JP2012150300A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device suppressing a temperature rise of an optical member by adjusting gain of images.SOLUTION: A projection type display device 100 comprises: an optical system 10 including an image generation part 11 for generating images and a polarizing plate 12 on which images are made incident; a temperature detection part 2 for detecting a temperature; a gain adjustment part 3 for adjusting the gain of the images generated in the image generation part 11; a control part 4 for controlling the gain adjustment part 3; and a housing 1 for housing the optical system 10, the gain adjustment part 3 and the control part 4. In the projection type display device 100, the control part 4 controls the gain adjustment part 3 to lower the gain of the images when the temperature detected by the temperature detection part 2 is a predetermined threshold or more.

Description

  The present invention relates to a projection display device, and more particularly to a projection display device in which a temperature rise of an optical member is suppressed.

  Conventionally, an optical member such as a polarizing plate provided on the light exit side of a liquid crystal panel in a color separation optical system is deteriorated as the temperature rises due to incident light and continues to be used in a high temperature state. It was a bad effect of high image quality. For example, Patent Document 1 discloses a cooling method for controlling the rotation of a cooling fan and cooling an optical member including a polarizing plate. Patent Document 2 discloses a control method for controlling the amount of light from the light source in addition to the rotation control of the cooling fan.

JP 2003-5146 A JP 2010-91882 A

  However, in Patent Document 1, since it is necessary to provide a mechanism for cooling the optical member inside the apparatus, the internal structure of the apparatus becomes complicated. In addition, the liquid crystal panel needs to maintain a certain temperature in order to display a high-quality image. When the temperature of the optical member is suppressed by increasing / decreasing the rotation of the fan, it is complicated considering the temperature change of the liquid crystal panel. Control is required.

  Moreover, in patent document 2, not only rotation control of a fan but the light quantity from the light source which injects into an optical member is adjusted, and the temperature rise of an optical member is controlled. However, a complex algorithm is required to control the temperature of the liquid crystal panel, which is affected by the increase / decrease in the number of rotations of the cooling fan and the amount of light from the light source, so as to be kept constant in order to display a high-quality image.

  Therefore, the present invention provides a projection display device in which the gain of the image is adjusted to suppress the temperature rise of the optical member.

  A projection display device according to one aspect of the present invention is generated by an image generation unit that generates an image, an optical system including an optical member on which the image is incident, a temperature detection unit that detects temperature, and the image generation unit. A gain adjustment unit that adjusts the gain of the video, a control unit that controls the gain adjustment unit, a housing that houses the optical system, the gain adjustment unit, and the control unit, The control unit controls the gain adjusting unit to decrease the gain of the video when the temperature detected by the temperature detecting unit is equal to or higher than a predetermined threshold.

  Other objects and features of the present invention are illustrated in the following examples.

  ADVANTAGE OF THE INVENTION According to this invention, the projection type display apparatus which adjusted the gain of the image | video and suppressed the temperature rise of the optical member can be provided.

1 is a block diagram of a projection display device in Embodiment 1. FIG. 3 is a flowchart of gain correction by the projection display device according to the first embodiment. It is a block diagram of the projection type display apparatus in Example 2. FIG. It is a block diagram of the projection type display apparatus in Example 2. FIG. 10 is a flowchart of gain correction by the projection display device according to the second embodiment. 6 is a relationship diagram between a temperature difference of a polarizing plate and a gain correction coefficient in Example 2. FIG. FIG. 6 is a relationship diagram between a gain correction coefficient and the amount of light incident on a polarizing plate in Example 2. 12 is a flowchart of gain correction by the projection display device according to the third embodiment. FIG. 10 is a relationship diagram between a current temperature and a gain correction coefficient in the third embodiment. FIG. 10 is a relationship diagram between a gain correction coefficient and an incident light amount in Example 3. FIG. 10 is a block diagram of a projection display device in Embodiment 4.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant description is omitted.

  First, with reference to FIG. 1, the projection type display apparatus in Example 1 of this invention is demonstrated. FIG. 1 is a block diagram of a projection display device 100 in this embodiment. Reference numeral 1 denotes a housing of the projection display apparatus, which houses an optical system 10, a gain adjustment unit 3, and a control unit 4 which will be described later. Reference numeral 2 denotes a temperature detection unit that detects the temperature of a predetermined member (optical member) inside the housing 1. In this embodiment, the temperature detection unit 2 detects the temperature of the polarizing plate provided on the light emission side of the image generation unit 11 described later. However, the present embodiment is not limited to this, and the temperature of another optical member such as an ND filter may be detected.

  Reference numeral 3 denotes a gain adjustment unit that adjusts the gain of a video (for each color) generated by the video generation unit 11 described later. 4 acquires temperature information from the temperature detection unit 2, that is, the temperature detected by the temperature detection unit 2, and gain adjustment information to the gain adjustment unit 3 so as to adjust the gain of the video according to the acquired temperature. It is a control part which transmits. As will be described later, when the temperature detected by the temperature detection unit 2 is equal to or higher than a predetermined threshold, the control unit 4 controls the gain adjustment unit 3 so as to decrease the gain of the video. As described above, the control unit 4 controls the gain adjustment unit 3, whereby deterioration of the optical member provided on the light emission side of the image generation unit 11 can be suppressed.

  Reference numeral 11 denotes a video generation unit including a display unit (not shown) such as a panel for generating video. A polarizing plate (optical member) 12 is provided on the light emission side of the video generation unit 11 and on which the video generated by the video generation unit 11 is incident. In addition to the polarizing plate 12, an optical member such as an ND filter may be provided on the light emission side of the video generation unit 11. Reference numeral 10 denotes an optical system, and the optical system 10 includes an image generation unit 11 and optical members such as a polarizing plate 12 and an ND filter provided on the light emission side of the image generation unit 11.

  Next, with reference to FIG. 2, the gain correction of each color by the projection display apparatus 100 will be described. FIG. 2 is a flowchart of a gain control method (gain correction method) for detecting the temperature of a predetermined member (optical member) inside the projection display apparatus 100 and controlling the gain value of each color.

  First, in step S001, the temperature detection unit 2 detects the current actual temperature (current temperature t) of the polarizing plate 12 provided on the light emission side of the liquid crystal panel (image generation unit 11), and the control unit 4 detects the detected temperature. Get current temperature information. The actual temperature is a temperature detected by the temperature detector 2. Subsequently, in step S002, the control unit 4 compares the current temperature t acquired in step S001 with a threshold temperature ta for determining the start and stop of gain correction control. If it is determined in step S002 that the current temperature t is equal to or higher than the threshold temperature ta, the process proceeds to step S003. On the other hand, if it is determined that the current temperature t is lower than the threshold temperature ta, the process returns to step S001. In this embodiment, the temperature threshold ta is determined in advance in consideration of the relationship between the temperature and the deterioration of the polarizing plate 12.

  In step S003, the control unit 4 determines the following based on the minimum gain correction coefficient a1 (correction coefficient per temperature unit) and the temperature difference d (d = t−ta) between the current temperature t and the threshold temperature ta. A gain correction coefficient a is obtained as expressed by equation (1).

a = 1− (d × a1) (1)
The minimum gain correction coefficient a1 is, for example, a correction coefficient in units of 0.1 ° C., but is not limited to this. The gain correction coefficient a can be calculated as appropriate in step S002 (and other steps), but a fixed value may be stored in advance in the storage unit for each temperature of the polarizing plate 12. Subsequently, in step S004, the control unit 4 uses the gain correction coefficient a calculated in step S003 for the gain value g (uncorrected gain value) when the gain correction of each color is not performed (before gain correction). The correction gain value gm is calculated using equation (2).

gm = g × a (2)
In step S005, the control unit 4 updates the gain value of each color of the video generated by the video generation unit 11 to the correction gain value gm of each color calculated in step S004. Thereby, the light quantity which injects into the polarizing plate 12 can be suppressed, and the temperature rise of the polarizing plate 12 can be prevented.

  In the present embodiment, the polarizing plate 12 provided on the light emission side of the video generation unit 11 is a target for suppressing the temperature rise, but the present invention is not limited to this. An ND filter or other optical member provided on the light emitting side of the image generation unit 11 may be a target for suppressing temperature rise (a target for preventing deterioration), and gain correction may be performed according to the temperature of these optical members. The video generation unit 11 can be configured with three liquid crystal panels of R (red), G (green), and B (blue), but is not limited thereto. The video generation unit may be a single liquid crystal panel (single plate configuration) that generates RGB three-color video in a time division manner, or may be one to three DLPs (Digital Light Processing).

  As described above, according to the projection display device of the present embodiment, the amount of light incident on the polarizing plate can be adjusted based on the temperature of the polarizing plate. For this reason, by adjusting the gain value of each color according to the temperature of the polarizing plate, the amount of light incident on the polarizing plate can be reduced, and deterioration of the polarizing plate can be suppressed.

  In addition, although Example 1 demonstrated the example which adjusts a gain value according to the temperature of a polarizing plate, it is not restricted to a polarizing plate, According to the temperature of other optical members (for example, ND filter etc.) which are easy to deteriorate by temperature rise. The gain value may be adjusted.

  Next, a projection type display apparatus according to Embodiment 2 of the present invention will be described with reference to FIGS.

  FIG. 3A is a block diagram of the projection display device 200 in this embodiment. Reference numeral 1 denotes a housing of the projection display device 200, and 2 denotes a temperature detection unit that detects the temperature of a predetermined member (optical member) inside the housing 1. In this embodiment, the temperature detection unit 2 detects the temperature of the polarizing plate 12 (optical member) provided on the light emission side of the liquid crystal panel 110 described later. Reference numeral 3 denotes a gain adjustment unit that adjusts the gain of each of the R, G, and B liquid crystal panels 110. Reference numeral 4 denotes a control unit. The control unit 4 acquires temperature information from the temperature detection unit 2, and gains of images generated in each of R, G, and B liquid crystal panels 110 described later according to the acquired temperature. The gain adjustment unit 3 is controlled so as to adjust the gain (gain adjustment information is transmitted to the gain adjustment unit 3). Such an operation of the control unit 4 can suppress deterioration of the polarizing plate 12 provided on the light emission side of the liquid crystal panel 110. Reference numeral 110 denotes a liquid crystal panel provided for each of R, G, and B colors. Reference numeral 12 denotes a polarizing plate provided on the light exit side of the R, G, B liquid crystal panel 110. A color separation optical system 101 includes an R, G, B liquid crystal panel 110 and a polarizing plate 12 provided on the light emission side of the liquid crystal panel 110.

  FIG. 3B is a configuration diagram of the projection display device according to the second embodiment. A light beam emitted in all directions from a light source (light emitting part of a lamp) 1001 is emitted as substantially parallel light by a parabolic reflector 1002. This parallel light beam enters an IR cut filter 1003 that cuts UV, and is split into a plurality of partial light beams by the first lens array 1004, and each of the partial light beams is collected. Each split light beam is condensed near the second lens array 1005, and each partial light beam forms a light source image (secondary light source image). The split luminous flux emitted from the second lens array 1005 is condensed by the condenser lens 1006 and illuminates the reflective liquid crystal panel 110 which is a video production unit in a superimposed manner. The illumination optical system is configured by the condenser lens 1006 from the IR cut filter 1003 described above.

  A dichroic mirror 1007 in FIG. 1 is a dichroic mirror that reflects B and R color light and transmits G color light, and 1008 is an incident side polarizing plate G for G in which a polarizing element is attached to a transparent substrate. Only S-polarized light is transmitted. Reference numeral 1009 denotes a first polarization beam splitter that transmits P-polarized light and reflects S-polarized light, and has a polarization separation surface.

  Reference numerals 110R, 110G, and 110B denote a red reflective liquid crystal panel (image generation unit) that reflects incident light and modulates an image, a green reflective liquid crystal panel, and a blue reflective liquid crystal panel. 110R, 110G, and 110B are a quarter wavelength plate for red, a quarter wavelength plate for green, and a quarter wavelength plate for blue, respectively. 1011 attaches a polarizing element that transmits S-polarized light to a transparent substrate, and the incident-side polarizing plate 1012 converts the polarization direction of B color light by 90 degrees, and does not convert the polarization direction of R color light. It is a sex phase difference plate. Reference numeral 1013 denotes a second polarization beam splitter that transmits P-polarized light and reflects S-polarized light, and has a polarization separation surface. Reference numeral 1014 denotes a second color selective phase difference plate that converts the polarization direction of the R color light by 90 degrees and does not convert the polarization direction of the B color light.

  Reference numeral 12 denotes an output-side polarizing plate (polarizing element) that transmits only S-polarized light. Reference numeral 1015 denotes a third polarization beam splitter (color synthesis means) that transmits P-polarized light and reflects S-polarized light, and has a polarization separation surface.

  The optical component from the dichroic mirror 1007 to the third polarizing beam splitter 1015 described above constitutes the color separation / synthesis optical system 101.

  Reference numeral 1016 denotes a projection lens optical system, and the illumination optical system, color separation / synthesis optical system, and projection lens optical system constitute an image display optical system.

  Reference numeral 2 denotes a temperature detection unit that detects the temperature of the polarizing plate 12. A gain adjusting unit 3 controls the gain of the liquid crystal panel 110 via the gain adjusting unit 3 according to the temperature acquired by the control unit 4 from the temperature detecting unit 2, thereby providing the polarizing plate 12 provided on the light emission side. To prevent deterioration. Next, gain correction for the R, G, B liquid crystal panel 110 by the projection display device 200 will be described with reference to FIG. FIG. 4 is a flowchart of a gain control method (gain correction method) for detecting the temperature of a predetermined member (optical member) inside the projection display apparatus 200 and controlling the gain values of R, G, and B.

  First, in step S <b> 101, the control unit 4 acquires the current temperature (actual temperature) of the polarizing plate 12 provided on the light emission side of the liquid crystal panel 110. Subsequently, in step S102, the control unit 4 compares the current temperature t acquired in step S101 with the threshold temperature ta, and if it is determined that the current temperature t is equal to or higher than the threshold temperature ta, the process proceeds to step S103. On the other hand, if the control unit 4 determines that the current temperature t is lower than the threshold temperature ta, the control unit 4 returns to step S101. As in the first embodiment, the threshold temperature ta is appropriately determined in consideration of the relationship between the temperature and the deterioration of the polarizing plate 12.

  In step S <b> 103, the control unit 4 calculates the gain correction coefficient a as shown in the above equation (1) based on the minimum gain correction coefficient a <b> 1 and the temperature difference d between the current temperature t and the threshold temperature ta. Subsequently, in step S104, the control unit 4 applies the gain correction coefficient a calculated in step S103 to each gain value (uncorrected gain value g) of the R, G, and B liquid crystal panels 110 before gain correction. Is used to calculate the correction gain value gm as in the above equation (2). In step S105, the control unit 4 updates the current gain value of each of the R, G, and B liquid crystal panels 110 to the correction gain value gm calculated in step S104. In this way, the amount of light incident on the polarizing plate 12 can be reduced to prevent the temperature of the polarizing plate 12 from rising.

  FIG. 5 is a graph showing the relationship between the temperature difference d of the polarizing plate 12 (the difference between the current temperature t and the threshold temperature ta) and the gain correction coefficient a. As the temperature difference d of the polarizing plate 12 increases, the value of the gain correction coefficient a changes so as to decrease. FIG. 6 is a graph showing the relationship between the gain correction coefficient a and the amount of light incident on the polarizing plate 12. As shown in FIG. 6, it is assumed that the gain correction coefficient a of R, G, and B before gain correction is 1, and the value of light quantity is 100%. At this time, by correcting the gain values of R, G, and B using the gain correction coefficient a (according to the gain correction coefficient), the amount of light incident on the polarizing plate 12 changes as shown in FIG.

  As described above, according to the projection display device of the present embodiment, the temperature of the polarizing plate can be detected and the amount of light incident on the polarizing plate can be adjusted. For this reason, it is possible to adjust the gain values of R, G, and B according to the temperature of the polarizing plate, to reduce the amount of light incident on the polarizing plate, and to suppress the deterioration of the polarizing plate. Moreover, the projection type display apparatus of the present embodiment does not require a special mechanism for cooling the polarizing plate, and can suppress the temperature rise of the polarizing plate by simple control.

  In the second embodiment, the example in which the gain value is adjusted according to the temperature of the polarizing plate has been described. For example, in addition to the polarizing plate 12, the temperature of the plastic lens used in the projection lens optical system 1016 (not shown) is used. The gain value may be adjusted according to the above. Or you may adjust a gain value according to the temperature of the polarizing plate arrange | positioned between a projection lens and a screen for 3D image display. That is, the gain value may be adjusted according to the temperature of the optical member for which deterioration is to be prevented.

  The location of the temperature detection unit 2 is not limited to the location shown in FIG. 3B, but may be a location where the temperature of the target optical member that is desired to suppress the temperature rise can be detected. Further, the temperature around the optical member (polarizing plate) may be detected as in the second embodiment, or the temperature of the optical member may be directly detected.

  Next, with reference to FIG. 7, the gain correction in the third embodiment of the present invention will be described. FIG. 7 is a flowchart of a gain control method (gain correction method) for controlling RGB gain values by the projection display apparatus of the present embodiment. In the present embodiment, when the temperature detected by the temperature detection unit 2 is equal to or higher than a predetermined threshold, the control unit 4 controls the gain adjustment unit 3 so as to decrease the gain of the video in stages.

  First, in step S <b> 201, the control unit 4 acquires the current temperature t of the polarizing plate 12 provided on the light emission side of the liquid crystal panel 110 from the temperature detection unit 2. Subsequently, in step S202, the control unit 4 determines that the current temperature t acquired in step S201 is higher than the follow-up correction temperature tm by the maximum correction temperature width tw or more, that is, the difference t-tm between the current temperature t and the follow-up correction temperature tm. It is determined whether the temperature is equal to or greater than the maximum correction temperature width tw. This determination is made based on the temperature difference d. As a result of the determination, if the current temperature t is higher than the follow-up correction temperature tm by the maximum correction temperature width tw or more, the process proceeds to step S203. On the other hand, if the current temperature t is lower than the maximum correction temperature width tw than the follow-up correction temperature tm, the process proceeds to step S204.

  In step S204, the control unit 4 determines whether the current temperature t acquired in step S201 is lower than the follow-up correction temperature tm by the maximum correction temperature width tw or more, that is, the difference tm-t between the follow-up correction temperature tm and the current temperature t is the maximum correction. It is determined whether or not the temperature width is tw or more. This determination is made based on the temperature difference d. As a result of the determination, if the current temperature t is lower than the follow-up correction temperature tm by the maximum correction temperature width tw or more, the process proceeds to step S205. On the other hand, if the current temperature t is higher than the maximum correction temperature width tw than the follow-up correction temperature tm, the process returns to S201. Here, the maximum correction temperature width tw means that when the current temperature t is equal to or higher than the threshold temperature ta, gain correction of the temperature difference between the current temperature t and the follow-up correction temperature tm is performed in stages in several steps. The maximum temperature range that can be corrected at one time. The follow-up correction temperature tm is a temperature value that is currently undergoing follow-up correction when performing gain correction step by step in units of the maximum correction temperature width tw while following the temperature difference with respect to the current temperature t.

  If the current temperature t is higher than the tracking correction temperature tm by the maximum correction temperature width tw in step S202, the control unit 4 adds the maximum correction temperature width tw to the tracking correction temperature tm in step S203 (the tracking correction temperature is changed to the tracking correction temperature tm). Update). If the current temperature t is equal to or higher than the temperature threshold ta but is lower than the follow-up correction temperature tm by the maximum correction temperature width tw in step S204, the control unit 4 determines from the follow-up correction temperature tm to the maximum correction temperature in step S205. The width tw is subtracted (following correction temperature is updated). In step S206, the control unit 4 compares the follow-up correction temperature tm with the threshold temperature ta. If the follow-up correction temperature tm is equal to or higher than the threshold temperature ta, the process proceeds to step S207. On the other hand, if the follow-up correction temperature tm is lower than the temperature threshold ta, the process proceeds to step S208.

  In step S207, the control unit 4 performs the above-described operation based on the minimum gain correction coefficient a1 (correction coefficient per temperature unit) and the temperature difference d (d = tm−ta) between the follow-up correction temperature tm and the threshold temperature ta. The gain correction coefficient a is obtained as expressed by the equation (1). In Step S208, control part 4 returns the value of follow-up correction temperature tm updated in Step S203 or Step S205 to the state before updating. After this process is completed, the process returns to step S201 and the correction process is resumed.

  In step S209, the control unit 4 uses the gain correction coefficient a calculated in step S207 for the gain value g (uncorrected gain value) when the gain correction of each color is not performed (before gain correction). A correction gain value gm is calculated. The correction gain values gm for R, G, and B are calculated as expressed by the above equation (2). In step S210, the control unit 4 updates the R, G, and B gain values of the video generated by the video generation unit 11 to the R, G, and B correction gain values gm calculated in step S209. After the gain adjustment, the control unit 4 returns to step S201 and repeats the above flow.

  FIG. 8 is a graph showing the relationship between the current temperature (temperature difference d) of the polarizing plate and the gain correction coefficient a in this example. In FIG. 8, when the temperature difference d between the current temperature t of the polarizing plate and the follow-up correction temperature tm is d3, the gain correction is performed using the gain correction coefficient a3 corresponding to the temperature difference d3. At this time, the control unit 4 updates the temperature difference d between the current temperature t and the follow-up correction temperature tm step by step as d1, d2, and d3, and the gain correction coefficient a is also stepped as a1, a2, and a3. Specifically, the gain values of R, G, and B are corrected. FIG. 9 is a graph showing the relationship between the gain correction coefficient a and the amount of light incident on the polarizing plate at this time. As shown in FIG. 9, it can be seen that by changing the gain correction coefficient a of R, G, and B in stages, the amount of light incident on the polarizing plate also changes in stages.

  According to the projection type display device of the present embodiment, when the temperature of the polarizing plate is detected and the amount of light incident on the polarizing plate is adjusted, the gain is corrected step by step following the temperature change of the polarizing plate. Can do. For this reason, it is possible to suppress discomfort given to the user due to a change in luminance of the projected video. The present embodiment can be applied not only to the polarizing plate but also to other optical members such as an ND filter.

  Next, with reference to FIG. 10, the projection type display apparatus in Example 4 of this invention is demonstrated. FIG. 10 is a block diagram of the projection display apparatus 300 in the present embodiment.

  The projection display device 300 in this embodiment includes a light source deterioration determination unit 5 that determines a deterioration state of a light source (not shown) in addition to the components of the projection display device 200 of the second embodiment (FIG. 3). Yes. The temperature detection unit 2 of the projection display device 300 is provided outside the housing 1 of the projection display device 300 and detects a temperature (outside air temperature) outside the housing 1. Based on the correlation between the outside air temperature acquired from the temperature detection unit 2 and the temperature of the polarizing plate 12 and the deterioration information of the light source acquired from the light source deterioration determination unit 5, the control unit 4 applies to the polarizing plate 12 due to the deterioration of the light source. The present temperature t of the polarizing plate 12 is calculated in consideration of the amount of change in incident light. Thus, the control unit 4 calculates the temperature of the optical member such as the polarizing plate 12 from the outside air temperature, and the control unit 4 preferably calculates the temperature of the optical member based on the outside air temperature and the determination result of the light source deterioration determination unit 5. calculate.

  Then, the control unit 4 corrects the gain value based on the calculated current temperature t. In calculating the current temperature t of the polarizing plate 12, the correlation between the outside air temperature and the polarizing plate temperature and the influence on the temperature of the polarizing plate 12 due to the light amount deterioration of the light source are investigated in advance and the current temperature t of the polarizing plate 12 is calculated. Is stored in a storage unit (not shown) as a parameter for calculating. The light source deterioration determination unit 5 may be an optical sensor that detects the light amount of the light source or a counter system that counts the usage time of the light source.

  According to the projection type display device of the present embodiment, when detecting the temperature of the polarizing plate and adjusting the amount of light incident on the polarizing plate, even if the sensor for detecting the temperature of the polarizing plate is not provided, It is possible to perform gain correction by calculating the temperature of the plate. The present embodiment can be applied not only to the polarizing plate but also to other optical members such as an ND filter.

  Each of the above embodiments can be applied to a form using a transmissive liquid crystal panel. The temperature detector 2 detects the temperature of the optical member or its surrounding temperature, and the controller 4 corrects the gain value of the transmissive liquid crystal panel according to the temperature. As a result, the amount of incident light on the optical member decreases, so that deterioration can be suppressed.

  Moreover, the effect of this invention can be acquired by applying with respect to the projection type image display apparatus using the panel (video production | generation part) which can make the emission direction of image light and unnecessary light differ.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 1 Case 2 Temperature detection part 3 Gain adjustment part 4 Control part 10 Optical system 11 Image | video production | generation part 12 Polarizing plate 100 Projection type display apparatus

Claims (7)

An optical system including an image generation unit for generating an image and an optical member on which the image is incident;
A temperature detector for detecting the temperature;
A gain adjusting unit for adjusting the gain of the video generated by the video generating unit;
A control unit for controlling the gain adjustment unit;
A housing that houses the optical system, the gain adjustment unit, and the control unit;
The control unit controls the gain adjustment unit to decrease the gain of the video when the temperature detected by the temperature detection unit is equal to or higher than a predetermined threshold. The video generation unit is an R, G, B liquid crystal panel,
2. The projection type according to claim 1, wherein the control unit controls the gain adjustment unit to adjust the gain of the video generated in each of the R, G, and B liquid crystal panels. Display device.   The projection display device according to claim 1, wherein the temperature detection unit is housed in the casing and detects a temperature of the optical member. The temperature detection unit is provided outside the casing, detects an outside air temperature outside the casing,
The projection display device according to claim 1, wherein the control unit calculates a temperature of the optical member from the outside air temperature. A light source deterioration determination unit for determining a deterioration state of the light source;
The projection display device according to claim 4, wherein the control unit calculates a temperature of the optical member based on the outside air temperature and a determination result of the light source deterioration determination unit.   The control unit controls the gain adjustment unit so that the gain of the video is gradually reduced as time passes when the temperature detected by the temperature detection unit is equal to or higher than a predetermined threshold. The projection display device according to any one of claims 1 to 5.   The projection type display device according to claim 1, wherein the optical member is a polarizing plate.