CN212255997U

CN212255997U - Single-chip LCD projector and optical system thereof

Info

Publication number: CN212255997U
Application number: CN202022156121.9U
Authority: CN
Inventors: 刘清卫
Original assignee: Shenzhen Geyi Innovation Electric Appliance Co ltd
Current assignee: Shenzhen Geyi Innovation Electric Appliance Co ltd
Priority date: 2020-09-27
Filing date: 2020-09-27
Publication date: 2020-12-29
Anticipated expiration: 2030-09-27

Abstract

The utility model discloses an optical system for a single-chip LCD projector, which comprises a light shaping component for converging and shaping a light source and converting the light source into parallel light, a lens for projecting images, and a light converging component for converging the images from a liquid crystal screen of the single-chip LCD projector to the lens; the light shaping assembly comprises a first condenser lens for converging and shaping the light source into a preset shape, a second condenser lens for converging and shaping again and a rear Fresnel lens; light from the second condenser lens is converted into parallel light through the rear Fresnel lens and then projected onto a liquid crystal screen of the single-chip LCD projector, and the single-chip LCD projector is small in size, and can improve the uniformity and brightness of a picture and the image effect of the single-chip LCD projector by using a specific light shaping assembly.

Description

Single-chip LCD projector and optical system thereof

Technical Field

The utility model belongs to the technical field of the projector technique and specifically relates to an optical system improvement of monolithic LCD projector is related to.

Background

The single-chip LCD projector is a projector product which uses a full-color and transmission type Liquid Crystal Display (LCD) as a screen, emits light from an illumination component, and magnifies and projects an image of the screen on the screen through a projection lens. The conventional single-chip LCD projector has two structural forms of a direct projection type and a reflection type according to the difference of optical path structures, wherein the direct projection type single-chip LCD projector has great inconvenience in carrying, storage and use due to large appearance, and the other is the reflection type, for example, in the Chinese patent application with the publication number of CN 109613788A, although the size of the disclosed single-chip LCD projector can be small, the quality of a projected image is poor, the practicability is poor, and improvement is urgently needed. In addition, the improvement of the projection brightness and uniformity of the single-chip LCD projector is a well-recognized problem in the industry, and especially in the miniaturization of products, too many factors need to be considered, so that the difficulty is increased.

The above background disclosure is only provided to aid in understanding the inventive concepts and solutions of the present application and it is not necessary for them to belong to the prior art of the present application, but it should not be used to assess the novelty and inventive step of the present application without explicit evidence that they have been disclosed at the filing date of the present application.

SUMMERY OF THE UTILITY MODEL

In order to overcome the technical problem of poor image quality in the prior art, the application provides an optical system for a single-chip LCD projector, which comprises an optical shaping component for converging, shaping and converting a light source into parallel light, a lens for projecting an image, and a light converging component for converging the image from a liquid crystal screen of the single-chip LCD projector to the lens; the light shaping assembly comprises a first condenser lens for converging and shaping the light source into a preset shape, a second condenser lens for converging and shaping again and a rear Fresnel lens; and the light from the second condenser lens is converted into parallel light through the rear Fresnel lens and then is projected onto a liquid crystal screen of the single-chip LCD projector.

Optionally, the first collecting mirror is a spherical mirror, one spherical side of the first collecting mirror faces the liquid crystal screen of the single-chip LCD projector, and the other spherical side of the first collecting mirror is a plane; the second condenser is a cylindrical mirror, is positioned between the first condenser and the liquid crystal screen of the single-chip LCD projector, and has one planar side facing the first condenser and one cylindrical side facing the liquid crystal screen of the single-chip LCD projector.

Optionally, the fresnel lens further includes a reflecting mirror, the reflecting mirror is disposed obliquely, and receives and reflects the light from the second condenser lens to the rear fresnel lens.

Optionally, the reflector is inclined at an angle of 38-55 degrees, that is, the optical axis of the light shaping assembly and the optical axis of the rear fresnel lens form an angle of 38-55 degrees with the mirror surface of the reflector.

Optionally, the light converging element is a front fresnel lens, and is disposed between a liquid crystal screen of the single-chip LCD projector and the lens.

The first condenser and the second condenser are arranged at a preset interval and the interval is adjustable.

The present application also provides a single-chip LCD projector comprising a light source, an optical system, a liquid crystal imaging system and a power supply, the optical system being an optical system as described hereinbefore; the imaging system is the liquid crystal screen of the single-chip LCD projector, and the liquid crystal screen is arranged between the light shaping component and the light converging component.

Preferably, the optical system satisfies the following condition:

2.3<L/Fh<3.3

3<L/fv<4

wherein L is the distance from the rear Fresnel lens to the light source,

fh is the horizontal focal length of the light shaping assembly,

fv is the vertical focal length of the light shaping component.

Compared with the prior art, the technical scheme of the application has at least the following beneficial effects: by using the specific light shaping component, the single-chip LCD projector not only has small volume, but also can improve the uniformity and brightness of the picture and improve the image effect of the single-chip LCD projector. In addition, the volume of the optical system and the single-chip LCD projector comprising the optical system can be further reduced by the obliquely arranged reflector, and the specific structural design and arrangement mode can avoid the amplification effect of adjustment such as trapezoidal correction on the change of the light path, so that the adjustment of the projection effect of the projector such as trapezoidal correction is more favorable compared with the prior art.

Drawings

Fig. 1 is a (partial) schematic diagram of an optical system according to an embodiment of the present invention, which is an XZ-direction view.

FIG. 2 is a YZ directional view of a structure (portion) of an optical system of the embodiment of FIG. 1;

fig. 3 is a (partial) schematic diagram of an optical system according to another embodiment of the present invention.

Detailed Description

The present invention will be described in further detail below with reference to examples and the accompanying drawings.

As shown in fig. 1 and 2, an optical system for a single-chip LCD projector includes a light shaping unit for converging, shaping and converting a light source 1 into parallel light (as understood by those skilled in the art, the parallel light is not absolute, and is also included in the case of approximate or near parallel light, and the parallel light is also referred to hereinafter), a liquid crystal panel 5 for a single-chip LCD projector, a lens for projecting an image, and a light converging unit for converging an image from the liquid crystal panel 5 to the lens; the light shaping component comprises a first condenser lens 2 for converging and shaping a light source into a preset shape, a second condenser lens 3 for converging and shaping again, and a rear Fresnel lens 4; the light from the second condenser 3 is converted into parallel light by the rear fresnel lens 4 and then projected onto the liquid crystal screen 5. The light shaping component can properly shape the light of the light source 1 required by the projector such as an LED light source through the shaping function, on one hand, the light of the light source 1 can be fully utilized, and on the other hand, a more uniform projection effect can be obtained. Specifically, in a specific embodiment, the first condenser 2 is a spherical mirror, one side of which is spherical and faces the liquid crystal screen, and the other side of which is a plane; the second condenser 3 is a cylindrical mirror, is located between the first condenser 2 and the liquid crystal screen 5, and has a planar side facing the first condenser 2 and a cylindrical side facing the liquid crystal screen 5. By combining the spherical mirror 2 and the cylindrical mirror 3 and combining the spherical mirror and the cylindrical mirror, the light of the light source 1 can be shaped, the light loss can be avoided, and the light of the light source can be utilized more fully.

When the optical system for the single-chip LCD projector is used, the following conditions are met:

2.3<L/Fh<3.3

3<L/fv<4

wherein L is the distance from the rear Fresnel lens 4 to the light source 1,

fh is the horizontal focal length of the light shaping assembly,

fv is the vertical focal length of the light shaping component.

The light converging component is a front Fresnel lens, is arranged between the liquid crystal screen 5 and the lens and is used for converging the parallel light from the liquid crystal screen 5 to the lens.

In addition, when the first condenser lens 2 and the second condenser lens 3 are arranged at a preset interval, the interval can be adjusted, so that the differentiation requirements of different users can be met to a certain extent.

On the basis of the above embodiment, it can be further improved that the optical system further includes a reflecting mirror 6, as shown in fig. 3, the reflecting mirror 6 is disposed obliquely to receive and reflect the light from the second condensing mirror 3 to the rear fresnel lens, so that the structure of the optical system in front of the liquid crystal panel 5 can be reduced, and the disposition is more advantageous for the trapezoidal adjustment of the projector because the trapezoidal adjustment of the projection and the like do not involve the optical path of this portion. Preferably, the reflector 6 is inclined at an angle of 38-55 degrees, that is, the optical axis of the light shaping assembly and the optical axis of the rear fresnel lens form an angle of 38-55 degrees with the mirror surface of the reflector 6.

The optical system for any one of the above single-chip LCD projectors may be combined with necessary components such as a light source, a liquid crystal imaging system, and a power supply to form a single-chip LCD projector having a small volume, and a high-quality image may be obtained because adjustment parameters affecting projection quality include curvature radius, thickness, refractive index, and the like of a lens, and even if a single condenser lens is used, even if R values of the condenser lens in a horizontal direction and a vertical direction are different, improvement of uniformity is limited due to parameter limitation, and is not obvious, and uniformity may be improved only in a manner of sacrificing brightness. The optical system of the present embodiment can almost double the adjustment parameter, so that the uniformity can be improved while maintaining the brightness, or the uniformity can be improved while maintaining the brightness.

The following are the relevant parameter settings for the single-chip LCD projector of one embodiment:

wherein the content of the first and second substances,

L＝75

Fh＝26.29

Fv＝20.54

L/Fh＝2.85

L/Fv＝3.65

l is the distance from the rear fresnel lens to the light source,

fh is the horizontal focal length of the light shaping assembly,

fv is the vertical focal length of the light shaping component.

The inventor tests and compares that the embodiment has higher display brightness and uniformity compared with other projectors with the same size on the market, or at least has better uniformity under the same display brightness and has higher brightness under the same display uniformity.

The following are relevant parameter settings of the single-chip LCD projector of another embodiment:

wherein the content of the first and second substances,

L＝75

Fh＝27.37

Fv＝21.47

L/Fh＝2.74

L/Fv＝3.49

l is the distance from the rear fresnel lens to the light source,

fh is the horizontal focal length of the light shaping assembly,

fv is the vertical focal length of the light shaping component.

Also, this embodiment has a higher display brightness and uniformity than other projectors of approximately the same size on the market, or at least a better uniformity at the same display brightness and a higher brightness at the same display uniformity. For example, taking a 3.5 inch lcd panel as an example, the simulation test is performed under the condition that the distance from the lcd panel to the LED light source is 85mm, and the results are as follows:

when the peripheral brightness of the screen is 50% of the central brightness, the brightness efficiency of the optical system of the invention is more than 10% than that of the optical system (one condenser lens) in the prior art.

In the case of a screen luminance efficiency of 50%, the optical system of the present invention has a peripheral and central luminance ratio more than 12% than that of the optical system of the related art (one condenser lens).

The following are embodiments regarding a single-chip LCD projection method.

The single-chip LCD projection method of this embodiment employs any one of the single-chip LCD projectors described above, and includes the following steps:

and a light shaping step, namely converging and shaping the light source into a preset shape, wherein the light shaping step can be realized by a combined lens of the spherical mirror and the cylindrical mirror.

And a light path adjusting step of performing reflection processing on the predetermined shape and reflecting the light to the rear Fresnel lens, which can be specifically realized in a manner that the reflecting mirror 6 is obliquely arranged.

A light conversion step of converting the light of the predetermined shape into parallel light by the rear fresnel lens.

And uniformly illuminating the liquid crystal screen, and illuminating the liquid crystal screen of the single-chip LCD projector by using the parallel light.

And a light converging step of converging the light with the image information from the liquid crystal screen of the single-chip LCD projector to a lens.

And a projection step, projecting the image through the lens and projecting.

Preferably, the light shaping step includes primary shaping by a spherical mirror and secondary shaping by a cylindrical mirror, and finally obtains light of a predetermined shape, which is a desired shape such as a rectangle, a square, or the like.

The foregoing is a more detailed description of the present invention, taken in conjunction with the specific preferred embodiments thereof, and it is not intended that the invention be limited to the specific embodiments shown and described. To the technical field of the utility model belongs to the prerequisite of not deviating from the utility model discloses, can also make a plurality of equal substitution or obvious variants, performance or usage are the same moreover, all should regard as belonging to the utility model's scope of protection.

Claims

1. An optical system for a single-chip LCD projector, comprising a light shaping component for converging, shaping and converting a light source into parallel light, a lens for projecting an image, and a light converging component for converging the image from a liquid crystal screen of the single-chip LCD projector to the lens;

the light shaping assembly comprises a first condenser lens for converging and shaping the light source into a preset shape, a second condenser lens for converging and shaping again and a rear Fresnel lens; and the light from the second condenser lens is converted into parallel light through the rear Fresnel lens and then is projected onto a liquid crystal screen of the single-chip LCD projector.

2. The optical system for a single-chip LCD projector as claimed in claim 1, wherein said first condenser lens is a spherical lens having one spherical side facing the liquid crystal screen of said single-chip LCD projector and the other side being a flat surface; the second condenser is a cylindrical mirror, is positioned between the first condenser and the liquid crystal screen of the single-chip LCD projector, and has one planar side facing the first condenser and one cylindrical side facing the liquid crystal screen of the single-chip LCD projector.

3. The optical system for a monolithic LCD projector as recited in claim 2, further comprising a mirror obliquely disposed to receive and reflect light from the second condenser lens to the rear fresnel lens.

4. The optical system for a monolithic LCD projector as recited in claim 3, wherein the reflector is tilted at an angle of 38-55 degrees, i.e., the optical axis of the light shaping assembly and the optical axis of the rear Fresnel lens are both at an angle of 38-55 degrees with respect to the mirror surface of the reflector.

5. The optical system for a single-chip LCD projector as claimed in claim 1, wherein said light converging means is a front fresnel lens disposed between a liquid crystal panel of said single-chip LCD projector and said lens.

6. The optical system for a single-chip LCD projector as claimed in any one of claims 1 to 5, wherein the first condenser lens and the second condenser lens are disposed at a predetermined interval and the interval is adjustable.

7. A single-chip LCD projector, comprising a light source, an optical system, an imaging system and a power supply, wherein the optical system is the optical system of any one of claims 1 to 6, the imaging system is a liquid crystal screen of the single-chip LCD projector of any one of claims 1 to 6, and the liquid crystal screen is arranged between the light shaping component and the light converging component.

8. The single-chip LCD projector as claimed in claim 7, wherein the optical system satisfies the following condition:

2.3<L/Fh<3.3

3<L/fv<4

wherein L is the distance from the rear Fresnel lens to the light source,

fh is the horizontal focal length of the light shaping assembly,

fv is the vertical focal length of the light shaping component.