CN110865464A - A laser projection device - Google Patents

Abstract

The laser projection device provided by the invention has the advantages that incident laser beams enter the zoom lens group after being expanded by the front fixed beam expanding lens group, the zoom lens group selects the diameter of the expanded beams and enters the compensating lens group, the compensating lens group compensates the light output by the zoom lens group and outputs collimated beams, the collimated beams are converged at the rear focal plane of the focusing lens group after passing through the focusing lens group, the beams diverged by the random bit picture at the rear focal plane are collimated by the rear fixed collimating lens group and then enter the fixed collimating lens group, and the collimated beams after being expanded are output by the rear fixed collimating lens group Collimation, light uniformization and speckle elimination.

Description

A laser projection device

technical field

The present invention relates to the technical field of laser display, in particular to a laser projection device.

Background technique

Laser has the characteristics of directionality, good coherence and high brightness, and is widely used in projection display, projection lithography lighting system and other fields. In particular, the laser projection lithography illumination system in the field of micro-nano processing has high requirements on the uniformity and collimation of the expanded laser beam. At the same time, due to the coherence of the laser, when the laser passes through the components or reaches the display panel, serious speckle noise will be generated due to the effects of reflection, refraction, interference, diffraction and scattering, which seriously affects the quality of lithography.

At present, there are two types of laser beam expanders: fixed magnification and variable magnification. The fixed magnification beam expander usually expands the laser divergence angle by fixing the lens group combination; the variable magnification beam expander adjusts the beam divergence angle by changing the relative position of the lens group. Laser beam expander collimator, that is to expand the beam diameter according to a certain magnification. The product of the spot size and the divergence angle of the laser beam output from the laser is an optical invariant and approximates a certain value. The compressed laser divergence angle is actually laser collimation. Compressing the divergence angle does not improve the beam quality, that is, simple laser beam expansion cannot improve the beam quality. Therefore, the current technology is to add devices such as microlens arrays or bitmaps to the collimated light path after the laser beam expander collimator to homogenize and dissipate the spot. The laser beam expander collimator is independent from the speckle dissipation device, and has a loose structure. The beam after homogenization is surface divergent light, and it is difficult to obtain a high-quality collimated beam with a mirror group. Another technique is to add vibratory bitmaps to the original laser beam, which is then collimated with a Fourier lens. Since the diameter of the output beam of the general laser is greater than 3mm, it is also difficult to obtain a high-quality uniform collimated beam with the integrated mirror group after passing through the bit image with a certain divergence angle.

In the current laser display or projection lithography illumination systems, speckle dissipation and uniform light collimation are generally realized by multiple discrete optical components, which have complex and loose structures, poor stability, and high system power consumption.

SUMMARY OF THE INVENTION

In view of this, it is necessary to provide a laser projection device that can simultaneously realize continuous variable magnification beam expansion, collimation, homogenization and speckle dissipation, aiming at the defects existing in the prior art.

To achieve the above object, the present invention adopts the following technical solutions:

The present invention provides a laser projection device, comprising: a front fixed beam expander group, a variable magnification mirror group, a compensation mirror group, a focusing mirror group, a random bit photo and a rear fixed collimating mirror group, which are sequentially arranged along the propagation direction of the laser beam ,in:

The incident laser beam is expanded by the front fixed beam expander group and then enters the variable magnification mirror group. The variable magnification mirror group selects the beam diameter after beam expansion and enters the compensation mirror group. The group compensates the light output by the variable magnification lens group and outputs a collimated beam, the collimated beam is collected at the back focal plane of the focusing lens group after passing through the focusing lens group, and is located at the The divergent beam of the random-bit photo at the rear focal plane enters the fixed collimating lens group, and is collimated by the rear-fixed collimating lens group to output a collimated beam, wherein the random-bit photo is the collimator of the incident beam. The straight beam acts to weaken the spatial coherence.

In some preferred embodiments, the front fixed beam expander group can amplify the beam divergence angle, and the front fixed beam expander group is a single lens or a combination of multiple lenses.

In some preferred embodiments, the variable magnification lens group can select the beam diameter by adjusting the position back and forth, and the variable magnification lens group is a single lens or a combination of multiple lenses.

In some preferred embodiments, the compensating lens group can adjust the position back and forth to collimate the light beam, and the compensating lens group is a single lens or a combination of multiple lenses.

In some preferred embodiments, the focusing lens group is a single lens or a combination of multiple lenses.

In some preferred embodiments, the random bit photo is installed with a vibration driver, and the vibration driver can make the random bit photo rotate at a high speed or vibrate radially rapidly, and the vibration frequency is greater than 1000 Hz.

In some preferred embodiments, the random bitmap is a thin component in which microstructures are etched on quartz glass or other transparent hard materials, and the microstructures are randomly arranged concavo-convex patterns.

In some preferred embodiments, the front-end variable magnification lens group is linked with the compensation lens group to realize variable magnification beam expansion. The combined beam expansion multiple of the rear focusing lens group and the rear fixed collimating lens group is 5X.

In some preferred embodiments, the beam expansion ratio of the laser projection device can be continuously changed in the range of 1.5X˜50X.

The advantages of the present invention adopting the above technical solutions are:

In the laser projection device provided by the present invention, the incident laser beam is expanded by the front fixed beam expander group and then enters the variable magnification lens group, and the variable magnification lens group selects the beam diameter after beam expansion and is incident on the A compensation lens group, which compensates the light output by the variable magnification lens group and outputs a collimated beam, and the collimated beam passes through the focusing lens group and converges on the back focus of the focusing lens group At the rear focal plane, the light beam diverged by the random bit sheet located at the rear focal plane enters the fixed collimating lens group, and outputs the expanded collimated beam through the rear fixed collimating lens group. Wherein, the random bitmap has the effect of weakening the spatial coherence of the incident collimated beam, and the laser projection device provided by the present invention, compared with the unexpanded laser beam, the expanded and then focused beam can be Collected into a smaller focus, which can be approximately regarded as a standard focus of the rear collimating lens group. Placing the random-bit photo at the focal point can play a very good role in homogenizing and dissipating speckles, and at the same time, it does not affect the collimating lens group behind to achieve high-quality collimated beams, so as to achieve continuous variable magnification beam expansion, collimation and collimation. Straight, uniform and scattered spots, simplify the optical path design, facilitate the optical path integration and miniaturization, reduce the difficulty of optical path adjustment, and improve the installation accuracy.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

FIG. 1 is a schematic structural diagram of a laser projection device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of the linkage mode of the variable magnification mirror group and the compensation mirror group during the continuous variable magnification beam expansion process of the laser projection device provided by the embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Referring to FIG. 1, the present invention provides a laser projection device, including a front fixed beam expander group 01, a variable magnification mirror group 02, a compensation mirror group 03, a focusing mirror group 04, a random bit Photo 05 and rear fixed collimating lens group 07.

The working mode of the above-mentioned laser projection device is as follows:

The incident laser beam is expanded by the front fixed beam expander group 01 and then enters the variable magnification mirror group 02, and the variable magnification mirror group 02 selects the beam diameter after beam expansion and enters the compensation mirror group 03, The compensation lens group 03 compensates the light output by the variable magnification lens group 02 and outputs a collimated beam, and the collimated beam passes through the focusing lens group 04 and converges on the back focus of the focusing lens group 04 At the rear focal plane, the light beam diverged by the random-bit photo at the rear focal plane is collimated by the rear fixed collimating lens group 07 and then enters the fixed collimating lens group 07, and is collimated by the rear fixed collimating lens group 07. The collimation lens group 07 outputs the expanded collimated beam, wherein the random bit image 05 reduces the spatial coherence of the incident collimated beam.

In some preferred embodiments, the front fixed beam expander group 01 can amplify the beam divergence angle, and the front fixed beam expander group 01 is a single lens or a combination of multiple lenses.

In some preferred embodiments, the variable magnification lens group 02 can select the beam diameter by adjusting the position back and forth, and the variable magnification lens group 02 is a single lens or a combination of multiple lenses.

It can be understood that the beam diameter is selected by the position of the variable magnification lens group 02, and the minimum distance between the variable magnification lens group 02 and the front fixed beam expander lens group 01 is that they do not contact.

In some preferred embodiments, the compensating lens group 03 can adjust the position back and forth to collimate the light beam, and the compensating lens group 03 is a single lens or a combination of multiple lenses.

It can be understood that the minimum distance between the compensating lens group 03 and the focusing lens group 04 is that they do not contact, and the position of the compensating lens group 03 is also constrained by the position of the variable magnification lens group 02, and the two are linked to achieve the best distance.

In some preferred embodiments, the focusing lens group 04 is a single lens or a combination of multiple lenses, the focusing lens group 04 can focus the incident light beam, and the focal length of the focusing lens group 04 is preferably 10 mm.

In some preferred embodiments, the random bit photo 05 is installed with a vibration driver 06, and the vibration driver 06 can make the random bit photo 05 rotate at a high speed or vibrate radially rapidly, and the vibration frequency is greater than 1000 Hz. The bitmap plays the role of homogenizing and dispersing speckle on the passing beam.

In some preferred embodiments, the random bit sheet 05 is a thin component with microstructures etched on quartz glass or other transparent hard materials. 1 μm.

It can be understood that the random bit photo 05 is designed based on the principle of light wave interference, using modern optical micromachining technology to etch thin components with microstructures on quartz glass or other transparent hard materials, and the vibrating surface microstructures are very The laser spatial coherence is weakened on a large scale, so as to achieve the effect of reducing speckle.

Since the random bit photo 05 is placed at the focal point of the beam behind the focusing lens group 04, the collimation of the beam by the rear fixed collimating lens group 07 can be guaranteed to a large extent.

In some preferred embodiments, the front-end variable magnification lens group 02 can be linked with the compensation lens group 03 to realize variable magnification beam expansion, and the continuous change range of the beam expansion magnification of the variable magnification beam expander is 0.3X～10X , the combined beam expansion multiple of the rear focusing lens group 04 and the rear fixed collimating lens group 07 is 5X.

It can be understood that due to the combination of the rear fixed collimating lens group 07 and the focusing lens group 04, the collimated beam incident on the focusing lens group has a beam expansion effect, and the beam expansion factor is equal to the rear fixed collimating lens group 07 and the focusing lens group 04. ratio of focal lengths.

The focusing lens group 04 plays the role of focusing the light beam on the random bit photo 05 to achieve uniform light and dispersing speckle, and forms a Fourier transform system with the rear fixed collimating lens group 07 to further expand the beam, and the beam expansion factor is 5X, The whole device finally realizes the functions of continuous variable magnification beam expansion, collimation, homogenization and speckle dissipation of 1.5X ~ 50X.

In some preferred embodiments, the beam expansion ratio of the laser projection device can be continuously changed in the range of 1.5X˜50X.

Please refer to FIG. 2 , which is a schematic diagram of the linkage mode of the variable magnification mirror group and the compensation mirror group during the continuous variable magnification beam expansion process of a laser projection device 02 provided by the present invention, including front fixed expansion mirrors arranged in sequence along the propagation direction of the laser beam. Beam lens group 01, variable magnification lens group 02, compensation lens group 03, focusing lens group 04, random position photo 05 and rear fixed collimating lens group 07. in:

12 is the distance between the front fixed beam expander group 01 and the zoom lens group 02, 23 is the distance between the zoom lens group 02 and the compensation lens group 03, 34 is the distance between the compensation lens group 03 and the focusing lens group 04, 45 is the distance between the focusing lens group 04 and the random position photo 05 , and 56 is the distance between the random position photo 05 and the fixed collimating lens group 07 .

In the above schematic diagram, the positions of the variable magnification mirror group 02 and the compensation mirror group 03 are adjusted at the same time, and the two are linked together. The schematic diagram 021, the schematic diagram 022 and the schematic diagram 023 are the front-end variable magnification mirror group 02 and the compensation mirror group during the variable magnification beam expansion process. 03 Schematic diagram of the positional relationship between the two during linkage. The schematic diagram illustrates the working method of changing the original laser beam diameter by 0.3X to 10X times.

In the laser projection device provided by the present invention, compared with the unexpanded laser beam, the expanded and then focused beam can be gathered into a smaller focus, which can be approximately regarded as a standard focus of the rear collimating lens group. The random-bit photo is placed at the focal point position, which can play a good role in homogenizing and dissipating spots, and at the same time does not affect the collimating lens group behind to achieve high-quality collimated beams, so as to achieve continuous variable magnification beam expansion and collimation. , uniform light and dissipated spots, simplify the optical path design, facilitate the integration and miniaturization of the optical path, reduce the difficulty of optical path adjustment, and improve the installation accuracy.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

Of course, the cathode material of the laser projection device of the present invention can also have various transformations and modifications, and is not limited to the specific structure of the above-mentioned embodiment. In a word, the protection scope of the present invention should include those changes or substitutions and modifications that are obvious to those of ordinary skill in the art.

Claims (9)

1. A laser projection device, comprising: preceding fixed beam expanding lens group, zoom lens group, compensation mirror group, focusing mirror group, random position photograph and back fixed collimating lens group that set gradually along laser beam propagation direction, wherein:

the laser beam enters the zoom lens group after being expanded by the front fixed beam expander group, the zoom lens group selects the expanded beam diameter and enters the compensation lens group, the compensation lens group compensates the light output by the zoom lens group and outputs collimated light beams, the collimated light beams are converged at the rear focal plane of the focusing lens group after passing through the focusing lens group, the light beams diverged by the random position photo positioned at the rear focal plane enter the fixed collimating lens group and are collimated by the rear fixed collimating lens group, and the collimated light beams are output, wherein the random position photo plays a role in weakening the spatial coherence of the incident collimated light beams.

2. The laser projection device as claimed in claim 1, wherein the front fixed beam expander set is capable of magnifying the beam divergence angle, and the front fixed beam expander set is a single lens or a multi-lens combination.

3. The laser projection apparatus as claimed in claim 1, wherein the variable power lens group is a single lens or a multi-lens combination, and the beam diameter can be selected by adjusting the position back and forth.

4. The laser projection device as claimed in claim 1, wherein the compensating optical group is a single lens or a multi-lens combination for collimating the light beam by adjusting the position back and forth.

5. The laser projection device of claim 1, wherein the focusing mirror assembly is a single lens or a multi-lens combination.

6. The laser projection apparatus as claimed in claim 1, wherein the random bit picture is installed with a vibration driver, the vibration driver can rotate the random bit picture at a high speed or vibrate the random bit picture radially at a high speed, and the vibration frequency is greater than 1000 Hz.

7. The laser projection device as claimed in claim 6, wherein the random bitmap is a thin component formed by etching a microstructure on quartz glass or other transparent hard materials, and the microstructure is randomly arranged concave-convex grains.

8. The laser projection device according to claim 1, wherein the front zoom lens group and the compensating lens group are linked to realize zoom beam expansion, the beam expansion ratio of the zoom beam expansion is continuously changed within a range of 0.3X to 10X, and the combined beam expansion ratio of the rear focusing lens group and the rear fixed collimating lens group is 5X.

9. The laser projection device as claimed in claim 1, wherein the beam expansion factor of the laser projection device can be continuously changed within a range of 1.5X to 50X.

Images