WO2004063789A1

WO2004063789A1 - A partitioned multi-line scanning laser projector

Info

Publication number: WO2004063789A1
Application number: PCT/CN2004/000027
Authority: WO
Inventors: Qing Shan Wang
Original assignee: Qing Shan Wang
Priority date: 2003-01-08
Filing date: 2004-01-08
Publication date: 2004-07-29
Also published as: CN1438510A

Abstract

The invention relates to A partitioned multi-line scanning laser projector. In prior scheme there are some disadvantages of low scanning efficiency and degraded quality of scanning lines or the like due to the restriction of the line scanning speed, without satisfying the demand for implement. This invention, according to the deviation of geometry sizes of facets, assigns signals to plural laser display units by using digital techniques. Plural laser display units form a series of light beam by directly arranging or passing through a light beam former, and images were partitioned multi-line scanned by a partitioning line deflecting polygonal drum, which has symmetrical facets setting or conjugated combination setting for facets. Light beams, which had been deflected, joint in the junction planes of the series of light beam. The system employs a light beam series lens group, which includes a quasi telescopic system for outputting parallel beams, focuses the light beam series, and uses projection lenses to project the beams onto the junction planes between light beam series, thus miniaturizing and being practicable.

Description

Division multi-line scanning laser projector

Technical field

The invention belongs to the technical field of laser projection display.

Background technique

Shortly after the advent of laser technology, electromechanical scanning laser projectors with flying dot scanners as their cores appeared. However, due to the high line deflection and the high drum rotation speed (more than 1,000 revolutions per second), noise became a major problem. Later, with the development of technology, air bearings were used, but the main problem of its further development was not fundamentally solved: the increase in the number of image scanning lines must depend on the increase in the number of mirrors of the line deflection polygon mirror drum and the increase in rotation speed. The resulting short pixel display time, poor scan line quality, shadows behind the pixels, and difficult field-to-line synchronization have all become difficult problems to solve. With the development of display technology, electron beam tube C RT projectors, liquid crystal light valve projectors, DMD reflective projectors, etc. have entered the market with their respective advantages, and laser projectors with flying spot scanners as the core are based on technology and cost. For a variety of reasons, there was no sound.

Summary of the Invention

The technical problem to be solved by the present invention is as follows: realize the multi-line partition scanning of the image, so as to improve the image scanning quality of the flying spot scanner.

The technical solution adopted by the present invention is: using a partitioned line deflection polygon mirror drum with a partitioned line scanning function, performing a partitioned multi-line scan on an image of a beam array formed by a plurality of laser display units driven by digital technology, and using a beam The column lens group and projection lens make the system practical.

The invention discloses a partitioned multi-line scanning laser projector. Pack

Confirm this Including signal distribution drive system, laser display unit, beam column former, beam column lens group, partitioned row deflection polygon mirror drum, fiber optic plate (not necessary for correcting the image) or translucent screen (used for rear projection), projection lens, diffuser Reflective screen. It is characterized by: (1) using digital technology to partition the picture transmission by rows, drive by columns, and cyclically allocate signals to the addresses of n display units. (2) There are beam columns for simultaneous scanning in multiple rows in the system. The arrangement direction is perpendicular to the scanning direction. The modulating laser array, the light valve array, or the output port of the beam column former inputting the light source of each display unit are arranged in order. (3) In the system, there is the same included angle or angle between each mirror surface and the end surface (Figure 2-4) (Figure 2-Z a). According to the rule of partition scanning, it is arranged by a combination of multiple mirror surfaces at a certain angle. The partitioned line deflects the mirror drum. (4) There is a beam array combining surface formed during the beam array partition scanning in the system. (5) The incident surface of the optical fiber board or transparent screen and the reflective surface of the diffuse reflection screen are located at the beam combining surface _ai b ₂ c ₃ (Figure 4) between three points or _ai b ₂ c _{3 are} located at the front focal plane of the projection lens. on.

Beneficial effects: (1) The scanning limit of the existing scheme is exceeded, and the scanning efficiency is doubled. (2) Line and field scanning are performed simultaneously on a partitioned line deflection polygon mirror drum, which can realize image scanning at low speed

(3) Use symmetrical arrangement or quasi-balanced combination arrangement to make the drum more stable during scanning. (4) The use of a beam array with the same light output direction can easily realize the superposition of scanning lines. (5) The use of a beam array former solves the arrangement inconvenience caused by the volume problem of the laser. (6) The beam array lens group is used to reduce the beam array and the projection lens is used to project the beam array junction surface to make the system compact and practical. (7) Oblate beam array A stripe scanning light spot is formed by the output port of the former and the cylindrical lens, which can effectively reduce the 'overlapping between two adjacent pixels' caused by signal transformation during scanning. (8) The position of each row and column is stable, and it is easy to realize high-precision projection. (9) Increasing the number of lines participating in one frame scanning and the mirror surface participating in one frame scanning can effectively improve sharpness. (10) Adjusting the signal distribution to the laser display unit according to the deviation of the actual geometric dimensions of the mirror surface can effectively improve the overlap and interval of the scanning lines at the junction of two adjacent areas, and reduces the precision requirements for the mirror drum. (1 1) Adjusting the number of participating scanning lines, the interval between the beams in the beam column, and the angle parameters of the mirrors in the deflection polygon mirror drum, can realize a variety of scanning methods such as frame scanning and partition interlaced scanning. (1 2) 釆 Use multiple parallel row storage units or memories to make the solution support multiple partition input of video signals, which can form extremely high definition and provide higher frame rate. (1 3) Multiple light sources can be used for projection.

BRIEF DESCRIPTION OF THE DRAWINGS

Appendix 1 Working Principles of the Invention

Figure 2 Side view of the output of the beam array former

Figure 3 ^ M-port front view of the beam array former

Figure 4 Stamping diagram of laser display unit

Figure 5 Side view of zoned line deflection polygon mirror drum

Figure 6 Schematic diagram of directly inputting light into the optical channel

Figure 7 Schematic diagram of focusing light into the optical channel

j¾

Figure 8 Front view of a bar-shaped cylindrical surface;

Figure 9 Front view of strip lens group

Figure 10 is a schematic diagram of the bonding surface formed by the beam array during the partition scanning. Figure;

FIG. 11 is a schematic diagram of multi-channel driving signal allocation;

Fig. 12 is a schematic view showing the mirror surface combination arrangement of the partition line deflection polygon mirror drum.

among them:

1. Laser display unit 2. Optical fiber or light channel with light reflection layer 3. Beam column former output port 4. Strip beam column lens group (schematic) 5. Strip cylindrical lens (group) 6. Mirror ( Set for layout) 7. Division line deflection polygon mirror drum 8, fiber optic plate 9 ·, projection lens group 10, diffuse reflection screen 11, arc line 12, oblate output port 13, semiconductor laser display unit 14, end face 15, Input of center line 16, tapered input port 17, optical channel 18, beamformer output port

detailed description

Taking China's standard full TV signal as an example, a frame of image is divided into 12 regions, and the mirror surface participating in one frame scanning is 12 planes, and the number of scanning lines participating in each region is 625 ÷ 12 52 lines. In practical applications, there is a deviation in the geometric dimension formed during the processing of the drum, which can be adjusted by adding a spare scanning line. Therefore, the number of scanning units in the beam column is greater than or equal to 52 lines.

1. Video signal distribution: The R, G, and B signals separated from the video signal are converted into eight-bit binary digital signals by the ADC, and then a mathematical algorithm is used to perform color pre-balance according to the display characteristics of the display unit. The address of (l-52) distributes the signal to a line memory unit composed of multiple shift registers or dynamic memories. Step signal control. Under the control of a line synchronization signal, the line memory stores one line of video signals at a time in parallel. Each signal is stored in synchronization with the ADC sampling clock, and the cyclic allocation method is adopted, that is, the first line memory stores the first line in the first allocation cycle, and the second: ^ allocation cycle stores the 11 + 1 Line (line 53), and store the 2n + l line (that is, line 105) in the third allocation cycle ..., the second line memory is stored in the line according to the allocation cycle

Line 2, line 54 (n + 2), line 1 06 (2n + 2), and so on. The above is the distribution method of the mirror drum in an ideal state. After a full frame is stored, it is controlled by the partition synchronization signal (at this time, the mirror is at the starting position of the scanning of the area) and the signal display clock (250KHZ). The second signal ... is input to a respective eight-bit binary DAC or laser driver or a grayscale modulator that outputs a serial grayscale signal, which becomes an effective current or a grayscale serial code, and simultaneously drives each semiconductor laser display unit to display. While displaying, the line storage unit that stores another frame performs data caching. The system can also use multiple storage units to redistribute signals to the display units. The system uses a two-frame or three-frame storage structure, and uses a dual or triple bus to control the read and write of the storage unit. When a three-frame memory unit is used, one of the frames delays the signal to meet the demand for the signal at different positions of the mirror, so that when the system changes signals (such as changing channels), 'synchronize the mirror drum and the signal Stay faster. At the same time, an infrared laser light source is added to the beam column, and one or more infrared receivers (set according to the number of partitions) are set next to the joint surface of the beam column to determine the mirror position, provide synchronization pulses for read signals and addressing for read addresses. signal. In addition, the system can also be rooted According to the geometrical size deviation of each mirror surface in the mirror, the information provided by the above-mentioned multiple infrared receivers is used to programmatically adjust the start time of the control zone read signal and compensate the displacement of the display unit address to compensate for the band of the mirror drum in processing Coming lack.

2 Beam array former: It consists of 52 optical fibers (or optical channels with a reflective layer inside) and a support. The input end is conical and the output is flat (see Figure 3). The light output direction of each output end is the same and is arranged in a straight line on a certain arc surface (Figure 2) or plane (Figure 6). The arc of the arc is the arc of the focus column and the arc formed by the partial scan after the beam column is focused. (As shown in Fig. 10 alc 3 arc). Will! The modulated laser beams emitted by the 52 semiconductor laser display units are directly input (Figure 6) or focused through lenses to each optical fiber (Figure 2). The RGB binary laser beams are mixed in the fiber and output from the output port to form a beam. Column (can use the self-focusing function of the optical fiber to reduce the divergence angle of the output beam or output a parallel beam).

3 Beam array lens group: A lens group with a quasi-telephoto system that outputs parallel beams as the core is used to reduce the beam array. The focusing lens can be set at the drum m, or it can be set at the back of the drum. When set in front of the drum, a focus column is formed on the partition surface. When setting behind the drum, it can be combined with the projection head. At the same time, in order to make the scanning light spots be slender strips (scanned pixels are square), a cylindrical deformed lens (group) is added to the lens group. Because the focus is only on the beam column, the shape of the lens group is long; space. In addition, a concave lens can be set in front of the lens group to avoid the laser beam from penetrating the air at high power. 4. Partition line deflection polygon drum: Divide the mirror surface of the partition line deflection mirror drum with 24 mirrors into two groups, each group has 12 faces, and the angle between each mirror surface and the end surface (the end surface is perpendicular to the axis of the mirror drum) Set at the ideal angle as follows: A84. 84375 ° Z B85. 78125 ° Z C86. 71875 °

Z D87. 65625 ° E88. 59375 ° Z F89. 53125 °

Z G90.46875 ° Z H9 1.40625 ° Z 192.34375 °

J93. 28125 ⁰ Z K94. 21875 ° Z L95. 15625 °. The 90 ° angle bisects the angle difference between ZF and ZG (when the number of mirrors is odd, the middle side is 90 °). The rest increase or decrease by 0.9375 °. The centerline of each mirror surface (that is, the centerline between the two end surfaces. See Figure 5) is on the side of a regular polygon. The above is the setting of 12 mirrors forming a frame scan, and the remaining 12 mirrors are set in the same requirements and order (for example, the second group and the first group can be scanned at an angle different from each other to form an interlaced scan). A segmented line deflection polygonal drum with a line deflection angle of 30 ° and a zone reflection angle (field deflection angle) of 22.5 ° is thus obtained. (The aspect ratio of the image formed on the joint surface of the beam array is 4: 3), and one rotation can realize the scanning of two frames of images. In addition, the mirror surfaces in the drum can be arranged crosswise to reduce the adjustment of balance and the vibration caused by the inconsistency of the centers of gravity of the two surfaces of the drum when the mirrors are scanned in a frame. For convenience of explanation, Z l, Z 2s 3, ... are used instead of ZA, ZB, ZC, ..., Z 1 = 1 °, and each mirror surface is increased by 1 °. The method is: Pair and combine each mirror: 1 12, Z 2Z 1 Z 3 Z 1 0, 4Z 9, / 5Z 8, Z 6 Z 7. The sum of the angles of each mirror combination is equal to 13 ° (When the angle parameters above to ZL are set in this way, ZA + ZL = Z B + ZK ... two 180 °). Similarly, when the interlaced scanning mirror surface is set, the rows 歹 ij are as follows: Z 1 Z 12,, Z 2Z 11 Z 3 Z 10 '. The above-mentioned mirror combinations can be arranged sequentially or non-sequentially around the drum. The same method can be used to set up an odd number of mirror drums or zone progressive scan mirror groups. When the mirror surfaces of the paired combination are arranged according to a certain rule, the angles on both sides of the evenly distributed bisectors of the drum are equal (see Figure 12).

5. Optical fiber board or translucent screen: The function of the optical fiber board is to correct the image, and the focus of each area scanning is formed on the incident surface of the optical fiber board to form a connection. The radian parameter of the incident surface is set according to the radian formed by the partition scan. The fiber board is set according to the requirements, and can be omitted. When the system projects the beam array combining surface onto the incident surface of the light-transmitting screen, a rear projection system can be formed. '

6. Projection lens: Select lens group with zoom function. The front focal plane of the lens is on the beam array combining surface or the output surface of the fiber board.

The video signal is distributed by the signal distribution drive system, driving 52 laser display units, and outputting the RGB tri-color laser from the port through the beam array former to form a beam array, which is focused by the beam array lens group, reflected by the reflector, and projected. At a rotation speed of 750 rpm, a 12-zone line deflection polygon mirror drum with two frames scanned per revolution forms a 16 million colors on the combined surface of the beam column with a vertical resolution of 624 lines and a horizontal The resolution is no less than 825 lines, and the image is divided into 25 frames per second (equivalent to 50 frames per second), and the image is projected on the diffuse reflection screen by the projection lens. Additional information:

1. Considering that directly projecting the beam column joint surface may cause the diameter of the projection lens to be too large, a field lens can be set on the beam column joint surface. For the same reason, at the output port of the beam column former (each scanning beam is output on a plane) (Linear arrangement) Set the field lens.

2. Each spare scan line can be composed of two output ports displaying the same signal. Adjust the signal distribution according to the deviation of the projection position of each area to make the overlap and interval of the splicing place below 1/4 line.

3. When using a laser array, the three light source columns can be mixed with a mirror and a dichroic mirror.

4. The beam column combining surface also includes the combination of the various regions scanned by the mirror reflection in the virtual image and the combining surface formed by the beam column output port in the virtual image.

Claims

Rights request

1. A kind of partitioned multi-row scanning laser projector, including: a signal distribution drive system, a laser display unit, a beam column former, a beam column lens group, a drum, a fiber optic board or a light-transmitting screen, a projection lens, and diffuse reflection The screen is characterized by: a. The projector system has beam columns for simultaneous scanning in multiple rows, which are arranged by the output ports of a modifiable laser array, light valve array or beam column former; b. The mirror drum Deflection polygon mirror drum for the partition line; (:, the beam array combining surface formed by the partition scan exists in the projector system: d, the incident surface of the optical fiber board or the transparent screen or the reflective surface of the diffuse reflection screen is formed by the partition scan Between the three points of the joint surface of the beam column or focus column or three points on the front focal plane of the projection lens.

2. A partitioned multi-line scanning laser projector according to claim 1, wherein the signal distribution driving system has three frames of storage units. '

3. A partitioned multi-row scanning laser projector according to claim 1, characterized in that the signal distribution driving system is partitioned by rows', driven by columns, and displayed in scan order on a mirror surface, according to the geometrical deviation of the mirror drum Assign signals to multiple display units.

4. The partitioned multi-line scanning laser projector according to claim 1, wherein the signal distribution driving system has multiple parallel storage units or memories.

5. The partitioned multi-line scanning laser projector according to claim 1, wherein the beam array lens group is a long or cylindrical lens or two features exist simultaneously.

6. The partitioned multi-row scanning laser projector according to claim 1, wherein the beam column former is composed of n optical channels, and the light output directions of the output ends are consistent, and are on a certain arc surface. Or plane

1 I is arranged in a straight line, and its output end is round or oblate. When it is flat 1), its height is greater than its width.

7. A partitioned multi-line scanning laser projector according to claim 1, characterized in that the angled elements in which the angle between each mirror or the group of mirrors and the end face increases or decreases at a certain angle exist in the partitioned line deflection polygon mirror drum. At the same time, the center line of each mirror surface or the parallel line of the center line is on a regular polygonal white side or at least one side is on a regular polyhedron. The sides of both sides are spatially parallel to the side.

8. The partitioned multi-line scanning laser projector according to claim 7, wherein the partitioned line deflection polygon mirror sequentially arranges the mirror surfaces of the scanning frame. When the number of mirror surfaces is an odd number, the middle side and the surface are clamped. The angle is 90 °. When the angle is an even number, the 90 ° angle bisects the angle difference between the two adjacent mirror surfaces.

9. A partitioned multi-line scanning laser projector according to claim 7, characterized in that the partitioned line deflection polygon mirror drums are formed by combining two or more mirrors that scan one frame in the same order.

10. The partitioned multi-line scanning laser projector according to claim 7, wherein the paired combination of adjacent mirror surfaces exists in the partitioned line deflection polygon mirror drum, and the angles of the paired mirror surfaces are equal to each other. .