JP2011118152A - Projection display - Google Patents

Abstract

The present invention provides a configuration for minimizing noise generated by a cooling fan without causing a fluctuation phenomenon of a projected image due to exhaust air.
A light source lamp, a cooling fan that blows air to the light source lamp and cools the light source lamp, and projection optics that modulates light emitted from the light source lamp and projects it from a projection lens with a zoom function. An exhaust port 4 that is arranged on the front panel of the design case 2 side by side with the projection lens 3 with the zoom function, and exhausts the exhaust air after the cooling fan blows and cools the light source lamp 6; And a control unit 8 for controlling the number of rotations of the cooling fan. The control unit 8 controls the number of rotations of the cooling fan according to the zoom state of the projection lens 3 with a zoom function. .

[Selection] Figure 4

Description

The present invention relates to a projection display device such as a liquid crystal projector or a DLP (registered trademark) projector, and in particular, controls the number of revolutions of an air cooling fan provided in a front projection type projection display device to reduce noise caused by the air cooling fan. It is related to the technology to make.

Regardless of the liquid crystal system or the DLP system, the projection display device generally requires a large light output from the light source lamp in order to display a bright and clear projection image. Therefore, when the light output is increased, the heat generation increases, and the light source lamp becomes very hot. Discharge lamps that are generally used as light source lamps in recent years include metal halide lamps and ultra-high pressure mercury lamps. The discharge lamp lamp surface of the discharge lamp is extremely high, and the temperature rises to about 1000 ° C.

  However, if the discharge lamp is cooled to a temperature lower than a predetermined temperature, the lamp itself deteriorates and its life is shortened. Therefore, an air flow is generated around the light source lamp using an air cooling fan, and the discharge lamp is cooled while maintaining a certain high temperature. There is a need. For this reason, the exhaust air after cooling the light source lamp must be at a high temperature. And, if it is a structure that discharges this hot exhaust air to the back and sides of the projection display device, the exhaust air is blown to the viewer, causing discomfort, or a device such as a personal computer placed on the side or back There is a problem of injecting warm air into the air intake.

  Therefore, conventionally, there is known a structure in which an exhaust port is arranged on a front panel of a design case along with a projection lens so that high-temperature exhaust air is discharged forward (direction toward the screen). For example, the projection type display device disclosed in Patent Document 1 has an exhaust port arranged side by side with a projection lens as shown in FIG. In such a case, there is a known problem that a fluctuation phenomenon (hot flame phenomenon) occurs in the projected image when the warm air discharged from the exhaust port enters the region of the projection light beam emitted from the projection lens. Therefore, a louver that creates an air flow in a direction away from the projection lens is provided at the exhaust port. Further, in Patent Document 1, a centrifugal fan (sirocco fan) is provided between the projection lens and the light source lamp and inside the front panel. This centrifugal fan also creates an air flow in which the exhaust air flows away from the projection lens.

  In addition, in such a configuration, if the amount of exhaust air exhausted from the exhaust port is not large to some extent, warm air stagnation occurs just outside the exhaust port, which enters the area of the projected luminous flux. And tend to cause a fluctuation phenomenon. Furthermore, if the projection angle of view is wide, the area of the projected light beam is closer to the front of the exhaust port, so that hot air stagnation easily enters the area of the projected light beam (FIG. 7A). ). Therefore, in order to prevent warm air stagnation, an air volume that is always larger than the minimum air volume required for cooling the light source lamp is generated so that stagnation does not occur in the exhaust air from the exhaust port ( FIG. 7B). The air volume is set according to the case where the projection light has a wide angle, that is, the condition is bad.

Japanese Patent Laying-Open No. 2005-301088 (page 3, FIG. 2)

  However, when the projection angle of view is narrow (telephoto) as shown in FIG. 8, the region of the projected light beam is away from the exhaust port, so that only the minimum air volume necessary for cooling the light source lamp is exhausted. It has been found that even if warm air stagnation occurs outside the mouth, this stagnation does not enter the region of the projected light flux. Also, as shown in FIG. 9A, when the projection light beam is used at a wide angle, it is often installed on a classroom table, and the viewer is often located behind the projection display device. . On the other hand, when the projection light beam is used at a telephoto position, as shown in FIG. 9B, the projection display device is often positioned so as to be surrounded by the viewer. In other words, it can be said that the noise of the cooling fan of the projection display device has a greater influence on the viewer when projecting at telephoto than when projecting at wide angle.

  Accordingly, an object of the present invention is to minimize noise generated by a cooling fan without causing a fluctuation phenomenon in a projected image in a projection display device in which an exhaust port is arranged on a front panel of a design case side by side with a projection lens. To do.

As a first aspect, the present invention provides a light source lamp, a cooling fan that blows air to the light source lamp to cool the light source lamp, and projection optics that modulates light emitted from the light source lamp and projects it from a projection lens with a zoom function. System and the projection lens with a zoom function arranged side by side on the front panel of the design case, an exhaust port for discharging exhaust air after the cooling fan blows and cools the light source lamp, and the rotation speed of the cooling fan And a control unit that controls the number of rotations of the cooling fan according to the zoom state of the projection lens with a zoom function.

As a second aspect, the present invention includes a detecting unit that detects a zoom state of the projection lens with a zoom function and transmits the detection result to the control unit. The projection according to the first aspect, wherein the rotation speed of the cooling fan is controlled to be high when the attached projection lens is in a wide-angle state, and the rotation speed of the cooling fan is controlled to be low when the projection lens is in a telephoto state. A type display device is provided.

Further, as a third aspect of the present invention, the control unit continuously changes the rotation speed of the cooling fan according to the zoom state of the projection lens with a zoom function. As a projection type display device.

  According to the present invention, according to the zoom state of the projection lens with a zoom function, it is possible to increase / decrease the air volume from the exhaust port arranged on the front panel of the design case side by side with the projection lens. When it is, it is possible to increase the air volume of the exhaust air, and when it is telephoto, it is possible to reduce the air volume of the exhaust air. With this function, the rotation speed of the cooling fan can be controlled to the minimum according to the zoom status of the projection lens with zoom, and the noise of the cooling fan can be reduced. Can be minimized to the extent that there is no.

1 is a schematic perspective view showing a projection display device according to an embodiment of the present invention. Sectional drawing which shows the internal structure of the projection type display apparatus which concerns on one Embodiment of this invention. Sectional drawing which shows the principal part which shows the internal airflow of the projection type display apparatus which concerns on one Embodiment of this invention. The block diagram which shows the drive control of the cooling fan which concerns on one Embodiment of this invention The graph which shows the relationship between the rotation speed of the fan which concerns on one Embodiment of this invention, and a zoom state Sectional view of a projection display device according to the prior art Partial sectional view showing the state of exhaust air of a projection display device according to the prior art Partial sectional view showing the relationship between the exhaust wind and the zoom state of the projection display device The top view which shows the positional relationship of a projection type display apparatus and a viewer

Next, the configuration of the cooling means of the projection display device according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing an external appearance of a projection display apparatus according to an embodiment of the present invention. The projection display device 1 includes a design case 2 made of a resin molded product, and a substantially rectangular parallelepiped space is provided therein. The front surface (arrow A) of the design case 2 is provided with a projection lens 3 with a zoom function, and the exhaust port 4 is also provided on the front surface. The high-temperature air stream exhausted from the exhaust port 4 is exhausted obliquely in a direction away from the projection lens 3 so as not to enter the optical path of the projection lens 3 and cause a fluctuation phenomenon. In addition, an intake port 5 is provided on the left side surface (arrow A) of the design case 2, and an intake port (not shown) is also provided on the back surface (arrow C) of the design case 2.

  FIG. 2 is a view of the projection display device 1 shown in FIG. 1 as viewed from above. FIG. In FIG. 2, reference numeral 6 denotes a light source lamp, 7 denotes a projection optical system that modulates light emitted from the light source lamp 6 and guides it to the projection lens 3, 8 denotes a control unit that includes the projection optical system 7 and controls the entire apparatus, and 9 A power supply apparatus 10 for inputting commercial power and supplying power to the entire apparatus, such as the light source lamp 3, the control unit 8, and other cooling fans, is an intake port on the back surface not shown in FIG. Reference numeral 11 denotes a fine tilting mirror in a matrix, and light modulating means for reflecting light from the light source lamp 6, 12 is a heat sink for radiating heat generated by the light modulating means 11, and 13 is a projection. A first air guide wall that restricts a flow path of cooling air for cooling the optical system 7, and 14 is a flow path of cooling air for cooling the power supply device 9 and the ballast unit 15 that drives the light source lamp 6. A second air guide wall 201 to be limited is a zoom detection unit that detects the zoom state of the projection lens 3.

  Outside air is taken into the design case 2 from the air inlet 5, and is guided to the air guide wall 13 to cool the projection optical system 7 including the heat sink 12 and is discharged from the air outlet 4. Outside air is also taken into the design case 2 from the air inlet 10 to cool the control unit 8, cool the power supply device 9 and the ballast unit 15 while being guided by the air guide wall 14, and further the outer surface of the reflector of the light source lamp 6. Is cooled and discharged from the exhaust port 4. Here, the outside air taken in from the air inlet 5 is blown by the first axial fan 16, and the outside air taken in from the air inlet 10 is blown by the second axial fan 17 and further the third axial fan 18. It is blown by. Further, the outside air taken in from the air inlet 10 cools the inside of the reflector of the light source lamp 6, that is, the region including the lamp bulb, by the centrifugal fan 19, and the exhaust air is discharged from the air outlet 4.

  Next, the air flow of the projection display apparatus will be described in more detail based on FIG. FIG. 3 is a view in which about half of the left side is omitted from the view of FIG. A dotted arrow indicates an air flow. First, when the centrifugal fan 19 blows air, cooling air is sent to the light emission side of the light source lamp 6. As soon as this cooling air exits the centrifugal fan 19, the direction of the air is restricted by the first baffle wall 20, and the air is blown into the interior of the reflector of the light source lamp 6, that is, the region where the lamp bulb is located. Then, the exhaust air flow that cools the lamp bulb and its surroundings is restricted in the direction of the wind by the second baffle wall 21, and the first exhaust air flow from the exhaust port 4 of the design case 2 in the direction away from the region of the projection light flux of the projection lens 3. It is discharged to the outside as (dotted arrow 101).

  Next, after the power supply device 9 and the ballast unit 15 are cooled, the air flow blown by the third axial fan 18 cools the outer surface of the reflector of the light source lamp 6, and the exhaust flow is changed from the third to the sixth. The wind direction is restricted by the wind control walls 22 to 25, and this is also discharged to the outside as a second exhaust flow (dotted arrow 102) from the exhaust port 4 of the design case 2 in a direction away from the projected light flux region of the projection lens 3. The Here, when the temperature of the outside air was measured at 26 ° C., the first exhaust flow (dotted arrow 101) cools the lamp bulb whose surface temperature is about 1000 ° C. The temperature rises to about 95 ° C. Further, since the second exhaust flow (dotted arrow 102) cools the reflector outer surface whose surface temperature becomes about 150 ° C., the temperature of the exhaust air after cooling rises to about 60 ° C.

  Further, the air flow blown by the first axial fan 16 is guided to the air guide wall 13, and the projection optical system 7 including the heat sink 12 is cooled to increase the temperature to about 45 ° C. (a third exhaust flow (dotted line). Arrow 103). This third exhaust flow (dotted arrow 103) is blown to the corner 27 by restricting the wind direction to the seventh wind control wall 26, and the direction of the flow is switched at the corner 27 to wind the wind direction to the wind control wall 21. And is discharged from the exhaust port 4. Again, this exhaust flow (dotted arrow 103) is also exhausted in a direction away from the projected light flux region of the projection lens 3.

  Therefore, when the temperature of the outside air is 26 ° C., the exhaust air of about 45 ° C. (dotted arrow 103) after the projection optical system 7 is cooled has its air volume changed by the increase / decrease of the rotational speed of the first axial fan 16. The exhaust air of about 95 ° C. (dotted arrow 101) that has been increased and decreased and cooled around the lamp bulb has its air volume increased and decreased as the number of revolutions of the centrifugal fan 19 increases and decreases, and the exhaust air of about 60 ° C. that cools the outer surface of the reflector. The wind volume (dotted arrow 102) increases or decreases as the rotational speed of the third axial fan 18 increases or decreases. And the control part 8 which controls the rotation speed of a fan can control now the rotation speed of each of the 1st axial flow fan 16, the centrifugal fan 19, and the 3rd axial flow fan 18 independently. Yes.

3 is a thermistor fixed to a lamp house (not shown) surrounding the light source lamp 6, and the thermistor 28 detects the temperature of the light source lamp 6 and transmits it to the control unit 8. Therefore, the control unit 8 can set the minimum number of rotations of the cooling fan for keeping the light source lamp 6 at a predetermined temperature by a signal from the thermistor 28. Separately from this, the control unit 8 stores the number of rotations of the cooling fan that does not cause a fluctuation phenomenon in the projected image in association with the zoom state of the projection lens.

  Next, the control system will be described with reference to FIG. This control system includes a fan drive circuit, is housed in the control unit 8 of FIG. 2, and is formed by electronic circuit components, circuit patterns, etc. provided on a circuit board (not shown). In FIG. 4, reference numeral 28 denotes a thermistor provided in the lamp house of the light source lamp 6, and transmits temperature information of the light source lamp 6 to the control unit 8. The control unit 8 generates a first control value corresponding to the rotational speeds of the centrifugal fan 19 and the third axial fan 18 in order to keep the light source lamp 6 at a predetermined temperature based on the temperature information from the thermistor 28. Here, the first axial fan 16 is not configured to cool the light source lamp 6, but in the case of the present embodiment, the centrifugal fan 19 is used in order not to change the temperature of the exhaust air discharged from the exhaust port 4 as much as possible. The rotational speed is increased or decreased at the same ratio as that of the third axial fan 18.

  Reference numeral 201 denotes zoom detection means for detecting the zoom state of the projection lens 3, and the control unit 8 inputs information from the detection means 201 and generates a second control value. Here, the second control value is generated using a control value corresponding to the rotational speed of the fan stored in advance in the control unit 8 in association with the zoom state of the projection lens 3. Then, the control unit 8 compares the first control value with the second control value, and controls the fan drive circuit with a control value that increases the rotational speed of the cooling fan. As a result, the drive control of the cooling fan as shown in FIG. 5 is performed.

  FIG. 5 is a graph showing the relationship between the rotational speed of the fan and the zoom state of the projection lens 3. The number of rotations of the fan based on the first control value (control value based on the temperature of the light source lamp 6) is denoted by A, and the rotation of the fan based on the second control value (control value based on the zoom state of the projection lens 3). The number is denoted by B. First, FIG. 5A shows a graph of the rotation speed of a normal fan, and the rotation of the fan according to the second control value until the zoom state of the projection lens 3 reaches from the wide angle to the telephoto. This is a state where the number B exceeds the rotational speed A of the fan according to the first control value.

  In such a state, the rotational speed of the fan continuously changes corresponding to only the zoom state of the projection lens 3. In other words, when the zoom state is wide-angle, increasing the fan speed increases the amount of exhaust air exhausted from the exhaust port, and when the zoom state is telephoto, the fan speed is decreased to lower the fan speed. The amount of exhaust air to be discharged is reduced. On the other hand, the graph shown in FIG. 5B shows a state where the rotational speed of the fan according to the first control value has to be high due to a high outside air temperature. In this case, the zoom of the projection lens 3 Since the number of rotations of the fan according to the first control value is higher than the number of rotations of the fan set in advance as the second control value corresponding to the case where the state is telephoto, the zoom state is telephoto. In the vicinity, the fan rotation speed (first control value) corresponding to the temperature of the light source lamp 6 is preferentially used as the fan drive control value.

  As described above, in this embodiment, the rotation speed of the cooling fan is continuously changed in accordance with the zoom state of the projection lens 3, and the rotation speed of the cooling fan is minimized within a range in which the fluctuation phenomenon does not occur in the projected image. To the limit. However, the rotational speed of the cooling fan may be a stepwise change instead of a continuous change, and the rotational speed control of the first axial fan 16 shown in FIG. The second control value (control value based on the zoom state of the projection lens 3) is not necessarily changed at the same ratio, regardless of the level of the first control value (control value based on the temperature of the light source lamp 6). It is also possible to perform control corresponding to only.

DESCRIPTION OF SYMBOLS 1 Projection type display apparatus 2 Design case 3 Projection lens 4 Exhaust port 5, 10 Intake port 6 Light source lamp 7 Projection optical system 8 Control part 9 Power supply device 11 Light modulation means 12 Heat sink 13, 14 Air guide wall 15 Ballast part 16 1st Axial flow fan 17 Second axial flow fan 18 Third axial flow fan 19 Centrifugal fan 20, 21, 22, 23, 24, 25, 26 Air control wall 27 Corner portion 28 Thermistor 201 Zoom detection means

Claims (3)

A light source lamp, a cooling fan that blows air to the light source lamp to cool the light source lamp, a projection optical system that modulates light emitted from the light source lamp and projects the light from a projection lens with a zoom function, and the projection lens with a zoom function And arranged on the front panel of the design case, and an exhaust port that exhausts the exhaust air after the cooling fan blows and cools the light source lamp, and a control unit that controls the rotation speed of the cooling fan, The control unit controls the number of rotations of the cooling fan according to the zoom state of the projection lens with a zoom function. When the zoom lens of the projection lens with a zoom function is detected and a detection unit that transmits the detection result to the control unit is provided, and the projection lens with the zoom function is in a wide-angle state as a detection result of the detection unit 2. The projection display device according to claim 1, wherein the rotation speed of the cooling fan is controlled to be high and the rotation speed of the cooling fan is controlled to be low when in a telephoto state. The projection display device according to claim 2, wherein the control unit continuously changes the rotation speed of the cooling fan according to a zoom state of the projection lens with a zoom function.

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