CN110764356A - DLP projection system and method for enhancing dynamic contrast - Google Patents
DLP projection system and method for enhancing dynamic contrast Download PDFInfo
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- CN110764356A CN110764356A CN201911085331.9A CN201911085331A CN110764356A CN 110764356 A CN110764356 A CN 110764356A CN 201911085331 A CN201911085331 A CN 201911085331A CN 110764356 A CN110764356 A CN 110764356A
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- 238000000034 method Methods 0.000 title claims abstract description 15
- 230000002708 enhancing effect Effects 0.000 title claims abstract description 9
- 230000005540 biological transmission Effects 0.000 claims abstract description 4
- 230000004907 flux Effects 0.000 claims description 2
- 230000003014 reinforcing effect Effects 0.000 claims 1
- 239000004973 liquid crystal related substance Substances 0.000 description 4
- 239000011521 glass Substances 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 239000010409 thin film Substances 0.000 description 2
- 241001270131 Agaricus moelleri Species 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/20—Lamp housings
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/005—Projectors using an electronic spatial light modulator but not peculiar thereto
- G03B21/008—Projectors using an electronic spatial light modulator but not peculiar thereto using micromirror devices
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/142—Adjusting of projection optics
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/20—Lamp housings
- G03B21/2066—Reflectors in illumination beam
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/001—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background
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- Engineering & Computer Science (AREA)
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Abstract
The invention provides a DLP projection system and a method for enhancing dynamic contrast, wherein the system comprises a light source, a light path lens, a TIR prism, a DMD chip, a lens and a control unit, wherein an LCD contrast unit is arranged between the TIR prism and the lens, and a corresponding area on the LCD contrast unit corresponds to a corresponding micromirror unit on the DMD chip; the light emitted by the light source is transmitted through the light path lens and then projected to the TIR prism, total reflection is carried out at the bonding surface of the TIR prism, the total reflected light irradiates on the micro mirror of the DMD chip, the light enters the TIR prism again after being reflected by the micro mirror, the transmission path of the light in the TIR prism is not changed, the emitted light is projected to the LCD contrast unit, the control unit analyzes and calculates the color and the gray scale of each pixel point on an ideal projection picture, the voltage size of a corresponding area on the LCD contrast unit is adjusted, and the emission degree of the corresponding tricolor light is controlled. Compared with the prior art, the system and the method greatly improve the overall contrast of the projection picture of the projection system.
Description
Technical Field
The invention mainly relates to the technical field of projection, in particular to a DLP projection system and method for enhancing dynamic contrast.
Background
DLP (digital light processing) projection systems use a DMD (digital micro reflector) as the light valve imaging device, and other components include a light source, a light path mirror, a TIR prism, a mirror, and the like. The working principle is as follows: light emitted by the light source is decomposed into RGB tricolor light through the light path lens, the RGB tricolor light is projected onto the DMD chip after being totally reflected by the TIR prism, the DMD chip reflects the light into the lens, and finally the light is projected onto the screen from the lens. The DMD chip is composed of millions of small lenses, each lens can deflect independently at a certain angle to present an 'on' or 'off' state, the switching rate of the micro-mirror can reach thousands of times per second, and clear, bright and vivid-color pictures can be presented on a projection screen by controlling the deflection frequency of the micro-mirror to different primary color light in unit time and utilizing the visual delay of human eyes. The actual absence of black in a DLP projection system is considered to be black in a DLP projection system when the DMD micromirrors remain "off" and light is incident on the gaps between the DMD micromirrors and most of the light is absorbed. In fact, a small amount of light rays strike the DMD micromirror and enter the lens after being reflected, which causes the brightness of a dark image of the image projected by the DLP projection system to be still high, thereby affecting the contrast of the DLP system.
The principle of LCD (liquid crystal display) is that a liquid crystal box is arranged between two parallel glass substrates, a thin film transistor is arranged on a lower glass substrate, a color filter is arranged on an upper glass substrate, and the rotation direction of liquid crystal molecules is controlled by adjusting the voltage on the thin film transistor, so that the emergent degree of polarized light of each pixel point is controlled, and the purpose of displaying different gray scales is achieved. The liquid crystal itself cannot emit light and it is only used to block or allow light to pass through.
In view of the limitation of DLP projection systems in terms of contrast performance, there is a need to provide an improved method for improving the contrast of DLP projection systems without affecting the performance indicators such as brightness and color performance of DLP projection systems.
Disclosure of Invention
In order to solve the defects of the prior art, the invention provides a DLP projection system and a DLP projection method for enhancing dynamic contrast ratio by combining the prior art and starting from practical application, so that the overall contrast ratio of the picture of the projection system is greatly improved compared with the prior art.
The technical scheme of the invention is as follows:
according to one aspect of the invention, a DLP projection system for enhancing dynamic contrast is provided, which comprises a light source, a light path lens, a TIR prism, a DMD chip, a lens and a control unit, wherein an LCD contrast unit is arranged between the TIR prism and the lens, and a corresponding area on the LCD contrast unit corresponds to a corresponding micro mirror unit on the DMD chip;
the light emitted by the light source is transmitted through the light path lens and then projected to the TIR prism, the light is totally reflected at the bonding surface of the TIR prism, the totally reflected light irradiates the micromirror of the DMD chip, the light reflected by the micromirror enters the TIR prism again, the light does not change the transmission path in the TIR prism, the emitted light is projected to the LCD contrast unit, the control unit analyzes and calculates the color and the gray scale of each pixel point on an ideal projection picture, adjusts the voltage size of a corresponding area on the LCD contrast unit, controls the emission degree of the corresponding tricolor light, the emitted tricolor light enters the lens, and the emitted tricolor light is projected on a screen to form a picture after being emitted from the lens.
According to another aspect of the present invention, there is provided a DLP projection method for enhancing dynamic contrast, the method being used in the above-mentioned projection system, wherein the respective areas CXX on the LCD contrast unit correspond to the respective micromirror units AXX on the DMD chip, the method comprising:
setting a gray scale threshold value delta;
when analyzing the pixel point BXX corresponding to the micromirror unit AXX, the control unit compares the ideal gray value HXX of the pixel point BXX with the gray level threshold delta,
when HXX is larger than delta, the control unit sends a signal to the LCD contrast unit to control the voltage value VXX of the area CXX of the LCD contrast unit so that the area does not shield light,
when HXX is more than or equal to 0 and less than or equal to delta, the control unit sends a signal to the LCD contrast unit to control the voltage value VXX of the CXX area of the LCD contrast unit, so that the luminous flux of the area is reduced;
when HXX is equal to 0, the control unit sends a signal to the LCD contrast unit to control the voltage value VXX of the area of the LCD contrast unit CXX, so that the area does not allow light to pass through.
The invention has the beneficial effects that:
the invention improves the dynamic contrast of the DLP projection system by combining the LCD technology, so that the brightness of a high-brightness pixel area on a projection picture is not influenced and the high-brightness state of the original DLP system is still maintained; in the low-brightness pixel area on the projection picture, the brightness of the original light is further reduced after passing through the LCD contrast unit, so that the overall contrast of the picture is greatly improved compared with the prior art.
Drawings
FIG. 1 is a schematic diagram of the structure of the present invention;
FIG. 2 is a flow chart of the method for improving contrast ratio of DLP projection system according to the present invention.
Reference numerals shown in the drawings:
1. a lens; 2. a control unit; 3. an LCD contrast unit; 4. a TIR prism; 5. a DMD chip; 6. an optical path lens; 7. a light source.
Detailed Description
The invention is further described with reference to the accompanying drawings and specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and these equivalents also fall within the scope of the present application.
As shown in fig. 1, the DLP projection system for enhancing dynamic contrast provided by the present invention includes a light source 7, a light path lens 6, a TIR prism 4, a DMD chip 5, a lens 1, a control unit 2, and an LCD contrast unit 3. The light source 7 can emit white light, yellow light, blue light and other primary color lights, and the light path lens 6 comprises some light splitting, filtering and exciting units. The primary color light emitted by the light source 7 is split into red, green and blue three primary color light after passing through a series of light path lenses 6, the three primary color light enters the TIR prism 4 at a fixed switching frequency and then is totally reflected by the TIR prism 4 to be emitted to the DMD chip 5, a micromirror on/off state of the DMD chip 5 is switched according to a deflection instruction sent by the control unit 2, the three primary color light is reflected or absorbed at a certain frequency, the three primary color light reflected by the micromirror passes through the TIR prism 4 again and then is transmitted out, the projected three primary color light passes through the LCD contrast unit 3 to enter the lens 1, and finally, the light is emitted from the lens 1 and projected on a screen to form a picture.
The contrast of a projection system refers to the ratio of the brightness when a full white picture is projected to the brightness when a full black picture is projected. In a traditional DLP system, each micromirror AXX on the DMD chip 5 corresponds to a pixel BXX of a final projection picture, the total number of times of turning each DMD micromirror in red, blue and green light segments determines the color and gray level of a pixel point corresponding to each DMD micromirror, the control unit 2 analyzes the color and gray level characteristics of each pixel point, calculates the number of times that each DMD micromirror should be turned in red, blue and green light segments respectively, and sends a signal to the DMD chip 5, and the DMD chip 5 controls each micromirror to turn in the corresponding light segment according to the signal sent from the control unit 2.
The present invention introduces an LCD contrast unit 3 between the TIR prism 4 and the lens 1 in a conventional DLP projection system. The emergent light of the light source is transmitted by the light path lens 6 and then projected onto the TIR prism 4, the total reflection is carried out at the bonding surface of the TIR prism 4, the totally reflected light irradiates the micro mirror of the DMD chip 5, the light reflected by the micro mirror enters the TIR prism 4 again, the transmission path of the light in the TIR prism 4 is not changed, the emergent light is projected onto the LCD contrast unit 3, the control unit 2 analyzes and calculates the color and the gray scale of each pixel point on an ideal projection picture, the voltage of the corresponding area on the LCD contrast unit 3 is adjusted, and the emergent degree of the corresponding three-primary-color light is controlled.
The present invention also provides a projection method for the above projection system, as shown in fig. 2, a corresponding area CXX on the LCD contrast unit 3 corresponds to a corresponding micromirror unit AXX on the DMD chip 5, and the AXX gray scale is MXX. Setting a gray scale threshold value delta, comparing an ideal gray scale value HXX of a pixel point BXX with the gray scale threshold value delta by the control unit 2 when analyzing the color and gray scale characteristics of the pixel point BXX corresponding to the micromirror unit AXX, if HXX is larger than delta, indicating that the pixel point BXX requires higher brightness, sending a signal to the LCD contrast unit 3 by the control unit 2, and controlling a voltage value VXX of a CXX area of the LCD contrast unit 3 to enable the area not to shield light, wherein the light is in a full-pass state, the light hitting the CXX area on the LCD contrast unit 3 is completely transmitted, and an actual gray scale value H' XX of the BXX is HXX; when HXX is greater than or equal to 0 and less than or equal to δ, which indicates that the required brightness of the pixel BXX is low at this time, the control unit 2 sends a signal to the LCD contrast unit 3, and controls the voltage value VXX in the CXX region of the LCD contrast unit 3, so that the light transmittance of the region is reduced, the actual gray value H 'XX of BXX is less than HXX, the HXX value is smaller, the light which is allowed to pass through the LCD contrast unit 3 needs to be controlled less, when HXX is 0, the LCD contrast unit 3CXX region is controlled not to allow light to pass through, and then the actual gray value H' XX of the pixel BXX on the final projection picture is 0.
By the projection system and the method, the brightness of the high-brightness pixel area on the projection picture is not affected, and the high-brightness state of the original DLP system is still maintained; in the low-brightness pixel area on the projection picture, the brightness of the light is further reduced after the original light passes through the LCD contrast unit, so that the overall contrast of the projection picture is greatly improved.
Claims (2)
1. The utility model provides an DLP projection system of reinforcing dynamic contrast, includes light source, light path lens, TIR prism, DMD chip, camera lens, the control unit, its characterized in that: an LCD contrast unit is arranged between the TIR prism and the lens, and the corresponding area on the LCD contrast unit corresponds to the corresponding micro mirror unit on the DMD chip;
the light emitted by the light source is transmitted through the light path lens and then projected to the TIR prism, the light is totally reflected at the bonding surface of the TIR prism, the totally reflected light irradiates the micromirror of the DMD chip, the light reflected by the micromirror enters the TIR prism again, the light does not change the transmission path in the TIR prism, the emitted light is projected to the LCD contrast unit, the control unit analyzes and calculates the color and the gray scale of each pixel point on an ideal projection picture, adjusts the voltage size of a corresponding area on the LCD contrast unit, controls the emission degree of the corresponding tricolor light, the emitted tricolor light enters the lens, and the emitted tricolor light is projected on a screen to form a picture after being emitted from the lens.
2. A DLP projection method for enhancing dynamic contrast for use in the projection system of claim 1, in which a respective area CXX on an LCD contrast unit corresponds to a respective micromirror unit AXX on a DMD chip, the method comprising:
setting a gray scale threshold value delta;
when analyzing the pixel point BXX corresponding to the micromirror unit AXX, the control unit compares the ideal gray value HXX of the pixel point BXX with the gray level threshold delta,
when HXX is larger than delta, the control unit sends a signal to the LCD contrast unit to control the voltage value VXX of the area CXX of the LCD contrast unit so that the area does not shield light,
when HXX is more than or equal to 0 and less than or equal to delta, the control unit sends a signal to the LCD contrast unit to control the voltage value VXX of the CXX area of the LCD contrast unit, so that the luminous flux of the area is reduced;
when HXX is equal to 0, the control unit sends a signal to the LCD contrast unit to control the voltage value VXX of the area of the LCD contrast unit CXX, so that the area does not allow light to pass through.
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN116564245A (en) * | 2023-05-19 | 2023-08-08 | 深圳市龙源智慧显控有限公司 | Multi-partition light source projection device, system and control method based on time domain |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1482487A (en) * | 2002-09-14 | 2004-03-17 | 邱新萍 | Projecting color display |
CN1670791A (en) * | 2004-02-12 | 2005-09-21 | 精工爱普生株式会社 | Light modulation device and optical display device, and light modulation method and image display method |
CN101604116A (en) * | 2008-06-13 | 2009-12-16 | 索尼株式会社 | Image display device and control method thereof |
CN102621698A (en) * | 2012-03-31 | 2012-08-01 | 福建网讯科技有限公司 | Optical projection system for improving stray light near projection picture |
CN106842790A (en) * | 2012-09-28 | 2017-06-13 | 深圳市绎立锐光科技开发有限公司 | Light-source system and relevant projecting system |
CN108227356A (en) * | 2016-12-21 | 2018-06-29 | 深圳市光峰光电技术有限公司 | A kind of projection display system |
CN108663886A (en) * | 2018-04-24 | 2018-10-16 | 深圳摩方新材科技有限公司 | A kind of optical system of multi-project mode splicing |
CN109976076A (en) * | 2017-12-28 | 2019-07-05 | 深圳光峰科技股份有限公司 | Wavelength converter, light supply apparatus and projection device |
CN210465982U (en) * | 2019-11-08 | 2020-05-05 | 珠海市大晟云视传媒科技有限公司 | DLP projection system for enhancing dynamic contrast |
-
2019
- 2019-11-08 CN CN201911085331.9A patent/CN110764356A/en active Pending
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1482487A (en) * | 2002-09-14 | 2004-03-17 | 邱新萍 | Projecting color display |
CN1670791A (en) * | 2004-02-12 | 2005-09-21 | 精工爱普生株式会社 | Light modulation device and optical display device, and light modulation method and image display method |
CN101604116A (en) * | 2008-06-13 | 2009-12-16 | 索尼株式会社 | Image display device and control method thereof |
CN102621698A (en) * | 2012-03-31 | 2012-08-01 | 福建网讯科技有限公司 | Optical projection system for improving stray light near projection picture |
CN106842790A (en) * | 2012-09-28 | 2017-06-13 | 深圳市绎立锐光科技开发有限公司 | Light-source system and relevant projecting system |
CN108227356A (en) * | 2016-12-21 | 2018-06-29 | 深圳市光峰光电技术有限公司 | A kind of projection display system |
CN109976076A (en) * | 2017-12-28 | 2019-07-05 | 深圳光峰科技股份有限公司 | Wavelength converter, light supply apparatus and projection device |
CN108663886A (en) * | 2018-04-24 | 2018-10-16 | 深圳摩方新材科技有限公司 | A kind of optical system of multi-project mode splicing |
CN210465982U (en) * | 2019-11-08 | 2020-05-05 | 珠海市大晟云视传媒科技有限公司 | DLP projection system for enhancing dynamic contrast |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN116564245A (en) * | 2023-05-19 | 2023-08-08 | 深圳市龙源智慧显控有限公司 | Multi-partition light source projection device, system and control method based on time domain |
CN116564245B (en) * | 2023-05-19 | 2024-04-26 | 深圳市龙源智慧显控有限公司 | Multi-partition light source projection device, system and control method based on time domain |
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