JP2006017902A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device constituted to surely prevent the soiling and the adhesion of dust on the light incident surfaces of optical parts on which illuminating light from a light source is made incident without causing difficulty in manufacture or the steep rise of manufacture cost. <P>SOLUTION: The light transmissive surfaces of the respective optical parts 22, 26, 27 and 28 through which the illuminating light from the light source 1 is transmitted are set as nearly vertical surfaces, and cooling air whose speed is ≥1.5m/s is sent to the light transmissive surfaces by a cooling means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image display apparatus that displays an image by enlarging and projecting illumination light from a light source on a screen through a spatial light modulation element such as a liquid crystal panel.

  In an image display device such as a so-called liquid crystal projector device, a light emitting tube such as a small and high-intensity ultra-high pressure mercury lamp is used as a light source for illuminating a liquid crystal panel serving as a spatial light modulator.

  The ultra-high pressure mercury lamp has a light emission characteristic close to that of a point light source, and therefore has high light utilization efficiency, and the emission spectrum can be continuously emitted by maintaining the pressure in the arc tube at 150 to 200 atmospheres. In addition, since the ultrahigh pressure mercury lamp has high conversion efficiency to visible light (wavelength of about 400 nm to 700 nm) with respect to applied energy, it is suitable as a light source in an image display apparatus such as a liquid crystal projector apparatus. At present, a projection type image display apparatus uses a 70 W to 280 W class ultra high pressure mercury lamp.

  By the way, in order to maximize the luminous performance of the ultra-high pressure mercury lamp, the pressure inside the arc tube must be kept higher than a predetermined pressure. For this purpose, the temperature at the coldest spot of the arc tube must be maintained. Need to keep high. On the other hand, in order to realize a stable operation for a long time, it is necessary to suppress the crystallization of quartz glass constituting the arc tube by suppressing the maximum temperature of the arc tube to a predetermined temperature or less.

  That is, when using an ultra high pressure mercury lamp, it is necessary to perform appropriate cooling so that the temperature of the arc tube is within a predetermined temperature range.

  Therefore, the conventional image display device employs a configuration in which the peripheral portion of the ultra-high pressure mercury lamp having a large calorific value and the optical component to which the illumination light from the ultra-high pressure mercury lamp is incident are separately cooled. ing.

  For example, in Patent Document 1, as shown in FIG. 9, an optical block 102 composed of a spatial light modulation element and a projection optical system is disposed in a sealed space 109 on the upper side of a housing 106, and a power source that generates a large amount of heat. An image display device in which the circuit 105 and the lamp 101 are arranged in an open space 112 on the lower side of the housing is described.

  The upper closed space 109 and the lower open space 112 are separated by a partition wall 107.

In this image display device, the optical block 102 is cooled by the cooling fan 108 circulating air in the upper closed space 109. The power supply circuit 105 and the lamp 101 are cooled by discharging the air heated by the power supply circuit 105 and the lamp 101 to the outside of the casing and taking in new cooling air from the outside of the casing. The
JP 2000-147449 A

  In the conventional image display apparatus as described above, air is circulated in a sealed space in the housing in order to prevent the light incident surface of the optical component on which the illumination light from the light source is incident from being attached and dirt from being attached. It was trying to cool by.

  However, even if the inside of the housing is sealed and shut off from the outside air, dust can easily enter the housing having a large volume, and there is a possibility that dirt or dust will adhere to the optical components.

  As a cause of such dirt and dust adhesion, when the housing is assembled, dust adheres to the structural material constituting the housing, or to the optical parts and the constituent materials constituting the optical block, Alternatively, it is conceivable that dust is trapped, and even during normal use, the air in the housing repeatedly expands and contracts, creating a gap in the structural material that constitutes the housing. It is possible that dust is mixed.

  It is difficult to completely eliminate dust contamination during assembly and dust intrusion into the housing during use. Therefore, the manufacturing becomes difficult and the manufacturing cost increases.

  Therefore, the present invention is proposed in view of the above-described circumstances, and the light incident surface of the optical component on which the illumination light from the light source is incident without causing difficulty in manufacturing and an increase in manufacturing cost. An object of the present invention is to provide an image display device that can reliably prevent dirt and dust from adhering.

  In order to solve the above-described problems and achieve the above object, an image display device according to the present invention projects an image light from the back side of a screen and displays the image toward the front side through the screen. A display device having a sealed structure with a screen on the front side of the device, a light source, an integrator optical system housed in the housing for projecting image light onto the screen, and illumination by the integrator optical system An optical system block composed of a spatial light modulation element and a projection optical system that forms an image of the modulated light of the spatial light modulation element on the back side of the screen, and a housing for cooling the optical components constituting the optical system block A light transmitting surface of each optical component through which the illumination light from the light source is transmitted is substantially a vertical surface. The these light transmitting surface, the blowing means, the wind speed is characterized in that the cooling air over per second 1.5m is sent.

  In this image display device, the light transmitting surface of each optical component through which the illumination light from the light source is transmitted is substantially vertical, so that dust and the like are not easily attached, and the wind speed is 1.5 m / s. By sending the cooling air described above, adhesion of dust and the like is reliably prevented.

  In the image display device according to the present invention, since the light transmission surface of each optical component that transmits illumination light from the light source is substantially vertical, dust or the like adheres to these light transmission surfaces. It has become difficult. Moreover, in this image display apparatus, dust and the like can be reliably prevented from being sent to these light transmission surfaces by sending cooling air having a wind speed of 1.5 m / s or more. In the image display device, dirt and dust are prevented from adhering to the optical components, so that deterioration of light transmittance in these optical components and heat generation due to light absorption are prevented.

  That is, according to the present invention, dirt on the light incident surface of the optical component on which the illumination light from the light source is incident and dust adhesion are reliably prevented without causing difficulty in production or an increase in production cost. It is possible to provide an image display device made in the above.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing a schematic configuration of an image display apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the image display device is configured to include a housing 30, and an optical system block is installed in a lower portion of the housing 30.

  FIG. 2 is a perspective view showing a configuration of an optical system block in the image display apparatus according to the embodiment of the present invention.

  As shown in FIG. 2, the optical system block includes an illumination light source unit 1 including a light source device, an integrator optical system 2 that equalizes the illuminance of illumination light from the illumination light source unit 1, and a light modulation unit 3. The projection optical system 4 is an image optical system. Each part constituting these optical system blocks is housed in a housing.

  This optical system block spatially modulates illumination light emitted from the illumination light source unit 1 and passed through the integrator optical system 2 to the light modulation unit 3 based on image information by a spatial light modulation element in the light modulation unit 3, The illumination light thus spatially modulated is projected obliquely upward by the projection optical system 4. In the image display device, as shown in FIG. 1, the illumination light projected from the projection optical system 4 is reflected by a mirror 31 installed in the housing 30 and forms a front portion of the image display device. The light is projected onto the transparent screen 32 from the back side of the translucent screen 32. The illumination light projected on the translucent screen 32 in this way forms a display image on the translucent screen 32.

  In the housing 30 of the image display device, an upper space 33 in which a mirror 31 and a translucent screen 32 are installed and a lower space 34 in which an optical system block is installed are separated by a partition wall. The upper space 33 is a substantially sealed space in order to prevent light from entering from outside, light leakage from inside to outside, and dust from entering.

  And the housing | casing which accommodated the integrator optical system 2, the light modulation part 3, and the projection optical system 4 among the optical system blocks is connected with the upper side space 33 of the housing | casing 30 via the several duct. On the other hand, the housing that houses the illumination light source unit 1 in the optical system block is connected to the lower space 34 of the housing 30 via a plurality of ducts. That is, in this optical system block, the internal air flows between the housing containing the illumination light source unit 1 and the housing containing the integrator optical system 2, the light modulation unit 3, and the projection optical system 4. Separated so that there is no.

  Cooling of the integrator optical system 2, the light modulation unit 3, and the projection optical system 4 is performed by circulating air in the upper space 33 of the housing of the image display device by a blowing unit. That is, the integrator optical system 2, the light modulation unit 3, and the projection optical system 4 are cooled as shown by an arrow A in FIG. 2 in which the air in the upper space 33 of the housing 30 passes through the duct to block the optical system. This is done by being fed into the housing. The air that has cooled the integrator optical system 2, the light modulation unit 3, and the projection optical system 4 is discharged from the housing of the optical system block as shown by an arrow B in FIG. Returned to the side space 33. The air in the upper space 33 of the casing 30 is cooled by a cooling fan or the like (not shown) in the upper space 33 and in the casing in which the integrator optical system 2, the light modulator 3, and the projection optical system 4 are housed. By means, it circulates.

  In the integrator optical system 2, the light modulation unit 3, and the projection optical system 4 except the illumination light source unit 1, heat is mainly generated by the light-transmitting optical component absorbing the irradiation light from the illumination light source unit 1. Therefore, sufficient cooling can be performed by the cooling air circulating in the upper space 33 of the substantially sealed casing 30.

  On the other hand, the illumination light source unit 1 is cooled by air taken into the lower space 34 of the housing 30 from the outside by an axial fan 12 serving as a cooling means, as shown in FIG. The cooling air that has been sent into the illumination light source unit 1 by the axial flow fan 12 and has cooled the illumination light source unit 1 is discharged to the outside of the housing 30 via the duct 23.

  The amount of heat generated in the illumination light source unit 1 is the largest among the optical system blocks. For this reason, this cooling air is taken from outside the housing 30, and after the illumination light source unit 1 is cooled, it is discharged to the outside of the housing 30 so that it does not easily affect other optical systems.

  FIG. 3 is an exploded perspective view showing the configuration of the illumination light source unit 1.

  The illumination light source unit 1 includes an ultrahigh pressure mercury lamp unit 5 as shown in FIG. The ultra-high pressure mercury lamp unit 5 includes an ultra-high pressure mercury lamp that is an arc tube and a concave reflector 14 that holds the ultra-high pressure mercury lamp. The ultra-high pressure mercury lamp unit 5 is inserted into a case-like lamp housing 6 and fixed to the lamp housing 6 by a holding bracket 7.

  In this ultra high pressure mercury lamp unit 5, the light emitting point of the arc tube is located in the concave reflector 14, and the illumination light emitted from this light emitting point is reflected by the concave reflecting surface on the inner surface of the concave reflector 14. , Emitted to the front side. The optical axis of the luminous flux thus emitted is substantially horizontal.

  The ultra-high pressure mercury lamp unit 5 is normally handled as a replacement part in a state of being housed in the lamp housing 6, and lamp replacement or the like is performed while being housed in the lamp housing 6.

  In the illumination light source unit 1, cooling air is blown from the side of the lamp housing 6 to the side surface of the ultrahigh pressure mercury lamp unit 5 by the axial fan 12.

  Between the lamp housing 6 and the axial fan 12, a wind direction guide 24 attached to the holding bracket 7 is installed. When the wind direction guide 24 guides the cooling air from the axial fan 12, the cooling air is efficiently introduced into the lamp housing 6 from the cooling air intake port provided in the lamp housing 6.

  If the axial fan 12 cannot be disposed in the vicinity of the illumination light source unit 1, the axial light fan 12 may be disposed from the axial fan 12 even if the axial fan 12 is disposed at a location away from the illumination light source unit 1. If the air guide path leading to is formed, the illumination light source unit 1 can be efficiently cooled.

  FIG. 4A is a perspective view showing the configuration of the extra-high pressure mercury lamp unit 5.

  As shown in FIG. 4A, the ultra-high pressure mercury lamp unit 5 has a concave reflector 14 such as a spheroid or a paraboloid having a cold mirror reflecting film that transmits an infrared light region on its inner surface. The both-end sealed arc tube is fixed to the most concave portion of the concave reflector 14. The front end of the concave reflector 14 is an open light irradiation opening, and the light irradiation opening is closed by the transparent glass 11. In the ultrahigh pressure mercury lamp unit 5, the concave reflector 14 and the transparent glass 11 have a structure in which the inside is substantially sealed.

  The first electrode 9 of the arc tube is led out to the rear side of the concave reflector 14 through a hole provided in the most concave portion of the concave reflector 14.

  FIG. 4B is a perspective view showing the internal structure of the ultrahigh pressure mercury lamp unit 5 with a part thereof broken.

  One end of a lead wire 18 is connected to the second electrode 10 of the arc tube 8. The other end side of the lead wire 18 is drawn out of the concave reflector 14 through a curved slope of the concave reflector 14 or an extraction hole 19 provided in the side surface. As described above, the direction in which the other end side of the lead wire 18 is drawn outward is preferably obliquely above the optical axis of the illumination light emitted from the concave reflector 14.

  And the other end side of the 1st electrode 9 and the lead wire 18 is connected to the connector 13a via the conductive wires 13 and 13, respectively. The connector 13a is fixed to the lamp housing 6, and is connected to an arc tube driving power source (not shown) when the illumination light source unit 1 is mounted on the optical system block.

  Both ends sealed arc tube 8 has a basic structure in which mercury, argon gas and a small amount of halogen gas are enclosed in a bulb made of quartz glass. The central part of this bulb is the light emitting point. In the bulb, a discharge electrode made of a tungsten alloy is disposed with the tip portions thereof facing each other with an interval of 1 mm to 1.5 mm. A molypden foil is connected to the base end side of these discharge electrodes, and a first electrode 9 and a second electrode 10 which are external lead electrodes are connected to the molypden foil. The first electrode 9 and the second electrode 10 are drawn out to the outer sides of the bulb toward the both ends of the bulb. The portion of the molypden foil is tightly sealed against the quartz glass forming the bulb.

  FIG. 5 is an exploded perspective view showing the configuration of the illumination light source unit 1 as seen from the axial flow fan 12 side.

  As shown in FIG. 5, the side surface of the lamp housing 6 that covers the ultrahigh pressure mercury lamp unit 5 has an opening 6 a into which a first cooling air 15 for cooling the concave reflector 14 is introduced, and a lead wire 18. And an opening 6b into which the second cooling air 16 for cooling the other end of the air is introduced.

  In addition, in the side part of the lamp housing 6, the part facing the motor in the central part of the axial fan 12 is closed. In the axial fan 12, since the cooling air sent from the central portion is small, the portion facing the central portion is closed to close the concave reflector 14 and the lead through the openings 6a and 6b around the central portion. The first and second cooling air 15 and 16 are concentrated and sent to the other end side of the line 18.

  In this image display measure, the other end portion of the lead wire 18 projecting obliquely upward as viewed from the optical axis of the illumination light emitted from the concave reflector 14 and on the windward side of the second cooling air 16 is cooled. The second cooling air 16 that intensively cools the other end portion of the lead wire 18 and then cools the upper portion of the concave reflector 14, that is, the high-temperature portion. Done.

  FIG. 6 is a perspective view showing a configuration around the illumination light source unit 1.

  Further, as shown in FIG. 6, a third cooling air 17 for cooling the transparent glass 11 closing the light irradiation opening of the concave reflector 14 is provided between the lamp housing 6 and the holding placket 7. An opening into which is introduced is provided. The third cooling air 17 cools not only the transparent glass 11 but also the UV / IR cut filter (ultraviolet infrared reflection filter) 22 that becomes the light incident surface of the integrator optical system 2.

  In this embodiment, the air flow between the axial fan 12 and the irradiation light source unit 1 is not sealed, and the cooling air leaked from between the axial fan 12 and the irradiation light source unit 1 to the periphery. Thus, the outer portions of the lamp housing 6 and the holding bracket 7 are also cooled.

  Here, each cooling air 15, 16, and 17 which cools the irradiation light source unit 1 and its periphery is the external air taken in from the outside. These cooling airs contain some dust, and there is a possibility that these dusts adhere to optical components.

  In particular, when dust adheres to the surface of the transparent glass 11 that closes the front portion of the ultra-high pressure mercury lamp unit 5 and the UV / IR cut filter 22, the illumination light is absorbed by the dust, and the brightness of the display image is increased. It will deteriorate significantly.

  FIG. 7 is a perspective view showing the configuration of the integrator optical system 2. Note that FIG. 7 is a diagram in a state where the upper cover is removed to show the optical components arranged in the sealed space.

  As shown in FIG. 7, the irradiation light emitted from the irradiation light source unit 1 is transmitted through the UV / IR filter 22 and is incident on the integrator optical system 2 formed into a sealed space. Irradiation light incident on the integrator optical system 2 is bent 90 degrees by a reflection mirror disposed on the inner surface of the wall surface 25 inclined by 45 ° with respect to the optical axis, and the first fly-eye lens and polarization conversion prism group 26, passes through the second fly-eye lens 27, the first field lens 28, a polarizing plate (not shown), and the like and travels toward the light modulation unit 3.

  Each optical component constituting the integrator optical system 2, that is, the UV / IR filter 22, the reflection mirror, the first fly-eye lens and polarization conversion prism group 26, the second fly-eye lens 27, the first field lens 28, and the polarizing plate. The transparent glass 11 of the irradiation light source unit 1 is arranged with the light incident surface and the light emitting surface being vertical surfaces.

  Therefore, dust does not accumulate and adhere to the light incident surface and the light emitting surface of each optical component.

  And in this image display measure, the cooling wind sent to each optical component by each cooling means described above is such that the wind speed at the light incident surface and light exit surface of each optical component is 1.5 m / s or more. Yes.

  FIG. 8 is a graph showing the relationship between the wind speed of the cooling air 17 flowing between the transparent glass 11 and the UV / IR cut filter 22 and the variation in transmittance.

  Here, when the relationship between the wind speed of the third cooling air 17 flowing between the transparent glass 11 and the UV / IR cut filter 22 and the transmittance of the transparent glass 11 and the UV / IR cut filter 22 is examined, FIG. As shown in FIG. 8, when the wind speed of the 3rd cooling wind 17 is small, the transmittance | permeability will fall and it turns out that the dust has adhered to the surface of the optical component. Then, as the wind speed of the third cooling air 17 is gradually increased, the transmittance increases, and the wind speed is substantially saturated when the wind speed is 1.5 m / s or more.

  That is, it can be seen that if the wind velocity at the light incident surface and the light exit surface of each optical component is 1.5 m or more per second, dust can be prevented from adhering to the surfaces of these optical components.

  The data shown in FIG. 8 is obtained by leaving the image display measure in an operating state in high-concentration dust, and the conditions such as the dust concentration are “JIS D 0207” (dust-proof And the dust resistance test general rules).

  In addition, when taking in cooling air from the outside of a housing | casing, you may make it take in this cooling air via a dust removal filter.

1 is a perspective view illustrating a schematic configuration of an image display device according to an embodiment of the present invention. It is a perspective view which shows the structure of the optical system block in the image display apparatus which concerns on embodiment of this invention. It is a disassembled perspective view which shows the structure of the illumination light source unit in the said image display apparatus. It is a perspective view which shows the structure of the ultra high pressure mercury lamp unit in the said image display apparatus. FIG. 3 is a perspective view showing a part of the internal structure of the ultrahigh pressure mercury lamp unit in the image display device. It is the disassembled perspective view seen from the axial flow fan side which shows the structure of the illumination light source unit in the said image display apparatus. It is a perspective view which shows the periphery structure of the illumination light source unit in the said image display apparatus. It is a perspective view which shows the structure of the integrator optical system in the said image display apparatus. It is a graph which shows the relationship between the wind speed of the cooling air which flows between transparent glass and UV / IR cut filter, and the fluctuation | variation of the transmittance | permeability in the said image display apparatus. It is the plane part (a) and side view (b) which show the structure of the conventional light source device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Illumination light source unit 2 Integrator optical system 3 Light modulation part 4 Projection optical system 5 Super high pressure mercury lamp unit 6 Lamp housing 7 Holding bracket 8 Light emission tube 9 1st electrode 10 2nd electrode 11 Transparent glass 12 Axial flow fan 13 Connector 14 Concave surface Reflector 15 First cooling air 16 Second cooling air 17 Third cooling air 22 UV / IR cut filter

Claims (1)

An image display device that projects image light from the back side of the screen and displays the image toward the front side through the screen,
A sealed housing having the screen on the front side of the device;
A light source;
An integrator optical system that is housed in the housing and projects image light onto the screen, a spatial light modulation element that is illuminated by the integrator optical system, and the modulated light of the spatial light modulation element on the back surface of the screen An optical system block comprising a projection optical system that forms an image on the side;
In order to cool the optical components constituting the optical system block, air blowing means for circulating the air in the casing in the casing;
With
The light transmission surfaces of the optical components through which the illumination light from the light source passes are substantially vertical surfaces. The light transmission surfaces are provided with cooling air having a wind speed of 1.5 m / s or more by the blowing means. An image display device characterized in that

Images