CN216160962U

CN216160962U - Digital projection device and projector

Info

Publication number: CN216160962U
Application number: CN202122224201.8U
Authority: CN
Inventors: 高怡玮; 程炎; 侯伟
Original assignee: Shenzhen Anhua Optoelectronics Technology Co Ltd
Current assignee: Shenzhen Anhua Photoelectric Technology Co ltd
Priority date: 2021-09-13
Filing date: 2021-09-13
Publication date: 2022-04-01
Anticipated expiration: 2031-09-13

Abstract

The utility model provides a digital projection device and a projector, comprising a shell, a light source module, a lens module, a DMD module and an optical adjusting module, wherein the optical adjusting module comprises a fly-eye lens, a spherical lens assembly and a prism assembly; the direction parallel to the optical axis of the lens module is a first direction, the direction perpendicular to the optical axis of the lens module is a second direction, the spherical lens assembly comprises a plurality of spherical side-cut lenses which are sequentially arranged along the second direction, the space occupied by the spherical side-cut lenses in the second direction enables a space A to exist between the optical axes of the fly-eye lens and the lens module in the second direction, the lens module comprises an ultra-short-focus lens, the diameter of a first section of the ultra-short-focus lens is minimum, the minimum distance between the side wall of the first section and the optical axis is W1, and A is larger than W1. The utility model adopts a plurality of spherical surface trimming lenses to adjust the light path, can meet the installation requirement of the ultra-short focal lens, effectively saves the space of the digital projection device and reduces the development cost.

Description

Digital projection device and projector

Technical Field

The utility model relates to the field of projection equipment, in particular to a digital projection device and a projector.

Background

The digital projection optical machine generally comprises a shell, and a light source module, a lens module, a DMD module and an optical adjustment module which are arranged on the shell, wherein the optical adjustment module generally comprises a fly-eye lens, a prism assembly and a spherical lens assembly positioned between the fly-eye lens and the prism assembly, and light emitted by the light source module reaches the DMD module after being adjusted by the optical adjustment module, and then is projected by the lens module. In the existing digital projection optical machine, the spherical lens assembly usually adopts a full-circle spherical lens, and a reflector is usually disposed in the optical path to cooperate with the full-circle spherical lens so as to make the light incident into the prism assembly along a predetermined path.

SUMMERY OF THE UTILITY MODEL

In view of the above-described situation, a main object of the present invention is to provide a compact and compact digital projector and projector with a reduced production cost.

In order to achieve the purpose, the technical scheme adopted by the utility model is as follows:

in a first aspect, the present invention provides a digital projection apparatus, which includes a housing, and a light source module, a lens module, a DMD module and an optical adjustment module mounted on the housing, wherein a direction parallel to an optical axis of the lens module is a first direction, and a direction perpendicular to the optical axis of the lens module is a second direction; the optical adjustment module comprises a fly-eye lens, a spherical lens component and a prism component:

the spherical lens assembly comprises a plurality of spherical edge-cutting lenses which are sequentially arranged between the fly-eye lens and the prism assembly along the second direction, and the space occupied by the plurality of spherical edge-cutting lenses in the second direction enables a spacing dimension A to exist between the fly-eye lens and the optical axis of the lens module in the second direction;

the lens module includes the super short focus lens, the lens cone of super short focus lens divide into the different multistage of external diameter in the axial, wherein, is close to what the casing is first section, the external diameter of first section is minimum, first section is including being close to the first lateral wall of light source module, on the second direction, first lateral wall is apart from the distance size of the optical axis of lens module is W1, A > W1.

Preferably, each spherical edged lens has a first end and a second end, wherein the thickness at the first end is less than the thickness at the second end; the plurality of spherical surface edge cutting lenses comprise a first spherical surface edge cutting lens, a second spherical surface edge cutting lens and a third spherical surface edge cutting lens, wherein the first end of the first spherical surface edge cutting lens, the first end of the second spherical surface edge cutting lens and the second end of the third spherical surface edge cutting lens are positioned on the same side of the axis of the light path.

Preferably, a distance between the first end of the first spherical edge-cutting lens and the first end of the second spherical edge-cutting lens is greater than a distance between the second end of the first spherical edge-cutting lens and the second end of the second spherical edge-cutting lens, and a distance between the first end of the second spherical edge-cutting lens and the second end of the third spherical edge-cutting lens is greater than a distance between the second end of the second spherical edge-cutting lens and the first end of the third spherical edge-cutting lens.

Preferably, the minimum distance between the first spherical-edged lens and the second spherical-edged lens is greater than the minimum distance between the second spherical-edged lens and the third spherical-edged lens.

Preferably, the lens barrel of the ultra-short-focus lens further includes a second section in the axial direction, the second section includes a second sidewall close to the light source module, in the second direction, the minimum distance between the second sidewall and the optical axis of the lens module is W2, W2 is greater than or equal to a, the second section includes a back wall close to the DMD module, and the distance between the back wall and the DMD module is X; the light source module comprises a front wall far away from the DMD module, and the distance between the front wall and the DMD module is Y, and X is larger than Y.

Preferably, the light incident surface of the first spherical surface edge-cutting lens is a convex surface, and the light emergent surface is a concave surface or a plane; the light incident surface of the second spherical surface edge-cutting lens is a concave surface or a plane, and the light emergent surface of the second spherical surface edge-cutting lens is a convex surface; the light incident surface of the third spherical edge-cutting lens is a convex surface, and the light emergent surface is a convex surface, a concave surface or a plane.

In a second aspect, the utility model also provides a projector comprising a digital projection device as described above.

According to the digital projection device and the projector provided by the utility model, in the optical adjustment module in the digital projection device, the optical path is adjusted by adopting the plurality of spherical edge cutting lenses which are part of the spherical lenses, so that the manufacturing cost can be effectively reduced, the projection work can be completed without matching with a reflector, and the occupied space enables enough space to be reserved between the fly-eye lens and the optical axis of the lens module to meet the requirement of mounting the ultra-short-focus lens after the plurality of spherical edge cutting lenses are arranged according to the requirement of optical path propagation.

Other advantages of the present invention will be described in the detailed description, and those skilled in the art will understand the technical features and technical solutions presented in the description.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

fig. 1 is a schematic front view of a digital projection apparatus according to a preferred embodiment of the present invention;

FIG. 2 is a schematic rear perspective view of a digital projection apparatus according to a preferred embodiment of the present invention;

FIG. 3 is a schematic optical path diagram of a preferred embodiment of the digital projection apparatus provided in the present invention;

FIG. 4 is one of schematic perspective views of a preferred embodiment of a spherical edged lens according to the present invention;

FIG. 5 is a second schematic perspective view of a preferred embodiment of a spherical edged lens according to the present invention;

FIG. 6 is a schematic diagram of a process for manufacturing a spherical edged lens according to the present invention;

FIG. 7 is a schematic front view of a digital projection apparatus in accordance with a preferred embodiment of the present invention, with the optical engine housing and the trimming lens mounting structure removed;

FIG. 8 is an enlarged view of a portion of the spherical cut lens of FIG. 7;

FIG. 9 is a schematic rear perspective view of a digital projection apparatus in accordance with a preferred embodiment of the present invention, with the optical engine housing and the trimming lens mounting structure removed;

fig. 10 is an enlarged view of a portion of the spherical-surface-trimmed lens region of fig. 9.

Detailed Description

The present invention will be described below based on examples, but the present invention is not limited to only these examples. In the following detailed description of the present invention, certain specific details are set forth in order to avoid obscuring the nature of the present invention, well-known methods, procedures, and components have not been described in detail.

Further, those of ordinary skill in the art will appreciate that the drawings provided herein are for illustrative purposes and are not necessarily drawn to scale.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, what is meant is "including, but not limited to".

In the description of the present invention, it is to be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

In a first aspect, referring to fig. 1, 2 and 7-10 of the specification, the present invention provides a digital projection apparatus, i.e. a digital projection optical machine, which includes a housing, and a light source module 100, a lens module 200, a DMD module 300 and an optical adjustment module 400 mounted on the housing; the optical adjustment module 400 includes a fly-eye lens 420, a spherical lens assembly 410, and a prism assembly 430. In the present invention, a direction parallel to the optical axis 230 of the lens module 200 is defined as a first direction, and a direction perpendicular to the optical axis 230 of the lens module 200 is defined as a second direction.

The spherical lens assembly 410 includes a plurality of spherical cut lenses, such as a first spherical cut lens 411, a second spherical cut lens 412, and a third spherical cut lens 413. Wherein the first spherical edge-cutting lens 411, the second spherical edge-cutting lens 412 and the third spherical edge-cutting lens 413 are sequentially arranged along the second direction between the fly-eye lens 420 and the prism assembly 430; the space occupied by these spherical-edged lenses in the second direction is such that there is a spacing dimension a between the fly-eye lens 420 and the optical axis 230 of the lens module 200 in the second direction;

the lens module 200 includes an ultra-short focus lens, a lens barrel of the ultra-short focus lens is axially divided into a plurality of sections with different outer diameters, wherein a first section 210 is adjacent to the housing, the outer diameter of the first section 210 is the smallest, the first section 210 includes a first sidewall 211 close to the light source module 100, a distance dimension from the first sidewall 211 to an optical axis 230 of the lens module 200 in a second direction is W1, and a > W1.

On the convergent light path inside the optical adjustment module 400, on one hand, a plurality of spherical edge-cutting lenses are adopted to realize the convergence of light rays, each spherical edge-cutting lens can be a part of a complete full-circle spherical lens, and compared with the scheme that the complete spherical lens is adopted to realize the convergence of light rays, the scheme effectively saves the space size, for example, the size in the thickness direction of the digital projection device, and is obviously beneficial to the requirement of miniaturization and portability of the digital projection device because the size of the spherical edge-cutting lens is obviously smaller than that of the complete spherical lens; on the other hand, compare in the current scheme that adopts the speculum, through the arrangement direction that combines together a plurality of sphere side cut lenses with the direction of arranging of light source module, still realized not only making the size of digital projection device second direction keep reasonable compactness, thereby it is convenient for install ultrashort burnt camera lens to make to have reasonable interval size between the optical axis of fly-eye lens and lens module again, and can not receive light source module's interference. Moreover, the arrangement of a reflector is avoided, the internal structure of the digital projection device is simplified, and the problems that extra workload is brought by adjusting the reflector when the reflector is used and the reflector cannot accurately correct light path propagation errors are also solved.

Further, in the digital projection apparatus of the present invention shown in fig. 3 of the specification, only the optical path schematic diagram after the optical path participating components is retained, in a preferred embodiment of the digital projection apparatus provided by the present invention, three spherical edge-cut lenses are used to form the lens assembly, the three spherical edge-cut lenses are sequentially arranged between the fly-eye lens and the prism assembly, and while effective convergence of light and necessary refraction of light can be achieved, so that as many effective light as possible enters the DMD module to improve the overall efficiency of the digital projection apparatus, a space occupied by the three spherical edge-cut lenses in the second direction enables a space a to exist between the fly-eye lens 420 and the optical axis of the lens module 100 in the second direction, and the space a has a meaning that the installation requirement of the ultra-short-focus lens can be satisfied (see fig. 7). As will be understood by those skilled in the art, since the size of the ordinary lens is usually smaller than that of the ultra-short-focus lens, the technical solution of the present application can satisfy the installation requirement of the ultra-short-focus lens, and naturally can also completely satisfy the requirement of the digital projection apparatus using the ordinary lens.

The lens barrel of the ultra-short focus lens is generally divided into a plurality of sections with different outer diameters in the axial direction, wherein a first section 210 is adjacent to the housing, the outer diameter of the first section 210 is the smallest, the first section 210 comprises a first side wall 211 close to the light source module 100, the distance between the first side wall 211 and the optical axis 230 of the lens module 200 in the second direction is W1, a > W1, and the lens barrel of the ultra-short focus lens can be smoothly installed on the digital projection device housing close to the first section of the digital projection device housing without being interfered by the light source module located at the front end of the fly-eye lens.

Meanwhile, the three spherical trimming lenses can be a part of the spherical glass lens, and the processing equipment of the spherical glass lens is universal equipment, so that a specific mould is not required to be arranged, and the development cost of the optical machine is reduced. When one spherical glass lens can be made into two spherical edge-cut lenses, namely two first spherical edge-cut lenses 411 can be formed by cutting one spherical glass lens, two second spherical edge-cut lenses 412 can be formed by cutting one spherical glass lens, and two third spherical edge-cut lenses 413 can be formed by cutting one spherical glass lens, two spherical edge-cut lenses can be formed by cutting one complete spherical glass lens, so that the three complete spherical glass lenses can be processed to form two sets of spherical edge-cut glass lenses of two optical machines, thereby further reducing the production cost of the optical machines, and being particularly suitable for development and production of small-batch optical machines. The production cost can be further saved, and the method is particularly suitable for development and production of small-batch photomechanical.

Specifically, as an alternative manufacturing method, when manufacturing the spherical edge-cut lens of the present invention, a spherical glass lens with a circular cross section meeting the size requirement is taken, the lens is clamped along the two end directions of a diameter of the lens, then, as shown in fig. 6 of the specification, the two sides of the lens are symmetrically ground along the diameter direction perpendicular to the diameter (refer to the direction indicated by the arrow in fig. 6), after reaching a predetermined grinding amount, the ground lens is cut and divided into at least two parts (for example, a ground spherical glass lens is cut into two knives to form two spherical edge-cut lenses each smaller than one half of the ground spherical glass lens and a waste part in the middle part, or only the ground spherical glass lens is cut into one knife to form two symmetrical spherical edge-cut lenses), the upper and lower surfaces formed by grinding are the upper and lower cut surfaces of the formed spherical edge-cut lens respectively, the side cut surface of the spherical edge-cut lens is formed by cutting, the side edge surface is a part of the inherent edge surface of the circular spherical glass lens, and the light incident surface and the light emergent surface are also the light incident/emergent surfaces of the circular spherical glass lens. The person skilled in the art knows that, if necessary, after cutting, the area where the side cut surface is located may be further ground until the portion that does not need to be transparent is substantially ground away to form the final finished product of the cut-surface edge-cut lens, so that the size of the spherical edge-cut lens is further reduced, which is beneficial to further miniaturizing the optical machine structure.

Those skilled in the art can understand that the respective sizes of the three spherical cut-edge lenses can be designed according to actual needs, and the sizes of the first spherical cut-edge lens, the second spherical cut-edge lens and the third spherical cut-edge lens are not required to be completely consistent.

Preferably, referring to fig. 3, 4 and 7-10 of the specification, each spherical cut lens has a first end 17 and a second end 18, wherein the thickness at the first end 17 is less than the thickness at the second end 18, and the first end 17 of the first spherical cut lens 411, the first end 17 of the second spherical cut lens 412 and the second end 18 of the third spherical cut lens 413 are located on the same side of the optical path axis.

In a preferred embodiment, in the spherical cut-edge lens of the present invention, the outer side surface of the first end 17 is an edge surface inherent to the complete round spherical glass lens, the outer side surface of the second end 18 is a cut surface obtained by cutting the complete round spherical glass lens, and the thickness of the first end 17 is smaller than that of the second end 18, so that refraction conditions of external parallel incident light after the incident light enters the first end and the second end are different, and thus, the characteristic of the spherical cut-edge lens can be utilized to adjust the incident light angle to obtain a desired emergent light angle and light convergence degree. The means of adjusting the optical path includes having the first end 17 of the first spherical cut lens 411, the first end 17 of the second spherical cut lens 412, and the second end 18 of the third spherical cut lens 413 on the same side of the optical path axis, and so on. The aforementioned "on the same side of the optical path axis" may specifically be that, in the first direction, the first ends 17 of the first spherical cut lens 411 and the second spherical cut lens 412 are closer to the DMD module 300 than the second ends 18, and the second ends 18 of the third spherical cut lenses 413 are closer to the DMD module 300 than the first ends 17.

Further preferably, a distance between the first end 17 of the first spherical cut lens 411 and the first end 17 of the second spherical cut lens 412 is greater than a distance between the second end 18 of the first spherical cut lens 411 and the second end 18 of the second spherical cut lens 412, and a distance between the first end 17 of the second spherical cut lens 412 and the second end 18 of the third spherical cut lens 413 is greater than a distance between the second end 18 of the second spherical cut lens 412 and the first end 17 of the third spherical cut lens 413.

With reference to fig. 3 of the specification, light emitted from the light source module 100 enters the fly-eye lens 420 in the optical adjustment module 400 along the second direction and then exits, the exiting light enters the second spherical cut-edge lens 412 after passing through the first spherical cut-edge lens 411, at this time, the light passing through the fly-eye lens 420 can substantially exit through the first spherical cut-edge lens 411 because the first spherical cut-edge lens 411 is disposed on the main light path after the fly-eye lens 420, and because in the first direction, the first ends 17 of the first spherical cut-edge lens 411 and the second spherical cut-edge lens 412 are closer to the DMD module 300 than the second ends 18, and in the second direction, the distance between the first end 17 of the first spherical cut-edge lens 411 and the second end 18 of the second spherical cut-edge lens 412 are closer to the fly-eye lens 420 than the second ends 412, and the second end 18 of the second spherical cut-edge lens 412 is smaller than the distance between the first end 17 of the second spherical cut-edge lens 412 and the first spherical cut-edge lens 411 The distance between the first ends 17 of the surface-cut lenses 411, and therefore the light exiting through the first spherical-cut lens 411, can substantially enter the second spherical-cut lens 412 and exit to the third spherical-cut lens 413 along the predetermined direction, and the second end 18 of the third spherical-cut lens 413 is closer to the DMD module 300 than the first end 17, and the distance between the second end 18 of the third spherical-cut lens 413 and the first end 17 of the second spherical-cut lens 412 is smaller than the distance between the first end 17 of the third spherical-cut lens 413 and the second end 18 of the second spherical-cut lens 412, so that the light exiting the second spherical-cut lens 412 can substantially enter the third spherical-cut lens 413. Through the specific shape and position relation arrangement of the three spherical trimming lenses, on one hand, light rays emitted by the light source module 100 can enter the prism assembly 430 and then enter the DMD module 300 after passing through the lens assembly 410 as much as possible, so that the DMD is reflected to form effective light rays for the incident lens module to complete projection work, and light ray loss in the transmission process is reduced; on the other hand, the spherical surface trimming lenses can be compactly arranged, the distance does not need to be overlarge, an ideal propagation light path can be obtained, and the miniaturization of the optical machine is fully guaranteed.

Further preferably, a minimum distance between the first spherical cut lens 411 and the second spherical cut lens 412 is greater than a minimum distance between the second spherical cut lens 412 and the third spherical cut lens 413.

The minimum distance between the first spherical cut lens 411 and the second spherical cut lens 412, and the minimum distance between the second spherical cut lens 412 and the third spherical cut lens 413 are also adjustable objects on the converging optical path inside the optical adjustment module of the present invention. With the foregoing arrangement, light can be made to enter and exit the converging optical path along a specific route.

Preferably, referring to fig. 7 in the specification, the barrel of the ultra-short focus lens further includes a second section 220 in the axial direction, the second section 220 includes a second sidewall 221 close to the light source module 100, in the second direction, a minimum distance dimension of the second sidewall 221 from an optical axis 230 of the lens module 200 is W2, W2 is greater than or equal to a, the second section 220 includes a rear wall 222 close to the DMD module 300, and a distance between the rear wall 222 and the DMD module 300 is X; the light source module 100 includes a front wall 110 far from the DMD module 300, and a distance between the front wall 110 and the DMD module 300 is Y, X > Y.

Ultra-short-focus lenses are significantly larger in size, particularly at the size W2, than other types of lenses, such as telephoto lenses. Therefore, in the design of the optical machine, on one hand, the loss in the light transmission process is avoided and the miniaturization is considered, on the other hand, enough space is reserved for the installation of the ultra-short focal lens, because the technical proposal provided by the utility model adjusts the light path by the specific arrangement and the coordination of the three spherical trimming lenses in the second direction, in this way, in the first direction, the rear wall of the light source module is adaptively lower than the three spherical cut-edge lenses, and the distance Y from the front wall of the light source module to the DMD module may be significantly smaller than the distance X from the rear wall of the second section of the ultra-short focal lens barrel to the DMD module, whereby, although the minimum distance dimension W2 of the second sidewall from the optical axis of the lens module in the second direction is greater than or equal to a, however, the arrangement of the second section is not interfered by the light source module, and the normal installation and use of the ultra-short focal lens are ensured.

As an alternative embodiment, referring to fig. 3 and 7-10 of the specification, the prism assembly 430 includes a first prism 431 and a second prism 432, each of which has a triangular cross section, the first prism includes a bottom surface 4311 and a first side surface 4312, an obtuse angle is formed between the bottom surface 4311 and the first side surface 4312, the bottom surface 4311 faces the DMD module 300, and the first side surface 4312 faces the light-emitting surface of the third spherical edge-cutting prism 413.

Specifically, the prism assembly 430 is configured to include a first prism 431 and a second prism 432 with a triangular cross section, and a first side surface 4312 included in the first prism 431 is adjacent to the light-emitting surface of the third spherical edge-cutting prism 413, so that the light emitted from the third spherical edge-cutting prism 413 can be sufficiently incident on the prism assembly 430 as far as possible, and the light loss in the propagation process is further reduced; furthermore, the arrangement of the fly-eye lens 420 and the prism assembly 430 is matched with the specific spherical lens assembly 410 composed of the three spherical edge-cut lenses, so that on one hand, effective light rays can be incident into the DMD module as much as possible in the light propagation process, and on the other hand, the structure of the optical machine is compact and the size of the optical machine is further reduced. The first prism is preferably an obtuse triangle in cross section, and the second prism is preferably a right triangle in cross section for ease of fabrication and to avoid obstruction of the OFF light transmission path.

Preferably, referring to fig. 3-5 and 7-10 of the specification, the light incident surface of the first spherical edge-cut lens 411 is a convex surface, and the light emergent surface is a concave surface or a plane surface; the light incident surface of the second spherical edge-cutting lens 412 is a concave surface or a plane, and the light emergent surface is a convex surface; the light incident surface of the third spherical edge-cutting lens 413 is a convex surface, and the light emergent surface is a convex surface, a concave surface or a plane.

In order to converge the light rays, at least one of the light incident surface and the light incident surface of each spherical surface edge-cut lens is a convex surface. Further, the light incident surface of the first spherical edge-cut lens and the light incident surface of the third spherical edge-cut lens are selected to be a convex surface, the light emergent surface of the first spherical edge-cut lens is a concave surface or a plane, the light incident surface of the second spherical edge-cut lens is a concave surface or a plane, and the light emergent surface of the second spherical edge-cut lens is a convex surface, so that the light path is further adjusted to be transmitted along the predetermined specific direction.

It will be understood that the embodiments described above are illustrative only and not restrictive, and that various obvious and equivalent modifications and substitutions for details described herein may be made by those skilled in the art without departing from the basic principles of the utility model.

Claims

1. A digital projection device comprises a shell, a light source module (100), a lens module (200), a DMD module (300) and an optical adjusting module (400) which are arranged on the shell, wherein the direction parallel to the optical axis (230) of the lens module (200) is a first direction, and the direction vertical to the optical axis of the lens module (200) is a second direction; the optical adjustment module (400) comprises a fly-eye lens (420), a spherical lens assembly (410) and a prism assembly (430), and is characterized in that:

the spherical lens assembly (410) comprises a plurality of spherical-edged lenses (411, 412, 413), the plurality of spherical-edged lenses (411, 412, 413) being arranged in sequence in the second direction between the fly-eye lens (420) and a prism assembly (430), the plurality of spherical-edged lenses (411, 412, 413) occupying a space in the second direction such that a spacing dimension a exists in the second direction between the fly-eye lens (420) and the optical axis (230) of the lens module (200);

the lens module (200) comprises an ultra-short focus lens, a lens barrel of the ultra-short focus lens is axially divided into a plurality of sections with different outer diameters, wherein a first section (210) is arranged adjacent to the shell, the outer diameter of the first section (210) is the smallest, the first section (210) comprises a first side wall (211) close to the light source module (100), the distance between the first side wall (211) and an optical axis (230) of the lens module (200) is W1 in the second direction, and A is larger than W1.

2. The digital projection device of claim 1, wherein: each spherical edged lens having a first end and a second end, wherein the thickness at the first end is less than the thickness at the second end; the plurality of spherical cut lenses (411, 412, 413) comprises a first spherical cut lens (411), a second spherical cut lens (412), and a third spherical cut lens (413), a first end of the first spherical cut lens, a first end of the second spherical cut lens, and a second end of the third spherical cut lens being located on a same side of an optical path axis.

3. The digital projection device of claim 2, wherein: the distance between the first end of the first spherical cut lens (411) and the first end of the second spherical cut lens (412) is greater than the distance between the second end of the first spherical cut lens (411) and the second end of the second spherical cut lens (412), and the distance between the first end of the second spherical cut lens (412) and the second end of the third spherical cut lens (413) is greater than the distance between the second end of the second spherical cut lens (412) and the first end of the third spherical cut lens (413).

4. The digital projection device of claim 3, wherein: the minimum distance between the first spherical cut lens (411) and the second spherical cut lens (412) is greater than the minimum distance between the second spherical cut lens (412) and the third spherical cut lens (413).

5. The digital projection device of claim 1, wherein: the lens barrel of the ultra-short focal lens further comprises a second section (220) in the axial direction, the second section (220) comprises a second side wall (221) close to the light source module, in the second direction, the minimum distance between the second side wall (221) and an optical axis (230) of the lens module (200) is W2, W2 is larger than or equal to A, the second section (220) comprises a rear wall (222) close to the DMD module (300), and the distance between the rear wall (222) and the DMD module (300) is X;

the light source module (100) comprises a front wall (110) far away from the DMD module (300), and the distance between the front wall (110) and the DMD module (300) is Y, X > Y.

6. The digital projection device of any of claims 2-4, wherein: the light incident surface of the first spherical edge-cutting lens (411) is a convex surface, and the light emergent surface is a concave surface or a plane; the light incident surface of the second spherical edge-cutting lens (412) is a concave surface or a plane, and the light emergent surface is a convex surface; the light incident surface of the third spherical edge-cutting lens (413) is a convex surface, and the light emergent surface is a convex surface, a concave surface or a plane.

7. A projector, characterized in that it comprises a digital projection device according to any one of claims 1 to 6.