JP2006003607A - Projector and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector which will not cause abnormal displays, even if it is affected by high-frequency noise generated by the lighting of a light source section. <P>SOLUTION: A lamp lighting sensing station 17 detects the lighting state of a light source section, comprising a discharge lamp 1 by means of a light sensor and gives a detection signal to a controller 9 through an I/F section 12. The controller 9 compares the signal level from the I/F section 12 with a reference signal level stored in a storage section 10, to detect lighting or non-lighting of the lamp 1. When the controller 9 detects lighting of the lamp 1, it reads out a preset value of voltage of a counter electrode stored in the storage section 10 and sets the preset value to a register 18 in a D/A converter 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector including a discharge light source unit such as a discharge lamp.

  There is known a projector that optically projects and displays an image using a light modulation element such as a transmissive liquid crystal light valve. In such a projector, the counter electrode voltage required for driving a liquid crystal light valve used as a light modulation element is generated by a DA converter controlled by a control signal (see, for example, Patent Document 1). On the other hand, in such a projector, for example, a high pressure mercury lamp, a discharge lamp such as a metal halide lamp and a halogen lamp is used as a light source. Although these discharge lamps can obtain high luminance, it takes time of several seconds to several tens of seconds until the lamp is turned on. For this reason, at the time of start-up, various initial settings of the projector are performed first, and then the lamp lighting process starts.

  FIG. 9 is a flowchart showing a flow of initial setting in a conventional projector. When the power switch of the projector is turned on in step S30, initialization processing of each unit and each circuit is performed in step S31. In step S32, predetermined data necessary for various initial settings is read from the storage device, and initial settings of the DA converter and the like are made. In step S33, adjustment of each related part and image processing are performed along the set data. Here, the predetermined data of the initial setting corresponds to, for example, a setting value of the counter electrode voltage of the liquid crystal light valve, a parameter relating to γ correction for displaying a digital image with gradation using the liquid crystal light valve, and the like. In step S34, the lamp lighting process starts. When the lamp lighting is confirmed in step S35, the lamp lighting process ends, and image projection starts.

JP 2002-287716 A

  When the above-described discharge lamp is lit, it is necessary to form a discharge path by causing dielectric breakdown by applying a high-frequency high voltage between the lamp electrodes during startup. The voltage at this time instantaneously becomes about 20 KV, which may become high frequency noise and affect the peripheral circuit. However, in the above-described conventional projector, since various initial settings are made before the lamp is turned on, the set data may be destroyed by the high-frequency noise.

  For example, when the counter electrode voltage of the liquid crystal light valve is set in the register of the DA converter of the liquid crystal panel drive unit before the lamp is turned on, and then the data is destroyed due to the high frequency noise accompanying the lamp lighting. Think. It is assumed that a gray solid image is set as an initial setting image of the projector. If the register data of the DA converter is destroyed, the voltage applied between the counter electrodes of the liquid crystal light valve cannot be predicted except that it is a DC voltage. For example, when a voltage with a biased potential other than a set value (hereinafter referred to as a DC offset voltage) is applied between the counter electrodes, a display mark when the DC offset voltage is applied, a so-called burn-in phenomenon. Will occur.

  It is also assumed that an image that should originally be a gray solid image has an image of a different tone. Furthermore, it is conceivable that an abnormal voltage is applied, the pixel is overloaded, and the life of the liquid crystal light valve itself is shortened. In addition, it is assumed that the user suspects a failure of the projector by seeing such a phenomenon. As described above, in the conventional projector, since various initial settings are made only before the lamp is lit, the setting data may be destroyed due to the high-frequency noise accompanying the lamp lighting, which may cause an abnormal display. is there.

  In order to solve the above-described problems, it is an object of the present invention to provide a projector that does not cause abnormal display even under the influence of high-frequency noise associated with lighting of a light source unit.

  In order to achieve the above object, a projector according to the present invention includes a discharge-type light source unit that supplies illumination light, a lighting detection unit that detects a lighting state of the light source unit, and light that modulates illumination light according to an image signal. A data setting unit for setting predetermined data regarding a modulation element, an operation condition when the light modulation element operates, or a processing condition of an image signal that affects an image generated by the light modulation element; An operation processing unit for operating the light modulation element under a predetermined operation condition based on the predetermined data set in the above, or for processing the image signal sent to the light modulation element under a predetermined processing condition; A storage unit that stores data, a light source unit, a lighting detection unit, a data setting unit, an operation processing unit, and a control unit that controls the storage unit, the control unit is a detection signal from the lighting detection unit Turn on the light source When exiting, it reads predetermined data from the storage unit, and sets the data setting unit.

  According to this configuration, the lighting detection unit detects the lighting state of the light source unit of the projector and sends a detection signal to the control unit. The light source unit of the projector is a discharge type that can obtain high luminance. When the control unit detects lighting of the light source unit from the detection signal from the lighting detection unit, the control unit reads predetermined data from the storage unit and sets the data in the data setting unit. As a result, after the high frequency noise generated when the light source unit is turned on is settled, the operating condition when the light modulation element operates in the data setting unit or the image signal that affects the image generated by the light modulation element It is possible to set predetermined data for the processing conditions. The operation processing unit operates the light modulation element under a predetermined operation condition based on the predetermined data set in the data setting unit, or processes the image signal sent to the light modulation element under the predetermined processing condition. be able to. Therefore, it is possible to provide a projector that does not perform abnormal display even when it is affected by high-frequency noise associated with the lighting of the light source unit.

  According to a preferred aspect of the projector of the present invention, the operation processing unit is a signal generation unit that supplies a predetermined counter electrode voltage to the light modulation element, and the data setting unit is a register provided in the signal generation unit. The storage unit stores a set value of a predetermined counter electrode voltage as predetermined data, and when the control unit detects lighting of the light source unit based on a detection signal from the lighting detection unit, the storage unit stores the predetermined counter electrode. A set value of the voltage is read and set in a register of the signal generation unit.

  According to this configuration, when the control unit detects the lighting of the light source unit based on the detection signal from the lighting detection unit, the control unit reads the set value of the counter electrode voltage as predetermined data from the storage unit, and is a signal that is a data setting unit Set in the register of the generator. Thereby, after the high frequency noise generated when the light source unit is turned on is settled, a predetermined counter electrode voltage can be set in the register of the signal generation unit. A signal generation unit that is an operation processing unit generates a counter electrode voltage in accordance with a set value of the counter electrode voltage set in the register. Therefore, even if affected by the high frequency noise associated with the lighting of the light source unit, the above-described image sticking phenomenon, color tone deviation, and the like do not occur, and an appropriate projected image according to the set value can be obtained.

  According to a preferred aspect of the projector of the present invention, the operation processing unit is an image signal processing unit that performs processing on the image signal sent to the light modulation element under predetermined processing conditions, and the data setting unit is configured to perform image signal processing. A register provided in the unit, wherein the storage unit stores predetermined data on processing conditions applied to the image signal, and the control unit stores the data when detecting the lighting of the light source unit by the detection signal from the lighting detection unit. The predetermined data on the processing conditions applied to the image signal is read from the image signal, and set in a register of the image signal processor.

  According to this configuration, when the control unit detects lighting of the light source unit based on the detection signal from the lighting detection unit, the control unit reads predetermined data on processing conditions applied to the image signal from the storage unit, and the image signal which is the data setting unit Set in the register of the processing unit. Thereby, after the high frequency noise generated when the light source unit is turned on is settled, predetermined data relating to the image signal suitable for the light modulation element can be set in the register of the image signal processing unit. The image signal processing unit, which is an operation processing unit, processes the image signal along predetermined data regarding processing conditions applied to the image signal set in the register, and sends the processed image signal to the light modulation element. Therefore, a desired projection image along predetermined data can be obtained even under the influence of high-frequency noise accompanying lighting of the light source unit.

  Further, according to a preferred aspect of the projector of the present invention, when the control unit detects lighting of the light source unit based on a detection signal from the lighting detection unit, the control unit initializes the image signal processing unit, and the initialization is completed. Then, predetermined data regarding processing conditions applied to the image signal read from the storage unit is set in the register of the image signal processing unit. According to this configuration, when the control unit detects lighting of the light source unit from the detection signal from the lighting detection unit, the control unit initializes the image signal processing unit prior to setting predetermined data. As a result, the image signal processing unit performs hardware reset including the registers provided therein, so that predetermined data can be set in a more stable state than when hardware reset is not performed. Can do. Therefore, a desired projection image along predetermined data can be obtained even under the influence of high-frequency noise accompanying lighting of the light source unit.

  According to a preferred aspect of the projector of the present invention, the control unit reads predetermined data from the storage unit and sets the data in the data setting unit even before the light source unit is turned on. According to this configuration, even in the time of several seconds to several tens of seconds necessary for the discharge type light source unit to be lit, the operation condition when the light modulation element operates or the image generated by the light modulation element Predetermined data is set for the processing conditions of the image signal that has an effect, and an appropriate voltage or image signal is applied to the light modulation element from the operation processing unit. Therefore, even before the light source unit is turned on, no overvoltage or abnormal image signal is applied to the light modulation element, so that the light modulation element and related parts can be protected.

  The projector control method according to the present invention includes a discharge-type light source unit that supplies illumination light, a light modulation element that modulates illumination light according to an image signal, and operating conditions when the light modulation element operates, or A data setting unit that sets data on processing conditions of an image signal that affects an image generated by the light modulation element, and a storage unit that stores predetermined data, and the lighting that detects the lighting state of the light source unit It includes a detection step and a data setting step of reading predetermined data from the storage unit and setting the data setting unit when lighting of the light source unit is detected in the lighting detection step.

  According to this control method, the lighting state of the light source unit is detected in the lighting detection step. In the data setting step, when lighting of the light source unit is detected in the lighting detection step, predetermined data is read from the storage unit and set in the data setting unit. As a result, even if the influence of the high frequency noise accompanying the lighting of the light source unit described above is performed, the predetermined data is set after the lighting of the light source unit in which the influence of the high frequency noise is greatly reduced. The possibility of data corruption is reduced. Therefore, it is possible to provide a projector control method that does not cause abnormal display even under the influence of high-frequency noise associated with the lighting of the light source unit.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment.
(Embodiment 1)

  FIG. 1 is a schematic configuration diagram illustrating a projector 100 according to the first embodiment of the invention. The projector 100 separates the light emitted by the lamp 1 as the light source unit into three primary color components of red light (hereinafter referred to as R light), blue light (hereinafter referred to as B light), and green light (hereinafter referred to as G light). The liquid crystal light valve 2 for each color light as a light modulation element modulates each color light in accordance with an image signal, and then re-synthesizes and projects the image onto the screen SC. Here, first, the schematic configuration of the projector 100 will be described, then the display principle of the liquid crystal light valve and various characteristics of the liquid crystal light valve will be described in detail, and finally the startup routine of the projector 100 will be described.

  In FIG. 1, an image signal supply device 3 is a device that supplies an image signal from the outside, such as a personal computer or a video recorder, and is connected to an external connection terminal (not shown) of the projector 100. The image signal VS from the image signal supply device 3 is an analog image signal, and is supplied to the projector 100 as, for example, an RGB signal representing a computer image of a personal computer or a composite signal from a video recorder or a television receiver. The analog image signal VS from the image signal supply device 3 is input to the image signal processing unit 4. The image signal processing unit 4 includes an image converter 5, a γ correction circuit 6, a color unevenness correction circuit 7, and the like.

  The image converter 5 performs AD conversion on the analog image signal VS and outputs it as a digital image signal DS. The image signal DS includes a vertical synchronization signal, a horizontal synchronization signal, and a clock signal as timing signals. The image data of the digital image signal DS is continuously output for each pixel as 24-bit image data per pixel. One-pixel image data is composed of 8-bit color data for each of R, G, and B colors. The γ correction circuit 6 corrects the digital image signal DS so that the change characteristic of transmittance with respect to the voltage applied to the liquid crystal light valve 2 (hereinafter referred to as VT characteristic) changes more linearly. This correction is called γ correction. Details of γ correction will be described later. The color unevenness correction circuit 7 corrects the digital image signal DSγ after γ correction so as to suppress color unevenness occurring in the image displayed on the screen SC, and further performs DA conversion to obtain an analog image signal DSc. Output to the liquid crystal panel drive unit 8. Details of the color unevenness correction will be described later.

  The liquid crystal panel drive unit 8 includes a DC bias circuit and a gain adjustment circuit (both not shown) which will be described later. The liquid crystal panel drive unit 8 performs DC bias adjustment and gain adjustment on the analog image signal DSc including the above-described synchronization signal and the like by a DC bias circuit and a gain adjustment circuit, and supplies the analog image signal DSe to the liquid crystal light valve 2. . The DC bias adjustment and gain adjustment will be described later.

  The control unit 9 includes a CPU and the like, and is connected to the image signal processing unit 4, the liquid crystal panel drive unit 8, the storage unit 10, the DA converter (DAC) 11 and the I / F unit 12 described above via a bus. And controls each part. The storage unit 10 includes a nonvolatile memory such as a flash memory or an EEPROM, for example, and stores various predetermined parameters necessary for displaying an image on the liquid crystal light valve 2. The DA converter 11 as an operation processing unit generates a counter electrode voltage to be supplied to the liquid crystal light valve 2. A register 18 is provided as a data setting unit inside the DA converter 11. An indicator unit 13, an operation unit 14, a main power supply unit 15, a lamp driving unit 16, and a lamp lighting detection unit 17 are connected to the I / F unit 12. The I / F unit 12 bridges information between the control unit 9 and each unit connected to the I / F unit 12. Therefore, the units 13 to 17 connected to the I / F unit 12 are controlled by the control unit 9 via the I / F unit 12.

  The indicator unit 13 is composed of, for example, a plurality of LEDs and a TN liquid crystal panel, and indicates the operating state of the projector 100. The operation unit 14 includes a plurality of operation switches (not shown), and the projector 100 can be operated by the plurality of switches. The same operation can be performed with a remote controller (not shown). The main power supply unit 15 converts the power from the external AC power source into a power format required for each unit of the projector 100 and supplies the power to each unit. As the lamp 1, for example, a high-pressure mercury lamp, a discharge lamp such as a metal halide lamp and a halogen lamp is used. The lamp driving unit 16 applies an high voltage between the electrodes of the lamp 1 at the time of lighting, causes an insulation breakdown to form a discharge path, and stabilizes arc discharge after the lamp is turned on. And a ballast circuit (not shown) for maintaining the lamp 1 to turn on and off the lamp 1.

  The lamp lighting detection unit 17 as a lighting detection unit is provided with a photosensor such as a photodiode 19. Note that a phototransistor or a CDS may be used as the optical sensor. When the lamp 1 is turned on, the lamp lighting detection unit 17 detects a part of the light emitted from the lamp 1 by this optical sensor and sends a detection signal to the I / F unit 12. The I / F unit 12 converts the detection signal from the lamp lighting detection unit 17 into a predetermined signal format and sends it to the control unit 9. The illumination light emitted from the lamp 1 is separated into R, G, and B color light components while preventing the illumination light from being dispersed by an illumination optical system (not shown) including a color light separation optical system. The light enters the liquid crystal light valve 2. The modulated light modulated in accordance with the image signal for each color light by the liquid crystal light valve 2 for each color light is synthesized as projection light by a projection optical system including a synthesis optical system for synthesizing each color light of R, G, B. Then, a full color image is projected on the screen SC.

  Here, the display principle and counter electrode voltage of the liquid crystal light valve 2 will be described. The liquid crystal light valve 2 applies light according to a pixel signal corresponding to each pixel to the liquid crystal forming each pixel, and controls the transmittance of light irradiated to each pixel to form light. It is a modulation element. FIG. 2 is an explanatory diagram showing an equivalent circuit of an arbitrary pixel of the liquid crystal light valve 2 and an applied voltage waveform applied to the one pixel. As shown in FIG. 2A, one pixel PE is provided at the intersection of the scanning line SL and the signal line DL orthogonal to each other via a TFT (Thin Film Transistor) 50 that is a switching element. The gate electrode of the TFT (hereinafter referred to as “TFT switch”) 50 is connected to the scanning line SL, the drain electrode is connected to the signal line DL, and the source electrode is connected to the pixel electrode 51 of the pixel PE. The counter electrode 52 facing the pixel electrode 51 is connected to a counter electrode signal line LCCOM that is an output line from the DA converter 11 of FIG. Note that the counter electrode 52 is usually formed as an electrode common to all pixels, and is also referred to as a common electrode signal line.

  A liquid crystal is sandwiched between the pixel electrode 51 and the counter electrode 52. This liquid crystal is equivalently regarded as a capacitance (hereinafter referred to as “liquid crystal capacitance”) CLC. Further, a storage capacitor Cs is added in parallel with the liquid crystal capacitor CLC. The combined capacitance Cpe (= CLC · Cs / (CLC + Cs)) of the liquid crystal capacitance CLC and the storage capacitance Cs is called “pixel capacitance”. Of the image signal DSe supplied from the liquid crystal panel driving unit 8 of FIG. 1 through the signal line DL, the pixel signal voltage Vd corresponding to this pixel is turned on by the switch voltage Vg of the scanning line driving signal supplied by the scanning line SL. Data is written to the pixel capacitor Cpe via the TFT switch 50 that is controlled to be turned off. Specifically, as shown in FIG. 2B, the pixel signal voltage Vd is written into the pixel capacitor Cpe as the pixel electrode voltage Vp in the sampling period Ts, and the pixel electrode voltage Vp is held in the hold period Th. . As a result, the liquid crystal on the pixel electrode 51 is operated by the potential difference between the pixel electrode voltage Vp supplied to the pixel electrode 51 and the counter electrode voltage Vcom supplied to the counter electrode 52. The same applies to a plurality of other pixels arranged in a matrix.

  Here, when a DC voltage is applied to the liquid crystal for a long time, the material properties change due to the occurrence of polarization due to impurity ions in the liquid crystal, and a deterioration phenomenon such as a decrease in resistivity appears. As an example of this deterioration phenomenon, the screen burn-in described above corresponds. Conventionally, in order to solve this problem, AC driving of each pixel has been performed. As shown in FIG. 2B, the pixel electrode voltage Vp applied to the pixel electrode 51 is inverted every frame scanning period with respect to the counter electrode voltage Vcom applied to the counter electrode 52, so that the pixel electrode 51 and the counter electrode The driving is performed such that the average voltage applied to the liquid crystal 52 is 0 and no DC offset voltage is applied to the liquid crystal. For this reason, the counter electrode voltage Vcom is set to a predetermined DC voltage value such that the average voltage applied between the pixel electrode 51 and the counter electrode 52 is zero. As the set value of the common electrode voltage Vcom, which is this predetermined data, an optimum value is derived at the design stage, and is stored in the storage unit 10 of FIG. 1, and is stored in the register 18 of the DA converter 11 according to an instruction from the control unit 9. Is set.

  Next, various characteristics of the liquid crystal light valve 2 will be described. FIG. 3A is a graph showing the transmittance (T) when a predetermined voltage (V) is applied to liquid crystal light valves for light of R, G, and B colors using twisted nematic liquid crystal. In this case, the voltage applied to the liquid crystal light valve is in the range of 0V to 6V, but the transmittance in the white level where the transmittance is approximately 100% and the transmittance in the black level region where the transmittance is approximately 0% are both applied voltages. Is saturated. Therefore, the saturated voltage range is invalid for the transmittance. Therefore, the DC bias of the video signal is adjusted by limiting the voltage applied to the liquid crystal light valve to about 3.8 V, which is the amplitude of the voltage effective for changing the transmittance. This adjustment is called brightness adjustment. In the present embodiment, a DC bias adjustment circuit (not shown) is included in the liquid crystal panel drive unit 8 of FIG. 1, and the liquid crystal panel drive unit 8 performs DC bias adjustment.

  Further, the VT characteristics of the liquid crystal light valve 2 for each color light of R, G, B are different in inclination for each color light, the white level with a transmittance of about 100% and the black level with a transmittance of about 0%. There is a variation in the voltage to reach. In order to reduce this variation, the gain of the video signal is adjusted. This adjustment is called gain adjustment. In the present embodiment, the liquid crystal panel drive unit 8 of FIG. 1 includes a gain adjustment circuit including an OP amplifier (not shown) and the like, and the liquid crystal panel drive unit 8 performs gain adjustment. Note that these parameters relating to the DC bias adjustment and gain adjustment are determined by the characteristics of the liquid crystal light valve 2 and can be grasped in advance. In the present embodiment, optimum setting values are derived for these predetermined parameters at the design stage, stored in the storage unit 10 of FIG. 1, and set in the register 18 of the liquid crystal panel driving unit 8 according to an instruction from the control unit 9. Is done.

  FIG. 3B shows a VT characteristic in a state where the above-described brightness adjustment and gain adjustment are performed. The voltage axis is represented by the gradation value of an 8-bit digital input signal. Here, for each color light, the change amount of the transmittance with respect to the change of the gradation value is small at the black level where the transmittance is approximately 0%. Therefore, sufficient resolution cannot be obtained as it is. In order to obtain a sufficient resolution, it is desirable that the amount of change in transmittance per gradation value be uniform, and for this purpose, the VT characteristic can be brought close to the ideal γ characteristic shown in FIG. is necessary. Here, by applying correction using the γ correction characteristic shown in FIG. 4A, the γ characteristic shown in FIG. 4B can be obtained. This correction is called γ correction. In the present embodiment, γ correction is performed by the γ correction circuit of the image signal processing unit 4 in FIG. It should be noted that the parameter relating to γ correction is determined by the characteristics of the liquid crystal light valve 2 and can be grasped in advance. For the parameters relating to γ correction, optimum setting values are derived at the design stage, stored in the storage unit 10 of FIG. 1, and set in the register 18 of the γ correction circuit 6 according to instructions from the control unit 9.

  The projection screen of the projector expands the projection light from the liquid crystal light valve of several centimeters to several tens of inches. For this reason, for example, slight color unevenness of illumination light, liquid crystal light valve characteristics, or slight transmission defects due to some pixel defects, etc. are enlarged, and color unevenness occurs in the projected image. As a means for correcting such color unevenness, after assembling the projector 100, an image signal of a certain luminance level, for example, a gray solid image is input and projected on a screen to check the occurrence of color unevenness. There is a way to apply the necessary correction. FIG. 5 is an explanatory diagram of this color unevenness correcting means, and the screen SC is divided into 9 blocks a to i in a lattice shape. Parameters relating to color unevenness correction include, for example, a luminance meter that measures the luminance of each of nine blocks a to i of a projected image with an image signal of a certain luminance level projected on the screen SC, and the measured value and reference value. It can be obtained from the difference between Moreover, it is good also as measuring brightness | luminance by image | photographing with imaging means, such as a video camera, instead of a luminance meter. The parameters relating to the color unevenness correction are stored in the storage unit 10 of FIG. 1 and set in the register 18 of the color unevenness correction circuit 7 according to an instruction from the control unit 9.

  Next, a startup routine for the projector 100 will be described. FIG. 6 is a flowchart showing a startup routine of projector 100. Hereinafter, a description will be given with reference to FIG. 6 and FIG. To start the projector 100, a power switch (not shown) of the operation unit 14 is turned on in step S1. When the power switch is turned on, initialization processing of each unit is performed in step S2. As an initialization process, first, the main power supply unit 15 rises and supplies power to each unit. Next, a hardware reset is applied to each part. At this time, the image converter 5, the γ correction circuit 6, and the color unevenness correction circuit 7 of the image signal processing unit 4 are also hardware reset, and the setting contents of the registers 18 are also cleared. Similarly, the liquid crystal panel driving unit 8 and the DA converter 11 are also reset by hardware and the setting contents of the register 18 are cleared. Although not shown in the flowchart, when the power switch is turned on in step S1, the indicator unit 13 lights, for example, an LED indicating an activated state.

  Subsequently, in step S3, set values and parameters as predetermined data relating to various characteristics of the liquid crystal light valve 2 are set. The control unit 9 reads the set value of the counter electrode voltage stored in the storage unit 10 and sets it in the register 18 of the DA converter 11. By repeating the same operation, the control unit 9 drives the liquid crystal panel to set parameters related to γ correction in the register 18 of the γ correction circuit 6 and parameters related to color unevenness correction in the register 18 of the color unevenness correction circuit 7. In the register 18 of the unit 8, a parameter relating to DC bias adjustment and a parameter relating to gain adjustment are respectively set. Further, in the present embodiment, data related to the initial screen display at the time of activation is also stored in the storage unit 10 and is set in the resist 18 of the image converter 5 by the control unit 9. Here, for example, a gray solid image is set as the initial screen data.

  In step S4, each circuit adjustment, image processing, etc. are performed according to the setting value and parameter set in step S3. In the DA converter 11, a counter electrode voltage along the set value in the register 18 is generated and supplied to the liquid crystal light valve 2. In the image converter 5, a gray solid image is generated along the parameters in the register 18 and sent to the γ correction circuit 6 as a digital image signal DS. The γ correction circuit 6 performs γ correction according to the parameters in the register 18 on the digital image signal DS, and sends the digital image signal DSγ to the color unevenness correction circuit 7. The color unevenness correction circuit 7 performs color unevenness correction on the digital image signal DSγ according to the parameters in the register 18, further performs DA conversion, and sends the analog image signal DSc to the liquid crystal drive unit 8. The liquid crystal driving unit 8 performs DC bias adjustment and gain adjustment according to the parameters in the register 18 on the analog image signal DSc by an internal DC bias adjustment circuit and a gain adjustment circuit (both not shown), and the analog image signal It is supplied to the liquid crystal light valve 2 as DSe.

  When step S4 is completed, since the lamp 1 is not lit, no projected image is displayed, but the liquid crystal light valve 2 displays a gray solid image which is an initial setting image. In step S5, a lamp ON operation is performed. The control unit 9 sends a lamp ON signal to the lamp driving unit 16 via the I / F unit 12. The igniter circuit (not shown) of the lamp driving unit 16 that has received the lamp ON signal applies a high voltage between the electrodes of the lamp 1 to form a discharge path by dielectric breakdown. The voltage at this time instantaneously becomes about 20 KV, and this may become high-frequency noise and affect each peripheral part. For example, there is a possibility that a parameter related to the counter electrode voltage set in the register 18 of the DA converter 11 is destroyed. When a high voltage is applied by an igniter circuit (not shown) of the lamp driving unit 16 to form a discharge path by dielectric breakdown between the electrodes of the lamp 1, the lamp 1 is turned on. The lamp driving unit 16 stops the operation of the igniter circuit when a certain time elapses regardless of whether the lamp 1 is turned on or not, and starts a ballast circuit (not shown) that stabilizes arc discharge after the lamp is turned on. .

  In step S6, it is detected whether or not the lamp 1 is lit by the lamp ON operation in step S5. The light receiving unit of the photodiode 19 of the lamp lighting detection unit 17 is installed at a position where a part of light emitted from the lamp 1 is incident when the lamp 1 is lit. The photodiode 19 passes a reverse current proportional to the amount of light incident on the light receiving unit when the lamp 1 is turned on. The lamp lighting detection unit 17 sends a predetermined detection signal proportional to the reverse current amount to the I / F unit 12. The I / F unit 12 converts the detection signal from the lamp lighting detection unit 17 into a predetermined signal format by A / D conversion or the like and sends the signal to the control unit 9. Even when the lamp 1 is not lit, the I / F unit 12 converts the detection signal from the lamp lighting detection unit 17 into a predetermined signal format by A / D conversion or the like and sends it to the control unit 9. The control unit 9 compares the signal level from the I / F unit 12 with a reference signal level stored in the storage unit 10 in advance, and detects whether the lamp 1 is lit or not. Here, when the control part 9 detects lighting of the lamp | ramp 1, it progresses to step S7. If non-lighting is detected, the process proceeds to a lamp non-lighting process routine in step S9. The lamp non-lighting process routine in step S9 will be described later.

  When the lighting of the lamp 1 is detected and the process proceeds to step S7, predetermined data relating to various characteristics of the liquid crystal light valve 2 is set again here. In the present embodiment, the counter electrode voltage is reset. In the stage where the lamp 1 is lit, the ballast circuit (not shown) of the lamp driving unit 16 is activated as described above. Therefore, as long as the lamp 1 is turned off and the lighting operation is not performed again, there is no fear of being affected by high-frequency noise due to the high voltage applied by the igniter circuit (not shown) of the lamp driving unit 16. The control unit 9 reads the set value of the counter electrode voltage as predetermined data stored in the storage unit 10 and sets it again in the data setting unit including the register 18 of the DA converter 11 as the operation processing unit.

  In step S8, circuit adjustment is performed along the parameters set in step S7. The DA converter 11 generates the counter voltage Vcom along the set value in the register 18 and supplies it to the liquid crystal light valve 2. When step S8 is completed, the activation routine is completed, and a standby state in which a gray solid image, which is an initial setting image, is projected onto the screen SC. At this stage, when the image signal VS is input from the image signal supply unit, the image signal is subjected to the image signal processing as described above in the image signal processing unit 4 and the liquid crystal panel driving unit 8 as the image signal DSe. Supplied to the liquid crystal light valve 2. The illumination light from the lamp 1 is modulated by the liquid crystal light valve 2 by the image signal DSe, synthesized and projected by a projection optical system (not shown), and a full color image is displayed on the screen SC.

  Here, the lamp non-lighting process routine in step S9 will be described. When the control unit 9 determines that the lamp 1 is not lit, the process proceeds to the lamp non-lighting process routine of FIG. From here, FIG. 6 and FIG. First, in step S20, the counter in the control unit 9 counts the number of times the lamp 1 has been continuously turned off. If the number of times the lamp 1 has been continuously turned off is equal to or greater than the reference number set in the storage unit 10 in advance, the process proceeds to the abnormality processing routine of step S24. In the present embodiment, the reference number is set to 3 times. Therefore, when the lamp 1 is not lit three times continuously, the process proceeds to the abnormality processing routine. In the abnormality processing routine of step S24, for example, the abnormality warning LED of the indicator unit 13 is blinked or the repair request LED is blinked to notify the user of the abnormality. If the number of times the lamp 1 is not lit is detected less than 3, the process proceeds to the lamp OFF operation in step S22.

  As described above, the lamp driving unit 16 stops the operation of the igniter circuit and activates the ballast circuit (both not shown) regardless of whether the lamp is lit or not. Therefore, it is necessary to end the operation of the lamp driving unit 16 once. The control unit 9 sends a reset signal to the lamp driving unit 16 via the I / F unit 12. In step S22, the lamp ON operation is performed again. The lamp ON operation is the same as that described in step S5. In step S23, it is detected again whether the lamp 1 is lit. The lamp lighting detection is the same as that described in step S6. If the control unit 9 determines that the lamp is lit in step S23, the control unit 9 exits the lamp non-lighting process routine and returns from step S10 to the predetermined parameter setting in step S7 of the startup routine. If the controller 9 determines in step S23 that the lamp is not lit, the process returns to the non-lighting detection frequency routine in step S20 again.

As described above, according to the first embodiment, the following effects can be obtained.
(1) The lamp lighting detection unit 17 as the lighting detection unit detects the lighting state of the light source unit composed of the discharge lamp 1 by the photodiode 19, and sends a detection signal to the control unit 9 via the I / F unit 12. send. The control unit 9 compares the signal level from the I / F unit 12 with a reference signal level stored in the storage unit 10 in advance, and detects whether the lamp 1 is lit or not. When detecting the lighting of the lamp 1, the control unit 9 reads the set value of the counter electrode voltage as predetermined data stored in the storage unit 10, and as a data setting unit in the DA converter 11 as the operation processing unit. Is set in the register 18. Thus, the counter electrode voltage can be set in the DA converter 11 after the high-frequency noise generated when the lamp is turned on is settled. Therefore, since the abnormal DC offset voltage can be prevented from being applied to the liquid crystal light valve 2, the above-mentioned printing does not occur. Therefore, deterioration of the liquid crystal light valve 2 due to baking can also be prevented. Further, after the lamp 1 is turned on, an appropriate counter electrode voltage is applied, so that the color tone abnormality of the initial setting image does not occur. Therefore, it is possible to provide a projector that does not perform abnormal display even under the influence of high-frequency noise associated with the lighting of the lamp 1 as the light source unit.

  (2) In step S3 in FIG. 6, set values and parameters as predetermined data regarding various characteristics of the liquid crystal light valve 2 as the light modulation element are set even before the lamp 1 as the light source unit is turned on. Yes. The control unit 9 reads set values and parameters as predetermined data related to the counter electrode voltage, γ correction, color unevenness correction, DC bias adjustment, gain adjustment, and initial screen display stored in the storage unit 10, and each data setting unit Is set in each register 18. As described above, the liquid crystal light valve 2 displays the initial setting image, although the projected image is not displayed even before the lamp 1 is turned on. As a result, the operating condition when the liquid crystal light valve 2 operates or the image generated by the liquid crystal light valve 2 is affected even in the time from several seconds to several tens of seconds necessary for the discharge lamp 1 to light. Predetermined data on the processing conditions of the image signal to be applied is set, and an appropriate voltage or image signal is applied to the liquid crystal light valve 2 from the DA converter 11 and the image signal processing unit 4 as the operation processing unit. Yes. Therefore, even before the lamp 1 serving as the light source unit is turned on, no overvoltage or abnormal image signal is applied to the liquid crystal light valve 2, so that the liquid crystal light valve 2 serving as the light modulation element and related parts are protected. be able to.

(Embodiment 2)
Subsequently, a second embodiment of the present invention will be described based on the drawings. FIG. 8 is a startup flowchart of the projector 110 (not shown) according to the second embodiment. The same parts as those of the projector 100 according to the first embodiment are denoted by the same reference numerals, and redundant description is omitted. The schematic block configuration of projector 110 (not shown) and the operation of each part are the same as projector 100. Here, only differences from the projector 100 will be described with reference to FIGS. 1, 6, and 7, focusing on the startup flowchart of FIG.

  Regarding the startup flow of projector 110 (not shown), steps S1 to S6 are the same as when projector 100 is started. In step S1, power ON processing is performed, and in step S2, initialization processing of each unit is performed. Subsequently, in step S3, set values and parameters as predetermined data relating to various characteristics of the liquid crystal light valve 2 are set. In step S4, each circuit adjustment, image processing, etc. are performed according to the setting value and parameter set in step S3. In step S5, a lamp ON operation is performed. In step S6, it is detected whether or not the lamp 1 is lit by the lamp ON operation in step S5. Further, the branch to the lamp non-lighting process routine shown in FIG. 7 when the non-lighting of the lamp 1 is detected in step S6 and the feedback from the lamp non-lighting process routine in step S10 are also in the first embodiment. This is the same as the projector 100.

  If the lighting of the lamp 1 is detected and the process proceeds to step S7, the set values and parameters as predetermined data relating to the various characteristics of the liquid crystal light valve 2 are used again here, the DA converter 11 as the operation processing unit and the image signal processing. Set to part 4. In the present embodiment, setting values and parameters related to the counter electrode voltage, γ correction, color unevenness correction, DC bias adjustment, gain adjustment, and initial screen display are reset in each register 18 as each data setting unit. The control unit 9 reads the set value of the counter electrode voltage stored in the storage unit 10 and sets it in the register 18 of the DA converter 11. By repeating the same operation, the control unit 9 drives the liquid crystal panel to set parameters related to γ correction in the register 18 of the γ correction circuit 6 and parameters related to color unevenness correction in the register 18 of the color unevenness correction circuit 7. A parameter relating to DC bias adjustment and a parameter relating to gain adjustment are set in the register 18 of the unit 8, and data relating to initial screen display is set in the resist 18 of the image converter 5, respectively.

  In step S8, each circuit adjustment, image processing, etc. are performed according to the setting value and parameter set in step S7. In the DA converter 11, a counter electrode voltage along the set value in the register 18 is generated and supplied to the liquid crystal light valve 2. In the image converter 5, for example, a gray solid image is generated along the parameters in the register 18, and is sent to the γ correction circuit 6 as a digital image signal DS. The γ correction circuit 6 performs γ correction according to the parameters in the register 18 on the digital image signal DS, and sends the digital image signal DSγ to the color unevenness correction circuit 7. The color unevenness correction circuit 7 corrects the color unevenness according to the parameters in the register 18 to the digital image signal DSγ, further performs DA conversion, and sends the analog image signal DSc to the liquid crystal drive unit 8. The liquid crystal driving unit 8 performs DC bias adjustment and gain adjustment according to the parameters in the register 18 on the analog image signal DSc by an internal DC bias adjustment circuit and a gain adjustment circuit (both not shown), and the analog image signal It is supplied to the liquid crystal light valve 2 as DSe.

  When step S8 is completed, the activation routine is completed, and a standby state in which a gray solid image, which is an initial setting image, is projected onto the screen SC. At this stage, when the image signal VS is input from the image signal supply unit 3, the image signal is subjected to the image signal processing as described above in the image signal processing unit 4 and the liquid crystal panel driving unit 8 as the image signal DSe. , Supplied to the liquid crystal light valve 2. The illumination light from the lamp 1 is modulated by the liquid crystal light valve 2 by the image signal DSe, synthesized and projected by a projection optical system (not shown), and a full color image is displayed on the screen SC.

  As described above, according to the configuration of the second embodiment, the following effects can be obtained in addition to the effects of the first embodiment.

  (1) The lamp lighting detection unit 17 as the lighting detection unit detects the lighting state of the light source unit composed of the discharge lamp 1 by the photodiode 19, and sends a detection signal to the control unit 9 via the I / F unit 12. send. The control unit 9 compares the signal level from the I / F unit 12 with a reference signal level stored in the storage unit 10 in advance, and detects whether the lamp 1 is lit or not. When the control unit 9 detects the lighting of the lamp 1, the control unit 9 reads set values and parameters as predetermined data stored in the storage unit 10, and registers each of the DA converter 11 as the operation processing unit and the image signal processing unit 4. The data setting unit consisting of 18 is reset. Thereby, after the high frequency noise generated when the lamp 1 is turned on is settled, predetermined data relating to the image signal suitable for the liquid crystal light valve 2 is set in each register 18 of the image signal processing unit 4 as the operation processing unit. be able to. The image signal processing unit 4 processes the image signal along predetermined data regarding processing conditions applied to the image signal set in each register 18. Therefore, a desired projection image along predetermined data can be obtained even under the influence of high-frequency noise associated with the lighting of the lamp 1 as the light source unit.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below.

  (Modification 1) In the second embodiment, when the projector 110 (not shown) detects the lighting of the lamp 1, the initialization of the image signal processing unit 4 as the operation processing unit is performed prior to setting of predetermined data. It is also good to do. This will be described with reference to FIGS. When the controller 9 detects lighting of the lamp 1 from the detection signal from the lamp lighting detection unit 17 in step S6, the control unit 9 initializes the image signal processing unit 4, and after the initialization is completed, the control unit 9 proceeds to step S7. Then, set values and parameters as predetermined data read from the storage unit 10 are set in the image signal processing unit 4. According to this configuration, when the control unit 9 detects the lighting of the lamp 1 based on the detection signal from the lamp lighting detection unit 17, the image converter 5 of the image signal processing unit 4 and the γ correction prior to setting predetermined data. The hardware reset of the circuit 6 and the color unevenness correction circuit 7 and the set contents of the register 18 are cleared. Thereby, since the hardware reset is performed in the image signal processing unit 4, it is possible to set the predetermined data in a more stable state as compared with the case where the hardware reset is not performed. Therefore, a desired projection image along predetermined data can be obtained even under the influence of high-frequency noise associated with the lighting of the lamp 1 as the light source unit.

  (Modification 2) In the projectors of the above embodiments, when lighting of the lamp 1 is detected not only at the time of startup, a predetermined parameter may be read and reset in each data setting unit each time. As described above, many projectors continue to light after the lamp is turned on at startup until the projection ends and the power is turned off.For example, to reduce power consumption, only the lamp is in operation. A specification that turns off the light can also be assumed. In such a projector, when the lighting of the lamp 1 is detected not only at the time of activation, the predetermined data is read out every time and is reset in each data setting unit, thereby generating the above-mentioned each time the lamp is turned on. The influence of high frequency noise can be reduced. Therefore, it is possible to provide a projector that does not perform abnormal display even under the influence of high-frequency noise associated with the lighting of the lamp 1 as the light source unit.

  (Modification 3) The technique for reducing the influence of high-frequency noise associated with the lighting of the lamp 1 serving as the light source unit according to the configuration of each unit and the startup flowchart in each of the above embodiments is not limited to the projector. The present invention can be applied to any device that uses a discharge-type lamp that requires a high voltage to be applied to the light source unit. For example, a discharge lamp is used as a light source and includes three light modulation elements for R light, G light, and B light, and an optical system substantially similar to a projector. You may apply to a projector. Accordingly, it is possible to provide a rear projector that does not perform an abnormal display even under the influence of high-frequency noise accompanying lighting of the discharge lamp. Furthermore, although the spatial light modulation unit of the projector according to each of the above embodiments is configured to use a transmissive liquid crystal light valve, the present invention is not limited to this. For example, a reflective liquid crystal display device or a tilt mirror device may be used.

  The technical ideas other than the claims that can be grasped from the respective embodiments and modifications will be described below together with the effects thereof.

  When a discharge-type light source unit that supplies illumination light, a lighting detection unit that detects a lighting state of the light source unit, a light modulation element that modulates the illumination light according to an image signal, and the light modulation element operate A data setting unit for setting predetermined data regarding the operating condition of the image signal or the processing condition of the image signal that affects the image generated by the light modulation element, and the predetermined data set in the data setting unit And operating the light modulation element under a predetermined operation condition, or processing the image signal sent to the light modulation element under a predetermined processing condition, and storing the predetermined data A storage unit, the light source unit, the lighting detection unit, the data setting unit, the operation processing unit, and a control unit that controls the storage unit, and the control unit includes the lighting detection unit Detection signal from Upon detection of lighting of the light source unit by the from the storage unit reads the predetermined data, the image display apparatus characterized by setting the data setting unit.

  According to this, a lighting detection part detects the lighting state of the light source part of an image display apparatus, and sends a detection signal to a control part. When the control unit detects lighting of the light source unit from the detection signal from the lighting detection unit, the control unit reads predetermined data from the storage unit and sets the data in the data setting unit. As a result, after the high frequency noise generated when the light source unit is turned on is settled, the operating condition when the light modulation element operates in the data setting unit or the image signal that affects the image generated by the light modulation element It is possible to set predetermined data for the processing conditions. The operation processing unit operates the light modulation element under a predetermined operation condition based on the predetermined data set in the data setting unit, or processes the image signal sent to the light modulation element under the predetermined processing condition. be able to. Therefore, it is possible to provide an image display device that does not perform abnormal display even under the influence of high-frequency noise accompanying lighting of the light source unit.

1 is a schematic configuration diagram of a projector according to a first embodiment. Explanatory drawing of arbitrary 1 pixels of a liquid crystal light valve. The VT characteristic view of a liquid crystal light valve. Explanatory drawing about (gamma) correction | amendment of a liquid crystal light valve. Explanatory drawing about the color nonuniformity correction of a projector. The startup flowchart of a projector. Projector lamp non-lighting processing routine. FIG. 6 is a flowchart for starting up a projector according to a second embodiment. FIG. 10 is a flowchart for starting up a conventional projector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lamp as light source part, 2 ... Liquid crystal light valve as light modulation element, 3 ... Image signal supply apparatus, 4 ... Image signal processing part as operation | movement process part, 5 ... Image converter, 6 ... γ correction circuit, 7 Color unevenness correction circuit 8 Liquid crystal panel drive unit 9 Control unit 10 Storage unit 11 DA converter as operation processing unit 12 I / F unit 13 Indicator unit 14 Operation unit DESCRIPTION OF SYMBOLS 15 ... Main power supply part, 16 ... Lamp drive part, 17 ... Lamp lighting detection part as lighting detection part, 18 ... Register as data setting part, 19 ... Photodiode, 100 ... Projector, SC ... Screen.

Claims (6)

A discharge-type light source unit for supplying illumination light;
A lighting detection unit for detecting a lighting state of the light source unit;
A light modulation element that modulates the illumination light in accordance with an image signal;
A data setting unit for setting predetermined data for operating conditions when the light modulation element operates, or processing conditions of the image signal affecting the image generated by the light modulation element;
Based on the predetermined data set in the data setting unit, the light modulation element is operated under a predetermined operation condition, or the image signal sent to the light modulation element is processed under a predetermined processing condition. , Motion processing part,
A storage unit for storing the predetermined data;
The light source unit, the lighting detection unit, the data setting unit, the operation processing unit, and a control unit for controlling the storage unit,
When the control unit detects lighting of the light source unit based on a detection signal from the lighting detection unit, the control unit reads the predetermined data from the storage unit and sets the data in the data setting unit. The operation processing unit is a signal generation unit that supplies a predetermined counter electrode voltage to the light modulation element, and the data setting unit is a register provided in the signal generation unit,
The storage unit stores a set value of a predetermined counter electrode voltage as the predetermined data,
When the control unit detects lighting of the light source unit based on a detection signal from the lighting detection unit, the control unit reads the set value of the predetermined counter electrode voltage from the storage unit and sets the value in the register of the signal generation unit The projector according to claim 1. The operation processing unit is an image signal processing unit that processes the image signal sent to the light modulation element under predetermined processing conditions, and the data setting unit is a register provided in the image signal processing unit. And
The storage unit stores predetermined data about processing conditions applied to the image signal,
When the control unit detects lighting of the light source unit based on a detection signal from the lighting detection unit, the control unit reads predetermined data on processing conditions applied to the image signal from the storage unit, and stores the data in a register of the image signal processing unit. The projector according to claim 1, wherein the projector is set.   Furthermore, when the control unit detects lighting of the light source unit based on a detection signal from the lighting detection unit, the control unit initializes the image signal processing unit, and after the initialization is completed, The projector according to claim 3, wherein predetermined data regarding processing conditions to be applied to the image signal read from the storage unit is set in the register.   5. The control unit according to claim 1, wherein the control unit reads the predetermined data from the storage unit and sets the data in the data setting unit even before the light source unit is turned on. projector. A discharge-type light source unit that supplies illumination light, a light modulation element that modulates the illumination light according to an image signal, operating conditions when the light modulation element operates, or generated by the light modulation element A method for controlling a projector, comprising: a data setting unit that sets data on processing conditions of the image signal that affects an image; and a storage unit that stores the predetermined data, and detects a lighting state of the light source unit And a data setting step of reading the predetermined data from the storage unit and setting the data setting unit when the lighting of the light source unit is detected in the lighting detection step. Control method.

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