JP4858182B2 - LIGHT SOURCE DEVICE, PROJECTOR, AND LIGHT SOURCE DEVICE CONTROL METHOD - Google Patents

Description

  The present invention relates to a light source device, a projector, and a control method for the light source device, and more particularly to a technology of a light source device that supplies laser light.

  In recent years, a technique using a laser light source that supplies laser light has been proposed in a light source device of a projector. Compared with a UHP lamp conventionally used as a light source device for a projector, a light source device using a laser light source has advantages such as high color reproducibility, instant lighting, and long life. As a light source device using a laser light source, one that directly supplies a fundamental wave laser from a laser light source and one that converts and supplies the wavelength of the fundamental laser are known. As a wavelength conversion element that converts the wavelength of the fundamental laser, for example, a second-harmonic generation (SHG) element is known. By using the wavelength conversion element, it is possible to supply laser light having a desired wavelength using a general-purpose laser light source that can be easily obtained. Further, a configuration capable of supplying a sufficient amount of laser light can also be employed. In the SHG element, it is known that when the refractive index distribution changes due to a temperature change, the phase matching condition is broken and the wavelength conversion efficiency is lowered. In order to supply a highly efficient and stable laser beam, it is desired to reduce the temperature change of the wavelength conversion element. For example, in the technique proposed in Patent Document 1, the temperature of the wavelength conversion element is adjusted after the resonator structure is thermally stabilized by laser light.

JP 7-306429 A

  In the case of the configuration proposed in Patent Document 1, it takes a long time to thermally stabilize the resonator structure. If a long time is required for thermal stabilization of the resonator structure, it becomes difficult to supply a necessary amount of laser light in a short time. As described above, according to the conventional technique, there is a problem that it is difficult to obtain a laser beam having a stable light amount with high efficiency in a short time. The present invention has been made in view of the above-described problems, and provides a light source device capable of reducing temperature change of a wavelength conversion element and capable of supplying a laser beam with a high efficiency and a stable amount of light in a short time, and a light source device thereof. It is an object of the present invention to provide a projector to be used and a method for controlling the light source device.

  In order to solve the above-described problems and achieve the object, according to the present invention, a light source unit that supplies laser light, a wavelength conversion element that converts the wavelength of the laser light from the light source unit, and the temperature of the wavelength conversion element A temperature adjusting unit that adjusts the temperature of the wavelength conversion element to a first target value after the light source unit starts supplying laser light, and the light source unit Before starting the supply of laser light, the temperature of the wavelength conversion element is adjusted to be a second target value between the initial value and the first target value at the time of starting the adjustment of the temperature of the wavelength conversion element. The light source device characterized by the above can be provided.

  Before starting the supply of the laser light, the temperature of the wavelength conversion element is adjusted in advance to a second target value between the initial value and the first target value, so that the wavelength conversion element is started after the supply of the laser light is started. It is possible to shorten the time until the temperature is set to the first target value. By shortening the time until the temperature of the wavelength conversion element is set to the first target value, it is possible to supply high-efficiency and stable laser light in a short time. In addition, since the temperature change width of the wavelength conversion element after the supply of the laser light can be reduced, the temperature of the wavelength conversion element can be stabilized at an early stage. By appropriately setting the second target value smaller than the first target value, it is possible to avoid the temperature of the wavelength conversion element from exceeding the first target value after the supply of laser light is started. By stabilizing the temperature of the wavelength conversion element at an early stage, the amount of laser light can be stabilized at an early stage. Thereby, a light source device capable of supplying a laser beam with a high efficiency and a stable light amount in a short time can be obtained.

  Moreover, as a preferable aspect of the present invention, the temperature adjustment unit includes a temperature measurement unit that measures the temperature of the wavelength conversion element, and a heat adjustment that moves heat between the wavelength conversion element by at least one of supply and absorption of heat. And a control unit that controls the heat adjustment unit according to the measurement result of the temperature measurement unit. As the heat adjusting unit, a heater for supplying heat, a Peltier element for supplying and absorbing heat, or the like can be used. A control part performs feedback control of a temperature control part based on the measurement result by a temperature measurement part. Thereby, the temperature change of a wavelength conversion element can be reduced.

  As a preferred aspect of the present invention, the temperature adjustment unit sets the temperature of the wavelength conversion element as the second target value before the light source device is connected to an external power source and the light source unit starts supplying laser light. It is desirable to make adjustments. Thereby, when the light source device is in a standby state before starting the supply of laser light, the temperature of the wavelength conversion element can be adjusted to the second target value.

  Moreover, as a preferable aspect of the present invention, the temperature adjustment unit adjusts the temperature of the wavelength conversion element as the second target value according to the detection result by the detection unit that detects the presence of the moving body around the light source device. It is desirable to do. Thereby, before the operation for starting the supply of laser light by the light source device is performed, the temperature of the wavelength conversion element can be adjusted to the second target value. In addition, since the temperature adjustment unit can be driven only when there is a possibility that the operation of starting the light source device is performed, low power consumption can be achieved.

  Furthermore, according to the present invention, it is possible to provide a projector including the light source device described above and a spatial light modulation device that modulates light from the light source device in accordance with an image signal. By using the above light source device, it is possible to supply a laser beam with a high efficiency and a stable amount of light in a short time. Thereby, a projector capable of obtaining a bright display in a short time can be obtained.

  Furthermore, according to the present invention, the method includes a laser light supply process for supplying laser light, a wavelength conversion process for converting the wavelength of the laser light by the wavelength conversion element, and a temperature adjustment process for adjusting the temperature of the wavelength conversion element. The temperature adjustment process includes a laser light supply post-adjustment process in which the temperature of the wavelength conversion element is adjusted to the first target value after starting the laser light supply in the laser light supply process, and a laser in the laser light supply process. Laser light that adjusts the temperature of the wavelength conversion element to a second target value between the initial value and the first target value at the start of adjustment of the temperature of the wavelength conversion element before starting the supply of light It is possible to provide a method for controlling a light source device, characterized by including a pre-supply adjustment step. Thereby, it is possible to supply a laser beam with a high efficiency and a stable light amount in a short time.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of a projector 10 according to an embodiment of the present invention. The projector 10 is a front projection type projector that views light by supplying light to the screen 19 and observing light reflected by the screen 19. The projector 10 includes a red (R) light source device 11R, a green (G) light source device 11G, and a blue (B) light source device 11B. The projector 10 displays an image using light from each color light source device 11R, 11G, 11B.

  The R light source device 11R is a light source device that supplies R light. The diffusing element 12 shapes and enlarges the illumination area, and makes the light amount distribution of the laser light uniform in the illumination area. As the diffusing element 12, for example, a computer generated hologram (CGH) which is a diffractive optical element can be used. The field lens 13 collimates the laser light from the diffusing element 12 and makes it incident on the spatial light modulator for R light 14R. The spatial light modulator for R light 14R is a spatial light modulator that modulates R light in accordance with an image signal, and is a transmissive liquid crystal display device. The R light modulated by the R light spatial light modulator 14R is incident on the cross dichroic prism 15 which is a color synthesis optical system.

  The light source device 11G for G light is a light source device that supplies G light. The laser light that has passed through the diffusing element 12 and the field lens 13 enters the G light spatial light modulator 14G. The spatial light modulation device 14G for G light is a spatial light modulation device that modulates G light according to an image signal, and is a transmissive liquid crystal display device. The G light modulated by the G light spatial light modulator 14G enters the cross dichroic prism 15 from a side different from the R light.

  The light source device 11B for B light is a light source device that supplies B light. The laser light that has passed through the diffusing element 12 and the field lens 13 enters the spatial light modulator 14B for B light. The spatial light modulation device 14B for B light is a spatial light modulation device that modulates B light according to an image signal, and is a transmissive liquid crystal display device. The B light modulated by the B light spatial light modulator 14B enters the cross dichroic prism 15 from a side different from the R light and the G light. As the transmissive liquid crystal display device, for example, a high temperature polysilicon TFT liquid crystal panel (HTPS) can be used.

  The cross dichroic prism 15 has two dichroic films 16 and 17 arranged substantially orthogonal to each other. The first dichroic film 16 reflects R light and transmits G light and B light. The second dichroic film 17 reflects B light and transmits R light and G light. The cross dichroic prism 15 combines the R light, the G light, and the B light incident from different directions and emits them in the direction of the projection lens 18. The projection lens 18 projects the light combined by the cross dichroic prism 15 toward the screen 19.

FIG. 2 schematically shows a schematic configuration of the G light source device 11G. The G light source device 11G is a semiconductor laser pumped solid state (DPSS) laser oscillator. The light source device 11G for G light has a resonator structure using the first resonance mirror 22 and the second resonance mirror 28. The excitation laser 21 is a semiconductor laser that supplies laser light having a wavelength of 808 nm, for example, and is an edge-emitting laser. The laser beam from the excitation laser 21 passes through the first resonance mirror 22 and then enters the laser crystal 23. As the laser crystal 23, for example, a Nd: YVO ₄ crystal or a Nd: YAG (Y ₃ Al ₅ O ₁₂ ) crystal can be used. The laser crystal 23 oscillates when excited, and supplies laser light having a wavelength of 1064 nm, for example. The excitation laser 21 and the laser crystal 23 are light source units that supply laser light.

  The SHG element 24 is a wavelength conversion element that converts the wavelength of laser light from the laser crystal 23. The SHG element 24 converts the laser beam from the laser crystal 23 into a laser beam having a half wavelength and emits it. As the SHG element 24, for example, a nonlinear optical crystal can be used. The support unit 25 supports the SHG element 24. The heater 26 is a heat supply unit that supplies heat to the SHG element 24 and is a heat adjustment unit that moves heat to and from the SHG element 24 by supplying heat. The thermistor 27 is provided at a position in contact with the SHG element 24 in the support portion 25. The thermistor 27 is a temperature measurement unit that measures the temperature of the SHG element 24. The second resonance mirror 28 is provided on the side opposite to the laser crystal 23 with respect to the SHG element 24.

  The SHG element 24 converts, for example, a 1064 nm laser beam into a 532 nm laser beam. The second resonance mirror 28 has a function of selectively reflecting laser light having a predetermined wavelength, for example, 1064 nm, and transmitting laser light having other wavelengths. The laser beam converted to a desired wavelength, for example, 532 nm by the SHG element 24 passes through the second resonance mirror 28 and is emitted from the G light source device 11G. Laser light having a wavelength other than the desired wavelength is reflected by the second resonance mirror 28. Similar to the second resonance mirror 28, the first resonance mirror 22 selectively reflects laser light of a predetermined wavelength, for example, 1064 nm, and transmits light of other wavelengths. With the resonator structure, laser light with a desired wavelength can be emitted efficiently.

  The excitation laser 21 may be a surface emitting laser in addition to the edge emitting laser. The light source device for R light 11R and the light source device for B light 11B can have the same configuration as the light source device for G light 11G except that the wavelength of the emitted laser light is different. Each color light source device 11R, 11G, 11B is not limited to a DPSS laser oscillator. A light source device that makes laser light from a semiconductor laser, which is a light source unit, incident on a wavelength conversion element may be used. In this case, a semiconductor laser may be used as the light source unit, and a solid laser, liquid laser, gas laser, or the like may be used.

  FIG. 3 shows a block configuration of the temperature control unit. The temperature adjustment unit includes a thermistor 27, a temperature control unit 29, and a heater 26. The thermistor 27 outputs a change in temperature to the temperature control unit 29 as a change in resistance value. The temperature control unit 29 calculates the amount of power supplied to the heater 26 from the temperature difference between the temperature measured by the thermistor 27 and the set temperature of the SHG element 24, and supplies the heater 26 with power corresponding to the calculated power amount. To do. The temperature control unit 29 is a control unit that performs feedback control of the heater 26 according to the measurement result by the thermistor 27. The heater 26 supplies heat according to the control of the temperature control unit 29. The temperature of the SHG element 24 is adjusted by the temperature adjustment unit having such a configuration.

  FIG. 4 is a flowchart illustrating a temperature adjustment process by the temperature adjustment unit shown in FIG. FIG. 5 shows the relationship between the temperature of the SHG element 24 and time. In FIG. 5, it is assumed that the units on the vertical axis and the horizontal axis are arbitrary. The light source units of the light source devices 11R, 11G, and 11B start supplying laser light at time t0. The temperature of the SHG element 24 at the time of starting the adjustment of the temperature of the SHG element 24 is set as an initial value T1 of the temperature of the SHG element 24. If temperature adjustment by the temperature adjustment unit is not performed before time t0, the temperature of the SHG element 24 is substantially the same as the ambient temperature around the projector 10, and therefore the temperature T1 is substantially the same as the ambient temperature around the projector 10. Become. The temperature T3 is a temperature at which the SHG element 24 can perform wavelength conversion of laser light with the highest efficiency, and is a first target value.

  In step S <b> 1 shown in FIG. 4, the temperature adjustment unit adjusts the SHG element 24 to the temperature T <b> 2 by driving the heater 26. The temperature T2 is a temperature between the temperature T1 that is an initial value and the temperature T3 that is a first target value, and is a second target value. Step S1 is a laser light supply pre-adjustment step in which the temperature of the SHG element 24 is adjusted to the second target value before time t0 when the light source unit starts supplying the laser light.

  After time t0, the excitation laser 21 is driven in step S2. The light source unit supplies laser light by driving the excitation laser 21. Simultaneously with the driving of the excitation laser 21, the SHG element 24 converts the wavelength of the laser light from the light source unit. Step S <b> 2 is a laser light supply process for supplying laser light and a wavelength conversion process for converting the wavelength of the laser light by the SHG element 24. In step S3, the temperature adjustment unit adjusts the SHG element 24 to the temperature T3. Step S3 is a laser light post-adjustment step in which the temperature of the SHG element 24 is adjusted to the first target value after time t0 when the light source unit starts supplying the laser light. As described above, the temperature of the SHG element 24 is adjusted in the temperature adjustment step.

  As shown in FIG. 5, when adjusting the temperature of the SHG element 24 to T2 before the time t0 (solid line in FIG. 5), when not adjusting the temperature of the SHG element 24 to T2 (FIG. 5). 5, the time when the temperature of the SHG element 24 becomes T3 can be advanced from t2 to t1. In this way, by setting the SHG element 24 to the temperature T2 in advance before starting the supply of the laser light, the time from the start of the supply of the laser light to the temperature T3 of the SHG element 24 being shortened. Can do.

  By shortening the time from the time t0 when the supply of laser light is started to the time when the temperature of the SHG element 24 is set to the first target value, it is possible to supply a highly efficient and stable amount of laser light in a short time. In addition, since the temperature change width of the SHG element 24 after the supply of the laser beam can be reduced, the temperature of the SHG element 24 can be stabilized at an early stage. By appropriately setting the second target value smaller than the first target value, it is possible to avoid the temperature of the SHG element 24 from exceeding the first target value after the supply of laser light is started. By stabilizing the temperature of the SHG element 24 at an early stage, the amount of laser light can be stabilized at an early stage. Thereby, there is an effect that it is possible to supply a laser beam having a high efficiency and a stable light amount in a short time. Further, a bright display by the projector 10 can be obtained in a short time.

  After the time t0 when the laser light is supplied from the light source unit, the SHG element 24 is heated by absorbing a part of the energy of the laser light from the light source unit. The temperature T2, which is the second target value, is desirably set so that the SHG element 24 reaches the temperature T3 by the supply of laser light after time t0. By setting the temperature T2 that satisfies such conditions, the time until the SHG element 24 reaches the temperature T3 can be minimized.

  Although the laser itself can be activated in nanosecond units, it takes time, for example, in seconds to bring the SHG element 24 from the temperature T1 close to room temperature to the temperature T3 that is the first target value. When the purpose is to display an image, the longer it takes to display a stable image, the more difficult it is to view the image. In the present invention, by adjusting the SHG element 24 to the temperature T2 that is the second target value in advance before supplying the laser beam, the time until the SHG element 24 is set to the temperature T3 can be set to, for example, milliseconds. It becomes possible. According to the present invention, it is possible to view a comfortable image by shortening the time until a stable image is displayed.

  The projector 10 is not limited to the case where a transmissive liquid crystal display device is used as the spatial light modulation device. As the spatial light modulator, a reflective liquid crystal display (Liquid Crystal On Silicon; LCOS), DMD (Digital Micromirror Device), GLV (Grating Light Valve), or the like may be used. The heat adjusting unit is not limited to the configuration using the heater 26, and for example, a Peltier element may be used. When a Peltier element is used for the temperature adjustment unit, in addition to supplying heat, the temperature of the SHG element 24 may be adjusted by absorbing heat.

  FIG. 6 shows a block configuration for adjusting the temperature of the SHG element 24 as the second target value when the projector 10 is in a standby state. The standby state represents a case where the projector 10 is in an energized state and is not activated. The projector 10 is energized by inserting the plug 30 into an outlet. When the projector 10 is energized, each color light source device 11R, 11G, 11B is connected to an external power source.

  FIG. 7 is a flowchart for explaining the temperature adjustment step by the configuration shown in FIG. FIG. 8 shows the relationship between the temperature of the SHG element 24 and time. It is assumed that the time t ′ is the start of energization of the projector 10 and the time t0 is the start of activation. The temperature adjustment unit stops the temperature adjustment before time t ′. The SHG element 24 has a temperature T1 that is substantially the same as the ambient temperature around the projector 10.

  In step S11 shown in FIG. 7, it is determined whether or not the projector 10 is connected to an external power source. Whether or not it is connected to an external power source can be determined by the presence or absence of energization through the plug 30. If it is determined that the projector 10 is connected to the external power supply, the temperature control unit 29 starts driving the heater 26 in step S12. The temperature adjustment unit adjusts the SHG element 24 to the temperature T <b> 2 by driving the heater 26. As described above, the temperature adjustment unit sets the temperature of the SHG element 24 to the second target value before each of the color light source devices 11R, 11G, and 11B is connected to the external power source and the light source unit starts supplying laser light. Make adjustments. If it is determined that the heater 26 is not connected to the external power supply, the heater 26 is kept stopped until the connection to the external power supply is made in step S11.

  In step S13, the excitation laser 21 is driven by starting the projector 10 at time t0. Simultaneously with the drive of the excitation laser 21, the temperature adjustment unit performs adjustment to set the SHG element 24 to the temperature T3 in step S14. The front projection type projector 10 is often in a state in which the plug 30 is removed from the outlet during storage. By inserting the plug 30 into the outlet, the projector 10 is energized and at the same time the temperature of the SHG element 24 is adjusted, so that the time until the temperature of the SHG element 24 becomes the first target value at the start of the startup of the projector 10 can be obtained. It can be shortened. The temperature adjustment unit may start temperature adjustment of the SHG element 24 even when the temperature adjustment unit is in a standby state other than energization using the plug 30. For example, temperature adjustment may be started when the projector 10 enters a standby state due to the attachment of a rechargeable battery to the projector 10.

  FIG. 9 shows a block configuration for performing adjustment using the temperature of the SHG element 24 as the second target value in accordance with the detection result by the detection unit 35. The detection unit 35 is a so-called human sensor, and is an infrared sensor that detects infrared rays. The detection unit 35 is provided on the surface of the projector 10 and detects a moving body in a predetermined area around the projector 10, for example, within a range of about 1 m from the projector 10. The moving body is detected by detecting a change amount of infrared rays per time. The mobile object that is the object of detection by the detection unit 35 is a user who approaches the power switch 36. The power switch 36 switches between driving and stopping of the projector 10. The light source driving unit 37 drives the light source devices 11R, 11G, and 11B for each color light.

  FIG. 10 is a flowchart for explaining a temperature adjustment step with the configuration shown in FIG. Also in the case of performing temperature adjustment according to the detection result by the detection unit 35, the relationship between the temperature of the SHG element 24 and time is the same as that shown in FIG. In step S21, the detection unit 35 monitors the presence or absence of a moving body. While the detection unit 35 monitors the presence or absence of a moving body, the projector 10 is in a standby state, and the temperature adjustment by the temperature adjustment unit is stopped. In step S22, it is determined whether or not the detection unit 35 has detected the presence of the moving object.

  When the presence of the moving body is detected by the detection unit 35, the temperature control unit 29 starts driving the heater 26 in step S23. The temperature adjustment unit adjusts the SHG element 24 to the temperature T <b> 2 by driving the heater 26. As described above, the temperature adjustment unit starts adjustment using the temperature of the SHG element 24 as the second target value in accordance with the detection result by the detection unit 35. When the detection of the moving body is not performed by the detection unit 35, the process returns to steps S21 and S22 to monitor the presence or absence of the moving body.

  Next, in step S24, it is determined whether or not the power switch 36 is operated. When the projector 10 is activated by the power switch 36, the excitation laser 21 is driven in step S25. Further, in step S26, the temperature adjusting unit adjusts the SHG element 24 to the temperature T3. In this way, it is possible to adjust the temperature of the SHG element 24 to the second target value before starting the supply of laser light.

  If the operation of the power switch 36 is not performed in step S24, it is determined in step S27 whether or not a predetermined time, for example, about 30 seconds has elapsed since the presence of the moving body is detected. When a predetermined time has elapsed since the detection of the presence of the moving body, the driving of the heater 26 is stopped in step S28. By stopping the driving of the heater 26, the temperature adjustment of the SHG element 24 by the temperature adjusting unit is stopped. By stopping the temperature adjustment of the SHG element 24, the process returns to step S21. When the predetermined time has not elapsed since the detection of the presence of the moving body, the process returns to step S23, and the temperature adjustment of the SHG element 24 by the driving of the heater 26 is continued.

  When the power switch 36 is operated, a user approaching the power switch 36 is detected by the detection unit 35. Further, unless the moving unit is detected by the detecting unit 35, the power switch 36 is not operated. By adopting a configuration in which the temperature adjustment is performed according to the detection result by the detection unit 35, the temperature adjustment unit can be driven only when there is a possibility that the power switch 36 is operated. As a result, it is possible to shorten the time until the temperature of the SHG element 24 is set to the first target value at the start of startup of the projector 10, and to reduce the power consumption of the projector 10. The detection unit 35 only needs to be able to detect the presence of the moving body, and may use a sensor other than the infrared sensor.

  The projector 10 is not limited to a configuration including a spatial light modulator for each color light. The projector 10 may be configured to modulate two or three or more color lights with one spatial light modulator. The projector may be a so-called rear projector that supplies light to one surface of the screen and observes an image by observing light emitted from the other surface of the screen. Furthermore, the light source device of the present invention is not limited to being applied to a projector. For example, the present invention may be applied to an exposure apparatus that performs exposure using laser light, a monitor apparatus that monitors an image illuminated by laser light, and the like.

  As described above, the light source device according to the present invention is suitable for use in a projector.

1 is a diagram showing a schematic configuration of a projector according to an embodiment of the invention. The figure which shows the structure of the light source device for G light which is a light source device. The figure which shows the block structure of a temperature control part. The flowchart explaining the temperature control process by a temperature control part. The figure which shows the relationship between the temperature of a SHG element, and time. The figure which shows the block structure for performing the temperature control of a SHG element. The flowchart explaining the temperature control process by the structure shown in FIG. The figure which shows the relationship between the temperature of a SHG element, and time. The figure which shows the block structure for performing the temperature control of a SHG element. The flowchart explaining the temperature control process by the structure shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Projector, 11R R light source device, 11G G light source device, 11B B light source device, 12 Diffusing element, 13 Field lens, 14R R light spatial light modulator, 14G G light spatial light modulator, 14B spatial light modulator for B light, 15 cross dichroic prism, 16 first dichroic film, 17 second dichroic film, 18 projection lens, 19 screen, 21 excitation laser, 22 first resonance mirror, 23 laser crystal, 24 SHG Element, 25 Support section, 26 Heater, 27 Thermistor, 28 Second resonance mirror, 29 Temperature control section, 30 Plug, 35 Detection section, 36 Power switch, 37 Light source drive section

Claims (6)

A light source unit for supplying laser light;
A wavelength conversion element that converts the wavelength of the laser light from the light source unit;
A temperature adjustment unit for adjusting the temperature of the wavelength conversion element,
The temperature adjusting unit adjusts the temperature of the wavelength conversion element as a first target value after the light source unit starts supplying the laser beam, and the light source unit starts supplying the laser beam. Before performing the adjustment, the temperature of the wavelength conversion element is adjusted to be a second target value between the initial value and the first target value at the start of the adjustment of the temperature of the wavelength conversion element. Light source device. The temperature control unit is
A temperature measurement unit for measuring the temperature of the wavelength conversion element;
A heat adjusting unit that moves heat to and from the wavelength conversion element by at least one of supply and absorption of heat; and
The light source device according to claim 1, further comprising: a control unit that controls the heat adjustment unit according to a measurement result by the temperature measurement unit.   The temperature adjustment unit adjusts the temperature of the wavelength conversion element as the second target value before the light source device is connected to an external power source and the light source unit starts supplying the laser light. The light source device according to claim 1 or 2.   The temperature adjustment unit adjusts the temperature of the wavelength conversion element as the second target value in accordance with a detection result of a detection unit that detects the presence of a moving body around the light source device. Item 3. The light source device according to Item 1 or 2. The light source device according to any one of claims 1 to 4,
And a spatial light modulator that modulates light from the light source device in accordance with an image signal. A laser beam supplying step for supplying a laser beam;
A wavelength conversion step of converting the wavelength of the laser beam by a wavelength conversion element;
Adjusting the temperature of the wavelength conversion element, and
The temperature adjustment step includes
After the start of the supply of the laser light in the laser light supply step, after the laser light supply adjustment step of adjusting the temperature of the wavelength conversion element as a first target value;
Before starting the supply of the laser light in the laser light supply step, the temperature of the wavelength conversion element is set between the initial value and the first target value at the start of adjusting the temperature of the wavelength conversion element. And a laser light supply pre-adjustment step for adjusting the second target value.

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