JP4476250B2 - Projection display - Google Patents

Description

  The present invention includes a plurality of light sources, a light modulation element that modulates light emitted from the plurality of light sources in units of pixels, and a projection type that controls a modulation amount of light that the light modulation elements modulate in units of pixels in units of frames. The present invention relates to a display device.

  In a projection display device that synthesizes and emits RGB light emitted from each RGB liquid crystal panel into a single color image by a synthesis prism and projects it onto a screen through a lens, each RGB light source causes deterioration with time. Therefore, it is necessary to perform control for measuring the deterioration rate of each color light source and aligning the brightness of the other light source with the most deteriorated light source, that is, temporal change correction control. In order to correct such a change with time, conventionally, a plurality of optical sensors are installed corresponding to each RGB light source, and control is performed to correct the light source according to the state of each light source.

  However, in such a conventional projection display device, it is necessary to install an optical sensor in the vicinity of each RGB light source, and there is a problem that it is difficult to reduce the cost, and the device configuration is complicated. There was a problem to become.

In order to solve this conventional technical problem and make it possible to correct temporal changes with one sensor without installing a photo sensor for each light source, light from a plurality of light sources transmitted through the liquid crystal panel. Install a light sensor at a position where multiple light quantities can be measured later, and how much light from all display areas on the liquid crystal panel is included in the light quantity measured by the light sensor, It is necessary to consider the contribution to the amount of light for each display area of the liquid crystal panel.
Japanese Patent Laid-Open No. 9-200662

  The present invention has been made in view of the above-described conventional technical problems, and maintains the white balance by appropriately controlling the light amount of each light source even if a light amount sensor for detecting the light amount is not provided for each light source. It is an object of the present invention to provide a projection display device that can do this.

  One feature of the present invention is that a plurality of light sources (light sources 13), a light modulation element (such as the liquid crystal panel 11 and the liquid crystal panel 110) that modulates light emitted from the plurality of light sources in units of pixels, and a video signal in units of frames. Based on the modulation amount control unit (modulation amount control unit 220) that controls the modulation amount of the light that the light modulation element modulates in units of pixels, and the light synthesis unit that combines the light modulated by the light modulation element ( A projection display device including a color synthesis prism 15 and a dichroic prism 120) and a projection lens unit (projection lens unit 130) that projects the light emitted from the light synthesis unit onto a screen is synthesized by the light synthesis unit. A light amount detection unit (light sensor 16, light amount sensor 140) for detecting the amount of light, a divided region that is a region where the light modulation element is divided, and the divided region A contribution storage unit (contribution storage unit 20 and contribution storage unit 230) that stores the degree of contribution of the modulated light that reaches the light amount detection unit in association with each other, and the video signal for each frame And an estimated light amount calculation unit that calculates an estimated light amount of light emitted from the light source for each light source based on the reaching contribution degree stored in the contribution degree storage unit and the light amount detected by the light amount detection unit. (The average signal value calculating unit 22, the estimated light amount calculating unit 250) and the estimated light amount calculated for each light source by the estimated light amount calculating unit and the reference light amount of the light emitted from the light source are compared, and the reference A deterioration rate calculation unit (deterioration rate calculation unit 26, control unit 260) that calculates a deterioration rate, which is a ratio of light amount deterioration from the light amount, for each light source, and the deterioration calculated for each light source by the deterioration rate calculation unit. According to rate , And summarized in that and a light quantity control unit for controlling the amount of light the plurality of light sources emitted (the light amount control unit 21, the control unit 260).

  According to such a feature, the estimated light amount calculation unit converts the frame-by-frame video signal (the modulation amount of the light modulation element), the arrival contribution stored in the contribution storage unit, and the light amount detected by the light amount detection unit. Based on this, an estimated light amount of light emitted from the light source is calculated for each light source. In addition, the deterioration rate calculation unit compares the estimated light amount calculated for each light source by the estimated light amount calculation unit with the reference light amount of light emitted from the light source, and calculates a deterioration rate that is a ratio of the light amount deterioration from the reference light amount. Calculate every time. Furthermore, the light quantity control unit controls the light quantity of light emitted from the plurality of light sources in accordance with the deterioration rate calculated for each light source by the deterioration rate calculation unit.

  Therefore, even if a light amount sensor for detecting the light amount is not provided for each light source, the white balance can be maintained by appropriately controlling the light amount of each light source.

  One feature of the present invention is that a plurality of light sources (light sources 13), a light modulation element (such as the liquid crystal panel 11 and the liquid crystal panel 110) that modulates light emitted from the plurality of light sources in units of pixels, and a video signal in units of frames. Based on the modulation amount control unit (modulation amount control unit 220) that controls the modulation amount of the light that the light modulation element modulates in units of pixels, and the light synthesis unit that combines the light modulated by the light modulation element ( A projection display device including a color synthesis prism 15 and a dichroic prism 120) and a projection lens unit (projection lens unit 130) that projects the light emitted from the light synthesis unit onto a screen is synthesized by the light synthesis unit. A light amount detection unit (light sensor 16, light amount sensor 140) for detecting the amount of light, a divided region that is a region where the light modulation element is divided, and the divided region A contribution storage unit (contribution storage unit 20 and contribution storage unit 230) that stores the degree of contribution of the modulated light that reaches the light amount detection unit in association with each other, and the video signal for each frame And an estimated light amount for calculating an estimated light amount to be detected by the light amount detection unit for each light source based on the reaching contribution degree stored in the contribution degree storage unit and a reference light amount of light emitted from the light source Comparing the estimated light amount calculated for each light source by the calculating unit (average signal value calculating unit 22, estimated light amount calculating unit 250) and the light amount detected by the light amount detecting unit The deterioration rate is calculated for each light source by a deterioration rate calculation unit (deterioration rate calculation unit 26, control unit 260) that calculates a deterioration rate for each light source. Said inferiority Depending on the rate, and summarized in that and a light quantity control unit for controlling the light quantity of the plurality of light sources emit light (light amount control unit 21, the control unit 260).

  According to such a feature, the estimated light amount calculation unit is based on the video signal in units of frames (the modulation amount of the light modulation element), the arrival contribution stored in the contribution storage unit, and the reference light amount of light emitted from the light source. Thus, the estimated light amount to be detected by the light amount detection unit is calculated for each light source. The deterioration rate calculation unit compares the estimated light amount calculated for each light source by the estimated light amount calculation unit with the light amount detected by the light amount detection unit, and calculates a deterioration rate that is a ratio of the light amount deterioration from the reference light amount. Calculate for each light source. Furthermore, the light quantity control unit controls the light quantity of light emitted from the plurality of light sources in accordance with the deterioration rate calculated for each light source by the deterioration rate calculation unit.

  Therefore, even if a light amount sensor for detecting the light amount is not provided for each light source, the white balance can be maintained by appropriately controlling the light amount of each light source.

  One feature of the present invention is that, in the above-described feature of the present invention, the estimated light amount calculation unit calculates the estimated light amount based on a video signal input in a calculation target frame that is a plurality of frames. And

  One feature of the present invention is that in the above-described feature of the present invention, the modulation amount control unit performs the light emission between the end of scanning of one frame and the start of scanning of another frame continuous with the one frame. In a blanking period in which the scanning position of the modulation element is returned to the reference position, the modulation amount of the light modulation element is individually controlled, and the estimated light amount calculation unit calculates the one frame or the other frame. Video signal input in the target frame, the arrival contribution stored in the contribution storage unit, the amount of light detected by the light amount detector in the calculation target frame, and a video input during the blanking period The gist is to calculate the estimated light amount based on the signal and the light amount detected by the light amount detection unit in the blanking period.

  One feature of the present invention is that, in the above-described feature of the present invention, the contribution degree storage unit includes a pixel position of the light modulation element and a degree to which light modulated at the pixel position reaches the light amount detection unit. The gist is to store a certain degree of contribution contribution in association with each other.

  One feature of the present invention is that in the above-described feature of the present invention, as the number of the divided regions increases as the amount of light detected by the light amount detection unit when all of the plurality of light sources are turned on, the divided regions are increased. The gist is that the number is set to be large.

  One feature of the present invention is that in the above-described feature of the present invention, the size of the divided region is set such that the larger the distance from the light amount detection unit to the divided region, the larger the size of the divided region. It is a summary.

  One feature of the present invention is that, in the above-described feature of the present invention, the projection lens unit has a diaphragm section (diaphragm section 131) for narrowing a range of light projected on the screen. However, it is constituted by a non-light-transmitting member that blocks a part of the light emitted from the light combining unit, and the light amount detecting unit is provided in the diaphragm unit.

  One feature of the present invention is that in the above-described feature of the present invention, the light amount detector is disposed outside a region through which light emitted from the light synthesizer passes and diffuses light emitted from the light synthesizer. The gist is to detect the amount of light.

  One aspect of the present invention is the dichroic prism according to the above aspect of the present invention, wherein the light combining unit includes a plurality of reflection surfaces that transmit light of a specific wavelength and reflect light of another wavelength. The light amount detection unit is provided to face the side surface of the dichroic prism excluding the light incident surface on which light is incident and the light emitting surface from which light is emitted, and from a position where the plurality of reflective surfaces intersect. Is also provided on the projection lens unit side.

  One feature of the present invention is that, in the above-described feature of the present invention, the light amount detection unit includes a plurality of light receiving units (a red light receiving unit 140r, a green light receiving unit 140g, a blue light) corresponding to each of the plurality of light sources. The light receiving unit 140b) is provided, and the plurality of light receiving units are arranged in order along a direction perpendicular to the light emitting surface of the light combining unit.

  One feature of the present invention is that, in the above-described feature of the present invention, the light amount detection unit includes a plurality of light receiving units (a red light receiving unit 140r, a green light receiving unit 140g, a blue light) corresponding to each of the plurality of light sources. A plurality of light receiving units arranged in order along a direction parallel to the light emitting surface of the light combining unit, and the light corresponding to the light receiving unit from the light receiving unit. The gist is that the optical path length to the modulation element is arranged in a combination that increases.

  One feature of the present invention is the difference between the modulation amount of the light modulation element in one frame and the modulation amount of the light modulation element in another frame continuous with the one frame in the above-described feature of the present invention. A scene change determining unit that determines whether a certain modulation amount difference exceeds a predetermined threshold; and the light amount control unit, when the modulation amount difference exceeds the predetermined threshold, The gist is to control the amount of light emitted from the plurality of light sources between other frames.

  According to the present invention, it is possible to provide a projection display apparatus capable of maintaining white balance by appropriately controlling the light amount of each light source without providing a light amount sensor for detecting the light amount for each light source. it can.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. There are two types of projection display devices, a front projection type and a rear projection type, and the present invention can be applied to either of them. In the following embodiments, the rear projection type is taken as an example. I will explain. There are two types of display elements, transmissive and reflective. The transmissive display element includes a transmissive liquid crystal panel. The reflective display element includes a reflective liquid crystal panel represented by LCOS and a digital micro display. There is a mirror device, and the present invention can be applied to any of these. In the following embodiments, a transmissive liquid crystal panel will be described as an example.

(First embodiment)
FIG. 1 shows the configuration of a time-varying correction device for a projection display apparatus according to a first embodiment of the present invention, and FIGS. 2 to 4 show the element arrangement of a projection display apparatus 100 employing the same.

  As shown in FIG. 2, the projection display device 100 includes a liquid crystal projection device 10 having the configuration shown in FIGS. 3 and 4, and the composite video light from the liquid crystal projection device 10 is magnified by a projection lens 14 to be a mirror. 12 is reflected on the screen 11, projected onto the screen 11, and displayed on a large screen.

  As shown in FIGS. 3 and 4, the liquid crystal projector 10 has RGB light sources 13R, 13G, and 13B arranged at three locations that are 90 degrees apart from each other in the horizontal direction. In addition, RGB liquid crystal panels 11R, 11G, and 11B are installed in front of the light emission directions of the light sources 13R, 13G, and 13B, respectively, and a color synthesis prism 15 is installed in the center. The color lights from 13B and 13G are transmitted through the RGB liquid crystal panels 11R, 11G, and 11B to become RGB image lights, and the color synthesis prism 15 transmits or refracts each of them in the direction of the projection lens 14 to perform color synthesis. Thus, the light is emitted as the color composite image light 32. For the RGB light sources 13R, 13B, and 13G, for example, LEDs and lasers are employed.

  An optical sensor 16 is installed at an arbitrary position of the color synthesis prism 15, preferably at a position near the projection lens 14 above or below the center of the color synthesis prism 15. Measure the amount of diffused light. The optical sensor 16 has a sensing range 35 of the color synthesizing prism 15 as shown, for example.

  As shown in FIG. 1, the time-varying correction device of the projection display device according to the present embodiment includes light sources 13R, 13B, and 13G that project light onto the respective liquid crystal panels 11R, 11G, and 11B, in a stage before factory shipment. The contribution degree storage unit 20 that stores the registered contribution degree data (reaching contribution degree), the light source control unit 21 that controls the luminance of each of the light sources 13R, 13B, and 13G, and the calculation described later for an image from the input image data 31 An average signal value calculation unit 22 that calculates an average signal value by an expression, a light amount measurement unit 23 that measures a light amount based on a signal of an optical sensor 16 that detects leakage light from the color synthesizing prism 15, and is registered in advance before the factory shipment. The initial adjustment value storage unit 24 that stores the initial adjustment value data (reference light amount) that is stored, the memory 25 that temporarily holds the calculated value, the measurement light amount output from the light amount measurement unit 23, and the initial value Calculating the light source deterioration rate from the initial adjustment value held in Seichi storage unit 24, and a deterioration rate calculator 26 for output for light control to the light source control unit 21 as well as stored in the memory 25.

  The white balance aging correction operation by the aging correction apparatus of the above embodiment will be described. FIG. 5 is a flowchart of the temporal change correction process according to the present embodiment. As shown in FIGS. 3 and 4, a photosensor 16 is installed at the upper center of the color synthesizing prism 15 so that the amount of light of the color synthesized image after color synthesis can be measured a plurality of times. In the apparatus of the present embodiment, since the diffused light of the RGB light sources 13R, 13B, and 13G is measured, the amount of diffused light from the optical member such as the color synthesizing prism 15 is large, and the light is emitted at a position where the diffused light can be measured with high sensitivity. A sensor 16 is installed. However, since the amount of light is measured from an arbitrary position above or below the color synthesis prism 15, the measurement amount varies depending on the display position of the liquid crystal panels 11R, 11G, and 11B. Accordingly, the liquid crystal panels 11R, 11G, and 11B are turned on for each pixel, and the contributions in the respective regions of the liquid crystal panels 11R, 11G, and 11B are calculated in advance as shown in FIG. Stored in the unit 20 (step S1).

  Then, in actual use, the subsequent control is executed periodically or every time when the lighting integrated time of the light sources 13R, 13B, and 13G elapses a predetermined time. First, an average RGB signal value of an arbitrary image is calculated from the contribution degree of light transmitted through the liquid crystal panels 11R, 11G, and 11B calculated in advance (step S3).

When the liquid crystal panels 11R, 11G, and 11B are turned on for each pixel, the average signal values (Rt, Gt, and Bt) in consideration of the contribution are expressed by Equations 1 to 3. This calculation is executed by the average signal value calculation unit 22. Here, I is the number of pixels in the horizontal direction of the image, J is the number of lines in the vertical direction, and the contributions of the liquid crystal panels 11R, 11G, and 11B for the RGB of the pixel of interest (i, j) are CR _{i, j} , CG. Let _{i, j} , CB _{i, j} , and RGB signal values be R _{i, j} , G _{i, j} , B _{i, j} .

  For the image when the average signal value (Rt, Gt, Bt) considering the degree of contribution is calculated, the light quantity L detected by the light sensor 16 and measured by the light quantity measuring unit 23 is used as the average signal value (Rt). , Gt, Bt) and stored in the memory 25 (step S5).

  The correspondence between the average signal value (Rt, Gt, Bt) and the measured light quantity L in consideration of such contribution is obtained for other images, and the above correspondence is obtained for each of three different image scenes 1 to 3. Save in the memory 25 (step S7). In the following, it should be noted that an image scene may be referred to as a frame.

After acquiring the three corresponding relationships of scene 1 to scene 3, the light quantity of each of the RGB light sources 13R, 13B, and 13G is estimated by the following series of arithmetic processing of the deterioration rate calculation unit 26 (step S9). Here, the current light amount of the R light source 13R is x, the current light amount of the G light source 13G is y, and the current light amount of the B light source 13B is z. First, the average RGB signal at the time of scene 1 is (Rt1, G1t, Bt1), and the light quantity at that time is L1. The relationship at this time is shown in Formula 4. Similarly, Equation 5 shows the relationship between the average RGB signal (Rt2, Gt2, Bt2) and the amount of light L2 for the scene 2, and Equation 6 shows the relationship between the average RGB signal (Rt3, Gt3, Bt3) and the amount of light L3 for the scene 3. Show the relationship.

Equation 7 is calculated from the relationship between scene 1 and scene 2, and equation 8 is calculated from the relationship between scene 1 and scene 3.

Expression 9 is derived from the calculated expressions 4 and 5.

From Expression 9, the light quantity x for the R light source 13R becomes Expression 10. Similarly, the light amount y of the G light source 13G and the light amount z of the B light source 13B are expressed by Equations 11 and 12, respectively.

As described above, after calculating the current light amount of only RGB (the estimated light amount of light emitted from each light source), the following formula is compared with the RGB light amount (x ₀ , y ₀ , z ₀ ) at the time of initial adjustment. The deterioration rate (Ix, Iy, Iz) is calculated from 13 to Equation 15 (step S11).

The deterioration rate calculation unit 26 outputs the calculated deterioration rates (Ix, Iy, Iz) to the light source control unit 27, and the light source control unit 21 matches the white balance with reference to the deterioration rate of the light source with the most advanced deterioration rate. Then, the control amount that is the aperture amount of the output of the other light source is calculated (step S13). Wherein when the minimum deterioration rate of Iz, becomes R, G, source 13R of B, 13B, 13G respective control amount _{C R, C G, C B} is the following equation 16 to equation 18.

  The light source control unit 21 controls the output of each of the RGB light sources 13R, 13B, and 13G based on the control amount thus calculated (step S15).

  As described above, according to the temporal change correction apparatus of the projection display apparatus of the present embodiment, the single photosensor is installed at a position where the light quantity after the light of the plurality of RGB light sources passes through the liquid crystal panel can be measured. Based on the measurement signal value of the optical sensor, the individual light amounts of RGB are calculated, the deterioration rate is calculated, and the brightness of the light source of the color with the most deterioration is controlled to match the brightness of the light source of the other color. Therefore, the white balance can always be corrected correctly.

(Second Embodiment)
A temporal change correction apparatus for a projection display apparatus according to a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is characterized in that the optical sensor 16 is installed at the upper center of the color synthesis prism 15. Therefore, the temporal change correction apparatus according to the present embodiment has the configuration shown in FIG. 1 as in the first embodiment, but the data stored in the contribution storage unit 20 is different from that in the first embodiment. ing. Also, the calculation processing contents of the average signal value calculation unit 22 are slightly different. Hereinafter, these different points will be described.

  Since the measurement amount according to the display position of the liquid crystal panels 11R, 11G, and 11B varies depending on the installation position of the optical sensor 16, in the case of the present embodiment, the liquid crystal panels 11R, 11G are preliminarily used as shown in FIG. , 11B, the contribution in each region (divided region) divided from the top to the bottom is calculated and stored in the contribution storage unit 20 (step S1A).

  Then, in actual use, the subsequent control is executed periodically or every time when the lighting integrated time of the light sources 13R, 13B, and 13G elapses a predetermined time. First, an average RGB signal value of an arbitrary image is calculated from the contribution degree of light transmitted through the liquid crystal panels 11R, 11G, and 11B calculated in advance (step S3).

When the liquid crystal panels 11R, 11G, and 11B are equally divided into N and turned on, the average signal values (Rt, Gt, and Bt) in consideration of the contribution are expressed by Equations 19 to 21. Here, the contribution degree of the divided area (divided area) is Cn, the number of pixels in the horizontal direction of the divided area is I, the number of lines in the vertical direction is J, and the RGB signal value at the pixel of interest (i, j) _Is R _{i, j} , G _{i, j} , B _{i, j} .

  For the image when the average signal value (Rt, Gt, Bt) considering the degree of contribution is calculated, the light quantity L detected by the light sensor 16 and measured by the light quantity measuring unit 23 is used as the average signal value (Rt). , Gt, Bt) and stored in the memory 25 (step S5).

  The subsequent processing is the same as that of the first embodiment, and the correspondence between the average signal value (Rt, Gt, Bt) and the measured light quantity L in consideration of such contribution is obtained for other images and is different. The above correspondence relationship is stored in the memory 25 for each of the three images (step S7). Then, the processes in steps S9 to S15 are executed in the same manner as in the first embodiment, and the deterioration rate of the light source that has advanced most among the deterioration rates calculated by the deterioration rate calculation unit 26 is used as a reference. Control the output of other light sources to match the white balance.

  In the present embodiment, the same operations and effects as in the first embodiment are achieved, and in addition, the area is compared with the case where the contribution for each pixel is used as in the first embodiment. There is an advantage that the calculation processing time can be shortened by using the contribution degree for each (divided region).

(Third embodiment)
Next, a temporal change correction apparatus for a projection display apparatus according to a third embodiment of the present invention will be described with reference to FIGS. The present embodiment is characterized by a time-varying correction apparatus that measures the light amounts of the R, G, and B light sources 13R, 13B, and 13G and that simplifies the arithmetic processing.

  The hardware configuration of this embodiment is the same as that of the first embodiment, and is applied to the light source control of the liquid crystal projection device 10 in the projection display device of FIG. 2, and has the functional configuration of FIG. ing. The temporal change correction apparatus according to the present embodiment is additionally provided with a blanking detection unit 27 in addition to the first embodiment shown in FIG. 1, and details of calculation processing of the deterioration rate calculation unit 26 will be described later. It is characterized by having been changed to.

  Here, the blanking detection unit 27 is a blanking period which is a period during which the scanning position of the liquid crystal panel is returned to the reference position between the end of scanning of one frame and the start of scanning of another frame continuous to one frame. Is detected.

  The temporal change correction process by the temporal change correction apparatus of the third embodiment having the above configuration will be described with reference to the flowchart of FIG. The contribution degree for each pixel is measured at the time of initial adjustment before factory shipment, and is stored in the contribution degree storage unit 20 (step S21).

  Then, in actual use, the subsequent control is executed periodically or every time when the lighting integrated time of the light sources 13R, 13B, and 13G elapses a predetermined time. First, as in the first embodiment, the average RGB signal value (Rt4, Gt4, Bt4) of the image is calculated based on the contribution calculated in advance (step S23).

Next, L4 of the following expression 22 is obtained for an input image at an arbitrary timing, and the output of only the R light source is controlled in the blanking period immediately before or immediately after (here, immediately after) the blanking period. 23 L4 _R is obtained, and the light source output is restored (steps S25, S27, S29). Subsequently, the output of only the G light source 13G is controlled during the same blanking period, L4 _G of the following Expression 24 is obtained, and the light source output is restored (steps S25, S27, S29). Subsequently, the output of only the B light source 13B is controlled in the same blanking period, L4 _B of the following Expression 25 is obtained, and the light source output is restored (steps S25, S27, S29).

Here, the RGB light amounts (x ₀ , y ₀ , z ₀ ) at the time of initial adjustment are set, the control amounts of the RGB light source outputs are set as C _R , C _G , and C _B , respectively, and the average RGB signal of the input image at an arbitrary timing It is assumed that the value is (Rt4, Gt4, Bt4), the measured light amount before control of the light source output is L4, and the light amounts when the R light source, G light source, and B light source are controlled are L4 _R , L4 _G , L4 _B.

If the above processing is completed for all of the RGB light sources 13R, 13B, and 13G (step S31), the deterioration rate calculation unit 26 performs the following arithmetic processing to calculate the RGB light source 13R deterioration rate. By comparing Expression 22 and Expression 23, Expression 22 and Expression 24, and Expression 22 and Expression 25, respectively, the current light amounts x, y, and z of the respective RGB light sources are as follows (step S33).

  The subsequent processing is the same as in the first embodiment, and the deterioration rate is calculated by the deterioration rate calculation unit 26 in comparison with the light amounts of the RGB light sources 13R, 13B, and 13G at the time of initial adjustment (step S35). . Then, the light source control unit 21 calculates the control amount of the light source output for matching the white balance with reference to the minimum deterioration rate (step S37), and outputs the light sources 13R, 13B, and 13G based on the calculated light source control amount. Is controlled (step S39).

  In this embodiment, the same degree of contribution as in the first embodiment is adopted, but instead, the same degree of contribution as in the second embodiment can be adopted.

  Thereby, according to the third embodiment, the same operation and effect as the first embodiment can be obtained, and in addition, the calculation formulas of the light amounts x, y, and z of the RGB light sources can be simplified. There is an advantage that the load on the arithmetic processing unit can be reduced or the control response speed can be increased. Further, if the contribution is set as in the second embodiment, the merit becomes even more remarkable.

  In this embodiment, the same degree of contribution as in the first embodiment is adopted. However, instead of this, the same degree of contribution as in the second embodiment can be adopted. It can be further reduced.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. In the third embodiment, an average signal value is calculated for any one input image, the amount of light of the color composite image corresponding to the input image is measured, and immediately after one blanking period. The RGB light sources 13R, 13B, and 13G are individually controlled to measure the light amounts L4 _R , L4 _G , and L4 _B , the light source control amounts (C _R , C _G , and C _B ) and the measured light amounts L4 and L4 _R and L4 _G , L4 _B is applied to Equations 26 to 28 to determine the light amounts x, y, z of the RGB light sources 13R, 13B, 13G. As a more general application, the RGB light sources 13R, 13B, It is also possible to obtain the light amounts x, y, and z of 13G.

First, as in the first embodiment, the average RGB signal value (Rt4, Gt4, Bt4) of the input image is calculated at an arbitrary timing based on the contribution calculated in advance (step S21). Then, the light sensor 16 measures the amount of light with respect to the color composite image corresponding to this input image, obtains L4 of the following expression 29, and the R light source in the blanking period immediately before or after (here, immediately after) Only the output is controlled, L4 _R of the following Expression 30 is obtained, and the light source output is restored. Next, average RGB signal values (Rt4 ′, Gt4 ′, Bt4 ′) are calculated based on the contribution calculated in advance for the input image or the same input image at another arbitrary timing. Then, the light sensor 16 measures the amount of light with respect to the color composite image corresponding to this input image, obtains L4 ′ of the following equation 31, controls the output of only the G light source 13G in the blanking period immediately after that, L4 _R of the following equation 32 is obtained, and the light source output is restored. Next, the average RGB signal values (Rt4 ″, Gt4 ″, Bt4 ″) are calculated at an arbitrary timing in the same manner for the B light source 13B. Then, the light is output for the color composite image corresponding to this input image. The amount of light is measured by the sensor 16 to obtain L4 ″ of the following equation 33, and the output of only the B light source 13B is controlled in the blanking period immediately thereafter, and the amount of light is measured to obtain L4 _R of equation 34 below. Return the light source output to its original state.

The numerical value group obtained by the above average value calculation and measurement, and the known numerical value group are RGB light amounts (x ₀ , y ₀ , z ₀ ) at the time of initial adjustment, and control amounts C _R , C of RGB light source outputs. _G , C _B , average RGB signal values (Rt4, Gt4, Bt4), (Rt4 ′, Gt4 ′, Bt4 ′), (Rt4 ″, Gt4 ″, Bt4 ″) of the input image immediately before each blanking, light source output The light amounts L4 _R , L4 _G , and L4 _B when the light amounts L4, L4 ′, L4 ″, R light source, G light source, and B light source before control are controlled.

Using these numerical values, the deterioration rate calculation unit 26 performs arithmetic processing of the following formulas 35 to 37, and calculates the light amounts x, y, and z of the current RGB.

  In the subsequent processing, the deterioration rate is calculated in comparison with the light amounts of the RGB light sources 13R, 13B, and 13G at the time of initial adjustment in the same manner as in the third embodiment, and the minimum deterioration rate is calculated. The control amount of the light source output for matching the white balance is calculated as a reference, and the output of each light source 13R, 13B, 13G is controlled based on this.

  In the case of the present embodiment, it is not necessary to sequentially control each of the RGB light sources 13R, 13B, and 13G within one blanking period as in the third embodiment, and the speed requirement of the arithmetic processing is eased.

  In the present embodiment, the same degree of contribution as in the first embodiment is adopted, but instead, the same degree of contribution as in the second embodiment can be adopted, and the load of calculation processing is reduced. It can be further reduced.

(Fifth embodiment)
A time-varying correction apparatus for a projection display apparatus according to a fifth embodiment of the present invention will be described with reference to FIGS. Depending on the arrangement of the optical sensor and the light source, the leakage light of the light source itself may be measured in addition to the transmitted light of the liquid crystal. In that case, the relational expression for estimating the light quantity of each RGB light source can be simplified by controlling the light source output for each light source and measuring the light quantity. The third embodiment is characterized by a time-varying correction apparatus that can measure the leakage light of each of the R, G, and B light sources 13R, 13B, and 13G and simplify the arithmetic processing.

  The hardware configuration of this embodiment is the same as that of the first embodiment, and is applied to the light source control of the liquid crystal projection device 10 in the projection display device of FIG. 2, and has the functional configuration of FIG. ing. The time-varying correction apparatus according to the present embodiment is additionally provided with a blanking detection unit 27 in addition to the second embodiment shown in FIG. 1, and also stores leaked light data together with initial adjustment values as initial data. The initial adjustment value / leakage light data storage unit 24 'is provided, and the calculation processing content of the deterioration rate calculation unit 26 is changed as described later.

The temporal change correction process by the temporal change correction apparatus of the fifth embodiment having the above configuration will be described with reference to the flowchart of FIG. During the initial adjustment before shipment from the factory, the amount of leakage light (R _D , G _D , B _D ) of each of the RGB light sources 13R, 13B, 13G is measured. Since the leakage light 36 of the light sources 13R, 13B, and 13G needs to be measured for each RGB, this corresponds to the measurement amount when only one light source is turned on, the black image is displayed, and the transmitted light from the liquid crystal panel is eliminated. The amount of light leaks from the light source color. The amount of leakage light is stored as data in the initial adjustment value / leakage light data storage unit 24 '(step S20). Similarly to the first embodiment, the liquid crystal panels 11R, 11G, and 11B are turned on for each pixel, and the contribution in each region of the liquid crystal panels 11R, 11G, and 11B is calculated in advance as shown in FIG. And stored in the contribution storage unit 20 (step S21).

  Then, in actual use, the subsequent control is executed periodically or every time when the lighting integrated time of the light sources 13R, 13B, and 13G elapses a predetermined time. First, as in the first embodiment, the average RGB signal value (Rt4, Gt4, Bt4) of the image is calculated based on the contribution calculated in advance (step S23).

Next, L4 in Expression 38 below is obtained for an input image at an arbitrary timing, and immediately after that, the output of only the R light source is controlled, L4 _R in Expression 39 below is obtained, and the light source output is restored ( Steps S25, S27, S29). Similarly, the output of only the G light source 13G is controlled, L4 _G of the following expression 40 is obtained, and the light source output is restored (steps S25, S27, S29). Subsequently, the output of only the B light source 13B is controlled, L4 _B of the following expression 41 is obtained, and the light source output is restored (steps S25, S27, S29).

Again, the RGB light amount (x ₀ , y ₀ , z ₀ ) at the time of initial adjustment is set, the control amounts of the RGB light source output are C _R , C _G , and C _B , respectively, and the average RGB signal value of the image immediately before blanking (Rt4, Gt4, Bt4), the light amount before the light source output control is L4, and the light amounts when the R light source, the G light source, and the B light source are controlled are L4 _R , L4 _G , and L4 _B.

If the above processing is completed for all of the RGB light sources 13R, 13B, and 13G (step S33), the deterioration rate calculation unit 26 then performs the following arithmetic processing to calculate the RGB light source 13R deterioration rate. By comparing Expression 38 and Expression 39, Expression 38 and Expression 40, and Expression 38 and Expression 41, respectively, the current light amounts x, y, and z of the respective RGB light sources become Expressions 42 to 44 below (step S33). .

  The subsequent processing is the same as in the first embodiment, and the deterioration rate is calculated by the deterioration rate calculation unit 26 in comparison with the light amounts of the RGB light sources 13R, 13B, and 13G at the time of initial adjustment (step S35). . Then, the light source control unit 21 calculates the control amount of the light source output for matching the white balance with reference to the minimum deterioration rate (step S37), and outputs the light sources 13R, 13B, and 13G based on the calculated light source control amount. Is controlled (step S39).

  According to the fifth embodiment described above, the same operations and effects as those of the third embodiment can be achieved, and more accurate temporal correction can be performed by taking the leakage light amount into consideration.

  In the present embodiment, the same degree of contribution as in the first embodiment is adopted, but instead, the same degree of contribution as in the second embodiment can be adopted, thereby reducing the calculation processing. The load can be further reduced. Also in this embodiment, general application using equations similar to equations 29 to 37 in the fourth embodiment is also possible.

(Sixth embodiment)
In each of the above embodiments, the installation location of the photosensor 16 is not particularly limited. However, in this embodiment, a preferred installation location of the photosensor 16 will be described. The plan view of FIG. 15 and the front view of FIG. 16 show a portion of the liquid crystal projector 10. If the optical sensor 16 is located above the central axis of the combined light emitted from the color combining prism 15 and is installed at the upper front position A, the upper central position B, and the upper rear position C, the color combined light from the light combining prism 15 is obtained. In order to receive the diffused light, the position B is preferable to the position C, and the position A is more preferable because it can receive the most diffused light of the color composite light. Therefore, in the first to fifth embodiments described above, the optical sensor 16 can receive the largest amount of light by being installed at the position A in front of the center of the light synthesizing prism 15. Deterioration rate control is possible.

(Seventh embodiment)
In the first to sixth embodiments, in order to measure the contribution of each of the RGB liquid crystal panels 11R, 11G, and 11B, for example, the contribution for each pixel is measured as shown in FIG. If it is necessary to store the information in advance or reduce the processing time, the contribution for each area can be divided by dividing equally from above to below or from below to above as shown in FIG. Measurement is performed and the degree-of-contribution storage unit 20 stores it in advance, and an average signal value is calculated for an input image using this. However, the area division of each of the liquid crystal panels 11R, 11G, and 11B for setting the contribution is not limited thereto.

  For example, as shown in FIG. 17, the liquid crystal panels 11R, 11G, and 11B are divided into regions so as to become rougher as they move away from the upper side near the installation position of the optical sensor 16, and each region (divided region) is divided. Can be measured and stored in the contribution storage unit 20. In particular, when the optical sensor 16 is installed above the color combining light prism 15 and at a position corresponding to the optical axis of the emitted light, as shown in FIG. The finest mesh at the center can be set so that the mesh gradually becomes coarser as it goes to the side and downward. The closer to the optical sensor 16, the greater the amount of light received, and the further away, the less light received. Therefore, by dividing the region more finely as it approaches the optical sensor 16, it becomes possible to calculate the contribution with a certain accuracy, and as a result, the accuracy of the temporal correction can be improved.

  Further, as shown in FIG. 19, when the divided areas are set in the liquid crystal panels 11R, 11G, and 11B, the liquid crystal panel that can be regarded as almost zero diffused light that is far from the optical sensor 16 and that reaches the optical sensor 16 from the light transmitted therethrough. The contribution of the lower part of can also be set to zero. Further, when mesh regions are set for the liquid crystal panels 11R, 11G, and 11B as shown in FIG. 20, the liquid crystal that is far from the optical sensor 16 and from which light diffuses to reach the optical sensor 16 can be regarded as almost zero. The contributions of the left and right and lower peripheral portions of the panel can be set to zero. Thereby, the number of meshes can be reduced and the calculation processing time can be shortened.

(Eighth embodiment)
Next, a time-varying correction apparatus for a projection display apparatus according to an eighth embodiment of the invention will be described with reference to FIGS. The present embodiment is characterized in that the number of divided regions is variably set according to the characteristics of each device when measuring the contribution for each divided region stored in the contribution storage unit. That is, as shown in the block diagram of FIG. 21, with respect to the aging correction apparatus of the second embodiment described with reference to FIG. , 13B are all lit and received by the optical sensor 16, the light amount is measured by the light amount measuring unit 23, and the number of divided areas of the liquid crystal panels 11R, 11G, 11B is set based on the measured light amount. It has. In the present embodiment, the other constituent elements are the same as those shown in FIG. 1, and the common elements are denoted by the same reference numerals.

  Next, the temporal change correction processing according to the present embodiment will be described with reference to the flowchart of FIG. In the case of the present embodiment, at the factory adjustment stage, first, the division number setting unit 20A causes the light source control unit 21 to turn on each of the RGB light sources 13R, 13G, and 13B and cause the light sensor 16 to receive the light. The number of divided areas is set to an appropriate value for each apparatus according to the amount of light (steps S01 and S02). Then, after setting the number of divided areas, the contribution degree for each area is measured and stored in the contribution degree storage unit 20 as in the second embodiment (step S1).

  The reason for this adjustment is as follows. The installation location of the optical sensor is determined at a predetermined position by design. However, in production, the occurrence of individual differences for each apparatus is unavoidable. For example, even if the maximum light amount is 100 in a certain device, the maximum light amount may be 90 in another device. In such a case, if the number of divisions is 10 in both the former apparatus and the latter apparatus, the amount of light that can be received in each divided region is 9/10 of the latter with respect to the former. Thus, if the amount of light in each region is large or small, in the latter case, the resolution may be low and correct values may not be read. Therefore, in the latter case, the number of area divisions is set to 9. By doing so, the amount of light that can be received per region can be increased, and a correct value can be read.

  The processes in steps S3 to S15 after the contribution setting process are the same as those in the second embodiment, and the deterioration rates of the RGB light sources 13R, 13G, and 13B are obtained, and the light source with the most advanced deterioration rate is obtained. Then, control is performed so that the outputs of the other light sources coincide with each other, so that white balance can be maintained even if a change with time occurs.

  In the case of the present embodiment, the division number setting unit 20A is further added to the second embodiment. However, the present invention is not limited to this, and when the region is divided unevenly in the horizontal direction, The same can be applied to the case of dividing into mesh regions.

  The embodiment shown here is an example of the present invention and does not limit the scope of the claims of the present invention.

(Ninth embodiment)
The ninth embodiment of the present invention will be described below with reference to the drawings. In the following, differences between the above-described embodiment and the ninth embodiment will be mainly described.

  Specifically, in the above-described embodiment, the sensor (for example, the above-described optical sensor 16) that detects the amount of image light is disposed in the vicinity of the color combining prism 15 that combines the respective color lights. Light leaking from the prism 15 is detected.

  On the other hand, in the ninth embodiment, the sensor for detecting the amount of image light is provided in the aperture portion of the projection lens unit that projects the image light combined by the color combining prism on the screen.

(Configuration of optical system)
First, the positional relationship between the color synthesizing prism and the projection lens unit according to the ninth embodiment of the present invention will be described with reference to the drawings. FIG. 23A is a diagram showing the positional relationship between the color combining prism and the projection lens unit according to the ninth embodiment of the present invention.

  As shown in FIG. 23A, the dichroic prism 120 combines the red light emitted from the liquid crystal panel 110r, the green light emitted from the liquid crystal panel 110g, and the blue light emitted from the liquid crystal panel 110b, Image light is emitted to the projection lens unit 130 side.

  Specifically, the dichroic prism 120 has a red light incident surface 121r, a green light incident surface 121g, and a blue light incident surface 121b as light incident surfaces on which each color light is incident. The dichroic prism 120 has an image light exit surface 122 as a light exit surface from which the image light in which the respective color lights are combined is emitted.

  The dichroic prism 120 reflects blue light to the projection lens unit 130 side, reflects the green light to the projection lens unit 130 side, reflects red light to the projection lens unit 130 side, and reflects green light to the projection lens unit 130 side. And a mirror surface 123b that transmits to the projection lens unit 130 side.

  Next, the configuration of a projection lens unit 130 according to a ninth embodiment of the present invention will be described with reference to the drawings. FIG. 23B is a diagram showing a configuration of a projection lens unit 130 according to the ninth embodiment of the present invention.

  As shown in FIG. 23B, the projection lens unit 130 includes a diaphragm 131 and a projection lens 132.

  The diaphragm 131 is formed of a non-light-transmissive member that blocks a part of light emitted from the light source 13 (light source 13R, light source 13G, light source 13B), and narrows down a region through which light emitted from the light source 13 passes. Specifically, the diaphragm 131 narrows the region through which the image light combined by the dichroic prism 120 passes.

  The projection lens 132 projects the light narrowed down by the diaphragm 131 onto the screen.

  The light quantity sensor 140 is provided in the diaphragm 131. Specifically, the light quantity sensor 140 is provided on the side surface of the diaphragm 131 provided on the dichroic prism 120 (light source 13) side.

(Function and effect)
According to the ninth embodiment of the present invention, the light amount sensor 140 is provided in the diaphragm 131 of the projection lens unit 130. Therefore, it is possible to efficiently detect the amount of light to be projected onto the effective screen area of the screen. As a result, the amount of light projected on the screen can be controlled effectively.

  Further, since the light amount sensor 140 is provided in the diaphragm 131 of the projection lens unit 130, it does not affect the light projected on the screen. Accordingly, it is possible to prevent the viewer from feeling uncomfortable due to a decrease in the brightness of the light projected on the screen.

(Tenth embodiment)
The tenth embodiment of the present invention will be described below with reference to the drawings. In the following description, differences between the above-described ninth embodiment and the tenth embodiment will be mainly described.

  Specifically, in the ninth embodiment described above, the light amount sensor 140 is provided in the diaphragm 131 of the projection lens unit 130.

  On the other hand, in the tenth embodiment, the light quantity sensor 140 is provided in the dichroic prism 120. The light quantity sensor 140 has a plurality of light receiving portions that individually receive light of each color.

(Configuration of optical system)
Hereinafter, the arrangement relationship of the light quantity sensor 140 according to the tenth embodiment of the present invention will be described with reference to the drawings. FIG. 24 is a diagram showing an arrangement relationship of the light quantity sensor 140 according to the tenth embodiment of the present invention.

  As shown in FIG. 24, the dichroic prism 120 has a red light incident surface 121r, a green light incident surface 121g, and a blue light incident surface 121b as light incident surfaces on which each color light is incident, as in FIG. The image light emitting surface 122 is provided as a light emitting surface from which the image light in which the respective color lights are combined is emitted. The dichroic prism 120 has side surfaces (a side surface 124a and a side surface 124b) excluding the light incident surface and the light output surface.

  The light amount sensor 140 is provided to face the side surface 124 a of the dichroic prism 120 and detects the amount of leaked light (diffused light) leaking from the dichroic prism 120. The light amount sensor 140 includes a red light receiving unit 140r that receives the amount of red light, a green light receiving unit 140g that receives the amount of green light, and a blue light receiving unit 140b that receives the amount of blue light. .

  Here, the red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b are sequentially arranged along a direction parallel to the image light emitting surface 122 of the dichroic prism 120.

  Further, the red light receiving unit 140r is provided at a position farthest from the red light incident surface 121r as compared to the light receiving units of other colors, and the blue light receiving unit 140b is blue light compared to the light receiving units of other colors. It is provided at a position farthest from the incident surface 121b. That is, each light receiving part is arranged in a combination that increases the optical path length from each light receiving part to the liquid crystal panel corresponding to each light receiving part.

  The light amount sensor 140 may be provided to face the side surface 124b of the dichroic prism 120 instead of the side surface 124a of the dichroic prism 120.

(Function and effect)
According to the tenth embodiment of the present invention, the red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b are sequentially arranged along a direction parallel to the image light emitting surface 122 of the dichroic prism 120. Has been. In addition, each light receiving unit is arranged in a combination that increases the optical path length from each light receiving unit to the liquid crystal panel corresponding to each light receiving unit.

  Accordingly, each light receiving unit can receive light incident on the dichroic prism 120 more efficiently than when the optical path length from each light receiving unit to the liquid crystal panel corresponding to each light receiving unit is short.

(Eleventh embodiment)
Hereinafter, an eleventh embodiment of the present invention will be described with reference to the drawings. In the following description, differences between the tenth embodiment and the eleventh embodiment will be mainly described.

  Specifically, in the tenth embodiment described above, the red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b are along a direction parallel to the image light exit surface 122 of the dichroic prism 120. Arranged in order.

  On the other hand, in the eleventh embodiment, the red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b are sequentially arranged along a direction perpendicular to the image light emitting surface 122 of the dichroic prism 120. Has been.

(Configuration of optical system)
Hereinafter, the arrangement relationship of the light quantity sensor 140 according to the eleventh embodiment of the present invention will be described with reference to the drawings. FIG. 25 is a diagram showing an arrangement relationship of the light quantity sensor 140 according to the eleventh embodiment of the present invention.

  As shown in FIG. 25, the light quantity sensor 140 is provided facing the side surface (side surface 124a) of the dichroic prism 120 excluding the light incident surface and the light emitting surface, and leaked light (diffuse light) leaking from the dichroic prism 120. ) Is detected.

  Here, the red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b are sequentially arranged along a direction perpendicular to the image light emitting surface 122 of the dichroic prism 120.

  Note that the arrangement order of the red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b is not particularly limited, unlike the tenth embodiment described above.

  Further, similarly to the above-described tenth embodiment, the light amount sensor 140 may be provided to face the side surface 124b of the dichroic prism 120 instead of the side surface 124a of the dichroic prism 120.

(Function and effect)
According to the eleventh embodiment of the present invention, the red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b are sequentially arranged along a direction perpendicular to the image light emitting surface 122 of the dichroic prism 120. Has been.

  Here, since the mirror surface 123a and the mirror surface 123b are inclined with respect to the image light exit surface 122, each light receiving portion is arranged along a direction parallel to the image light exit surface 122. There is a possibility that the amount of light detected by the light receiving unit varies for each color.

  On the other hand, in the eleventh embodiment of the present invention, each light receiving portion is arranged along a direction perpendicular to the image light emitting surface 122, so the amount of light detected by each light receiving portion is different for each color. The variation can be suppressed.

(Twelfth embodiment)
The twelfth embodiment of the present invention will be described below with reference to the drawings. In the following description, differences between the tenth embodiment and the twelfth embodiment will be mainly described.

  Specifically, in the tenth embodiment described above, the dichroic prism 120 has a substantially cubic shape.

  On the other hand, in the eleventh embodiment, as shown in FIG. 26, the dichroic prism 150 that synthesizes the light emitted from each liquid crystal panel has a complicated shape instead of the shape of a legislature. ing. However, it should be noted that the dichroic prism 150 has the same function as the dichroic prism 120 described above from the viewpoint of combining the light emitted from the liquid crystal panels.

  Specifically, like the dichroic prism 120 described above, the dichroic prism 150 includes a red light incident surface 151r, a green light incident surface 151g, and a blue light incident surface 151b as light incident surfaces on which each color light is incident. Have. In addition, the dichroic prism 150 has an image light exit surface 152 as a light exit surface from which the image light in which the respective color lights are combined is emitted.

  The light amount sensor 140 is provided to face the side surface of the dichroic prism 150 excluding the light incident surface and the light exit surface, and detects the amount of leaked light (diffused light) leaking from the dichroic prism 150.

  The red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b are sequentially arranged along a direction parallel to the image light emitting surface 152 of the dichroic prism 150. In addition, each light receiving unit is arranged in a combination that increases the optical path length from each light receiving unit to the liquid crystal panel corresponding to each light receiving unit.

  The red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b are sequentially arranged along a direction perpendicular to the image light emitting surface 152 of the dichroic prism 150, as in the eleventh embodiment. It may be arranged.

(Thirteenth embodiment)
Hereinafter, a thirteenth embodiment of the present invention will be described with reference to the drawings. In the following description, differences between the tenth embodiment and the thirteenth embodiment will be mainly described.

  Specifically, in the tenth embodiment described above, the light modulation element is a transmissive liquid crystal panel. In the thirteenth embodiment, the light modulation element is a reflective liquid crystal panel (LCOS). Liquid Crystal on Silicon).

(Configuration of optical system)
The configuration of the optical system according to the thirteenth embodiment of the present invention will be described below with reference to the drawings. FIG. 27 is a diagram showing a configuration of an optical system according to the thirteenth embodiment of the present invention.

  As shown in FIG. 27, the projection display apparatus 100 includes a reflective liquid crystal panel 111r, a reflective liquid crystal panel 111g, and a reflective liquid crystal panel 111b instead of the transmissive liquid crystal panel. In addition, the projection display apparatus 100 includes a dichroic mirror 160 (a dichroic mirror 160r, a dichroic mirror 160g, and a dichroic mirror 160b) provided corresponding to each color reflective liquid crystal panel.

  The light amount sensor 140 is provided to face the side surface of the dichroic prism 120 excluding the light incident surface and the light exit surface, and detects the amount of leaked light (diffused light) leaking from the dichroic prism 120.

  Here, the red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b are along a direction parallel to the image light emitting surface 152 of the dichroic prism 150, as in the tenth embodiment described above. Arranged in order. In addition, each light receiving unit is arranged in a combination that increases the optical path length from each light receiving unit to the liquid crystal panel corresponding to each light receiving unit.

  The red light receiving unit 140r, the green light receiving unit 140g, and the blue light receiving unit 140b are sequentially arranged along a direction perpendicular to the image light emitting surface 152 of the dichroic prism 150, as in the eleventh embodiment. It may be arranged.

(Fourteenth embodiment)
The fourteenth embodiment of the present invention will be described below with reference to the drawings. In the following description, differences from the first embodiment will be mainly described.

  Specifically, in the first embodiment described above, the estimated light amount is calculated based on the modulation amount of the light modulation element, the degree of contribution, and the detected light amount.

  On the other hand, in the fourteenth embodiment, the estimated light amount is calculated based on the modulation amount of the light modulation element, the reaching contribution, and the reference light amount. In the fourteenth embodiment, as shown in the tenth to thirteenth embodiments, the light quantity sensor 140 includes a plurality of light receiving units (red light receiving units 140r corresponding to the respective colors). , A green light receiving unit 140g and a blue light receiving unit 140b).

(Function of projection display device)
The function of the projection display apparatus according to the fourteenth embodiment of the invention will be described below with reference to the drawings. FIG. 28 is a block diagram showing functions of the projection display apparatus 100 according to the fourteenth embodiment of the invention.

  As shown in FIG. 28, the projection display apparatus 100 includes a video signal input unit 210, a modulation amount control unit 220, a contribution storage unit 230, a reference, in addition to the light source 13, the liquid crystal panel 110, and the light amount sensor 140. The light amount storage unit 240, the estimated light amount calculation unit 250, and the control unit 260 are included.

  The video signal input unit 210 inputs a video signal in units of frames to the modulation amount control unit 220 and the estimated light amount calculation unit 250. Here, the video signal is, for example, a signal indicating the ratio of red (R), green (G), and blue (B) in units of pixels, and is a signal generated in units of frames. The video signal is, for example, a signal indicating a color tone ratio of red (R), green (G), and blue (B) within a range of 0 to 255 bits, and (R, G, B) = (128 , 128, 196).

  Based on the video signal acquired from the video signal input unit 210, the modulation amount control unit 220 controls the modulation amount that the liquid crystal panel 110 modulates in units of pixels in units of frames. For example, the modulation amount control unit 220 controls the amount of light emitted from the liquid crystal panel 110 for each color based on the video signal acquired from the video signal input unit 210.

  The contribution degree storage unit 230 stores the ratio of the light emitted from each pixel position of the liquid crystal panel 110 reaching the light amount sensor 140 (hereinafter referred to as contribution degree) and the pixel position in association with each other. Here, the degree of contribution is calculated based on the amount of light detected by the light amount sensor 140 for light emitted from each pixel position of the liquid crystal panel 110 when the projection display apparatus 100 is shipped from the factory. Further, the contribution degree is represented by, for example, a relative ratio of the light amount corresponding to each pixel position. The contribution degree storage unit 230 stores the modulation amount (that is, the video signal) of the liquid crystal panel 110 and the contribution degree in association with each other when the contribution degree is calculated.

  Here, since the distance and optical path from each pixel position to the light quantity sensor 140 differ depending on each pixel position of the liquid crystal panel 110, the light emitted from each pixel position gives the light quantity detected by the light quantity sensor 140. The impact is different. Therefore, the degree of contribution is used to improve the accuracy of light amount control of light emitted from the light source 13.

  Further, the contribution degree may be recalculated based on the light amount detected again by the light amount sensor 140 for the light emitted from the light source 13 when performing maintenance of the projection display device 100 after the projection display device 100 is shipped from the factory. Good.

  The reference light quantity storage unit 240 stores a light quantity (hereinafter referred to as a reference light quantity) that serves as a reference for light emitted from the light source 13 for each color. Here, the reference light amount is, for example, the light amount (initial light amount) detected by the light amount sensor 140 for the light emitted from the light source 13 when the projection display device 100 is shipped from the factory. Note that the reference light amount storage unit 240 stores the modulation amount (that is, the video signal) of the liquid crystal panel 110 and the reference light amount in association with each other when the reference light amount is detected.

  Further, the reference light amount may be a light amount detected again by the light amount sensor 140 with respect to light emitted from the light source 13 when performing maintenance of the projection display device 100 after the projection display device 100 is shipped from the factory.

  In the fourteenth embodiment, the modulation amount (ie, video signal) of the liquid crystal panel 110 when the reference light amount is detected is the modulation amount (ie, video signal) of the liquid crystal panel 110 when the contribution is calculated. Shall be the same.

  The estimated light amount calculation unit 250 stores the video signal acquired from the video signal input unit 210 (that is, the modulation amount of the liquid crystal panel 110), the contribution stored in the contribution storage unit 230, and the reference light storage unit 240. Based on the reference light amount, an estimated light amount to be detected by the light amount sensor 140 is calculated.

Specifically, the estimated light amount calculation unit 250 assumes that the pixel position is (i (1 ≦ i ≦ I), j (1 ≦ j ≦ J)), a coefficient (red coefficient) for each color of the entire frame. (Rt), the green coefficient (Gt), and the blue coefficient (Bt)) are calculated by the following equation (51). Note that “C _{ri, j} ”, “Cg _{i, j} ”, and “Cb _{i, j} ” are the contributions for each color associated with the pixel position (i, j), and “R _{i, j} ”. , “G _{i, j} ” and “B _{i, j} ” are video signals (modulation amounts).

  Subsequently, the estimated light amount calculation unit 250 calculates the estimated light amount to be detected by the light amount sensor 140 based on the modulation amount (video signal) of the liquid crystal panel 110 corresponding to a plurality of frames (frame 1 to frame 3) for each color ( Red, green and blue) for each calculation.

Specifically, the reference light amount of each color light stored in the reference light amount storage unit 240 is “x _rs ”, “x _gs ”, and “x _bs ”, the red light amount is “x _rp ”, and the green light amount is estimated. Is “x _gp ”, and the estimated light quantity of blue is “x _bp ”, the estimated light quantity calculation unit 250 can establish simultaneous equations of the following expression (52).

The estimated light amount calculation unit 250 calculates the estimated light _amounts (x _rp , x _gp, and x _bp ) of each color to be detected by the light amount sensor 140 by solving the simultaneous equations described above.

The control unit 260 calculates the control amount of the light amount output from the light source 13 (output of the light source 13) based on the estimated light amount calculated by the estimated light amount calculation unit 250 and the detected light amount detected by the light amount sensor 140. To do. Specifically, the control unit 260 detects the light amount control amount of each color output from the light source 13 as “I _r ”, “I _g ”, and “I _b ” and is detected by each light receiving unit of the light amount sensor 140. When the detected light amount of each color light is “x _rd ”, “x _gd ”, and “x _bd ”, the control amount (I _r , I _g, I _b ) of the light amount output from the light source 13 is _expressed by the following formula ( 53).

Further, the control unit 260 controls the amount of light of each color output from the light source 13 based on the calculated control amounts (I _r , _Ig, and I _b ).

(Operation of projection display device)
The operation of the projection display apparatus according to the fourteenth embodiment of the invention will be described below with reference to the drawings. FIG. 29 is a flowchart showing the operation of the projection display apparatus 100 according to the fourteenth embodiment of the invention.

  As shown in FIG. 29, in step 110, the projection display apparatus 100 controls the modulation amount of the liquid crystal panel 110 based on the video signal (for example, the color tone ratio of R, G, and B).

  In step 120, the projection display apparatus 100 reads the contribution degree of each pixel position from the contribution degree storage unit 230.

  In step 130, the projection display apparatus 100 reads the reference light amount from the reference light amount storage unit 240.

  In step 140, the projection display apparatus 100 estimates based on the modulation amount (video signal) controlled in step 110, the contribution read in step 120, and the reference light amount read in step 130. Calculate the amount of light.

Specifically, the projection display apparatus 100 sets the reference light amount of each color light read from the reference light amount storage unit 240 as “x _rs ”, “x _gs ”, and “x _bs ”, and the estimated light amount of each color light. When “x _rp ”, “x _gp ”, and “x _bp ” are set, the estimated light amount (x _rp x _gp and x _bp ) is calculated by solving the following simultaneous equations (52).

  In step 150, the projection display apparatus 100 detects the light amount of the light whose modulation amount is controlled in step 110 by the light amount sensor 140.

  In step 160, the projection display apparatus 100 calculates the light amount of each light source 13 (the output of each light source 13) based on the estimated light amount calculated in step 140 and the detected light amount detected in step 150. A control amount is calculated.

Specifically, the projection display apparatus 100 detects each light amount control amount of each color output from the light source 13 as “I _r ”, “I _g ”, and “I _b ” by each light receiving unit of the light amount sensor 140. When the detected light amounts of the respective color lights are “x _rd ”, “x _gd ”, and “x _bd ”, the control amounts (I _r , I _g, and I _b ) of the light amounts output from the light source 13 are as follows: Calculated according to equation (53).

  The amount of light emitted from each light source 13 is controlled so that white balance is maintained.

In step 170, the projection display apparatus 100 controls the amount of light output from each light source 13 based on the control amounts (I _r , _Ig and I _b ) calculated in step 160.

(Fifteenth embodiment)
The fifteenth embodiment of the present invention will be described below with reference to the drawings. In the following description, differences between the above-described fourteenth embodiment and fifteenth embodiment will be mainly described.

  Specifically, in the fourteenth embodiment described above, the control unit 260 controls the amount of light emitted from each light source 13, but in the fifteenth embodiment, the control unit 260 includes each liquid crystal. The modulation amount of the panel 110 is corrected.

(Function of projection display device)
The configuration of the projection display apparatus according to the fifteenth embodiment of the invention will be described below with reference to the drawings. FIG. 30 is a block diagram showing a configuration of a projection display apparatus 100 according to the fifteenth embodiment of the present invention. In FIG. 30, it should be noted that the same components as those in FIG. 28 described above are denoted by the same reference numerals.

  As shown in FIG. 30, the control unit 260 is connected to the modulation amount control unit 220 instead of the light source 13. Further, the control unit 260 calculates the correction amount of the modulation amount of each liquid crystal panel 110 based on the estimated light amount calculated by the estimated light amount calculation unit 250 and the reference light amount stored in the reference light amount storage unit 240.

Specifically, the control unit 260 sets the correction amount of the modulation amount of each liquid crystal panel 110 as “C _r ”, “C _g ”, and “C _b ”, and outputs each color light detected by each light receiving unit of the light amount sensor 140. _Assuming that the detected light quantity is “x _rd ”, “x _gd ”, and “x _bd ”, the modulation amount correction amount (C _r , C _g, and C _b ) of each liquid crystal panel 110 is _expressed by the following equation (54): Calculated by

  Note that the modulation amount of each liquid crystal panel 110 is controlled so that white balance is maintained.

(Operation of projection display device)
The operation of the projection display apparatus according to the fifteenth embodiment of the invention will be described below with reference to the drawings. FIG. 31 is a flowchart showing the operation of the projection display apparatus 100 according to the fifteenth embodiment of the invention. In FIG. 31, the same steps as those in FIG. 29 are given the same step numbers.

  As shown in FIG. 31, in step 180, the projection display apparatus 100 corrects the modulation amount of each liquid crystal panel 110 based on the estimated light amount calculated in step 140 and the detected light amount detected in step 150. Calculate the amount.

Specifically, the projection display device 100 detects the amount of correction of the modulation amount of each liquid crystal panel 110 as “C _r ”, “C _g ”, and “C _b ” and is detected by each light receiving unit of the light amount sensor 140. When the detected light amount of each color light is “x _rd ”, “x _gd ”, and “x _bd ”, the modulation amount correction amount (C _r , C _g, and C _b ) of each liquid crystal panel 110 is _expressed by the following formula ( 54).

  Note that the modulation amount of each liquid crystal panel 110 is controlled so that white balance is maintained.

(Sixteenth embodiment)
The sixteenth embodiment of the present invention will be described below with reference to the drawings. In the following description, differences between the above-described fourteenth embodiment and fifteenth embodiment will be mainly described.

  Specifically, although not particularly mentioned in the fourteenth embodiment described above, in the sixteenth embodiment, the control unit 260 controls the amount of light emitted by each light source 13 at the timing of a scene change.

(Function of projection display device)
The configuration of the projection display apparatus according to the sixteenth embodiment of the invention will be described below with reference to the drawings. FIG. 32 is a block diagram showing a configuration of a projection display apparatus 100 according to the sixteenth embodiment of the present invention. In FIG. 32, it should be noted that the same components as those in FIG.

  Specifically, the projection display apparatus 100 includes a scene change determination unit 280 in addition to the configuration shown in FIG.

  The scene change determination unit 280 determines whether or not the video displayed on the screen is switched based on the video signal acquired for each frame from the video signal input unit 210 (that is, a scene change).

  Specifically, the scene change determination unit 280 determines whether the video signal in one frame (the modulation amount of the liquid crystal panel 110) and the video signal in another frame continuous with the one frame (the modulation amount of the liquid crystal panel 110). The difference (modulation amount difference) is calculated. Subsequently, the scene change determination unit 280 determines whether the modulation amount difference exceeds a predetermined threshold value.

  Further, when the modulation amount difference exceeds the predetermined threshold, the scene change determination unit 280 notifies the control unit 260 that the modulation amount difference exceeds the predetermined threshold.

  The control unit 260 controls the amount of light emitted from each light source 13 (output of each light source 13) at a timing when it is notified that the modulation amount difference exceeds a predetermined threshold.

(Function and effect)
According to the projection display apparatus 100 according to the sixteenth embodiment of the present invention, the control unit 260 controls the amount of light emitted from each light source 13 (output of each light source 13) at the timing of a scene change. To do. Therefore, it is possible to suppress the viewer from feeling uncomfortable by switching the light amount of the light emitted from each light source 13.

(Other embodiments)
Although the present invention has been described with reference to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the first to sixteenth embodiments described above, the projection display device is a three-plate type provided with a plurality of light modulation elements (liquid crystal panels), but is not limited thereto. It is not a thing. Specifically, the projection display device may be a single plate type provided with a single light modulation element (liquid crystal panel).

The block diagram which shows the function structure of the time-dependent correction apparatus of the 1st Embodiment of this invention. The block diagram of the projection type display apparatus provided with the liquid crystal projector which mounts the time-dependent correction apparatus of the said embodiment. The top view of the liquid crystal projector which mounts the time-dependent change correction apparatus of the said embodiment. The front view of the liquid crystal projector which mounts the temporal change correction apparatus of the said embodiment. The flowchart of the time-dependent change correction process of the light source output by the time-change correction apparatus of the said embodiment. Explanatory drawing which illustrates the contribution of each part of the liquid crystal panel in the aging correction apparatus of the above embodiment. The top view of the liquid crystal projector which mounts the aging correction apparatus of the 2nd Embodiment of this invention. The front view of the liquid crystal projector which mounts the temporal change correction apparatus of the said embodiment. The flowchart of the time-dependent change correction process of the light source output by the time-change correction apparatus of the said embodiment. Explanatory drawing which illustrates the contribution of each part of the liquid crystal panel in the aging correction apparatus of the above embodiment. The block diagram which shows the function structure of the time-dependent correction apparatus of the 3rd Embodiment of this invention. The flowchart of the time-dependent change correction process of the light source output by the time-change correction apparatus of the said embodiment. The block diagram which shows the function structure of the time-dependent correction apparatus of the 5th Embodiment of this invention. The flowchart of the time-dependent change correction process of the light source output by the time-change correction apparatus of the said embodiment. The top view which showed the installation place of the optical sensor in the aging correction apparatus of the 6th Embodiment of this invention by contrast. The front view which contrasted and showed the installation place of the optical sensor in the time-dependent correction apparatus of the said embodiment. The front view which shows an example of the preferable area | region division of a liquid crystal panel in the time-dependent correction apparatus of the 7th Embodiment of this invention. The front view which shows another example of the preferable area | region division of a liquid crystal panel in the time-dependent correction apparatus of the said embodiment. The front view which shows another example of the preferable area | region division of a liquid crystal panel in the time-dependent correction apparatus of the said embodiment. The front view which shows another example of the preferable area | region division of a liquid crystal panel in the time-dependent correction apparatus of the said embodiment. The block diagram of the time-dependent change correction apparatus of the 8th Embodiment of this invention. The flowchart of the time-dependent change correction process of the light source output by the time-change correction apparatus of the said embodiment. It is a figure which shows the structure of the optical system which concerns on the 9th Embodiment of this invention. It is a figure which shows the structure of the optical system which concerns on the 10th Embodiment of this invention. It is a figure which shows the structure of the optical system which concerns on the 11th Embodiment of this invention. It is a figure which shows the structure of the optical system which concerns on the 12th Embodiment of this invention. It is a figure which shows the structure of the optical system which concerns on the 13th Embodiment of this invention. It is a block diagram which shows the function of the projection type display apparatus 100 in 14th Embodiment of this invention. It is a flowchart which shows operation | movement of the projection type display apparatus 100 in the 14th Embodiment of this invention. It is a block diagram which shows the function of the projection type display apparatus 100 in 15th Embodiment of this invention. It is a flowchart which shows operation | movement of the projection type display apparatus 100 in the 15th Embodiment of this invention. It is a block diagram which shows the function of the projection type display apparatus 100 in the 16th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal projector, 11 ... Liquid crystal panel, 13 ... Light source, 15 ... Color composition prism, 16 ... Optical sensor, 20 ... Contribution storage part, 20A ... Division Number setting unit, 21 ... Light source control unit, 22 ... Average signal value calculation unit, 23 ... Light quantity measurement unit, 24 ... Initial adjustment value storage unit, 24 '... Initial adjustment value Optical data storage unit 25 ... Memory 26 ... Degradation rate calculation unit 27 ... Blanking detection unit 31 ... Input image data 32 ... Output image 35 ... Sensing Range: 36 ... Leakage light, 100 ... Projection display device, 110 ... Liquid crystal panel, 111 ... Reflective liquid crystal panel, 120 ... Dichroic prism, 121 ... Light incident surface, 122: Light exit surface, 123: Mirror surface, 124 ... Side surface 130: Projection lens unit, 131: Diaphragm unit, 132: Projection lens, 140: Light quantity sensor, 140r, g, b: Light receiving unit, 150: Dichroic prism, 151. Light incident surface, 152 ... light exit surface, 160 ... dichroic mirror, 210 ... video signal input unit, 220 ... modulation amount control unit, 230 ... contribution storage unit, 240 ... Reference light amount storage unit 250 ... Estimated light amount calculation unit 260 ... Control unit 280 ... Scene change determination unit

Claims (13)

Based on a plurality of light sources, a light modulation element that modulates light emitted from the plurality of light sources in units of pixels, and a video signal in units of frames, the light modulation element controls a modulation amount of light that is modulated in units of pixels. A projection display device comprising: a modulation amount control unit; a light combining unit that combines light modulated by the light modulation element; and a projection lens unit that projects light emitted from the light combining unit onto a screen. ,
A light amount detector for detecting the amount of light combined by the light combiner;
A contribution degree storage unit that associates and stores a divided region that is a region into which the light modulation element is divided and a reaching contribution degree that is a degree that the light modulated in the divided region reaches the light amount detection unit;
Based on the video signal in units of frames, the reaching contribution degree stored in the contribution degree storage unit, and the light amount detected by the light amount detection unit, an estimated light amount of light emitted from the light source is determined for each light source. An estimated light amount calculation unit to calculate,
The estimated light amount calculated for each light source by the estimated light amount calculation unit is compared with a reference light amount of light emitted from the light source, and a deterioration rate that is a ratio of the light amount deteriorated from the reference light amount is determined for each light source. A deterioration rate calculation unit to calculate,
A projection display device comprising: a light amount control unit that controls the amount of light emitted from the plurality of light sources according to the deterioration rate calculated for each light source by the deterioration rate calculation unit. Based on a plurality of light sources, a light modulation element that modulates light emitted from the plurality of light sources in units of pixels, and a video signal in units of frames, the light modulation element controls a modulation amount of light that is modulated in units of pixels. A projection display device comprising: a modulation amount control unit; a light combining unit that combines light modulated by the light modulation element; and a projection lens unit that projects light emitted from the light combining unit onto a screen. ,
A light amount detector for detecting the amount of light combined by the light combiner;
A contribution degree storage unit that associates and stores a divided region that is a region into which the light modulation element is divided and a reaching contribution degree that is a degree that the light modulated in the divided region reaches the light amount detection unit;
Based on the video signal in units of frames, the arrival contribution stored in the contribution storage unit, and a reference light amount of light emitted from the light source, an estimated light amount to be detected by the light amount detection unit is determined as the light source. An estimated light amount calculation unit to be calculated every time,
The estimated light amount calculated for each light source by the estimated light amount calculation unit and the light amount detected by the light amount detection unit are compared, and a deterioration rate that is a ratio of the light amount deteriorated from the reference light amount is determined for each light source. A deterioration rate calculation unit to calculate
A projection display device comprising: a light amount control unit that controls the amount of light emitted from the plurality of light sources according to the deterioration rate calculated for each light source by the deterioration rate calculation unit.   The projection display device according to claim 1, wherein the estimated light amount calculation unit calculates the estimated light amount based on a video signal input in a calculation target frame that is a plurality of frames. . The modulation amount control unit is a blanking period in which the scanning position of the light modulation element is returned to the reference position from the end of scanning of one frame to the start of scanning of another frame continuous with the one frame. And individually controlling the modulation amount of the light modulation element,
The estimated light amount calculation unit includes a video signal input in a calculation target frame that is the one frame or the other frame, the reaching contribution degree stored in the contribution degree storage unit, and the calculation target frame. The estimated light amount is calculated based on a light amount detected by a light amount detection unit, a video signal input during the blanking period, and a light amount detected by the light amount detection unit during the blanking period. The projection display device according to claim 1.   The contribution storage unit stores a pixel position of the light modulation element and an arrival contribution which is a degree at which light modulated at the pixel position reaches the light amount detection unit in association with each other. The projection display device according to claim 1 or 2.   The number of the divided regions is set such that the larger the amount of light detected by the light amount detection unit when all the plurality of light sources are turned on, the larger the number of the divided regions. The projection display device according to claim 1 or 2.   The size of the divided area is set such that the larger the distance from the light amount detection unit to the divided area is, the larger the size of the divided area is. Projection display device. The projection lens unit has a diaphragm portion that narrows a range of light projected on the screen,
The aperture section is configured by a non-light transmissive member that blocks a part of the light emitted from the light combining section,
The projection display device according to claim 1, wherein the light amount detection unit is provided in the diaphragm unit.   The said light quantity detection part is arrange | positioned outside the area | region through which the light radiate | emitted from the said photosynthesis part passes, and detects the light quantity of the diffused light of the light radiate | emitted from the said photosynthesis part, The Claim 1 or Claim characterized by the above-mentioned. Item 3. A projection display device according to Item 2. The light combining unit is a dichroic prism having a plurality of reflection surfaces that transmit light of a specific wavelength and reflect light of other wavelengths,
The light amount detection unit is provided facing a side surface of the dichroic prism except for a light incident surface on which light is incident and a light emitting surface from which light is emitted, and a position where the plurality of reflection surfaces intersect The projection display device according to claim 1, wherein the projection display unit is provided closer to the projection lens unit. The light amount detection unit includes a plurality of light receiving units corresponding to the plurality of light sources,
The projection display device according to claim 10, wherein the plurality of light receiving units are sequentially arranged along a direction perpendicular to the light emitting surface of the light combining unit. The light amount detection unit includes a plurality of light receiving units corresponding to the plurality of light sources,
The plurality of light receiving units are sequentially arranged along a direction parallel to the light emitting surface of the light combining unit, and the optical path length from the light receiving unit to the light modulation element corresponding to the light receiving unit is increased. The projection display device according to claim 10, wherein the projection display device is arranged as follows. It is determined whether a modulation amount difference, which is a difference between a modulation amount of the light modulation element in one frame and a modulation amount of the light modulation element in another frame continuous with the one frame, exceeds a predetermined threshold value. A scene change determination unit,
The light amount control unit controls the amount of light emitted from the plurality of light sources between the one frame and the other frame when the modulation amount difference exceeds the predetermined threshold value. The projection display device according to claim 1 or 2.

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