Display device

Abstract

The present invention provides a display device, including an image processing module, an array light source, a light source displacement module and an imaging module. The image processing module is used to split a frame of image into multiple sub-frames displayed in a time-division multiplexing manner, and each sub-frame includes multiple pixels. The array light source includes multiple light sources arranged in an array, and the multiple light sources are used to form multiple light spots in a one-to-one correspondence, and the multiple light spots correspond to multiple sub-frames displayed in a time-division multiplexing manner. The light source displacement module is used to move the multiple light spots to arrange each light spot into multiple time-sequentially displayed light spots corresponding to multiple pixels. The imaging module is used to image each sub-frame on the screen. The display device provided by the present invention arranges the light spots of the sparse array light source into a dense array light source corresponding to the pixels in the image of the video signal module to display high-resolution variable dot matrix or variable structured light, and display high-brightness and high-resolution images.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a display device. Background Art

[0002] With the advancement of optical technology, 3D imaging and display technologies are becoming increasingly mature. Existing display technologies primarily include the following three types: One is based on laser scanning display solutions. Existing beam scanning image display solutions primarily use lasers as the primary light source, with optical modulators used to modulate the beam intensity. Common optical modulators include electro-optical modulation and acousto-optic modulation. Three laser colors, after passing through a modulator loaded with a video signal, are transformed into laser beams of varying intensities. These beams then pass through a color-combining system comprised of optical thin films to form a single beam. This beam then enters an XY scanning system. This solution uses optical modulators, resulting in high system power consumption and size. Due to the small number of laser light sources employed, the control bandwidth requirements for the modulator and scanning equipment are high, resulting in lower image resolution, a narrow field of view, and a strong speckle effect. Another approach is based on DLP (Digital Light Processing) XPR fast-switching technology. XPR fast-switching leverages the principle of persistence of vision in the human eye to achieve improved resolution by micro-vibrating the DMD at the pixel level. However, the number of pixels that can be replicated by XPR technology is limited. Therefore, to obtain high resolution, a DMD chip with higher resolution native pixels is required, which is expensive. The other is based on a polygonal mirror scanner. The polygonal mirror is a rotating optical element mainly composed of three or more small mirrors. It is suitable for unidirectional scanning, high scanning rate, large aperture, large scanning angle and high throughput scenarios. In most applications, the polygonal mirror scanner is matched with another technology for beam control or target movement to form a second axis to achieve the function of repeated scanning. However, due to the limitation of the beam angle resolution, there is a positive correlation between the size of the polygonal scanning mirror and the imaging resolution. If high resolution is to be obtained, the required polygonal scanner is larger, the size of the lens will also become larger, the entire system will be large and the cost will be high. The above three existing solutions cannot meet production needs. Summary of the Invention

[0003] The object of the present invention is to provide a display device to solve the above problem. The embodiment of the present invention achieves the above object through the following technical solutions.

[0004] The present invention provides a display device comprising an image processing module, an array light source, a light source displacement module, and an imaging module. The image processing module is configured to split a frame of an image into multiple subframes displayed in a time-division multiplexing manner, each subframe comprising multiple pixels. The array light source comprises multiple light sources arranged in an array, the multiple light sources being configured to form multiple light spots in a one-to-one correspondence, each of which corresponds to a plurality of subframes displayed in a time-division multiplexing manner. The light source displacement module is configured to move the multiple light spots so as to arrange each light spot into multiple time-sequentially displayed light spots corresponding to a plurality of pixels. The imaging module is configured to image each subframe on a screen.

[0005] In one embodiment, the display device further includes a light source brightness control module, which is configured to control the brightness of each light spot in each time sequence to control the grayscale of each pixel in each subframe.

[0006] In one embodiment, the light source is a pulse light source, and the grayscale of each pixel is controlled by controlling the duty cycle of each light spot.

[0007] In one embodiment, two adjacent light spots in the plurality of light spots displayed in a time sequence at least partially overlap.

[0008] In one embodiment, the display device further includes a video signal module electrically connected to the image processing module, and the image processing module is further configured to receive an image from the video signal module and perform decoding processing on the image.

[0009] In one embodiment, the light source displacement module includes a first displacement module and a second displacement module, the first displacement module is used to move the light spot in a first direction, and the second displacement module is used to move the light spot in a second direction perpendicular to the first direction.

[0010] In one embodiment, the light source displacement module causes the light spot to be displaced by deflecting the light beam.

[0011] In one embodiment, the first displacement module is a continuous scanning device, and the second displacement module is a step-by-step scanning device.

[0012] In one embodiment, the first displacement module and the second displacement module are both step-scan devices.

[0013] In one embodiment, the display device further includes a light combining module, which is located between the array light source and the imaging module and is configured to combine the multiple light spots.

[0014] Compared with the existing technology, the display device provided by the present invention realizes the movement of the light spots of a sparse array light source through a light source displacement module, and arranges the light spots of the sparse array light source into a dense array light source corresponding to the pixels in the image of the video signal module, so as to display high-resolution variable dot matrix or variable structured light, and display high-brightness and high-resolution images.

[0015] These and other aspects of the present invention will become more apparent from the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution in this embodiment, the following briefly introduces the drawings required for use in the description of the embodiment. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 2 is a schematic structural diagram of a display device provided by an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of image deframing provided by an embodiment of the present invention.

[0019] Figure 3 Schematic diagram of the light spot distribution of the array light source and the light spot distribution after scanning provided by an embodiment of the present invention.

[0020] Figure 4 This is a timing diagram of the displacement and driving voltage (current) of the light source displacement module provided in an embodiment of the present invention.

[0021] Figure 5 This is a timing diagram of the displacement of the light source displacement module and the light source sampling frequency (scanning speed is a constant value) provided in an embodiment of the present invention.

[0022] Figure 6 This is a timing diagram of the displacement of the light source displacement module and the light source sampling frequency (the scanning speed is not a constant value) provided in an embodiment of the present invention.

[0023] Figure 7 It is a structural schematic diagram of a display device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0024] To facilitate understanding of this embodiment, a more comprehensive description of this embodiment will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in this embodiment are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0026] See also Figure 1 The present invention provides a display device 100, comprising an image processing module 20, an array light source 30, a light source displacement module 40, and an imaging module 60. The image processing module 20 is configured to split a frame of an image into multiple subframes displayed in a time-division multiplexing manner, each subframe including multiple pixels. The array light source 30 is configured to form multiple light spots, each of which corresponds to a plurality of subframes displayed in a time-division multiplexing manner. The light source displacement module 40 is configured to move the multiple light spots so as to arrange each light spot into a plurality of time-sequentially displayed light spots corresponding to a plurality of pixels. The imaging module 60 is configured to image each subframe on a screen.

[0027] The display device 100 also includes a video signal module 10 electrically connected to the image processing module 20. The image processing module 20 is also used to receive images from the video signal module 10 and decode the images. Specifically, the image processing module 20 can decode the video signal module 10 and generate an image signal. The image signal can be used to control the brightness of each light spot, thereby completing the brightness control of a sub-frame image. The image processing module 20 is also used to split the image into multiple sub-frames displayed in a time-division multiplexing manner, wherein time-division multiplexing refers to transmitting different signals at different time periods through the same component to achieve the purpose of multi-channel transmission. Figure 2 As shown, as an example, the image processing module 20 splits a frame of image into 2*2 subframes. At each time point in a frame, each pixel is located at position 1, 2, 3, and 4 of the display area. For example, at time t1, the pixel is located at position 1, at time t2, the pixel is located at position 2, and so on. Thus, the 2*2 pixel area forms a 4*4 pixel area as a whole.

[0028] See also Figure 3 The array light source 30 includes a plurality of light sources arranged in an array, and the plurality of light sources are continuous light sources, which are used to form a plurality of light spots in a one-to-one correspondence. In this embodiment, the array light source 30 is arranged into an M*N dot matrix, and through the optical imaging lens, M*N sparse pixel points can be realized on the screen. The present invention requires that the light spot corresponding to each light source be expanded into densely packed m*n time-sequentially displayed light spots through time division multiplexing, corresponding to m*n densely packed pixels in a frame of image. Accordingly, the M*N light spots can be expanded into densely packed Mm*Nn time-sequentially displayed light spots through time division multiplexing to display high-resolution variable dot matrix or variable structured light, and display high-brightness and high-resolution images. The dense arrangement can be that the expanded light spots just fill the gaps between adjacent light sources. Since the overall resolution is achieved by the light source array, the modulation bandwidth of a single light source can be effectively reduced. In addition, since a certain area in the overall image is formed by moving a single light source, the image uniformity can be effectively improved, and when the array light source is a laser, the speckle of the displayed image can also be effectively reduced by scanning the light spots, thereby improving the imaging quality.

[0029] The array light source 30 includes but is not limited to VCSEL (Vertical-Cavity Surface-Emitting Laser), EEL (Edge Emitting Laser), LED or Micro LED.

[0030] In other embodiments, adjacent light spots in the multiple time-sequential displays at least partially overlap. That is, adjacent light spots overlap. This arrangement can prevent the appearance of dead pixels on the screen due to insufficient light spot brightness, which can affect the display. Furthermore, the overlapping portions can increase display brightness. When the light spots expand at a uniform rate, the overlapping portions can be of the same size, resulting in a more uniform image displayed on the screen.

[0031] As an example, the pixel is an ideal rectangular light spot with a length and width of a and b respectively. Gapa and Gapb are the distances between the edges of two pixel points in the length and width directions respectively. When Gapa and Gapb are both greater than 0, the image has a certain duty cycle, duty cycle FF = (a*b) / (a+Gapa)(b+Gapb); when Gapa and Gapb are equal to 0, the pixels are densely packed, that is, there is no gap between two adjacent pixels; when Gapa and Gapb are both less than 0, the pixels overlap, and at this time, the video signal module 10 can be processed by software to achieve higher resolution.

[0032] As another example, when the pixel point is a Gaussian spot, the energy distribution of the beam of the Gaussian spot is

[0033]

[0034] The length a and width b of the light spot are defined as the widths when the energy decays to 1 / e, which are w0x and w0y respectively. Its control and driving method is similar to that of the rectangular light spot and will not be repeated here.

[0035] The array light source 30 also includes multiple electrodes, which are connected to the multiple light sources in a one-to-one correspondence. The electrodes are similar to the switches of the light sources, which can control the brightness, on / off switching, and other properties of the light sources. The electrodes control the brightness of the light sources, and the light sources form multiple light spots. The multiple light spots correspond one-to-one to the multiple subframes, and each light spot can be arranged into multiple time-sequential display spots corresponding to multiple pixels. Therefore, by controlling the brightness, on / off switching of each individual light source, the brightness, on / off switching of each pixel in the displayed image can be controlled, thereby achieving high contrast and high dynamic range of the image.

[0036] In this embodiment, the light source displacement module 40 moves the light spot by scanning. The light source displacement module 40 can be one of an acousto-optic deflector, a voice coil motor, a stepping piezoelectric motor, and a piezoelectric deflection table. Since the light source of the embodiment of the present invention is an M*N rectangular dot matrix light source, the light source can be scanned along two directions perpendicular to each other. Specifically, the light source displacement module 40 includes a first displacement module and a second displacement module, the first displacement module is used to move the light spot in a first direction, and the second displacement module is used to move the light spot in a second direction perpendicular to the first direction. In other embodiments, when the array light source 30 is a light source in other array forms, such as a circular array, the light source displacement module 40 can move the light spot along a circular trajectory.

[0037] See also Figure 4 , Sm is the displacement stroke of the first displacement module along the first direction, Sn is the displacement stroke of the second displacement module along the second direction. In this embodiment, the first direction is the horizontal direction, and the second direction is the vertical direction. VSYNC and HSYNC are the timing of the driving voltage (current) in the vertical and horizontal directions respectively. In this embodiment, the first displacement module and the second displacement module are both step scanning devices. The first displacement module and the second displacement module include but are not limited to piezoelectric devices such as stepping piezoelectric motors and fast piezoelectric deflection tables, and can also be acousto-optic devices such as acousto-optic deflectors. Since the response time of these devices is tens of microseconds to several microseconds, high-resolution step scanning can be achieved. In this embodiment, the time for the first displacement module to move each step is the same, ensuring uniform brightness of the pixel points. In other embodiments, the time for the first displacement module to move each step may also be different. In this embodiment, the subframes are arranged in an m*n array, and the light spot corresponding to each light source is expanded through time-division multiplexing into m*n closely spaced light spots corresponding to the subframes. The specific expansion steps are as follows: during the time period from T1 to T2, when the driving voltage (current) drives the first displacement module to move m steps in the first direction, the driving voltage (current) drives the second displacement module to move one step in the second direction; during the time period from T2 to T3, the driving voltage (current) then drives the first displacement module to move m steps in the direction opposite to the first direction, and the driving voltage (current) drives the second displacement module to move one step in the second direction; after 2*Tn, the light spot returns to the origin, thus completing the scanning of a frame of image. After scanning the array light source 30 in this manner, the light spot of the M*N array light source 30 can be scanned into a light spot with mM*nN pixels closely spaced.

[0038] See also Figure 5Assuming that the required resolution can be obtained when the center spacing of the light spots is △x, and assuming that the time required to move △x is △t, then v=△x / △t, and the scanning frequency fscanning=1 / △t=v / △x. At this time, only the current sampling frequency fsampling≥fscanning is required to achieve scanning display. The grayscale display within each current sampling frequency can be achieved through PWM (Pulse Width Modulation) control. △ts determines the lateral duty cycle of the pixel. When △ts≤△t, the duty cycle is approximately △ts / △t. In one embodiment, the array light source 30 is a continuous light source, and the first displacement module is a continuous scanning device. The first displacement module includes but is not limited to a piezoelectric device such as a piezoelectric shift stage or a fast piezoelectric deflection stage; an acousto-optic device such as an acousto-optic deflector or a voice coil motor; and the second displacement module is a stepping scanning device. The second displacement module includes but is not limited to a piezoelectric device such as a stepping piezoelectric motor and a fast piezoelectric deflection stage, and can also be an acousto-optic device such as an acousto-optic deflector. The subframes are arranged in an m*n array. When the first displacement module continuously moves a distance of m steps along the first direction, the second displacement module moves one step along the second direction. In this embodiment, the scanning speed of the first displacement module can be a constant value to ensure a constant brightness of each pixel.

[0039] See also Figure 6 In other embodiments, the scanning speed of the first displacement module may not be a constant value. The brightness of the pixel point can be kept constant by changing the sampling frequency of the light source current. For example, the sampling time is selected as t1, t2, ... ti, ensuring that △x1 = △x2 = ... = △xi, and △tsj / △tj is a constant value, which can also ensure that the brightness of each pixel point is constant.

[0040] In one embodiment, the light source is a pulsed light source. Assuming that the pulse frequency of the light source is much greater than the sampling frequency, the grayscale of each pixel is controlled by controlling the value of △tsj / △tj (i.e., the duty cycle of each light spot). In this case, PWM modulation of the light source is no longer required.

[0041] When both dimensions are scanned continuously, the control frequency of the light source displacement module 40 is reduced by sampling the current of the light source. Therefore, the devices that can be used include but are not limited to piezoelectric devices such as piezoelectric level shifting stages, fast piezoelectric deflection stages, or acousto-optic devices such as acousto-optic deflectors, voice coil motors, etc.

[0042] Because the second displacement module's scanning speed in the second direction is relatively slow, the displacement of the first displacement module in the second direction during each round trip in the first direction is very small, only approximately half a pixel. Considering the fixed size of the light spot, the displacement of the second displacement module in the second direction can be roughly considered a step-scan motion. The control of the scanning device and the sampling method of the light source are similar to those of the step-and-continuous scanning scheme and will not be repeated here.

[0043] In other embodiments, the light source displacement module 40 causes the light spot to displace by deflecting the light beam. Specifically, the light beam can be deflected or translated by deflecting some optical devices such as the light source itself, a reflective surface, or a refractive surface, and other light path guiding elements, thereby achieving the movement of the light spot.

[0044] See also Figure 7 In this embodiment, the display device 100 also includes a light source brightness control module 50, which is used to control the brightness of each light spot to control the grayscale of each pixel in each subframe. The light source brightness control module 50 is electrically connected to a plurality of electrodes to control the brightness of each light spot by controlling the voltage or current of the plurality of electrodes. Specifically, after receiving the image signal generated by the video signal module 10 after decoding by the image processing module 20, the light source brightness control module 50 controls the brightness of each light spot position to achieve different grayscales, thereby completing the regulation of a subframe image. When it comes to another subframe, the light source brightness control module 50 controls the array light source 30 according to the grayscale corresponding to the subframe, so that the corresponding subframe grayscale distribution is displayed on the image. Similarly, the brightness control of the image on the screen can be achieved. Since the light spot corresponding to a single light source only needs to cover a certain area in the overall image, the control bandwidth of the light source brightness control module 50 can be effectively reduced.

[0045] In this embodiment, the light source brightness control module 50 controls the brightness of the light spot and the light source displacement module 40 moves the light spot synchronously, that is, after adjusting the brightness of one light spot, the brightness of the next light spot is adjusted until all the light spots displayed in the time sequence are adjusted, which can effectively improve the uniformity of the image display.

[0046] In other embodiments, the display device 100 further includes a light combining module 70 , which is located between the array light source 30 and the imaging module 60 and is used to combine multiple light spots. The combined light spots are finally imaged on the screen after passing through the imaging module 60 .

[0047] In summary, the display device 100 provided by the present invention arranges the light spots of the sparse array light source 30 into a dense array light source 30 corresponding to the pixels in the image of the video signal module 10 to display high-resolution variable dot matrix or variable structured light, and display high-brightness and high-resolution images.

[0048] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A display device, characterized in that: include: An image processing module, configured to split a frame of image into a plurality of sub-frames displayed in a time-division multiplexing manner, each sub-frame including a plurality of pixels; An array light source, comprising a plurality of light sources arranged in an array, the plurality of light sources being used to form a plurality of light spots in a one-to-one correspondence, the plurality of light spots corresponding to the plurality of sub-frames displayed in a time-division multiplexing manner; a light source displacement module, configured to move the plurality of light spots so as to arrange each of the light spots into a plurality of time-sequentially displayed light spots corresponding to the plurality of pixels; and The imaging module is used to image each subframe on the screen.

2. The display device according to claim 1, wherein The display device further includes a light source brightness control module, which is used to control the brightness of each light spot in each time sequence to control the grayscale of each pixel in each subframe.

3. The display device according to claim 2, wherein: The light source is a pulse light source, and the grayscale of each pixel is controlled by controlling the duty cycle of each light spot.

4. The display device according to claim 1, wherein Two adjacent light spots in the plurality of time-sequentially displayed light spots at least partially overlap.

5. The display device according to claim 1, wherein The display device further includes a video signal module electrically connected to the image processing module. The image processing module is further configured to receive the image from the video signal module and perform decoding processing on the image.

6. The display device according to claim 1, wherein The light source displacement module includes a first displacement module and a second displacement module. The first displacement module is used to move the light spot in a first direction, and the second displacement module is used to move the light spot in a second direction perpendicular to the first direction.

7. The display device according to claim 6, wherein: The light source displacement module causes the light spot to be displaced by deflecting the light beam.

8. The display device according to claim 6, wherein: The first displacement module is a continuous scanning device, and the second displacement module is a step-by-step scanning device.

9. The display device according to claim 6, wherein: The first displacement module and the second displacement module are both step-scan devices.

10. The display device according to claim 1, wherein The display device further includes a light combining module, which is located between the array light source and the imaging module and is used to combine the multiple light spots.

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