JPH0949985A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the thickness of a display device so as to improve the portability while keeping the cooling effect of a liquid crystal panel by separating the peripheral space of a panel part from the peripheral space of other members. SOLUTION: The peripheral space of the panel part having liquid crystal panels 25, 30 and 31, a condensing lens 33, an incident side polarizing plate 34 and an emitting side polarizing plate 35 is shut off from the space of other members by two glass plates 39 and a shutoff fitting 40. As for the space of the panel part, the peripheral space of the blue display liquid crystal panel 25, the peripheral space of the red display liquid crystal panel 30, and the peripheral space of the green display liquid crystal panel 31 are connected, and aperture parts on the disconnected sides of the peripheral space of the panel 25 and the peripheral space of the panel 31 are connected with external space. Cooling fans are respectively provided at two aperture parts communicated with the external space. Thus, a fan does not exist on a side plate as in the conventional device, so that the thickness of the device is only the thickness between side plates, and the device is made thin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display device. Specifically, while maintaining the cooling effect of the liquid crystal panel,
The present invention relates to a projection display device that has a reduced thickness to improve portability.

[0002]

2. Description of the Related Art FIG. 5 shows an optical system configuration diagram of a conventional projection display device, and FIG. A halogen lamp, a metal halide lamp, or the like is used as the light source of this projection display device, and a dichroic mirror, a dichroic prism, or the like is used as the color separation optical element and the combining optical element. In FIG. 5, the white light emitted from the light source 1 is obtained by cutting the ultraviolet light and the infrared light by the UV / RI cut filter 2, and then the first dichroic mirror 3
Causes light in the blue band to pass therethrough and reflects light in the green to red bands.

The blue light travels along the optical path 90 at the first total reflection mirror 4.
The angle is changed, and the light is incident on the first liquid crystal panel 5, where it is optically modulated according to an input signal. The modulated light is incident on the second dichroic mirror 6, but since the second dichroic mirror 6 has a characteristic of passing other than red band light, the modulated blue light passes through the second dichroic mirror 6. , Towards the third dichroic mirror 7. Since the third dichroic mirror 7 has a characteristic of reflecting light other than the green band light, blue light is reflected by the third dichroic mirror 7.
The light is reflected by and is incident on the projection lens 8 with the direction of 90 ° changed.

On the other hand, the green-red light reflected by the first dichroic mirror 3 and changed in direction by 90 ° is incident on the fourth dichroic mirror 9. The fourth dichroic mirror 9 has a characteristic of reflecting red light. Here, the red light is reflected, changes its direction by 90 °, and is incident on the second liquid crystal panel 10. The light-modulated red light is incident on the second dichroic mirror 6, but since the second dichroic mirror 6 has a characteristic of reflecting the red light, it is reflected here.
Change the direction by 0 °. Since the third dichroic mirror 7 has a characteristic of reflecting the light other than the green light, the red light is reflected and is incident on the projection lens 8 with its direction changed by 90 °.

The green light transmitted through the fourth dichroic mirror 9 is incident on the third liquid crystal panel 11. here,
The green light subjected to the light modulation is 90 ° by the second total reflection mirror 12.
The direction is changed and the light enters the third dichroic mirror 7.
Since the third dichroic mirror 7 has a characteristic of transmitting green band light, the green light passes through the third dichroic mirror 7 as it is and enters the projection lens 8. Then, the light that has entered the projection lens 8 is projected on the screen to form an image. The condensing lens 13 provided adjacent to each liquid crystal panel is for allowing the light emitted from the panel to efficiently enter the projection lens. In addition, an incident side polarization plate 14 and an emission side polarization plate 1 are provided before and after each liquid crystal panel.
5 are provided.

The space around the liquid crystal panel including the incident side polarization plate 14, the liquid crystal panel and the emission side polarization plate 15 needs to be set within a predetermined temperature range for optimum operation. Therefore, these members are air-cooled by the cooling fan. As shown in FIG. 6, in the cooling fan, an intake fan 18 and a filter 19 are attached to one of side plates 17 and 17 'that fix the optical member 16 in between, and an exhaust fan 20 is attached to the rear portion.

[0007]

In the conventional projection type display device having the above structure, the width of the device is large because the cooling fan 18 is provided on one side of the side plate. That is, in addition to the thickness between the side plates 17 and 17 'and the thickness of the fan 18, a predetermined distance is provided between the side plate 17 and the fan 18 and between the fan 18 and the filter 19 in order to further suppress wind noise during fan operation. Therefore, the width of the device is considerably large. For this reason, the device is difficult to hold by hand, and portability is extremely poor.

In view of the above conventional problems, the present invention reduces the thickness of the device while maintaining the cooling effect of the liquid crystal panel,
It is an object to realize a projection display device with improved portability.

[0009]

In the projection type display device of the present invention, at least a light source section, a plurality of liquid crystal panel sections for modulating light from the light source, and projection optics for projecting the modulated light. In a projection display device composed of two parts,
The two plates face each other at a certain interval, and the constituent members are fixed between the spaces (a) formed between the two plates, and the spaces around the panel section are connected to each other in the space (a). Further, the panel group peripheral space group is shielded from the space around other constituent members, and two or more openings are provided so that the space around the panel unit is connected to the outside of the space (a). And

In addition to the above, at least one of the openings where the space around the panel is connected to the outside of the space (a).
It is characterized by having means for generating a positive pressure or a negative pressure in one opening. In addition, the space around the panel portion has two openings connected to the outside of the space (a), one having a means for generating a positive pressure and the other having a means for generating a negative pressure. To do.

In addition, the spaces around the plurality of panel portions are connected in series, an opening is provided on the side not connected, and means for generating a positive pressure or a negative pressure is provided in the opening. Characterize. In addition, the spaces around a plurality of panel parts are connected in series, with an opening on the non-connected side, a means for generating a positive pressure on one side, and a negative pressure on the other side. It is characterized by having means. Also, the means for generating positive pressure or negative pressure is
It is characterized in that it exists in an extended space between the two plates.

In addition, in the space around the panel unit, on the surface side where light is emitted from the liquid crystal panel toward the projection optical unit, the polarization optical member is shielded from the space around other members. And Further, in the space of the panel unit peripheral group, on the surface side where light is emitted from the liquid crystal panel in the direction of the projection optical unit, shielding with other member peripheral spaces is made by a polarizing plate to which a polarizing film is attached, Moreover, the film surface is directed to the liquid crystal panel side.

Further, the polarizing optical member is characterized in that, in the space around the panel unit, on the surface side where light is incident from the light source unit in the direction of the liquid crystal panel, the space around other members is shielded by the polarization optical member. . Further, in the space around the panel unit, on the surface side where light is incident from the light source unit toward the liquid crystal panel,
It is characterized in that the surrounding space of other members is shielded by a polarizing plate to which a polarizing film is attached, and the film surface is directed to the liquid crystal panel side. Further, in the space of the panel unit peripheral group, the light is incident from the light source unit in the direction of the liquid crystal panel, and the light is incident from the light source unit to the liquid crystal panel.

Further, in the space of the panel peripheral group, on the surface side where the light is incident from the light source in the direction of the liquid crystal panel, the condensing lens shields the peripheral space of other members,
Moreover, a polarizing film is attached to the liquid crystal panel side. Furthermore, of the space around the panel area,
On the surface side where the light is emitted from the liquid crystal panel toward the projection optical section, the glass plate is shielded from the space around other members, and the polarizing film is attached to the glass surface of the liquid crystal panel. It is characterized by

Then, as described above, by making the peripheral space of the panel portion and the peripheral space of other members separate,
The cooling space becomes the minimum necessary, and the cooling efficiency by the cooling fan improves. Moreover, since the fan is not provided on the side plates as in the conventional case, the thickness of the device is purely the thickness between the side plates, and the device is thin.

[0016]

1 and 2 are views showing a first embodiment of the present invention. FIG. 1 is a front view and FIG. 2 is a side sectional view. In the figure, 21 is a light source, 22 is a UV / IR cut filter for blocking ultraviolet rays and infrared rays, and 23 is a first dichroic that transmits blue band light and reflects green to red band light of white light from the light source. Mirror, 24 is first
Total reflection mirror, 25 is the first liquid crystal panel for blue display, 2
6 is a second that transmits light in the blue band and reflects light in the red band
Dichroic mirror, 27 is a third dichroic mirror that reflects light in the blue and red bands and transmits light in the green band, 28 is a projection lens, and 29 is a fourth dichroic that transmits light in the green band and reflects light in the red band Mirror, 30
Is a second liquid crystal panel for displaying red, 31 is a third liquid crystal panel for displaying green, and 32 is a second total reflection mirror.

Further, a condenser lens 33 and an incident side polarization plate 34 and an emission side polarization plate 35 as polarization optical members are provided in front of and behind each of the liquid crystal panels 25, 30, 31 to form a panel section. There is. (The polarizing optical member is a polarizing film or a polarizing plate in which the polarizing film is attached to a glass plate.) These optical members are two side plates 3
The optical system unit 37 is arranged between the components 6 and 36 ', and is housed in the housing 38. And the liquid crystal panel 2
5, 30, 31, a condensing lens 33, an incident side polarization plate 34, and an emission side polarization plate 35, the space around the panel portion is set to 2
The glass plate 39 and the blocking member 40 are shielded from other member spaces. The glass plate 39 shields at least the space of the optical path surface, and the shield fitting 40 shields the space other than the optical path surface. These panel spaces are connected to the first liquid crystal panel 25 peripheral space for blue display, the second liquid crystal panel 30 peripheral space for red display, and the third liquid crystal panel 31 peripheral space for green display, and are connected to each other in blue display. Liquid crystal panel 2 for
The openings that are not connected to the peripheral space 5 and the peripheral space of the third liquid crystal panel 31 for green display are connected to the external space.

A cooling fan is provided in each of the two openings connected to the external space. For example, the fan on the side of the first liquid crystal panel 25 is an intake fan 41 that generates a positive pressure, and the other fan. The fan on the side of the third liquid crystal panel 31 is an exhaust fan 42 that generates negative pressure. Reference numeral 43 denotes a device cooling fan provided in the casing 38 so as to discharge the air blown out from the exhaust fan 42 to the outside.
Reference numeral 44 is a filter for the intake fan.

In the first embodiment having such a configuration, the blue, red, and green lights separated by the first dichroic mirror 23 and the fourth dichroic mirror 29 are divided into the first to third parts.
The image is modulated by the liquid crystal panels 25, 30 and 31, and the image-modulated light is modulated by the second dichroic mirror 26 and the third dichroic mirror 26.
It can be combined by the dichroic mirror 27 and projected on the screen by the projection lens 28.

In this case, the air sucked from the intake fan 41 provided at one opening of the shutoff fitting 40 is
The three liquid crystal panels 25, 30, and 31 are sequentially cooled, and are discharged by the exhaust fan 42 provided in the other opening. Thereby, the temperature rise of each liquid crystal panel 25, 30, 31 is suppressed. Further, the air discharged by the exhaust fan 42 is discharged to the outside of the housing by the device cooling fan 43 while cooling the power supply unit, the circuit unit, the light source unit and the like. The exhaust fan 42 may also serve as the device cooling fan 43.

Further, although the fans are provided in the two openings of the panel space, respectively, only one of them may be provided. In that case, the cooling effect is weakened. May be selected according to the degree of cooling. The liquid crystal panel cooling fan is installed in the extended space between the side plates. Therefore, the thickness of the device is purely the thickness between the side plates. Moreover, even if a sufficient distance is provided between the fan and the filter for reducing the wind noise of the fan, there is no influence in the thickness direction of the device.

According to the first embodiment, the shut-off metal fitting 4
0 and the glass plate 39 separate the panel peripheral space from the other member peripheral space, the cooling space is minimized and the cooling efficiency of the cooling fan is improved. Also, because the fan is not on the side plate as in the past,
Since the thickness of the device is purely the thickness between the side plates, it is possible to reduce the thickness.

FIG. 3 is a side sectional view showing a second embodiment of the present invention. In the figure, 21 is a light source, 22 is a UV / IR cut filter for blocking ultraviolet rays and infrared rays, 2
3 transmits the blue light of the white light from the light source and transmits the green light.
First dichroic mirror that reflects light in the red band, 2
Reference numeral 4 is a first total reflection mirror, 25 is a first liquid crystal panel for displaying blue, 26 is a second dichroic mirror that transmits light in the blue band and reflects light in the red band, and 27 is light in the blue and red bands. A third dichroic mirror that transmits light in the green band, 28 is a projection lens, 29 is a fourth dichroic mirror that transmits light in the green band and reflects light in the red band, and 30 is a second liquid crystal panel for red display. Reference numeral 31 is a third liquid crystal panel for displaying green, and 32 is a second total reflection mirror.

Further, a condenser lens 33, an incident side polarization plate 34, and an emission side polarization plate 35 are provided in front of and behind each of the liquid crystal panels 25, 30, 31 to form a panel section. Similar to the previous embodiment, these optical members are arranged between the two side plates 36 and 36 'to form an optical system section and are further housed in the housing 38. The difference from the previous embodiment is that the glass panel 39 and the shutoff metal fitting 40 are used to shut off the liquid crystal panel peripheral space from other member spaces. In this embodiment, instead of the two glass plates 39, two incident side polarization plates 3 are used.
4 and the exit side polarization plate 35, and the condenser lens 33 is arranged outside the blocking fitting 40. The polarizing films of the incident-side and exit-side polarizing plates are arranged facing the liquid crystal panel side.

In the second embodiment having such a configuration, since the polarizing film of the polarizing plate faces the panel side, the cooling air comes into direct contact with the polarizing film surface, so that the cooling effect of the polarizing film is obtained. Increase. Further, as compared with the first embodiment, since the number of glasses is reduced, light quantity loss (about 10%) due to surface reflection does not occur, and thus high-luminance display can be performed. In this embodiment, the polarizing plate on the incident side and the polarizing plate on the emitting side are used for blocking the space. However, only one of them may be used. (The remaining means is the same as in the first embodiment)

FIG. 4 is a side sectional view showing a third embodiment of the present invention. The third embodiment is different from the second embodiment in that a condenser lens 33 is used in place of the incident side polarization plate 34 which shields the space around the panel portion of the second embodiment. It is that. The condensing lens 33 is a plano-convex type, the plane thereof faces the liquid crystal panel side, and the polarizing film 45 is attached to the plane side.

In the third embodiment configured as described above, one glass plate can be further removed as compared with the second embodiment, and the light amount loss (about 10%) due to that can be eliminated, so that High brightness can be achieved. The polarizing film may not be attached to the condenser lens and may be installed between the panel and the condenser lens. Further, although the condenser lens is provided on the incident side of the panel in the present embodiment, the same effect can be obtained even if the condenser lens is provided on the emitting side. Furthermore, although a plano-convex lens is used as the condenser lens, a Fresnel lens may be used. Also in the case of a Fresnel lens, the plane may be directed to the panel surface side. Further, the polarizing film of the polarizing plate shown in FIG. 4 may be attached to the glass surface of the liquid crystal panel and replaced with a glass plate instead of the blocking polarizing plate.

[0028]

According to the present invention, the space around the panel portion and the space around other members are separated from each other, so that the cooling space is minimized and the cooling efficiency by the cooling fan is improved. Further, since the fan is not provided on the side plates as in the conventional case, the thickness of the device is purely the thickness between the side plates, and it is possible to reduce the thickness and improve the portability of the device.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of the present invention.

FIG. 2 is a side sectional view showing the first embodiment of the present invention.

FIG. 3 is a side sectional view showing a second embodiment of the present invention.

FIG. 4 is a side sectional view showing a third embodiment of the present invention.

FIG. 5 is a configuration diagram showing an optical system of a conventional projection display device.

FIG. 6 is a diagram showing an example of the outer shape of a conventional projection display device,
(A) is a front view, (b) is a side view.

[Explanation of symbols]

 21 ... Light source 22 ... UV / IR cut filter 23 ... First dichroic mirror 24 ... First total reflection mirror 25 ... First liquid crystal panel 26 ... Second dichroic mirror 27 ... Third dichroic mirror 28 ... Projection lens 29 ... Fourth dichroic Mirror 30 ... Second liquid crystal panel 31 ... Third liquid crystal panel 32 ... Second total reflection mirror 33 ... Condensing lens 34 ... Incident side polarization plate 35 ... Emission side polarization plate 36, 36 '... Side plate 37 ... Optical system part 38 ... Housing 39 ... Glass plate 40 ... Blocking metal fitting 41 ... Intake fan 42 ... Exhaust fan 43 ... Device cooling fan 44 ... Filter 45 ... Polarizing film

Claims (13)

[Claims] 1. A projection display device comprising at least a light source section, a plurality of liquid crystal panel sections for modulating light from a light source, and a projection optical section for projecting the modulated light, wherein two plates are provided. The constituent members are fixed in a space (a) formed between the two sheets facing each other at a certain interval, and the spaces around the panel portion are connected to each other in the space (a), and this panel The projection type is characterized in that the group of peripheral space groups is cut off from the space around other components, and that the space around the panel section is provided with two or more openings that connect to the outside of the space (a). Display device. 2. The means for generating a positive pressure or a negative pressure in at least one of the openings connected to the outside of the space (a) in the space around the panel portion. Projection display device. 3. A space around the panel portion has two openings connected to the outside of the space (a), one having means for generating a positive pressure and the other having means for generating a negative pressure. The projection display device according to claim 1 or 2. 4. Spaces around a plurality of panel parts are connected in series, an opening is provided on the side not connected, and means for generating a positive pressure or a negative pressure is provided in the opening. The projection display device according to claim 1 or 2. 5. The space around a plurality of panel parts is connected in series, and an opening is provided on the non-connected side, a means for generating a positive pressure is provided on one side, and a negative pressure is provided on the other side. The projection display device according to claim 1 or 3, further comprising a means for generating the. 6. The projection display device according to claim 1, wherein means for generating a positive pressure or a negative pressure is present in an extended space between the two plates. . 7. A polarizing optical member is used to shield the surrounding space of other members on the surface side of the panel unit peripheral group where light is emitted from the liquid crystal panel toward the projection optical unit. The projection display device according to any one of claims 1 to 6. 8. A polarizing plate to which a polarizing film is adhered is arranged to shield the space around other members on the surface side of the panel unit peripheral group where light is emitted from the liquid crystal panel toward the projection optical unit. The projection display device according to claim 7, wherein the film surface is directed to the liquid crystal panel side. 9. The polarizing optical member is characterized in that, in the space of the panel unit peripheral group, on the surface side where light is incident from the light source unit in the direction of the liquid crystal panel, it is shielded from the other member peripheral space by the polarization optical member. The projection display device according to claim 1. 10. A polarizing plate to which a polarizing film is adhered is used to shield the space around other members on the surface side of the panel unit peripheral group where light is incident from the light source unit toward the liquid crystal panel. 10. The projection display device according to claim 9, wherein the film surface is directed to the liquid crystal panel side. 11. A condensing lens shields the space around other members from the surface side of the panel unit peripheral group where light is incident from the light source unit toward the liquid crystal panel. The projection display device according to claim 1, wherein the projection display device is a display device. 12. A condensing lens shields the space around other members on the surface side of the panel unit peripheral group where light is incident from the light source unit in the direction of the liquid crystal panel, and the liquid crystal thereof is provided. The projection display device according to claim 1, further comprising a polarizing film attached to the panel side. 13. The surface of the panel unit peripheral group in which light is emitted from the liquid crystal panel toward the projection optical unit,
The glass plate shields the space around other members.
The projection display device according to any one of claims 1 to 6, wherein the polarizing film is attached to the glass surface of the liquid crystal panel.