TW581927B - Reflective LCD projector - Google Patents

Abstract

A reflective LCD projector comprising a first LED array, a second LED array, a first PBS, a first panel, a first lens, a color switch, a second PBS, a second panel, and a second lens is provided. The first LED array provide a light with a first color, the light with the first color incident into the first PBS and the first panel and then form an image by the first lens. The second LED array provide a light with a second color and a third color, by the color switch, the light with the second and the third color will alternatively incident into the second PBS and the second panel and then form an image by the second lens.

Description

581927 V. Description of the invention (l) The invention belongs to a kind of reflective liquid crystal projection device, and particularly relates to a light emitting diode array (LED array) as a light source, and only two Reflective liquid crystal projection device with a liquid crystal panel. Prior art

In recent years, liquid crystal display elements have gradually been widely used in daily life, such as direct-view displays such as the most common LCD screens, notebook computers, and LCD TVs, as well as displays used in LCD projectors and rear-projection TVs. Non-direct view display panels, such as Liquid Crystal On Silicon (LCOS) panels, high-temperature polycrystalline silicon liquid crystal panels (HTPS-LCD), etc. Since direct-view displays still have many restrictions on large-size displays, liquid crystal projectors and rear-projection televisions with high-resolution non-direct-view display panels and optical engines to achieve large-size displays have gradually become the mainstream trend.

Fig. 1 is a schematic diagram showing the structure of a conventional reflective liquid crystal projection device. Please refer to FIG. 1. The conventional reflection type liquid crystal projection device is mainly composed of a light source 102, a lens array 104, a polarization conversion element 106, a condenser lens 108, and a two-color beam splitting mirror 110. 128, reflecting mirrors 112, 124, 126, collimating lenses 114, 130, 136, polarization beam splitting elements 116, 132, 138, liquid crystal panels 118, 134, 140, X- 稜鏡 1 20, and projection objective 122, etc. Composed of. Please also refer to FIG. 1. In the conventional reflective liquid crystal projection device 100, the light source 102 is usually an ultra-high pressure mercury bulb, and the light rays R, G, and B emitted by the light source 丨 〇2 will pass through the lens array 丨. 4 to achieve uniformity

l〇363twf.ptd

581927 V. Description of the invention (2) ’Fruit. Then, the light rays R, G, and B will pass through a polarization conversion element (Ps converter) 106 and exit with the light rays RS, Gs, and Bs of the S polarization type. Then, the light rays Rs, Gs, and Bs pass through a condenser lens 108 and are incident on a two-color dichroic mirror (DM) 110. The two-color dichroic mirror 110 allows the light ray Rs to pass through, and the light rays Gs, Bs reflection. The following will sequentially describe the light paths of the light rays Rs and the light rays Gs and Bs. The light Rs penetrating the dichroic beam splitter 110 will be incident on the reflecting mirror 112 ', and the light Rs reflected by the reflecting mirror 112 will pass through the collimator lens 114 and be incident on the polarization beam splitter (PBS) 116. Since the optical coating 11 6a in the polarization beam splitting element 11 16 has the characteristics of polarization selection, such as reflecting the light of s polarization # and letting the light of P polarization pass through, the optical coating Π 6a reflects the light Rs to the liquid crystal panel 118 on. Thereafter, the S-polarized light Rs incident on the liquid crystal panel 118 changes its polarization type, and the p-polarized light Rp is incident from the liquid crystal panel 118 into the polarization beam splitter 116, and the light Rp penetrates the polarization beam splitter 116. The optical coating 116a is incident on X- 稜鏡 120. Since the optical coating 120a in X- 稜鏡 120 has wavelength-selective properties, such as reflecting light in the red light wavelength range and allowing light outside the red light wavelength range to pass through, the optical coating 120a will light Rp Reflected into the projection objective lens 122. The light rays Gs and Bs reflected by the two-color beam splitter mirror 110 are incident on the reflection mirror 124 and the reflection mirror 126 in sequence, and the light rays Gs and Bs reflected by the reflection mirror 126 are incident on the two-color beam splitter mirror 128. In the above, the dichroic mirror 128 allows light Bs to penetrate and reflects light Gs. The light Bs penetrating the dichroic mirror 128 passes through the collimating lens 130 and

10363twf.ptd Page 8 581927 V. Description of the invention (3) It is incident on the polarization beam splitting element 132. Since the optical coating 132a in the polarization beam splitting element 132 has the characteristics of polarization selection, for example, the light polarized by s is reflected and the light polarized by P is transmitted. Therefore, the optical coating 13 2a reflects the light Bs to the liquid crystal panel 134. After that, the S-polarized light Bs incident on the liquid crystal panel 134 changes its polarization type, and the p-polarized light Bp is incident from the liquid crystal panel 134 into the polarization beam splitting element 132, and the light Bp passes through the light in the polarization beam splitting element 132. The coating film 132a is incident on X- 稜鏡 120. Since the optical coating 120b in X- 稜鏡 120 also has the characteristics of wavelength selection, such as reflecting light in the blue light wavelength range and allowing light outside the blue light wavelength range to pass through, the optical coating 120b reflects the light Bp to the projection Objective lens 122. The light Gs reflected by the dichroic beam splitter mirror 128 passes through the collimating lens 136 and is incident on the polarization beam splitting element 138. Since the optical coating 138a in the polarization beam splitting element 138 has polarization-selective properties, such as reflecting s-polarized light and allowing P-polarized light to pass through, the optical coating 138a reflects the light Gs to the liquid crystal panel 140. Thereafter, the S-polarized light Gs incident on the liquid crystal panel 140 changes its polarization type, and the p-polarized light gp is incident from the liquid crystal panel 140 into the polarization beam splitting element 138, and the light Gp passes through the optical beam The coating film 138a is incident on X- 稜鏡 120. Since both the optical mineral film 120b and the optical key film 120b in the X-prism 120 allow light Gp to pass through, the light Gp will directly penetrate X-X120 and be incident on the projection objective lens 122. The conventional reflection type liquid crystal projection device mainly has the following disadvantages: 1. The conventional reflection type liquid crystal projection device must use a three-piece liquid crystal panel IH1 10363twf.ptd page 9 581927

acos), three polarizing beamsplitters, and one x-prism can be used for projection, but because the price of liquid crystal panels (LC0s) is high, the manufacturing cost of conventional reverse liquid crystal projection devices cannot be effectively reduced. 2. It is known that the number of polarization beam splitting elements and χ_ 习 used is four, so that the size and weight of the projection device cannot be further reduced. 3. Since it is conventional to use an ultra-high pressure mercury lamp as a light source, it has a lifetime π 1 limit (about 2000 hours) and the brightness decays rapidly, so the projection device must be replaced after a period of use. In addition, the operating temperature of the ultra-high mercury lamp is high, which easily affects the quality of other optical components.

In the conventional projection device, in order to increase the use of ultra-high pressure mercury bulbs, a more complicated lighting procedure is usually used, so the warm-up waiting time is longer. % Invention invention Therefore, the object of the present invention is to provide a reflective liquid crystal projection device ', which requires only two liquid crystal panels in the design to reduce the manufacturing cost. Another object of the present invention is to provide a reflective liquid crystal projection device, which does not need to be used in design, and only needs to use two liquid crystal panels to further reduce the volume and weight of the projection device. Still another object of the present invention is to provide a reflective liquid crystal projection device which uses light emitting diode arrays of different colors of light (red, green, blue) as a source to improve insufficient light source life, rapid brightness decay, and operating temperature. Over surface, and complicated lighting procedures. The invention provides a reflective liquid crystal projection device, which is mainly composed of a first

581927 V. Description of the invention (5)

Light-emitting diode array, second light-emitting diode array, first polarization beam splitting element, first liquid crystal panel, first projection objective lens, color switching element, second polarization beam splitting element, second liquid crystal panel, and second projection objective lens Made. Among them, the first light-emitting diode array can provide the first [light K such as red light]; the second light-emitting diode array can provide the second color light (for example, ^ light) and the second color light (for example, blue light) ; The first polarization beam splitting element ^ has been placed on the light path of the first color light after the first light emitting diode array; the first liquid crystal panel is disposed on the light path of the first color light after the first polarization beam splitting element

The light of the first color behind the liquid crystal panel is the second after the second light emitting diode array, and the color switching element allows the second

On the path; the color switching element is arranged on the light path of the dichroic light and the third color light to alternately pass the colored light and the third color light; the second polarization beam splitting element is arranged on the light path of the second color light and the third color light after the color switching element; The two liquid crystal panels are disposed on the light paths of the second color light and the third color light after the second polarization beam splitting element; and the second projection objective is disposed on the light paths of the second color light and the third color light after the second polarization beam splitting element.

In the reflective liquid crystal projection device of this embodiment, a first lens array and a first polarization conversion element are sequentially arranged on the light path of the first colored light between the first light emitting diode array and the first polarization beam splitting element, for example. , A first condenser lens, a plurality of first reflecting mirrors, and a collimating lens. The first polarization conversion element can convert the first color light into a first polarization type (for example, S polarization). In the reflective liquid crystal projection device of this embodiment, the light paths of the second color light and the third color light are between the second light emitting diode array and the color switching element.

10363twf.ptd Page 11 581927 V. Description of Invention (6) For example, a second lens array, a second polarization conversion element, and a second condenser lens are arranged on the description. The 'second polarization conversion element can convert, for example, the second color light and the third color light into a first polarization type (for example, S polarization). In the reflective liquid crystal projection device of this embodiment, a plurality of second reflecting mirrors and collimating lenses are arranged on the light path of the second color light and the third color light between the second polarization beam splitting element and the color switching element, for example. In the reflective liquid crystal projection device of this embodiment, the first polarization beam splitting element and the first polarization beam splitting element have a first optical key film and a second optical coating film respectively, and the first optical coating film and the second optical coating film will polarize the first polarization Light of a type (for example, S polarization) is reflected on the liquid crystal panel, and light of a second polarization type (for example, P polarization) is allowed to penetrate out. ° In the reflective liquid crystal projection device of this embodiment, the first liquid crystal panel and the second liquid crystal panel are reflective liquid crystal panels, such as, for example, a Shi Xijing panel (LCOS). In the reflective liquid crystal projection device of this embodiment, the first light-emitting diode array and the second light-emitting diode array are arranged on a single body, for example, and the second light-emitting diode array is, for example, a plurality of first light-emitting diode arrays. The two-color light-emitting diodes and a plurality of third-color light-emitting diodes are arranged in an array on the seat frame. In this embodiment, the first light-emitting diode array and the second light-emitting-diode array are used as light sources, and a color switching element is matched so that the second three-color light can pass through alternately and be incident on the corresponding liquid crystal panel. The life of the light source is increased to more than 10,000 hours, and the purpose of color display can be achieved by using only two liquid crystal panels.

10363twf.ptd Page 12 581927 V. Description of the invention (7) The development in cost, volume and weight is very advantageous. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below in conjunction with the accompanying drawings for detailed description as follows: Embodiment 2 is shown in accordance with FIG. A preferred embodiment of the present invention is a schematic structural diagram of a reflective liquid crystal projection device. Please refer to FIG. 2. The reflective liquid crystal projection device 200 of this embodiment is mainly composed of a first light emitting diode array 202, a second light emitting diode array 204, a base 206, a first lens array 208, and a first polarization. Conversion element 21, first condenser lens 212, first reflecting mirrors 214, 216, first collimating lens 218, first polarization beam splitting element 220, first liquid crystal panel 222, first projection objective lens 224, second lens Array 226, second polarization conversion element 228, second condenser lens 230, color switch 232, second reflecting mirrors 234, 236, second collimator lens 238, second polarization beam splitting element 240, first It is composed of two liquid crystal panels 242 and a second projection objective 244. Referring also to FIG. 2, in the reflective liquid crystal projection device 200 of this embodiment, the first light-emitting diode array 202 and the second light-emitting diode array 204 are, for example, disposed on different surfaces of the base body 206. . The second light-emitting diode array 204 is configured by, for example, arranging a plurality of second-color light-emitting diodes 204a and a plurality of third-color light-emitting diodes 204b in an array on the base 206. . Since the light-emitting diode itself can directly provide light sources of different colors, no further spectroscopic action is required. The following will sequentially describe the optical paths of the rays R, G, and B.

581927 V. Description of the invention (8) The light R emitted by the first light emitting diode array 202 will pass through the first lens array 208 to achieve a uniform effect. The light R then passes through the first PS converter 210 and exits as the S-polarized light Rs. Then, the light Rs passes through the first condenser lens 212, the first reflecting mirrors 214, 216, and the first condenser lens 218 and is incident on the first polarization beam splitting element 220. Since the first optical coating 220a in the first polarization beam splitting element 220 has polarization selection characteristics, such as reflecting S-polarized light and allowing P-polarized light to pass through, the first optical coating 220a reflects the light Rs to the first A liquid crystal panel 222. After that, the S-polarized light Rs incident on the first liquid crystal panel 222 changes its polarization type, and the P-polarized light Rp is incident from the first liquid crystal panel 222 to the first polarization beam splitter 220, and the light Rp passes through The first optical coating 220a in the first polarization beam splitting element 220 is transmitted and incident on the first projection objective lens 224 to project an image. The light rays G and B emitted from the second light emitting diode array 204 will pass through the second lens array 2 2 6 to achieve a uniform effect. Then, the light rays g and B pass through the second polarization conversion element 228 and exit as the light rays Gs and Bs of the S polarization type. Then, the light Gs and Bs are incident on the color switching element 232 through the second condenser lens 230, and the color switching element 232 can allow the light Gs and the light bs to pass alternately. Then, the light Gs and light Bs passing through the color switching element 232 in an alternating manner will sequentially pass through the second reflecting mirrors 234 and 236 and the second condenser lens 238 and enter the second polarization beam splitting element 240. Because the second optical mineral film 240a in the first polarization beam splitting element 240 has polarization selection characteristics, such as reflecting S-polarized light and letting p-polarized light page 14 581927 5. Invention description (9) penetrates, so The second optical coating film 240a reflects the light Gs, Bs onto the second liquid crystal panel 242. After that, the S-polarized light Gs, Bs incident on the second liquid crystal panel 242 changes its polarization type, and the P-polarized light Gp, Bp is incident from the second liquid crystal panel 242 into the second polarization beam splitter 240, and The light rays Gp and Bp will pass through the second optical coating 24 0a in the second polarization beam splitting element 24 0 and enter the second projection objective lens 244 to project an image. It is worth noting that the color switching element 232 and the second liquid crystal panel 2 4 2 in this embodiment are driven by, for example, a driving circuit (not shown), so that the second liquid crystal panel 242 can alternately receive colors from Switch the light Gs and light Bs of the element 232 to achieve the purpose of projection display. In the above embodiment, the first and second light-emitting diode arrays can directly separate one of the three primary light colors (R, G, B). , And the other two kinds of color light can achieve the display function through the synchronous control of the color switching element and the liquid crystal panel. As for the independent light is red, green, or blue light, it depends on the color switching element and the LCD panel used. In other words, the light paths of the colored lights in the above-mentioned embodiments of the present invention are for illustration only, and are not intended to limit the red, green, and blue light to follow the paths shown in the figure. The reflection type liquid crystal projection device of the present invention has at least the following advantages: 1. The reflection type liquid crystal projection device of the present invention, which uses a light-emitting diode array = as a light source, can improve the insufficient life of the light source of the ultra-high pressure mercury lamp, the brightness decays quickly, Problems such as too high operating temperature and complicated lighting procedures 2 · The reflective liquid crystal projection device of the present invention requires only use in design

581927 V. Description of the invention (ίο) Two liquid crystal panels, so the production cost can be greatly reduced. 3 · The reflective liquid crystal projection device of the present invention does not need to use X- 稜鏡 in design, and only needs two liquid crystal panels, so the volume and weight of the projection device can be further reduced. Although the present invention is limited to the scope and scope of the present invention, the scope of protection has been disclosed as above with a preferred embodiment. However, it is not intended to be used by anyone skilled in the art. It can be done without departing from the scope of the present invention. Changes and retouching, so as defined in the scope of the patent application attached today. Mingzhibao

581927 Brief description of the drawings Figure 1 is a schematic diagram showing the structure of a conventional reflective liquid crystal projection device; and Figure 2 is a schematic diagram showing the structure of a reflective liquid crystal projection device according to a preferred embodiment of the present invention. Description of the drawings 100 Conventional reflective liquid crystal projection device 102 Light source 104 Lens array 106 Polarization conversion element 108 Condensing lens 110, 128: Two-color spectroscopic mirror 112, 124, 126: Reflective mirror 114, 130, 136: Collimation Lenses 116, 132, 138: Polarizing beam splitters 116a, 120a, 120b, 132a, 13 8a: Optical coatings 118, '134, 140: LCD panel 120 X-稜鏡 122 Projection objective 200 The reflective liquid crystal projection of this embodiment Device 202 First light-emitting diode array 204 Second light-emitting diode array 204a: Second-color light-emitting diode 204b: Third-color light-emitting diode

10363twf.ptd Page 17 581927 Brief description of the diagram 206: Base body 208: First lens array 210: First polarization conversion element 212: First condenser lens 214, 216: First reflecting mirror 218: First collimation Lens 220: first polarization beam splitting element 220a: first optical coating 222: first liquid crystal panel 224: first projection objective lens 2 2 6: second lens array 228: second polarization conversion element 230: second condenser lens 232: Color switching elements 234, 236: second reflecting mirror 238: second collimating lens 240: second polarizing beam splitting element 240a: second optical coating 242: second liquid crystal panel 244: second projection objective lens

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Claims (1)

1. A reflective liquid crystal projection device, a first light-emitting diode array, including the -th-polarizing beam splitting element, provided for: providing the -th-color light; then on the light path of the first-color light; The first liquid crystal panel of the first light emitting diode array is arranged on the light path of the first color light; and the first projection objective lens after the first polarization beam splitting element is allocated the light of M 4 M color light On the path; after the first crystal panel, the first : A second light-emitting diode array, adapted to provide a second color light and a second color light; ^: a color switching element, which is arranged after the second light-emitting diode array, the first color light and the second color light And the color switching element allows the second color light of the δH to alternately pass through the third color light; a second polarization beam splitting element is disposed on the light path of the second color light and the third color light after the color switching element A second liquid crystal panel disposed on the light path of the second color light and the third color light after the second polarization beam splitting element; and a second projection objective disposed on the second color light after the second polarization beam splitting element And the third color light on the light path. 2. The reflective liquid crystal projection device as described in item 1 of the scope of patent application, further comprising a first polarization conversion element disposed between the first light emitting diode array and the first polarization beam splitting element. The light path of the light to convert the first color light into a first polarization type. 3 · Reflective liquid crystal projection device as described in item 2 of the scope of patent application 10363twf.ptd Page 19 581927 6. The scope of the patent application includes a first lens array and the light path of the first colored light between the first light emitting diode array and the first polarization conversion element. on. 4 · The reflective liquid crystal projection device according to item 2 of the scope of the patent application further includes a first condenser lens, the first colored light is placed between the first polarization conversion element and the first polarization beam splitting element. Light path. 5 · The reflective liquid crystal projection device as described in item 4 of the scope of the patent application, further comprising a plurality of first reflecting mirrors' disposed between the first condenser lens and the first polarization beam splitting element. Light path. 6 · The reflective liquid crystal projection device according to item 5 of the scope of patent application, further comprising a first collimating lens disposed between the first reflecting mirrors and the first polarizing beam splitting element. Light path. 7 · The reflective liquid crystal projection device according to item 1 of the scope of patent application, further comprising a second polarization conversion element disposed between the second light emitting diode array and the color switching element, the second color light and the On the light path of the third color light, the second color light and the third color light are converted into a first polarization type. 8 · The reflective liquid crystal projection device described in item 7 of the scope of the patent application further includes a second lens array disposed between the second light emitting diode array and the second polarization conversion element. The third color light is on the light path. 9 · The reflective liquid crystal projection device as described in item 7 of the scope of patent application, further comprising a second condenser lens disposed between the second polarization conversion element and the color switching element, the second color light and the third light 0 on colored light path 10363twf.ptd Page 20 581927 VI. Patent application scope I 0 · The reflective liquid crystal projection device as described in item 9 of the patent application scope further includes a plurality of second reflecting mirrors arranged on the second condenser lens and On the light path between the second color light and the third color light between the second polarization beam splitting element. II · The reflective liquid crystal projection device as described in item 10 of the scope of patent application, further comprising a second collimating lens disposed between the second reflecting mirrors and the second polarization beam splitting element. And the third color light on the light path. 1 2 · The reflective liquid crystal projection device according to item 丨 of the patent application range, wherein the first polarization beam splitting element has a first optical coating, the first optical clock film reflects light of a first polarization type, and Light of the second polarization type is allowed to pass. 1 3 · The reflective liquid crystal projection device described in item 12 of the scope of patent application 'wherein the first polarization mode is S polarization and the second polarization mode is p polarization 0 1 4 · As in the first scope of patent application In the reflective liquid crystal projection device described in the item, the second polarization beam splitting element has a second optical coating, and the second, chain film reflects the light of the first polarization type and allows the light of the second polarization type. by. 1 ·· The reflective liquid crystal projection device as described in item 14 of the scope of the patent application, wherein the first polarization mode is S polarization and the second polarization mode is ρ offset, 16 · As the scope of patent application The reflective liquid crystal projection device described in item 1 further includes a body, and the first light emitting diode array and the second light emitting diode 581927 VI. Scope of patent application The photodiode array is arranged on the base. 17. The reflective liquid crystal projection device according to item μ in the scope of the patent application, wherein the second light-emitting diode array includes: a plurality of second-color light-emitting diodes: and a plurality of third-color light-emitting diodes, The second color light-emitting diodes and the third color light-emitting diode system are disposed on the base. 1 8. The reflective liquid crystal projection device as described in item 1 of the scope of patent application, wherein the first liquid crystal panel and the second liquid crystal panel are reflective liquid crystal panels. 19 · The reflective liquid crystal projection device according to item 1 of the scope of patent application, wherein the first color light, the second color light is green, and the third color light is two primary colors. l〇363twf.ptd Page 22