JP2005234287A - Liquid crystal projector device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently cool a liquid crystal display element and an optical element. <P>SOLUTION: The liquid crystal projector device is equipped with a color separation optical system equipped with a light source, 1st, 2nd and 3rd reflection type liquid crystal display elements and a projection lens, and separating light from the light source to the light respectively corresponding to the 1st, the 2nd and the 3rd refection type liquid crystal display elements, and a color composing optical system composing modulated light which is the light separated by the color separation optical system and made incident on the 1st to the 3rd reflection type liquid crystal display elements so as to be modulated, and enlarges and projects the modulated light composed by the color composing optical system by the projection lens. In the device, the color separation optical system is equipped with a color separation mirror for separating the light to the 1st color component light corresponding to the 1st and the 2nd reflection type liquid crystal display elements, and the 2nd color component light corresponding to the 3rd reflection type liquid crystal display element. Then, at least one cooling fan is installed so that cooling air may flow nearly in parallel with the front and back surfaces of the reflection surface of the color separation mirror. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to cooling of a liquid crystal projector provided with a reflective liquid crystal display element.

  In recent years, in a projection type liquid crystal projector apparatus using a liquid crystal display element, cooling of the liquid crystal display element and the optical element has become an issue more than ever due to an increasing demand for higher brightness of the apparatus. Regarding the element, not only the transmission type liquid crystal display element but also the reflection type liquid crystal display element has the same problem.

  Furthermore, there is an increasing demand for downsizing the apparatus, and there is a demand for downsizing the cooling means as well as efficient cooling.

  FIG. 8 is a plan view showing an outline of a projection type liquid crystal projector apparatus D5 using three conventional reflective liquid crystal display elements. FIG. 9 is a color separation for separating light corresponding to each of the liquid crystal display elements. FIG. 2 is a plan view showing an outline of an optical system and a color combining optical system that combines modulated light separated by the color separation optical system and modulated by being incident on the first to third reflective liquid crystal display elements. Yes (see, for example, Patent Document 1).

  8 and 9, the white light projected from the projection lamp 1 that is a light source is emitted as substantially parallel light L <b> 1 by the reflector constituting the projection lamp 1, and is converted to S-polarized L <b> 2 by the polarization conversion element 2. .

  L2 is incident on the RB transmitting dichroic mirror 3 which is a color separation mirror, L3 (RB) including R and B components which are the first color component light is transmitted as it is, and the second color component light including the G component is transmitted. L2 (G) is reflected and separated into R, B spectroscopy and G component light.

  The L3 (RB) of S-polarized light then enters the first polarization rotation element 5 having wavelength selectivity.

  The first polarization rotation element 5 is set to have a characteristic of transmitting the incident RB component light with the R component transmitted as S-polarized light and rotating the B component into P-polarized light, and the incident L3 (RB) is The light is emitted as an S-polarized R component L4 (R) and a P-polarized B component L4 (B).

  Reference numeral 10 denotes a first polarizing beam splitter prism (hereinafter referred to as a first PBS prism), which reflects S-polarized light and transmits P-polarized light.

  The L4 (R) and L4 (B) are incident on the first PBS prism 10, and the S4 polarized light L4 (R) is reflected by the first PBS prism 10 and is emitted after being bent 90 degrees in the optical path direction. .

  The emitted L4 (R) is incident on the reflective liquid crystal display element 20R, becomes modulated light L5 (R) modulated in accordance with the R color video signal and converted into P-polarized light, and the reflective liquid crystal display element 20R. Is emitted.

  The P-polarized modulated light L5 (R) is incident on the first PBS prism 10 again, and since it is P-polarized light, it is transmitted through the first PBS prism 10 and emitted.

  Since the P-polarized light L4 (B) incident on the first PBS prism 10 is P-polarized light, it is transmitted through the first PBS prism 10 and emitted.

  The emitted L4 (B) enters the reflective liquid crystal display element 20B, is modulated and converted into S-polarized light in accordance with a B-color video signal, and is converted into S-polarized modulated light L5 (B). Since it is S-polarized light, it is reflected by the first PBS prism 10 and bent 90 degrees in the optical path direction, and then synthesized and emitted in the same direction as the L4 (R).

  Reference numeral 11 denotes a second polarizing beam splitter prism (hereinafter, referred to as a second PBS prism), which reflects S-polarized light and transmits P-polarized light in the same manner as the first PBS prism 10.

  The G component L3 (G) separated by the RB transmission dichroic mirror 3 is reflected by the RB transmission dichroic mirror 3, bent by 90 degrees in the optical path direction, and then transmitted through L3 (RB). The light passes through the dummy glass 30 installed to make the optical path length equal to 5 and enters the second PBS prism 11.

  Since the L-polarized light L3 (G) is S-polarized light, it is reflected by the second PBS prism 11 and is emitted after being bent in the optical path direction by 90 degrees, and enters the reflective liquid crystal display element 20G.

  L3 (G) incident on the reflective liquid crystal display element 20G is modulated and converted into P-polarized light according to the G-color video signal, and is incident again on the third PBS prism 11 as P-polarized modulated light L4 (G). Since it is P-polarized light, it passes through the second PBS prism 11 and exits from the second PBS prism 11.

  Reference numeral 12 denotes a third polarizing beam splitter prism (hereinafter referred to as a third PBS prism), which reflects S-polarized light and transmits P-polarized light.

  Between the first PBS prism 10 and the third PBS prism 12, a second polarization rotating element 6 having wavelength selectivity is installed.

  The second polarization rotator 6 is set to have the characteristic that the incident RB component light is transmitted with the R component as S-polarized light and the B component is rotated into P-polarized light. (R) is emitted as S-polarized light and is set to L6 (R). Similarly, the incident B component L5 (B) is set to the characteristic of rotating to S-polarized light and is emitted as S-polarized light L6 (B). .

  The L6 (R) and L6 (B) are then incident on the third PBS prism 12 and are both S-polarized light. Therefore, the L6 (R) and L6 (B) are reflected by the third PBS prism 12 and bent in the optical path direction by 90 degrees. It is emitted in 40 directions.

  L6 (G), which is P-polarized light, passes through the third PBS prism 12, is combined with L6 (R) and L6 (B), and is emitted toward the projection lens 40.

  The combined L6 (R), L6 (B), and L6 (G) enter the projection lens 40 after exiting the third PBS prism 12, and are enlarged and projected on a screen (not shown).

  In the projection type liquid crystal projector device D5, a cooling fan 60 for cooling the reflection type liquid crystal display elements 20R and 20B is provided below the reflection type liquid crystal display elements 20R and 20B. A cooling fan 611 for cooling the reflective liquid crystal display element 20G is installed in the lower part.

  The cooling air from the cooling fans 60 and 61 is flowed upward, and passes through the display surface side and the back surface side of each of the reflection type liquid crystal display elements, thereby cooling each reflection type liquid crystal display element, and The optical element disposed around each reflective liquid crystal display element is cooled.

Japanese Patent Application Laid-Open No. 07-231460

  In a liquid crystal projector apparatus using three reflective liquid crystal display elements, as shown in the projection type liquid crystal projector apparatus D5, three PBS prisms are used.

  Here, the reflective liquid crystal display elements 20R and 20B arranged on the two surfaces of the first PBS prism 10 and the reflective liquid crystal display element 20G arranged on the one surface of the second PBS prism 11 sandwich the third PBS prism 12. Therefore, the position of one reflective liquid crystal display element is separated from the other two sheets.

  Therefore, in the projection type liquid crystal projector apparatus D5, the cooling fan 60 for cooling the reflection type liquid crystal display elements 20R and 20B and the reflection type liquid crystal display element 20G are provided below the reflection type liquid crystal display elements 20R and 20B. A cooling fan 61 for cooling the reflective liquid crystal display element 20G is installed in the lower part, and each liquid crystal display element at a distant position is cooled, so that the position of one reflective liquid crystal display element is changed to another. Measures are taken for leaving two sheets apart.

  However, when the two cooling fans 60 and 61 are used, the space occupied by the cooling fans increases, which not only hinders downsizing of the apparatus, but also increases noise.

  In addition, when the cooling fans 60 and 61 are installed below the respective reflective liquid crystal display elements, it is difficult to meet this requirement when the apparatus is required to be thin.

  In order to meet the demand for thinner devices, there is a method of installing a cooling fan on the side surface of the reflective liquid crystal display element. In this case as well, as described above, the reflective liquid crystal display elements 20R and 20B are provided. On the other hand, since the reflection type liquid crystal display element 20G is separated, it is necessary to install a plurality of cooling fans, which similarly hinders increase in noise and downsizing.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal projector device capable of efficiently cooling a liquid crystal display element and an optical element.

To achieve the above object, the present invention comprises a light source, first, second and third reflective liquid crystal display elements and a projection lens, and the light from the light source is reflected in the first, second and third reflective types. A color separation optical system that separates light corresponding to each of the liquid crystal display elements and a modulated light that is separated by the color separation optical system and modulated by being incident on the first to third reflective liquid crystal display elements A color synthesizing optical system, and a liquid crystal projector that performs enlarged projection of the modulated light synthesized by the color synthesizing optical system using the projection lens,
The color separation optical system includes a first color component light corresponding to the first and second reflective liquid crystal display elements and a second color component light corresponding to the third reflective liquid crystal display element. A color separation mirror for separation is provided, and at least one cooling fan is installed so that cooling air flows substantially parallel to the front and back surfaces of the reflection surface of the color separation mirror.

  According to the present invention, by installing the cooling fan 50 so that the cooling air flows substantially parallel to the front and back of the reflecting surface of the RB transmitting dichroic mirror 3, the cooling air W1 from the cooling fan 50 is The RB transmitting dichroic mirror 3 can be used as an air guide member, and can be separated into cooling air W110, W111, W112 and W120, W121, W122.

  The cooling air W110 and W111 pass through the back side and the display surface side of the reflective liquid crystal display element 20R, thereby allowing the reflective liquid crystal display element 20R to be cooled.

  In addition, when an optical element such as a 1 / 4λ plate is disposed in the gap between the first PBS prism 10 and the reflective liquid crystal display element 20R, the W111 can also cool the optical element.

  Further, since the cooling air W112 passes through the gap between the first PBS prism 10 and the third PBS prism 12, an optical element, RB emission in this embodiment, is placed in the gap between the first PBS prism 10 and the third PBS prism 12. When the polarizing plate 8 is disposed, the RB outgoing polarizing plate 8 can be cooled by passing through the front and back surfaces of the RB outgoing polarizing plate 8.

  Further, since the cooling air W111 and W112 pass through the periphery of the reflective liquid crystal display element 20B and are then discharged from the exhaust port 101, the reflective liquid crystal display element 20B can be cooled, and further, the first PBS prism 10 can be cooled. When the optical element is disposed in the gap between the reflective liquid crystal display element 20B, the optical element can be cooled.

  The cooling air W120 and W121 pass through the back side and the display surface side of the reflective liquid crystal display element 20G, thereby allowing the reflective liquid crystal display element 20G to be cooled.

  Further, the cooling air W121 can cool the optical element when an optical element such as a 1 / 4λ plate is disposed in the gap between the second PBS prism 11 and the reflective liquid crystal display element 20G.

  Further, since the cooling air W122 passes through the gap between the second PBS prism 11 and the third PBS prism 12, an optical element, in this embodiment G emission, is placed in the gap between the second PBS prism 11 and the third PBS prism 12. When the polarizing plate 9 is disposed, the cooling air W122 passes through the front and back surfaces of the G outgoing polarizing plate 9, thereby allowing the G outgoing polarizing plate 9 to be cooled.

  Further, according to the present invention, the cooling air W1 from the cooling fan 50 is provided by installing the cooling fan 50 so that the cooling air flows substantially parallel to the front and back surfaces of the reflecting surface of the RB transmitting dichroic mirror 3. The RB transmitting dichroic mirror 3 can be used as a wind guide member, and separated into cooling winds W110, W111, W112 and W120, W121, W122, and the cooling winds W110, W111, and W112 The flow direction 202 can be changed by the air guide shape 202 formed in the device D1, and the cooling air flows toward the side surface of the reflective liquid crystal display element 20G and flows through the back surface of the reflective liquid crystal display element 20G. Cooling air W1 flowing through a gap between W130, the first PBS prism 10, and the reflective liquid crystal display element 20G 1.

  Here, the cooling air W130 and W131 pass through the back side and the display surface side of the reflective liquid crystal display element 20G, thereby allowing the reflective liquid crystal display element 20G to be cooled.

  Further, the cooling air W131 can cool the optical element when an optical element such as a 1 / 4λ plate is disposed in the gap between the first PBS prism 10 and the reflective liquid crystal display element 20G. .

  Thereby, the cooling air W1 from the cooling fan 40, in particular, the cooling air W11 flows efficiently by the air guide shape 202 formed in the projection type liquid crystal projector device D2, and the reflection type liquid crystal display element 20R is more effective. The cooling effect of the reflective liquid crystal display element 20B can be changed in order to cool the reflective liquid crystal display element 20B by the air guide shape 202. Can be increased.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the liquid crystal projector apparatuses D1 to D4 according to the embodiment of the present invention include a projection lamp 1, a polarization conversion element 2, an RB transmission dichroic mirror 3, an RB incident polarization plate 4, a first polarization rotation element 5, and a G Incident polarizer 7, second polarization rotating element 6, RB exit polarizer 8, G exit polarizer 9, first PBS prism 10, second PBS prism 11, third PBS prism 12, R reflective liquid crystal display element 20R, for G The reflection type liquid crystal display element 20G, the B reflection type liquid crystal display element 20B, the incident dummy glass 30, the emission dummy glass 31, the projection lens 40, and the cooling fan 50 are arranged in the casing 100, respectively.

  The substantially parallel light L1 emitted from the reflector constituting the projection lamp 1 that is a light source is converted into S2 polarized light L2 by the polarization conversion element 2.

  L2 is incident on the RB transmitting dichroic mirror 3 which is a color separation mirror, L3 (RB) including R and B components which are the first color component light is transmitted as it is, and the second color component light including the G component is transmitted. L3 (G) is reflected and bent in the optical path direction by 90 degrees to be separated into R, B and G components.

  The S-polarized L3 (RB) is transmitted through the RB incident polarizing plate 4, and the remaining P-polarized light component is further cut, and enters the first polarization rotation element 5 having wavelength selectivity.

  The first polarization rotation element 5 is set so that the R component is transmitted as the S polarization and the B component is rotated to the P polarization, and the L3 (RB) is the R component L4 (R) of the S polarization. , P-polarized B component L4 (B) is transmitted.

  Reference numeral 10 denotes a first polarizing beam splitter prism (hereinafter referred to as a first PBS prism), which is formed by joining the first light-transmissive member 10a and the second light-transmissive member 10b with the dielectric multilayer film 10c interposed therebetween. ing.

  Here, the dielectric multilayer film 10c is set to reflect S-polarized light and transmit P-polarized light.

  The L4 (R) and L4 (B) are incident on the first PBS prism 10, and the S4 polarized light L4 (R) is reflected by the dielectric multilayer film 10c and bent in the optical path direction by 90 degrees. The prism 10 is emitted from the translucent member 10a side.

  The emitted L4 (R) enters the reflective liquid crystal display element 20R, and is modulated and converted into P-polarized light in accordance with the R color video signal to become modulated light L5 (R), which is reflected by the reflective liquid crystal display element 20R. Is emitted.

  The P-polarized modulated light L5 (R) is incident again on the first PBS prism 10 and is P-polarized light. Therefore, the P-polarized modulated light L5 (R) is transmitted through the dielectric multilayer film 10c and from the second translucent member 10b side. Is emitted.

  Since the P-polarized light L4 (B) is P-polarized light, it passes through the dielectric multilayer film 10c of the first PBS prism 10 and exits the first PBS prism 10 from the second translucent member 10b side.

  The emitted L4 (B) enters the reflective liquid crystal display element 20B, and is modulated and converted into S-polarized light according to the B-color video signal, and is again transmitted to the first PBS prism 10 as modulated light L5 (B). Since it is incident and is S-polarized light, it is reflected by the dielectric multilayer film 10c, bent in the optical path direction by 90 degrees, synthesized with the L5 (R), and emitted from the first PBS prism 10 from the second translucent member 10b side. To do.

  The G component L3 (G) reflected and separated by the RB transmitting dichroic mirror 3 is incident on the G incident polarizing plate 7, and the remaining P polarized component is further cut and transmitted.

  Further, L3 (G) is installed in order to make the optical path length equal to the amount of the first polarization rotation element 5 that L3 (RB) transmits in order to make the optical path length equal to the optical paths of R and B described above. And passes through the dummy glass 30 to become L4 (G).

  Reference numeral 11 denotes a second polarizing beam splitter prism (hereinafter referred to as a second PBS prism). Like the first PBS prism 10, the first light-transmissive member 11a and the second light-transmissive member 11a are sandwiched between the dielectric multilayer films 11c. The optical member 11b is joined and configured to reflect S-polarized light and transmit P-polarized light.

  Since S-polarized L4 (G) incident on the second PBS prism 11 is S-polarized light, it is reflected by the dielectric multilayer film 11c, bent 90 degrees in the optical path direction, and then from the first translucent member 11a side. The light exits from the second PBS prism 11 and enters the reflective liquid crystal display element 20G.

  L4 (G) incident on the reflective liquid crystal display element 20G is modulated and converted into P-polarized light in accordance with the G-color video signal, and is incident again on the second PBS prism 11 as P-polarized modulated light L5 (G). And since it is P polarization | polarized-light, it permeate | transmits the said dielectric multilayer film 11c, and radiate | emits the 2nd PBS prism 11 from the 2nd translucent member 11b side.

  Reference numeral 12 denotes a third polarizing beam splitter prism (hereinafter, referred to as a third prism). Like the first prism 10 and the second prism, the first light-transmissive member 12a is sandwiched between the dielectric multilayer film 12c. The second translucent member 12b is joined and configured to reflect S-polarized light and transmit P-polarized light.

  Here, between the first PBS prism 10 and the third PBS prism 12, a second polarization rotation element 6 having wavelength selectivity and an RB emission polarizing plate 8 are installed.

  Here, the second polarization rotation element 6 is set so that the R component is transmitted as S-polarized light and the B component is rotated to S-polarized light.

  The S5 polarized light L5 (R) and the P polarized light L5 (B) emitted from the second PBS prism 11 are incident on the second polarization rotating element 6 and are the R component L5 (R). Is emitted as S-polarized light as L6 (R), and B component L5 (B) is rotated to S-polarized light and emitted as S-polarized L6 (B).

  Next, L6 (R) and L6 (B) are transmitted through the S-polarized RB exit polarizing plate 8 to further remove unnecessary P-polarized light components.

  Between the second PBS prism 11 and the third PBS prism 12, an outgoing dummy glass 31 and a G outgoing polarizing plate 9 are installed.

  The L5 (G) is transmitted through the dummy glass 31 installed in order to make the optical path length equal to the amount of the second polarization rotation element 6 that L6 (R) and L6 (B) transmit.

  Next, L5 (G) passes through the P-polarized G transmission polarizing plate 9 to further remove unnecessary S-polarized light components, and is emitted as L6 (G).

  The L6 (R), L6 (B), and L6 (G) are incident on the third PBS prism 12, respectively.

  The L6 (R) and L6 (B), which are S-polarized light incident on the third PBS prism 12 from the first translucent member 12a side, are reflected by the dielectric multilayer film 12c of the third PBS prism 12, and the optical path direction. Is bent 90 degrees, and is emitted from the translucent member 12a side.

  L6 (G), which is P-polarized light, is incident from the first light transmitting member 12b side, and is P-polarized light, so that it passes through the dielectric multilayer film 12c, and the L6 (R), L6 (B), and the like. After being synthesized, the light is emitted from the translucent member 12a side, enters the projection lens 40, and is enlarged and projected onto a screen (not shown).

  In the liquid crystal projector device D1, the cooling fan 50 is substantially perpendicular to the front and back of the reflecting surface of the RB transmitting dichroic mirror 3 so that the cooling air flows substantially parallel to the front and back of the reflecting surface of the RB transmitting dichroic mirror 3. Is installed.

<Embodiment 1>
The first embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a plan view schematically showing a liquid crystal projector apparatus D1 using a reflective liquid crystal display element according to the present invention.

  FIG. 2 shows a color separation optical system that separates light corresponding to each of the liquid crystal display elements in the liquid crystal projector device D1, and white light from a light source is separated by the color separation optical system. It is the top view which showed the outline of the color synthetic | combination optical system which synthesize | combines the modulated light modulated by making it enter.

  In FIGS. 1 and 2, the cooling fan 50 is approximately on the reflecting surface of the RB transmitting dichroic mirror 3 so that the cooling air flows substantially parallel to the reflecting surface of the RB transmitting dichroic mirror 3. It is installed vertically.

  Further, exhaust ports 101 and 102 are provided on the back surface of the reflective liquid crystal display element 20B and the side surface of the reflective liquid crystal display element 20G.

  FIG. 3 is a schematic view showing the flow of cooling air from the cooling fan 50 in the liquid crystal projector device D1.

  In the liquid crystal projector device D1, the cooling air W1 from the cooling fan 50 is separated by the RB transmitting dichroic mirror 3 installed in front of the cooling fan 50 as a wind guiding member, and the back side of the reflecting surface of the RB transmitting dichroic mirror 3 is separated. The cooling air W11 that flows through the 3R side and the cooling air W12 that flows through the 3F side that is the front surface of the reflecting surface are separated.

  Further, the cooling air W11 is an optical element arranged on the front surface side of the incident surface of the first PBS prism 10, in this embodiment, the RB incident polarizing plate 4 serves as an air guiding member, and the reflective liquid crystal display element 20R Cooling air W110 passing through the back surface, cooling air W111 passing through the gap between the first PBS prism 10 and the reflective liquid crystal display element 20R, and cooling air W112 passing through the gap between the first PBS prism 10 and the second PBS prism 11. Separated.

  Here, the cooling air W110 and W111 pass through the back side and the display surface side of the reflective liquid crystal display element 20R, so that the reflective liquid crystal display element 20R can be cooled.

  In addition, when an optical element such as a quarter λ plate is disposed in the gap between the first PBS prism 10 and the reflective liquid crystal display element 20R, the W111 can also cool the optical element.

  Further, since the cooling air W112 passes through the gap between the first PBS prism 10 and the third PBS prism 12, an optical element, RB emission in this embodiment, is placed in the gap between the first PBS prism 10 and the third PBS prism 12. In the case where the polarizing plate 8 is disposed, the cooling air W112 passes through the front and back surfaces of the RB output polarizing plate 8 so that the RB output polarizing plate 8 can be cooled.

  Further, since W111 and W112 pass through the periphery of the reflective liquid crystal display element 20B and are discharged from the exhaust port 101, the reflective liquid crystal display element 20B can be cooled, and further, the first PBS prism can be cooled. When an optical element is arranged in the gap between the reflective liquid crystal display element 20B and the reflective liquid crystal display element 20B, the optical element can be cooled.

  The cooling air W12 is an optical element disposed on the front side of the incident surface of the second PBS prism 11, in this embodiment, the G incident polarizing plate 7 serves as a wind guiding member, and the back surface of the reflective liquid crystal display element 20R is used. The cooling air W120 that passes through, the cooling air W121 that passes through the gap between the second PBS prism 11 and the reflective liquid crystal display element 20G, and the cooling air W122 that passes through the gap between the second PBS prism 11 and the third PBS prism 12 are separated. Is done.

  Here, the cooling air W120 and W121 passes through the back side and the display surface side of the reflective liquid crystal display element 20G, thereby cooling the reflective liquid crystal display element 20G.

  Further, when an optical element such as a 1 / 4λ plate is disposed in the gap between the second PBS prism 11 and the reflective liquid crystal display element 20G, the W121 can also cool the optical element. .

  Further, since the cooling air W122 passes through the gap between the second PBS prism 11 and the third PBS prism 12, an optical element, G emission in this embodiment, is placed in the gap between the second PBS prism 11 and the third PBS prism 12. When the polarizing plate 9 is disposed, the cooling air W122 passes through the front and back surfaces of the G outgoing polarizing plate 9 so that the G outgoing polarizing plate 9 can be cooled.

  In addition, arrangement | positioning of each transmissive | pervious liquid crystal display element of each color of R, G, B in embodiment of this invention is an example, and is not limited to this arrangement | positioning.

  Further, in the present embodiment, an embodiment in a front projection type liquid crystal projector apparatus is shown, but a similar configuration can be adopted as a projection unit in a rear projection type liquid crystal projector apparatus.

<Embodiment 2>
The second embodiment of the present invention will be described below with reference to FIGS.

  In the present embodiment, the air guide shape 202 is formed in the device D2, and the cooling air W1 from the cooling fan 50 is introduced. Further, an exhaust port 201 is formed on the side surface of the reflective liquid crystal display element 20G.

  The cooling air W1 from the cooling fan 50 is separated by the RB transmitting dichroic mirror 3 installed in front of the cooling fan 50 as an air guiding member, and flows on the 3R side that is the back side of the reflecting surface of the RB transmitting dichroic mirror 3. The cooling air is separated into the cooling air W11 and the cooling air W12 flowing on the 3F side which is the front side of the reflecting surface.

  Further, the cooling air W11 is an optical element arranged on the front side of the incident surface of the first PBS prism, in this embodiment, the PB incident polarizing plate 4 serves as a wind guide member, and the rear surface of the reflective liquid crystal display element 20R. Cooling air W110 passing through the first PBS prism 10, the cooling air W111 passing through the gap between the reflective liquid crystal display elements 20R, and the cooling air W112 passing through the gap between the first PBS prism 10 and the third PBS prism 12. Separated.

  Here, the cooling air W110 and W111 flow along the air guide shape 202 formed in the device D2, and pass through the back surface side and the display surface side of the reflective liquid crystal display element 20R, thereby the reflective liquid crystal. The display element 20R can be cooled.

  Further, when an optical element such as a 1 / 4λ plate is disposed in the gap between the first PBS prism 10 and the reflective liquid crystal display element 20R by the W111, the optical element can be cooled.

  Further, since the cooling air W112 passes through the gap between the first PBS prism 10 and the third PBS prism 12, an optical element, RB emission in this embodiment, is placed in the gap between the first PBS prism 10 and the third PBS prism 12. When the polarizing plate 8 is disposed, the RB emission polarizing plate 8 can be cooled.

  Further, the flow direction of the W110, W111, and W112 can be changed by the air guide shape 202 formed in the device D0, and the W110, W111, and W112 flows toward the side surface of the reflective liquid crystal display element 20G, and The cooling air W130 flows through the back surface of 20G and the cooling air W131 flows through the gap between the first PBS prism 10 and the reflective liquid crystal display element 20G.

  Here, the cooling air W130 and W131 pass through the back side and the display surface side of the reflective liquid crystal display element 20G, thereby allowing the reflective liquid crystal display element 20G to be cooled.

  Further, the cooling air W131 can cool the optical element when an optical element such as a 1 / 4λ plate is disposed in the gap between the first PBS prism 10 and the reflective liquid crystal display element 20G. .

  Further, since the cooling air W132 passes through the gap between the first PBS prism 10 and the third PBS prism 12, an optical element, RB emission in this embodiment, is placed in the gap between the first PBS prism 10 and the third PBS prism 12. In the case where the polarizing plate 8 is disposed, the polarizing plate 8 can be cooled by passing through the front and back surfaces of the RB emission polarizing plate 8.

  The cooling air W12 is an optical element arranged on the front side of the incident surface of the second PBS prism 11, in this embodiment, the G incident polarizing plate 7 serves as an air guiding member, and the back surface of the reflective liquid crystal display element 20G is used. The cooling air W120 that passes through, the cooling air W121 that passes through the gap between the second PBS prism 11 and the reflective liquid crystal display element 20G, and the cooling air W122 that passes through the gap between the first PBS prism and the second PBS prism are separated. .

  Here, the cooling air W120 and W121 pass through the back side and the display surface side of the reflective liquid crystal display element 20G, thereby allowing the reflective liquid crystal display element 20G to be cooled.

  Further, when an optical element such as a 1 / 4λ plate is disposed in the gap between the second PBS prism 11 and the reflective liquid crystal display element 20G by the W121, the optical element can also be cooled. .

  Further, since the cooling air W122 passes through the gap between the second PBS prism 11 and the third PBS prism 12, an optical element, G emission in this embodiment, is placed in the gap between the second PBS prism 11 and the third PBS prism 12. When the polarizing plate 9 is disposed, the G emitting polarizing plate 9 can be cooled by passing through the front and back surfaces of the G emitting polarizing plate 9.

  The W112, W130, and W131 pass through the side surface of the third PBS prism 12, and are exhausted out of the apparatus D2 through the exhaust port 201 together with W120, W121, and W122.

  Thereby, in addition to the effects in the first embodiment, the cooling air W1, particularly W11 from the cooling fan 40 efficiently flows due to the air guide shape 202 formed in the device D2, and the reflective liquid crystal display element 20R. The cooling air flow direction can be changed in order to cool the reflective liquid crystal display element 20B by the air guide shape 202, so that the air guide shape 202 can be cooled. In comparison, the cooling effect of the reflective liquid crystal display element 20B can be enhanced.

  Further, as shown in FIG. 6, by forming the air guide shape 203 in addition to the air guide shape 202, the flow of the cooling air W120, W121, W122 separated from the cooling air W12 is guided. The cooling air flows efficiently, and an optical element such as a 1 / 4λ plate is disposed in the gap between the reflective liquid crystal display element 20G and the reflective liquid crystal display element 20G and the second PBS prism 11. Can improve the cooling effect of the optical element, which is even better.

  Here, the air guide shapes 202 and 203 may be part of the apparatus housing.

  In addition, as shown in FIG. 7, if the mirror holding portion 204 that holds the RB transmitting dichroic mirror 3 is also used as a wind guide shape, the cooling air W1 can be efficiently separated into W11 and W12.

  In addition, the holding portions of other optical elements may be used in the same manner as a wind guide shape.

  The present invention is useful for a liquid crystal projector device provided with a reflective liquid crystal display device.

It is a top view which shows schematic structure of the liquid crystal projector device which concerns on Embodiment 1 of this invention. FIG. 3 is a schematic diagram of the periphery of a reflective liquid crystal display element and a PBS prism in the liquid crystal projector device according to the first embodiment of the present invention. FIG. 3 is a schematic diagram showing a flow of cooling air around a reflective liquid crystal display element and a PBS prism in the liquid crystal projector device according to the first embodiment of the present invention. It is a top view which shows schematic structure of the liquid crystal projector device which concerns on Embodiment 2 of this invention. It is the schematic of the reflection type liquid crystal display element and PBS prism periphery in the liquid crystal projector device which concerns on Embodiment 2 of this invention. It is a top view which shows schematic structure of the liquid crystal projector device in the liquid crystal projector device which concerns on Embodiment 2 of this invention. It is a top view which shows schematic structure of the liquid crystal projector device which concerns on Embodiment 3 of this invention. It is a top view which shows schematic structure of the conventional liquid crystal projector device. It is the schematic of the reflection type liquid crystal display element and PBS prism periphery in the conventional liquid crystal projector device.

Explanation of symbols

D1 to D5 Liquid crystal projector apparatus 1 Projection lamp 2 Polarization conversion element 3 RB transmission dichroic mirror 3F Incident surface front side of RB transmission dichroic mirror 3R Incident surface back side of PB transmission dichroic mirror 4 PB incident polarizing plate 5 First polarization rotation element 6 Second Polarization rotator 7 G incident polarizing plate 8 RB outgoing polarizing plate 9 G outgoing polarizing plate 10 first PBS prism 10a first light transmitting member 10b second light transmitting member 10c dielectric multilayer film 11 second PBS prism 11a first light transmitting member 11b 2nd translucent member 11c Dielectric multilayer film 12 3rd PBS prism 12a 1st translucent member 12b 2nd translucent member 12c Dielectric multilayer film 20R R reflective liquid crystal display element 20G G reflective liquid crystal display element 20B For B Reflective liquid crystal display element 30 Incident dummy glass 31 Output dummy glass 40 Projection lens 50 to 61 Cooling fan 100 Device housing 101 Opening portion 102 Opening portion 201 Opening portion 202 Air guide shape 203 Air guide shape 204 Mirror holding portion W1, W11 Cooling air W110 to W112 Cooling air W12 Cooling air W120 to W122 Cooling air W130, W131 Cooling air

Claims (5)

A light source, and first, second, and third reflective liquid crystal display elements and a projection lens, and the light from the light source is converted into light corresponding to the first, second, and third reflective liquid crystal display elements, respectively. A color separation optical system for separating, and a color synthesis optical system for synthesizing modulated light separated by the color separation optical system and modulated by being incident on the first to third reflective liquid crystal display elements, In the liquid crystal projector device that projects the modulated light synthesized by the color synthesis optical system in an enlarged manner by the projection lens,
The color separation optical system includes a first color component light corresponding to the first and second reflective liquid crystal display elements and a second color component light corresponding to the third reflective liquid crystal display element. A liquid crystal projector apparatus comprising: a color separation mirror for separation, and at least one cooling fan installed so that cooling air flows substantially parallel to the front and back surfaces of the reflection surface of the color separation mirror. First, second, and third polarizing beam splitter prisms are disposed, and the first polarizing beam splitter prism is disposed on an optical path of the first color component light separated by being transmitted through the color separation mirror. The second polarization beam splitter prism is disposed on the optical path of the second color component light; and the third polarization beam splitter prism is disposed on the first and second reflective liquid crystal displays. On the optical path of the modulated light emitted after the modulated light modulated by the element is combined by the first polarizing beam splitter, and modulated by the third reflective liquid crystal display element, the second polarized beam A color synthesizing optical system that is arranged on an optical path of modulated light emitted from a splitter and synthesizes each modulated light modulated by the first to third reflective liquid crystal display elements,
Of the cooling airs that have flowed substantially parallel to the front and back of the reflective surface of the color separation mirror, the cooling air that has flowed to the space including the first polarizing beam splitter is the first reflective liquid crystal display element. And the gap between the first polarizing beam splitter and / or the gap between the second reflective liquid crystal display element and the first polarizing beam splitter, and both of the reflecting surfaces of the color separation mirror. Of the cooling winds that have flowed substantially in parallel, the cooling wind that has flowed to the space side including the second polarizing beam splitter passes through the gap between the third reflective liquid crystal display element and the second polarizing beam splitter. The liquid crystal projector device according to claim 1, wherein the liquid crystal projector device passes. First, second, and third polarizing beam splitter prisms are disposed, and the first polarizing beam splitter prism is disposed on an optical path of the first color component light separated by being transmitted through the color separation mirror. The second polarization beam splitter prism is disposed on the optical path of the second color component light; and the third polarization beam splitter prism is disposed on the first and second reflective liquid crystal displays. On the optical path of the modulated light emitted after the modulated light modulated by the element is combined by the first polarizing beam splitter, and modulated by the third reflective liquid crystal display element, the second polarized beam A color synthesizing optical system that is arranged on an optical path of modulated light emitted from a splitter and synthesizes each modulated light modulated by the first to third reflective liquid crystal display elements,
Of the cooling winds that have flowed substantially parallel to the front and back of the reflecting surface of the color separation mirror, the cooling wind that has flowed to the space including the first polarizing beam splitter is the first polarizing beam splitter prism. Among the cooling winds that have passed through the gaps of the third polarization beam splitter prism and flowed substantially in parallel, the cooling winds that flowed to the space side including the second polarization beam splitter are the second The liquid crystal projector device according to claim 1, wherein the liquid crystal projector device passes through a gap between the polarizing beam splitter prism and the third polarizing beam splitter prism.   An air guide shape for guiding the flow of at least one cooling air among the cooling airs flowing substantially parallel to the front and back surfaces of the color separation mirror is formed in the apparatus. The liquid crystal projector apparatus of any one of Claims 1-3.   5. The liquid crystal projector device according to claim 1, wherein at least one of the cooling fans is disposed substantially perpendicular to a reflection surface of the color separation mirror.

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