JP2022152648A - Light source device and projector - Google Patents

Abstract

To reduce the size of a light source device and a projector.SOLUTION: A light source device 11 include a light emitter 12 for emitting light, and a scan element 13 for scanning the light. A progress vector of the light includes only a positive component for a component perpendicular to a surface of the scan element 13. The light emitter 12 and the scan element 13 are thus unified.SELECTED DRAWING: Figure 1

Description

The present invention relates to a light source device and a projector incorporating this light source device.

2. Description of the Related Art Conventionally, projectors have been used as image projection devices for projecting images such as computer screens and video images onto a screen. In these projectors, light emitted from a light source device is reflected on a MEMS (Micro Electro Mechanical Systems) mirror and scanned, thereby projecting an image onto a screen (for example, Patent Document 1).

JP 2008-185943 A

However, in conventional projectors, it is difficult to reduce the size of the projector because the light source and the mirror are separated from each other in the configuration in which the light from the light source is reflected on the mirror.

In order to solve the above-described problems, a light source device according to the present invention includes a light emitting element that emits light and a scanning element that scans the light, and the traveling vector of the light is directed to the surface of the scanning element. It is characterized by including only positive components in the vertical direction.

Further, in the light source device according to the present invention, the scanning element may rotate in biaxial directions.

Further, in the light source device according to the present invention, a light emitting element may be mounted on the scanning element.

Further, in the light source device according to the present invention, the scanning element may include a light transmitting portion, and light emitted from the light emitting element may pass through the light transmitting portion.

Further, in the light source device according to the present invention, a photorefractive element may be provided in the light transmitting portion.

Further, in the light source device according to the present invention, the scanning element includes a fixed frame, a movable frame, and a movable portion, and the movable frame is moved through first beams formed on both sides of the movable frame. , the movable portion is connected to the interior of the movable frame via second beams formed on both sides of the movable portion, and the direction of the first beam is the It may be perpendicular to the direction of the second beam.

A projector according to the present invention includes the light source device and a control section.

According to the present invention, a light emitting element and a scanning element can be integrated, and a compact light source device and projector can be provided.

FIG. 1 is a block diagram showing the configuration of a projector according to the first embodiment of the invention. FIG. 2 is a diagram for explaining the operation of the light source device according to the first embodiment of the invention. FIG. 3 is a diagram showing the configuration of the light source device according to the first embodiment of the present invention. FIG. 4 is a schematic side view for explaining the operation of the light source device according to the first embodiment of the invention. FIG. 5 is a diagram showing the configuration of a light source device according to a second embodiment of the invention.

<First embodiment>
A light source device and a projector according to a first embodiment of the invention will be described with reference to FIGS.

<Structure of Light Source Device and Projector>
As shown in FIG. 1, the projector 1 according to this embodiment includes a light source device 1_1 and a control section 1_4. The light source device 1_1 includes a light emitting element 1_2 and a scanning element 1_3, and the control section 1_4 includes a light emitting element driving power supply 1_5 and a scanning element driving power supply 1_6. The light emitting element 1_2 is connected to the light emitting element driving power supply 1_5, and the scanning element 1_3 is connected to the scanning element driving power supply 1_6.

<Operation of Light Source Device>
The operation of the light source device 1_1 in the projector 1 according to this embodiment will be described with reference to FIG. 2(a). For comparison, FIG. 2B shows the configuration of a light source device of a conventional projector.

Here, the direction perpendicular to the exit surface (surface) of the light source device 1_1 or the scanning element 1_3' is defined as the Z direction. Also, the positive direction (Z+ direction) in the Z direction is defined as the direction in which light is emitted from the light source device 1_1 or the scanning element 1_3'. Also, the negative direction (Z− direction) in the Z direction is the direction opposite to the side from which light is emitted from the light source device 1_1 or the scanning element 1_3'.

In the configuration of the light source device of the conventional projector, the emitted light L of the light emitting element 1_2' is reflected by the scanning element 1_3', and the scanning element 1_3' is driven (rotated) to scan the reflected light R.

In this configuration, as shown in FIG. 2(b), the traveling vector of the emitted light L from the light emitting element 1_2' includes a negative Z-direction component (Z-), and the traveling vector of the reflected light R from the scanning element 1_3' A vector contains a positive Z-direction component (Z+).

Thus, the light travel vector in this configuration includes a negative Z-direction component (Z−) and a positive Z-direction component (Z+).

Therefore, in the configuration of the light source device of the conventional projector, since the reflected light R is used, a predetermined distance is required between the light emitting element 1_2' and the scanning element 1_3', which makes it difficult to reduce the size of the projector.

On the other hand, in the light source device 1_1 of the projector 1 according to the present embodiment, the emitted light L or the transmitted light T is used without using reflected light by integrating the light emitting element 1_2 and the scanning element 1_3. The emitted light L or transmitted light T is scanned and projected by driving (rotating) the scanning element 1_3.

In this configuration, as shown in FIG. 2(a), the traveling vector of the emitted light L or the transmitted light T from the light source device 1_1 does not contain the negative Z-direction component (Z-) and the positive Z-direction component (Z+ ) only.

Therefore, in the light source device 1_1 according to the present embodiment, the light emitting element 1_2 and the scanning element 1_3 are integrated without using reflected light, so that the size of the projector can be reduced.

<First embodiment>
A light source device and a projector according to a first embodiment of the invention will be described with reference to FIGS.

<Structure of Light Source Device and Projector>
A projector 10 according to this embodiment has the same configuration as that of the first embodiment. Also, the light source device 11 according to this embodiment includes a light emitting element 12 and a scanning element 13 .

3A and 3B respectively show a schematic bird's-eye view and a schematic front view of the light source device 11 according to this embodiment. In the light source device 11, the light emitting element 12 is mounted on the scanning element 13 as shown in FIGS.

An electromagnetically driven MEMS is used for the scanning element 13 . The scanning element 13 includes a movable frame 132 rotatable about a first axis 130_1, a fixed frame 131 supporting the movable frame 132, and a second axis 130_2 orthogonal to the first axis 130_1. and a movable portion 133 formed to be rotatable.

Also, on both sides of the fixed frame 131, there are a first magnet (N pole) 135_1 and a second magnet (S pole) 135_2 for forming a magnetic field in the direction between the first axis 130_1 and the second axis 130_2. are placed respectively. For example, the north pole of the first magnet 135_1 and the south pole of the second magnet 135_2 are arranged on the diagonal line of the fixed frame 131 . The first magnet (north pole) 135_1 and the second magnet (south pole) 135_2 can be formed of permanent magnets or electromagnets, for example.

The movable frame 132 is connected inside the fixed frame 131 via first beams 134_1 formed on both sides of the movable frame 132 in the direction of the first axis 130_1.

Further, as shown in FIG. 3B, the movable frame 132 is provided with a first drive coil 136_1 for rotating the movable frame 132 about the first axis 130_1. For example, the first drive coil 136_1 is wound multiple times in the plane of the movable frame 132, and one end of the first drive coil 136_1 is connected to the first electrode 137_1 of the fixed frame 131 via the first beam 134_1. The other end is connected to the second electrode 137_2 of the fixed frame 131 via the first beam 134_1.

A first signal for driving the movable frame 132 is applied to the first drive coil 136_1. When the first signal is applied to the first driving coil 136_1, the magnetic field formed by the first magnet (N pole) 135_1 and the second magnet (S pole) 135_2 and the current flowing through the first driving coil 136_1. The generated Lorentz force drives the movable frame 132 to rotate about the first shaft 130_1.

On the other hand, the movable part 133 is arranged inside the movable frame 132 and connected to the movable frame 132 . The movable portion 133 is connected to the interior of the movable frame 132 via second beams 134_2 formed on both sides of the movable portion 133 in the direction of the second axis 130_2.

Here, the direction of the first axis 130_1 and the direction of the second axis 130_2 are directions orthogonal to each other. Therefore, extension lines of the first beam 134_1 and the second beam 134_2 are also orthogonal to each other.

Further, as shown in FIG. 3B, the movable portion 133 is provided with a second drive coil 136_2 for rotating the movable portion 133 about the second shaft 130_2. For example, the second drive coil 136_2 is wound multiple times in the plane of the movable part 133, and one end of the second drive coil 136_2 is connected to the fixed frame 131 via the first beam 134_1 and the second beam 134_2. It is connected to a third electrode 137_3, and the other end is connected to a fourth electrode 137_4 of the fixed frame 131 via a first beam 134_1 and a second beam 134_2.

A second signal for driving the movable portion 133 is applied to the second drive coil 136_2. When the second signal is applied to the second driving coil 136_2, the magnetic field formed by the first magnet (N pole) 135_1 and the second magnet (S pole) 135_2 and the current flowing through the second driving coil 136_2. The generated Lorentz force drives the movable portion 133 to rotate about the second shaft 130_2.

The light emitting element 12 is mounted on the movable portion 133 of the scanning element 13 . The light emitting element 12 is composed of a red light source element that emits red laser light, a green light source element that emits green laser light, and an element that emits blue laser light.

For example, the red light source element, the green light source element, and the blue light source element are semiconductor lasers (LD) having center wavelengths of 630 nm, 530 nm, and 430 nm, respectively.

In this way, the light emitting element 12 can emit red wavelength band light, green wavelength band light, and blue wavelength band light, and each light is combined to change the chromaticity.

In the projector 10 according to the present embodiment, the light emitting element drive power supply includes a red light source drive power supply, a green light source drive power supply, and a blue light source drive power supply for driving the red light source element, the green light source element, and the blue light source element, respectively. , to drive each.

By changing the driving current of each of the red light source element, the green light source element, and the blue light source element, the respective light amounts (light intensity) are changed, and the chromaticity of the synthesized light is changed.

<Operation of Light Source Device>
The light emitted from the light emitting element 12 scans in the horizontal and vertical directions by driving the scanning element 13 and rotating it around the second axis 130_2 and the first axis 130_1. As a result, the image is projected onto the screen in two dimensions.

For example, when the scanning element 13 is rotated about the second axis 130_2 and the light emitted from the light emitting element 12 is scanned in the horizontal direction, it is desirable to be driven by a high-frequency signal in order to scan the emitted light at high speed. .

Therefore, when driving the movable portion 133 of the scanning element 13 in the horizontal direction, a high-frequency signal is used as the second signal applied to the second driving coil 136_2 from the scanning element driving power source. Here, the movable part 133 and the second beam 134_2 are designed to have mass and elastic rigidity suitable for high-frequency vibration.

Further, for example, when the scanning element 13 is rotated around the first axis 130_1 and the light emitted from the light emitting element 12 is scanned in the vertical direction, it is not necessary to scan the emitted light in the vertical direction at high speed. It may be driven by a low frequency signal.

Therefore, when the movable frame 132 of the scanning element 13 is driven in the vertical direction, a low-frequency signal is used as the first signal applied to the first driving coil 136_1 from the scanning element driving power source. Here, the movable frame 132 and the first beam 134_1 are each designed to have mass and elastic stiffness suitable for low-frequency vibration.

In this manner, the light source device 11 according to the present embodiment drives the scanning element 13 and rotates it about the second axis 130_2 and the first axis 130_1, thereby causing the light emitted from the light emitting element 12 to move horizontally and horizontally. Can be scanned vertically.

Further, in the light source device 11 according to the present embodiment, unlike the conventional light source device, the light emitted from the light emitting element 12 is scanned and projected without reflecting the light emitted from the light emitting element. Therefore, the traveling vector of light in the light source device 11 according to this embodiment includes only a positive component (Z+ direction component) in the direction perpendicular to the surface of the scanning element 13, as shown in FIG.

According to the light source device and the projector according to this embodiment, the light emitting element and the scanning element can be integrated, so that the light source device and the projector can be miniaturized.

<Second embodiment>
A projector according to a second embodiment of the invention will be described with reference to FIG.

<Structure of Light Source Device and Projector>
The projector 20 according to this embodiment has the same configuration as the projector 10 according to the first embodiment.

5A and 5B respectively show a schematic bird's-eye view and a schematic side view of the light source device 21 according to this embodiment. The light source device 21 includes a support base 27, a scanning element 23, and a light emitting element 22, as shown in FIG. 5(a).

In the light source device 21 , the scanning element 23 is arranged above the light emitting element 22 . As an example, as shown in FIG. 5, the light emitting element 22 is mounted on the upper surface of the bottom wall of the support base 27 and the scanning element 23 is arranged above the light emitting element 22 .

The scanning element 23 has a light transmitting portion 238 on the movable portion 233 . The light transmitting portion 238 is provided with a transmitting plate such as plate-shaped glass or a lens. Moreover, the light transmitting portion 238 may be arranged on the entire surface of the movable portion 233 or may be arranged on a part of the movable portion 233 as long as the light emitted from the light emitting element 22 is transmitted therethrough.

In the scanning element 23, the configuration of the drive mechanism and the like other than the light transmitting portion 238 is the same as that of the first embodiment.

The configuration of the light emitting element 22 is similar to that of the first embodiment.

<Operation of Light Source Device>
As shown in FIG. 5B, the emitted light L of the light emitting element 22 is transmitted through the light transmitting portion 238 of the scanning element 23, and the transmitted light T is scanned by the driving of the scanning element 23 onto a screen (not shown). projected onto. FIG. 5B shows the manner in which the scanning element 23 rotates about the first axis 230_1, but the scanning element 23 rotates similarly about the second axis 230_2.

When the lens 239 is provided in the light transmitting portion 238 , the emitted light L of the light emitting element 22 is transmitted through the light transmitting portion 238 and the lens 239 and refracted, and the transmitted light T is emitted from the scanning element 23 . As a result, the scanning range of the transmitted light T can be expanded because the angle of refraction at the lens 239 is greater than in the case of providing the transmission plate in this embodiment and in the first embodiment. A similar effect can be obtained by providing an element (photorefractive element) such as a prism that refracts light instead of the lens.

In addition, the light transmitting portion 238 may be provided with a half mirror, a polarizing plate, or the like. In addition, if a diffraction grating, photonic crystal, or the like is used, even a single-color light source can change its color by tilting the scanning element. Optical elements that utilize the transmission of light, such as elements associated with holography, may also be provided.

Also, the light transmitting portion 238 may be provided with a blind structure. For example, a blind structure in which light-transmitting portions and light-blocking portions are alternately arranged is used. By rotating the scanning element, the amount of light transmitted through the blind structure can be varied.

In this way, the light source device 21 according to the present embodiment drives the scanning element 23 and rotates it about the second axis and the first axis, so that the light emitted from the light emitting element 22 is directed horizontally and vertically. can be scanned to

Further, in the light source device 21 according to the present embodiment, the emitted light L of the light emitting element 22 is transmitted through the scanning element 23 and projected without reflecting the emitted light of the light emitting element 22 as in the conventional light source device. Therefore, the traveling vector of light in the light source device 21 according to this embodiment includes only a positive component (Z+ direction component) with respect to the vertical direction component with respect to the surface of the scanning element 23 .

According to the projector according to this embodiment, the light emitting element and the scanning element can be integrated, so the size of the projector can be reduced.

In the embodiments and examples of the present invention, an example of using an electromagnetically driven MEMS as a scanning element is shown, but an electrostatically driven MEMS, a piezoelectrically driven MEMS, or the like may also be used.

When an electrostatically driven MEMS is used, instead of the magnets in the embodiments of the present invention, electrostatic capacitive elements are added to the opposing portions of the fixed frame and the movable frame and the opposing portions of the movable frame and the movable portion. electrodes may be provided.

Further, when a piezoelectric driven MEMS is used, piezoelectric elements may be provided on the first and second beams instead of the magnets in the embodiment of the present invention.

In the embodiments and examples of the present invention, in the configurations of the light source device and the projector, examples of the structure, dimensions, materials, etc. of each component have been shown, but the present invention is not limited to this. It may be anything as long as it exhibits the function of the projector and produces an effect.

The present invention can be applied to projection type projectors and image display devices.

10 Projector 11 Light source device 12 Light emitting element 13 Scanning element 131 Fixed frame 132 Movable frame 133 Movable parts 134_1, 134_2 Beams 135_1, 135_2 Magnets 136_1, 136_2 Drive coils 137_1, 137_2, 137_3, 137_4 Electrode 1_4 Control part 1_5 Light-emitting element driving power supply 1_6 Scanning element drive power supply

Claims (7)

comprising a light emitting element that emits light and a scanning element that scans the light,
A light source device, wherein the traveling vector of the light includes only a positive component with respect to a vertical direction component with respect to the surface of the scanning element. 2. The light source device according to claim 1, wherein said scanning element rotates in two axial directions. 3. The light source device according to claim 1, wherein the light emitting element is mounted on the scanning element. the scanning element comprises a light transmitting portion,
3. The light source device according to claim 1, wherein the light emitted from the light emitting element is transmitted through the light transmitting portion. 5. The light source device according to claim 4, wherein a photorefractive element is provided in said light transmitting portion. the scanning element comprises a fixed frame, a movable frame, and a movable portion;
the movable frame is connected within the fixed frame via first beams formed on both sides of the movable frame;
the movable portion is connected to the interior of the movable frame via second beams formed on both sides of the movable portion;
The light source device according to any one of claims 1 to 5, wherein the direction of the first beam is perpendicular to the direction of the second beam. a light source device according to any one of claims 1 to 6;
A projector comprising a controller and .

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