JP2017215418A - Light source device, image projection device and light source control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device used for image projection device etc. capable of being reused while avoiding damages on optical components when any abnormality is detected on a fluorescent body.SOLUTION: A light source device 101 has a solid light source 2 which emits an excitation ray 3 and a fluorescent body 7 which converts the excitation ray into fluorescent light and emits the same to outputs illumination light including the fluorescent light. The light source device includes: illumination light detection means 11 that detects illumination light; determination means 23 that determines whether the fluorescent body is normal/abnormal based on the detection result by the illumination light detection means; and control means 1 that controls the output amount of the illumination light from light source device to reduce to be lower than that before the abnormality determination by the determination means according to the abnormality determination.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light source device using a solid light source and a phosphor, and more particularly to a light source device suitable for an image projection apparatus such as a liquid crystal projector.

  In an image projection apparatus, illumination light including fluorescent light generated by irradiating a fluorescent material with excitation light from a laser diode or LED is guided to a light modulation element such as a liquid crystal panel by an illumination optical system and modulated by the element. Some display images by projecting image light with a projection lens. However, in such an image projection apparatus, if the phosphor irradiated with the high-intensity excitation light is deteriorated or burned off or peeled off from the substrate, the excitation light is directly applied to the illumination optical system, the light modulation element, and the projection lens. This may damage these optical components.

  Patent Document 1 discloses an image projection apparatus that stops driving an excitation light source in response to detecting that the intensity of light from a phosphor has fallen below a predetermined threshold due to abnormality such as damage to the phosphor. Has been.

JP 2014-235323 A

  However, in the image projection apparatus disclosed in Patent Document 1, after stopping the excitation light source by detecting the abnormality of the phosphor, when the excitation light source is turned on again (restarted), the same amount of light as before the abnormality detection is obtained. If the excitation light is emitted, the optical component may be damaged. Further, if such restarting cannot be performed, when the drive of the excitation light source is stopped due to erroneous detection of phosphor abnormality, it cannot be used until the image projection apparatus is repaired, and usability is significantly impaired.

  The present invention provides a light source device that enables reuse and the like while avoiding damage to optical components when an abnormality of a phosphor is detected, and an image projection device including the light source device.

  A light source device according to one aspect of the present invention includes a solid-state light source that emits excitation light and a phosphor that converts the excitation light into fluorescence and emits fluorescence light, and emits illumination light including the fluorescence light. The light source device includes: an illumination light detection unit that detects illumination light; a determination unit that determines whether the phosphor is normal or abnormal based on a detection result by the illumination light detection unit; and a response to abnormality determination by the determination unit And control means for performing light amount reduction control for reducing the emitted light amount of the illumination light from the light source device more than before the abnormality determination.

  Note that an image projection apparatus that includes the light source device and an optical system that projects an image by modulating illumination light from the light source device with a light modulation element also constitutes another aspect of the present invention.

  A light source control program according to another aspect of the present invention includes a solid-state light source that emits excitation light and a phosphor that converts the excitation light into fluorescence and emits fluorescence light, and includes illumination light including the fluorescence light. A computer program for operating a computer of an image projection apparatus that emits and has illumination light detection means for detecting the illumination light. The program causes the computer to determine whether the phosphor is normal or abnormal based on the detection result by the illumination light detection means, and according to the abnormality determination by the determination process, the light source device than before the abnormality determination And a light amount reduction control for reducing the amount of light emitted from the illumination light.

  According to the present invention, when an abnormality of a phosphor is determined, a light source device that can be reused after stopping driving or continuously used in the case of erroneous error determination while avoiding damage to optical components on which illumination light enters. Can be provided.

1 is a diagram illustrating a configuration of a projector that is Embodiment 1 of the present invention. FIG. 5 is a flowchart illustrating processing performed by the projector according to the first embodiment. 10 is a flowchart illustrating processing performed by the projector according to the second embodiment. FIG. 6 is a diagram illustrating a configuration of a projector that is Embodiment 3 of the present invention. 10 is a flowchart illustrating processing performed by the projector according to the third embodiment. FIG. 10 is a diagram illustrating a configuration of a projector that is Embodiment 4 of the present invention. 10 is a flowchart illustrating processing performed by the projector according to the fourth embodiment.

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

  FIG. 1 shows a configuration of a liquid crystal projector as an image projection apparatus including a light source device that is Embodiment 1 of the present invention. In the following description, R, G, and B mean red, green, and blue, respectively. The projector of this embodiment includes a light source unit and an illumination light detection unit that constitute the light source device 101, and a projector optical system. In the light source unit, 2 is an excitation light source, 3 is excitation light, 4 is an excitation light reflecting member, 5 is a glass plate, 6 is a first lens, 7 is a phosphor, and 8 is a phosphor support member. 9 is illumination light. In the illumination light detection unit, 10 is a first light branching unit, and 11 is a first light measurement unit (illumination light detection means).

  In the projector optical system, 12a is a first fly-eye lens, 12b is a second fly-eye lens, 13 is a polarization conversion element, 14 is a second lens, 15 is a dichroic mirror, and 16 is a color selector. Further, 17RB is a polarizing beam splitter for RB, 17G is a polarizing beam splitter for G, 18R is a λ / 4 plate for R, 18G is a λ / 4 plate for G, and 18B is a λ / 4 plate for B. Further, 19R is an R light modulation element, 19G is a G light modulation element, 19B is a B light modulation element, 20 is a color synthesis prism, and 21 is a projection lens.

  The projector also has a control unit (control means) 1. The control unit 1 is configured by a computer such as a CPU, and performs an operation for controlling the entire projector according to a computer program. The excitation light source 2 is a semiconductor laser as a solid light source that emits blue laser light. An LED may be used as the excitation light source 2. The driving of the excitation light source 2 is controlled by the control unit 1. That is, the control unit 1 is a control unit of the light source device (light source unit).

  Excitation light 3 emitted from the excitation light source 2 is reflected by the excitation light reflecting member 4 and irradiated onto the phosphor 7 via the first lens 6. The excitation light reflecting member 4 is provided only on the portion of the surface of the glass plate 5 where the excitation light 3 is irradiated. The first lens 6 collects the excitation light 3 to form an excitation light irradiation region of a predetermined size on the phosphor 7.

  The phosphor 7 is supported by a phosphor support member (substrate) 8. The phosphor 7 converts part of blue light as excitation light to wavelength conversion (fluorescence conversion) and emits yellow light as fluorescence light. The other part of the excitation light is diffused and reflected as non-converted light that is not converted to fluorescence, and travels in the direction of the first lens 6. The material of the phosphor 7 is, for example, YAG: Ce. It is desirable that the phosphor support member 8 has high rigidity, a high reflectance with respect to blue light and yellow light, and easily dissipates heat generated by the phosphor 7. Therefore, the material of the phosphor support member 8 is typically a metal plate such as aluminum. However, if it has the same function as a metal plate, it does not remain in a metal plate.

  The combined light of fluorescent light (yellow light) and non-converted light (blue light) from the phosphor 7 is incident on the first lens 6 as white illumination light 9. The first lens 6 at this time has a role of making the illumination light 9 parallel light.

  The illumination light 9 that has passed through the first lens 6 further passes through portions of the glass plate 5 other than the excitation light reflector 4. A part of the illumination light 9 transmitted through the glass plate 5 is branched by the first light branching unit 10 and guided to the first light measurement unit 11. The first light branching portion 10 is formed of, for example, flat glass, but may be anything as long as it can branch a part of the illumination light 9.

  The illumination light 9 that has passed through the first light branching unit 10 is split into a plurality of light beams while being transmitted through the first fly-eye lens 12 a and the second fly-eye lens 12 b, and enters the polarization conversion element 13. The polarization conversion element 13 converts the illumination light 9 that is non-polarized light into linearly polarized light having one polarization direction. In the present embodiment, the polarization conversion element 13 converts the illumination light 9 into linearly polarized light (P-polarized light) having a polarization direction parallel to the paper surface of FIG. A plurality of light beams as the illumination light 9 emitted from the polarization conversion element 13 are collected by the second lens 14 and superimposed on each light modulation element (19R, 19G, 19B). Thereby, each light modulation element is illuminated uniformly.

  The illumination light 9 transmitted through the second lens 14 is guided to the dichroic mirror 15. The dichroic mirror 15 reflects the RB light 9RB in the illumination light 9 and transmits the G light 9G. The RB light 9 RB reflected by the dichroic mirror 15 enters the color selector 16. The color selector 16 rotates the polarization direction of the B light by 90 degrees to be S-polarized light, and transmits the R light as P-polarized light having the same polarization direction.

  The RB light 9RB transmitted through the color selector 16 enters the RB polarization beam splitter 17RB. The RB polarization beam splitter 17RB transmits the R light 9R that is P-polarized light and reflects the B light 9B that is S-polarized light. The R light 9R transmitted through the RB polarization beam splitter 17RB is converted into circularly polarized light by the R λ / 4 plate 18R and is incident on the R light modulation element 19R. On the other hand, the B light 9B is reflected by the RB polarization beam splitter 17RB, converted into circularly polarized light by the B λ / 4 plate 18B, and is incident on the B light modulation element 19B.

  The G light 9G that has passed through the dichroic mirror 15 passes through the G polarization beam splitter 17G, is converted into circularly polarized light by the G λ / 4 plate 18G, and enters the G light modulation element 19G. Each light modulation element is constituted by a reflective liquid crystal panel in this embodiment. A transmissive liquid crystal panel or a digital micromirror device (DMD) may be used as the light modulation element. Each light modulation element is driven by the control unit 1 in accordance with an image signal input to the projector, thereby modulating each incident color light for each pixel.

  The R light 9R as the R image light modulated by the R light modulation element 19R is converted to S polarization by the R λ / 4 plate 18R, reflected by the RB polarization beam splitter 17RB, and guided to the color synthesis prism 20. It is burned. The B light 9B as the B image light modulated by the B light modulation element 19B is converted to P-polarized light by the B λ / 4 plate 18B, passes through the RB polarization beam splitter 17RB, and enters the color synthesis prism 20. To do. The G light 9G as the G image light modulated by the G light modulation element 19G is converted into S-polarized light by the G λ / 4 plate 18G, reflected by the G polarizing beam splitter 17G, and applied to the color combining prism 20. Incident. The R light 9R and B light 9B transmitted through the color combining prism 20 and the G light 9G reflected by the color combining prism 20 are combined with each other and projected onto the screen 22 via the projection lens 21. As a result, a color image as a projection image is displayed on the screen 22.

  The first light measurement unit 11 described above has a function of measuring (detecting) the chromaticity of the illumination light 9. The measurement result (detection result) in the first light measurement unit 11 is sent to the determination unit (determination means) 23. The determination unit 23 performs a determination process for determining whether or not the illumination light 9 is normal by comparing the measurement result from the first light measurement unit 11 with a threshold value stored in advance in the storage unit 24. The threshold value here is a reference value for determining whether or not the illumination light 9 is within the allowable range (normal range) as white light. For example, the intensity of RGB light is detected by a photodiode, and the y value of the illumination light is calculated by calculation. When the y value of the illumination light 9 is in the range of 0.28 to 0.38, it is determined to be abnormal when it is out of this range. Further, the threshold value is stored in the storage unit 24 for each drive current value of the excitation light source 2 (for example, for the maximum rated current value or a drive current value lower than the maximum rated current value). The threshold value may be rewritable with respect to the storage unit 24.

  Whether or not the illumination light 9 is normal means whether or not yellow light having a light amount necessary for generating the illumination light 9 as white light is emitted from the phosphor 7. If an abnormality occurs in the phosphor 7 such as deterioration or burning of the phosphor 7 or peeling from the phosphor support member 8, the amount of emitted fluorescent light is reduced and white light falls outside the allowable range. Become. For this reason, it can be said that the determination part 23 performs the determination process which determines abnormality of the fluorescent substance 7 based on the measurement result from the 1st light measurement part 11. FIG.

  The determination result by the determination unit 23 is sent to the control unit 1. When the determination result indicates abnormality (abnormality determination is made by the determination unit 23), the control unit 1 reduces the emitted light amount of the illumination light from the light source unit, that is, the incident light amount to the projector optical system as described later. In order to achieve this, the light amount reduction control is performed. In addition, when the abnormality determination is an erroneous determination as described later, the control unit 1 returns the emitted light amount of the illumination light from the light source unit (incident light amount to the projector optical system) to the light amount before the light amount reduction control. Perform light intensity increase control.

  Next, image projection control processing (light source control processing) from the start of the projector to the end of driving performed by the control unit 1 will be described with reference to the flowchart of FIG. The control unit 1 executes this processing according to an image projection control program (light source control program) that is a computer program.

  In step S1, when the user powers on the projector, the control unit 1 activates the projector. Next, in step S2, the control unit 1 determines whether an error has occurred during the previous driving of the projector (hereinafter referred to as the previous driving). This determination can be made based on whether or not an error history is left in step S12 described later during the previous driving. The controller 1 proceeds to step S3 if no error has occurred during the previous drive, and proceeds to step S13 if an error has occurred.

  In step S3, the control unit 1 sets the driving current value (driving value) of the excitation light source 2 to the maximum rated current value (maximum rated value), and then starts driving (lighting) the excitation light source 2 in step S4. Next, in step S5, the control unit 1 causes the first light measurement unit 11 to measure the chromaticity of the illumination light 9, and acquires the measurement result.

  Further, in step S6, the control unit 1 causes the determination unit 23 to compare the measurement result obtained by the first light measurement unit 11 and the threshold value stored in the storage unit 24 to determine whether the phosphor 7 is normal or abnormal. Then, the determination result is acquired from the determination unit 23.

  Next, in step S7, the control unit 1 determines whether the determination result acquired from the determination unit 23 is a normal determination or an abnormality determination. If the determination result is a normal determination, the control unit 1 proceeds to step S8. move on.

  In step S <b> 8, the control unit 1 drives the light modulation elements 19 </ b> R, 19 </ b> G, and 19 </ b> B according to the input image signal to project an image on the screen 22. Subsequently, in step S9, the control unit 1 determines whether or not to continue image projection. For example, when the user performs an operation for turning off the power, the image projection is not continued, and the process proceeds to step S10. If it is determined in step S9 that image projection is to be continued, the process returns to step S3.

  In step S <b> 10, the control unit 1 stops (extinguishes) driving of the excitation light source 2. In step S11, the driving of the projector is terminated.

  On the other hand, the control unit 1 that has proceeded to step S13 because an error has occurred during the previous drive in step S2 sets the drive current value of the excitation light source 2 to a predetermined drive current value lower than the maximum rated current value. That is, the light amount reduction control is performed to reduce the light emission amount of the illumination light from the light source unit by reducing the light emission amount of the excitation light source 2 and to reduce the light amount incident on the projector optical system. Even if the excitation light from the excitation light source 2 is reflected by the phosphor support member 8 that is exposed when the phosphor 7 is peeled off or the like and is incident on the projector optical system, the predetermined drive current value is applied to the optical component that constitutes the predetermined drive current value. This is a drive current value for turning on the excitation light source 2 with a light amount that does not cause damage. Examples of optical components that may be damaged include the dichroic mirror 15, the polarizing beam splitters 17G and 17RB, the λ / 4 plates 18R, 18G, and 18B, the light modulation elements 19R, 19G, and 19B, and the projection lens 21.

  In step S7, the control unit 1 that has acquired the abnormality determination from the determination unit 23 and proceeds to step S12 leaves (records) an error history, proceeds to step S10, turns off the excitation light source 2, and further performs step S11. Then, the driving of the projector is finished.

  As described above, in this embodiment, when an error (abnormality determination) is made during the previous driving, the drive current value of the excitation light source 2 during the current driving of the projector (at the time of restarting) is set to the previous driving (before the abnormality determination). ) Is set to a predetermined drive current value lower than the maximum rated current value. Thus, when the user restarts the projector (that is, turns on the power) after the excitation light source 2 is turned off in Steps S10 and S11 after the abnormality determination at the previous driving and the projector is driven, the maximum rated current value is obtained. Excitation light having a lower intensity than that during lighting is emitted from the excitation light source 2. For this reason, the possibility that the optical component of the projector optical system is damaged by emitting high-intensity excitation light corresponding to the maximum rated current value from the excitation light source 2 in a state where the phosphor 7 is abnormal. be able to.

  Note that the comparison in step S6 after restarting the projector uses the threshold value stored in the storage unit 24 corresponding to the predetermined drive current value. In this case, when an abnormality determination is made, it is desirable to present a warning such as limiting the restart of the projector again to prompt repair.

  On the other hand, if the normal determination is made in step S6 (S7) after the restart when the abnormality determination is unacceptable during the previous driving, that is, the abnormality determination during the previous driving is an erroneous determination (such as erroneous detection of chromaticity). In such a case, image projection is performed in a state in which low-intensity excitation light is emitted from the excitation light source 2. However, in this case, the user may restart the projector again. Thereby, the drive current value of the excitation light source 2 is set to the maximum rated current value in step S9. That is, the control unit 1 performs light quantity increase control. As described above, in this embodiment, even after the projector is stopped due to an erroneous abnormality determination, the projector can be continuously used in the same state as in the normal determination.

  In this embodiment, the case where the excitation light source 2 is turned off and the driving of the projector is terminated when the abnormality determination is made has been described. However, when the abnormality determination is made, the drive current value of the excitation light source 2 is lowered. The excitation light source 2 may be turned on and the projector may be continuously driven. In this case, a warning display that informs the user that an abnormality has been detected may be performed.

  In the projector according to the second embodiment of the present invention, an image projection control process (light source control process) from the start of the projector to the end of driving performed by the control unit 1 will be described with reference to the flowchart of FIG. The control unit 1 executes this processing according to an image projection control program (light source control program) that is a computer program. The configuration of the projector is the same as that of the first embodiment shown in FIG.

  In a projector using a solid light source as an excitation light source, the brightness of the projected image decreases as the excitation light source deteriorates. For this reason, in order to keep the brightness of the projected image constant, the drive current value of the excitation light source may be increased with the deterioration of the excitation light source. In this case, the initial drive current value is generally set lower than the maximum rated current value and is gradually increased so as to approach the maximum rated current value. Projection modes of the projector include a projection mode for projecting a dark image, such as a cinema mode. In such a projection mode, the drive current value of the excitation light source 2 is set lower than the maximum rated current value. The present embodiment is an embodiment that assumes these cases.

  Here, step S14 and step S15 which are different from the flowchart of the first embodiment (FIG. 2) in the flowchart of FIG. 3 will be mainly described.

Control unit 1 determines that no error has occurred during the previous drive in step S2, the process proceeds to step S14, sets the drive current value of the pumping light source 2 first driving current value (first drive value) I ₁ Then, the process proceeds to step S4. As described above, the first drive current value I ₁ is initially set lower than the maximum rated current value, and is gradually increased to approach the maximum rated current value. Value.

On the other hand, the control unit 1 determines that an error has occurred during the previous drive in step S2, the process proceeds to step S15, the second driving current value the drive current value lower than I ₁ of the excitation light source 2 (second driving value) It is set to I _2. That is, the light amount reduction control is performed to reduce the light emission amount of the illumination light from the light source unit by reducing the light emission amount of the excitation light source 2 and to reduce the light amount incident on the projector optical system. Thereafter, the process proceeds to step S4.

The storage unit 24 stores threshold values corresponding to a plurality of drive current values that can be selected as the first and second drive current values I ₁ and I _2. Comparison and determination are performed using a threshold value corresponding to the drive current value at.

Further, the control unit 1 stores the drive current value (I ₁ ) or projection mode at the time of abnormality determination in step S12 as one item of error history, and the stored drive current value or projection in step S15 after restart. A new drive current value (I ₂ ) is set according to the mode.

In this embodiment, even when the drive current value (I ₁ ) of the excitation light source 2 at the time of abnormality determination at the previous drive is lower than the maximum rated current value, after the projector driving according to the abnormality determination is stopped. At the time of restart, the drive current value is set to I ₂ lower than I ₁ before the abnormality determination. For this reason, even when restarting in such a case, the possibility that the optical components of the projector optical system are damaged can be reduced.

  FIG. 4 shows the configuration of a liquid crystal projector that is Embodiment 3 of the present invention. The projector of this embodiment is different from the light source device 101 of the projector of Embodiment 1 shown in FIG. 1 in that the second light branching section 25, the second light measuring section (excitation light detecting means) 26, and the color filter 27. Has the light source device 102 added.

  The second light branching unit 25 branches a part of the excitation light 3 emitted from the excitation light source 2 and guides it to the second light measurement unit 26. The excitation light 3 transmitted through the second light branching portion 25 is guided to the excitation light reflecting portion 4. In the present embodiment, the second light branching portion 25 is made of flat glass, but may be anything as long as it can branch a part of the excitation light 3.

  The color filter 27 is a filter that is disposed between the first light branching unit 10 and the first light measurement unit 11 and cuts blue light and transmits yellow light. For this reason, yellow light is guided to the first light measurement unit 11. The first light measurement unit 11 measures the amount of yellow light as fluorescent light, and the second light measurement unit 26 measures the amount of blue light as excitation light 3.

  The measurement result in the first light measurement unit 11 and the measurement result in the second light measurement unit 26 are sent to the determination unit 23. The storage unit 24 is a predetermined range (normal range) in which the light amount ratio, which is the ratio between the measurement result (light amount) in the first light measurement unit 11 and the measurement result (light amount) in the second light measurement unit 26, is normal. ) Is stored. The determination unit 23 calculates this ratio and determines whether the calculated ratio is within the normal range, that is, whether the phosphor 7 is normal.

  In the projector of this embodiment, the image projection control process (light source control process) from the start of the projector to the end of driving performed by the control unit 1 will be described with reference to the flowchart of FIG. The control unit 1 executes this processing according to an image projection control program (light source control program) that is a computer program. Here, in the flowchart of FIG. 5, steps S16 to S18 different from the flowchart of the second embodiment (FIG. 3) will be mainly described.

Control unit 1 starts the driving of the pumping light source 2 with the driving current I ₁ at step S4, to measure the amount of the yellow light among the illumination light 9 at step S16 to the first optical measuring section 11, the result of the measurement To get. Next, in step S <b> 17, the control unit 1 causes the second light measurement unit 26 to measure the amount of blue light as the excitation light 3 and acquires the measurement result.

  In step S <b> 18, the control unit 1 causes the determination unit 23 to store a light amount ratio, which is a ratio between the measurement result of the first light measurement unit 11 and the measurement result of the second light measurement unit 26, in the storage unit 24. It is determined whether it is within the stored normal range, and the determination result is acquired. Thereafter, the process proceeds to step S7.

In this embodiment, the abnormality of the phosphor 7 can be detected (determined) by determining the light quantity ratio between the excitation light 3 and the fluorescent light. Then, the drive current value (I ₂ ) of the excitation light source 2 is lower than the drive current value (I ₁ ) at the previous drive (before abnormality determination) at the time of restart after the drive of the projector is stopped due to the abnormality determination at the previous drive. (I.e., light quantity reduction control is performed). This can reduce the possibility of damage to the optical components of the projector optical system during restart.

  FIG. 6 shows the configuration of a liquid crystal projector that is Embodiment 4 of the present invention. The projector of this embodiment has a light source device 103 in which a shutter 28 is added to the light source device 101 of the projector of the first embodiment shown in FIG. The shutter 28 is disposed between the phosphor 7 and the first fly-eye lens 12a, that is, between the phosphor 7 and the projector optical system. By changing the aperture area of the shutter 28, the shutter 28 is transmitted through the projector optical system. Controls the amount of light incident on. The driving of the shutter 28 is controlled by the control unit 1.

  In the projector of this embodiment, the image projection control process (light source control process) from the start of the projector to the end of driving performed by the control unit 1 will be described with reference to the flowchart of FIG. The control unit 1 executes this processing according to an image projection control program (light source control program) that is a computer program. Here, in the flowchart of FIG. 7, step S19 different from the flowcharts of the first to third embodiments will be mainly described.

  The control unit 1 that has determined that an error has occurred during the previous drive in step S2 proceeds to step S19, and reduces the amount of light emitted from the light source unit by making the opening area of the shutter 28 narrower than normal (before abnormality determination). Let That is, the light amount reduction control for reducing the incident light amount to the projector optical system is performed. Thereafter, the process proceeds to step S4.

  By making the opening area of the shutter 28 smaller than usual, the amount of illumination light 9 from the phosphor 7, that is, the amount of incident light of the fluorescent light and the excitation light (non-converted light) to the projector optical system is lowered than usual. Can do. As a result, even when the excitation light source 2 is turned on at the maximum rated current value at the time of restart after the abnormality determination is made, it is possible to avoid that the high-intensity excitation light is directly incident on the projector optical system, and the optical of the projector optical system The possibility of parts being damaged can be reduced.

In this embodiment, the case where the shutter 28 is disposed between the first light branching unit 10 and the first fly-eye lens 12a has been described. However, it is disposed at an arbitrary position where the amount of incident light on at least a part of the projector optical system can be reduced, such as between the second lens 14 and the dichroic mirror 15 or between the color synthesis prism 20 and the projection lens 21. can do.
(Other examples)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  Each embodiment described above is only a representative example, and various modifications and changes can be made to each embodiment in carrying out the present invention.

DESCRIPTION OF SYMBOLS 1 Control part 2 Excitation light source 3 Excitation light 7 Phosphor 9 Illumination light 11 1st light measurement part 23 Determination part
101, 102, 103 light source device

Claims (13)

A solid-state light source that emits excitation light; and a phosphor that converts the excitation light into fluorescence and emits fluorescence light, and a light source device that emits illumination light including the fluorescence light,
Illumination light detection means for detecting the illumination light;
Determination means for determining whether the phosphor is normal or abnormal based on a detection result by the illumination light detection means;
A light source device comprising: control means for performing light amount reduction control for reducing the amount of emitted light of the illumination light from the light source device in response to the abnormality determination by the determination means than before the abnormality determination.   The light source device according to claim 1, wherein the illumination light includes the fluorescent light and a part of the excitation light.   3. The control unit according to claim 1, wherein the control unit stops light emission of at least the solid light source according to the abnormality determination, and performs the light amount reduction control when starting light emission of the solid light source next time. The light source device described.   4. The light source device according to claim 1, wherein the control unit performs control to reduce a light emission amount of the solid-state light source as the light amount reduction control. 5.   The control means drives the solid light source at a drive value lower than the maximum rated value as the light amount reduction control when the solid light source is driven at a maximum rated value before the abnormality determination. The light source device according to claim 4.   When the solid-state light source is driven with a first drive value lower than a maximum rated value before the abnormality determination, the control unit lowers the solid-state light source below the first drive value as the light amount reduction control. The light source device according to claim 4, wherein the light source device is driven with a second drive value. A shutter between the phosphor and the optical system;
4. The light source device according to claim 1, wherein the control unit performs control for narrowing the illumination light by the shutter as the light amount reduction control. 5.   The determination unit determines again whether the phosphor is normal or abnormal based on a detection result by the illumination light detection unit in a state where the light amount reduction control is performed. 8. The light source device according to any one of 7.   2. The control unit according to claim 1, wherein when a normal determination is made in the determination of whether the normality is abnormal again, the control unit performs a light amount increase control for returning the incident light amount to a light amount before the light amount reduction control. The light source device according to any one of 1 to 8. The illumination light detection means detects the chromaticity of the illumination light,
The light source apparatus according to claim 1, wherein the determination unit performs the abnormality determination when the detected chromaticity is out of a predetermined range. Having excitation light detection means for detecting the excitation light;
The light source apparatus according to claim 1, wherein the determination unit performs the abnormality determination by using the detection results of the illumination light detection unit and the excitation light detection unit together. The light source device according to any one of claims 1 to 11,
An image projection apparatus comprising: an optical system that modulates and projects the illumination light by a light modulation element. Illumination light detection means having a solid light source that emits excitation light and a phosphor that converts the excitation light into fluorescence and emits fluorescence light, emits illumination light containing the fluorescence light, and detects the illumination light A computer program for operating a computer of a light source device having:
A determination process for determining whether the phosphor is normal or abnormal based on a detection result by the illumination light detection unit;
An image projection control program for performing light amount reduction control for reducing the amount of emitted light of the illumination light from the light source device more than before the abnormality determination in response to the abnormality determination by the determination process.