CN113281888A

CN113281888A - Imaging lens, projection light path system and projection equipment

Info

Publication number: CN113281888A
Application number: CN202110460092.1A
Authority: CN
Inventors: 武宇
Original assignee: Chengdu Transview Technology Co ltd
Current assignee: Chengdu Transview Technology Co ltd
Priority date: 2021-04-27
Filing date: 2021-04-27
Publication date: 2021-08-20

Abstract

The invention relates to the technical field of projection equipment, and provides an imaging lens, a projection optical path system and projection equipment, which comprise a first lens and a second lens which are oppositely arranged, wherein the first lens comprises a first convex surface S1 and a first concave surface S2, the second lens comprises a second convex surface S3 and a second concave surface S4, the first convex surface S1 of the first lens and the second concave surface S4 of the second lens are incident surfaces, and the first concave surface S2 of the first lens and the second convex surface S3 of the second lens are emergent surfaces. On the basis of meeting the requirement of normal projection of short-focus projection equipment, only two lenses are used as projection lenses of the imaging lens, so that the structure of the imaging lens can be simplified, and the manufacturing cost of the imaging lens is reduced; meanwhile, the rear working distance of the imaging lens in the projection optical path system can be shortened by adopting the imaging lens, so that a smaller projection ratio is obtained, a larger-size picture is projected in a shorter projection distance, and the projection effect is improved.

Description

Imaging lens, projection light path system and projection equipment

Technical Field

The invention relates to the technical field of projection equipment, in particular to an imaging lens, a projection optical path system and projection equipment.

Background

A short-focus projector is a projection apparatus having a very short throw ratio, by which it is possible to view bright and colorful large-screen images in any room, classroom, and conference room.

The short-focus projector appearing in the market at present has two forms, one is a reflection type projector, and the working principle is that an aspheric surface reflector is added in front of a short-focus projection lens and is projected to a screen after reflection. And the other is a normal short-focus projector. However, in practical applications, there are some problems in both of the above short-focus projectors: one is that a large number of lenses are arranged in the imaging lens to ensure the projection quality, so that the imaging lens has a complex structure and high manufacturing cost; secondly, the size of the projector can be increased by adopting the non-spherical reflector, meanwhile, the cost of the non-spherical reflector is relatively high, and the non-spherical reflector brings large imaging errors, so that the cost of the projector is increased and the projection effect is reduced.

Disclosure of Invention

The first objective of the present invention is to provide an imaging lens, which can be used in a short-focus projection device by using two lenses, thereby greatly simplifying the structure of the imaging lens and reducing the manufacturing cost.

A second objective of the present invention is to provide a projection optical path system, which can omit a mirror used in a conventional reflective projector to reduce the size of a projection device, and improve the projection effect and reduce the cost.

A third object of the invention is to provide a projection device which is smaller in size and has a better projection effect than existing short-focus projection devices.

The embodiment of the invention is realized by the following technical scheme:

the invention provides an imaging lens, which comprises a first lens and a second lens, wherein the first lens and the second lens are oppositely arranged, the first lens comprises a first convex surface S1 and a first concave surface S2, the second lens comprises a second convex surface S3 and a second concave surface S4, the first convex surface S1 of the first lens and the second concave surface S4 of the second lens are incident surfaces, the first concave surface S2 of the first lens and the second convex surface S3 of the second lens are emergent surfaces, and the second concave surface S4 of the second lens is used for receiving light rays emitted by the second concave surface S2 of the first lens.

Optionally, the first lens and the second lens are aspheric lenses made of PMMA.

Optionally, the diameter of the first lens is 29.5mm, and the edge thickness of the first lens is 3.12 ± 0.1 mm; the diameter of the second lens is 30mm, and the edge thickness of the second lens is 3.96 +/-0.1 mm.

Optionally, the lens barrel further comprises a lens barrel, a pressing ring and a spacer ring, the first lens and the second lens are oppositely arranged inside the lens barrel, the spacer ring is arranged between the first lens and the second lens, the pressing ring is sleeved outside the lens barrel and is in threaded connection with the lens barrel, and the pressing ring is used for supporting the second lens inside the lens barrel.

Secondly, the invention provides a projection optical path system, which comprises a light source, and a first lens, an LCD screen, a second lens and the imaging lens which are sequentially arranged along an optical path, wherein a first convex surface S1 of the first lens is used for receiving light emitted by the second lens.

Optionally, the rear working distance of the imaging lens is 42-46.5mm, and the distance from the second lens to the LCD screen is 9-14 mm.

Optionally, the LCD screen has a size of 2.4 inches or 2.6 inches.

Optionally, a heat insulation glass is arranged between the first lens and the LCD screen.

The invention further provides a projection device which comprises the projection optical path system.

The technical scheme of the embodiment of the invention at least has the following advantages and beneficial effects:

1. the projection lens is reasonable in design, the first concave surface S2 of the first lens faces the second concave surface S4 of the second lens, and on the basis of meeting the requirement of normal projection of short-focus projection equipment, only two lenses are used as projection lenses of the imaging lens, so that the structure of the imaging lens can be simplified, and the manufacturing cost of the imaging lens is reduced; meanwhile, the rear working distance of the imaging lens in the projection optical path system can be shortened by adopting the imaging lens, so that a smaller projection ratio is obtained, a larger-size picture is projected in a shorter projection distance, and the projection effect is improved.

2. The invention can omit a reflector used in the existing reflective projection equipment, and shorten the rear working distance of the imaging lens, thereby compressing the size of the projection equipment, reducing the manufacturing cost of the projection equipment, simultaneously avoiding the problem of influencing the projection effect caused by the reflector, and improving the projection effect of the projection equipment.

3. The imaging lens provided by the invention has the advantages that the aspheric lens formed by PMMA plastic injection molding is adopted, the weight and the cost of the imaging lens can be reduced on the basis of meeting the projection requirement, so that the projection equipment is lighter and the manufacturing cost of the projection equipment is reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of an imaging lens provided in embodiment 1 of the present invention;

fig. 2 is a schematic structural diagram of a projection optical path system provided in embodiment 2 of the present invention.

Icon: 1-imaging lens, 101-first lens, 102-second lens, 103-lens cone, 104-pressing ring, 105-spacing ring, 2-second lens, 3-LCD screen, 4-first lens, 5-light source and 6-heat insulation glass.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship which is usually placed when the product of this application is used, the description is merely for convenience and simplicity of description, and it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be further noted that unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1

Referring to fig. 1, the present embodiment provides an imaging lens 1, which includes a first lens 101 and a second lens 102 disposed oppositely; the first lens 101 includes a first convex surface S1 and a first concave surface S2, the second lens 102 includes a second convex surface S3 and a second concave surface S4, the first convex surface S1 of the first lens 101 and the second concave surface S4 of the second lens 102 are both incident surfaces, the first concave surface S2 of the first lens 101 and the second convex surface S3 of the second lens 102 are both emergent surfaces, the second concave surface S4 of the second lens 102 is used for receiving light emitted from the second concave surface S2 of the first lens 101, and finally the light is projected onto the screen through the second convex surface S3 of the second lens 102.

In the embodiment, the first concave surface S2 of the first lens 101 faces the second concave surface S4 of the second lens 102, and on the basis of meeting the requirement of normal projection of the short-focus projection apparatus, only two lenses are used as projection lenses of the imaging lens 1, so that the structure of the imaging lens 1 can be simplified, and the manufacturing cost of the imaging lens 1 can be reduced; meanwhile, the imaging lens 1 can shorten the rear working distance of the imaging lens 1 in the projection light path system, so that a smaller projection ratio is obtained, a larger-size picture is projected within a shorter projection distance, and the projection effect is improved.

Meanwhile, the existing imaging lens 1 is mostly made of glass, so that the imaging lens is heavy in weight and high in cost. Therefore, the first lens 101 and the second lens 102 of the present embodiment are both aspheric lenses made of PMMA. Through adopting light in weight and with low costs PMMA plastic injection moulding's aspheric surface lens as imaging lens 1's lens, combine foretell structure to arrange, can further reduce imaging lens 1's cost of manufacture on the basis of satisfying normal projection demand, alleviate imaging lens 1's weight to make projection equipment light more.

In the present embodiment, the diameter of the first lens 101 is 29.5mm, and the edge thickness thereof is 3.12 ± 0.1 mm; the diameter of the second lens 102 is 30mm, and the edge thickness thereof is 3.96 ± 0.1mm, and the projection effect of the projection device can be further improved by using the lens with the above parameters as the lens of the imaging lens 1.

In addition, the imaging lens 1 further includes a lens barrel 103, a pressing ring 104 and a spacer 105, the first lens 101 and the second lens 102 are oppositely disposed inside the lens barrel 103, the spacer 105 is disposed between the first lens 101 and the second lens 102, the pressing ring 104 is sleeved outside the lens barrel 103 and is in threaded connection with the lens barrel 103, and the pressing ring 104 is used for pressing the second lens 102 inside the lens barrel 103. Through the arrangement, on the basis of ensuring the structural stability of the first lens 101 and the second lens 102, the first lens 101 and the second lens 102 can be conveniently disassembled and assembled.

Example 2

Referring to fig. 2, the present embodiment provides a projection optical path system, which includes a light source 5, and a first lens 4, an LCD screen 3, a second lens 2 and the imaging lens 1 sequentially disposed along an optical path, wherein a first convex surface S1 of the first lens 101 is used for receiving light emitted by the second lens 2.

It should be noted that, in this embodiment, the first lens 4 is a light-equalizing fresnel lens, and the second lens 2 is a trapezoidal fresnel lens, which belongs to a general configuration in an LCD projection system, where the light-equalizing fresnel lens can convert a point light source into parallel light, and the trapezoidal fresnel lens converges the parallel light onto the imaging lens 1, and then the imaging lens 1 magnifies the image and projects the image onto a projection screen for imaging.

Through using above-mentioned imaging lens 1 in projection optical path system of projection equipment, can realize omitting the speculum that uses among the current reflection formula projection equipment to shorten imaging lens 1's back working distance, thereby compression projection equipment's size reduces projection equipment's cost of manufacture, can also avoid appearing the problem of the influence projection effect that brings by the speculum simultaneously, promotes projection equipment's projection effect.

Specifically, the back working distance of the imaging lens 1 is 42-46.5mm, and the distance from the second lens 2 to the LCD screen 3 is 9-14 mm. In the present embodiment, the rear working distance of the imaging lens 1 refers to a distance C from the first convex surface S1 of the first lens 101 to the exit surface of the second lens 2; and the distance from the second lens 2 to the LCD screen 3 refers to the distance D from the incident surface of the second lens 2 to the exit surface of the LCD screen 3.

This embodiment is through further injecing imaging lens's 1 back working distance and second lens 2 to LCD screen 3's distance to optimize imaging lens 1, second lens 2 and LCD screen 3's the position that sets up, realize promoting the projection effect, and for current short burnt projection equipment, because imaging lens's 1 back working distance shortens by a wide margin, thereby can compress projection equipment's size, make projection equipment lighter.

In this embodiment, the size of the LCD panel 3 is 2.4 inches or 2.6 inches, the resolution of the LCD panel 3 is 800 × 480 or 640 × 360, and under the size parameter, the length of the imaging lens 1 is 42.5mm, and at this time, the projection optical path system satisfies 40 inches projected by 1 meter, so as to realize projecting a larger image at a shorter projection distance.

The length of the imaging lens 1 refers to the distance between the first convex surface S1 of the first lens 101 and the second convex surface S3 of the second lens 102.

In this embodiment, in order to make the projection optical path system more reliable in practical application, a heat insulating glass 6 is disposed between the first lens 4 and the LCD panel 3.

In addition, this embodiment still provides a projection equipment, including the aforesaid projection optical path system through adopting foretell projection optical path system for projection equipment's size is littleer, and it is more convenient to carry, can reduce projection equipment's cost of manufacture on the basis of the projection effect that promotes projection equipment simultaneously.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An imaging lens comprises a first lens and a second lens which are oppositely arranged, wherein the first lens comprises a first convex surface S1 and a first concave surface S2, the second lens comprises a second convex surface S3 and a second concave surface S4, and the imaging lens is characterized in that the first convex surface S1 of the first lens and the second concave surface S4 of the second lens are incident surfaces, the first concave surface S2 of the first lens and the second convex surface S3 of the second lens are emergent surfaces, and the second concave surface S4 of the second lens is used for receiving light rays emitted by the second concave surface S2 of the first lens.

2. The imaging lens of claim 1, wherein the first lens and the second lens are aspheric lenses made of PMMA.

3. Imaging lens according to claim 1 or 2, characterized in that the first lens has a diameter of 29.5mm and an edge thickness of 3.12 ± 0.1 mm; the diameter of the second lens is 30mm, and the edge thickness of the second lens is 3.96 +/-0.1 mm.

4. The imaging lens according to claim 1, further comprising a lens barrel, a pressing ring and a spacer ring, wherein the first lens and the second lens are disposed inside the lens barrel in an opposite manner, the spacer ring is disposed between the first lens and the second lens, the pressing ring is sleeved outside the lens barrel and is in threaded connection with the lens barrel, and the pressing ring is used for pushing the second lens inside the lens barrel.

5. A projection optical path system, comprising a light source, and a first lens, an LCD screen, a second lens and the imaging lens of any one of claims 1-3, which are sequentially disposed along an optical path, wherein the first convex surface S1 of the first lens is used for receiving light emitted from the second lens.

6. The projection optical path system as claimed in claim 5, wherein the rear working distance of the imaging lens is 42-46.5mm, and the distance from the second lens to the LCD screen is 9-14 mm.

7. The projection optical path system of claim 5, wherein the LCD screen has a size of 2.4 inches or 2.6 inches.

8. The projection optical path system according to claim 5, wherein a heat insulation glass is arranged between the first lens and the LCD screen.

9. A projection apparatus comprising the projection optical path system according to any one of claims 5 to 8.