JP7086637B2 - Projection device - Google Patents

Description

The present invention relates to a projection device.

In a projection device using a laser as a light source, a technique is known in which a wavelength conversion element such as a phosphor is irradiated with light emitted by the light source to change the wavelength of the light. When irradiating a phosphor with light, the temperature of the phosphor becomes high by converging the light using a lens or the like. In order to prevent the temperature of the phosphor from becoming higher than the heat resistant temperature of the phosphor, there is a method of rotating a rotating plate coated with the phosphor (hereinafter referred to as a phosphor) to dissipate heat. When light is irradiated while the phosphor is rotated, flicker may occur according to the rotation frequency of the phosphor.

In a general projection device, the phosphor is rotated at a rotation speed at which the flicker cannot be visually recognized, but the combination of the rotation speed of the phosphor and the frequency controlled by the PWM (Pulse Width Modulation) of the light source causes the flicker to be displayed on the projection screen. Noise (eg, horizontal streaks) may occur. Patent Document 1 discloses a technique of controlling the rotation frequency of a phosphor and the frequency of PWM control of a light source to reduce the noise on the screen generated by the combination of the rotation frequency and the frequency of the light source.

Japanese Unexamined Patent Publication No. 2012-103398

By the way, due to the influence of the voltage ripple synchronized with the frequency of the commercial power supply, the voltage of each part of the projection device may fluctuate, and the light amount of the light source may fluctuate in synchronization with the frequency of the commercial power supply. In such a case, even if the technique disclosed in Patent Document 1 is used, there is a problem that flicker is generated due to the influence of the voltage ripple of the commercial power supply.

Therefore, the present invention has been made in view of these points, and an object of the present invention is to provide a projection device capable of reducing flicker on a projection surface.

The projection device of the present invention is a projection device that modulates illumination light with an optical modulation element and projects an image, and the light source and at least a part of the first light from the light source are the first light. A wavelength conversion element that converts light into second light having a different wavelength, a frequency detecting means that detects a power frequency that is the frequency of power supplied from the outside to the projection device, and the power frequency detected by the frequency detecting means . A control means for rotating the wavelength conversion element according to a rotation frequency determined based on the above, a part of the first light from the light source, and the second light converted by the wavelength conversion element are modulated by the light modulation element. It has a projection means for projecting image light, and the control means rotates the wavelength conversion element at a frequency that is an integral multiple of the power frequency, or starts from a frequency 20 Hz lower than a frequency that is an integral multiple of the power frequency. It is characterized in that the wavelength conversion element is rotated at a frequency not included in the range up to a frequency 20 Hz higher than a frequency that is an integral multiple of the power frequency.

According to the present invention, there is an effect that flicker on the projection surface can be reduced.

It is a figure which shows the functional structure of a projection apparatus. It is a figure which shows the structure of the peripheral part of a fluorescent substance. It is a figure for demonstrating the relationship between the amount of light of a light source part, and the rotation frequency of a phosphor. It is a flowchart of the process executed by a projection apparatus. It is a figure for demonstrating the relationship between the amount of light of a light source part and the rotation frequency of a fluorescent substance in 2nd Embodiment. It is a flowchart of the process executed by the projection apparatus which concerns on 2nd Embodiment.

<First Embodiment>
[Overview of projection device]
Flicker due to the influence of the voltage ripple of the commercial power supply is caused when the rotation frequency corresponding to the rotation speed of the phosphor matches a frequency that is an integral multiple of the frequency of the commercial power supply, or the rotation frequency is within a predetermined frequency range from the power frequency. If it is not included, it is difficult for people to recognize it. Therefore, the projection device according to the first embodiment detects the frequency of the commercial power supply, and the frequency is an integral multiple of the frequency of the commercial power supply, or the rotation frequency is a frequency not included in the predetermined frequency range from the frequency of the commercial power supply. Rotate. By doing so, the projection device can rotate the phosphor at a frequency at which the flicker caused by the influence of the voltage ripple of the commercial power supply is hard to be recognized by humans. As a result, the projection device can reduce flicker on the projection surface.

In this embodiment, a commercial power source is assumed as a power source for supplying electric power to the projection device. Therefore, the voltage ripple will be described as an AC (Alternating Current) ripple caused by the frequency component (50 Hz or 60 Hz) of the commercial power supply.

[Functional configuration of projection device 1]
FIG. 1 is a diagram showing a functional configuration of the projection device 1. The projection device 1 stores a light source unit 10, a light source drive unit 11, a phosphor 12, a phosphor drive unit 13, a cooling unit 14, a projection unit 15, a power supply unit 16, a frequency detection unit 17, and a storage unit. A unit 18 and a control unit 19 are provided.

The light source unit 10 is a light source that emits light. The light source unit 10 is, for example, a laser oscillator having a blue laser diode and emits blue light. The light source driving unit 11 drives the light source unit 10 to cause the light source unit 10 to emit light.

The phosphor 12 is a wavelength conversion element that converts at least a part of blue light, which is the first light from the light source unit 10, into yellow light, which is the second light having a wavelength different from that of the blue light. The phosphor 12 is, for example, a phosphor wheel in which phosphor particles that change the wavelength of light are mixed with a binder and coated on a metal substrate. When light is incident on the phosphor 12, the phosphor 12 emits fluorescence different from the wavelength of the incident light. The phosphor 12 in the present embodiment emits yellow light different from the blue light emitted by the light source unit 10. The phosphor 12 is connected to the phosphor driving unit 13 and is rotated by being driven by the phosphor driving unit 13.
The phosphor drive unit 13 is a device for rotating the phosphor 12, for example, a motor.

The cooling unit 14 cools the phosphor 12 by blowing air toward the phosphor 12. The cooling unit 14 is, for example, a blower fan.

The projection unit 15 has a light modulation element such as a liquid crystal panel or a digital mirror device (DMD), a projection optical system including a plurality of lenses, and a plurality of actuators for driving each of the plurality of lenses. The projection unit 15 produces image light (synthetic light) generated by modulating a part of the first light from the light source unit 10 and the second light (illumination light) converted by the phosphor 12 by an optical modulation element. , A projection means that projects an image by projecting it through a projection optical system.

Here, the configuration of the phosphor peripheral portion A surrounded by the broken line in FIG. 1 will be described. FIG. 2 is a diagram showing the configuration of the peripheral portion A of the phosphor. The optical system OS includes a plurality of lenses and a plurality of mirrors M1 and M2. The mirror M1 transmits a part of the blue light emitted by the light source unit 10 and reflects a part of the blue light. Further, the mirror M1 reflects light having a color other than blue.

A part of the blue light emitted from the light source unit 10 passes through the plurality of lenses and the mirror M1 and is incident on the phosphor 12. Further, the blue light reflected by the mirror M1 without being transmitted by the mirror M1 is incident on the mirror M2. The wavelength of a part of the blue light incident on the phosphor 12 is converted by the phosphor 12 and converted into yellow light. The converted yellow light is reflected by the mirror M1 and incident on the mirror M2. The blue light and yellow light incident on the mirror M2 are combined into white light. The combined white light is incident on the projection unit 15. Then, the projection unit 15 projects an image using white light in which the yellow light after the wavelength of the light emitted by the light source unit 10 is changed by the phosphor 12 and the blue light emitted by the light source unit 10 are combined. do.

The power supply unit 16 converts commercial power into a predetermined voltage and supplies electric power to each unit of the projection device 1. For example, the power supply unit 16 supplies the light source unit 10 with electric power obtained by converting the voltage of the commercial power source into the rated voltage of the light source unit 10. The frequency detection unit 17 detects the power frequency, which is the frequency of the power supplied to the projection device 1 from the outside. In the following description, it is assumed that the frequency detection unit 17 detects 50 Hz as the power frequency.

The storage unit 18 is a storage medium including a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The storage unit 18 stores a program executed by the control unit 19. Further, the storage unit 18 stores the amount of light of the light source unit 10 in association with the initial frequency which is the initial value of the frequency at which the phosphor 12 is rotated.

The control unit 19 is, for example, a CPU (Central Processing Unit). The control unit 19 controls each unit of the projection device 1 by executing the program stored in the storage unit 18. The control unit 19 acquires the drive power set value of the light source unit 10, and controls the light source drive unit 11 based on the acquired drive power set value, so that the light source unit 10 emits light of a light amount corresponding to the drive power set value. Generate in. The control unit 19 controls the cooling unit 14 so as to cool by the cooling performance based on the rotation frequency of the phosphor 12 and the amount of light emitted by the light source unit 10. For example, the control unit 19 controls the cooling unit 14 so as to cool the phosphor 12 with higher cooling performance as the amount of light of the light source unit 10 increases.

The control unit 19 controls the phosphor drive unit 13 to rotate the phosphor 12. The control unit 19 rotates the phosphor 12 at a rotation frequency determined based on the power frequency detected by the frequency detection unit 17. For example, the control unit 19 rotates the phosphor 12 at a frequency that is an integral multiple of the power frequency. Further, the control unit 19 rotates the phosphor 12 with a rotation frequency not included in a predetermined frequency range larger than a frequency that is an integral multiple of the power frequency and a predetermined frequency range smaller than the frequency. The predetermined frequency range is, for example, a flicker generation frequency range in which flicker is generated in the light projected by the projection unit 15. The flicker generation frequency is a frequency that is 20 Hz lower than a frequency that is an integral multiple of the power frequency and 20 Hz or less that is 20 Hz higher than a frequency that is an integral multiple of the power frequency. The control unit 19 rotates the phosphor 12 at a frequency 20 Hz or more lower than a frequency that is an integral multiple of the power frequency, or a rotation frequency that is 20 Hz or more higher than a frequency that is an integral multiple of the power frequency. By doing so, the control unit 19 can rotate the phosphor 12 at a frequency at which the flicker caused by the influence of the voltage ripple of the commercial power supply is not recognized by humans.

When the initial frequency of the phosphor 12 associated with the amount of light of the light source unit 10 is stored in the storage unit 18, the control unit 19 rotates the phosphor 12 at a rotation frequency equal to or higher than the initial frequency. For example, the control unit 19 rotates at a rotation frequency higher than the initial frequency based on the relationship between the initial frequency of the phosphor 12 and the power frequency. Specifically, the control unit 19 rotates at a rotation frequency based on the relationship between the initial frequency and the power frequency. More specifically, when the initial frequency is higher than the frequency that is an integral multiple of the power frequency and is within a predetermined frequency range from the frequency that is an integral multiple of the power frequency, the control unit 19 sets the rotation frequency in a predetermined frequency range. Rotate at a higher frequency. Further, when the initial frequency is equal to or less than an integral multiple of the power frequency and is within a predetermined frequency range from an integral multiple of the power frequency, the control unit 19 sets the rotation frequency to an integral multiple of the power frequency. Rotate.

FIG. 3 is a diagram for explaining the relationship between the amount of light of the light source unit 10 and the rotation frequency of the phosphor 12. In FIG. 3, the horizontal axis represents the amount of light and the vertical axis represents the rotation frequency. In FIG. 3, a frequency (100 Hz) that is an integral multiple (twice in FIG. 3) of the power frequency (50 Hz) is shown by a alternate long and short dash line. Further, in FIG. 3, a frequency (80 Hz) lower than a frequency (100 Hz) that is an integral multiple of the power frequency by a predetermined frequency (20 Hz) and a frequency (20 Hz) higher than a frequency (100 Hz) that is an integral multiple of the power frequency (20 Hz). 120Hz) is indicated by a two-point chain line. The broken line R in FIG. 3 is a graph showing the initial frequency of the phosphor 12 stored in the storage unit 18 in relation to the amount of light. In FIG. 3, the solid line is a graph showing the rotation frequency of the phosphor 12.

The region L1 shown in parentheses in FIG. 3 indicates a region in which the initial frequency is higher than 100 Hz and 120 Hz or less. Further, the region L2 shown in curly braces indicates a region in which the initial frequency is 100 Hz or less and is larger than 80 Hz.

When the initial frequency is within the region L1, the control unit 19 rotates the phosphor 12 at 120 Hz, as shown by the solid line in FIG. When the initial frequency is within the region L1, the control unit 19 may rotate the phosphor 12 at a frequency lower than 130 Hz, which is higher than 120 Hz and 20 Hz lower than the frequency three times the power frequency (150 Hz). When the initial frequency is within the region L2, the control unit 19 rotates the phosphor 12 at 100 Hz, which is an integral multiple of the power frequency, as shown by the solid line in FIG. By doing so, the control unit 19 can rotate the phosphor 12 at a rotation frequency at which the flicker caused by the influence of the voltage ripple of the commercial power supply is not recognized by humans, and the generation of flicker on the projection surface can be reduced. ..

[Processing performed by the projection device 1]
Hereinafter, the flow of processing executed by the projection device 1 will be described with reference to FIG. FIG. 4 is a flowchart of the process executed by the projection device 1.

In step S1, the control unit 19 determines whether or not there is a lighting instruction to light the light source unit 10 of the projection device 1. If there is no lighting instruction (No in step S1), the control unit 19 waits until the lighting instruction is given. When there is a lighting instruction (Yes in step S1), the control unit 19 proceeds to step S2.

In step S2, the control unit 19 causes the frequency detection unit 17 to detect the power frequency of the commercial power source. In step S3, the control unit 19 acquires a drive power set value corresponding to the amount of light of the light source unit 10. Then, in step S4, the control unit 19 sets the rotation frequency of the phosphor 12 to the initial frequency associated with the amount of light corresponding to the acquired drive power set value.

Subsequently, in step S5, the control unit 19 determines whether the determined rotation frequency is larger than the frequency that is an integral multiple of the detected power frequency and is within the frequency range of 20 Hz or less with respect to the frequency that is an integral multiple of the power frequency. Judge whether or not. When the control unit 19 determines that the frequency is within the frequency range (Yes in step S5), the control unit 19 proceeds to step S6. In step S6, the control unit 19 changes the rotation frequency of the phosphor 12 to a frequency 20 Hz higher than the frequency that is an integral multiple of the power frequency, and proceeds to step S9.

When the control unit 19 determines that the frequency is not within the frequency range (No in step S5), the control unit 19 proceeds to step S7. In step S7, the control unit 19 determines whether or not the determined rotation frequency is within a frequency range of an integral multiple of the detected power frequency and within 20 Hz with respect to a frequency that is an integral multiple of the power frequency. do. When the control unit 19 determines that the frequency is within the frequency range (Yes in step S7), the control unit 19 proceeds to step S8. In step S8, the control unit 19 changes the rotation frequency of the phosphor 12 to a frequency that is an integral multiple of the power frequency, and proceeds to step S9. When the control unit 19 determines that the frequency is not within the frequency range (No in step S7), the control unit 19 proceeds to step S9.

In step S9, the control unit 19 rotates the phosphor 12 at a set rotation frequency. Next, in step S10, the control unit 19 controls the cooling unit 14 so as to cool with the cooling performance based on the rotation frequency of the phosphor 12 and the drive power set value of the light source unit 10. Subsequently, in step S11, the control unit 19 controls the light source drive unit 11 to light the light source unit 10 with the acquired drive power set value.

Then, in step S12, the control unit 19 determines whether or not there is an instruction to turn off the light source unit 10. When the control unit 19 determines that there is no turn-off instruction (No in step S12), the control unit 19 proceeds to step S2. When the control unit 19 determines that there is a turn-off instruction (Yes in step S12), the control unit 19 controls the light source drive unit 11 to turn off the light source unit 10 and ends this process.

(Modification 1)
The control unit 19 may always determine a frequency that is an integral multiple of the power frequency detected by the frequency detection unit 17 as the rotation frequency of the phosphor 12. In this case, the control unit 19 always rotates the phosphor 12 at a rotation frequency that is an integral multiple of the power frequency. By doing so, the control unit 19 can rotate the phosphor 12 at a frequency at which the flicker is not recognized by humans.

(Modification 2)
In the above description, the power source for supplying electric power to the projection device 1 is assumed to be a commercial power source, but the power source for supplying electric power to the projection device 1 is not limited to this, and may be a switching power source. In this case, the projection device 1 acquires the switching frequency of the switching power supply, and rotates the phosphor 12 at a frequency that is an integral multiple of the switching frequency or a frequency that is not included in a predetermined frequency range from the switching frequency. By doing so, the projection device 1 can rotate the phosphor 12 at a frequency at which the flicker caused by the influence of the switching ripple due to the switching frequency is not recognized by humans.

[Effect of Projection Device 1 According to First Embodiment]
As described above, the projection device 1 according to the first embodiment detects the power frequency of the commercial power source and rotates the phosphor at a frequency that is an integral multiple of the power frequency of the commercial power source. Alternatively, the projection device rotates the phosphor at a rotation frequency at which the rotation frequency of the phosphor is not included in the predetermined frequency range from the power frequency of the commercial power source. In this way, the projection device rotates the phosphor at a frequency at which the flicker associated with the influence of the voltage ripple of the commercial power supply is not recognized by humans. Therefore, the projection device can reduce flicker on the projection surface.

<Second embodiment>
The projection device 1 according to the first embodiment rotates the phosphor 12 at a rotation frequency higher than the initial frequency stored in the storage unit 18 so as not to generate flicker due to the influence of the voltage ripple of the commercial power supply. Not limited to this, the projection device 1 may rotate the phosphor 12 at a rotation frequency equal to or lower than the initial frequency. In this case, the projection device 1 may not be able to dissipate heat due to a decrease in the rotation speed of the phosphor 12 and a decrease in heat dissipation capacity. Therefore, the projection device 1 according to the second embodiment cools the phosphor 12 with a higher intensity when the rotation frequency of the phosphor 12 is less than the initial frequency. By doing so, the projection device 1 can cool the phosphor 12 while suppressing the flicker caused by the influence of the voltage ripple of the commercial power source from being recognized by humans.

[Functional configuration of projection device 1 according to the second embodiment]
Hereinafter, the functional configuration of the projection device 1 according to the second embodiment will be described with respect to differences from the first embodiment, and the same points will be omitted as appropriate.

The control unit 19 of the projection device 1 according to the second embodiment rotates at a rotation frequency equal to or lower than the initial frequency of the phosphor 12 associated with the amount of light of the light source unit 10. For example, the control unit 19 rotates at a rotation frequency equal to or lower than the initial frequency determined based on the relationship between the initial frequency of the phosphor 12 and the power frequency. Specifically, when the initial frequency of the phosphor 12 is equal to or higher than an integral multiple of the power frequency and is within a predetermined frequency range from an integral multiple of the power frequency, the control unit 19 is an integer of the power frequency. The phosphor 12 is rotated at twice the rotation frequency. Further, when the initial frequency is less than an integral multiple of the power frequency and is within a predetermined frequency range from an integral multiple of the power frequency, the control unit 19 rotates at a rotation frequency less than the predetermined frequency range. ..

The control unit 19 controls the cooling unit 14 with a cooling setting based on the rotation frequency of the phosphor 12 and the amount of light of the light source unit 10. For example, the control unit 19 controls the cooling unit 14 so as to cool the wavelength conversion element with a higher intensity when the rotation frequency of the phosphor 12 is lower than the initial frequency as compared with the case where the rotation frequency is higher than the initial frequency. do. Specifically, when the rotation frequency is lower than the initial frequency, the control unit 19 cools the phosphor 12 with a performance higher than the initial cooling performance by the cooling unit 14 associated with the amount of light stored in the storage unit 18. The cooling unit 14 is controlled so as to do so. More specifically, the control unit 19 rotates the cooling unit 14 at a rotation speed higher than the rotation speed of the fan corresponding to the initial cooling performance.

FIG. 5 is a diagram for explaining the relationship between the amount of light of the light source unit 10 and the rotation frequency of the phosphor 12 in the second embodiment. Since FIG. 5 is the same as FIG. 3, the points different from FIG. 3 will be described.

When the initial frequency is the region indicated by the curly braces L1, the control unit 19 rotates the phosphor 12 at 100 Hz, which is an integral multiple of the power frequency, as shown by the solid line in FIG. When the initial frequency is in the region indicated by the curly braces L2, the control unit 19 rotates the phosphor 12 at 80 Hz as shown by the solid line in FIG. When the initial frequency is within the region L2, the control unit 19 may rotate the phosphor 12 at a frequency of 70 Hz or higher, which is lower than 80 Hz and 20 Hz higher than the frequency (50 Hz) which is one times the power frequency. Then, when the rotation frequency is lower than the initial frequency, the control unit 19 controls the cooling unit 14 so as to cool the phosphor 12 with a performance higher than the initial cooling performance.

[Process executed by the projection device 1 according to the second embodiment]
Hereinafter, the flow of processing executed by the projection device 1 will be described with reference to FIG. FIG. 6 is a flowchart of the process executed by the projection apparatus 1 according to the second embodiment.

Since the processing from step S21 to step S24 is the same as the processing from step S1 to step S4 in the flowchart of FIG. 4, the description thereof will be omitted.

The control unit 19 determines whether or not the determined rotation frequency is larger than the frequency that is an integral multiple of the detected power frequency and is within the frequency range of 20 Hz or less from the frequency that is an integral multiple of the power frequency. When the control unit 19 determines that the frequency is within the frequency range (Yes in step S25), the control unit 19 proceeds to step S26. In step S26, the control unit 19 changes the rotation frequency of the phosphor 12 to a frequency that is an integral multiple of the power frequency, and shifts to step S29.

When the control unit 19 determines that the frequency is not within the frequency range (No in step S25), the control unit 19 proceeds to step S27. In step S27, the control unit 19 determines whether or not the determined rotation frequency is within a frequency range of an integral multiple of the detected power frequency and within 20 Hz from the frequency that is an integral multiple of the power frequency. When the control unit 19 determines that the frequency is within the frequency range (Yes in step S27), the control unit 19 proceeds to step S28. In step S28, the control unit 19 changes the rotation frequency of the phosphor 12 from a frequency that is an integral multiple of the power frequency to a frequency that is less than 20 Hz lower, and shifts to step S29. When the control unit 19 determines that the frequency is not within the frequency range (No in step S27), the control unit 19 proceeds to step S29.

In step S29, the control unit 19 rotates the phosphor 12 at a set rotation frequency. Next, in step S30, the control unit 19 controls the cooling unit 14 with a cooling setting based on the rotation frequency of the phosphor 12 and the driving power of the light source unit 10. When the rotation frequency of the phosphor 12 is lower than the initial frequency, the control unit 19 controls the cooling unit 14 so that the cooling performance is higher than the initial cooling performance. When the rotation frequency is the initial frequency, the control unit 19 controls the cooling unit 14 so as to have the initial cooling performance.

Subsequently, in step S31, the control unit 19 turns on the light source unit 10 with the drive power set value acquired by controlling the light source drive unit 11. Then, in step S32, the control unit 19 determines whether or not there is an instruction to turn off the light source unit 10. When the control unit 19 determines that there is no turn-off instruction (No in step S32), the control unit 19 proceeds to step S22. When the control unit 19 determines that there is a turn-off instruction (Yes in step S32), the control unit 19 controls the light source drive unit 11 to turn off the light source unit 10 and ends this process.

[Effect of Projection Device 1 According to Second Embodiment]
As described above, the projection device 1 rotates the phosphor 12 at a rotation frequency equal to or lower than the initial frequency, and cools the phosphor 12 with a higher intensity when the rotation frequency of the phosphor 12 is lower than the initial frequency. .. By doing so, the projection device 1 can cool the phosphor 12 while suppressing the human recognition of flicker due to the influence of the voltage ripple of the commercial power source.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes can be made within the scope of the gist. be. For example, the specific embodiment of the distribution / integration of the device is not limited to the above embodiment, and all or a part thereof may be functionally or physically distributed / integrated in any unit. Can be done. Also included in the embodiments of the present invention are new embodiments resulting from any combination of the plurality of embodiments. The effect of the new embodiment produced by the combination has the effect of the original embodiment together.

1 Projection device 10 Light source unit 12 Fluorescent material 14 Cooling unit 15 Projection unit 17 Frequency detection unit 18 Storage unit 19 Control unit

Claims (8)

A projection device that modulates illumination light with a light modulation element and projects an image.
Light source and
A wavelength conversion element that converts at least a part of the first light from the light source into a second light having a wavelength different from that of the first light.
A frequency detection means for detecting a power frequency, which is the frequency of power supplied to the projection device from the outside, and
A control means for rotating the wavelength conversion element according to a rotation frequency determined based on the power frequency detected by the frequency detection means, and a control means.
It has a projection means for projecting an image light obtained by modulating a part of the first light from the light source and the second light converted by the wavelength conversion element by the light modulation element.
The control means rotates the wavelength conversion element at a frequency that is an integral multiple of the power frequency, or is 20 Hz lower than a frequency that is an integral multiple of the power frequency and 20 Hz higher than a frequency that is an integral multiple of the power frequency. A projection device characterized by rotating the wavelength conversion element at a frequency not included in the frequency range. Further having a storage means for storing the light amount of the light source in association with the initial frequency which is the initial value of the frequency for rotating the wavelength conversion element.
The projection device according to claim 1, wherein the control means rotates the wavelength conversion element based on the relationship between the initial frequency and the power frequency stored in the storage means. The control means is within a frequency range in which the initial frequency stored in the storage means in relation to the amount of light is higher than the frequency that is an integral multiple of the power frequency and 20 Hz higher than the frequency that is an integral multiple of the power frequency. 2. The projection device according to claim 2, wherein the wavelength conversion element is rotated at a frequency higher than a frequency range 20 Hz higher than a frequency that is an integral multiple of the power frequency. The control means has a frequency in which the initial frequency stored in the storage means in relation to the amount of light is equal to or less than an integral multiple of the power frequency and is 20 Hz lower than the frequency obtained by an integral multiple of the power frequency. 3. The projection device according to claim 3, wherein the wavelength conversion element is rotated at a frequency that is an integral multiple of the power frequency. The control means has a frequency in which the initial frequency stored in the storage means in relation to the amount of light is equal to or higher than an integral multiple of the power frequency and is 20 Hz higher than a frequency obtained by an integral multiple of the power frequency. 2. The projection device according to claim 2, wherein the wavelength conversion element is rotated at a frequency that is an integral multiple of the power frequency. The control means has a frequency in which the initial frequency stored in the storage means in relation to the amount of light is less than a frequency that is an integral multiple of the power frequency and is 20 Hz lower than a frequency that is an integral multiple of the power frequency. The projection device according to claim 5, wherein the wavelength conversion element is rotated at a frequency less than a frequency range 20 Hz lower than a frequency that is an integral multiple of the power frequency. Further having a cooling means for cooling the wavelength conversion element,
Claims 2 to 6 are characterized in that the control means controls the cooling means so as to cool the wavelength conversion element when the frequency for rotating the wavelength conversion element is lower than the initial frequency. The projection device according to any one of the above. Further having a cooling means for cooling the wavelength conversion element,
The storage means stores the initial cooling performance by the cooling means in relation to the amount of light.
The control means controls the cooling means so as to cool the wavelength conversion element with a performance higher than the initial cooling performance when the frequency for rotating the wavelength conversion element is lower than the initial frequency. The projection device according to any one of claims 2 to 6, wherein the projection device is characterized.

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