JP2010054712A - Projection type video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection type video display device capable of detecting degree of degradation in an optical element. <P>SOLUTION: The projection type video display device 100 includes: a first optical sensor 80a provided between a light source 10 and the optical element, and measuring illuminance of light emitted from the light source 10; a second optical sensor 80b provided between the optical element and the projection optical system, and measuring illuminance of light emitted from the optical element; and a detection part 220 detecting the degree of degradation R of the optical element on the basis of the measured results Da and Db of the first optical sensor 80a and the second optical sensor 80b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a projection display apparatus having a light source, an optical element irradiated with light emitted from the light source, and a projection optical system that projects light emitted from the optical element.

  2. Description of the Related Art Conventionally, there has been known a projection display apparatus including a light source, an optical element that modulates light emitted from the light source, and a projection optical system that projects light emitted from the optical element. In general, an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like is used as a light source.

In such a projection display apparatus, the light source is deteriorated with time, so the brightness of the light source (for example, illuminance, luminance, brightness, light amount, etc.) decreases with the accumulated lighting time. Therefore, a method has been proposed in which the power supplied to the light source is increased as the integrated lighting time of the light source becomes longer (see Patent Document 1). According to this method, even if the light source is deteriorated with time, a decrease in the brightness of the light source can be suppressed.
Japanese translation of PCT publication No. 2002-506331

  On the other hand, in the above-described projection display apparatus, the light emitted from the light source is irradiated, so that the optical element also deteriorates with time. However, with the method described in Patent Document 1, although the approximate deterioration degree of the light source can be detected, the deterioration degree of the optical element cannot be detected. For this reason, measures for alleviating the progress of deterioration of the optical element and replacement of the optical element at an appropriate time cannot be performed.

  Therefore, the present invention has been made in view of the above-described situation, and an object thereof is to provide a projection display apparatus that can detect the degree of deterioration of an optical element.

  A projection display apparatus according to the features of the present invention includes a light source, an optical element irradiated with light emitted from the light source, a projection optical system that projects light emitted from the optical element, a light source, and an optical element. Between the first optical sensor that measures the brightness of light emitted from the light source and between the optical element and the projection optical system, and measures the brightness of light emitted from the optical element. The gist is to include a second optical sensor and a detection unit that detects the degree of deterioration of the optical element based on the measurement results of the first optical sensor and the second optical sensor.

  According to the projection display apparatus according to the feature of the present invention, it is possible to detect the degree of deterioration of the optical element separately from the degree of deterioration of the light source. Therefore, measures for alleviating the progress of deterioration of the optical element and replacement of the optical element at an appropriate time can be performed.

  In the characteristics of the present invention, the detection unit may detect the degree of deterioration of the optical element based on a ratio of the brightness of the light emitted from the optical element to the brightness of the light emitted from the light source.

  In the features of the present invention, a cooling device that cools the optical element and a cooling control unit that controls the cooling device are provided, and the cooling control unit cools the optical element when the degree of deterioration becomes greater than a first threshold value. The temperature to be used may be lowered.

  In the feature of the present invention, a notification device may be provided that notifies the user that the degree of deterioration detected by the detection unit is greater than the second threshold.

  In the features of the present invention, the optical element includes a red optical element that transmits red component light, a green optical element that transmits green component light, and a blue optical element that transmits blue component light. The optical sensor includes a red light sensor that measures the brightness of red component light, a green light sensor that measures the brightness of green component light, and a blue light sensor that measures the brightness of blue component light. The detection unit is based on the measurement results of the red light sensor, the green light sensor, the blue light sensor, and the first light sensor, and each of the red optical element, the green optical element, and the blue optical element is deteriorated. The degree may be detected.

  In the features of the present invention, the red optical element includes a red light modulation element that modulates red component light, the green optical element includes a green light modulation element that modulates green component light, and a blue optical element. Includes a blue light modulation element that modulates blue component light, and includes a video control unit that controls a modulation amount in each of the red light modulation element, the green light modulation element, and the blue light modulation element. The unit may control the modulation amount according to the degree of deterioration of each of the red optical element, the green optical element, and the blue optical element.

  ADVANTAGE OF THE INVENTION According to this invention, the projection type video display apparatus which can detect the degradation degree of an optical element can be provided.

  Hereinafter, a projection display apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

  However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[First Embodiment]
(Configuration of projection display device)
Hereinafter, the configuration of the projection display apparatus 100 according to the first embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of the projection display apparatus 100.

  As shown in FIG. 1, the projection display apparatus 100 includes a light source 10, a UV / IR cut filter 20, a fly-eye lens unit 30, a PBS array 40, and a plurality of liquid crystal panels 50 (a liquid crystal panel 50R, a liquid crystal). Panel 50G, liquid crystal panel 50B), cross dichroic prism 60, and projection lens unit 70.

  The light source 10 is a UHP lamp that emits white light. The light emitted from the light source 10 includes red component light, green component light, and blue component light.

  The UV / IR cut filter 20 transmits visible light components (red component light, green component light, and blue component light), and shields external light components (for example, infrared component light and ultraviolet component light).

  The fly-eye lens unit 30 makes the light emitted from the light source 10 uniform. Specifically, the fly eye lens unit 30 includes a fly eye lens 30a and a fly eye lens 30b.

  The fly-eye lens 30a and the fly-eye lens 30b are each composed of a plurality of minute lenses. Each micro lens guides the light emitted from the light source 10 so that the light emitted from the light source 10 is irradiated on the entire surface of the liquid crystal panel 50.

  The PBS array 40 aligns the polarization state of the light emitted from the fly-eye lens unit 30. For example, the PBS array 40 aligns the light emitted from the fly-eye lens unit 30 with S-polarized light.

  Further, the projection display apparatus 100 includes a mirror group (dichroic mirror 111, dichroic mirror 112, reflection mirror 121 to reflection mirror 123) and lens group (condenser lens 131 to condenser lens 133, condenser lens 140R, condenser lens 140G, A condenser lens 140B, a relay lens 151 to a relay lens 153).

  The dichroic mirror 111 transmits red component light out of the light emitted from the PBS array 40. The dichroic mirror 111 reflects green component light and blue component light in the light emitted from the PBS array 40.

  The dichroic mirror 112 transmits blue component light out of the light reflected by the dichroic mirror 111. The dichroic mirror 112 reflects green component light out of the light reflected by the dichroic mirror 111.

  The reflection mirror 121 reflects the red component light and guides the red component light to the liquid crystal panel 50R side. The reflection mirror 122 and the reflection mirror 123 reflect the blue component light and guide the blue component light to the liquid crystal panel 50B side.

  The condenser lens 131 is a lens that collects white light emitted from the light source 10. The condenser lens 132 condenses the red component light that has passed through the dichroic mirror 111. The condenser lens 133 condenses the green component light and the blue component light reflected by the dichroic mirror 111.

  The condenser lens 140R collimates the red component light so that the liquid crystal panel 50R is irradiated with the red component light. The condenser lens 140G collimates the green component light so that the liquid crystal panel 50G is irradiated with the green component light. The condenser lens 140B makes the blue component light substantially parallel so that the liquid crystal panel 50B is irradiated with the blue component light. A UV cut filter 21 that shields the ultraviolet component is provided on the light exit surface side of the condenser lens 140B.

  The relay lenses 151 to 153 substantially form an image of the blue component light on the liquid crystal panel 50B while suppressing the expansion of the blue component light.

  The liquid crystal panel 50R is a red light modulation element that modulates red component light by rotating the polarization direction of the red component light. On the light incident surface side of the liquid crystal panel 50R, a compensation plate 51R that suppresses light diffusion and improves the contrast ratio and transmittance is provided.

  An incident-side polarizing plate 52R that transmits light having one polarization direction (for example, P-polarized light) and shields light having another polarization direction (for example, S-polarized light) on the light incident surface side of the compensation plate 51R. Is provided. On the light incident surface side of the incident-side polarizing plate 52R, an incident-side pre-polarizing plate 53R that reduces the amount of light incident on the incident-side polarizing plate 52R and the thermal burden is provided.

  On the other hand, on the light exit surface side of the liquid crystal panel 50R, an exit-side pre-polarizer 54R that reduces the amount of light incident on an exit-side polarizer 55R, which will be described later, and the thermal burden is provided. On the light exit surface side of the exit side pre-polarizing plate 54R, the exit side that blocks light having one polarization direction (for example, P polarization) and transmits light having another polarization direction (for example, S polarization). A polarizing plate 55R is provided.

  Similarly, the liquid crystal panel 50G is a green light modulation element that modulates green component light by rotating the polarization direction of the green component light. A compensation plate 51G, an incident side polarizing plate 52G, and an incident side pre-polarizing plate 53G are provided on the light incident surface side of the liquid crystal panel 50G. On the other hand, an exit side pre-polarizing plate 54G and an exit side polarizing plate 55G are provided on the light exit surface side of the liquid crystal panel 50G.

  Similarly, the liquid crystal panel 50B is a blue light modulator that modulates blue component light by rotating the polarization direction of the blue component light. A compensation plate 51B, an incident side polarizing plate 52B, and an incident side pre-polarizing plate 53B are provided on the light incident surface side of the liquid crystal panel 50B. On the other hand, an emission side pre-polarizing plate 54B and an emission side polarizing plate 55B are provided on the light emission surface side of the liquid crystal panel 50B.

  The cross dichroic prism 60 combines light emitted from the liquid crystal panel 50R, the liquid crystal panel 50G, and the liquid crystal panel 50B. The cross dichroic prism 60 emits combined light to the projection lens unit 70 side.

  The projection lens unit 70 projects the combined light (image light) emitted from the cross dichroic prism 60 onto a screen or the like.

  Here, the liquid crystal panel 50, the compensation plate 51, the incident side polarizing plate 52, the incident side pre-polarizing plate 53, the output side pre-polarizing plate 54, the output side polarizing plate 55, the condenser lenses 140R and 140G, and the relay lens 153 are as follows. The optical element according to the first embodiment is configured. Such an optical element may be heated and deteriorated by irradiation with light emitted from the light source 10, and therefore is cooled by, for example, a cooling device 200 such as a cooling fan (not shown) as shown in FIG. . On the other hand, the projection lens unit 70 constitutes the projection optical system according to the first embodiment. Such a projection optical system projects light emitted from the optical element.

  Further, as shown in FIG. 1, the projection display apparatus 100 includes an optical sensor 80 (first optical sensor 80a, second optical sensor 80b).

  The first optical sensor 80 a is provided between the light source 10 and the optical element, and measures the brightness of light emitted from the light source 10. Specifically, the first optical sensor 80a according to the present embodiment is disposed between the condenser lens 131 and the dichroic mirror 111, and measures the brightness of light emitted from the condenser lens 131.

  The second optical sensor 80b is provided between the optical element and the projection optical system, and measures the brightness of the light emitted from the optical element. Specifically, the second optical sensor 80b according to the present embodiment is disposed between the cross dichroic prism 60 and the projection lens unit 70, and measures the brightness of light emitted from the cross dichroic prism 60. .

  In general, “light brightness” is represented by illuminance, luminance, brightness, light quantity, or the like. In the present embodiment, “illuminance” will be described as an example of an index of “light brightness”.

(Function of projection display device)
Hereinafter, functions of the projection display apparatus according to the first embodiment will be described with reference to the drawings. FIG. 2 is a block diagram showing the configuration of the projection display apparatus 100 (control unit 300) according to the first embodiment.

  As shown in FIG. 2, the control unit 300 includes a video control unit 210, a detection unit 220, a cooling control unit 230, and a notification control unit 240.

  The video control unit 210 acquires a video input signal including a red input signal Rin, a green input signal Gin, and a blue input signal Bin. The video controller 210 outputs a video output signal including a red output signal Rout, a green output signal Gout, and a blue output signal Bout. Accordingly, the video control unit 210 controls the liquid crystal panel 50.

  The detection unit 220 detects the degree of deterioration of the optical element. As described above, the optical elements include the liquid crystal panel 50, the compensation plate 51, the incident side polarizing plate 52, the incident side pre-polarizing plate 53, the output side pre-polarizing plate 54, the output side polarizing plate 55, the condenser lenses 140R and 140G, and the relay lens. 153. The detector 220 detects the degree of deterioration of the optical element based on the ratio of the illuminance of the light emitted from the optical element to the illuminance of the light emitted from the light source.

  Specifically, the detection unit 220 acquires a first illuminance Da indicating the illuminance of light emitted from the light source 10 (condenser lens 131) from the first optical sensor 80a. In addition, the detection unit 220 acquires the second illuminance Db indicating the illuminance of light emitted from the optical element (cross dichroic prism 60) from the second optical sensor 80b.

The detection unit 220 calculates a ratio Db / Da of the second illuminance Db to the first illuminance Da. The detection unit 220 detects the degree of deterioration of the optical element based on the ratio Db / Da. Specifically, as illustrated in FIG. 3, the detection unit 220 acquires the degree of degradation R according to the ratio Db / Da. The degree of deterioration R increases as the ratio Db / Da decreases. The ratio Db / Da is a value between the minimum value 0 and the maximum value 1. Deterioration degree R is the value of the minimum value 0 Maximum value _{R MAX.} The degree of degradation R is a minimum value 0 when the ratio Db / Da is a maximum value 1, and a maximum value R _MAX when the ratio Db / Da is a minimum value 0.

In the present embodiment, detection unit 220, if the ratio Db / Da is smaller than the value F _1, i.e., if the deterioration degree R becomes larger than the first threshold value R _1, cooling the fact Notify the control unit 230. Further, when the ratio Db / Da becomes smaller than the value F ₂ , that is, when the deterioration degree R becomes larger than the second threshold value R ₂ , the detection unit 220 notifies the notification control unit 240 to that effect. .

The cooling control unit 230 starts control of the cooling device 200 in response to the power-on of the projection display apparatus 100 or the start of image display by the image control unit 210. Specifically, the cooling control unit 230 controls the temperature of the cooling air sent from the cooling device 200 to the optical element. The temperature of the cooling air sent from the cooling device 200 to the optical element is usually controlled to a predetermined temperature. Cooling control unit 230, the deterioration degree R from the detecting unit 220 when receiving a notification that is larger than the first threshold value R _1, the temperature of the cooling air sent to the optical element below a predetermined temperature. Thereby, the cooling efficiency of the optical element is promoted.

The notification control unit 240 controls the operation of the notification device 400 for performing a predetermined notification to the user. The notification device 400 is, for example, a monitor that displays a warning message such as “The optical element needs to be replaced.” Or a speaker that emits a warning sound. Notification control unit 240, the deterioration degree R from the detecting unit 220 when receiving a notification that is larger than the second threshold value R _2, or a warning sound or displays a warning message to the notification device 400. As a result, the user is notified that the deterioration of the optical element has progressed considerably.

(Operation of projection display device)
Hereinafter, the operation of the projection display apparatus according to the first embodiment will be described with reference to the drawings. FIG. 4 is a flowchart showing the operation of the projection display apparatus 100 (control unit 300) according to the first embodiment.

  As shown in FIG. 4, in step S10, the control unit 300 acquires the first illuminance Da and the second illuminance Db.

  In step S20, the control unit 300 acquires the deterioration degree R based on the ratio Db / Da of the second illuminance Db to the first illuminance Da (see FIG. 3).

In step S30, the control unit 300 determines whether the acquired deterioration degree R is larger than the first threshold value R _1. If deterioration degree R is greater than the first threshold value _{R 1,} the process proceeds to step S40. When the deterioration degree R is the first threshold value R ₁ or less, the process ends.

  In step S40, the control unit 300 controls the cooling device 200 to improve the cooling capacity of the optical element.

In step S50, the control unit 300 determines whether the acquired deterioration degree R greater than a second threshold value R _2. If deterioration degree R is greater than the second threshold value _{R 2,} the process proceeds to step S60. When the deterioration degree R is a second threshold value R ₂ or less, the process ends.

  In step S60, the control unit 300 operates the notification device 400 to notify the user that the deterioration of the optical element has progressed considerably.

(Function and effect)
The projection display apparatus 100 according to the first embodiment is provided between a light source 10 and an optical element, and includes a first optical sensor 80a that measures the illuminance of light emitted from the light source 10, an optical element, and projection optics. A second optical sensor 80b that measures the illuminance of light emitted from the optical element, and the measurement results Da and Db of the first optical sensor 80a and the second optical sensor 80b. And a detector 220 for detecting the degree of deterioration R.

  According to the projection display apparatus 100 according to the first embodiment, the deterioration degree of the optical element can be detected separately from the deterioration degree of the light source. Therefore, measures for alleviating the progress of deterioration of the optical element and replacement of the optical element at an appropriate time can be performed.

Specifically, the cooling control unit 230 to the projection display apparatus 100, when the deterioration degree R becomes larger than the first threshold value R _1, to lower the temperature for cooling the optical element. Accordingly, the progress of the deterioration of the optical element can be mitigated.

The notification device 400 for projection display apparatus 100, when the deterioration degree R becomes larger than the second threshold value R _2, and notifies the user. Therefore, the user can recognize that the deterioration of the optical element has progressed to a considerable extent, and can replace the optical element.

[Second Embodiment]
Hereinafter, the projection display apparatus 101 according to the second embodiment will be described with reference to the drawings. In the following, differences between the first embodiment and the second embodiment described above will be mainly described. Specifically, in the second embodiment, the second light sensor 80b for measuring the brightness of light includes a red light sensor 80b _R , a green light sensor 80b _G, and a blue light sensor 80b _B. including. In the second embodiment, “light quantity” will be described as an example of an index of “light brightness”.

(Configuration of projection display device)
FIG. 5 is a schematic diagram showing a configuration of the projection display apparatus 101 according to the second embodiment. As shown in FIG. 5, the projection display apparatus 101 includes a red light sensor 80b _R , a green light sensor 80b _G, and a blue light sensor 80b _B. The red light sensor 80b _R , the green light sensor 80b _G, and the blue light sensor 80b _B constitute a second light sensor 80b.

  Here, the liquid crystal panel 50R, the compensation plate 51R, the incident-side polarizing plate 52R, the incident-side pre-polarizing plate 53R, the emission-side pre-polarizing plate 54R, the emission-side polarizing plate 55R, and the condenser lens 140R described above relate to the second embodiment. Constructs a red optical element. The red optical element transmits red component light out of the light emitted from the light source 10. The liquid crystal panel 50R is a red light modulation element that modulates the red component light by rotating the polarization direction of the red component light.

  In addition, the liquid crystal panel 50G, the compensation plate 51G, the incident-side polarizing plate 52G, the incident-side pre-polarizing plate 53G, the emission-side pre-polarizing plate 54G, the emission-side polarizing plate 55G, and the condenser lens 140G described above are green according to the second embodiment. The system optical element is configured. The green optical element transmits green component light in the light emitted from the light source 10. The liquid crystal panel 50G is a green light modulation element that modulates green component light by rotating the polarization direction of the green component light.

  Further, the liquid crystal panel 50B, the compensation plate 51B, the incident-side polarizing plate 52B, the incident-side pre-polarizing plate 53B, the emission-side pre-polarizing plate 54B, the emission-side polarizing plate 55B, and the relay lens 153 described above are blue according to the second embodiment. The system optical element is configured. The blue optical element transmits blue component light in the light emitted from the light source 10. The liquid crystal panel 50B is a blue light modulation element that modulates blue component light by rotating the polarization direction of the blue component light.

The red light sensor 80b _R is provided between the red light optical element and the projection optical system, and measures the brightness of light emitted from the red light optical element. Specifically, reddish light sensor 80b _R according to the present embodiment is disposed between the exit side polarizer 55R and the cross dichroic prism 60, the amount of light emitted from the emission side polarization plate 55R taking measurement.

The green light sensor 80b _G is provided between the green light optical element and the projection optical system, and measures the brightness of light emitted from the green light optical element. Specifically, greenish light sensor 80b _G according to the present embodiment is arranged between the exit-side polarization plate 55G and the cross dichroic prism 60, the amount of light emitted from the emission side polarization plate 55G taking measurement.

The blue light sensor 80b _B is provided between the blue optical element and the projection optical system, and measures the brightness of light emitted from the blue optical element. Specifically, the blue light sensor 80b _{B according} to the present embodiment is disposed between the emission-side polarizing plate 55B and the cross dichroic prism 60, and determines the amount of light emitted from the emission-side polarizing plate 55B. taking measurement.

(Function of projection display device)
FIG. 6 is a block diagram showing the configuration of the projection display apparatus 101 (control unit 301) according to the second embodiment. As shown in FIG. 6, the control unit 301 includes a video control unit 211 and a detection unit 221.

The video control unit 211 acquires a video input signal including a red input signal Rin, a green input signal Gin, and a blue input signal Bin. The video controller 211 outputs a video output signal including a red output signal Rout, a green output signal Gout, and a blue output signal Bout. In the present embodiment, the video control unit 211 changes the modulation amounts in the liquid crystal panel 50R, the liquid crystal panel 50G, and the liquid crystal panel 50B according to GAIN _R , GAIN _G, and GAIN _B acquired from the detection unit 221 as described later. Control.

  The detection unit 221 detects the degree of deterioration of each of the red optical element, the green optical element, and the blue optical element.

Specifically, the detection unit 221 acquires a first light amount Da indicating the amount of light emitted from the light source 10 (condenser lens 131) from the first optical sensor 80a. The detecting unit 221, a reddish light quantity D _R indicating the amount of light emitted from the reddish optical element (light-exit-side polarization plate 55R), obtained from reddish light sensor 80b _R. Similarly, the detection unit 221, a green-based light quantity D _G indicating the amount of light emitted from the green-based optical element (light-exit-side polarization plate 55G), obtained from green-based light sensor 80b _G. Similarly, the detection unit 221, the blue-based light quantity D _B indicating the amount of light emitted from the blue-based optical element (light-exit-side polarization plate 55B), obtained from bluish light sensor 80b _B.

Subsequently, the detection unit 221, and the ratio _D R / Da for the first light quantity Da reddish light amount _{D R,} and the ratio _D G / Da for the first light intensity Da of greenish light quantity _{D G,} and blue-based light quantity _{D B} A ratio D _B / Da with respect to the first light amount Da is calculated.

Next, the detection unit 221, based on the ratio _D R / Da, to detect the deterioration degree _{R R} reddish optical element. Specifically, as illustrated in FIG. 7, the detection unit 221 acquires the deterioration degree R _R according to the ratio D _R / Da. The deterioration degree R _R increases as the ratio D _R / Da decreases. The ratio D _R / Da is a value between the minimum value 0 and the maximum value F ₀ .

Similarly, the detection unit 221 acquires the degradation degree R _G of the green optical element based on the ratio D _G / Da, and the degradation degree R _B of the blue optical element based on the ratio D _B / Da.

Next, in the video control unit 211, the detection unit 221 includes a red contribution GAIN _R , a green contribution GAIN _G, and a green contribution GAIN _G for adjusting the light amounts of the red input signal Rin, the green input signal Gin, and the blue input signal Bin. Blue system contribution degree GAIN _B is calculated. In the following, the deterioration degree R _R, by comparing the deterioration degree R _G and deterioration degree R _B, where deterioration degree R _R having the greatest value will be described as an example.

First, the red contribution GAIN _R is set to “1”. Next, the green contribution GAIN _G is set to “R _G / R _R ”, and the blue contribution GAIN _B is set to “R _B / R _R ”. By using such red contribution GAIN _R , green contribution GAIN _G, and blue contribution GAIN _B , it is possible to match the light quantity of the system with a small degree of degradation to the light quantity of the system with a large degree of degradation.

Detection unit 221, the calculated reddish contribution GAIN _R, a green-based contribution GAIN _G, and blue-based contributions GAIN _B, and notifies the video controller 211. The video control unit 211 controls the modulation amount in each of the liquid crystal panel 50R, the liquid crystal panel 50G, and the liquid crystal panel 50B according to the red contribution GAIN _R , the green contribution GAIN _G, and the blue contribution GAIN _B, respectively.

(Function and effect)
In the projection display apparatus 101 according to the second embodiment, the second optical sensor 80b includes a reddish light sensor 80b _R, and green-based light sensor 80b _G, and a blue-based light sensor 80b _B. Detection unit 221, based on the ratio _D R / Da for the first light quantity Da reddish light amount _{D R,} to detect the deterioration degree _{R R} reddish optical element. Similarly, the detection unit 221, a green-based light quantity _D deterioration degree _{R G} of the green-based optical element based on the ratio _D G / Da for the first light intensity Da of _G, the ratio of the first light quantity Da bluish light quantity _{D B} Based on D _B / Da, the degradation degree R _B of the blue optical element is detected.

  Therefore, the degree of deterioration can be individually detected for each of the red optical element, the green optical element, and the blue optical element. As a result, measures for alleviating the progress of deterioration and replacement at an appropriate time can be performed for each optical element.

The detecting unit 221, the deterioration degree _{R R,} based on the deterioration degree _{R G} and deterioration degree _{R B,} calculates a reddish contribution GAIN _R, greenish contribution GAIN _G, and blue-based contributions GAIN _B. The video control unit 211 modulates the red component light, the green component light, and the blue component light constituting the video input signal according to the red contribution GAIN _R , the green contribution GAIN _G, and the blue contribution GAIN _B, respectively. Control the amount.

  Therefore, even when the red optical element, the green optical element, and the blue optical element have different degrees of deterioration, that is, when the brightness of each component light is different, in each liquid crystal panel (light modulation element), The brightness of each component light can be made uniform. Specifically, the brightness of the component light of the other system can be made equal to the brightness of the component light of the system having the greatest deterioration degree. As a result, the color of the image can be made natural.

(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 above-described embodiment, the “illuminance” and “light quantity” of light are measured by the optical sensor, but the present invention is not limited to this. The optical sensor only needs to be able to measure an index of “brightness of light”. For example, the optical sensor may be one that measures the luminance, luminous intensity, luminous flux, and the like of light.

  Moreover, although not touched in particular in 2nd Embodiment mentioned above, the control unit 301 may be provided with the cooling control part 230 and the notification control part 240 which concern on 1st Embodiment. In this case, it is possible to increase the cooling for each optical element of each system or to prompt the user to replace each optical element of each system.

  In the above-described embodiment, the liquid crystal panel 50 is used as the display device, but the present invention is not limited to this. As the display device, LCOS (Liquid Crystal on Silicon), DMD (Digital Micromirror Device), or the like may be used.

  In the embodiment described above, a solid light source is used as the light source, but the present invention is not limited to this. A UHP lamp that emits white light may be used as the light source.

  Although not particularly mentioned in the above embodiment, the cooling device 200 may have a configuration in which the optical element is cooled by supplying cooling air to the optical element using a compressor.

1 is a diagram illustrating a configuration of a projection display apparatus 100 according to a first embodiment. It is a block diagram which shows the structure of the control unit 300 which concerns on 1st Embodiment. It is a graph which shows the relationship between ratio Db / Da and degradation degree R which concerns on 1st Embodiment. It is a flowchart which shows operation | movement of the control unit 300 which concerns on 1st Embodiment. It is a figure which shows the structure of the projection type video display apparatus 101 which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the control unit 301 which concerns on 2nd Embodiment. Is a graph showing the relationship between the ratio D _{R /} Da and deterioration degree R _R according to the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Light source, 20 ... Cut filter, 21 ... UV cut filter, 30 ... Fly eye lens unit, 30a ... Fly eye lens, 30b ... Fly eye lens, 40 ... PBS array, 50 ... Liquid crystal panel, 51 ... Compensation plate, 52 ... Incident side polarizing plate, 53 ... Incident side pre-polarizing plate, 54 ... Outgoing side pre-polarizing plate, 55 ... Outgoing side polarizing plate, 60 ... Cross dichroic prism, 70 ... Projection lens unit, 80 ... Optical sensor, 80a ... First Light sensor, 80b ... second light sensor, 80b _B ... blue light sensor, 80b _G ... green light sensor, 80b _R ... red light sensor, 100, 101 ... projection display apparatus, 111, 112 ... dichroic mirror 121-123 ... reflecting mirror, 131-133 ... condenser lens, 140B, 140G, 140R ... condenser lens, 51-153 ... relay lens, 200 ... cooling device, 210, 211 ... video control unit, 220 and 221 ... detector, 230 ... cooling control unit, 240 ... notification control unit, 300, 301 ... control unit, 400 ... notification unit

Claims (6)

A light source;
An optical element irradiated with light emitted from the light source;
A projection optical system for projecting light emitted from the optical element;
A first optical sensor provided between the light source and the optical element and measuring the brightness of light emitted from the light source;
A second optical sensor provided between the optical element and the projection optical system and measuring the brightness of light emitted from the optical element;
A projection display apparatus comprising: a detection unit that detects a degree of deterioration of the optical element based on measurement results of the first optical sensor and the second optical sensor. The detection unit detects a degree of deterioration of the optical element based on a ratio of brightness of light emitted from the optical element to brightness of light emitted from the light source. The projection type image display device described in 1. A cooling device for cooling the optical element;
A cooling control unit for controlling the cooling device,
3. The projection display apparatus according to claim 1, wherein the cooling control unit improves cooling capacity when the degree of deterioration is greater than a first threshold value. 4. The projection display apparatus according to claim 1, further comprising a notification device that notifies a user that the degree of deterioration detected by the detection unit is greater than a second threshold. 5. . The optical element is
A red optical element that transmits red component light;
A green optical element that transmits green component light;
A blue optical element that transmits blue component light,
The second photosensor is
A red light sensor for measuring the brightness of the red component light;
A green light sensor for measuring the brightness of the green component light;
A blue light sensor for measuring the brightness of the blue component light,
The detector is
Based on the measurement results of the red light sensor, the green light sensor, the blue light sensor, and the first light sensor, the red optical element, the green optical element, and the blue optical element are deteriorated. The projection display apparatus according to claim 1, wherein the projection degree is detected. The red optical element includes a red light modulating element that modulates the red component light,
The green optical element includes a green light modulating element that modulates the green component light,
The blue optical element includes a blue light modulating element that modulates the blue component light,
A video control unit that controls a modulation amount in each of the red light modulation element, the green light modulation element, and the blue light modulation element;
The projection type according to claim 5, wherein the image control unit controls the modulation amount according to a degree of deterioration of each of the red optical element, the green optical element, and the blue optical element. Video display device.

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