Near-to-eye display device and color feedback method

文档序号：1658148 发布日期：2019-12-27 浏览：12次中文

阅读说明：本技术 一种近眼显示装置及色彩反馈方法 (Near-to-eye display device and color feedback method ) 是由宋海涛其他发明人请求不公开姓名于 2019-08-09 设计创作，主要内容包括：本发明公开了一种近眼显示装置及色彩反馈方法,包括R、G、B光源,用于出射待显示图像对应的显示图像光；光扫描器件；光波导；图像采集单元；通过所述图像采集单元采集透过所述光波导的显示图像光,生成采集图像与待显示图像的RGB灰度值进行分析和比较,实现色彩矫正。上述方案用于解决现有技术中存在的激光器也易受温度、湿度、长时间工作老化的影响导致性能衰退,产生波长漂移、输出功率变化,会引起色彩、灰度失真,致使成像画质劣化的技术问题,使得激光器能够在不同环境、以及长时间工作的条件下保持性能稳定,保证成像质量。(The invention discloses a near-eye display device and a color feedback method, comprising an R, G, B light source for emitting display image light corresponding to an image to be displayed; an optical scanning device; an optical waveguide; an image acquisition unit; the image acquisition unit acquires the display image light penetrating through the optical waveguide, and the RGB gray values of the generated acquired image and the image to be displayed are analyzed and compared to realize color correction. The technical problem that the performance of a laser is prone to performance degradation caused by the fact that the laser is influenced by temperature, humidity and long-time working aging, wavelength drift and output power change are generated, color and gray level distortion can be caused, imaging image quality is deteriorated is solved, the laser can keep stable in performance under the conditions of different environments and long-time working, and imaging quality is guaranteed.)

1. A near-eye display device is characterized by comprising R, G, B light sources for emitting display image light corresponding to an image to be displayed; an optical scanning device for scanning and emitting the display image light; an optical waveguide including a coupling-in unit for coupling light emitted from the optical scanning device partially into the optical waveguide and partially through the optical waveguide;

the optical scanning device and the image acquisition unit are arranged on two sides of the optical waveguide, and the image acquisition unit is arranged facing the optical scanning device;

a readable storage medium having a program stored thereon, the program when executed by a processor implementing the steps of:

collecting display image light penetrating through the optical waveguide through the image collecting unit to generate a collected image;

selecting a target color area from the collected image, wherein the colors of all pixel points in the target color area are the same or similar, and performing color analysis on the target color area to obtain a collected RGB gray value of the target color area;

carrying out color analysis on an original color area corresponding to the target color area in the image to be displayed to obtain a standard RGB gray value of the original color area;

calculating an RGB gray difference value for representing the color distortion degree of the R, G, B light source according to the collected RGB gray value, the standard RGB gray value and the light transmittance of the light guide;

judging whether the RGB gray difference value is zero or not;

and if the RGB gray scale difference value is not zero, adjusting the output power of a corresponding light source in the R, G, B light source based on the RGB gray scale difference value.

2. The near-eye display device of claim 1, wherein the program when executed by the processor to perform the step of adjusting the output power of the corresponding one of the R, G, B light sources based on the RGB grayscale difference value specifically comprises the steps of:

acquiring a corresponding relation between the RGB gray scale difference value and output power, and adjusting the output power of a corresponding light source in the R, G, B light source based on the corresponding relation; or

And adjusting the output power of the corresponding light source in the R, G, B light sources by a preset value.

3. The near-eye display device according to claim 1 or 2, wherein the program executed by the processor to implement the step of collecting the display image light transmitted through the optical waveguide by the image collecting unit to generate the collected image specifically includes the steps of:

judging whether the target color area exists in the shot area in the image to be displayed, and obtaining a judgment result;

and when the judgment result is yes, controlling the image acquisition unit to acquire the display image light penetrating through the optical waveguide to generate an acquired image.

4. The near-eye display device according to claim 1 or 2, wherein the program executed by the processor to implement the step of collecting the display image light transmitted through the optical waveguide by the image collecting unit to generate the collected image specifically includes the steps of:

when the near-eye display device is started, the image acquisition unit acquires display image light penetrating through the optical waveguide to generate an acquired image; or

After the near-to-eye display device is started, the image acquisition unit acquires the display image light penetrating through the optical waveguide at preset intervals to generate an acquired image.

5. The near-eye display device of claim 1 wherein the program when executed by the processor to perform the step of calculating an RGB gray-scale value representing the degree of color distortion of the R, G, B light source based on the captured RGB gray-scale value, the standard RGB gray-scale value, and the light transmittance of the light guide comprises the steps of:

dividing the collected RGB gray value by the light transmittance of the optical waveguide to obtain an RGB gray intermediate value; calculating the difference value between the standard RGB gray value and the RGB gray intermediate value as the RGB gray difference value; or

Multiplying the standard RGB gray value by the light transmittance of the optical waveguide to obtain an RGB gray intermediate value; and calculating the difference value between the collected RGB gray value and the RGB gray intermediate value as the RGB gray difference value.

6. The near-eye display device of claim 1, wherein the incoupling unit is an incoupling grating, wherein the first order diffracted light emitted from the incoupling grating is coupled into the optical waveguide, and the zero order diffracted light emitted from the incoupling grating is transmitted through the optical waveguide.

7. The near-eye display device of claim 1 wherein the incoupling unit is an incoupling grating, and the optical scanning device emits display image light at an angle of incidence relative to the incoupling grating that is greater than a diffraction angle bandwidth of the incoupling grating.

8. A color feedback method is applied to a near-eye display device, and is characterized in that the near-eye display device comprises an R, G, B light source and a color feedback unit, wherein the R, G, B light source is used for emitting display image light corresponding to an image to be displayed; an optical scanning device for scanning and emitting the display image light; an optical waveguide including a coupling-in unit for coupling light emitted from the optical scanning device partially into the optical waveguide and partially through the optical waveguide; the optical scanning device and the image acquisition unit are arranged on two sides of the optical waveguide, and the image acquisition unit is arranged facing the optical scanning device; the method comprises the following steps:

collecting display image light penetrating through the optical waveguide through the image collecting unit to generate a collected image;

carrying out color analysis on an original color area corresponding to the target color area in the image to be displayed to obtain a standard RGB gray value of the original color area;

judging whether the RGB gray difference value is zero or not;

and if the RGB gray scale difference value is not zero, adjusting the output power of a corresponding light source in the R, G, B light source based on the RGB gray scale difference value.

9. The method as claimed in claim 8, wherein said adjusting output power of a corresponding one of said R, G, B light sources based on said RGB grayscale difference comprises the steps of:

And adjusting the output power of the corresponding light source in the R, G, B light sources by a preset value.

10. The method according to claim 8 or 9, wherein said collecting display image light transmitted through said light guide by said image collecting unit to generate a collected image comprises the steps of:

judging whether the target color area exists in the shot area in the image to be displayed, and obtaining a judgment result;

and when the judgment result is yes, the image acquisition unit acquires the display image light penetrating through the optical waveguide to generate an acquired image.

11. The method as claimed in claim 8 or 9, wherein the step of capturing the display image light emitted from the optical scanning device by the image capturing unit to generate the captured image comprises the steps of:

when the near-eye display device is started, the image acquisition unit acquires display image light penetrating through the optical waveguide to generate an acquired image; or

12. The method as claimed in claim 8, wherein the step of calculating the RGB gray-scale difference value for representing the color distortion degree of the R, G, B light source according to the collected RGB gray-scale value, the standard RGB gray-scale value and the light transmittance of the light guide comprises the following steps:

Technical Field

The invention relates to the field of projection display, in particular to a near-eye display device and a color feedback method.

Background

The imaging principle of the fiber scanning display technology (FSD) is that a scanning optical fiber is driven by an optical fiber scanner to perform a motion of a predetermined two-dimensional scanning track, and light emitted from a light source is modulated, i.e., light corresponding to each pixel point of an image to be displayed is modulated, and then the light corresponding to each pixel point of the image to be displayed is projected onto a projection plane one by one through the scanning optical fiber, thereby forming a projection picture.

The laser is often used as a light source in an optical fiber scanning display technology due to the characteristics of high brightness, high directivity, high monochromaticity, high coherence and the like, but the laser is also susceptible to performance degradation caused by temperature, humidity and long-time working aging, wavelength drift, output power change and the like are generated, color and gray scale distortion is caused, and imaging quality is deteriorated.

Disclosure of Invention

The invention aims to provide a near-eye display device and a color feedback method, which are used for solving the technical problems that in the prior art, a laser is easily influenced by temperature, humidity and long-time working aging to cause performance degradation, wavelength drift and output power change are generated, color and gray scale distortion is caused, and imaging image quality is deteriorated.

In order to achieve the above object, a first aspect of embodiments of the present invention provides a near-eye display device, including R, G, B a light source for emitting display image light corresponding to an image to be displayed; an optical scanning device for scanning and emitting the display image light; an optical waveguide including a coupling-in unit for coupling light emitted from the optical scanning device partially into the optical waveguide and partially through the optical waveguide;

the optical scanning device and the image acquisition unit are arranged on two sides of the optical waveguide, and the image acquisition unit is arranged facing the optical scanning device;

a readable storage medium having a program stored thereon, the program when executed by a processor implementing the steps of:

collecting display image light penetrating through the optical waveguide through the image collecting unit to generate a collected image;

carrying out color analysis on an original color area corresponding to the target color area in the image to be displayed to obtain a standard RGB gray value of the original color area;

judging whether the RGB gray difference value is zero or not;

and if the RGB gray scale difference value is not zero, adjusting the output power of a corresponding light source in the R, G, B light source based on the RGB gray scale difference value.

Optionally, when the program is executed by the processor to implement the step of adjusting the output power of the corresponding light source in the R, G, B light source based on the RGB grayscale difference value, the method specifically includes the following steps:

And adjusting the output power of the corresponding light source in the R, G, B light sources by a preset value.

Optionally, when the program is executed by the processor to realize the step of acquiring the display image light transmitted through the optical waveguide by the image acquisition unit to generate the acquired image, the method specifically includes the following steps:

judging whether the target color area exists in the shot area in the image to be displayed, and obtaining a judgment result;

and when the judgment result is yes, controlling the image acquisition unit to acquire the display image light penetrating through the optical waveguide to generate an acquired image.

when the near-eye display device is started, the image acquisition unit acquires display image light penetrating through the optical waveguide to generate an acquired image; or

Optionally, when the program is executed by the processor to implement the step of calculating the RGB gray-scale difference value used for characterizing the color distortion degree of the R, G, B light source according to the collected RGB gray-scale value, the standard RGB gray-scale value, and the light transmittance of the light guide, the method specifically includes the following steps:

Optionally, the coupling-in unit is a coupling-in grating, the first-order diffracted light emitted from the coupling-in grating is coupled into the optical waveguide, and the zero-order diffracted light emitted from the coupling-in grating passes through the optical waveguide.

Optionally, the coupling-in unit is a coupling-in grating, and an incident angle of the display image light emitted from the optical scanning device with respect to the coupling-in grating is greater than a diffraction angle bandwidth of the coupling-in grating.

A second aspect of the embodiments of the present invention provides a color feedback method, which is applied to a near-eye display device, where the near-eye display device includes an R, G, B light source, configured to emit display image light corresponding to an image to be displayed; an optical scanning device for scanning and emitting the display image light; an optical waveguide including a coupling-in unit for coupling light emitted from the optical scanning device partially into the optical waveguide and partially through the optical waveguide; the optical scanning device and the image acquisition unit are arranged on two sides of the optical waveguide, and the image acquisition unit is arranged facing the optical scanning device; the method comprises the following steps:

collecting display image light penetrating through the optical waveguide through the image collecting unit to generate a collected image;

carrying out color analysis on an original color area corresponding to the target color area in the image to be displayed to obtain a standard RGB gray value of the original color area;

judging whether the RGB gray difference value is zero or not;

and if the RGB gray scale difference value is not zero, adjusting the output power of a corresponding light source in the R, G, B light source based on the RGB gray scale difference value.

Optionally, the adjusting the output power of the corresponding light source in the R, G, B light source based on the RGB grayscale difference specifically includes the following steps:

And adjusting the output power of the corresponding light source in the R, G, B light sources by a preset value.

Optionally, the acquiring, by the image acquisition unit, the display image light transmitted through the optical waveguide to generate the acquired image specifically includes the following steps:

judging whether the target color area exists in the shot area in the image to be displayed, and obtaining a judgment result;

and when the judgment result is yes, the image acquisition unit acquires the display image light penetrating through the optical waveguide to generate an acquired image.

Optionally, the image acquisition unit is configured to acquire display image light emitted by the optical scanning device to generate an acquired image, and the method specifically includes the following steps:

when the near-eye display device is started, the image acquisition unit acquires display image light penetrating through the optical waveguide to generate an acquired image; or

Optionally, the step of calculating an RGB gray-scale difference value for representing the color distortion degree of the R, G, B light source according to the collected RGB gray-scale value, the standard RGB gray-scale value, and the light transmittance of the optical waveguide specifically includes the following steps:

One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

in the scheme of the embodiment of the invention, the display image light emitted by the optical scanning device is collected through the image collection unit to generate a collected image, a target color area is selected from the collected image to carry out color analysis to obtain a collected RGB gray value, an RGB gray difference value used for representing the color distortion degree of the R, G, B light source is calculated according to the collected RGB gray value and the light transmittance of the optical waveguide of a standard RGB gray value, and then the output power of a corresponding light source in the R, G, B light source is adjusted based on the RGB gray difference value until the RGB gray difference value is zero, so that the technical problems that a laser in the prior art is susceptible to temperature, humidity and long-time working aging to cause performance degradation, wavelength drift and output power change are generated, color and gray distortion are caused, and the imaging quality of the laser can be degraded in different environments are solved, and the laser can be used in different environments, And the performance is kept stable under the condition of long-time working, and the imaging quality is ensured.

In addition, in the scheme of the embodiment of the invention, the image acquisition unit is arranged facing the optical scanning device to acquire the light emitted by the optical scanning device so as to perform color feedback, the structure is simple, the vibration states of the optical scanning device and the optical fiber are not influenced, and the light transmitted out of the waveguide is used for detection feedback by utilizing the property of the waveguide coupling-in unit, so that the utilization rate of the imaging light is not reduced because the light is not used for imaging.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without inventive exercise:

FIGS. 1A and 1B are schematic diagrams of a fiber scanning imaging system according to an embodiment of the present invention;

fig. 2A is a schematic diagram of a possible structure of smart glasses according to an embodiment of the present invention;

fig. 2B is a schematic diagram of another possible structure of smart glasses according to an embodiment of the present invention;

fig. 3A and 3B are schematic structural diagrams of a near-eye display device according to an embodiment of the present invention;

fig. 3C is a block diagram of a near-eye display device according to an embodiment of the invention;

FIG. 4 is a flowchart illustrating a color feedback method according to an embodiment of the present invention;

fig. 5 is a schematic diagram of a corresponding relationship between an RGB grayscale difference and an output power according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of another possible near-eye display device according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1A and fig. 1B, fig. 1A and fig. 1B are schematic diagrams of an optical fiber scanning imaging system according to an embodiment of the present invention. The optical fiber scanning imaging system mainly comprises: the device comprises a processor, a scanning driving circuit, a light source module, a light source modulation module, an optical fiber scanner 11, a light source beam combining module 12 and an optical fiber 13. The working principle of the optical fiber scanning imaging system is as follows: the processor drives the optical fiber scanner 11 by sending an electric control signal to the scan driving circuit, and at the same time, the processor controls the light emitting condition of the light source module by sending an electric control signal to the light source modulation module. The signal transmission among the processor, the scanning driving circuit and the light source modulation module can be performed through an electronic input/output device, the light source modulation module outputs a light source modulation signal according to a received control signal to modulate light emitting units (such as a laser/a light emitting diode, and the like, and red, green, blue, and RGB three-color laser shown in fig. 1A) with multiple colors in the light source module, light generated by the light emitting units with each color in the light source module is combined by a light source combining module 12 to generate light corresponding to each pixel point in an image one by one, light beams generated by the light source combining module 12 are guided into an optical fiber scanner 11 through an optical fiber 13, and simultaneously, the scanning driving circuit outputs a scanning driving signal according to the received control signal to control the optical fiber 13 in the optical fiber scanner 11 to perform two-dimensional scanning tracks (such as spiral scanning and grid type scanning) in a predetermined manner, Lissajous scanning), and then the optical system amplifies and projects the light of each pixel point emitted from the optical fiber 13 onto a projection surface to form an image. In the embodiment of the invention, the light emitted by the optical fiber scanning imaging system directly enters human eyes.

Referring to fig. 2A, which is a schematic view of a possible structure of an intelligent glasses according to an embodiment of the present invention, an optical fiber scanner 20 is disposed at a temple of the intelligent glasses, as shown in fig. 2A, the optical fiber scanner 20 is disposed at a connecting end of the temple close to a frame, a light source module 22 is disposed at a terminal end of the temple, the optical fiber scanner 20 is connected to the light source module 22 through an optical fiber 21, an optical system 23 is disposed on an emergent light path of the optical fiber scanner 20, and light emitted from the optical system 23 is guided into a human eye 25 through an optical waveguide 24.

Referring to fig. 2B, another possible structural schematic diagram of the smart glasses according to the embodiment of the present invention is shown, and is different from the smart glasses in fig. 2A, the optical fiber scanner 20 is disposed at a frame of the smart glasses, the optical fiber scanner 20 is connected to the light source module 22 through an optical fiber 21, the optical system 23 is disposed on an emergent light path of the optical fiber scanner 20, and light emitted from the optical system 23 is guided into a human eye 25 through an optical waveguide 24.

Referring to fig. 3A to fig. 3C, fig. 3A and fig. 3B are schematic structural diagrams of a near-eye display device according to an embodiment of the present invention, and fig. 3C is a schematic module diagram of the near-eye display device according to the embodiment of the present invention, where the near-eye display device includes R, G, B a light source 31 for emitting display image light corresponding to an image to be displayed; an optical scanning device 32 connected to the R, G, B light source 31 for scanning the display image light; an optical waveguide 33 including a coupling-in unit 330 for coupling light emitted from the optical scanning device 32 partially into the optical waveguide 33 and partially through the optical waveguide 33; r, G, B the light source 31 may be a RGB laser. The optical scanning device 32 may be a fiber scanner, or may be a MEMS (micro electro Mechanical Systems) scanning mirror or the like.

Image acquisition unit 34, light scanning device 32 with image acquisition unit 34 sets up the both sides of light guide 33, image acquisition unit 34 faces light scanning device 32 sets up, image acquisition unit 34 is used for gathering the demonstration image light that passes through light guide 33 obtains the collection image that the image of waiting to show corresponds. The image capturing unit 34 may be implemented by a device having an imaging function, such as a camera or a video camera. Readable storage medium 35 includes, but is not limited to, disk storage, CD-ROM (Compact disk Read-Only Memory), optical storage, and the like. The readable storage medium 35 has stored thereon a program which, when executed by the processor 36, implements the following steps, as shown in fig. 4.

Step 401, collecting the display image light transmitted through the optical waveguide by the image collecting unit to generate a collected image.

Step 402, selecting a target color area from the acquired image, wherein the colors of all pixel points in the target color area are the same or similar, and performing color analysis on the target color area to obtain an acquired RGB gray value of the target color area. In the embodiment of the present invention, the RGB gray-scale values refer to an R gray-scale value, a G gray-scale value, and a B gray-scale value. For the selected target color area, the colors of all pixels are the same, and because the color of each pixel point in a certain small area is almost impossible to appear in the real display scene is always completely different, the target color scale area with the same or similar colors to all the pixel points can be selected.

In the embodiment of the present invention, the same color means that the RGB grayscale values of each pixel in the target color region are the same, and the close colors can be understood as that the difference values between the R, G grayscale values and the B grayscale values between the pixels are smaller than the threshold, and the thresholds corresponding to R, G and the B grayscale values may be the same or different. For example, taking the R gray scale value as an example, assuming that the threshold is 5, the difference between the R gray scale values of two pixels is less than 5, and the difference between the G gray scale value and the B gray scale value is less than the corresponding threshold, the two pixels are considered to have similar colors, so that the target regions with similar colors are selected in this way.

Step 403, performing color analysis on an original color region corresponding to the target color region in the image to be displayed to obtain a standard RGB gray value of the original color region. The standard RGB gray scale value refers to the original color information (i.e., RGB ratio) of the pixels in the region in the source video signal.

And 404, calculating an RGB gray level difference value for representing the color distortion degree of the R, G, B light source according to the collected RGB gray level value, the standard RGB gray level value and the light transmittance of the light guide. The RGB gray scale difference values refer to R gray scale difference values, G gray scale difference values, and B gray scale difference values. In step 404, the standard RGB gray value is compared with the collected RGB gray value to know whether the color is distorted. For example, when the standard RGB gray-scale values are all 100, the R gray-scale value obtained by actual analysis is 90, and the G gray-scale value and the B gray-scale value are both 100, it indicates that the actual output gray-scale value of R is insufficient.

Step 405, determining whether the RGB grayscale difference is zero. If the RGB gray scale difference is not zero, go to step 406; and if the RGB gray difference value is zero, finishing the correction. In step 405, the RGB gray scale difference value is not zero, which may be understood as at least one of the R gray scale difference value, the G gray scale difference value, and the B gray scale difference value is not zero.

And 406, adjusting output power of a corresponding light source in the R, G, B light source based on the RGB grayscale difference value. Following the example in step 404, if the actual output gray scale of R is not enough, in step 406, the output energy (i.e. output power) of the R light source is increased, and then steps 401-406 are repeated until the RGB gray scale difference value is zero, so that the R gray scale value is also 100 in the finally collected RGB gray scale value.

In this embodiment of the present invention, in the implementation step 404, when the RGB gray-scale difference value used for representing the color distortion degree of the R, G, B light source is calculated according to the collected RGB gray-scale value, the standard RGB gray-scale value, and the light transmittance of the light guide, there may be the following two possible implementation manners, and in practical applications, the implementation manner is not limited to the following two manners.

In one possible embodiment, the acquired RGB gray scale value is divided by the transmittance of the optical waveguide to obtain an RGB gray scale intermediate value, and then a difference value between the standard RGB gray scale value and the RGB gray scale intermediate value is calculated as the RGB gray scale difference value. The transmittance of the optical waveguide refers to the transmittance of light emitted by the optical scanning device and incident on the optical waveguide, and the transmittances of the RGB three-color light may be the same or different, and when the transmittances of the RGB three-color light are different, calculation needs to be performed according to the different transmittances.

In another possible implementation, the standard RGB gray value is multiplied by the transmittance of the optical waveguide to obtain an RGB gray intermediate value; and calculating the difference value between the collected RGB gray value and the RGB gray intermediate value as the RGB gray difference value.

In the embodiment of the present invention, in the step 406, when the output power of the corresponding light source in the R, G, B light source is adjusted based on the RGB grayscale difference, there may be the following two possible implementations, and in practical applications, the implementations are not limited to the following two implementations.

In one possible embodiment, the near-eye display device stores a corresponding relationship between the RGB grayscale difference and the output power, where the corresponding relationship may be a predetermined value stored in the near-eye display device in advance, or may be a value obtained by continuously updating the iteration through multiple corrections during the operation of the near-eye display device. And adjusting the output power of a corresponding light source in the R, G, B light sources by acquiring the corresponding relation between the RGB gray scale difference value and the output power and based on the corresponding relation. As shown in fig. 5, the corresponding relationship between the RGB gray scale difference values and the output powers is illustrated, and the data in fig. 5 is only an example and is not limited in particular.

In another possible embodiment, the output power of the corresponding light source in the R, G, B light sources is adjusted by a preset value, and if the preset value is a, the output power of the corresponding light source is directly increased or decreased by a when the output power of the corresponding light source needs to be adjusted.

In the embodiment of the invention, in order to avoid extremely severe color change (namely large difference between all adjacent pixel points) of the area shot by the image acquisition unit under some extreme display conditions, the system can make a prejudgment when accessing the video signal. Specifically, since the shot area cannot be always in a display state with a drastic color change, some image frames always meet the requirements with the change of the display scene, and then feedback correction can be performed by shooting the images meeting the requirements. In other words, most of the real display scenes have color blocks, and the colors of all the pixels in such color blocks are the same or similar. Therefore, when the video signal is accessed, the system can make a prejudgment to judge whether a target color area with the same or similar colors of all pixels in the area exists in the shot area of the image to be displayed, and if the target color area exists, the system controls the image acquisition unit to acquire the display image light emitted by the optical scanning device to generate an acquired image. The captured region may be a whole image or a partial image, which is not limited in the present invention.

The optical scanning device displays a frame of image and the time delay between the frame of image acquired by the image acquisition unit is fixed, and the acquired image and the image to be displayed can be accurately corresponding as long as the optical scanning device and the image acquisition unit are synchronized. Of course, even if there is no precise synchronization between the optical scanning device and the image capturing unit, the color correction in the embodiment of the present invention is not affected because there is no drastic color change in the adjacent several or more than ten frames of images in a general video signal.

It should be noted that, in the embodiment of the present invention, as long as the shooting and the determination are accurate, only one pixel point is theoretically needed to complete the color feedback correction process, and therefore, the color change of the display scene does not have a substantial influence on the color correction. In the embodiment of the invention, the camera can shoot more easily by selecting the large-area color block (namely the color area), so that the requirement on hardware is lower, and the accuracy is improved.

In the embodiment of the invention, because the color distortion of the laser is a slowly changing process and does not need to be corrected in real time, the correction can be performed when the near-eye display device is started, or the correction can be performed once at preset time intervals after the near-eye display device is started, so that the performance requirement is reduced. Moreover, since the color distortion is a slow process, the performance of the laser is aged very slowly along with the extension of the working time, and therefore, only fine adjustment is needed, and additional problems such as influence on the modulation of the laser and the like are not caused.

Next, a mode of setting the image pickup unit in the embodiment of the present invention will be described.

In the embodiment of the present invention, the coupling unit 330 is configured to couple part of the light emitted from the optical scanning device 32 into the optical waveguide 33 and part of the light passes through the optical waveguide 33. In a possible embodiment, with continued reference to fig. 3A and 3B, the image capturing unit 34 is disposed opposite to the optical waveguide 33 of the fiber scanner 32 along the exit light path of the fiber scanner 32, the coupling-in unit 330 is a coupling-in grating, the exit light of the optical scanner 32 is collimated by the optical system 37 and then enters the optical waveguide 33 via the coupling-in grating to propagate as +1/-1 st-order diffracted light (shown by solid lines in fig. 3A and 3B), but the 0 th-order diffracted light (shown by dotted lines in fig. 3A and 3B) of the exit light of the optical scanner 32 directly enters the image capturing unit 34. It should be noted that, in fig. 3A, the 0 th order diffracted light is projected into the image capturing unit 34, and the three light rays represent three fields of view which are not parallel light, and are only used for indication and do not represent actual light path traces as shown in fig. 3A.

In another possible implementation manner, as shown in fig. 6, which is a schematic diagram of another possible arrangement manner of the image capturing unit in the embodiment of the present invention, wherein the incoupling unit 330 is an incoupling grating, and since the incoupling grating has a diffraction angle bandwidth (generally, around 35 °), and the incoupling grating has little diffraction effect on the incident light with an incident angle exceeding the diffraction angle bandwidth, the incoupling grating directly transmits the incoupling grating. Therefore, the incident angle of the light emitted from the optical scanning device 32 with respect to the coupling grating may be slightly larger than the diffraction angle bandwidth, for example, 35 °, the designed incident angle is 0 ° - (35+ n) °, and n may be a relatively small value such as 1, 2, and the like. Thus, 0-35 of the incident light is propagated by the incoupling waveguide, and the remaining n of the incident light is transmitted through the incoupling grating into the corresponding image pick-up unit 34.

It should be noted that, in the embodiment corresponding to fig. 3A and 3B, the shooting area of the image capturing unit 34 is an area that can be seen by the user, whereas in the embodiment corresponding to fig. 6, the light transmitted through the optical waveguide 33 can only be projected by the incident light at the above-mentioned remaining n °, the area shot by the image capturing unit 34 is an area that cannot be seen by the user, and the color feedback correction is realized by the display area with fixed edge, so that the image capturing unit 34 with large field angle FOV is not needed, which is beneficial to reducing the cost and the requirement of hardware selection.

Based on the same inventive concept, the embodiment of the present invention further provides a color feedback method, which is applied to a near-eye display device, where the near-eye display device includes R, G, B light sources for emitting display image light corresponding to an image to be displayed; an optical scanning device for scanning and emitting the display image light; an optical waveguide including a coupling-in unit for coupling light emitted from the optical scanning device partially into the optical waveguide and partially through the optical waveguide; the optical scanning device and the image acquisition unit are arranged on two sides of the optical waveguide, and the image acquisition unit is arranged facing the optical scanning device; the method comprises the following steps: