JP6303542B2 - Light source device and image projection device - Google Patents

Description

  The present invention relates to an improvement of a light source device and an image projection device.

  In recent years, large-screen display devices have rapidly spread, and meetings, presentations, training, etc. using them have become common.

  There are various types of displays such as liquid crystal and plasma, and an appropriate display is selected depending on the size of the place and the number of participants. Among them, an image projection apparatus (also referred to as a projector) that can project and enlarge an image on a projection surface such as a screen is relatively inexpensive and excellent in portability (that is, small and light and easy to carry). This is the most widely used large screen display.

  In such a background, recently, scenes and situations that require communication are increasing. For example, in offices, there are many small meeting rooms and a lot of meeting spaces partitioned by partitions, and meetings and meetings using projectors are frequently performed.

  Conventionally, projectors using a high-intensity discharge lamp as a light source such as an ultra-high pressure mercury lamp have been the mainstream. However, in recent years, development has been made to use solid light-emitting elements such as red, green, and blue light-emitting diodes (LEDs) and organic EL as light sources, and many proposals have been made.

  For example, a solid-state light-emitting element that generates visible light in the first wavelength band, an optical path switching member that switches visible light in the first wavelength band emitted from the solid-state light-emitting element to a first optical path and a second optical path, and a second optical path And a phosphor that emits fluorescence as visible light in the second wavelength band by being irradiated with visible light in the first wavelength band as excitation light.

  A projector including this type of light source device is configured to project a color image by generating time-divisionally visible light in the first wavelength band and visible light in the second wavelength band by an optical path switching member. (See Patent Document 1).

  In this device, visible light in the first wavelength band emitted from the solid state light emitting device is irradiated as excitation light to the phosphor, so that high output (high power) excitation light is continuously irradiated to the same portion of the phosphor. If it continues, the temperature of the location will rise, and along with this temperature change, there is a problem that an optical element such as a lens arranged in the optical path of the light source device is thermally damaged.

  Therefore, in this type of projector, the phosphor is rotated at a predetermined rotation speed by a drive motor, and the irradiation position of the phosphor by the excitation light is changed. However, if the drive motor breaks down, the same problem may occur. For this reason, this type of projector is provided with a detection unit that detects the rotational speed of the drive motor.

  According to this configuration, when the detection unit detects a failure or the like of the drive motor, the control unit (information processing unit) can stop the driving of the solid state light emitting device in terms of software or hardware, so that thermal damage is prevented. This can be prevented and contributes to the improvement of safety.

  However, even when the phosphor is rotating normally at a predetermined rotation speed, if deterioration due to phosphor damage or the like exists in the phosphor itself, for example, due to scattering of excitation light irradiated to the phosphor, There is a problem in that the optical elements arranged and, in turn, the components and modules arranged in the projector are thermally damaged and the safety is lowered.

  Further, if the excitation light irradiated on the phosphor returns to the solid light emitting element as it is, the solid light emitting element itself may be damaged.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a light source device capable of coping with a decrease in safety due to deterioration of a phosphor.

A light source device according to the present invention includes a light source that generates excitation light, a light source driving unit that drives the light source, a control unit that controls the light source driving unit, and a phosphor that generates fluorescence when excited by the excitation light. An optical path separating member that separates the excitation light guided to the phosphor, the reflected excitation light reflected by the phosphor, and the fluorescence, and the reflected excitation light separated by the optical path separation member. A detection unit that detects deterioration, and the control unit controls the light source driving unit so that light emission of the light source is stopped when the detection unit detects deterioration of the phosphor , The optical path separation member utilizes a polarized light and a wavelength separation member that separates the excitation light and the fluorescence using a difference between the wavelength of the excitation light from the light source and the wavelength of the fluorescence excited by the excitation light. The excitation light from the light source and the phosphor Ri and a polarization separating member for separating the reflected reflected excitation light.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect which can cope with the fall of the safety | security resulting from deterioration of a fluorescent substance.

FIG. 1 is an explanatory diagram showing a main configuration of a light source device according to Embodiment 1 of the present invention. 2A and 2B are explanatory views schematically showing an example of the phosphor wheel shown in FIG. 1, wherein FIG. 2A is a plan view and FIG. 2B is a side view thereof. FIG. 3 is an explanatory view showing an example of detection when a defect occurs in the phosphor wheel shown in FIG. FIG. 4 is an explanatory diagram showing a main configuration of a light source device according to Embodiment 2 of the present invention. FIG. 5 is an explanatory view showing the main configuration of a light source apparatus according to Embodiment 3 of the present invention. FIG. 6 is an explanatory diagram showing a main configuration of a light source device according to Embodiment 4 of the present invention. FIG. 7 is a schematic diagram showing a configuration of an image projection apparatus according to Embodiment 5 of the present invention. FIG. 8 is an explanatory diagram of the image forming light generated by the image projection apparatus according to the fifth embodiment, and is a timing chart for explaining the color of the image forming light generated within one period of the image frame. FIG. 9 is an explanatory view showing another embodiment of the phosphor wheel used in the image projection apparatus according to Embodiment 5 of the present invention.

Example 1
1 to 3 are optical diagrams of a light source device G according to Embodiment 1 of the present invention.
In FIG. 1, reference numeral 1 denotes a light source that generates excitation light P1. The light source 1 is composed of an LD module. Here, the LD module includes a plurality of laser diodes (laser light sources) LD for generating blue light, and collimator lenses CL respectively provided corresponding to the laser diodes LD.

The laser diode LD is controlled to emit light by an LD driving unit 2 as a light source driving unit. The excitation light P1 from the light source 1 has the same polarization direction. Here, it is assumed that P-polarized excitation light P1 is emitted.
A condensing optical system 3 that condenses the excitation light P1 and converts the condensed excitation light P1 into a parallel light beam is provided in front of the traveling direction of the excitation light P1.

  A fluorescent member 5 is provided in front of the traveling direction of the excitation light P1. The fluorescent member 5 includes a drive motor M1 and a fluorescent wheel (phosphor) 6. The fluorescent wheel 6 is rotationally driven by a drive motor M1. 2 (a) and 2 (b) show an example of the fluorescent member 5. Reference numeral 7 denotes a rotating shaft of the drive motor M1, and reference numeral 8 denotes a ring-shaped fluorescent film formed on a metal reflective substrate of the fluorescent wheel 6. It is. Here, it is assumed that the annular fluorescent film 8 generates green fluorescence G1 by irradiation with the excitation light P1.

  In the traveling light path of the excitation light P1 between the condensing optical system 3 and the fluorescent wheel 6, the excitation light P1 guided to the fluorescent wheel 6 and the reflected excitation light P1 ′ reflected by the fluorescent wheel 6 and the fluorescent wheel 6 are generated. An optical path separation member for separating the fluorescent G1 is provided. This optical path separation member is composed of a polarization separation member PBS and a wavelength separation member 9.

  Between the wavelength separation member 9 and the fluorescent wheel 6, the excitation light P1 is collected, and the reflected excitation light P1 ′ reflected on the fluorescent wheel 6 is spot-irradiated on the fluorescent wheel 6, and the excitation light P1. And a condensing optical system 4 that condenses the fluorescence G1 excited by the light and converts it into a parallel light beam.

  The wavelength separation member 9 has a function of separating the fluorescence G1 and the excitation light P1 using the difference between the wavelength of the fluorescence G1 and the wavelength of the excitation light P1. Here, the wavelength separating member 9 is constituted by a dichroic mirror that reflects the fluorescence G1 and transmits the excitation light P1.

  A collimating lens 10 that condenses the fluorescent G1 and converts it into a parallel light beam, and a reflecting mirror 11 that deflects the traveling optical path of the fluorescent G1 are reflected in the optical path ahead of the reflection direction of the fluorescent G1 reflected by the wavelength separation member 9. An emission optical system 12 that collects the fluorescence G1 reflected by the reflection mirror 11 and emits it as light source light G1 ′ is provided.

  The polarization separation member PBS is provided between the condensing optical system 3 and the wavelength separation member 9. The polarization separating member PBS has a function of separating the excitation light P1 from the light source 1 and the reflected excitation light P1 'reflected by the fluorescent wheel 6 using polarized light.

  A part of the P-polarized excitation light P <b> 1 becomes S-polarized light when reflected by the fluorescent wheel 6. Here, the polarization separation member PBS is configured by a polarization beam splitter that transmits the P-polarized excitation light P1 and reflects the S-polarized reflected excitation light P1 '.

  In the optical path ahead of the traveling direction of the S-polarized reflected excitation light P <b> 1 ′ reflected by the wavelength separation member PBS, a detection unit 13 that detects deterioration of the phosphor by the reflected excitation light P <b> 1 ′ is provided. The detection unit 13 includes a condensing optical system 14 that condenses the S-polarized reflected excitation light P1 ′, a photodiode PD that receives the reflected excitation light P1 ′ and converts the reflected excitation light P1 ′ into an electric signal PDI, and an electric signal from the photodiode PD. An amplifier 15 that amplifies the signal PDI and outputs an amplified voltage PDV, and a comparator 16 are provided.

  The comparator 16 receives the threshold value VREF and an amplified voltage PDV that means the magnitude of the electric signal PDI. The comparator 16 compares the threshold value VREF with the amplified voltage PDV, and when the amplified voltage PDV exceeds the threshold value VREF. Then, an abnormal signal S1 indicating deterioration of the phosphor wheel 6 is output toward the control unit 17. Here, the comparator 16 compares the amplified voltage PDV with the threshold value VREF. However, the magnitude of the electric signal PDI of the photodiode PD and the threshold value VREF may be directly compared.

(Function of the control unit 17)
Next, functions of the control unit 17 will be described.
For example, a control signal CTRL and a synchronization signal SYNC as activation commands are input to the control unit 17 by an external operation or the like. The control signal CTRL is input to the control unit 17 using, for example, a serial communication interface (not shown) such as I2C or SPI.

  When the activation command is input, the control unit 17 outputs a motor control signal (motor activation signal) MTC to the motor driving unit 18 toward the motor driving unit 18. Accordingly, the motor drive unit 18 outputs a motor drive signal MD1 toward the drive motor M1. As a result, the phosphor wheel 6 starts to rotate.

  The drive motor M1 has a rotation state detection unit (not shown). Along with the rotation of the drive motor M1, a rotation state detection signal MX1 indicating that the drive motor M1 has reached a predetermined rotation speed (constant speed rotation state) is output from the rotation state detection unit. The rotation state detection signal MX1 is input to the control unit 17.

  When the rotation state detection signal MX1 is input, the control unit 17 outputs a control signal LDC to the LD drive unit (laser drive unit) 2 based on a synchronization signal SYNC generated every cycle of one frame. The LD drive unit 2 is driven by the control signal LDC and outputs a laser drive current IL1 toward the light source 1.

  The light source 1 outputs P-polarized blue laser light as excitation light P1 by the laser driving current IL1. The LD module constituting the light source 1 has a heat sink function for suppressing the temperature rise of the laser diode LD. Thereby, the laser diode LD is kept in a predetermined temperature range.

  The P-polarized blue laser light is condensed by the condensing optical system 3, is transmitted through the polarization separating member PBS and guided to the wavelength separating member 9, passes through the wavelength separating member 9, and is condensed by the condensing optical system 4. The wheel 6 is spot-irradiated.

  The phosphor wheel 6 generates green fluorescence G1 by irradiation with the blue laser light. The green fluorescence G1 and the blue laser light reflected by the phosphor wheel 6 are condensed by the condensing optical system 4 to be a parallel light beam, and are guided to the wavelength separation member 9 again.

  The fluorescence G1 is reflected by the wavelength separation member 9, converted into a parallel light beam by the collimating lens 10, reflected by the reflection mirror 11, and emitted from the emission optical system 12 as light source light G1 '.

  When the P-polarized excitation light P1 is reflected by the phosphor wheel 6, a part thereof becomes S-polarized light. The S-polarized reflected excitation light P1 ′ passes through the wavelength separation member 9, is guided to the polarization separation member PBS, is reflected by the polarization separation member PBS, is condensed by the condensing optical system 14, and is reflected on the photodiode PD. Led.

  When the electric signal PDI of the photodiode PD is equal to or smaller than a predetermined value, the amplified voltage PDV is equal to or lower than the threshold value VREF, and the abnormal signal S1 is not output. The abnormal signal S1 is, for example, low when the magnitude of PDI <threshold value VREF, and high when the magnitude of threshold value VREF ≦ the magnitude of the electric signal PDI.

  It is assumed that some defect has occurred in the phosphor wheel 6. For example, when the ring-shaped fluorescent film 8 is scratched or defective, and the fluorescence conversion efficiency decreases, the amount of reflected excitation light P1 ′ that passes through the wavelength separation member 9 and returns to the polarization separation member PBS as shown in FIG. Therefore, the magnitude of the electric signal PDI output from the photodiode PD increases.

  As a result, when the amplified voltage PDV input to the comparator 16 exceeds the threshold value VREF, the abnormal signal S1 changes from low to high. When the abnormal signal S1 becomes high, the control unit 17 determines that the deterioration of the phosphor is detected by the detection unit 13, and controls the LD driving unit 2 so that the light emission of the light source 1 is stopped. Thereby, the light emission of the light source 1 is stopped, and safety is improved.

(Example 2)
In the second embodiment, as shown in FIG. 4, the P-polarized excitation light P1 is converted into circularly-polarized excitation light P1 in the traveling optical path of the excitation light P1 between the polarization separation member PBS and the wavelength separation member 9. In addition, a quarter-wave plate 20 is provided for converting the circularly polarized reflected excitation light P1 ′ into S-polarized reflected excitation light P1 ′. Since other configurations are the same as those in the first embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  According to the second embodiment, the circularly polarized reflected excitation light P1 ′ reflected by the phosphor wheel 6 can be converted into S-polarized reflected excitation light P1 ′ and efficiently guided to the detection unit 13. The deterioration of the body wheel 6 can be detected more precisely.

That is, in the case of Example 1, the reflected excitation light P1 ′ reflected by the phosphor wheel 6 includes S-polarized reflected excitation light P1 ′ and P-polarized reflected excitation light P1 ′. For this reason, when the fluorescent film 8 of the phosphor wheel 6 deteriorates, a part of the reflected excitation light P1 ′ passes through the polarization separation member PBS and returns to the light source 1.
On the other hand, according to this embodiment, since most of the reflected excitation light P1 ′ passes through the quarter-wave plate and becomes S-polarized light, the detection accuracy of deterioration of the fluorescent film 8 is improved.

(Example 3)
In the third embodiment, the detection unit 13 includes a holding circuit 21 as illustrated in FIG. The control unit 17 is supplied with power PS from a power supply unit (power supply unit) 22, and the LD drive unit 2 is supplied with LD drive power PLD 1 through a relay circuit 23 ′ serving as a power supply cutoff unit.

  When the abnormal signal S1 changes from low to high, the holding circuit 21 outputs a power cutoff signal S2 that changes from low to high toward the relay circuit 23 '. The relay circuit 23 'is forcibly turned off (becomes a non-energized state) when the power cutoff signal S2 changes from low to high.

  As a result, the LD driving power PLD1 supplied to the LD driving unit 2 is cut off by hardware. When the relay circuit 23 ′ is turned off by the power cutoff signal S 2, the control unit 17 controls the LD driving unit 2 so that the light emission of the light source 1 is stopped by software. The holding circuit 21 continues to hold the power cutoff signal S2 high for a certain period after the irradiation of the excitation light P1 is stopped, and changes from high to low after a predetermined time has elapsed.

  According to the third embodiment, since the LD driving unit 2 is turned off by hardware, even when the off time of the LD driving unit 2 is delayed by the software control of the control unit 17 such as a microcontroller, The driving of the LD driving unit 2 can be stopped immediately.

Even if the power cutoff signal S2 changes from high to low and the power supply from the power supply unit 22 to the LD drive unit 2 is resumed, the drive of the LD drive unit 2 is stopped by the control unit 17, The light emission stop of the light source 1 is maintained.
As a result, further improvement in safety is ensured. Since other configurations are the same as those of the second embodiment, detailed description thereof is omitted.

Example 4
In the fourth embodiment, as shown in FIG. 6, the detection unit 13 includes a thermostat switch 13a as a power cutoff unit. The control unit 17 and the LD driving unit 2 are connected to the power supply unit 22 via the thermostat switch 13a.

  Similarly to the third embodiment, the control unit 17 is supplied with power PS from the power supply unit (power supply unit) 22, and the LD drive unit 2 is supplied with LD drive power PLD1 via the thermostat switch 13a.

  The thermostat switch 13a generates heat by irradiation with the S-polarized reflected excitation light P1 ', and forcibly cuts off the LD driving power PLD1 when the temperature becomes equal to or higher than a threshold temperature that means deterioration of the phosphor. As a result, the LD driving unit 2 is turned off by hardware. The control unit 17 controls the LD driving unit 2 so that the light emission of the light source 1 is stopped by software as the LD driving power PLD1 is cut off.

  When the light emission of the light source 1 is stopped, the excitation light P1 is not applied to the phosphor wheel 6. As a result, the S-polarized reflected excitation light P1 'is not applied to the thermostat switch 13a. For this reason, when the temperature of the thermostat switch 13a decreases and becomes lower than the threshold temperature, the power supply from the power supply unit 22 to the LD driving unit 2 is resumed, but the driving of the LD driving unit 2 is stopped by the control unit 17. Therefore, the light emission stop of the light source 1 is maintained.

In the fourth embodiment, a comparator and an amplifier are not provided, and the other configuration is the same as that of the third embodiment, and thus detailed description thereof is omitted.
According to the fourth embodiment, the configuration of the detection unit 13 can be simplified.

(Example 5)
FIG. 7 shows a schematic diagram of an image projection apparatus having this light source device. Here, the light source device includes a light source device R that emits red light as light source light R1 ′, a light source device G that emits green light as light source light G1 ′, and a light source device B that emits blue light as light source light B1 ′. ing.
As the light source devices R, G, and B, those having the configuration shown in any one of the first to fourth embodiments are used.

Each of the light source devices R, G, and B is controlled to be turned on by the video processing unit 23. Image data VIN is input to the video processing unit 23. The video processing unit 23 controls the control signal CTRL based on the image data VIN. R to light source device R, control signal CTRL G to light source device G, control signal CTRL B is output to the light source device B, respectively.
In addition, the video processing unit 23 outputs a synchronization signal SYNC to each of the light source devices R, G, and B according to the frame frequency of the image data VIN.

  The image projection apparatus is provided with dichroic mirrors 24 and 25 as optical path combining members in the optical paths of the light source lights R1 ', G1' and B1 'from the light source apparatuses R, G and B. The dichroic mirror 24 has an optical characteristic of transmitting blue light and reflecting green light. The dichroic mirror 25 has an optical characteristic of transmitting blue light and green light and reflecting red light.

  An illumination optical system 26 is provided in the combined optical path of the light source lights R1 ', G1', and B1 '. The illumination optical system 26 is roughly composed of a condensing lens 27, a rod integrator 28 as a light amount distribution uniforming member, a condensing lens 29, and a reflecting mirror 30.

  Each light source light R 1 ′, G 1 ′, B 1 ′ of blue light, green light, and red light is collected by the condenser lens 27 and incident on the rod integrator 28, and the light quantity distribution when propagating through the rod integrator 28. Are made uniform and ejected from the rod integrator 28. The light source lights R1 ', G1', B1 'emitted from the rod integrator 28 are reflected by the reflection mirror 30 and guided to a micromirror device DMD as a display element.

  The display element (DMD) is controlled by a control signal DMDD from the video processing unit 23, and the light source lights R1 ′, G1 ′, B1 ′ are modulated by the display element (DMD), and thereby according to the image data VIN. Image forming light is generated. The image forming light is projected onto a screen (not shown) via a projection optical system, and an image is displayed on the screen.

  FIG. 8 shows the generation timing of the image forming light. In FIG. 8, the symbol T0 indicates one cycle of the synchronization signal SYNC. In this embodiment, the image is output during the half cycle T1 = T0 / 2. The generation periods of the image forming light are allocated so that blue, yellow, green, and red can be sequentially generated as the colors of the forming light.

  In this embodiment, in the period T2 during which blue light (light source light B1 ′) is generated, the control unit 17 is supplied with the drive current IL1_B to the light source device B, and supplies the drive current IL1_R to the light source device R and the light source device G. Each of the light source devices R, G, and B is controlled so that the supply of the drive current IL1_G to is stopped.

  In the period T3 during which yellow light is generated, the control unit 17 is supplied with the drive current IL1_R to the light source device R, is supplied with the drive current IL1_G to the light source device G, and stops supplying the drive current IL1_B to the light source device B. Thus, each light source device R, G, B is controlled.

  In a period T4 in which green light (light source light G1 ′) is generated, the control unit 17 is supplied with the drive current IL1_G to the light source device G, supplies the drive current IL1_R to the light source device R, and drives the light source device IL1_B. The light source devices R, G, and B are controlled so that the supply of light is stopped.

  In the period T4 in which red light (light source light R1 ′) is generated, the control unit 17 is supplied with the drive current IL1_R to the light source device R, the supply of the drive current IL1_G to the light source device G, and the drive current to the light source device B. The light source devices R, G, and B are controlled so that the supply of IL1_B is stopped.

  Within any period, when the fluorescent wheel 6 deteriorates and the amount of the reflected excitation light P1 'exceeds the threshold, the light source device corresponding to the deteriorated fluorescent wheel 6 stops emitting light.

This image projection device is provided with an indicator (LED) 31 that warns that an abnormality has occurred in any of the phosphor wheels 6 of the light source device B, the light source device G, and the light source device R. In response to the warning signal ALT, the indicator (LED) 31 is turned on.
Therefore, according to this embodiment, the light emission of the light source is stopped and a warning is displayed by the indicator 31.

(Other examples)
For the light source device B, blue laser light itself may be used.
Further, the phosphor wheel 6 is not limited to the ring-shaped phosphor film 8 shown in FIG. 2, and for example, as shown in FIG. 9, the phosphor wheel 6 is divided in the rotation direction to form a fan-shaped red phosphor film 8 a You may comprise from the fan-shaped green fluorescent film 8b and the fan-shaped transmission area | region 8c which lets blue laser light pass. In this embodiment, the optical system of the image projection apparatus can be made compact and downsized. In addition, it is good also as a notch instead of the fan-shaped permeation | transmission area | region 8c.

DESCRIPTION OF SYMBOLS 1 ... Light source 2 ... LD drive part (light source drive part)
6. Phosphor wheel (phosphor)
13 ... Detection unit 17 ... Control unit G ... Light source device P1 ... Excitation light P1 '... Reflected excitation light

JP 2012-141581 A

Claims (10)

A light source that generates excitation light, a light source driving unit that drives the light source, a control unit that controls the light source driving unit, a phosphor that is excited by the excitation light and generates fluorescence, and is guided to the phosphor An optical path separation member that separates excitation light, reflected excitation light reflected by the phosphor, and the fluorescence; and a detection unit that detects deterioration of the phosphor by the reflected excitation light separated by the optical path separation member. Have
The control unit controls the light source driving unit so that light emission of the light source is stopped when the detection unit detects deterioration of the phosphor ,
The optical path separating member utilizes a polarized light and a wavelength separating member that separates the excitation light and the fluorescence using a difference between the wavelength of the excitation light from the light source and the wavelength of the fluorescence excited by the excitation light. And a polarization separation member for separating the excitation light from the light source and the reflected excitation light reflected by the phosphor . The light source according to claim 1 , wherein the wavelength separation member is provided between the light source and the phosphor, and the polarization separation member is provided between the light source and the wavelength separation member. apparatus. The light source device according to claim 2 , wherein the light source is a laser light source that generates excitation light having a uniform polarization direction. The polarization direction of the excitation light from the light source is P-polarized light, and the polarization separation member transmits the P-polarized excitation light and reflects the reflected excitation light that is reflected by the phosphor and becomes S-polarized light. The light source device according to claim 3 , wherein the light source device is a light source device. Between the polarization separation member and the wavelength separation member, the P-polarized excitation light emitted from the light source is converted into circularly polarized light, and the circularly polarized reflected excitation light reflected by the phosphor is reflected as S-polarized light. The light source device according to claim 4 , further comprising a quarter-wave plate for converting into excitation light. The detection unit receives the reflected excitation light and converts it into an electrical signal, and compares the magnitude of the electrical signal from the photosensor with a threshold to control the electrical signal when the magnitude of the electrical signal is equal to or greater than the threshold. the light source device according to any one of claims 1 to 5, characterized in that it comprises a comparator which outputs an abnormality signal indicating the deterioration of the phosphor toward the part. A power supply unit that supplies power to the light source driving unit is connected via a power cutoff unit, and the power cutoff unit forcibly cuts off power supply to the light source driving unit by the abnormal signal. Item 7. The light source device according to Item 6 . The detection unit includes a thermostat switch, and a power supply unit that supplies power to the light source driving unit is connected via the thermostat switch, and the thermostat switch has a temperature deteriorated due to irradiation of the reflected excitation light. the light source device according to any one of claims 1 to 5, characterized in that forcibly interrupting the power supply to the light source driving section at least threshold temperature, which means. A light source device according to any one of claims 1 to 8 , a display element that generates image forming light by modulating light source light from the light source device based on image data, and a light source device from the light source device. An irradiation optical system for irradiating the display element with light source light, a projection optical system for projecting image forming light generated by modulation of the display element onto a screen, and a video processing unit for controlling at least the display element An image projection apparatus comprising: The light source of the light source device according to any one of claims 1 to 8 generates blue excitation light, and the phosphor according to any one of claims 1 to 8 is divided in a rotation direction. The image projection apparatus according to claim 9 , further comprising a fan-shaped phosphor film that generates red fluorescence and a fan-shaped phosphor film that generates green fluorescence.