CN1105458C - Reflecting liquid crystal projector - Google Patents
Reflecting liquid crystal projector Download PDFInfo
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- CN1105458C CN1105458C CN 00137419 CN00137419A CN1105458C CN 1105458 C CN1105458 C CN 1105458C CN 00137419 CN00137419 CN 00137419 CN 00137419 A CN00137419 A CN 00137419A CN 1105458 C CN1105458 C CN 1105458C
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- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 51
- 230000003287 optical effect Effects 0.000 claims abstract description 62
- 239000011248 coating agent Substances 0.000 claims abstract description 49
- 238000000576 coating method Methods 0.000 claims abstract description 49
- 238000001914 filtration Methods 0.000 abstract 4
- 238000010586 diagram Methods 0.000 description 8
- 230000010287 polarization Effects 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
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Abstract
The present invention relates to a reflection liquid crystal projector which comprises an incident light source and three color filtering prisms, wherein a first color filtering prism has a first optical coating with the normal vector of (1, 0, 1) and splits the incident light source into two directions, namely reflected red and blue light and transmitted green light; a second color filtering prism has a second optical coating with the normal vector of (1, 1, 0), reflects the reflected red light to a red liquid crystal display panel, and transmits the reflected blue light to a blue liquid crystal display panel; a third color filtering prism has a third optical coating with the normal vector of (1, 0, 1) and transmits the transmitted green light to a green liquid crystal display panel continuously.
Description
The present invention relates to a projection device of a reflective liquid crystal projector, and more particularly, to an optical path in a projection device of a reflective liquid crystal projector.
In recent years, liquid crystal display devices have been widely used in daily life, such as liquid crystal televisions, portable computers, and liquid crystal projectors. The optical path design of the light splitting element in a general reflective liquid crystal projector can be divided into Off-axis (Off axis) design and On-axis (On line) design. The off-axis design means that the incident light source and the emergent light source are not on the same straight line, and the on-axis design means that the incident light source and the emergent light source are on the same straight line.
Please refer to fig. 1, which is a schematic diagram of an optical path design in an off-axis liquid crystal projector. First, an incident light source 100 is provided, and the incident light source 100 is polarized into an S-polarized type. Then, a Polarization Beam Splitter (PBS) reflects the S-polarized light into the color filter prism 102 for splitting, and the split light is projected onto the reflective liquid crystal display panel 104. Then, the reflective liquid crystal display panel 104 reflects a corresponding P-polarized light. The P-polarized light is combined by a light combiner 106 and finally projected on a screen through a projection objective 108.
In the above-mentioned optical path design of the off-axis liquid crystal projector, the color filter prism 102 is used to split light, and the light combiner 106 is used to combine light, and the splitting and combining steps are performed separately, so that an image with high contrast can be generated. Although the technology of the off-axis liquid crystal projector is mature at present, the whole mechanism is difficult to adjust because the light paths are not on the same straight line and involve the problems of alignment and light path. In addition, the off-axis liquid crystal projector has the disadvantages of difficult production, high production cost, high height of the produced optical machine (about 6 inches), difficult lens design, large element size and the like.
Please refer to fig. 2, which is a schematic diagram of an optical path design of the PHILIPS prism. The polarized light source 200 passes through a Polarizing Beam Splitter (PBS), and reflects the S-polarized incident light source 200 into the light splitting/combining element.
First, regarding the light splitting aspect, after the S-polarized light in the incident light source 200 is reflected into the light splitting/combining element, taking PHILIPS prism as an example, the light splitting/combining element is composed of three triangular color filter prisms 202, 204 and 206. A first optical coating 208 is disposed between the color filter prism 202 and the color filter prism 204, and a second optical coating 210 is disposed between the color filter prism 204 and the color filter prism 206. The first optical coating film 208 has a function of transmitting red light and green light, and completely reflecting blue light. The second optical coating film 210 has a function of allowing green light to transmit and red light to be completely reflected.
Referring to fig. 2, the incident light source 200 enters the color filter prism 202, the red light and the green light in the incident light source 200 enter the color filter prism 204 through the first optical coating 208, and the blue light is reflected to the blue lcd panel 212 to activate the same. After the red and green lights enter the color filter prism 204 through the first optical coating 208, the green light will continue to pass through the second optical coating 210 and be incident on the green lcd panel 214 to activate it, and the red light will be reflected by the second optical coating 210 to the red lcd panel 216 to activate it.
Then, referring to fig. 3, after the lcd panel is activated, blue, green and red lights of P-polarization type are reflected by the blue lcd panel 212, the green lcd panel 214 and the red lcd panel 216, respectively, and then reflected by the original path to the light splitting element, and then pass through the polarization beam splitter 218, and then enter the projection objective 220, and finally projected to the screen for imaging.
Fig. 4 is a schematic diagram of the optical path design of the color CONOR. A light source 300 first passes through a polarization beam splitter, and S-polarized light from the incident light source 300 is reflected into the color CONOR splitter/combiner.
First, regarding the light splitting aspect, after the S-polarized light in the incident light source 300 is reflected into the light splitting/combining element, taking the color CONOR light splitting/combining element as an example, the light splitting/combining element is composed of three square color filter prisms, including the color filter prisms 302, 304 and 306. The color filter prism 302 has a function of allowing the red light and the blue light to be completely reflected and the green light to be transmitted. The color filter prism 304 has a function of transmitting red light and reflecting blue light completely. The three colors of green, red, and blue light are split by the light splitting element onto a green lcd panel 308, a red lcd panel 310, and a blue lcd panel 312, respectively. Then, in terms of light combination, after the liquid crystal display panel is activated, blue light, green light and red light of P-polarization type are reflected by the green liquid crystal display panel 308, the red liquid crystal display panel 310 and the blue liquid crystal display panel 312, respectively, and are reflected by the light splitting/combining element, thereby completing the light combination operation.
Although the optical path design of the above on-axis liquid crystal projector does not have the disadvantages of the off-axis device, the volume of the whole optical machine cannot be effectively reduced by the design of the existing light splitting device.
The light splitting elements available on the market today, whether they are PHILIPS prisms, color CONER or color LINK, are designed to split light in a plane, i.e. the incident light and the outgoing light are on the same horizontal plane. And because the projection objective will be lifted up to a fixed position from the position of the light emitted from the original beam splitting/combining element when the liquid crystal projector is OFF-SET, some space is reserved above the beam splitting/combining element such as PHILIPS prism and color cone, and the space is not properly utilized.
Therefore, the invention provides a light splitting and combining element which can utilize space more effectively, and the light path design in the light splitting/combining element is changed from a plane type to a three-dimensional type, wherein the three-dimensional type is the light path design that the incident light and the emergent light are not positioned on the same horizontal plane, so that the space reserved above the light splitting/combining element can be utilized more effectively.
The invention provides a reflection type liquid crystal projector, which comprises an incident light source, a polarizing beam splitter and a color filter prism group. First, the polarizing beam splitter reflects the light of S polarization type in the incident light source to the color filter prism set. The color filter prism group comprises a first color filter prism, a second color filter prism and a third color filter prism. The first color filter prism has the first optical coating film, the normal vector of the first optical coating film plane is (1, 0, 1), and the incident light source can be divided into two directions, one is the direction for reflecting red light and blue light, and the other is the direction for transmitting green light. The second color filter prism is arranged on one side of the first color filter prism, namely on the light path of red light and blue light reflected by the first color filter prism. The second color filter prism has a second optical coating film, the normal vector of the second optical coating film plane is (1, 1, 0), can reflect the red light in the incident light source to the red liquid crystal display panel, and transmit the blue light to the blue liquid crystal display panel. And the third color filter prism is arranged above the first color filter prism, namely on a path along which the transmitted green light travels. The third color filter prism has a third optical coating, the normal vector of the third optical coating plane and the normal vector of the first optical coating are the same as (1, 0, 1), so that the green light can continuously transmit to the green liquid crystal display panel.
In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below. Wherein,
FIG. 1 is a schematic diagram of a prior art optical path design for an off-axis liquid crystal projector;
FIG. 2 is a schematic diagram of the optical path design of the PHILIPS prism;
FIG. 3 is a schematic diagram of the combination of the light path design of the PHILIPS prism with its projection objective and polarizing beam splitter;
FIG. 4 is a schematic diagram of the optical path design of the color CONOR;
FIG. 5 is a schematic diagram of a three-dimensional optical path design according to a preferred embodiment of the present invention.
First, an incident light source 400 is provided. The incident light source 400 passes through the polarization beam splitter, and reflects the S-polarized light in the incident light source 400 into the light splitting element.
The light splitting/combining element is a combination of color filter prisms, and comprises a first color filter prism, a second color filter prism and a third color filter prism, wherein the first, second and third color filter prisms are in a cubic structure. The first color filter prism 402 has a first optical coating 404, and the normal vector of the plane of the first optical coating 404 is (1, 0, 1). The incident light source 400 enters the first color filter prism 402 from the lower side of the first color filter prism 402 along the direction of (0, 0, 1), and when the incident light source 400 travels to the first optical coating 404, the first optical coating 404 can reflect the red and blue light in the incident light source 400 and enter the second color filter prism 406 along the direction of (-1, 0, 0). The green light passes through the first optical coating 404 to the third color filter prism 410 along the original direction (0, 0, 1).
The red and blue light of the incident light source 400 is reflected by the first optical coating 404 and travels along the direction of (-1, 0, 0), and the second color filter prism 406 is disposed at one side of the first color filter prism 402, i.e. on the light path of the red and blue light reflected by the first optical coating 404. The second color filter prism 406 has a second optical coating 408, and the normal vector of the plane of the second optical coating 408 is (1, 1, 0). The second optical coating 408 may re-reflect the red light reflected by the first optical coating 404 to project onto the red lcd panel 416 in the (0, 1, 0) direction and transmit the blue light to the blue lcd panel 418.
As can be seen from the above, after the light splitting/combining element performs the light splitting, the traveling direction of the green light is (0, 0, 1), the traveling direction of the blue light is (-1, 0, 0), and the traveling direction of the red light is (0, 1, 0), and the path directions of the three color lights are three-dimensional stereo forms, not two-dimensional plane forms.
The green light in the first color filter prism 402 is transmitted through the first optical coating 404 to the third color filter prism 410 along the original direction (0, 0, 1). The third color filter prism 410 is located above the first color filter prism 402, i.e. on the light path of the green light after transmission. The third color filter prism has a third optical coating 412, and the normal vector of the third optical coating 412 and the normal vector of the first optical coating 404 can be the same as (1, 0, 1), so that the green light can be transmitted to the green liquid crystal display panel 414.
The green light in the third color filter prism 410 can also be reflected to the green liquid crystal display panel 414 through the third optical coating 412, and the green liquid crystal display panel 414 must be disposed on the path of the reflected green light. If the green light is transmitted through the third optical coating 412 in the third color filter prism 410 and reflected to the green liquid crystal display panel 414, the third color filter prism 410 can be replaced by a triangular prism having the same function, and the volume is reduced.
Finally, the green LCD panel 414, the blue LCD panel 418 and the red LCD panel 416 reflect a corresponding P-polarization type of green, blue and red lights to the projection objective lens, and finally to the screen.
The invention is characterized in that the first optical coating and the second optical coating for light splitting are in a nonparallel planar relationship, so that the traveling path of an incident light source is three-dimensional and is not limited on the same plane, and the occupied area can be effectively saved.
The area occupied by the light splitting element used by the invention is only the area of two color filter prisms, and is reduced by a lot compared with the area of three color filter prisms in the prior art. In addition, in the prior art, the space reserved above the PHILIPS prism and the color CONER due to the lifting of the projection objective is not effectively utilized, and the third color filter prism is arranged above the third color filter prism, so that the operation of elements is not influenced, and the space above the third color filter prism can be effectively utilized.
Although the present invention has been described in terms of a preferred embodiment, it is not intended to be limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (8)
1. A reflective liquid crystal projector, comprising:
a light source, which is incident in the direction of (0, 0, 1);
a first color filter prism having a first optical coating film, wherein the normal vector of the first optical coating film plane is (1, 0, 1), and the first optical coating film can transmit green light and reflect red light and blue light;
the second color filter prism is arranged at one end of the first color filter prism, from which the blue light and the red light are emitted, and is provided with a second optical coating film, the normal vector of the plane of the second optical coating film is (1, 1, 0), and the second optical coating film can transmit the blue light and reflect the red light;
the third color filter prism is arranged at one end of the first color filter prism where the green light is emitted;
a green liquid crystal display panel arranged at one end of the third color filter prism where the green light is emitted;
the blue liquid crystal display panel is arranged at one end of the second color filter prism, which transmits the outgoing blue light; and
and the red liquid crystal display panel is arranged at one end of the second color filter prism, which reflects the red light to be emitted.
2. The reflection type liquid crystal projector according to claim 1, wherein the third color filter prism has a third color filter prism for transmitting green light to the green liquid crystal display panel.
3. The reflection type liquid crystal projector according to claim 1, wherein the third color filter prism has a third color filter prism for transmitting green light to the green liquid crystal display panel.
4. The reflective liquid crystal projector of claim 1, wherein the first, second, and third color filter prisms are in a cubic configuration.
5. A reflective liquid crystal projector, comprising:
a light source, which is incident in the direction of (0, 0, 1) and has a first primary color light, a second primary color light, and a third primary color light;
a first color filter prism having a first optical coating film, wherein the normal vector of the first optical coating film plane is (1, 0, 1), the first optical coating film can transmit the first primary color light, and the second primary color light and the third primary color light are reflected;
the second color filter prism is arranged at one end of the first color filter prism, from which the second primary color light and the third primary color light are emitted, and is provided with a second optical coating, the normal vector of the plane of the second optical coating is (1, 1, 0), and the second optical coating can enable the second primary color light to transmit and the third primary color light to reflect;
the third color filter prism is arranged at one end of the first color filter prism, from which the first primary color light exits;
a green liquid crystal display panel arranged at one end of the third color filter prism, from which the first primary color light exits;
a blue liquid crystal display panel arranged at one end of the second primary color light transmitted in the second color filter prism; and
and the red liquid crystal display panel is arranged at one end of the second color filter prism, which reflects the third primary color light and emits the third primary color light.
6. The reflection type liquid crystal projector according to claim 5, wherein the third color filter prism has a third color filter prism for transmitting the first primary color light to the first primary color liquid crystal display panel.
7. The reflection type liquid crystal projector according to claim 5, wherein the third color filter prism has a third color filter prism for reflecting the first primary color light to the first primary color liquid crystal display panel.
8. The reflective liquid crystal projector of claim 5 wherein the first, second and third color filter prisms are in a cubic configuration.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 00137419 CN1105458C (en) | 2000-12-27 | 2000-12-27 | Reflecting liquid crystal projector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 00137419 CN1105458C (en) | 2000-12-27 | 2000-12-27 | Reflecting liquid crystal projector |
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| Publication Number | Publication Date |
|---|---|
| CN1361442A CN1361442A (en) | 2002-07-31 |
| CN1105458C true CN1105458C (en) | 2003-04-09 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 00137419 Expired - Fee Related CN1105458C (en) | 2000-12-27 | 2000-12-27 | Reflecting liquid crystal projector |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100438095C (en) * | 2005-01-14 | 2008-11-26 | 财团法人工业技术研究院 | Light emitting diode with quasi-omnibearing reflector |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101109584B1 (en) * | 2004-11-27 | 2012-01-31 | 삼성전자주식회사 | Illuminating unit and projection type image display apparatus employing the same |
| JP2012108458A (en) * | 2010-10-26 | 2012-06-07 | Seiko Epson Corp | Projection type display device and optical unit |
| CN104678691A (en) * | 2013-11-28 | 2015-06-03 | 台达电子工业股份有限公司 | Light source system and display device |
| CN109620106B (en) * | 2019-01-25 | 2022-06-10 | 上海澳华内镜股份有限公司 | Endoscope light source subassembly and endoscope |
-
2000
- 2000-12-27 CN CN 00137419 patent/CN1105458C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100438095C (en) * | 2005-01-14 | 2008-11-26 | 财团法人工业技术研究院 | Light emitting diode with quasi-omnibearing reflector |
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| Publication number | Publication date |
|---|---|
| CN1361442A (en) | 2002-07-31 |
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