CN212255997U - Single-chip LCD projector and optical system thereof - Google Patents

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

A single-chip LCD projector and its optical system

technical field

The utility model relates to the technical field of projectors, in particular to an optical system improvement of a single-chip LCD projector.

Background technique

A single-chip LCD projector refers to a projector product that uses a full-color, transmissive liquid crystal screen (LCD) as the screen, light is emitted from the lighting component, and the image of the screen is enlarged and projected on the screen through the projection lens. Existing single-chip LCD projectors have two types of structures, direct projection type and reflective type, according to different optical path structures. Among them, the direct projection type single LCD projector is inconvenient to carry, store and use due to its large shape. The other is the reflective type, such as the Chinese invention patent application with publication number CN 109613788A. Although the single-chip LCD projector disclosed therein may be small in size, the projected image quality and practicability are poor, and improvement is urgently needed. In addition, the improvement of projection brightness and uniformity of single-chip LCD projectors is a recognized problem in the industry. Especially in miniaturized products, too many factors need to be considered, so it is even more difficult.

The disclosure of the above background technology content is only used to assist the understanding of the utility model concept and technical solution of the present application, and it does not necessarily belong to the prior art of the present application. In this case, the above background art should not be used to evaluate the novelty and inventive step of the present application.

Utility model content

In order to overcome the aforementioned technical problem of poor image quality in the prior art, the present application provides 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 for projecting an image a lens, and a light-converging component that converges the image from the liquid crystal screen of the single-chip LCD projector to the lens; the light-shaping component includes a first condenser lens that gathers and shapes the light source into a predetermined shape, and gathers and reshapes the light source again. A second condenser lens, and a rear Fresnel lens; the light from the second condenser lens is converted into parallel light by the rear Fresnel lens and then projected onto the liquid crystal screen of the single-chip LCD projector.

Optionally, the first condenser lens is a spherical mirror, one side of which is spherical faces the liquid crystal screen of the single-chip LCD projector, and the other side is flat; the second condenser mirror is a cylindrical mirror, located in the second condenser. Between a condenser lens and the liquid crystal screen of the single-chip LCD projector, the flat side faces the first condenser lens, and the cylindrical side faces the liquid crystal screen of the single-chip LCD projector.

Optionally, it further includes a reflector, which 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 to 55 degrees, that is, the optical axis of the light shaping component and the optical axis of the rear Fresnel lens are both 38 to 55 degrees from the mirror surface of the reflector. horn.

Optionally, the light converging component is a front Fresnel lens, which is arranged between the liquid crystal screen of the single-chip LCD projector and the lens.

The first condenser lens and the second condenser lens are arranged at a predetermined interval, and the interval is adjustable.

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

Preferably, the optical system satisfies the following conditions:

2.3<L/Fh<3.3

3<L/fv<4

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

Fh is the horizontal focal length of the light shaping component,

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

Compared with the prior art, the technical solution of the present application has at least the following beneficial effects: by using a specific light shaping component, the single-chip LCD projector can be made small in size, and the image uniformity and brightness can be improved, and the single-chip LCD can be improved. Projector image effects. In addition, the obliquely arranged reflector can further reduce the volume of the optical system and the single-chip LCD projector including the optical system, and the specific structural design and arrangement can avoid keystone correction and other adjustments to the change of the optical path. Therefore, compared with the prior art, it is more conducive to the adjustment of projection effects such as keystone correction of the projector.

Description of drawings

FIG. 1 is a schematic view of the structure (part) of an optical system according to an embodiment of the present invention, and is a view in the XZ direction in the figure.

Fig. 2 is the YZ direction view of the optical system structure (part) of the embodiment of Fig. 1;

FIG. 3 is a schematic diagram of a structure (part) of an optical system according to another embodiment of the present invention.

Detailed ways

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

As shown in FIG. 1 and FIG. 2, an optical system for a single-chip LCD projector includes converging, shaping and converting a light source 1 into parallel light (those skilled in the art understand that the parallel light mentioned here is not absolute, approximate In other words, the case of close to parallel light should obviously also be included, and the light shaping component of the parallel light mentioned later), the liquid crystal screen 5 for a single-chip LCD projector, the lens for projecting images, and the The image of the liquid crystal screen 5 is converged to the light-converging component of the lens; the light-shaping component includes a first condensing mirror 2 that gathers and shapes the light source into a predetermined shape, a second condensing mirror 3 that gathers and reshapes again, and a rear Fresnel lens. 4. The light from the second condenser lens 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 its shaping function. Specifically, in a specific embodiment, the first condenser mirror 2 is a spherical mirror, one side of which is spherical faces the liquid crystal screen, and the other side is flat; the second condenser mirror 3 is a cylindrical mirror, located at Between the first condensing lens 2 and the liquid crystal panel 5 , the plane side faces the first condensing lens 2 , and the cylindrical side faces the liquid crystal panel 5 . Through the combination and combination of the spherical mirror 2 and the cylindrical mirror 3, the present embodiment can not only shape the light of the light source 1, but also avoid light loss and more fully utilize the light of the light source.

The optical system for the single-chip LCD projector is in use, and it satisfies the following conditions:

2.3<L/Fh<3.3

3<L/fv<4

Among them, 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 component,

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

The light converging component is a front Fresnel lens, which 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, while the first condenser lens 2 and the second condenser lens 3 are arranged at predetermined intervals, the intervals can also be set to be adjustable, so as to meet the differentiated needs of different users to a certain extent.

On the basis of the above embodiment, it can be further improved that the optical system further includes a reflector 6, as shown in FIG. 3, the reflector 6 is inclined and arranged to receive and reflect the light from the second condenser The rear Fresnel lens, in this way, can reduce the structure of the optical system before the liquid crystal screen 5, and this setting method is more favorable for the trapezoidal adjustment of the projector, because the trapezoidal adjustment of the projection does not involve the optical path of this part . Preferably, the reflector 6 is inclined at an angle of 38 to 55 degrees, that is, the optical axis of the light shaping component and the optical axis of the rear Fresnel lens are both 38 to 55 degrees from the mirror surface of the reflector 6 55 degree angle.

Any of the above-mentioned optical systems for single-chip LCD projectors can be combined with necessary components such as light sources, liquid crystal imaging systems, and power supplies to form a small-volume single-chip LCD projector, and high-quality images can be obtained because, The adjustment parameters that affect the projection quality include the curvature radius, thickness, refractive index, etc. of the lens. When a single condenser is used, even if the R values of the condenser in the horizontal and vertical directions are different, the uniformity improvement is limited due to the limited parameters. It is not obvious, and the uniformity can only be improved by sacrificing brightness. However, by using the optical system of the present embodiment, the adjustment parameters can be almost doubled, so that the brightness can be taken into consideration when the uniformity is improved, or the uniformity can be taken into account when the brightness is enhanced.

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

in,

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 component,

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

Compared with other projectors of the same size on the market, this embodiment has higher display brightness and uniformity, or at least better uniformity under the same display brightness, and the same display uniformity. degrees have higher brightness.

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

in,

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 component,

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

Likewise, this embodiment has higher display brightness and uniformity than other projectors of approximately the same size on the market, or at least better uniformity at the same display brightness, and higher display uniformity at the same display uniformity brightness. For example, taking a 3.5-inch LCD screen as an example, the simulation test is carried out under the condition that the distance from the LCD screen 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 present invention is more than 10% higher than that of the prior art optical system (one condenser lens).

When the screen brightness efficiency is 50%, the optical system of the present invention has more than 12% more peripheral and central brightness ratios than the prior art optical system (one condenser lens).

The following is an example of a single-chip LCD projection method.

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

In the light shaping step, the light source is converged and shaped into a predetermined shape, which can be specifically realized by a combined lens of the spherical mirror and the cylindrical mirror.

In the step of adjusting the optical path, the predetermined shape is subjected to reflection processing and reflected to the rear Fresnel lens, which can be specifically realized by the inclined arrangement of the reflecting mirror 6 .

In the light conversion step, the light of the predetermined shape is converted into parallel light through the rear Fresnel lens.

In the step of uniformly illuminating the liquid crystal screen, the parallel light is used to illuminate the liquid crystal screen of the single-chip LCD projector.

The light condensing step is to condense the light with image information from the liquid crystal screen of the single-chip LCD projector to the lens.

In the projection step, the image is projected through the lens for projection.

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, and the predetermined shape is a desired shape such as a rectangle or a square.

The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art to which the present utility model belongs, without departing from the concept of the present utility model, several equivalent substitutions or obvious modifications can be made, and the performance or use is the same, which shall be regarded as belonging to the present utility model. protected range.

Claims (8)

1. an optical system for a single-chip LCD projector, characterized in that it comprises a light-shaping assembly that converges, shapes and converts a light source into parallel light, a lens for projecting an image, and a lens for projecting images from the single-chip LCD. The image of the LCD screen of the projector is converged to the light converging part of the lens; The light shaping component includes a first condenser lens for converging and shaping the light source into a predetermined shape, a second condenser lens for converging and shaping again, and a rear Fresnel lens; the light from the second condenser lens passes through the rear Fresnel lens. The lens is converted into parallel light and then projected onto the liquid crystal screen of the single-chip LCD projector. 2. The optical system for a single-chip LCD projector according to claim 1, wherein the first condenser lens is a spherical mirror, and its spherical side faces the liquid crystal screen of the single-chip LCD projector, The other side is a plane; the second condenser is a cylindrical mirror, located between the first condenser and the liquid crystal screen of the single-chip LCD projector, and the plane side faces the first condenser, showing One side of the cylinder faces the liquid crystal screen of the single-chip LCD projector. 3. The optical system for a single-chip LCD projector as claimed in claim 2, further comprising a reflecting mirror, the reflecting mirror is inclined and arranged to receive and reflect the light from the second condenser to the Post Fresnel lens. 4 . The optical system for a single-chip LCD projector according to claim 3 , wherein the reflecting mirror is inclined at an angle of 38 to 55 degrees, that is, the optical axis of the light shaping component and the rear The optical axes of the Fresnel lenses all form an angle of 38-55 degrees with the mirror surface of the reflector. 5. The optical system for a single-chip LCD projector according to claim 1, wherein the light-converging component is a front Fresnel lens, which is arranged between the liquid crystal screen of the single-chip LCD projector and the between the lenses. 6 . The optical system for a single-chip LCD projector according to claim 1 , wherein the first condenser lens and the second condenser lens are arranged at a predetermined interval, and the interval is adjustable. 7 . 7. A single-chip LCD projector, characterized in that it comprises a light source, an optical system, an imaging system and a power supply, the optical system is the optical system according to any one of claims 1 to 6, and the imaging system is The liquid crystal screen of a single-chip LCD projector according to any one of claims 1 to 6, wherein the liquid crystal screen is arranged between the light shaping component and the light converging component. 8. The single-chip LCD projector according to claim 7, wherein the optical system satisfies the following conditions: 2.3<L/Fh<3.3 3<L/fv<4 where L is the distance from the rear Fresnel lens to the light source, Fh is the horizontal focal length of the light shaping component, Fv is the vertical focal length of the light shaping component.

Images