Control device and projection type video display device

Abstract

This control device is for controlling the number of rotations of a phosphor wheel. The control device comprises: an atmospheric pressure sensor for acquiring atmospheric pressure information indicating the atmospheric pressure around the phosphor wheel; and a control unit for controlling the number of rotations of the phosphor wheel on the basis of the atmospheric pressure information.

Description

Technical Field

[0001] The present disclosure relates to a control device and a projection type video display device.

Background Art

[0002] Patent Document 1 discloses a light source device used in a projector. The light source device described in Patent Document 1 includes a light source, a rotating body on which a phosphor layer that emits light by receiving light irradiated from the light source is disposed, a drive source that rotates the rotating body, a rotation speed control means that variably controls the rotation speed of the rotating body, and a temperature measurement means that measures the temperature of the rotating body. The rotation speed control means variably controls the rotation speed of the rotating body so as to keep the temperature of the rotating body at a predetermined value based on the temperature information from the temperature measurement means.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] In recent years, it has been required to appropriately control the rotation speed of a phosphor wheel.

[0005] An object of the present disclosure is to provide a control device and a projection type video display device capable of appropriately controlling the rotation speed of a phosphor wheel.

[0006] A control device according to one aspect of the present disclosure is a control device for controlling the rotation speed of a phosphor wheel, and includes a pressure sensor that acquires pressure information indicating the air pressure around the phosphor wheel, and a control unit that controls the rotation speed of the phosphor wheel based on the pressure information.

[0007] A projection type video display device according to one aspect of the present disclosure includes the control device according to the above aspect.

[0008] The present disclosure can provide a control device and a projection type video display device capable of appropriately controlling the rotation speed of a phosphor wheel.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

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Figure 7

Figure 8

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Figure 10

Figure 11

Figure 12

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, a more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art.

[0011] Note that the attached drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0012] (Embodiment 1) [1-1. Configuration of Control Device] FIG. 1 is a block diagram showing a schematic configuration of a control device 1 according to Embodiment 1. As shown in FIG. 1, the control device 1 includes an air pressure sensor 10 and a control unit 11. The control device 1 controls the rotation speed of the phosphor wheel 20. The control device 1 is used, for example, in a projection-type video display device such as a projector that displays video.

[0013] The air pressure sensor 10 acquires air pressure information related to the air pressure around the phosphor wheel 20 (air pressure information indicating the air pressure around the phosphor wheel 20). Specifically, the air pressure sensor 10 acquires information on the outside air pressure. For example, the outside air pressure means the air pressure outside the housing in which the phosphor wheel 20 is housed.

[0014] For example, the air pressure sensor includes a piezoresistive or capacitive sensor using a semiconductor. For example, a piezoresistive sensor detects a change in electrical resistance due to the piezoresistive effect generated by the deformation of a diaphragm by an external pressure, and calculates the air pressure from the change in electrical resistance. For example, a capacitive sensor detects a change in capacitance generated by the deformation of a diaphragm by an external pressure, and calculates the air pressure from the change in capacitance.

[0015] The air pressure information acquired by the air pressure sensor 10 is sent to the control unit 11.

[0016] The control unit 11 controls the rotation speed of the phosphor wheel 20 based on the air pressure information. The control unit 11 can be realized by a semiconductor element or the like. The control unit 11 can be composed of, for example, a microcomputer, CPU, MPU, GPU, DSP, FPGA, or ASIC. The functions of the control unit 11 may be configured by hardware only, or may be realized by combining hardware and software. The control unit 11 reads data and programs stored in a storage unit such as a memory and performs various arithmetic processes to realize a predetermined function.

[0017] FIG. 2 is a diagram showing an example of the schematic configuration of the phosphor wheel 20. As shown in FIG. 2, the phosphor wheel 20 includes a phosphor 21, a wheel body 22, and a motor 23.

[0018] The phosphor 21 emits light, for example, when receiving light from a light source. For example, the phosphor 21 is a YAG phosphor that is excited by blue light LB and emits yellow light LY including green and red wavelength components.

[0019] The wheel body 22 is a plate-like member having a first surface and a second surface opposite to the first surface. The phosphor 21 is applied to the first surface of the wheel body 22. For example, the wheel body 22 has a disc shape. The wheel body 22 is rotatably held. The wheel body 22 is formed of, for example, a circular aluminum substrate. Fins (not shown) are provided on the second surface of the wheel body 22. When the phosphor wheel 20 has fins on the second surface of the wheel body 22, the phosphor wheel 20 itself can be efficiently cooled when the rotation speed of the phosphor wheel 20 is controlled as described later.

[0020] The motor 23 rotates the wheel body 22. The motor 23 is disposed at the center of the wheel body 22. The motor 23 is controlled by the control unit 11.

[0021] [1-2. Operation of the control device] For the control device 1 configured as described above, the operation will be described below with reference to FIG. 3. FIG. 3 is a flowchart of an example of the control method according to the first embodiment.

[0022] As shown in FIG. 3, in step S10, the pressure sensor 10 acquires pressure information. Specifically, the pressure sensor 10 acquires pressure information related to the pressure around the phosphor wheel 20. For example, the pressure sensor 10 acquires information on the external pressure.

[0023] The pressure sensor 10 transmits the acquired pressure information to the control unit 11.

[0024] In step S20, the control unit 11 controls the rotation speed of the phosphor wheel 20 based on the pressure information. Specifically, the control unit 11 determines the adjustable range of the rotation speed of the phosphor wheel 20 according to the pressure.

[0025] In this embodiment, the control unit 11 determines the adjustable range of the rotation speed of the phosphor wheel 20 using a first table showing the relationship among a plurality of pressure conditions, the temperature of the phosphor wheel 20, and the rotation speed of the phosphor wheel 20.

[0026] FIG. 4 is a diagram showing an example of the first table 30. As shown in FIG. 4, the first table 30 shows the relationship among a plurality of pressure conditions P1 to P6, the rotation speeds R1 to R7 of the phosphor wheel 20, and the temperatures T1 to T15 of the phosphor wheel 20.

[0027] In FIG. 4, the plurality of pressure conditions P1 to P6 decrease from the pressure condition P1 to the pressure condition P6. That is, among the plurality of pressure conditions, the pressure condition P1 is the largest and the pressure condition P6 is the smallest.

[0028] The rotation speeds R1 to R7 of the phosphor wheel 20 indicate the rotation speeds that can be changed in each of the plurality of pressure conditions P1 to P6. The rotation speeds R1 to R7 of the phosphor wheel 20 decrease from the rotation speed R1 to the rotation speed R7. That is, the rotation speed R1 is the largest and the rotation speed R7 is the smallest.

[0029] The temperatures T1 to T15 of the phosphor wheel 20 indicate the temperatures of the phosphor 21 when the rotational speed of the phosphor wheel 20 is changed under each of a plurality of pressure conditions P1 to P6. The temperatures T1 to T15 of the phosphor wheel 20 shown in the first table 30 are the temperatures measured in advance under a plurality of pressure conditions P1 to P6. The temperatures T1 to T15 increase from temperature T1 to temperature T15. That is, temperature T1 is the smallest and temperature T15 is the largest.

[0030] In the first table 30, it shows the relationship that the lower the pressure P is, the higher the temperature T of the phosphor wheel 20 becomes, and the lower the rotational speed R is, the higher the temperature T of the phosphor wheel 20 becomes. That is, the first table 30 shows the relationship that the lower the pressure P indicated by a plurality of pressure conditions P1 to P6 is, the higher the temperature T of the phosphor wheel 20 becomes, and the lower the rotational speed R of the phosphor wheel 20 is, the higher the temperature T of the phosphor wheel 20 becomes.

[0031] The first table 30 determines the adjustable range of the rotational speed of the phosphor wheel 20 under each of a plurality of pressure conditions P1 to P6 by using the first threshold temperature TL1 of the temperature of the phosphor wheel 20. The first threshold temperature TL1 is determined based on, for example, a temperature at which the phosphor 21 does not melt. For example, the first threshold temperature TL1 is set to a temperature lower than the temperature upper limit of the material constituting the phosphor wheel 20. Note that the first threshold temperature TL1 may be changed according to the type of the phosphor 21.

[0032] In the present embodiment, the first threshold temperature TL1 is set to temperature T9. As shown in FIG. 4, under each of a plurality of pressure conditions P1 to P6, the rotational speed R of the phosphor wheel 20 corresponding to temperatures T10 to T15 exceeding temperature T9 is not settable. On the other hand, the rotational speed R of the phosphor wheel 20 corresponding to temperatures T1 to T9 that are below temperature T9 is settable.

[0033] Thus, in the first table 30, the lower limit value of the adjustable range of the rotation speed of the phosphor wheel 20 is determined based on the first threshold temperature TL1 of the phosphor wheel 20.

[0034] FIG. 5 is a diagram showing the adjustable range of the rotation speed R of the phosphor wheel 20 according to the first embodiment. As shown in FIG. 5, for example, in the case of the atmospheric pressure conditions P1 and P2, the rotation speed R can be set in the range of the rotation speeds R1 to R7, and in the case of the atmospheric pressure condition P4, the rotation speed R can be set in the range of the rotation speeds R1 to R4.

[0035] Thus, as the atmospheric pressure decreases, the lower limit value of the rotation speed R in the adjustable range increases. For example, as shown in FIGS. 4 and 5, the lower limit values of the rotation speed R for the atmospheric pressure conditions P1 to P6 are set to the rotation speeds R7, R7, R6, R4, R3, and R1, respectively.

[0036] Based on the first table 30, the control unit 11 increases the lower limit value of the rotation speed R of the phosphor wheel 20 in the adjustable range as the atmospheric pressure decreases.

[0037] FIG. 6 is a flowchart of an example of the rotation speed control according to the first embodiment. FIG. 6 shows an example of the detailed control of step S20 shown in FIG. 5.

[0038] As shown in FIG. 6, in step S21, the control unit 11 selects the atmospheric pressure condition corresponding to the atmospheric pressure information using the first table 30. Specifically, the control unit 11 selects the atmospheric pressure condition corresponding to the atmospheric pressure acquired by the atmospheric pressure sensor 10 from among the plurality of atmospheric pressure conditions P1 to P6 in the first table 30. For example, the control unit 11 selects the atmospheric pressure condition with the smallest difference between the atmospheric pressure acquired by the atmospheric pressure sensor 10 and the atmospheric pressures of the atmospheric pressure conditions P1 to P6.

[0039] In step S22, the control unit 11 determines the lower limit value of the rotation speed R of the phosphor wheel 20 under the selected air pressure condition using the first table 30. For each of the plurality of air pressure conditions P1 to P6, the lower limit value of the rotation speed R of the phosphor wheel 20 determined by the first threshold temperature TL1 is set. For example, under the air pressure condition P3, the lower limit value of the rotation speed R of the phosphor wheel 20 is the rotation speed R6, and under the air pressure condition P5, the lower limit value of the rotation speed R of the phosphor wheel 20 is the rotation speed R3. That is, when the air pressure condition P5 is selected, the control unit 11 determines the smallest rotation speed R3 among the rotation speeds (rotation speeds R1 to R3) corresponding to the temperatures (temperatures T7 to T9) equal to or lower than the first threshold temperature TL1 under the air pressure condition P5 as the lower limit value.

[0040] In this way, the control unit 11 determines the smallest rotation speed among the rotation speeds R1 to R7 at which the temperature of the phosphor wheel 20 becomes equal to or lower than the first threshold temperature TL1 under the selected air pressure condition as the lower limit value. Thereby, the control unit 11 determines the adjustable range of the rotation speed of the phosphor wheel 20.

[0041] In step S23, the control unit 11 sets the rotation speed R of the phosphor wheel 20 to the lower limit value. For example, under the air pressure condition P3, since the adjustable range of the rotation speed R of the phosphor wheel 20 is the rotation speeds R1 to R6, the control unit 11 sets the rotation speed R of the phosphor wheel 20 to the rotation speed R6 under the air pressure condition P3. Alternatively, under the air pressure condition P5, since the adjustable range of the rotation speed R of the phosphor wheel 20 is the rotation speeds R1 to R3, the control unit 11 sets the rotation speed R of the phosphor wheel 20 to the rotation speed R3 under the air pressure condition P5.

[0042] In this way, in the present embodiment, the control unit 11 determines the lower limit value of the rotation speed R of the phosphor wheel 20 according to the air pressure, and sets the rotation speed R of the phosphor wheel 20 to the lower limit value.

[0043] [1-3. Configuration of Projection-Type Video Display Device] FIG. 7 is a block diagram showing an example of the schematic configuration of the projection-type video display device 100.

[0044] As shown in Fig. 7, the projection type video display device 100 includes a light source unit 2, a projection optical system unit 3, and a projection lens 4. The light source unit 2 includes a control device 1, a phosphor wheel 20, and a light source 5.

[0045] The light source unit 2 generates white light from the light emitted from the light source 5 by, for example, the phosphor wheel 20 or the like, and emits it to the projection optical system unit 3.

[0046] The projection optical system unit 3 receives the light emitted from the light source unit 2, for example, and projects the projection light through the projection lens 4.

[0047] The projection lens 4 is a lens that is attached to the projection optical system unit 3 and projects the projection light.

[0048] As described above, the projection type video display device 100 includes the control device 1 described above and controls the rotation speed of the phosphor wheel 20.

[0049] [1-4. Effects, etc.] The control device 1 of the present disclosure is a control device for controlling the rotation speed of the phosphor wheel 20. The control device 1 includes a pressure sensor 10 that acquires pressure information related to the atmospheric pressure around the phosphor wheel 20, and a control unit 11 that controls the rotation speed of the phosphor wheel 20 based on the pressure information. With such a configuration, the rotation speed of the phosphor wheel 20 can be appropriately controlled according to the atmospheric pressure.

[0050] For example, when the atmospheric pressure decreases, the wind speed around the phosphor wheel 20 decreases, so the cooling efficiency of the phosphor wheel 20 may decrease. According to the control device 1, since the rotation speed of the phosphor wheel 20 is controlled according to the atmospheric pressure, a decrease in the cooling efficiency of the phosphor wheel 20 due to the influence of the atmospheric pressure can be suppressed. Thereby, the reliability of the phosphor wheel 20 can be improved.

[0051] Moreover, by controlling the rotation speed of the phosphor wheel 20 according to the atmospheric pressure, the noise caused by the rotation of the phosphor wheel 20 can be reduced. For example, when the temperature of the phosphor wheel 20 is relatively low, the noise can be reduced by decreasing the rotation speed of the phosphor wheel 20.

[0052] The control unit 11 determines the adjustable range of the rotation speed of the phosphor wheel 20 according to the atmospheric pressure. With such a configuration, the rotation speed of the phosphor wheel 20 can be controlled more appropriately.

[0053] As the atmospheric pressure decreases, the control unit 11 increases the lower limit value of the rotation speed of the phosphor wheel 20 within the adjustable range. With such a configuration, the decrease in the cooling efficiency of the phosphor wheel 20 can be more suppressed.

[0054] The control unit 11 determines the lower limit value based on a first table 30 showing the relationships among a plurality of atmospheric pressure conditions P1 to P6, rotation speeds R1 to R7 of the phosphor wheel 20, and temperatures T1 to T15 of the phosphor wheel 20, a first threshold temperature TL1 of the temperature of the phosphor wheel 20, and atmospheric pressure information. With such a configuration, the control unit 11 can more easily control the rotation speed of the phosphor wheel 20 according to the atmospheric pressure using the first table 30. Furthermore, the control unit 11 can more appropriately control the rotation speed of the phosphor wheel 20 according to the atmospheric pressure while suppressing the decrease in the cooling efficiency of the phosphor wheel 20.

[0055] The first table 30 shows the relationship that the lower the atmospheric pressure, the higher the temperature of the phosphor wheel 20, and the lower the rotation speed, the higher the temperature of the phosphor wheel 20. The control unit 11 uses the first table 30 to select an atmospheric pressure condition corresponding to the atmospheric pressure information from among the plurality of atmospheric pressure conditions P1 to P6, and determines the smallest rotation speed among the rotation speeds at which the temperature of the phosphor wheel 20 is equal to or lower than the first threshold temperature TL1 under the selected atmospheric pressure condition as the lower limit value. With such a configuration, the noise caused by the rotation of the phosphor wheel 20 can be reduced while maintaining the cooling performance of the phosphor wheel 20.

[0056] The control unit 11 sets the rotation speed of the phosphor wheel 20 to a lower limit value. With such a configuration, while maintaining the cooling performance of the phosphor wheel 20, the noise caused by the rotation of the phosphor wheel 20 can be further reduced.

[0057] The projection type video display device 100 of the present disclosure includes the control device 1 in the above-described manner. With such a configuration, the same effects as those of the control device 1 described above can be achieved.

[0058] (Embodiment 2) Hereinafter, Embodiment 2 will be described with reference to FIGS. 8 and 9. FIG. 8 is a block diagram showing an example of the schematic configuration of the control device according to Embodiment 2, and FIG. 9 is a flowchart of an example of the control method according to Embodiment 2.

[0059] In Embodiment 2, mainly the differences from Embodiment 1 will be described. In Embodiment 2, the same reference numerals will be used for the same or equivalent configurations as those in Embodiment 1, and the description thereof will be given. Also, in Embodiment 2, the description overlapping with that in Embodiment 1 will be omitted.

[0060] In Embodiment 2, it is different from Embodiment 1 in that the control device 1A includes a temperature sensor 12 and controls the rotation speed of the phosphor wheel 20 based on the air pressure information and the temperature information.

[0061] [2-1. Configuration] As shown in FIG. 8, the control device 1A includes an air pressure sensor 10, a control unit 11, and a temperature sensor 12. Since the configurations of the air pressure sensor 10 and the control unit 11 are the same as those in Embodiment 1, the description thereof will be omitted.

[0062] The temperature sensor 12 acquires temperature information related to the temperature of the phosphor wheel 20. Specifically, the temperature sensor 12 measures the temperature of the phosphor 21. For example, the temperature sensor 12 is a non-contact temperature sensor that acquires the temperature without touching the phosphor wheel 20. The non-contact temperature sensor may be, for example, an infrared thermometer that measures the amount of infrared energy.

[0063] The temperature information acquired by the temperature sensor 12 is sent to the control unit 11.

[0064] The control unit 11 controls the rotation speed of the phosphor wheel 20 based on the air pressure information acquired by the air pressure sensor 10 and the temperature information acquired by the temperature sensor 12.

[0065] [2-2. Operation] Regarding the control device 1A configured as described above, the operation will be described below with reference to FIG. 9.

[0066] As shown in FIG. 9, in step S10, the air pressure sensor 10 acquires air pressure information. The air pressure sensor 10 transmits the acquired air pressure information to the control unit 11.

[0067] In step S30, the temperature sensor 12 acquires temperature information. Specifically, the temperature sensor 12 acquires the temperature of the phosphor 21 of the phosphor wheel 20.

[0068] The temperature sensor 12 transmits the acquired temperature information to the control unit 11.

[0069] In step S40, the control unit 11 controls the rotation speed of the phosphor wheel 20 based on the air pressure information and the temperature information. Specifically, the control unit 11 determines the adjustable range of the rotation speed of the phosphor wheel 20 according to the air pressure and the temperature of the phosphor wheel 20.

[0070] In the present embodiment, in addition to the first table 30, the control unit 11 uses a second table showing the relationship among a plurality of air pressure conditions, the rotation speed of the phosphor wheel 20, and the motor temperature of the motor 23 to determine the adjustable range of the rotation speed of the phosphor wheel 20.

[0071] FIG. 10 is a diagram showing an example of the second table 31. As shown in FIG. 10, the second table 31 shows the relationship among a plurality of air pressure conditions P1 to P6, the rotation speeds R1 to R7 of the phosphor wheel 20, and the motor temperatures Tm1 to Tm10 of the motor 23.

[0072] In FIG. 10, the motor temperatures Tm1 to Tm10 of the motor 23 indicate the temperature of the motor 23 when the rotation speed of the phosphor wheel 20 is changed under each of a plurality of atmospheric pressure conditions P1 to P6. The motor temperatures Tm1 to Tm10 shown in the second table 31 are the temperatures measured in advance under a plurality of atmospheric pressure conditions P1 to P6. The motor temperatures Tm1 to Tm10 of the motor 23 decrease from the motor temperature Tm1 to the motor temperature Tm10. That is, the motor temperature Tm1 is the highest, and the motor temperature Tm10 is the lowest.

[0073] Note that the plurality of atmospheric pressure conditions P1 to P6 and the rotation speeds R1 to R7 of the phosphor wheel 20 are the same as those in the first embodiment.

[0074] In the second table 31, it shows the relationship that the lower the atmospheric pressure P is, the lower the motor temperature Tm is, and the lower the rotation speed R is, the lower the motor temperature Tm is. That is, the second table 31 shows the relationship that the higher the atmospheric pressure P indicated by the plurality of atmospheric pressure conditions is, the lower the motor temperature Tm is, and the higher the rotation speed R of the motor 23 is, the higher the motor temperature Tm is.

[0075] The second table 31 determines the adjustable range of the rotation speed of the phosphor wheel 20 under each of a plurality of atmospheric pressure conditions P1 to P6 by using the second threshold temperature TL2 of the motor temperature Tm. The second threshold temperature TL2 is, for example, the upper limit temperature at which the motor 23 operates normally. Note that the second threshold temperature TL2 may be changed according to the type and specifications of the motor 23.

[0076] In this embodiment, the second threshold temperature TL2 is set to the motor temperature Tm4. As shown in FIG. 10, under each of a plurality of atmospheric pressure conditions P1 to P6, the rotation speed R of the phosphor wheel 20 corresponding to the motor temperatures Tm1 to Tm3 exceeding the motor temperature Tm4 is not settable. On the other hand, the rotation speed R of the phosphor wheel 20 corresponding to the motor temperatures Tm4 to Tm10 that are equal to or lower than the motor temperature Tm4 is settable.

[0077] As described above, in the second table 31, the upper limit value of the adjustable range of the rotation speed of the phosphor wheel 20 is determined based on the second threshold temperature TL2 of the motor 23.

[0078] Also, in the present embodiment, similar to the first embodiment, the lower limit value of the adjustable range of the rotation speed of the phosphor wheel 20 is determined based on the first threshold temperature TL1 of the phosphor wheel 20 using the first table 30.

[0079] FIG. 11 is a diagram showing the adjustable range of the rotation speed R of the phosphor wheel 20 according to the second embodiment. As shown in FIG. 11, for example, in the case of the atmospheric pressure condition P1, the rotation speed R can be set in the range of the rotation speeds R4 to R7, and in the case of the atmospheric pressure condition P4, the rotation speed R can be set in the range of the rotation speeds R2 to R4.

[0080] As described above, as the atmospheric pressure decreases, the upper limit value and the lower limit value of the rotation speed R in the adjustable range increase. For example, as shown in FIG. 11, the upper limit values of the rotation speed R for the atmospheric pressure conditions P1 to P6 are set to the rotation speeds R4, R3, R3, R2, R2, and R1, respectively. The lower limit values of the rotation speed R for the atmospheric pressure conditions P1 to P6 are set to the rotation speeds R7, R7, R6, R4, R3, and R1, respectively.

[0081] Based on the second table 31, the control unit 11 increases the upper limit value of the rotation speed R of the phosphor wheel 20 in the adjustable range as the atmospheric pressure decreases. Also, based on the first table 30, the control unit 11 increases the lower limit value of the rotation speed R of the phosphor wheel 20 in the adjustable range as the atmospheric pressure decreases.

[0082] FIG. 12 is a flowchart of an example of the rotation speed control according to the second embodiment. FIG. 12 shows an example of the detailed control of step S40 shown in FIG. 9.

[0083] As shown in FIG. 12, in step S41, the control unit 11 selects a pressure condition corresponding to the pressure information using the second table. Specifically, the control unit 11 selects a pressure condition corresponding to the pressure acquired by the pressure sensor 10 from among a plurality of pressure conditions P1 to P6 in the second table 31. For example, the control unit 11 selects a pressure condition with the smallest difference between the pressure acquired by the pressure sensor 10 and the pressures of the pressure conditions P1 to P6.

[0084] In step S42, the control unit 11 determines an upper limit value of the rotation speed R of the phosphor wheel 20 under the selected pressure condition using the second table 31. For each of the plurality of pressure conditions P1 to P6, an upper limit value of the rotation speed R of the phosphor wheel 20 determined by the second threshold temperature TL2 of the motor temperature Tm is set. For example, under the pressure condition P3, the upper limit value of the rotation speed R of the phosphor wheel 20 is the rotation speed R3, and under the pressure condition P5, the upper limit value of the rotation speed R of the phosphor wheel 20 is the rotation speed R2. That is, when the pressure condition P5 is selected, the control unit 11 determines the largest rotation speed R2 among the rotation speeds (rotation speeds R2 to R7) corresponding to motor temperatures (motor temperatures Tm4 to Tm9) equal to or lower than the second threshold temperature TL2 under the pressure condition P5 as the upper limit value.

[0085] In this way, the control unit 11 determines the largest rotation speed among the rotation speeds R1 to R7 at which the motor temperature Tm of the motor 23 is equal to or lower than the second threshold temperature TL2 under the selected pressure condition as the upper limit value.

[0086] In step S43, the control unit 11 determines a lower limit value of the rotation speed R of the phosphor wheel 20 under the selected pressure condition using the first table 30. For each of the plurality of pressure conditions P1 to P6, a lower limit value of the rotation speed R of the phosphor wheel 20 determined by the first threshold temperature TL1 of the phosphor wheel 20 is set. For example, under the pressure condition P3, the lower limit value of the rotation speed R of the phosphor wheel 20 is the rotation speed R6, and under the pressure condition P5, the lower limit value of the rotation speed R of the phosphor wheel 20 is the rotation speed R3.

[0087] In this way, the control unit 11 determines the maximum rotation speed among the rotation speeds R1 to R7 at which the motor temperature Tm of the motor 23 is equal to or lower than the second threshold temperature TL2 under the selected air pressure condition as the upper limit value. Further, the control unit 11 determines the minimum rotation speed among the rotation speeds R1 to R7 at which the temperature T of the phosphor wheel 20 is equal to or lower than the first threshold temperature TL1 under the selected air pressure condition as the lower limit value. Thereby, the control unit 11 determines the range within which the rotation speed of the phosphor wheel 20 can be set.

[0088] In step S44, the control unit 11 sets the rotation speed R of the phosphor wheel 20 to the lower limit value. For example, under the air pressure condition P3, since the range within which the rotation speed R of the phosphor wheel 20 can be set is the rotation speeds R3 to R6, the control unit 11 sets the rotation speed R of the phosphor wheel 20 to the rotation speed R6 under the air pressure condition P3. Alternatively, under the air pressure condition P5, since the range within which the rotation speed R of the phosphor wheel 20 can be set is the rotation speeds R2 to R3, the control unit 11 sets the rotation speed R of the phosphor wheel 20 to the rotation speed R3 under the air pressure condition P5.

[0089] In step S45, the control unit 11 determines whether the temperature of the phosphor wheel 20 is greater than the third threshold temperature TL3. When the control unit 11 determines that the temperature of the phosphor wheel 20 is greater than the third threshold temperature TL3, the process proceeds to step S46. When the control unit 11 determines that the temperature of the phosphor wheel 20 is equal to or lower than the third threshold temperature TL3, the process proceeds to step S47.

[0090] The third threshold temperature TL3 may be the same as the first threshold temperature TL1, for example.

[0091] In step S46, the control unit 11 increases the rotation speed R of the phosphor wheel 20. For example, when the rotation speed R of the phosphor wheel 20 is set to the rotation speed R6 under the air pressure condition P3, the control unit 11 sets the rotation speed R of the phosphor wheel 20 to the rotation speed R5. That is, the control unit 11 increases the rotation speed R of the phosphor wheel 20 by one step. That is, the control unit 11 increases the rotation speed R of the phosphor wheel 20 from the rotation speed R6 to the rotation speed R5 based on the first table 30. Specifically, the control unit 11 sets the rotation speed R of the phosphor wheel 20 to the rotation speed R5 corresponding to the temperature T8 higher than the first threshold temperature TL1 (temperature T9) under the air pressure condition P3 of the first table 30.

[0092] In step S47, the control unit 11 determines whether or not the end condition is satisfied. If the control unit 11 determines that the end condition is satisfied, the process ends. If the control unit 11 determines that the end condition is not satisfied, the process returns to step S45.

[0093] The end condition is a condition for ending the rotation speed control by the control unit 11. For example, the end condition may be when the power supply of the control device 1A is turned off. Alternatively, the end condition may be when the rotation speed control function is turned off.

[0094] [2-3. Effects, etc.] The control device 1A of the present disclosure further includes a temperature sensor 12 that acquires temperature information related to the temperature of the phosphor wheel 20. The control unit 11 controls the rotation speed of the phosphor wheel 20 based on the temperature information. With such a configuration, the rotation speed of the phosphor wheel 20 can be more appropriately controlled according to the air pressure and the temperature of the phosphor wheel 20.

[0095] For example, when the temperature of the phosphor wheel 20 increases, the cooling efficiency of the phosphor wheel 20 can be improved by increasing the rotation speed of the phosphor wheel 20.

[0096] The phosphor wheel 20 includes a phosphor 21, a wheel body 22 coated with the phosphor 21, and a motor 23 that rotates the wheel body 22. The control unit 11 determines an upper limit value of the rotation speed of the phosphor wheel 20 based on a second table 31 showing the relationships among a plurality of air pressure conditions P1 to P6, rotation speeds R1 to R7 of the phosphor wheel 20, and motor temperatures Tm1 to Tm10 of the motor 23, and a second threshold temperature TL2 of the motor temperature. With such a configuration, based on the motor temperature Tm of the motor 23, the upper limit value of the rotation speed of the phosphor wheel 20 can be determined. Thereby, the rotation speed of the phosphor wheel 20 can be appropriately controlled, and the reliability of the phosphor wheel 20 can be improved.

[0097] The second table 31 shows a relationship in which the motor temperature Tm decreases as the air pressure increases, and the motor temperature Tm increases as the rotation speed R of the phosphor wheel 20 increases. In the second table 31, the control unit 11 selects an air pressure condition corresponding to the air pressure information from among the plurality of air pressure conditions P1 to P6, and determines, as the upper limit value, the largest rotation speed among the rotation speeds R1 to R7 at which the motor temperature Tm is equal to or lower than the second threshold temperature TL2 under the selected air pressure condition. With such a configuration, the rotation speed of the phosphor wheel 20 can be more appropriately controlled, and the reliability of the phosphor wheel 20 can be further improved.

[0098] When the temperature of the phosphor wheel 20 is higher than a third threshold temperature TL3, the control unit 11 increases the rotation speed of the phosphor wheel 20. With such a configuration, the cooling efficiency of the phosphor wheel 20 can be improved according to the temperature of the phosphor wheel 20.

[0099] The temperature sensor 12 is a non-contact temperature sensor that acquires the temperature of the phosphor wheel 20 without touching the phosphor wheel 20. With such a configuration, the temperature of the phosphor wheel 20 can be easily acquired.

[0100] In the above-described embodiment, the control using the first table 30 and the control using the first table 30 and the second table 31 have been described, but the present invention is not limited thereto. The control unit 11 may control the rotation speed of the phosphor wheel 20 using the second table 31 without using the first table 30. Alternatively, the control unit 11 may control the rotation speed of the phosphor wheel 20 according to the air pressure without using the first table 30 and the second table 31.

[0101] In the above-described embodiment, an example of setting the lower limit value of the rotation speed of the phosphor wheel 20 and an example of setting the upper limit value and the lower limit value of the rotation speed of the phosphor wheel 20 have been described, but the present invention is not limited thereto. For example, the upper limit value may be set without setting the lower limit value of the rotation speed of the phosphor wheel 20.

[0102] In the above-described embodiment, an example in which the control unit 11 sets the rotation speed of the phosphor wheel 20 to the lower limit value within the settable range has been described, but the present invention is not limited thereto. For example, the control unit 11 may determine the rotation speed of the phosphor wheel 20 within the settable range. For example, at the air pressure condition P3, the control unit 11 may set the rotation speed of the phosphor wheel 20 to a rotation speed R5 that is greater than the rotation speed R6 which is the lower limit value.

[0103] In the above-described embodiment, six air pressure conditions P1 to P6 and seven rotation speeds R1 to R7 are set in the first table 30 and the second table 31, but the present invention is not limited thereto. The number of set air pressure conditions and rotation speeds may be any number.

[0104] In the above-described embodiment, an example in which the third threshold temperature TL3 is the same as the first threshold temperature TL1 has been described, but the present invention is not limited thereto. For example, the third threshold temperature TL3 may be different from the first threshold temperature TL1.

[0105] In the above-described embodiment, an example in which the projection type video display device 100 includes the light source unit 2, the projection optical system unit 3, and the projection lens 4 has been described, but the present invention is not limited thereto. The projection type video display device 100 may include elements other than these elements.

[0106] As described above, embodiments have been described as examples of the technology in the present disclosure. For this purpose, the accompanying drawings and detailed descriptions have been provided. Therefore, among the components described in the accompanying drawings and detailed descriptions, there may be not only the components essential for solving the problems, but also the components not essential for solving the problems for the purpose of exemplifying the above technology. Therefore, just because those non-essential components are described in the accompanying drawings or the detailed description, it should not be immediately determined that those non-essential components are essential.

[0107] In addition, since the above-described embodiments are for exemplifying the technology in the present disclosure, various changes, replacements, additions, omissions, etc. can be made within the scope of the claims or their equivalents.

[0108] (Summary of Embodiment) (1) The control device of the present disclosure is a control device for controlling the rotation speed of a phosphor wheel, and includes a pressure sensor that acquires pressure information related to the atmospheric pressure around the phosphor wheel is disposed, and a control unit that controls the rotation speed of the phosphor wheel based on the pressure information.

[0109] (2) In the control device of (1), the control unit may determine a range within which the rotation speed can be set according to the atmospheric pressure.

[0110] (3) In the control device of (2), the control unit may increase the lower limit value of the rotation speed within the settable range as the atmospheric pressure decreases.

[0111] (4) In the control device of (3), the control unit may determine the lower limit value based on a first table showing the relationship among a plurality of atmospheric pressure conditions, the rotation speed of the phosphor wheel, and the temperature of the phosphor wheel, a first threshold temperature of the temperature of the phosphor wheel, and the pressure information.

[0112] (5) In the control device of (4), the first table shows the relationship that the lower the air pressure, the higher the temperature of the phosphor wheel, and the lower the rotation speed, the higher the temperature of the phosphor wheel. The control unit uses the first table to select an air pressure condition corresponding to the air pressure information from among a plurality of air pressure conditions, and may determine, as a lower limit value, the lowest rotation speed among the rotation speeds at which the temperature of the phosphor wheel is equal to or lower than the first threshold temperature under the selected air pressure condition.

[0113] (6) In any one of the control devices from (3) to (5), the control unit may set the rotation speed to the lower limit value.

[0114] (7) Any one of the control devices from (1) to (5) further includes a temperature sensor that acquires temperature information related to the temperature of the phosphor wheel, and the control unit may control the rotation speed of the phosphor wheel based on the temperature information.

[0115] (8) In the control device of (7), it includes a phosphor wheel, a phosphor, a wheel body coated with the phosphor, and a motor that rotates the wheel body. The control unit may determine an upper limit value of the rotation speed of the phosphor wheel based on a second table showing the relationship among a plurality of air pressure conditions, the rotation speed of the phosphor wheel, and the motor temperature of the motor, and a second threshold temperature of the motor temperature.

[0116] (9) In the control device of (8), the second table shows the relationship that the higher the air pressure, the lower the motor temperature, and the higher the rotation speed, the higher the motor temperature. The control unit selects, from among a plurality of air pressure conditions, an air pressure condition corresponding to the air pressure information in the second table, and may determine, as the upper limit value, the highest rotation speed among the rotation speeds at which the motor temperature is equal to or lower than the second threshold temperature under the selected air pressure condition.

[0117] (10) In any one of the control devices from (7) to (9), the control unit may increase the rotation speed of the phosphor wheel when the temperature of the phosphor wheel exceeds the third threshold temperature.

[0118] In any one of the control devices (11) to (10), the temperature sensor may be a non-contact temperature sensor that acquires the temperature without touching the phosphor wheel.

[0119] (12) The projection type video display device of the present disclosure includes any one of the control devices (1) to (11).

Industrial Applicability

[0120] The present disclosure can be used for a control device that controls the rotation speed of a phosphor wheel, a light source device, and a projection type video display device.

Explanation of Signs

[0121] 1,1A Control device 2 Light source unit 3 Projection optical system unit 4 Projection lens 5 Light source 10 Pressure sensor 11 Control unit 12 Temperature sensor 20 Phosphor wheel 21 Phosphor 22 Wheel body 23 Motor 30 First table 31 Second table 100 Projection type video display device

Claims

1. A control device for controlling the rotational speed of a phosphor wheel, comprising: a pressure sensor that acquires pressure information indicating the air pressure around the phosphor wheel; a control unit that controls the rotational speed of the phosphor wheel based on the pressure information; The control device.

2. The control unit determines a settable range of the rotational speed according to the air pressure indicated by the pressure information. The control device according to Claim 1.

3. As the air pressure indicated by the pressure information decreases, the control unit increases the lower limit value of the settable range of the rotational speed. The control device according to Claim 2.

4. The control unit determines the lower limit value based on a first table, a first threshold temperature of the phosphor wheel, and the pressure information. The first table shows the relationship between a plurality of air pressure conditions, the rotational speed of the phosphor wheel, and the temperature of the phosphor wheel. The control device according to Claim 3.

5. The first table shows: a relationship in which the temperature of the phosphor wheel increases as the air pressure indicated by the plurality of air pressure conditions decreases; a relationship in which the temperature of the phosphor wheel increases as the rotational speed decreases; The control unit: uses the first table to select an air pressure condition corresponding to the pressure information from among the plurality of air pressure conditions; determines, as the lower limit value, the smallest rotational speed among the rotational speeds corresponding to temperatures equal to or lower than the first threshold temperature under the selected air pressure condition. The control device according to Claim 4.

6. The control unit sets the rotational speed to the lower limit value. The control device according to Claim 3.

7. The control device further includes a temperature sensor that acquires temperature information indicating the temperature of the phosphor wheel, and the control unit controls the rotational speed of the phosphor wheel based on the pressure information and the temperature information. The control device according to Claim 1.

8. The phosphor wheel includes a phosphor, a wheel body coated with the phosphor, and a motor that rotates the wheel body. The control unit determines an upper limit value of the settable range of the rotational speed of the phosphor wheel based on a second table and a second threshold temperature of the motor. The second table shows the relationship between a plurality of air pressure conditions, the rotational speed of the phosphor wheel, and the temperature of the motor. The control device according to Claim 7.

9. The second table shows: a relationship in which the temperature of the motor decreases as the air pressure indicated by the plurality of air pressure conditions increases; It shows the relationship that the higher the rotation speed, the higher the temperature of the motor. The control unit uses the second table to select a pressure condition corresponding to the pressure information from among the plurality of pressure conditions, and determines the maximum rotation speed among the rotation speeds corresponding to the temperature of the motor equal to or lower than the second threshold temperature under the selected pressure condition as the upper limit value. The control device according to claim 8.

10. When the temperature of the phosphor wheel exceeds the third threshold temperature, the control unit increases the rotation speed of the phosphor wheel. The control device according to claim 7.

11. The temperature sensor is a non-contact temperature sensor that acquires the temperature without touching the phosphor wheel. The control device according to claim 7.

12. The device further includes a temperature sensor that acquires temperature information indicating the temperature of the phosphor wheel. When the temperature of the phosphor wheel exceeds the third threshold temperature, the control unit increases the rotation speed of the phosphor wheel based on the first table. The third threshold temperature is the same as the first threshold temperature. The control device according to claim 5.

13. When the temperature of the phosphor wheel exceeds the third threshold temperature, the control unit sets the rotation speed of the phosphor wheel to the rotation speed corresponding to a temperature higher than the first threshold temperature under the selected pressure condition in the first table. The control device according to claim 12.

14. A control device according to any one of claims 1 to 13, comprising the phosphor wheel. A projection type video display device.

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