CN-121995631-A - Optical system and display device

Abstract

An optical system and a display device. The optical system includes a lens structure including at least one lens, and a transflective film and a reflective polarizing film disposed on the lens structure, the image light transmitted through the transflective film being configured to be folded back between the transflective film and the reflective polarizing film and to exit from the reflective polarizing film. The optical system further comprises a calibration lens which is positioned on one side of the transflective film far away from the reflective polarizing film, the optical axis of the lens structure does not pass through the calibration lens, one of the lens structure and the calibration lens has a positive focal length, the other of the lens structure and the calibration lens has a negative focal length, and the calibration lens comprises at least one free curved surface, so that the freedom degree of the optical system design is improved, the non-centrality caused by the lens structure is effectively corrected, the aberration generated by the off-axis optical system is corrected, the imaging quality is improved, the camera calibration process is simplified, and the accuracy of sight tracking and iris recognition is improved.

Inventors

• ZHOU YAN
• LI XIN
• LIU RUNYU
• FU LIAN
• ZHANG BOWEI
• LU JIANHONG
• CHI LIYING
• LONG XIANG
• LI XIAOKAI

Assignees

• 北京字跳网络技术有限公司
• 脸萌有限公司

Dates

Publication Date

20260508

Application Date

20241107

Claims (16)

1. 1. An optical system, comprising: A lens structure, and a transflective film and a reflective polarizing film disposed on the lens structure, the image light transmitted through the transflective film being configured to be folded back between the transflective film and the reflective polarizing film and to exit from the reflective polarizing film, the lens structure including at least one lens, Wherein the optical system further comprises a collimating lens positioned on a side of the transflective film away from the reflective polarizing film, the optical axis of the lens structure not passing through the collimating lens; One of the lens structure and the collimating lens has a positive focal length and the other has a negative focal length, and the collimating lens includes at least one free-form surface.
2. 2. The optical system of claim 1, wherein the focal length of the lens structure is negative and the focal length of the collimating lens is positive.
3. 3. The optical system of claim 1, wherein a maximum radius of curvature of the free-form surface is less than a minimum radius of curvature of a surface of the lens structure closest to the collimating lens.
4. 4. The optical system of claim 1, wherein one of a focal length of the free-form surface in a first direction perpendicular to an optical axis of the lens structure and a focal length of the free-form surface in a second direction perpendicular to the optical axis is positive and the other is negative, the first direction being perpendicular to the second direction, and the first direction being configured to be perpendicular to a binocular eye connection.
5. 5. The optical system of claim 1, wherein an included angle between an optical axis of the free-form surface and an optical axis of the lens structure is 15-45 degrees.
6. 6. The optical system of claim 1, wherein at least a surface of the collimating lens closest to the lens structure is a free-form surface.
7. 7. The optical system according to any one of claims 1 to 6, further comprising a camera and a light source, the camera being located on a side of the transflective film remote from the reflective polarizing film, Wherein the optical axis of the lens structure does not pass through the camera and the light source, and the camera is configured to acquire an eye image; the camera comprises a camera lens, and an included angle between an optical axis of the camera lens and an optical axis of the lens structure is 15-45 degrees.
8. 8. The optical system of claim 7, wherein the light source is located on a side of the transflective film remote from the reflective polarizing film; The collimating lens is located between the lens structure and at least one of the camera and the light source.
9. 9. The optical system of claim 8, wherein the collimating lens is disposed between the camera and the lens structure, the collimating lens configured such that light rays emitted by the light source pass through the lens structure and the collimating lens to converge at an optical center of the camera.
10. 10. The optical system of claim 7, wherein the collimating lens is a structure within the camera.
11. 11. The optical system of claim 7, wherein an optical axis of at least one surface of the collimating lens other than the free-form surface coincides with an optical axis of the camera lens.
12. 12. The optical system of claim 11, wherein a surface of the collimating lens closest to the lens structure is a free-form surface, a side of the free-form surface remote from the lens structure being provided with an aspherical surface, an optical axis of the aspherical surface coinciding with an optical axis of the camera lens.
13. 13. The optical system of claim 8, wherein the collimating lens is disposed between the light source and the lens structure.
14. 14. The optical system of any of claims 1-6, further comprising a phase retardation film and a linear polarizing film on the lens structure, wherein the phase retardation film is on a side of the transflective film facing the reflective polarizing film, and the linear polarizing film is on a side of the reflective polarizing film facing away from the transflective film.
15. 15. A display device comprising a display screen and the optical system of any one of claims 1-14, wherein the display screen is located on a side of the transflective film remote from the lens structure.
16. 16. The display device according to claim 15, wherein the image light of the display screen incident on the transflective film does not pass through the collimating lens.

Description

Optical system and display device Technical Field Embodiments of the present disclosure relate to an optical system and a display device. Background Currently, near-eye display devices, such as Virtual Reality (VR) display devices or Augmented Reality (AR) display devices, are provided with lenses to enlarge images displayed on a display screen, so that a user experiences an immersive sensation. The near-eye display device captures user eye information and calculates user gaze information by providing eye movement tracking (EYE TRACKING, ET) means, such as sensors. Disclosure of Invention The present disclosure provides an optical system and a display device. An optical system provided by an embodiment of the present disclosure includes a lens structure including at least one lens, and a transflective film and a reflective polarizing film disposed on the lens structure, image light transmitted through the transflective film being configured to be folded back between the transflective film and the reflective polarizing film and to exit from the reflective polarizing film. The optical system further comprises a collimating lens which is positioned on one side of the transflective film away from the reflective polarizing film, wherein an optical axis of the lens structure does not pass through the collimating lens, one of the lens structure and the collimating lens has a positive focal length, the other has a negative focal length, and the collimating lens comprises at least one free-form surface. For example, according to an embodiment of the present disclosure, the focal length of the lens structure is negative and the focal length of the collimating lens is positive. For example, according to embodiments of the present disclosure, the maximum radius of curvature of the free-form surface is less than the minimum radius of curvature of the surface of the lens structure closest to the collimating lens. For example, according to an embodiment of the present disclosure, one of a focal length of the free-form surface in a first direction perpendicular to an optical axis of the lens structure and a focal length of the free-form surface in a second direction perpendicular to the optical axis is a positive value, the other is a negative value, the first direction is perpendicular to the second direction, and the first direction is configured to be perpendicular to a binocular eye connecting line. For example, according to the embodiment of the disclosure, an included angle between the optical axis of the free-form surface and the optical axis of the lens structure is 15-45 degrees. For example, according to embodiments of the present disclosure, at least the surface of the collimating lens closest to the lens structure is a free-form surface. For example, according to an embodiment of the present disclosure, the optical system further includes a camera and a light source, the camera being located on a side of the transflective film remote from the reflective polarizing film. The optical axis of the lens structure does not pass through the camera and the light source, the camera is configured to acquire an eye image, the camera comprises a camera lens, and an included angle between the optical axis of the camera lens and the optical axis of the lens structure is 15-45 degrees. For example, according to an embodiment of the present disclosure, the light source is located on a side of the transflective film remote from the reflective polarizing film, and the collimating lens is located between the lens structure and at least one of the camera and the light source. For example, according to an embodiment of the present disclosure, the collimating lens is disposed between the camera and the lens structure, and the collimating lens is configured such that light rays emitted from the light source pass through the lens structure and the collimating lens and then converge on the optical center of the camera. For example, according to an embodiment of the present disclosure, the collimating lens is a structure within the camera. For example, according to an embodiment of the present disclosure, an optical axis of at least one surface of the collimating lens other than the free-form surface coincides with an optical axis of the camera lens. For example, according to an embodiment of the present disclosure, a surface of the collimating lens closest to the lens structure is a free-form surface, and an aspheric surface is disposed on a side of the free-form surface away from the lens structure, and an optical axis of the aspheric surface coincides with an optical axis of the camera lens. For example, according to an embodiment of the present disclosure, the collimating lens is disposed between the light source and the lens structure. For example, according to an embodiment of the present disclosure, the optical system further includes a phase retardation film and a linear polarization film on the lens structure, wherein the phase