KR100686132B1 - Apparatus for speckle reduction in laser and projection system of the same - Google Patents

Abstract

The present invention is to provide a device that can reduce the laser spots without blurring or brightness deterioration of the screen, and to provide an optical system using the same, in the incident lens unit and the incident lens unit for outputting the input beam as parallel light of a desired size It comprises a rotating diffuser having a plurality of diffusing particles (diffuser) and a focusing lens for collecting and outputting the beam diffused from the diffuser in order to diffuse a constant size of parallel light emitted to a desired angle .

Laser Spot, Collimator, Diffuser, Goodman

Description

Apparatus for speckle reduction in laser and projection system of the same}

1 is an overall configuration diagram showing an optical system using a laser spot reduction apparatus according to the present invention

2 is a block diagram showing an incident lens of the optical system according to the present invention

* Explanation of symbols for main parts of the drawings

100: light source 200: laser spot reduction device

210: focusing lens 220: diffuser

300: incident lens unit 310: incident lens

320: collimator 330: appearance barrel

340: inner tube 400: projection system

500: screen

TECHNICAL FIELD The present invention relates to the field of laser illumination, and more particularly, to an apparatus for reducing illumination of laser spots detected by an intensity detector by observing a surface irradiated by laser illumination and an optical system using the same.

Recently, with the rapid development of the display field, consumers want to see brighter and clearer images on a larger screen. As one of means for satisfying the needs of consumers, the development of displays using lasers is actively progressing.

However, because laser light is coherent, when it is diffused by a screen, it creates laser spots, which are bright and dark interference patterns in the human eye. Therefore, due to this phenomenon, a phenomenon in which the original image cannot be seen clearly appears.

Conventional methods used to eliminate such laser spots have been reduced by superimposing N uncorelated spot patterns known by Goodman.

That is, multiple spot patterns are generated by moving the viewing screen or fiber with vibration using the time average known by Goodman. The vibration then typically follows a small circle or a small ellipse about the optical axis. This causes the spot pattern to shift with respect to the eye viewing the viewing screen, forming multiple spot patterns over time.

Thus, even if the amount of spots does not change at any time, the eye perceives the reduced spots when the oscillation speed is above the threshold speed. That is, the eye will detect reduced spots if the integration time for the eye is long enough for the vibration to produce an irrelevant spot pattern within the integration time.

It is also known in the field of laser illumination displays that diffractive optical elements can be added to the laser illumination imaging system to reduce laser spots. That is, the diffractive optical element is located in or near the intermediate image plane and is moved in the intermediate image plane, which is a rotational or annular pattern about the display system optical layer to produce a varying phase in the display screen. This changing phase generates an irrelevant spot pattern over time to detect reduced spots using a time average.

However, the method of detecting the reduced spots by generating multiple spot patterns by moving the viewing screen or the fiber may cause discomfort to viewing due to the flickering of the screen, and also has problems such as deterioration of brightness.

Accordingly, an object of the present invention is to provide a device and an optical system using the same, which can reduce laser spots without blurring or deteriorating brightness of a screen.

Another object of the present invention is to diversify the movement path of the laser light.

Still another object of the present invention is to implement an optical system that does not use an optical fiber.

A feature of the laser spot reduction apparatus according to the present invention for achieving the above object is an angle of the incidence lens unit for outputting the input beam to the parallel light of the desired size and the parallel light of a constant size emitted from the incident lens unit It comprises a rotating diffuser having a plurality of diffusing particles (diffuser) and a focusing lens for collecting and exiting the beam diffused from the diffuser to diffuse to the.

Preferably, the incidence lens unit includes an incidence lens receiving an input beam and a collimator for making the beam incident on the incidence lens into parallel light having a predetermined size.

Preferably, the size of the parallel light generated by the collimator is characterized in that it is generated with a size between 3mm ~ 10mm.

Preferably, the incident lens unit, the diffuser and the focusing lens surface are formed with an anti-reflection (AR) coating.

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Preferably, the diffuser is composed of a structure in which a diffusing film is coated on polycarbonate or glass.

Preferably, the diffuser is configured to rotate at a speed of 8000 to 12000 rpm about its center.

Preferably, it is configured to adjust the distance between the incident lens and the collimator in the incident lens unit according to the rotation.

The optical system using the laser spot reduction apparatus according to the present invention for achieving the above object is a light source for providing a source of the beam (beam), and the incident light from the light source to the parallel light of the desired size as an input A lens unit, a diffuser for diffusing a constant size of parallel light emitted from the incident lens unit at a desired angle, a focusing lens for collecting and emitting a beam diffused from the diffuser, and a light exiting from the focusing lens And a projection system that enlarges and projects an image on a screen using a beam.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments with reference to the accompanying drawings.

Referring to the accompanying drawings, a preferred embodiment of the laser spot reduction apparatus and the optical system using the same according to the present invention will be described.

1 is an overall configuration diagram showing an optical system using a laser spot reduction apparatus according to the present invention.

As shown in FIG. 1, a light source 100 providing a source of a beam, an incident lens unit 300 which emits light as parallel light having a desired size as an input from the light source 100, and the incident lens unit 300. A diffuser 220 for diffusing parallel light of a constant size emitted from the 300 at a desired angle, a focusing lens 210 for collecting and emitting the beam diffused from the diffuser 220, and the focusing point; It is composed of a projection system 400 for magnifying and projecting the image on the screen 500 by using the beam emitted from the lens 210.

The incident lens unit 300 includes an incident lens 310 that receives a beam input from a light source, and a collimator 320 for making the beam incident on the incident lens 310 into parallel light having a predetermined size. It consists of.

At this time, the size of the parallel light generated by the collimator 320 is configured to selectively use the desired diameter between 3mm ~ 10mm according to the system. At this time, the diameter of the parallel light may be larger than 10 mm, but it is preferable to generate a size of 5 mm in consideration of the efficiency of the entire system.

And all the lenses and all the surfaces of the diffuser (Diffuser), including the incident lens unit 200 is configured to minimize the reflection of light by the anti-reflection (AR) coating.

The diffuser 220 includes a plurality of diffusion grains and a structure in which a diffusing film is coated on polycarbonate or glass.

In addition, the diffuser 220 is configured to rotate about an axis by a motor.

And the incident lens unit 300, as shown in Figure 2, the collimator (Collimator) 320 is fixed to the exterior barrel 330, the exterior barrel 330 can move back and forth in the exterior lens 330, the incident lens 310 It consists of an inner tube barrel 340 is attached. Thus, when manufacturing the incident lens unit 300, the inner tube barrel is moved back and forth to adjust the distance between the incident lens 310 and the collimator (320) to adjust the size of the parallel light.

At this time, the rotation speed of the diffuser 220 rotates at a speed of about 10000 rpm.

Referring to the accompanying drawings, the operation of the optical system using the laser spot reduction apparatus according to the present invention configured as described above will be described in detail as follows.

First, the beam emitted from the laser light source 100 passes through the collimator 320 to receive the incident surface of the optical device incident lens unit 300 and to produce parallel light having a desired size.

At this time, the size of the parallel light generated by the collimator 320 is configured to selectively use the desired diameter between 3mm ~ 10mm according to the system. At this time, the diameter of the parallel light may be larger than 10 mm, but it is preferable to generate a size of 5 mm in consideration of the efficiency of the entire system.

In this way, the beam emitted as parallel light from the collimator 320 proceeds while passing through the diffuser 220 which is rotating as it is.

In this case, the diffuser 220 is formed by diffusing granules formed on a surface of a polycarbonate or glass coated with a diffusing film.

Therefore, since the diffuser 220 rotates continuously, the beam passing through the diffuser 220 causes continuous change while simultaneously passing through the portion with and without the diffusion grains.

Through this process, the light path is continuously changed while passing through the diffuser 220.

Due to this light path change, different laser spot patterns are independently generated on the screen 500. When these independent laser spot patterns are seen on the screen, they are shown as the average of these patterns, which has the same effect as reducing laser spots.

As a result, the beam from the laser light diminishes the coherency properties inherent during the stated optics, resulting in a reduction of laser spots on the screen.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Laser spot reduction apparatus according to the present invention as described above has the following advantages.

As described above, the present invention has the effect of reducing laser spots on the screen by reducing the coherence, which is a unique characteristic of the laser, by varying the path of the laser.

Therefore, the present invention can see the effect of realizing a clearer image by applying to the display field using the laser as a light source.

Claims (10)

An incident lens unit configured to emit an input beam as parallel light having a desired size; A diffuser rotating with a plurality of diffusion grains to diffuse parallel light of a constant size emitted from the incident lens unit at a desired angle; And a focusing lens for collecting and emitting the beam diffused from the diffuser again. The method of claim 1, wherein the incident lens unit An incident lens that receives an input beam, Laser spot reduction apparatus characterized in that it comprises a collimator (Collimator) for making a beam incident on the incident lens into a parallel light of a predetermined size. The method of claim 2, Laser spot reduction apparatus, characterized in that the size of the parallel light generated by the collimator is generated in the size of 3mm ~ 10mm. The method of claim 1, And the anti-reflection (AR) coating is formed on the incident lens unit, the diffuser, and the condenser lens surface. delete The method of claim 1, The diffuser is a laser spot reduction apparatus characterized in that the diffusion structure is coated on a polycarbonate (glass) or a glass (Diffusing Film) is coated. The method of claim 1, And the diffuser is configured to rotate about an axis. The method of claim 7, wherein The laser spot reduction apparatus, characterized in that the rotational speed of the diffuser rotates at a speed of 8000 ~ 12000rpm. The method of claim 1, The incident lens unit has an exterior barrel having a collimator fixed thereto; Laser spot reduction apparatus characterized in that it comprises a inner tube which is movable back and forth within the outer barrel and the incident lens is attached. A light source providing a source of a beam, An incident lens unit for emitting a beam from the light source as parallel light having a desired size; A diffuser rotating with a plurality of diffusion grains to diffuse parallel light of a constant size emitted from the incident lens unit at a desired angle; A focusing lens for collecting and emitting the beam diffused from the diffuser; And a projection system configured to enlarge and project an image on a screen by using the beam emitted from the focusing lens.

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