A laser rod coupling system based on cylindrical lens pre-shaping

Abstract

The utility model relates to digital movie projection technical field, concretely relates to a kind of laser light stick coupling system based on cylindrical lens pre-shaping;The utility model is equal to the length-width ratio of light stick by XY two-degree-of-freedom cylindrical lens group focal length ratio, light X direction corresponding light stick long side after converging by cylindrical lens group, Y direction corresponding light stick short side;Cylindrical lens X before collocation full angle 1.6 ° scattering piece;Cylindrical lens Y after collocation full angle 1.6 ° vibration scattering piece and full angle 9 ° scattering piece;Two cylindrical lenses are between through mirror folding light path, shorten horizontal dimension;The utility model two-degree-of-freedom adjustment light spot ratio, fully match the optical expansion of light stick, and cylindrical lens group front and rear portion simultaneously collocation scattering piece of different angle, folding mirror folding light path is added between cylindrical lens, realize compact simple and light efficiency high, field uniformity good light stick coupling system.

Description

Technical Field

[0001] This utility model relates to the field of digital cinema projection technology, specifically to a laser beam coupling system based on cylindrical mirror pre-shaping. Background Technology

[0002] Early digital cinema projectors primarily used xenon lamps or UHP (ultra-high pressure mercury lamps) as light sources, which had many limitations. They suffered from low luminous efficacy and poor energy utilization; xenon lamp efficacy was typically only 30-50 lm / W. They also had short lifespans, requiring frequent replacements and lasting only a few thousand hours. Furthermore, their color gamut was narrow, covering only about 80% of the Rec.709 color gamut, making it difficult to meet HDR requirements. In addition, the low luminous efficiency led to heat dissipation problems, affecting the stability of optical components. Laser light sources, due to their high brightness, long lifespan, and wide color gamut, have gradually replaced various filament light sources in the cinema market, but they still face some technical challenges. Laser beams typically have a Gaussian distribution, and direct entry into the laser rod can lead to uneven energy distribution (uniformity <70%). When a standard spherical lens focuses the laser, the convergence spot and the mismatch between the spot and the laser rod result in significant energy loss. Currently, there are many coupling schemes, such as using a high-order aspherical lens group in front of the light bar to correct aberrations and match the rectangular light bar, but this has high processing costs and temperature changes can cause a certain degree of focal length drift; adding a microlens array in front of the light bar for pre-uniform light, but this is expensive and will introduce diffraction loss, resulting in a large energy loss; using a combination of a single cylindrical mirror, an aspherical lens and a light bar in front of the light bar, the system is relatively complex. Summary of the Invention

[0003] This invention addresses the technical problem that after an RGB laser array is collimated by a fast-axis collimating lens, it needs to be converged to a rectangular integrating light rod through a suitable coupling system. However, current coupling systems suffer from complex structures, high costs, and inability to meet the requirements of matching the optical extension of the light rod and achieving good uniformity. This invention provides a laser light rod coupling system based on pre-shaping with a cylindrical mirror.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: a laser beam coupling system based on cylindrical mirror pre-shaping, including a blue collimating laser with vertical light output direction, an S-polarized green collimating laser, a P-polarized green collimating laser, an S-polarized red collimating laser, and a P-polarized red collimating laser. A first reflecting mirror is provided along the output direction of the blue collimated laser; a second reflecting mirror is provided along the output direction of the S-polarized green collimated laser; a green polarization beam combiner and a blue-transmitting, green-reflecting wavelength beam combiner are provided sequentially from near to far along the output direction of the P-polarized green collimated laser; a third reflecting mirror is provided along the output direction of the S-polarized red collimated laser; and a red polarization beam combiner and a red-reflecting, blue-transmitting, and green-transmitting wavelength beam combiner are provided sequentially from near to far along the output direction of the P-polarized red collimated laser. The second reflecting mirror, green polarization beam combiner, third reflecting mirror, and red polarization beam combiner are all located at the same vertical height and have the same tilt angle. On the right side of the red-to-blue-green wavelength beam combiner, at the same vertical height, from near to far, are also arranged a full-angle 1.6° scattering sheet, a cylindrical mirror X, and a folding reflector; Above the folding reflector, in order from near to far, are arranged a cylindrical mirror Y, a light rotator, a full-angle 1.6° vibrating scattering plate, a full-angle 9° scattering plate, and a light bar 2.

[0005] Furthermore, the first reflector, the second reflector, the green light polarizing beam combiner, the third reflector, the blue-transmitting and green-reflecting wavelength beam combiner, the red light polarizing beam combiner, and the red-reflecting and blue-transmitting wavelength beam combiner all have an angle of 45° with the horizontal direction.

[0006] Furthermore, the full-angle 1.6° scattering sheet and the cylindrical mirror X are vertically arranged, and the angle between the folding reflector and the horizontal direction is 45°.

[0007] Furthermore, the horizontal direction is defined as the X direction and the vertical direction as the Y direction. The focal length ratio of the two-degree-of-freedom cylindrical mirror group in the XY direction is equal to the length-to-width ratio of the light bar. The light converged by the cylindrical mirror group corresponds to the long side of the light bar in the X direction and the short side of the light bar in the Y direction.

[0008] Compared with the prior art, the present invention has the following beneficial effects: This invention achieves a compact, simple, highly efficient, and well-uniformed light rod coupling system by adjusting the light spot ratio with two degrees of freedom, and by simultaneously equipping the front and rear of the cylindrical mirror group with scattering plates at different angles, and adding folding mirrors between the cylindrical mirrors to fold the light path. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the laser beam coupling system based on cylindrical mirror pre-shaping according to this utility model.

[0010] The markings in the image are as follows: 1-Blue collimated laser, 2-S-polarized green collimated laser, 3-P-polarized green collimated laser, 4-S-polarized red collimated laser, 5-P-polarized red collimated laser, 6-First reflecting mirror, 7-Second reflecting mirror, 8-Green light polarization combiner, 9-Blue-transmitting and green-reflecting wavelength combiner, 10-Third reflecting mirror, 11-Red light polarization combiner, 12-Red-reflecting and blue-green-transmitting wavelength combiner, 13-Full-angle 1.6° scattering plate, 14-Cylindrical mirror X, 15-Folding reflecting mirror, 16-Cylindrical mirror Y, 17-Optical rotator, 18-Full-angle 1.6° vibrating scattering plate, 19-Full-angle 9° scattering plate, 20-Light rod. Detailed Implementation

[0011] The present invention will be further described below with reference to specific embodiments. Example

[0012] like Figure 1 As shown, a laser beam coupling system based on cylindrical mirror pre-shaping includes a blue collimated laser 1 with vertical light output direction, an S-polarized green collimated laser 2, a P-polarized green collimated laser 3, an S-polarized red collimated laser 4, and a P-polarized red collimated laser 5. A first reflecting mirror 6 is provided along the output direction of the blue collimated laser 1; a second reflecting mirror 7 is provided along the output direction of the S-polarized green collimated laser 2; a green polarization beam combiner 8 and a blue-transmitting, green-reflecting wavelength beam combiner 9 are provided sequentially from near to far along the output direction of the P-polarized green collimated laser 3; a third reflecting mirror 10 is provided along the output direction of the S-polarized red collimated laser 4; and a red polarization beam combiner 11 and a red-reflecting, blue-transmitting, and green-transmitting wavelength beam combiner 12 are provided sequentially from near to far along the output direction of the P-polarized red collimated laser 5. The second reflecting mirror 7, the green polarization beam combiner 8, the third reflecting mirror 10, and the red polarization beam combiner 11 are located at the same vertical height and have the same tilt angle. The first reflecting mirror 6, the blue-transmitting, green-reflecting wavelength beam combiner 9, and the red-transmitting, blue-transmitting, and green-transmitting wavelength beam combiner 12 are located at the same vertical height and have the same tilt angle. On the right side of the red-to-blue-green wavelength beam combiner 12, at the same vertical height, a full-angle 1.6° scattering plate 13, a cylindrical mirror X14, and a folding reflector 15 are also arranged sequentially from near to far. The folding reflector 15 is arranged vertically above the cylindrical mirror Y16, the optical rotator 17, the full-angle 1.6° vibrating scatterer 18, the full-angle 9° scatterer 19, and the light bar 20 in sequence from near to far.

[0013] Furthermore, the first reflector 6, the second reflector 7, the green light polarizing beam combiner 8, the third reflector 10, the blue-transmitting and green-reflecting wavelength beam combiner 9, the red light polarizing beam combiner 11, and the red-reflecting and blue-transmitting wavelength beam combiner 12 all have an angle of 45° with the horizontal direction.

[0014] Furthermore, the full-angle 1.6° scattering sheet 13 and the cylindrical mirror X14 are vertically arranged, and the folding reflector 15 is at an angle of 45° to the horizontal direction.

[0015] Furthermore, the horizontal direction is defined as the X direction and the vertical direction as the Y direction. The focal length ratio of the two-degree-of-freedom cylindrical mirror group in the XY direction is equal to the length-to-width ratio of the light bar 20. The light converged by the cylindrical mirror group corresponds to the long side of the light bar 20 in the X direction and the short side of the light bar 20 in the Y direction.

[0016] Working principle: such as Figure 1 As shown, the S-polarized green collimated laser 2, after being reflected by the second mirror 7, produces an S-beam, and the P-polarized green collimated laser 3, after being passed through a green polarization combiner 8, forms green elliptically polarized light. This light is then combined with the blue light output from the blue laser 1 via the first mirror 6, and then passed through a blue-transmitting, green-reflecting wavelength combiner 9. Simultaneously, the S-polarized red collimated laser 4, after being reflected by the third mirror 10, and the P-polarized red collimated laser 5, after being passed through a red polarization combiner 11, form red elliptically polarized light. The polarized combined red light and the wavelength-combined blue-green mixed light are then combined through a red-reflecting, blue-transmitting, green wavelength combiner 12. After beam combining, the RGB hybrid collimated laser beam passes through a 1.6° full-angle scatterer 13 and is then incident on a cylindrical mirror X 14 for X-direction focusing. It then illuminates a folding mirror 15 at a 45° angle, rotating the light path by 90°. The beam is then focused in the Y direction using a cylindrical mirror Y 16. The light beam, which is focused in both directions, passes through a rotator mirror 17 for decoherence and then through a 1.6° full-angle vibrating scatterer 18 and a 9° full-angle scatterer 19. The light beam enters the rectangular integrating light rod 20 for homogenization with the smallest spot size that matches the size of the light rod aperture.

[0017] Thus, the RGB hybrid collimated laser beam path diffuses the divergence angle through three scattering plates, and is converged by XY dual-degree-of-freedom cylindrical mirrors so that the incident angle of the light entering the light bar is 18°. After multiple total internal reflections in the light bar, the RGB hybrid laser achieves the desired homogenization effect. The homogenized light source is then incident on the DMD chip through a relay lens.

[0018] This invention features a dual-degree-of-freedom cylindrical mirror assembly with a focal length ratio equal to the length-to-width ratio of the light rod. The light converged by the cylindrical mirror assembly has its X-direction corresponding to the long side of the light rod and its Y-direction corresponding to the short side. A 1.6° full-angle diffuser is placed in front of the X-mirror, and a 1.6° full-angle vibrating diffuser and a 9° full-angle diffuser are placed behind the Y-mirror. The optical path between the two cylindrical mirrors is folded using a reflector to shorten the lateral dimension. This invention allows for dual-degree-of-freedom adjustment of the light spot ratio, fully matching the optical extension of the light rod. Furthermore, the cylindrical mirror assembly is equipped with diffusers of different angles at both the front and rear, and a folding reflector is added between the cylindrical mirrors to fold the optical path, achieving a compact, simple, highly efficient, and well-uniformed light rod coupling system.

Claims

1. A laser rod coupling system based on cylindrical mirror pre-shaping, characterized in that, Including a blue collimated laser (1) with all light output directions in the vertical direction, an S-polarized green collimated laser (2), a P-polarized green collimated laser (3), an S-polarized red collimated laser (4), and a P-polarized red collimated laser (5); A first reflecting mirror (6) is provided along the light output direction of the blue collimated laser (1), a second reflecting mirror (7) is provided along the light output direction of the S-polarized green collimated laser (2), a green polarization beam combiner (8) and a blue-transmitting, green-reflecting wavelength beam combiner (9) are provided sequentially from near to far along the light output direction of the P-polarized green collimated laser (3), a third reflecting mirror (10) is provided along the light output direction of the S-polarized red collimated laser (4), and the P-polarized red collimated laser (5) is provided along the light output direction of the S-polarized red collimated laser (4). The beam output direction is arranged from near to far with a red light polarizing beam combiner (11) and a red-reflecting, blue-transmitting, and green-wavelength beam combiner (12); the second reflector (7), the green light polarizing beam combiner (8), the third reflector (10), and the red light polarizing beam combiner (11) are located at the same vertical height and have the same tilt angle; the first reflector (6), the blue-transmitting, green-reflecting beam combiner (9), and the red-reflecting, blue-transmitting, and green-wavelength beam combiner (12) are located at the same vertical height and have the same tilt angle. On the right side of the red-to-blue-green wavelength beam combiner (12), at the same vertical height, a full-angle 1.6° scattering sheet (13), a cylindrical mirror X (14), and a folding reflector (15) are arranged sequentially from near to far. The folding reflector (15) is arranged vertically above the cylindrical mirror Y (16), the optical rotator (17), the full-angle 1.6° vibrating scatterer (18), the full-angle 9° scatterer (19), and the light bar (20) in sequence from near to far.

2. The laser rod coupling system based on cylindrical mirror pre-shaping according to claim 1, characterized in that, The first reflector (6), the second reflector (7), the green light polarizing beam combiner (8), the third reflector (10), the blue-transmitting and green-reflecting wavelength beam combiner (9), the red light polarizing beam combiner (11), and the red-reflecting and blue-transmitting wavelength beam combiner (12) all have an angle of 45° with the horizontal direction.

3. The laser rod coupling system based on cylindrical mirror pre-shaping according to claim 1, characterized in that, The full-angle 1.6° scattering sheet (13) and cylindrical mirror X (14) are vertically arranged, and the folding reflector (15) is at an angle of 45° to the horizontal direction.

4. The laser rod coupling system based on cylindrical mirror pre-shaping according to claim 1, characterized in that, The horizontal direction is set as the X direction and the vertical direction is set as the Y direction. The focal length ratio of the two-degree-of-freedom cylindrical mirror group in the XY direction is equal to the length-width ratio of the light bar (20). The light after being converged by the cylindrical mirror group corresponds to the long side of the light bar (20) in the X direction and the short side of the light bar (20) in the Y direction.

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