JP2004206142A - Projection display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a projection display device provided with an attaching mechanism, which allows a light valve to be detached and is hardly affected by thermal distortion. <P>SOLUTION: The projection display device which decomposes a luminous flux from a light source into a plurality of color luminous fluxes and synthesizes again modulated luminous fluxes of respective colors after modulation through the light valve to project an enlarged image comprises; a fixed frame plate 54 which is fixed to a light entrance surface of a prism body by an adhesive; a frame plate holding the light valve; a fixing means for detachably attaching the frame plate to the fixed frame plate; and a positioning means for positioning the light valve with respect to the light entrance surface of the prism body. The fixed frame plate 54 is made of a material of which the coefficient of linear expansion is 1/4 to 4 times as high as that of the prism material, and the light valve frame plate is made of a material of which the coefficient of linear expansion is 1/5 to 5 times as high as that of the fixed frame plate, and an intermediate frame plate is provided which is arranged between the fixed frame plate and the light valve frame plate and is fixed with the positioning means by adhesion. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention decomposes a white light beam from a light source into three color light beams of red, blue and green, and modulates and modulates each of these color light beams through a light valve composed of a liquid crystal panel or the like in accordance with video information. The present invention relates to a projection display apparatus that recombines modulated light beams of the respective colors by a light combining unit and enlarges and projects the modulated light beam on a projection surface via a projection unit.

  As a mechanism for attaching a light valve to a prism body as a light combining means in a projection display device, for example, there is a mechanism disclosed in Japanese Patent Application Laid-Open No. Hei 6-118368. In this mounting mechanism, the light valve is directly adhered and fixed to the light incident surface of the prism body with an adhesive.

  If this configuration is adopted, in particular, a mechanism for mutual pixel alignment adjustment (alignment adjustment) of a plurality of light valves for modulating light separated into red, green, and blue, and an object within the focus allowable depth of the projection lens It is possible to omit a mechanism for adjusting (focus adjustment) such that the respective image forming surfaces are located. Therefore, the size and weight of the optical system of the projection display device can be reduced, and the number of components can be reduced.

  However, when the light valve is directly bonded and fixed to the light incident surface of the prism body, there are the following problems to be solved.

  First, when external light entering from outside the device enters the light valve, each element of the light valve may malfunction. Further, it is not preferable to handle the light valve as it is because the light valve may be damaged. For example, when the light valve is glued to the prism body and the light valve is directly chucked by a jig, the edges, corners, and the like of the light valve may be damaged. Further, since the light valve is easily affected by static electricity, it is not preferable to directly touch the light valve and perform the work of attaching the light valve to the prism body.

  Further, the light valve adhered to the prism body may cause a defect or the like in a part of the pixel due to a change with time. If a defect occurs in the light valve, it must be replaced with a new one. However, since the light valve is adhered and fixed to the prism body, it is difficult to replace only the defective light valve. That is, it is not easy to remove the light valve bonded and fixed thereto without damaging the light incident surface of the prism body. For this reason, for example, it may be necessary to replace the prism body as well, which is not economical.

Further, when the light valve is directly adhered and fixed to the prism body, the light valve may be distorted by heat due to a difference in linear expansion coefficient between the light valve and the prism body.
JP-A-6-118368

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a projection display device having a light valve mounting mechanism in which a light valve can be removed and the light valve is not easily distorted by heat.

  In order to solve the above problems, the present invention decomposes a light beam from a light source into light beams of a plurality of colors, modulates each color light beam through a light valve in accordance with video information, and modulates the modulated light beam of each color after the modulation. A configuration in which the periphery of the light valve is protected so that external light does not enter, break, etc., in a projection display device that recombines the light with a light combining unit composed of a prism body and projects the enlarged image on the projection surface via the projection unit. And a configuration in which the light valve is detachably attached to the prism body.

That is, in the present invention, the light beam from the light source is decomposed into light beams of a plurality of colors, and the light beams of each color are modulated according to the video information through the light valve. In a projection display device that recombines and enlarges and projects on a projection surface via projection means,
A fixing frame plate fixed to the light incident surface of the prism body with an adhesive, a light valve frame plate holding the light valve, and fixing means for detachably attaching and fixing the light valve frame plate to the fixing frame plate; And positioning means for positioning the light valve with respect to the light incident surface of the prism body,
The fixed frame plate is formed from a material whose linear expansion coefficient is in a range of 1/4 to 4 times the linear expansion coefficient of the prism body,
The light valve frame plate is formed of a material whose linear expansion coefficient is in a range of 1/5 to 5 times the linear expansion coefficient of the fixed frame plate,
Furthermore, an intermediate frame plate is provided between the fixed frame plate and the light valve frame plate, and the intermediate frame plate is fixed to the fixed frame plate by the fixing means, and is fixed to the light valve frame plate. In addition, it is adhesively fixed while being positioned by the positioning means.

  In the projection display device of the present invention configured as described above, the light valve is held by the light valve frame plate. A fixed frame plate is bonded and fixed to the light incident surface of the prism body, and a light valve frame plate holding the light valve is detachably fixed to the fixed frame plate.

  Therefore, since the periphery of the light valve is protected by the light valve frame plate, there is no possibility that the light valve is damaged during the work of attaching the light valve to the prism body or the like. Further, in a state where the light valve is used by being incorporated into the projection display device, since the outer periphery is covered with the light valve frame plate, there is no possibility that external light may enter and malfunction may occur.

  If a defect occurs due to the light valve aging, the light valve frame plate holding the light valve is removed from the fixed frame plate to which the prism body is adhered and fixed, and a new light valve is held. The light valve frame plate may be attached to the fixed frame plate. As described above, since the light valve is not directly adhered and fixed to the prism body, the replacement work of the light valve can be easily performed, and the surface of the prism body is not damaged during the replacement work.

  The fixed frame plate and the light valve frame plate each have a linear expansion coefficient in the specific range with respect to the prism body, so that distortion of each member due to thermal expansion is adversely affected on focus adjustment and alignment adjustment. Is not given. Furthermore, assuming that the linear expansion coefficients of the prism body, the fixed frame plate, and the light valve frame plate are E1, E2, and E3, it is most preferable that the linear expansion coefficients E1, E2, and E3 are the same. It is desirable that at least the relationship of E1 <E2 <E3 be satisfied. As described above, the line of the fixed frame plate located between the prism body usually made of optical glass having a small linear expansion coefficient and the light valve frame plate usually made of a material having a linear expansion coefficient larger than this prism body. By making the expansion coefficient larger than that of the prism body and smaller than that of the light valve frame plate, it is possible to reduce the influence of thermal distortion due to the difference in the linear expansion coefficients of the three members.

  Also, an intermediate frame plate is arranged between the fixed frame plate and the light valve frame plate, and the intermediate frame plate is fixed to the fixed frame plate by the fixing means, and is fixed to the light valve frame plate. It is possible to adopt a configuration in which the adhesive is fixed in a state where it is positioned by the positioning means.

  The intermediate frame plate may have a temporary fixing mechanism capable of temporarily fixing between the intermediate frame plate and the light valve frame plate. In this case, it is preferable that the intermediate frame plate and the light valve frame plate are temporarily fixed by using a temporary fixing mechanism, and then the positioning is performed by using the positioning device, and then the positioning device is adhesively fixed. .

  As the light valve frame plate, a structure having a first frame plate and a second frame plate and capable of holding the light valve sandwiched between these frame plates can be adopted.

  Further, a plurality of wedge-shaped members can be used as the positioning means. The positioning means is used to adjust the position of the fixed frame plate bonded and fixed to the light incident surface of the prism body, or to adjust the mounting position of the light valve with respect to the fixed frame plate. In general, the wedge-shaped member may be bonded and fixed to the member after positioning the member to be positioned.

  Further, a liquid crystal device can be used as the light valve. The present invention is particularly effective in the case of a liquid crystal device which is susceptible to static electricity and liable to malfunction due to invasion of external light.

  Further, the light valve includes a light transmission type and a light reflection type. In the case of using a light-reflection type light valve, the light synthesizing means generally also serves as a light decomposing means for decomposing a light beam from a light source into light beams of a plurality of colors.

  There are two types of projection display devices: a front projection display device in which projection is performed from the side observing the projection surface, and a rear projection display device in which projection is performed from a direction opposite to the side observing the projection surface. Although present, the invention is applicable to both types.

  When a dichroic prism is used as the prism body, the light valve is positioned and fixed to the surface of the dichroic prism using a fixed frame plate, a light valve frame plate, fixing means, and positioning means. It is conceivable to apply the present invention to a structure in which a solid-state image sensor such as a CCD is positioned and fixed to a color separation prism in a camera or the like.

  Hereinafter, a projection display device to which the present invention is applied will be described with reference to the drawings.

(overall structure)
FIG. 1 shows the appearance of a projection display device to which the present invention is applied. The projection display device 1 of this example has an outer case 2 having a substantially rectangular parallelepiped shape. The outer case 2 basically includes an upper case 3, a lower case 4, and a front case 5 defining the front of the apparatus. A front end portion of the projection lens unit 6 protrudes from the center of the front case 5.

  FIG. 2 shows an arrangement of each component inside the outer case 2 of the projection display device 1. As shown in this figure, a power supply unit 7 is disposed at the rear end side inside the outer case 2. A light source lamp unit 8 and an optical lens unit 9 are disposed at positions adjacent to the front side of the apparatus. The base end of the projection lens unit 6 is located at the center of the front side of the optical lens unit 9.

  On the other hand, on one side of the optical lens unit 9, an interface board 11 on which an input / output interface circuit is mounted is arranged in the front-rear direction of the apparatus, and in parallel with this, a video board 12 on which a video signal processing circuit is mounted. Is arranged. Further, a control board 13 for controlling driving of the apparatus is disposed above the light source lamp unit 8 and the optical lens unit 9. Speakers 14R and 14L are disposed at left and right corners on the front end side of the apparatus, respectively.

  A cooling intake fan 15A is arranged at the center on the upper surface side of the optical lens unit 9, and a circulation fan 15B for forming a cooling circulation flow is arranged at the center on the bottom surface side of the optical lens unit 9. An exhaust fan 16 is disposed on the side of the apparatus, which is the back side of the light source lamp unit 8. An auxiliary cooling fan 17 for sucking cooling airflow from the intake fan 15A into the power supply unit 7 is disposed at a position facing the ends of the substrates 11 and 12 in the power supply unit 7.

  Further, a floppy disk drive unit (FDD) 18 is disposed immediately above the power supply unit 7 at a position on the left side of the apparatus.

(Optical lens unit and optical system)
FIG. 3A shows a portion of the optical lens unit 9. As shown in this figure, the optical lens unit 9 has a configuration in which optical elements other than the prism unit 20 constituting the color synthesizing means are held between upper and lower light guides 901 and 902 from above and below. Has become. The upper light guide 901 and the lower light guide 902 are fixed to the upper case 3 and the lower case 4 by fixing screws, respectively. The upper and lower light guide plates 901 and 902 are similarly fixed to the prism unit 20 by fixing screws.

  The prism unit 20 is fixed to the back surface of a thick head plate 30, which is a die-cast plate, with fixing screws. The base end side of the projection lens unit 6 is similarly fixed to the front surface of the head plate 30 by a fixing screw. Therefore, in the present example, the prism unit 20 and the projection lens unit 6 are fixed so as to be integrated with the head plate 30 interposed therebetween. With the rigid head plate 30 sandwiched in this way, both of these components are integrated. Therefore, even if an impact or the like acts on the side of the projection lens unit 6, no displacement occurs between these two members.

  FIG. 3B shows a schematic configuration of an optical system incorporated in the projection display device 1. The optical system of this example includes an illumination optical system 923 including the light source lamp 805, integrator lenses 921 and 922 that are uniform illumination optical elements, and a white light beam W emitted from the illumination optical system 923. , A color separation optical system 924 for separating light beams R, G, and B of each color, three liquid crystal panels 40R, 40G, and 40B as light valves for modulating each color light beam. It comprises a prism unit 20 as a color synthesizing optical system to be synthesized, and a projection lens unit 6 for enlarging and projecting the synthesized light beam on a projection surface. In addition, it has a light guide system 927 for guiding the blue light beam B among the respective color light beams separated by the color separation optical system 924 to the corresponding liquid crystal panel 40B.

  As the light source lamp 805, a halogen lamp, a metal halide lamp, a xenon lamp, or the like can be used. The uniform illumination optical system 923 includes a reflection mirror 931 so that the central optical axis 1a of the light emitted from the light source lamp 805 is bent at a right angle toward the front of the device. The integrator lenses 921 and 922 are arranged to be orthogonal to the front and rear with the reflection mirror 931 interposed therebetween.

  The color separation optical system 924 includes a blue-green reflecting dichroic mirror 941, a green reflecting dichroic mirror 942, and a reflecting mirror 943. First, the white light beam W is reflected by the blue-green reflecting dichroic mirror 941 at right angles to the blue light beam B and the green light beam G contained therein, and travels toward the green reflecting dichroic mirror 942. The red light flux R passes through the mirror 941, is reflected at a right angle by the rear reflection mirror 943, and is emitted from the emission section 944 of the red light flux toward the prism unit 20 side. The blue and green light beams B and G reflected by the mirror 941 are reflected only at a right angle by the green reflecting dichroic mirror 942, and only the green light beam G is emitted to the prism unit 20 side from the emitting portion 945 of the green light beam. . The blue light flux B that has passed through the mirror 942 is emitted from the emission part 946 of the blue light flux to the light guide system 927 side. In this example, the distances from the emission part of the white light flux of the uniform illumination optical element to the emission parts 944, 945, 946 of the respective color light fluxes in the color separation optical system 924 are all set to be equal.

  Condensing lenses 951, 952, and 953 are arranged on the emission sides of the emission portions 944, 945, and 946 of the respective color light beams of the color separation optical system 924. Therefore, each color light beam emitted from each emission unit is incident on these condenser lenses 951, 952, 953 and is collimated.

  The red and green luminous fluxes R and G among the parallelized luminous fluxes R, G and B are incident on the liquid crystal panels 40R and 40G and modulated, and video information corresponding to each color light is added. That is, these liquid crystal panels are switching-controlled by driving means (not shown) in accordance with the video information, and thereby each color light passing therethrough is modulated. As such a driving unit, a known unit can be used as it is. On the other hand, the blue luminous flux B is guided to the corresponding liquid crystal panel 40B via the light guide system 927, where it is similarly modulated according to video information. As the liquid crystal panel of this embodiment, for example, a liquid crystal panel using a polysilicon thin film transistor (TFT) as a switching element can be used.

  The light guide system 927 includes an entrance-side reflection mirror 971, an exit-side reflection mirror 972, an intermediate lens 973 disposed therebetween, and a condenser lens 953 disposed on the near side of the liquid crystal panel 40B. The light path length of each color light beam, that is, the distance from the light source lamp 805 to each liquid crystal panel is the longest for the green light beam B, and therefore, the light amount loss of this light beam is the largest. However, by interposing the light guide system 927, the light amount loss can be suppressed. Therefore, the optical path length of each color light beam can be made substantially equivalent.

  Next, each color light beam modulated through each of the liquid crystal panels 40R, 40G, and 40B is incident on a color synthesizing optical system, where it is recombined. In this example, as described above, the color combining optical system is configured by using the prism unit 20 including the diclick prism. The recombined color image is enlarged and projected on the projection surface 7 at a predetermined position via the projection lens unit 6.

(Structure of prism unit and head plate)
FIG. 4 shows the head plate 30 and the prism unit 20 attached to the back surface thereof. As shown in this figure, the head plate 30 is basically composed of a vertical wall 31 extending vertically in the width direction of the apparatus and a bottom wall 32 extending horizontally from the lower end of the vertical wall 31. ing. The vertical wall 31 is formed with a rectangular opening 31B through which light emitted from the prism unit 20 passes. Further, a large number of reinforcing ribs are formed on the vertical wall 31 to increase its rigidity.

  The prism unit 20 and the projection lens unit 6 are fixed with the vertical wall 31 interposed therebetween and aligned (see FIG. 3A). Therefore, these are highly integrated, and even if an impact force or the like is applied, there is very little possibility that mutual displacement will occur.

  The prism unit 20 is attached to the bottom wall 32 of the head plate 30. The prism unit 20 is composed of a rectangular parallelepiped prism composite body 22 formed by joining together four prisms 21 (see FIG. 5) having a right-angled isosceles triangular cross section. The bottom of the prism composite 22 is fixed to the surface of a prism support plate 33 attached to and fixed to the bottom wall 32 of the head plate by means such as adhesion. A liquid crystal panel unit 50 having the same structure is attached to each of three side surfaces which function as a light incident surface among the side surfaces of the prism composite 22. These liquid crystal panel units 50 (50R, 50G, 50B) hold liquid crystal panels 40R, 40G, 40B, respectively (only the liquid crystal panels 40R, 40G are shown in FIG. 4).

(LCD panel mounting structure)
FIG. 5 is an exploded view of each component of the unit 50R of the liquid crystal panel unit 50 that holds the liquid crystal panel 40R. The mounting structure for mounting the liquid crystal panel to the prism composite 22 will be described with reference to FIG.

  First, as shown in FIG. 5, the liquid crystal panel unit 50 (50R) includes a light valve frame plate 51 that holds the liquid crystal panel 40R. The light valve frame plate 51 includes a first frame plate 52 and a second frame plate 53, and is held with the liquid crystal panel 40R sandwiched between these frame plates 52, 53.

  On the other hand, the liquid crystal panel unit 50 includes a fixed frame plate 54 fixed to the light incident surface 22R of the prism composite 22 with an adhesive. The light valve frame plate 51 is detachably fixed to the fixed frame plate 54 via the intermediate frame plate 55.

  The structure of each part will be described in detail. First, the light valve frame plate 51 will be described. The first frame plate 52 of the light valve frame plate 51 has a rectangular opening 52a for light passage, and a peripheral wall 52b having a constant thickness is formed on four sides. A rectangular opening 53a for light passage is also formed on the second frame plate 53 side. The second frame plate 53 is sized to fit inside the peripheral wall 52b of the first frame plate 52. An engagement protrusion 53c is formed at the center of the left and right edges of the second frame plate 53. An engagement groove 52c into which the engagement protrusion 53c fits is formed at the center of the left and right peripheral walls 52b of the first frame plate 52. Therefore, when the liquid crystal panel 40R is sandwiched between the first and second frame plates 52 and 53, and they are overlapped with each other, and their engaging projections 53c are fitted into the corresponding engaging grooves 52c, the liquid crystal is interposed therebetween. The light valve frame plate 51 held with the panel 40R sandwiched therebetween is configured.

  Next, the intermediate frame plate 55 is a rectangular frame having substantially the same size as the first frame plate 52 of the light valve frame plate 51, and has a rectangular opening 55a for light passage. The intermediate frame plate 55 has engagement protruding pieces 55d extending vertically from the surface of the frame plate at four corners of the rectangular opening 55a. On the other hand, on the side of the first frame plate 52 of the light valve frame plate 51, engagement holes 52d into which these can be inserted are formed at positions corresponding to the respective engagement projections 55d. Accordingly, when the engaging protrusions 55b of the intermediate frame plate 55 are aligned with the engaging holes 52d of the light valve frame plate 51 and overlapped with each other, the engaging protrusions 55d are inserted into the respective engaging holes 52d. A temporary fixing state is formed.

  On the other hand, the fixed frame plate 54 is also a rectangular frame plate in which a rectangular opening 54a for light passage is formed. The back surface of the fixed frame plate 54 is fixed to the light incident surface 22R of the prism composite 22 by an adhesive layer A1 described later in detail. The adhesive layer A1 is formed along opposing sides of the light incident surface 22R. Screw holes 54c are formed in the upper left and right corners of the fixed frame plate 54. Screw holes 55c are also formed in the intermediate frame plate 55 corresponding to these screw holes 54c.

  The lower frame portion of the fixed frame plate 54 is a protruding frame 54 b protruding toward the intermediate frame 55. The lower frame portion of the intermediate frame plate 55 is a protruding frame 55b in which the protruding frame 54b is fitted from the back side. The light valve frame plate 51 is held on the protruding frames 54b and 55b. In addition, screw holes 54e and 55e are formed in these projecting frames 54b and 55b at two locations on the left and right, respectively.

  As described above, the screw holes 54c, 54e and 55c, 55e are formed in the fixed frame plate 54 and the intermediate frame plate 55 at positions corresponding to each other, and the four countersunk screws screwed into these screw holes. These are fastened and fixed by 56. That is, the intermediate frame plate 55 is screwed to the fixed frame plate 53 attached to the prism composite 22.

  Further, the liquid crystal panel unit 50 includes four wedge-shaped members 57 as positioning means. FIG. 5 shows only one of them. A total of four wedge-shaped member guide surfaces 52e are formed on the left and right peripheral wall portions of the first frame plate 52 of the light valve frame plate 51, with which the inclined surface 57a of the wedge-shaped member 57 abuts. As described above, after temporarily fixing the light valve frame plate 51 to the intermediate frame plate 55, four wedge-shaped members 57 are driven into the left and right sides of the first frame plate 52, and the pushing amounts of these wedge-shaped members 57 are adjusted. Thus, the positioning of the liquid crystal panel 40R is performed.

  The fixed frame plate 54 is desirably formed of a material whose linear expansion coefficient is 1/4 to 4 times, preferably 1/2 to 2 times the linear expansion coefficient of the prism composite 22. The light valve frame plate 51 is desirably formed of a material whose linear expansion coefficient is 1/5 to 5 times, preferably 1/2 to 2 times the linear expansion coefficient of the fixed frame plate 54. Further, it is desirable that the linear expansion coefficient of the intermediate frame plate 55 is set to be the same as or intermediate between the fixed frame plate 54 and the light valve frame plate 51. When the linear expansion coefficients of the fixed frame plate 54, the intermediate frame plate 55, and the light valve frame plate 51 are set in the above ranges, the distortion of the respective members due to the thermal expansion may adversely affect focus adjustment and alignment adjustment. There can be no range.

  The light valve frame plate 51 (the first frame plate 52, the second frame plate 53), the intermediate frame plate 55, and the fixed frame plate 54 are not particularly limited as long as they satisfy the above-described range of the linear expansion coefficient. It can be composed of metal or various composite materials.

The fixed frame plate 54 is made of, for example, metal or a composite material of metal.
As the metal, iron, aluminum, copper, or alloys thereof, for example, brass, aluminum bronze, stainless steel, and the like are preferably used in consideration of the ease of molding, specific gravity, adhesiveness, and the like, in addition to the coefficient of linear expansion. Can be.

  The light valve frame plate 51 is made of, for example, resin or a composite material of resin. As the resin, polypropylene, polyphenylene sulfide, polycarbonate, ABS (acrylonitrile-butadiene-styrene) resin, polystyrene, AS (acrylonitrile-styrene) resin, in consideration of ease of molding, specific gravity, etc., in addition to the coefficient of linear expansion. Polyacetal, PET (polyethylene terephthalate), or a composite material thereof can be preferably used. As the composite material, a granular filler (calcium carbonate, barium sulfate, etc.), a plate-like filler (talc, mica, etc.) and an acicular filler (glass fiber, carbon fiber, calcium silicide, boron fiber, metal fiber, etc.) are used as a resin. Mixtures can be used. When such a composite resin material is used, its coefficient of linear expansion is closer to that of glass or metal as compared with a general resin material.

  The intermediate frame plate 55 is made of the above-described metal, resin, or a composite material thereof.

In the following, some of the materials of each component are illustrated together with their linear expansion coefficients. The linear expansion coefficient is a numerical value (X) × 10 ⁻⁶ cm / ° C. shown in parentheses.

Prism composite;
Optical glass BK-7 (7.5)
Fixed frame plate, intermediate frame plate;
Iron (11.8)
Iron / zinc plating (11.8)
Fernico: 54% iron, 31% nickel, 15% cobalt (5.0)
Copper (16.5)
Brass (17.5)
Brass / chrome plating (17.5)
Aluminum (23.1)
Aluminum bronze (15.9)
Light valve frame plate;
Polyphenylene sulfide (PPS) + carbon fiber (43)
PPS + 40% glass fiber (62)
PPS + calcium carbonate (24)
Polycarbonate (PC) + filler (32)
PC + glass fiber (37)
Polypropylene (PP) + 40% talc (43)
PP + 30% glass fiber (43)
PP + 20% glass fiber (53)
PP + Talc 30% (54)
PPS + 30% glass fiber (56)
PP + barium sulfide (65)
PP + glass fiber 10% (66)
PP + calcium silicide 10% (93)
PP block copolymer (120)
Acrylic resin (80-100)
Ceramics (8.5)

(Test example)
Next, the results of a heat shock test using a test piece will be described.

a. Test Method (1) An ultraviolet-curable adhesive “TB3062E” (manufactured by Three Bond) is applied to one surface of the test piece 1, and the test piece 1 is adhered to the test piece 2 to form a sample. The test piece materials are shown in Tables 1 to 3. The size of the test piece is as follows.

Test piece 1;
Length: 6mm Width: 40mm Thickness: 1mm
Test piece 2;
Length: 40mm Width: 40mm Thickness: 5-6mm

  (2) The sample is left for 1 hour and 30 minutes in a thermostat at a temperature of + 65 ° C.

  (3) Then, the sample is left for 1 hour and 30 minutes in a constant temperature bath at a temperature of -25 ° C.

  (4) The above procedures (2) and (3) are repeated for 30 cycles.

b. Evaluation method and evaluation results: good (〇) when deterioration of the adhesive of the sample, specifically cracks or partial peeling of the adhesive layer is not visually observed (良好), and poor (た). Tables 1 to 3 show the results of the evaluation.

  Table 1 shows the combination of the optical glass material forming the prism body and the metal forming the fixed frame plate. Tables 2 and 3 show the metal forming the fixed frame plate and the resin or composite forming the light valve frame plate. This shows a combination with a resin material. Tables 1 to 3 also show the ratio of the linear expansion coefficient of the test piece 1 to the test piece 2.

(Assembly of LCD panel unit)
The liquid crystal panel unit 50 is attached to the light incident surface 22R of the prism composite 22 in the following procedure. First, a light valve frame plate 51 holding the liquid crystal panel 40R is prepared. Then, the fixed frame plate 54 is positioned on the surface 22R of the prism composite 22 and fixed by the adhesive layer A1. As the adhesive for the adhesive layer A1, for example, an acrylic resin, an epoxy resin, a urethane resin, or the like can be used.

  In addition, as the adhesive, a photocurable resin that is cured by ultraviolet light or visible light, particularly ultraviolet light can be preferably used because it is not affected by heat during curing. The adhesive preferably has a glass transition temperature of 50 to 200 ° C. and an elongation of 100 to 400%. When the adhesive has these characteristic values, thermal distortion due to the difference in linear expansion coefficient between the prism composite 22 and the fixed frame plate 54 can be absorbed, and a stable bonding state can be maintained for a long time.

  As described above, an ultraviolet-curing adhesive can be used as an adhesive for bonding and fixing the fixed frame plate 54 to the prism composite 22. However, a base material is applied to improve the adhesiveness. It is desirable. That is, in the prism composite 22, as described above, the incident surface 22R of the red light beam and the incident surface 22B of the blue light beam face each other. Since the blue light beam has a short wavelength, a part of the blue light beam may pass through the reflective film of the prism composite 22 and reach the opposite red light incident surface 22R. When such backlight is incident on the liquid crystal panel 40R, a malfunction occurs. In order to avoid this, a filter is generally attached to the incident surface 22R of the red light beam to block such backlight.

  The reason why the filter is attached only to the incident surface 22R of the red light beam is that the influence of the backlight of the blue light beam is the largest, but this is not the case when the influence of the backlight of the other light beam is great. A filter may be provided on another surface, or a filter may be provided on a plurality of surfaces.

  However, when such a filter is present, the ultraviolet rays are blocked during bonding and fixing, and an ultraviolet-curing adhesive for bonding and fixing the fixed frame plate 54 to the incident surfaces 22R, 22G, and 22B of the prism composite 22. However, there is a possibility that a part insufficiently irradiated with ultraviolet rays may occur. In order to avoid this adverse effect and securely fix the fixing frame plate 54 to the incident surface 22R, as described above, a base material is applied to these bonding surfaces, and an anaerobic type adhesive is used. It is desirable to use together. Of course, the same processing may be performed on the incident surface where such a filter does not exist.

  Although the use of a photocurable adhesive has been described as the adhesive, other adhesives may be used. For example, if the fixing and fixing of the fixing frame plate 54 and the fixing and fixing of the wedge-shaped member 57 are performed by using a hot-melt type adhesive, it is not necessary to consider the above-mentioned problem caused by the filter.

  Next, the intermediate frame plate 55 is positioned on the surface of the fixed frame plate 54 that is bonded and fixed, and the intermediate frame plate 55 is screwed with four screws 56. Thereafter, the light valve frame plate 51 holding the liquid crystal panel 40R is positioned on the intermediate frame plate 55 and temporarily fixed thereto. That is, the engaging projection 55d of the intermediate frame plate 55 is matched with the engaging hole 52d of the light valve frame plate 51, and the light valve frame plate 51 is pushed toward the intermediate frame plate 55 in this state.

  Thereafter, the liquid crystal panel 40R is positioned with respect to the surface 22R of the prism composite 22 using the wedge-shaped member 57 as a positioning means. That is, the four wedge-shaped members 57 are inserted between the temporarily fixed light valve frame plate 51 and the intermediate frame plate 55 along the wedge-shaped member guide surface 52e formed on the first frame plate 52. Then, by adjusting the insertion amount of each wedge-shaped member 57, alignment adjustment and focus adjustment of the liquid crystal panel 40R are performed.

  When the positioning is completed, these wedge-shaped members 57 are bonded and fixed to the light valve frame plate 51 and the intermediate frame plate 55 which are members to be positioned by the adhesive layer A2. As the adhesive used in this case, it is preferable to use the same adhesive as that used for bonding the prism composite 22 and the fixed frame plate 54 described above.

  Here, the operation of positioning the wedge-shaped member 57 and the operation of bonding and fixing the wedge-shaped member 57 will be described in more detail according to the fixing order.

  First, the focus surface of the liquid crystal panel 40G is adjusted within the focus surface of the projection lens 6 using a dedicated adjustment device. In this state, as described above, for example, an ultraviolet curable adhesive is injected into a gap formed by the engagement projection 55d of the intermediate frame plate 55 entering the engagement hole 52d of the light valve frame plate 51, It is cured and temporarily fixed by irradiation. Next, the intermediate frame plate 55 and the wedge guide surface 52e provided on the first frame plate 52 are bonded to the ultraviolet-curable adhesive by irradiating ultraviolet rays from the exposed end surface of the wedge-shaped member 57 to perform permanent fixing. With reference to the liquid crystal panel 40G arranged at the center of the liquid crystal panels 40G, 40R, and 40B, the focus adjustment and the pixel alignment adjustment between the liquid crystal panels 40R and 40B are similarly performed to temporarily fix and permanently fix.

  In addition, since the temporary fixing operation is performed by setting the prism composite 22 and the projection lens 6 on the head plate 30 in the adjusting device, the optimal adjustment according to the characteristics of each component can be performed. The chucking of the light valve frame plate 51 to the adjusting device is performed based on the outer shape of the first frame plate 52.

  As the wedge-shaped member 57, generally, a member made of glass can be used. However, when the first frame plate 52 is formed of a resin molded product, the linear expansion coefficient is larger than that of glass. Therefore, the wedge-shaped member 57 is easily peeled off from these frame plates due to the difference in the linear expansion coefficient. The member 57 may be broken by a change in temperature. In order to avoid this, it is desirable that the wedge-shaped member 57 is formed of an acrylic resin or the like. In addition, since the wedge-shaped member 57 can be formed by using an acrylic material, the cost can be significantly reduced as compared with a glass material. By using a material that transmits ultraviolet light as the material of the wedge-shaped member 57, a light-curing adhesive that has a small rise in temperature during curing and has a short curing time can be used as an adhesive for bonding and fixing the wedge-shaped member 57. Can be.

  The liquid crystal panel unit 50 holding the liquid crystal panels 40G, 40G other than the liquid crystal panel 40R has the same structure, and the description thereof will be omitted.

  FIG. 4 shows a state in which the liquid crystal panel unit 50 is attached to the three surfaces 22R, 22B, and 22G of the prism composite 22 in this manner. In this figure, a member extending upward from each liquid crystal panel unit 50 is a flexible cable 41 for wiring.

  The liquid crystal panel unit 50 configured as described above has the following effects.

  First, the liquid crystal panel 40R is in a state where its periphery is covered and protected by a rectangular light valve frame plate 51. Therefore, there is no need to directly touch the liquid crystal panel 40R to perform the mounting operation on the side of the prism composite 22. Therefore, it is possible to prevent the liquid crystal panel 40R from being damaged or lost due to hitting another portion. Further, the periphery of the liquid crystal panel 40R is covered with a frame plate 51, and can block external light. Therefore, no malfunction occurs in the liquid crystal panel 40 due to the invasion of external light.

  Second, the light valve frame plate 51 holding the liquid crystal panel 40R is screwed to the surface 22R of the prism composite 22 via the intermediate frame plate 55. Therefore, for example, when a defect occurs in the liquid crystal panel 40R, the replacement can be performed by a simple operation of removing the screw 56. In addition, since the liquid crystal panel 40R is not directly bonded and fixed to the prism composite 22, the side of the prism composite 22 is not damaged during such replacement.

  Third, the light valve frame plate 51 holding the liquid crystal panel 40R can be temporarily fixed to the intermediate frame plate 55. After the provisionally fixed state is formed, the liquid crystal panel 40R and the surface 22R of the prism composite 22 can be positioned using the wedge-shaped member 57. As described above, since the temporary fixing state can be formed, the positioning operation using the wedge-shaped member 57 can be easily performed.

  Fourth, the coefficient of linear expansion of the material forming the fixed frame plate 54 and the intermediate frame plate 55 is set to the prism composite 22 and the coefficient of linear expansion of the material forming the light valve frame plate 51 is set to the fixed frame plate 54 and the intermediate By setting the linear expansion coefficient of the frame plate 55 to a specific range, the thermal strain of each member can be set to a range that does not affect the alignment and focusing accuracy.

  When it is not necessary to temporarily fix the light valve frame plate 51 to the intermediate frame plate 55, a temporary fixing mechanism formed between the light valve frame plate 51 and the intermediate frame plate 55 is omitted as shown in FIG. do it. That is, the formation of the engagement hole 52d formed on the side of the light valve frame plate 51 and the engagement protrusion 55d formed on the side of the intermediate frame plate 55 shown in FIG. The other configuration is the same as that shown in FIG.

  Even when the liquid crystal panel unit 500R having the configuration shown in FIG. 6 is used, the above-described first, second, and fourth effects obtained by the liquid crystal panel unit 50 (50R) shown in FIG. 5 can be obtained.

(Other embodiments)
FIG. 7 shows another embodiment of the liquid crystal panel unit. The liquid crystal panel unit 60 (60R) shown in this figure also includes a light valve frame plate 61 holding the liquid crystal panel 40R, and a fixed frame plate 64 fixed to the surface 22R of the prism composite 22 by the adhesive layer A3. I have. However, the intermediate frame plate 55 is not provided, and the light valve frame plate 61 is directly screwed to the fixed frame plate 64 side. The other configuration is the same as that shown in FIG.

  More specifically, the configuration of the light valve frame plate 61 is the same as the configuration of the light valve frame plate 51 described above, and includes a first frame plate 62 and a second frame plate 63, and a liquid crystal panel therebetween. 40R is held in a sandwiched state. An engaging hook 63c and an engaging claw 62c are formed to hold the first and second frame plates 62, 63 in an engaged state. The first and second frame plates 62, 63 are formed with rectangular openings 62a, 63a for light passage.

  On the other hand, the fixed frame plate 64 has a shape in which a hook, that is, a peripheral wall 64e having a constant width is formed on four sides of the rectangular frame portion. The light valve frame plate 61 can be fitted inside the peripheral wall 64e. Further, screw holes 64f are formed at the four inner corners of the peripheral wall 64e. Screw holes 62f are also formed at the four corners of the first frame plate 62 of the light valve frame plate 61 corresponding to these screw holes 64f. By screwing the screws 66 into these, the light valve frame plate 61 is screwed and fixed to the fixed frame plate 64 side.

  On the other hand, on the peripheral wall 64e of the fixed frame plate 64, wedge-shaped member guide surfaces 64g are formed at two upper and lower locations on one side surface. On the other side surface, a wedge-shaped member guide surface 64g is formed at one central position in the vertical direction.

  The liquid crystal panel unit 60R having this structure is configured by screwing the light valve frame plate 61 to the fixed frame plate 64 with screws 66. Thereafter, the position is determined with respect to the surface 22R of the prism composite 22. In this state, the three wedge-shaped members 67 are inserted into the wedge guide surfaces 64g, and are positioned so that the gap becomes zero due to the surface tension of the ultraviolet-curing adhesive already applied to the joining surface of the wedge-shaped members. Hold. After the positioning of the wedge-shaped member 67 is performed in this way, ultraviolet rays are irradiated from the exposed end surface of the wedge-shaped member 67 to cure and bond the adhesive.

  Note that the wedge-shaped members 67 may be arranged one by one at the center of both sides of the peripheral wall 64e of the fixed frame plate 64. When the size of the fixed frame plate 64 is increased, the influence of expansion and contraction due to a temperature change can be minimized, which contributes to improvement in reliability.

  Also in the liquid crystal panel unit 60 (60R) having this configuration, the liquid crystal panel 40R is covered and protected by the frame 61. The frame 61 holding the liquid crystal panel 40R is screwed to the fixed frame plate 64 side. Therefore, the liquid crystal panel 40R is in a protected state, and no external light enters. Further, when replacing the liquid crystal panel, it is sufficient to simply remove the screw, so that the operation can be performed by a simple operation. Further, the surface of the prism composite is not damaged during the replacement work. Further, thermal distortion due to a difference in linear expansion coefficient of each member can be suppressed.

  As described above, in the projection display device of the present invention, the light valve can be reliably positioned and fixed to the prism body, so that the amount of misalignment of pixels can be suppressed, and the focus adjustment can be accurately performed, so that higher definition can be achieved. Easily possible. In addition, since the prism body can be downsized while having a structure in which the light valve can be replaced, it contributes to downsizing and weight reduction of the product, and enables commercialization with improved reliability.

  Further, in the projection display device of the present invention, the light valve disposed on the light incident surface of the prism body is held with its periphery protected by the light valve frame plate. Further, the light valve frame plate holding the light valve is detachably attached to a fixed frame plate adhered and fixed to the light incident surface of the prism body. Therefore, according to the light valve mounting mechanism of the present invention, since the periphery of the light valve is covered and protected by the frame, there is no possibility that the light valve may be damaged during handling. In addition, there is no possibility that external light enters from the surroundings and malfunctions occur in the light valve. Further, the replacement work of the light valve can be easily performed, and the surface of the prism body is not damaged at the time of replacement.

  In addition, with the recent increase in the definition of light valves, pixels may be defective. In such a case, only defective light valves can be replaced, and other components can be reused. This is advantageous.

  Furthermore, by setting the linear expansion coefficient of the fixed frame plate and the light valve frame plate to a specific range for each of the prism body and the fixed frame plate, thermal distortion due to a difference in linear expansion coefficient of each member is suppressed, Highly accurate alignment and focus can be maintained.

FIG. 1 is an external perspective view of a projection display device to which the present invention is applied. 2A and 2B are views showing the arrangement of each component inside the apparatus of FIG. 1, FIG. 2A is a view showing its planar arrangement, and FIG. 2B is a view showing its three-dimensional arrangement. FIG. 3A is a diagram showing the optical lens unit and the projection lens unit, and FIG. 3B is a schematic configuration diagram of an optical system. FIG. 4 is a partial perspective view showing the head plate and the parts of the prism unit and the liquid crystal panel unit supported by the head plate. FIG. 5 is an exploded perspective view showing the configuration of the liquid crystal panel unit of FIG. FIG. 6 is an exploded perspective view showing a modification of the liquid crystal panel unit of FIG. FIG. 7 is an exploded perspective view showing another embodiment of the liquid crystal panel unit.

Explanation of reference numerals

Reference Signs List 20 prism composite, 50 liquid crystal panel unit, 51 light valve frame plate, 52 first frame plate, 52 a, 53 a, 55 a rectangular opening for light passage, 52 b peripheral wall, 52 d engagement hole, 53 second frame plate, 53c engagement protrusion, 54 fixed frame plate, 55 intermediate frame plate, 55b, 55d engagement protrusion, 57 wedge-shaped member

Claims (11)

Decomposes the light beam from the light source into light beams of multiple colors, modulates each color light beam through the light valve in accordance with the video information, recombines the modulated light beam of each color by the light synthesizing means consisting of a prism body, and projects In a projection display device for enlarging and projecting on a projection surface via means,
A fixing frame plate fixed to the light incident surface of the prism body with an adhesive, a light valve frame plate holding the light valve, and fixing means for detachably attaching and fixing the light valve frame plate to the fixing frame plate; And positioning means for positioning the light valve with respect to the light incident surface of the prism body,
The fixed frame plate is formed from a material whose linear expansion coefficient is in a range of 1/4 to 4 times the linear expansion coefficient of the prism body,
The light valve frame plate is formed of a material whose linear expansion coefficient is in a range of 1/5 to 5 times the linear expansion coefficient of the fixed frame plate,
Furthermore, an intermediate frame plate is provided between the fixed frame plate and the light valve frame plate, and the intermediate frame plate is fixed to the fixed frame plate by the fixing means, and is fixed to the light valve frame plate. And a projection display device which is adhesively fixed while being positioned by the positioning means. In claim 1,
Assuming that the linear expansion coefficients of the prism body, the fixed frame plate, and the light valve frame plate are E1, E2, and E3, respectively, a projection display device in which a relationship of E1 <E2 <E3 is satisfied. In claim 1 or 2,
The projection display device, wherein the fixed frame plate is formed of a material having a linear expansion coefficient in a range of 1/2 to 2 times a linear expansion coefficient of the prism body. In any one of claims 1 to 3,
The projection display device, wherein the light valve frame plate is formed of a material having a linear expansion coefficient in a range of 1/2 to 2 times a linear expansion coefficient of the fixed frame plate. In any one of claims 1 to 4,
The projection type display device, wherein the fixed frame plate is formed from a metal or a composite material including a metal. In any one of claims 1 to 5,
The projection type display device, wherein the light valve frame plate is formed of a resin or a composite material containing the resin. In claims 1 to 6,
A projection display device, wherein a temporary fixing mechanism for temporarily fixing them is formed between the intermediate frame plate and the light valve frame plate. In claims 1 to 7,
The projection display device, wherein the positioning means is a plurality of wedge-shaped members fixed by an adhesive. In claim 8,
The projection display device, wherein the adhesive is a light-curable adhesive. In any one of claims 1 to 9,
The projection type display device, wherein the light valve frame plate includes a first frame plate and a second frame plate, and the light valve is held between the frame plates. In any one of claims 1 to 10,
The projection display device, wherein the light valve is a liquid crystal light valve.

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