CN100507705C - Projector - Google Patents

Abstract

The invention provides a projector which not only carries out correct gray level control of light modulation elements among display images, but also reduces the unevenness of image display. The projector has a light source unit (2), liquid crystal light valves (33r, 33g, 33b) which modulate the light emitted by the light source unit (2) based on image data, a light adjusting mechanism (32) which adjusts the quantity of the incident light of liquid crystal light valves (33r, 33g, 33b) as well as a control unit which controls the liquid crystal light valves (33r, 33g, 33b) and the light adjusting mechanism (32), wherein the control unit carries out light adjusting control of the light adjusting mechanism (32) which adjusts the quantity of the incident light of the liquid crystal light valves (33r, 33g, 33b) according to the luminance distribution graph of the image data; moreover, the control unit also carries out correction control of the liquid crystal light valves (33r, 33g, 33b) during correcting the display unevenness of the image data based on the adjustment of the quantity of light.

Description

Projector

technical field

The present invention relates to a projector including a light modulation element that modulates light from a light source unit, and a light adjustment unit that adjusts the light quantity of light incident on the light modulation element from the light source unit.

Background technique

A projector using an LCD (Liquid Crystal Display) as a light modulation element has been conventionally known. In this case, in the LCD, the liquid crystal molecules are displaced by controlling the voltage applied to the internal liquid crystal molecules, and the gradation level of the LCD changes according to the amount of displacement, and the projected light is projected on the screen to display an image. For example, when displaying a dark-colored image, control of the applied voltage is performed in a low-voltage region. However, in general, since it is difficult to accurately control the displacement amount of liquid crystal molecules in a low-voltage region, there is a problem in this type of projector when displaying images in a high dynamic range including dark regions, for example. There is such a problem that it is difficult to accurately perform gradation control of the LCD. A projection display device disclosed in JP-A-2001-100699 is known as a technique capable of solving this problem. This projection type display device includes an illumination light quantity modulation mechanism such as a diaphragm provided between a light source and a light modulator such as a liquid crystal display panel. The light volume of the light is composed. Therefore, for example, when displaying a dark-colored image, it is possible to display an image with a high dynamic range by reducing the amount of light incident on the liquid crystal display panel.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2001-100699 (page 8, FIG. 10 )

However, conventional projection display devices have the following problems. That is, in this projection display device, the light quantity of light incident on the liquid crystal display panel is adjusted by, for example, an illumination light quantity modulation mechanism constituted by a diaphragm. However, when the amount of light is adjusted by this method, there is non-uniformity in the amount of light caused by the light incident on the liquid crystal display panel, and unevenness in brightness (shading) or unevenness in color occurs on the displayed image (the two are combined below). called "display unevenness").

Here, in conventional projection display devices, it is also considered to provide a light source driving circuit that directly adjusts the luminance of the light source instead of the above-mentioned illumination light amount modulation mechanism. Generally, the adjustment range of the luminance of the light source is narrowed, so when displaying a dark image, the luminance control becomes unstable, and the luminance may vary.

Contents of the invention

The present invention has been made in view of such a problem, and an object of the present invention is to provide a projector capable of reducing image display unevenness while performing accurate gradation control on a light modulator when displaying an image.

A projector according to the present invention for achieving the above-mentioned object includes a light source unit, a light modulation element that modulates light from the light source unit based on image data, and adjustment of the light quantity of light incident on the light modulation element from the light source unit. a light unit, and a control unit for controlling the light modulation element and the light adjustment unit, the control unit performs light adjustment control on the light control unit to adjust the amount of light according to the luminance distribution pattern of the image data, and controls the light adjustment unit. The modulation element executes correction control for correcting display unevenness of the aforementioned image data based on the aforementioned adjustment of the light amount.

According to this projector, since gradation control in an appropriate gradation region can be performed by performing dimming control on the dimming unit, it is possible to accurately perform gradation control on the light modulation element. In addition, even if the amount of light incident on the light modulation element varies by performing correction control on the light modulation element, the unevenness can be canceled out, so that image display unevenness can be reliably reduced.

In addition, according to the projector of the present invention, in the above projector, adjustment amounts of the light quantities corresponding to the luminance distribution patterns of the plurality of image data are stored, and adjustment amounts corresponding to the respective light adjustment amounts are stored. The storage unit for the correction content for the correction control, the control unit reads the dimming amount corresponding to the luminance distribution pattern of the image data to be displayed from the storage unit to execute the dimming control, and reads the dimming control from the storage unit The storage unit reads the correction content corresponding to the dimming amount to execute the correction control.

According to this projector, the dimming control and correction control are executed by reading the dimming amount and correction content corresponding to the luminance distribution pattern of the displayed image data from the storage unit, and the dimming control and correction can be executed at high speed. control.

In addition, according to the projector of the present invention, the projector includes a pair of lens arrays disposed between the light source unit and the light modulation element, and the light adjustment unit includes a light shield and a moving unit that moves the light shield. The control unit performs the dimming control by moving the light shielding plate between the pair of lens arrays by the moving unit to block light from the lens arrays.

According to this projector, the light quantity is adjusted by blocking the light by moving the visor between the pair of lens arrays, and the light quantity can be reliably adjusted with a simple configuration.

Furthermore, in the projector according to the present invention, in the projector, the lens array includes a plurality of optical elements, and the control unit moves the visor in units of the optical elements. In particular, when a plurality of optical elements are periodically arranged at a predetermined array pitch, the control unit moves the light shielding plate in units of the array pitch.

According to this projector, by moving the shading plate in units of the arrangement pitch of the optical elements in the lens array, it is possible to specify in advance the degree of unevenness in the incident light intensity due to the adjustment of the light intensity according to the moving amount of the shading plate. Therefore, image display unevenness can be surely corrected only by performing correction control according to the correction content graphically corresponding to each movement amount of the visor. Furthermore, the storage capacity of the correction table can be minimized.

Furthermore, according to the projector of the present invention, in the projector, the control unit moves the visor in units of lengths of 1/n (n is an integer equal to or greater than 2) of an arrangement pitch of the optical elements.

According to this projector, finer dimming control can be performed according to the luminance distribution pattern of an image to be displayed by moving the visor in units of 1/n of the arrangement pitch of the optical elements.

In addition, according to the projector of the present invention, the projector includes a pair of lens arrays arranged between the light source unit and the light modulation element, and the light adjustment unit includes a liquid crystal lens arranged between the pair of lens arrays. The control means controls the liquid crystal element to change the light transmittance to perform the dimming control.

According to this projector, by controlling the liquid crystal element arranged between the pair of lens arrays to change the light transmittance to adjust the light quantity, the light can not be partially blocked, so the light can be relatively uniformly incident on the light modulation element. As a result, Display unevenness can be sufficiently suppressed.

Furthermore, according to the projector of the present invention, in the above projector, when the control unit executes the correction control on the light modulation element, the correction is performed on the liquid crystal element based on the adjustment of the light amount by the liquid crystal element. Correction control of image display unevenness.

According to this projector, by performing correction control on the liquid crystal element when performing correction control on the light modulation element, for example, even if unevenness in transmittance occurs in the liquid crystal element due to uneven polishing at the time of manufacturing, it is possible to perform correction on the liquid crystal element. Correction control for correcting the gradation so as to counteract this transmittance unevenness, and when the light quantity of light incident on the light modulation element cannot be completely uniformly controlled only by this correction control, can be almost completely achieved by performing correction control on the light modulation element. Fix uneven display.

Further, in the projector of the present invention, in the above projector, the luminance distribution pattern of the image data is defined by the dynamic range and average luminance of the luminance distribution of the image. Thereby, a display with a high dynamic range corresponding to the characteristics of the image data can be realized.

In addition, in the projector of the present invention, in the above-mentioned projector, display unevenness of image data due to light quantity adjustment corresponds to spatially non-uniform illumination of light modulators due to spatial arrangement of light shielding plates. In this case, the degree of freedom in the shape and arrangement of the visor is high, and the adjustment range of dimming can be relatively wide.

Description of drawings

FIG. 1 is a block diagram showing the configuration of a projector 1 .

FIG. 2 is a configuration diagram showing a schematic configuration of the light source unit 2 and the optical system 3 .

FIG. 3 is a configuration diagram of the dimming mechanism 32 in a non-dimming state.

FIG. 4 is a relational diagram showing the relationship among average luminance (APL), dynamic range (DR), and luminance distribution patterns A1 to A9 .

5(A) and (B) are a display screen view of the image G1 and a histogram of the luminance distribution of the image G1.

FIG. 6 is a configuration diagram of the dimming mechanism 32 when the light shielding plate 51 has moved by three times the pitch P. As shown in FIG.

7(A) and (B) are a display screen diagram of the image G2 and a histogram of the luminance distribution of the image G2.

FIG. 8 is a configuration diagram of the dimming mechanism 32 when the visor 51 has moved by twice the pitch P. As shown in FIG.

9(A) and (B) are a display screen diagram of the image G3 and a histogram of the luminance distribution of the image G3.

FIG. 10 is a configuration diagram of the dimming mechanism 32 when the visor 51 has moved by the amount of the pitch P. As shown in FIG.

FIG. 11 is a relational diagram showing the relationship among a luminance distribution pattern, a dimming amount, a gradation area, and a correction pattern.

FIG. 12 is a flowchart of projection processing 60 .

FIG. 13 is a configuration diagram of the dimming mechanism 32 that moves the light shielding plate 51 in units of length T. As shown in FIG.

FIG. 14 is a configuration diagram of the optical system 3A.

Explanation of labels

1 projector, 2 light source unit, 4 control unit, 5 memory, 31a, 31b lens array, 32 dimming mechanism, 33, 33b, 33g, 33r liquid crystal light valve, 41 optical element, 51 light shielding plate, 52 moving part, 71 Liquid crystal element, A1～A9 luminance distribution pattern, L light, Lb blue light, Lg green light, Lr red light, Lw light, P pitch, C1, C2, C3 correction pattern, T length

Detailed ways

Next, the best mode of the projector of the present invention will be described with reference to the drawings. A projector 1 shown in FIG. 1 is an example of the projector of the present invention, and is configured by including a light source unit 2 , an optical system 3 , a control unit 4 and a memory 5 . The light source unit 2 includes, for example, a high-intensity lamp such as a metal halide lamp or a high-pressure mercury lamp, is turned on under the control of the control unit 4, and emits light Lw including red light Lr, green light Lg, and blue light Lb (hereinafter , also referred to as "light L" when these individual lights are not distinguished).

The optical system 3, as shown in FIG. 2 , comprises a pair of lens arrays 31a, 31b, an overlapping lens 42, a dimming mechanism 32, and liquid crystal light valves 33r, 33g, 33b (hereinafter also referred to as "liquid crystal light valves" when not distinguished). Valve 33"), dichroic mirrors 34r, 34b, mirrors 35a-35d, relay lenses 36, 36, prism 37 and projection lens 38. The lens array 31a has a function as a beam splitting optical element that splits the beam from the light source lamp into a plurality of partial lights, and is provided with a lens array arranged in a matrix at a predetermined pitch (arrangement pitch) P in a plane perpendicular to the illumination optical axis. A plurality of optical elements 41, 41... are constituted (referring to Fig. 3), and the lens array 31b is an optical element that adjusts the divergence angles of a plurality of partial light beams divided by the lens array 31a, and has the same functions as the lens array 31a in connection with illumination. A plurality of optical elements 41 , 41 . . . are arranged in a matrix in a plane perpendicular to the optical axes. The overlapping lens 42 is also referred to as a condensing lens, and condenses a plurality of partial light beams passing through the pair of lens arrays 31 a and 31 b to be superimposed on the image forming area of the liquid crystal light valve 33 . The dimming mechanism 32 is an example of dimming means in the present invention, and includes shade plates 51 , 51 and moving parts 52 , 52 as shown in the figure. In this case, the dimming mechanism 32 makes the light shielding plate 51 approach each other between the two lens arrays 31a, 31b in units of the pitch P of the optical elements 41, 41 . . . By moving to block the light L, the light quantity of the light L incident on each liquid crystal light valve 33 is adjusted (hereinafter also referred to as “dimming”).

The liquid crystal light valves 33r, 33g, and 33b correspond to light modulation elements in the present invention, and modulate red light Lr, green light Lg, and blue light Lb respectively based on the image data Dg under the control of the control unit 4. The dichroic mirrors 34r and 34b, the reflection mirrors 35a to 35d and the relay lenses 36 and 36 are arranged in the optical path of the light L so that the light L enters the respective liquid crystal light valves 33 as shown in FIG. 2 . In this case, the dichroic mirror 34r transmits the red light Lr and reflects the green light Lg and the blue light Lb. Also, the dichroic mirror 34b transmits the blue light Lb and reflects the green light Lg. In addition, the reflection mirrors 35a to 35d reflect the light L (total reflection). Therefore, only the red light Lr of the light Lw enters the liquid crystal light valve 33r, only the green light Lg of the light Lw enters the liquid crystal light valve 33g, and only the blue light Lb of the light Lw enters the liquid crystal light valve 33b. The prism 37 synthesizes the red light Lr, green light Lg, and blue light Lb modulated by the respective liquid crystal light valves 33r, 33g, and 33b. The projection lens 38 magnifies the light (projection light Lp) synthesized by the prism 37 and projects it on the screen 10 as shown in FIG. 1 .

The control unit 4 controls turning on and off of the light source unit 2 . Further, the control unit 4 modulates the light L from the light source unit 2 by controlling the respective liquid crystal light valves 33 of the optical system 3 based on the image data Dg from the external device. Furthermore, the control unit 4 performs dimming control on the dimming mechanism 32 described below so that the light quantity of the light L incident on the liquid crystal light valve 33 becomes a light quantity corresponding to the luminance distribution pattern of an image to be displayed. In addition, the control unit 4 corrects the display unevenness of the image due to the adjustment (dimming) of the light amount by performing correction control described later on each liquid crystal light valve 33 . The memory (storage unit in the present invention) 5 stores the luminance distribution pattern of the image, the dimming amount of the light L necessary for correctly displaying the image with the respective luminance distribution patterns, and A data table corresponding to a correction pattern (correction content in the present invention) of display unevenness of an image that occurs when the amount of light is controlled by dimming. In this case, the data table, for example, as a typical luminance distribution pattern, classifies the dynamic range of luminance distribution (hereinafter also referred to as "DR") as "wide (wide)" , "medium (medium)" and "narrow (narrow)", the average luminance (hereinafter also referred to as "APL") is classified into "high (high)", "medium (medium)" and The "low (low)" three types are composed of dimming amounts and correction patterns respectively corresponding to nine types of luminance distribution patterns A1 to A9 defined by these combinations.

Next, the relationship among the luminance distribution pattern, dimming amount, and correction pattern will be described with reference to the drawings. Due to the characteristics of the liquid crystal light valve 33 , accurate gradation control when displaying dark-colored images is relatively difficult. Therefore, in order to correctly display the image G1 with low APL and narrow DR (see the histogram in FIG. That is, the luminance distribution pattern is classified into the image G1 of the luminance distribution pattern A9 shown in FIG. The light quantity of light L. Therefore, as shown in FIG. 11, data indicating that the dimming amount is "large" corresponds to the luminance distribution pattern A9. In this case, when the control unit 4 executes the dimming control based on the data indicating that the dimming amount is “large”, for example, as shown in FIG. Three times the pitch P of the optical element 41 in 31a moves in the optical path between the lens arrays 31a, 31b to block the light L. Thereby, dimming with a "large" dimming amount is performed. As a result, as shown in FIG. 11, accurate modulation control of the light L can be performed by performing gray scale control on the liquid crystal light valve 33 in the range of the gray scale area except for the low range and slightly high range, and it is possible to perform The luminance that should be displayed correctly displays image G1.

In addition, like the image G2 shown in FIG. 7(A), for example, when displaying the image G2 in which both the APL and DR are moderate (see the histogram in FIG. 7(B)), that is, the luminance distribution pattern thereof is When classified into the image G2 of the luminance distribution pattern A5 shown in FIG. become moderate. Therefore, as shown in FIG. 11 , data representing the dimming amount "medium" corresponds to the luminance distribution pattern A5. In this case, when the control unit 4 executes dimming control based on the data representing the dimming amount "medium", for example, as shown in FIG. The optical elements 41 in 31a are moved by twice the pitch P of the lens arrays 31a, 31b to block the light L in the optical path. Thereby, the dimming of the dimming amount "medium" is performed. As a result, as shown in FIG. 11, relatively accurate modulation control of the light L can be performed by performing grayscale control on the liquid crystal light valve 33 in the range of the grayscale region except the low range and the high range, and it is possible to achieve The image G2 is correctly displayed at the luminance that should be displayed.

In addition, like the image G3 shown in FIG. 9(A), for example, in the image G3 showing a high APL and a wide DR (see the histogram in FIG. 9(B)), that is, showing that the luminance distribution pattern is classified When the image G3 of the luminance distribution pattern A1 shown in FIG. If the amount of light is too low, it will be difficult to display the bright color area in the image G3, so it is better to set the amount of light adjustment to be small. Therefore, as shown in FIG. 11 , data indicating that the dimming amount is "small" corresponds to the luminance distribution pattern A1. In this case, when the control unit 4 executes the dimming control based on the data indicating that the dimming amount is "small", for example, as shown in FIG. The amount of the pitch P of the optical elements 41 in the lens arrays 31a, 31b moves in the optical path between the lens arrays 31a, 31b to block the light L. Thereby, dimming with a "small" dimming amount is performed. As a result, as shown in FIG. 11, by performing grayscale control on the liquid crystal light valve 33 in almost all grayscale regions, accurate modulation control of the light L can be performed, and the brightness of the original display can be accurately displayed. Image G3 is displayed.

On the other hand, when dimming is performed by the light-shielding plates 51, 51, as shown in the incident light quantity distribution pattern B1 of FIG. Unevenness in the amount of incident light may cause display unevenness in the image G. Such display unevenness occurs corresponding to the spatial arrangement of the shading plates 51, 51, and is caused by the change in the shape of the aperture of the illumination light defined by the shading plates 51, 51, and the luminance distribution in the space of the light L changes. As a result, the liquid crystal The light valve 33 is illuminated inconsistently. Therefore, correction control for correcting display unevenness of the image G is performed, for example, by increasing the gradation level of an area of the liquid crystal light valve 33 where the amount of incident light is small to cancel out the difference in the amount of incident light. 8 and 10, with respect to the incident light distribution pattern B1 and the incident light distribution patterns B2 and B3 described later, the liquid crystal light valve 33 (see FIG. 6 ) is schematically shown along the vertical axis. The panel surface of , along the horizontal axis, schematically shows the incident light amount of the light L incident on the liquid crystal light valve 33 .

In this case, when the dimming control is performed based on the data indicating that the dimming amount is "large" corresponding to the above-mentioned luminance distribution pattern A9, as shown in the incident light quantity distribution pattern B1 of FIG. The amount of incident light decreases in a relatively wide range at the outer peripheral portion. Therefore, as shown in FIGS. 6 and 11 , the correction pattern C1 for increasing the gradation level in a relatively wide range of the outer periphery of the liquid crystal light valve 33 corresponds to the luminance distribution pattern A9. 8 and 10, the panel surface of the liquid crystal light valve 33 (refer to FIG. The horizontal axis schematically shows the correction amount of the gradation level in the correction control.

Further, when the dimming control is performed based on the data indicating the dimming amount "medium" corresponding to the above-mentioned luminance distribution pattern A5, as shown in the incident light amount distribution pattern B2 of FIG. The amount of incident light is reduced in the range of a moderate width. Therefore, as shown in FIGS. 8 and 11 , the correction pattern C2 for increasing the gradation level in the moderately wide range of the outer periphery of the liquid crystal light valve 33 corresponds to the luminance distribution pattern A5. Furthermore, when the dimming control is performed based on the data indicating that the dimming amount is "small" corresponding to the above-mentioned luminance distribution pattern A1, as shown in the incident light quantity distribution pattern B3 of FIG. The amount of incident light is reduced in a relatively narrow range at the portion. Therefore, as shown in FIGS. 10 and 11 , the correction pattern C3 for increasing the gradation level in a relatively narrow range at the outer periphery of the liquid crystal light valve 33 corresponds to the luminance distribution pattern A1. Furthermore, as shown in FIG. 11 , the brightness distribution patterns A2 to A4 and A6 to A8 are similar to the above. In order to display the image correctly with the brightness that should be displayed originally, the optimal dimming amount and the correction value are adjusted. The graphs correspond to the respective luminance distribution graphs.

Next, an example of the operation of the projector 1 will be described with reference to the drawings. In this projector 1, when the power is turned on, the control unit 4 executes projection processing 60 shown in FIG. 12 . In this projection processing 60, after the control unit 4 lights the light source unit 2 (step 61), it is determined whether or not the image data Dg is output from an external device such as a TV antenna or a DVD player (step 62). When judged to have been output, the control unit 4 calculates the APL and DR of the image to be displayed (for example, the image G1 shown in FIG. 5(A) ) based on the image data Dg (step 63 ). Next, the control unit 4 searches the data table stored in the memory 5, and specifies the luminance distribution pattern closest to the calculated APL and DR (step 64). In this case, as shown in the figure, the control unit 4 specifies the luminance distribution pattern A9 shown in FIG. 4 as the closest luminance distribution pattern because the APL of the image G1 is low and the DR is narrow.

Next, the control unit 4 reads data indicating "large" dimming amount corresponding to the specified luminance distribution pattern A9 from the data table, and executes dimming control on the dimming mechanism 32 (step 65). In this case, the control unit 4 controls the dimming mechanism 32 based on the read dimming amount data, and as shown in FIG. to the optical path between the lens arrays 31a, 31b. Thereby, part of the light L is blocked, and the light L incident on each liquid crystal light valve 33 is dimmed (that is, the light L is greatly dimmed corresponding to the "large" dimming amount). Next, the control unit 4 reads data for the correction pattern C1 corresponding to the luminance distribution pattern A9 from the data table (step 66). Next, the control unit 4 modulates the light L by controlling the liquid crystal light valves 33 based on the image data Dg. At this time, the control unit 4 executes correction control for each liquid crystal light valve 33 so as to increase the gradation in the range where the incident light amount is low, based on the read data for the correction pattern C1 (step 67). Accordingly, the light L is modulated by each liquid crystal light valve 33 to project the projection light Lp onto the screen 10 . At this time, by performing the correction control by the control unit 4, as shown in the corrected light quantity distribution pattern D1 of FIG. Display unevenness due to unevenness in the amount of incident light makes it possible to accurately display the image G1 with the luminance to be displayed.

Next, the control unit 4 judges based on the image data Dg whether the scene (image) has changed (step 68). At this time, when the scene has not changed, the control unit 4 repeatedly executes step 68, and when the scene has changed, executes steps 63 and 64 to specify the image of the next scene (such as the image G2 shown in Figure 7 (A)). The closest luminance distribution graph of APL and DR. In this case, as shown in the figure, since the APL and DR of the image G2 are both moderate, the control unit 4 specifies the luminance distribution pattern A5 shown in FIG. 4 as the closest luminance distribution pattern. Next, the control unit 4 reads from the data table in the memory 5 the data representing the dimming amount “medium” corresponding to the luminance distribution pattern A5, and performs dimming control on the dimming mechanism 32, whereby as shown in FIG. As shown, the shading plates 51, 51 are moved in the optical path between the lens arrays 31a, 31b by twice the pitch of the optical elements 41 (step 65). Next, after the control unit 4 reads the data for the correction pattern C2 corresponding to the luminance distribution pattern A5 (step 66), the light L is modulated by controlling each liquid crystal light valve 33 based on the image data Dg. At this time, the control unit 4 performs correction control on each liquid crystal light valve 33 based on the data for the correction pattern C2 read from the data table (step 67). Accordingly, the light L is modulated by each liquid crystal light valve 33 , and the projection light Lp is projected on the screen 10 . In this case, by executing the correction control by the control unit 4, as shown in the corrected light quantity distribution pattern D2 of FIG. The luminance of is displayed correctly.

Next, the control unit 4 executes step 68 . At this time, steps 63 and 64 are executed when the scene has changed, and the luminance distribution pattern of APL and DR of the image closest to the next scene (for example, image G3 shown in FIG. 9(A) ) is specified. In this case, as shown in the figure, since the image G3 has a high APL and a wide DR, the control unit 4 specifies the luminance distribution pattern A1 shown in FIG. 4 as the closest luminance distribution pattern. Next, the control unit 4 reads from the data table in the memory 5 the data corresponding to the luminance distribution pattern A1 indicating that the dimming amount is "small", and performs dimming control on the dimming mechanism 32, thereby, as shown in FIG. 10 As shown, the light-shielding plates 51, 51 are moved in the optical path between the lens arrays 31a, 31b by an amount corresponding to the pitch of the optical element 41 (step 65). Next, the control unit 4 reads the data for the correction pattern C3 corresponding to the luminance distribution pattern A1 (step 66), and then controls the liquid crystal light valves 33 to modulate the light L based on the image data Dg. At this time, the control unit 4 performs correction control on each liquid crystal light valve 33 based on the data for the correction pattern C3 read from the data table (step 67). Accordingly, each liquid crystal light valve 33 modulates the light L, and the projection light Lp is projected on the screen 10 . In this case, the control unit 4 executes the correction control so that, as shown in the corrected light quantity distribution pattern D3 of FIG. The luminance of is displayed correctly. Next, the control unit 4 repeatedly executes steps 68, 63 to 67, whereby dimming control and correction control are performed every time the scene changes. Furthermore, when switching the dimming amount instantaneously (in a short period of time), the dimming state changes rapidly, and the user may feel flickering (flickering with drastic luminance change). Therefore, when a scene change is detected and the dimming amount calculated from the APL and DR of the next scene is reflected, it is preferable to gradually change the dimming amount over a certain period of time.

In this way, according to the projector 1, by performing dimming control on the dimming mechanism 32, grayscale control can be performed in an appropriate grayscale region, so the grayscale of the liquid crystal light valve 33 can be correctly adjusted. Level control. In addition, even if unevenness occurs in the amount of light L incident on the liquid crystal light valve 33 by performing correction control on the liquid crystal light valve 33, the unevenness can be canceled out, so that the display unevenness of the image G can be reliably reduced.

Furthermore, dimming control and correction control are performed by reading the dimming amount and correction pattern corresponding to the luminance distribution pattern of the image G that should be displayed from the data table, for example, the same as every time the image G (scene) changes, Calculating the dimming amount from the luminance distribution pattern of the image G can perform dimming control and correction control at a high speed compared with the method of correcting the pattern.

Furthermore, by moving the light shielding plate 51 between the lens arrays 31a and 31b to adjust the light quantity of the light L, the light quantity can be reliably adjusted with a simple structure.

Furthermore, the control unit 4 can specify in advance the degree of unevenness in the incident light amount of the light L due to dimming according to the movement amount of the light shielding plate 51 by moving the light shielding plate 51 in units of the pitch P of the optical elements 41 . Therefore, the display unevenness of the image G can be reliably and easily corrected only by performing the correction control according to the correction pattern graphed in accordance with each movement amount of the light shielding plate 51 . According to this configuration, since the correction conditions can be defined in advance and the memory 5 for the data table can be minimized, the projector 1 can be configured at a low cost accordingly.

Furthermore, the present invention is not limited to the above configuration. For example, although an example of a data table including dimming amounts and correction patterns respectively corresponding to nine types of luminance distribution patterns A1 to A9 has been described above, the data structure of the data table is not limited to this and can be changed arbitrarily. . In this case, it is possible to predefine the types of luminance distribution patterns more than the above-mentioned 9 types, and to perform extremely fine dimming control and Correction control. In addition, although the example in which the visor 51 is moved in units of the pitch P of the optical elements 41 at the time of dimming control has been described above, as shown in FIG. A configuration in which the light shielding plate 51 is moved in units of the length (division length) T of 1/n (n is an integer equal to or greater than 2, for example, 4) of P. According to this configuration, finer dimming control can be performed based on the luminance distribution pattern of an image to be displayed. In addition, instead of using the data table, the control unit 4 may adopt a configuration in which the dimming amount and the correction pattern are calculated from the luminance distribution pattern of the image.

In addition, although the optical system 3 provided with the mechanical dimming mechanism 32 including the light shielding plate 51 and the moving part 52 has been exemplified, as shown in FIG. The optical system 3A of the liquid crystal element 71 between the lens arrays 31a and 31b optically performs multi-stage or stepless dimming of the light L. In this configuration, the control unit 4 controls the liquid crystal element 71 to change the light transmittance to adjust the light quantity of the light L from the lens array 31 a, thereby performing dimming (dimming). In this case, since the light L from the lens array 31 a is not partially blocked, the light L can be relatively uniformly incident on the liquid crystal light valve 33 , and as a result, display unevenness can be sufficiently suppressed. In addition, in this configuration, for example, even if the transmittance of the liquid crystal element 71 is uneven due to uneven polishing at the time of manufacture, the liquid crystal light valve 33 can be corrected for causing the transmittance unevenness. Correction control of display unevenness reliably reduces display unevenness. In addition, in this configuration, a method of performing correction control on both the liquid crystal light valve 33 and the liquid crystal element 71 may be employed. Specifically, at the time of the projection processing 60 described above, the control unit 4 executes correction control for correcting the gradation level of the liquid crystal element 71 according to the uneven transmittance of the liquid crystal element 71 (correction control for the liquid crystal element in the present invention). Correction control is performed on the liquid crystal light valve 33 in order to cancel out the variation in transmittance and when the incident light amount of the light L entering the liquid crystal light valve 33 cannot be completely uniformly controlled only by the correction control. Thereby, display unevenness can be almost completely corrected.

Furthermore, the light L from the lens array 31a can also be partially blocked by the liquid crystal element 71 . In this case, the shielding of the light L, the control of the optical system 3, and the like are the same as those of the embodiments described in FIGS. 2, 6, 8, 10 and the like.

Claims (12)

1. A projector comprising a light source unit, a light modulating element that modulates light from the light source unit based on image data, a dimming unit that adjusts the amount of light incident on the light modulating element from the light source unit, and controlling the aforementioned a light modulating element and a control unit of the aforementioned dimming unit, The control unit performs dimming control for adjusting the amount of light based on a luminance distribution pattern of the image data on the dimming unit, and corrects display unevenness of the image data based on the adjustment of the amount of light on the light modulation element. Correction control. 2. The projector according to claim 1 , comprising dimming amounts storing the light amounts corresponding to the luminance distribution patterns of the plurality of image data, and light adjusting amounts corresponding to the respective dimming amounts. a storage unit for the correction content for the aforementioned correction control, The control unit executes the dimming control by reading the dimming amount corresponding to the luminance distribution pattern of the displayed image data from the storage unit, and reads the light corresponding to the dimming amount from the storage unit. The above-mentioned correction control is executed according to the above-mentioned correction content. 3. The projector according to claim 1 or 2, comprising a pair of lens arrays disposed between the light source unit and the light modulation element, The light control unit includes a shade and a moving unit that moves the shade. 4. The projector according to claim 3, wherein the control unit executes the dimming control by moving the visor between the pair of lens arrays by the moving portion to block light from the lens arrays. . 5. The projector of claim 3, wherein: The aforementioned lens array has a plurality of optical elements, The control unit moves the visor in units of the optical elements. 6. The projector according to claim 5, wherein the plurality of optical elements are periodically arranged at a predetermined arrangement pitch, The control unit moves the visor in units of the arrangement pitch. 7. The projector according to claim 5, wherein the control unit moves the visor in units of 1/n of the arrangement pitch of the optical elements, wherein n is an integer greater than or equal to 2. 8. The projector according to claim 1 , further comprising a pair of lens arrays disposed between the light source unit and the light modulation element, The light adjustment unit includes a liquid crystal element disposed between the pair of lens arrays. 9. The projector according to claim 8, wherein the control unit executes the dimming control by controlling the liquid crystal element to change light transmittance. 10. The projector according to claim 9, wherein the control unit, when performing the correction control on the light modulation element, corrects the liquid crystal element based on the adjustment of the light amount by the liquid crystal element. Correction control for display unevenness. 11. The projector according to claim 1, wherein the luminance distribution pattern of the image data is defined by a dynamic range and an average luminance of the luminance distribution of the image. 12. The projector according to claim 3, wherein the display unevenness of the image data due to the adjustment of the light quantity and the spatially inconsistent illumination of the light modulation element due to the spatial arrangement of the light shielding plate Corresponding.

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