Virtual image distance adjustment mechanism and near-eye display

Abstract

The application discloses a kind of virtual image distance adjusting mechanism and near-eye display, comprising: display screen mounting bracket, optical lens group mounting bracket, rotating bracket and two fixed blocks, wherein, rotating bracket is rotatably arranged on display screen mounting bracket, and can rotate around fixed rotation axis;Rotating bracket includes arc-shaped bracket with handle, two connecting brackets and two arc-shaped threaded brackets, both ends of arc-shaped bracket are connected with arc-shaped threaded bracket by connecting bracket respectively;Arc-shaped threaded bracket and arc-shaped bracket are arranged on concentric circle with the position of rotation axis as center;The outside of arc-shaped threaded bracket is provided with external thread;Two fixed blocks are fixed on optical lens group mounting bracket;Fixed block is provided with arc-shaped internal thread matched with external thread;By poking the handle, rotating bracket rotates around rotation axis, under the action of external thread and internal thread, the distance between display screen mounting bracket and optical lens group mounting bracket is changed, and virtual image distance adjustment is realized.

Description

Technical Field

[0001] This invention relates to a virtual image distance adjustment mechanism, and also to a near-eye display including the above-described virtual image distance adjustment mechanism. Background Technology

[0002] Near-eye displays (NEDs), also known as head-mounted displays (HMDs) or smart glasses, project computer-generated images onto the user's eyes through an optical display system. This creates virtual images within the user's field of view (FOV), providing augmented reality (AR), mixed reality (MR), or virtual reality (VR) experiences. Because optical display systems are designed with a fixed imaging distance, the distance from the virtual image displayed in front of the user's eyes after passing through the optical display system is fixed. However, each person's required virtual image distance is different. To accommodate the needs of users with varying visual acuity, the virtual image distance of the optical display system needs to be adjusted.

[0003] The projection system of a head-mounted display device includes a display screen, optical lenses, a stand, and accessories. The display screen, optical lenses, and accessories are mounted on the stand. The light emitted from the display screen is transmitted through the optical lenses and projected onto the viewer's eyes, thus achieving AR or VR display functionality. By adjusting the distance between the display screen and the optical lenses, the virtual image distance of the optical module can be changed.

[0004] Common methods for adjusting virtual image distance use a threaded screw mechanism, which converts the rotation of the screw into a change in the distance between the display screen and the optical lens group. However, in some special cases, the adjustment range of the distance between the display screen and the optical lens group is extremely small (less than 1 mm). For such fine adjustments, the threaded screw mechanism is completely unsuitable. Summary of the Invention

[0005] The primary technical problem to be solved by this invention is to provide a virtual image distance adjustment mechanism.

[0006] Another technical problem to be solved by the present invention is to provide a near-eye display, including the above-mentioned virtual image distance adjustment mechanism.

[0007] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0008] A virtual image distance adjustment mechanism, comprising:

[0009] Display screen mounting bracket, used to support and secure the display screen;

[0010] Optical lens mounting bracket, used to fix the optical lens assembly;

[0011] A rotating bracket is rotatably mounted on the display screen mounting bracket and can rotate about a fixed rotation axis. The rotating bracket includes an arc-shaped bracket with a handle, two connecting brackets, and two opposing arc-shaped threaded brackets. Each end of the arc-shaped bracket is connected to one of the arc-shaped threaded brackets via a connecting bracket. The arc-shaped threaded bracket and the arc-shaped bracket are arranged on two concentric circles centered on the rotation axis. The radius of the arc-shaped threaded bracket is larger than the radius of the arc-shaped bracket. External threads are provided on the outer side of the arc-shaped threaded bracket.

[0012] Two fixing blocks are fixed on the optical lens assembly mounting bracket; the fixing blocks are provided with internal threads that mate with the external threads;

[0013] By turning the handle, the rotating bracket rotates around the rotating axis, and under the action of the external thread and the internal thread, the distance between the display screen mounting bracket and the optical lens assembly mounting bracket is changed.

[0014] Preferably, the arc-shaped threaded bracket is provided with a first arc-shaped groove.

[0015] The arc-shaped bracket is provided with a second arc-shaped groove;

[0016] The rotating bracket is mounted on the display screen mounting bracket by a plurality of fasteners, which pass through the first arc-shaped groove and the second arc-shaped groove respectively; the plurality of fasteners define the rotation trajectory and rotation range of the rotating bracket.

[0017] Preferably, the first arc-shaped groove is connected to the display screen mounting bracket by a fastener;

[0018] The second arc-shaped groove is connected to the display screen mounting bracket by two fasteners.

[0019] Preferably, the distance between the two arc-shaped threaded brackets is not less than the long side of the display screen.

[0020] Preferably, the radius of the arc-shaped bracket is no greater than 1 / 2 of the width of the display screen.

[0021] Preferably, the handle is located on the outside of the arc-shaped bracket and extends radially outward.

[0022] Preferably, the end of the handle protrudes beyond the overlapping area of ​​the display screen mounting bracket and the optical lens mounting bracket.

[0023] Preferably, the fixing block is embedded in the optical lens assembly mounting bracket.

[0024] Preferably, the internal thread and the external thread are double-ended threads.

[0025] A near-eye display including the aforementioned virtual image distance adjustment mechanism.

[0026] The virtual image distance adjustment mechanism and near-eye display provided by this invention include: a display screen mounting bracket, an optical lens assembly mounting bracket, a rotating bracket, and two fixed blocks. The relative movement between the display screen mounting bracket and the optical lens assembly mounting bracket is realized through the threaded transmission between the rotating bracket and the fixed blocks. By setting a handle with a large radius, a small axial movement can be converted into a large range of arc changes. At the same time, the concentric circle arrangement of the arc-shaped bracket and the arc-shaped threaded bracket in the rotating bracket avoids the display area of ​​the display screen and reduces the volume of the entire virtual image distance adjustment mechanism. Attached Figure Description

[0027] Figure 1 This is an exploded view of the virtual image distance adjustment mechanism provided by the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of the rotating bracket set on the display screen mounting bracket;

[0029] Figure 3 This is a schematic diagram of two fixing blocks mounted on the optical lens assembly bracket.

[0030] Figure 4 This is a schematic diagram illustrating the working principle of the rotating bracket and the two fixed blocks. Detailed Implementation

[0031] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, the present invention provides a near-eye display, including a display screen 2, an optical lens group 4, and a virtual image distance adjustment mechanism. The virtual image distance adjustment mechanism includes a display screen mounting bracket 1, an optical lens group mounting bracket 3, a rotating bracket 5, and two fixing blocks 6.

[0033] The near-eye display is preferably an AR or VR display. The display screen 2 used in the near-eye display is typically a rectangular screen with an aspect ratio of 16:9 or 4:3; trapezoidal or circular screens can also be used in special cases. The display screen 2 is fixed to the display screen mounting bracket 1, with its light-emitting surface facing the optical lens assembly mounting bracket 3. The optical lens assembly 4 is fixed to the optical lens assembly mounting bracket 3, with its light-incident surface positioned on the side of the optical lens assembly mounting bracket 3 facing the display screen mounting bracket 1. Light emitted from the display screen 2 passes through the light-incident surface of the optical lens assembly 4 and enters the optical lens assembly 4. By adjusting the distance between the display screen mounting bracket 1 and the optical lens assembly mounting bracket 3 using a virtual image distance adjustment mechanism, the distance between the light-emitting surface of the display screen 2 and the light-incident surface of the optical lens assembly 4 can be changed, thereby adjusting the virtual image distance.

[0034] The virtual image distance adjustment mechanism is located between the display screen mounting bracket 1 and the optical lens assembly mounting bracket 3. Due to the small size of near-eye displays, the installation and operating space between the display screen mounting bracket 1 and the optical lens assembly mounting bracket 3 is also small, which places high demands on the design of the virtual image distance adjustment mechanism.

[0035] like Figure 1 As shown, the virtual image distance adjustment mechanism provided in this application is a small-sized and highly accurate manual adjustment mechanism.

[0036] The virtual image distance adjustment mechanism includes: a display screen mounting bracket 1, an optical lens assembly mounting bracket 3, a rotating bracket 5, and two fixing blocks 6. The display screen mounting bracket 1 is used to support and fix the display screen 2; the optical lens assembly mounting bracket 3 is used to fix the optical lens assembly 4; the rotating bracket 5 is rotatably mounted on the display screen mounting bracket 1 and can rotate around a fixed rotation axis, which corresponds to a certain position in the display area of ​​the display screen; the rotating bracket 5 includes an arc-shaped bracket 52 with a handle 53, two connecting brackets 54, and two opposing arc-shaped threaded brackets 51. The two ends of the arc-shaped bracket 52 are respectively connected to one of the arc-shaped threaded brackets 51 via a connecting bracket 54; the arc-shaped threaded brackets 51 and the... The arc-shaped bracket 52 is set on two concentric circles with the rotation axis as the center. The radius of the arc-shaped threaded bracket 51 is larger than the radius of the arc-shaped bracket 52. The outer side of the arc-shaped threaded bracket 51 is provided with an external thread. Two fixing blocks 6 are fixed on the optical lens assembly mounting bracket 3. The fixing blocks 6 are provided with an internal thread 60 that mates with the external thread 50. When the handle 53 is turned, the rotating bracket 5 rotates around the rotation axis. Under the action of the external thread 50 and the internal thread 60, the distance between the display screen mounting bracket 1 and the optical lens assembly mounting bracket 3 is changed.

[0037] Specifically, such as Figure 2As shown, the rotating bracket 5 is a semi-enclosed, fork-shaped bracket, which is set on the upper side of the display mounting bracket 1. The rotating bracket 5 is set away from the display area of ​​the display screen 2, and the rotation axis of the rotating bracket 5 corresponds to a certain position in the display area of ​​the display screen 2.

[0038] The rotation axis of the rotating bracket 5 can coincide with or not coincide with the center of the display screen 2. When the rotation axis of the rotating bracket 5 is not coincident with the center of the display screen 2, and the rotation axis of the rotating bracket 5 is closer to the center of the display screen 2, the size of the rotating bracket 5 and the installation space can be reduced. Figure 2 In the figure, the rotation axis is located on one side (i.e., the upper side) of the handle 53 near the rotation bracket 5, relative to the center of the display screen 2.

[0039] The structure of the rotating bracket 5 is as follows Figure 1 and Figure 2 As shown, the rotating bracket 5 includes an arc-shaped support 52 with a handle 53, two connecting supports 54, and two arc-shaped threaded supports 51. The rotating bracket 5 is symmetrical about the line containing the handle 53. The two arc-shaped threaded supports 51 are positioned opposite each other on both sides of the wide side of the display screen 2, with the distance between them not less than the long side of the display screen 2, to avoid obstructing the display area of ​​the display screen 2. The arc-shaped support 52 is positioned outside the long side of the display screen 2, and its radius is not greater than half the wide side of the display screen 2, thus providing space for the handle 53. The radii of the arc-shaped threaded supports 51 and 52 are not in a fixed numerical ratio, but only need to meet their respective design requirements. The dimensions of the rotating bracket 5 in the two directions are significantly different, allowing the entire adjustment mechanism to adapt well to near-eye displays of different sizes.

[0040] The arc-shaped bracket 52 is an arc centered on the rotation axis O. The handle 53 is located on the outer side of the arc-shaped bracket 52 and extends radially outward. The end of the handle 53 extends beyond the overlapping area of ​​the display mounting bracket 1 and the optical lens assembly mounting bracket 3, protruding outward. By turning the handle 53, the arc-shaped bracket 52 can be rotated around the rotation axis.

[0041] Both ends of the arc-shaped bracket 52 are connected to the arc-shaped threaded bracket 51 via connecting brackets 54. The connecting bracket 54 is preferably a straight connecting rod, but an arc-shaped connecting rod can also be used. The connecting bracket 54 only serves a connecting function; its shape has no effect on the rotation of the arc-shaped bracket 52.

[0042] Two arc-shaped threaded brackets 51 are symmetrically arranged at both ends of the arc-shaped bracket 5, and external threads 50 are provided on the outer side of the arc-shaped threaded brackets 51. The power transmission between the display screen mounting bracket 1 and the optical lens assembly mounting bracket 3 is realized through the two arc-shaped threaded brackets 51, which can achieve a relatively smooth power transmission process.

[0043] The arc-shaped threaded bracket 51 and the arc-shaped bracket 52 are arranged on two concentric circles centered on the rotation axis, and the radius of the arc-shaped threaded bracket 51 is larger than the radius of the arc-shaped bracket 52. During the rotation of the rotating bracket 5, the arc-shaped threaded bracket 51 and the arc-shaped bracket 52 rotate synchronously, and their rotation angles are the same.

[0044] The outer side of the arc-shaped threaded bracket 51 is provided with an external thread, which extends along the circumference of the arc-shaped threaded bracket 51. More precisely, a threaded section is provided on the outer side of the arc-shaped threaded bracket 51, rather than a full circle of thread. Preferably, a double-ended thread is provided on the outer side of the arc-shaped threaded bracket 51 to further enhance the stability of the entire adjustment mechanism.

[0045] A rotating bracket 5 protrudes from the display screen mounting bracket 1. The rotating bracket 5 protrudes beyond the plane of the display screen mounting bracket 1. The arc-shaped threaded bracket 51 has a first arc-shaped groove 55, the extension direction of which coincides with the rotation direction of the arc-shaped threaded bracket 51. The arc-shaped bracket 52 has a second arc-shaped groove 56, the extension direction of which coincides with the rotation direction of the arc-shaped bracket 52. The rotating bracket 5 is mounted on the display screen mounting bracket 1 by multiple fasteners 7; the multiple fasteners 7 pass through the first arc-shaped groove 55 and the second arc-shaped groove 56 respectively, and the positions of the multiple fasteners 7 define the rotation trajectory and rotation range of the rotating bracket 5.

[0046] exist Figure 2 In the illustrated embodiment, the first arc-shaped groove 55 is connected to the display screen mounting bracket 1 via a fixing member 7, and the second arc-shaped groove 56 is connected to the display screen mounting bracket 1 via two fixing members 7. The rotatable range of the second arc-shaped groove 56 relative to the two fixing members 7 determines the rotation range of the entire rotating bracket 5.

[0047] like Figure 1 and Figure 3As shown, fixing blocks 6 are respectively provided on both sides of the rotating bracket 5. The fixing blocks 6 are embedded in the optical lens assembly mounting bracket 3 by fasteners 8. Through the cooperation of the rotating bracket 5 and the fixing blocks 6, the rotating bracket 5, which protrudes from the display mounting bracket 1, is embedded in the mounting area between the two fixing blocks 6, and the adjacent side surfaces of the display mounting bracket 1 and the optical lens assembly mounting bracket 3 can abut. The inner side of the fixing block 6 is provided with an internal thread 60 that mates with the external thread 50. Preferably, both the internal thread and the external thread are double-start threads.

[0048] The following is combined Figure 4 The adjustment principle of the virtual image distance adjustment mechanism described above is explained. During the adjustment process of the virtual image distance adjustment mechanism, the rotation of the rotating bracket 5 and the relative movement of the optical lens mounting bracket 3 and the display screen mounting bracket 1 are involved; the conversion between the two is achieved through the thread transmission of the external thread 50 and the internal thread 60.

[0049] Let φ represent the rotation angle of handle 53. The rotation angle of handle 53 is equal to the rotation angle of arc-shaped bracket 52, and also equal to the rotation angle of arc-shaped threaded bracket 51.

[0050] Let T represent the thread pitch, which is equal to the change in distance between the display screen mounting bracket 1 and the optical lens assembly mounting bracket 3 when the thread rotates one revolution.

[0051] When the rotation angle of the handle 53 is equal to φ, the change in distance d between the display screen mounting bracket 1 and the optical lens mounting bracket 3, Δd, satisfies the following formula with respect to the rotation angle φ of the handle:

[0052] Δd=T*(φ / 360) (1)

[0053] The angle φ that the handle needs to rotate can be calculated by the change Δd of the distance d between the display screen mounting bracket 1 and the optical lens mounting bracket 3.

[0054] Let S represent the rotation arc length of handle 53, that is, the actuation arc length, then:

[0055] S=π*R*(φ / 180); (2)

[0056] Where: R represents the radius of the handle, and R is defined as the distance from the top of the handle 53 (which can be understood as the center of the sphere corresponding to the top sphere of the handle in the figure) to the axis of rotation.

[0057] Using equations (1) and (2), the change in arc length S and distance d between display mounting bracket 1 and optical lens mounting bracket 3 can be calculated to satisfy the following relationship:

[0058] S=2πR*(Δd / T) (3)

[0059] When the change in distance d between the display mounting bracket 1 and the optical lens mounting bracket 3 is determined, the arc length S of the toggle can be increased by increasing the distance R between the end of the handle 53 and the rotation axis, thereby converting a small axial change into a larger arc length change.

[0060] For example, taking a 2.1-inch screen as an example, using a thread with a pitch of 3.6mm and a handle with a radius R of 25.5mm, when the rotation angle of the handle 53 is equal to 30 degrees, the distance d between the display screen mounting bracket 1 and the optical lens mounting bracket 3 can change by 0.3mm, and the rotation arc length is about 13.35mm; as the rotation angle of the handle 53 increases, the above-mentioned virtual image distance adjustment mechanism can accurately achieve fine adjustment within a range of 1mm.

[0061] In summary, the virtual image distance adjustment mechanism and near-eye display provided by this invention include: a display screen mounting bracket, an optical lens assembly mounting bracket, a rotating bracket, and two fixed blocks. The relative movement between the display screen mounting bracket and the optical lens assembly mounting bracket is achieved through threaded transmission between the rotating bracket and the fixed blocks. By providing a handle with a large radius, minute axial movements can be converted into large-range arc changes. Simultaneously, the concentric arrangement of the arc-shaped bracket and the arc-shaped threaded bracket in the rotating bracket effectively avoids obstructing the display area of ​​the display screen and reduces the overall volume of the virtual image distance adjustment mechanism.

[0062] The virtual image distance adjustment mechanism and near-eye display provided by the present invention have been described in detail above. Any obvious modifications made by those skilled in the art without departing from the essence of the present invention will constitute an infringement of the patent rights of the present invention and will incur corresponding legal liability.

Claims

1. A virtual image distance adjustment mechanism, characterized in that, include: Display screen mounting bracket, used to support and secure the display screen; Optical lens mounting bracket, used to fix the optical lens assembly; A rotating bracket is rotatably mounted on the display screen mounting bracket and can rotate around a fixed rotation axis. The rotating bracket includes an arc-shaped bracket with a handle, two connecting brackets, and two opposing arc-shaped threaded brackets. Each end of the arc-shaped bracket is connected to one of the arc-shaped threaded brackets via one of the connecting brackets. The arc-shaped threaded bracket and the arc-shaped bracket are arranged on two concentric circles centered on the rotation axis. The radius of the arc-shaped threaded bracket is larger than the radius of the arc-shaped bracket. External threads are provided on the outer side of the arc-shaped threaded bracket. Two fixing blocks are fixed on the optical lens assembly mounting bracket; the fixing blocks are provided with arc-shaped internal threads that mate with the external threads; By turning the handle, the rotating bracket rotates around the rotating axis, and under the action of the external thread and the internal thread, the distance between the display screen mounting bracket and the optical lens assembly mounting bracket is changed.

2. The virtual image distance adjustment mechanism as described in claim 1, characterized in that: The arc-shaped threaded bracket is provided with a first arc-shaped groove. The arc-shaped bracket is provided with a second arc-shaped groove; The rotating bracket is mounted on the display screen mounting bracket by a plurality of fasteners, which pass through the first arc-shaped groove and the second arc-shaped groove respectively; the plurality of fasteners define the rotation trajectory and rotation range of the rotating bracket.

3. The virtual image distance adjustment mechanism as described in claim 2, characterized in that: The first arc-shaped groove is connected to the display screen mounting bracket by a fastener; The second arc-shaped groove is connected to the display screen mounting bracket by two fasteners.

4. The virtual image distance adjustment mechanism as described in claim 1, characterized in that: The distance between the two arc-shaped threaded brackets is not less than the long side of the display screen.

5. The virtual image distance adjustment mechanism as described in claim 4, characterized in that: The radius of the arc-shaped bracket is no greater than 1 / 2 of the width of the display screen.

6. The virtual image distance adjustment mechanism as described in claim 1, characterized in that: The handle is located on the outside of the arc-shaped bracket and extends radially outward.

7. The virtual image distance adjustment mechanism as described in claim 1, characterized in that: The end of the handle protrudes from the overlapping area of ​​the display screen mounting bracket and the optical lens mounting bracket.

8. The virtual image distance adjustment mechanism as described in claim 1, characterized in that: The fixing block is embedded in the optical lens assembly mounting bracket.

9. The virtual image distance adjustment mechanism as described in claim 1, characterized in that: The internal thread and the external thread are double-ended threads.

10. A near-eye display comprising the virtual image distance adjustment mechanism according to any one of claims 1-9.

Images