JP2006267715A - Illuminating device and projection type video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminating device whose entire length is shortened and which is no restricted so much in terms of the structure of a cooling system or the like even when it is equipped with a plurality of light sources, and a projection type video display device. <P>SOLUTION: A polarized light changing device 12 comprises a 1st PBS 12a and a 2nd PBS 12b and a retardation plate (1/2 λplate) 12c provided between the 1st PBS 12a and the 2nd PBS 12b. The light incident surface (existing in the 1st PBS 12a) and the light emitting surface (existing in the 1st PBS 12a and the 2nd PBS 12b) of the polarized light changing device 12 are not parallel but orthogonal or nearly orthogonal. An LED 11 is arranged on the light incident surface of the polarized light changing device 12. The 1st PBS 12a makes P polarized light out of incident light pass through and changes the optical path of S polarized light by 90°. The P polarized light passing through the polarized light separation film of the 1st PBS 12a is changed to the S polarized light by passing through the retardation plate 12c. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

As an optical system for converting light emitted from a light source into a desired polarization direction, an optical system including a light source 100, a polarization conversion device 101, and a rod integrator 102 is known as shown in FIG. Thus, in the conventional optical system, the optical axis of the emitted light from the light source 100 and the emitted optical axis of the polarization conversion device 101 are substantially parallel (see Patent Document 1).
JP 2001-281600 A

  However, the conventional optical system has the following problems. That is, since the light source and the polarization conversion device are arranged in a substantially straight line on the optical axis, the entire length of the optical system becomes long. Also, when increasing the brightness by providing a plurality of light sources, the size of the light source itself and the cooling system associated with the light source are limited (for example, if there are multiple light sources, the area of the heat sink per light source) In the conventional structure, it is not easy to realize a structure having a plurality of light sources.

  In view of the above circumstances, the present invention can shorten the overall length of the lighting device, and even when a plurality of light sources are provided, the lighting device and the projection display that are not significantly limited in the structure of the cooling system or the like An object is to provide an apparatus.

  In the illumination device of the present invention, in order to solve the above problems, the light source, the light incident surface that receives the light emitted from the light source, and the light emission surface that emits the light after polarization conversion are orthogonal or substantially orthogonal. And a polarization conversion device that converts the received light into a single polarized light and emits it (hereinafter referred to as the first configuration in this section).

  If it is said structure, since a light source and a polarization converter can be arrange | positioned in parallel, the full length of an illumination optical system can be shortened. In addition, when a plurality of sets of light sources and polarization conversion devices are provided to achieve high brightness, it is easy to provide a plurality of light sources apart from each other. That is, it is possible to provide, for example, a sufficiently large cooling plate for each light source while increasing the brightness.

  In the illumination device having the first configuration, the polarization converter includes a polarization separation film that transmits the first polarized light of the received light and reflects the second polarized light in a direction of a light exit surface of the polarization converter. An optical means comprising a reflection function part that reflects the transmitted first polarized light in the direction of the light exit surface of the polarization conversion device and a conversion function part that converts the first polarization light into second polarization light; (Hereinafter referred to as the second configuration in this section).

  In the illumination device having the second configuration, after the first polarized light is converted into the second polarized light by the conversion function unit, the second polarized light is reflected by the reflection function unit in the direction of the light emitting surface. May be. In this configuration, the reflection function unit may be a polarization separation film or a mirror.

  In the illumination device having the second configuration, after the first polarized light is reflected in the direction of the light emitting surface by the reflection function unit, the first polarization light is converted into second polarized light by the conversion function unit. May be. In this configuration, the reflection function unit may be a mirror.

  In the illuminating device having these configurations, one or a plurality of light sources may be arranged for one polarization conversion device.

  The illumination device having these configurations may include a plurality of sets each including the light source and the polarization conversion device (hereinafter referred to as a third configuration in this section).

  In the illumination device having the third configuration, the light incident surfaces of the polarization conversion devices in the plurality of sets may face each other and exist in parallel.

  In the illumination device having the third configuration, the light incident surfaces of the polarization conversion devices in the plurality of sets may exist non-parallel. In the illumination device having such a configuration, it is preferable that a phase difference plate is provided on the light exit surface of the predetermined polarization conversion device so that the polarization directions of the light emitted from the polarization conversion device are aligned.

  In the illumination device having these configurations, an optical integrator may be provided at a position for receiving the light emitted from the polarization conversion device. In this configuration, the optical integrator may include at least one of an integrator lens composed of a pair of fly-eye lenses, a tapered rod integrator, and a non-tapered rod integrator.

  The illuminating device having these configurations may include a light integrator at a position where the light emitted from the light source is received, and the light emitted from the light integrator may be incident on the polarization conversion device. In this configuration, the optical integrator may include at least one of a tapered rod integrator and a non-tapered rod integrator. In the illumination device having such a configuration, a condensing element may be provided at a position where the light emitted from the light source is received.

  The illumination device having these configurations may emit predetermined color light (hereinafter referred to as a fourth configuration in this section). Alternatively, white light may be emitted (hereinafter referred to as the fifth configuration in this section).

  The illumination device of the present invention includes a fourth configuration illumination device that emits red light, a fourth configuration illumination device that emits green light, a fourth configuration illumination device that emits blue light, and each of the above-described colors. And an optical member that guides light in substantially the same direction (hereinafter referred to as a sixth configuration in this section).

  The illumination device of the sixth configuration may be configured such that red light, green light, and blue light are always emitted during illumination (hereinafter referred to as the seventh configuration in this section). Alternatively, the illuminating device of the sixth configuration may be configured such that red light, green light, and blue light are sequentially emitted for a predetermined time during illumination (hereinafter referred to as an eighth configuration in this section).

  The projection display apparatus of the present invention includes a fourth configuration illumination device that emits red light, a fourth configuration illumination device that emits green light, and a fourth configuration illumination device that emits blue light. And a light valve provided so as to receive light from each illuminating device, and means for combining and projecting each color image light passing through each light valve.

  According to another aspect of the present invention, there is provided a projection-type image display apparatus, a lighting apparatus having a fifth configuration or a seventh configuration, one full-color light valve, and a projection unit that projects image light obtained through the full-color light valve. , Provided.

  The projection display apparatus of the present invention includes an illuminating device having an eighth configuration, one light valve, and means for supplying a video signal for each color to the light valve in synchronization with the emission timing of each color light, And projection means for projecting image light obtained by passing through the light valve.

  According to the present invention, the overall length of the lighting device can be shortened, and even when a plurality of light sources are provided, there is an effect that the structure such as the cooling system is not so limited.

  Embodiments of the present invention will be described below with reference to FIGS.

  FIG. 1 is a diagram showing an optical system of the projection display apparatus 4. The projection display apparatus 4 includes three illumination devices 51R, 51G, and 51B (hereinafter, the reference numeral “51” is used to indicate each illumination device without specifying it). Each lighting device 51 includes an LED (light emitting diode) 11, a polarization conversion device 12, a non-tapered rod integrator (cuboid rod integrator) 13, and a tapered rod integrator 14. The illumination device 1R emits red light, the illumination device 1G emits green light, and the illumination device 1B emits blue light.

  The LED 11 includes an LED chip 11a, an LED substrate 11b, and a heat sink (heat radiating plate) 11c. The LED chip 11a in the illumination device 51R emits red light, the LED chip 11a in the illumination device 51G emits green light, and the LED chip 11a in the illumination device 51B emits blue light.

  As shown in FIG. 2, the polarization conversion device 12 includes a first PBS (polarization beam splitter) 12a, a second PBS 12b, and a retardation plate (1 / 2λ) provided between the first PBS 12a and the second PBS 12b. Plate) 12c. The polarization conversion device 12 shown in FIG. 1 receives light from the side surface, but the polarization conversion device 12 shown in FIG. 2 receives light from the upper surface. The polarization separation film of the first PBS 12a and the polarization separation film of the second PBS 12b are parallel. Further, the polarization separation films of the first PBS 12a and the second PBS 12b both transmit, for example, P-polarized light and reflect S-polarized light.

  The light incident surface (existing in the first PBS 12a) and the light emitting surface (existing in the first PBS 12a and the second PBS 12b) of the polarization converter 12 are not parallel but orthogonal or substantially orthogonal. An LED 11 is disposed on the light incident surface of the polarization conversion device 12. An air gap is provided between the LED chip 11 a of the LED 11 and the light incident surface of the polarization conversion device 12. The first PBS 12a passes the P-polarized light of the incident light and changes the S-polarized light by 90 °. The S-polarized light whose optical path is changed by the polarization separation film of the first PBS 12 a is emitted from the light exit surface of the polarization conversion device 12. Meanwhile, the P-polarized light that has passed through the polarization separation film of the first PBS 12a is converted into S-polarized light by passing through the retardation plate 12c. The converted S-polarized light has its optical path changed by 90 ° by the polarization separation film of the second PBS 12 b and is emitted from the light exit surface of the polarization converter 12. That is, in this case, almost all light is converted to S-polarized light. Of course, it is possible to adopt a configuration in which incident light is aligned with P-polarized light.

  A mirror may be arranged in place of the second PBS 12b. The direction of this mirror is the same as the direction of the polarization separation film of the second PBS 12b. When the mirror is disposed, the phase difference plate 12c may be brought to a position for receiving light whose optical path has been changed by the mirror. The same applies to other embodiments.

  The taperless rod integrator 13 is provided with its light incident surface facing the light emitting surface of the polarization conversion device 12. The tapered rod integrator 14 is provided with its light incident surface facing the light emitting surface of the non-tapered rod integrator 13. The light exit surface of the tapered rod integrator 14 is larger than the light incident surface. The transmissive liquid crystal display panel 4 is disposed on the light exit surface side of the tapered rod integrator 14. More specifically, the red liquid crystal display panel 1R is disposed on the light exit surface side of the tapered rod integrator 14 in the illumination device 51R, and the green liquid crystal display panel 1R is disposed on the light exit surface side of the taper rod integrator 14 in the illumination device 51G. A liquid crystal display panel 1G is disposed, and a blue liquid crystal display panel 1B is disposed on the light exit surface side of the tapered rod integrator 14 in the illumination device 51B. Since the rod integrators 13 and 14 reflect the incident light on the inner surface of the rod and guide it to the liquid crystal panel 1, the light intensity distribution of each color light is almost uniformized on the liquid crystal panel 1. Further, by using the taper type rod integrator 14, the light dispersion angle is reduced.

  A liquid crystal drive signal (video signal) for each color is supplied from a driver (not shown) to the liquid crystal panels 1R, 1B, and 1G. Each color image light modulated by passing through each liquid crystal panel 1 is combined by the cross dichroic prism 2 to become full color image light. This full-color image light is enlarged and projected by the projection lens 3 and projected and displayed on a screen (not shown).

  The projection display apparatus shown in FIG. 3 has a structure in which an illumination device 52 (52R, 52G, 52B) is provided instead of the illumination device 51 in the projection image display apparatus 4 of FIG. The illumination device 52 has a structure in which the polarization conversion device 12A is provided instead of the polarization conversion device 12 in the illumination device 51. As shown in FIGS. 4A and 4B, the polarization conversion device 12A corresponds to a structure in which two polarization conversion devices 12 are arranged. That is, the illumination device 52 has a structure provided with two sets of the polarization conversion device 12 and the LED 11 (hereinafter, this set may be referred to as a basic unit). The size of the light exit surface of the polarization converter 12 </ b> A matches the size of the light entrance surface of the rod integrator 13. In the case of the illumination device 52 shown in FIG. 3, the light incident surfaces of the polarization conversion devices 12 and 12 of the basic unit in the two sets face each other and exist in parallel. Accordingly, the two LEDs 11 exist relatively far apart (the heat sink 11c also exists relatively far apart), and sufficient heat countermeasures (cooling) are provided while providing the two LEDs 11 (while increasing the light intensity). Effect) is realized.

  FIG. 5 is a perspective view showing the lighting device 53. The polarization conversion device in the illumination device 53 is also provided with two basic units. The retardation plates 12c and 12c in the two basic units are in a horizontally arranged state and exist in the same plane. The light incident surface of one basic unit exists on the upper surface, and the light incident surface of the other basic unit exists on the lower surface. Even in such a configuration, the light incident surfaces of the two basic units exist in a parallel state obliquely opposite each other. Accordingly, the two LEDs 11 (the LED chip 11a is shown in the figure) are present relatively far apart (the heat sink 11c is also located relatively far apart), and the two LEDs 11 are provided (light quantity). Sufficient measures against heat (cooling effect) have been realized.

  FIG. 6 is a perspective view showing the lighting device 54. The polarization conversion device 12C in the illumination device 54 includes three polarization conversion devices 12 (three basic units exist). The phase difference plates 12c in two basic units among the three basic units are horizontally arranged parallel to each other. The planes of existence of the horizontally arranged retardation plates 12c and 12c are different. The light incident surface of one basic unit of these two basic units is formed on the upper surface, and the light incident surface of the other basic unit is formed on the lower surface. The retardation plate 12c in the remaining one basic unit is arranged vertically. The light incident surface in the remaining one basic unit exists on the back side in FIG. Here, since the phase difference plate 12c in the remaining one basic unit is arranged vertically, the S-polarized light for this basic unit is relative to the vibration direction of the S-polarized light emitted by the other two basic units. The difference is 90 ° (rotation). Therefore, by providing a phase difference plate (1 / 2λ plate) 30 on the light exit surface of the remaining one basic unit, the vibration directions of the light emitted by the three basic units are aligned.

  FIG. 7A is a perspective view showing the lighting device 55. The polarization conversion device 12D in the illumination device 55 includes four polarization conversion devices 12 (four basic units exist). The phase difference plates 12c in two basic units (lined diagonally) out of the four basic units are horizontally arranged parallel to each other. The retardation plates 12c in the other two basic units (lined diagonally) are vertically arranged parallel to each other. The S-polarized light emitted from the former two basic units and the S-polarized light emitted from the latter two basic units have different vibration directions as shown in FIG. 7B. Therefore, for example, a phase difference plate (1 / 2λ plate) 30 is provided on the light exit surfaces of the former two basic units, and the vibration directions of the light emitted by the four basic units are aligned.

  In the illuminating device described above, a combination of the rod integrator 13 and the rod integrator 14 is shown as an optical integrator, but a structure using only one of them may be adopted.

  FIGS. 8A and 8B are explanatory views showing other examples of basic units. The basic unit shown in FIG. 8A includes a biconvex lens 31 that is a condensing element between the LED 11 and the polarization conversion device 12. The basic unit shown in FIG. 8B includes a taper type rod integrator 32 between the LED 11 and the polarization conversion device 12. The tapered rod integrator 32 has a light exit surface that is larger than the light incident surface, but may have a reverse structure. Moreover, you may employ | adopt a rod integrator without a taper. Further, in the configuration of FIG. 8B, a condensing element may be provided between the LED 11 and the rod integrator 32. Further, a non-tapered rod integrator or the like may be provided on the light exit side of the polarization conversion device 12.

  FIG. 9 is a perspective view showing a projection display apparatus. The illumination device 56 of the projection display apparatus includes an optical integrator 33 on the light exit surface of the polarization conversion device 12. The optical integrator 33 includes a non-tapered rod integrator 33a that receives light emitted from the polarization converter 12, and an integrator lens 33b that receives light emitted from the rod integrator 33a. The integrator lens 33b is composed of a pair of fly-eye lenses. Each pair of lenses in the integrator lens 33b guides light from each corresponding region on the light output surface of the rod integrator 33a to the entire surface of the liquid crystal display panel 1, and therefore uneven brightness on the light output surface of the rod integrator 33a. The reflection on the liquid crystal display panel 1 can be prevented as much as possible. In the projection display apparatus of FIG. 9, the LED 11 emits white light, and the liquid crystal display panel 1 can be a single plate type provided with an RGB color filter.

  Further, it is possible to adopt a configuration in which the color light (red light, blue light, and green light) from the illumination device that emits each color light shown in FIG. 1 or the like is guided in the same direction by a cross dichroic prism or a cross dichroic mirror. A liquid crystal display panel used in a projection display apparatus using the illumination device having this configuration has a structure with an RGB color filter or a structure without an RGB color filter. When a liquid crystal display panel having a structure including an RGB color filter is used, all the lighting devices are simultaneously turned on to guide white light to the liquid crystal display panel. When a liquid crystal display panel having a structure without the RGB color filter is used, each lighting device is sequentially turned on for a predetermined time in a time-sharing manner, and images of each color are displayed on the liquid crystal display panel in synchronization with the lighting timing of the predetermined time. Supply signal.

  In the above description, the projection-type image display device uses a transmissive liquid crystal panel. However, the present invention is not limited to this, and a reflective liquid crystal panel may be used, or a pixel instead of the liquid crystal panel may be used. A display panel of a type in which a large number of micromirrors are individually driven may be used. In addition, the light source is not limited to a solid light emitting element such as an LED or organic / inorganic electroluminescence, and a lamp (e.g., an ultrahigh pressure mercury lamp, a metal halide lamp, or a xenon lamp) including a reflector (such as a parabolic reflector or an elliptical reflector) is used. it can.

  In the illumination device described above, a rod integrator having a hollow structure can be used as the light integrator. Further, the optical integrator can be omitted when sufficient uniformity is obtained in the light beam emitted from the light source. Further, a curved mirror for projection may be provided instead of the projection lens.

It is explanatory drawing which showed the optical system of the projection type video display apparatus of embodiment of this invention. 1A is a perspective view (shown in perspective) of an illuminating device used in the projection display apparatus of FIG. 1, and FIG. 1B is an explanatory diagram of the polarization conversion device. It is explanatory drawing which showed the optical system of the projection type video display apparatus of other embodiment of this invention. 3A is a perspective view (shown in perspective) of an illumination device used in the projection display apparatus of FIG. 3, and FIG. 3B is an explanatory view of the polarization conversion device. It is the perspective view (shown transparently) which showed the illuminating device of other embodiment of this invention. It is the perspective view (shown transparently) which showed the illuminating device of other embodiment of this invention. FIG. 4A is a perspective view (shown in perspective) showing an illumination apparatus according to another embodiment of the present invention, and FIG. 4B is an explanatory view of polarization conversion. FIG. 4A is an explanatory view showing a lighting device (basic unit) according to another embodiment of the present invention, and FIG. 4B shows a lighting device (basic unit) according to another embodiment of the present invention. FIG. It is explanatory drawing which showed the projection type video display apparatus of other Embodiment of this invention. It is explanatory drawing which showed the conventional illuminating device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 2 Cross dichroic prism 3 Projection lens 6 Projection type image display apparatus 11 LED
12, 12A Polarization conversion device 13, 14 Rod integrator 51, 52, 53, 54, 55, 56 Illumination device

Claims (24)

A light source, a light incident surface that receives light emitted from the light source, and a light emission surface that emits light after polarization conversion are formed to be orthogonal or substantially orthogonal, and the received light is converted into a single polarized light. And a polarization conversion device that emits light. The illumination device according to claim 1, wherein the polarization conversion device includes:
A polarization separation film that transmits the first polarized light of the received light and reflects the second polarized light in the direction of the light exit surface of the polarization converter;
An optical means comprising a reflection function part that reflects the transmitted first polarized light in the direction of the light exit surface of the polarization conversion device and a conversion function part that converts the first polarization light into second polarization light; An illumination device characterized by comprising: 3. The lighting device according to claim 2, wherein after the first polarized light is converted into the second polarized light by the conversion function unit, the second polarized light is directed to the light exit surface by the reflection function unit. A lighting device that is reflected. 4. The illumination device according to claim 3, wherein the reflection function unit is a polarization separation film or a mirror. 3. The illumination device according to claim 2, wherein after the first polarized light is reflected in the direction of the light emitting surface by the reflection function unit, the first polarization light is converted into second polarized light by the conversion function unit. A lighting device that is converted. 6. The lighting device according to claim 5, wherein the reflection function unit is a mirror. 7. The illuminating device according to claim 1, wherein one or a plurality of light sources are arranged for one polarization conversion device. 8. The illuminating device according to claim 1, comprising a plurality of sets each including the light source and the polarization conversion device. 9. The illuminating device according to claim 8, wherein the light incident surfaces of the polarization conversion devices in the plurality of sets face each other in parallel. The illumination device according to claim 8, wherein light incident surfaces of the polarization conversion devices in the plurality of sets exist non-parallel. The illumination device according to claim 10, wherein a phase difference plate is provided on a light exit surface of a predetermined polarization conversion device so that polarization directions of light emitted from the polarization conversion device are aligned. apparatus. 12. The illumination device according to claim 1, further comprising an optical integrator at a position where the light emitted from the polarization conversion device is received. 13. The illumination device according to claim 12, comprising at least one of an integrator lens composed of a pair of fly-eye lenses, a tapered rod integrator, and a non-tapered rod integrator as the optical integrator. . 14. The illumination device according to claim 1, further comprising a light integrator at a position where the light emitted from the light source is received, and the light emitted from the light integrator is incident on the polarization conversion device. A lighting device characterized by: 15. The lighting device according to claim 14, comprising at least one of a tapered rod integrator and a non-tapered rod integrator as the optical integrator. 16. The illuminating device according to claim 1, further comprising a condensing element at a position for receiving the light emitted from the light source. The illumination device according to any one of claims 1 to 16, wherein the illumination device emits predetermined color light. The illumination device according to any one of claims 1 to 16, wherein the illumination device emits white light. The illumination device according to claim 17, which emits red light, the illumination device according to claim 17, which emits green light, the illumination device according to claim 17, which emits blue light, and each of the color lights is substantially omitted. An illuminating device comprising: an optical member guided in the same direction. 20. The illumination device according to claim 19, wherein red light, green light, and blue light are always emitted during illumination. 20. The illumination device according to claim 19, wherein red light, green light, and blue light are sequentially emitted for a predetermined time during illumination. The illumination device according to claim 17, which emits red light, the illumination device according to claim 17, which emits green light, the illumination device according to claim 17, which emits blue light, and each illumination device. A projection-type image display device comprising: a light valve provided to receive light; and means for combining and projecting each color image light that has passed through each light valve. 21. A projection, comprising: the lighting device according to claim 18; a single full-color light valve; and a projection unit that projects image light obtained through the full-color light valve. Type image display device. The illumination device according to claim 21, one light valve, means for supplying a video signal for each color to the light valve in synchronization with the emission timing of each color light, and the light valve And a projection means for projecting image light.

Images