JP4169720B2 - Illumination device and projection display device - Google Patents

Description

  The present invention relates to an illumination device and a projection display apparatus.

As an illuminating device used for a liquid crystal projector or the like, a lighting device such as a super high pressure mercury lamp, a metal halide lamp, a xenon lamp or the like and a parabolic reflector that collimates the irradiation light is generally used. Furthermore, in recent years, it has been attempted to use a light emitting element as a light source. And the technique which uses a light emitting element as a light source and aims at the high density of a light beam is proposed (refer patent document 1).
JP 2003-177353 A

  However, the above-described conventional technology for increasing the density of light beams uses an expensive hologram element, so that there is a complaint that the illumination device is expensive. Even if the light flux is simply increased in density, there is a limit to the density of light emitting elements integrated in the same plane due to the heat generated by each light emitting element.

  In view of the above circumstances, an object of the present invention is to provide an illumination device and a projection display apparatus that can increase the density of light beams without using an expensive hologram element.

Lighting device according to the present invention, in order to solve the above problems, placing a first light-emitting element array formed by arranging at least two light emitting elements in the same plane, at least two light emitting elements in the same plane A second light emitting element array arranged adjacent to the first light emitting element array, parallel to the first light emitting element array and inconsistent with each other, and the first light emitting element array, A support member that supports the second light emitting element array, a regular reflection member that regularly reflects light emitted from the light emitting element, and the light emitting element provided between the light emitting element and the regular reflection member. The distance between the principal ray of light emitted from one light emitting element of the array and the principal ray of light emitted from another light emitting element is maintained, and the light emitted from one light emitting element of the first light emitting element array Chief ray of the light and the second And having a regular reflection surface area by reducing the distance between the other of the principal ray of the light emitted from the light emitting element of the optical element array guided to the regular reflection member.

  If it is said structure, since the light from each light emitting element array is reflected using the said regular reflection member or regular reflection surface area | region, the density of a light beam can be densified without using an expensive hologram element. Since each light emitting element array is supported so that the planes of the light emitting element arrays are not coincident with each other, the spatial element density is lower than a structure in which all the light emitting elements are arranged on the same plane. And heat dissipation is improved.

  In the illumination device having the above-described configuration, the regular reflection member may be a mirror member that specularly reflects light or a prism member that totally reflects light. In these configurations, the regular reflection member preferably has an integration function of superimposing light.

  In addition, the illumination device of the present invention includes a light emitting element array in which a plurality of light emitting elements are arranged in a line on the same plane, and a support member that supports each light emitting element array on an inclined facing surface. The inclined facing surfaces each form a regular reflection surface, and the light emitted from each light emitting element is reflected by the opposite inclined facing surface, and the light from the light emitting elements is superimposed and guided to the illumination object. Features.

  If it is said structure, since the light from each light emitting element array is reflected using the said inclination opposing surface (regular reflection surface), the density of a light beam can be densified without using an expensive hologram element. And since each light emitting element array is each supported on the inclination opposing surface, compared with the structure which arrange | positions all the light emitting elements on the same plane, a spatial element density becomes low and heat dissipation improves.

  In the illumination device having these configurations, the support member may be made of a material having excellent thermal conductivity. Further, it is preferable that cooling means for removing heat from the support member is formed or attached to the support member.

  The projection display apparatus of the present invention includes a light valve that receives light from the illumination device, and a projection lens that projects image light obtained through the light valve. To do.

  According to the present invention, it is possible to increase the density of a light beam without using an expensive hologram element. And the spatial element density becomes low with respect to the structure which arranges all the light emitting elements on the same plane, and heat dissipation is also improved.

  Hereinafter, an illuminating device and a projection display apparatus according to embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 is a diagram showing a lighting device 1. The illuminating device 1 includes four LED arrays 51. The LED array 51 includes a plurality of LEDs (light emitting diodes) 5 arranged in two rows in the same plane. Each LED 5 is preferably provided with a lens for collimation. In this figure, LED arrays 6 arranged in eight rows on the same plane are indicated by dotted lines. This LED array 6 is provided with the highest element density in consideration of heat generation. In this LED array 6, two rows are set and rotated clockwise by 45 °, which corresponds to the arrangement of the LED arrays 51. By superimposing light from adjacent LED arrays 51, it is possible to integrate light fluxes at a density that cannot be realized on the same plane.

  The support member 11 is alternately formed with a support surface 11a inclined 45 ° counterclockwise with respect to the X axis and a mirror surface (regular reflection surface) 11b parallel to the X axis. The LED array 51 is provided on the support surface 11a. The principal ray axis of each LED 5 is perpendicular to the support surface 11a. The light emitted from each LED 5 is regularly reflected by the mirror surface 11b. The support member 11 is made of a material having excellent thermal conductivity such as metal. A heat radiating plate 12 is provided on the bottom surface of the support member 11. The support member 11 and the heat radiating plate 12 do not need to be separate members, and may be integrally formed. A water cooling pipe or the like may be provided in place of the heat radiating plate 12 or together with the heat radiating plate.

  The regular reflection member 13 is made of a mirror surface member, receives the light reflected by the mirror surface 11b, and reflects it in the Y-axis direction (Y-axis is orthogonal to the X-axis). In addition, a vertical mirror surface portion 13a having a reflection function similar to that of the mirror surface 11b is formed at an end portion (non-emitting side) of the regular reflection member 13.

  Let A be the LED interval (pitch) in the LED array 6 described above. Further, if the principal ray interval of the LED light between adjacent LED arrays 51 is B, the relationship of B <A is realized. That is, the light flux density is improved as compared with the case where they are arranged on the same plane. In addition, since air can be blown in the direction perpendicular to the paper surface with respect to the arrangement positions of the LED arrays 51, it is easy to suppress the temperature rise of the LED arrays 51.

  The aspect ratio of the emitted light beam obtained by being reflected by the regular reflection member 13 is preferably set to be substantially the same as the aspect ratio of the illumination target (for example, a liquid crystal display panel). It is preferable that an integrator lens including a pair of fly-eye lenses is provided at a position for receiving the emitted light beam. By providing the integrator lens, the light intensity of the light beam cross section on the illumination object can be made uniform.

  When the integrator lens is used, a polarization conversion device can be provided. The polarization conversion device includes a polarization beam splitter array (hereinafter referred to as a PBS array). The PBS array includes a polarization separation film and a phase difference plate (1 / 2λ plate). Each polarization separation film of the PBS array passes, for example, P-polarized light out of the light from the integrator lens, and changes the optical path of S-polarized light by 90 °. The S-polarized light whose optical path has been changed is reflected by an adjacent polarization separation film, converted into P-polarized light by the retardation plate provided on the front side (light emitting side), and emitted. On the other hand, the P-polarized light transmitted through the polarization separation film is emitted as it is. That is, in this case, almost all light is converted to P-polarized light.

  In the above example, the specular reflection member 13 is a mirror member, but instead of this, as shown in FIG. 2, a regular reflection member 14 having an integration function of superimposing light may be used. The regular reflection member 14 is made of, for example, a glass prism. The regular reflection member 14 receives light reflected by the light incident surface 14a perpendicular to the principal ray axis of the LED 5, the regular reflection surface 14b having the same reflection function as the mirror surface 11b, and the regular reflection surface 14b. It has a regular reflection surface 14c for reflecting and a light emitting surface 14d for emitting light. The regular reflection surface 14b and the regular reflection surface 14c perform specular reflection or total reflection. The light reflected by the regular reflection surface 14c is repeatedly reflected inside the regular reflection member 14, the intensity distribution is made uniform, and is emitted from the light exit surface 14d. If the regular reflection member 14 having such an optical integration function is used, the light intensity of the light beam cross section can be made uniform on the light exit surface 14d, and an integrator lens need not be provided. It is not limited to using a glass prism, but can also have a light integration function with a hollow structure (inner surface is a mirror surface). In addition, the illuminating device using the regular reflection member which has such an optical integration function is set as the illuminating device 10 (refer FIG. 6).

  The polarization conversion device may be provided on the light exit side of the regular reflection member having an optical integration function. In this case, the polarization conversion device includes a single PBS (polarization beam splitter) corresponding to the size of the light emitting portion of the regular reflection member having an optical integration function, and a mirror provided in parallel to the polarization separation film in the PBS. And a phase difference plate provided on the light exit side of the mirror or PBS. However, in this case, the size of the light emitting portion of the polarization conversion device is twice the size of the light emitting portion of the regular reflection member having an optical integration function. Therefore, it is desirable that the overall shape of the light emitting part of the polarization conversion device substantially matches the aspect ratio of the illumination object (display panel). In this case, assuming that the aspect ratio of the liquid crystal panel is A: B, the aspect ratio of the outgoing light section of the regular reflection member having the optical integration function is, for example, A / 2: B. The configuration using the above-described polarization conversion device can be similarly applied to a case where a regular reflection member having an optical integration function is provided or a rod integrator is provided in a configuration example described later.

  FIG. 3 shows the lighting device 2. For convenience of explanation, the same members as those shown in FIG. The LED array 52 is formed by arranging two rows of LEDs 5 in the same plane, and the principal ray axis of the LEDs 5 is inclined by 45 ° with respect to the plane. A support surface 21a parallel to the X axis is formed on the support member 21, and the LED array 52 is supported on the support surface 21a. The light emitted from the LED 5 is reflected by a mirror surface (regular reflection surface) 21b parallel to the X axis. In this case, if the distance between the LEDs is C and the distance between the chief rays on the exit surface is D, C> D is established, so the chief ray spacing is reduced with respect to the element spacing of the LED, and the spatial element density is reduced. It can be further lowered. The illumination device 2 can also use the above-described integrator lens or a regular reflection member having a light integration function.

  FIG. 4 shows the lighting device 3. For convenience of explanation, the same members as those shown in FIG. The support member 31 has a sawtooth shape in which peaks and valleys are alternately formed as in the support member of FIG. 1, and is 30 ° counterclockwise with respect to the X axis passing through the deepest part of the valley. The inclined support surface 31a and the mirror surface (regular reflection surface) 31b inclined 15 ° clockwise with respect to the X axis are alternately provided. The LED array 51 is provided on the support surface 31a. The principal ray axis of each LED 5 is perpendicular to the support surface 31a. The light emitted from each LED 5 is regularly reflected by the mirror surface 31b. The regular reflection member 32 is made of a mirror member, and receives the light reflected by the mirror surface 31b and reflects it in the Y-axis direction. In addition, a reflection portion 33a having a reflection function similar to that of the mirror surface 31b is formed at the end portion (non-emitting side) of the regular reflection member 32. In the illumination device 3 as well, the above-described integrator lens or a regular reflection member having an optical integration function can be used as the regular reflection member 32.

  FIG. 5 shows the lighting device 4. For convenience of explanation, the same members as those shown in FIG. The support member 41 has a sawtooth shape in which peaks and valleys are alternately formed in the same manner as the support member of FIG. 1, and is 30 ° counterclockwise with respect to the X axis passing through the deepest part of the valley. The tilted support mirror surface 41a and the support mirror surface 41b tilted 30 ° clockwise with respect to the X-axis. The LED array 51 is provided on the support mirror surface 41a and the support mirror surface 41b. The principal ray axis of each LED 5 is perpendicular to the supporting mirror surfaces 41a and 41b. Further, in the LED array 51 facing each other, the LEDs facing each other are positioned with a half pitch shift in the direction perpendicular to the paper surface. The light emitted from each LED 5 is regularly reflected by the opposite support mirror surface 41b. An integrator lens or a rod integrator can be provided on the light emitting side of the illumination device 4.

  FIG. 6 shows an optical system of the projection display apparatus of this embodiment. This projection display apparatus includes three illumination devices 10R, 10G, and 10B. The illumination device 10 (10R, 10G, 10B) is an illumination device using a regular reflection member having a light integration function in the configuration of the illumination device 1 as described above. The illumination device 10R emits red light, the illumination device 10G emits green light, and the illumination device 10B emits blue light.

  On the three light incident surfaces of the cross dichroic prism 15, a red liquid crystal display panel 16R, a green liquid crystal display panel 16G, and a blue liquid crystal display panel 16B are provided. The illuminating device 10R is disposed with its light emitting end face facing the liquid crystal display panel 16R, the illuminating device 10G is disposed with its light emitting end surface facing the liquid crystal display panel 16G, and the illuminating device 10B has its light emitting end surface facing the liquid crystal display panel. It is arranged toward 16B. A lens is provided between each lighting device 10 and each liquid crystal display panel 16 as necessary.

  Each color light is optically modulated by the liquid crystal display panels 16R, 16G, and 16B. Each color modulated light (each color video light) is combined by the cross dichroic prism 15 to become full color video light, and this full color video light is enlarged and projected by the projection lens 17.

  The three lighting devices 10R, 10G, and 10B are not limited to being always turned on. The lighting devices 10 may be turned on and off alternately in units of a predetermined time. When such a lighting process is performed, the afterimage phenomenon can be reduced. In addition, it is a matter of course that a three-plate type projection display apparatus can be configured using other illumination devices 1, 2, 3, and 4.

  The present invention is not limited to a three-plate projection display apparatus. A single-plate projection display apparatus including one display panel may be used, and one lighting device may include a red LED, a green LED, and a blue LED. In addition, a single-plate projection type image display device having a single display panel is provided, which includes a red illumination device, a green illumination device, and a blue illumination device. The color light from each illumination device is cross-dichroic mirror (or prism). ) And may be led to the one display panel. The one display panel has a structure with an RGB color filter or a structure without an RGB color filter. When a display panel having an RGB color filter is used, the LEDs are simultaneously turned on to guide white light to the display panel. When a display panel having a structure not including the RGB color filter is used, the LEDs are sequentially lighted for a predetermined time in a time-sharing manner, and video signals of respective colors are supplied to the display panel in synchronization with the lighting timing for the predetermined time. .

  In the above example, an LED is shown as the light emitting element, but the present invention is not limited to this, and an organic / inorganic electroluminescent element or the like can be used.

It is explanatory drawing which showed the illuminating device of embodiment of this invention. It is explanatory drawing which showed the regular reflection member which has an optical integration function. It is explanatory drawing which showed the illuminating device of embodiment of this invention. It is explanatory drawing which showed the illuminating device of embodiment of this invention. It is explanatory drawing which showed the illuminating device of embodiment of this invention. It is explanatory drawing which showed the projection type video display apparatus using the illuminating device of embodiment of this invention.

Explanation of symbols

1, 2, 3, 4 Illumination device 11, 21, 31, 41 Support member 13, 14, 32 Regular reflection member 5 LED
51,52 LED array

Claims (6)

A first light emitting element array comprising at least two light emitting elements arranged in the same plane;
Second light emission comprising at least two light emitting elements arranged in the same plane, arranged adjacent to the first light emitting element array, parallel to the first light emitting element array and mutually inconsistent with each other. An element array;
A support member that supports the first light emitting element array and the second light emitting element array ;
A regular reflection member for regular reflection of light emitted from the light emitting element ;
Provided between the light emitting element and the specular reflection member, and maintains a distance between the principal ray of light emitted from one light emitting element of each light emitting element array and the principal ray of light emitted from another light emitting element. And the interval between the principal ray of light emitted from one light emitting element of the first light emitting element array and the principal ray of light emitted from other light emitting elements of the second light emitting element array is reduced. A regular reflection surface region that leads to the regular reflection member;
A lighting device comprising: The lighting device according to claim 1.
The illumination device according to claim 1, wherein the regular reflection member includes a mirror member that specularly reflects light or a prism member that totally reflects light. The lighting device according to claim 1 or 2,
The illumination device according to claim 1, wherein the regular reflection member has an integration function of superimposing light. In the illuminating device in any one of Claims 1 thru | or 3,
The lighting device according to claim 1, wherein the support member is made of a material having excellent thermal conductivity. In the illuminating device in any one of Claims 1 thru | or 5,
An illuminating device, wherein a cooling means for removing heat from the support member is formed or attached to the support member. A lighting device according to any one of claims 1 to 5,
A light valve for receiving light from the lighting device;
A projection lens that projects image light obtained by passing through the light valve;
A projection-type image display apparatus comprising:

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