JP2008032895A - Image display device - Google Patents

Abstract

An image display apparatus capable of accurately resonating a scanning unit and reliably preventing laser light from being irradiated to the outside when the scanning unit is stopped for some reason.
Light source devices 11a and 11b that emit laser beams in a plurality of different directions and irradiate different areas on a projection surface, and laser beams in a plurality of different emission directions emitted from the light source devices 11a and 11b. A scanning unit 20 that scans toward the projection surface; a housing 10 that houses the light source devices 11a and 11b and the scanning unit 20; and a control unit 40 that controls the emission of laser light from the light source devices 11a and 11b. When the scanning unit 20 is in an equilibrium state, the light source devices 11 a and 11 b are arranged so that a plurality of laser beams in different emission directions emitted from the light source devices 11 a and 11 b are not emitted to the outside of the housing 10. It is characterized by that.
[Selection] Figure 2

Description

  The present invention relates to an image display device.

  In recent projection type image display apparatuses, a discharge lamp such as an ultrahigh pressure mercury lamp is generally used as a light source. However, such a discharge lamp has problems such as a relatively short life, difficult to light instantaneously, a narrow color reproducibility range, and ultraviolet rays emitted from the lamp may deteriorate the liquid crystal light bulb. . Therefore, a projection type image display apparatus using a laser light source that emits monochromatic light instead of such a discharge lamp has been proposed.

  In the case of a scanning projection type image display apparatus, in order to display an image using a laser light source, it is necessary to make the intensity of the laser light emitted from the laser light source higher than a certain level. As a result, when the image display apparatus stops due to some factor, there is a possibility that the laser light continues to irradiate one point and causes damage to the projection surface. For this reason, there has been proposed a projector that prevents laser light from being emitted from the housing of the apparatus to the outside when the scanning unit stops due to some failure (see, for example, Patent Document 1 and Patent Document 2).

  The projector described in Patent Document 1 detects a scanning operation of a laser light source, a power supply unit that supplies power to the laser light source, a power transmission unit provided between the laser light source and the power supply unit, and an optical scanning unit. And an optical scanning detection unit. When the optical scanning detection unit detects that the optical scanning unit is operating normally, the power transmission unit transmits power to the laser light source. When the optical scanning detection unit detects that the optical scanning unit is not operating normally, the power transmission unit cuts off the power supply to the laser light source. Accordingly, the generation of the laser beam can be blocked by the optical scanning detection unit when the laser beam is not normally scanned.

The projector described in Patent Document 2 includes a laser light source, a scanning unit, and a holding unit that holds the scanning unit at a predetermined position. This holding unit constantly applies a load to the scanning unit. Then, when the scanning unit is stopped for some reason, a load is applied to the scanning unit so that the laser beam is forced to the outside of the opening of the housing. In this way, when the scanning operation of the scanning unit is not normally performed, the holding unit prevents the laser light from being emitted to the outside of the projector housing.
JP 2004-333698 A JP 2006-85189 A

  The following problems remain in the conventional technology. That is, in the projector described in Patent Document 1, when the optical scanning detection unit that stops the laser beam fails, the laser beam may be emitted outside the housing. In the projector described in Patent Document 2, the load works in a direction that hinders the high-speed operation of the scanning unit. In general, a high-speed operation of 10 kHz or more is required to move a scanning unit necessary for a laser scan display, and a scanning unit capable of this high-speed operation is limited to a resonance type scanning unit. However, when a load is applied to the scanning unit, there arises a problem that it is difficult for the scanning unit to resonate with high accuracy.

  The present invention has been made in order to solve the above-described problems, and resonates the scanning unit with high accuracy and ensures that the laser beam is irradiated to the outside when the scanning unit stops for some reason. An object of the present invention is to provide an image display device that can be prevented.

In order to achieve the above object, the present invention provides the following means.
An image display device according to the present invention emits laser light in a plurality of different directions, and each of the laser light irradiates at least a part of a different region of the projection surface, and a plurality of light emitted from the light source device Scanning means for scanning laser beams in different emission directions toward the projection surface, a housing for housing the light source device and the scanning means, and control means for controlling emission of the laser light from the light source device When the scanning means is in an equilibrium state, the light source device is arranged so that a plurality of laser beams in different emission directions emitted from the light source device are not emitted outside the casing. Features.

  In the image display apparatus according to the present invention, a plurality of laser beams in different emission directions emitted from the light source device are scanned toward the projection surface by the scanning unit. At this time, the emission of laser light from the light source device is controlled by the control means. Here, when the scanning unit fails for some reason, the scanning unit stops in an equilibrium state. When the scanning unit is in an equilibrium state, a plurality of laser beams in different directions emitted from the light source device are not emitted outside from the housing. That is, when the scanning unit is in an equilibrium state, the laser light is not scanned on the projection surface due to the arrangement of the light source device.

Therefore, since the scanning means of the present invention is not loaded in a direction that hinders high-speed operation as in the prior art, the scanning means can resonate with high accuracy. Furthermore, even if the scanning unit stops for some reason and is in an equilibrium state, even if the laser light is emitted from the light source device, the laser light is not irradiated outside the housing. Thereby, the image display apparatus of the present invention reliably prevents the laser light from being emitted outside the housing.
Furthermore, since the image display apparatus of the present invention irradiates the projection surface with a plurality of laser beams, compared with the case of irradiating the projection surface with one laser beam, the projection surface of the projection surface is irradiated with one laser beam. Since it is sufficient to illuminate a part, the scanning deflection angle of the scanning means can be reduced.
Note that the equilibrium state of the scanning means includes a state where the scanning unit is out of order and means a state where a force for scanning the laser beam is not applied.

  In the image display device of the present invention, the light source device emits laser light in a first light source device that emits laser light and an emission direction different from the emission direction of the laser light emitted from the first light source device. It is preferable that the control means controls the laser light to be emitted from one of the first light source device and the second light source device to the scanning means.

  In the image display device according to the present invention, the laser light emitted from the first light source device and the laser light emitted from the second light source device are scanned toward the projection surface by the scanning means. At this time, the control unit emits one of the laser light emitted from the first light source device and the laser light emitted from the second light source device according to the inclination of the scanning unit. Here, when the scanning unit fails and stops in an equilibrium state, the laser light emitted from the first light source device and the laser light emitted from the second light source device are not emitted to the outside.

  Thus, when the light source device includes the first light source device and the second light source device that emit laser beams in different emission directions, the laser light is not emitted outside the casing when the scanning unit is in an equilibrium state. In this way, the first light source device and the second light source device may be arranged. Thereby, the freedom degree of arrangement | positioning of a 1st light source device and a 2nd light source device increases. Therefore, since the arrangement of the first light source device and the second light source device is free, the direction of the laser light emitted from the light source device can be adjusted. Thereby, the image display device of the present invention reliably prevents the laser light emitted from the first light source device and the laser light emitted from the second light source device from being emitted outside the housing.

  In the image display device of the present invention, the light source device includes a light source that emits laser light, a branching unit that branches an optical path of the laser light emitted from the light source into a first optical path and a second optical path, Switching means for switching between the presence / absence of emission of laser light traveling in the first optical path and the presence / absence of emission of laser light traveling in the second optical path, and an emission direction of the laser light emitted from the first optical path; Unlike the emission direction of the laser light emitted from the second optical path, the control means emits laser light traveling in one of the first optical path and the second optical path to the scanning means. It is preferable to control the switching means.

In the image display device according to the present invention, the laser light emitted from the light source is branched by the branching means into the laser light traveling in the first optical path and the laser light traveling in the second optical path. These laser beams are scanned toward the projection surface by the scanning means. At this time, either one of the laser light emitted from the first optical path and the laser light emitted from the second optical path according to the inclination of the scanning means is emitted by the control means. Here, in the image display device of the present invention, when the scanning unit fails and stops in an equilibrium state, the laser light emitted from the first optical path and the laser light emitted from the second optical path are emitted to the outside. Can be prevented.
In this way, by providing the branching means, only one light source for emitting the laser light is required, so that the cost of the entire apparatus can be suppressed.

  In the image display device of the present invention, it is preferable that the first optical path and the second optical path are single mode waveguides.

  In the image display device according to the present invention, since the first optical path and the second optical path are single-mode waveguides transmitted in a single mode, the exit end face of each waveguide is regarded as a laser beam equivalent to a light source. be able to. That is, in the single mode, even if light having a strong straight traveling property is input, the laser light can travel with almost no dispersion in the waveguide. Therefore, since the laser beam can be propagated without impairing the quality of the laser beam, a high-quality and clear image can be displayed.

  In the image display device of the present invention, it is preferable that the scanning unit is a MEMS mirror.

  In the image display device according to the present invention, an image is projected onto a projection surface by scanning light emitted from the light source device with a MEMS (Micro Electro Mechanical Systems) mirror. In this way, by using the MEMS mirror, the optical system in the housing can be reduced in size, and furthermore, compared to the case of using other mirrors, the overall power consumption of the apparatus is reduced, the noise is reduced, the vibration is reduced, and the like. It becomes possible to obtain the effect.

  Hereinafter, an embodiment of an image display device according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

[First Embodiment]
FIG. 1 is a perspective view showing the internal structure of the image display apparatus according to the present embodiment, FIG. 2 is a top view showing scanning by the scanning means of the image display apparatus, and FIGS. It is a figure which shows the positional relationship of the screen and laser beam by an angle of declination.

As shown in FIG. 1, a projection optical system 2 that projects an image on a screen 30 is disposed inside the housing 10 of the image display device 1. In addition, an opening 5 is formed on the front surface 10a of the housing 10 so that laser light reflected by a MEMS mirror 20 described later can be emitted to the outside of the housing 10.
As shown in FIG. 2, the projection optical system 2 includes a first light source device (light source device) 11a and a second light source device (light source device) 11b that emit red laser light, and first and second light source devices 11a, And a MEMS mirror (scanning means) 20 that scans the laser light emitted from 11b. Further, as shown in FIG. 2, the projection optical system 2 controls the control unit 40 to control the laser light to be emitted from one of the first light source device 11a and the second light source device 11b to the screen 30. (Control means).

The first and second light source devices 11a and 11b are semiconductor lasers (laser diodes) that emit red laser light having a center wavelength of 658 nm. However, this wavelength is only an example.
As shown in FIG. 2, the MEMS mirror 20 scans laser light emitted from the first and second light source devices 11 a and 11 b on a screen (projected surface) 30. Further, the light reflected by the MEMS mirror 20 passes through the opening 5 and illuminates the screen 30.

Next, the MEMS mirror will be described.
As shown in FIG. 2, the MEMS mirror 20 is arranged so that the reflection surface 20 a is substantially parallel to the front surface 10 a of the housing 10 in an equilibrium state. The declination of the MEMS mirror 20 indicates the rotation angle of the MEMS mirror 20, and the state shown in FIG.
The 1st light source device 11a is arrange | positioned so that incident angle (theta) 1 with respect to the reflective surface 20a of the MEMS mirror 20 of the emitted laser beam may be set to about 60 degrees. In addition, the first light source device 11 a is disposed in the vicinity of the corner portion 10 b on the front surface 10 a side of the housing 10 with respect to the MEMS mirror 20. Similarly to the first light source device 11a, the second light source device 11b is arranged so that the incident angle θ2 of the emitted laser light is 60 °, and the corner portion 10b where the first light source device 11a is arranged. It is arrange | positioned in the vicinity of the corner | angular part 10c opposite to. That is, the emission direction of the laser light emitted from the first light source device 11a is different from the emission direction of the laser light emitted from the second light source device 11b.

The MEMS mirror 20 is provided with two pairs of permanent magnets and coils.
First, the pair of permanent magnets 21 and the coil 22 will be described. The permanent magnet 21 and the coil 22 vibrate the MEMS mirror 20.
Specifically, as shown in FIG. 2, the permanent magnet 21 is provided on a surface 20 b opposite to the reflecting surface 20 a of the MEMS mirror 20. In addition, a coil 22 is disposed inside the housing 10 so as to face the permanent magnet 21. The coil 22 is connected to the control unit 40. A magnetic field is generated between the permanent magnet 21 and the coil 22 by causing the control unit 40 to pass a current through the coil 22. Then, attractive force and repulsive force are generated by the magnetic force between the permanent magnet 21 and the coil 22. Therefore, when an electric current flows through the coil 22 and an attractive force is generated between the permanent magnet 21 and the coil 22, the MEMS mirror 20 vibrates clockwise around the rotation axis P, and between the permanent magnet 21 and the coil 22. When repulsive force is generated, the MEMS mirror 20 vibrates counterclockwise around the rotation axis P. Further, the MEMS mirror 20 can be driven biaxially around the rotation axis P and the rotation axis Q as shown in FIG.
In addition, the operation of the MEMS mirror on the horizontal scanning side, which requires high-speed operation, performs a resonance operation. On the other hand, the vertical scanning in which the MEMS mirror 20 operates at a low speed performs a flyback operation (an operation for returning the laser beam to a predetermined position) every frame.

Next, another pair of permanent magnet 26 and coil 27 will be described.
As shown in FIG. 2, the permanent magnet 26 is provided on the surface 20 b of the MEMS mirror 20 similarly to the permanent magnet 21. Further, a coil 27 is disposed inside the housing 10 so as to face the permanent magnet 26. The coil 27 is connected to the control unit 40. The control unit 40 calculates the deflection angle of the MEMS mirror 20 based on the current flowing through the coil 27. And the control part 40 drives the 1st light source device 11a or the 2nd light source device 11b according to the calculated deviation angle detection signal.

  Next, the positional relationship between the screen and the laser beam due to the deflection angle of the MEMS mirror will be described. The mirror is in an equilibrium state (initial state) with a declination of 0 °. That is, when the MEMS mirror 20 breaks down, it is stationary in this equilibrium state. 3B to 10B show the deflection angle of the MEMS mirror 20, and FIGS. 3A to 10A show the position of the laser beam with respect to the screen 30 as viewed from the MEMS mirror 20 side. In the figure, a black circle is a beam spot of laser light on the screen 30.

Specifically, as shown in FIGS. 3A and 3B, when the deflection angle of the MEMS mirror 20 is 0 °, the control unit 40 drives the second light source device 11b. Thereby, the laser light emitted from the second light source device 11b irradiates the outside of the left side 30a of the screen 30. When irradiating the outside of the left side 30 a and the outside of the right side 30 b of the screen 30, the laser light is actually blocked at the front surface 10 a of the housing 10, so that the laser beam is emitted from the opening 5 of the housing 10 to the outside. It is never injected.
Then, the control unit 40 vibrates the MEMS mirror 20 clockwise about the rotation axis P as shown in FIG. As a result, the laser light on the screen 30 moves to the center of the screen 30 (from the laser light indicated by the broken line to the laser light indicated by the solid line), as shown in FIGS.

Next, as shown in FIGS. 4A and 4B, the laser light on the screen 30 is scanned from the center of the screen 30 to the right side 30b side (the position of the maximum deflection angle in the clockwise direction of the MEMS mirror 20). Then, the control unit 40 vibrates the MEMS mirror 20 counterclockwise about the rotation axis P as shown in FIG. As a result, the laser beam on the screen 30 moves from the center of the screen 30 to the left side 30a (from the laser beam indicated by the broken line to the laser beam indicated by the solid line) as shown in FIGS. 6B, when the deflection angle of the MEMS mirror 20 is 0 °, the laser light emitted from the second light source device 11b is as shown in FIGS. 6A and 6B. The outside of the left side 30a side of the screen 30 is irradiated.
In this way, the laser light emitted from the second light source device 11b performs scanning in the region S shown in FIG.

Next, when the scanning of the region S shown in FIG. 2 is completed by the laser light, the controller 40 switches from driving the second light source device 11b to driving the first light source device 11a as shown in FIG. 7B. . As a result, the laser light emitted from the first light source device 11a irradiates the outer side of the screen 30 on the right side 30b side, as shown in FIGS.
Then, the control unit 40 causes the MEMS mirror 20 to vibrate counterclockwise about the rotation axis P as shown in FIG. As a result, the laser light on the screen 30 moves to the center of the screen 30 (from the laser light indicated by the broken line to the laser light indicated by the solid line), as shown in FIGS.

Next, as shown in FIGS. 8A and 8B, the laser beam on the screen 30 is scanned from the center of the screen 30 to the left side 30a slightly (the position of the maximum deflection angle in the counterclockwise direction of the MEMS mirror 20). Then, the control unit 40 vibrates the MEMS mirror 20 clockwise about the rotation axis P as shown in FIGS. 9 (a) and 9 (b). As a result, the laser beam on the screen 30 moves from the center of the screen 30 to the right side 30b (from the laser beam indicated by the broken line to the laser beam indicated by the solid line). Then, as shown in FIG. 10B, when the deflection angle of the MEMS mirror 20 is 0 °, the laser light emitted from the second light source device 11b is as shown in FIGS. 10A and 10B. The outside of the right side 30b side of the screen 30 is irradiated.
In this way, the laser light emitted from the first light source device 11a performs scanning within the region T shown in FIG.
When the scanning of the region T is completed by the laser light, the control unit 40 switches from driving the first light source device 11a to driving the second light source device 11b, and the positional relationship between the screen 30 and the laser light is shown in FIG. ) And (b).

  As described above, the control unit 40 alternately switches the driving of the first light source device 11a and the second light source device 11b. That is, switching between the first light source device 11a and the second light source device 11b is performed after the laser beam scans in the region S as shown in FIG. 6 (b) and in FIG. 10 (b). As shown, the laser light is performed after scanning the region T. As a result, the laser light emitted from the first light source device 11a and the laser light emitted from the second light source device 11b are scanned over the entire screen 30. Further, the region S and the region T overlap with each other at the center of the screen 30.

  As described above, when the region S and the region T are alternately scanned, the gradation data of each pixel is rearranged in accordance with the scanning operation of the laser beam based on the video signal, and the first light source device 11a and the second light source device are rearranged. By performing intensity modulation of the laser light emitted from 11b, a desired image can be displayed.

Further, as shown in FIG. 2, the first light source device 11a is configured such that when the deflection angle of the MEMS mirror 20 is 0 °, the emitted laser light is reflected by the MEMS mirror 20 and enters the second light source device 11b. Has been placed. Similarly, the second light source device 11b is arranged so that the emitted laser light is reflected by the MEMS mirror 20 and enters the first light source device 11a. In other words, when the MEMS mirror 20 fails for some reason, the deflection angle of the MEMS mirror 20 becomes 0 °, and therefore the MEMS mirror 20 is reflected by either the first light source device 11a or the second light source device 11b. The laser light thus emitted is not emitted from the opening 5 to the outside of the housing 10.
In FIG. 2, the optical axis O1 of the laser light emitted from the first light source device 11a and the optical axis O2 of the laser light emitted from the second light source device 11b are shifted from each other. O1 and the optical axis O2 overlap.

  In the image display device 1 according to the present embodiment, when the MEMS mirror 20 fails, the laser light is not scanned on the screen 30 due to the arrangement of the first light source device 11a and the second light source device 11b. Therefore, since the MEMS mirror 20 of the present invention is not loaded with the MEMS mirror 20 as in the prior art, the MEMS mirror 20 can resonate with high accuracy. Furthermore, even if the MEMS mirror 20 stops and becomes in an equilibrium state for some reason and the laser light is emitted from the first light source device 11a or the second light source device 11b, the laser light irradiates outside the opening 5. Therefore, the image display device 1 reliably prevents the laser light from being emitted outside the housing 10.

Furthermore, by providing the first light source device 11a and the second light source device 11b, the degree of freedom of arrangement of the first light source device 11a and the second light source device 11b is increased. Therefore, since the arrangement of the first light source device 11a and the second light source device 11b becomes free, the direction of the laser light emitted from the light source device can be adjusted.
When the deflection angle of the MEMS mirror 20 is 0 °, the first light source device 11a is arranged so that the emitted laser light is incident on the second light source device 11b, and the second light source device 11b is emitted. The laser beam was arranged so as to enter the first light source device 11a. Thereby, since the laser beam is not reflected inside the housing 10, it is possible to prevent disturbance from entering the MEMS mirror 20.
The control unit 40 controls the first light source device 11a or the second light source device 11b to be driven. However, when the MEMS mirror 20 is in an equilibrium state, laser light is emitted from both the light source devices 11a and 11b. You may control so that.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIGS. In each embodiment described below, portions having the same configuration as those of the image display device 1 according to the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
The MEMS mirror 20 of the image display device 50 according to the present embodiment has the same configuration as that of the first embodiment, but the configuration of the light source device 60 is different from that of the first embodiment. That is, the scanning on the screen 30 of the laser light reflected by the MEMS mirror 20 is the same as in the first embodiment.

  As shown in FIG. 11, the light source device 60 includes a light source 61 that emits laser light, and a Y-shaped branch member (branching means) 65 that guides the laser light emitted from the light source 61. The branching member 65 includes a main waveguide 61a through which the laser light emitted from the light source 61 travels, a first waveguide (first optical path) 63 that branches the laser light guided through the main waveguide 61a into two laser beams, and a first optical path. 2 waveguides (second optical path) 64.

  Specifically, as shown in FIG. 12, the light source device 60 includes a coupling optical system 62 that causes the laser light emitted from the light source 61 to enter the branching member 65, and the emission end face 63 a side of the first waveguide 63. A collimator lens 66 is provided, and an AOM (acousto-optic element) 67 into which the light emitted from the collimator lens 66 enters. Similarly, a collimator lens 68 and an AOM (acousto-optic element) 69 are also provided on the exit end face 64 a side of the second waveguide 64.

The coupling optical system 62 is configured by a collimating lens, a cylindrical lens, or the like, and converts incident laser light into a light beam form suitable for the branching member 65.
The AOMs (switching means) 67 and 69 are connected to a control unit (control means) 70. When a high-frequency signal is input from the control unit 70, an ultrasonic wave corresponding to the high-frequency signal propagates, and an acoustooptic effect acts on the laser light transmitted through the inside. Diffraction occurs due to the action of the acousto-optic effect, and laser light having an intensity corresponding to the input high-frequency signal is emitted from the AOMs 67 and 69 as diffracted light. That is, the AOMs 67 and 69 control ON and OFF of the emission of the laser light emitted from the first and second waveguides 63 and 64 to the subsequent stage. In addition, the control unit 70 controls the AOM 67 and the AOM 69 so that the laser light enters the MEMS mirror 20 from one of the first waveguide 63 and the second waveguide 64.
Moreover, the control part 70 controls the drive of the MEMS mirror 20 similarly to the control part 40 of 1st Embodiment.

  Further, in FIG. 12, the laser beams emitted from the AOM 67 and AOM 69 are shown to be parallel to each other, but actually, as shown in FIG. The emission direction of the light is different from the emission direction of the laser light emitted from the emission end face 64 a of the second waveguide 64.

The first waveguide 63 is arranged so that the emitted laser light is reflected by the MEMS mirror 20 and incident on the second waveguide 64 when the deflection angle of the MEMS mirror 20 is 0 °. Similarly, the second waveguide 64 is arranged so that the emitted laser light is reflected by the MEMS mirror 20 and enters the first waveguide 63. That is, when the MEMS mirror 20 fails for some reason, the declination angle of the MEMS mirror 20 becomes 0 °. Therefore, the laser light is emitted from either the first waveguide 63 or the second waveguide 64. The laser light reflected by the MEMS mirror 20 is not emitted from the opening 5 to the outside of the housing 10.
The light source 61 is a semiconductor laser (laser diode) that emits red laser light having a center wavelength of 658 nm. However, this wavelength is only an example.

  In the image display device 50 according to the present embodiment, when the MEMS mirror 20 fails and stops in an equilibrium state, the laser light emitted from the first waveguide 63 and the laser light emitted from the second waveguide 64 are opened. Injecting from 5 to the outside of the housing 10 can be prevented. Furthermore, since the branch member 65 is provided, only one light source 61 for emitting laser light is required, so that the cost of the entire apparatus can be suppressed.

  The first and second waveguides 63 and 64 are preferably single mode waveguides. In this case, the exit end faces 63a and 64a of the respective waveguides 63 and 64 can be regarded as laser light equivalent to the light source 61. That is, in the single mode, even when light having a strong straight traveling property is input, the laser light can be advanced in the waveguides 63 and 64 with almost no dispersion. Therefore, since the laser beam can be propagated without impairing the quality of the laser beam, a high-quality and clear image can be displayed.

[Modification of Second Embodiment]
In the present embodiment, the AOMs 67 and 69 are used to control the laser light emitted from one of the first waveguide 63 and the second waveguide 64 so as to enter the MEMS mirror 20. You may control using the optical switch element (switching means) 80 as shown in FIG.

The optical switch element 80 includes a 3 dB directional coupler 81 provided with an incident end face 81a, a 3 dB directional coupler 83 provided with an exit end face 83b, a directional coupler 81, and a directional coupler 83. And an optical element 82 made of a material having an electro-optic effect disposed between the two. As the optical element 82, for example, a dielectric material having a secondary electro-optic effect and a high dielectric constant is used. As such a dielectric material, an electro-optic element of KTa _1-x Nb _x O ₃ (also referred to as KTN) is preferably used. The optical element 82 may be a photorefractive element, a thermo-optic element, or the like in addition to the electro-optic element.
Further, the laser light emitted from the first waveguide 63 is incident on the optical switch element 80, and the laser light emitted from the second waveguide 64 is incident and emitted. A fourth waveguide 85 is formed.

An electrode 82 a is formed on the third waveguide 84 of the optical element 82. Laser light is emitted from either the third waveguide 84 or the fourth waveguide 85 in accordance with the electric field applied to the electrode 82a.
In FIG. 13, the laser beams emitted from the third waveguide 84 and the fourth waveguide 85 are shown to be parallel to each other, but the emission direction of the laser beams emitted from the third waveguide 84 is shown. Unlike the emission direction of the laser light emitted from the fourth waveguide 85, the laser light emitted from the third and fourth waveguides 84 and 85 is incident on the MEMS mirror 20. .

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in each of the above embodiments, the first and second light source devices made of semiconductor lasers that emit red single-color laser light are used. As the light source device, semiconductor lasers of a plurality of types of wavelengths are provided, and each semiconductor laser is provided. May be controlled separately. In other words, full-color display is possible by using semiconductor lasers of three colors of R, G, and B or more and controlling them separately.
Further, the first and second light source devices may be plural instead of single. In this configuration, by using a plurality of semiconductor lasers for light of each wavelength, it is possible to obtain an effect of easily realizing improvement in luminance and gradation expression.
Further, although the MEMS mirror is used as the scanning means, it may be of a type that stops in an equilibrium state (initial state) with a declination of 0 ° when a failure occurs. For example, a galvanometer mirror may be used as a device other than the MEMS mirror. good.

When the deflection angle of the MEMS mirror 20 is 0 °, the first light source device is arranged so that the emitted laser light is incident on the second light source device, and the second light source device Although it arrange | positions so that it may inject into a 1st light source device, arrangement | positioning of a 1st, 2nd light source device is not restricted to this. That is, when the deflection angle of the MEMS mirror 20 is 0 °, the first and second light source devices are arranged so that the emitted laser beams are not emitted from the opening 5 of the housing 10 to the outside. good. The same applies to the first waveguide and the second waveguide of the second embodiment, and the arrangement is not limited to the above.
Further, the regions S and T are scanned with the laser beams so as to overlap each other at the center of the screen, but they do not have to be overlapped, and any configuration can be used as long as the entire screen can be illuminated by each laser beam.
Further, the light source device has been described by taking, as an example, a device that emits laser light in two different directions, but the screen may be irradiated with three or more laser beams.

It is a top view which shows the projection optical system of the image display apparatus which concerns on 1st Embodiment of this invention. It is a top view which shows the scanning by the scanning means of the image display apparatus of FIG. It is a figure which shows the positional relationship of the screen and laser beam by the deflection angle of the scanning means of FIG. It is a figure which shows the positional relationship of the screen and laser beam by the deflection angle of the scanning means of FIG. It is a figure which shows the positional relationship of the screen and laser beam by the deflection angle of the scanning means of FIG. It is a figure which shows the positional relationship of the screen and laser beam by the deflection angle of the scanning means of FIG. It is a figure which shows the positional relationship of the screen and laser beam by the deflection angle of the scanning means of FIG. It is a figure which shows the positional relationship of the screen and laser beam by the deflection angle of the scanning means of FIG. It is a figure which shows the positional relationship of the screen and laser beam by the deflection angle of the scanning means of FIG. It is a figure which shows the positional relationship of the screen and laser beam by the deflection angle of the scanning means of FIG. It is a schematic perspective view which shows the image display apparatus which concerns on 2nd Embodiment of this invention. It is a top view which shows the light source device of the image display apparatus of FIG. It is a perspective view which shows the modification of the image display apparatus which concerns on 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,50 ... Image display apparatus, 5 ... Opening part, 10 ... Housing | casing, 11a ... 1st light source device (light source device), 11b ... 2nd light source device (light source device), 20 ... MEMS mirror (scanning means), 30 ... screen (projected surface), 40, 70 ... control unit (control means), 63 ... first waveguide (first optical path), 64 ... second waveguide (second optical path), 67, 69 ... AOM (switching) Means), 80... Optical switch element (switching means)

Claims (5)

A light source device that emits laser light in a plurality of different directions, and each laser light irradiates at least a part of a different region of the projection surface;
Scanning means for scanning a plurality of laser beams in different emission directions emitted from the light source device toward the projection surface;
A housing that houses the light source device and the scanning means;
Control means for controlling the emission of the laser light from the light source device,
When the scanning means is in an equilibrium state, the light source device is arranged so that a plurality of laser beams in different emission directions emitted from the light source device are not emitted outside the casing. Image display device. The light source device includes a first light source device that emits laser light, and a second light source device that emits laser light in an emission direction different from the emission direction of the laser light emitted from the first light source device,
2. The image according to claim 1, wherein the control unit performs control so that laser light is emitted from one of the first light source device and the second light source device to the scanning unit. 3. Display device. The light source device emits laser light, and branching means for branching an optical path of the laser light emitted from the light source into a first optical path and a second optical path;
Switching means for switching presence / absence of emission of laser light traveling in the first optical path and presence / absence of emission of laser light traveling in the second optical path;
The emission direction of the laser light emitted from the first optical path is different from the emission direction of the laser light emitted from the second optical path,
The control means controls the switching means so that laser light traveling in either one of the first optical path and the second optical path is emitted to the scanning means. The image display device described.   The image display apparatus according to claim 3, wherein the first optical path and the second optical path are single-mode waveguides. The image display apparatus according to claim 1, wherein the scanning unit is a MEMS mirror.

Images