JP2004302357A - Light source device of projection display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize smaller size and lighter weight concerning a light source device of a single plate type projection display device using, as the light source, a light emitting diode that is advantageous for the small size, light weight and low cost. <P>SOLUTION: The light source device is composed of monochrome light sources 101-103 and a light composing means 104. The light composing means 104 is equipped with a movable mirror having two inclined conditions that consist of reflection areas formed with a wavelength selection film, and is also equipped with a driving means for driving the movable mirror. The first monochrome light source 101 emits a luminous flux to a two dimensional light modulator by irradiating a reflection area 105 inclined at a first angle. The second monochrome light source 102 emits a luminous flux to the two-dimensional light modulator by irradiating a reflection area 106 inclined at a second angle of the movable mirror. The third monochrome light source 103 is characterized in that it emits a luminous flux to the two-dimensional light modulator by passing through the movable mirror. One light composing means is sufficient, which leads to the miniaturization and the light weight. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light source device of a projection display device, and more particularly to a light source device of a projection display device pursuing further reduction in size and weight.
[0002]
[Prior art]
There is a projection display device as an electronic device capable of obtaining a large screen relatively easily. Conventional projection display devices are known as a three-panel type or a single-panel type depending on the number of two-dimensional light modulators used. In each system, a white discharge lamp is mainly used as a light source.
[0003]
In the three-plate type, white light from a light source is separated into three colors of R, G, and B using a dichroic mirror or the like to illuminate three corresponding two-dimensional light modulators, and the image is then used by a dichroic prism or the like. The images are synthesized and enlarged and projected on a screen using a projection lens. In many cases, a transmission type liquid crystal panel is mainly used for the two-dimensional light modulator.
[0004]
On the other hand, in a single-plate type, a DMD which is a reflection type element is generally used for a two-dimensional optical modulator. In this method, three colors of R, G, and B are formed in a time-division manner using a rotary disk on which a dichroic mirror is formed by depositing white light from a light source in a region-divided manner to illuminate a DMD. The DMD image is enlarged and projected on a screen via a projection lens. Compared to a three-panel type using a liquid crystal panel, only one two-dimensional light modulator is required, so that the optical system is simpler, which is advantageous for small size, light weight and low cost.
[0005]
By the way, the discharge lamp used in such a conventional projection display device has an ultraviolet component and an infrared component in its luminescent component, and these components are not required for image display. Need to be removed.
[0006]
Specifically, an optical filter that cuts ultraviolet light and infrared light is disposed, but there is a problem that even if these filters are used, they cannot be completely removed. The ultraviolet component is a serious problem that gradually causes fatal damage to the display device over a long period of time. It works especially well for blue liquid crystal panels. In addition, the infrared component similarly affects the operation characteristics of the display device, and it is necessary to finally discharge the infrared light to the outside of the device, so that it is necessary to install a fan.
[0007]
Furthermore, an essential problem of the discharge lamp is that the life characteristics are not good. The nominal life of this type of discharge lamp is said to be about 1500 to 3000 hours, depending on the lamp power. In consumer demand applications, reducing the running costs associated with lamp replacement is an important factor. Therefore, there is a movement to realize a projection display device using a solid-state light source instead of a discharge lamp.
[0008]
Light emitting diodes and semiconductor lasers are known as solid state light sources. Particularly, the recent increase in luminance of light-emitting diodes is remarkable. Light-emitting diodes have the potential to solve the problems of conventional white discharge lamps in that they consume relatively little power, have a long life, and exhibit a single luminescent color.
[0009]
Regarding the application of such a light emitting diode to a projection display device, for example, according to Non-Patent Document 1 published by Lumileds Lighting (US), a configuration as shown in FIG. 9 is being studied. In FIG. 9, the luminous fluxes from the light emitting diodes of three colors R901, G902, and B903 are sequentially turned on and selectively reflected or transmitted using two types of dichroic mirrors 904 and 905 to finally make the same path. The light is irradiated as a time-division color illumination light to a DMD 907 which is a two-dimensional light modulator via a total reflection prism 906. In this figure, a synthetic resin auxiliary optical element 908 having a mortar shape and having a convex lens near the center is used in order to improve the parallelism of the light emitted from the light emitting diode.
[0010]
The image modulated by the DMD 907 passes through the prism 906 and is enlarged and projected on a screen by the projection lens 909. Since monochromatic light emitting diodes are used for the R, G, and B light emitting diodes 901, 902, and 903, there is no need to worry about ultraviolet rays and infrared rays, and a compact structure without a rotating disk is required. In comparison with the single plate type using the DMD, the size, weight and cost are further reduced.
[0011]
In the above configuration, two dichroic mirrors are provided, and from the viewpoint of realizing reduction in size and weight, only one light combining unit such as a dichroic mirror is desired.
[0012]
The technique of Patent Document 1 provides a display system having a configuration that requires only one light combining unit, and is described in the third and fourth embodiments.
[0013]
However, in the structure of the display system disclosed in Patent Document 1, the light utilization efficiency of the light beam emitted from the light source is poor, and the brightness of the display is poor.
[0014]
That is, in the third embodiment, as shown in FIGS. 13 to 15, only one mirror array 71 is required, but not all of the R, G, and B light beams hit the mirror array 71. This is because, as shown in FIG. 15, the mirror elements are arranged in R / B and G every other row, so that the R, G and B light fluxes are not changed unless the R, G and B light fluxes are formed in a line. Will occur. Since each of the mirrors is very small, it is impossible to form the R, G, and B light fluxes in a line so as to correspond to the minute mirror. In the configuration of the third embodiment, Compared with that of the first embodiment, the brightness is 以下 or less in principle.
[0015]
In the fourth embodiment, as shown in FIG. 21, separate mirror elements are used for R, G, and B, so that FIG. 21 reflects light more than FIG. The area to be used is small, and the light use efficiency is deteriorated.
[0016]
[Patent Document 1]
Japanese Patent Publication No. 2000-501197 [Non-Patent Document 1]
Gerard Harbors, Steve Paolini, Matthijs Kepper, "Performance of High-Power LED Illuminators in Projection Displays", MICRODISP PLAYER, 2002-2002DIGE.
[0017]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a light source device for a single-plate projection display device using a light emitting diode as a light source, which is advantageous in reducing the size, weight, and cost. An object of the present invention is to realize a further reduction in size and weight without lowering.
[0018]
[Means for Solving the Problems]
In order to solve such an object, the invention according to claim 1 is a light source device of a projection display device using a two-dimensional light modulator as a display device, wherein the light source device emits a light beam of a predetermined monochromatic light. Three types of light emitting means, and a light combining means for irradiating the projection display device with a light beam of monochromatic light emitted from the light emitting means, and the light combining means has wavelength selectivity of light. A film is formed, and includes a movable reflecting unit having a reflecting surface that reflects a light beam of monochromatic light emitted from the light emitting unit, and a driving unit that drives the reflecting unit, and the driving unit includes: Driving the reflecting means to two kinds of inclined states that form a first angle or a second angle between a surface perpendicular to an optical axis of a light beam irradiated to the projection display device and the reflection surface. The first light-emitting means is characterized in that: By irradiating the two-dimensional light modulator with a light beam by irradiating the reflecting surface inclined at a first angle of the light emitting means, the second light emitting means emits a light beam at a second angle of the reflecting means. By irradiating the inclined reflecting surface, a light beam is emitted to the two-dimensional light modulator, and the third light emitting unit emits a light beam to the two-dimensional light modulator through the reflecting unit. It is characterized by doing.
[0019]
According to a second aspect of the present invention, in the first aspect, the first to third light emitting units use light emitting diodes having different emission colors as light sources.
[0020]
According to a third aspect of the present invention, in the first or second aspect of the present invention, the first to third light emitting units are configured by using a plurality of light emitting diodes arranged in an array as a light source. Features.
[0021]
According to a fourth aspect of the present invention, in the first aspect of the present invention, the light source device controls the irradiation timing so as to alternately emit a monochromatic light beam of the light emitting unit. A light emitting control unit that emits a monochromatic light beam corresponding to the first light emitting unit when the reflecting surface of the reflecting unit is inclined at a first angle. When the reflecting surface of the reflecting means is inclined at a second angle, the light beam of monochromatic light corresponding to the second light emitting means is irradiated, and the reflecting surface of the reflecting means has a first angle and a second angle. The irradiation timing is controlled so that the light beam of the monochromatic light corresponding to the third light-emitting means is irradiated while the light is inclined at an angle.
[0022]
According to a fifth aspect of the present invention, in the first aspect of the present invention, the light source device controls the irradiation timing so as to alternately emit the monochromatic light flux of the light emitting unit. A light emitting control unit that emits a monochromatic light beam corresponding to the first light emitting unit when the reflecting surface of the reflecting unit is inclined at a first angle. After that, the light beam of the monochromatic light corresponding to the second light emitting means is irradiated, and when the reflecting surface of the reflecting means is inclined at the second angle, the light beam of the monochromatic light corresponding to the third light emitting means is emitted. The light emitting means controls the irradiation timing so as not to irradiate the corresponding monochromatic light beam while the reflecting surface of the reflecting means is inclined at the first angle and the second angle. It is characterized by the following.
[0023]
The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the range of the first angle or the second angle is 10 ° to 20 °. And
[0024]
With the above configuration, a mirror (dichroic mirror) having one wavelength selectivity is used to form an optical system for photosynthesis, whereas at least two types of dichroic mirrors are conventionally required, and a time-division color filter is used. Light beams can be formed, each light beam is emitted from the light source device with the same light beam width, the light use efficiency is high, the optical system is simple, and the size can be reduced.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0026]
<Configuration of First Embodiment>
FIG. 1 is a diagram showing a first embodiment of the light source device of the present invention. In FIG. 1, the light combining means 104 includes a movable mirror having two inclined states (105 or 106) and a driving means (not shown) for operating the movable mirror. The movable mirror has wavelength selectivity. A dielectric multilayer is deposited.
[0027]
As the photosynthesis means 104, a commercially available galvanomirror can be applied. The galvanometer mirror has a mirror 201 fixed to a support member 202 as shown in the external view of the galvanometer scanner in FIG. 2, and the support member 202 is rotatable on a galvanometer body 205 via a drive shaft 203 and a roller bearing 204. , And are alternately rotated bidirectionally within a very small angle range by a driving device such as a motor built in the galvano body 205, whereby the mirror 201 swings around the driving shaft 203. It is a mechanism to do. Therefore, the mirror 201 can be easily configured by using a dichroic mirror on which the dielectric multilayer film is deposited.
[0028]
The green light-emitting diode 101 and the red light-emitting diode 102 reflect light beams emitted from each of them when the movable mirror of the light combining means 104 reaches the first tilt state 105 and the second tilt state 106. They are arranged in a positional relationship such that they have the same route later. The blue light emitting diode 103 is disposed so as to transmit regardless of the tilted state of the movable mirror and to substantially match the reflected light beams from the green and red light emitting diodes.
[0029]
That is, as shown in FIG. 6, when the optical axis after reflection by the movable mirror is 601, the first and second inclined states (105 and 106) of the movable mirror are inclined by + α ° and −α °. If so, the positional relationships are + 2α ° and −2α ° with respect to the optical axis 601 respectively.
[0030]
It is desirable that α be as small as possible in consideration of the reduction in size and weight of the device. However, the size of the green light-emitting diode 101 and the red light-emitting diode 102 and the interference phenomenon between irradiated monochromatic light are considered. In this case, it is not desired that the movable mirror is too close, and the tilt state of the movable mirror may be about 10 ° ≦ α ≦ 20 °.
[0031]
<Operation of First Embodiment>
Next, the operation of the first embodiment will be described with reference to FIG. The movable mirror 301 is driven so as to repeatedly perform the inclination states of α ° and −α °.
[0032]
First, the light emitting diode 102 for red is turned on (FIG. 3A). At this time, the movable mirror 301 is in a state of being inclined by α °. The light flux from the upper left direction by the red light emitting diode 102 undergoes a reflection action according to the tilt angle of the movable mirror 301, and changes its traveling direction to a right above direction.
[0033]
Next, the light emitting diode 103 for blue is turned on during a period in which the movable mirror 301 is tilted from α ° to −α ° (FIG. 3B). Here, the movable mirror is provided with a dichroic mirror coating having a characteristic of reflecting red and green light and transmitting blue light, and a light beam from the light emitting diode 103 transmits through the movable mirror 301 due to this characteristic. And proceed just above. When the blue light emitting diode 103 is on, the red light emitting diode 102 is off. The traveling directions of the red light beam reflected by the movable mirror 103 and the blue light beam transmitted through the movable mirror 103 are substantially the same.
[0034]
Then, when the movable mirror 301 reaches a position inclined by -α °, the green light emitting diode 101 is turned on (FIG. 3C). The blue light emitting diode 102 is turned off immediately before the green light emitting diode 101 is turned on. The traveling direction of the green luminous flux reflected from the movable mirror 301 from the upper right direction is changed right above by the reflection mirror. The traveling direction of this light beam and the blue light beam transmitted through the movable mirror 301 are almost the same.
[0035]
Next, the movable mirror 301 shifts to the inclined state of α °, during which the blue light emitting diode 103 is turned on (FIG. 3B). The green light emitting diode 101 is off. By repeating this process as one cycle, a color illumination light beam is formed by repeating time division of red → blue → green → blue → red → blue → green..., And two-dimensional light modulation is performed by this illumination light beam. By synchronizing the devices, a single-panel projection display device can be configured. FIG. 5 shows the above lighting timing.
[0036]
Note that the light emitting diode may have a plurality of array configurations. In this case, a high-luminance illumination light beam is obtained according to the number used. Further, it is not necessary to use the same number of red, blue and green light emitting diodes. In general, the luminous efficiency of a light emitting diode differs depending on the luminescent color. That is, the brightness obtained by the light emitting diodes of the same series (light emitting chip size, outer shape, etc.) is different.
[0037]
For example, a high-luminance type light-emitting diode manufactured by Nichia Corporation has a standard luminous intensity rank. The red (model name NSPR346BS) is 0.305 candela, and the blue (model name NSPB346BS) is 0.5. For candela and green (model name NSPG346BS), the number is 1.73 candela.
[0038]
The Luxeon series light emitting diodes manufactured by U.S. Lumileds, Inc. are 25 lumens for red (model LXHL-BD01), 5 lumens for blue (model LXHL-BB01), and 25 for green (model LXHL-BM01). It is lumen. This is considered to be due to the material of the light emitting element and the like.
[0039]
If the same number is used, it may not be possible to use all the light emitting diodes in a state where the maximum light output is obtained. Specifically, in the NTSC, the light amount ratio of red, green, and blue constituting white is approximately 3: 6: 1.
[0040]
Therefore, in the Nichia light emitting diodes, it is necessary to arrange each light emitting diode in a ratio of one for green, 2.8 for red, and 0.57 for blue. This means that 2.8 times red is required for green and 0.56 times blue is required.
[0041]
In Luxeon series manufactured by Lumileds, Inc., the ratio is one for green, 0.5 for red, and 0.83 for blue. Therefore, it is preferable that the light emitting diode is constituted by a predetermined number of light emitting diodes in consideration of white balance.
[0042]
<Second embodiment>
FIG. 4 is a diagram showing a second embodiment of the light source device of the present invention. The difference from the first embodiment is that the characteristics of the dichroic mirror formed on the movable mirror portion of the light combining means 104 are such that the red and blue wavelength components are reflected and the green wavelength component is transmitted. The point is that the blue light emitting diode 103 is arranged in the upper left direction, the red light emitting diode 102 is arranged in the upper right, and the green light emitting diode 101 is arranged in the lower center.
[0043]
In addition, control is performed so that the green light emitting diode 101 is turned on in one inclined state of the movable mirror. That is, in the first embodiment, the time-division color luminous flux has a repeating cycle of red → blue → green → blue → red → blue → green... In the second embodiment, It is configured to repeat → green → red. With this configuration, the signal processing of the two-dimensional optical modulator to be synchronized can be simplified.
[0044]
Further, as compared with the case where the lighting is performed also during the rotation period as shown in FIG. 5 of the first embodiment, the lighting of all the light emitting diodes is performed only when the movable mirror is stationary at one of the inclined positions. Is to be implemented. With this configuration, the signal processing of the two-dimensional optical modulator to be synchronized can be simplified. FIG. 7 shows the above lighting timing.
[0045]
FIG. 8 is a diagram showing a configuration of a projection display device using the light source devices of the first and second embodiments. A light source device 801 including red, blue, and green light emitting diodes 102, 103, and 101, a light combining unit 104, and a driving mechanism 802 for driving the light combining unit 104, a prism 804, and a DMD 805 that is a two-dimensional light modulator. And a signal processing circuit 803 for controlling the projection lens 806 and the DMD 805.
[0046]
The time-division color light beam formed by the light source device 801 illuminates the DMD 805 via the prism 804, and the image of the DMD 805 is again enlarged and projected by the projection lens 806 via the prism 804. Thus, a single-panel projection display device can be realized.
[0047]
【The invention's effect】
As described above, according to the light source device of the present invention, the light beams from the red, blue, and green light emitting diodes are formed into a time-division color light beam by the light combining means having one dichroic mirror. A small light source device can be realized while maintaining efficiency.
In addition, since a plurality of light emitting diodes can be provided, it is possible to easily increase the luminance and obtain a small and bright light source device for a projection display device.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a light source device of a projection display device according to a first embodiment.
FIG. 2 is an external view of a galvano scanner.
FIG. 3 is a state transition diagram of the light source device of the projection display device according to the first embodiment.
FIG. 4 is a configuration diagram of a light source device of a projection display device according to a second embodiment.
FIG. 5 is a diagram for explaining the lighting timing of each light emitting diode in the first embodiment.
FIG. 6 is a diagram relating to an inclined state of a movable mirror.
FIG. 7 is a diagram for explaining lighting timing of each light emitting diode in the second embodiment.
FIG. 8 is a configuration diagram of a projection display device.
FIG. 9 is a configuration diagram of a projection display device of Non-Patent Document 1.
[Explanation of symbols]
101, 902 Green light-emitting diode 102, 901 Red light-emitting diode 103, 903 Blue light-emitting diode 104 Photosynthesis means 105 First inclined state 106 Second inclined state 201 Mirror 202 Support member 203 Drive shaft 204 Roller bearing 205 Galvano main body 301 Movable mirror 601 Optical axis 801 Light source device 802 Driving mechanism 803 Signal processing circuit 804, 906 Prism 805, 907 DMD
806, 909 Projection lenses 904, 905 Dichroic mirror 908 Auxiliary optical element

Claims (6)

A light source device of a projection display device using a two-dimensional light modulator as a display device, wherein the light source device irradiates three types of light emitting means for irradiating a light beam of predetermined monochromatic light, and monochromatic light emitted from the light emitting means. Light synthesizing means for irradiating the projection display device with a light beam of light,
The light combining means includes a movable reflecting means having a reflecting surface formed with a film having light wavelength selectivity and reflecting a light beam of monochromatic light emitted from the light emitting means, and a drive for driving the reflecting means. Means for forming a first angle or a second angle between a surface perpendicular to an optical axis of a light beam irradiated to the projection display device and the reflection surface. Driving the reflection means in various kinds of inclined states,
The first light-emitting means emits a light beam to the two-dimensional light modulator by irradiating the reflection surface inclined at a first angle of the reflection means,
The second light-emitting means emits a light beam to the two-dimensional light modulator by irradiating the reflection surface inclined at a second angle of the reflection means,
The third light emitting unit transmits a light beam to the two-dimensional light modulator through the reflecting unit, and the light source device of the projection display device. The light source device of a projection display device according to claim 1, wherein the first to third light emitting units use light emitting diodes having different emission colors as light sources. 3. The light source device of a projection display device according to claim 1, wherein the first to third light emitting units are configured by using a plurality of light emitting diodes arranged in an array as a light source. The light source device further includes a light emission control unit that controls irradiation timing so as to alternately emit a light beam of monochromatic light of the light emission unit, wherein the light emission control unit includes:
When the reflection surface of the reflection unit is inclined at a first angle, the first light emission unit is irradiated with a light beam of monochromatic light corresponding to the first light emission unit,
When the reflection surface of the reflection unit is inclined at a second angle, the second light-emitting unit is irradiated with a light beam of monochromatic light corresponding to the second light-emitting unit,
Irradiation timing is controlled so that the third light emitting unit is irradiated with a light beam of monochromatic light while the reflecting surface of the reflecting unit is inclined at the first angle and the second angle. The light source device for a projection display device according to claim 1. The light source device further includes a light emission control unit that controls irradiation timing so as to alternately emit a light beam of monochromatic light of the light emission unit, wherein the light emission control unit includes:
When the reflecting surface of the reflecting means is inclined at a first angle, the light beam of monochromatic light corresponding to the first light emitting means is irradiated, and then the light beam of monochromatic light corresponding to the second light emitting means is irradiated. Let
When the reflecting surface of the reflecting means is inclined at a second angle, the third light emitting means is irradiated with a light beam of monochromatic light corresponding thereto,
While the reflecting surface of the reflecting means is inclined at the first angle and the second angle, the light emitting means controls the irradiation timing so as not to irradiate the corresponding monochromatic light beam. The light source device for a projection display device according to claim 1. The light source device of the projection display device according to claim 1, wherein the range of the first angle or the second angle is 10 ° to 20 °.

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