and detecting it using an element that senses the change in luminance of the light can be considered. In this system, a mirror that reflects, for example, 5% is provided on each optical path separated into three colors of R (red), G (green), and B (blue) by a dichroic color separation filter, and reflected by this mirror. Light is detected by a sensor.

  However, in such a configuration, it is necessary to provide the mirrors and sensors as described above between the optical systems, and a certain size is required, and if each of the three colors of light is supported, the mechanism becomes complicated and the cost is reduced. The problem of rising. This is a direction that hinders the downsizing of sets in recent years, and it is not appropriate to incorporate such functions.

  The present invention has been made to solve such problems. That is, according to the present invention, a pair of substrates that are superimposed via a predetermined gap and liquid crystal is sealed in the gap, and light emitted from the light source toward the liquid crystal on one of the pair of substrates. A liquid crystal display device including an optical sensor for detecting the amount.

  In the present invention, an optical sensor is provided on one of a pair of substrates in which liquid crystal is sealed, and the amount of light emitted from the light source toward the liquid crystal is detected by the optical sensor. The amount of light incident on the liquid crystal can be accurately detected and reflected in the control of the amount of light and display.

  Here, the optical sensor has a configuration including a photodiode capable of converting the amount of received light into an electrical signal, and for example, a CMOS (Complementary Metal Oxide Semiconductor) sensor is suitable. In other words, when one of the pair of substrates is constituted by a semiconductor substrate such as silicon, if an optical sensor composed of a CMOS sensor or the like is incorporated together with an element for driving a liquid crystal formed on the semiconductor substrate, the optical sensor is separately provided. The number of processes can be reduced and the size of the set can be reduced as compared with the configuration in which the is provided.

  The output of the optical sensor is sent to a control unit that controls the light source, a correction unit that corrects driving of the liquid crystal, and a light amount adjustment unit that controls the amount of light traveling from the light source toward the light irradiation region of the liquid crystal. Thereby, according to the light quantity detected with the optical sensor, the output of a light source, the drive of a liquid crystal, and light quantity adjustment on an optical path can be performed now.

  In particular, the present invention superimposes the opposing substrate on which the transparent electrode is formed, the driving substrate on which the reflective electrode is formed, the opposing substrate and the driving substrate through a predetermined gap, and encloses the gap. A liquid crystal display device comprising: a liquid crystal to be applied; and a photosensor formed at a position where light from a light source is irradiated on a part of the driving side substrate.

  This liquid crystal display device is a reflective liquid crystal display device that reflects and outputs a liquid crystal image by a drive side substrate, and an optical sensor is provided on the drive side substrate to detect the amount of incident light from the light source on the substrate. It can be used to control the amount of irradiation light and liquid crystal drive.

  The liquid crystal display system of the present invention is constructed by a configuration including such a liquid crystal display device, a light source, and a control unit that controls the light irradiation amount of the light source. In addition, when the light source is a solid light source such as an LED (Light Emitting Diode) or a laser diode, the current to the solid light source such as an LED or laser is controlled according to the light amount detected by the optical sensor, and the light amount is accurately and accurately measured. Can be adjusted.

  The liquid crystal display device of the present invention is used in a liquid crystal projector that projects a generated image through an optical system. This makes it possible to provide a stable video display by controlling the amount of light applied to the liquid crystal and driving the liquid crystal by detecting the amount of light with an optical sensor, even in a display system in which strict requirements are imposed on the control of the amount of irradiated light.

  Therefore, according to the present invention, it is possible to optimally control the amount of light applied to the liquid crystal and the liquid crystal drive in accordance with the amount of light emitted from the light source toward the liquid crystal. In addition, for example, in a silicon reflective liquid crystal display device, by integrating a sensor that detects light in the silicon drive substrate, the luminance from the light source to the device can be detected simultaneously with the video display, and in accordance with the change in the luminance of the light source, By adjusting the power of the power supply or adjusting the transmittance of the device, it is possible to cancel the luminance change and provide a stable image. In addition, the change of the three colors can be kept constant, and a high-quality color image can be stably displayed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view for explaining the liquid crystal display device according to the present embodiment. That is, the liquid crystal display device 1 is a reflective liquid crystal device, and is provided on one of the pair of substrates and a pair of substrates that are superposed via a predetermined gap and enclose liquid crystal in the gap. The optical sensor 15 is provided.

  Since FIG. 1 is a schematic plan view, a driving side substrate 10 is shown among a pair of substrates. In the reflective liquid crystal device, a semiconductor substrate such as silicon (including a substrate on which a semiconductor film is formed) is used as the driving-side substrate 10, and a switching element for driving liquid crystal and a liquid crystal from the switching element are formed on the substrate by a semiconductor process technique. Are formed in a matrix shape. The formation range of the reflection electrode 14 is a display area S1 of an image by liquid crystal. In addition, a scanning driver 12 and a data driver 11 that drive the switching elements and an electrode pad group 13 that is a signal extraction I / O line are also formed around the display area S1 of the driving substrate 10.

  A glass substrate is used as the substrate facing the driving substrate 10. A transparent electrode is uniformly formed on the glass substrate, and is used as a counter electrode for the reflective electrode 14 of the driving side substrate 10. The driving-side substrate 10 and the glass substrate are bonded together as a pair of substrates via a sealing agent (not shown), and the liquid crystal is sealed in the inter-substrate gap constituted by the thickness of the sealing agent.

  Further, in the liquid crystal display device 1 of the present embodiment, the optical sensor 15 is formed outside the display region S1 in the driving side substrate among the pair of substrates. The optical sensor 15 is incorporated in the drive side substrate 10 as a CMOS sensor, for example. Since the CMOS sensor can be formed by the same semiconductor process technology as that for forming a switching element or the like on the driving side substrate 10, it can be easily incorporated.

  As an arrangement place of the optical sensor 15, it is provided outside the display area S1 and inside the light irradiation area S2. That is, the light emitted from the light source is applied to an area (light irradiation area S2) slightly larger than the display area S1. For this reason, the optical sensor 15 is provided in the area | region where the light from a light source is irradiated outside the display area S1 so that the image | video to display may not be affected.

  The optical sensor 15 can detect the illuminance of the light applied to the device and extract the detected signal from a part of the electrode pad group 13 of the device. By using this signal, it can be used for various controls of the liquid crystal display device 1.

  In this way, by incorporating the optical sensor 15 in the driving side substrate 10, it is possible to directly detect the light applied to the display area S1 without having to split the optical path with a mirror or disposing a separate optical sensor. Therefore, it is possible to detect the irradiation light amount with high accuracy as well as downsizing the set.

  Note that light is mostly absorbed in the portion where the optical sensor 15 is disposed, but light slightly reflected on the sensor surface is not converted in polarization, and therefore optically does not go in the emission direction in principle. When the liquid crystal display device 1 is used in a display system such as rear projection, the end portion of the display surface is not displayed by overscan. Even if there is reflected light from the optical sensor, the light sensor part is placed in the overscan area at the end of the display part, so that the original display is not affected at all, and the light irradiated on the device surface Can be detected.

  The amount of light detected by the optical sensor 15 is converted into an electrical signal and taken out from the electrode pad group 13 to the outside of the device through, for example, a flexible cable. Then, the signal is transmitted to a signal processing board (not shown) and fed back to the control of the power source of the light source, for example.

  In particular, when the liquid crystal display device 1 of the present embodiment is made of a silicon reflective liquid crystal device, the switching element can be made of silicon. Therefore, if a CMOS sensor is used as the optical sensor 15, the same substrate surface as the display driving switching element can be used. It can easily be formed in a stack.

  Next, an application example of the liquid crystal display device 1 according to the present embodiment to a system will be described. FIG. 2 is a schematic diagram for explaining the first liquid crystal display system according to the present embodiment. The liquid crystal display system 100 includes a liquid crystal display device 1 described above, a light source 1012 that irradiates light to the liquid crystal display device 1, a drive circuit 105 of the liquid crystal display device 1, and light emitted from the light source 1012. A beam splitter 104 that reflects the image light reflected on the device 1 side and that is reflected by the liquid crystal display device 1 and a control unit 1013 of the light source 1012 are provided.

  In the liquid crystal display system 100, the light emitted from the light source 1012 is reflected by the beam splitter 104 toward the liquid crystal display device 1, and irradiated to the light irradiation region S <b> 2 (see FIG. 1) of the liquid crystal display device 1. The liquid crystal display device 1 is driven by a drive circuit 105, drives a liquid crystal by applying a voltage to a reflective electrode 14 (see FIG. 1) corresponding to an image to be displayed, and controls the reflectance of light emitted from the light source 1012. By this reflectance control, the light emitted from the light source 1012 is modulated and output as an image.

  Since the liquid crystal display device 1 used in the liquid crystal display system 100 of the present embodiment is provided with the optical sensor 15 (see FIG. 1) as described above, it is emitted from the light source 1012 and irradiated onto the liquid crystal display device 1. The amount of light emitted can be detected by the optical sensor 15 in real time. A light amount signal (detection signal S) detected by the optical sensor 15 is fed back to the control unit 1013 of the light source 1012. Then, the control unit 1013 performs light amount control of the light source 1012 based on the light amount detection signal S sent from the optical sensor 15.

  Specifically, in order to keep the amount of light irradiated from the light source 1012 to the liquid crystal display device 1 constant, when the light amount detected by the optical sensor 15 is smaller than the reference value, the emitted light amount of the light source 1012 is increased, On the contrary, when the detected light amount is larger than the reference value, the control unit 1013 controls the light source 1012 so as to decrease the emitted light amount of the light source 1012.

  Here, when the light source 1012 is formed of a white lamp, the control unit 1013 performs control by increasing or decreasing the supply voltage to the light source 1012. When the light source 1012 is a solid light source such as an LED or a laser diode, the control unit 1013 performs control by increasing or decreasing the supply current to the light source 1012. When the light source 1012 is a solid-state light source, it is possible to perform light amount adjustment with high accuracy by current control. As a result, even when the amount of light emitted from the light source 1012 fluctuates due to environmental changes or changes over time, the liquid crystal display device 1 can always maintain a stable amount of irradiation light.

  FIG. 3 is a schematic diagram for explaining the second liquid crystal display system according to the present embodiment. The liquid crystal display system 100 includes a liquid crystal display device 1 described above, a light source 1012 that irradiates light to the liquid crystal display device 1, a drive circuit 105 of the liquid crystal display device 1, and light emitted from the light source 1012. A beam splitter 104 that reflects the image light reflected to the device 1 side and straightly reflects the liquid crystal display device 1 is provided, and a correction unit 1051 that corrects driving of the liquid crystal.

  The video output method in the liquid crystal display system 100 is the same as that of the first liquid crystal display system shown in FIG. 2, but in the second liquid crystal display system 100, the signal of the light amount detected by the optical sensor 15 of the liquid crystal display device 1 ( The difference is that the detection signal S) is fed back to the correction unit 1051. The correction unit 1051 corrects the driving of the liquid crystal by the driving circuit 105 based on the light quantity detection signal S sent from the optical sensor 15.

  Specifically, in order to keep the light reflectance with respect to certain data in the liquid crystal display device 1 constant, when the light amount detected by the optical sensor 15 is smaller than the reference value, the drive circuit 105 is designed to increase the reflectance by the liquid crystal. On the contrary, when the detected light quantity is larger than the reference value, the drive circuit 105 is corrected so as to reduce the reflectance by the liquid crystal. Thereby, even if there is a change in the light amount of the light source 1012, it is possible to display an image with a stable reflectance.

  FIG. 4 is a schematic diagram for explaining a third liquid crystal display system according to the present embodiment. The liquid crystal display system 100 includes a liquid crystal display device 1 described above, a light source 1012 that irradiates light to the liquid crystal display device 1, a drive circuit 105 of the liquid crystal display device 1, and light emitted from the light source 1012. A beam splitter 104 that reflects the image light reflected by the liquid crystal display device 1 and travels straight, and a light amount adjustment unit 1020 that is provided on an optical path from the light source 1012 toward the beam splitter 104 and adjusts the light amount of the light source 1012. It has.

  The video output method in the liquid crystal display system 100 is the same as the first and second liquid crystal display systems shown in FIGS. 2 and 3, but in the third liquid crystal display system 100, the optical sensor 15 of the liquid crystal display device 1 is used. The difference is that the detected light amount signal (detection signal S) is fed back to the light amount adjustment unit 1020. The light amount adjustment unit 1020 controls the amount of light emitted from the light source 1012 based on the light amount detection signal S sent from the optical sensor 15.

  Specifically, in order to keep the light reflectance with respect to certain data in the liquid crystal display device 1 constant, when the amount of light detected by the optical sensor 15 is smaller than a reference value, the transmission amount of light emitted from the light source 1012 Is controlled by the light amount adjusting unit 1020, and conversely, when the detected light amount is larger than the reference value, the light amount adjusting unit 1020 is controlled to decrease the transmission amount of the light emitted from the light source 1012. As a result, even if there is a light amount variation due to the change of the light source 1012 with time, it is possible to always maintain a stable irradiation light amount to the liquid crystal display device 1.

  Next, application of the liquid crystal display device according to the present embodiment to a liquid crystal projector will be described. FIG. 5 is a schematic diagram showing an example of a first liquid crystal projector using the liquid crystal display device of the present embodiment. That is, the liquid crystal projector 1000 includes a lamp light source 101, a lens unit 102, a dichroic color separation filter 103, beam splitters 104r, 104g, and 104b, liquid crystal display devices 1r, 1g, and 1b, drive circuits 105r, 105g, and 105b, and prisms (dichroic mirrors). ) 106 and the projection lens 107.

  As the liquid crystal display devices 1r, 1g, and 1b, the reflection type liquid crystal display device according to the present embodiment described above is used. Therefore, the reflective electrode 14 provided on the driving side substrate 10 shown in FIG. The transparent electrode is used as the counter electrode formed on the glass substrate on the opposite side.

  In this system, the light emitted from the lamp light source 101 is sent from the lens unit 102 to the dichroic color separation filter 103, where it is separated in two directions. The light separated in two directions corresponds to three colors R (RED), G (GREEN), and B (BLUE) by total reflection mirrors 108 and 109, beam splitters 104r, 104g, and 104b, dichroic mirror 110, and prism 106. Each of them is sent to a display unit composed of a reflective liquid crystal display device 1r, 1g, 1b.

  For example, the light from the lamp light source 101 is incident on the liquid crystal display device 1r corresponding to R (RED) from the dichroic color separation filter 103 via the total reflection mirror 108 and the beam splitter 104r, and corresponds to G (GREEN). Light from the lamp light source 101 enters the liquid crystal display device 1g through the total reflection mirror 108, the dichroic mirror 110, and the beam splitter 104g from the dichroic color separation filter 103, and enters the liquid crystal display device 1b corresponding to B (BLUE). The light from the lamp light source 101 enters from the dichroic color separation filter 103 via the total reflection mirror 109 and the beam splitter 104b.

  Each of the liquid crystal display devices 1r, 1g, and 1b is provided via beam splitters 104r, 104g, and 104b in a state corresponding to the plurality of surfaces of the prism 106 that is a dichroic mirror. Each of the liquid crystal display devices 1r, 1g, and 1b is driven by the corresponding drive circuits 105r, 105g, and 105b, reflects the incident light as an image on the liquid crystal layer, synthesizes it by the prism 106, and sends it to the projection lens 107. . As a result, an image corresponding to three colors R (RED), G (GREEN), and B (BLUE) is projected onto a screen (not shown) and reproduced as a color image.

  Further, since each of the liquid crystal display devices 1r, 1g, and 1b is provided with the optical sensor 15 (see FIG. 1) as described above, the liquid crystal display devices 1r, 1g, and 1b are emitted from the lamp light source 101. Each light sensor 15 can detect the amount of light emitted in real time. Light quantity signals (detection signals Sr, Sg, Sb) detected by the optical sensor 15 are fed back to the control unit 120 of the lamp light source 101. Then, the control unit 120 performs light amount control of the lamp light source 101 based on the light amount detection signals Sr, Sg, and Sb sent from the optical sensor 15.

  Specifically, in order to keep the amount of light emitted from the lamp light source 101 to the liquid crystal display devices 1r, 1g, and 1b constant, when the light amount detected by the optical sensor 15 is smaller than the reference value, the lamp light source 101 is used. The controller 120 controls the controller 120 to reduce the amount of emitted light by lowering the supply voltage to the lamp light source 101 when the amount of emitted light is increased and the detected amount of light is larger than the reference value.

  As a result, even if the amount of light emitted from the light source 101 fluctuates due to environmental changes or changes over time, the liquid crystal display devices 1r, 1g, and 1b can always maintain a stable irradiation light amount, and can be stably supplied from the liquid crystal projector 1000. Video can be provided.

  FIG. 6 is a schematic diagram showing an example of a second liquid crystal projector using the liquid crystal display device of the present embodiment. The second liquid crystal projector 1000 includes a lens unit 102, a dichroic color separation filter 103, beam splitters 104r, 104g, 104b, liquid crystal display devices 1r, 1g, 1b, drive circuits 105r, 105g, 105b, a prism (dichroic mirror) 106, and Although it is the same as the first liquid crystal projector in that it includes the projection lens 107 and the control unit 120, it is different in that a solid light source 1010 is used instead of the lamp light source 101.

  As the solid-state light source 1010, an ELD or a laser diode corresponding to each color of R (RED), G (GREEN), and B (BLUE) is used. The light emitted from the solid-state light source 1010 is sent from the lens unit 102 to the dichroic color separation filter 103, where it branches in two directions, and is totally reflected mirrors 108, 109, beam splitters 104r, 104g, 104b, and dichroic mirror 110. , And prism 106, the light is sent to a display unit including reflective liquid crystal display devices 1r, 1g, and 1b corresponding to three colors R (RED), G (GREEN), and B (BLUE).

  For example, R (RED) light from the solid-state light source 1010 enters the liquid crystal display device 1r corresponding to R (RED) from the dichroic color separation filter 103 via the total reflection mirror 108 and the beam splitter 104r, and G ( G (NREE) compatible liquid crystal display device 1g receives G (GREEN) light from solid light source 1010 from dichroic color separation filter 103 via total reflection mirror 108, dichroic mirror 110 and beam splitter 104g, and B (BLUE) The B (BLUE) light from the solid-state light source 1010 is incident on the liquid crystal display device 1b corresponding to) from the dichroic color separation filter 103 via the total reflection mirror 109 and the beam splitter 104b.

  Each of the liquid crystal display devices 1r, 1g, and 1b is provided via beam splitters 104r, 104g, and 104b in a state corresponding to the plurality of surfaces of the prism 106 that is a dichroic mirror. Each of the liquid crystal display devices 1r, 1g, and 1b is driven by the corresponding drive circuits 105r, 105g, and 105b, reflects the incident light as an image on the liquid crystal layer, synthesizes it by the prism 106, and sends it to the projection lens 107. . As a result, an image corresponding to three colors R (RED), G (GREEN), and B (BLUE) is projected onto a screen (not shown) and reproduced as a color image.

  Further, since each of the liquid crystal display devices 1r, 1g, and 1b is provided with the optical sensor 15 (see FIG. 1) as described above, the liquid crystal display devices 1r, 1g, and 1b are emitted from the solid light source 1010. The amount of light of each color irradiated can be detected by the optical sensor 15 in real time. Light quantity signals detected by the optical sensor 15 (detection signals Sr, Sg, Sb) are fed back to the control unit 120 of the solid-state light source 1010. Then, the control unit 120 controls the light amount of each color corresponding to the solid light source 1010 based on the detection signals Sr, Sg, Sb of the light amount of each color sent from the optical sensor 15.

  By using the solid light source 1010 corresponding to each color of RGB as the light source, the control unit 120 can perform light amount control independently for each color. Specifically, the amount of light detected by the optical sensor 15 of each liquid crystal display device 1r, 1g, 1b is compared with a reference value, and if it is smaller than the reference value, the solid light source 1010 is supplied to the corresponding color. The controller 120 controls the controller 120 to increase the amount of emitted light by increasing the current, and on the other hand, if the detected amount of light is larger than the reference value, the supply current to the corresponding color of the solid light source 1010 is lowered to reduce the amount of emitted light. To do.

  As a result, even when the amount of light emitted from the solid-state light source 101 fluctuates due to environmental changes or changes over time, the liquid crystal display devices 1r, 1g, and 1b can always maintain a stable amount of irradiation light, which is stable from the liquid crystal projector 1000. Video can be provided. Further, since the light amounts of the RGB colors of the solid-state light source 1010 can be controlled independently, it is possible to perform control in consideration of the balance of each color.

  FIG. 7 is a schematic diagram showing an example of a third liquid crystal projector using the liquid crystal display device of the present embodiment. The third liquid crystal projector 1000 includes liquid crystal display devices 1r, 1g, and 1b, drive circuits 105r, 105g, and 105b, a prism (dichroic mirror) 106, a projection lens 107, and a control unit 120. Although it is the same as a projector, it differs in that the light source is provided separately for each of R (RED), G (GREEN), and B (BLUE).

  That is, in the third liquid crystal projector 1000, since the light sources of the respective colors are provided independently, the lens unit 102, the dichroic color separation filter 103, and the beam splitters 104r, 104g, and 104b provided in the first and second liquid crystal projectors are unnecessary. It has become.

  The light source includes a light source 1010r corresponding to R (RED), a light source 1010g corresponding to G (GREEN), and a light source 1010b corresponding to B (BLUE). Even if these light sources are lamp light sources, ELD, laser diode, etc. It may be a solid light source. Here, a solid light source is used because of its high controllability.

  The light of each color emitted from the RGB light sources 1010r, 1010g, and 1010b is reflected by the corresponding beam splitters 104r, 104g, and 104b, and sent to the liquid crystal display devices 1r, 1g, and 1b corresponding to the respective RGB colors.

  For example, R (RED) light is incident on the liquid crystal display device 1r corresponding to R (RED) from the light source 1010r via the beam splitter 104r, and the liquid crystal display device 1g corresponding to G (GREEN) G (GREEN) light enters from 1010g through the beam splitter 104g, and B (BLUE) light enters from the light source 1010b through the beam splitter 104b into the liquid crystal display device 1b corresponding to B (BLUE).

  Each of the liquid crystal display devices 1r, 1g, and 1b is driven by the corresponding drive circuit 105r, 105g, and 105b, reflects the incident light as an image on the liquid crystal layer, synthesizes it by the prism 106, and sends it to the projection lens 107. As a result, an image corresponding to three colors R (RED), G (GREEN), and B (BLUE) is projected onto a screen (not shown) and reproduced as a color image.

  In addition, since each of the liquid crystal display devices 1r, 1g, and 1b is provided with the optical sensor 15 (see FIG. 1) as described above, the liquid crystal display devices 1r, 1g, The amount of light of each color irradiated to 1b can be detected in real time by this optical sensor 15. Light quantity signals (detection signals Sr, Sg, Sb) detected by the optical sensor 15 are fed back to the control units of the light sources 1010r, 1010g, 1010b. Then, the control unit performs light amount control of each color corresponding to each of the light sources 1010r, 1010g, 1010b based on the detection signals Sr, Sg, Sb of the light amount of each color sent from the optical sensor 15.

  By providing each RGB color separately as a light source, each control unit can perform light amount control independently for each color. Specifically, the light amounts detected by the optical sensors 15 of the respective liquid crystal display devices 1r, 1g, and 1b are respectively compared with the reference values, and when the light amounts are smaller than the reference values, the corresponding light sources 1010r, 1010g, and 1010b are supplied. In the control unit, the supply current is increased to increase the amount of emitted light, and conversely, if the detected amount of light is larger than the reference value, the supply current to the corresponding light source 1010r, 1010g, 1010b is lowered to reduce the amount of emitted light. Control.

  As a result, even when the amount of light emitted from each of the light sources 1010r, 1010g, and 1010b fluctuates due to environmental changes, changes over time, etc., it becomes possible to always maintain a stable irradiation light amount for the liquid crystal display devices 1r, 1g, and 1b. The video can be provided stably from 1000. In addition, since the light amounts of the light sources 1010r, 1010g, and 1010b can be controlled independently, control in consideration of the balance of each color is also possible.

  FIG. 8 is a schematic diagram showing an example of a fourth liquid crystal projector using the liquid crystal display device of the present embodiment. The first to third liquid crystal projectors described above are three-plate systems that include the liquid crystal display devices 1r, 1g, and 1b corresponding to the respective RGB colors. However, the fourth liquid crystal projector 1000 corresponds to the respective RGB colors. This is a single-plate system that sequentially emits and drives each color. Therefore, the fourth liquid crystal projector 1000 is configured by the three-color light source 1011, the beam splitter 104, the liquid crystal display device 1, the drive circuit 101, and the projection lens 107, and can be most miniaturized.

  The three-color light source 1011 sequentially outputs light corresponding to R (RED), G (GREEN), and B (BLUE) at a predetermined timing. The drive circuit 105 is driven in accordance with the timing of light emission of each color, and the liquid crystal display device 1 displays the video of each color sequentially and repeatedly. The three-color light source 1011 may be a lamp light source or a solid light source such as an ELD or a laser diode, but a solid light source is used because of its high controllability.

  Since the liquid crystal display device 1 is provided with the optical sensor 15 (see FIG. 1) as described above, the amount of light of each color irradiated from the three-color light source 1010 to the liquid crystal display device 1 is determined. The light sensor 15 can sequentially detect. That is, the detection signals Sr, Sg, and Sb of each color are sequentially output from the optical sensor 15 in synchronization with the RGB light emission timing, and fed back to the control unit of the three-color light source 1011. Then, the control unit performs light amount control of each color corresponding to the three-color light source 1011 based on light amount signals (detection signals Sr, Sg, Sb) transmitted from the optical sensor 15.

  Specifically, the light amount of each color sequentially detected by the optical sensor 15 of the liquid crystal display device 1 is compared with each reference value. If the light amount is smaller than the reference value, the supply current is increased when the corresponding color is emitted. When the amount of emitted light of the color is increased and the detected amount of light is larger than the reference value, the control unit controls to reduce the amount of emitted light of the color by reducing the supply current when the corresponding color is emitted.

  As a result, even when the amount of light emitted from the three-color light source 1011 fluctuates due to environmental changes or changes over time, the liquid crystal display device 1 can always maintain a stable amount of irradiation light. Can be provided. Further, since the light emission amounts of the respective colors of the three-color light source 1011 can be controlled independently, it is possible to perform control in consideration of the balance of the respective colors.

  The liquid crystal display device according to the present embodiment described above mainly uses an example of a reflection type device, but can be applied to a transmission type device. In this case, both the driving side substrate and the opposite side substrate are made of glass. A substrate may be used and a transparent electrode may be used as the electrode. Moreover, although the example which forms an optical sensor in a drive side board | substrate was demonstrated in the said embodiment, even if it is the structure provided in an opposing board | substrate, it is realizable.

It is a schematic plan view explaining the liquid crystal display device which concerns on this embodiment. It is a schematic diagram explaining the 1st liquid crystal display system which concerns on this embodiment. It is a schematic diagram explaining the 2nd liquid crystal display system which concerns on this embodiment. It is a schematic diagram explaining the 3rd liquid crystal display system which concerns on this embodiment. It is a schematic diagram which shows the example of the 1st liquid crystal projector using the liquid crystal display device of this embodiment. It is a schematic diagram which shows the example of the 2nd liquid crystal projector using the liquid crystal display device of this embodiment. It is a schematic diagram which shows the example of the 3rd liquid crystal projector using the liquid crystal display device of this embodiment. It is a schematic diagram which shows the example of the 4th liquid crystal projector using the liquid crystal display device of this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device, 10 ... Drive side board | substrate, 11 ... Data driver, 12 ... Scan driver, 13 ... Electrode pad group, 14 ... Reflective electrode, 15 ... Optical sensor, 100 ... Liquid crystal display system, 101 ... Lamp light source, 120 ... Control unit, 1012 ... Light source, 1000 ... Liquid crystal projector

Claims (13)

A pair of substrates that are overlapped via a predetermined gap and in which liquid crystal is sealed;
An optical sensor that detects an amount of light emitted from a light source toward the liquid crystal on one of the pair of substrates. The said optical sensor is provided in a part inside the irradiation area | region of the light radiate | emitted from the said light source outside the display area which produces | generates an effective image | video with the said liquid crystal. Liquid crystal display device. The liquid crystal display device according to claim 1, wherein the photosensor is formed on a substrate having a circuit for driving the liquid crystal among the pair of substrates. 2. The liquid crystal display device according to claim 1, wherein the photosensor is formed on a semiconductor substrate having a circuit for driving the liquid crystal in the pair of substrates. A counter substrate on which a transparent electrode is formed;
A drive-side substrate on which a reflective electrode is formed;
A liquid crystal sealed in the gap in a state where the opposing substrate and the driving substrate are overlapped with each other with a predetermined gap;
A liquid crystal display device comprising: an optical sensor formed at a position where a part of the driving side substrate is irradiated with light from a light source. The liquid crystal display device according to claim 5, wherein the precursor driving side substrate is formed of a semiconductor substrate. A pair of substrates that are overlapped via a predetermined gap and in which liquid crystal is sealed;
A light source that emits light toward the liquid crystal;
On one of the pair of substrates, an optical sensor that detects the amount of light from the light source;
A liquid crystal display system comprising: a control unit that controls a light irradiation amount of the light source according to a light amount detected by the optical sensor. The liquid crystal display system according to claim 7, wherein the light source is a solid light source. A pair of substrates that are overlapped via a predetermined gap and in which liquid crystal is sealed;
A light source that emits light toward the liquid crystal;
On one of the pair of substrates, an optical sensor that detects the amount of light from the light source;
A liquid crystal display system, comprising: a correction unit that corrects driving of the liquid crystal according to the amount of light detected by the optical sensor. A pair of substrates that are overlapped via a predetermined gap and in which liquid crystal is sealed;
A light source that emits light toward the liquid crystal;
On one of the pair of substrates, an optical sensor that detects the amount of light from the light source;
A liquid crystal display system comprising: a light amount adjusting unit that controls an amount of light traveling from the light source toward the light irradiation region according to a light amount detected by the optical sensor. In a liquid crystal projector that irradiates a liquid crystal display device with light emitted from a light source and projects an image generated by the liquid crystal display device through an optical system.
One of the pair of substrates constituting the liquid crystal display device is provided with an optical sensor that detects the amount of light emitted from the light source toward the liquid crystal of the liquid crystal display device,
A liquid crystal projector, wherein the amount of light emitted from the light source to the liquid crystal display device is controlled according to the amount of light detected by the optical sensor. The liquid crystal projector according to claim 11, wherein the light source is a solid light source. The light source and the liquid crystal display device are provided corresponding to a plurality of colors, and the amount of light emitted from the light source of each color to the liquid crystal display device according to the amount of light detected by the optical sensor of each liquid crystal display device, respectively The liquid crystal projector according to claim 11, wherein the liquid crystal projector is controlled independently.

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