JP2005202210A - Light source for projection type display device and projection type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device for a projection type liquid crystal display device by which a luminous flux necessary for color display can be supplied to a projection type display device that has a single liquid crystal display panel, and in which the light use efficiency of a light source is high, and a light source part is very compact. <P>SOLUTION: The light source device 1 is composed of many light emitting diode lamps which exhibit R, G and B light emission colors. The light emitting diode lamps are arranged on the same plane so that their optical axes are parallel to each other. One light emitting diode lamp unit 10 is composed such that the two kinds of light emitting diode lamps 101 and 102 whose light emission colors are different are combined with dichroic mirrors 111 and 112, respectively, 1/4 wavelength plates 121 and 122, respectively, and polarizing beam splitters 131 and 132, respectively. From the one light emitting diode lamp unit 10, light rays of two light emission colors integrated as one of the polarized light rays of them are emitted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a light source device for a projection display device and a projection display device including the light source device, and more particularly to a light source device for a projection display device using a light emitting diode as a light source and a single-plate projection type including the light source device. The present invention relates to a display device.

  The luminous flux from the high-intensity white light source is separated into R (red), G (green), and B (blue) wavelength ranges, and the corresponding R, G, and B liquid crystal display panels are irradiated with these color lights. In addition, a projection type liquid crystal display device that combines R, G, and B images modulated by a liquid crystal display panel with a dichroic prism and enlarges and projects them using a projection lens has been put into practical use. In addition, a disk-shaped disk in which a single DMD (digital mirror device) is used as a display element instead of a liquid crystal display panel, and a filter for selecting light beams from a high-intensity white light source and R, G, and B color lights is formed. A single-plate projection display apparatus that repeatedly generates color light of R → G → B by rotating the light, irradiates this light onto the DMD, modulates the DMD, and enlarges and projects a color image in a color sequential manner Has also been put to practical use. Both disclosed technologies have a common point in that a high-intensity white light source of a discharge lamp is used.

  Although not yet put into practical use, there is also a proposal for a projection display device that uses a light source other than a discharge lamp. For example, a light emitting diode is used as a light source. The light-emitting diode has features that are not possessed by conventional discharge lamps that emit high-intensity white light, such as low cost, long life, and low power consumption, and is promising as a light source for a projection display device.

  Referring to Patent Literature 1, three light source arrays arranged in a plane composed of a group of light emitting diodes that emit three types of color light of R, G, and B are prepared, and these light source arrays are finally formed by a dichroic prism. A light source device that emits light with a common optical path is configured, and the liquid crystal display panel is irradiated with a light beam from the light source device. Here, there is one liquid crystal display panel, and a color image can be obtained by a color sequential display method with a single-plate configuration. When a low-cost projection display apparatus is to be realized, the fact that only one display panel is required causes a great cost merit. Further, the method of arranging the light source array in a U-shape so as to surround the dichroic prism and synthesizing the light beam can greatly reduce the size of the entire display device because the light source device can be made compact.

  However, if we want to make the light source part more compact, we would like to have one light source if possible. That is, if there is only one planar light source, and the light source emits R → G → B color light sequentially, and the emitted light flux can be efficiently used for illumination of the display panel, it is very compact. A single-plate projection display device can be realized.

  By the way, some considerations are required in using a light emitting diode as a light source of a projection display device. First, although the light emitting diode has characteristics close to those of a discharge lamp in terms of luminous efficiency, it can be said that the amount of a single luminous flux is small. In a projection display apparatus that has been put into practical use, for example, a discharge lamp having an optical output exceeding 6000 Lm (lumen) with a power of 100 W is used. On the other hand, even what is currently known as a light emitting diode that emits the largest luminous flux has a light output of about 120 Lm at most, which is far from the light output of the discharge lamp. Therefore, it is inevitable to use a large number of light emitting diodes when trying to obtain a large output light beam from the light source device. Although a single light emitting diode is small, the use of many light emitting diodes increases the size of the light source, which is against the demand for compactness.

Therefore, it is necessary to consider using the luminous flux from one light emitting diode as efficiently as possible. Alternatively, it is necessary to avoid the increase in the size of the light source device at the same time as securing the amount of luminous flux by arranging the light emitting diodes as closely as possible. It is also important that the light beam emitted from the light emitting diode usually has a random polarization component. That is, when a projection type liquid crystal display device using a TN liquid crystal display panel or the like as a display device is configured, it is desirable that the light beam emitted from the light source device is linearly polarized light. For example, as disclosed in Patent Document 2, if a polarization conversion optical system including a polarization beam splitter array having a half-wave plate is used, random polarized light from a light-emitting diode is efficiently converted into linearly polarized light. As a result, the light utilization rate can be increased.
Japanese Patent No. 3319438 Japanese Patent Application Laid-Open No. 2002-244211

  However, with the configuration disclosed in Patent Document 2, it is difficult to increase the light output from the light source device by providing a large number of light emitting diodes. This is because a polarization conversion optical system constituted by a polarization beam splitter provided with a half-wave plate having a size approximately twice as large as that of one light-emitting diode is compatible. Therefore, the distance between the light emitting diodes cannot be approached to the limit. That is, when a large number of light emitting diodes are used, there is a problem that the light source portion becomes large.

  Further, since the dichroic prism is arranged in a U-shape in the light source unit, three light source arrays are required for R, G, and B, and further improvement is desired in terms of compactness.

  An object of the present invention is to provide a projection type liquid crystal display that can supply a luminous flux necessary for color display in a projection type display device having a single liquid crystal display panel, has a high light utilization rate of a light source, and has a very compact light source part. An object of the present invention is to provide a light source device for an apparatus.

The light source device of the projection display device of the present invention is
A light source device for a projection display device using a light emitting diode lamp, wherein the light source device includes a first light emitting diode lamp that emits one or more first color lights and a second light emission that emits second color light. The light emitting diode lamp includes a diode lamp and a third light emitting diode lamp that emits light of a third color, and the light emitting diode lamps are arranged on the same plane so that their optical axes are parallel to each other, and have different emission colors. Two types of light-emitting diode lamps are assembled, and a dichroic mirror, a quarter-wave plate, and a polarizing beam splitter are sequentially arranged on each optical axis, and the reflected light beam reflected by the polarization separation surface of each polarizing beam splitter Are arranged so as to be incident on a pair of polarizing beam splitters to form a set of light-emitting diode lamp units, and a dichroic mirror and a polarizing beam The splitter is combined so that light of two kinds of emission colors unified to one polarized light is emitted from one set of light emitting diode lamp units, and the light source device is composed of a plurality of light emitting diode lamp units. Yes. Here, the first color light may be R color (red), the second color light may be G color (green), and the third color light may be B color (blue).

  The characteristic of the dichroic mirror disposed between the first light-emitting diode lamp and the polarization beam splitter is a characteristic of transmitting the color light of the first light-emitting diode lamp and reflecting the color light of the second and third light-emitting diode lamps. And the dichroic mirror disposed between the second light-emitting diode lamp and the polarization beam splitter transmits the color light of the second light-emitting diode lamp, and the color light of the first and third light-emitting diode lamps The dichroic mirror disposed between the third light-emitting diode lamp and the polarization beam splitter transmits the color light of the third light-emitting diode lamp, and the first and second light emission It is desirable to have the property of reflecting the color light of the diode lamp.

  The quarter wave plate of the light emitting diode lamp unit may be integrally formed, the polarization beam splitter of the light emitting diode lamp unit may be integrally formed, and the polarization of the plurality of light emitting diode lamp units may be further integrated. The beam splitter may be configured integrally, and the polarization beam splitter may be a polarization beam splitter having a structure in which right angle prisms made of two optical glasses each having a dielectric multilayer film formed on the oblique side are bonded together, Alternatively, it may be a flat polarizing beam splitter, the quarter wavelength plate and the dichroic mirror may be formed integrally, and the quarter wavelength plate and the polarizing beam splitter are formed integrally. May be.

The projection display device of the present invention is
The above light source device is provided, a light beam from the light source device is irradiated onto a single liquid crystal display panel, and an image modulated by the liquid crystal display panel is enlarged and displayed by a projection lens.

  Since a predetermined number of the light emitting diode lamp units can be arranged on the same plane in a predetermined arrangement, the respective light emitting diode lamps can be closely arranged in a plane, and the light emitting diode lamp that emits two kinds of light emission colors. By arranging the units in a predetermined combination, it is possible to obtain the desired emission intensity of each emission color.

  The first effect of the present invention is to provide a compact light source device that emits only R, G, and B light fluxes sequentially or simultaneously and emits only linearly polarized light. Therefore, a compact single-plate projection liquid crystal display device can be provided. It can be provided.

  The second effect is that a single liquid crystal display panel can be uniformly illuminated with linearly polarized light whose polarization is unified by combining the light flux from the light source device with the integrator optical system.

  The reason is that since the light emitting diode lamps exhibiting R, G, and B emission colors are arranged on the same plane, only one light source array is required, and unpolarized light emitted from the light source array is unified to provide a light source. This is because the light is emitted from the apparatus and the light emitting diode lamps can be arranged in close contact with each other.

  Embodiments of a light source device and a projection display device of the present invention will be described with reference to the drawings.

(First embodiment)
The light source device of the present invention is composed of a large number of light emitting diode lamps exhibiting R, G, and B emission colors, and the light emitting diode lamps are arranged on the same plane so that their optical axes are parallel to each other. Two types of light-emitting diode lamps with different emission colors are combined into one light-emitting diode lamp unit that is sequentially combined with a dichroic mirror, a quarter-wave plate, and a polarization beam splitter. The diode lamp unit emits light of two kinds of light emission colors unified into one polarized light. Since a predetermined number of light-emitting diode lamp units can be arranged on the same plane in a predetermined arrangement, the respective light-emitting diode lamps can be closely arranged, and the light-emitting diode lamp units that emit two kinds of light-emitting colors are predetermined. By arranging in combination, it is possible to obtain the desired emission intensity of each emission color.

  FIG. 1 is a schematic plan view showing a basic configuration of a light source device according to a first embodiment of the present invention, and FIG. 2 is an explanatory diagram showing characteristics of a dichroic mirror of the light source device of the present invention. In FIG. 1, a light source device 1 according to a first embodiment of the present invention will be described by taking a light emitting diode lamp unit 10 having two light emitting diode lamps having different emission colors as an example of a basic configuration. Here, the two light emitting diode lamps are a light emitting diode lamp (G) 101 and a light emitting diode lamp (R) 102. Here, each luminous flux is displayed by enclosing the code in parentheses.

  The light emitting diode lamp unit 10 constituting the light source device 1 includes a light emitting diode lamp (G) 101 that emits G color, a light emitting diode lamp (R) 102 that emits R color, and an emission side of the light emitting diode lamp (G) 101. The dichroic mirror (G) 111 that transmits the G color shown in the characteristic (G) 202 of FIG. 2 and reflects the R color and the B color, and a diagram provided on the emission side of the light emitting diode lamp (R) 102 The dichroic mirror (R) 112 that transmits the R color and reflects the G and B colors indicated by the characteristic (R) 201 of FIG. 2, and a quarter-wave plate provided on the exit side of each of the dichroic mirrors 111 and 112 121 and 122, and quarter-wave plates 121 and 122, which are provided on the exit side, and their polarization separation surfaces 141 and 142 transmit P-polarized light and S-polarized light. Provided and the polarization beam splitter 131 for reflecting the a, respectively are opposed to the reflection surfaces of the polarization beam splitter 132 of the polarization beam splitter 131 are arranged to intersect at approximately 90 degrees. Accordingly, the polarization separation surface 141 and the polarization separation surface 142 are provided so as to be approximately 45 ° with respect to the emitted light.

  As the light-emitting diode lamps 101 and 102, a bullet-type light-emitting diode lamp having a lens shape in which a light-emitting element is sealed with an epoxy resin or the like, which is generally available commercially, can be used. This type of light-emitting diode lamp can increase the density of the luminous flux emitted on the optical axis by setting the lens shape to a predetermined value. The luminous flux obtained from this type of light emitting diode lamp is random polarized light.

  As the dichroic mirror (G) 111 disposed on the emission side of the light emitting diode lamp (G) 101, for example, a thin film having characteristics of transmitting G color light and reflecting R color light is deposited on a glass substrate. used. Further, as the dichroic mirror (R) 112 disposed on the emission side of the light emitting diode lamp (R) 102, a thin film having characteristics of transmitting R color light and reflecting G color light is deposited on a glass substrate, for example. Is used. Such a dichroic mirror can be obtained using a known technique.

  As the quarter-wave plates 121 and 122, a commercially available film-type quarter-wave plate bonded to a transparent glass substrate is used.

  As the polarization beam splitters 131 and 132, those in which dielectric multilayer films serving as polarization separation surfaces 141 and 142 are formed on the oblique sides of two right-angle prisms made of optical glass are used. As the polarization separation characteristic, it is preferable to have a characteristic of separating incident random light in the visible range into P-polarized light and S-polarized light at a ratio of about 1: 1. The polarization separation surfaces 141 and 142 of the polarization beam splitter 131 and the polarization beam splitter 132 are orthogonal to each other, and S-polarized light reflected by the polarization beam splitters 131 and 132 is directed to the polarization separation surfaces 142 and 141. It is preferable to arrange each polarization beam splitter so as to face.

  Various modifications can be made to the first embodiment. In the first modification, a light-emitting diode lamp, a dichroic mirror corresponding to the emission color, a quarter-wave plate, and predetermined polarized light are used. A polarization beam splitter that transmits only the other light and reflects the other polarized light is arranged in a row on the optical axis to form a half unit, and each half unit that emits a desired combination of emission colors has its polarization separation surface. Are combined so as to face each other to form a light emitting diode lamp unit 10.

  In the second modification, in FIG. 1, the quarter wavelength plate 121 and the quarter wavelength plate 122, which are provided independently of each other, are integrated, and the polarization beam splitter 131 provided independently of each other. And the polarizing beam splitter 132 are joined together. Thereby, the configuration of the light emitting diode lamp unit 10 is simplified.

  Further, in the third modified example, the number of the light emitting diode lamps, each of which is one, is two rows and two, and four, and four light emitting diode lamps of the same color, one dichroic mirror corresponding to the light emitting color, One quarter-wave plate and one polarizing beam splitter that transmits only predetermined polarized light and reflects other polarized light are arranged in a line on the optical axis to form a half unit. The light emitting diode lamp unit is formed by combining half units that emit a desired combination of light emission colors so that their polarization separation surfaces face each other. Here, the quarter wavelength plates provided independently may be integrated, and the polarization beam splitters provided independently may be joined together. Although the height of the polarization beam splitter is increased, the configuration of the light emitting diode lamp unit 10 is simplified. Here, the number of light-emitting diode lamps arranged in the joining direction of the half units may be increased, so that the height of the polarizing beam splitter does not increase.

  The operation of the light-emitting diode lamp unit 10 according to the embodiment of the present invention will be described with reference to FIG. In FIG. 1, a light beam (121) having a random polarization component emitted from a G light emitting diode lamp (G) 101 first passes through a dichroic mirror (G) 111 arranged perpendicular to the optical axis. The dichroic mirror (G) 111 has the characteristic (G) 202 of FIG. 2 that transmits G color and reflects other than G color. The light beam (121) having a random polarization component that has passed through the dichroic mirror (G) 111 then passes through the quarter-wave plate 121. Even when random polarized light passes through the quarter-wave plate 121, the polarization component remains random. Thereafter, the light beam (121) having a random polarization component reaches the polarization separation surface 141 of the polarization beam splitter 131, where separation into P-polarized light and S-polarized light is performed. Here, the polarization separation surface 141 has a characteristic of transmitting P-polarized light and reflecting S-polarized light among random polarization components of the light beam (121). Accordingly, the P-polarized light (122) travels straight through the polarization beam splitter 131 as it is, and becomes an emitted light beam (P) 11 of the light source device 1. On the other hand, the S-polarized light (123) reflected by the polarization separation surface 141 changes its traveling direction to the adjacent polarization beam splitter 132 and reaches the polarization separation surface 142 of the polarization beam splitter 132. Here, the polarization separation surface 142 is also configured to transmit the P-polarized light and reflect the S-polarized light, so that the S-polarized light (123) is reflected and reflected as an R-color light emitting diode lamp (124). R) travels in the direction of 102, exits the polarization beam splitter 132, and then passes through the quarter-wave plate 122. Here, the luminous flux (124) which was S-polarized light is once converted into circularly polarized light (125) and reaches the dichroic mirror (R) 112. Since the dichroic mirror (R) 112 has a characteristic (R) 201 that transmits the R color shown in FIG. 2 and reflects other than the R color, the circularly polarized G color light (125) is reflected, and again. The quarter wave plate 122 travels toward the polarization beam splitter 132 side. Here, the circularly polarized light (125) is polarized and converted into P-polarized light (126) and reaches the polarization separation surface 142. Since the polarization separation surface 142 has a characteristic of transmitting the P-polarized light and reflecting the S-polarized light, the P-polarized light (126) is transmitted through the polarization separation surface 142 and emitted from the light source device 1 (P) 12. It becomes.

  A light beam (131) having a random polarization component emitted from the R light emitting diode lamp (R) 102 is first transmitted through a dichroic mirror (R) 112 arranged perpendicular to the optical axis. The dichroic mirror (R) 112 has a characteristic (R) 201 that transmits the R color shown in FIG. 2 and reflects other colors than the R color. The light beam (131) having a random polarization component that has passed through the dichroic mirror (R) 112 then passes through the quarter-wave plate 122. Even when random polarized light passes through the quarter-wave plate 122, the polarization component remains random. Thereafter, the light beam (131) having a random polarization component reaches the polarization separation surface 142 of the polarization beam splitter 132, where separation into P-polarized light and S-polarized light is performed. The polarization separation surface 142 has a characteristic of transmitting P-polarized light and reflecting S-polarized light among random polarization components of the light beam (131). Accordingly, the P-polarized light (132) travels straight through the polarization beam splitter 132 as it is, and becomes an emitted light beam (P) 13 of the light source device 1. On the other hand, the S-polarized light (133) reflected by the polarization separation surface 142 changes its traveling direction to the adjacent polarization beam splitter 131 and reaches the polarization separation surface 141 of the polarization beam splitter 131. Since the polarization separation surface 141 is also configured to transmit the P-polarized light and reflect the S-polarized light, the S-polarized light (133) is reflected and reflected as a luminous flux (134). Then, after exiting the polarization beam splitter 131, it passes through the quarter-wave plate 121. Here, the light beam (134) which has been S-polarized light is once converted into circularly polarized light (135) and reaches the dichroic mirror (G) 111. Since the dichroic mirror (G) 111 has a characteristic of transmitting the G color and reflecting the colors other than the G color, the circularly polarized R color light (135) is reflected, and the ¼ wavelength plate 121 is again transmitted to the polarization beam. Proceed toward the splitter 131 side. Here, the circularly polarized light (135) is polarized and converted into P-polarized light (136) and reaches the polarization separation surface 141. Since the polarization separation surface 141 has characteristics of transmitting P-polarized light and reflecting S-polarized light, the P-polarized light (136) passes through the polarization separation surface 141 and is emitted from the light source device 1 (P) 14. It becomes.

  As described above, all the projected light beams 11 to 14 from the light emitting diode lamp unit 10 are projected as P-polarized light.

  Although FIG. 1 shows the case where the adjacent light emitting diode lamps 101 and 102 are G color and R color, the operation is also performed when the adjacent light emitting diode lamps are G and B colors or R and B colors. The same. The difference is the characteristic of the dichroic mirror arranged on the side close to the light emitting diode lamp. In other words, when the G color and the B color are adjacent to each other, a dichroic mirror disposed on the side close to the G color light emitting diode lamp has a characteristic of transmitting the G color and reflecting other than the G color. As a dichroic mirror disposed on the side close to the B-color light emitting diode lamp, a dichroic mirror that transmits B color and reflects other than B color may be prepared. When the R color and the B color are adjacent to each other, a dichroic mirror having a characteristic of transmitting the R color and reflecting other than the R color is disposed on the optical axis of the R light emitting diode lamp, and transmits the B color. Thus, a dichroic mirror having a characteristic of reflecting colors other than B color may be disposed on the optical axis of the B light emitting diode lamp.

  As described above, almost all of the light of the random polarization component emitted from the light emitting diode lamp is separated into P-polarized light and S-polarized light, and then the S-polarized light is subjected to polarization conversion and emitted from the light source device as P-polarized light. Therefore, a light source device with high light utilization efficiency can be configured.

  In order to perform color display, R, G, and B light fluxes must be generated from the light source device. Therefore, the light source device is provided with light emitting diode lamps that emit R, G, and B colors. is necessary. FIG. 3 is a basic schematic diagram showing an example of a light source device in which light-emitting diode lamps that emit three colors of R, G, and B are provided.

  In FIG. 3, a light emitting diode lamp unit 31 having a G light emitting diode lamp (G) 301 and an R light emitting diode lamp (R) 302, a G light emitting diode lamp (G) 303, and a B light emitting diode lamp ( B) By combining the light emitting diode lamp unit 32 provided with 304, two G light emitting diode lamps and one R and B light emitting diode lamps are prepared. The R, G, and B light emitting diode lamps are not limited to two G light emitting diode lamps and one R and B light emitting diode lamps as shown in FIG. The number ratio of R, G and B light emitting diode lamps may be G: R: B = 2: 1: 1: 1 or 1: 2: 1: 1 or 1: 1: 2. In order to increase the brightness, it is desirable to arrange a large number of these light emitting diode lamp units on a plane.

  In FIG. 3, four light emitting diode lamps are arranged in the horizontal direction on the paper surface. However, the light emitting diode lamps can also be arranged in the vertical direction on the paper surface. That is, as in the above-described third modification, it is possible to adopt a configuration in which the light emitting diode lamps are arranged in a matrix on the same plane.

  However, it is avoided that the light-emitting diode lamps of the same color are adjacent to each other, and the polarizing beam splitters are arranged so that the S-polarized light reflected by the polarizing beam splitters arranged on these optical axes is directed to the polarization separation surfaces. Should.

  In the present embodiment, the case where the light beam emitted from the light source device 1 is P-polarized light is shown. However, when only S-polarized light is to be obtained, a half-wave plate is provided immediately after the light source device 1 is emitted. That's fine. By setting it as such a structure, the light source device which emits only S polarized light with a high light utilization factor can be comprised.

  As described above, the light source device of the present invention is a small and thin light source device that sequentially or simultaneously generates R, G, B or R, G, B, W (white) color light, and emits light from the light source device. Since the light beam is P-polarized light or S-polarized light having a uniform polarization direction, it is a light source device suitable for a single-plate projection liquid crystal display device in which the display panel is a liquid crystal display panel.

  Various modifications can be made to the dichroic mirror, quarter-wave plate, and polarizing beam splitter described in FIG. For example, in order to make the light source device more compact, the polarizing beam splitter and the quarter wave plate can be integrated instead of being arranged independently.

  FIG. 4 is a schematic diagram showing a first modification of the light source device shown in FIG. 3 of the present invention. The polarization beam splitter 430 is composed of four beam splitters 331, 332, 333, and 334 shown in FIG. Are combined to form a single beam splitter 430, and a film-type quarter-wave plate 420 is bonded to the incident surface. By doing so, the number of parts can be reduced. Furthermore, by adopting such a configuration, the surface that comes into contact with air is reduced as compared with the case where each is arranged independently, so that the reflection loss is reduced and the light utilization rate of the light flux from the light emitting diode lamp is further increased. improves.

  FIG. 5 is a schematic diagram showing a second modification of the light source device shown in FIG. 3 according to the present invention. The polarization beam splitters 331, 332, 333, and 334 are not prism type but plate-like wire grid type polarization beams. Splitters 531, 532, 533, and 534 are used. A wire grid type polarization beam splitter is commercially available from Moxtec, Inc., and can be significantly reduced in weight compared to a prism type polarization beam splitter. Further, here, the quarter-wave plates 521, 522, 523, and 524 are integrated with the dichroic mirrors 511, 512, 513, and 514, respectively. That is, a dichroic mirror was formed on the surface of the glass substrate, and a quarter wavelength plate was bonded to the back surface. In this way, the number of parts is reduced.

  Furthermore, in order to improve the parallelism of the light beam emitted from the light emitting diode lamp, an auxiliary optical element may be arranged in the light emitting diode lamp. As the auxiliary optical element, a lens, a prismatic rod having a tapered shape, or the like can be considered. By adding such an auxiliary optical element, a highly parallel light beam can be made incident on the polarizing beam splitter, and the light utilization rate in the light source device is further increased.

(Second Embodiment)
Next, a projection display apparatus according to a second embodiment of the present invention will be described. FIG. 6 is a schematic configuration diagram showing an example of a single-plate projection liquid crystal display device including the light source device according to the first embodiment of the present invention.

  A single-plate type projection liquid crystal display device 600 according to the second embodiment of the present invention includes a light source device 3 according to the first embodiment, a liquid crystal display panel 610, a first lens plate 601, and a second lens plate 601. Lens plate 602, first convex lens 603, second convex lens 604, first polarizing plate 605, second polarizing plate 606, and projection lens 607.

  When a single liquid crystal display panel is illuminated by the light source device of the present invention, it is preferable to provide an integrator optical system between the light source device and the liquid crystal display panel. That is, the light flux from the light emitting diode lamp is emitted from the light source device via the polarizing beam splitter on its own optical axis and the polarizing beam splitter on the optical axis of the adjacent light emitting diode lamp. By arranging a lens system that superimposes and illuminates the luminous flux on the display panel, the luminous flux from the light source can be used efficiently. As such a lens system, an integrator optical system composed of two sets of fly-eye lenses and two sets of field lenses is effective.

  For example, a light beam emitted from the light emitting diode lamp (G) 301 of G color emitted from the light source device 3 of the present invention described with reference to FIG. 3 in the first embodiment is a polarization beam splitter 331 and a polarization beam splitter. The light is emitted as P-polarized light from the light source device 3 via 332. Here, a first lens plate 601 and a second lens plate 602 are arranged as fly-eye lenses so as to correspond to the polarization beam splitters 331 and 332. Further, a first convex lens 603 and a second convex lens 604 are arranged as field lenses at the tip of the second lens plate 602. The first lens plate 601, the second lens plate 602, the first convex lens 603, the first convex lens 603, and the second convex lens 603 are arranged so that the outline of each lens constituting the lens plates 601 and 602 forms an image on the effective display area of the liquid crystal display panel 610. The curvature radius and interval of the second convex lens 604 are set to be predetermined numerical values. Since both the light beam a and the light beam b emitted from the light source device 3 from the G light emitting diode lamp (G) 301 reach the same region of the liquid crystal display panel 610, the liquid crystal display panel 610 having very high light utilization efficiency. Illumination is performed. In general, a first polarizing plate 605 and a second polarizing plate 606 are disposed before and after the liquid crystal display panel 610. The same applies to the other light-emitting diode lamp (R) 302, light-emitting diode lamp (G) 303, and light-emitting diode lamp (B) 304.

  In order to perform color display, for example, a light flux of G → R → B may be generated from the light source device 3 and the liquid crystal display panel 610 may be irradiated with the light flux. Accordingly, the light-emitting diode lamp (G) 301, the light-emitting diode lamp (R) 302, the light-emitting diode lamp (G) 303, and the light-emitting diode lamp (B) 304 are individually driven to be turned on / off. At this time, color display of the liquid crystal display panel 610 is performed by driving the liquid crystal display panel 610 in synchronization with the irradiated color light. In addition to the repetition of G → R → B, a time for lighting the respective light emitting diode lamps at the same time is provided to project W color light, that is, the lighting control such as the repetition of G → R → B → W is performed. It is also possible to do this.

  The image displayed on the liquid crystal display panel 610 is enlarged and projected on the screen by the projection lens 607.

  In the second embodiment, a single-plate projection liquid crystal display device using a liquid crystal display panel that desirably uses polarized light having a uniform polarization direction as a light source has been described as an example. Similarly, the light source device of the present invention can be used.

1 is a schematic plan view showing a basic configuration of a light source device according to a first embodiment of the present invention. It is explanatory drawing which shows the characteristic of the dichroic mirror of the light source device of this invention. It is a basic schematic diagram showing an example of a light source device provided with a light emitting diode lamp that emits three colors of R, G, and B. It is a schematic diagram which shows the 1st modification of the light source device shown in FIG. 3 of this invention. It is a schematic diagram which shows the 2nd modification of the light source device shown in FIG. 3 of this invention. 1 is a schematic configuration diagram illustrating an example of a single-plate projection liquid crystal display device including a light source device according to a first embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source device 10, 31, 32 Light emitting diode lamp unit 11, 12, 13, 14, 31, 32, 33, 34, 35, 36, 37, 38 Projection light (P)
101, 301, 303, 401, 403, 501, 503 Light emitting diode lamp (G)
102, 302, 402, 502, light emitting diode lamp (R)
111, 311, 313, 411, 413, 511, 513 Dichroic mirror (G)
112, 312, 412, 512 Dichroic mirror (R)
121, 122, 321, 322, 323, 324, 421, 422, 423, 424, 521, 522, 523, 524 quarter wave plates 131, 132, 331, 332, 333, 334, 430, 531, 532, 533, 534 Polarization beam splitter 141, 142, 341, 342, 343, 344, 440, 544 Polarization separation surface 201 Characteristics (R)
202 Characteristics (G)
203 Characteristics (B)
304, 404, 504 Light-emitting diode lamp (B)
314, 414, 514 Dichroic mirror (B)
600 Projection type liquid crystal display device 601 First lens plate 602 Second lens plate 603 First convex lens 604 Second convex lens 605 First polarizing plate 606 Second polarizing plate 607 Projection lens 610 Liquid crystal display panel (121) ~ (126), (131) ~ (136), a, b

Claims (11)

A light source device for a projection display device using a light emitting diode lamp,
The light source device includes a first light emitting diode lamp that emits one or more first color lights, a second light emitting diode lamp that emits second color light, and a third light emitting diode lamp that emits third color light. And
Each of the light emitting diode lamps is arranged on the same plane so that the respective optical axes are parallel,
Two types of light emitting diode lamps with different emission colors are combined, and a dichroic mirror, a quarter wavelength plate, and a polarization beam splitter are sequentially arranged on each optical axis. The reflected light beams reflected are arranged so as to enter a pair of polarizing beam splitters to form a set of light emitting diode lamp units, and the dichroic mirror and the polarizing beam splitter are combined into a set of light emitting diode lamps. It is combined so that light of two kinds of emission colors unified to one polarized light is emitted from the unit,
The light source device is a light source device for a projection display device, which includes a plurality of the light emitting diode lamp units.   The light source of the projection display apparatus according to claim 1, wherein the first color light is R color (red), the second color light is G color (green), and the third color light is B color (blue). apparatus.   The characteristics of the dichroic mirror disposed between the first light emitting diode lamp and the polarization beam splitter are such that the color light of the first light emitting diode lamp is transmitted, and the second and third light emitting diode lamps are transmitted. The dichroic mirror disposed between the second light-emitting diode lamp and the polarization beam splitter transmits the color light of the second light-emitting diode lamp, The characteristics of the dichroic mirror disposed between the third light-emitting diode lamp and the polarization beam splitter have a characteristic of reflecting the color light of the first and third light-emitting diode lamps. Transmits color light from the light emitting diode lamp and reflects color light from the first and second light emitting diode lamps Having to properties, the light source device of a projection display device according to claim 1 or claim 2.   4. The light source device for a projection display device according to claim 1, wherein the quarter-wave plate of the light-emitting diode lamp unit is integrally formed. 5.   5. The light source device of the projection display device according to claim 1, wherein the polarization beam splitter of the light emitting diode lamp unit is integrally formed.   6. The light source device for a projection display device according to claim 5, wherein the polarization beam splitters of a plurality of the light emitting diode lamp units are integrally formed.   7. The polarization beam splitter according to claim 1, wherein the polarization beam splitter is a polarization beam splitter having a structure in which right-angle prisms made of two optical glasses each having a dielectric multilayer film formed on a hypotenuse are bonded to each other. Light source device.   The light source device according to claim 1, wherein the polarizing beam splitter is a flat polarizing beam splitter.   The light source device according to claim 1, wherein the quarter-wave plate and the dichroic mirror are integrally formed.   The light source device according to any one of claims 1 to 9, wherein the quarter-wave plate and the polarization beam splitter are formed integrally.   A light source device according to any one of claims 1 to 10, wherein the light beam from the light source device is irradiated onto a single liquid crystal display panel, and an image modulated by the liquid crystal display panel is projected by a projection lens. Projection-type display device that displays an enlarged image.

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