JP2006018083A - Aspherical mirror member and back projection type video display device using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To project a distinct video on a screen by restraining the distortion of a mirror face plate 2 in an aspherical mirror member which enlarges and reflects video light and a back projection type video display device using the same. <P>SOLUTION: The aspherical mirror member 1, which reflects the video light projected to a screen surface along an optical axis, is constituted of the aspherical mirror face plate 2 reflecting the video light and a mount member 3 supporting the mirror face plate 2 and fixing it in the device. The mount member 3 is constituted of a fixed plate piece 5 directly fixed on the device side, and a mirror face plate supporting part 6 made to intervene between the fixed plate piece 5 and the mirror face plate 2 and supporting the mirror face plate 2 while restraining the distortion of the mirror face plate 2 in a state where the mirror face plate 2 is fixed on the device side via the fixed plate piece 5. The mirror face plate supporting part 6 is constituted of a plate material for reinforcement 9 disposed in a direction nearly perpendicular to the mirror face plate 2 on the back surface of the mirror face plate 2. Cushioning parts 15, 16 and 17 allowing deformation caused by thermal expansion or the like are provided between the fixed plate piece 5 and the mirror face plate supporting part 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an aspherical mirror member that magnifies and reflects image light and a rear projection image display apparatus using the same.

  As a rear projection type image display device such as a liquid crystal projector, the one described in Patent Document 1 is generally known. This rear projection type image display apparatus will be described with reference to FIGS.

  The rear projection type image display apparatus is configured as shown in FIG. In this rear projection type image display device, the image light projected from the projection lens (not shown) of the light source device 101 is reflected by the front surface of the aspherical mirror 102, the reflected light is reflected by the flat mirror 103, and further the plane The image is reflected on the screen 105 by being reflected by the mirror 104. The aspherical mirror 102 has a rectangular shape made of synthetic resin, has a front surface formed in a curved shape such as an aspherical surface, and is held by a mirror holding mechanism 107 fixed to a base member 106 that supports the light source device 101. ing.

  The aspherical mirror 102 is fixed to the support frame of the mirror holding mechanism 107 with screws passing through the four corners. Since the aspherical mirror 102 is made of synthetic resin, the amount of thermal expansion / contraction due to temperature change increases. When the temperature rises, there is no escape space for stress generated inside the aspherical mirror 102, so that the aspherical mirror 102 curves in a circular arc shape so as to protrude forward, thereby changing the display position of the image, In some cases, distortion occurred.

  In order to solve this problem, the mirror holding mechanism 107 is improved. As shown in FIG. 3, the mirror holding mechanism 107 supports the mirror 102 so that the mirror 102 can expand and contract radially around the center at the lower end, and locally abuts on the front side of the mirror 102. The support frame 110 formed on the rear surface of the mirror 102 is disposed so as to face the back surface of the mirror 102 with a gap therebetween, and the rear surface member 111 fixed to the support frame 110 and the mirror 102 with respect to the rear surface side member 111. And an urging member (not shown) that elastically urges forward.

  Specifically, the mirror 102 is supported by the lower regulating member 113 at the lower end center, the upper regulating member 114 at the center of the upper end surface, and the pressing members 115 at the left and right ends of the upper end surface.

  By holding the mirror 102 with the above mirror mounting structure, the position accuracy of the reflecting surface of the mirror 102 can be set extremely high.

In addition to this, there is a structure in which a mirror is supported via a spring as in Patent Document 2, for example. With this holding structure, deterioration of video quality due to temperature change is prevented.
JP 2003-215713 A JP 2002-228905 A

  However, in the case of the configuration like the conventional mirror holding mechanism 107 of Patent Document 1 described above, even a rear projection type video display device having a certain size can be handled without problems. The mirror 102 can be accurately held by the mirror holding mechanism 107 and an image without distortion can be displayed on the screen 105.

  However, when the rear projection image display device is enlarged, it is difficult to cope with the enlargement in the case of a structure that directly supports the aspherical mirror 102 like the conventional mirror holding mechanism 107. That is, when the rear projection image display device is enlarged, the aspherical mirror 102 is also enlarged, and the amount of deformation and its own weight due to heat increase. If the amount of deformation of the aspherical mirror 102 due to heat increases, the displacement at the end of the aspherical mirror 102 also increases, and the mirror holding mechanism 107 cannot cope with it, and the mirror surface may be distorted.

  Further, if the weight of the aspherical mirror 102 is increased, the aspherical mirror 102 is easily bent, and the mirror holding mechanism 107 cannot cope with it, and the mirror surface may be distorted.

  As a result, there is a problem that the surface accuracy of the aspherical mirror 102 is deteriorated and the image quality of the image projected on the screen 105 is lowered.

  In the case of Patent Document 2, the same problem as that of Patent Document 1 described above arises in terms of the structure for directly supporting the mirror.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an aspherical mirror member that can be accurately supported while suppressing distortion and maintaining high positional accuracy of the mirror surface.

  In order to solve such a problem, an aspherical mirror member according to a first aspect of the present invention is provided in a rear projection image display device, and is a non-reflection device that reflects image light finally projected on a screen surface along an optical axis. A spherical mirror member, comprising: an aspherical mirror face plate that reflects the image light; and an attachment member that supports the mirror face plate and is fixed to the apparatus side, and the attachment member is directly fixed to the apparatus side. A fixed plate piece, and a mirror that is interposed between the fixed plate piece and the mirror face plate and that supports the mirror face plate while suppressing the distortion while being fixed to the device side via the fixed plate piece. And a face plate support portion.

  With the above configuration, the mirror plate support part is fixed to the device side by fixing the fixed plate piece to the device side. Thus, the mirror face plate is fixed in the apparatus via the mirror face plate support portion, and the mirror face plate is supported with its distortion suppressed.

  The aspherical mirror member according to a second aspect of the invention is characterized in that the mirror face plate support portion is composed of a reinforcing plate material disposed on the back surface of the mirror face plate in a direction substantially perpendicular to the mirror face plate. .

  With the above configuration, the reinforcing plate supports the mirror face plate from the back surface. At this time, since the reinforcing plate supports the mirror face plate from a direction substantially orthogonal thereto, the reinforcing face plate reinforces the direction in which the mirror face plate bends and the direction in which the mirror face plate extends and contracts along the reinforcing plate. Thus, the mirror face plate is supported while suppressing its bending and expansion and contraction due to heat.

  An aspherical mirror member according to a third aspect of the present invention is characterized in that the aspherical mirror member is provided between the fixed plate piece and the mirror face plate or the mirror face plate support portion and includes a buffer portion that allows deformation due to thermal expansion or the like. To do.

  With the above configuration, when the dimensions of the mirror face plate change due to thermal expansion or the like, the buffer portion allows this and suppresses distortion of the mirror face plate.

  The aspherical mirror member according to a fourth aspect of the invention is characterized in that the buffer portion is constituted by a foot portion provided continuously to the fixed plate piece.

  With the above configuration, the buffer portion is configured by the foot portion, so that the change in the dimension of the mirror face plate due to thermal expansion or the like is absorbed by the deflection of the foot portion. Thereby, distortion of the mirror face plate is suppressed.

  The aspherical mirror member according to a fifth aspect of the present invention is characterized in that the buffer portion is constituted by a slit provided in the reinforcing plate material in succession to the fixed plate piece.

  With the configuration described above, the buffer portion is formed of a slit, so that a change in the dimension of the mirror face plate due to thermal expansion or the like is absorbed by the deflection of the slit portion. Thereby, distortion of the mirror face plate is suppressed.

  An aspherical mirror member according to a sixth aspect of the invention is configured such that the buffer portion is provided between the fixed plate piece and the mirror face plate support portion, and is formed by a thin portion that allows deformation due to thermal expansion or the like by bending. It is characterized by that.

  With the above configuration, by configuring the buffer portion with a thin portion, a change in the dimension of the mirror face plate due to thermal expansion or the like is absorbed by the deflection of the thin portion. Thereby, distortion of the mirror face plate is suppressed.

  A rear projection type image display apparatus according to a seventh aspect of the present invention is a rear projection type image display apparatus comprising an aspherical mirror member that reflects image light from a light source while enlarging and projects it onto a screen. As the mirror member, the aspherical mirror member according to any one of the first to sixth inventions is used.

  With the above configuration, the mirror surface is accurately supported by the mounting member, so that distortion of the mirror face plate can be suppressed and a clear image can be displayed on the screen.

  As described above, according to the present invention, the mirror face plate can be accurately supported by the mounting member while suppressing the distortion, and a clear image can be displayed on the screen.

  Hereinafter, an embodiment of an aspherical mirror member according to the present invention will be described in detail with reference to the drawings. Here, only the aspherical mirror member will be described, and the description of the configuration of the rear projection type image display device will be omitted. The overall configuration of the rear projection display apparatus to which the aspherical mirror member according to the present invention is applied may be the conventional rear projection display apparatus described above or another structure. The aspherical mirror member of the present embodiment can be applied as long as the aspherical mirror member has a function of reflecting the image light toward the screen along the set optical axis. When the reflection is repeated several times from the light source to the screen, the aspherical mirror member of this embodiment may be used for all of the reflection mirrors, or the aspherical mirror member of this embodiment may be used as a part. The aspherical surface of the present invention is particularly suitable for a rear projection TV that has a thin depth and requires that the surface shape accuracy of the mirror surface be several microns or less of the design value. The mirror member functions effectively.

[First embodiment]
FIG. 1 is a perspective view showing an aspherical mirror member according to the first embodiment. FIG. 4 is a plan view showing the aspherical mirror member according to the first embodiment. FIG. 5 is a perspective view showing the aspherical mirror member according to the first embodiment.

  The aspherical mirror member 1 includes a mirror face plate 2 and a mounting member 3.

  The mirror face plate 2 is a plate material for reflecting video light from the light source along the optical axis while enlarging it. The mirror surface plate 2 is configured as a substantially rectangular plate material as a whole, and its surface (lower surface in FIG. 1) is an aspherical reflecting surface 4. An attachment member 3 is attached to the back surface of the mirror face plate 2. One or more mirror face plates 2 are arranged on the optical axis from the light source to the screen.

  The attachment member 3 is a member for supporting the mirror face plate 2 and fixing it in the rear projection type image display device. The attachment member 3 is composed of a fixed plate piece 5 and a mirror face plate support 6.

  The fixed plate piece 5 is a plate piece fixed directly to the device side. The fixing plate piece 5 is provided with a screw hole 7 through which a screw (not shown) is passed and fixed directly to the apparatus side. The fixed plate pieces 5 are provided at three locations on the mirror face plate support 6. Two of the fixing plate pieces 5 are provided with positioning holes 8 together with the screw holes 7. A fitting projection (not shown) is provided at a position corresponding to the two positioning holes 8 on the rear projection image display device side, and positioning is performed by fitting the positioning holes 8 to the fitting projections. In this state, the aspherical mirror member 1 is fixed by passing a screw through each screw hole 7. A screw hole (not shown) into which a screw is screwed is provided at a position corresponding to each screw hole 7 on the rear projection display apparatus side.

  The mirror face plate support 6 is a member for supporting the mirror face plate 2 while suppressing distortion. The mirror face plate support 6 is composed of a reinforcing plate 9 disposed on the back surface of the mirror face plate 2 in a direction substantially perpendicular to the mirror face plate 2. The mirror face plate support 6 is provided on each of the four sides which are the peripheral edges of the substantially square mirror face plate 2. Each mirror face plate support 6 is provided integrally from the edge of the mirror face plate 2 and substantially orthogonal to the mirror face plate 2. Thereby, the bending of the mirror face plate 2 and the expansion and contraction in the direction along the four sides of the mirror face plate 2 are suppressed.

  Further, the fixed plate piece 5 is integrally attached to the other end of the mirror face plate support 6 in a state where the mirror face plate 2 is integrally attached to one end of the mirror face plate support 6. Thus, the mirror face plate support 6 is interposed between the fixed plate piece 5 and the mirror face plate 2 to suppress distortion from the fixed plate piece 5 side. That is, when the three fixing plate pieces 5 are fixed to the apparatus side with screws, if the mounting position of each fixing plate piece 5 deviates from the set position due to the dimensional error of the contact surface on the apparatus side, stress is generated. Although the mirror face plate 2 may be distorted, the mirror face plate support portion 6 provided substantially orthogonal to the mirror face plate 2 suppresses stress and suppresses distortion of the mirror face plate 2.

  The aspherical mirror member 1 configured as described above is disposed at a set position on the optical axis from the light source to the screen of the rear projection display apparatus. That is, the aspherical mirror member 1 is positioned by fitting the positioning hole 8 of the fixing plate piece 5 to the fitting protrusion provided at the set position, and fixed to the screw hole 7 through the screw. At this time, if the position of the fixed plate piece 5 is deviated from the original position due to a dimensional error or the like on the apparatus side, stress is generated by this, but this stress is supported by the mirror face plate support 6.

  In normal use, image light from the light source is reflected by the mirror face plate 2 of the aspherical mirror member 1 and projected on the screen. When the mirror face plate 2 of the aspherical mirror member 1 is warmed by heat generated from the light source, the mirror face plate 2 gradually expands and the dimensions of the mirror face plate 2 change. On the other hand, since the mirror face plate support portion 6 is provided on the mirror face plate 2, the mirror face plate support portion 6 suppresses the change of the mirror face plate 2 and accurately supports it while suppressing the distortion of the mirror face plate 2.

  Thereby, the image light reflected by the mirror face plate 2 can be irradiated to an accurate position on the screen, and a clear image can be projected on the screen.

[Second Embodiment]
The present embodiment is an example in which the mirror face plate support 6 is provided on three pieces in the aspherical mirror member 1 of the first embodiment. Specifically, as shown in FIGS. 6 and 7, mirror face plate support portions 6A, 6B, and 6C are provided on three pieces on the base end side and on both sides. A mirror face plate support portion is not provided on the distal end side, a foot portion 11 is provided, and a fixed plate piece 5 is provided at the distal end of the foot portion 11. The thickness of the foot portion 11 is set so as to be somewhat bent with respect to the mirror face plate 2. That is, when the mirror face plate 2 is thermally expanded and contracted, the foot portion 11 is easily deformed with respect to the expansion and contraction of the mirror face plate 2 to allow the mirror face plate 2 to expand. The foot portion 11 serves as a buffer portion that allows deformation of the mirror face plate 2 due to thermal expansion or the like. Other structures are the same as those of the aspherical mirror member 1 of the first embodiment.

  With the above configuration, the mirror face plate support portions 6A, 6B, 6C provided on the three pieces on the base end side and the both sides suppress the dimensional change of the mirror face plate 2 due to thermal expansion or the like, and these mirror face plate support portions 6A, 6B. , 6C is allowed to absorb the dimensional change that cannot be suppressed by the bending of the foot 11.

  Further, the displacement of the mounting position of the fixed plate piece 5 due to the dimensional error on the main body side is allowed and absorbed by the bending of the foot portion 11.

  Thereby, the dimensional change of the mirror face plate 2 due to heat can be suppressed by three sides and absorbed by one side, and the position accuracy of the reflecting surface of the mirror 102 can be maintained extremely high.

[Third Embodiment]
This embodiment is an example in which the mirror face plate support 6 is provided on three pieces different from the second embodiment in the aspherical mirror member 1 of the first embodiment. The structure of this embodiment is effective when the dimensional change due to heat or the like of the mirror face plate 2 is not so large.

  As shown in FIGS. 8 and 9, the aspherical mirror member is provided with mirror face plate support portions 6B, 6C, and 6D on three pieces on the tip side and both sides. The base face side is not provided with a mirror face plate support, and is hollow. The fixed plate piece 5 is provided on each mirror face plate support 6B, 6C, 6D, respectively. Other structures are the same as those of the aspherical mirror member 1 of the first embodiment.

  With the above configuration, the mirror face plate support portions 6B, 6C, and 6D provided on the three pieces on the front end side and the both sides suppress the dimensional change of the mirror face plate 2 due to thermal expansion or the like.

  Thereby, the dimensional change of the mirror surface plate 2 due to heat can be suppressed by three sides, and the position accuracy of the reflecting surface of the mirror 102 can be maintained extremely high.

[Fourth Embodiment]
The present embodiment is an example in which the mirror face plate support 6 is provided on two pieces in the aspherical mirror member 1 of the first embodiment. Specifically, as shown in FIGS. 10 and 11, mirror face plate support portions 6 </ b> B and 6 </ b> C are provided on two pieces on both sides of the mirror face plate 2. The base face side is not provided with a mirror face plate support, and is hollow. A mirror face plate support is not provided on the front end side, and it is hollow.

  With the above configuration, the mirror face plate support portions 6B and 6C provided on the two pieces on both sides suppress the dimensional change of the mirror face plate 2 due to thermal expansion or the like.

  Thereby, the dimensional change of the mirror surface plate 2 due to heat can be suppressed by two sides, and the positional accuracy of the reflecting surface of the mirror 102 can be maintained extremely high.

[Fifth Embodiment]
This embodiment is an example in which the mirror face plate support 6 is provided on two pieces different from the fourth embodiment in the aspherical mirror member 1 of the first embodiment. Specifically, as shown in FIGS. 12 and 13, mirror face plate support portions 6 </ b> A and 6 </ b> D are provided on two pieces on the distal end side and the proximal end side. The mirror face plate support portions are not provided on both sides and are hollow. In this case, the two fixed plate pieces 5 on the base end side are respectively provided on both sides of the mirror face plate support 6A.

  With the above configuration, the mirror face plate support portions 6A and 6D provided on the two pieces on the distal end side and the proximal end side suppress the dimensional change of the mirror face plate 2 due to thermal expansion or the like.

  Thereby, the dimensional change of the mirror surface plate 2 due to heat can be suppressed by two sides, and the positional accuracy of the reflecting surface of the mirror 102 can be maintained extremely high.

  Each of the above embodiments is appropriately selected according to various conditions such as the mounting position of the aspherical mirror member 1 and the expansion / contraction characteristics of the mirror face plate 2 in the rear projection display apparatus. That is, depending on conditions such as the case where it becomes easy to bend in a specific direction depending on the state of the mounting position in the rear projection type image display device, or the case where the mirror face plate 2 tends to expand and contract in a specific direction, The aspherical mirror member 1 having a form in which the face plate support 6 is disposed is used.

  Thereby, the mirror face plate 2 can be accurately supported by the mounting member 3 while suppressing the distortion, and a clear image can be displayed on the screen.

[Modification]
In each of the above embodiments, the fixed plate piece 5 is provided directly and integrally with the mirror face plate support portion 6, but deformation due to thermal expansion or the like is allowed between the fixed plate piece 5 and the mirror face plate support portion 6. A buffer portion may be provided. Specifically, as shown in FIG. 14, two slits 14 are provided at the mounting position of the fixed plate piece 5 in the mirror face plate support portion 6 </ b> D, and the foot-shaped buffer portion 15 continuous with the fixed plate piece 5 is provided. It may be provided. Thereby, the buffer part 15 bends, and the thermal expansion and contraction of the mirror face plate 2 are permitted. Thereby, the mirror face plate 2 can be accurately supported while suppressing the distortion.

In addition to the buffer 15, a second buffer may be further provided. Specifically, as shown in FIG. 15, thin portions 16 and 17 as second buffer portions may be provided on the buffer portion 15 and the fixed plate piece 5. Since the buffer portion 15 and the fixed plate piece 5 are easily bent by the thin portions 16 and 17, the strain is absorbed more flexibly. The thickness and attachment position of the thin portions 16 and 17 are appropriately set according to various conditions such as the degree of thermal expansion of the mirror face plate 2. Only one of the thin portions 16 and 17 may be provided.
Furthermore, the slit 14 and the thin portions 16 and 17 may be provided in other mirror face plate support portions 6A, 6B, and 6C.

  Thereby, the change in the dimension of the mirror face plate 2 due to thermal expansion or the like can be absorbed by the bending of the thin portions 16 and 17, and the distortion of the mirror face plate 2 can be suppressed.

It is a perspective view which shows the aspherical mirror member which concerns on 1st Embodiment of this invention. It is side surface sectional drawing which shows the conventional rear projection type video display apparatus. It is a perspective view which shows the conventional mirror holding mechanism. It is a top view which shows the aspherical mirror member which concerns on 1st Embodiment of this invention. It is a perspective view which shows the aspherical mirror member which concerns on 1st Embodiment of this invention from the other. It is a perspective view which shows the aspherical mirror member which concerns on 2nd Embodiment of this invention. It is a perspective view which shows the aspherical mirror member which concerns on 2nd Embodiment of this invention from the other. It is a perspective view which shows the aspherical mirror member which concerns on 3rd Embodiment of this invention. It is a perspective view which shows the aspherical mirror member which concerns on 3rd Embodiment of this invention from the other. It is a perspective view which shows the aspherical mirror member which concerns on 4th Embodiment of this invention. It is a perspective view which shows the aspherical mirror member which concerns on 4th Embodiment of this invention from the other. It is a perspective view which shows the aspherical mirror member which concerns on 5th Embodiment of this invention. It is a perspective view which shows the aspherical mirror member which concerns on 5th Embodiment of this invention from the other. It is a perspective view which shows the 1st modification of this invention. It is a perspective view which shows the 2nd modification of this invention.

Explanation of symbols

  1: aspherical mirror member, 2: mirror face plate, 3: mounting member, 4: reflecting surface, 5: fixed plate piece, 6: mirror face plate support, 7: screw hole, 8: positioning hole, 9: reinforcement Plate material, 11: foot part, 14: slit, 15: buffer part, 16, 17: thin part.

Claims (7)

An aspherical mirror member that reflects the image light projected on the screen surface along the optical axis,
An aspherical mirror face plate that reflects the image light, and an attachment member that supports the mirror face plate and fixes it to the apparatus side;
In a state in which the mounting member is fixed to the device side via the fixing plate piece interposed between the fixing plate piece and the mirror face plate that is fixed directly to the device side. An aspherical mirror member, comprising: a mirror face plate support portion that supports the mirror face plate while suppressing distortion thereof. The aspherical mirror member according to claim 1,
An aspherical mirror member, wherein the mirror face plate support portion is composed of a reinforcing plate material disposed on a back surface of the mirror face plate in a direction substantially orthogonal to the mirror face plate. The aspherical mirror member according to claim 1 or 2,
An aspherical mirror member provided with a buffer portion provided between the fixed plate piece and the mirror face plate or the mirror face plate support portion and allowing deformation due to thermal expansion or the like. The aspherical mirror member according to claim 3,
An aspherical mirror member, wherein the buffer portion is constituted by a foot portion provided continuously to the fixed plate piece. The aspherical mirror member according to claim 3,
The aspherical mirror member, wherein the buffer portion is constituted by a slit provided in the reinforcing plate material continuously from the fixed plate piece. The aspherical mirror member according to claim 3,
An aspherical mirror member, wherein the buffer portion is formed by a thin portion that is provided between the fixed plate piece and the mirror face plate support portion and is allowed to deform due to thermal expansion by bending. A rear projection type image display device comprising an aspherical mirror member that reflects and projects image light from a light source on a screen,
A rear projection type image display apparatus using the aspherical mirror member according to any one of claims 1 to 6 as the aspherical mirror member.

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