# US 12,111,513 B2 · Optical lens and head-mounted display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,111,513 B2 - Document ID: US12111513B2 - Status: Granted - Kind: B2 - Application number: 16/901,000 - Filed: 2020-06-15 - Published: 2020-12-31 - Granted: 2024-10-08 - Earliest claimed: 2019-06-26 - Assignees: Coretronic Corporation - Applicants: Coretronic Corporation - Inventors: Tao-Hung Kuo; Fu-Ming Chuang - Web page: https://patentgrep.com/patent/US12111513B2 ## CPC - G02B 9/34: having four components only - G02B 6/0025: {Diffusing sheet or layer; Prismatic sheet or layer} - G02B 6/0036: {2-D arrangement of prisms, protrusions, indentations or roughened surfaces} - G02B 13/004: {having four lenses} - G02B 13/16: for use in conjunction with image converters or intensifiers {, or for use with projectors, e.g. objectives for projection TV} - G02B 13/18: with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration {(G02B13/002 takes precedence)} - G02B 25/001: {Eyepieces} - G02B 27/0172: {characterised by optical features} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optical lens and a head-mounted display device are provided. The optical lens includes a first lens, a second lens, a third lens, and a fourth lens sequentially arranged from a light exit side to a light incident side. Refractive powers of the first lens, the second lens, the third lens and the fourth lens are sequentially positive, negative, positive and positive. An image generator is disposed at the light incident side. The optical lens is configured to receive an image beam provided by the image generator. The image beam forms a stop at the light exit side. The stop has the minimum cross-sectional area of beam convergence of the image beam. The optical lens and the head-mounted display device of the disclosure have advantages of smaller size, light weight, large viewing angle and high resolution. ## Claims ### Claim 1 An optical lens, adapted to receive an image beam from an image generator, wherein a prism is disposed between the optical lens and the image generator, the optical lens comprising: a first lens, a second lens, a third lens, and a fourth lens sequentially arranged from a light exit side to a light incident side, and refractive powers of the first lens, the second lens, the third lens, and the fourth lens being sequentially positive, negative, positive, and positive, wherein the image generator is disposed at the light incident side, the image beam forms a stop at the light exit side, and the stop has the minimum cross-sectional area of beam convergence of the image beam, wherein the prism does not have a refractive power and is configured to guide the image beam from the image generator to the fourth lens, and the image beam is directly incident onto the fourth lens after the image beam leaves from the prism, wherein the fourth lens is a concavo-convex lens and has a concave surface facing the light incident side, wherein the first lens is a biconvex lens, the second lens is a convexo-concave lens and has a convex surface facing the light incident side, the third lens is a biconvex lens. ### Claim 2 (depends on 1) The optical lens of claim 1, wherein the optical lens is complied with B×D<130, wherein B is a total lens length of the optical lens, and D is a clear aperture of the largest lens in the optical lens. ### Claim 3 (depends on 1) The optical lens of claim 1, wherein the optical lens is complied with A+C<20, wherein A is a distance between the stop and the optical lens on an optical axis, and C is a distance between the optical lens and the image generator on the optical axis. ### Claim 4 (depends on 1) The optical lens of claim 1, wherein the optical lens is complied with FOV/(B×D)>0.4, wherein B is a total lens length of the optical lens, D is a clear aperture of the largest lens in the optical lens, and FOV is a field of view of the optical lens. ### Claim 5 (depends on 1) The optical lens of claim 1, wherein the optical lens is complied with FOV>50, wherein FOV is a field of view of the optical lens. ### Claim 6 (depends on 1) The optical lens of claim 1, wherein the first lens, the second lens, the third lens and the fourth lens are glass aspherical lenses. ### Claim 7 (depends on 1) The optical lens of claim 1, wherein the optical lens is complied with A+C<25, wherein A is a distance between the stop and the optical lens on an optical axis, and C is a distance between the optical lens and the image generator on the optical axis. ### Claim 8 (depends on 1) The optical lens of claim 1, wherein the optical lens is complied with FOV/(B×D)>0.2, wherein B is a total lens length of the optical lens, D is a clear aperture of the largest lens in the optical lens, and FOV is a field of view of the optical lens. ### Claim 9 (depends on 1) The optical lens of claim 1, wherein the optical lens is complied with FOV>40, wherein FOV is a field of view of the optical lens. ### Claim 10 (depends on 1) The optical lens of claim 1, wherein the first lens and the second lens are plastic aspherical lenses, and the third lens and the fourth lens are glass aspherical lenses. ### Claim 11 (depends on 1) The optical lens of claim 1, wherein the second lens and the third lens are plastic aspherical lenses, and the first lens and the fourth lens are glass aspherical lenses. ### Claim 12 (depends on 1) The optical lens of claim 1, wherein the second lens and the fourth lens are plastic aspherical lenses, and the first lens and the third lens are glass aspherical lenses. ### Claim 13 (depends on 1) The optical lens of claim 1, wherein the first lens, the second lens and the third lens are plastic aspherical lenses, and the fourth lens is a glass aspherical lens. ### Claim 14 (depends on 1) The optical lens of claim 1, further comprising a first prism disposed between the optical lens and the stop, wherein the image beam leaves the optical lens, passes through the first prism, and is converged to the stop, and the image beam is diverged after passing through the stop. ### Claim 15 (depends on 1) The optical lens of claim 1, wherein the stop is formed at a coupling entrance of a waveguide element, the image beam passes through the stop and enters the waveguide element through the coupling entrance, and is transmitted to a coupling exit of the waveguide element for being projected to a target. ### Claim 16 (depends on 1) The optical lens of claim 1, wherein the optical lens is complied with following conditions: B×D<130, A+C<20, FOV/(B×D)>0.4, FOV>50, wherein A is a distance between the stop and the optical lens on an optical axis, B is a total lens length of the optical lens, C is a distance between the optical lens and the image generator on the optical axis, D is a clear aperture of the largest lens in the optical lens, and FOV is a field of view of the optical lens, wherein a shape of the stop is a circle. ### Claim 17 (depends on 1) The optical lens of claim 1, wherein the optical lens is complied with following conditions: B×D<170, A+C<25, FOV/(B×D)>0.2, FOV>40, wherein A is a distance between the stop and the optical lens on an optical axis, B is a total lens length of the optical lens, C is a distance between the optical lens and the image generator on the optical axis, D is a clear aperture of the largest lens in the optical lens, and FOV is a field of view of the optical lens, wherein a shape of the stop is a circle. ### Claim 18 (depends on 1) The optical lens of claim 1, wherein the optical lens is complied with B×D<170, wherein B is a total lens length of the optical lens, and D is a clear aperture of the largest lens in the optical lens. ### Claim 19 A head-mounted display device, comprising: an image generator; an optical lens, comprising a first lens, a second lens, a third lens, and a fourth lens sequentially arranged from a light exit side to a light incident side, and refractive powers of the first lens, the second lens, the third lens, and the fourth lens being sequentially positive, negative, positive, and positive, wherein the first lens is a biconvex lens, the second lens is a convexo-concave lens and has a convex surface facing the light incident side, the third lens is a biconvex lens, wherein the image generator is set at the light incident side, and the optical lens is configured to receive an image beam provided by the image generator, the image beam forms a stop at the light exit side, and the stop has the minimum cross-sectional area of beam convergence of the image beam; a prism, disposed between the optical lens and the image generator, wherein the prism does not have a refractive power and is configured to guide the image beam from the image generator to the fourth lens, and the image beam is directly incident onto the fourth lens after the image beam leaves from the prism, wherein the fourth lens is a concavo-convex lens and has a concave surface facing the light incident side; and a waveguide element, wherein the stop is formed at a coupling entrance of the waveguide element, the image beam passes through the stop to enter the waveguide element through the coupling entrance, and is transmitted to a coupling exit of the waveguide element for being projected to a target. ### Claim 20 (depends on 19) The head-mounted display device of claim 19, further comprising: a first prism disposed between the optical lens and the stop, wherein the image beam leaves the optical lens, passes through the first prism, and is converged to the stop, and the image beam is diverged after passing through the stop. ### Claim 21 (depends on 19) The head-mounted display device of claim 19, wherein the waveguide element comprises optical microstructures disposed at the coupling exit, and the optical microstructures project the image beam transmitted to the coupling exit to the target.