WO2019214317A1

WO2019214317A1 - Projection device

Info

Publication number: WO2019214317A1
Application number: PCT/CN2019/075892
Authority: WO
Inventors: 阴亮; 董淑斌
Original assignee: 青岛海信激光显示股份有限公司
Priority date: 2018-05-08
Filing date: 2019-02-22
Publication date: 2019-11-14

Abstract

A projection device comprises a light source and a digital micro-mirror element. The digital micro-mirror element is configured to receive and modulate light emitted from the light source to form an image beam. The projection device further comprises a refractor set (22) and a reflector (23) sequentially provided along a traveling direction of the image beam emitted from the digital micro-mirror element. The refractor set (22) comprises a first lens group (221), a second lens group (222), and a third lens group (223) sequentially provided along the traveling direction of the image beam. A distance between the third lens group (223) and the reflector (23) is fixed, and at least one of the first lens group (221) and the second lens group (222) is configured to be capable of moving along the traveling direction of the image beam or moving along a direction opposite to the traveling direction of the image beam, so as to adjust a focal plane of a projection imaging system (20) consisting of the refractor set (22) and the reflector (23). The diopter of the first lens group (221) and the second lens group (222) is positive, and the diopter of the third lens group (223) is negative.

Description

Projection device

This application is required to be submitted to the Chinese Patent Office on May 8, 2018, the application number is 201810433755.9, the invention name is "projection imaging system and laser projection device", the application number is 201101834257.6, the invention name is "projection lens and laser projection device" and The priority of the Chinese Patent Application No. 20181043371, entitled "Projection Imaging System and Laser Projection Apparatus", the entire contents of which is incorporated herein by reference.

Technical field

The present disclosure relates to the field of optical devices, and in particular to a projection device.

Background technique

With the advancement of science and technology, projection imaging systems are increasingly used in people's work and life, such as education, office, home or entertainment. For projection imaging systems, such as projection imaging systems used in home theaters, the higher the resolution of the projection imaging system, the higher the user's viewing experience. Therefore, people are increasingly demanding projection imaging systems.

Summary of the invention

Some embodiments of the present disclosure provide a projection apparatus that includes a light source and a digital micromirror element. The digital micromirror element is configured to receive and modulate light exiting the light source to form an image beam. The projection device further includes a refractor group and a mirror which are sequentially disposed along a traveling direction of the image beam emitted from the digital micromirror element. The refracting mirror group includes a first mirror group, a second mirror group, and a third mirror group that are sequentially disposed along a traveling direction of the image beam. The distance between the third mirror and the mirror is fixed. At least one of the first mirror group and the second mirror group is configured to be movable in a direction opposite to a traveling direction of the image beam or a traveling direction of the image beam to adjust the refractor group and the The focal plane of the projection imaging system consisting of mirrors. The diopter of the first mirror group and the second mirror group is positive, and the refracting power of the third mirror group is negative.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present disclosure. Other drawings may also be obtained from those of ordinary skill in the art in light of the inventive work.

1 is a schematic illustration of an implementation environment of some embodiments of the present disclosure;

2 is a schematic structural diagram of a projector provided by some embodiments of the present disclosure;

3 is a schematic structural diagram of another projector provided by some embodiments of the present disclosure;

4 is a schematic structural diagram of still another projector provided by some embodiments of the present disclosure;

FIG. 5 is a schematic structural diagram of still another projector according to some embodiments of the present disclosure; FIG.

FIG. 6 is a schematic structural diagram of still another projector according to some embodiments of the present disclosure; FIG.

Figure 7 is a top plan view of the adjustment ring in the projector of Figure 5.

The drawings and the text are not intended to limit the scope of the present disclosure in any way, and the description of the present disclosure will be described by those skilled in the art by reference to the specific embodiments.

detailed description

The embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

1 is a schematic diagram of an implementation environment of some embodiments of the present disclosure. Projector 20 can project an image beam onto screen 10 that is capable of forming an image on screen 12. The current development trend is to reduce the projection ratio of the projector 20 (the projection ratio is the ratio of the projection distance s and the screen width h, and the projection distance s is the distance between the projector 20 and the screen 10). The smaller the projection ratio, the smaller the projected image can be projected by the projector at a shorter projection distance. Projectors with a small projection ratio are prone to various aberrations such as distortion (English: Distortion), astigmatism (English: Astigmatism), field curvature (English: Field Curvature), and coma (English: Coma).

In order to effectively overcome aberrations, the related art ultra-short-throw projection apparatus generally adopts one of three modes of refraction, reflection, and hybrid to realize lens design. Among them, the hybrid lens generally includes a refractive lens group and a mirror group. This solution combines the characteristics of refraction and reflection to become the current mainstream design. When projecting on different planes, the focal plane of the projection device can be adjusted by adjusting the distance between the mirror group and the mirror.

FIG. 2 is a schematic structural diagram of a projection imaging system projector according to an embodiment of the present disclosure. The projection imaging system projector can be a projection imaging system projector 20 that is used in the implementation environment shown in FIG. Projection Imaging System Projector 20 provided by an embodiment of the present disclosure is for receiving a image beam and projecting onto a screen for imaging. The projection imaging system projector 20 provided by the embodiment of the present disclosure may also be, for example, a projection lens, which is applied in a projection device.

The projector includes a light source, a digital micromirror component, and a projection imaging system. The digital micromirror element is configured to receive and modulate light exiting the light source to form an image beam. The projection imaging system 20 includes a refractive mirror group 22 and a mirror 23 that are sequentially disposed along the traveling direction of the light. In some embodiments, the projection imaging system 20 further includes a light valve 21, and the refractive mirror group 22 and the mirror 23 are sequentially disposed along the light exiting direction of the light valve 21. In other embodiments, the light valve 21 is not included in the projection imaging system 20, i.e., the light valve 21 is located outside of the projection imaging system 20 provided by embodiments of the present disclosure. The projection imaging system 20 can receive the light beam emitted by the light valve 21. In some embodiments, the light valve 21 and the projection imaging system (projection lens) are located within the same projection device. The light valve 21 may be that the light valve may be a Digital Micromirror Device (DMD).

The above-described refractor group 22 includes a first mirror group 221, a second mirror group 222, and a third mirror group 223 which are sequentially arranged in the traveling direction d of light (i.e., image beam). The third mirror group 223 is also referred to as a front group mirror group, the second mirror group 222 is also referred to as a middle group mirror group, and the first mirror group 221 is also referred to as a rear group mirror group. The distance L2 between the third mirror group 223 and the mirror 23 is fixed. Both the first mirror group 221 and the second mirror group 222 are movable in the traveling direction d of the light or in the opposite direction of the traveling direction d of the light to adjust the focal plane of the projection imaging system. In some embodiments, the positions of the third mirror group 223 and the mirror 23 are fixed, and both the first mirror group 221 and the second mirror group 222 are movable in the traveling direction d of the light or in the opposite direction. The diopter of the first mirror group 221 and the second mirror group 222 is positive, and the refracting power of the third mirror group 223 is negative.

The distance L2 between the third mirror group 223 and the mirror 23 is such that the distance between the mirror group 22 and the mirror 23 is fixed. The first mirror group 221 and the second mirror group 222 can be moved to adjust the focal plane of the projection imaging system while the distance between the third mirror group 223 and the mirror 23 remains unchanged, thereby avoiding large distortion.

In summary, the projector provided by the embodiment of the present disclosure divides the refractor group into a first mirror group, a second mirror group, and a third mirror group, which are sequentially disposed in the traveling direction of the light, and makes the first The mirror group and the second mirror group are movable in the traveling direction of the light or in the opposite direction of the direction, that is, the focal plane of the projector can be adjusted without changing the distance between the mirror group and the mirror. The problem that the distortion of the picture caused by adjusting the distance between the refractor group and the mirror in the related art may be large, so that the image quality of the projector is low, and the imaging quality of the projector is high.

In some embodiments of the present disclosure, the refractive mirror group 22 and the mirror 23 satisfy the first formula, and the first formula is: 0.9 < L1/L2 < 1.2. L1 is the length of the refractive mirror group 22, and L2 is the spacing between the refractive mirror group 22 and the mirror 23. L2 is a value within a preset range, which may be, for example, 69 mm (mm) to 91 mm. For example, L2 can be 73mm or 87mm. L2 can be 69mm or 91mm. The L2 is an immutable value after the projector is shipped, so that it can stably control distortion at various projection sizes. The above distance or length is a length value in the d direction.

In some embodiments of the present disclosure, the first mirror group 21, the second mirror group 22, and the third mirror group 23 of the refracting mirror group 22 satisfy the second formula, and the second formula is:

Where F is the equivalent focal length of the refractor group 22, FB is the equivalent focal length of the first mirror group 221, FM is the equivalent focal length of the second mirror group 222, and FF is the equivalent focal length of the third mirror group 223, FC It is the equivalent focal length of the mirror 23.

In some embodiments of the present disclosure, the mirror 23 is a concave aspheric mirror or a free-form mirror, the concave curved surface of which is configured to receive the light emitted by the third mirror.

The light valve 21 is, for example, a digital micromirror device (English: Digital Micromirror Device; abbreviation: DMD), and the DMD may be 2K resolution or 4K resolution. In addition, the light valve 21 includes a mirror array and a control circuit. When the light valve 21 is illuminated, the control circuit controls the mirror array to reflect the light beam emitted by the light source system, generates an image beam, and exits the projection imaging system. The light source refers to an optical component that provides a light beam for the light valve 21 in the projection device. The related art of how the light valve 21 specifically generates an image beam is not described herein.

The projector provided by the embodiment of the present disclosure may include at least two structures, and the two structures are respectively described below as an example.

As shown in FIG. 3, a first configuration of a projector provided by some embodiments of the present disclosure is capable of achieving high resolution (e.g., 4K) projection imaging. The projector 20 includes a refractive mirror group 22 and a mirror 23. The projector 20 also includes a vibrating lens 24. The vibrating lens 24 is located upstream of the refractor group in the optical path. For example, as shown in FIG. 3, the vibrating lens 24 may be disposed on the optical path between the light valve 21 and the refractor group 22.

The vibrating lens 24 is configured such that the optical path of the image beam corresponding to the adjacent two frames of the vibrating lens does not completely overlap by the self-vibration, and the image beams corresponding to the adjacent two frames of the projected image are sequentially directed to the refractor group, and the projected image is projected. An image that is rendered on a projection screen after the image beam passes through the projection imaging system.

In some embodiments of the present disclosure, the vibrating lens 24 can be a flat glass or other transparent substrate. The vibrating lens 24 is capable of vibrating such that light rays emerging in different vibration states have different offsets. The vibrating lens 24 vibrates such that the optical paths of the image beams corresponding to the adjacent two-frame projected images of the vibrating lens 24 do not completely overlap, so that the positions of the pixels of the same relative position in the adjacent pixel frames are not overlapped and have a certain offset. In addition, the resolution of the imaging is improved, and the image beam corresponding to the pixels of the same relative position of the adjacent two frames of the projected image is slightly staggered due to the vibration of the vibrating lens 24, thereby making the excessive transition between the pixels smoother, thereby improving the delicate feeling of imaging. In turn, the image quality is improved and high-resolution image quality is achieved.

In some embodiments, the projection imaging system projector may further include a total reflection prism 25. The total reflection prism 25 is located upstream of the vibrating mirror 24 in the optical path, for example, the total reflection prism 25 is located on the optical path between the light valve 21 and the vibrating lens 24. The total reflection prism 25 may include two glued total reflection prisms, respectively a first total reflection prism and a second total reflection prism (not shown in FIG. 3). The light beam emitted from the light valve 21 is first directed toward the first total reflection prism, and when the light beam is directed toward the first total reflection prism, the light beam is totally reflected, and the totally reflected light beam is directed to the light valve. When the totally reflected light beam is directed to the light valve 21, the light valve 21 reflects the light beam to generate an image light beam, and then the generated image light beam is directed from the light valve 21 to the total reflection prism 25. When the image beam is directed from the light valve 21 to the total reflection prism 25, the image beam does not undergo total reflection, but directly directs the image beam toward the vibrating lens 24. Since the first total reflection prism causes total reflection of the light beam directed to itself, the total reflection prism 25 can be used to reflect the light beam onto the light valve 21, thereby eliminating the need for multiple reflections by a plurality of ordinary mirrors, thereby reducing The number of ordinary mirrors used greatly reduces the size of the projection imaging system projector. In addition, the total reflection prism 25 causes the light beam passing therethrough to become a uniform light beam parallel to the optical axis z, thereby satisfying the demand for the telecentric optical path, since the image beam generated by the light valve 21 is made uniform, thereby also improving the projected image. quality.

The first mirror group 221 may include, for example, 11 lenses, the second mirror group 222 may include 3 lenses, and the third mirror group 223 may include 1 lens. The first mirror group 221 can be used to correct aberrations other than distortion, the second mirror group 222 can be used to correct chromatic aberration, and the third mirror group 223 can be used to correct distortion, and the third mirror group 223 and the mirror 23 can be used for correction. distortion.

In some embodiments, the first mirror group 221 may include a first lens a1, a second lens a2, a third lens a3, a fourth lens a4, a fifth lens a5, and a sixth lens which are sequentially disposed along the traveling direction d of the light. A6, a seventh lens a7, an eighth lens a8, a ninth lens a9, an eleventh lens a11, wherein the diopter of the fourth, eighth, and eleventh lenses is negative, first, second, third, fifth, sixth, seventh The diopter of the nine lens is positive. In some embodiments, the second lens a2, the sixth lens a6, and the seventh lens a7 are aspherical lenses, and the lenses of the first lens group 221 other than the second lens a2, the sixth lens a6, and the seventh lens a7 are It is a spherical lens.

The sixth lens a6 and the seventh lens a7 are used to enhance the resolution of the large field of view. The second lens a2 is used to improve the coma. The second lens a2 cooperates with the ninth lens a9 to increase the rear working distance of the lens. In some embodiments of the present disclosure, the first mirror group may further include a tenth lens a10 disposed between the ninth lens a9 and the eleventh lens a11, and the tenth lens a10 is used for temperature relaxation. The diopter of the tenth lens a10 is positive.

In some embodiments, the second mirror group 222 may include a twelfth lens a12, a thirteenth lens a13, and a fourteenth lens a14 that are sequentially disposed along the traveling direction d of the light, the twelfth lens a12 and the The thirteenth lens a13 has a positive dioptric power, and the fourteenth lens a14 has a negative dioptric power. The lenses in the second lens group 222 may all be spherical lenses.

In some embodiments, the third lens group 223 may include a fifteenth lens a15, and the fifteenth lens a15 is an aspherical lens. The fifteenth lens a15 is negative in diopter. The fifteenth lens a15 is used to improve astigmatism and distortion.

The first mirror group 221, the second mirror group 222, the third mirror group 223, and the mirror 23 are located on the same main optical axis z.

In some embodiments of the present disclosure, the second lens a2, the sixth lens a6, the seventh lens a7, and the fifteenth lens a15 are axially symmetric lenses.

In some embodiments of the present disclosure, the first lens a1, the fifth lens a5, the sixth lens a6, and the tenth lens a10 are the meniscus lenses, and the convex portions of the fifth lens a5 and the sixth lens a6 are oriented toward the light. In the opposite direction of the direction d, the convex portion of the tenth lens a10 faces the traveling direction d of the light. The second lens a2, the third lens a3, the seventh lens a7, and the ninth lens a9 are lenticular lenses. The fourth lens a4, the eighth lens a8, and the eleventh lens a11 are biconcave lenses.

In one embodiment of the present invention, the second lens a2 having a positive diopter is further provided between the first lens a1 and the third lens a3. The second lens a2 is an aspherical lens, and is preferably an axisymmetric aspherical lens. The second lens a2 is for improving the coma aberration, and the second lens a2 is engaged with the ninth lens a9 to increase the rear working distance of the lens. In this embodiment, the back focal length (BFL) of the projection imaging system can reach a value between 20 mm and 34 mm.

In some embodiments of the present disclosure, one side of the fourth lens a4 is combined with the third lens a3, and the other side of the fourth lens a4 is combined with the fifth lens a5 to reduce chromatic aberration. The third lens a3, the fourth lens a4, and the fifth lens a5 may be bonded together by gluing. The combination may be a mutual fit.

The Abbe number of the fourth lens a4 is between 22 and 17, and the refractive index of the fourth lens a4 is greater than 1.8. The refractive indices of the third lens a3 and the fifth lens a5 are smaller than the refractive index of the fourth lens a4, and the Abbe numbers of the third lens a4 and the fifth lens a5 are larger than the Abbe number of the fourth lens a4. Abbe number (English: Abbe) is a physical quantity used to measure the degree of light dispersion of a medium. The greater the refractive index of the material, the stronger the dispersion and the lower the Abbe number.

In some embodiments of the present disclosure, the tenth lens a10 and the eleventh lens a11 are combined with each other to reduce axial chromatic aberration. For example, the tenth lens a10 and the eleventh lens a11 may be bonded to each other by gluing. The refractive index of the tenth lens is larger than that of the eleventh lens, and the Abbe number of the tenth lens is smaller than the Abbe number of the eleventh lens.

In some embodiments of the present disclosure, the thirteenth lens a13 and the fourteenth lens a14 are combined with each other to reduce chromatic aberration. The refractive index of the thirteenth lens is smaller than the refractive index of the fourteenth lens, and the Abbe number of the thirteenth lens is larger than the Abbe number of the fourteenth lens. The thirteenth lens a13 and the fourteenth lens a14 may be bonded to each other by gluing.

In the projector shown in FIG. 3, the third lens a3, the fourth lens a4, and the fifth lens a5 constitute a set of mutually coupled lenses, and the tenth lens a10 and the eleventh lens a11 constitute a set of mutually coupled lenses. The thirteenth lens a13 and the fourteenth lens a14 form a set of mutually combined lenses, and the three sets of mutually combined lenses can be used to improve the spherical aberration of different spectra of the projector, and the axial chromatic aberration of the projector and the vertical The axial color difference is corrected.

In the projector shown in FIG. 3, the diopter of the first lens, the second lens, the third lens, the fifth lens, the sixth lens, the seventh lens, the ninth lens, and the tenth lens is positive, the fourth lens, the first lens The diopter of the eight lens and the eleventh lens is negative. The overall diopter of the first mirror group 221 is positive.

The dioptence of the twelfth lens in the second mirror group 22 is positive, the dioptric power of the thirteenth lens is positive, and the dioptric power of the fourteenth lens is negative. The overall diopter of the second mirror group 222 is positive. The fifteenth lens in the third lens group has a negative diopter.

The distance from the light valve 21 to the first lens a1 is the back focus (English: Back Focus Length; BFL for short), and the BFL satisfies 0.29 < BFL/L2 < 0.37. In some embodiments of the present disclosure, the light incident surface of the seventh lens a7 may also be provided with an aperture.

The structure shown in FIG. 3 is a secondary imaging structure. After the image beam of the light valve 21 passes through the refractor group, the first imaging is performed between the mirror and the refractor group, and the first image is reflected by the mirror and then on the screen. A second undistorted image is formed on the image. The projector provided by the embodiment of the present disclosure is compact overall, and the correction of the large field of view aberration by the aperture setting, the aspherical lens and the mirror improves the resolution of the projector, thereby realizing high-resolution imaging quality.

After the projector shown in FIG. 3 is manufactured, the distance between the third mirror group 223 and the mirror 23 is fixed, and the distance between the first mirror group 221 and the second mirror group 222 can be adjusted. The distance between the mirror group 222 and the third mirror group 223 can also be adjusted.

In some embodiments of the present disclosure, the effective focal length (English: Effective Focal Length) of the projector shown in FIG. 3 is -2.09 mm (mm), and the offset (English: offset) is 140% to 148%. The ability to achieve 93 line pairs / mm (lp / mm), can project a screen size of 80 to 120 inches, projection ratio of 0.20 to 0.22.

In some embodiments of the present disclosure, the projector meets the following conditions: Effective Focal Length = -2.1 mm, Offset = 140% - 148%, resolution of 93 lp / mm, can be projected The screen size is 65 to 80 inches, and the projection ratio (projection distance/screen length direction) is 0.20 to 0.22.

As shown in FIG. 4, a second structure of a projector provided by some embodiments of the present disclosure is capable of achieving projection imaging of an ultra-short focal length. The projector 20 includes a refractive mirror group 22 and a mirror 23. The first mirror group 221 includes 10 lenses, the second mirror group includes 3 lenses, and the third mirror group includes 1 lens.

The first mirror group 221 includes a twenty-first lens a21, a twenty-second lens a22, a twenty-third lens a23, a twenty-fourth lens a24, a twenty-fifth lens a25, which are sequentially disposed along the traveling direction d of the light, The twenty-sixth lens a26, the twenty-seventh lens a27, the twenty-eighth lens a28, the twenty-ninth lens a29, and the thirtieth lens a30. The twenty-sixth lens a26 and the twenty-seventh lens a27 are aspherical lenses, and the lenses of the first mirror group 221 other than the twenty-sixth lens a26 and the twenty-seventh lens a27 are spherical lenses. Compared to the projector shown in FIG. 3, the number of aspherical mirrors in the projector shown in FIG. 4 is small, and the number of lenses is also small, thereby reducing the cost and length of the projector. The refracting power of the twenty-fourth lens a24, the twenty-eighth lens a28, and the twenty-ninth lens a29 is negative, the twenty-first lens a21, the twenty-second lens a22, the twenty-third lens a23, the twenty-fifth The diopter of the lens a25, the twenty-sixth lens a26, the twenty-seventh lens a27, and the thirtieth lens a30 is positive.

In some embodiments of the present disclosure, the twenty-third lens a23, the twenty-fourth lens a24, and the twenty-fifth lens a25 are sequentially glued together, and the twenty-ninth lens a29 and the thirty-th lens a30 are glued together.

In some embodiments of the present disclosure, the twenty-fifth lens a25 and the twenty-sixth lens a26 are convex-concave lenses in which the convex portions are opposite to the traveling direction d of the light. The twenty-first lens a21, the twenty-second lens a22, the twenty-third lens a23, the twenty-seventh lens a27, and the thirtieth lens a30 are lenticular lenses. The twenty-fourth lens a24, the twenty-eighth lens a28, and the twenty-ninth lens a29 are biconcave lenses.

The second mirror group 222 includes: a twelfth lens a12, a thirteenth lens a13, and a fourteenth lens a14 which are sequentially disposed in the traveling direction of the light; the twelfth lens a12 and the thirteenth lens a13 have a positive diopter, and the tenth The four lens a14 diopter is negative.

The third mirror group a13 includes a fifteenth lens a15 having a negative diopter, and the fifteenth lens a15 is an aspherical lens.

In at least one embodiment, the projector shown in FIG. 4 can have an effective focal length of -2.1 mm, an offset of 140% to 148%, a resolution of 93 lp/mm, and a projected screen size of 65 to 80. Inches, the throw ratio is 0.20 to 0.22.

As shown in FIG. 6, in some embodiments of the present disclosure, the projector 20 includes a light valve 102, a total reflection prism 103, a first mirror group 120, a second mirror group 130, and a third mirror which are sequentially disposed along the optical axis 101. Group 140 and mirror 150. The third mirror group 140 includes an aspherical plastic lens, and the shape of the light-emitting surface of the lens is recurved, which is suitable for plastic injection molding. The shape of the fifteenth lens a15 in Fig. 4 is suitable for glass molding. In FIG. 6, the total reflection prism 103 is closer to the first lens of the second mirror group 120, the first lens of the second lens group 120 in the traveling direction of the light is a lenticular lens, and the second lens is a convex-concave lens. And the second lens is a spherical lens. The light valve 102, the total reflection prism 103, the remaining lenses of the first mirror group 120, and the second mirror group 130 are substantially similar to those of FIG. 4 and will not be described in detail.

The distance between different lenses, groups of mirrors involved in some embodiments of the present disclosure is the distance on the optical axis z.

In summary, the projector provided by the embodiment of the present disclosure splits the refractor group into a first mirror group, a second mirror group, and a third mirror group which are sequentially disposed along the traveling direction of the light, and the first A mirror group and a second mirror group are capable of moving the direction of travel of the light or the opposite direction of the direction to adjust the focal plane of the projector, that is, the projector can be adjusted without changing the distance between the mirror group and the mirror Focal plane. The problem that the distortion of the picture caused by adjusting the distance between the refractor group and the mirror in the related art may be large, so that the imaging quality of the projector is low is solved. The effect of high image quality of the projector is achieved.

In the projector provided by the embodiment of the present disclosure, the first mirror group and the second mirror group can be moved in the traveling direction of the light or the opposite direction of the direction through various moving structures, as shown in FIG. 6 , which is A schematic structural diagram of a projector provided by an embodiment of the present disclosure.

The projector further includes a first barrel A1, a main barrel A2, a second barrel A3, and a mirror barrel A4, the first mirror group being disposed in the first barrel A1 and the third mirror group being disposed in the main barrel A2 The second lens group is disposed in the third lens barrel A3 (for convenience of explanation, only the partial lens in each lens group is shown in FIG. 5, the structure of the lens in each lens group may refer to the above embodiment), and the mirror is disposed at In the mirror barrel A4, the position of the main barrel A2 with respect to the mirror barrel A4 is constant to ensure that the position between the third mirror group and the mirror 23 is relatively fixed. The first barrel A1 and the main barrel A2 are rotatably connected by an adjusting ring C1. The adjusting ring C1 includes a first roller (Roller is a roller) C11 and a second roller C12, and the first roller C11 and the first barrel A1 is rotatably connected, the second roller C12 is rotatably connected to the main barrel A2, and the adjusting ring C1 is provided with a straight groove along the circumferential direction of the first barrel A1 which is engaged with the first roller C11 (not shown in FIG. 5). The adjusting ring C1 is further provided with a chute (not shown in FIG. 5) along the circumferential direction of the first barrel A1 in cooperation with the second roller C12.

Since the second roller C12 is coupled to the main barrel A2, and the movement track groove of the second roller C12 is a straight groove. Therefore, the adjustment ring C1 is relatively stationary with respect to the main barrel A2 in the traveling direction d of the light when it is rotated. The first roller C11 is connected to the first barrel A1, and the movement track groove of the first roller C11 is a chute. Therefore, when the adjustment ring C1 rotates, the first roller C11 is driven along the main barrel A2 along the light. The traveling direction d (or the opposite direction of the direction d) moves, thereby causing the first barrel A1 to move relative to the main barrel A2 in the traveling direction d of the light (or the opposite direction of the traveling direction d of the light).

As shown in FIG. 7, which is a top view of the adjustment ring C1 in the projector shown in FIG. 6, it can be seen that the adjustment ring C1 is provided with a straight groove g1 and a chute g2.

In addition, the connection between the main barrel A2 and the second barrel A3 is similar to that of the main barrel A2 and the first barrel A1, and will not be described herein.

According to a second aspect of the present disclosure, an embodiment of the present disclosure further provides a laser projection apparatus including a light source, a light valve, and the projection imaging system provided by the above embodiment; wherein the light valve modulates the laser beam incident from the light source to be projected to the projection Imaging system. The light valve is for example a digital micromirror element.

The laser projection apparatus of the present disclosure can adjust the focal plane of the projection imaging system without changing the distance between the refractive mirror group and the mirror, avoiding image distortion caused by adjusting the distance between the refractive mirror group and the mirror, Improve the imaging quality of the projection imaging system.

In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above is only the specific embodiment of the present disclosure, but the scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the disclosure, and should cover It is within the scope of protection of the present disclosure. Therefore, the scope of protection of the disclosure should be determined by the scope of the claims.

Claims

A projection apparatus comprising a light source, a digital micromirror element configured to receive and modulate light emitted by a light source to form an image beam;

And a refractor group and a mirror sequentially disposed along a traveling direction of the image beam emitted from the digital micromirror device, the refractor group including a first lens group sequentially disposed along a traveling direction of the image beam a second mirror group and a third mirror group, wherein

The distance between the third mirror and the mirror is fixed.

At least one of the first mirror group and the second mirror group is configured to be movable in a direction opposite to a traveling direction of the image beam or a traveling direction of the image beam to adjust the refractor group and the a focal plane of a projection imaging system consisting of mirrors, and

The diopter of the first mirror group and the second mirror group is positive, and the refracting power of the third mirror group is negative.
The projection apparatus according to claim 1, wherein the refractor group and the mirror satisfy a first formula, the first formula is: 0.9 < L1/L2 < 1.2, and the L1 is the refractor The length of the group, the L2 being the spacing between the set of refractive mirrors and the mirror.
The projection apparatus according to claim 2, wherein 69 mm ≤ L2 ≤ 91 mm.
The projection apparatus according to claim 2, wherein said first mirror group, said second mirror group, and said third mirror group of said refractive mirror group satisfy a second formula, said second public

The formula is:

Wherein F is an equivalent focal length of the refractive mirror group, the FB is an equivalent focal length of the first mirror group, the FM is an equivalent focal length of the second mirror group, and the FF is An equivalent focal length of the third mirror group, the FC being an equivalent focal length of the mirror.
The projection apparatus of claim 1, wherein the projection imaging system further comprises a vibrating lens located upstream of the refractor group in the optical path, and

The vibrating lens is configured such that the image beams corresponding to the adjacent two frames of the projected image of the vibrating lens do not completely overlap by the self-vibration, and the image beams corresponding to the adjacent two frames of the projected image are sequentially directed toward the The refractor set is an image that is presented on the projection screen after the image beam passes through the projection imaging system.
The projection apparatus according to claim 5, wherein the vibrating lens comprises a vibratable flat glass.
The projection apparatus of claim 5, wherein the projection imaging system further comprises a total reflection prism located upstream of the vibrating lens in the optical path.
The projection apparatus according to claim 1, wherein the first mirror group includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens which are sequentially disposed along a traveling direction of the image beam. a sixth lens, a seventh lens, an eighth lens, a ninth lens, and an eleventh lens, wherein the diopter of the fourth, eighth, and eleventh lenses is negative, first, second, third, fifth, sixth, seventh, and nine The diopter of the lens is positive.
The projection apparatus according to claim 8, wherein the second lens, the sixth lens, and the seventh lens are aspherical lenses, and the first lens group is apart from the second lens, The sixth lens and the lens outside the seventh lens are spherical lenses.
The projection apparatus according to claim 9, wherein the second lens, the sixth lens, and the seventh lens are axisymmetric lenses.
The projection apparatus according to claim 8, wherein the first mirror group further includes a tenth lens disposed between the ninth lens and the eleventh lens, the diopter of the tenth lens being positive .
The projection apparatus according to claim 11, wherein the first lens, the fifth lens, the sixth lens, and the tenth lens are meniscus lenses, the first lens and the fifth lens And a convex portion of the sixth lens faces an opposite direction of a traveling direction of the image light beam, and a convex portion of the tenth lens faces a traveling direction of the image light beam;

The second lens, the third lens, the seventh lens and the ninth lens are lenticular lenses;

The fourth lens, the eighth lens, and the eleventh lens are biconcave lenses.
The projection apparatus according to claim 8, wherein one side of the fourth lens and the third lens are attached to each other;

The other side of the fourth lens and the fifth lens are attached to each other.
The projection apparatus according to claim 11, wherein the tenth lens and the eleventh lens are attached to each other.
The projection apparatus according to claim 8, wherein the second mirror group includes a twelfth lens, a thirteenth lens, and a fourteenth lens which are sequentially disposed along a traveling direction of the image beam, wherein the The twelve lens and the thirteenth lens have a positive dioptric power, and the fourteenth lens has a negative dioptric power.
The projection apparatus according to claim 15, wherein the lenses in the second mirror group are all spherical lenses.
The projection apparatus according to claim 15, wherein the third mirror group includes a fifteenth lens, and the fifteenth lens has a negative refractive power.
The projection apparatus according to claim 17, wherein the fifteenth lens is an aspherical lens.
The projection apparatus according to claim 15, wherein the thirteenth lens and the fourteenth lens are attached to each other.
The projection apparatus according to claim 1, wherein the first mirror group includes a twenty-first lens, a twenty-second lens, a twenty-third lens, and a second, which are sequentially disposed along a traveling direction of the image beam a fourteenth lens, a twenty-fifth lens, a twenty-sixth lens, a twenty-seventh lens, a twenty-eighth lens, a twenty-ninth lens, a thirtieth lens; wherein

The twenty-sixth lens and the twenty-seventh lens are aspherical lenses, and the lenses of the first lens group other than the twenty-sixth lens and the twenty-seventh lens are spherical lenses ;

The twentieth lens, the twenty-eighth lens, and the twenty-ninth lens have negative diopter, and the twenty-first lens, the twenty-second lens, the twenty-third lens, the twenty-fifth lens, The diopter of the twenty-sixth lens, the twenty-seventh lens, and the thirtieth lens is positive.
The projection apparatus according to claim 20, wherein said twenty-third lens, said twenty-fourth lens and said twenty-fifth lens are sequentially glued together, said twenty-ninth lens and said thirtyth lens Glued together.
The projection apparatus according to claim 20, wherein the twenty-fifth lens and the second sixteenth lens are convex and concave lenses in which a convex portion faces in a direction opposite to a traveling direction of the image light beam;

The twenty-first lens, the twenty-second lens, the twenty-third lens, the twenty-seventh lens, and the thirtieth lens are all lenticular lenses;

The twenty-fourth lens, the twenty-eighth lens, and the twenty-ninth lens are both biconcave lenses.
The projection apparatus according to claim 18, wherein

The fifteenth lens is an axisymmetric aspheric lens.
The projection apparatus according to claim 1, wherein a back focus BFL of the projection imaging system satisfies: 20 mm ≤ BFL ≤ 34 mm.
The projection apparatus according to claim 1, wherein the mirror is a concave aspherical mirror or a free-form surface mirror.