CN101446749B - Projection optical system and optical projection method thereof - Google Patents

Abstract

A projection optical system comprising: the lens comprises a light source module, a shaping sheet, an imaging panel and a lens group. The light source module provides a laser beam formed by mixing monochromatic lasers, the laser beam forms a surface light source after passing through the shaping sheet, the imaging panel generates an image by using the surface light source, and the image is projected onto a screen through the lens group. In the projection optical system, because the monochromatic laser is used as the light source, the light filter capable of isolating ultraviolet light, the array lens, the polarization converter, the light splitting system and the light combining system are not required to be adopted to generate the uniform R, G, B light source, so that the required optical elements are few, the assembly is simple, the cost is low, and the assembled projector is small in volume and convenient to carry; and the light source has long service life and high brightness.

Description

A kind of projection optical system and its optical projection method

technical field

The present invention relates to a projection optical system, in particular to a projection optical system using a laser light source.

Background technique

Traditional projectors or rear projection machines use ultra-high performance light sources (Ultra High Performance) as projection light sources, so there are deficiencies in color performance and light source life, and ultra-high performance light sources are used Additional filters, array lenses, polarity converters, and lens groups that can isolate ultraviolet light are required, and a beam splitting system and a light combining system are required to generate uniform R, G, and B light sources, which not only requires a lot of high cost The optical components and the assembly are quite difficult, resulting in difficulties in mass production; and the light machine is large in size, and it is difficult to develop a hand-held miniaturized projection light machine.

Contents of the invention

In view of this, the present invention provides a projection optical system using monochromatic laser light as a light source.

According to an aspect of the present invention, a projection optical system is provided, comprising:

A light source module for providing colored light beams;

Plastic film;

imaging panels; and

A lens group, wherein the light beam passes through the shaping sheet to form a surface light source, and the imaging panel uses the surface light source to generate an image, and projects the image onto a screen through the lens group.

In the projection optical system of the present invention, the light source module includes:

a first color light source, a second color light source and a third color light source;

a first reflector, configured to reflect the first color light emitted by the first color light source into the optical path;

a first filter, configured to transmit the first color light, and reflect the second color light emitted by the second color light source into the light path;

a second filter for transmitting the first and second colored lights, and reflecting the third colored light emitted by the third colored light source into the optical path;

Wherein, the first colored light, the second colored light and the third colored light are mixed in the optical path and then directly directed to the shaping sheet.

In the projection optical system of the present invention, the light source module includes:

a first color light source, a second color light source and a third color light source;

a first reflector, configured to reflect the first color light emitted by the first color light source into the optical path;

a first filter, configured to transmit the first color light, and reflect the second color light emitted by the second color light source into the light path;

The second filter is used to transmit the first and second color light, and reflect the third color light emitted by the third color light source into the light path; wherein, the first color light, the second color light and the first color light The three-color light is mixed in the light path;

The second reflecting mirror is used for reflecting the mixed light of the first, second and third color lights to the shaping sheet.

In the projection optical system of the present invention, it includes:

a diffuser, placed behind the shaping sheet in the light path, to uniform the brightness of each area on the surface light source; and

The reciprocating mechanism is used to install the diffuser, so that the diffuser can reciprocate in a direction perpendicular to the normal of the surface light source.

In the projection optical system of the present invention, the imaging panel includes a liquid crystal device for transmitting the surface light source.

In the projection optical system of the present invention, the imaging panel includes a digital microlens device for reflecting the surface light source.

According to another aspect of the present invention, an optical projection method is provided, comprising the following steps:

providing a laser beam;

shaping the light beam into a surface light source by using a shaping sheet;

converting the surface light source into an image using an imaging panel; and

The image is projected onto the screen through the lens set.

In the optical projection method of the present invention, it includes using a diffuser to even out the brightness of each area on the surface light source, so as to project a uniform light source.

In the optical projection method of the present invention, it includes: using a reciprocating mechanism to install the diffusion sheet, so that the diffusion sheet reciprocates in a direction perpendicular to the normal of the surface light source.

In the optical projection method of the present invention, the laser beam is formed by mixing three beams of monochromatic light, and the method includes:

using a first reflector to reflect the first color light in the three beams of monochromatic light;

using the first filter to transmit the first color light and reflect the second color light in the three beams of monochromatic light;

using a second filter to transmit the first and second color lights, and reflect the third color light in the three beams of monochromatic light; and

The second reflection mirror reflects the first, second and third color lights to the shaping sheet.

Implementing the projection optical system and method of the present invention, since a monochromatic laser is used as a light source, there is no need to use filters, array lenses, polarity converters, beam splitting systems and light combining systems that can isolate ultraviolet light to produce uniform R, G , B light source, so less optical elements are needed, the assembly is simple, the cost is low, and the assembled projector is small in size and easy to carry; and the light source has a long service life and high brightness.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, a preferred embodiment is specifically cited below, and in conjunction with the accompanying drawings, the detailed description is as follows:

Description of drawings

FIG. 1 is a schematic structural diagram of the projection optical system of the present invention.

Among them, the main component symbols are explained as follows:

A～optical path;

5 ~ screen;

10 ~ the first laser light source (green light source);

20 ~ the second laser light source (red light source);

30 ~ the third laser light source (blue light source);

40～plastic tablets;

50～diffusers;

52 ~ seat;

60～imaging panel;

70～lens group;

80～reciprocating mechanism;

82 ~ motor;

84 ~ rack;

91～the first reflector;

92～the first optical filter;

93～second reflector;

94～second optical filter;

100～projection optical system.

Detailed ways

The present invention uses red, green, and blue laser light sources as the light source of the projector, and uses the beam shaping sheet of the diffraction element to shape the point light source of the laser into a rectangular surface light source, and then passes through the diffuser (Diffuser) to diffuse the light source to produce Diffusion, so that the surface light source forms a uniform surface light source with the same brightness value at each point, and then the image on the imaging panel is projected through the lens group, and the spot effect caused by the laser light source ( Speckle) eliminated.

As shown in Figure 1, the projection optical system 100 of the present invention includes a first laser light source (green light source) 10, a second laser light source (red light source) 20, a third laser light source (blue light source) 30, a plastic plate 40, The diffusion sheet 50 , the imaging panel 60 , the lens group 70 , the reciprocating mechanism 80 , the first mirror 91 , the second mirror 93 , the first filter 92 and the second filter 94 .

The green light (first color light) from the first laser light source 10 is reflected into the optical path A through the first reflector 91, the green light travels in the optical path A, and then passes through the first filter 92, and comes from the second laser light source 20 red light (second color light) is reflected by the first filter 92 and enters the optical path A and mixes with the green light. The mixed green light and red light pass through the second filter 94 and come from the third laser light source 93 The blue light (third color light) is reflected by the second filter 94 and enters the optical path A, and mixes with the green light and red light in the optical path A to form a mixed light, and after the mixed light is reflected by the second reflector 93, Through the shaping sheet 40, the light beam of the original point light source is diffused into a rectangular light beam, thereby converting the light of the point light source into the light of the surface light source. The rectangular light beam passes through the diffusion sheet 50 to make the rectangular light beam more uniform, and the reciprocating mechanism 80 is connected. on the diffuser 50, and make the diffuser 50 reciprocate in a direction perpendicular to the traveling direction of the rectangular light beam, thereby eliminating the spot effect generated by the laser.

The homogenized light beam passes through the imaging panel 60 to form an image, and then is projected onto the screen 5 through the lens group 70 .

The imaging panel 60 in this embodiment may include a liquid crystal device (LCD) through which an image is formed by light passing through the liquid crystal device. In another embodiment, the imaging panel 60 may include a digital microlens device (DMD), and the reflection of the light beam through the digital microlens device may also form an image.

The reciprocating mechanism 80 includes a motor 82 and a rack 84. The rack 84 is formed on the seat 52 of the diffuser 50, and a gear (not shown) is combined on the rotating shaft of the motor 82. When the motor 82 rotates, the gear on the rotating shaft The gear rotates to drive the rack 84, thereby moving the seat 52, thereby achieving the effect of reciprocating movement. Certainly, the above-mentioned reciprocating mechanism formed by the gear and the rack is only an embodiment, and the present invention is not limited to this structure, as long as the reciprocating movement of the diffuser is achieved.

It should be noted that the light source module in the projection optical system of the present invention can also be implemented in a manner different from the embodiment shown in FIG. 1 . For example, in another embodiment of the present invention (not shown), the second reflector may not be provided. In this case, the optical path A shown in FIG. 1 should be rotated 90 degrees clockwise, and the orientations of the three laser light sources should also be rotated 90 degrees clockwise. In short, in the present invention, the light source module is used to provide a laser beam formed by mixing at least two beams (three beams in the embodiment) of monochromatic laser beams. That is to say, before the shaping sheet, the light source module should complete the mixing of each monochromatic light beam, so that the light wave reaching the shaping sheet is a mixed beam, and when reaching the shaping sheet, the direction of the mixed light beam should be in line with the normal line of the shaping sheet. The same direction.

In addition, as a special application, the present invention can also be implemented by using multiple monochromatic light sources such as two monochromatic light sources and four monochromatic light sources. In this case, only one monochromatic light source and an optical filter need to be correspondingly reduced or added in the light source module, which is not intended to limit the present invention.

The invention uses a laser light source, which can have better color performance, and the life of the light source is longer than that of the traditional UHP light source, and because three monochromatic light sources are used, it is not necessary to perform light splitting and then combine light, which can be achieved to a considerable extent. The number of components can be reduced to a minimum, and the speckle effect (Speckle) caused by the laser light source can be eliminated by using the timing transformation method, thereby improving the image quality.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, this The scope of protection of an invention should be defined by the claims.

Claims (10)

1. a projection optical system is characterized in that, comprising:

Light source module is in order to provide the coloured light that is mixed by three monochromic beams light beam;

The beam shaping sheet of single use diffraction element;

Imaging panel; And

Lens set, wherein said light beam form the area source of rectangle after by described shaping sheet, and described imaging panel utilizes described area source to produce image, and via described lens set described image is projected on the screen.

2. projection optical system according to claim 1 is characterized in that, described light source module comprises:

First color light source, second color light source and three-color light source;

First catoptron reflexes in the light path in order to first coloured light with described first color light source emission;

First optical filter, in order to described first coloured light of transmission, and second coloured light that described second color light source is launched reflexes in the described light path;

Second optical filter makes described first, second coloured light transmission, and the 3rd coloured light that reflects the emission of described three-color light source is to described light path;

Wherein, described first coloured light, second coloured light and the 3rd coloured light mix the directly described shaping sheet of guiding of back in light path.

3. projection optical system according to claim 1 is characterized in that, described light source module comprises:

First color light source, second color light source and three-color light source;

First catoptron reflexes in the light path in order to first coloured light with described first color light source emission;

First optical filter, in order to described first coloured light of transmission, and second coloured light that described second color light source is launched reflexes in the described light path;

Second optical filter makes described first, second coloured light transmission, and the 3rd coloured light that reflects the emission of described three-color light source is to described light path; Wherein, described first coloured light, second coloured light and the 3rd coloured light mix in light path;

Second catoptron is used for the mixed light of described first, second and the 3rd coloured light is reflexed to described shaping sheet.

4. according to claim 2 or 3 described projection optical systems, it is characterized in that, comprising:

Diffusion sheet is placed on described in the described light path after the shaping sheet, in order to each the regional brightness on the even described area source; And

Reciprocator in order to settle described diffusion sheet, makes the normal direction to-and-fro movement of described diffusion sheet in vertical described area source.

5. according to claim 2 or 3 described projection optical systems, it is characterized in that wherein said imaging panel comprises liquid-crystal apparatus, in order to the described area source of transmission.

6. according to claim 2 or 3 described projection optical systems, it is characterized in that wherein said imaging panel comprises digital microlens device, in order to reflect described area source.

7. an optical projection method is characterized in that, comprises the following steps:

The laser beam that is mixed by three monochromic beams is provided;

Utilize the single beam shaping sheet of diffraction element that uses with the area source of described beam shaping as rectangle;

Utilize imaging panel to convert described area source to image; And

Via lens set described image is projected on the screen.

8. optical projection method according to claim 7 is characterized in that, comprises, utilizes each the regional brightness on the even described area source of diffusion sheet, to project uniform source of light.

9. optical projection method according to claim 8 is characterized in that, comprising: utilize reciprocator to settle described diffusion sheet, make the normal direction to-and-fro movement of described diffusion sheet in vertical described area source.

10. optical projection method according to claim 7 is characterized in that, described method comprises:

Utilize first coloured light in described three monochromic beams of first mirror reflects;

Utilize described first coloured light of the first optical filter transmission, and reflect second coloured light in described three monochromic beams;

Utilize described first, second coloured light of the second optical filter transmission, and reflect the 3rd coloured light in described three monochromic beams; And

Second catoptron reflexes to described shaping sheet with described first, second, third coloured light.

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