CN101295123B - Display system based on blazed grating photomodulator - Google Patents

Abstract

The invention discloses a display system based on a blazed grating light modulator, which comprises a light source (10), an illuminating lens device (11) arranged on a path of rays at the light emission port of the light source and used for reshaping light beams and shimming, the blazed grating light modulator (12) arranged on the output path of rays of the illuminating lens device (11) and used for reflecting the light beams and a projection lens device (13) arranged on the reflection path of rays of the blazed grating light modulator (12), and the emergent light of the projection lens device (13) is launched onto a projection screen (14). The display system of the invention has high utilization rate of the light source, higher brightness and higher resolution factor, and the diffraction efficiency of work, namely, the utilization rate of luminous energy can achieve above 90 percent.

Description

A Display System Based on Blazed Grating Light Modulator

technical field

The present invention relates to a display device, in particular to a display system based on a blazed grating light modulator controlled by a Micro-Electrical-Mechanical System (MEMS for short). the

Background technique

Existing display technologies can be divided into two categories: active luminescence and passive luminescence. the

Active luminescent display technologies include cathode ray tube (CRT), plasma panel (PDP), surface conduction emission (SED), carbon nanotube field emission (CNT) and organic electroluminescent diode (OLED), etc.; passive luminescent display technologies include liquid crystal Display (LCD), liquid crystal display on silicon (LCOS), digital micromirror device display (DMD), interferometric adjustment iMoD (Interfer-Omitric-Modulation Device, referred to as iMoD) display and grating light valve (GLV) display, etc. Among them, in the passive light-emitting display technology, LCOS will lose 50% of the energy of the light source by means of the polarization effect of the liquid crystal, the light utilization rate is not high, and the manufacturing process is complicated. iMoD display technology utilizes the principle of interference to produce color, but the brightness and contrast of the screen are far from enough to produce larger projected images. DLP is one of the most successful all-digital display technologies, suitable for theaters and rear-projection TVs, but due to the use of UHP (Ultra High Pressure Mercury Lamp) and xenon lamps as light sources, its light splitting and light combining systems cause a large loss of light energy. The energy utilization rate is only 20% to 30%. GLV is the only successful color display technology based on the principle of diffraction. It has a high light utilization rate and can produce large-screen projection images by using a laser light source. Most of the energy of the diffracted light, therefore, the highest theoretical diffraction efficiency of the GLV that uses the 1st order diffracted light to generate a picture is only 40.5%. the

Therefore, a display system with higher light source utilization rate, higher brightness and higher resolution is required. the

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a display system based on a blazed grating light modulator with higher light source utilization, higher brightness and higher resolution. the

In order to achieve the above object, the present invention adopts the following technical solutions.

A display system based on a blazed grating light modulator, comprising a light source; an illumination lens device (11) arranged on the light path at the light outlet of the light source for beam shaping and shimming, the illumination lens device The blazed grating light modulator (12) that is arranged on the output light path of (11) is used for beam reflection The exit light from the lens arrangement (13) is incident on a projection screen (14). the

In the above technical solution, further, the light source (10) includes three monochromatic light sources, which are red (Red, referred to as R) light source, green (Green, referred to as G) light source and blue (Blue, referred to as B) light source. Light source; described red, green, blue light source forms white light output from described light source through beam combiner; Described beam combiner comprises prism beam combiner and fiber coupling beam combiner; Described blazed grating light modulator ( 12) is an area array blazed grating light modulator, each pixel unit of the blazed grating has three blaze angles respectively corresponding to red, green, and blue light, and the blazed grating light modulator (12) controls each pixel unit time-sharing Changing the blaze angle is used to modulate the display in red, green and blue cycles. the

In the above technical solution, further, the light source (10) includes three monochromatic light sources, namely a red light source, a green light source and a blue light source; the combination of the red, green and blue light sources forms white light through a beam combiner Output from the light source; the beam combining device includes a prism beam combining device and an optical fiber coupling beam combining device; the blazed grating light modulator (12) is an area array blazed grating light modulator; the pixel of each blazed grating The unit is composed of three sub-pixels, and each of the three sub-pixels has a blaze angle corresponding to red, green, and blue light respectively. The blazed grating light modulator (12) controls the three sub-pixels of each pixel unit to change its The blaze angle and the time to maintain the blaze angle are used to output the desired brightness. the

In the above technical solution, further, the light source (10) includes three monochromatic light sources, namely red light source, green light source and blue light source; the blazed grating light modulator (12) includes three independent surface The array blazed grating light modulators are composed of the first, second, and third area blazed grating light modulators; the illumination lens device includes three illumination lens units, which are respectively the first, second, and third illumination lenses unit; the light beams emitted by the red, green, and blue light sources respectively pass through the first, second, and third illumination lens units used for beam shaping and shimming on their respective optical paths, and then enter the first, second, and third illumination lens units respectively. The second and third area array blazed grating light modulators are reflected and then enter a color combining device (30) for synthesizing the three beams of red, green and blue light into one beam. The color combining device is arranged on the projection lens device ( 13) input end part; each pixel of the first area blazed grating light modulator has a blaze angle corresponding to red light, and each pixel of the second area blazed grating light modulator has a value corresponding to green A blaze angle of light, each pixel of the third area blazed grating light modulator has a blaze angle corresponding to blue light.

In the above technical solution, further, the light source (10) includes three monochromatic light sources, which are respectively a red light source, a green light source, and a blue light source; the red, green, and blue light sources form white light from the Output in the light source; the beam combining device includes a prism beam combining device and an optical fiber coupling beam combining device; the blazed grating light modulator (12) is a linear array blazed grating light modulator, and the pixel unit of each blazed grating There are three blaze angles respectively corresponding to red, green, and blue light, and the blazed grating light modulator (12) controls each pixel unit to time-divisionally change the blaze angle for display according to red, green, and blue cyclic modulation; it also includes a A galvanometer (15) positioned between the projection lens device (13) and the projection screen (14) is used to reflect light emitted by the projection lens device (13) onto the projection screen (14); The linear blazed grating light modulator and the galvanometer act in coordination to realize scanning imaging on the projection screen. the

In the above technical solution, further, the light source (10) includes three monochromatic light sources, which are respectively a red light source, a green light source, and a blue light source; the red, green, and blue light sources form white light from the Output in the light source; the beam combining device includes a prism beam combining device and an optical fiber coupling beam combining device; the blazed grating light modulator (12) is a linear array blazed grating light modulator; the pixel unit of each blazed grating Consists of three sub-pixels, the three sub-pixels respectively have a blaze angle corresponding to red, green, and blue light, and the blazed grating light modulator (12) controls the three sub-pixels of each pixel unit to change its blaze angle and maintain the blaze angle The time is used to output the required brightness; also includes a rotatable galvanometer (15) between the projection lens device (13) and the projection screen (14), used for the projection lens device (13 ) is reflected onto the projection screen (14); the linear blazed grating light modulator and the galvanometer act in coordination to realize scanning imaging on the projection screen (14). the

In the above technical solution, further, the light source (10) includes three monochromatic light sources, namely red light source, green light source and blue light source; the blazed grating light modulator (12) includes three linear array blazed The grating light modulators are the first, second, and third linear blazed grating light modulators; the illumination lens device includes three illumination lens units, which are respectively the first, second, and third illumination lens units; the The light beams emitted by the red, green, and blue light sources respectively pass through the first, second, and third illumination lens units used for shaping and shimming the light beams on their respective optical paths, and then enter the first, second, and third illumination lens units respectively. After being reflected on the three-line array blazed grating light modulator, it enters a color combining device (30) for combining three beams of red, green and blue lights into one beam, and the color combining device is arranged at the input end of the projection lens device (13) part; each pixel of the first linear blazed grating light modulator has a blaze angle corresponding to red light, and each pixel of the second linear blazed grating light modulator has a blaze angle corresponding to green light, Each pixel of the third linear blazed grating light modulator has a blaze angle corresponding to blue light; it also includes a rotatable vibrating mirror located between the projection lens device (13) and the projection screen (14) (15), used to reflect the light emitted by the projection lens device (13) onto the projection screen (14); the first, second, and third linear array blazed grating light modulators and the vibrating mirror act in coordination to realize scanning imaging on the projection screen. the

In the above technical solution, further, the blazed grating light modulator has a micro-electromechanical system for controlling the blaze angle. the

In the above technical solution, further, the light source includes a red, green or blue monochromatic laser, and a red, green or blue monochromatic LED (light emitting diode) device. the

Compared with prior art, the advantage of the present invention is:

Due to the great overlap between the diffraction factor of the unit and the interference factor between the units of the traditional grating, the light energy is scattered in all levels of the spectrum, and the diffraction principle of the blazed grating is used to concentrate the light energy to a certain level of spectrum required, thereby improving the intensity of light energy. collection efficiency. The size of the blaze angle θ of the blazed grating based on micro-electromechanical systems (MEMS) of the present invention can be controlled by MEMS, and the blaze angle θ of the grating can be changed to separate the 0th order of diffraction and the 0th order of interference of the grating, so that light energy can be transferred and concentrated separately To the required spectral order, the light source utilization rate of the display system is high, the brightness is higher and the resolution is higher. The diffraction efficiency of the work, that is, the light energy utilization rate can reach more than 90%. It works in digital line scanning and surface imaging. way, suitable for monochromatic laser or monochromatic LED (Light Emitting Diode) as light source. the

Description of drawings

Figure 1 is a schematic diagram of a display system based on a linear array MEMS blazed grating;

Figure 2 is a schematic diagram of a display system based on an area array MEMS blazed grating;

Fig. 3 is a schematic diagram of a display system based on an area array MEMS blazed grating with a blaze angle;

Fig. 4 is a line array blazed grating pixel arrangement diagram with three sub-pixels per pixel;

Fig. 5 is a schematic cross-sectional view of a pixel of a linear array blazed grating with three blaze angles per pixel;

Fig. 6 is the working light path diagram of the linear array blazed grating pixel with three blaze angles for each pixel;

Fig. 7 is the pixel sectional schematic diagram of the area array blazed grating that each pixel has a blaze angle;

Fig. 8 is a working light path diagram of an area (or line array) blazed grating pixel with each pixel having a blaze angle. the

Graphic description:

10—light source; 11—lighting lens device;

12---blazed grating light modulator; 13---projection lens device;

14---projection screen; 15---galvanometer;

30----light combining device. the

101---red light source; 102---green light source; 103---blue light source;

111—the first lighting lens unit; 112—the second lighting lens unit; 113—the third lighting lens unit;

121—the first area blazed grating light modulator; 122—the second area blazed grating light modulator; 123—the third area blazed grating light modulator;

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

The blazed grating in the present invention mainly takes the planar reflective grating as an example, the angle θ between the groove surface and the grating surface is called the blaze angle, and the size of the blaze angle θ of the blazed grating based on microelectromechanical system (MEMS) is controlled by MEMS , change the blaze angle θ of the grating, so that the 0th order of diffraction and the 0th order of interference of the grating are separated, so that the light energy can be transferred and concentrated to the required spectral order respectively. When the rotatable blazed grating is irradiated with a monochromatic light source, changing the blaze angle θ of the grating can make the beam shine in a specific direction, and the pulse width modulation is used to control the rotation of the pixels of the blazed grating light modulator to produce RGB three primary colors and dark The dwell time on the state position can make the three colors corresponding to each pixel have different brightness. Using the persistence of vision of the human eye, through the combination of pixels with different brightness and different primary colors, various colors required by a pixel can be produced. Multiple pixels form an array, such as forming an area array, to form a display screen. Or form a line array, and the display screen can be formed by projection scanning. the

Example 1

As shown in Fig. 1, realize the display system based on the linear array MEMS blazed grating light modulator of the present invention, specifically include: a light source 10; Field illumination lens 11, a blazed grating light modulator 12 for reflecting light beams is arranged on the output optical path of the illumination lens group 11, and a projection lens device 13 is arranged on the reflected light path of the blazed grating light modulator 12 A projection screen 14 is arranged in front of the output end of the projection lens device 13 . The blazed grating light modulator 12 is a linear array blazed grating light modulator, and the system also includes a rapidly rotating array mirror 15 located between the projection lens device 13 and the projection screen 14, and the array mirror 15 transmits the light emitted by the projection lens device 13 reflected onto the projection screen 14. the

Light source 10 is made up of three kinds of monochromatic light sources, is respectively red light source, green light source and blue light source; Said red, green, blue light source forms white light from described light source 10 through beam combiner (not shown in the figure). Output; the beam combining device adopts such as a prism beam combining device or an optical fiber coupling beam combining device, etc.; the illumination lens device 11 adopts an aspheric lens combination and shimming through a light bar; the blazed grating light modulator 12 is a linear array blazed grating light modulator , each pixel unit of the blazed grating has three blaze angles respectively corresponding to red, green, and blue light, and the blazed grating light modulator 12 controls each pixel unit to time-divisionally change the blaze angle for cycling according to red, green, and blue Modulation display. The projection lens device 13 adopts a commercially available projection lens according to the distance and size of the projection screen 14 , and the vibrating mirror 15 adopts a commercially available vibrating mirror with a working frequency greater than 2KHz. the

The working mode of each pixel unit is shown in Figure 6. The direction 8 is the projection direction (ie, the direction of light emission), and the white light 6 (ie, the direction of light incidence) is incident perpendicular to the grating surface 5. When the blazed grating is at position 4, The light returns along the original path. At this time, the projection direction 8 corresponds to the dark field. According to the wavelengths of the three primary colors, the blaze angle of the grating is designed so that when the grating micromirror turns to positions 1, 2, and 3 under the control of MEMS, the direction The 8 locations correspond to the bright fields produced by the blazing angles of the red, green, and blue colors respectively. Each pixel unit is composed of a single grating as shown in Figure 6. The pulse width modulation is used to control the dwell time of the blazed grating unit to rotate to produce four fixed positions of red, green, blue and dark state, so that a single pixel Available in different colors and brightness. A plurality of pixels form an array, as shown in Figure 5, which is a cross-sectional view of a line array blazed grating pixel. the

The linear blazed grating light modulator 12 and the vibrating mirror 15 cooperate to realize scanning imaging on the projection screen. Each blazed grating pixel unit changes the blaze angle in time-sharing, and cyclically modulates the display according to the display time ratio of red, green, and blue colors, and the time ratio is determined by the color temperature of the white light matched with the light source during display. MEMS controls the blaze angle of the area blazed grating pixels to rotate to the dwell time of the red, green, blue field and dark state positions through PWM (Pulse Width Modulation), so that the three colors corresponding to each pixel have different brightness. When the system is working, the linear array light modulator corresponds to a column of displayed images. When a column is displayed, the galvanometer controls the light beam to reach the position of the next column of images, and so on until a monochromatic image (such as a red image) is scanned and displayed. Then the blue image and the green image are displayed in sequence, and the observer will see an image with complete color due to the persistence of vision of the human eye. the

Example 2

On the basis of embodiment 1, different from embodiment 1 is:

The blazed grating light modulator 12 is a linear array blazed grating light modulator; the pixel unit of each blazed grating is composed of three sub-pixels, and the three sub-pixels respectively have a blaze angle corresponding to red, green and blue light, and the blazed grating light The modulator 12 controls the three sub-pixels of each pixel unit to change its blaze angle and maintain the blaze angle for outputting the required brightness; the linear array blazed grating light modulator and the vibrating mirror act in coordination to create a blaze angle on the projection screen. Realize scanning imaging.

As shown in Figure 8, each sub-pixel has only one blaze angle, the direction 8 is the projection direction, that is, the light emission direction of the blazed grating, and the monochromatic light 6 is incident perpendicular to the grating surface 5. Going back the same way, the projection direction 8 is in the dark field at this time; when the blazed grating pixel unit is at position 1, the projection direction 8 is in the bright field, and each sub-pixel of the linear blazed grating is controlled by PWM (pulse width modulation). The stay time of bright field and dark field makes the three colors corresponding to each sub-pixel have different brightness, thus forming different colors; the angle between position 1 and position 2 is the blaze angle corresponding to monochromatic light, and the three colors Each of the sub-pixels corresponds to the blaze angle required for red, green, and blue light work. Figure 4 is a pixel arrangement diagram based on a linear array blazed grating micromirror. Multiple pixels are arranged in a linear array, and each pixel 1, 2, 3... is composed of three adjacent sub-pixels. For example, pixel 1 is composed of sub-pixels. Pixels 1-1, 1-2 and 1-3 are composed. the

Other technical features are the same as in Embodiment 1. the

Example 3

As shown in Figure 2, the display system based on the MEMS area blazed grating light modulator is realized, which specifically includes: a light source 10; on the optical path at the light outlet of the light source 10, a lens for beam shaping and shim lighting is set 11. A blazed grating light modulator 12 for reflecting light beams is set on the output light path of the illumination lens group 11, and a projection lens device 13 is set on the reflection light path of the blazed grating light modulator 12. The projection lens A projection screen 14 is arranged in front of the output end of the device 13; the blazed grating light modulator 12 is an area array blazed grating light modulator, and each pixel unit of the blazed grating has three blaze angles respectively corresponding to red, green, and blue light. The light modulator 12 controls each pixel unit to time-divisionally change the blaze angle for red, green and blue cyclic modulation display. The light source 10 includes three kinds of monochromatic light sources, which are red light source, green light source and blue light source respectively; the red, green and blue light sources cooperate to form white light output from the light source 10; the illuminating lens device 11 adopts an aspheric lens combination and passes Light rod shimming; the light beam emitted by the light source 10 passes through the illumination lens devices 11 used for beam shaping and shimming, and then is reflected by the area array blazed grating light modulator 12 in time-sharing, and then projected on the display screen 14 through the projection lens device 13 Three superimposed red, green and blue images are formed on the top; the time-sharing switch works according to the time sequence of the blazed grating light modulator 12, and the time-sharing is sequentially modulated and displayed according to the display time ratio of the three color lights of red, green and blue. The time ratio is determined by the color temperature of the white light used for display. By means of PWM (Pulse Width Modulation) to control the residence time of the area blazed grating pixels to rotate to the positions where red, green, blue fields and dark states are generated respectively, so that the three colors corresponding to each pixel have different brightness . The projection lens device 13 adopts a commercially available projection lens according to the distance and size of the projection screen 14 . the

Example 4

On the basis of embodiment 3, different from embodiment 3 is:

The blazed grating light modulator 12 is an area array blazed grating light modulator; the pixel unit of each blazed grating is composed of three sub-pixels, and the three sub-pixels respectively have a blaze angle corresponding to red, green and blue light, and the blazed grating light The modulator 12 controls the time for the three sub-pixels of each pixel unit to change its blaze angle and maintain the blaze angle to output the required brightness. The structure and working mode of each sub-pixel are the same as those in Embodiment 2. the

Other technical characteristics are the same as embodiment 3. the

Example 5

As shown in Figure 3, a display system based on a MEMS area blazed grating light modulator is realized, wherein the light source 10 includes three monochromatic light sources, which are respectively a red light source 101, a green light source 102, and a blue light source 103; The device 12 includes three independent area array blazed grating light modulators, which are respectively the first, second and third area array blazed grating light modulators 121, 122, 123, and each blazed grating light modulator has one for A micro-electro-mechanical system for controlling the blaze angle; the lighting lens device 11 includes three lighting lens units, which are respectively first, second and third lighting lens units 111, 112, 113; red, green, and blue light sources 101, 102, 103 The emitted light beams respectively pass through the first, second, and third illumination lens units 111, 112, and 113 on their respective optical paths for shaping and shimming the light beams, and then enter the first, second, and third surfaces respectively. After being reflected by the blazed grating light modulators 121, 122, 123, it enters a color combining device 30 for combining the three beams of red, green and blue lights into one beam. The color combining device 30 is arranged at the input end part of the projection lens device 13 ; Each pixel of the first area blazed grating light modulator 121 has a blaze angle corresponding to red light, and each pixel of the second area blazed grating light modulator 122 has a blaze angle corresponding to green light Blaze angle, each pixel of the third area blazed grating light modulator 123 has a blaze angle corresponding to blue light; the projection objective device 13 is projected on the display screen 14 to form three superimposed red, green, and blue images; Each color light is incident from the same angle and works at the same time according to the timing of the blazed grating light modulator. The first, second, and third area blazed grating pixels are controlled to rotate to generate red and green respectively by means of PWM (pulse width modulation). , the blue field and the dwell time on the dark state position, so that the three colors corresponding to each pixel have different brightness. the

The blaze angle and working method of each pixel are shown in Figure 8. Each pixel has only one blaze angle. When the pixel unit is at position 2, the light returns along the original path, and at this time the projection direction 8 is in the dark field; when the blazed grating pixel unit is at position 1, the projection direction 8 is in the bright field. Fig. 7 is a cross-sectional view of a pixel based on an area blazed grating. the

In this embodiment, the red light source 101, the green light source 102 and the blue light source 103 of the light source 10 respectively adopt red, green and blue monochromatic LED light sources, and the first, second and third lighting lens units 111, 111, and 11 of the lighting lens device 11 112 and 113 are combined by aspherical lenses and shimmed by light rods. The projection lens device 13 is a commercially available projection lens according to the distance and size of the projection screen 14. The color combination device 30 is an X-CUBE color combination prism. the

Example 6

On the basis of embodiment 5, different from embodiment 5 is:

The blazed grating light modulator 12 includes three independent linear array blazed grating light modulators, which are respectively the first, second and third linear array blazed grating light modulators; each pixel of the first linear array blazed grating light modulator There is a blaze angle corresponding to red light, each pixel of the second linear blazed grating light modulator has a blaze angle corresponding to green light, and each pixel of the third linear blazed grating light modulator has a blaze angle corresponding to blue light. Blaze angle; an array mirror that can rotate quickly is also added between the projection lens device 13 and the projection screen 14, and the array mirror reflects the light emitted by the projection lens device 13 onto the projection screen 14; the linear array blazed grating light modulator Coordinated with the vibrating mirror to realize scanning imaging on the projection screen. The array mirror adopts a vibrating mirror sold in the market with a working frequency greater than 2KHz. the

Others are the same as embodiment 5. the

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit them. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent replacements to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all of them should be included in the scope of the present invention. within the scope of the claims.

Claims (6)

1. the display system based on blazed grating photomodulator comprises light source (10), and said light source (10) is made up of redness, green and blue-light source, and said redness, green and blue-light source form white light output through beam merging apparatus; What on the light path at the light-emitting window place of said light source, be provided with is used for the illuminating lens device (11) to beam shaping, shimming; What on the output light path of said illuminating lens device (11), be provided with is used for the blazed grating photomodulator (12) with beam reflection, and said blazed grating photomodulator (12) shifts luminous energy respectively and focuses on the required spectral order time through the blazing angle that changes blazed grating; Each pixel cell of blazed grating has three blazing angles that correspond respectively to red, green, blue, and said blazed grating photomodulator (12) is controlled each pixel cell timesharing change blazing angle and is used for showing according to red, green, blue look circulation modulation; A projecting lens apparatus (13) that on the reflected light path of said blazed grating photomodulator (12), is provided with, the emergent light of projecting lens apparatus (13) incides on the projection screen (14).

2. according to the said display system based on blazed grating photomodulator of claim 1, wherein, said light source (10) comprises three monochromatic sources, is respectively red light source, green light source and blue-light source; Said redness, green, blue-light source form white light through beam merging apparatus and from said light source, export; Said beam merging apparatus comprises prism beam merging apparatus or optical fiber coupling bundle beam merging apparatus.

3. according to the said display system based on blazed grating photomodulator of claim 2, wherein, said blazed grating photomodulator (12) is a face battle array blazed grating photomodulator.

4. according to the said display system based on blazed grating photomodulator of claim 2, wherein, said blazed grating photomodulator (12) is the linear array blazed grating photomodulator; Also comprise a galvanometer (15) that is positioned between said projecting lens apparatus (13) and the said projection screen (14), be used for the light that projecting lens apparatus (13) sends is reflexed to said projection screen (14); Said linear array blazed grating photomodulator and said galvanometer coordination realize scanning imagery to go up at said projection screen (14).

5. according to each said display system based on blazed grating photomodulator of claim 1-4, wherein, said blazed grating photomodulator has a MEMS that is used to control blazing angle.

6. according to the said display system based on blazed grating photomodulator of claim 5, wherein, said light source comprises red, green and blue mono-colour laser, and perhaps said light source comprises red, green and blue single color LED device.

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