JP2018136480A - Projector, and method for controlling projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector that can appropriately cool a discharge lamp even when devitrification occurs.SOLUTION: One aspect of a projector of the present invention comprises: a discharge lamp that has a pair of electrodes and emits light; a cooling part that cools the discharge lamp; a control part that controls the cooling part; a light modulation device that modulates the light emitted from the discharge lamp according to image information; and a projection optical device that projects the light modulated by the light modulation device. The control part controls the cooling part on the basis of control information indicating the relationship between a voltage between the electrodes of the discharge lamp and the number of rotations of the cooling part. When determining that devitrification occurs in the discharge lamp, the control part increases the degree of the number of rotations corresponding to the voltage between the electrodes in the control information.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a projector and a projector control method.

A projector that changes the number of rotations of a cooling fan that cools a discharge lamp is known. For example, Patent Document 1 describes a configuration in which the number of rotations of a cooling fan is changed in accordance with electric power supplied to a discharge lamp.

JP 2003-295320 A

In the discharge lamp (discharge lamp) as described above, devitrification that crystallizes and becomes cloudy may occur due to the inner wall of the discharge lamp becoming hot. When light from the discharge lamp is irradiated on the devitrified portion of the inner wall of the discharge lamp, the irradiated light is scattered and partly absorbed by the devitrified portion. Therefore, the temperature of the portion of the discharge lamp that has become devitrified rises. Thereby, in the discharge lamp after devitrification occurs, the temperature of the discharge lamp is likely to rise compared to before devitrification occurs, and the number of revolutions of the cooling fan (cooling unit) is set using the above method. Even if it is changed, the discharge lamp may not be cooled properly. Therefore, the life of the discharge lamp may not be sufficiently improved.

The present invention was made in view of the above problems, and even when devitrification occurs,
An object is to provide a projector capable of appropriately cooling a discharge lamp, and a control method for such a projector.

One aspect of the projector of the present invention includes a discharge lamp having a pair of electrodes and emitting light,
A cooling unit that cools the discharge lamp, a control unit that controls the cooling unit, a light modulation device that modulates light emitted from the discharge lamp according to image information, and light modulated by the light modulation device And the control unit controls the cooling unit based on control information indicating a relationship between the voltage between the electrodes of the discharge lamp and the number of rotations of the cooling unit, and the control unit Is characterized in that, when it is determined that devitrification has occurred in the discharge lamp, the degree of the rotational speed corresponding to the inter-electrode voltage in the control information is increased.

According to one aspect of the projector of the present invention, when the control unit determines that devitrification has occurred in the discharge lamp, the control unit increases the degree of rotation of the cooling unit corresponding to the inter-electrode voltage in the control information. Therefore, after devitrification occurs in the discharge lamp, the degree of cooling of the discharge lamp can be increased,
The discharge lamp can be suitably cooled. Therefore, according to one aspect of the projector of the present invention, it is possible to obtain a projector capable of appropriately cooling the discharge lamp even when devitrification occurs. Thereby, the lifetime of a discharge lamp can be improved.

The relationship between the voltage between the electrodes indicated by the control information and the number of rotations is indicated by a linear function, and when the control unit determines that devitrification has occurred in the discharge lamp, the voltage between the electrodes in the control information. It is good also as a structure which enlarges the ratio of the variation | change_quantity of the said rotation speed with respect to this variation | change_quantity.
According to this configuration, the number of revolutions of the cooling unit is preferably easily changed so that the change in the temperature of the discharge lamp caused by the change in the voltage between the electrodes after devitrification has occurred, and the temperature of the discharge lamp is preferably adjusted. It is easy to make a value. Therefore, the life of the discharge lamp can be further improved.

The controller may be configured to increase the ratio within a range smaller than three times when it is determined that devitrification has occurred in the discharge lamp.
According to this configuration, the discharge lamp can be more easily cooled after devitrification occurs, and the life of the discharge lamp can be further improved.

The controller may be configured to increase the rotational speed when it is determined that devitrification has occurred in the discharge lamp.
According to this configuration, immediately after devitrification occurs, the number of rotations of the cooling unit can be increased, and the degree of cooling of the discharge lamp can be improved. Thereby, a discharge lamp can be cooled more suitably.

The control unit may be configured to determine that devitrification has occurred in the discharge lamp when the cumulative lighting time of the discharge lamp becomes a predetermined value or more.
According to this configuration, the control unit can easily detect devitrification by using a predetermined value obtained experimentally in advance or by estimating the predetermined value. Therefore, when devitrification occurs in the discharge lamp, it is possible to suitably increase the degree of the rotational speed of the cooling unit corresponding to the interelectrode voltage in the control information.

One aspect of the projector control method of the present invention is a projector control method comprising a discharge lamp that has a pair of electrodes and emits light, and a cooling unit that cools the discharge lamp. When the cooling unit is controlled based on control information indicating the relationship between the voltage between the electrodes of the electric lamp and the number of revolutions of the cooling unit, and it is determined that devitrification has occurred in the discharge lamp, the voltage between the electrodes in the control information The degree of the rotational speed corresponding to is increased.

According to one aspect of the projector control method of the present invention, as described above,
Even when devitrification occurs, a projector control method capable of appropriately cooling the discharge lamp can be obtained.

It is a schematic block diagram of the projector of 1st Embodiment. It is a figure which shows the light source device of 1st Embodiment. It is a partial expanded sectional view of the discharge lamp of 1st Embodiment. It is a circuit diagram of the discharge lamp lighting device and control part of a 1st embodiment. It is a block diagram which shows the example of 1 structure of the control part of 1st Embodiment. It is a block diagram which shows the various components of the projector of 1st Embodiment. It is a graph which shows an example of change of the number of rotations of a cooling part to change of a lamp voltage in a 1st embodiment. It is a graph which shows an example of the change of the discharge lamp temperature in a discharge lamp with respect to the change of a lamp voltage. It is a flowchart which shows an example of the control procedure of the control part in 1st Embodiment. It is a graph which shows an example of the change of the lamp voltage with respect to the change of accumulation lighting time. It is a graph which shows an example of change of the number of rotations of a cooling part to change of a lamp voltage in a 2nd embodiment.

Hereinafter, a projector according to an embodiment of the invention will be described with reference to the drawings.
The scope of the present invention is not limited to the following embodiment, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, the actual structure may be different from the scale, number, or the like in each structure.

<First Embodiment>
FIG. 1 is a schematic configuration diagram of a projector 500 according to the present embodiment. As shown in FIG.
The projector 500 of this embodiment includes a light source device 200, a collimating lens 305, an illumination optical system 310, a color separation optical system 320, and three liquid crystal light valves (light modulation devices) 330.
R, 330G, 330B, cross dichroic prism 340, and projection optical device 35
0.

The light emitted from the light source device 200 passes through the collimating lens 305 and the illumination optical system 310.
Is incident on. The collimating lens 305 collimates the light from the light source device 200.

The illumination optical system 310 converts the illuminance of light emitted from the light source device 200 to the liquid crystal light valve 3.
It adjusts so that it may become uniform on 30R, 330G, 330B. Furthermore, the illumination optical system 310 aligns the polarization direction of the light emitted from the light source device 200 in one direction. The reason is,
This is because the light emitted from the light source device 200 is effectively used by the liquid crystal light valves 330R, 330G, and 330B.

The light whose illuminance distribution and polarization direction are adjusted enters the color separation optical system 320. The color separation optical system 320 separates incident light into three color lights of red light (R), green light (G), and blue light (B). The three color lights are liquid crystal light valves 330R, 330G, and 33 associated with the respective color lights.
By 0B, the signal is modulated according to the image signal (image information). That is, the liquid crystal light valves 330R, 330G, and 330B modulate light emitted from the discharge lamp 90 according to image information. The liquid crystal light valves 330R, 330G, and 330B are liquid crystal panels 5 described later.
60R, 560G, 560B and a polarizing plate (not shown). The polarizing plates are disposed on the light incident side and the light emitting side of the liquid crystal panels 560R, 560G, and 560B, respectively.

The three modulated color lights are combined by the cross dichroic prism 340. The combined light is incident on the projection optical device 350. The projection optical device 350 transmits incident light to the screen 70.
Projects to 0 (see FIG. 6). That is, the projection optical device 350 includes the liquid crystal light valve 330.
The light modulated by R, 330G, and 330B is projected. As a result, the screen 700
The video is displayed above. The collimating lens 305, the illumination optical system 310, and the color separation optical system 3
As the respective configurations of the 20, dichroic prism 340 and the projection optical device 350, known configurations can be employed.

The light source device 200 includes a light source unit 210, a discharge lamp lighting device 10, a control unit 40, and a cooling unit 50.
FIG. 2 is a diagram illustrating the light source device 200. FIG. 2 shows a cross-sectional view of the light source unit 210. In FIG. 2, illustration of the control unit 40 and the cooling unit 50 is omitted.

As illustrated in FIG. 2, the light source unit 210 includes a discharge lamp 90 and a reflecting mirror 112. The discharge lamp 90 emits light. The discharge lamp lighting device 10 supplies the drive current I to the discharge lamp 90 to light the discharge lamp 90. The reflecting mirror 112 reflects the light emitted from the discharge lamp 90 in the irradiation direction D. The irradiation direction D is parallel to the optical axis AX of the discharge lamp 90.

The discharge lamp 90 includes a discharge lamp main body 510, and a first electrode (electrode) 92 and a second electrode (electrode) 93 as a pair of electrodes. The shape of the discharge lamp main body 510 is a rod shape extending along the irradiation direction D. One end of the discharge lamp main body 510, that is, one end of the discharge lamp 90 is defined as a first end 90e1. The other end of the discharge lamp main body 510, that is, the other end of the discharge lamp 90 is defined as a second end 90e2. The discharge lamp main body 510 has a top portion 510a and a bottom portion 510.
b. The top portion 510 a is an end portion on the upper side in the vertical direction in the discharge lamp main body 510. The bottom 510b is the lower end of the discharge lamp main body 510 in the vertical direction.

The material of the discharge lamp main body 510 is a translucent material such as quartz glass, for example. Discharge lamp body 5
The central portion of 10 swells in a spherical shape, and the inside is a discharge space 91. The discharge space 91 is filled with a gas that is a discharge medium containing halogen, mercury, rare gas, metal halide compound, and the like. Halogen includes, for example, bromine Br.

In the discharge space 91, the tips of the first electrode 92 and the second electrode 93 protrude. The first electrode 92 is disposed on the first end portion 90 e 1 side of the discharge space 91. The second electrode 93 is disposed on the second end 90 e 2 side of the discharge space 91. The shape of the first electrode 92 and the second electrode 93 is a rod shape extending along the optical axis AX. In the discharge space 91, the electrode tip portions of the first electrode 92 and the second electrode 93 are arranged to face each other with a predetermined distance. First electrode 9
The material of the second and second electrodes 93 is, for example, a metal such as tungsten.

FIG. 3 is an enlarged cross-sectional view showing a portion of the discharge lamp 90.
As shown in FIG. 3, the first electrode 92 includes a core rod 533, a coil portion 532, and a main body portion 531.
And a protrusion 531p. The first electrode 92 is formed by winding a wire rod of an electrode material (tungsten or the like) around the core rod 533 to form a coil portion 532 and heating and melting the formed coil portion 532 before being sealed in the discharge lamp main body 510. It is formed by doing. This
A main body portion 531 having a large heat capacity is formed on the distal end side of the first electrode 92. The projection 531p is formed by melting and solidifying a part of the tip of the main body portion 531 by turning on the manufactured discharge lamp 90. The protrusion 531p is a position where the arc AR is generated.

The second electrode 93 includes a core rod 543, a coil portion 542, a main body portion 541, and a protrusion 541p. The second electrode 93 is formed in the same manner as the first electrode 92.
In addition, since the 1st electrode 92 and the 2nd electrode 93 are the same structures, in the following description, only the 1st electrode 92 may be demonstrated as a representative. Further, since the protrusion 531p at the tip of the first electrode 92 and the protrusion 541p at the tip of the second electrode 93 have the same configuration, only the protrusion 531p may be described as a representative in the following description.

As shown in FIG. 2, a first terminal 536 is provided at the first end 90 e 1 of the discharge lamp 90. The first terminal 536 and the first electrode 92 include a conductive member 53 that penetrates the inside of the discharge lamp 90.
4 is electrically connected. Similarly, a second terminal 546 is provided at the second end 90 e 2 of the discharge lamp 90. The second terminal 546 and the second electrode 93 are electrically connected by a conductive member 544 that penetrates the inside of the discharge lamp 90. The material of the first terminal 536 and the second terminal 546 is, for example, a metal such as tungsten. As a material of the conductive members 534 and 544, for example, a molybdenum foil is used.

The first terminal 536 and the second terminal 546 are connected to the discharge lamp lighting device 10. The discharge lamp lighting device 10 supplies driving power for driving the discharge lamp 90 to the first terminal 536 and the second terminal 546. As a result, arc discharge occurs between the first electrode 92 and the second electrode 93. Light (discharge light) generated by the arc discharge is radiated in all directions from the discharge position, as indicated by the dashed arrows.

As shown in FIG. 3, when the discharge lamp 90 is turned on, the gas sealed in the discharge space 91 is heated by the generation of the arc AR and convects in the discharge space 91. Specifically, Arc A
Since R and the region in the vicinity thereof are extremely hot, the arc AR is formed in the discharge space 91.
A convection AF (indicated by a one-dot chain line arrow in FIG. 3) that flows upward in the vertical direction is formed. The convection AF hits the inner wall of the discharge lamp main body 510, moves along the inner wall of the discharge lamp main body 510, and descends while being cooled by passing through the core rods 533, 543 and the like of the first electrode 92 and the second electrode 93.

The descending convection AF further descends along the inner wall of the discharge lamp main body 510, but the arc AR
Ascend so as to collide with each other on the lower side in the vertical direction and return to the upper arc AR. Convection AF
However, the discharge lamp main body 510 is heated by moving along the inner wall of the discharge lamp main body 510. Here, the convection AF has the highest temperature on the upper side in the vertical direction of the arc AR. Therefore, the top 51 of the discharge lamp main body 510 that contacts the convection AF on the upper side in the vertical direction of the arc AR.
0a is the hottest part that is the highest temperature in the discharge lamp main body 510 (discharge lamp 90). on the other hand,
Since the temperature of the convection AF is lower in the vertical direction in the discharge space 91, the temperature of the bottom 510b is lower than the temperature of the top 510a.

As shown in FIG. 2, the reflecting mirror 112 is fixed to the first end 9 of the discharge lamp 90 by a fixing member 114.
It is fixed at 0e1. The reflecting mirror 112 reflects light traveling toward the opposite side of the irradiation direction D in the discharge light toward the irradiation direction D. Reflecting surface of the reflecting mirror 112 (surface on the discharge lamp 90 side)
The shape of is not particularly limited as long as the discharge light can be reflected in the irradiation direction D,
For example, it may be a spheroidal shape or a rotating parabolic shape. For example, the reflecting mirror 11
When the shape of the reflecting surface 2 is a rotating parabolic shape, the reflecting mirror 112 can convert the discharge light into light substantially parallel to the optical axis AX. Thereby, the collimating lens 305 can be omitted.

The material of the fixing member 114 is not particularly limited as long as it is a heat resistant material that can withstand the heat generated from the discharge lamp 90, and is, for example, an inorganic adhesive.

FIG. 4 is a diagram illustrating an example of a circuit configuration of the discharge lamp lighting device 10 and the control unit 40.
As shown in FIG. 4, the discharge lamp lighting device 10 includes a power control circuit 20, a polarity inversion circuit 30, an operation detection unit 60, and an igniter circuit 70.

The power control circuit 20 generates driving power to be supplied to the discharge lamp 90. In the present embodiment, the power control circuit 20 includes a down chopper circuit that receives the voltage from the DC power supply device 80 as an input, steps down the input voltage, and outputs a DC current Id.

The power control circuit 20 includes a switch element 21, a diode 22, a coil 23, and a capacitor 24. The switch element 21 is composed of, for example, a transistor. In the present embodiment, one end of the switch element 21 is connected to the positive voltage side of the DC power supply device 80, and the other end is connected to the cathode terminal of the diode 22 and one end of the coil 23.

One end of a capacitor 24 is connected to the other end of the coil 23, and the other end of the capacitor 24 is connected to the anode terminal of the diode 22 and the negative voltage side of the DC power supply device 80. A current control signal is input from the control unit 40 to the control terminal of the switch element 21 to switch the switch element 2.
ON / OFF of 1 is controlled. Examples of the current control signal include PWM (Pulse Wi
dth Modulation) control signal may be used.

When the switch element 21 is turned on, a current flows through the coil 23 and energy is stored in the coil 23. Thereafter, when the switch element 21 is turned OFF, the energy stored in the coil 23 is released through a path passing through the capacitor 24 and the diode 22. As a result, a direct current Id corresponding to the proportion of time during which the switch element 21 is turned on is generated.

The polarity inversion circuit 30 inverts the polarity of the direct current Id input from the power control circuit 20 at a predetermined timing. As a result, the polarity inversion circuit 30 generates and outputs a drive current I that is a direct current that lasts for a controlled time, or a drive current I that is an alternating current having an arbitrary frequency. In the present embodiment, the polarity inverting circuit 30 is configured by an inverter bridge circuit (full bridge circuit).

The polarity inversion circuit 30 is, for example, a first switch element 3 constituted by a transistor or the like.
1, second switch element 32, third switch element 33, and fourth switch element 34
Is included. The polarity inversion circuit 30 includes a first switch element 31 and a second switch connected in series.
The switch element 32 and the third switch element 33 and the fourth switch element 34 connected in series are connected in parallel to each other. The polarity inversion control signal is input from the control unit 40 to the control terminals of the first switch element 31, the second switch element 32, the third switch element 33, and the fourth switch element 34, respectively. Based on this polarity inversion control signal, the ON / OFF operation of the first switch element 31, the second switch element 32, the third switch element 33, and the fourth switch element 34 is controlled.

In the polarity inverting circuit 30, the first switch element 31 and the fourth switch element 34.
Then, the operation of alternately turning on / off the second switch element 32 and the third switch element 33 is repeated. Thereby, the polarity of the direct current Id output from the power control circuit 20 is alternately inverted. The polarity inversion circuit 30 is controlled from the common connection point between the first switch element 31 and the second switch element 32 and the common connection point between the third switch element 33 and the fourth switch element 34. A drive current I that is a direct current that continues the same polarity state or a drive current I that is an alternating current having a controlled frequency is generated and output.

That is, the polarity inverting circuit 30 includes the first switch element 31 and the fourth switch element 3.
When 4 is ON, the second switch element 32 and the third switch element 33 are OFF, and when the first switch element 31 and the fourth switch element 34 are OFF, the second switch element 32 and the third switch element 32 Control is performed so that the switch element 33 is ON. Therefore, when the first switch element 31 and the fourth switch element 34 are ON, the drive current I flowing from the one end of the capacitor 24 in the order of the first switch element 31, the discharge lamp 90, and the fourth switch element 34 is generated. To do. Second switch element 32 and third switch element 33
Is ON, the third switch element 33, the discharge lamp 90,
A drive current I that flows in the order of the second switch element 32 is generated.

In the present embodiment, the combined portion of the power control circuit 20 and the polarity inversion circuit 30 corresponds to the discharge lamp driving unit 230. That is, the discharge lamp driving unit 230 supplies the driving current I for driving the discharge lamp 90 to the discharge lamp 90.

The operation detection unit 60 detects the lamp voltage (interelectrode voltage) Vla of the discharge lamp 90 and controls the control unit 4.
0 includes a voltage detector that outputs lamp voltage information. Further, the operation detection unit 60 is configured to drive the drive current I
And a current detection unit that outputs drive current information to the control unit 40. In the present embodiment, the operation detection unit 60 is configured to include a first resistor 61, a second resistor 62, and a third resistor 63.

In the present embodiment, the voltage detection unit of the operation detection unit 60 includes the lamp voltage Vl in parallel with the discharge lamp 90 by the voltage divided by the first resistor 61 and the second resistor 62 connected in series with each other.
a is detected. In the present embodiment, the current detection unit detects the drive current I based on the voltage generated in the third resistor 63 connected in series to the discharge lamp 90.

The igniter circuit 70 operates only when the discharge lamp 90 starts to be lit. The igniter circuit 70 is a high voltage (discharge) necessary for forming a discharge path by dielectric breakdown between the electrodes of the discharge lamp 90 (between the first electrode 92 and the second electrode 93) at the start of lighting of the discharge lamp 90. (A voltage higher than that during normal lighting of the lamp 90) is supplied between the electrodes of the discharge lamp 90 (between the first electrode 92 and the second electrode 93). In the present embodiment, the igniter circuit 70 is connected in parallel with the discharge lamp 90.

The control unit 40 controls various operations from the start of operation of the projector 500 to the stop of operation. The control unit 40 controls the discharge lamp driving unit 230 according to the driving current waveform of the driving current I. Further, the control unit 40 controls the cooling unit 50. In the example of FIG. 4, the control unit 40 controls the power control circuit 20 and the polarity inversion circuit 30 to set parameters such as a holding time for the drive current I to maintain the same polarity, a current value of the drive current I, and a frequency. Control. Control unit 4
0 represents the drive current I with respect to the polarity inversion circuit 30 according to the polarity inversion timing of the drive current I.
The polarity inversion control is performed to control the holding time, the frequency of the drive current I, and the like that continue with the same polarity.
The control unit 40 performs current control for controlling the current value of the output direct current Id on the power control circuit 20.

The configuration of the control unit 40 is not particularly limited. In the present embodiment, the control unit 40 includes a system controller 41, a power control circuit controller 42, and a polarity inversion circuit controller 43. Note that a part or all of the control unit 40 may be configured by a semiconductor integrated circuit.

The system controller 41 controls the power control circuit 20 and the polarity inversion circuit 30 by controlling the power control circuit controller 42 and the polarity inversion circuit controller 43. The system controller 41 detects the lamp voltage Vla detected by the operation detector 60.
Based on the driving current I, the power control circuit controller 42 and the polarity inversion circuit controller 43 may be controlled.

In the present embodiment, a storage unit 44 is connected to the system controller 41.
The system controller 41 may control the power control circuit 20 and the polarity inversion circuit 30 based on information stored in the storage unit 44. The storage unit 44 may store, for example, information related to drive parameters such as a holding time during which the drive current I continues with the same polarity, a current value of the drive current I, a frequency, a waveform, and a modulation pattern.

The power control circuit controller 42 controls the power control circuit 20 by outputting a current control signal to the power control circuit 20 based on the control signal from the system controller 41.

The polarity inversion circuit controller 43 controls the polarity inversion circuit 30 by outputting a polarity inversion control signal to the polarity inversion circuit 30 based on the control signal from the system controller 41.

The control unit 40 is realized using a dedicated circuit, and can perform the above-described control and various types of control of processing to be described later. On the other hand, for example, the control unit 40 can function as a computer by executing a control program stored in the storage unit 44 to perform various controls of these processes.

FIG. 5 is a diagram for explaining another configuration example of the control unit 40. As shown in FIG. 5, the control unit 40 includes a current control unit 40 that controls the power control circuit 20 according to a control program.
-1, it may be configured to function as polarity inversion control means 40-2 for controlling the polarity inversion circuit 30.

The cooling unit 50 cools the discharge lamp 90 of the light source unit 210. The cooling unit 50 is, for example,
It is composed of fans. The fan of the cooling unit 50 is composed of, for example, a sirocco fan. The fan of the cooling unit 50 sucks air inside and outside the housing of the projector 500,
Cooling air is blown to the light source unit 210. More specifically, the cooling unit 50 includes the discharge lamp main body 5.
The cooling air is blown to the ten top portions 510a to cool the top portions 510a.

Hereinafter, the circuit configuration of the projector 500 will be described.
FIG. 6 is a diagram illustrating an example of a circuit configuration of the projector 500 according to the present embodiment. In addition to the configuration shown in FIG. 1, the projector 500 includes an image signal converter 501, a DC power supply device 80, liquid crystal panels 560R, 560G, and 560B, and an image processing device 57, as shown in FIG.
0.

The image signal conversion unit 501 converts an image signal (image information) 502 (brightness-color difference signal, analog RGB signal, etc.) input from the outside into a digital RGB signal having a predetermined word length to generate an image signal (image information) 512R. , 512G, 512B are generated and supplied to the image processing apparatus 570.

The image processing device 570 performs image processing on each of the three image signals 512R, 512G, and 512B. The image processing device 570 receives drive signals 572R, 572G, and 572B for driving the liquid crystal panels 560R, 560G, and 560B, respectively.
Supplied to 560G and 560B.

The DC power supply device 80 converts an AC voltage supplied from an external AC power supply 600 into a constant DC voltage. The DC power supply device 80 includes an image signal conversion unit 501 on the secondary side of a transformer (not shown, but included in the DC power supply device 80), an image processing device 570, and a discharge lamp lighting device 10 on the primary side of the transformer. Supply DC voltage.

The discharge lamp lighting device 10 generates a high voltage between the electrodes of the discharge lamp 90 at the time of startup, and causes a dielectric breakdown to form a discharge path. Thereafter, the discharge lamp lighting device 10 supplies the drive current I for the discharge lamp 90 to maintain the discharge.

The liquid crystal panels 560R, 560G, and 560B include the liquid crystal light valves 330R and 3 described above.
30G and 330B are provided. Liquid crystal panel 560R, 560G, 560B
Modulates the transmittance (luminance) of color light incident on the liquid crystal panels 560R, 560G, and 560B via the optical system described above based on the drive signals 572R, 572G, and 572B, respectively.

Next, control of the cooling part 50 by the control part 40 of this embodiment is demonstrated. In the present embodiment, the control unit 40 controls the cooling unit 50 by PWM control. The control unit 40 modulates the duty ratio of the current pulse supplied to the cooling unit 50 and adjusts the rotational speed Rf of the cooling unit 50. The duty ratio of the current pulse supplied to the cooling unit 50 is the rotational speed R of the cooling unit 50.
It is proportional to f. That is, the rotational speed Rf of the cooling part 50 in the following description is set to the cooling part 5
It can also be replaced with the duty ratio of the current pulse supplied to zero.

FIG. 7 shows the rotation speed Rf of the cooling unit 50 with respect to the change in the lamp voltage Vla in the present embodiment.
It is a graph which shows an example of a change of. In FIG. 7, the vertical axis represents the rotation speed Rf of the cooling unit 50, and the horizontal axis represents the lamp voltage Vla. FIG. 8 is a graph showing an example of a change in the discharge lamp temperature Tm in the discharge lamp 90 with respect to the change in the lamp voltage Vla. In FIG.
The vertical axis represents the discharge lamp temperature Tm, and the horizontal axis represents the lamp voltage Vla. In the present embodiment, the discharge lamp temperature Tm is the temperature of the top 510a of the discharge lamp main body 510.

As shown in FIG. 7, the control unit 40 can execute the first cooling control C1, the second cooling control C2, and the third cooling control C3. In the example of FIG. 7, the first cooling control C1 is the lamp voltage Vl.
This is executed in the first voltage range P1 where a is equal to or less than the initial upper limit value VlaU. Second cooling control C2
Is executed in the second voltage range P2 where the lamp voltage Vla is larger than the initial upper limit value VlaU and smaller than the devitrification occurrence value VlaC. The third cooling control C3 is executed in a third voltage range P3 in which the lamp voltage Vla is equal to or greater than the devitrification occurrence value VlaC.

The initial upper limit value VlaU is an upper limit value of variation in the initial lamp voltage Vla0 of the discharge lamp 90. The initial lamp voltage Vla0 is determined by the manufacturing variation of the discharge lamp 90.
It varies from the initial lower limit value VlaL, which is the lower limit value of the variation of la0, to the initial upper limit value VlaU. As an example, when the target value of the initial lamp voltage Vla0 is 65V, the initial upper limit value VlaU is 75V, and the initial lower limit value VlaL is 60V.

The devitrification occurrence value VlaC is the lamp voltage Vla when devitrification starts to occur in the discharge lamp 90. The devitrification is a phenomenon in which the inner wall of the discharge lamp main body 510 of the discharge lamp 90 is crystallized and becomes clouded due to high heat. When the discharge lamp 90 is devitrified, the illuminance (light emission efficiency) of the discharge lamp 90 is reduced.
The devitrification occurrence value VlaC is larger than the initial upper limit value VlaU.

The first cooling control C1 is a control in which the rotation speed Rf of the cooling unit 50 does not depend on the lamp voltage Vla. That is, when performing the first cooling control C1, the control unit 40 controls the rotation speed Rf of the cooling unit 50 without being based on the lamp voltage Vla. In the present embodiment, the rotational speed Rf of the cooling unit 50 in the first cooling control C1 is constant. That is, the control unit 40 maintains the rotation speed Rf of the cooling unit 50 at a constant value in the first voltage range P1 in which the first cooling control C1 is performed.
In the example of FIG. 7, the rotational speed Rf of the cooling unit 50 is the specified rotational speed Rf in the first cooling control C1.
Maintained at 0. When the initial lamp voltage Vla0 is the target value, the specified rotation speed Rf0 is the rotation speed of the cooling unit 50 that can set the discharge lamp temperature Tm to a suitable value at the initial stage when the discharge lamp 90 is used. Rf.

The second cooling control C2 is a first that indicates the relationship between the lamp voltage Vla and the rotational speed Rf of the cooling unit 50.
It is control which controls the cooling unit 50 based on control information (control information) CI1. In the present embodiment, the relationship between the lamp voltage Vla indicated by the first control information CI1 and the rotation speed Rf of the cooling unit 50 is represented by a linear function. Cooling unit 5 for lamp voltage Vla in first control information CI1
The inclination of the rotational speed Rf of 0 is positive. That is, in the first control information CI1, it is set so that the rotation speed Rf of the cooling unit 50 increases along the linear line as the lamp voltage Vla increases.

When the lamp voltage Vla is smaller than the devitrification occurrence value VlaC, that is, the first control information CI1 is the lamp voltage Vla and the discharge lamp temperature for each rotation speed Rf of the cooling unit 50 in the first voltage range P1 and the second voltage range P2. It can be obtained experimentally by measuring the relationship with Tm. In FIG. 8, in the first voltage range P1 and the second voltage range P2, the change in the discharge lamp temperature Tm with respect to the change in the lamp voltage Vla when the rotation speed Rf of the cooling unit 50 is constant at the specified rotation speed Rf0. An example is shown. As shown in FIG. 8, in the first voltage range P1 and the second voltage range P2, the change in the discharge lamp temperature Tm with respect to the lamp voltage Vla is expressed by a linear function with a positive slope. That is, when the lamp voltage Vla rises for some reason in the first voltage range P1 and the second voltage range P2, the discharge lamp temperature Tm rises according to a linear line corresponding to the rotation speed Rf of the cooling unit 50.

In addition, it became clear by the present inventors that the relationship between the discharge lamp temperature Tm and the lamp voltage Vla in the first voltage range P1 and the second voltage range P2 is expressed by such a linear function. The slope and intercept of the linear function can be obtained experimentally for each discharge lamp.

By obtaining the rotation speed Rf for each lamp voltage Vla when the discharge lamp temperature Tm is set to a desired value from the relationship between the discharge lamp temperature Tm and the lamp voltage Vla for each rotation speed Rf of the cooling unit 50 as described above. First control information CI1 is obtained. In the present embodiment, the first rotation speed Rf is obtained for each lamp voltage Vla when the discharge lamp temperature Tm is maintained at a constant appropriate temperature Tm1.
Control information CI1 is obtained. As an example, from the graph of FIG. 8, when the lamp voltage Vla is the initial upper limit value VlaU, the discharge lamp temperature Tm can be set to the appropriate temperature Tm1 by setting the rotation speed Rf of the cooling unit 50 to the specified rotation speed Rf0. I understand.

Since the controller 40 performs the second cooling control C2 based on the first control information CI1 in the second voltage range P2, the controller 40 can maintain the discharge lamp temperature Tm at the appropriate temperature Tm1 in the second voltage range P2. As shown in FIG. 7, in the first control information CI1 of the present embodiment, the rotational speed Rf of the cooling unit 50 when the lamp voltage Vla is the initial upper limit value VlaU is the specified rotational speed Rf.
0. In the first control information CI1 of the present embodiment, the lamp voltage Vla is the devitrification occurrence value V.
The rotational speed Rf of the cooling unit 50 when laC is the rotational speed Rfa. First cooling control C1
The rotational speed Rf of the cooling unit 50 at the second rotational speed Rf of the cooling unit 50 in the second cooling control C2
It is as follows.

The third cooling control C3 is a second value indicating the relationship between the lamp voltage Vla and the rotational speed Rf of the cooling unit 50.
It is control which controls the cooling unit 50 based on control information (control information) CI2. In the present embodiment, the relationship between the lamp voltage Vla indicated by the second control information CI2 and the rotation speed Rf of the cooling unit 50 is represented by a linear function. Cooling unit 5 for lamp voltage Vla in second control information CI2
The inclination of the rotational speed Rf of 0 is positive. That is, in the second control information CI2, it is set so that the rotation speed Rf of the cooling unit 50 increases along the linear line as the lamp voltage Vla increases.

The degree of the rotation speed Rf of the cooling unit 50 corresponding to the lamp voltage Vla in the second control information CI2 is the rotation speed R of the cooling unit 50 corresponding to the lamp voltage Vla in the first control information CI1.
It is larger than the degree of f. In this specification, the “degree of the rotational speed of the cooling section corresponding to the lamp voltage” means the value of the rotational speed of the cooling section corresponding to the lamp voltage and the change in the rotational speed of the cooling section with respect to the amount of change in the lamp voltage. And a proportion of the amount.

In the present embodiment, the ratio of the change amount of the rotation speed Rf of the cooling unit 50 to the change amount of the lamp voltage Vla in the second control information CI2 is the rotation of the cooling unit 50 with respect to the change amount of the lamp voltage Vla in the first control information CI1. It is larger than the rate of change of the number Rf. In other words, the gradient of the change in the rotation speed Rf of the cooling unit 50 in the second control information CI2 shown in FIG. 7 is larger than the gradient of the change in the rotation speed Rf of the cooling unit 50 in the first control information CI1. Second control information C
The ratio of the change amount of the rotation speed Rf of the cooling unit 50 to the change amount of the lamp voltage Vla in I2 is, for example, the cooling unit 50 with respect to the change amount of the lamp voltage Vla in the first control information CI1.
Is greater than 1 times the rate of change in the rotation speed Rf, less than 3 times, and preferably less than 2 times. By setting it as such a numerical value range, it is easy to make control of the cooling unit 50 by the third cooling control C3 suitable.

In the second control information CI2 of the present embodiment, the rotation speed Rf of the cooling unit 50 when the lamp voltage Vla is the devitrification occurrence value VlaC is the rotation speed Rfa, similar to the first control information CI1. The rotational speed Rf of the cooling unit 50 in the second cooling control C2 is equal to or lower than the rotational speed Rf of the cooling unit 50 in the third cooling control C3.

The control unit 40 switches each cooling control based on the lamp voltage Vla and the cumulative lighting time tt.
FIG. 9 is a flowchart illustrating an example of a control procedure of the control unit 40 in the present embodiment. FIG. 10 is a graph showing an example of the change in the lamp voltage Vla with respect to the change in the cumulative lighting time tt. In FIG. 10, the vertical axis represents the lamp voltage Vla, and the horizontal axis represents the cumulative lighting time tt. The cumulative lighting time tt is the total time when the discharge lamp 90 is lit. That is, the cumulative lighting time tt is the accumulated discharge lamp 9 from when the discharge lamp 90 is lit for the first time.
It is 0 lighting time.

As shown in FIG. 9, the control unit 40 starts lighting the discharge lamp 90 (step S1).
It is determined whether or not the lamp voltage Vla is larger than the initial upper limit value VlaU (step S2).
. When the lamp voltage Vla is equal to or lower than the initial upper limit value VlaU (step S2: NO), the control unit 4
0 executes the first cooling control C1 (step S3). On the other hand, when the lamp voltage Vla is larger than the initial upper limit value VlaU (step S2: YES), the control unit 40 executes the second cooling control C2 (step S4). That is, when the lamp voltage Vla is larger than the initial upper limit value VlaU, the control unit 40 switches from the first cooling control C1 to the second cooling control C2.

The controller 40 determines whether or not the cumulative lighting time tt is equal to or longer than the devitrification occurrence time (predetermined value) tt4 while executing the first cooling control C1 or the second cooling control C2 (step S5). The devitrification occurrence time tt4 is a cumulative lighting time tt at which devitrification starts to occur in the discharge lamp 90. The devitrification occurrence time tt4 is obtained experimentally, for example, and is stored in the storage unit 44 in advance. The devitrification occurrence time tt4 can also be estimated from the integral value of the discharge lamp temperature Tm. In this case, the controller 40 may estimate the devitrification occurrence time tt4 from the change in the discharge lamp temperature Tm while performing the first cooling control C1 or the second cooling control C2.

When the cumulative lighting time tt is shorter than the devitrification occurrence time tt4 (step S5: NO), the control unit 40 determines that the discharge lamp 90 is not devitrified, and the lamp voltage Vla is higher than the initial upper limit value VlaU. While determining whether it is large (step S2), the first cooling control C1 or the second cooling control C2 is executed (steps S3 and S4). On the other hand, when the cumulative lighting time tt is equal to or longer than the devitrification occurrence time tt4 (step S5: YES), the control unit 40 determines that devitrification has occurred in the discharge lamp 90, and executes the third cooling control C3 (step S6). ). That is, when the controller 40 determines that devitrification has occurred in the discharge lamp 90, the first cooling control C1 or the second cooling control C2 is used.
To the third cooling control C3. Thereafter, the control unit 40 continues to execute the third cooling control C3.

As shown in FIG. 10, for example, the lamp voltage Vla gradually decreases at an initial stage where the cumulative lighting time tt is relatively small. This is because, in the initial stage, the protrusion 531p tends to extend, and the distance between the first electrode 92 and the second electrode 93 tends to be small. FIG.
In the example of 0, the initial lamp voltage Vla0 is a value between the initial lower limit value VlaL and the initial upper limit value VlaU, and the lamp voltage Vla decreases until the cumulative lighting time tt reaches the value tt1. When the cumulative lighting time tt reaches the value tt1, the lamp voltage Vla is smaller than the initial lamp voltage Vla0 and larger than the initial lower limit value VlaL.

Thereafter, the lamp voltage Vla is maintained at or near the lowered value.
Then, when the cumulative lighting time tt becomes relatively large, the lamp voltage Vla starts to gradually increase. In the example of FIG. 10, when the cumulative lighting time tt becomes equal to or greater than the value tt2 that is greater than the value tt1, the lamp voltage Vla starts to increase. After the lamp voltage Vla starts to rise, when the cumulative lighting time tt becomes the switching time (first time) tt3 that is larger than the value tt2, the lamp voltage Vl
a is the initial upper limit value VlaU. Thereafter, the lamp voltage Vla continues to rise as the cumulative lighting time tt increases.

In the example of FIG. 10, the range in which the cumulative lighting time tt is equal to or shorter than the switching time tt3 is the lamp voltage Vla.
Is the first voltage range P1 that is equal to or lower than the initial upper limit value VlaU. The cumulative lighting time tt is the switching time tt
A range larger than 3 and smaller than the devitrification occurrence time tt4 is a second voltage range P2 in which the lamp voltage Vla is larger than the initial upper limit value VlaU and smaller than the devitrification occurrence value VlaC. When the cumulative lighting time tt is equal to or greater than the devitrification occurrence time tt4, the lamp voltage Vla is the devitrification occurrence value VlaC.
This is the third voltage range P3.

In the present embodiment, for example, since the lamp voltage Vla changes as described above, when the cumulative lighting time tt is equal to or shorter than the switching time tt3, the control unit 40 executes the first cooling control C1. When the lamp voltage Vla is larger than the initial upper limit value VlaU, that is, when the cumulative lighting time tt is larger than the switching time tt3, the control unit 40 performs the second cooling control C1 to the second cooling control C1.
Switch to cooling control C2. Thereafter, since the lamp voltage Vla continues to rise, the control unit 40
Continues to execute the second cooling control C2 until the accumulated lighting time tt becomes the devitrification occurrence time tt4. When the accumulated lighting time tt is equal to or longer than the devitrification occurrence time tt4, the control unit 40
The cooling control C2 is switched to the third cooling control C3.

As described above, the control unit 40 controls the cooling unit 50 by switching from the first cooling control C1 to the third cooling control C3.

The control of the control unit 40 described above can also be expressed as a projector control method. That is, the control method of the projector 500 of the present embodiment includes the discharge lamp 90 that has a pair of first electrode 92 and second electrode 93 and emits light, and the cooling unit 50 that cools the discharge lamp 90. A method of controlling the projector 500, which includes the lamp voltage Vla of the discharge lamp 90 and the cooling unit 5
Control information (first control information CI1 and second control information CI2) indicating the relationship with the rotational speed Rf of 0
), The cooling unit 50 is controlled, and when it is determined that devitrification has occurred in the discharge lamp 90, the degree of the rotational speed Rf of the cooling unit 50 corresponding to the lamp voltage Vla in the control information is increased. .

For example, when light emitted from the arc AR is irradiated on the devitrified portion of the discharge lamp main body 510, the irradiated light is scattered and part of the light is absorbed by the devitrified discharge lamp main body 510. The Therefore, the illuminance of the discharge lamp 90 decreases, and the temperature of the portion of the discharge lamp main body 510 that has become devitrified increases due to the light emitted from the arc AR. As a result, in the discharge lamp 90 after devitrification occurs, the discharge lamp temperature Tm changes by adding the temperature increase due to the increase in the lamp voltage Vla and the temperature increase due to devitrification. Therefore, in the second cooling control C2 using the first control information CI1 based on the change in the discharge lamp temperature Tm with respect to the lamp voltage Vla in the first voltage range P1 and the second voltage range P2, the discharge lamp 90 cannot be suitably cooled. There is.

On the other hand, according to the present embodiment, when the control unit 40 determines that devitrification has occurred in the discharge lamp 90, the degree of the rotation speed Rf of the cooling unit 50 corresponding to the lamp voltage Vla is the first control information. Third cooling control C for controlling the cooling unit 50 based on the second control information CI2 larger than CI1.
Switch to 3. In other words, when the control unit 40 determines that devitrification has occurred in the discharge lamp 90, the control unit 40 increases the degree of the rotation speed Rf of the cooling unit 50 corresponding to the lamp voltage Vla in the control information. Therefore, after devitrification occurs in the discharge lamp 90, the degree of cooling of the discharge lamp 90 can be increased, and the discharge lamp 90 can be suitably cooled. Therefore, according to this embodiment, even when devitrification occurs, the projector 5 that can cool the discharge lamp 90 appropriately.
00 is obtained. Thereby, the lifetime of the discharge lamp 90 can be improved.

For example, after devitrification occurs, the degree of devitrification increases as the discharge lamp 90 deteriorates, that is, the lamp voltage Vla increases. Therefore, the lamp voltage V is higher than before devitrification occurs.
The amount of change in the discharge lamp temperature Tm increases with respect to the amount of change in la. The change in the discharge lamp temperature Tm with respect to the lamp voltage Vla after devitrification (the third voltage range P3) is, for example, FIG.
As shown in FIG. 3, it is considered that the linear function has a larger slope than the change in the discharge lamp temperature Tm with respect to the lamp voltage Vla before devitrification occurs (the first voltage range P1 and the second voltage range P2).

On the other hand, according to the present embodiment, the relationship between the lamp voltage Vla indicated by the second control information CI2 and the rotation speed Rf of the cooling unit 50 is expressed by a linear function, and the lamp voltage Vla in the second control information CI2 is shown. The ratio of the amount of change in the rotational speed Rf of the cooling unit 50 to the amount of change in is greater than the ratio of the amount of change in the rotational speed Rf of the cooling unit 50 to the amount of change in the lamp voltage Vla in the first control information CI1. In other words, when it is determined that devitrification has occurred in the discharge lamp 90, the control unit 40 increases the ratio of the amount of change in the rotation speed Rf of the cooling unit 50 to the amount of change in the lamp voltage Vla in the control information. As a result, the rotation speed Rf of the cooling unit 50 is preferably easily changed so that the change in the discharge lamp temperature Tm caused by the change in the lamp voltage Vla after devitrification has occurred, and the discharge lamp temperature Tm is suitably set. Easy to value. Therefore, the life of the discharge lamp 90 can be further improved.

Further, according to the present embodiment, the ratio of the change amount of the rotation speed Rf of the cooling unit 50 to the change amount of the lamp voltage Vla in the second control information CI2 is the cooling with respect to the change amount of the lamp voltage Vla in the first control information CI1. Greater than one time the rate of change of the rotational speed Rf of the section 50;
Less than 3 times. In other words, when the control unit 40 determines that devitrification has occurred in the discharge lamp 90, the ratio of the change amount of the rotation speed Rf of the cooling unit 50 to the change amount of the lamp voltage Vla in the control information is a range smaller than three times. Increase in size. Thereby, it is easy to make cooling of the discharge lamp 90 after devitrification occur more suitable, and the life of the discharge lamp 90 can be further improved.

Further, according to the present embodiment, the controller 40 determines that the accumulated lighting time tt is the devitrification occurrence time tt4 (
When it is equal to or greater than (predetermined value), it is determined that devitrification has occurred in the discharge lamp 90. For this reason, the controller 40 can easily detect devitrification by using the devitrification occurrence time tt4 obtained experimentally in advance or by estimating the devitrification occurrence time tt4 as described above. Therefore, when devitrification occurs in the discharge lamp 90, the cooling control can be suitably switched to the third cooling control C3.

Further, for example, consider controlling the cooling unit 50 only by the second cooling control C2 and the third cooling control C3 described above. In this case, immediately after starting to use the discharge lamp 90, the lamp voltage Vl.
The rotational speed Rf of the cooling unit 50 changes according to a. In this case, for example, when the initial lamp voltage Vla0 is the initial upper limit value VlaU, the rotation speed Rf of the cooling unit 50 becomes larger than when the initial lamp voltage Vla0 is the target value. Here, the discharge lamp 90 in the initial stage
Since blackening is likely to occur, blackening may be more likely to occur when the rotational speed Rf of the cooling unit 50 is increased in the initial stage. When blackening occurs, the temperature of the blackened part rises and devitrification tends to occur. Therefore, in the above case, devitrification occurs in the initial stage,
The life of the discharge lamp 90 may be reduced.

On the other hand, according to the present embodiment, the control unit 40 determines that the lamp voltage Vla is equal to the initial upper limit value V.
When it is larger than laU, the first cooling control C1 is switched to the second cooling control C2. That is, when the lamp voltage Vla is equal to or lower than the initial upper limit value VlaU, the control unit 40 does not depend on the lamp voltage Vla and the rotation speed R is equal to or lower than the rotation speed Rf of the cooling section 50 in the second cooling control C2.
The first cooling control C1 that is f is executed. Therefore, the rotation speed Rf of the cooling unit 50 in the initial stage can be controlled regardless of variations in the initial lamp voltage Vla0, and the rotation speed Rf of the cooling unit 50
Can be suppressed. Thereby, it can suppress that blackening arises and devitrification arises in the discharge lamp 90 in an initial stage.

On the other hand, when the discharge lamp 90 is turned on to some extent and the cumulative lighting time tt is increased to some extent,
Blackening is less likely to occur. When the discharge lamp 90 is in such a state, it is preferable to perform the second cooling control C2 that changes the rotational speed Rf of the cooling unit 50 according to the lamp voltage Vla. This is because by maintaining the discharge lamp temperature Tm at the appropriate temperature Tm1, it is possible to suppress an increase in the integrated value of the discharge lamp temperature Tm and to increase the devitrification occurrence time tt4 until devitrification occurs.

On the other hand, in the present embodiment, when the lamp voltage Vla is larger than the initial upper limit value VlaU, the first cooling control C1 is switched to the second cooling control C2, so that the accumulated lighting time tt has passed to some extent. The control of the cooling unit 50 can be preferably switched. Therefore, the discharge lamp 90 can be suitably cooled when the lamp voltage Vla is larger than the initial upper limit value VlaU.

As described above, according to the present embodiment, it is possible to obtain the projector 500 that can cool the discharge lamp 90 appropriately regardless of the manufacturing variation of the discharge lamp 90. Thereby, the lifetime of the discharge lamp 90 can be further improved.

As described above, in the initial stage of the discharge lamp 90, the protrusion 531p tends to extend, and the lamp voltage Vla decreases. Therefore, for example, even when the initial lamp voltage Vla0 is the initial upper limit value VlaU, it is possible to suppress the lamp voltage Vla from immediately exceeding the initial upper limit value VlaU in the initial stage. Thereby, the first cooling control C1 can be suitably executed in the initial stage.

For example, in the case where the cooling unit 50 is controlled only by the second cooling control C2 described above,
When the initial lamp voltage Vla0 is relatively large, the rotational speed Rf of the cooling unit 50 is relatively large. For this reason, there is a problem that noise generated by the cooling unit 50 increases immediately after the projector 500 starts to be used.

On the other hand, according to the present embodiment, it is possible to suppress an increase in the rotational speed Rf of the cooling unit 50 in the initial stage regardless of variations in the initial lamp voltage Vla0. Therefore, it is possible to suppress an increase in noise generated by the cooling unit 50 immediately after starting to use the projector 500.

Further, according to the present embodiment, the control unit 40 sets the rotation speed Rf of the cooling unit 50 to a constant value in the first cooling control C1. Therefore, in the initial stage of the discharge lamp 90, it is easy to maintain the rotation speed Rf of the cooling unit 50 at a value at which blackening hardly occurs.

Further, according to the present embodiment, the lamp voltage Vla and the rotation speed Rf indicated by the first control information CI1.
The relationship is expressed by a linear function. Therefore, based on the first control information CI1, the cooling unit 50
By controlling the rotation speed Rf, the discharge lamp temperature Tm that changes in a linear function with respect to the lamp voltage Vla can be maintained at a constant value. Thereby, the discharge lamp temperature Tm can be maintained at the appropriate temperature Tm1 by the second cooling control C2, and the life of the discharge lamp 90 can be further improved.

Second Embodiment
The second embodiment differs from the first embodiment in how the rotation speed Rf of the cooling unit 50 changes with respect to the lamp voltage Vla. FIG. 11 is a graph illustrating an example of a change in the rotational speed Rf of the cooling unit 50 with respect to a change in the lamp voltage Vla in the present embodiment. In FIG. 11, the vertical axis indicates the rotation speed Rf of the cooling unit 50, and the horizontal axis indicates the lamp voltage Vla. In addition,
About the structure similar to the said embodiment, description may be abbreviate | omitted by attaching | subjecting the same code | symbol suitably.

The rotation speed Rf of the cooling unit 50 in the first cooling control C1a of the present embodiment is the second cooling control C1.
2, the rotation speed Rf of the cooling unit 50 when the lamp voltage Vla is the initial upper limit value VlaU.
Smaller than. In the present embodiment, the rotation speed Rf of the cooling unit 50 in the first cooling control C1a.
Is constant at a low rotational speed Rfb smaller than the specified rotational speed Rf0.

In the first cooling control C1a, since the rotation speed Rf of the cooling unit 50 is the low rotation speed Rfb, the discharge lamp temperature Tm is higher than the appropriate temperature Tm1. The low rotational speed Rfb is the discharge lamp temperature T
It is preferable to set m to be a value within + 30 ° C. with respect to the appropriate temperature Tm1 in the first voltage range P1. Thereby, it can suppress that the devitrification generation | occurrence | production time tt4 until devitrification arises becomes short.

The third cooling control C3a of the present embodiment controls the cooling unit 50 based on the second control information CI2a. In the second control information CI2a, the rotation speed Rf of the cooling unit 50 when the lamp voltage Vla is the devitrification occurrence value VlaC is the cooling unit when the lamp voltage Vla in the first control information CI1 is the devitrification occurrence value VlaC. The high rotational speed Rfc is higher than the rotational speed Rfa of 50.

The degree of the rotation speed Rf of the cooling unit 50 corresponding to the lamp voltage Vla in the second control information CI2a of the present embodiment is the rotation speed of the cooling unit 50 corresponding to the lamp voltage Vla in the second control information CI2 of the first embodiment. It is larger than the degree of Rf. Second control information CI of this embodiment
The gradient of the rotational speed Rf of the cooling unit 50 with respect to the lamp voltage Vla at 2a is, for example, the first
The rotation speed R of the cooling unit 50 with respect to the lamp voltage Vla in the second control information CI2 of the embodiment.
It is the same as the inclination of f.

In the present embodiment, the control unit 40 increases the rotation speed Rf of the cooling unit 50 when the lamp voltage Vla becomes larger than the initial upper limit value VlaU. Specifically, the control unit 40 increases the rotational speed Rf of the cooling unit 50 from the low rotational speed Rfb to the specified rotational speed Rf0. Further, when determining that the discharge lamp 90 has been devitrified, the control unit 40 increases the rotational speed Rf of the cooling unit 50. Specifically, the control unit 40 increases the rotational speed Rf of the cooling unit 50 from the rotational speed Rfa to the high rotational speed Rfc when the accumulated lighting time tt becomes the devitrification occurrence time tt4. Other configurations and methods of the present embodiment are the same as those of the first embodiment.

According to the present embodiment, when the control unit 40 determines that devitrification has occurred in the discharge lamp 90, the control unit 40 increases the rotational speed Rf of the cooling unit 50. Therefore, immediately after the devitrification occurs, the rotation speed Rf of the cooling unit 50 can be increased to improve the cooling degree of the discharge lamp 90. Thereby, the discharge lamp 90 can be cooled more suitably.

Further, for example, when the initial lamp voltage Vla0 is smaller than the target value due to manufacturing variations of the discharge lamp 90, if the rotation speed Rf of the cooling unit 50 is set to the specified rotation speed Rf0 in the first cooling control, the cooling degree of the discharge lamp 90 is increased. It may become large and blackening is likely to occur.

On the other hand, according to the present embodiment, the rotation speed Rf of the cooling unit 50 in the first cooling control C1a is the rotation of the cooling unit 50 when the lamp voltage Vla is the initial upper limit value VlaU in the second cooling control C2. It is smaller than the number Rf. Therefore, in the initial stage of the discharge lamp 90, the rotation speed Rf of the cooling unit 50 can be further reduced, and blackening occurs even when the initial lamp voltage Vla0 is smaller than the target value due to manufacturing variations of the discharge lamp 90. Can be suppressed. Furthermore, noise generated by the cooling unit 50 can be further suppressed.

In each of the above embodiments, the following configurations and methods may be employed.
In each of the above embodiments, the switching between the first cooling control C1, C1a and the second cooling control C2 is as follows:
Although it performed based on the lamp voltage Vla, it is not restricted to this. The controller 40 may switch between the first cooling control C1 and C1a and the second cooling control C2 based on the cumulative lighting time tt. In this case, for example, when the cumulative lighting time tt of the discharge lamp 90 is longer than the switching time tt3, the control unit 40 may switch from the first cooling control C1, C1a to the second cooling control C2. That is, when the lamp voltage Vla is greater than the initial upper limit value VlaU, or when the cumulative lighting time tt of the discharge lamp 90 is greater than the switching time tt3 (first time), the control unit 40
The cooling control C1 is switched to the second cooling control C2. The same applies to the projector control method.

Further, when switching between the first cooling control C1, C1a and the second cooling control C2 based on the cumulative lighting time tt, the rotational speed Rf of the cooling unit 50 in the first cooling control C1a of the second embodiment described above is In the 2 cooling control C2, the rotation speed Rf is smaller than the cumulative lighting time tt that is the switching time tt3. That is, the cooling unit 5 in the first cooling control C1a of the second embodiment.
The rotational speed Rf of 0 is smaller than the rotational speed Rf of the cooling unit 50 when the lamp voltage Vla is the initial upper limit value VlaU in the second cooling control C2, or the cumulative lighting time tt is switched in the second cooling control C2. The rotational speed Rf is smaller than that at time tt3.

In the example of the first embodiment described above, after switching from the first cooling control C1 to the second cooling control C2, the process proceeds to the third cooling control C3 without returning to the first cooling control C1. Not limited to. For example, when the lamp voltage Vla becomes larger than the initial upper limit value VlaU and then becomes equal to or lower than the initial upper limit value VlaU, the control unit 40 switches from the second cooling control C2 to the first cooling control C1. Note that, as described above, the control unit 40 performs the cumulative lighting time tt.
When switching between the first cooling control C1, C1a and the second cooling control C2 based on the
There is no return from the cooling control C2 to the first cooling control C1.

Further, the first cooling control C1, C1a may be control for changing the rotation speed Rf of the cooling unit 50 instead of being constant. However, even in this case, the first cooling control C1, C1a does not depend on the lamp voltage Vla. Further, the relationship between the lamp voltage Vla indicated by the first control information CI1 and the rotation speed Rf of the cooling unit 50 may be expressed by a function other than a linear function. For example, the relationship between the lamp voltage Vla indicated by the first control information CI1 and the rotation speed Rf of the cooling unit 50 is expressed by the lamp voltage Vla.
The relationship may be such that the rotational speed Rf of the cooling unit 50 changes step by step with respect to the change of. The same applies to the second control information CI2 and CI2a.

Further, in each of the embodiments described above, the control unit 40 determines whether devitrification has occurred based on the cumulative lighting time tt, but is not limited thereto. How to determine if devitrification has occurred
There is no particular limitation. For example, the control unit 40 may determine whether or not devitrification has occurred based on a change in the lamp voltage Vla, a change in the protrusion 531p, a change in light emitted from the discharge lamp 90, and the like.

Further, the control unit 40 may be configured not to execute the first cooling control C1 and C1a. In this case, the control unit 40 performs the cooling control based on whether or not devitrification has occurred, the second cooling control C2.
And the third cooling control C3, C3a.

In the above embodiment, the change in the discharge lamp temperature Tm after devitrification occurs is the lamp voltage V
Although an example in which a linear function changes with respect to la is shown, the present invention is not limited to this. The change in the discharge lamp temperature Tm after devitrification occurs is not particularly limited.

In each of the above-described embodiments, an example in which the present invention is applied to a transmissive projector has been described. However, the present invention can also be applied to a reflective projector. Here, the “transmission type” means that a liquid crystal light valve including a liquid crystal panel or the like is a type that transmits light. “Reflective type” means that the liquid crystal light valve reflects light. The light modulation device is not limited to a liquid crystal panel or the like, and may be a light modulation device using a micromirror, for example.

In each of the above embodiments, the three liquid crystal panels 560R, 560G, and 560B (
Although an example of the projector 500 using the liquid crystal light valves 330R, 330G, and 330B) has been described, the present invention can be applied to a projector using only one liquid crystal panel and a projector using four or more liquid crystal panels. is there.

Moreover, each structure demonstrated above can be suitably combined in the range which is not mutually contradictory.

The usefulness of the present embodiment was confirmed by comparing Example 1 with Comparative Example 1. The discharge lamp used in each example was a mercury lamp rated at 200W. In the first embodiment, the control of the cooling unit is switched between the second cooling control and the third cooling control. Comparative example 1 is a comparative example in which only the second cooling control is executed.

The relationship between the lamp voltage Vla indicated by the control information of the second cooling control and the third cooling control in each example and the rotation speed Rf of the cooling unit is a linear function. The ratio of the change amount of the rotation speed Rf of the cooling unit to the change amount of the lamp voltage Vla in the second control information is the lamp voltage V in the first control information.
The ratio of the amount of change in the number of rotations Rf of the cooling unit to the amount of change in la was twice.

In the first embodiment, devitrification is determined based on the cumulative lighting time tt, and the second cooling control is switched to the third cooling control. The devitrification occurrence time tt4 is 2000 h (hours). Example 1 and Comparative Example 1 were turned on, and the life and devitrification area of the discharge lamp were measured. The devitrification area was measured when the cumulative lighting time tt was 6000 h (hours). The results are shown in Table 1.

In Table 1, “◯” for each cooling control indicates that the cooling control is executed, and “×”.
Indicates that the cooling control is not executed. Moreover, the life [h (hour)] of the discharge lamp is
The cumulative lighting time tt until the illuminance maintenance rate of the discharge lamp becomes 50% or less. Further, the devitrification area is shown as a reduction rate [%] when Comparative Example 1 is used as a reference. In other words, the devitrification area reduction rate refers to how much the devitrification area in the discharge lamp in Example 1 is based on the devitrification area of the discharge lamp in Comparative Example 1 when the cumulative lighting time tt is 6000 h. Indicates whether it is decreasing. From Table 1, it was confirmed that in Example 1, the life of the discharge lamp was longer and the devitrification area was smaller than in Comparative Example 1. Thus, it was confirmed that the life of the discharge lamp can be improved by combining the second cooling control and the third cooling control.

40 ... Control unit, 50 ... Cooling unit, 90 ... Discharge lamp, 92 ... First electrode (electrode), 93 ... Second electrode (electrode), 330R, 330G, 330B ... Liquid crystal light valve (light modulation device), 350
... projection optical device, 500 ... projector, 502, 512R, 512G, 512B ... image signal (image information), CI1 ... first control information (control information), CI2 ... second control information (control information), Rf ... rotational speed , Tt ... cumulative lighting time, tt4 ... devitrification occurrence time (predetermined value), Vla
... Ramp voltage (interelectrode voltage)

Claims (6)

A discharge lamp having a pair of electrodes and emitting light;
A cooling section for cooling the discharge lamp;
A control unit for controlling the cooling unit;
A light modulation device that modulates light emitted from the discharge lamp according to image information;
A projection optical device for projecting light modulated by the light modulation device;
With
The control unit controls the cooling unit based on control information indicating a relationship between the voltage between the electrodes of the discharge lamp and the rotation number of the cooling unit,
When the controller determines that devitrification has occurred in the discharge lamp, the control unit increases the degree of the rotation speed corresponding to the voltage between the electrodes in the control information. The relationship between the voltage between the electrodes indicated by the control information and the rotation speed is represented by a linear function,
2. The projector according to claim 1, wherein when the controller determines that devitrification has occurred in the discharge lamp, the control unit increases a ratio of a change amount of the rotation speed to a change amount of the interelectrode voltage in the control information. The projector according to claim 2, wherein when the controller determines that devitrification has occurred in the discharge lamp, the ratio is increased within a range smaller than three times. When the controller determines that devitrification has occurred in the discharge lamp, the controller increases the rotational speed.
The projector according to any one of claims 1 to 3. The projector according to any one of claims 1 to 4, wherein the control unit determines that devitrification has occurred in the discharge lamp when the cumulative lighting time of the discharge lamp becomes equal to or greater than a predetermined value. A control method of a projector comprising a discharge lamp having a pair of electrodes and emitting light, and a cooling unit for cooling the discharge lamp,
Controlling the cooling unit based on control information indicating the relationship between the voltage between the electrodes of the discharge lamp and the rotation number of the cooling unit;
When it is determined that devitrification has occurred in the discharge lamp, the degree of the number of rotations corresponding to the voltage between the electrodes in the control information is increased.

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