Display device and head-mounted display device

Abstract

The application provides a display device, comprising: a first display screen, comprising a low-pixel display area and a hollow area surrounded by the low-pixel display area; a second display screen embedded in the hollow area of the first display screen, the second display screen comprising a high-pixel display area; the pixel density of the low-pixel display area is less than the pixel density of the high-pixel display area. The display device has different screen resolutions in different field angles of the human eye, so that the human eye has a better experience when watching the display image of the display device. The application also provides a head-mounted display device comprising the display device.

Description

Technical Field

[0001] This application relates to a display device, and a head-mounted display device including the display device. Background Technology

[0002] Currently, some head-mounted display devices on the market use displays with excessively low screen resolution (Pixels per inch, PPI) and spatial resolution (Pixels per degree, PPD), resulting in unclear images for the human eye. Other head-mounted display devices use displays with very high PPI, allowing the human eye to see details. However, the human eye can only clearly distinguish a visual area within a 30° field of view (FOV). Beyond a 30° FOV, the human eye can only perceive the environment and the general presence of objects, unable to discern specific details; an excessively high PPD is wasteful. Therefore, if all head-mounted display devices used high-PPI displays, it would increase the cost of manufacturing the displays, making the devices prohibitively expensive. Summary of the Invention

[0003] The first aspect of this application provides a display device, comprising:

[0004] The first display screen includes a low-pixel display area and a cutout area surrounded by the low-pixel display area;

[0005] The second display screen is embedded in the hollowed-out area of ​​the first display screen, and the second display screen includes a high-pixel display area;

[0006] The pixel density of the low-pixel display area is less than that of the high-pixel display area.

[0007] The aforementioned display device includes a first display screen and a second display screen. The screen resolution of the low-pixel display area in the first display screen is lower than the screen resolution of the high-pixel display area in the second display screen. That is, the image displayed on the second display screen is clearer than the image displayed on the first display screen. The human eye can only clearly distinguish details of images within the central area of ​​the human eye's field of view (generally FOV 30°). For scenes outside the central area of ​​the field of view, only the environment and the general presence of objects can be perceived, but specific details within the scene cannot be identified. In the display device of this application, the second display screen is located within the central area of ​​the field of view, and the first display screen is located outside the central area of ​​the field of view. At this time, the eye can clearly see the clear image displayed on the second display screen, and simultaneously, the eye can also perceive the general image content displayed on the first display screen outside the central area of ​​the field of view. Compared to display devices with the same display area but using high screen resolution across the entire display area, the display device of this application reduces the manufacturing cost of the display screen while also meeting the spatial resolution required by the human eye when viewing the display screen, thereby improving the user experience when using the display device.

[0008] A second aspect of this application provides a head-mounted display device, comprising:

[0009] frame;

[0010] The display device described above is fixed within the frame and is used to display images.

[0011] The aforementioned head-mounted display device integrates the aforementioned display apparatus, thus achieving all the beneficial effects of the aforementioned display apparatus. Attached Figure Description

[0012] Figure 1 This is a side view of the display device according to the first embodiment of this application.

[0013] Figure 2 for Figure 1 A schematic diagram of the planar structure in which the first and second displays are assembled together.

[0014] Figure 3 for Figure 1 A schematic diagram of the planar structure of the first display screen in the image.

[0015] Figure 4 for Figure 1 A schematic diagram of the planar structure of the second display screen.

[0016] Figure 5 for Figure 1 A schematic diagram of the lens structure.

[0017] Figure 6This is a side view of a display device according to a second embodiment of this application.

[0018] Figure 7 This is a schematic diagram of a modified example of the lens of the display device of this application.

[0019] Figure 8 This is a three-dimensional structural diagram of a head-mounted display device according to an embodiment of this application.

[0020] Figure 9 for Figure 8 An exploded view of the head-mounted display device.

[0021] Explanation of main component symbols

[0022] Display devices 100, 300

[0023] First display screen 10

[0024] First pixel 101

[0025] Long side 102

[0026] Short side 103

[0027] Low-pixel display area 11

[0028] The upper part 111

[0029] Hollowed-out area 12

[0030] The first side length is 121.

[0031] Pixel connection 13

[0032] Interval 14

[0033] Second display screen 30

[0034] Second pixel 301

[0035] The second side length is 302.

[0036] High-pixel display area 31

[0037] Lenses 50a, 50b, 50c

[0038] Page 501

[0039] First curved surface 501a

[0040] Second surface 501b

[0041] Second page 502

[0042] Area 1, 503

[0043] Zone 2, Room 504

[0044] Area 3, 505

[0045] First lens section 51

[0046] Second lens section 52

[0047] First lens element 53

[0048] Second lens element 54

[0049] Third lens element 55

[0050] First driving circuit 70

[0051] Head-mounted display device 200

[0052] Frame 20

[0053] First Framework 21

[0054] Second Framework 22

[0055] Third Framework 23

[0056] Motherboard 40

[0057] Processing device 60

[0058] Cover plate 80

[0059] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0060] Existing head-mounted display devices mostly use display devices with low screen resolution to display images, resulting in unclear images perceived by the human eye. Some head-mounted display devices use display devices with high screen resolution, increasing manufacturing costs. The display device of this application combines two displays with different screen resolutions to display images, thereby solving the above problems.

[0061] Please refer to the following: Figure 1 and Figure 2 The display device 100 of the first embodiment of this application includes a first display screen 10 and a second display screen 30. For the sake of clarity, Figure 2The borders that may exist between the first display screen 10 and the second display screen 30 are omitted, and only the display areas of the first display screen 10 and the second display screen 30 are shown. The first display screen 10 includes a low-pixel display area 11 and a cutout area 12 surrounded by the low-pixel display area 11. The second display screen 30 is embedded in the cutout area 12 of the first display screen 10, and the second display screen 30 includes a high-pixel display area 31. The pixel density of the low-pixel display area 11 is lower than the pixel density of the high-pixel display area 31, making the screen resolution of the first display screen 10 lower than the screen resolution of the second display screen 30.

[0062] The first display screen 10 and the second display screen 30 are used to jointly display the same image. That is, the first display screen 10 and the second display screen 30 are used to display different parts of the same image, or they can be used to display the same or different images. The first display screen 10 and the second display screen 30 are used to jointly display the same image. The display device 100 also includes a first driving circuit 70 and a second driving circuit (not shown). The first driving circuit 70 is located at the edge of the first display screen 10 away from the cutout area 12, and the second driving circuit is located on the side of the second display screen 30 that does not emit image light. The first driving circuit 70 and the second driving circuit respectively drive the first display screen 10 and the second display screen 30 to emit image light. When the first display screen 10 and the second display screen 30 are used to jointly display the same image, all the image light emitted by the first display screen 10 and all the image light emitted by the second display screen 30 are received by the human eye, ultimately allowing the human eye to see the complete display image.

[0063] Please see Figure 3 The first display screen 10 is an Organic Light-Emitting Diode (OLED) display screen or a Liquid Crystal Display (LCD). The low-pixel display area 11 of the first display screen 10 is arrayed with a plurality of first pixels 101, each electrically connected to the first driving circuit 70. The cutout area 12 is a through-hole formed on the first display screen 10, penetrating the opposing front and rear surfaces of the first display screen 10. A plurality of pixel lines 13 are arranged within the cutout area 12 near the edge of the low-pixel display area 11, and these pixel lines 13 are located in the gap between the second display screen 30 and the first display screen 10. The pixel lines 13 are also located on the side of the low-pixel display area 11 where no image light is emitted. The plurality of first pixels 101 in the upper portion 111 of the low-pixel display area 11, located on the side of the cutout area 12 away from the first driving circuit 70, are electrically connected to the first driving circuit 70 via the pixel lines 13, enabling the first pixels 101 in the upper portion 111 to receive electrical signals and thus emit image light.

[0064] Please see Figure 4The second display screen 30 is an inorganic light-emitting diode display screen, including a micro-light-emitting diode (MicroLED) display screen or a nano-scale light-emitting diode (NanoLED) display screen. The high-pixel display area 31 array of the second display screen 30 is provided with a plurality of second pixels 301, and the plurality of second pixels 301 are electrically connected to the second driving circuit respectively.

[0065] Please see Figure 2 Taking the case where the outer edge of the display surface of the first display screen 10 is rectangular, including a long side 102 and a short side 103, and the display surface of the second display screen 30 is square as an example, the low-pixel display area 11 of the first display screen 10 is a frame structure with a rectangular opening, and the projected outline of the cutout area 12 in the direction perpendicular to the thickness of the first display screen 10 is a square, which includes multiple first side lengths 121. The display surface of the second display screen 30 is also square, including multiple second side lengths 302, and the length of the first side length 121 is greater than the length of the second side length 302. Taking the application of display device 100 in a head-mounted display device as an example, when a user wears the head-mounted display device, since the position of the human eye relative to display device 100 is fixed, the field of view (FOV) is determined when the human eye views the display image. The area of ​​the outer edge shape of the display surface of the first display screen 10 is also determined. At this time, the lengths of the long side 102 and the short side 103 of the outer edge shape of the display surface of the first display screen 10 are also determined. Both the first display screen 10 and the second display screen 30 are located within the area enclosed by the human eye's field of view. To ensure that the second display screen 30 is located within the central area of ​​the field of view where the human eye can clearly distinguish image details, according to the Pythagorean theorem, given the size of the human eye's FOV, the size of the central FOV area, and the lengths of the long side 102 and the short side 103 of the outer edge shape of the display surface of the first display screen 10, the size of the second side length 302 of the display surface of the second display screen 30 can be estimated using the following relationship, thereby determining the area of ​​the display surface of the second display screen 30:

[0066]

[0067]

[0068]

[0069]

[0070] Ap = L × W

[0071] Ac=Lc 2

[0072] Wherein, Dp is the length of the diagonal of the outer edge of the display surface of the first display screen 10, in inches; L is the length of the long side 102, in millimeters; W is the length of the short side 103, in millimeters; dist is the distance (viewing distance) between the human eye and the display surface of the second display screen 10, in millimeters; Lc is the length of the second side 302, in millimeters; Dc is the length of the diagonal of the display surface of the second display screen 30, in inches; Ap is the area of ​​the rectangular region formed by the long side 102 and the short side 103, in square millimeters; Ac is the area of ​​the display surface of the second display screen 10, in square millimeters; FOVp is the FOV of the human eye, in degrees; FOVc is the FOV of the central region of the human eye's field of view, in degrees; and 25.4 is the conversion factor between millimeters and inches.

[0073] Based on the above formula, it can be concluded that the percentage reduction in the area of ​​the display surface of the second display screen 30 compared to the area of ​​the rectangle enclosed by the long side 102 and the short side 103 of the outer edge shape of the display surface of the first display screen 10 is:

[0074]

[0075] In other embodiments, the outer edge shape of the display surface of the first display screen 10 and the display surface of the second display screen 30 can be other shapes. For example, when the outer edge shape of the display surface of the first display screen 10 is circular, the low-pixel display area 11 is a frame structure with a circular opening, the projection outline of the cutout area 12 perpendicular to the thickness direction of the first display screen 10 is circular, and the display surface of the second display screen 30 is also circular. Furthermore, the area of ​​the display surface of the second display screen 30 is smaller than the area enclosed by the projection outline of the cutout area 12 perpendicular to the thickness direction of the first display screen 10. In this case, if the diameter of the outer edge shape of the display surface of the first display screen 10, the FOV of the human eye, and the FOV of the central region of the human eye's field of view are known, the size of the second side length 302 of the display surface of the second display screen 30 and the area of ​​the display surface of the second display screen 30 can be calculated according to the above formula and combined with the formula for calculating the area of ​​a circle. This allows for the estimation of the percentage reduction in the area of ​​the display surface of the second display screen 30 compared to the area enclosed by the long side 102 and the short side 103 of the outer edge shape of the display surface of the first display screen 10.

[0076] The display device 100 of this application includes a first display screen 10 and a second display screen 30. The screen resolution of the low-pixel display area 11 in the first display screen 10 is lower than the screen resolution of the high-pixel display area 31 in the second display screen 30. That is, the image displayed on the second display screen 30 is clearer than the image displayed on the first display screen 10. The human eye can only clearly distinguish the details of the image within the central area of ​​the human eye's field of view (generally FOV 30°). For scenes located outside the central area of ​​the field of view, only the environment and the general existence of objects can be perceived, but the specific details within the scene cannot be identified. In the display device 100 of this application, the second display screen 30 is located within the central area of ​​the field of view, and the first display screen 10 is located outside the central area of ​​the field of view. At this time, the human eye can clearly see the clear image displayed on the second display screen 30, and at the same time, the human eye can also perceive the general image content displayed on the first display screen 10, which is located outside the central area of ​​the field of view. Compared to display devices with the same display area but using high screen resolution across the entire display area, the display device 100 of this application has a significantly smaller high screen resolution display area. Therefore, while reducing the manufacturing cost of the display screen, the display device 100 of this application also meets the spatial resolution required by the human eye when viewing the display screen, thereby improving the user experience when using the display device 100.

[0077] Please see Figure 1 The display device 100 further includes a lens 50a, located in the optical path of the image light emitted from the first display screen 10 and the second display screen 30, for transmitting the image light emitted from the first display screen 10 and the second display screen 30, thereby changing the optical path of the image light. The lens 50a includes a first surface 501 and a second surface 502 opposite to each other. The first surface 501 is curved and located on the side of the lens 50a closer to the first display screen 10, for receiving the image light emitted from the first display screen 10 and the second display screen 20. The second surface 502 is located on the side of the lens 50a away from the first display screen 10, for emitting the image light transmitted through the lens 50a, so that the image light emitted from the second surface 502 is received by the human eye, ultimately allowing the human eye to see the displayed image.

[0078] Please refer to the following: Figure 1 and Figure 5Lens 50a includes a first lens portion 51 and a second lens portion 52 connected to and surrounding the first lens portion 51. The optical axis of the first lens portion 51 coincides with the optical axis of the second lens portion 52. The first surface 501 and the second surface 502 of lens 50a are both formed by the first lens portion 51 and the second lens portion 52. The first lens portion 51 is disposed corresponding to the second display screen 30, and the second lens portion 52 is disposed corresponding to the first display screen 10. The outline of the projection of lens 50a onto the first display screen 10 extends beyond or coincides with the outer edge of the low-pixel display area 11, allowing lens 50a to transmit image light emitted from the first display screen 10 and the second display screen 30. The outline of the projection of the first lens portion 51 onto the second display screen 30 extends beyond or coincides with the edge of the high-pixel display area 31, and the outline of the projection of the first lens portion 51 onto the first display screen 10 does not extend beyond the edge of the cutout area 12, allowing the first lens portion 51 to transmit image light emitted from the second display screen 30 but not to transmit image light emitted from the first display screen 10. The inner edge of the projection outline of the second lens portion 52 onto the first display screen 10 is located within the cutout area 12, but not within the projection of the high-pixel display area 31 onto the first display screen 10. Alternatively, the inner edge of the projection outline of the second lens portion 52 onto the first display screen 10 may coincide with the inner edge of the low-pixel display area 11, and the outer edge of the projection outline of the second lens portion 52 onto the first display screen 10 may extend beyond the outer edge of the low-pixel display area 11 or coincide with the outer edge of the low-pixel display area 11.

[0079] The curvature of the first lens portion 51 on the first surface 501 and the curvature of the second lens portion 52 on the first surface 501 are both negative or both positive, and the absolute value of the curvature of the first lens portion 51 on the first surface 501 is greater than the absolute value of the curvature of the second lens portion 52 on the first surface 501. The curved surface of the second lens portion 502 on the first surface 501 is a first curved surface 501a, and the curved surface of the first lens portion 51 on the first surface 501 is a second curved surface 501b. The first curved surface 501a connects to and surrounds the second curved surface 501b. In this embodiment, both the first curved surface 501a and the second curved surface 501b are curved away from the second surface 502, and the degree of curvature of the second curved surface 501b is greater than the degree of curvature of the first curved surface 501a. That is, the curvature of the first curved surface 501a and the curvature of the second curved surface 501b are both positive, and the curvature of the second curved surface 501b is greater than the curvature of the first curved surface 501a.

[0080] There is a gap region 14 between the second display screen 30 and the first display screen 10. The gap region 14 has no pixels and does not emit image light. In the area between the lens 50a and the first display screen 10 and the second display screen 30, along the direction of image light propagation, the area corresponding to the first display screen 10 is the first area 503, the area corresponding to the second display screen 30 is the second area 504, the second area 504 is surrounded by the first area 503, and the area corresponding to the gap region 14 is the third area 505, which is located between the first area 503 and the second area 504.

[0081] The first curved surface 501a and the second curved surface 501b respectively receive the image light propagating in the first region 503 and the second region 504, and deflect the image light toward the optical axis of the first lens portion 51. When the image light is emitted from the second surface 502, the image light located in the first region 503 and the image light located in the second region 504 are received by the human eye, so that the human eye sees a continuous display screen (borderless visual effect). That is, the lens 50a is used to deflect the image light emitted by the first display screen 10 near the cutout area 12 toward the second display screen 30, so that the display screen corresponding to the first region 503 and the display screen corresponding to the second region 504 are connected to form a continuous (non-disconnected) screen.

[0082] Please see Figure 6 The display device 300 of the second embodiment of this application is similar to the display device 100 of the first embodiment, except that the first curved surface 501a and the second curved surface 501b of the lens 50b are both curved towards the second surface 502, and the curvature of the second curved surface 501b is greater than that of the first curved surface 501a. That is, the curvature of the first curved surface 501a and the curvature of the second curved surface 501b are both negative, and the curvature of the second curved surface 501b is less than that of the first curved surface 501a. At this time, the first curved surface 501a and the second curved surface 501b respectively receive the image light propagating in the first region 503 and the second region 504, and deflect the image light away from the optical axis of the first lens portion 51. At this time, the lens 50b is used to deflect the image light emitted from the edge of the second display screen 30 toward the first display screen 10, so that the display screen corresponding to the first region 503 and the display screen corresponding to the second region 504 are connected to form a continuous (non-disconnected) screen, and finally the eye 300 sees a continuous screen.

[0083] Please see Figure 5Taking the example where the curvature of the first surface 501a and the curvature of the second surface 501b are both positive, according to the lens imaging formula, given the refractive index of the medium between the lens 50a and the first display screen 10 and the second display screen 30, the refractive index of the medium inside the lens 50a, the refractive index of the medium between the lens 50a and the eye 300, the thickness of the thickest part of the lens 50a (i.e., the maximum distance between the first surface 501 and the second surface 502), the distance at which the lens 50a can focus parallel light rays to the focal point, the overall focal length corresponding to the optical effect produced by the lens 50a, and the imaging distance of the lens 50a, the radius of curvature of the first surface 501a and the radius of curvature of the second surface 501b can be deduced using the following relationship:

[0084]

[0085]

[0086]

[0087] Wherein, n1 is the refractive index of the medium between lens 50a and the first display screen 10 and the second display screen 30, n2 is the refractive index of the medium inside lens 50a, n3 is the refractive index of the medium between lens 50a and eye 300, T is the thickness of the thickest part of lens 50a, f is the distance at which lens 50a can focus parallel light rays to the focal point, Ft is the overall focal length corresponding to the optical effect produced by lens 50a as a whole, i is the imaging distance of lens 50a, R1 is the radius of curvature of the second surface 501b, and R2 is the radius of curvature of the first surface 501a.

[0088] Please see Figure 7 In another modified embodiment, lens 50c includes a plurality of lens elements arranged sequentially along the optical path of the image light emitted from the first display screen 10 and the second display screen 30. These are a first lens element 53, a second lens element 54, and a third lens element 55 arranged at intervals. The optical axes of the first lens element 53, the second lens element 54, and the third lens element 55 coincide, and the outlines of the projections of the first lens element 53, the second lens element 54, and the third lens element 55 on the first display screen 10 extend beyond the outer edge of the low-pixel display area 11 or coincide with the outer edge of the low-pixel display area 11. By adjusting the curvature of the surface of each lens element on the side for receiving image light, the plurality of lens elements cooperate with each other to shift the optical path of the image light, so that the display image corresponding to the first area 503 and the display image corresponding to the second area 504 form a complete and continuous display image after being transmitted through lens 50c.

[0089] Please refer to the following: Figure 8 and Figure 9The head-mounted display device 200 of this application embodiment includes a frame 20 and a display device 100 fixed within the frame 20. The frame 20 includes a first frame 21 for placing a first display screen 10 and a second display screen 30, a second frame 22 for placing a lens 50a, and a third frame 23 for fixing the head-mounted display device 200 to the user's head. The head-mounted display device 200 also includes a main board 40, a processing device 60, and a cover plate 80. The main board 40 is located on the side of the display device 200 away from the user's eyes and includes a base plate (not shown) and multiple sidewalls (not shown). The base plate and multiple sidewalls enclose a space for placing the display device 100 and the processing device 60. The processing device 60 is located between the main board 40 and the display device 100, and the cover plate 80 is located on the side of the main board 40 away from the processing device 60. After receiving electrical signals transmitted from the first driving circuit 70 and the second driving circuit, the first display screen 10 and the second display screen 30 in the display device 100 emit image light to the lens 50a. The image light is transmitted through the lens 50a and received by the human eye, so that the human eye can see a continuous and complete display screen composed of the display screen corresponding to the first area 503 and the display screen corresponding to the second area 504, thereby improving the user experience.

[0090] Those skilled in the art should recognize that the above embodiments are only used to illustrate this application and are not intended to limit this application. Any appropriate changes and variations made to the above embodiments within the essential spirit and scope of this application fall within the scope of protection claimed in this application.

Claims

1. A display device, characterized in that, include: The first display screen includes a low-pixel display area and a cutout area surrounded by the low-pixel display area; The second display screen is embedded in the hollowed-out area of ​​the first display screen, and the second display screen includes a high-pixel display area; The pixel density of the low-pixel display area is less than the pixel density of the high-pixel display area; The display device further includes a lens, which is located in the light path of the image light emitted from the first display screen and the second display screen; The lens includes a first surface and a second surface opposite to each other. The first surface is a curved surface and is located on the side of the lens closer to the first display screen, for receiving image light emitted from the first display screen and the second display screen. The second surface is located on the side of the lens away from the first display screen, and is used to emit image light transmitted through the lens; The lens includes a first lens portion and a second lens portion connected to and surrounding the first lens portion, wherein the first lens portion is disposed corresponding to the second display screen and the second lens portion is disposed corresponding to the first display screen; The curvature of the first lens portion on the first surface and the curvature of the second lens portion on the first surface are both negative or both positive, and the absolute value of the curvature of the first lens portion on the first surface is greater than the absolute value of the curvature of the second lens portion on the first surface, and the optical axis of the first lens portion coincides with the optical axis of the second lens portion. as well as The lens is used to deflect the image light emitted by the first display screen near the cutout area toward the second display screen, or to deflect the image light emitted by the edge of the second display screen toward the first display screen.

2. The display device as claimed in claim 1, characterized in that, The outline of the projection of the lens onto the first display screen extends beyond or coincides with the outer edge of the low-pixel display area, and the lens is used to transmit the image light emitted from the first display screen and the second display screen.

3. The display device as claimed in claim 2, characterized in that, The lens includes a plurality of lens portions arranged sequentially along the optical path of the image light emitted from the first display screen and the second display screen. The optical axes of the plurality of lens portions coincide, and the outline of the projection of each lens portion onto the first display screen extends beyond the outer edge of the low-pixel display area or coincides with the outer edge of the low-pixel display area.

4. The display device as claimed in claim 1, characterized in that, The outline of the projection of the first lens group on the second display screen extends beyond the edge of the high-pixel display area or coincides with the edge of the high-pixel display area, and the outline of the projection of the first lens group on the first display screen does not extend beyond the edge of the cutout area.

5. The display device as claimed in claim 1, characterized in that, The display device further includes a first driving circuit and a second driving circuit, the low-pixel display area array is provided with a plurality of first pixels, and the high-pixel display area array is provided with a plurality of second pixels; The plurality of first pixels are electrically connected to the first driving circuit, and the plurality of second pixels are electrically connected to the second driving circuit.

6. The display device as claimed in claim 5, characterized in that, The first driving circuit is located at the edge of the first display screen away from the cutout area. Multiple pixel lines are arranged at the edge of the cutout area near the low-pixel display area. Multiple first pixels of the low-pixel display area located on the side of the cutout area away from the first driving circuit are electrically connected to the first driving circuit through the pixel lines.

7. A head-mounted display device, characterized in that, include: frame; The display device as described in any one of claims 1-6 is fixed within the frame and is used to display images.

Images