WO2010147061A1

WO2010147061A1 - Rgb light source module

Info

Publication number: WO2010147061A1
Application number: PCT/JP2010/059956
Authority: WO
Inventors: 永井　拓也; 武晃前畑; 酒井　重史
Original assignee: アルプス電気株式会社
Priority date: 2009-06-17
Filing date: 2010-06-11
Publication date: 2010-12-23
Also published as: TW201106014A

Abstract

Disclosed is a low-cost RGB light source module which enables high-quality image display when used in an image display device. Specifically disclosed is an RGB light source module (1A) which is configured of a green light-emitting element (2), a blue light-emitting element (3), a red light-emitting element (4), a first filter (5) for multiplexing green light emitted from the green light-emitting element (2) and blue light emitted from the blue light-emitting element (3), a second filter (6) for further multiplexing the multiplexed light and red light emitted from the red light-emitting element (4), a filter block unit that is obtained by firmly bonding the first and second filters (5, 6) to a filter block main body, a monitor (8) for detecting the light intensity of white light demultiplexed by the second filter (6), and a case (9) for integrally holding the light-emitting elements (2, 3, 4), the filter block main body, and the monitor (8).

Description

RGB light source module

The present invention relates to an RGB light source module that integrally includes a light source that emits red light, a light source that emits green light, and a light source that emits blue light, and is obtained by combining light emitted from each light source. The present invention relates to a configuration of a monitor unit that monitors white light.

FIG. 6 shows an example of an image display device using an RGB light source module as a light source (see, for example, FIG. 1 of Patent Document 1).

As shown in FIG. 6, the image display apparatus of this example includes a red light emitting element 101 that emits red light, a green light emitting element 102 that emits green light, a blue light emitting element 103 that emits blue light, and a green light. The first dichroic mirror 104 that combines blue light with the second light, the second dichroic mirror 105 that combines red light with the combined green light and blue light, and the light emitted from each light source are combined. The white light to be incident on the light modulator 106, the projection lens 108 for enlarging and displaying the display image light L1 light-modulated by the light modulator 106 on a screen (not shown), and the light modulator 106 are demultiplexed. In addition, the optical sensor 109 that detects unnecessary light L2 that is not used as a display image and the drive of the optical modulator 106 are controlled to generate a required display image and the optical sensor 109. And a control unit 110 which controls the drive of each light-emitting

element

101, 102, 103 in accordance with the output.

Thus, the image display apparatus of this example monitors the light emission intensity of the

light emitting elements

101, 102, 103 by the optical sensor 109, and drives the

light emitting elements

101, 102, 103 so that the white point and the brightness are constant. Therefore, even when the light emission intensity of the

light emitting elements

101, 102, 103 changes with time or temperature change, the wavelength of the display image light L1 does not shift, and a high quality image is displayed over a long period of time. be able to.

WO2007 / 023681

However, the technique described in Patent Document 1 provides a period during which the light modulator 106 performs black display in one cycle of image display including a red image display period, a green image display period, and a blue image display period. Since the light intensity of each of the

light emitting elements

101, 102, 103 is monitored by the optical sensor 109 during this period, the optical modulator 106 displays an enlarged display on the screen according to the length of the period during which black display is performed. There is a problem that the display quality of the image to be deteriorated.

As means for solving such inconvenience, instead of the configuration in which the unnecessary light L2 is demultiplexed by the optical modulator 106, a demultiplexing filter separate from the optical modulator 106 is arranged on the optical path of white light, and this demultiplexing is performed. It is conceivable that the light emission intensity of each

light emitting element

101, 102, 103 is monitored based on the white light demultiplexed by the filter.

However, according to such a configuration, a demultiplexing filter separate from the optical modulator 106 is required, so that the cost of the image display device is increased and the intensity of the display image light L1 is reduced by transmitting the demultiplexing filter. As a result, the brightness of the display image decreases. Such a problem is a fatal inconvenience in an RGB light source module applied to a low-cost and low-output image display device or the like.

The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide an RGB light source module that enables high-quality image display when applied to an image display device at a low cost. There is to do.

In order to solve the above problems, the present invention provides an RGB light source module having a plurality of light sources having different emission colors, a light reflection surface and a transmission surface, and combining the light emission of the plurality of light sources. A filter that demultiplexes the waved light to the output side and the monitor side is provided.

According to such a configuration, since the light incident on the monitor is demultiplexed using the filter that multiplexes the light emission of the plurality of light sources, it is not necessary to provide a special demultiplexing filter, and the RGB light source module can be reduced in cost. Can do. Further, since light incident on the monitor can be obtained without passing through a special demultiplexing filter, it is possible to suppress a decrease in output of main light used as display image light or the like.

In the RGB light source module having the above-described configuration, the plurality of light sources include a red light emitting element that emits red light, a green light emitting element that emits green light, and a blue light emitting element that emits blue light. The filter includes a first filter for combining the green light and the blue light, and a second filter for combining the red light with the combination of the green light and the blue light. The light incident on the monitor is extracted from the reflection surface of the filter.

According to this configuration, the red light emitted from the red light emitting element, the green light emitted from the green light emitting element, and the blue light emitted from the blue light emitting element are combined using the first and second filters. Since the light waves, white light can be obtained, and the RGB light source module of this configuration can be used as a light source device for an image display device such as a projector.

According to the present invention, in the RGB light source module having the above-described configuration, a light emitting element including a photodetector is used as the red light emitting element and the blue light emitting element, and a light emitting element including a green SHG element is used as the green light emitting element. The green light detection sensor is provided on the optical path of the light extracted from the reflection surface of the first filter.

As the red light emitting element and the blue light emitting element, semiconductor lasers that emit red light and blue light have been developed, respectively, so that the intensity can be detected using a normal photodetector. On the other hand, a semiconductor laser emitting green light has not been developed yet, and wavelength conversion to green light is performed using a SHG (Second-Harmonic-Generation) element. Must be done. According to the above configuration, since the green light detection sensor is provided on the optical path of the light extracted from the reflecting surface of the first filter, the red light and the blue light can be combined with the green light as the reference light. The assembly of the RGB light source module can be facilitated, and the optical axes of the respective color lights can be strictly matched.

In the RGB light source module having the above-described configuration, the present invention includes a filter block in which the first filter and the second filter are integrally attached to the filter block body in a predetermined arrangement, and the filter block is fixed to the housing. It was configured as follows.

According to such a configuration, unlike the case where the first filter and the second filter are directly attached to the housing, it is possible to easily correct the mounting posture of each filter with respect to the optical axis. Can be made easier.

According to the present invention, the RGB light source module has a plurality of light sources having different emission colors, a light reflection surface and a light transmission surface, and combines the light emission of the plurality of light sources and outputs the combined light. Since the filter for demultiplexing is provided on the monitor side and the monitor side, it is not necessary to provide a special demultiplexing filter for demultiplexing light incident on the monitor, and the cost of the RGB light source module can be reduced. In addition, since light incident on the monitor can be obtained without passing through a special demultiplexing filter, it is possible to suppress a decrease in the output of main light, and display image light with high brightness when applied to an image display device. Can be obtained.

It is a block diagram of the RGB light source module which concerns on 1st Embodiment. It is an optical circuit diagram of the RGB light source module according to the first embodiment. It is a perspective view of the filter block used for the RGB light source module concerning a 1st embodiment. It is a table | surface figure which shows the optical characteristic of each filter used for the RGB light source module which concerns on 1st Embodiment. It is a block diagram of the RGB light source module which concerns on 2nd Embodiment. It is an optical circuit diagram of the image display apparatus which concerns on a prior art example.

Hereinafter, embodiments of the RGB light source module according to the present invention will be described.

<First Embodiment>
1 to 4 show an RGB light source module 1A according to the first embodiment. As shown in these drawings, the RGB light source module 1A according to the first embodiment includes a green light emitting element 2, a blue light emitting element 3, a red light emitting element 4, and green light and blue light emitted from the green light emitting element 2. A first filter 5 for combining the blue light emitted from the light emitting element 3, a second filter 6 for further combining the combined light with the red light emitted from the red light emitting element 4, and these The filter block unit 7 formed by fixing the first and

second filters

5 and 6 to the filter block main body 7a, the monitor 8 for detecting the light intensity of the white light demultiplexed by the second filter 6, and the light emission It is mainly composed of

elements

2, 3, and 4, a filter block body 7 and a housing 9 that holds the monitor 8 together.

As the green light emitting element 2, a semiconductor laser that emits light that has been wavelength-converted into green light LG by a green SHG element is used. As the blue light emitting element 3 and the red light emitting element 4, a blue semiconductor that emits blue light LB, respectively. A red semiconductor laser that emits a laser and red light LR is used. The light emitted from each of the

light emitting elements

2, 3, 4 is combined by matching the optical axes, and is emitted as a white light LW from an exit (not shown) provided in the housing 9. Means for matching the optical axes of the green light LG, the blue light LB, and the red light LR will be described later.

As the first filter 5 and the second filter 6, a dichroic mirror formed by forming a dielectric multilayer film on one side of a transparent substrate is used. As shown in FIG. 4, in the first filter 5, the transmittance of the green light LG and the transmittance of the blue light LB on the A surface (incident surface 5a of the green light LG) exceeds 98%, and the green light LG on this surface is In which the reflectance of blue light LB is less than 2%. Further, the transmittance of the green light LG on the B surface (blue light LB incident surface 5b) which is the opposite surface of the A surface is more than 98%, and the transmittance of the blue light LB is less than 2%. The light LG having a reflectance of less than 2% and the blue light LB having a reflectance of more than 98% is used. On the other hand, the second filter 6 has a red light LR transmittance, a green light LG transmittance, and a blue light LB transmittance exceeding 98% on the A surface (incident surface 6a of the red light LR). The red light LR reflectance, the green light LG reflectance, and the blue light LB reflectance are each less than 2%. Further, the transmittance of the blue light LB and the transmittance of the green light LG on the B surface (the exit surface 6b of the monitor light LM) that is the opposite surface of the A surface exceeds 98%, and the transmittance of the red light LR is less than 2%. Thus, a blue light LB reflectance and a green light LG reflectance of less than 2% and a red light LR reflectance of more than 98% are used on this surface. The

filters

5 and 6 are attached to the filter block main body 7 by adhesion. As an adhesive used at that time, an adhesive having a small curing shrinkage, for example, a UV adhesive is used.

As shown in FIG. 3, the filter block main body 7 a is formed of a resin material in a substantially triangular prism shape, and two surfaces intersecting at right angles are attachment surfaces of the

filters

5 and 6. On the side surface of the filter block body 7a, a green light LG transmission hole, a blue light LB transmission hole, a red light LR transmission hole, and a white light LW transmission hole (each of these transmission holes is denoted by reference numeral 10). ) Is opened. The filter block unit 7 is attached to a predetermined position in the housing 9 and then integrated with the housing 9 by means such as adhesion or fastening.

The monitor 8 is disposed on the optical path of the monitor light LM, and detects the intensity change of the white light LW combined from the green light LG, the blue light LB, and the red light LR. The control unit provided in the image display device or the like generates drive signals for the

light emitting elements

2, 3, and 4 according to the intensity change of the white light LW detected by the monitor 8, and the white point and the brightness are constant. Thus, the drive of each light emitting

element

2, 3, 4 is controlled. Thereby, when the RGB light source module of this example is applied to an image display device such as a projector, the wavelength of the display image light is not shifted, and a high-quality image can be displayed over a long period of time.

The manufacture of the RGB light source module 1A of this example can be performed by the following procedure. First, the first filter 5 and the second filter 6 are mounted in a predetermined direction on the filter mounting surface of the filter block body 7a, and the required filter block unit 7 is manufactured. At the same time, the green light emitting element 2, the blue light emitting element 3, the red light emitting element 4 and the sensor 8 are temporarily fixed to the housing 9 in the arrangement shown in FIG. Next, the filter block unit 7 is fixed to a required position of the housing 9 in a required direction. Next, the mounting posture of the green light emitting element 2 with respect to the housing 9 is adjusted so that the optical axis is within the reference position. Next, an optical axis of the blue light LB emitted from the blue light emitting element 3 and an optical axis of the red light LR emitted from the red light emitting element 4 are arranged on the optical axis of the green light LG emitted from the green light emitting element 2. The mounting postures of the blue light emitting element 3 and the red light emitting element 4 with respect to the housing 9 are adjusted so as to match. Finally, the mounting position of the sensor 8 with respect to the housing 9 is adjusted so that the optical axis of the monitor light LM is at the center of the light receiving surface in a state where all of the green light emitting element 2, the blue light emitting element 3 and the red light emitting element 4 emit light. After that, the sensor 8 is fixed to the housing 9. Thus, the optical circuit shown in FIG. 2 is configured.

The RGB light source module 1 </ b> A of this example combines the green light LG emitted from the green light emitting element 2 and the blue light LB emitted from the blue light emitting element 3 using the first filter 5, and the first filter 5. The green light LG and the blue light LB combined with each other and the red light LR emitted from the red light emitting element 4 are combined using the second filter 6, and the monitor light LM is demultiplexed from the second filter 6. Therefore, it is not necessary to provide a special demultiplexing filter used only for obtaining the monitor light LM, and the cost of the RGB light source module can be reduced. Moreover, since the monitor light LM can be obtained without passing through a special demultiplexing filter, it is possible to suppress a decrease in the output of main light used as display image light or the like. Furthermore, since the first and

second filters

5 and 6 are not directly fixed to the housing 9, but are attached to the housing 9 via the filter block main body 7a, the first and second filters that are excessively deformed due to the fixing are attached. The attachment of the

second filters

5 and 6 can be prevented in advance, and an RGB light source module having excellent optical characteristics can be manufactured. In addition, since the blue light emitting element 3 and the red light emitting element 4 are arranged on both sides of the green light LG through the optical axis, the light refraction by the first and

second filters

5 and 6 is not considered. The blue light LB and the red light LR can be combined, and the degree of coincidence of the optical axes of the respective color lights can be increased. Further, the set interval between the blue light emitting element 3 and the red light emitting element 4 can be reduced, and the overall length of the RGB light source module can be shortened.

Second Embodiment
FIG. 5 shows an RGB light source module 1B according to the second embodiment. As shown in this figure, the RGB light source module 1B according to the second embodiment is characterized in that the green light LG reflected by the first filter 5 is detected by a sensor 20 for detecting green light. About others, since it is the same as 1 A of illuminating devices which concern on 1st Embodiment, the same code | symbol is attached | subjected to a corresponding part and description is abbreviate | omitted.

Since the RGB light source module 1B of this example senses the green light LG extracted from the reflection surface of the first filter 5 by the green light detection sensor 20, the red light LR and the blue light LB using the green light LG as reference light. As a result, the assembly of the RGB light source module can be facilitated, and the optical axes of the respective color lights can be precisely matched.

In the RGB light source module 1B according to the second embodiment, both the white light detection monitor 8 and the green light detection sensor 20 are provided, but the blue light emitting element 3 and the red light emitting element 4 are provided inside. In the case of using a light emitting element equipped with a photodetector, the white light detection monitor 8 can be omitted. As a result, the RGB light source module can be further reduced in size and cost.

The present invention can be used for a light source device of an image display device.

1A, 1B RGB light source module 2 green light emitting element 3 blue light emitting element 4 red light emitting element 5 first filter 6 second filter 7 filter block unit 7a filter block body 8 monitor 9 housing 10 light transmission hole 20 for detecting green light Sensor

Claims

A plurality of light sources having different emission colors; a light reflection surface and a transmission surface; a filter that multiplexes the light emission of the plurality of light sources and demultiplexes the combined light to the output side and the monitor side; An RGB light source module comprising:
The plurality of light sources includes a red light emitting element that emits red light, a green light emitting element that emits green light, and a blue light emitting element that emits blue light, and the green light and the blue light are used as the filters. A first filter for combining the green light and the blue light, and a second filter for combining the red light with the combined light of the green light and the blue light, and the light incident on the monitor from the reflection surface of the second filter. The RGB light source module according to claim 1, wherein the RGB light source module is extracted.
The red light emitting element and the blue light emitting element are light emitting elements having a light detector, and the green light emitting element is a light emitting element having a green SHG element, and is taken out from the reflecting surface of the first filter. The RGB light source module according to claim 2, further comprising a green light detection sensor on an optical path of the light.
3. The RGB according to claim 2, comprising a filter block in which the first filter and the second filter are integrally attached to a filter block main body in a predetermined arrangement, and the filter block is fixed to a housing. Light source module.