JP2009031800A - Projection type display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection type display capable of projecting an image free from nonuniform luminance onto a screen and being manufactured inexpensively. <P>SOLUTION: The projection type display includes: a reflection type display element 1 by which light made incident from an incident direction inclined in one direction to the direction of front is reflected and emitted to the direction of the front and the emission of light from a plurality of pixels is controlled to display an image; a power source system 20 by which the luminous flux of light from a light source 11 is diverged by a power source lens 21 and it is projected to the reflection type display element 1 from the incident direction; a projection system 23 by which the luminous flux of light emitted from the reflection type display element 1 is diverged by a projection lens 24 and projected; and a relay optical member 25 which is disposed in front of the reflection type display element 1 and by which projection light from the power source system 20 is corrected to parallel light along a direction inclined in the incident direction by a specific angel to the direction of the front of the reflection type display element 1 and the parallel light is made incident on the reflection type display element 1, and the luminous flux of reflected light emitted in the direction of the front of the element 1 is converged and made incident on the projection system lens 24. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projection display device using a reflective display element.

  Recently, development of a projection display device using a reflective display element such as a reflective liquid crystal display element or a micromirror element (Digital Micromirror Device) generally abbreviated as DMD has been studied.

  FIG. 4 is a side view of a conventional projection display device using the micromirror element. The display device includes a micromirror element 1, a light source system 10 that projects light onto the micromirror element 1, and the micromirror element 1. The projection system 18 projects the light emitted from the mirror element 1 onto a screen (not shown).

  The micromirror element 1 is formed by micromirrors made of ultrathin metal pieces (for example, aluminum pieces) each having a vertical and horizontal width of 10 μm to 20 μm, and the inclination direction of these micromirrors is determined. An image is displayed by switching.

  FIG. 5 shows the display principle of the micromirror element 1. The micromirror element 1 is inclined in one direction and the other direction with respect to a reference plane L substantially perpendicular to the front direction. A plurality of pixels including a plurality of operating micromirrors 2 have a display area A arranged along the reference plane L in the row direction and the column direction.

  The plurality of micromirrors 2 are respectively provided on a plurality of CMOS-based mirror drive elements (not shown) arranged in a matrix in the row direction and the column direction. By applying a digital signal to the driving element, it is tilted at an inclination angle of about 10 ° with respect to the reference plane L in each of the one direction and the other direction.

  The micromirror element 1 has an incident angle within a predetermined angle range from an incident direction inclined in one inclination direction of the micromirror 2 with respect to the front direction, that is, the direction along the normal h of the reference plane L. The light incident on the display area A is reflected in the front direction and the oblique direction by switching the tilt direction of the plurality of micromirrors 2, and the micromirror 2 is shown by a solid line in FIG. When the tilting operation is performed in the direction indicated by, the light incident from the incident direction is reflected by the micromirror 2 toward the front of the micromirror element 1 as shown by the solid line in the figure, and the micromirror The display viewed from the front direction of the pixel corresponding to 2 is bright.

  Further, when the micromirror 2 is tilted in the direction indicated by the two-dot chain line in FIG. 5, the light incident from the incident direction is routed by the micromirror 2 as shown by the broken line in the drawing. The display viewed from the front direction of the pixel corresponding to the micromirror 2 is reflected darkly (black) with respect to the front direction.

  That is, the micromirror element 1 displays an image by controlling the brightness of the display viewed from the front direction of the pixels corresponding to the micromirrors 2 by switching the tilt directions of the plurality of micromirrors 2. Since the brightness of the bright display changes according to the time for which the incident light is reflected in the front direction, the time during which the micromirror 2 is tilted in the direction indicated by the solid line in FIG. 5 is controlled. An image with gradation can be displayed.

On the other hand, as shown in FIG. 4, the light source system 10 is disposed between the light source 11, the light guide rod 14 disposed on the emission side of the light source 11, and the light source 11 and the light guide rod 14. The color wheel 15 and a light source system lens 17 that projects the light emitted from the light guide rod 14 onto the micromirror element. The light source system 10 is incident on the micromirror element 1 in the incident direction (front side). The axis O ₁₀ of the projection optical path is set so that light is projected from a direction inclined in one of the inclination directions of the micromirror 2 with respect to the direction of the micromirror 2. The micromirror element 1 is disposed obliquely in front of the micromirror element 1 at a predetermined angle in one tilt direction.

  The light source 11 includes a light source lamp 12 such as an ultra-high pressure mercury lamp that emits white light with high luminance, and a reflector 13 that condenses and reflects light emitted from the light source lamp 12 toward the front.

  The color wheel 15 is provided to sequentially color the emitted light (white light) from the light source 11 into a plurality of colors, for example, three colors of red, green, and blue. FIG. 6 is a front view of the color wheel 15. The color wheel 17 is composed of a disc-shaped rotating plate in which three color filters 16R, 16G, and 16B of red, green, and blue are arranged in the circumferential direction. ing.

  The color wheel 15 rotates so that the color filters 16R, 16G, and 16B sequentially pass in front of the incident end face 15 of the light guide rod 14, and the center of rotation is on the side of the projection optical path to the micromirror element 1. It is arranged to be shifted toward.

  The light guide rod 14 is formed of a transparent square bar having a cross-sectional shape similar to the shape (rectangular shape) of the display area A of the micromirror element 1 or a square tube having a reflective film on the entire inner surface. The one end face is an incident end face and the other end face is an exit end face.

The light guide rod 14 is disposed on the emission side of the light source 11 with its incident end face facing the light source 11 and with its center axis aligned with the axis O ₁₀ of the projection light path.

  The light guide rod 14 is provided to make the light emitted from the light source 11 into a light beam having a uniform intensity distribution. The light guide rod 14 is condensed and reflected from the light source 11 by the reflector 13, and the color wheel 15 is emitted. The light colored in any one of red, green, and blue is made incident from the incident end face, and the light is air that is the outside air and each side surface of the light guide rod 14 as indicated by arrows in FIG. The light guide rod 14 is guided in its length direction while being totally reflected at the interface with the layer, and is emitted from the emission end face as a light beam having a uniform intensity distribution.

In addition, the light source system lens 17 is configured by combining a plurality of lenses in order to reduce lens aberration. The light source system lens 17 is arranged on the exit side of the light guide rod 14 with a lens optical axis. the are arranged to coincide with the axis O ₁₀ of the projection optical path.

The projection system 18 includes a projection system lens 19 having a small lens aberration, which is configured by combining a plurality of lenses. The projection system lens 18 has its lens optical axis as the micromirror element 1. Are arranged in front of the micromirror element 1 so as to coincide with the axis O ₁ of the light beam of the reflected light emitted in the front direction (light reflected in the front direction by the plurality of micromirrors 2).

  The projection display device emits light (white light) from the light source 11 and rotationally drives the color wheel 15 at a high speed, so that red, green, and blue light are sequentially emitted from the light source system 10 to the micromirror. In addition to projecting on the element 1, red, green, and blue image data are sequentially written in the micromirror element 1 in synchronization with the red, green, and blue light projection periods, thereby red on the micromirror element 1. , Green and blue images are sequentially displayed, and red, green and blue image lights sequentially emitted from the micromirror element 1 are enlarged by the projection system 18 and projected onto a screen (not shown). To observe the synthesized color image.

  By the way, the projection display device projects light that is incident on the micromirror element 1 from the incident direction, is reflected in the front direction by the plurality of micromirrors 2, and is emitted in the front direction of the micromirror element 1. Since the light is projected onto the screen by the lens 19, if the intensity distribution of the light emitted in the front direction of the micromirror element 1 and incident on the projection system lens 19 is not uniform, the image projected on the screen Luminance unevenness occurs.

  Therefore, in the conventional projection display device, as shown in FIG. 4, the projection light from the light source system 10 is projected at a predetermined angle in the incident direction with respect to the front direction of the micromirror element 1 by the light source system lens 17. By correcting the parallel light along the tilted direction and making it incident on the micromirror element 1, emitting parallel light with a uniform intensity distribution in the front direction of the micromirror element 1 and making it incident on the projection system lens 19. The image without brightness unevenness is projected on the screen.

  However, when the projection light from the light source system 10 is corrected to the parallel light by the light source system lens 17 and is incident on the micromirror element 1 as described above, the light source system lens 17 is displayed on the micromirror element 1. It is necessary to use a large-diameter lens capable of projecting parallel light over the entire area.

  In addition, since the conventional projection display device directly enters parallel light emitted in the front direction of the micromirror element 1 into the projection system lens 19, the projection system lens 19 is also a large-diameter lens. There is a need.

  As described above, the conventional projection display apparatus needs to use expensive large-diameter lenses as the light source system lens 17 and the projection system lens 19 in order to project an image having no luminance unevenness on the screen, and therefore, the cost is low. Difficult to manufacture.

  This is not limited to the projection display device using the micromirror element 1, but has a display area in which a plurality of pixels are arranged in a row direction and a column direction, and an incident direction inclined in one direction with respect to the front direction. Reflective display element that reflects light emitted from the light source and emits the light in the front direction and displays an image by controlling light emission from the plurality of pixels, for example, a projection type using a reflective liquid crystal display element This is also true for display devices.

  As a projection display device using a reflective display element, the present invention allows projection light from a light source system to enter the reflective display element as parallel light, and emits parallel light with a uniform luminance distribution from the reflective display element. An object of the present invention is to provide an image which can be emitted and projected onto a screen without uneven brightness, and which can be manufactured at low cost by using a light source lens and a projection lens as an inexpensive small-diameter lens. It is a thing.

  The projection display device of the present invention has a display area in which a plurality of pixels are arranged in a row direction and a column direction, reflects light incident from an incident direction inclined in one direction with respect to the front direction, and reflects the front surface. A reflective display element that emits light in a direction and displays an image by controlling the emission of light from the plurality of pixels, and expands a light beam from a light source by a light source system lens to the reflective display element. A light source system for projecting from an incident direction, a projection system for projecting light emitted from the reflective display element by expanding a light beam by a projection system lens, and a light source system disposed in front of the reflective display element. The projected light is corrected to parallel light along a direction inclined at a predetermined angle with respect to the incident direction with respect to the front direction of the reflective display element and is incident on the reflective display element, and in the front direction of the reflective display element. Outgoing reflected light It is characterized in that a relay optical member to be incident on the projection system lens by reducing the light flux.

  In the projection display device, the light from the light source is expanded by the light source system lens and the incident light is incident on the reflective display element in the incident direction (one direction with respect to the front direction of the reflective display element). ) And the projected light is parallel light along a direction inclined by a predetermined angle with respect to the front direction of the reflective display element by the relay optical member disposed in front of the reflective display element. And the reflected light emitted in the front direction of the reflective display element is made incident on the projection system lens by reducing the luminous flux by the relay optical member. The light beam is enlarged by the projection system lens and projected onto a screen (not shown).

  According to the projection display device, since the projection light from the light source system is incident on the reflection type display element as parallel light, parallel light with a uniform intensity distribution is emitted from the reflection type display element. Therefore, light having a uniform intensity distribution can be incident on the projection system lens, and an image without unevenness in brightness can be projected onto the screen.

  In the projection display device, the light source system is configured to project light from the light source system from the incident direction by enlarging a light beam from the light source system with a light source system lens, and projecting the light from the incident direction. Is converted into parallel light by the relay optical member and incident on the reflective display element, and the parallel light emitted from the reflective display element is reduced by the relay optical member and incident on the projection system lens. Therefore, the light source system lens and the projection system lens may be an inexpensive small-diameter lens, and can be manufactured at a low cost.

  In the projection display device according to the present invention, the reflective display element includes a plurality of micromirrors that are tilted in one direction and the other direction with respect to a reference plane substantially perpendicular to the front direction. The pixels have display areas arranged in a row direction and a column direction along the reference plane, and light incident from an incident direction inclined in one inclination direction of the micromirror with respect to the front direction is the plurality of microscopic pixels. A micromirror element that displays an image by reflecting in the front direction and the oblique direction by switching the tilt direction of the mirror is preferable.

  The relay optical member is a lens having a convex lens-like curved surface, and the optical axis of the lens is substantially parallel to the front direction of the reflective display element and the display area of the reflective display element. Of these, it is preferable that they are arranged so as to coincide with a straight line passing through the vicinity of the center of the edge opposite to the incident direction of light from the light source system.

  Further, it is more preferable that the relay optical member is a lens having a shape obtained by cutting a part of a circular convex lens into a shape corresponding to the display area of the reflective display element.

  Further, it is desirable that the projection system lens is disposed so that the lens optical axis thereof substantially coincides with the lens optical axis of the relay optical member made of the lens.

  The projection display device of the present invention has a display area in which a plurality of pixels are arranged in a row direction and a column direction, reflects light incident from an incident direction inclined in one direction with respect to the front direction, and reflects the front surface. A reflective display element that emits light in a direction and displays an image by controlling the emission of light from the plurality of pixels, and expands a light beam from a light source by a light source system lens to the reflective display element. A light source system for projecting from an incident direction, a projection system for projecting light emitted from the reflective display element by expanding a light beam by a projection system lens, and a light source system disposed in front of the reflective display element. The projected light is corrected to parallel light along a direction inclined at a predetermined angle with respect to the incident direction with respect to the front direction of the reflective display element and is incident on the reflective display element, and in the front direction of the reflective display element. Outgoing reflected light And a relay optical member that reduces the luminous flux and makes it incident on the projection system lens. Therefore, the projection light from the light source system is incident on the reflective display element as parallel light, and is reflected from the reflective display element. It can emit parallel light with a uniform luminance distribution and project an image with no luminance unevenness on the screen, and the light source system lens and the projection system lens can be made into an inexpensive small-aperture lens and can be manufactured at low cost. .

  In the projection display device according to the present invention, the reflective display element includes a plurality of micromirrors that are tilted in one direction and the other direction with respect to a reference plane substantially perpendicular to the front direction. The pixels have display areas arranged in a row direction and a column direction along the reference plane, and light incident from an incident direction inclined in one inclination direction of the micromirror with respect to the front direction is the plurality of microscopic pixels. A micromirror element that displays an image by reflecting in the front direction and the oblique direction by switching the tilt direction of the mirror is preferable. By using this micromirror element, a high-definition and bright image is projected onto the screen. Can do.

  The relay optical member is a lens having a convex lens-like curved surface, the lens optical axis of which is substantially parallel to the front direction of the reflective display element, and the display of the reflective display element. Of the peripheral edge of the area, it is preferable to be arranged to coincide with a straight line passing through the vicinity of the center of the edge opposite to the incident direction of the light from the light source system. The projected light is corrected into parallel light and made incident on the reflective display element, and the parallel light emitted in the front direction of the reflective display element can be reduced and made incident on the projection system lens. . Further, since the relay optical member made of the lens is very inexpensive compared to the light source system lens and the projection system lens, the manufacturing cost of the projection display device can be further reduced.

  Furthermore, it is preferable that the relay optical member is a lens having a shape obtained by cutting a part of a circular convex lens into a shape corresponding to the display area of the reflective display element. The optical member can be made cheaper, the manufacturing cost of the projection display device can be further reduced, and the relay optical member can be arranged so as not to protrude around the reflective display element, and the space can be saved. .

  In addition, it is desirable that the projection system lens is arranged so that the lens optical axis thereof substantially coincides with the lens optical axis of the relay optical member made of the lens. The light emitted in the front direction and reduced in light flux by the relay optical member and incident on the projection system lens is arranged in parallel with the front surface of the reflective display element by expanding the light flux by the projection system lens. The image can be formed on the screen as a high-quality image in focus.

  1 and 2 show a first embodiment of the present invention. FIG. 1 is a side view of a projection display device, and FIG. 2 is a front view of a relay optical member disposed in front of a micromirror element. .

  The projection display device of this embodiment uses a micromirror element 1 as a reflective display element, and projects light onto the micromirror element 1 and the micromirror element 1 as shown in FIG. A light source system 20, a projection system 23 that projects light emitted from the micromirror element 1, and a relay optical member 25 disposed in front of the micromirror element 1 are provided.

  As shown in FIG. 5, the micromirror element 1 includes a plurality of micromirrors 2 that are tilted in one direction and the other direction with respect to a reference plane L substantially perpendicular to the front direction. A plurality of pixels having a display area A arranged in a row direction and a column direction along the reference plane L, and the front direction, that is, the direction along the normal h of the reference plane L. An image is displayed by controlling a reflection direction of light incident at an incident angle within a predetermined angle range from an incident direction tilted in one tilt direction of the micromirror 2 by switching the tilt directions of the plurality of micromirrors 2.

On the other hand, the light source system 20 includes a light source 11, a light guide rod 14 disposed on the emission side of the light source 11, a color wheel 15 disposed between the light source 11 and the light guide rod 14, and the light guide. The light emitted from the exit end face of the optical rod 14 is enlarged in its luminous flux and enters the micromirror element 1 in the incident direction (a direction inclined in one inclination direction of the micromirror 2 with respect to the front direction of the micromirror element 1). The light source system 20 projects the axis O ₂₀ of the projection optical path in a predetermined inclination direction of the micromirror 2 with respect to the front direction of the micromirror element 1. The micromirror element 1 is disposed obliquely forward at an angle.

  Since the light source 11, light guide rod 14, and color wheel 17 of the light source system 21 are the same as those of the conventional display device shown in FIG. 4, the description thereof will be omitted with the same reference numerals.

The light source system lens 21 is configured by combining a plurality of lenses in order to reduce lens aberration. The light source system lens 21 has a lens optical axis on the exit side of the light guide rod 14. They are arranged so as to coincide with the axis O ₂₀ of the projection optical path.

  On the other hand, the relay optical member 25 disposed in front of the micromirror element 1 is composed of a single lens having a convex lens-like curved surface.

  As shown in FIG. 2, the relay optical member 25 has a shape obtained by cutting a part of a convex lens 26 indicated by a virtual line (two-dot chain line) in the figure into a rectangular shape corresponding to the display area A of the micromirror element 1. It consists of a lens, and has a lens optical axis 26a near the center of one side edge of the rectangular shape.

  As shown in FIG. 1, the relay optical member 25 has its lens optical axis 25 a placed in front of the micromirror element 1 (along the normal h of the reference plane L) immediately before the micromirror element 1. Direction) and, on the periphery of the display area A of the micromirror element 1, the edge on the opposite side of the light incident direction from the light source system 20 (the lower edge in FIG. 1) ) Are arranged so as to coincide with a straight line passing through the center.

As shown in FIG. 1, the relay optical member 25 corrects the projection light from the light source system 20 into parallel light along a direction inclined by a predetermined angle with respect to the incident direction with respect to the front direction of the micromirror element 1. The axis O ₁ of the light beam of the reflected light (light reflected in the front direction by the plurality of micromirrors 2) that is incident on the micromirror element 1 and emitted in the front direction of the micromirror element 1 is used as the lens optical axis 25a. The light beam is refracted in the direction, and is reduced so as to be converged toward the lens optical axis 25a, and is incident on the projection system lens 24.

  The projection system 23 includes a projection system lens 24 having a small lens aberration, which is formed by combining a plurality of lenses. The projection system lens 24 has its lens optical axis 24 a connected to the relay optical member 25. The lens optical axis 25a is substantially aligned with the lens optical axis 25a.

  The projection system lens 24 emits light that is emitted in the front direction of the micromirror element 1 and is incident upon being reduced in its luminous flux by the relay optical member 25, and expands the luminous flux to form a front surface of the micromirror element 1. Projection is performed on a screen (not shown) arranged in parallel (parallel to the reference plane L of the micromirror element 1).

  In this projection type display device, the light from the light source 11 is expanded by the light source system lens 21 and is incident on the micromirror element 1 in the incident direction (one of the micromirrors 2 with respect to the front direction of the micromirror element 1). The projection light is projected in a predetermined direction in the incident direction with respect to the front direction of the micromirror element 1 by the relay optical member 25 arranged in front of the micromirror element 1. The projection light is corrected to parallel light along an inclined direction and is incident on the micromirror element 1, and the reflected light emitted in the front direction of the micromirror element 1 is reduced by the relay optical member 25 to reduce the projection. The light is incident on the system lens 24, and the light is enlarged by the projection system lens 24 and projected onto the screen.

  That is, in this embodiment, as described above, the relay optical member 25 made of a lens having a convex lens-like curved surface is arranged such that its lens optical axis 25a is substantially parallel to the front direction of the micromirror element 1, and Of the peripheral edge of the display area A of the micromirror element 1, the light source 11 is arranged so as to coincide with a straight line passing through the vicinity of the center of the edge opposite to the light incident direction from the light source system 20. The light that has been emitted from the light source system 21 and expanded from the light source system 21 and projected onto the micromirror element 1 from the incident direction is transmitted to the front direction of the micromirror element 1 by the relay optical member 25. A microphone that is corrected to parallel light along a direction inclined by a predetermined angle with respect to the incident direction and enters the micromirror element 1, and the light is tilted in the direction indicated by the solid line in FIG. The mirror 2 toward the front of the micro-mirror element 1 is reflected as parallel light along the normal h of the reference plane L.

  Then, the parallel light emitted in the front direction of the micromirror element 1 enters the relay optical member 25 again, and the light beam is reduced by the relay optical member 25 so as to be converged toward the lens optical axis 25a. Then, the light enters the projection system lens 24, the light flux is enlarged by the projection system lens 24, and is projected onto a screen arranged in parallel with the front surface of the micromirror element 1.

  According to the projection display apparatus, since the projection light from the light source system 20 is incident on the micromirror element 1 as parallel light, parallel light with a uniform intensity distribution is emitted from the plurality of micromirrors 2. Accordingly, light having a uniform intensity distribution can be incident on the projection system lens 24, and an image having no luminance unevenness can be projected onto the screen.

  In the projection display device, the light source system 20 is configured to project the light from the light source 11 on the micromirror element 1 from the incident direction by expanding the light beam by the light source system lens 21. The incident light is corrected to parallel light by the relay optical member 25 and is incident on the micromirror element 1, and the parallel light emitted in the front direction of the micromirror element 1 is reduced by the relay optical member 25. Thus, the light source system lens 21 and the projection system lens 24 may be inexpensive small-diameter lenses, and can be manufactured at a low cost.

  Further, since the projection display device is configured such that the parallel light emitted in the front direction of the micromirror element 1 is incident on the projection system lens 24 by reducing the luminous flux by the relay optical member 25. The number of lenses of the projection system lens 24 constituted by a plurality of lenses can be made smaller than the number of lenses of the projection system lens 19 of the conventional projection display device shown in FIG.

  That is, since the conventional projection display device shown in FIG. 4 directly enters the parallel light emitted in the front direction of the micromirror element 1 into the projection system lens 19, the projection system lens 19 is connected to the parallel light. Must be designed to be refracted toward the lens focus. Therefore, the projection system lens 19 must be composed of a large number of lenses.

  On the other hand, in the projection display apparatus of this embodiment, the parallel light emitted in the front direction of the micromirror element 1 is incident on the projection system lens 24 by reducing the luminous flux by the relay optical member 25, and the light is incident on the projection system lens 24. The projection system lens 24 enlarges the light beam and projects it onto the screen, and the relay optical member 25 has a function to replace the incident side lens of the projection system lens 19 in the conventional projection display device. The number of system lenses 24 can be reduced, and the projection system lens 24 can be made more inexpensive, thereby reducing the manufacturing cost of the projection display device.

  In this embodiment, the relay optical member 25 is a lens having a convex lens-like curved surface, and the relay optical member 25 has a lens optical axis 25 a substantially parallel to the front direction of the micromirror element 1. And, in the periphery of the display area A of the micromirror element 1, it is arranged so as to coincide with a straight line passing through the vicinity of the center of the edge opposite to the incident direction of the light from the light source system 20. The projection light from the light source system 20 is corrected into parallel light and is incident on the micromirror element 1, and the parallel light emitted in the front direction of the micromirror element 1 is reduced in its luminous flux to have a small diameter projection system lens. 24 can be made incident.

  The relay optical member 25 made of the lens is very inexpensive as compared with the light source system lens 21 and the projection system lens 24. Therefore, the manufacturing cost of the projection display device can be further reduced.

  Further, in this embodiment, the relay optical member 25 is a lens having a shape obtained by cutting a part of the circular convex lens 26 into a shape corresponding to the display area A of the micromirror element 1 as shown in FIG. For this reason, the relay optical member 25 is further reduced in cost, the manufacturing cost of the projection display device is further reduced, and the relay optical member 25 is disposed so as not to protrude around the micromirror element 1, thereby saving the space. Can be

  In this embodiment, the projection system lens 24 is arranged such that its lens optical axis 24a substantially coincides with the lens optical axis 25a of the relay optical member 25. The light that has been reduced to the incident light by the relay optical member 25 and incident on the projection system lens 24 is expanded in parallel by the projection system lens 24 and arranged parallel to the front surface of the micromirror element 1. The image can be formed on the screen as a high-quality image in focus.

  In addition, according to the projection display device, the angle formed by the light source system 20 and the projection system 23 is set so that the light source system lens 21 and the projection system lens 24 are projected by the projection system 23 and the projection light path from the light source system 20. The size of the apparatus can be reduced without causing interference with the apparatus.

  That is, in the conventional projection display device shown in FIG. 4, the projection light from the light source system 10 is corrected to parallel light by the large-diameter light source system lens 17 and is incident on the micromirror element 1. Since the parallel light reflected in the front direction of 1 is incident on the projection lens 19 having a large diameter, the light source lens 17 is prevented from interfering with the projection light path by the projection system 10, and the projection lens 19 In order not to interfere with the projection optical path from the light source system 10, it is necessary to increase the angle formed by the light source system lens 10 and the projection system 18, and it is therefore difficult to reduce the size of the apparatus.

  On the other hand, in the projection display device of this embodiment, the light from the light source 11 is projected onto the micromirror element 1 by expanding the light flux by the light source system lens 21 having a small diameter, and the light is projected by the relay optical member 25. The collimated light is incident on the micromirror element 1 after being corrected, and the parallel light reflected in the front direction of the micromirror element 1 is reduced in its luminous flux by the relay optical member 25 to have a small diameter projection system lens 24. Without causing the light source system lens 21 to interfere with the projection optical path by the projection system 23 and without causing the projection system lens 24 to interfere with the projection optical path from the light source system 20. The angle formed by the light source system lens 20 and the projection system 23 can be reduced, and thus the apparatus can be miniaturized.

  FIG. 3 is a side view of a projection display apparatus according to a second embodiment of the present invention. The projection display apparatus according to this embodiment emits a light source system 20 from an emission end face of a light guide rod 14 and a light source. The light projected from the system lens 21 with the luminous flux expanded is reflected by the mirror 22 and projected onto the micromirror element 1.

  In the projection display device of this embodiment, the light source system 20 is provided with a mirror 22, and the light source system 20 is arranged so as to project the light reflected by the mirror 22 onto the micromirror element 1 from its incident direction. However, the other configuration of the light source system 20 is the same as that of the first embodiment described above, and the relay optical member 25 disposed in front of the projection system 23 and the micromirror element 1 is also the first. The same reference numerals are given to the drawings, and the description is omitted.

  The projection display devices according to the first and second embodiments use the micromirror element 1 as a reflective display element. The reflective display element has a plurality of pixels in the row direction and the column direction. The display area is arranged in the front, and the light incident from the incident direction inclined in one direction with respect to the front direction is reflected and emitted in the front direction, and the light emission from the plurality of pixels is controlled. As long as it can display an image, it is not limited to the micromirror element 1 and may be, for example, a reflective liquid crystal display element (active matrix liquid crystal display element or simple matrix liquid crystal display element).

  In that case, the reflective liquid crystal display element is incident from the incident direction inclined in one direction with respect to the front direction, that is, the direction along the normal line of the pair of substrates facing each other across the liquid crystal layer. Light that is transmitted through the layer and reflected by the reflective film may be refracted by a prism sheet or the like and emitted in the front direction.

  However, when the micromirror element 1 is compared with the liquid crystal display element, the micromirror element 1 has a pixel size (width and width of the micromirror 2) of 10 μm to 20 μm and a pixel size of the liquid crystal display element (about 100 μm to 200 μm). ) And does not require a polarizing plate unlike a liquid crystal display element, and therefore, incident light is efficiently reflected with almost no loss.

  Therefore, the reflective display element is preferably the micromirror element 1, and by using the micromirror element 1, a high-definition and bright image can be projected onto the screen.

1 is a side view of a projection display device according to a first embodiment of the present invention. The front view of the relay optical member of the said projection type display apparatus. The side view of the projection type display apparatus which shows 2nd Example of this invention. The side view of the conventional projection type display apparatus. The figure which shows the display principle of a micromirror element. Front view of the color wheel provided in the light source system

Explanation of symbols

1. Micromirror element (reflection display element)
2 ... Micromirror L ... Reference plane 20 ... Light source system 11 ... Light source 14 ... Light guide rod 15 ... Color wheel 21 ... Light guide rod 21 ... Light source system lens 22 ... Mirror 23 ... Projection system 24 ... Projection system lens 24a ... Projection system Lens optical axis 25 of lens ... Relay optical member 25a ... Lens optical axis of relay optical member

Claims (5)

A plurality of pixels have display areas arranged in a row direction and a column direction, reflect light incident from an incident direction inclined in one direction with respect to the front direction, and emit the light in the front direction. A reflective display element that displays an image by controlling the emission of light from the pixel;
A light source system that expands a light beam from a light source by a light source system lens and projects the light from the incident direction to the reflective display element;
A projection system for projecting light emitted from the reflective display element by enlarging a light beam by a projection system lens;
The reflective type is arranged in front of the reflective display element, and corrects the projection light from the light source system into parallel light along a direction inclined by a predetermined angle with respect to the incident direction with respect to the front direction of the reflective display element. A projection display device comprising: a relay optical member that causes the reflected light emitted in the front direction of the reflective display element to be incident on the display element and reduces the luminous flux to enter the projection system lens. .   The reflective display element has a plurality of pixels composed of a plurality of micromirrors tilting in one direction and the other direction with respect to a reference plane substantially perpendicular to the front direction in a row direction along the reference plane. And a display area arranged in the column direction, and the light incident from the incident direction inclined in one inclination direction of the micromirror with respect to the front direction is changed to the front direction by switching the inclination direction of the plurality of micromirrors. The projection display device according to claim 1, wherein the projection display device is a micromirror element that displays an image reflected in an oblique direction.   The relay optical member is formed of a lens having a convex lens-like curved surface, and its lens optical axis is substantially parallel to the front direction of the reflective display element and the peripheral edge of the display area of the reflective display element. 2. The projection display device according to claim 1, wherein the projection display device is arranged so as to coincide with a straight line passing through the vicinity of the center of the edge opposite to the incident direction of light from the light source system.   The projection display device according to claim 3, wherein the relay optical member is a lens having a shape obtained by cutting a part of a circular convex lens into a shape corresponding to a display area of the reflective display element.   5. The projection display device according to claim 3, wherein the projection system lens is disposed so that a lens optical axis thereof substantially coincides with a lens optical axis of the relay optical member.

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