JP2006330154A - Illuminating optical system and projector apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve the long lifetime and low power consumption of a diaphragm mechanism. <P>SOLUTION: An illuminating optical system includes: LED arrays 1, 3, and 5, in each of which a plurality of LEDs are two-dimensionally arranged; lens optical systems 2, 4, 6, 8, 9 to 11 for making luminous fluxes from the LED arrays 1, 3, and 5 uniform; and an LED control section 15 that controls the turning on or off of each of the LEDs of the LED arrays 1, 3, and 5 according to a desired contrast of light. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an illumination optical system that illuminates an object such as a liquid crystal panel or DMD, and a projector apparatus using the illumination optical system.

  The configuration of a conventional projector device is shown in FIG. Conventional projector apparatuses are disclosed in, for example, Patent Document 1 and Patent Document 2. A conventional projector device includes an arc tube 101, a reflector 102, an ultraviolet / infrared cut filter 103, lens arrays 104 and 105, a diaphragm 106, a polarization beam splitter and polarization conversion element 107, a lens 108, an R- Dichroic mirror 109, mirror 110, lens 111, R-LCD (liquid crystal panel) 112, G-dichroic mirror 113, lens 114, G-LCD 115, mirror 116, B-relay lens 117, mirror 118, a lens 119, a B-incident side polarizing plate 120, a B-LCD 121, a B-exit side polarizing plate 122, an X-dichroic prism 123, and a projection lens 124.

  The light emitted from the arc tube 101 is reflected by the reflector 102, enters the ultraviolet / infrared cut filter 103, and the ultraviolet and infrared rays are removed. Note that the reflector 102 has a function of transmitting infrared light among the light emitted from the arc tube 101. The lens array 104 condenses the light emitted from the ultraviolet / infrared cut filter 103 on the lens array 105. The light emitted from the lens array 105 passes through the aperture of the diaphragm 106 and enters the polarization beam splitter and the polarization conversion element 107. The polarization beam splitter and polarization conversion element 107 aligns the polarization plane of the emitted light in a certain direction. The light emitted from the polarization beam splitter and polarization conversion element 107 passes through the lens 108 and enters the R-dichroic mirror 109.

  The R-dichroic mirror 109 reflects only red light out of the light emitted from the lens 108 and transmits other color light. The red light reflected by the R-dichroic mirror 109 is reflected by the mirror 110, passes through the lens 111, and enters the R-LCD 112. On the other hand, the G-dichroic mirror 113 reflects only green light out of the light transmitted through the R-dichroic mirror 109 and transmits other color light, that is, blue light. The green light reflected by the G-dichroic mirror 113 passes through the lens 114 and enters the G-LCD 115. The blue light transmitted through the G-dichroic mirror 113 is reflected by the mirror 116, passes through the B-relay lens 117, and is reflected by the mirror 118. Further, the light reflected by the mirror 118 passes through the lens 119 and the B-incident side polarizing plate 120 and enters the B-LCD 121.

  A drive circuit (not shown) that receives R, G, B input video signals input from the outside converts them into R, G, B liquid crystal drive signals, and R-LCD 112, G-LCD 115, B -Output to LCD 121 respectively. As a result, an image related to the R component of the input image is displayed on the R-LCD 112, an image related to the G component of the input image is displayed on the G-LCD 115, and B of the input image is displayed on the B-LCD 121. An image relating to the component is displayed. Thus, the red light, the green light, and the blue light incident on the LCDs 112, 115, and 121 are modulated according to the input video signal. The blue light transmitted through the B-LCD 121 passes through the B-exit side polarizing plate 122. Next, the X-dichroic prism 123 combines the red light transmitted through the R-LCD 112, the green light transmitted through the G-LCD 115, and the blue light transmitted through the B-emission side polarizing plate 122. Finally, the light synthesized by the X-dichroic prism 123 is projected on a screen (not shown) by the projection lens 124.

Japanese Patent Laid-Open No. 11-032278 Japanese Patent Laid-Open No. 2001-228569

In the projector apparatus shown in FIG. 5, the contrast and brightness of the projected image are changed by changing the size of the diaphragm 106.
However, the conventional projector device has a problem that the life of the diaphragm 106 is short. This is because (1) the thermal load is large and the diaphragm 106 is thermally deformed. As a result, the life of the diaphragm 106 is shortened, or there is a limit on the amount that can be squeezed. A motor is required to drive 106, and the life of the motor is shortened due to high heat. (3) The diaphragm 106 is composed of a plurality of diaphragm blades, and the diaphragm blades slide with each other. Because. In addition, the conventional projector device has a problem that a cooling fan or the like is required, which is disadvantageous in terms of cost and space.
Further, in the conventional projector apparatus, when the F value is increased by changing the size of the diaphragm 106 and the contrast of the projected image is increased, the brightness of the projected image is decreased, but the brightness is decreased. Therefore, there is a problem that power consumption does not decrease. The reason is that the decrease in brightness is caused by the decrease in the amount of light due to the aperture 106 and the amount of light in the arc tube 101 does not change.

  The present invention has been made to solve the above problems, and an object thereof is to provide an illumination optical system and a projector apparatus capable of realizing a long life and low power consumption of an aperture mechanism.

An illumination optical system of the present invention includes a light emitting element array in which a plurality of light emitting elements are two-dimensionally arranged, and a control unit that controls lighting / non-lighting of each light emitting element of the light emitting element array according to a desired light contrast; It is what has.
Further, in one configuration example of the illumination optical system according to the present invention, the control unit has a lower power consumption when the light emitting element array is partially lit than when the light emitting element array is fully lit. The brightness of the light emitting element to be lit is increased.

The projector device of the present invention includes the illumination optical system, a modulation unit that modulates light from the illumination optical system according to an input video signal, and a projection lens that projects light modulated by the modulation unit. It is what you have.
In one configuration example of the projector device according to the present invention, the control unit of the illumination optical system controls lighting / non-lighting of each light emitting element of the light emitting element array according to the input video signal.
In one configuration example of the projector device according to the present invention, the control unit of the illumination optical system links the contrast adjustment by the aperture of the projection lens and the contrast adjustment by the light emitting element array.

  According to the present invention, by controlling the lighting / non-lighting of each light emitting element of the light emitting element array, the same state as that achieved by the mechanical diaphragm can be realized, and the optical contrast can be increased. In the present invention, since the mechanical aperture is not used, the lifetime of the aperture mechanism can be extended. Moreover, there is no sound during the diaphragm operation, and the response speed of the diaphragm can be made very fast compared to the mechanical diaphragm. Further, according to the present invention, the optical contrast can be increased, and at the same time, the power consumption can be reduced and the cooling load can be reduced.

  In the present invention, when the light emitting element array is partially lit, the brightness of the light emitting element to be lit is increased within a range where the power consumption is lower than when the light emitting element array is fully lit. The contrast can be increased while suppressing a decrease in illuminance.

  In the present invention, when an illumination optical system is used in a projector apparatus, the contrast is optimized according to the video scene by controlling the lighting / non-lighting of each light emitting element of the light emitting element array according to the input video signal. Can be achieved, and the image quality in a very dark video scene can be improved.

  Further, in the present invention, when the illumination optical system is used in a projector apparatus, the contrast can be further improved by linking the contrast adjustment by the projection lens aperture and the contrast adjustment by the light emitting element array. The width can be further increased.

[First Embodiment]
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the projector apparatus according to the first embodiment of the present invention. The projector apparatus according to the present embodiment includes an R-LED (light emitting diode) array 1, a lens array 2, a G-LED array 3, a lens array 4, a B-LED array 5, a lens array 6, and an X The lighting / non-lighting of the dichroic prism 7, the lens array 8, the lenses 9, 10, 11, the total reflection prism 12, the DMD (trademark) 13, the projection lens 14, and the LED arrays 1, 3, 5 And an LED control unit 15 to be controlled. The lens arrays 2, 4, 6, and 8 and the lenses 9 to 11 constitute a lens optical system that uniformizes the light beams from the LED arrays 1, 3, and 5, and the total reflection prism 12 and the DMD 13 are input video signals. A modulation unit that modulates light according to the above is configured.

  Hereinafter, the operation of the projector apparatus according to the present embodiment will be described. In this embodiment mode, an aggregate of light emitting elements is used as a light source. The R-LED array 1 is a two-dimensional arrangement of red LEDs as light emitting elements, the G-LED array 3 is a two-dimensional arrangement of green LEDs, and the B-LED array 5 is a two-dimensional arrangement of blue LEDs. Are arranged. One LED of the R-LED array 1 corresponds to one lens cell of the lens array 2 and one lens cell of the lens array 8. Similarly, one LED of the G-LED array 3 corresponds to one lens cell of the lens array 4 and one lens cell of the lens array 8, and one LED of the B-LED array 5 is The lens array 6 corresponds to one lens cell and the lens array 8 corresponds to one lens cell.

  The X-dichroic prism 7 is obtained by bonding four right-angle prisms and forming a dichroic layer on the bonding surface. Each lens cell of the lens array 2 reflects red light emitted from the corresponding red LED of the R-LED array 1 by the X-dichroic prism 7 and then enters the corresponding lens cell of the lens array 8. The red light is condensed. In each lens cell of the lens array 4, green light emitted from the corresponding green LED of the G-LED array 3 passes through the X-dichroic prism 7 and then enters the corresponding lens cell of the lens array 8. Collect green light. Each lens cell of the lens array 5 is reflected by the X-dichroic prism 7 after the blue light emitted from the corresponding blue LED of the B-LED array 5 is incident on the corresponding lens cell of the lens array 8. Condenses blue light.

  Thus, the red light beam, the green light beam, and the blue light beam emitted from the R-LED array 1, the G-LED array 3, and the B-LED array 5 are collected by the lens arrays 2, 4, and 6, respectively. However, the X-dichroic prism 7 synthesizes it uniaxially. These synthesized light fluxes are collected by the lens array 8 and converted into telecentric light (light parallel to the optical axis) by the lenses 9 to 11. The light emitted from the lens 11 is reflected by the total reflection prism 12 and enters the DMD 13.

  The DMD (Digital Micromirror Device) 13 is a micron-sized micromirror arranged two-dimensionally, for example, hundreds of thousands, and has a role of changing the light emitting direction by changing the inclination of each micromirror. Have When the angle of the micromirror is on, the light beam reflected by the micromirror passes through the total reflection prism 12 and enters the projection lens 14, and is projected onto a screen (not shown) by the projection lens 14. That is, the pixel corresponding to the micromirror is brightened. On the other hand, when the micromirror is at the off-state angle, the light beam reflected by the micromirror does not enter the projection lens 14 but is incident on a predetermined light absorbing portion (not shown) and absorbed. Therefore, the pixel corresponding to the micromirror becomes dark

  The DMD 13 performs such light on / off at a high speed for each micromirror according to the input video signal. The light emitted from the DMD 13 is on / off pulsed light, but the pulse width is extremely short, so that the eyes of the person who sees the image projected on the screen recognize the result of integrating the pulsed light. Thus, brightness and color gradation are expressed by integration of spatio-temporal light, and an image is projected on the screen.

  The present embodiment is provided with the LED control unit 15 in the projector apparatus as described above in order to realize the same function as the conventional diaphragm. 2 (a) and 2 (b) are plan views of the R-LED array 1 viewed from the lens array 2 side, and FIG. 2 (a) shows a state in which the red LEDs are fully lit. (B) shows a state in which the red LED is partially lit. 2A and 2B, L indicates an LED that is lit and N indicates an LED that is not lit.

  The LED control unit 15 normally lights all the LEDs of the R-LED array 1, the G-LED array 3, and the B-LED array 5 as shown in FIG. In order to increase the contrast of the image, as shown in FIG. 2B, the peripheral LEDs of the LED arrays 1, 3 and 5 are turned off, and only the central LED is turned on. A state in which only the central portion of the LED array is lit is equivalent to a state in which the diaphragm 106 is narrowed in the projector apparatus shown in FIG.

  Thus, in the present embodiment, by turning off some of the LEDs in the LED array, the same state as that obtained when the aperture is stopped by a mechanical aperture is realized, and the F value is obtained by reducing the size of the pupil of the light source. To increase the contrast of the video. In order to change the contrast to an arbitrary value, the relationship between the contrast and the lighting state of the LED arrays 1, 3, 5 is set in the LED control unit 15 in advance. Then, according to the set relationship, the LED control unit 15 may control lighting / non-lighting of each LED of the LED arrays 1, 3, and 5 so that the required contrast is obtained.

  FIG. 3 is a diagram for explaining the effect of the projector device according to the present embodiment. FIG. 3A is a diagram showing changes in illuminance and contrast due to changes in the lighting state of the LED array, and FIG. The figure which shows the change of power consumption, FIG.3 (c) is a figure which shows the change of cooling load. 3A to 3C, A indicates a case where all the LEDs of the LED arrays 1, 3, and 5 are lit, and B indicates a case where the LEDs are partially lit.

In this embodiment, since a mechanical aperture is not used, the lifetime of the aperture mechanism can be extended. Further, since the diaphragm blades do not slide with each other, there is no sound during the diaphragm operation, and the response speed of the diaphragm can be made much faster than the mechanical diaphragm.
Further, as shown in FIG. 3B, assuming that the power consumption at the time of all lighting is 100, when the contrast is increased (changed from A to B), the LED controller 15 changes the LED array 1, Since the power supplied to 3 and 5 can be reduced, the power consumption can be reduced to, for example, 50, which is half, and energy saving can be realized.
The LED arrays 1, 3, and 5 are provided with cooling units (not shown) such as a heat sink, an electric fan, and a Peltier element as necessary. In this embodiment, as shown in FIG. 3C, if the cooling load at the time of full lighting is 1, the cooling load can be reduced to, for example, 0.5, when the contrast is increased.

[Second Embodiment]
According to the first embodiment, the contrast of an image can be increased by changing the lighting state of the LED array, but there is a problem that the brightness decreases when the contrast is increased. For example, in the example shown in FIG. 3A, assuming that the illuminance at the time of full lighting is 100, the illuminance is reduced to 50, which is half, for example, when the contrast is increased. The purpose of this embodiment is to solve such problems. Also in the present embodiment, since the configuration of the projector device is the same as that of the first embodiment, description will be made using the reference numerals in FIG.

  The LED control unit 15 in the present embodiment turns off the LEDs in the peripheral portions of the LED arrays 1, 3, and 5, as in the first embodiment, when increasing the contrast of the video in response to a user request. Only the central LED is turned on. At this time, if the peripheral LED is turned off with the same cooling performance, the cooling performance for one LED is relatively improved. Therefore, it is possible to increase the electric power supplied to one LED as compared with the case of full lighting. Therefore, when only the central LED is lit, the LED control unit 15 of the present embodiment increases the brightness of the central LED within a range in which the power consumption is lower than the power consumption during full lighting. In other words, in the present embodiment, power that is no longer needed by turning off the LEDs in the periphery of the LED arrays 1, 3 and 5 is input to the LEDs in the center. Thereby, the maximum illuminance can be increased while maintaining the contrast (dynamic range) as compared with the partial lighting in the first embodiment.

  FIG. 4 is a diagram for explaining the effect of the projector device according to the present embodiment. FIG. 4 (a) is a diagram showing changes in illuminance and contrast due to changes in the lighting state of the LED array, and FIG. 4 (b) is a diagram. The figure which shows the change of power consumption, FIG.4 (c) is a figure which shows the change of cooling load. 4A to 4C, A indicates a case where all the LEDs of the LED arrays 1, 3 and 5 are lit, and C indicates a case where the LEDs are partially lit.

  As shown in FIG. 4A, the maximum illuminance when the contrast is increased (when changed from A to C) is 75, for example, with respect to the maximum illuminance 100 when all the lights are turned on. The maximum illuminance can be increased compared to. Further, as shown in FIG. 4B, the power consumption when the contrast is increased is, for example, 75, which is larger than the power consumption 50 when the partial lighting of the first embodiment is performed, A value lower than the power consumption 100 can be realized. Further, as shown in FIG. 4C, the cooling load when the contrast is increased is, for example, 0.75, which is larger than the cooling load 0.5 at the time of partial lighting in the first embodiment. A value lower than the cooling load 1 at the time of full lighting can be realized.

[Third Embodiment]
In the first and second embodiments, the lighting state of the LED array is changed according to the user's request. However, the contrast is adjusted by changing the lighting state of the LED array according to the gain of the input video signal. You may do it. For example, when the level of the input video signal is low, the contrast is increased at the same time as lowering the brightness. When the level of the input video signal is high, the brightness is increased and the contrast is decreased at the same time. Contrast optimization can be realized and the image quality in a very dark video scene can be improved.

[Fourth Embodiment]
The projection lens 14 of the projector apparatus may be provided with a mechanical diaphragm mechanism, and the contrast of the image can be adjusted by the diaphragm mechanism. The contrast adjustment by the diaphragm mechanism and the first to third contrasts can be performed. The contrast adjustment by the LED array described in the embodiment may be interlocked. For example, the LED control unit 15 moves the aperture of the projection lens 14 in a direction to increase the contrast, and when the pupil of the projection lens 14 becomes small, the LED arrays 1, 3, and 5 also enter the pupil of the projection lens 14. The lighting state is controlled so that the size is sufficient. Accordingly, the contrast can be further improved without wasting power, and the width of the dynamic range of the video can be further widened.

  The present invention can be applied to an illumination optical system and a projector apparatus using the illumination optical system.

It is a block diagram which shows the structure of the projector apparatus used as the 1st Embodiment of this invention. It is a top view of the LED array in the projector apparatus of FIG. It is a figure for demonstrating the effect of the projector apparatus of FIG. It is a figure for demonstrating the effect of the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the conventional projector apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... R-LED array, 2, 4, 6, 8 ... Lens array, 3 ... G-LED array, 5 ... B-LED array, 7 ... X-dichroic prism, 9, 10, 11 ... Lens, 12 ... All Reflective prism, 13... DMD, 14... Projection lens, 15.

Claims (5)

A light emitting element array in which a plurality of light emitting elements are two-dimensionally arranged;
An illumination optical system comprising: a control unit that controls lighting / non-lighting of each light emitting element of the light emitting element array according to a desired light contrast. The illumination optical system according to claim 1,
The control unit increases the brightness of the light emitting elements to be lit when the light emitting element array is partially lit within a range where power consumption is lower than when the light emitting element array is fully lit. Illumination optical system. The illumination optical system according to claim 1 or 2,
A modulation unit that modulates light from the illumination optical system according to an input video signal;
A projector apparatus, comprising: a projection lens that projects light modulated by the modulation unit. The projector device according to claim 3, wherein
The projector device according to claim 1, wherein the control unit of the illumination optical system controls lighting / non-lighting of each light emitting element of the light emitting element array according to the input video signal. In the projector apparatus of Claim 3 or 4,
The control unit of the illumination optical system links the contrast adjustment by the aperture of the projection lens with the contrast adjustment by the light emitting element array.

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