JP2024003641A - Optical unit and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical unit which incorporates a plurality of wavelength conversion parts and which can achieve cooling optimized for a temperature condition of each wavelength conversion part while suppressing an increase in size of a light source unit, and a display device.

SOLUTION: An optical unit includes: a laser source; at least two wavelength conversion parts for generating laser beams with a wavelength different from that of a laser beam generated by the laser source; an air flow generation part for generating an air flow; and a duct structure for leading the air flow generated from the air flow generation part to the wavelength conversion parts. The duct structure includes a structure part for dividing the air flow generated from the air flow generation part in at least two directions.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to an optical unit and a display device.

Light source units such as projector light sources that use a laser light source and a phosphor wheel (an example of a wavelength conversion unit) have been developed. Patent Document 1 discloses a device equipped with a cooling mechanism that controls the rotation of the phosphor wheel or cools a plurality of phosphor wheels with one fan, with the aim of maintaining the luminous efficiency of the phosphor wheel in an optimal state. A light source technology is disclosed.

In the above-mentioned projector light source, one fan (an example of an airflow generation part) is responsible for cooling the plurality of phosphor wheels, but it is difficult to efficiently cool each phosphor wheel according to its temperature condition. Furthermore, if a cooling mechanism is installed to suit each phosphor wheel, there is a risk that the size of the projector light source and the number of parts will increase.

The present invention has been made in view of the above, and achieves cooling optimized for the temperature state of each wavelength conversion section while suppressing an increase in the size of the light source unit in a light source unit incorporating a plurality of wavelength conversion sections. An object of the present invention is to provide an optical unit and a display device that can perform the following steps.

In order to solve the above-mentioned problems and achieve the objects, the present invention includes a laser light source, at least two wavelength converters that generate laser light of a wavelength different from the wavelength of the laser light generated by the laser light source, and an air flow. and a duct structure that guides the airflow generated from the airflow generation section to the wavelength conversion section, and the duct structure is a structure that divides the airflow generated from the airflow generation section into at least two directions. has.

According to the present invention, in a light source unit incorporating a plurality of wavelength conversion sections, it is possible to achieve cooling optimized for the temperature state of each wavelength conversion section while suppressing an increase in the size of the light source unit. .

FIG. 1 is a schematic configuration diagram of a projection device to which a display device according to the present embodiment is applied. FIG. 2 is a diagram showing an example of the configuration of the light source device of the projection device according to the present embodiment. FIG. 3 is a diagram for explaining an example of the configuration of the light source device according to this embodiment. FIG. 4 is a diagram showing an example of a specific configuration of the projector light source unit according to this embodiment. FIG. 5 is a diagram showing an example of a control block of the light source device according to this embodiment. FIG. 6 is a diagram illustrating an example of the hardware configuration of a control section included in the light source device according to the present embodiment. FIG. 7 is a diagram for explaining an example of a heat dissipation section included in the light source device according to the present embodiment. FIG. 8 is a diagram for explaining an example of a heat dissipation section included in the light source device according to the present embodiment. FIG. 9 is a diagram for explaining an example of the flow of the air volume ratio control process by the light source device according to the present embodiment.

Embodiments of an optical unit and a display device will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a projection device to which a display device according to the present embodiment is applied. The projection device 1 according to the present embodiment is an example of a display device such as a projector, and includes a housing 10, a light source device 20, a light homogenizing element 30, an illumination optical system 40, and an image forming element (image display device). element) 50 and a projection optical system 60.

The housing 10 houses a light source device 20, a light homogenizing element 30, an illumination optical system 40, an image forming element 50, and a projection optical system 60.

The light source device 20 emits, for example, laser light containing wavelengths corresponding to each color of RGB. The internal configuration of the light source device 20 will be described in detail later.

The light homogenizing element 30 homogenizes the laser beams emitted from the light source device 20 by mixing them. As the light homogenizing element 30, for example, a light tunnel formed by combining four mirrors, a rod integrator, a fly's eye lens, etc. are used.

The illumination optical system 40 illuminates the image forming element 50 substantially uniformly with the light uniformized by the light equalizing element 30. The illumination optical system 40 includes, for example, one or more lenses, one or more reflective surfaces, and the like.

The image forming element 50 includes a light valve such as a digital micromirror device (DMD), a transmissive liquid crystal panel, and a reflective liquid crystal panel. The image forming element 50 forms an image by modulating the light illuminated by the illumination optical system 40 (laser light from the light source optical system of the light source device 20). That is, the image forming element 50 functions as an example of a spatial modulator that turns on and off light for each pixel of the image formed by the light source device 20 to form an image.

The projection optical system 60 enlarges and projects the image formed by the image forming element 50 onto a screen (projection surface) 70 . The projection optical system 60 includes, for example, one or more lenses.

FIG. 2 is a diagram showing an example of the configuration of the light source device of the projection device according to the present embodiment. The light source device 20 (an example of a light source unit) according to this embodiment includes wavelength conversion light source sections A and B. In the following description, the configuration of the wavelength conversion light source section A will be explained, but it is assumed that the wavelength conversion light source section B also has a similar configuration.

The wavelength conversion light source section A has a laser light source 1a including 2×4 semiconductor lasers. Laser light (ray, light source light) emitted from the laser light source 1a is focused on the collimator lens CL, and guided to the dichroic mirror DM by the optical system of the focusing elements L1 and L2. The light source light guided to the dichroic mirror DM is reflected by the dichroic mirror DM, and is irradiated onto the first wavelength conversion region A1 of the wavelength conversion section 2a (for example, phosphor) formed on the substrate C.

The image of the wavelength conversion area (first wavelength conversion area A1) of the wavelength conversion unit 2a, which the light source light reaches, is formed at a conjugate position in an imaging relationship by optical elements L3, L4, mirrors M1, M2, etc. . The conjugate position is a position where an image of the wavelength-converted light (image of the first wavelength-converted light) located in the first wavelength conversion area A1 shown in FIG. 2 is formed. Here, the wavelength-converted light is light whose wavelength has been converted by the wavelength conversion element F1.

On the other hand, the second wavelength conversion area A2 of the wavelength conversion unit (phosphor) 2b, which is different from the first wavelength conversion area A1 of the wavelength conversion unit 2a, is irradiated with the light source light from the laser light source 1b, and the second wavelength conversion area A2 is The image of the wavelength-converted light (image of the second wavelength-converted light) having a conjugate positional relationship with the conversion region A2 is adjacent to (or superimposed).

One image in which the image of the first wavelength converted light and the image of the second wavelength converted light are combined is located at the entrance aperture of the light homogenizing element 30 shown by the broken line. It is reflected inside 30 and is made uniform.

The laser light sources 1a and 1b may be any light source that emits excitation light for the wavelength conversion sections 2a and 2b, such as in the blue and ultraviolet regions. Specifically, the laser light sources 1a and 1b function as an example of a plurality of excitation light sources that irradiate light to each of the first wavelength conversion area A1 and the second wavelength conversion area A2 at the same timing. In this embodiment, the laser light sources 1a and 1b may have one LD, or may be an LD array in which LDs are arranged in a plurality of rows so that the whole is rectangular. Further, in this embodiment, the laser light sources 1a and 1b are eight 2×4 LD arrays, but may be of a multi-chip type. In addition, in this embodiment, the same light source is used as the laser light sources 1a and 1b, but the 4×4 LDs are divided into halves by mirrors or separated by half mirrors to create two It may also be used as a laser light source.

Further, in this embodiment, the first wavelength conversion area A1 and the second wavelength conversion area A2 of the wavelength conversion units 2a and 2b are each formed of wavelength conversion units formed on different substrates C. The present invention is not limited to this, and they may be formed on the same substrate C. A preferable configuration of the substrate C is that the phosphor is coated on a disc-shaped substrate having higher thermal conductivity than the phosphor, such as a ceramic or metal substrate, or is fixed with an adhesive member. Further, the substrate C is formed into a disk shape and rotated around its center as a central axis to form a phosphor (wavelength conversion portions 2a, 2b) along the circumference. It may also be in the form of a phosphor wheel that moves the phosphor.

FIG. 3 is a diagram for explaining an example of the configuration of the light source device according to this embodiment. The light source device 20 according to this embodiment is a projector optical unit or the like. Specifically, as shown in FIG. 3, the light source device 20 includes laser light sources 1a and 1b, wavelength converters 2a and 2b, an airflow generator 3, a duct structure 4, and a light source container 5. This is an example of a light source unit. The light source device 20 according to the present embodiment includes an optical system that irradiates an image forming element 50 (an example of an image forming unit) with light generated from the light source device 20 and projects an image formed by the image forming element 50. It is applicable to a display device such as a projector equipped with the projection optical system 60, which is an example.

The light source container 5 is a housing that houses the laser light sources 1a and 1b, the wavelength converters 2a and 2b, the airflow generator 3, and the duct structure 4. The laser light sources 1a and 1b are examples of laser light sources that emit (irradiate) laser light (excitation light).

The wavelength converter 2a is an example of a wavelength converter that generates laser light having a wavelength different from the wavelength of the laser light emitted from the laser light source 1a. The wavelength converter 2b is an example of a wavelength converter that generates laser light having a wavelength different from the wavelength of the laser light emitted from the laser light source 1b. In the present embodiment, the light source device 20 has two wavelength converters 2a and 2b, but it may have at least two wavelength converters, and may have three or more wavelength converters. You can leave it there.

The airflow generator 3 is an example of an airflow generator, such as a sirocco fan, that generates an airflow inside the light source container 5. The duct structure 4 is an example of a duct structure that guides the airflow generated from the airflow generation device 3 to the wavelength conversion sections 2a and 2b. Further, the duct structure 4 includes a structure portion 4a (for example, a partition plate) that divides the airflow generated from the airflow generation device 3 into at least two directions. Thereby, it is possible to cool the wavelength converters 2a, 2b by dividing the airflow generated from one airflow generating device 3 according to the respective temperature conditions of the wavelength converters 2a, 2b. As a result, in a light source device 20 incorporating a plurality of wavelength converters 2a, 2b, it is possible to achieve cooling optimized for the temperature state of each wavelength converter 2a, 2b while suppressing an increase in the size of the light source device 20. can.

The wavelength converters 2a and 2b generate heat by being irradiated with excitation light (laser light) from the laser light sources 1a and 1b, but are cooled by air blowing from the airflow generator 3. The air blown from the airflow generating device 3 is divided into multiple directions by the structure portion 4a of the duct structure 4, and collides with each wavelength conversion portion 2a, 2b. By dividing the cooling air by the structural part 4a of the duct structure 4, it becomes possible to cool a plurality of wavelength converters 2a and 2b with one airflow generating device 3.

FIG. 4 is a diagram showing an example of a specific configuration of the projector light source unit according to this embodiment. In this embodiment, a sirocco fan may be used as the airflow generating device 3. Moreover, a phosphor wheel may be used for the wavelength converters 2a and 2b. Further, the structure portion 4a included in the duct structure 4 divides the airflow generated from the airflow generation device 3 into two directions.

FIG. 5 is a diagram showing an example of a control block of the light source device according to this embodiment. As shown in FIG. 5, the light source device 20 according to this embodiment includes a control section 301, a temperature sensor 302, a temperature sensor 303, and a duct structure air volume adjustment section 304.

The duct structure air volume adjustment section 304 is an actuator or the like, and is an example of a changing section that controls the structure section 4a to arbitrarily change the ratio (air volume ratio) at which the airflow generated from the airflow generation device 3 is divided. The temperature sensor 302 is a temperature sensor that is attached to the wavelength conversion section 2a and detects the temperature of the wavelength conversion section 2a. The temperature sensor 303 is a temperature sensor that is attached to the wavelength conversion section 2b and detects the temperature of the wavelength conversion section 2b. That is, the temperature sensors 302 and 303 are examples of temperature sensors that detect the respective temperatures of the wavelength conversion units 2a and 2b.

The control unit 301 is an example of a control unit that controls the duct structure air volume adjustment unit 304 based on the temperature detection results of the temperature sensors 302 and 303, and controls the ratio of air volume divided by the structure 4a. Thereby, the volume of cooling air to each of the wavelength converters 2a, 2b can be controlled in accordance with the temperature of the wavelength converters 2a, 2b.

Specifically, when the temperature detected by the temperature sensor 302 or the temperature sensor 303 exceeds a specified temperature, the control unit 301 controls the air volume ratio to the wavelength conversion unit in which a temperature higher than the specified temperature is detected. Enlarge. Here, the prescribed temperature may be the rated temperature of the wavelength converters 2a, 2b. Thereby, the temperature of the wavelength converters 2a, 2b can be prevented from exceeding the rated temperature.

Further, the control unit 301 controls the duct structure air volume adjustment unit 304 according to the output of the excitation light emitted from each of the laser light sources 1a and 1b, and controls the cooling air to each of the wavelength conversion units 2a and 2b. It is also possible to control the air volume (air volume ratio). Thereby, even if the temperature of the wavelength converters 2a, 2b changes depending on the output of the laser light sources 1a, 1b, the cooling conditions of the wavelength converters 2a, 2b can be made to correspond to the change. That is, efficient cooling can be performed in accordance with the output of the excitation light irradiated to the wavelength converters 2a and 2b.

FIG. 6 is a diagram showing an example of the hardware configuration of the control section included in the light source device according to the present embodiment. As shown in FIG. 6, the control unit 301 includes a CPU (Central Processing Unit) 241, a ROM (Read Only Memory) 242, a RAM (Random Access Memory) 243, an I/O port 244, and a bus line 245. , is equipped with.

The CPU 241 is an arithmetic device that sequentially executes branching, repeating processing, etc. by executing programs stored in the ROM 242 . The ROM 242 is a nonvolatile storage device that stores programs and the like executed by the CPU 241. The RAM 243 is a memory that functions as a work area for the operation of the CPU 241. The bus line 245 is an address bus, a data bus, etc. for electrically connecting each component such as the CPU 241.

The I/O port 244 is an interface that receives the output signal of the rotary encoder and outputs a control signal for controlling the motor via the motor driver. Among the functions of the embodiment described above, the functions executed by the control unit 301 can be realized by one or more processing circuits. Here, the control unit 301 in this specification refers to a processor programmed to execute each function by software, such as a processor implemented by an electronic circuit, or an ASIC designed to execute each function described above. (Application Specific Integrated Circuit), DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), and conventional circuit modules.

7 and 8 are diagrams for explaining an example of a heat dissipation section included in the light source device according to this embodiment. In this embodiment, as shown in FIGS. 7 and 8, the light source device 20 is connected thermally to the outside of the projector light source unit before the intake port of the airflow generator 3 (for example, a sirocco fan) that blows cooling air. It has a connected fin shape 6 (an example of a heat radiation part). Here, the fin shape 6 is an example of a heat radiating part that is provided on the intake flow path of the airflow generation device 3 and is thermally connected to the outside of the light source device 20. As a result, when the air inside the light source device 20 is sucked into the duct structure 4, heat can be released to the outside. wheels) can be cooled. That is, the temperature of the air supplied to the wavelength converters 2a, 2b can be lowered.

FIG. 9 is a diagram for explaining an example of the flow of the air volume ratio control process by the light source device according to the present embodiment. First, the temperature sensors 302 and 303 detect the temperatures of the wavelength converters 2a and 2b (step S901). Next, the control unit 301 determines whether the temperature detected by the temperature sensor 302 or the temperature sensor 303 exceeds a specified temperature (step S902).

If the temperature detected by the temperature sensor 302 or 303 exceeds the specified temperature (step S902: Yes), the control unit 301 controls the air volume ratio to the wavelength conversion unit in which the temperature exceeding the specified temperature is detected. is increased (step S903). On the other hand, if the temperature detected by the temperature sensor 302 and the temperature sensor 303 is below the specified temperature (step S902: No), the control unit 301 ends the air volume ratio control process.

As described above, according to the light source device 20 according to the present embodiment, the airflow generated from one airflow generation device 3 is divided according to the respective temperature conditions of the wavelength conversion units 2a and 2b, and the airflow is divided into wavelength conversion units 2a and 2b. , 2b can be cooled. As a result, in a projector optical unit incorporating a plurality of wavelength converters 2a, 2b, it is possible to achieve cooling optimized for the temperature state of each wavelength converter 2a, 2b while suppressing an increase in the size of the projector optical unit. can.

This embodiment is, for example, as follows.
<1> Laser light source,
at least two wavelength converters that generate laser light with a wavelength different from the wavelength of the laser light generated by the laser light source;
an airflow generation section that generates airflow;
a duct structure that guides the airflow generated from the airflow generation section to the wavelength conversion section,
In the light source unit, the duct structure has a structural part that divides the airflow generated from the airflow generation part into at least two directions.

<2> The light source unit according to <1>, further comprising a changing section that arbitrarily changes an air volume ratio at which the air flow generated from the air flow generation section is divided.

<3> A temperature sensor is attached to each of the wavelength conversion units,
The light source unit according to <2>, further comprising a control section that controls the changing section based on a temperature detection result by the temperature sensor to change the air volume ratio.

<4> When the temperature detected by the temperature sensor exceeds a predetermined temperature, the control section increases the air volume ratio to the wavelength conversion section in which a temperature higher than the predetermined temperature is detected. 3>.

<5> The light source unit according to <2>, further comprising a control section that changes the air volume ratio by controlling the changing section according to the output of laser light from the laser light source to each of the wavelength conversion sections.

<6> The light source unit according to any one of <1> to <5>, further comprising a heat radiating section thermally connected to the outside of the light source unit on the intake flow path of the airflow generating section.

<7> A display device including an optical system that irradiates an image forming section with light generated from the light source unit according to any one of <1> to <6> and projects the image.

1 Projection device 1a, 1b Laser light source 2a, 2b Wavelength conversion section 3 Airflow generation device 4 Duct structure 4a Structure section 5 Light source container 6 Fin shape 10 Housing 20 Light source device 30 Light homogenization element 40 Illumination optical system 50 Image forming element 60 Projection optical system 241 CPU
242 ROM
243 RAM
244 I/O port 301 Control unit 302, 303 Temperature sensor 304 Air volume adjustment unit in duct structure

Japanese Patent Application Publication No. 2011-145681

Claims (7)

a laser light source;
at least two wavelength converters that generate laser light with a wavelength different from the wavelength of the laser light generated by the laser light source;
an airflow generation section that generates airflow;
a duct structure that guides the airflow generated from the airflow generation section to the wavelength conversion section,
In the light source unit, the duct structure has a structural part that divides the airflow generated from the airflow generation part into at least two directions. The light source unit according to claim 1, further comprising a changing section that controls the structural section to arbitrarily change an air volume ratio at which the airflow generated from the airflow generating section is divided. A temperature sensor is attached to each of the wavelength conversion units,
The light source unit according to claim 2, further comprising a control section that controls the changing section based on a temperature detection result by the temperature sensor to change the air volume ratio. 4. The controller according to claim 3, wherein when the temperature detected by the temperature sensor exceeds a predetermined temperature, the control section increases the air volume ratio to the wavelength conversion section in which a temperature higher than the predetermined temperature is detected. Light source unit as described. The light source unit according to claim 2, further comprising a control section that controls the changing section according to the output of laser light from the laser light source to each of the wavelength conversion sections to change the air volume ratio. The light source unit according to claim 1, further comprising a heat dissipation section thermally connected to the outside of the light source unit on an intake flow path of the airflow generation section. A display device comprising an optical system that irradiates an image forming section with light generated from the light source unit according to claim 1 and projects the image.

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