JP2009086233A - Optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent temperature rise of a lens barrel to prevent deterioration of optical performance of an optical device even if the lens barrel holding a lens within a projection lens unit is exposed to unnecessary light of projected light. <P>SOLUTION: A light beam emitted from a color composition prism 14 is transmitted by lens groups L6-L11 and reaches a forward projection screen. An effective light beam emitted from the color composition prism 14 is prevented from directly reaching an inside diameter part 38c of a cam cylinder 48 by an aperture diaphragm 43. Since a fixed diaphragm 44 is provided, the reflected light by the inside diameter part 38c of the cam cylinder 48 is shielded by the periphery of the fixed diaphragm 44 so as not to reach the screen, and the shielded luminous flux is shown in the drawing by an alternate long and short dash line. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector device that irradiates a display device device such as a liquid crystal panel with an illumination optical system and enlarges and projects a display image on the display device with a projection lens, and relates to an optical device having a projection lens unit.

  Conventionally, a high-intensity light source such as an ultra-high pressure mercury lamp is used to illuminate a liquid crystal panel, which is a display device, using an illumination optical system that uses a compound eye lens, mirror, polarizing plate, etc., and the displayed image is enlarged to the screen using a projection lens. Projectors that project are known.

  With the recent miniaturization of display devices, higher definition, and higher illuminance of projected images, the accuracy required for illumination optical systems has become high. Furthermore, in order to obtain the brightness, for example, as in Patent Documents 1 and 2, the intensity of light from the light source is increased, the illumination optical system is improved, the aperture ratio of the liquid crystal panel is improved, and the luminance emitted from the liquid crystal panel Is raised.

  There is also known a projection display device that enlarges and projects an image formed by various modulation devices such as a liquid crystal panel and a micromirror device (DMD) onto a screen by a projection lens. In this projection type display device, light shielding means is disposed in the illumination optical system and the projection optical system in order to improve the image quality of the projected image, and light rays that do not directly contribute to image formation are removed by the light shielding means.

  When unnecessary light is shielded by the light shielding means arranged in the projection lens unit, the brightness of the light shielding means becomes extremely high because the luminance is high as described above.

Japanese Unexamined Patent Publication No. 7-199183 JP 2005-128217 A

  However, in Patent Document 1, a reflection member is provided on a diaphragm arranged near the light source, so that light rays that do not directly contribute to image formation are reflected to the light source side. Here, when the stop is disposed near the light source, the brightness of the light source used in the projection display device is very high, and thus the temperature of the stop becomes extremely high.

  Further, in Patent Document 2, a lens barrel in which a reflection region having a reflectance of 30% or more is provided on at least a part of the surface of the holding member holding the lens on the image display element side.

  The object of the present invention is to solve the above-mentioned problems and prevent the lens barrel from rising in temperature even when unnecessary light in the projection light hits the lens barrel that holds the lens inside the projection lens unit. An object of the present invention is to provide an optical device that can effectively prevent performance degradation.

  The technical feature of the optical apparatus according to the present invention for achieving the above object is that a display image on a display device is received through a projection optical system in which lenses are held by a plurality of movable lens barrels using irradiation light from a light source. The light shielding means is disposed between a plurality of the movable lens barrels, and at least one of the movable lens barrel and the light shielding means is made of a metal material.

  Further, the technical feature of the optical apparatus according to the present invention is that the display image on the display device is projected onto the projection surface via the projection optical system using the irradiation light from the light source and holding the lenses by a plurality of movable lens barrels. An optical device for projecting, wherein the movable barrel is made of a highly crystalline resin.

  Furthermore, the technical feature of the optical apparatus according to the present invention is that a display image on a display device is projected onto a projection surface via a projection optical system in which lenses are held by a plurality of movable lens barrels using irradiation light from a light source. An optical apparatus for projecting, wherein the lens group closest to the display device is a fixed lens group, the moving lens group of the movable lens barrel is adjacent to the fixed lens group, and the focal length of the fixed lens group is f, The zoom lens barrel has a configuration in which D1 / f> 0.15 when the moving amount of the moving lens group is D1.

  Furthermore, the technical feature of the optical apparatus according to the present invention is that a display image on a display device is projected onto a projection surface via a projection optical system in which lenses are held by a plurality of movable lens barrels using irradiation light from a light source. An optical apparatus for projecting, wherein a lens group closest to the display device is a fixed lens group, a moving lens group that holds a lens having the smallest effective diameter is disposed on a projection surface side of the fixed lens group, and the fixed lens The zoom lens barrel has a configuration in which D2 / f> 0.15, where f is the focal length of the group and D2 is the amount of movement of the moving lens group.

  The technical feature of the optical apparatus according to the present invention is that the display image on the display device is projected onto the projection surface via the projection optical system in which the lens is held by a plurality of movable lens barrels using the irradiation light from the light source. An optical apparatus, wherein a lens group closest to the display device is a fixed lens group, a moving lens group that holds a lens having the smallest effective diameter is disposed on a projection surface side of the fixed lens group, and the fixed lens group The zoom lens barrel has a configuration in which D3 / f> 0.15 when the focal length is f and the distance between the moving lens group and the fixed lens group is D3.

  According to the optical device of the present invention, the member inside the lens barrel is heated by the projection light, and heat is not trapped in the projection lens unit, so that the optical component is hardly deteriorated. Moreover, since reflection by the inner surface of the lens barrel is prevented and unnecessary light is not projected, deterioration of the projected image is reduced.

  The present invention will be described in detail based on the embodiments shown in the drawings.

  1 is a configuration diagram of an image display apparatus having a projection lens of Example 1. FIG. In FIG. 1, a light source 1 is surrounded by a reflector 2, and a first fly eye lens 3, a second fly eye lens 4, a polarization conversion element 5, a condenser lens 6, and a mirror 7 are arranged in front of the light source 1. . A dichroic mirror 8 and a mirror 9 are arranged in the reflection direction of the mirror 7, and a dichroic mirror 10 and a mirror 11 are arranged in the reflection direction of the dichroic mirror 8.

  In the reflection direction of the mirror 9, a field lens 12B, a blue light liquid crystal panel 13B, and a color synthesis prism 14 are arranged. A field lens 12G, a green light liquid crystal panel 13G, and a color synthesis prism 14 are arranged in the reflection direction of the dichroic mirror 10. In the reflection direction of the mirror 11, a mirror 16 is provided via a field lens 15. In the reflection direction of the mirror 16, a field lens 12R, a red light liquid crystal panel 13R, and a color synthesis prism 14 are arranged. A projection lens barrel 20 is disposed in the emission direction of the color combining prism 14 in which light beams from three directions are incident.

  Irradiation light from the light source 1 is reflected by a reflector 2 such as a paraboloid, and apparently substantially parallel light emitted from the light source 1 from an infinite distance is guided to the first fly-eye lens 3. The guided light is divided into a plurality of light beams by the action of the first fly-eye lens 3, and the divided light beams are guided to the second fly-eye lens 4. Each light beam from the second fly-eye lens 4 is aligned with the vibration surface from natural light, which is non-polarized light having a random vibration component, that is, the polarization vibration surface is converted so as to align the polarization direction, and is guided to the condenser lens 6. It is burned.

  The polarized light is color-separated by the dichroic mirrors 8 and 10, and further illuminates the liquid crystal panels 13R, 13G and 13B which are transmission type modulation devices through the field lenses 12R, 12G and 12B. The display images of the three liquid crystal panels 13R, 13G, and 13B are synthesized by the color synthesis prism 14, and are enlarged and projected on the projection surface formed by the projection lens barrel 20. The projection lens barrel 20 has a function of removing light rays that do not directly contribute to image formation.

  Further, even in an image display device using a reflective liquid crystal panel, image light formed by a liquid crystal panel, which is a reflection type modulation device, can be enlarged and projected onto a screen using the same projection lens barrel 20.

  FIG. 2 is a cross-sectional view of a projection lens barrel 20 that is a zoom lens barrel. Lens groups L1 to L6 are arranged in the optical axis direction, the first lens group L1 has negative power due to a plurality of lenses, is held by the first group barrel 31, and the second lens group L2 has positive power, The third lens group L3 is held by the second group barrel 32, and the third lens group L3 has a positive power and is held by the third group barrel 33. The fourth lens group L4 has negative power from a plurality of lenses and is held in the fourth group lens barrel 34, and the fifth lens group L5 has positive power from a plurality of lenses and is held in the fifth group lens barrel 35, and is a fixed lens. The sixth lens group L6, which is a group, has positive power and is held by the sixth group barrel. The first group barrel 31 to the fifth group barrel 35 are respectively movable barrels, and the sixth group barrel 36 is a fixed barrel.

  Images from the liquid crystal panels 13R, 13G, and 13B are synthesized by the color synthesizing prism 14, incident from the sixth lens group L6 side, enlarged by a predetermined magnification by the lens groups L6 to L1, and emitted from the first lens group L1. Projected onto the screen.

  In the projection lens barrel 20, a mount portion (not shown) is attached to the fixed barrel 37 and fixed to the prism base holding the color synthesis prism 14 with screws. A fitting portion 37 a that fits the outer diameter portion 38 a of the cam cylinder 38 is provided inside the fixed cylinder 37, the cam cylinder 38 and the fixed cylinder 37 are fitted together, and the cam cylinder 38 rotates inside the fixed cylinder 37. Possible configuration. In the cam cylinder 38, a cam groove 38b is cut in the cam cylinder 38 in order to move the moving lens group including the lens groups L2 to L5 at a predetermined interval. Cam followers provided in the lens groups L <b> 2 to L <b> 5 are fitted in the cam grooves 38 b, and the cam followers are provided in the fixed cylinder 37 and are also fitted in rectilinear grooves 37 b that penetrate the inner and outer diameters of the fixed cylinder 37.

  A fitting portion 37 c that fits with the inner diameter portion 39 a of the zoom ring 39 is provided on the outer diameter portion of the fixed cylinder 37. The zoom ring 39 and the fixed cylinder 37 are fitted together, and the zoom ring 39 is arranged around the fixed cylinder 37. It can be rotated. Inside the zoom ring 39, a protrusion 39c is provided for rotating without rotating in the optical axis direction when rotating at the outer diameter portion of the fixed cylinder 37, and is assembled with the fixed cylinder 37 by a bayonet configuration. . The zoom ring 39 has a straight groove 39b that passes therethrough, and a cam follower 40 that is screwed to the cam cylinder 38 passes therethrough.

  When the projection magnification of the projection lens barrel 20 is changed, the zoom ring 39 is rotated at a fixed position, and this rotational force is transmitted to the cam barrel 38. The moving lens group consisting of the lens groups L2 to L5 is the cam of the cam barrel 38. It moves along the groove 38b.

  Further, the zoom ring 39 is manually rotated by a lever protruding from the upper surface, side surface, or front surface of the projection lens barrel 20. The drive unit of the zoom ring 39 is provided in the zoom ring 39 by an output gear that sends a signal to the drive circuit by a switch provided in the projection lens barrel 20 and rotates the motor by the drive circuit. It can also be transmitted to the gear section and rotated.

  Further, a focus ring 41 is disposed on the outer diameter portion of the fixed cylinder 37, and a fitting portion 37 d that is fitted to the inner diameter portion 41 a of the focus ring 41 is provided on the fixed cylinder 37. The focus ring 41 and the fixed cylinder 37 are fitted together, and the focus ring 41 is rotatable at the outer diameter portion of the fixed cylinder 37. A projection (not shown) is provided on the inner diameter portion of the focus ring 41 so as not to move in the direction of the optical axis when rotating at the outer diameter portion of the fixed cylinder 37, and is assembled by the fixed cylinder 37 and the bayonet structure. It has been.

  The focus ring 41 is provided with an end face cam 41b for moving the first lens unit L1 by a predetermined amount. Further, a cam follower 42 fixed to the first group barrel 31 is in contact with the end face cam 41b, and the cam follower 42 is also fitted in a rectilinear groove 37e penetrating the inner and outer diameters of the cylinder provided in the fixed cylinder 37. .

  The focus ring 41 is manually rotated by a lever protruding from the upper surface, side surface, or front surface of the projection lens barrel 20. Alternatively, a signal is sent to the drive circuit by a switch provided in the projection lens barrel 20, the motor is rotated by the drive circuit, and the rotation from the motor is transmitted to the gear portion provided in the focus ring 41 by the output gear. The ring 41 can also be rotated.

  When the focus position of the projection lens barrel 20 is changed, the focus ring 41 rotates at a fixed position, the rotational force is transmitted to the first group barrel 31 via the cam follower 42, and the first lens group L1 is fixed to the fixed barrel 37. In the straight groove 37e.

  Between the third lens group L3 and the fourth lens group L4 of the projection lens barrel 20, an aperture stop 43 that moves along the same locus as the third group barrel 33 is provided. The aperture stop 43 has an inner diameter formed by a metal plate at the rear portion of the third group barrel 33 holding the third lens unit L3, that is, the mounting portion formed on the color synthesis prism 14 side.

  Further, a fixed stop 44 is disposed between the second lens unit L2 and the third lens unit L3. An inner diameter portion 38c of the cam cylinder 38 is fitted with an outer diameter section 44a of the fixed throttle 44, and the fixed throttle 44 is fixed to the cam cylinder 38 by a plurality of mounting screws. The fixed diaphragm 44 is rotated by the rotation of the cam cylinder 38, but does not move in the optical axis direction.

  FIG. 3 is a cross-sectional view of the optical path when the projection lens barrel 20 is set on the short focal side, and the optical path emitted from the color synthesizing prism 14 and the optical path of the light beam reaching the inner diameter portion 38c of the cam cylinder 38, An optical path reflected by the inner diameter portion 38c of the cam cylinder 38 is shown.

  Light rays emitted from the color synthesis prism 14 pass through the lens groups L6 to L1 and reach the front projection screen. The effective light beam emitted from the color combining prism 14 does not reach the inner diameter portion 38 c of the cam cylinder 38 directly by the aperture stop 43. However, the optical path outside the effective light beam emitted from the color synthesizing prism 14 is reflected by the mechanical parts of the projection lens barrel 20 and the lens surfaces of the lens groups L6 to L1, and reaches the inner diameter portion 38c of the cam barrel 38. It can happen. Such light rays are reflected by the inner diameter portion 38c of the cam cylinder 38 and reach the screen as unnecessary light, which degrades the performance of the projected image.

  In FIG. 3, since the fixed diaphragm 44 is provided, the reflected light is blocked by the periphery of the fixed diaphragm 44 so as not to reach the screen. The shielded light beam is illustrated by a one-dot chain line. Yes. When there is no fixed aperture 44, much of the reflected light from the inner diameter portion 38c of the cam cylinder 38 reaches the projection screen without being blocked.

  The inside of a normal lens barrel is blackened so that unnecessary light is not diffusely reflected, so that it looks black even when the inside is viewed from the front of the lens on the projection surface side. In the case of using a cam cylinder whose inner diameter is processed with aluminum for the inner black treatment, black alumite treatment (anodization treatment) is often performed. In anodizing, it is necessary to hold the member to be processed with an electrode under a predetermined load in the processing step, and the member may be deformed depending on the holding force and holding position, or transported to the processing step. This causes deterioration of lens performance, such as deformation inside.

  As another method, there is an example in which the inner diameter portion 38c of the cam cylinder 38 is painted black, but due to the recent improvement in image quality and brightness, the cam cylinder 38 is required to improve accuracy, and as much as possible is defective. It is necessary to delete the process.

  In this embodiment, the inner diameter portion 38c of the cam cylinder 38 formed of aluminum is not blackened, and the inner diameter section 38b of the cam cylinder 38 is formed with the material color of aluminum. The fixed aperture 44 is black-processed. When the projection lens barrel 20 is looked into the lens from the front, the inner diameter portion 38c of the cam barrel 38 is shielded by the fixed aperture 44, so that the color of the aluminum background Can not be seen.

  In the present embodiment, since the black processing step of the cam cylinder 38 is not required, the number of defective steps is reduced, the accuracy can be improved, and the cost can be reduced by reducing the number of steps.

  When the unnecessary light beam reaches the inner diameter portion 38 c of the cam cylinder 38, the light beam reflected by the inner diameter portion 38 c reaches the fixed aperture 44. However, if the light reaching the fixed aperture 44 is reflected and does not adversely affect the optical performance, there is no problem even if the processing on the color combining prism 14 side of the fixed aperture 44 is left as the material color. . However, when it is not desired to reflect unnecessary light from the fixed aperture 44, black processing on the color combining prism 14 side of the fixed aperture 44 is required.

  When looking in from the front of the projection lens barrel 20, the interior of the barrel need not be black, and if the projection performance is not adversely affected, there is no problem even if the base of the metal material is left as it is.

  The fixed stop 44 is provided to prevent unnecessary light from reaching the projection screen. Therefore, it is necessary to absorb light other than the effective light beam emitted from the color synthesizing prism 14 or reflect it in a direction in which there is no problem so as not to deteriorate the performance of the projected image. In order to make the fixed diaphragm 44 absorb light, it is best to blacken it. However, when blackened, unnecessary light is absorbed and the fixed diaphragm 44 becomes high temperature, and the temperature inside the lens gradually increases. End up.

  In recent years, projectors have been increased in brightness, and even with unnecessary light, the temperature of the fixed aperture 44 becomes 100 ° C. or higher when the light that has been shielded from it hits it. Therefore, in the plastic material, not only the performance of the projected image cannot be maintained, but also the deformation occurs and the shape cannot be maintained.

  Accordingly, it is desirable that the fixed aperture 44 be made of a metal material, and heat generated by the light absorbed by the fixed aperture 44 is applied to the cam cylinder 38 using a metal material having a thermal conductivity of, for example, 80 W / m · k or more. introduce. As a result, it is necessary to make the temperature of the entire lens uniform so that heat in the lens can be released or not only the temperature rise in the vicinity of the fixed diaphragm 44 is eliminated.

  FIG. 4 is a cross-sectional view of the projection lens barrel of the second embodiment, showing a lens arrangement state in a short focus state. In the projection lens barrel 20, a moving diaphragm 51 is disposed between the second lens groups L2 and L3. The outer diameter portion 51 a of the moving diaphragm 51 is fitted to the inner diameter portion 38 c of the cam cylinder 38.

  The outer diameter portion 51a of the movable diaphragm 51 has a structure extending in a cylindrical shape toward the second lens unit L2, and the contact area between the movable diaphragm 51 and the cam cylinder 38 is configured to be wide. A plurality of cam followers 52 are fixed to the moving diaphragm 51, and the cam followers 52 are fitted into cam grooves 38 b provided in the cam cylinder 38, and are further fitted into rectilinear grooves 37 b provided in the fixed cylinder 37. Yes.

  When the cam barrel 38 rotates by a predetermined amount, the moving lens group consisting of the lens groups L2 to L5 moves as shown in FIG. 5, and the projection lens barrel 20 changes to the long focus state. At this time, the moving diaphragm 51 also moves toward the second lens unit L2 along the cam groove 38b provided in the cam cylinder 38.

  By arranging and configuring in this way, it is possible to arrange the movable diaphragm 51 that can be moved to an effective position even in the projection lens barrel 20 having no space. Further, since the contact area between the cam cylinder 38 and the movable diaphragm 51 is large, even if the light received by the movable diaphragm 51 changes to heat, it is efficiently transmitted to the cam cylinder 38.

  Since the projection surface side of the moving diaphragm 51 is blackened, the inner diameter portion 38c of the cam cylinder 38 is shielded by the moving diaphragm 51 when looking into the lens from the front of the lens. Can not be seen.

  FIG. 6 is a cross-sectional view of the fifth group barrel 35 in the projection lens barrel of the third embodiment. The fifth lens barrel 35 molded from a resin material is provided with two lens fixing fitting portions 35a and 35b in which the lens L5a and the lens L5b constituting the fifth lens unit L5 are fitted, and the lens L5a And the lens L5b are kept coaxial. The inner diameters of the fitting portions 35a and 35b are made slightly smaller than the outer diameters of the lenses L5a and L5b, respectively, and numerically set to be -0.01 to -0.03 mm in diameter difference, and the lenses L5a and L5b are It is press-fitted into the fifth group barrel 35.

  As shown in FIG. 7, the inserted lens L5a is fixed by an adhesive 61 applied to an adhesive coating notch 35c provided in the fifth group barrel 35 after insertion. After fixing the lens L5a, as shown in FIG. 8, the lens L5b is inserted into the fifth group lens barrel 35 and similarly fixed by the adhesive 61 applied to the notch 35d.

  FIG. 9 is a perspective view of the fifth group barrel 35 of the fourth embodiment. The fifth group lens barrel 35 molded from a resin material is provided with fitting portions 35a and 35b (not shown) into which the lenses L5a and L5b of the fifth lens group L5 are fitted, respectively, as in the third embodiment. The lens L5b is held coaxially.

  The inner diameters of the fitting portions 35a and 35b are made slightly smaller than the outer diameters of the lenses L5a and L5b, respectively, and the diameter difference is set to −0.01 to −0.03 mm, and the lenses are press-fitted into the fifth group barrel 35. Inserting. The inserted lens L5a is fixed by fitting a C-ring 71 made of SUS wire or piano wire having spring properties into a spring groove 35e provided in the fifth group barrel 35 after insertion.

  After the lens L5a is fixed, the lens L5b is inserted into the fifth group barrel 35, and the C-ring 72 is inserted into the spring groove 35f in the same manner as the lens L5a is fixed, and the lens L5b is fixed.

  Conventional barrels are generally molded from polycarbonate resin, and the polycarbonate resin has a heat deformation temperature of about 150 ° C. under a load of 1.8 and 10 MPa. When the lens configuration is the same, the brightness and temperature rise are almost proportional, and in recent projection-type image display devices, if the material of the lens barrel is molded from polycarbonate resin, the lens barrel softens. It can be trapped or dissolve in the worst case.

  In the present embodiment, the resin material of the fifth group lens barrel 35 is molded from a highly crystalline polyphenylene sulfide resin made of a material having a heat deformation temperature of 260 ° C. or higher under a load of 1.8 MPa and 10 MPa. Alternatively, it is molded from a liquid crystal polymer resin having a heat deformation temperature of 250 ° C. to 300 ° C. or higher at a load of 1.8 or 10 MPa, or a polyether ether having a heat deformation temperature of about 280 ° C. at a load of 1.8 or 10 MPa. Molded with ketone resin.

  FIG. 10A is a cross-sectional view of the projection lens barrel 20 of Example 5 when adjusting the short focus side, and FIG. 10B is a cross-sectional view when adjusting the long focus.

The focal length of the sixth lens unit L6 is f, the amount of movement of the fifth lens unit L5 when changing from the short focal point to the long focal point is D2, the long focal point side of the adjacent sixth lens unit L6 and the fifth lens unit L5. Let the lens interval be D1. The fourth lens unit L4 is provided with a lens L4a that passes through the smallest effective diameter in the lens system, and the amount of movement of the fourth lens unit L4 when changing from a short focal point to a long focal point is D3. At this time, the relationship between the lens and the movement amount is expressed by the following expression, and even if each is independent, a lens configuration is formed by combining a plurality of expressions.
D1 / f> 0.15
D2 / f> 0.15
D3 / f> 0.15

  Rwide is a light beam emitted from the color synthesizing prism 14 and is substantially equal to the F number of the illumination optical system. The light rays displayed in the figure are only chief rays, and the color synthesis prism 14 includes unnecessary rays emitted as scattered light around the chief rays.

  In the state of short focus adjustment shown in FIG. 10A, the light beam emitted from the color synthesis prism 14 is efficiently guided to the sixth lens unit L6, and the refracted beam reaches the lens L5b of the fifth lens unit L5. To do. The light beam incident on the lens L5b is refracted and emitted, reaches the lens L5a, is refracted by the lens L5a, and is emitted. On the short focal side, the light rays reaching each lens efficiently reach the lens, and unnecessary light included outside the principal ray also reaches the lens.

  In the state during the long focus adjustment shown in (b), the light beam emitted from the color synthesis prism 14 is efficiently guided to the sixth lens unit L6, and the refracted light beam reaches the lens L5b of the fifth lens unit L5. At this time, the principal ray required on the long focal side is Rtele, and since the Ride ray is emitted from the color synthesizing prism 14, the difference between Rtele and Rwide becomes unnecessary light around the principal ray. It has reached the lens unit L6.

  The principal ray incident on the lens L5b of the fifth lens group L5 is refracted and emitted to reach the lens L5a, and refracted and emitted by the lens L5a. However, unnecessary light incident on the sixth lens group L6 Irradiates the outer diameter side of L5b and the fifth group barrel 35.

  On the long focal side, the light rays that reach each lens pass through each lens based on the optical design value, but unnecessary light on the long focal side of the difference between Rtele and Rwide becomes a plurality of lens mirrors. It is projected while being irradiated onto the tube.

  Unnecessary rays irradiated to the fifth group barrel 35 change the temperature of the fifth group barrel 35 to be high instead of thermal energy. If the temperature of the fifth group barrel 35 becomes abnormally high and exceeds the heat deformation temperature of the resin material, the lens cannot be held. Furthermore, the fifth group lens barrel 35 made of a resin material exceeds the melting point of the resin material and melts.

  In the projection lens barrel 20 of the present embodiment, the lens barrel with the largest amount of unnecessary light irradiation is the fifth lens unit L5. However, depending on the lens configuration, the fourth lens unit 34 of the fourth lens unit L4, The temperature may also rise in the sixth group lens barrel 36 of the sixth lens group L6.

  In such a case, the same effect can be obtained by molding the fourth group lens barrel 34 and the sixth group lens barrel 36 with polyphenylene sulfide resin, liquid crystal polymer resin, or polyether ether ketone resin.

  There are more lens barrels that block unnecessary light in the optical system of the projection lens on the side of the color synthesis prism 14 than the diaphragm configured in the projection lens barrel 20. The lens barrel on the side of the stop light color synthesizing prism 14 may be molded from polyphenylene sulfide resin, liquid crystal polymer resin, or polyether ether ketone resin.

  Further, even in a lens barrel having a moving diaphragm or a fixed diaphragm arranged between the lens groups, the diaphragm is heated to block harmful light, and may be melted by a normal polycarbonate resin.

  It is preferable to use the projection lens barrel 20 which is molded by a polyphenylene sulfide resin, a liquid crystal polymer resin, or a polyether ether ketone resin even on a diaphragm barrel which does not hold a lens.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof.

1 is an optical configuration diagram of an image display apparatus having a projection lens barrel of Example 1. FIG. It is sectional drawing of a projection lens barrel. It is an optical path sectional view of a projection lens barrel. FIG. 6 is a cross-sectional view of the projection lens barrel of Example 2 in a short focus state. FIG. 6 is a cross-sectional view of the projection lens barrel of Example 2 in a long focal state. 6 is a cross-sectional view of a fifth lens barrel in Embodiment 3. FIG. It is assembly explanatory drawing of a 5th lens-barrel. It is assembly explanatory drawing of a 5th lens-barrel. FIG. 10 is a perspective view of a fifth lens barrel of Example 4. FIG. 6 is a cross-sectional view of the third to sixth lens groups of Example 5 when adjusting the focus.

Explanation of symbols

L1 1st lens group L2 2nd lens group L3 3rd lens group L4 4th lens group L5 5th lens group L6 6th lens group 1 Light source 13 Liquid crystal panel 14 Color synthesis prism 20 Projection lens barrel 31 1 group lens barrel 32 2nd lens barrel 33 3rd lens barrel 34 4th lens barrel 35 5th lens barrel 36 6th lens barrel 37 Fixed barrel 38 Cam barrel 39 Zoom ring 40, 42 Cam follower 41 Focus ring 43 Aperture stop 44 Fixed aperture 51 Moving aperture 61 Adhesive 71, 72 C-ring

Claims (12)

  An optical apparatus for projecting a display image on a display device onto a projection surface via a projection optical system in which a lens is held by a plurality of moving barrels using irradiation light from a light source, the plurality of moving barrels An optical apparatus, wherein a light shielding means is arranged between the at least one movable lens barrel and the light shielding means.   The optical device according to claim 1, wherein the metal material has a thermal conductivity of 80 W / m · k or more.   The optical apparatus according to claim 1, wherein the light shielding unit is black processed.   The optical apparatus according to claim 3, wherein the black processing is performed on a projection surface side of the light shielding unit.   The optical apparatus according to claim 1, wherein the light shielding unit is movable.   An optical device for projecting a display image on a display device onto a projection surface through a projection optical system in which a lens is held by a plurality of movable lens barrels using irradiation light from a light source, and the material of the movable lens barrel An optical device characterized by being made of a highly crystalline resin.   The optical device according to claim 6, wherein the highly crystalline resin is a liquid crystal polymer resin.   8. The optical apparatus according to claim 6, wherein the movable lens barrel has at least two lens fixing fitting portions, and an inner diameter of the fitting portion is smaller than an outer diameter of the lens. .   The movable lens barrel has at least two lens fixing fitting portions, and at least two notch portions are formed between the fitting portions, and an adhesive is applied to the notch portions to apply the lens. The optical device according to claim 6 or 7, wherein the optical device is fixed.   An optical device for projecting a display image on a display device onto a projection surface via a projection optical system in which a lens is held by a plurality of movable lens barrels using irradiation light from a light source, which is closest to the display device When the lens group is a fixed lens group, the moving lens group of the movable lens barrel is adjacent to the fixed lens group, the focal length of the fixed lens group is f, and the moving amount of the moving lens group is D1, D1 / An optical apparatus characterized by being a zoom lens barrel having a configuration in which f> 0.15.   An optical device for projecting a display image on a display device onto a projection surface via a projection optical system in which a lens is held by a plurality of movable lens barrels using irradiation light from a light source, which is closest to the display device The lens group is a fixed lens group, a moving lens group that holds a lens having the smallest effective diameter is arranged on the projection surface side of the fixed lens group, the focal length of the fixed lens group is f, and the moving amount of the moving lens group A zoom lens barrel having a configuration in which D2 / f> 0.15 when D2 is D2.   An optical device for projecting a display image on a display device onto a projection surface via a projection optical system in which a lens is held by a plurality of movable lens barrels using irradiation light from a light source, which is closest to the display device The lens group is a fixed lens group, a moving lens group that holds a lens having the smallest effective diameter is disposed on the projection surface side of the fixed lens group, the focal length of the fixed lens group is f, and the moving lens group and the fixed lens group are fixed. An optical apparatus characterized in that the zoom lens barrel has a configuration in which D3 / f> 0.15 when the distance between the lens groups is D3.

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