CN220894639U - Projection lens for AR-HUD - Google Patents
Projection lens for AR-HUD Download PDFInfo
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- CN220894639U CN220894639U CN202322840402.XU CN202322840402U CN220894639U CN 220894639 U CN220894639 U CN 220894639U CN 202322840402 U CN202322840402 U CN 202322840402U CN 220894639 U CN220894639 U CN 220894639U
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- 239000011521 glass Substances 0.000 claims abstract description 14
- 230000004075 alteration Effects 0.000 claims abstract description 10
- 230000001276 controlling effect Effects 0.000 claims abstract description 8
- 230000001681 protective effect Effects 0.000 claims abstract description 5
- 230000001105 regulatory effect Effects 0.000 claims abstract description 4
- 238000005286 illumination Methods 0.000 claims description 3
- 238000009792 diffusion process Methods 0.000 abstract description 13
- 238000003384 imaging method Methods 0.000 abstract description 9
- 210000001747 pupil Anatomy 0.000 abstract description 5
- 230000003287 optical effect Effects 0.000 description 17
- 238000011156 evaluation Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000012937 correction Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000003190 augmentative effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 210000003128 head Anatomy 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000004304 visual acuity Effects 0.000 description 1
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Abstract
The utility model provides a projection lens for AR-HUD, comprising: the first lens group, the diaphragm, the second lens group, the light splitting device, the protective glass and the image source are sequentially arranged; the first lens group is used for regulating and controlling the size of the projection view angle and balancing the field curvature of the system, the second lens group is used for balancing the aberration and chromatic aberration of the system, and the diaphragm is used for controlling the light quantity of the light rays emitted by the image source; the light splitting device is used for splitting light beams emitted by the image source, the image source is used for emitting light beams, and the protective glass is used for protecting the image source; the first lens group includes: the first lens, the second lens, the third lens and the fourth lens are sequentially arranged; the front surface of the first lens is inclined at an angle of-12 degrees with the projection surface; the second lens group includes: a fifth lens, a sixth lens and a seventh lens which are sequentially arranged; the seventh lens rear surface is inclined at-0.76 °. The utility model solves the problems of the prior art that the lens can see the bright spots of the exit pupil of the lens through the diffusion film and the imaging quality is low.
Description
Technical Field
The utility model relates to the technical field of light projection, in particular to a projection lens for an AR-HUD.
Background
HUD, head up display system, is a technology that has evolved from reflector collimators. The gun sighting device is used for a gun sighting device and a fighter plane sighting device before a second war. After the second battle, HUD technology is gradually applied to the fighter plane, and the speed, altitude, radar information, sight, etc. can be displayed on the canopy or transparent plate of the fighter plane. By the 21 st century, HUD technology is applied to automobiles on a large scale, and the speed, navigation information and the like of the automobile can be projected onto a front windshield in real time, so that driving safety and human-computer interaction experience are greatly improved.
The PGU is an image source of the HUD, is a core device of the HUD, and has a TFT screen, a DLP and a diffusion film and other schemes.
The AR-HUD is an augmented reality head-up display system, has a larger field angle and a larger projection distance than a general HUD, so that the AR-HUD can be used for highly fusing projection information with a traffic environment, and is an important component of intelligent driving and intelligent cabin solutions.
The existing HUD is mostly the technical scheme of TFT, but because the sunshine flows backward and the like, the field angle and the projection distance of the HUD can not be made large, and the requirements of the large field angle and the large projection distance of the AR-HUD are difficult to meet.
And the DLP and diffusion film scheme can effectively prevent sunlight from flowing backward, can achieve larger field angle and projection distance, and meets the requirements of AR-HUD. However, the diffusion film cannot completely scatter light randomly, bright spots of the exit pupil of the lens can be seen through the diffusion film to the lens, and the imaging quality is low, so that the display effect of the final HUD is greatly affected.
Disclosure of utility model
In order to overcome the defects of the prior art, the utility model aims to provide a projection lens for an AR-HUD, which solves the problems that light rays cannot be scattered randomly due to a diffusion film in the AR-HUD in the prior art, bright spots of an exit pupil of the lens can be seen through looking at the lens through the diffusion film, and the imaging quality is low.
In order to achieve the above object, the present utility model provides the following solutions:
A projection lens for an AR-HUD, comprising:
The first lens group, the diaphragm, the second lens group, the light splitting device, the protective glass and the image source are sequentially arranged;
The first lens group is used for regulating and controlling the size of a projection view angle and balancing system field curvature, the second lens group is used for balancing system aberration and chromatic aberration, and the diaphragm is used for controlling the light quantity of light rays emitted by the image source; the light splitting device is used for splitting light beams emitted by the image source, the image source is used for emitting light beams, and the protection glass is used for protecting the image source;
The first lens group includes: the first lens, the second lens, the third lens and the fourth lens are sequentially arranged; the front surface of the first lens and the projection surface are inclined at an angle of-12 degrees;
The second lens group includes: a fifth lens, a sixth lens and a seventh lens which are sequentially arranged; the rear surface of the seventh lens is inclined at-0.76 degrees.
Preferably, the first lens and the second lens are both lenses with negative focal power, the third lens, the fourth lens and the seventh lens are all lenses with positive focal power, and the fifth lens and the sixth lens are double cemented lenses with negative focal power.
Preferably, the ratio of the focal length of the first lens group to the focal length of the projection lens is 1.559, the ratio of the focal length of the first lens to the focal length of the first lens group is-1.605, the ratio of the focal length of the second lens to the focal length of the first lens group is-1.409, the ratio of the focal length of the third lens to the focal length of the first lens group is 1.646, and the ratio of the focal length of the fourth lens to the focal length of the first lens group is 1.458.
Preferably, the ratio of the focal length of the second lens group to the focal length of the projection lens is 1.185, the ratio of the focal lengths of the fifth lens and the sixth lens to the focal length of the second lens group is-1.524, and the ratio of the focal length of the seventh lens to the focal length of the second lens group is 0.976.
Preferably, each of the first lens to the seventh lens is a glass lens.
Preferably, the relative illuminance full field of view of the projection lens is greater than 80%, and the full field of view MTF of the projection lens is greater than 70%.
Preferably, the distortion of the projection lens is less than 0.6%, and the TV distortion of the projection lens is less than 0.3%.
Preferably, the DMD chip of the projection lens is 0.3 inch, and the model is DLP3030.
According to the specific embodiment provided by the utility model, the utility model discloses the following technical effects:
The utility model provides a projection lens for AR-HUD, which improves the imaging quality of the projection lens and reduces the cost of the lens by arranging a lens for 100% off-axis and 12-degree oblique projection.
Drawings
In order to more clearly illustrate the embodiments of the present utility model or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a diagram of a projection lens for an AR-HUD according to an embodiment of the present utility model;
FIG. 2 is a schematic diagram of large off-axis and oblique projection of a projection lens according to an embodiment of the present utility model;
Fig. 3 is a diagram of a spatial frequency MTF provided by an embodiment of the present utility model;
FIG. 4 is a vertical axis color difference chart provided by an embodiment of the present utility model;
FIG. 5 is a graph of field curvature evaluation provided by an embodiment of the present utility model;
fig. 6 is a distortion evaluation chart provided in an embodiment of the present utility model.
Reference numerals illustrate:
1-first lens group, 2-second lens group, 3-diaphragm, 4-wind-light device, 5-protection glass, 6-image source, G1-first lens, G2-second lens, G3-third lens, G4-fourth lens, G5-fifth lens, G6-sixth lens, GM 7-seventh lens.
Detailed Description
The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.
The utility model aims to provide a projection lens for an AR-HUD, which solves the problems that light rays cannot be scattered randomly due to a diffusion film in the AR-HUD in the prior art, bright spots of the exit pupil of the lens can be seen through the diffusion film when the lens is seen, and the imaging quality is low.
In order that the above-recited objects, features and advantages of the present utility model will become more readily apparent, a more particular description of the utility model will be rendered by reference to the appended drawings and appended detailed description.
As shown in fig. 1, the present utility model provides a projection lens for an AR-HUD, comprising:
The optical lens comprises a first lens group 1, a diaphragm 3, a second lens group 2, a light splitting device 4, a protective glass 5 and an image source 6 which are sequentially arranged, wherein the first lens group 1 is positioned in front of the diaphragm 3, and the second lens group 2 is positioned behind the diaphragm 3;
The first lens group 1 is used for regulating and controlling the size of a projection view angle and balancing system field curvature, the second lens group 2 is used for balancing system aberration and chromatic aberration, and the diaphragm 3 is used for controlling the light quantity of the light rays emitted by the image source 6; the light splitting device 4 is used for splitting light beams emitted by the image source 6, the image source 6 is used for emitting light beams, and the protection glass 5 is used for protecting the image source 6;
As shown in fig. 2, the first lens group 1 includes: the first lens G1, the second lens G2, the third lens G3 and the fourth lens G4 are sequentially arranged; the front surface of the first lens G1 and the projection surface are inclined at an angle of-12 degrees; the tilt direction is a transverse coordinate tilt. The lens is 100% offset, and the lens is inclined at 12 ° to the diffusion film (projection plane).
The second lens group 2 includes: a fifth lens G5, a sixth lens G6, and a seventh lens GM7 arranged in this order; the rear surface of the seventh lens GM7 is inclined at an angle of-0.76 degrees, the S1 surface (front surface) and the S2 surface (back surface) of the seventh lens GM7 are aspheric, and the whole optical element of the lens behind the seventh lens GM7 is inclined at an angle of-0.76 degrees with the first lens group and the second lens group.
Further, the first lens G1 and the second lens G2 are both lenses with negative focal power, the third lens G3, the fourth lens G4 and the seventh lens GM7 are all lenses with positive focal power, and the fifth lens G5 and the sixth lens G6 are double cemented lenses with negative focal power, which can effectively eliminate chromatic aberration of the system.
Further, the ratio of the focal length of the first lens group 1 to the focal length of the projection lens is 1.559, the ratio of the focal length of the first lens group G1 to the focal length of the first lens group 1 is-1.605, the ratio of the focal length of the second lens G2 to the focal length of the first lens group 1 is-1.409, the ratio of the focal length of the third lens G3 to the focal length of the first lens group 1 is 1.646, and the ratio of the focal length of the fourth lens G4 to the focal length of the first lens group 1 is 1.458.
Further, the ratio of the focal length of the second lens group 2 to the focal length of the projection lens is 1.185, the ratio of the focal lengths of the fifth lens G5 and the sixth lens G6 to the focal length of the second lens group 2 is-1.524, and the ratio of the focal length of the seventh lens GM7 to the focal length of the second lens group 2 is 0.976.
Further, the first lens G1 to the seventh lens GM7 are all glass lenses, and have excellent temperature drift properties, and still have very excellent image quality performance at-40 ℃ to 85 ℃. Table 1 is a table of specific parameters of the objective lens system, and table 1 is specifically shown below:
Table 1 table of specific parameters of objective lens system
Table 2 shows the table of the coefficients of the aspherical lenses P2 and GM7, and table 2 is shown below:
table 2 table of coefficients of aspherical lenses P2 and GM7
Wherein C is curvature, and the inverse K of curvature radius is a conic coefficient. P is a plastic lens, and 2 is a serial number.
Further, the relative illumination full view field of the projection lens is more than 80%, and the full view field MTF of the projection lens is more than 70%.
Specifically, as shown in FIG. 3, the MTF (English name: modulation Transfer Function) index is the most accurate and scientific evaluation standard for the current lens. The ordinate is the contrast, the closer to 1, representing the better the lens imaging. The abscissa represents resolution in units of pairs per millimeter line. The pixel size of the image source 6 adopted by the embodiment of the application is 7.6um, and the corresponding design resolution is 66 line pairs per millimeter. The projection lens generally requires at least that the MTF value of each field of view be above 0.3 at the design resolution, whereas the MTF value of each field of view at each zoom position in the embodiments of the present application is above 0.7.
Fig. 4 is a vertical axis color difference diagram of a lens, the ordinate is the image height field value size, and the abscissa is the numerical value size in micrometers. In the figure, the dominant wavelength is used as a reference, and the color difference value of each view field among blue light, red light and green light (dominant wavelength) is respectively drawn. The projection lens generally requires that the color difference value is within 6 pixels of an image source, and the axial color difference of the embodiment of the application is controlled within 3um and is smaller than 0.4 pixels (the pixel size is 7.6 um).
Further, the distortion of the projection lens is less than 0.6%, and the TV distortion of the projection lens is less than 0.3%.
Specifically, fig. 5 is a field curvature evaluation chart, and fig. 6 is a distortion evaluation chart. The ordinate represents the field angle of the lens. The abscissa of the field curvature graph represents the magnitude of the field curvature value, and the abscissa of the distortion graph represents the distortion amount. Distortion is a very important index of projection lens, and is generally required to be controlled within 3%, while TV distortion is required to be controlled within 1%; the distortion shape of the embodiment of the application can lead the distortion of the system TV to be very small, the distortion of the system is within 0.6 percent, and the distortion of the TV is within 0.3 percent.
Further, the DMD chip of the projection lens is 0.3 inch, the model is DLP3030, and the lens F.NO is 2.4. Wherein the F number of the lens can also be written as F#; the smaller the F number, the larger the aperture.
The embodiment also specifically discloses that:
the optical lens satisfies the following conditional expression:
0.8<ENPD/IH<0.9 (1)
Wherein EPND denotes a clear aperture of the optical lens, and IH denotes an actual half-image height of the optical lens.
When the conditional expression (1) is satisfied, the reasonable balance between the large light flux of the lens and the large imaging surface can be realized.
In an embodiment, the optical lens satisfies the following conditional expression:
1.1mm-1<TL/f/IH<1.3mm-1 (2)
Wherein T L represents the total optical length of the optical lens, f represents the effective focal length of the optical lens, and IH represents the actual half-image height of the optical lens.
When the conditional expression (2) is satisfied, the relation between the total length of the lens and the resolving power can be reasonably balanced. The value of T L/f/IH exceeds the upper limit, the overall length of the lens is too large, or if the overall length is shortened, the image height is insufficient; when the value of T L/f/IH exceeds the lower limit, the lens aberration is difficult to correct due to the overlarge focal power of each lens, and the resolution is obviously reduced.
In an embodiment, the optical lens satisfies the following conditional expression:
9.5mm<IH/tanθ<10mm (3)
Where f represents an effective focal length of the optical lens, and θ represents a half field angle of the optical lens.
When the conditional expression (3) is satisfied, the distortion of the optical lens can be reasonably limited, and the difficulty of distortion correction is reduced. The value IH/tan theta exceeds the lower limit, and the distortion of the lens increases towards the negative direction; the distortion of the lens becomes large in the positive direction when the IH/tan θ exceeds the upper limit.
In an embodiment, the optical lens satisfies the following conditional expression:
CRA<1° (4)
Wherein CRA represents the chief ray incidence angle of the optical lens on the imaging plane.
When the conditional expression (4) is satisfied, the DMD chip can be well matched, and a good projection effect is realized.
The beneficial effects of the utility model are as follows:
the AR-HUD projection lens disclosed by the utility model is 100% offset, and the lens and the diffusion film (projection surface) are inclined at 12 degrees, so that pupil bright spots of the diffusion film can be effectively avoided.
The AR-HUD projection lens disclosed by the utility model has the advantages that the whole optical element at the back of the GM8 is inclined at 0.76 degrees with the first lens group and the second lens group, so that the image quality loss caused by the inclination of the lens and the diffusion film can be effectively balanced. Meanwhile, since the prism (light-splitting device) and the DMD (protection glass and image source) are inclined together, the influence of inclination on the illumination system is avoided.
The AR-HUD projection lens disclosed by the utility model has small total length, and can easily meet the requirement of getting on an automobile of the AR-HUD.
The AR-HUD projection lens disclosed by the utility model has the advantages that the relative illuminance full view field is higher than 80%, the full view field MTF is higher than 0.7, and the imaging quality is very excellent; the distortion can reach within 0.6%, the TV distortion is within 0.3%, and the distortion correction is excellent.
According to the AR-HUD projection lens disclosed by the utility model, the lens adopts the full-glass lens, so that the temperature drift of the lens is effectively reduced, and the excellent image quality performance still exists at the temperature of-40 ℃ to 85 ℃.
The AR-HUD projection lens disclosed by the utility model has the advantages of simple structure and low tolerance sensitivity, and only 7 lenses are used, so that the cost and the assembly difficulty of the lens are effectively reduced.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.
The principles and embodiments of the present utility model have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present utility model and the core ideas thereof; also, it is within the scope of the present utility model to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the utility model.
Claims (8)
1. A projection lens for an AR-HUD, comprising:
The first lens group, the diaphragm, the second lens group, the light splitting device, the protective glass and the image source are sequentially arranged;
The first lens group is used for regulating and controlling the size of a projection view angle and balancing system field curvature, the second lens group is used for balancing system aberration and chromatic aberration, and the diaphragm is used for controlling the light quantity of light rays emitted by the image source; the light splitting device is used for splitting light beams emitted by the image source, the image source is used for emitting light beams, and the protection glass is used for protecting the image source;
The first lens group includes: the first lens, the second lens, the third lens and the fourth lens are sequentially arranged; the front surface of the first lens and the projection surface are inclined at an angle of-12 degrees;
The second lens group includes: a fifth lens, a sixth lens and a seventh lens which are sequentially arranged; the rear surface of the seventh lens is inclined at-0.76 degrees.
2. The projection lens for an AR-HUD according to claim 1, wherein the first lens and the second lens are each lenses of negative power, the third lens, the fourth lens and the seventh lens are each lenses of positive power, and the fifth lens and the sixth lens are each cemented doublet of negative power.
3. The projection lens for an AR-HUD of claim 1, wherein a ratio of a focal length of the first lens group to a focal length of the projection lens is 1.559, a ratio of a focal length of the first lens to a focal length of the first lens group is-1.605, a ratio of a focal length of the second lens to a focal length of the first lens group is-1.409, a ratio of a focal length of the third lens to a focal length of the first lens group is 1.646, and a ratio of a focal length of the fourth lens to a focal length of the first lens group is 1.458.
4. The projection lens for an AR-HUD of claim 1, wherein a ratio of a focal length of the second lens group to a focal length of the projection lens is 1.185, a ratio of focal lengths of the fifth lens and the sixth lens to a focal length of the second lens group is-1.524, and a ratio of a focal length of the seventh lens to a focal length of the second lens group is 0.976.
5. The projection lens for an AR-HUD according to claim 1, wherein the first lens to the seventh lens are glass lenses.
6. The projection lens for an AR-HUD of claim 1 wherein,
The relative illumination full view field of the projection lens is more than 80%, and the full view field MTF of the projection lens is more than 70%.
7. The projection lens for an AR-HUD according to claim 1, wherein the distortion of the projection lens is less than 0.6% and the TV distortion of the projection lens is less than 0.3%.
8. The projection lens for an AR-HUD of claim 1 wherein the DMD chip of the projection lens is 0.3 inches, model DLP3030.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322840402.XU CN220894639U (en) | 2023-10-23 | 2023-10-23 | Projection lens for AR-HUD |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322840402.XU CN220894639U (en) | 2023-10-23 | 2023-10-23 | Projection lens for AR-HUD |
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| Publication Number | Publication Date |
|---|---|
| CN220894639U true CN220894639U (en) | 2024-05-03 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202322840402.XU Active CN220894639U (en) | 2023-10-23 | 2023-10-23 | Projection lens for AR-HUD |
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| Country | Link |
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| CN (1) | CN220894639U (en) |
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2023
- 2023-10-23 CN CN202322840402.XU patent/CN220894639U/en active Active
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