JP2013037252A - Projector device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive projector device using a laser source.SOLUTION: A projector device 1 projects outgoing light of a laser source 2 to a red phosphor 4 for emitting red fluorescence, a green phosphor 5 for emitting green fluorescence, and a blue phosphor 6 for emitting blue fluorescence respectively, causes an optical system 7 to deflect the fluorescent light of the respective phosphors 4-6, and projects it onto a projection surface 21. The projector device 1 includes a movable mirror 3 for projecting the outgoing light of the laser source 2 to a predetermined position of any of the red phosphor 4, the green phosphor 5, and the blue phosphor 6 according to a color and a pixel position prescribed by an input image signal.

Description

  The present invention relates to a projector apparatus using a laser light source.

As a light source for a projector apparatus, an ultra-high pressure mercury lamp is mainly used. However, since mercury is an environmentally hazardous substance, expectations are increasing for semiconductor light-emitting light sources such as LEDs. However, LEDs are inferior to ultra-high pressure mercury lamps in terms of brightness, and in order to obtain the same amount of light, it is necessary to use a large number of LEDs, and the device becomes large due to low optical efficiency. .
Therefore, conventionally, a projector apparatus using a laser light source, for example, an LD (semiconductor laser) having a high directivity and a very excellent optical efficiency is known. However, from the viewpoint of safety for human eyes, high directivity of laser and narrow spectral width are problems, and it is difficult to increase the amount of light.

  In view of this, there has been proposed a projector apparatus that has improved safety by converting the wavelength and making it incoherent with a phosphor without directly emitting laser light to the outside (see, for example, Patent Document 1). In this projector device, the laser light is condensed on one point of the phosphor, the light color-converted by the phosphor is condensed, and the light of each color is time-divided according to the data by DMD (Digital Mirror Device: trademark registration). It displays and projects a color image.

JP 2010-198805 A

However, the above-described conventional configuration has a problem that the apparatus is expensive because an expensive DMD is used.
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an inexpensive projector apparatus using a laser light source.

  In order to achieve the above-mentioned object, the present invention makes the light emitted from the laser light source incident on each of a red phosphor emitting red fluorescence, a green phosphor emitting green fluorescence, and a blue phosphor emitting blue fluorescence. In the projector device that deflects the fluorescent light of the body with an optical system and projects it onto the light projecting surface, the light emitted from the laser light source is converted into the red phosphor according to the color specified in the input image signal and the pixel position. And a movable mirror that is incident on a predetermined position of any one of the green phosphor and the blue phosphor.

The said structure WHEREIN: The said laser light source may radiate | emit the light below a blue wavelength range.
In the above configuration, the red phosphor, the green phosphor, and the blue phosphor may be of a reflective type.

  According to the present invention, since the movable mirror scans on the phosphor, an expensive DMD becomes unnecessary, and the cost of the projector device can be reduced.

It is a figure which shows typically the structure of the projector apparatus which concerns on this Embodiment of this invention. It is a timing chart which shows the projection operation | movement of a projector apparatus.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram schematically showing a configuration of a projector apparatus according to the present embodiment.
The projector device 1 includes a laser light source 2, a movable mirror 3, a red phosphor 4, a green phosphor 5, a blue phosphor 6, a prism 7, a projection lens group 8, and a control unit 10. ing.
The laser light source 2 is a light source that emits light (in the present embodiment, ultraviolet light) having a wavelength less than or equal to the blue wavelength band under the control of the control unit 10. For the laser light source 2, for example, an LD (semiconductor laser) is used. Can do. The light emitted from the laser light source 2 is reflected by the reflecting mirror 11 provided between the laser light source 2 and the movable mirror 3 to enter the movable mirror 3.

Under the control of the control unit 10, the movable mirror 3 selects the phosphors 4 to 6 on which light is incident, and scans the emitted light of the laser light source 2 on any of the selected phosphors 4 to 6. Specifically, the movable mirror 3 is configured by using a mirror that scans light by vibration, for example, a two-dimensional MEMS (Micro Electro Mechanical Systems) scanner mirror, and as indicated by an arrow A, the movable mirror 3 is angled by the drive mechanism 3A. Is adjusted, and the light emitted from the laser light source 2 is drawn for each pixel on one of the phosphors 4 to 6 under the control of the control unit 10.
In the present embodiment, a dichroic mirror 13R is provided between the movable mirror 3 and the red phosphor 4, and light from the movable mirror 3 is reflected by the dichroic mirror 13R and enters the red phosphor 4. Reflective mirrors 12G and 12B and dichroic mirrors 13G and 13B are provided between the movable mirror 3 and the phosphors 5 and 6, respectively, and light from the movable mirror 3 reflects the reflective mirrors 12G and 12B and the dichroic mirror. Reflected by 13G and 13B and enters the phosphors 5 and 6.

The phosphors 4 to 6 each emit ultraviolet light and emit the three primary colors of red (R), green (G), and blue (B). The phosphors 4 to 6 are configured, for example, by applying a phosphor material to the surfaces 4A to 6A of a resin base substrate. Examples of phosphor materials that emit light when excited by ultraviolet light include, for example, Y ₂ O ₂ S: Eu for the red phosphor 4, ZnS: Cu, Al for the green phosphor 5, and ZnS: for the blue phosphor 6. Ag can be used.
The phosphors 4 to 6 of the present embodiment are reflective phosphors arranged so that only the fluorescent light emitted from the surfaces 4A to 6A of the phosphors 4 to 6 is incident on the prism 7. The light transmitted through ˜6 is not directed to the prism 7. Further, the back surfaces 4B to 6B of the phosphors 4 to 6 are mirror-finished, and the light emission efficiency is improved by reflecting light to the back surfaces 4B to 6B.

The prism 7 is an optical system that deflects the fluorescent light of the phosphors 4 to 6. In the present embodiment, a cross dichroic prism is used for the prism 7, and the phosphors 4 to 6 are arranged to face each other on the three surfaces of the prism 7. Fluorescent light emitted from the phosphors 4 to 6 is transmitted through the dichroic mirrors 13R, 13G, and 13B, enters the prism 7, and exits toward the projection lens group 8.
The projection lens group 8 enlarges and projects the light emitted from the prism 7 toward the light projecting surface 21 of the screen 20 disposed in front of the projector apparatus 1, and in the R, G, and B color lights. In order to prevent the projected image from becoming unclear due to chromatic aberration or the like, the lens is configured as a combined lens in which a plurality of condensing elements are arranged in the optical axis direction.

  The control unit 10 has an angle control function for controlling the angle of the movable mirror 3, a lighting control function for controlling lighting of the laser light source 2, and a scanning control function for controlling scanning of the movable mirror 3. In the angle control, the control unit 10 outputs image data (input image signal) output from a computer 30 (which may be another electronic device having an image output function such as a digital video camera) connected to the projector device 1. ), An angle control signal S1 is output to the drive mechanism 3A to adjust the angle of the movable mirror 3. In the light emission control, the control unit 10 outputs a lighting control signal S2 to the laser light source 2 based on the input image signal, controls the lighting of the emitted light from the laser light source 2, and adjusts the luminance. In the scanning control, the control unit 10 outputs a scanning control signal S3 to the movable mirror 3 based on the input image signal, and scans the phosphors 4 to 6 with the light emitted from the laser light source 2.

Next, the operation of the present embodiment will be described. In the following description, it is assumed that the number of frames of an image displayed per second by the projector device 1 is 60 frames.
FIG. 2 is a timing chart showing the projection operation of the projector device 1.
When projecting an image of one frame, the projector apparatus 1 displays the R plane, G plane, and B plane obtained by separating the image into R, G, and B colors in one frame (1/60 second). The image is sequentially projected onto the screen 20 in a divided manner so that each image is visually synthesized and visually recognized.

  Specifically, one frame is divided into three to provide an R period Tr, a G period Tg, and a B period Tb, and the control unit 10 supplies the angle control signal S1 to the drive mechanism 3A in the R period Tr. Then, the angle of the movable mirror 3 is changed toward the red phosphor 4, and similarly, the movable mirror 3 is directed toward the green phosphor 5 during the G period Tg and toward the blue phosphor 6 during the B period Tb. change.

  In the R period Tr, following the supply of the angle control signal S1, the controller 10 supplies a lighting control signal S2 that has been subjected to a predetermined voltage or a predetermined PWM control according to the brightness required for each pixel to the laser light source 2. And the output of the laser light source 2 is adjusted. Thereby, red light is emitted in the R light emission period Ter, and similarly, green light is emitted in the G light emission period Teg and blue light is emitted in a time division manner in the B light emission period Teb. Therefore, the light of each color of R, G, B is sequentially emitted at a period (1/180 seconds) three times as long as one frame.

On the other hand, in the R period Tr, following the supply of the angle control signal S1, the control unit 10 outputs the scanning control signal S3 to the drive mechanism 3A based on the R plane indicating the R component of the image data to be projected. Thereby, in the R light emission period Ter, an image of only the R component is projected on the screen 20. Similarly, an image of only the G component is projected in the G light emission period Teg, and an image of only the B component is projected in the B light emission period Teb. As a result, R, G, and B color component images are sequentially projected during one frame, and the color component images are color-synthesized and viewed by humans.
In addition, when adjusting the brightness | luminance of a projection image, the laser light source 2 inject | emits by changing the voltage value or PWM control value (pulse width etc.) of the lighting control signal S2 which the control part 10 supplies to the laser light source 2. Controls the amount of light to be emitted.

  As described above, according to the present embodiment, the emitted light of the laser light source 2 is converted into the red phosphor 4, the green phosphor 5, and the blue phosphor according to the color and the pixel position specified in the input image signal. The movable mirror 3 that is incident on any predetermined position of the phosphor 6 is provided. With this configuration, since the movable mirror 3 scans the phosphors 4 to 6, an expensive DMD is unnecessary, and the cost of the projector device 1 can be reduced. In the case of an optical system using a conventional DMD, excess light is discarded in order to adjust the luminance for each pixel. In the present embodiment, by controlling the output of the laser light source 2, each pixel is controlled. Since the emission intensity of the phosphors 4 to 6 positioned can be adjusted, the brightness can be adjusted without outputting the light to be discarded, and the energy saving property is excellent. Further, since the output of the laser light source 2 is suppressed and excess light is not emitted, energy saving of the cooling mechanism provided in the projector device 1 can be achieved.

A plurality of laser light sources 2 may be provided. For example, when one laser light source 2 is used and the wavelength of the laser light is converted into light of each color of R, G, and B, for example, a laser light source is provided for each color. In comparison, the projector device 1 can be reduced in cost and energy saving can be achieved.
In addition, since the phosphors 4 to 6 are irradiated with the laser beam for each pixel, the thermal load of the phosphors 4 to 6 is higher than that of the conventional configuration in which the laser beam is focused on one point of the phosphor to increase the optical efficiency. And the lifetime of the phosphors 4 to 6 can be extended.

  In addition, according to the present embodiment, since the laser light source 2 emits light in the blue wavelength region or less, a phosphor material that can emit each color of R, G, and B with one laser light source 2 can be easily obtained. Can be selected.

  Further, according to the present embodiment, since the red phosphor 4, the green phosphor 5, and the blue phosphor 6 are of the reflection type, even if the phosphors 4 to 6 are damaged or detached, the projector device 1 The laser beam is not emitted from. Moreover, by making the phosphors 4 to 6 reflective, a cooling mechanism can be disposed on the back surfaces 4B to 6B of the phosphors 4 to 6, and the phosphors 4 to 6 can be easily cooled.

However, the above embodiment is an aspect of the present invention, and it is needless to say that the embodiment can be appropriately changed without departing from the gist of the present invention.
For example, in the above-described embodiment, the phosphor is a reflection type, but may be a transmission type in which light from the movable mirror is transmitted through the phosphor and incident on the prism.
Moreover, in the said embodiment, although the movable mirror was a MEMS scanner mirror, it is not limited to this, A galvanometer mirror may be sufficient.

In the above embodiment, the laser light source is a light source that emits light in the blue wavelength range or less, but is not limited thereto, and may emit light in other wavelength ranges. . In this case, a phosphor material that can emit R, G, and B colors with light in other wavelength ranges may be selected.
In the above embodiment, the case of using phosphors of three colors of red, green, and blue is described. However, the present invention is not limited to these colors, and two types of phosphors of two colors may be used. It is also possible to use three or more phosphors of three or more colors.

DESCRIPTION OF SYMBOLS 1 Projector apparatus 2 Laser light source 3 Movable mirror 4 Red fluorescent substance 5 Green fluorescent substance 6 Blue fluorescent substance 7 Prism (optical system)
21 Emitting surface

Claims (3)

The light emitted from the laser light source is incident on a red phosphor that emits red fluorescence, a green phosphor that emits green fluorescence, and a blue phosphor that emits blue fluorescence, and the fluorescence light of each phosphor is deflected by an optical system and projected. In a projector device that projects light onto a light surface,
Movable light that is emitted from the laser light source is incident on a predetermined position of the red phosphor, the green phosphor, or the blue phosphor according to the color specified in the input image signal and the pixel position. With mirror,
A projector device characterized by that.   The projector apparatus according to claim 1, wherein the laser light source emits light having a blue wavelength range or less.   The projector device according to claim 1, wherein the red phosphor, the green phosphor, and the blue phosphor are of a reflection type.

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