JP2000131763A - Projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the temperature of a lamp being turned on to an optimum temperature without depending on an atmospheric temperature and to efficiently project a bright picture by controlling the extent of the cooling performed by a cooling means which cools the air in the vicinity of an illuminating means in accordance with the detection result of the atmospheric temperature. SOLUTION: A heater 67, a Peltier element 66, which is a second cooling means, and a lamp temperature detecting sensor 64 are directly connected to a lamp 1. A control section 50 controls the element 66 and a heater 67 based on the detection result of the temperature of the lamp 1 being transmitted from a sensor 64. Moreover, the section 50 controls a fan 60, which is a first cooling means, based on the detection result of the atmospheric temperature transmitted from an atmospheric temperature detecting device 62. The fan 60 is arranged in the vicinity of a lamp unit and cools the atmosphere in the vicinity of the unit. By cooling the air in the vicinity of the lamp, the rising temperature of the lamp is indirectly reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector for illuminating a display means with illumination means comprising a lamp and a reflector to generate a projection image.

[0002]

2. Description of the Related Art In a space discharge type lamp used for a projector or the like, the lamp may be turned on unless the temperature of the lamp at the time of applying a voltage is lower than a predetermined temperature (hereinafter referred to as a relightable temperature). Can not. Therefore, after the lamp is turned off, it cannot be turned on again until the lamp is cooled to the relightable temperature. In the projector, an image can be observed with lighting of the lamp.

[0003] In a conventional projector, there is disclosed a projector that controls to increase the air cooling level in order to reduce the time required for the lamp to cool down to a relightable temperature after the lamp is turned off. Air cooling is generally performed by a fan. This fan is provided to cool the air around the lamp and indirectly cool the lamp so as not to overheat the lamp when the lamp emits light.

[0004]

However, although the air-cooling level increases, the time required to reach the relightable temperature has not been sufficiently reduced. In particular,
Recently, lamps have been developed, and various types of lamps have been disclosed. Some types of lamps are difficult to cool. When such a lamp is used, the time required to reach the relightable temperature becomes longer.

[0005] There is an optimum temperature for the light emission of the lamp. When the lamp is at the optimum temperature, the brightness of the light emission becomes the highest when the applied voltage is constant (the maximum brightness is reached). As the temperature deviates from the optimum temperature, the deviation of the brightness from the maximum brightness increases, and the luminous efficiency decreases.

Conventionally, in a projector having a fan, control for cooling a lamp during light emission has been performed.
The optimum temperature was not taken into account.

Further, in a conventional projector,
The time required from application of voltage to the lamp to lighting was long. This is because the lamp has a light emission temperature, and the lamp emits light only when the voltage reaches the light emission temperature after a voltage is applied, so that it takes a certain amount of time to emit light. In particular, when the temperature of the atmosphere was low, it was difficult to reach the emission temperature and it was difficult to light.

According to the present invention, regardless of the temperature of the atmosphere, the time required for actually projecting or reprojecting an image after an instruction to project an image is reduced, and the optimum temperature of light emission of the lamp is taken into consideration. It is intended to provide a projector which projects a bright image with high efficiency.

[0009]

In order to achieve the above object, the present invention comprises a display means for spatially modulating illumination light based on a video signal to form an optical image for projection, a lamp and a reflector. An illumination unit that generates the illumination light; and a projector having a projection optical system that projects the optical image on a projection screen, wherein a cooling unit that cools air around the illumination unit, and a detection unit that detects an atmospheric temperature. And control means for controlling the degree of cooling by the cooling means according to the detection result of the detection means.

In the above configuration, the degree of cooling of the lamp is controlled in accordance with the atmospheric temperature. For example, the degree of cooling is increased when the temperature is cold, and the degree of cooling is decreased when the temperature is hot. Can always be controlled to the optimum temperature.

Further, according to a second aspect of the present invention, a display means for spatially modulating illumination light based on a video signal to form an optical image for projection, and an illumination comprising a lamp and a reflector to generate the illumination light. Means, and a projection optical system for projecting the optical image on a projection screen, wherein a first cooling means for cooling the lamp when the lamp emits light, and a cooling means for cooling the lamp after the lamp is turned off. 2
And cooling means.

In the above configuration, the first cooling means can prevent the lamp from being overheated at the time of light emission, and the second cooling means can reset the lamp temperature after the lamp is turned off. The time required for cooling to the operable temperature can be reduced.

Further, according to a third aspect of the present invention, a display means for spatially modulating illumination light based on a video signal to form an optical image for projection, and an illumination comprising a lamp and a reflector to generate the illumination light. Means and a projection optical system for projecting the optical image on a projection screen, wherein the projector has a heating means for heating the lamp.

In the above configuration, the lamp can be preheated by the heating means. Since the difference between the lamp temperature and the light emission temperature is reduced by preheating, the time required for light emission after voltage application is reduced.

[0015]

FIG. 1 shows a simplified overall configuration diagram of a projector according to an embodiment of the present invention. The light generated by the lamp unit 27 enters the cross dichroic prism 3. The joining surface 3a of the cross dichroic prism 3 is provided with a dichroic coat that reflects only light in the R (red) wavelength range, and the joining surface 3b
Has a dichroic coat that reflects only light in the B (blue) wavelength range.

Therefore, the cross dichroic prism 3
Of the light incident on the liquid crystal panel 5R that forms an R optical image is reflected by the bonding surface 3a and then reflected by the reflection mirrors 4a and 4b. The light in the wavelength range B is reflected by the bonding surface 3b and then reflected by the reflection mirror 4
The light illuminates the liquid crystal panel 5B that is reflected by c and 4d and forms the B optical image. The light in the G (green) wavelength range is transmitted without being reflected by the cross dichroic prism 3, and illuminates the liquid crystal panel 5G that forms the G optical image.

Each of the liquid crystal panels 5 R, 5 G, and 5 B is a transmissive liquid crystal panel. Here, the illumination light is converted into an optical image of each color, and is then provided to the cross dichroic prism 6. Bonding surface 6a of cross dichroic prism 6
Is provided with a dichroic coat that reflects only light in the R wavelength range, and similarly, the bonding surface 6b is provided with a dichroic coat that reflects only light in the B wavelength range.

Of the light incident on the cross dichroic prism 6, the R image light emitted from the liquid crystal panel 5R is reflected by the bonding surface 6a and the B image light emitted from the liquid crystal panel 5B.
Is reflected by the joint surface 6b, and the G image light emitted from the liquid crystal panel 5G is not reflected by any surface. Therefore, the cross dichroic prism 6 combines and emits the image lights of the three colors. This light is projected on a screen (not shown) by the projection lens 7. Reference numeral 8 denotes a base to which each component is fixed.

FIG. 2 is a vertical sectional view of the lamp unit 27. As shown in FIG. In the lamp unit 27, the reflector 2 composed of a spheroidal reflection mirror is fixed to the box 9, and the lamp 1 is fixed to the reflector 2. Light emitted from the lamp 1 is reflected by the reflector 2 and enters the cross dichroic prism 3.

Next, the temperature control means provided in the projector of the embodiment will be described. First, FIG.
The components of the temperature control means will be described with reference to FIG. The temperature control means includes a fan 60, an atmospheric temperature detection device 62, a signal transmission line 61, and a heater 67 for adjusting a lamp temperature according to a signal transmitted from the signal transmission line 61.
And a control unit 50 that controls the fan 60, the heater 67, and the Peltier element 66 based on data detected by the Peltier element 66, a lamp temperature detection sensor 64 that detects the temperature of the lamp, an atmospheric temperature detection device 62, and the lamp temperature detection sensor 64. Consists of

The heater 67, the Peltier element 66, and the lamp temperature detection sensor 64 are directly bonded to the lamp 1.
The bonding position is a position where the light emitted from the lamp 1 is not blocked. The atmospheric temperature detection device 62 is configured on the base 8 and detects the temperature of the atmosphere. The fan 60
It is configured on the base 8 near the lamp unit 27 and cools the atmosphere around the lamp unit 27.

FIG. 3 shows a block diagram of a portion related to the temperature control means of the present embodiment. The control unit 50 controls the power supply circuit 65 based on the operation of the power switch by the user. Further, the control unit 50 controls the lamp temperature detection sensor 6.
The Peltier device 66 and the heater 67, which are the second cooling means configured in the lamp unit 27, are controlled based on the detection result of the temperature of the lamp 1 sent from the lamp unit 4. This data transmission and control is performed by the signal transmission line 61.
Done through. Further, the control unit 50 controls the fan 60 as the first cooling unit based on the detection result of the atmospheric temperature sent from the atmospheric temperature detecting device 62.

The temperature control by the fan 60 will be described. Even if there is no change in the applied voltage, the brightness of the lamp 1 varies depending on the temperature of the lamp at the time of light emission. FIG. 4 shows the relationship between the temperature and the brightness of the lamp 1 when the applied voltage is constant. The horizontal axis represents temperature, and the vertical axis represents brightness. As shown in FIG. 4, the lamp 1 has an optimum temperature T1 at which the brightest light emission can be obtained, and the brightness decreases as the temperature of the lamp 1 moves away from the optimum temperature T1. Therefore, in order to obtain bright illumination efficiently, it is desirable that the lamp 1 emits light at the optimum temperature T1.

The temperature of the lamp 1 rises because the lamp 1 continues to emit heat when emitting light. In the present embodiment, in order to keep the temperature of the lamp 1 at the optimum temperature T1, when the lamp 1 emits light, the fan 60 is operated to cool the air around the lamp to indirectly lower the rising lamp temperature.

The cooling level of the fan 60 required to maintain the temperature near the optimum temperature T1 differs depending on the atmospheric temperature. The cooling level may be lower if the ambient temperature is lower. The higher the ambient temperature, the higher the cooling level must be. Therefore, in the present embodiment, the cooling level is determined based on the detection result of the atmospheric temperature by the atmospheric temperature detecting device 62, and the drive of the fan 60 is controlled according to the cooling level. Specifically, the rotation speed of the fan 60 is adjusted according to the cooling level.

Next, the temperature control by the Peltier element 66 and the heater 67 will be described. The user can operate
It can instruct ON / OFF of the main power supply and ON / OFF of the sub power supply. When an instruction is given to turn on the sub power supply when the main power supply is turned on, a voltage is applied, and an image is projected (the lamp 1 is turned on) when the temperature of the lamp 1 reaches the light emission temperature. When the sub power supply is turned off when the lamp 1 is turned on, the temperature of the lamp 1 drops from the light emission temperature and is turned off.

When a certain time has elapsed since the image was turned off, the lamp 1
When the temperature is cooled to a predetermined relightable temperature or less, a voltage can be applied to the lamp 1. Although the lamp 1 is manufactured to emit light at a predetermined emission temperature, the lamp 1 is not turned on even if a voltage is applied to reach the emission temperature at a time when the temperature is higher than the relightable temperature.

If the auxiliary power supply is turned on when the temperature of the lamp 1 is higher than the relightable temperature, the lamp 1 cannot be relighted even when a voltage is applied. After waiting until it is cooled down, control to execute an instruction to turn on the sub power supply is performed. In the present embodiment, the control for shortening the predetermined time required for the temperature of the lamp 1 to be cooled to the relightable temperature or less after the image is turned off is performed using the Peltier element 66 of the temperature control unit.

Based on this control, the lamp 1 with respect to time
FIG. 5 shows an example of how the temperature changes. Time on the horizontal axis,
The vertical axis represents temperature. The state of the temperature change based on the control of the present embodiment is indicated by a solid line 70, and the state of the temperature change based on the conventional control is indicated by a chain line 71 and a dotted line 71 'as a reference example. When the image is on, the lamp 1 maintains the light emission temperature T10. When the sub-power supply is turned off at time t11, in the present embodiment, the lamp is rapidly cooled using the Peltier element 66. Due to this rapid cooling, the relightable temperature T1 at time t13
The lamp 1 is cooled down to 1. That is, the time required for cooling to the relightable temperature T11 is t12-t1.
It becomes 1.

Further, in the present embodiment, the heater 6
7, the control for maintaining the relightable temperature T11 is performed. When the sub-power supply is turned on at time t15, the lamp 1 is heated using the heater 67, and the light emission temperature T is quickly set.
Control to reach 10. At time t16, lamp 1
Reaches the light emission temperature T10, and an image is projected on the eyes of the observer.

According to the conventional control, even if the sub-power supply is turned off at the time t10, the rapid cooling control is not performed, so that the time required to reach the relightable temperature T11 is long, and the time t1
7 had been reached. Therefore, time t1 earlier than time t17
Even if the sub power supply is turned on in 3, it is ignored as indicated by a dotted line 71 ′, or waits until the time t 17 when the relightable temperature T11 is reached as indicated by the dashed line 71, and then, based on the instruction to turn on the sub power supply. The lighting control of the lamp was performed.

In the lighting control of the lamp, since there is no means for forcibly heating the lamp, it takes a long time to reach the emission temperature T10 from the relightable temperature T11, and the temperature of the lamp is increased at the time t18. When the temperature reached T10, an image was to be projected on the eyes of the observer.
Thus, even if the sub power is turned on at the same time t15,
The time required for an image to be actually projected on the observer's eye was much longer in the conventional case.

FIG. 6 shows the temperature change of the lamp 1 based on the control of the present embodiment when an instruction to turn on the sub-power supply is given before the temperature of the lamp 1 is cooled to the relightable temperature T11. Shown at 72. At time t11, there is an instruction to turn off the sub power supply, and rapid cooling is started. Time t immediately after quenching started
12, when the sub power supply is turned on, the relightable temperature T1
1 and waits until the temperature reaches the relightable temperature T11, and performs control based on the instruction to turn on the sub power at time t13.

Specifically, a voltage is applied to the lamp 1 and the lamp 1 is heated using the heater 67. By this control, an image is projected on the eyes of the observer at time t4. In this case, a waiting time from when the sub-power supply is turned on to when the sub-power supply is turned on is required, but a very short time is required as compared with the related art.

Next, a description will be given of temperature control by the Peltier element 66 and the heater 67 which is different from the above-mentioned rapid cooling.
If the lamp 1 is lower than the relightable temperature T11 when the main power supply is turned on, the lamp 67 is preheated by the heater 67, and control is performed to maintain the temperature of the lamp 1 at the relightable temperature T11. By performing this control, the time required for the lamp 1 to reach the light emission temperature T10 after the auxiliary power supply is turned on is reduced.

Based on this control, the lamp 1 with respect to time
An example of the temperature change is shown by a solid line 73 in FIG. still,
In FIG. 7, a dash-dot line 74 shows how the temperature of the lamp changes based on the conventional control as a reference example. The horizontal axis indicates time, and the vertical axis indicates temperature. The main power is turned on at time t20. In the present embodiment, the lamp 1 is preheated using the heater 67 in accordance with the turning on. The temperature of the lamp 1 is controlled to maintain the relightable temperature T11.

At time t21, the sub power supply is turned on. In the present embodiment, the voltage is applied to the lamp 1 with the turning on, and the lamp 1 is heated again by the heater 67,
Control is performed to reduce the time required to reach the light emission temperature T10. With this control, an image can be observed at time t23.

Conventionally, control has been performed to apply a voltage to the lamp when the sub-power supply is turned on at time t21. The temperature of the lamp rises due to the applied voltage, reaches the light emission temperature T10 at time t24, and an image is projected on the eyes of the observer. However, it took a very long time to raise the temperature of the lamp to the light emission temperature T11 only by the applied voltage from the state where the lamp was not preheated. Even if the sub-power supply is turned on at the same time t21, there is a large difference in the time required until an image is actually projected between the present embodiment and the conventional example, and the present embodiment is shorter.

FIG. 8 shows a control flow relating to the temperature control of the present embodiment. When the main power supply is turned on in step # 5, preheating by the heater 67 is started in step # 10. The preheating is continued until the temperature T of the lamp 1 reaches the relightable temperature T11. In step # 15, it is determined whether the sub power supply is on. If the sub power supply is off, it is determined in step # 20 whether the main power supply is off. If the main power supply is off, the preheating is turned off in step # 25, and the control ends. If the main power is not off, the process returns to step # 15.

If the sub power supply is turned on in step # 15,
In step # 30, the lamp 1 is directly heated by the heater 67. Then, in step # 35, it is determined whether or not the temperature T of the lamp 1 is equal to or higher than the light emission temperature T10. When T10 or more, the process proceeds to step # 40, in which the direct heating of the lamp 1 by the heater 67 is stopped, and in step # 45, the fan 60 is driven to start air cooling. Step # 50
When the sub power supply is turned off, the direct cooling of the lamp 1 by the Peltier element 66 is started in step # 55. Then, in step # 60, the process waits until the temperature T of the lamp 1 becomes equal to or lower than T11. The lamp temperature T becomes the relightable temperature T
When it becomes 11 or less, the process proceeds to step # 65, in which the direct cooling is stopped, the driving of the fan 60 is stopped in step # 70, and the process returns to step # 15.

[0041]

According to the projector of the first aspect, since the temperature of the lamp at the time of light emission can be controlled to the optimum temperature regardless of the atmospheric temperature, a bright image can be projected with high efficiency.

According to the projector of the second aspect,
Since the time required for the lamp temperature to be cooled to the relightable temperature can be reduced, the time required until the image is actually reprojected after the instruction to reproject the image is reduced.

According to the projector of the third aspect,
The preheating shortens the time required after the instruction to project the image until the image is actually projected.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a projector according to an embodiment.

FIG. 2 is a vertical sectional view of a lamp unit of the projector according to the embodiment.

FIG. 3 is a block diagram of a part related to a temperature control unit of the projector according to the embodiment.

FIG. 4 is a diagram showing a relationship between lamp temperature and brightness.

FIG. 5 is a diagram showing a state of a temperature change with respect to time based on control of a temperature control unit.

FIG. 6 is a diagram illustrating a state of a temperature change with respect to time based on control of a temperature control unit when an instruction to turn on an image is issued at a time different from that in FIG. 5;

FIG. 7 is a view showing a state of a temperature change based on preheating control in the projector of the embodiment.

FIG. 8 is a view showing a control flow relating to temperature control of the projector of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp 2 Reflector 5R Liquid crystal panel for R 5G Liquid crystal panel for 5G Liquid crystal panel for B 7 Projection lens 8 Base 27 Lamp unit 60 Fan 62 Atmospheric temperature detecting device 64 Lamp temperature detecting sensor 66 Peltier element 67 Heater

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasumasa Sawai 2-3-13 Azuchicho, Chuo-ku, Osaka City Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Akira Kawabata 2-3-3 Azuchicho, Chuo-ku, Osaka City No. 13 Osaka International Building Minolta Co., Ltd.

Claims (3)

[Claims] 1. A display means for spatially modulating illumination light based on a video signal to form an optical image for projection, an illumination means comprising a lamp and a reflector to generate the illumination light, and a projection screen for displaying the optical image. A projector having a projection optical system for projecting thereon, a cooling unit for cooling air around the illuminating unit, a detecting unit for detecting an atmospheric temperature, and a cooling unit for cooling by the cooling unit according to a detection result of the detecting unit. And a control means for controlling the degree. 2. A display means for spatially modulating illumination light based on a video signal to form an optical image for projection, an illumination means comprising a lamp and a reflector to generate the illumination light, and a projection screen for displaying the optical image. A projector having a projection optical system for projecting thereon, comprising: a first cooling unit that cools the lamp when the lamp emits light; and a second cooling unit that cools the lamp after the lamp is turned off. Features projector. 3. A display means for spatially modulating illumination light based on a video signal to form an optical image for projection, an illumination means comprising a lamp and a reflector to generate the illumination light, and a projection screen for displaying the optical image. A projector, comprising: a projection optical system for projecting the light onto the lamp; and a heating means for heating the lamp.