Single-tube binocular eyepiece system and vehicle-mounted near-eye display device

Abstract

The application discloses a single-tube binocular eyepiece system, which comprises, from an observation side of a human eye to a display device side, a first lens group and a second lens group arranged coaxially along an optical axis, wherein the first lens group comprises at least a first lens, a second lens, a third lens and a fourth lens, the first lens is a positive lens, the second lens is a negative lens, the third lens is a positive lens, the fourth lens is a negative lens, and the third lens and the fourth lens form a positive-negative cemented lens; the second lens group comprises at least a fifth lens and a sixth lens, the fifth lens is a positive lens, and the sixth lens is a negative lens; the exit pupil distance of the single-tube binocular eyepiece system is not less than 35 mm, and the exit pupil diameter is not less than 72 mm. The single-tube binocular eyepiece system has a large exit pupil distance and exit pupil diameter, can be used for an observer to observe the same optical system with both eyes at the same time, can directly observe different parts of the same optical system without any image interruption, can quickly capture a target, reduces fatigue and prolongs working time.

Description

Technical Field

[0001] This invention relates to a monocular binocular eyepiece system and also to a vehicle-mounted near-eye display device. Background Technology

[0002] Binocular observation devices for vehicles have become a hot topic in the field of near-eye display technology in recent years. These devices magnify the image on the display through an eyepiece optical system and provide feedback to the human eye regarding the surrounding scenery and environment.

[0003] The eyepiece assembly of a binocular observation device for vehicles consists of two parts: the eyepiece optical system and the display (LCD or OLED display). Traditional binocular eyepieces for vehicle observation devices typically use a pair of monocular eyepieces combined side-by-side, with the optical path divided into left and right paths. Information from the two displays is synchronized for binocular observation. This requires the user's eyes to be positioned at the exit pupil of the optical system. Furthermore, the exit pupil distance and pupil diameter of traditional monocular eyepieces (binoculars can be considered a combination of two monocular eyepieces) are very small. The observer's eyes must remain constantly against the eyepiece cover, preventing immediate target acquisition and causing fatigue and visual discomfort within a short period. As an auxiliary driving device, vehicle movement causes the eyes to leave the exit pupil; this asynchronous human-machine displacement affects the driver's judgment of driving or flight status. Since the left and right eyes of a binocular eyepiece are two relatively independent optical systems, the left and right optical axes must be strictly parallel; otherwise, image quality will be severely affected. Summary of the Invention

[0004] The primary technical problem to be solved by this invention is to provide a monocular binocular eyepiece system.

[0005] Another technical problem to be solved by the present invention is to provide an in-vehicle near-eye display device, including the above-mentioned monocular binocular eyepiece system and display screen.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0007] According to one aspect of the present invention, a monocular binocular eyepiece system is provided, comprising: [insert components] coaxially arranged along the optical axis from the human eye observation side to the display device side.

[0008] The first lens group includes at least a first lens, a second lens, a third lens, and a fourth lens, wherein the first lens is a positive lens, the second lens is a negative lens, the third lens is a positive lens, and the fourth lens is a negative lens, and the third and fourth lenses form a positive-negative cemented lens; and

[0009] The second lens group includes at least a sixth lens and a seventh lens, wherein the sixth lens is a positive lens and the seventh lens is a negative lens;

[0010] The exit pupil distance of the monocular binocular eyepiece system is not less than 35mm, and the exit pupil diameter is not less than 72mm.

[0011] Optionally, the first lens is a biconvex lens, wherein the radius of curvature of the surface facing the human eye is smaller than the radius of curvature of the surface facing the display.

[0012] The second lens is a negative meniscus lens that is concave towards the human eye.

[0013] The sixth lens is an approximately plano-convex lens, with a convex surface facing the human eye and an approximately flat surface facing the display.

[0014] The seventh lens is a biconcave lens.

[0015] Optionally, the third lens is a biconvex lens, and the fourth lens is a negative meniscus lens; in a positive-negative cemented lens, the radius of curvature of the cemented surface is smaller than the radius of curvature of the two side surfaces.

[0016] Optionally, the third lens is a positive meniscus lens convex towards the human eye, and the fourth lens is a negative meniscus lens concave towards the display side; in the positive-negative cemented lens, the radius of curvature of the cemented surface is greater than the radius of curvature of the two side surfaces.

[0017] The first lens group also includes a fifth lens, which is a biconvex lens, and is disposed between the fourth lens and the sixth lens.

[0018] Optionally, the total focal length of the eyepiece system is f. w It satisfies the following relationship: 55mm <f w <60mm.

[0019] Optionally, the back focal length of the eyepiece shall not exceed 6 mm.

[0020] Optionally, the overall size of the monocular binocular eyepiece system shall not exceed φ80×115mm, and the diameter shall not be less than 72mm.

[0021] Optionally, in the monocular binocular eyepiece system, the human eye observes from the aperture stop, and the distance between the left and right eye positions and the optical axis along the Y-axis or X-axis is within the range of ±29mm to ±34mm. The exit pupil of the left and right eyes at the human eye position is 4mm.

[0022] According to another aspect of the present invention, an in-vehicle near-eye display device is provided, including the above-described monocular binocular eyepiece system, and also including a display.

[0023] Optionally, the display is any one of LCD, OLED, or Lcos, and the size of the display is no greater than 3 inches and no less than 1 inch.

[0024] The monocular binocular eyepiece system provided by this invention has a large exit pupil distance and diameter, allowing the observer to simultaneously observe the same optical system with both eyes. It also allows direct viewing of different parts of the same optical system without any image interruption, enabling rapid target acquisition, reducing fatigue, and extending working time. Furthermore, since the observer's two eyes observe through the same set of optical elements, there is no error due to the parallelism of the optical axes found in binocular eyepieces. Attached Figure Description

[0025] Figure 1 This is a structural diagram of a monocular binocular eyepiece system provided in an embodiment of the present invention;

[0026] Figure 2 yes Figure 1 The diagram shows the optical path of human eye observation in a monocular binocular eyepiece system.

[0027] Figure 3 This is a schematic diagram showing the position of the Eye Box and the light-transmitting aperture in a monocular binocular eyepiece system;

[0028] Figure 4 yes Figure 2 The distortion diagram of the monocular binocular eyepiece system shown;

[0029] Figure 5 This is a structural diagram of a monocular binocular eyepiece system provided in another embodiment of the present invention;

[0030] Figure 6 yes Figure 5 The diagram shows the optical path of human eye observation in a monocular binocular eyepiece system.

[0031] Figure 7 yes Figure 5 The distortion diagram of the monocular binocular eyepiece system shown. Detailed Implementation

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] This invention provides a monocular binocular near-eye display device, comprising a monocular binocular eyepiece system and a display screen. The monocular binocular eyepiece system is an optical system that allows the observer's two eyes to use the same set of optical elements for observation, and both eyes can directly view different parts of the same optical system without any image interruption. Using this monocular binocular eyepiece system, due to its larger exit pupil distance and diameter, the observer's eyes no longer need to be constantly pressed against the eyepieces; both eyes can observe simultaneously and quickly capture the target, reducing fatigue and extending working hours. Furthermore, since the observer's two eyes observe through the same set of optical elements, there is no error due to the parallelism of the optical axes found in binocular eyepieces.

[0034] The monocular binocular eyepiece system provided by this invention can meet the following display requirements in several embodiments: exit pupil distance not less than 35mm, exit pupil diameter not less than 72mm, field of view 38°, and overall optical size not exceeding φ80×115mm and diameter not less than 72mm.

[0035] First Embodiment

[0036] like Figure 1 The monocular binocular eyepiece system shown includes seven lenses. From the human eye's observation side to the display device side, the following lenses are arranged coaxially along the optical axis: aperture EPD, first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, and seventh lens L7. Lens L1 is a positive lens, L2 is a negative lens, L3 is a positive lens, and L4 is a negative lens. Lens L3 and L4 form a positive-negative cemented lens to correct chromatic aberration. Lenses L1 to L4 can be considered as the first lens group I. Lens L5 is a positive lens, L6 is a positive lens, and L7 is a negative lens. Lenses L5, L6, and L7 can be considered as the second lens group II. Lenses L5, L6, and L7 correct field-related aberrations, including distortion and field curvature. The system's distortion is well controlled (below 1%). In the above eyepiece system, the distance between the aperture stop surface EPD and the surface of the first lens L1 facing the aperture stop surface is 35mm, that is, the exit pupil distance is 35mm.

[0037] Among them, the first lens L1 is a biconvex lens, and the radius of curvature of its surface facing the human eye is smaller than the radius of curvature of its surface facing the display screen; the second lens L2 is a negative meniscus lens concave to the human eye; the third lens L3 is a positive meniscus lens convex to the human eye; the fourth lens L4 is a negative meniscus lens concave to the display screen, and in the positive-negative cemented lens, the radius of curvature of the cemented surface is larger than the radii of curvature of the two side surfaces; the fifth lens L5 is a biconvex lens; the sixth lens L6 is an approximately plano-convex lens, with a convex surface facing the human eye and an approximately flat surface facing the display screen; and the seventh lens L7 is a biconcave lens.

[0038] The combined focal length of the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 is f14 (that is, the focal length of the first lens group f). I The combined focal length of the fifth lens L5, the sixth lens L6, and the seventh lens L7 is f. 57 (That is, the focal length f of the second lens group) II The total focal length of the system is f. w Each focal length satisfies the following relationship:

[0039] (1)2.3 <f14 / f w <2.5;

[0040] (2) 0.81 <f 57 / f w <0.88;

[0041] (3) 55mm <f w <60mm.

[0042] Furthermore, the material of the aforementioned lens meets the following requirements:

[0043] Nd3>1.8, Nd7>1.8, Vd1>40; Vd3>40; Vd5>40; Vd6>40;

[0044] Nd3 and Nd7 represent the refractive indices of the third lens L3 and the seventh lens L7 on the d-line, respectively. Vd1, Vd3, Vd5, and Vd6 represent the Abbe numbers of the first lens L1, the third lens L3, the fifth lens L5, and the sixth lens L6 on the d-line, respectively, all of which are greater than 40.

[0045] In the first lens group, the combined focal length f of the first lens L1 and the second lens L2 is... 12 , with the system's total focal length f w Satisfy the following formula:

[0046] (4)2.8 <f 12 / f w <3;

[0047] In the second lens group, the focal length f5 of the fifth lens L5, and the combined focal length f of the sixth lens L6 and the seventh lens L7 are... 67 , respectively with the system's total focal length f w Satisfy the following formula:

[0048] (5) 1.47 <f5 / f w <1.6;

[0049] (6)2 <f 67 / f w <2.21.

[0050] like Figure 2 and Figure 3 As shown, in the above-mentioned monocular binocular eyepiece system, when the human eye is positioned at the aperture stop, the distance between the left and right eye positions and the optical axis along the Y-axis or X-axis ranges from ±29mm to ±34mm. The exit pupils of the left and right eyes at the human eye's position are 4mm. The relative position of the human eye to the eyepiece system and the field of view are as follows. Figure 2 As shown. Figure 3The relationship between the left eyebox, the right eyebox, and the eyepiece aperture is shown, along with multiple pupil positions. This demonstrates that even if the human eye moves slightly left or right relative to the eyepiece within the eyepiece aperture range, it will not affect the observation effect through the eyepiece.

[0051] In this embodiment, the display device used can be an LCD, OLED, Lcos, or similar display device. Preferably, due to the large field of view, exit pupil distance, and exit pupil diameter of the system, using a display device that is too small would increase design difficulty. Therefore, an Lcos or OLED display device of 1 inch or larger is selected as the image source. The display device size of 1 inch or larger used in the monocular binocular eyepiece system can effectively improve the field of view and resolution. The field of view brightness of this monocular binocular eyepiece system is also relatively high, ensuring the image brightness required for human eye observation in nighttime environments.

[0052] The following description uses a seven-element monocular binocular eyepiece system suitable for a 1.57-inch display screen, with a focal length of 57.14mm, an exit pupil diameter of 72mm, and an exit pupil distance of 35mm as an example to specifically explain the surface parameters of each lens in the first embodiment. Starting with the aperture stop surface number 1, the lenses are sequentially numbered from the human eye side to the display side, with the display device surface numbered 17. Surfaces 15 and 16 are the screen protection glass surfaces. All optical surfaces in the lenses are spherical. The eyepiece design data for the first embodiment is shown in Table 1 below.

[0053] Table 1 shows the surface profile parameters of each optical surface in the first embodiment (unit: mm).

[0054]

[0055]

[0056] In this embodiment, the total length of the eyepiece system from the front surface 2 of the first lens L1 to the display screen surface 17 is 113.4 mm, which is less than 115 mm, and the diameter φ of the eyepiece system is less than 80 mm, resulting in a small volume.

[0057] Figure 4 This is a distortion diagram of the eyepiece system in this embodiment. It can be seen that within a field of view of ±19 degrees, the system distortion is less than ±1%, which is very small.

[0058] Second embodiment:

[0059] This embodiment uses the system of the first embodiment, but the back focal length is adjusted (the back focal length is no greater than 6mm) to ensure good imaging within this back focal length range, effectively reducing the impact of tolerances in large-aperture optical systems. The aperture stop surface number is 1, and so on. The display device surface number is 17, and surfaces 15 and 16 are the screen protection glass surfaces. The eyepiece design data for the second embodiment is shown in Table 2 below.

[0060] Table 2 shows the surface profile parameters of each optical surface in the second embodiment (unit: mm).

[0061]

[0062]

[0063] The distortion diagram in this embodiment is similar to that in the first embodiment, and will not be shown here again.

[0064] Third embodiment:

[0065] like Figure 5 The monocular binocular eyepiece system shown includes six lenses. Compared to the first embodiment, the surface parameters of the cemented doublet lenses in the first lens group have been significantly adjusted, and the fifth lens is not used in the second lens group.

[0066] Specifically, this monocular binocular eyepiece system consists of the following components arranged coaxially from the human eye observation side to the display device side: aperture EPD, first lens L1', second lens L2', third lens L3', fourth lens L4', sixth lens L6', and seventh lens L7'. The first lens L1' is a positive lens, the second lens L2' is a negative lens, the third lens L3' is a positive lens, and the fourth lens L4' is a negative lens. The third lens L3' and the fourth lens L4' form a positive-negative cemented lens to correct chromatic aberration. The first lens L1' to the fourth lens L4' can be considered as the first lens group I. The sixth lens L6' is a positive lens, and the seventh lens L7' is a negative lens. The sixth lens L6' and the sixth lens L7' can be considered as the second lens group II. L6' and L7' correct field-related aberrations, including distortion and field curvature. The system's distortion is well controlled (below 1%).

[0067] Among them, the first lens L1' is a biconvex lens, and the radius of curvature of its surface facing the human eye is smaller than the radius of curvature of its surface facing the display; the second lens L2' is a negative meniscus lens concave towards the human eye; the third lens L3' is a biconvex lens, the fourth lens L4' is a negative meniscus lens convex towards the display, and in the positive-negative cemented lens, the radius of curvature of the cemented surface is smaller than the radii of curvature of the two side surfaces; the seventh lens L6' is an approximately plano-convex lens, with a convex surface facing the human eye and an approximately flat surface facing the display; the seventh lens L7' is a biconcave lens.

[0068] The combined focal length of the first lens L1', the second lens L2', the third lens L3', and the fourth lens L4' is f. 14 '(That is, the focal length f of the first lens group) I The combined focal length of the sixth lens L6' and the seventh lens L7' is f. 67 '(That is, the focal length f of the second lens group) II The total focal length of the system is f. w Each focal length satisfies the following relationship:

[0069] (7)1.3 <f 14 ' / f w <1.43;

[0070] (8)-1.3 <f 67 ' / f w <-1.2;

[0071] (9) 55mm <f w <60mm.

[0072] Furthermore, the material of the aforementioned lens meets the following requirements:

[0073] Nd2>1.8, Nd4>1.8, Nd7>1.8, Vd1>40, Vd3>40, Vd6>40;

[0074] Nd2, Nd4, and Nd7 represent the refractive indices of the second lens L2, the fourth lens L4, and the seventh lens L7 along the d-line, respectively. Vd1, Vd3, and Vd6 represent the Abbe numbers of the first lens L1, the third lens L3, and the sixth lens L6 along the d-line, respectively, all of which are greater than 40.

[0075] In the first lens group, the combined focal length f of the first lens L1' and the second lens L2' is... 12 The combined focal length f of the third lens L3' and the fourth lens L4' 34 ', respectively with the system's total focal length f w Satisfy the following formula:

[0076] (10)2.5 <f 12' / f w <2.75;

[0077] (11)1.53 <f 34 ' / f w <1.68.

[0078] like Figure 6 As shown, similar to the first embodiment, in the above-described monocular binocular eyepiece system, when the human eye is positioned at the aperture stop, the distance between the left and right eye positions and the optical axis along the Y-axis or X-axis is within the range of ±29mm to ±34mm, and the exit pupils of the left and right eyes at the human eye position are 4mm. The relative position of the human eye and the eyepiece system and the field of view are as follows. Figure 6 As shown.

[0079] In this embodiment, the display device used can be an LCD, OLED, Lcos, or other similar display device. Preferably, since the system has a large field of view, exit pupil distance, and exit pupil diameter, using a display device that is too small would increase the design difficulty. Therefore, an Lcos or OLED display device of 1 inch or larger is selected as the image source.

[0080] The following uses a six-element monocular binocular eyepiece system suitable for a 1.57-inch display screen, with a focal length of 57.14mm, an exit pupil diameter of 72mm, and an exit pupil distance of 35mm as an example to specifically explain the surface parameters of each lens in the first embodiment. Starting with the aperture stop surface number 1, the lenses are sequentially numbered from the human eye side to the display side, with the display device surface numbered 14. Surface 13 is the screen protective glass surface. All optical surfaces in the above lenses are spherical. The eyepiece design data of the third embodiment is shown in Table 3 below.

[0081] Table 3 shows the surface profile parameters of each optical surface in the third embodiment (unit: mm).

[0082]

[0083]

[0084] In this embodiment, the total length of the eyepiece system from the front surface 2 of the first lens L1' to the display screen surface 14 is 114.78 mm, which is less than 115 mm, and the diameter φ of the eyepiece system is less than 80 mm, resulting in a small volume.

[0085] Figure 7 This is a distortion diagram of the eyepiece system in this embodiment. It can be seen that within a field of view of ±19 degrees, the system distortion is less than ±1%, which is very small.

[0086] This invention also provides a vehicle-mounted near-eye display device using the aforementioned monocular binocular eyepiece system. The monocular binocular eyepiece system provided by this invention has a simple structure, is easy to use, provides comfortable observation, and has reliable performance; it has a large exit pupil diameter and exit pupil distance, allowing for free observation within a certain spatial range and facilitating continuous observation of target images; it can be fixed to the vehicle body without increasing the burden on the head, reducing fatigue, and is suitable for continuous observation of surrounding scenery or related information using a vehicle-mounted binocular observation device.

[0087] The optical system has an optical length not exceeding 115mm, and the eyepiece assembly can be fixed in front of the driver's seat for binocular observation of displays larger than 1 inch but not larger than 3 inches. When using a 1.57-inch display, the overlap area of ​​the left and right eye's field of view is approximately 1 / 3 of the horizontal field of view; in binocular observation with both eyes at the designed aperture position, the entire field of view of the display can be seen. The binocular eye distance range is 56mm to 72mm; in binocular observation, when the distance between the eyes and the outer surface of the eyepiece is within an axial range of no more than 35mm, a portion of the image including the center of the display screen can still be observed. In monocular observation, as long as one eye is within a diameter of φ72mm centered on the eyepiece's optical axis and the distance between the eye and the outer surface of the eyepiece is no more than 35mm, a portion of the image including the center of the display screen can still be observed. In other words, this embodiment allows for both binocular and monocular observation, facilitating continuous observation of the target image even when the vehicle is vibrating or bumping, or when the user is slightly moving their head.

[0088] The above provides a detailed description of the monocular binocular eyepiece system and vehicle-mounted near-eye display device provided by the present invention. 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 monocular binocular eyepiece system, characterized in that, This includes components arranged coaxially along the optical axis from the viewer's perspective to the display device side: The first lens group includes at least a first lens, a second lens, a third lens, and a fourth lens, wherein the first lens is a positive lens, the second lens is a negative lens, the third lens is a positive lens, and the fourth lens is a negative lens, and the third and fourth lenses form a positive-negative cemented lens; and The second lens group includes at least a sixth lens and a seventh lens, wherein the sixth lens is a positive lens and the seventh lens is a negative lens; The exit pupil distance of the monocular binocular eyepiece system is 35mm, and the exit pupil diameter is 72mm.

2. The monocular binocular eyepiece system as described in claim 1, characterized in that: The first lens is a biconvex lens, and the radius of curvature of its surface facing the human eye is smaller than the radius of curvature of its surface facing the display. The second lens is a negative meniscus lens that is concave towards the human eye. The sixth lens is an approximately plano-convex lens, with a convex surface facing the human eye and an approximately flat surface facing the display. The seventh lens is a biconcave lens.

3. The monocular binocular eyepiece system as described in claim 2, characterized in that: The third lens is a biconvex lens, and the fourth lens is a negative meniscus lens; in a positive-negative cemented lens, the radius of curvature of the cemented surface is smaller than the radius of curvature of the two side surfaces.

4. The monocular binocular eyepiece system as described in claim 2, characterized in that: The third lens is a positive meniscus lens convex towards the human eye, and the fourth lens is a negative meniscus lens concave towards the display side; in the positive-negative cemented lens, the radius of curvature of the cemented surface is greater than the radius of curvature of the two side surfaces. The first lens group also includes a fifth lens, which is a biconvex lens, and is disposed between the fourth lens and the sixth lens.

5. The monocular binocular eyepiece system as described in claim 1, characterized in that: The total focal length of the eyepiece system is f. w It satisfies the following relationship: 55mm <f w < 60mm.

6. The monocular binocular eyepiece system as described in claim 4, characterized in that: The back focal length of the eyepiece does not exceed 6 mm.

7. The monocular binocular eyepiece system as described in claim 4, characterized in that: The overall size of the monocular binocular eyepiece system does not exceed [the specified value]. φ 80×115mm, with a diameter of not less than 72mm.

8. The monocular binocular eyepiece system as described in claim 1, characterized in that: When the human eye observes from the aperture stop in the monocular binocular eyepiece system, the distance between the left and right eye positions and the optical axis along the Y-axis or X-axis is within the range of ±29mm to ±34mm, and the exit pupil of the left and right eyes is 4mm at the position of the human eye.

9. A vehicle-mounted near-eye display device, comprising the monocular binocular eyepiece system as described in any one of claims 1-8, and further comprising a display.

10. The vehicle-mounted near-eye display device as described in claim 9, characterized in that: The display is any one of LCD, OLED, or Lcos, and the size of the display is no greater than 3 inches and no less than 1 inch.

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