JP2020034614A - Light source device and image projection device - Google Patents

Abstract

To minimize CODs to light sources.SOLUTION: A light source device is provided, comprising a plurality of first light sources RLD, control means 1, 3 for controlling the plurality of first light sources, and detection means 4 for detecting anomaly in each of the plurality of first light sources. When anomaly is detected in any of the first light sources by the detection means while the plurality of first light sources is driven to be turned on, the control means provides control to reduce emission intensity of the first light sources free of anomaly.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light source device suitable for an image projection device such as a liquid crystal projector.

  2. Description of the Related Art A laser diode (LD) is used as a light source in an image projection apparatus (hereinafter, referred to as a projector) that modulates an image of light emitted from a light source by a light modulation element such as a liquid crystal panel and projects the light on a projection surface such as a screen. There is something. Some of such projectors use a plurality of LDs (blue LD and red LD) that emit light of different wavelengths, as disclosed in Patent Document 1.

JP 2016-224304 A

  However, the red LD has a property of easily causing optical damage (COD: Catastrophic Optical Damage) when the temperature is particularly low, as compared with the blue LD. Further, in a light source device using a plurality of red LDs, when an abnormality occurs in a certain red LD, light emission and heat generation are stopped even when a drive current is supplied to the red LD, and the normal red light adjacent to the abnormal red LD does not emit light. The temperature of the red LD decreases. As a result, COD may occur in the normal red LD.

  The present invention provides a light source device and a projector capable of suppressing the occurrence of COD of a light source such as a red LD.

  A light source device according to one aspect of the present invention includes a plurality of first light sources, a control unit configured to control the plurality of first light sources, and a detection unit configured to detect abnormality of each of the plurality of first light sources. Having. The control unit is configured to, when driving the plurality of first light sources to light up, detect an abnormality in any one of the first light sources, and detect the first light source in which no abnormality is detected. Characterized in that control is performed to reduce the amount of light emission.

  Note that an image projection device using the above light source device also constitutes another aspect of the present invention.

  Further, a control method according to another aspect of the present invention is applied to a light source device having a plurality of first light sources. The control method includes the steps of: detecting an abnormality of any of the plurality of first light sources while driving the plurality of first light sources to light up; and detecting an abnormality of the first light source. And performing a control to reduce the light emission amount of the first light source in which no abnormality is detected.

  Note that a computer program that causes a computer of the light source device to execute processing according to the above control method also constitutes another aspect of the present invention.

  According to the present invention, when an abnormality occurs in any of the first light sources, it is possible to suppress the occurrence of COD in the first light source in which no abnormality has occurred.

FIG. 1 is a diagram illustrating a configuration of a projector that is Embodiment 1 of the present invention. FIG. 2 is a diagram illustrating an arrangement of a plurality of LDs according to the first embodiment. 5 is a flowchart illustrating fail-safe processing performed by the projector according to the first embodiment. FIG. 2 is a diagram illustrating a configuration of a projector that is Embodiment 2 of the present invention. 9 is a flowchart illustrating a fail-safe process performed by the projector according to the second embodiment. FIG. 9 is a diagram illustrating a configuration of a projector that is Embodiment 3 of the present invention. 9 is a flowchart illustrating a fail-safe process performed by the projector according to the third embodiment. 9 is a flowchart illustrating a fail-safe process performed by the projector according to the fourth embodiment of the present invention. 14 is a flowchart illustrating a fail-safe process performed by the projector according to the fifth embodiment of the present invention. 16 is a flowchart illustrating a fail-safe process performed by the projector according to the sixth embodiment of the invention. The figure which shows the light source device which is Example 7 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration of a projector as an image projection device according to a first embodiment of the present invention. In the following description, R, G, and B mean red, green, and blue, respectively. 1 is a system control unit, 3 is a drive current calculation unit, and 4 is a light source drive unit. 5ba, 5bb, and 5bc are B light sources, and 5rd is an R light source. 6b is a heat sink for the B light source, 6r is a heat sink for the BR light source, 7b is a cooling unit for the B light source, 7r is a cooling unit for the BR light source, and 8 is a cooling control unit.

  9ba, 9bb, and 9bc are B collimating lenses, and 9rd is an R collimating lens d. Reference numeral 10 denotes a first lens, 11 denotes a second lens, 13 denotes a light reflecting member, 14 denotes a glass plate, and 15 denotes a third lens. 16 is a phosphor, 17 is a phosphor support member, 18 is a motor, and 19 is a motor control unit. 21a is a first fly-eye lens, 21b is a second fly-eye lens, 22 is a polarization conversion element, and 23 is a fourth lens.

  24 is a dichroic mirror, 25 is a wavelength-selective phase plate, 26RB is a RB polarizing beam splitter, 26G is a G polarizing beam splitter, 27R is a λ / 4 plate for R, 27G is a λ / 4 plate for G, and 27B is B Λ / 4 plate. 28R is a light modulation unit for R, 28G is a light modulation unit for G, and 28B is a light modulation unit for B. Reference numeral 30 denotes a color combining prism, and 32 denotes a projection lens.

  The drive current calculation unit 3 calculates drive currents of the B light sources 5ba, 5bb, 5bc and the R light source 5rd according to an instruction from the system control unit 1. The light source drive unit 4 supplies each drive current calculated by the drive current calculation unit 3 to each light source to drive it. The system control section 1 and the drive current calculation section 3 constitute control means.

  Each of the B light sources 5ba, 5bb, and 5bc is configured using a plurality of semiconductor laser diodes (second light source: hereinafter, referred to as BLD) that emit the B light (blue light). The peak wavelength of the B light sources 5ba, 5bb, 5bc is, for example, 455 nm. The R light source 5rd is configured using a plurality of the same semiconductor laser diodes (first light source: hereinafter, referred to as RLD) that emit R light (red light). The peak wavelength of the R light source 5rd is, for example, 635 nm. The B light sources 5ba, 5bb are attached to a B light source heat sink 6b. The B light source 5bc and the R light source 5rd are attached to a BR light source heat sink 6r as a heat transfer member. As each heat sink, a copper plate or the like provided with a radiation fin is used. It is preferable that each light source and each heat sink be in close contact with a heat transfer member such as a heat conductive sheet.

  On the back of the heat sink 6b for the B light source and the heat sink 6r for the BR light source, a cooling unit for the B light source (hereinafter referred to as a cooling fan for the B light source) 7b and a cooling unit for the BR light source (cooling means: , BR light source cooling fan) 7r. The cooling air from each of the cooling fan 7b for the B light source and the cooling fan 7r for the BR light source cools the heat sink 6b for the B light source and the heat sink 6r for the BR light source. The rotation speeds of the B light source cooling fan 7b and the BR light source cooling fan 7r are controlled by the cooling control unit 8 based on an instruction from the system control unit 1. In FIG. 1, the directions of the arrows protruding from the cooling fan 7b for the B light source and the cooling fan 7r for the BR light source indicate the direction of the cooling air.

  The BR light source heat sink 6r transmits the heat generated by the B light source 5bc to the R light source 5rd. Further, the BR light source heat sink 6r averages the heat generated by each of the B light source 5bc and the R light source 5rd. By cooling the BR light source heat sink 6r with the R light source cooling fan 7r, the B light source 5bc and the R light source 5rd can be cooled simultaneously.

  The B lights emitted from the B light sources 5ba, 5bb, 5bc enter the B collimating lenses 9ba, 9bb, 9bc, respectively. The R light emitted from the R light source 5rd enters the R collimating lens 9rd. Each collimating lens converts light from each light source into substantially parallel light. The direction of the arrow from each light source in FIG. 1 indicates the optical path and traveling direction of the light. This is the same in the following optical paths.

  Light emitted from each collimating lens enters the first lens 10 and the second lens 11 and is emitted as excitation light 12. The first lens 10 and the second lens 11 have a role of adjusting the beam diameter of light emitted from each collimating lens.

  The excitation light 12 is reflected by the light reflecting member 13 provided on the surface of the glass plate 14 and irradiates the phosphor 16 via the third lens 15. The light reflecting member 13 is provided only on a portion of the surface of the glass plate 14 where the excitation light 12 is irradiated. Further, the third lens 15 condenses the excitation light 12 to form a light irradiation area of a predetermined size on the phosphor 16.

  The material of the phosphor 16 is, for example, YAG: Ce. The phosphor 16 is provided in a circumferential direction around the rotation axis of the motor 18 and is supported by a phosphor support member 17. The material of the phosphor support member 17 is typically a metal plate such as aluminum. However, it is not limited to a metal plate as long as it has the same function as the metal plate. The motor 18 rotates the phosphor 16 and the phosphor support member 17 in order to efficiently radiate heat from the phosphor 16. The rotation speed of the motor 18 is controlled by the motor control unit 19 in accordance with an instruction from the system control unit 1.

  The phosphor 16 converts the wavelength of a part of the B light in the excitation light 12 to generate yellow fluorescent light. The fluorescent light, the excitation light of B (non-converted light) that has not been wavelength-converted by the phosphor 16 and the R light are combined to generate the illumination light 20 as white (W) light.

  The illumination light 20 enters the third lens 15 and is converted into substantially parallel light. The illumination light 20 transmitted through the third lens 15 is further transmitted through a portion of the glass plate 14 other than the light reflecting member 13, and transmitted through the first fly-eye lens 21a and the second fly-eye lens 21b. Is split into a plurality of light beams and enters the polarization conversion element 22. The polarization conversion element 22 converts the illumination light 20 that is unpolarized light into linearly polarized light having one specific polarization direction. Generally, the light beam from the LD is linearly polarized light, but the illumination light 20 from the phosphor 16 is unpolarized light. For this reason, in order to efficiently perform the polarization separation by the polarization beam splitter described later, the light is converted into linearly polarized light (S-polarized light having a polarization direction perpendicular to the paper surface of FIG. 1) by providing the polarization conversion element 22.

  A plurality of light fluxes as the illumination light 20 emitted from the polarization conversion element 22 are condensed by the fourth lens 23 and are superimposed on the three light modulators 28R, 28G, 28B. Thereby, each light modulator is uniformly illuminated.

  The illumination light 20 transmitted through the fourth lens 23 is guided to the dichroic mirror 24. The dichroic mirror 24 reflects the RB light 20RB of the illumination light 20 and transmits the G light 20G. The S-polarized G light 20G transmitted through the dichroic mirror 24 is incident on the G polarization beam splitter 26G, is reflected by the polarization splitting surface, and reaches the G light modulation unit 28G. Here, the G light modulation section 28G is a digitally driven reflective liquid crystal display element, and forms an original image for modulating the G light 20G. The system control unit 1 drives the G light modulation unit 28G to form an original image in response to an externally input video signal. At this time, the system control unit 1 drives each pixel of the G light modulation unit 28G ON / OFF during each frame period, and controls the duty of the ON / OFF drive to control the G light modulation unit 28G. Is expressed. The same applies to the R light modulation unit 28R and the B light modulation unit 28B.

  The G light modulator 28G modulates and reflects the G light 20G according to the original image. Thus, the modulated light 29G is emitted from the G light modulator 28G. The S-polarized light component of the modulated light 29G is reflected by the polarization splitting surface of the G polarization beam splitter 26G, returned to the light source side, and removed from the projection light. On the other hand, the P-polarized light component of the modulated light 29G passes through the polarization splitting surface of the G polarization beam splitter 26G. At this time, in a state where all the polarization components are converted into S-polarized light (hereinafter, referred to as an all black display state), the slow axis or the fast axis of the λ / 4 plate 27G is changed to the incident optical axis to the G polarizing beam splitter 26G. And the direction perpendicular to the plane containing the reflected optical axis. Accordingly, it is possible to suppress the influence of the disorder of the polarization state generated in the G polarization beam splitter 26G and the G light modulation unit 28G. The modulated light 29G emitted from the G polarization beam splitter 26G enters the color combining prism 30.

  The RB light 20 RB reflected by the dichroic mirror 24 enters the wavelength-selective phase plate 25. The wavelength-selective phase plate 25 converts the R light into P-polarized light by rotating its polarization direction by 90 degrees, and transmits the B light as S-polarized light without rotating its polarization direction. The RB light 20RB transmitted through the wavelength-selective phase plate 25 enters the RB polarizing beam splitter 26RB.

  The RB polarization beam splitter 26RB transmits the P light R light 20R and reflects the S light B light 20B. The R light 20R transmitted through the polarization splitting surface of the RB polarization beam splitter 26RB is modulated and reflected by the R light modulation unit 28R and emitted as modulated light 29R. The P-polarized light component of the modulated light 29R passes through the polarization splitting surface of the RB polarization beam splitter 26RB, returns to the light source side, and is removed from the projection light. On the other hand, the S-polarized light component of the modulated light 29 </ b> R is reflected by the polarization splitting surface of the RB polarization beam splitter 26 RB and enters the color combining prism 30.

  The B light 20B reflected by the polarization splitting surface of the RB polarization beam splitter 26RB is modulated and reflected by the B light modulation unit 28B to become a modulated light 29B. The S-polarized light component of the modulated light 29B is reflected by the polarization splitting surface of the RB polarization beam splitter 26RB, returned to the light source side, and removed from the projection light. On the other hand, the P-polarized light component of the modulated light 29B passes through the polarization splitting surface of the RB polarization beam splitter 26RB and enters the color combining prism 30. At this time, by adjusting the slow axes of the λ / 4 plates 27R and 27B in the same manner as in the G λ / 4 plate 27G, it is possible to adjust each of the R and B full black display states. The RB light 29RB thus combined into one light beam and emitted from the RB polarizing beam splitter 26RB enters the color combining prism 30.

  The color combining prism 30 transmits the RB light 20RB and reflects the G light 29G to combine them to generate the projection light 31. The projection light 31 is enlarged and projected through a projection lens 32 onto a projection surface (not shown) such as a screen. Thereby, a color image is displayed as a projection image. The optical path shown in FIG. 1 is when the projector is displaying an all-white image. Also in the following embodiments, it is assumed that the projector displays an all-white image unless otherwise specified.

  FIG. 2 shows an arrangement of a plurality of LDs included in each of the B light source 5bc and the R light source 5rd. The B light source 5bc includes a plurality (9) of BLDs arranged adjacent to each other in a 3 × 3 matrix. The R light source 5rd includes a plurality (9) of RLDs arranged adjacent to each other in a 3 × 3 matrix. The plurality of BLDs and the plurality of RLDs are attached to the same BR light source heat sink 6r. Further, the light source drive unit 4 that supplies a drive current to each of the plurality of BLDs and the plurality of RLDs can detect an applied voltage (also referred to as a drive voltage) for each LD as a detection unit. The drive current calculation unit 3 can adjust the drive current supplied to each LD according to the applied voltage detected by the light source drive unit 4.

  Here, a mechanism will be described in which when an abnormality (failure) occurs in at least one of the plurality of RLDs in the R light source 5rd, CОD is likely to occur in a normal RLD adjacent to the abnormal RLD. When a drive current is supplied to the RLD, the electrons of the drive current are converted to light to emit light, but the light is converted to a part of the supplied electrons, and a large amount of energy is lost, resulting in heat. Is converted to For this reason, it is necessary to cool the RLD using a cooling means such as a heat sink or a cooling fan.

  However, an abnormality such as a short circuit may occur in the current supply circuit of the RLD, and even if a drive current is supplied, the abnormal RLD may not emit light and generate no heat. Since heat is no longer generated from the RLD, the degree of cooling by the cooling unit is relatively increased, and as a result, the temperature of the normal RLD adjacent to the abnormal RLD decreases. When the temperature of a normal RLD decreases, the amount of light emitted from the RLD increases and COD easily occurs.

  For this reason, in the present embodiment, control is performed so that the light emission amount (light output) of the normal RLD adjacent to the abnormal RLD is lower than the light emission amount that has increased due to the temperature drop.

  The flowchart in FIG. 3 illustrates the fail-safe processing performed by the system control unit 1 (and the drive current calculation unit 3) in the present embodiment. The system control unit 1 executes this processing according to a computer program. In the following description, “S” means a step.

  When the power of the projector is turned on by the user operating a power button provided on the projector or a power button provided on the remote controller, the system control unit 1 controls the B light sources 5ba, 5bb, 5bc and the R light source 5rd. A light source lighting process for lighting is performed. After the end of the light source lighting process, the system control unit 1 starts the fail-safe process.

  In step S1, the system control unit 1 causes the light source driving unit 4 as a detection unit to detect applied voltages (hereinafter, simply referred to as voltages) of a plurality of RLDs of the R light source 5rd.

  Next, in S2, the system control unit 1 determines whether any one of the voltages of the plurality of RLDs is lower than a predetermined value. If the voltages of all the RLDs are equal to or higher than the predetermined value, the system control unit 1 determines that all the RLDs are normal, proceeds to S3, continues lighting all the RLDs, and returns to S1.

  On the other hand, if there is an RLD whose voltage is lower than the predetermined value, the system control unit 1 determines that an abnormality has occurred in the RLD and proceeds to S4. In an abnormal RLD, even if the same drive current is supplied, the applied voltage decreases, so that it is possible to detect the occurrence of an abnormality in the RLD through the voltage.

  In S4, the system control unit 1 causes the drive current calculation unit 3 to have no abnormality located adjacent to the RLD in which an abnormality has occurred (hereinafter, referred to as abnormal RLD), that is, a normal RLD (hereinafter, referred to as normal RLD). ) Is calculated. In calculating the drive current, a parameter stored in the drive current calculation unit 3 for adjusting the drive current in accordance with the number of abnormal RLDs arranged adjacent to each other is used. Further, the normal RLD disposed adjacent to the abnormal RLD includes all RLDs of the R light source 5rd except the abnormal RLD. In other words, the adjacent arrangement means that the abnormal RLD is arranged close enough to be affected by the temperature drop. The parameters stored in the drive current calculation unit 3 are used for calculating the drive current, and the meaning of the adjacent arrangement is the same in other embodiments described later.

  Note that the system control unit 1 causes the drive current calculation unit 3 to set the drive current supplied to the abnormal RLD to 0.

  Further, the system control unit 1 causes the drive current calculation unit 3 to calculate, as the drive current to be supplied to the normal RLD, a drive current that is smaller than before the occurrence of the abnormal RLD. Further, by calculating the drive current to be supplied to the normal RLD using the temperature of the normal RLD, the accumulated lighting time, and the like, it is possible to set the optimum drive current (that is, the light emission amount and the temperature of the normal RLD), COD generation in normal RLD can be suppressed.

  Next, in S5, the system control unit 1 supplies the drive current calculated in S4 to the normal RLD via the light source drive unit 4. Then, the system control unit 1 returns to S1 via S3.

  According to the present embodiment, when an abnormal RLD is detected, the drive current supplied to the normal RLD is reduced to reduce the amount of light emission, thereby suppressing the occurrence of COD in the normal RLD.

  In this embodiment, the case where the B light source 5bc and the R light source 5rd are arranged on the same BR light source heat sink 6r has been described. However, the heat of the B light source is transferred using a heat transfer member such as a heat pipe other than the heat sink. May be transmitted.

  Next, a second embodiment of the present invention will be described. FIG. 4 illustrates a configuration of the projector according to the second embodiment. The projector of the present embodiment is obtained by adding a temperature sensor 40 for detecting the temperature of each of the RLDs included in the R light source 5rd to the projector of the first embodiment.

  The flowchart in FIG. 5 illustrates the fail-safe processing performed by the system control unit 1 in the present embodiment. As in the first embodiment, after the light source lighting process is completed, the system control unit 1 starts the fail-safe process.

  In S11, the system control unit 1 detects the temperature of each of the plurality of RLDs of the R light source 5rd by the temperature sensor 40 as a detecting unit.

  Next, in S12, the system control unit 1 determines whether any one of the plurality of RLDs has a temperature lower than a predetermined value. If the temperatures of all the RLDs are equal to or higher than the predetermined value, the system control unit 1 determines that all the RLDs are normal, proceeds to S13, continues lighting all the RLDs, and returns to S11.

  On the other hand, if there is an RLD whose temperature is lower than the predetermined value, the system control unit 1 determines that an abnormality has occurred in the RLD and proceeds to S14. In the abnormal RLD, even if the same drive current is supplied, the amount of generated heat is reduced, so that it is possible to detect the occurrence of an abnormality in the RLD through the temperature.

  In S14, the system control unit 1 causes the drive current calculation unit 3 to calculate, as the drive current to be supplied to the normal RLD disposed adjacent to the abnormal RLD, a drive current that is smaller than before the occurrence of the abnormal RLD. At this time, by calculating the drive current supplied to the normal RLD using the voltage of the normal RLD, the accumulated lighting time, and the like, it is possible to set the optimum drive current (that is, the light emission amount and the temperature of the normal RLD). The occurrence of COD in a normal RLD can be suppressed. Note that the system control unit 1 causes the drive current calculation unit 3 to set the drive current supplied to the abnormal RLD to 0.

  Next, in S15, the system control unit 1 supplies the drive current calculated in S14 to the normal RLD via the light source drive unit 4. Then, the system control unit 1 returns to S11 via S13.

  Also in the present embodiment, when an abnormal RLD is detected, the generation of COD in the normal RLD can be suppressed by reducing the drive current supplied to the normal RLD to reduce the light emission amount.

  In this embodiment, the case where the drive current of the normal RLD is reduced by the fact that the temperature of the RLD detected by the temperature sensor 40 is lower than a predetermined value has been described. However, the temperature of the components near the R light source 5rd, such as the temperature of the B light source 5bc and the temperature of the BR light source heat sink 6r, is detected, and the drive current of the normal RLD is reduced as the temperature becomes lower than a predetermined value. May be.

  Further, in the present embodiment, a case has been described in which a temperature sensor is provided for each of the plurality of RLDs and the temperature sensor 40 that can detect the temperature of each RLD is used. However, using one temperature sensor, a plurality of RLDs are turned on one by one in order, and the temperature change is measured. If the temperature rises proportionally, the RLD is determined to be normal, and the temperature rise is non-linear. In some cases, it may be determined that an abnormality has occurred in the RLD.

  Next, a third embodiment of the present invention will be described. FIG. 6 illustrates a configuration of a projector according to the third embodiment. The projector according to the present embodiment is obtained by adding a light amount sensor 50 as detecting means for detecting the amount of light emitted from each of the RLDs included in the R light source 5rd to the projector according to the first embodiment. The light quantity sensor 50 detects light (leakage light) deviating from the principal ray among the light emitted from the RLD. Further, by using the dichroic filter 51 that selectively transmits light of a specific wavelength (for example, R light), the light amount from each of the plurality of RLDs can be detected without being affected by the change in the light amount of B light. Can be.

  The flowchart in FIG. 7 illustrates the fail-safe processing performed by the system control unit 1 in the present embodiment. As in the first embodiment, after the light source lighting process is completed, the system control unit 1 starts the fail-safe process.

  In S21, the system control unit 1 detects the light emission amount of each of the plurality of RLDs of the R light source 5rd using the light amount sensor 50.

  Next, in S22, the system control unit 1 determines whether the light emission amount of any of the plurality of RLDs is lower than a predetermined value. For example, a plurality of RLDs are sequentially turned on one by one, and the change in the light amount is measured. If the light amount increases proportionally, the RLD is determined to be normal. If the change in the light amount is nonlinear, the RLD is abnormal. Can be determined to have occurred. If the light emission amounts of all the RLDs are equal to or greater than the predetermined value, the system control unit 1 determines that all the RLDs are normal, proceeds to S23, continues lighting all the RLDs, and returns to S21.

  On the other hand, if there is an RLD whose light emission amount is lower than the predetermined value, the system control unit 1 determines that an abnormality has occurred in the RLD and proceeds to S24. In the abnormal RLD, even if the same drive current is supplied, the light emission amount decreases, so that it is possible to detect the occurrence of an abnormality in the RLD through the light emission amount.

  In S24, the system control unit 1 causes the drive current calculation unit 3 to calculate, as the drive current to be supplied to the normal RLD disposed adjacent to the abnormal RLD, a drive current smaller than before the occurrence of the abnormal RLD. At this time, by calculating the drive current to be supplied to the normal RLD using the temperature of the normal RLD, the accumulated lighting time, and the like, it is possible to set the optimum drive current (that is, the light emission amount and the temperature of the normal RLD). The occurrence of COD in a normal RLD can be suppressed. Note that the system control unit 1 causes the drive current calculation unit 3 to set the drive current supplied to the abnormal RLD to 0.

  Next, in S25, the system control unit 1 supplies the drive current calculated in S24 to the normal RLD via the light source drive unit 4. Then, the system control unit 1 returns to S21 via S23.

  Also in the present embodiment, when an abnormal RLD is detected, the generation of COD in the normal RLD can be suppressed by reducing the drive current supplied to the normal RLD to reduce the light emission amount.

  Next, a fourth embodiment of the present invention will be described. The configuration of the projector according to the fourth embodiment is the same as that of the projector according to the first embodiment. The flowchart in FIG. 8 illustrates a light source lighting process performed by the system control unit 1 in the present embodiment. As in the first embodiment, after the light source lighting process is completed, the system control unit 1 starts the fail-safe process.

  In S31, the system control unit 1 detects respective voltages of the plurality of RLDs of the R light source 5rd, as in S1 of the first embodiment.

  Next, in S32, the system control unit 1 determines whether any of the plurality of RLDs is lower than a predetermined value, as in S2 of the first embodiment. If the voltages of all the RLDs are equal to or higher than a predetermined value, the system control unit 1 determines that all the RLDs are normal, proceeds to S33 without changing the rotation speed of the BR light source cooling fan 7r, and proceeds to S33. The lighting of the RLD is continued, and the process returns to S1.

  On the other hand, if there is an RLD whose voltage is lower than the predetermined value, the system control unit 1 determines that an abnormality has occurred in the RLD and proceeds to S34, as in S3 of the first embodiment.

  In S34, the system control unit 1 calculates the rotation speed of the BR light source cooling fan 7r. At this time, the system control unit 1 calculates, as the rotation speed of the BR light source cooling fan 7r, a rotation speed lower than before the occurrence of the abnormal RLD. At this time, the light source driving unit 4 adjusts the rotation speed of the BR light source cooling fan 7r in accordance with the number of adjacently arranged abnormal RLDs stored in the system control unit 1. It is calculated using parameters. Also, by calculating the rotation speed of the BR light source cooling fan 7r using the temperature of the normal RLD, the accumulated lighting time, and the like, the optimum rotation speed (that is, the temperature of the normal RLD) can be set. COD generation in RLD can be suppressed.

  Note that the system control unit 1 causes the drive current calculation unit 3 to set the drive current supplied to the abnormal RLD to 0.

  Next, in S35, the light source driving unit 4 rotates the BR light source cooling fan 7r at the rotation speed calculated in S34. Then, the system control unit 1 returns to S31 via S33.

  Also in the present embodiment, when an abnormal RLD is detected, the rotation speed of the BR light source cooling fan 7r for cooling the normal RLD is reduced to weaken the cooling for the normal RLD, thereby generating COD due to the temperature drop of the normal RLD. Can be suppressed.

  In this embodiment, the case where the BR light source cooling fan 7r is used as the cooling means has been described. However, when a Peltier element is used as the cooling means, the current supplied to the Peltier side is controlled, and when a liquid cooling system is used, the flow rate of the cooling liquid is controlled to weaken the cooling of the normal RLD. Can be.

  As a method of raising the temperature of the normal RLD, a method of increasing the driving current of the B light source 5bc to increase the amount of heat generated therefrom may be used. In this case, it is more preferable to reduce the drive current of the B light sources 5ba, 5bb and adjust the light emission amounts from all the B light sources 5ba, 5bb, 5bc. Thereby, the color balance of the light emitted from the light source device can be adjusted.

  Next, a fifth embodiment of the present invention will be described. The configuration of the projector according to the fifth embodiment is the same as that of the projector according to the first embodiment. The flowchart in FIG. 9 illustrates a light source lighting process performed by the system control unit 1 in the present embodiment.

  As in the first embodiment, after the light source lighting process is completed, the system control unit 1 starts the fail-safe process. In step S41, the system control unit 1 detects respective voltages of the plurality of RLDs of the R light source 5rd, as in step S2 of the first embodiment.

  Next, in S42, the system control unit 1 determines whether any of the plurality of RLDs is lower than a predetermined value, as in S2 of the first embodiment. If the voltages of all the RLDs are equal to or higher than the predetermined value, the system control unit 1 determines that all the RLDs are normal, proceeds to S43, continues lighting all the RLDs, and returns to S41.

  On the other hand, if there is an RLD whose voltage is lower than the predetermined value, the system control unit 1 determines that an abnormality has occurred in the RLD and proceeds to S44, as in S3 of the first embodiment.

  In S44, similarly to S4 of the first embodiment, the system control unit 1 sets the drive current calculation unit 3 as a drive current to be supplied to the normal RLD disposed adjacent to the abnormal RLD as compared to before the occurrence of the abnormal RLD. The reduced drive current is calculated. Note that the system control unit 1 causes the drive current calculation unit 3 to set the drive current supplied to the abnormal RLD to 0.

  Next, in S45, the system control unit 1 causes the drive current calculation unit 3 to calculate the drive current to be supplied to the B light sources 5ba, 5bb, 5bc. At this time, the drive current calculation unit 3 calculates a parameter for adjusting the drive current in accordance with the number of stored abnormal RLDs or a drive current to be supplied to the RLD, and the voltages of the B light sources 5ba, 5bb, and 5bc. The driving current to be supplied to the B light sources 5ba, 5bb, 5bc is calculated using the temperature, the cumulative lighting time, and the like. Specifically, a drive current that is smaller than before the occurrence of the abnormal RLD is calculated. That is, a reduction amount equivalent to the reduction amount of the light emission amount of the R light source 5rd is caused in the light emission amounts of the B light sources 5ba, 5bb, 5bc. Accordingly, it is possible to suppress a change in color of light emitted from the light source device due to a decrease in the amount of light emitted from the normal RLD in response to the occurrence of the abnormal RLD.

  Next, in S46, the system control unit 1 supplies the drive current calculated in S44 and S45 to the R light source 5rd and the B light sources 5ba, 5bb, 5bc through the light source drive unit 4. Then, the system control unit 1 returns to S41 via S43.

  Also in the present embodiment, when an abnormal RLD is detected, the generation of COD in the normal RLD can be suppressed by reducing the drive current supplied to the normal RLD to reduce the light emission amount. In addition, by reducing the drive current supplied to the B light sources 5ba, 5bb, 5bc, it is possible to suppress a change in the light emitted from the light source device, that is, a change in the color of the image projected from the projector.

  Next, a sixth embodiment of the present invention will be described. The configuration of the projector according to the sixth embodiment is the same as that of the projector according to the first embodiment. The flowchart in FIG. 10 illustrates a light source lighting process performed by the system control unit 1 in the present embodiment.

  In step S51, the system control unit 1 detects each voltage of the plurality of RLDs of the R light source 5rd, as in step S2 of the first embodiment.

  Next, in S52, the system control unit 1 determines whether any of the plurality of RLDs is lower than a predetermined value, as in S2 of the first embodiment. If the voltages of all the RLDs are equal to or higher than the predetermined value, the system control unit 1 determines that all the RLDs are normal, proceeds to S53, continues lighting all the RLDs, and returns to S51.

  On the other hand, if there is an RLD whose voltage is lower than the predetermined value, the system control unit 1 determines that an abnormality has occurred in the RLD and proceeds to S54 as in S3 of the first embodiment.

  In S54, similarly to S4 of the first embodiment, the system control unit 1 sets the drive current calculation unit 3 as a drive current to be supplied to the normal RLD disposed adjacent to the abnormal RLD as compared to before the occurrence of the abnormal RLD. The reduced drive current is calculated. Note that the system control unit 1 causes the drive current calculation unit 3 to set the drive current supplied to the abnormal RLD to 0.

  Next, in S55, the system control unit 1 supplies the drive current calculated in S54 to the normal RLD via the light source drive unit 4.

  In S56, the system control unit 1 as the light modulation control unit changes the modulation parameters of the light modulation units 28R, 28G, and 28B according to the normal RLD drive current calculated in S54. When the abnormal RLD occurs and the R light emitted from the light source device decreases by reducing the drive current of the normal RLD, the intensity of red in the image projected from the projector decreases, and the color balance of the projected image changes. For this reason, in the present embodiment, the color of the projected image is adjusted by changing the modulation parameters of the light modulators 28R, 28G, and 28B so as to correct such a change in the color of the projected image.

  Specifically, since the R light is insufficient, the gradation of the light modulating unit for B light 28B and the light modulating unit for G 28G is lowered to adjust the balance of the R light, G light and B light forming the projection pixels. I do. As a method for lowering the gradation, a method of applying a gain of less than 1 to the video signal (video data) of the R and B color components of the external input video signal, a video signal of the R and B color components ( A method of converting video data) with table data (for example, γ table data) can be used.

  Thereafter, the system control unit 1 returns to S51 via S53.

  Also in the present embodiment, when an abnormal RLD is detected, the generation of COD in the normal RLD can be suppressed by reducing the drive current supplied to the normal RLD to reduce the light emission amount. In addition, it is possible to suppress a change in the color of the projected image due to a decrease in the light emission amount of the normal RLD.

  The arrangement of the B light sources 5ba, 5bb, 5bc and the R light source 5rd is not limited to the arrangement as shown in FIGS. 1, 4 and 6 but all in the same direction, and is an orthogonal arrangement as shown in FIG. You may. Specifically, the light from the B light sources 5ba and 5bb is reflected by the reflection unit 71 provided on the glass plate 70, and the light from the B light source 5bc and the light from the R light source 5rd is reflected from the portion of the glass plate 70 other than the reflection unit 71. May be transmitted and combined with light from the B light sources 5ba and 5bb.

  In each of the above-described embodiments, the semiconductor laser that emits B light and the semiconductor laser that emits R light are used. However, a semiconductor laser that emits G light may be combined.

  Further, in each of the embodiments described above, the case where the phosphor 16 rotates is described, but the phosphor does not necessarily need to rotate. The phosphor may be of a transmission type instead of a reflection type as in each embodiment.

Further, in each of the above-described embodiments, the case where a digitally driven reflective liquid crystal display element is used as the light modulation unit has been described. Alternatively, a digital micromirror device may be used.
(Other Examples)
The present invention supplies a program for realizing one or more functions of the above-described embodiments to a system or an apparatus via a network or a storage medium, and one or more processors in a computer of the system or the apparatus read and execute the program. This processing can be realized. Further, it can also be realized by a circuit (for example, an ASIC) that realizes one or more functions.

  Each of the embodiments described above is only a typical example, and various modifications and changes can be made to each embodiment when the present invention is implemented.

Reference Signs List 1 system control unit 3 drive current calculation units 5ba, 5bb, 5bc blue (B) light source 5rd red (R) light source

Claims (12)

A plurality of first light sources;
Control means for controlling the plurality of first light sources;
Detecting means for detecting an abnormality of each of the plurality of first light sources,
The control unit, when driving the plurality of first light sources to turn on, if the detection unit detects an abnormality in any of the first light sources, the abnormality is not detected. A light source device, wherein control is performed to reduce the light emission amount of the first light source.   The light source device according to claim 1, wherein the control unit reduces a drive current supplied to the first light source in which the abnormality is not detected.   The light source device according to claim 1, wherein the control unit performs control to increase a temperature of the first light source in which the abnormality is not detected. Cooling means for cooling the plurality of first light sources,
4. The light source device according to claim 3, wherein the control unit weakens cooling by the cooling unit to increase a temperature of the first light source in which the abnormality is not detected. 5. The plurality of first light sources emit light having the same wavelength as each other;
A second light source that emits light having a wavelength different from the plurality of first light sources,
4. The light source device according to claim 3, wherein the control unit performs control to raise the temperature of the second light source in order to raise the temperature of the first light source in which the abnormality is not detected. 5. The light source device according to claim 5, wherein the control unit increases a drive current supplied to the second light source to increase a temperature of the second light source. The plurality of first light sources emit light having the same wavelength as each other;
A second light source that emits light having a wavelength different from the plurality of first light sources,
2. The control device according to claim 1, wherein the control unit performs control to reduce the light emission amount of the first light source in which the abnormality is not detected, and performs control to reduce the light emission amount of the second light source. The light source device according to any one of items 1 to 4.   The apparatus according to claim 1, wherein the detection unit detects the abnormality by using any one of an applied voltage, a light emission amount, and a temperature with respect to a drive current of each of the plurality of first light sources. The light source device according to claim 1. A light source device according to any one of claims 1 to 8,
A light modulation unit that modulates light from the light source device,
An image projection apparatus, wherein an image is displayed by projecting light from the light modulation unit onto a projection surface.   When the control for reducing the light emission amount of the first light source in which the abnormality does not occur is performed, the light modulation control unit controls the light modulation unit so as to adjust the color of the image. The image projection device according to claim 9. A method for controlling a light source device having a plurality of first light sources,
Detecting an abnormality in any of the plurality of first light sources while driving the plurality of first light sources to light up;
Performing a control to reduce a light emission amount of the first light source in which no abnormality is detected, when an abnormality of the first light source is detected.   A computer program for causing a computer of a light source device having a plurality of first light sources to execute a process according to the control method according to claim 11.