Projection display optical system of secondary fold

Abstract

The utility model discloses a kind of projection display optical systems of secondary turn-back, optical system is sequentially provided with: illumination module, lens module, first reflector, second reflector and projection curtain from object plane to image plane along light direction;Illumination module, lens module, first reflector three are sequentially arranged on the same horizontal plane;Second reflector and projection curtain two are sequentially arranged on the same horizontal plane, and second reflector and projection curtain are set on illumination module, lens module, first reflector three;The mirror surface of first reflector is towards lens module, the mirror surface of second reflector is towards projection curtain;Illumination module is used to emit light beam;Lens module is used to enlarge shaping light beam;First reflector and second reflector are used for reflecting light beam;Projection curtain is used for receiving light beam projection.This application can significantly reduce projection distance, reduce optical system volume and improve image quality by using two pieces of turn-back reflector of first reflector and second reflector.

Description

Technical Field

[0001] This utility model belongs to the field of projection display optical technology, and in particular relates to a projection display optical system with double reflection. Background Technology

[0002] With the continuous development of micro-projection display technology and the market's ultimate pursuit of "small size, large screen," all consumer electronics products are moving towards miniaturization and integration. Traditional long-throw projectors require a huge "projection distance," which cannot meet this demand. At the same time, certain specific application scenarios require a very long focal length, but due to physical space limitations, a long projection distance cannot be provided, and traditional direct-projection optical systems simply cannot be squeezed into a small space.

[0003] At the same time, users are no longer satisfied with simply being able to "see," but are pursuing effects such as "high definition," "no distortion," and "high brightness," thus raising their requirements for image quality. While traditional ultra-short-throw solutions (such as fisheye lenses) can achieve short-distance projection, they introduce serious image distortion (especially trapezoidal distortion and field curvature) and edge image quality degradation. Utility Model Content

[0004] The purpose of this utility model embodiment is to provide a projection display optical system with double reflection. By using two reflection mirrors, a first reflector and a second reflector, the projection distance can be significantly reduced, the size of the optical system can be reduced, and the image quality can be improved.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: This utility model embodiment provides a projection display optical system with secondary reflection. The optical system is provided with the following components arranged sequentially from the object plane to the image plane along the light direction: an illumination module, a lens module, a first reflector, a second reflector, and a projection screen. The lighting module, the lens module, and the first reflector are arranged sequentially on the same horizontal plane; The second reflector and the projection screen are arranged sequentially on the same horizontal plane, and the second reflector and the projection screen are arranged on top of the lighting module, the lens module, and the first reflector; The mirror surface of the first reflector faces the lens module, and the mirror surface of the second reflector faces the projection screen; The lighting module is used to emit a light beam; The lens module is used to amplify and shape the beam; Both the first and second reflectors are used to reflect light beams; The projection screen is used to receive beam projections.

[0006] In some embodiments, the lens module is a 100% bias lens.

[0007] In some embodiments, the aperture position of the lens module is provided with an adjustable positioning hole.

[0008] In some embodiments, the first reflector and the second reflector are deflected relative to the vertical direction at an angle of 7.5°.

[0009] This invention provides a projection display optical system with a double-folding reflection. By using two double-folding reflectors, a first reflector and a second reflector, the optical path can be "folded" with a double-folding reflection. Without sacrificing optical performance (such as focal length), the physical size is reduced by more than 50%, significantly reducing the volume of the optical system.

[0010] This invention provides a projection display optical system with a double-folding projection, which can provide a longer effective focal length and better optical performance in a more compact body, reduce image distortion, especially trapezoidal distortion, and improve MTF (modulation transfer function, a measure of sharpness). By optimizing the internal structure of the optical system and beam shaping technology, it further improves the utilization rate of the laser source and the display effect, thereby enhancing image quality.

[0011] This invention provides a double-folding projection display optical system that achieves a small size, large screen, and high performance through optical path folding. This meets the modern display device's pursuit of "smaller, brighter, and clearer" performance and is one of the core optical solutions driving the development of cutting-edge technologies such as ultra-short-throw projection, AR-HUD, and AR glasses. Therefore, the double-folding projection display optical system provided by this invention is an advanced technology with broad prospects, capable of significantly improving display quality and user experience. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual process of the method, etc. involved in the embodiments of this disclosure.

[0013] Figure 1 This is a schematic diagram of the structure of a projection display optical system with secondary reflection according to some embodiments of the present disclosure; Figure 2 This is a schematic diagram of the adjustable positioning hole for the lens module stop position according to some embodiments of the present disclosure; Figure 3 This is a light spot pattern on the effective surface of the projection screen based on an optical system using LightTools software. Detailed Implementation

[0014] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0015] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0016] This utility model embodiment provides a projection display optical system with secondary reflection, such as... Figure 1 As shown, the optical system consists of the following components arranged sequentially from the object plane to the image plane along the direction of light: illumination module 1, lens module 2, first reflector 3, second reflector 4, and projection screen 5.

[0017] In some embodiments, the lighting module 1, the lens module 2, and the first reflector 3 are arranged sequentially on the same horizontal plane, and the second reflector 4 and the projection screen 5 are arranged sequentially on the same horizontal plane, with the second reflector 4 and the projection screen 5 positioned above the lighting module 1, the lens module 2, and the first reflector 3.

[0018] In some embodiments, the mirror surface of the first reflector 3 faces the lens module 2, and the mirror surface of the second reflector 4 faces the projection screen 5. In this way, the first reflector 3 reflects the light beam emitted from the lens module 2 back to the second reflector 4, and the second reflector 4 then reflects the light beam back a second time.

[0019] In some embodiments, the lighting module 1 is used to emit a light beam; the lens module 2 is used to magnify and shape the light beam; the first reflector 3 and the second reflector 4 are both used to reflect the light beam; and the projection screen 5 is used to receive the light beam projection.

[0020] For example, the lighting module 1 includes optical components such as a light source, a shaping system, and a display chip, which provide image display output for the entire projection display optical system.

[0021] After the lighting module 1 emits a light beam, it passes through the lens module 2 and shines on the first reflector 3. The first reflector 3 reflects the light beam back to the second reflector 4, and the second reflector 4 reflects the light beam back a second time. Finally, the light beam is projected onto the projection screen 5.

[0022] This invention provides a projection display optical system with a double-folding reflection. By using two double-folding reflectors, a first reflector and a second reflector, the optical path can be "folded" with a double-folding reflection. Without sacrificing optical performance (such as focal length), the physical size is reduced by more than 50%, significantly reducing the volume of the optical system.

[0023] This invention provides a projection display optical system with a double-folding projection, which can provide a longer effective focal length and better optical performance in a more compact body, reduce image distortion, especially trapezoidal distortion, and improve MTF (modulation transfer function, a measure of sharpness). By optimizing the internal structure of the optical system and beam shaping technology, it further improves the utilization rate of the laser source and the display effect, thereby enhancing image quality.

[0024] This invention provides a double-folding projection display optical system that achieves a small size, large screen, and high performance through optical path folding. This meets the modern display device's pursuit of "smaller, brighter, and clearer" performance and is one of the core optical solutions driving the development of cutting-edge technologies such as ultra-short-throw projection, AR-HUD, and AR glasses. Therefore, the double-folding projection display optical system provided by this invention is an advanced technology with broad prospects, capable of significantly improving display quality and user experience.

[0025] In some embodiments, lens module 2 is a 100% offset lens. That is, lens module 2 is 100% offset relative to illumination module 1, which avoids light reflection affecting the optomechanical structure interference. The maximum light angle emitted by lens module 2 is 25.8°.

[0026] In some embodiments, an adjustable positioning hole 21 is provided at the aperture position of the lens module 2. In this way, the offset of the lens module 2 can be adjusted between 92% and 108% through the adjustable positioning hole 21.

[0027] For example, such as Figure 2 As shown, the adjustable positioning hole 21 is elliptical in shape, and the screw is cylindrical. After passing through the adjustable positioning hole 21, the screw can move within the adjustable positioning hole 21, thereby adjusting the offset of the lens module 2. Once the offset of the lens module 2 is determined, tightening the screw to keep its position in the adjustable positioning hole 21 will fix the offset of the lens module 2.

[0028] In some embodiments, the first reflector 3 and the second reflector 4 are deflected relative to the vertical direction, and the deflection angle is 7.5° for both. That is, the angle between the deflection direction of the first reflector 3 and the second reflector 4 and the vertical direction is 7.5°.

[0029] For example, the detailed parameters of the first reflector 3 and the second reflector 4 are shown in Table 1 below.

[0030] Table 1 Detailed parameters of the first reflecting mirror 3 and the second reflecting mirror 4: First reflecting mirror 3 75mm 42.7mm 1mm Second reflecting mirror 4 209mm 130mm 2mm Figure 3 This is a light spot diagram of the optical system based on LightTools software on the effective surface of the projection screen 5 in this embodiment. The light spot diagram shows the distribution of light on the projection surface. It can be seen that the illumination uniformity of the projection display optical system with secondary reflection provided by this utility model is good.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A projection display optical system with double reflection, characterized in that: The optical system comprises, in sequence from the object plane to the image plane along the direction of light: an illumination module, a lens module, a first reflecting mirror, a second reflecting mirror, and a projection screen; The lighting module, the lens module, and the first reflector are arranged sequentially on the same horizontal plane; The second reflector and the projection screen are arranged sequentially on the same horizontal plane, and the second reflector and the projection screen are arranged on top of the lighting module, the lens module, and the first reflector; The mirror surface of the first reflector faces the lens module, and the mirror surface of the second reflector faces the projection screen; The lighting module is used to emit a light beam; The lens module is used to amplify and shape the beam; Both the first and second reflectors are used to reflect light beams; The projection screen is used to receive beam projections.

2. The projection display optical system with secondary reflection as described in claim 1, characterized in that, The lens module is a 100% offset lens.

3. The projection display optical system with secondary reflection as described in claim 2, characterized in that, The lens module has an adjustable positioning hole at the aperture position.

4. The projection display optical system with secondary reflection as described in claim 1, characterized in that, The first and second reflectors are set at angles that are deflected relative to the vertical direction, and the angle of deflection is 7.5° for both.

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