JP2004361856A - Projection type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the luminance and contrast of a projection type display device compatible with each other by mounting a variable aperture thereon and to prevent the variable aperture from being deformed or damaged by rise in temperature without increasing the weight and volume of the device as a whole. <P>SOLUTION: The projection type display device is equipped with a light source 3, a spatial light modulator which modulates incident light following an applied image signal and emits it, an illumination optical system which condenses light from the light source 3 on the spatial light modulator and makes the light illuminate it, a projection lens to project light emitted from the spatial light modulator on a screen, a light shielding means disposed either on the side of the illumination optical system or on the side of the projection lens varying the amount of shielded light and a control means which controls the amount of the light shielded with the light shielding means and an amount of light incident on the light shielding means from the light source 3 in conjunction with each other so as to reduce the amount of light incident on the light shielding means from the light source 3 in conjunction with increase of the amount of the light shielded with the light shielding means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a projection type display device (projector), and more particularly to a projection type display device having a light blocking means such as an aperture for improving contrast.
[0002]
[Prior art]
2. Description of the Related Art Projection display devices that perform image display by widely modulating and spatially modulating light incident on a spatial light modulator in accordance with an electric signal applied to the spatial light modulator and collecting and projecting the emitted light have become widespread. . Such a projection display device generally has a lamp and a condenser mirror as a light source, and has an illumination optical system that collects light emitted from the lamp and makes it incident on a spatial light modulator. Light from the modulation element is projected on a screen or the like by a projection lens.
[0003]
At present, as typical examples of the spatial light modulator, there are a type in which a liquid crystal material is contained inside, and the direction of oscillation of incident polarized light is rotated by an electric field applied to the liquid crystal (referred to as a liquid crystal type). A type that has a working mirror, reflects incident light with a small working mirror, and performs spatial modulation by changing the holding angle of the small working mirror according to video signals (referred to as a DMD (digital micromirror device) type). ('DMD' is a registered trademark).
[0004]
FIG. 1 shows a basic configuration of a liquid crystal type projection display device (liquid crystal projector). Light emitted from the light source 21 travels to the reflecting mirror 22. A large amount of light is collected by a reflection mirror 22 and an illumination optical system 23 to a liquid crystal element (liquid crystal panel) 25 which is a spatial light modulation element. The collected light is incident on the polarizer 24 before being incident on the liquid crystal element 25, and one-way polarized light is extracted. Then, a video signal is applied to the liquid crystal element 25, and the light emitted from the polarizer 24 and incident on the liquid crystal element 25 is spatially modulated, and the polarization direction is rotated according to the video signal. The light exiting the liquid crystal element 25 enters the analyzer 26, and the light to be projected is selected. The light emitted from the analyzer 26 enters a projection lens 27 and is projected and displayed on a screen (not shown).
[0005]
Next, FIG. 2 shows a basic configuration of a DMD type projection display device (DMD projector). Light emitted from the light source 31 travels to the reflecting mirror 32. A large amount of light is collected by a reflecting mirror 32 and an illumination optical system 33 to a DMD element (DMD panel) 34 which is a spatial light modulation element. An image signal is applied to the DMD element 34, spatially modulates incident light, and the tilt of the micro-operation mirror changes according to the image signal, thereby changing the light emission direction. The light selected by the DMD element 34 enters the projection lens 35 and is projected and displayed on a screen (not shown).
[0006]
In comparison of images between the projection display device and another image display device, the contrast of the projection display device is low. The contrast described here is a ratio of luminance between when a white screen is displayed and when a black screen is displayed.
[0007]
In the projection type display device as shown in FIGS. 1 and 2, even if an attempt is made to display a black screen, a small amount of light is incident on the projection lens. This is because the light source is constantly operated.
[0008]
As a measure to solve this drawback, in recent years, in a projection display device, a stop is provided in an illumination optical system or a projection lens (for example, see Patent Document 1).
[0009]
The reason why the contrast is increased by setting the aperture is as follows. In the case of a liquid crystal projector, as a characteristic of the liquid crystal element, the contrast is degraded as the angle of light incident on the liquid crystal panel surface increases. Therefore, in the liquid crystal projector shown in FIG. 1, as shown in FIG. 3, a stop 41 is provided in or near the illumination optical system 23 to reduce the angle of a light beam incident on the liquid crystal panel 25. The contrast increases.
[0010]
Alternatively, in the liquid crystal projector shown in FIG. 1, as shown in FIG. 4, an aperture 41 is provided in the projection lens 27, and among rays emitted from the liquid crystal panel 25, those having a large panel incident angle are shielded by the aperture 41. This also increases the contrast.
[0011]
On the other hand, in the case of a DMD projector, as described above, when a black screen is displayed, light incident on the DMD element does not enter the projection lens. However, since the DMD element is an aggregate of minute mirrors, scattered light is generated between the mirrors. For this reason, light that does not normally go to the projection lens is generated. By providing a stop in the projection lens so that this is not actually projected as much as possible, it is possible to increase the contrast.
[0012]
[Patent Document 1]
JP 2001-264728 A (paragraphs 0049 to 0054, FIG. 1)
[0013]
[Problems to be solved by the invention]
As described above, there is a conventional projection display device in which the contrast is increased by installing a stop. However, using a stop having a constant light blocking amount (for example, an aperture stop having a fixed opening shape) as the stop has a disadvantage that the luminance when displaying a white screen is reduced.
[0014]
A measure to prevent this adverse effect is to use a variable aperture (a variable amount of light blocking) to enable a plurality of states when the aperture is opened and when the aperture is blocked. The problem of the contrast of the projected image depends on the brightness of the environment in which the image is projected. In a bright room, the screen shines on the screen depending on the brightness of the room (lighting, the sun, etc.) regardless of the presence or absence of the projection display device. For this reason, even if a black screen is displayed, floating of the black portion by the device does not pose a problem due to external light. It is necessary to have a white screen luminance that only cancels out external light.
[0015]
Conversely, when there is no external light, the floating of the black screen is noticeable. Conversely, the brightness of a white screen is not so necessary because it is a dark place. This is because human eyes get used to it.
[0016]
For this reason, in an environment with external light, the aperture is opened to brighten white and express a high-luminance image. On the other hand, in an environment without external light, the aperture is closed to suppress the white color and increase the contrast. In this way, both the brightness and the contrast can be achieved by the variable aperture.
[0017]
However, providing such a variable aperture has the following problems. That is, when the variable aperture is closed, a part of the light to be shielded is absorbed so that the temperature of the variable aperture rises, and the variable aperture may be deformed or damaged. It is difficult for the variable diaphragm to have light resistance and heat resistance since it has an operating part. Further, if an air-cooling fan or the like that cools the variable aperture is installed in order to reduce the heat generated by the variable aperture, the weight and volume of the entire projection display apparatus increase.
[0018]
In view of the above, the present invention provides a light-shielding unit having a variable light-shielding amount such as a variable aperture in order to achieve both luminance and contrast, and without increasing the weight and volume of the entire apparatus, It is an object of the present invention to provide a projection display device capable of preventing deformation and breakage of light shielding means due to a rise in temperature when the amount of light shielding is increased.
[0019]
[Means for Solving the Problems]
In order to solve this problem, the present applicant has developed a light source, a spatial light modulator that modulates incident light in accordance with an applied video signal, and emits the light, and illumination optics that condenses and illuminates light from the light source to the spatial light modulator. System, a projection lens for projecting the light emitted from the spatial light modulator, a light-shielding unit arranged on either side of the illumination optical system or the projection lens, the light-shielding amount being variable, and a light-shielding amount of the light-shielding unit. A projection type including a control unit that controls the amount of light shielding from the light source and the amount of incident light from the light source to the light shielding unit so that the amount of light incident on the light shielding unit from the light source decreases with the increase. A display device is proposed.
[0020]
In this projection display device, in an environment with external light, the amount of light shielding by the light shielding unit can be reduced, and white can be brightened to perform high-luminance image expression. Since the contrast can be increased by suppressing the white color by increasing the amount of light shielding, it is possible to achieve both luminance and contrast.
[0021]
The projection type display device includes a light-shielding amount of the light-shielding unit and an incident light amount from the light source to the light-shielding unit such that the amount of incident light from the light source to the light-shielding unit decreases with an increase in the amount of light-shielding of the light-shielding unit. Control means for controlling in conjunction with each other is provided. Therefore, when the light blocking amount of the light blocking unit is increased in order to increase the contrast in an environment where there is no external light, the amount of light incident on the light blocking unit from the light source decreases in conjunction with the increase.
[0022]
As described above, when the light blocking amount of the light blocking unit is increased, the amount of light incident on the light blocking unit from the light source is reduced, so that the amount of light absorbed by the light blocking unit is reduced. This suppresses a rise in the temperature of the light shielding means, thereby preventing deformation and breakage of the light shielding means. Further, unlike the case where an air-cooling fan or the like is installed, the weight and volume of the entire projection display device are not increased.
[0023]
Moreover, if the amount of light incident from the light source to the light-shielding means is reduced in accordance with the increase in the amount of light-shielded light by the light-shielding means, when the amount of light-shielded light from the light-shielding means is increased, the “projection due to the increase in the amount of light-shielded light by the light-shielding means In addition to the fact that the amount of light in the image decreases, and that the brightness of the black projection screen decreases as the contrast increases due to the increase in the amount of light shielding by the light shielding means, the image projection By "decreasing the amount of light", the luminance of the black projected image is greatly reduced. Thus, in an environment where there is no external light, floating (luminance) of the all-black projected image is suppressed, and high-quality image expression is possible.
[0024]
In this projection display device, as an example, the control unit controls the light-shielding amount of the light-shielding unit and the power supplied to the light source so that the power supplied from the power supply to the light source decreases as the light-shielding amount of the light-shielding unit increases. Is preferably controlled in conjunction with.
[0025]
Some existing projection display devices can variably set the power supplied from the power supply to the light source.Therefore, in such a projection display device, the power supplied to the light source is increased with an increase in the amount of light blocking of the light blocking means. When the amount of light is reduced, the amount of light emitted from the light source is reduced when the amount of light blocked by the light shielding means is increased, so that the amount of light incident on the light shielding means from the light source is reduced. As a result, the amount of light incident from the light source to the light shielding unit can be reduced as the light shielding amount of the light shielding unit increases without adding a new circuit or optical element.
[0026]
In addition, in the projection display device, as an example, the projection display device further includes a light detection unit that detects a light amount around the projection display device, and the control unit determines a light shielding amount of the light shielding unit based on a detection result of the light detection unit. It is preferable to control the amount of light incident on the light shielding unit in conjunction with the light amount.
[0027]
Thereby, it can be automatically detected from the detection result of the light detecting means that the environment has become free from external light, so that the light shielding amount of the light shielding means can be increased and the light quantity incident on the light shielding means can be reduced. become.
[0028]
When such a light detecting means is provided, it is more preferable to further comprise means for interrupting the projection of the light from the projection lens upon detection by the light detecting means.
[0029]
Thereby, for example, even when the light detection means is installed at a position where the projection light from the projection lens is likely to be incident, the projection light does not enter the light detection means at the time of detection, so that there is no external light. It becomes possible to accurately detect whether or not it has become.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be specifically described with reference to the drawings. FIG. 5 shows a configuration example of a liquid crystal projector to which the present invention is applied, and portions common to FIG. 1 are denoted by the same reference numerals. Light emitted from the light source 21 travels to the reflecting mirror 22. A large amount of light is collected by a reflection mirror 22 and an illumination optical system 23 to a liquid crystal element (liquid crystal panel) 25 which is a spatial light modulation element.
[0031]
The variable stop 1 is provided near the illumination optical system 23. The variable diaphragm 1 is a mechanical shutter having a variable opening area. The variable diaphragm driving unit 2 (a motor for displacing the operation unit of the variable diaphragm 1, a motor driver for driving the motor, and the like) has an area of the opening. Is increased or decreased.
[0032]
The light collected by the reflecting mirror 22 and the illumination optical system 23 enters the polarizer 24 through the variable stop 1 before entering the liquid crystal element 25, and one-way polarized light is extracted. Then, a video signal is applied to the liquid crystal element 25, and the light emitted from the polarizer 24 and incident on the liquid crystal element 25 is spatially modulated, and the polarization direction is rotated according to the video signal. The light exiting the liquid crystal element 25 enters the analyzer 26, and the light to be projected is selected. The light emitted from the analyzer 26 enters a projection lens 27 and is projected and displayed on a screen (not shown).
[0033]
The output power of the light source power supply 3 is supplied to the light source 21. The light source power supply adjustment circuit 4 is a circuit that adjusts the output power of the light source power supply 3 from, for example, 200 W to 40 W.
[0034]
Although not shown, an aperture adjustment button for opening and closing the variable aperture 1 (adjusting the area of the opening in two stages, large and small) is provided on an operation panel and a remote controller of the main body of the liquid crystal projector. Is provided. The CPU 5 controls each unit in the liquid crystal projector, and is also supplied with a signal by operating the aperture adjustment button.
[0035]
The CPU 5 executes the following processes (a) and (b) based on the supplied signal.
(A) When the operation of opening the variable aperture 1 is performed, the variable aperture drive unit 2 is controlled to open the variable aperture 1 (to maximize the area of the opening), and the light source power supply adjustment circuit 4 is operated. Under control, the light source power supply 3 outputs a power of a predetermined first magnitude (for example, 200 W).
[0036]
(B) When the operation of closing the variable aperture 1 is performed, the variable aperture drive unit 2 is controlled to narrow the variable aperture 1 (to make the area of the opening smaller than the maximum area) and to adjust the light source power supply. The circuit 4 is controlled to output a power of a second magnitude (for example, 40 W) smaller than the first power from the light source power supply 3.
[0037]
Next, the operation of the liquid crystal projector will be described.
When using the liquid crystal projector in an environment with external light, the user performs an operation of opening the variable aperture 1 with the above-described aperture adjustment button. Then, the area of the opening of the variable diaphragm 1 is maximized under the control of the CPU 5, so that the amount of light blocking at the variable diaphragm 1 is reduced, so that white is bright and high-luminance video expression is performed.
[0038]
On the other hand, when using this liquid crystal projector in an environment where there is no external light, the user performs an operation of closing the variable aperture 1 with the above-described aperture adjustment button. Then, the area of the opening of the variable aperture 1 is reduced based on the control of the CPU 5, and the amount of light shielding of the variable aperture 1 is increased, so that white color is suppressed and the contrast is increased. In this way, it is possible to achieve both luminance and contrast.
[0039]
Then, when the operation of closing the variable aperture 1 is performed, the output power of the light source power supply 3 is reduced based on the control of C5, so that the amount of light emitted from the light source 21 is reduced. The amount of light incident on the light source decreases.
[0040]
Accordingly, when the variable aperture 1 is closed, the amount of light absorbed by the variable aperture 1 is reduced, and a rise in the temperature of the variable aperture 1 is suppressed, so that the variable aperture 1 is prevented from being deformed or damaged. Unlike the case where an air-cooling fan or the like is installed, the total weight and volume of the liquid crystal projector do not increase.
[0041]
In addition, if the amount of light incident on the variable diaphragm 1 from the light source 3 is reduced in accordance with the increase in the amount of light blocked by the variable diaphragm 1, when the amount of light blocked by the variable diaphragm 1 is increased, the “ In addition to the fact that the amount of light in the projected image decreases due to an increase in the amount of light blocking, and that the contrast increases due to an increase in the amount of light blocking of the variable aperture 1, the brightness of the black projection screen decreases. The brightness of the black projected image is greatly reduced by "the light amount of the projected image is reduced by the reduction in the light amount itself". Thus, in an environment where there is no external light, floating (luminance) of the all-black projected image is suppressed, and high-quality image expression is possible.
[0042]
Further, some existing liquid crystal projectors have a circuit corresponding to the light source power supply adjustment circuit 4 (one that can variably set the power supplied from the power supply to the light source). By doing so, it is possible to reduce the amount of light incident on the variable aperture 1 with an increase in the amount of light blocking of the variable aperture 1 without adding a new circuit or optical element.
[0043]
Next, FIG. 6 shows another configuration example of the liquid crystal projector to which the present invention is applied, and the same reference numerals are given to portions common to FIGS. In this example, the variable stop 1 is installed in the projection lens 27, and the other configuration is the same as the example in FIG.
[0044]
In this example as well, it is possible to achieve both luminance and contrast in exactly the same manner as described with reference to the example of FIG. 5, and it is possible to reduce the weight when the variable aperture 1 is closed without increasing the weight or volume of the entire apparatus. Deformation and breakage of the variable diaphragm 1 due to a rise in temperature are prevented, and in an environment where there is no external light, floating (brightness) of the all-black projected image is suppressed, and high-quality image expression is possible.
[0045]
Next, FIG. 7 shows still another example of the configuration of the liquid crystal projector to which the present invention is applied, and portions common to FIGS. 1 and 5 are denoted by the same reference numerals. In this example, an optical sensor 7 for detecting the amount of light around the liquid crystal projector 6 is provided on the surface of the liquid crystal projector 6, and an output signal of the optical sensor 7 is sent to the CPU 5 via the A / D converter 8. Can be
[0046]
The CPU 5 executes the following processes (c) and (d) based on the signal from the optical sensor 7 instead of the processes (a) and (b) in the example of FIG. The other parts of the configuration of the liquid crystal projector are the same as those in the example of FIG.
[0047]
(C) When the amount of ambient light detected by the optical sensor 7 is equal to or more than a predetermined amount (in an environment with external light), the variable aperture driving unit 2 is controlled to open the variable aperture 1 (opening section). And the light source power supply adjusting circuit 4 is controlled so that the light source power supply 3 outputs a power of a predetermined first magnitude (for example, 200 W).
[0048]
(D) When the amount of ambient light detected by the optical sensor 7 is less than the above-mentioned fixed amount (in an environment without external light), the variable aperture driving unit 2 is controlled to reduce the variable aperture 1 (opening). Is made smaller than the maximum area) and the light source power supply adjustment circuit 4 is controlled to output a second power (for example, 40 W) smaller than the first power from the light source power supply 3.
[0049]
In this example as well, it is possible to achieve both luminance and contrast in exactly the same manner as described with reference to the example of FIG. 5, and it is possible to reduce the weight when the variable aperture 1 is closed without increasing the weight or volume of the entire apparatus. Deformation and breakage of the variable diaphragm 1 due to a rise in temperature are prevented, and in an environment where there is no external light, floating (brightness) of the all-black projected image is suppressed, and high-quality image expression is possible.
[0050]
Further, in this example, the CPU 5 automatically detects from the detection result of the optical sensor 7 that the environment has become free from external light, increases the light blocking amount of the variable diaphragm 1 and reduces the amount of light incident on the variable diaphragm 1. Can be reduced.
[0051]
Next, FIG. 8 shows still another example of the configuration of the liquid crystal projector to which the present invention is applied, and portions common to FIGS. 1 and 7 are denoted by the same reference numerals. In this example, a black signal generating circuit 9 for generating a black signal and a selector 10 for selecting one of the black signal and the video signal and applying the selected signal to the liquid crystal element 25 are added to the example of FIG. Have been.
[0052]
The CPU 5 controls the selector 10 to select the black signal from the black signal generating circuit 9 only for a momentary timing every fixed period (for example, several seconds to several minutes), and only the timing (c) in the example of FIG. ) And (d) are executed. At other times, the selector 10 is controlled to select a video signal, and the processes (c) and (d) in the example of FIG. 7 are not executed. The other parts of the configuration of the liquid crystal projector are the same as those in the example of FIG.
[0053]
In this example, when the CPU 5 detects from the detection result of the optical sensor 7 whether or not the environment is free of external light, the selector 9 selects a black signal, so that the black signal is supplied to the liquid crystal element 25. Therefore, the projection of light from the projection lens 27 is interrupted.
[0054]
Thus, in addition to obtaining the same operation and effect as the example of FIG. 7, even when the optical sensor 7 is installed at a position where the projection light from the projection lens 27 is likely to enter, for example, It is possible to accurately detect whether or not the environment has become empty.
[0055]
In each of the above examples, the current open / closed state of the variable aperture 1 may be displayed in a device operation table displayed on part or all of the projection image.
[0056]
In each of the above examples, the power supply to the light source 3 is increased or decreased in conjunction with the opening and closing of the variable aperture 1. However, as another example, a mode in which the opening and closing of the variable aperture 1 and the power supply to the light source 3 are linked in this manner (for example, a mode named “cinema mode”); Two modes, i.e., a mode in which supply power is not linked, may be prepared so that a user can select a desired mode by operating an operation panel or a remote controller.
[0057]
In each of the above examples, the present invention is applied to a liquid crystal projector. However, the present invention may be applied to other projection display devices. For example, when the present invention is applied to a DMD projector, the variable aperture 1 may be provided in the projection lens.
[0058]
In each of the above examples, the variable aperture 1 (mechanical shutter) is used as the light blocking means. However, as another example, a liquid crystal shutter composed of a transmissive liquid crystal element may be used as the light blocking means.
[0059]
Further, the present invention is not limited to the above-described example, and it is needless to say that various other configurations can be adopted without departing from the gist of the present invention.
[0060]
【The invention's effect】
As described above, according to the projection display device of the present invention, in an environment with external light, the amount of light shielding by the light shielding unit can be reduced, white can be brightened, and high-luminance image expression can be performed. In an environment where there is no external light, the amount of light blocking by the light blocking means can be increased, and white can be suppressed to increase contrast, so that an effect of achieving both luminance and contrast can be obtained.
[0061]
It is also desirable to prevent the deformation and breakage of the light-shielding means due to a rise in temperature when the light-shielding amount of the light-shielding means is increased without increasing the weight and volume of the entire apparatus, while achieving both the luminance and the contrast in this way. Is obtained.
[0062]
In addition, when the light shielding amount of the light shielding means is increased, the "light amount of the projected image is reduced by increasing the light shielding amount of the light shielding means" or "the contrast is increased by increasing the light shielding amount of the light shielding means. In addition to the fact that the brightness of the projected image decreases due to the decrease in the amount of light incident on the light-shielding means itself, the brightness of the black projected image greatly decreases. The effect of suppressing floating (luminance) of the all-black projection image and enabling high-quality video expression is also obtained.
[0063]
In addition, in existing projection display devices that can variably set the power supplied from the power supply to the light source, new circuits and optical elements are added by reducing the power supplied to the light source as the amount of light blocking by the light blocking means increases. Without this, it is possible to obtain an effect that the amount of light incident on the light shielding means can be reduced with an increase in the light shielding amount of the light shielding means.
[0064]
In addition, it is possible to automatically detect the environment where there is no external light from the detection result of the light detecting means, thereby increasing the amount of light shielding of the light shielding means and reducing the amount of light incident on the light shielding means. can get.
[0065]
In addition, for example, even when the light detection means is installed at a position where the projection light from the projection lens is likely to be incident, an effect of accurately detecting whether or not the environment is free of external light can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a basic configuration of a liquid crystal projector.
FIG. 2 is a diagram showing a basic configuration of a DMD projector.
FIG. 3 is a diagram showing a conventional liquid crystal projector provided with a stop.
FIG. 4 is a diagram showing a conventional liquid crystal projector provided with a stop.
FIG. 5 is a diagram illustrating a configuration example of a liquid crystal projector to which the present invention has been applied.
FIG. 6 is a diagram showing another configuration example of a liquid crystal projector to which the present invention has been applied.
FIG. 7 is a diagram showing another configuration example of a liquid crystal projector to which the present invention is applied.
FIG. 8 is a diagram showing another configuration example of a liquid crystal projector to which the present invention has been applied.
[Explanation of symbols]
Reference Signs List 1 variable aperture, 2 variable aperture drive, 3 light source power supply, 4 light source power supply adjustment circuit, 5 CPU, 7 optical sensor, 9 black signal generation circuit, 10 selector, 21 light sources, 22 reflecting mirror, 23 illumination optical system, 25 liquid crystal Element, 27 projection lens

Claims (4)

A light source,
A spatial light modulator that modulates and emits incident light according to an applied video signal,
An illumination optical system that condenses and illuminates light from the light source onto the spatial light modulator,
A projection lens that projects light emitted from the spatial light modulator,
Light-shielding means arranged on either side of the illumination optical system and the projection lens, the light-shielding amount being variable;
The amount of light incident on the light-shielding unit and the amount of light incident on the light-shielding unit are controlled in conjunction with each other so that the amount of light incident on the light-shielding unit from the light source decreases with an increase in the amount of light-shielding of the light-shielding unit. A projection type display device comprising: The projection display device according to claim 1,
The control unit controls the light-blocking amount of the light-blocking unit and the power supplied to the light source in conjunction with each other so as to reduce the power supplied from the power supply to the light source with an increase in the light-blocking amount of the light-blocking unit. A projection type display device characterized by the above-mentioned. The projection display device according to claim 1, wherein
Further comprising light detection means for detecting the amount of light around the projection display device,
The projection type display device, wherein the control means controls the amount of light shielding of the light shielding means and the amount of light incident on the light shielding means in conjunction with each other based on a detection result of the light detecting means. The projection display device according to claim 3,
A projection display apparatus, further comprising means for interrupting the projection of light from the projection lens upon detection by the light detection means.

Images