CN104238250A - Mini-type LCOS projection optical engine - Google Patents

Abstract

The present invention provides a kind of miniature LCOS projection optical engine, comprising a light emitting unit and an imaging unit and a projection unit arranged on the light propagation direction, according to the LCOS projection optical engine provided by the present invention, since the light emitting unit includes a The light source and the light guide plate used to convert the point light source emitted by the light source into a surface light source. The light source adopts a plurality of low-power white LEDs arranged in a point array. The light guide plate includes a light guide surface, a reflective surface and a light output surface with a 3D texture structure. Only one light guide plate is needed to achieve uniform emission of light, so that the micro LCOS projection optical engine provided by the present invention has a simple structure, small volume, high utilization rate of light energy, and further reduces the cost.

Description

Miniature LCOS projection optical engine

technical field

The invention belongs to the field of optical imaging, in particular to a miniature LCOS projection optical engine.

Background technique

Projection display technology refers to the method of using optical system and projection space to enlarge the image and display it on the projection screen. With the popularity of smart phones and wearable devices, there are more requirements for displays in different scenarios. Among them, the miniaturized projector is very suitable for integration on such devices due to its small size, light weight and ability to meet the basic functions of projection, which expands the scope of use of the projector and has broad market prospects.

As one of the basic micro-projection technologies, LCOS optical engine has the characteristics of low price and excellent projection performance compared with other technologies, and it is the most likely commercialized micro-projection technology. The LCOS optical engine system generally includes a light source, a display chip and an imaging system. The traditional LCOS optical engine system uses a compound eye array to complete the spatial conversion of light from uneven distribution to uniform distribution on the lighting panel. However, when the compound eye array achieves uniform illumination, two For compound eye arrays whose optical axes are parallel to each other, a condenser lens needs to be placed behind the second compound eye array, which has a complex structure and a large volume, resulting in a high cost of the LCOS optical engine.

Contents of the invention

The present invention is carried out in order to solve the above problems, and the purpose is to further simplify the existing micro LCOS projection by providing a micro LCOS projection optical engine that uses a light guide plate to complete the space conversion of light from uneven distribution to uniform distribution on the lighting plate. The structure of the optical engine while reducing the volume.

The present invention adopts following technical scheme:

The miniature LCOS projection optical engine provided by the present invention has such characteristics, including: a light emitting unit for emitting light, including a light source and a light guide plate arranged on the light propagation direction, the light source is used for emitting light, and the light guide plate is used for The line light source emitted by the light source is transformed into a surface light source; the imaging unit is connected with the light emitting unit for imaging the light emitted by the light emitting unit; and the projection unit is connected with the imaging unit and is used for projecting the image formed by the imaging unit on the screen.

Wherein, the light guide plate includes a light guide surface, a reflective surface, and a light output surface. The light guide surface is opposite to the exit of the light emission unit, and is used to guide the light emitted by the light source. The surface and the imaging unit are set opposite to each other, and are used to uniformly emit light from the light guide plate. The light-emitting surface has a 3D texture structure, and the 3D texture structure is used to scatter the light reflected from the reflective surface, so that the light is evenly emitted from the light-emitting surface. .

The miniature LCOS projection optical engine provided by the present invention can also have such characteristics: the imaging unit includes PBS prisms and LCOS chips connected in sequence, and the PBS prism is used to divide the unpolarized light incident by the light emitting unit into two bundles of mutually perpendicular P lines Polarized light and S linearly polarized light, the LCOS chip is used to convert the transmitted light of the PBS prism into a color image.

The miniature LCOS projection optical engine provided by the present invention may also have such a feature: the light emitting unit further includes an ultraviolet absorbing component for absorbing ultraviolet rays in the light emitted by the light emitting unit.

The miniature LCOS projection optical engine provided by the present invention can also have the following features: the light source is composed of at least one white LED and a reflective surface, the white LED is used to emit light, and the reflective surface is used to collect light and inject the light into the light guide plate.

The miniature LCOS projection optical engine provided by the present invention can also have such a feature: the imaging unit also includes a polarizing component, and the polarizing component is located between the PBS prism and the LCOS chip, and is used to filter out stray light.

The miniature LCOS projection optical engine provided by the present invention can also have the feature that the LCOS chip is a color filter type.

The miniature LCOS projection optical engine provided by the present invention can also have such characteristics: there is a signal control light valve assembly in the LCOS chip, and the signal control light valve assembly is used to convert the white light transmitted by the PBS prism into a color image, and simultaneously convert the color image Images were converted to P-linearly polarized light.

Invention function and effect

The present invention provides a kind of miniature LCOS projection optical engine, comprising a light emitting unit and an imaging unit and a projection unit arranged on the light propagation direction, according to the LCOS projection optical engine provided by the present invention, since the light emitting unit includes a The light source and the light guide plate used to convert the point light source emitted by the light source into a surface light source. The light source adopts a plurality of low-power white LEDs arranged in a point array. The light guide plate includes a light guide surface, a reflective surface and a light output surface with a 3D texture structure. Only one light guide plate is needed to achieve uniform emission of light, so that the micro LCOS projection optical engine provided by the present invention has a simple structure, small volume, high utilization rate of light energy, and further reduces the cost.

Description of drawings

Fig. 1 is the structural representation of miniature LCOS projection optical engine of the present invention;

Fig. 2 is a schematic structural view of the light source of the present invention;

3 is a schematic structural view of the light guide plate of the present invention;

Fig. 4 is a schematic diagram of the upper structure of the present invention.

Detailed ways

The specific implementation manners of the present invention will be described below in conjunction with the accompanying drawings.

In this embodiment, a white light LED, a wedge-shaped light guide plate, a PBS prism, and a color filter type LCOS chip are used to systematically illustrate the miniature LCOS projection optical engine of the present invention, but the scope of this embodiment does not limit the scope of the present invention.

FIG. 1 is a schematic structural diagram of the micro LCOS projection optical engine of this embodiment.

As shown in Figure 1, the micro LCOS projection optical engine 100 includes a light emitting unit 1, an imaging unit 2, a projection unit 3 and a screen 4, the light emitting unit 1 includes a light source 11, a light guide plate 12 and an ultraviolet absorbing assembly 13, and the imaging unit 2 includes The PBS prism 21 , the LCOS chip 22 and the polarizer 23 located between the PBS prism 21 and the LCOS chip 22 , and the LCOS chip 22 also has a signal control light valve assembly 221 .

The light source 11 is used to emit light, the light guide plate 12 is used to convert the line light source emitted by the light source into a surface light source, and the ultraviolet absorbing component 13 is used to absorb the ultraviolet rays in the light emitted by the light guide plate, so as to avoid the damage of ultraviolet rays to the LCOS chip 22; the imaging unit 2 Among them, the PBS prism 21 is used to divide the unpolarized light incident by the light emitting unit 1 into two beams of P linearly polarized light and S linearly polarized light which are perpendicular to each other, and the LCOS chip 22 is used to convert the transmitted light of the PBS prism into a color image , the polarizer 23 is used to filter out the stray light in the color image.

FIG. 2 is a schematic structural diagram of the light source in this embodiment.

As shown in Figure 2, the light source 11 includes a parabolic reflective surface 111 with a parabolic cross section and a plurality of white LED arrays 112 placed at the bottom of the reflective surface. The inside of the parabolic reflective surface 111 is coated with a cold reflective film. array arrangement.

FIG. 3 is a schematic structural diagram of the light guide plate in this embodiment.

Fig. 4 is a schematic diagram of the upper structure in this embodiment.

As shown in Figures 3 and 4, the light guide plate 12 includes: a side surface 121, a bottom surface 122, an inclined surface 123, and an upper surface 124, and the upper surface 124 includes a 3D textured surface 1241 with a 3D textured structure and a surface not occupied by the 3D textured structure that is located on the upper surface. The upper left 1242 on the left side of 124, the bottom surface 122 and the upper left 1242 are opposite to each other, and the 3D textured surface 1241 and the slope 123 are opposite to each other.

The side surface 121 is a light guide surface, facing the exit of the light source 11, and is used to guide the light emitted by the light source 11. The bottom surface 122, the inclined surface 123 and the upper left surface 1242 are all coated with reflective films, which are reflective surfaces, and are used to reflect the light emitted by the light source 11. To the 3D textured surface 1241 as the light-emitting surface.

After the light emitted by the light source 11 is introduced by the side surface 121, the light is reflected to the 3D textured surface 1241 through the reflective film on the bottom surface 122, the inclined surface 123 or the upper left 1242, and after being scattered by the 3D texture structure, it is evenly emitted from the light guide plate 12; The incident positions are different. Some light rays can reach the 3D textured surface 1241 after one reflection (as shown in light a in FIG. As shown in ray b) in Figure 3.

As shown in Figures 1 to 4, in the miniature LCOS projection optical engine 100, the parabolic reflective surface 111 in the light source 11 is placed laterally, the outlet faces the side 121 of the light guide plate 12, and the 3D textured surface 1241 as the light-emitting surface faces the PBS prism 21 , the ultraviolet absorbing component 13 is placed between the 3D textured surface 1241 and the PBS prism 21 , and the polarizer 23 is placed between the LCOS chip 22 and the PBS prism 21 .

The realization process of the miniature LCOS projection optical engine 100 is as follows: the white light LED 112 emits light, which is collected by the parabolic reflective surface 111, and injected into the side 121 of the light guide plate 12 through the reflection of the cold reflective film inside, and the light passes through the light guide plate 12 through multiple After the secondary reflection and the scattering of the 3D textured surface 1241, it is evenly emitted from the light guide plate 12, and the ultraviolet light in the light is secondarily absorbed and filtered by the ultraviolet absorbing component 13, and then enters the PBS prism 21; the PBS prism 21 converts the light emitting unit 1 The outgoing unpolarized light is divided into two beams of P linearly polarized light and S linearly polarized light that are perpendicular to each other, the S linearly polarized light passes through the PBS prism 21, the P linearly polarized light is reflected, and the transmitted S linearly polarized light enters the LCOS chip 22 , the signal in the LCOS chip 22 controls the light valve assembly 221 to form white light into a color image of RGB combination, and internally converts the S linearly polarized light presented in the color image into P linearly polarized light, and filters out the stray light through the polarizer 23 Finally, it is reflected by the PBS prism 21, and the reflected light passes through the projection unit 3 and is projected on the screen 4 to obtain an ideal new and clear image.

In this embodiment, the 3D texture structure is composed of a plurality of small protrusion structures, and the shape of the small protrusions is circular or polygonal.

Function and effect of embodiment

This embodiment provides a micro LCOS projection optical engine, including a light emitting unit and an imaging unit and a projection unit arranged on the direction of light propagation. According to the LCOS projection optical engine provided by the present invention, since the light emitting unit contains The light source and the light guide plate used to convert the point light source emitted by the light source into a surface light source. The light source adopts a plurality of low-power white LEDs arranged in a point array. The light guide plate includes a light guide surface, a reflective surface and a light output surface with a 3D texture structure. Only one light guide plate is needed to realize the uniform emission of light, so that the micro LCOS projection optical engine provided by the present invention has a simple structure and small volume, and the luminous efficiency of the LED is improved, thereby reducing the cost.

Claims (7)

1. A miniature LCOS projection optical engine is characterized in that, comprising: The light emitting unit is used to emit light, including a light source and a light guide plate arranged in the direction of light propagation, the light source is used to emit light, and the light guide plate is used to convert the line light source emitted by the light source into a surface light source; an imaging unit, connected to the light emitting unit, for imaging the light emitted by the light emitting unit; and a projection unit, connected to the imaging unit, for projecting the image formed by the imaging unit on a screen, Wherein, the light guide plate includes a light guide surface, a reflective surface and a light output surface, the light guide surface is opposite to the exit of the light emitting unit, and is used to guide the light emitted by the light source, and the reflective surface is used to guide the light emitted by the light source. The light introduced by the light guide surface is reflected to the light exit surface, and the light exit surface and the imaging unit are arranged opposite to each other, so as to uniformly emit the light from the light guide plate, The light-emitting surface has a 3D texture structure, and the 3D texture structure is used to scatter the light reflected from the reflective surface, so that the light is evenly emitted from the light-emitting surface. 2. miniature LCOS projection optical engine according to claim 1, is characterized in that: Wherein, the imaging unit includes sequentially connected PBS prisms and LCOS chips, and the PBS prisms are used to divide the unpolarized light incident on the light emitting unit into two beams of P linearly polarized light and S linearly polarized light that are perpendicular to each other, so The LCOS chip is used to convert the transmitted light of the PBS prism into a color image. 3. miniature LCOS projection optical engine according to claim 1, is characterized in that: Wherein, the light emitting unit further includes an ultraviolet absorbing component for absorbing ultraviolet rays in the light emitted by the light emitting unit. 4. miniature LCOS projection optical engine according to claim 1, is characterized in that: Wherein, the light source is composed of at least one white LED and a reflective surface, the white LED is used to emit light, and the reflective surface is used to collect the light and inject the light into the light guide plate. 5. miniature LCOS projection optical engine according to claim 2, is characterized in that: Wherein, the imaging unit further includes a polarizing component, the polarizing component is located between the PBS prism and the LCOS chip, and is used to filter out stray light in the color image. 6. miniature LCOS projection optical engine according to claim 2, is characterized in that: Wherein, the LCOS chip is a color filter type. 7. miniature LCOS projection optical engine according to claim 7, is characterized in that: Wherein, there is a signal control light valve assembly in the LCOS chip, and the signal control light valve assembly is used to convert the transmitted white light of the PBS prism into a color image, and at the same time convert the color image into P linearly polarized light .