An apparatus for expanding pixel resolution and a projection display system

Abstract

The present application discloses a device for expanding pixel resolution and a projection display system. The device includes: an offset wheel, a compensation wheel, and a driver. The offset wheel is configured to receive an incident light beam and includes a plurality of offset regions. The compensation wheel is disposed on the outgoing light path of the offset wheel and is configured to receive the light beam emitted by the offset wheel and includes a plurality of compensation regions. The driver is connected to the offset wheel and the compensation wheel and is configured to drive the offset wheel and the compensation wheel to rotate. Among them, the offset regions and the compensation regions are correspondingly arranged, and the position of the virtual image formed after the incident light beam passes through the offset wheel and the compensation wheel in sequence remains unchanged. By the above method, the present application can eliminate imaging aberration and make the imaging clear.

Description

Technical Field

[0001] This application relates to the technical field of projection display, and particularly relates to a device for expanding pixel resolution and a projection display system. Background Art

[0002] In DLP (Digital Light Procession) projection display technology, DMD (Digital Micromirror Device) is a crucial optical component that directly determines the image resolution. Currently, display systems with 4K resolution (the number of pixel values per row in the horizontal direction reaches or approaches 4096) have gradually become the mainstream display technology. However, the price of 4K resolution DMD chips is relatively high and not applicable in many scenarios. Therefore, pixel offset resolution technology is adopted. Pixel offset resolution technology realizes image display with a higher resolution than the original DMD chip by offsetting pixels (such as moving half a pixel distance in a specific direction). For example, XPR (Extended Pixel Resolution) can be used to expand pixels, so as to achieve high-resolution display effects with low-resolution dimming devices. However, the current XPR solution has an inherent imaging aberration, resulting in unclear imaging. Summary of the Invention

[0003] This application provides a device for expanding pixel resolution and a projection display system, which can eliminate imaging phase difference and make the imaging clear.

[0004] To solve the above technical problems, the technical solution adopted in this application is: providing a device for expanding pixel resolution, which includes: an offset wheel, a compensation wheel, and a driver. The offset wheel is used to receive incident light beams and includes a plurality of offset regions; the compensation wheel is arranged on the outgoing light path of the offset wheel and is used to receive the light beams emitted by the offset wheel and includes a plurality of compensation regions; the driver is connected to the offset wheel and the compensation wheel and is used to drive the offset wheel and the compensation wheel to rotate synchronously; wherein, the offset regions and the compensation regions are correspondingly arranged, and the position of the virtual image formed after the incident light beam passes through the offset wheel and the compensation wheel in sequence remains unchanged.

[0005] To solve the above technical problems, another technical solution adopted in this application is: providing a projection display system, which includes: a light source and a device for expanding pixel resolution. The light source is used to generate projection light beams; the device for expanding pixel resolution is arranged on the outgoing light path of the light source and is used to expand the resolution of the projection light beams, wherein, the device for expanding pixel resolution is the above-mentioned device for expanding pixel resolution.

[0006] Through the above solution, the beneficial effects of the present application are as follows: An offset wheel is used to deflect the incident light beam. Since the virtual images generated by the light beams emerging from different offset regions of the offset wheel may not be on the same horizontal / vertical plane, a compensation wheel is provided. The compensation wheel has a compensation region that matches the offset region in the offset wheel. Due to the existence of the compensation region, the position difference caused by the differences between the offset regions can be compensated. On the premise of achieving the expansion of the resolution of the projection light beam, the virtual images formed by all the light beams emerging from the offset regions are on the same horizontal / vertical plane after passing through the corresponding compensation regions, thereby eliminating the imaging parallax and contributing to improving the imaging clarity. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:

[0008] Figure 1 is a schematic diagram of the optical path of the incident light beam passing through the flat plate;

[0009] FIG. 2(a) is a schematic diagram of the optical path of the light beam incident on the first region of the turntable;

[0010] FIG. 2(b) is a schematic diagram of the optical path of the light beam incident on the second region of the turntable;

[0011] Figure 3 is a schematic structural diagram of an embodiment of the device for expanding the pixel resolution provided by the present application;

[0012] Figure 4 is Figure 3 a schematic structural diagram of the offset wheel in the shown embodiment;

[0013] Figure 5 is Figure 3 a schematic structural diagram of the compensation wheel in the shown embodiment;

[0014] Figure 6 is a schematic structural diagram of an embodiment of the device for expanding the pixel resolution provided by the present application;

[0015] FIG. 7(a) is a schematic diagram of the virtual image position formed by using a single offset wheel;

[0016] FIG. 7(b) is a schematic diagram of the virtual image position formed by using an embodiment of the device for expanding the pixel resolution provided by the present application;

[0017] Figure 8 is a schematic structural diagram of another embodiment of the device for expanding the pixel resolution provided by the present application;

[0018] Figure 9 It is a schematic structural diagram of an embodiment of the projection display system provided by this application. Specific embodiments

[0019] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0020] As Figure 1 shown, the flat plate 10 is deflected clockwise by an angle θ in the direction perpendicular to the incident light beam A, and the thickness of the flat plate 10 is t, and the refractive index of the flat plate 10 is n. When the incident light beam A passes through the flat plate 10, according to the law of refraction, the light beam that originally advanced in the B direction advances along the C direction due to the refraction of the flat plate 10, thereby realizing a light beam offset of Δy. The offset amount Δy of the deflected incident light beam A is:

[0021]

[0022] Therefore, by adjusting the values of Δy, θ, and t, a quantitative offset of pixels can be achieved. According to the above principle, a wheel with different thicknesses and / or refractive indices at different positions can be used to achieve the XPR function. As Figure 2(a) - Figure 2(b) shown, a turntable 101 that can rotate along the axis 105 is divided into a first region 102 and a second region 106. The first region 102 and the second region 106 have different refractive indices n1 and n2 respectively, and the angles with the wavefront plane of the light are θ1. The first region 102 and the second region 106 have different thicknesses t1 and t2 respectively. Among them, 100 is the light beam emitted from the spatial light modulator to the wheel. As shown in Fig. 2(a), after the light beam 100 passes through the first region 102 with a thickness of t1, the formed offset amount Δy1 is:

[0023]

[0024] When the turntable 101 rotates to the second region 106, as shown in Fig. 2(b), after the light beam 100 passes through the second region 106 with a thickness of t2, the formed offset amount Δy2 is:

[0025]

[0026] In summary, when using a flat wheel structure to implement the XPR function, since light will repeatedly pass through flat regions with different thicknesses and / or different refractive indices alternately, the light will repeatedly shift to two positions at this time, realizing different pixel offsets in time sequence. Based on this, the original resolution can be expanded and increased, that is, the XPR function is realized.

[0027] However, it is known that when light passes through a flat plate with a thickness of t and a refractive index of n, due to the refraction of the flat plate, the position of the virtual image obtained by reversing the outgoing light will be displaced relative to the position of the light source. When the incident angle of the light beam corresponding to the light-emitting point is relatively small, since sin(θ)=θ, the displacement amount can be expressed as Δs = t - t / n.

[0028] It can be seen from this that when using a flat wheel structure with multiple flat regions having different thicknesses and / or different refractive indices to achieve different offsets of light, it will cause different positions of the formed virtual images. If the light beam also needs to pass through a lens for imaging and the back focal depth of the lens is relatively short, different virtual image positions will result in the inability to simultaneously form clear and sharp images of different sub-frames of XPR, restricting the use scenarios of the rotary XPR device.

[0029] Based on the rotary XPR device, in view of the inherent imaging parallax in the existing implementation schemes of rotary XPR, by combining and setting a compensation wheel to solve the problem that when the rotary XPR is in use, due to the different thicknesses or refractive indices of the multiple offset regions of the offset wheel, the virtual images generated by the outgoing light beams cannot be located on the same horizontal / vertical plane, resulting in changes in the virtual image positions. The compensation wheel has a compensation region matching the offset region. Due to the existence of the compensation region, it can compensate for the position differences caused by the differences between the offset regions, so that the virtual images formed by all the light beams emerging from the offset regions are located on the same horizontal / vertical plane after passing through the corresponding compensation regions, thereby achieving the effect of eliminating the imaging parallax, and thus ensuring the imaging clarity and quality of the rotary XPR. Please refer to Figure 3 , Figure 3 is a schematic structural diagram of an embodiment of a device for expanding pixel resolution provided by the present application. The device 30 for expanding pixel resolution includes: a driver 31, an offset wheel 32, and a compensation wheel 33.

[0030] The driver 31 is connected to the offset wheel 32 and the compensation wheel 33, and is used to drive the offset wheel 32 and the compensation wheel 33 to rotate; specifically, after receiving a control instruction, the driver 31 can drive the offset wheel 32 and the compensation wheel 33 to rotate synchronously at a preset speed. The driver 31 can drive the offset wheel 32 and the compensation wheel 33 simultaneously, or the driver 31 includes two driving devices, one driving device drives the offset wheel 32, and the other driving device drives the compensation wheel 33.

[0031] The offset wheel 32 is used to receive the incident light beam. Specifically, as Figure 4 shown, the offset wheel 32 can be a transparent plastic plate with a refractive index of n or other transparent materials with a refractive index greater than that of air. It includes a plurality of offset regions 321, and the thickness and / or refractive index of each offset region 321 are different. The number of offset regions 321 is not limited to Figure 4 the 4 shown, and can be set according to specific needs.

[0032] The compensation wheel 33 is arranged on the outgoing light path of the offset wheel 32 and is used to receive the light beam emitted by the offset wheel 32. Specifically, as Figure 5 shown, the compensation wheel 33 includes a plurality of compensation regions 331, and the thickness and / or refractive index of each compensation region 331 are different. The number of compensation regions 331 is not limited to Figure 5 the 4 shown, and can be set according to specific needs. The offset regions 321 and the compensation regions 331 are correspondingly arranged, and the number of offset regions 321 matches the number of compensation regions 331. The offset wheel 32 and the compensation wheel 33 rotate synchronously, that is, the rotation speeds of the offset wheel 32 and the compensation wheel 33 are the same. After the incident light beam passes through the offset wheel 32 and the compensation wheel 33 in sequence, it is offset by a preset offset amount in the vertical direction. The virtual image position differences generated after the incident light beam passes through the offset regions 321 and the corresponding compensation regions 331 in sequence are the same. This virtual image position difference is the horizontal distance between the virtual image formed by the light beam emitted from each compensation region 331 and the light source generating the incident light beam.

[0033] Please refer to Figure 6 Figure 6, Figure 7(a) and Figure 7(b). Figure 6 is a schematic structural diagram of an embodiment of the device for expanding pixel resolution provided by the present application. In this embodiment, the angle between the rotation axis of the offset wheel 61 and the vertical direction is the first preset angle, and the angle between the rotation axis of the compensation wheel 62 and the vertical direction is the second preset angle.

[0034] The refractive index or thickness of the multiple offset regions changes monotonically along the rotation direction of the offset wheel 61 to offset the incident light beam by the first preset offset amount in sequence within the rotation period. The refractive index or thickness of the multiple compensation regions changes monotonically along the rotation direction of the compensation wheel 62.

[0035] Furthermore, the multiple offset regions include a first offset region 611 and a second offset region 612, and the multiple compensation regions include a first compensation region 621 and a second compensation region 622. The incident light beam A passes through the offset wheel 61 and the compensation wheel 62 in sequence. The rotation of the offset wheel 61 and the compensation wheel 62 is synchronous, so that the two regions of the two wheels always remain consistent, that is, after the incident light beam A passes through the first offset region 611, it needs to pass through the first compensation region 621, and after the incident light beam A passes through the second offset region 612, it needs to pass through the second compensation region 622.

[0036] In a specific embodiment, the compensation wheel 62 is configured to sequentially offset the light beam emitted from the offset wheel 61 by a second preset offset amount within a rotation period. The preset offset amount generated when the light beam corresponding to the light-emitting point A1 and the light beam corresponding to the light-emitting point A2 pass through one of the offset regions and the corresponding compensation region is equal to the sum of the first preset offset amount and the second preset offset amount. Specifically, when the incident angle of the light beam corresponding to the light-emitting point is relatively small, since sin(θ)=θ, the first offset amount generated when the incident light beam corresponding to the light-emitting point A1 passes through the first offset region 611 and the first compensation region 621 in sequence is:

[0037]

[0038] The second offset amount generated when the incident light beam passes through the second offset region 612 and the second compensation region 622 in sequence is:

[0039]

[0040] where θ is the first preset angle, θ' is the second preset angle, t1 and n1 are respectively the thickness and refractive index of the first offset region 611, t2 and n2 are respectively the thickness and refractive index of the second offset region 612, t1 ' and n1 ' are respectively the thickness and refractive index of the first compensation region 621, and t'2 and n'2 are respectively the thickness and refractive index of the second compensation region 622.

[0041] Referring to Figure 7(a) - Figure 7(b) , Figure 7(a) - Figure 7(b) FIG. 7(a) is a schematic diagram of the virtual image positions formed by a device using a single offset wheel and the device for expanding the pixel resolution according to this embodiment. As shown in FIG. 7(a), when using a single offset wheel to implement the XPR function, the virtual image positions formed by the light beam passing through different regions of the offset wheel are not in the same vertical plane. That is to say, since the light beam will pass through offset regions with different thicknesses or different refractive indices, when different offsets of the light beam are achieved, the positions of the formed virtual images will also be different.

[0042] As shown in FIG. 7(b), when using the device for expanding the pixel resolution according to this embodiment to implement the XPR function, the virtual image formed by the light beam emitted after the incident light beam of the light-emitting point A1 passes through the first offset region 611 and the first compensation region 621 in sequence is denoted as B1, and the first position difference generated by the position of the virtual image B1 relative to the position of the light-emitting point A1 is:

[0043]

[0044] The virtual image formed by the light beam emitted after the incident light beam of the light-emitting point A2 passes through the second offset region 612 and the second compensation region 622 in sequence is denoted as B2, and the second position difference generated by the position of the virtual image B2 relative to the light-emitting point A2 is:

[0045]

[0046] Among them, to meet the requirement of implementing the XPR function, the first offset and the second offset are not equal, while to meet the requirement that the position of the dashed line remains unchanged, the first position difference and the second position difference are equal. It can be found through the equation that as long as the first preset angle θ and the second preset angle θ' are different, it can be ensured that when Δs1 = Δs2, Δx1 and Δx2 are different, that is, the XPR function can be implemented without changing the position of the virtual image.

[0047] In another specific embodiment, as Figure 8 shown, the second preset angle is 0°, that is, the rotation axis of the compensation wheel 62 is completely aligned with the vertical direction; the first offset is equal to the first preset offset, that is, the compensation wheel 62 does not offset the light beam emitted from the offset wheel 61; the thickness of the first offset region 611 is the same as that of the second compensation region 622, the refractive index of the first offset region 611 is the same as that of the second compensation region 622, the thickness of the second offset region 612 is the same as that of the first compensation region 621, and the refractive index of the second offset region 612 is the same as that of the first compensation region 621, that is, the offset wheel 61 and the compensation wheel 62 are the same wheels, only the angles of the rotation axes are different.

[0048] The incident light beam A passes through the offset wheel 61 to obtain the light beam B. Different offset regions make the incident light beam have different offsets and different virtual image positions. The light beam B further passes through the compensation wheel 62. Since the rotation axis of the compensation wheel 62 is completely horizontal, the light beam B does not offset after passing through the compensation wheel 62, only changing the position of the formed virtual image; when the incident light beam passes through the two regions of the offset wheel 61 and the compensation wheel 62, since the regions passed through are both a thick and a thin region with matching refractive indices, the positions of the virtual images are the same. And since the compensation wheel 62 does not produce an additional offset to the light beam, the offsets generated when the light beam passes through different regions are different. This embodiment uses two wheels to achieve the offset of the incident light beam. The thickness, refractive index, and the angle between the rotation axis and the vertical direction of the two wheels are different, and the pixel expansion function can be implemented on the premise that the position of the virtual image remains unchanged.

[0049] It can be understood that the second preset angle can also be set to 0°, that is, the rotation axis of the offset wheel is completely consistent with the vertical direction; the preset offset is equal to the second preset offset, that is, the offset wheel does not offset the incident light beam; similar to the above embodiment, the offset wheel and the compensation wheel are the same wheels, and there is only a difference in the angle of the rotation axis. The incident light beam does not generate an offset after passing through the offset wheel, and the outgoing light beam further passes through the compensation wheel. Different compensation regions make the incident light beam have different offsets. However, since the incident light beam passes through two regions of the offset wheel and the compensation wheel, the regions passed through are both one thick and one thin, and the refractive indices of the two regions match each other. Therefore, the position of the virtual image is the same, and the pixel expansion function can be realized on the premise that the position of the virtual image remains unchanged.

[0050] Please refer to Figure 9 , Figure 9 which is a schematic structural diagram of an embodiment of a projection display system provided by the present application. The projection display system 90 includes: a light source 91 and a device 92 for expanding the pixel resolution. The light source 91 is used to generate a projection light beam; the device 92 for expanding the pixel resolution is disposed on the outgoing light path of the light source 91, and is used to expand the projection light beam. The device 92 for expanding the pixel resolution is the device for expanding the pixel resolution in the above embodiment.

[0051] The projection display system 90 in this embodiment uses a device 92 for expanding the pixel resolution with corrected imaging aberration, which realizes a higher display resolution while ensuring low cost. The projection display system 90 can be applied to a 3LCD (Liquid Crystal Display) display system and an LCOS (Liquid Crystal on Silicon) display system to achieve pixel expansion.

[0052] The above are only embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied to other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. An apparatus for expanding pixel resolution, characterized in that, Comprising: A deflection wheel for receiving an incident light beam, including a plurality of deflection regions; A compensation wheel disposed on the outgoing light path of the deflection wheel for receiving the light beam emitted by the deflection wheel, including a plurality of compensation regions; A driver connected to the deflection wheel and the compensation wheel for driving the deflection wheel and the compensation wheel to rotate; Wherein, the deflection regions and the compensation regions are correspondingly arranged, and the virtual images formed after the incident light beam passes through the deflection wheel and the compensation wheel in sequence are in the same horizontal / vertical plane.

2. The device for expanding pixel resolution according to claim 1, wherein The deflection wheel and the compensation wheel rotate synchronously. After the incident light beam passes through the deflection wheel and the compensation wheel in sequence, it is deflected by a preset deflection amount in the vertical direction. The position differences generated after the incident light beam passes through the deflection regions and the corresponding compensation regions are the same. Wherein, the position difference is the horizontal distance between the virtual image formed by the light beam emitted from each compensation region and the light source generating the incident light beam.

3. The device for expanding pixel resolution according to claim 2, wherein The refractive indices or thicknesses of the plurality of deflection regions vary monotonically along the rotation direction of the deflection wheel to sequentially deflect the incident light beam by a first preset deflection amount within a rotation period. The angle between the rotation axis of the deflection wheel and the vertical direction is a first preset angle; the refractive indices or thicknesses of the plurality of compensation regions vary monotonically along the rotation direction of the compensation wheel, and the angle between the rotation axis of the compensation wheel and the vertical direction is a second preset angle, wherein the first preset angle is different from the second preset angle.

4. The device for expanding pixel resolution according to claim 3, wherein The compensation wheel is further configured to sequentially deflect the light beam emitted by the deflection wheel by a second preset deflection amount within the rotation period, and the preset deflection amount is equal to the sum of the first preset deflection amount and the second preset deflection amount.

5. The device for expanding pixel resolution according to claim 3, wherein The second preset angle is 0°, and the preset deflection amount is equal to the first preset deflection amount.

6. The device for expanding pixel resolution according to claim 3, wherein The plurality of deflection regions include a first deflection region and a second deflection region, and the plurality of compensation regions include a first compensation region and a second compensation region.

7. The apparatus for expanding pixel resolution according to claim 6, wherein The first position difference generated after the incident light beam passes through the first deflection region and the first compensation region is: The second position difference generated after the incident light beam passes through the second deflection region and the second compensation region is: Wherein, the first position difference is equal to the second position difference, t1 and n1 are respectively the thickness and refractive index of the first offset region, t2 and n2 are respectively the thickness and refractive index of the second offset region, and t1 ' and n1 ' are respectively the thickness and refractive index of the first compensation region, and t'2 and n'2 are respectively the thickness and refractive index of the second compensation region.

8. The apparatus for expanding pixel resolution according to claim 7, wherein The first deflection amount generated after the incident light beam passes through the first deflection region and the first compensation region is: The second deflection amount generated after the incident light beam passes through the second deflection region and the second compensation region is: Wherein, θ is the first preset angle, and θ' is the second preset angle.

9. The device for expanding pixel resolution according to claim 6, wherein The thickness and refractive index of the first offset region are the same as those of the second compensation region, and the thickness and refractive index of the second offset region are the same as those of the first compensation region.

10. A projection display system, characterized in that, Comprising: A light source and a device for expanding pixel resolution, the light source being used for generating a projection beam; The device for expanding pixel resolution is disposed on the outgoing light path of the light source and is used for expanding the resolution of the projection beam, wherein the device for expanding pixel resolution is the device for expanding pixel resolution according to any one of claims 1-9.

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