CN207571403U - Speckle elimination device, laser light source and laser projection system - Google Patents

Abstract

The utility model discloses one kind and disappears speckle device, laser light source and laser projection system, the speckle device that disappears includes controller and the liquid crystal display panel in laser beam exits light path, controller applies the deflection voltage that voltage value is different and voltage value changes over time to the different location of liquid crystal display panel respectively, so that the deflection direction difference of the liquid crystal of the different location and deflection direction of the liquid crystal of each position changes over time in liquid crystal display panel.The utility model can eliminate laser speckle phenomenon.

Description

Speckle elimination device, laser light source and laser projection system

technical field

The utility model relates to the technical field of lasers. More specifically, it relates to a speckle elimination device, a laser light source and a laser projection system.

Background technique

When the laser light source is used as the light source of the projection system, the high coherence of the laser will cause the laser beam itself to produce spot interference (self-coherence). The conditions for the self-coherence of the laser beam are: the same laser frequency, the same vibration direction and a constant phase difference. Spot interference will lead to the formation of stray light with uneven brightness next to the laser exit spot, which is called laser speckle. Laser speckle phenomenon will affect the imaging effect of projection. The rougher the surface on which the laser is projected, the more obvious the laser speckle phenomenon will be.

Therefore, it is necessary to provide a speckle elimination device, a laser light source and a laser projection system for eliminating laser speckle phenomenon by making the vibration directions of the laser light in the laser beam different.

Utility model content

The purpose of this utility model is to provide a speckle elimination device, a laser light source and a laser projection system to eliminate laser speckles by making the vibration direction of the laser in the laser beam different, or by making the phase relationship of the laser in the laser beam different.

In order to achieve the above object, the utility model adopts the following technical solutions:

The utility model discloses a speckle dissipating device, which comprises a controller and a liquid crystal panel located on a laser beam exit optical path, and the controller applies deflection voltages with different voltage values to different positions of the liquid crystal panel and whose voltage values vary with time, so as to The deflection directions of the liquid crystals at different positions in the liquid crystal panel are different, and the deflection directions of the liquid crystals at each position change with time.

Preferably, the liquid crystal panel includes a first substrate, a second substrate, and a liquid crystal disposed between the first substrate and the second substrate, the first substrate is provided with a plurality of first electrodes with different positions, and the second The substrate is provided with a plurality of second electrodes opposite to the first electrodes, and the controller applies deflection voltages to the first electrodes at different positions and the opposite second electrodes respectively.

Preferably, the controller applies a deflection voltage in the form of a sine wave to different positions of the liquid crystal panel.

Preferably, the controller alternately applies the deflection voltages of the first voltage value and the second voltage value to different positions of the liquid crystal panel.

Preferably, the first voltage value or the second voltage value is 0V.

Preferably, the duration of the controller applying the deflection voltage of the first voltage value and the deflection voltage of the second voltage value to different positions of the liquid crystal panel is 0.5-1 ms.

The utility model also discloses a laser light source, which includes a laser that emits laser light, and also includes the above-mentioned speckle dissipating device.

The utility model also discloses a laser projection system, which includes the above-mentioned laser light source.

The beneficial effects of the utility model are as follows:

The technical solution of the utility model eliminates the laser speckle phenomenon by making the vibration direction of the laser in the laser beam different, or by making the phase of the laser in the laser beam different, and the technical solution of the utility model is small in size, simple in structure and reliable High performance and low energy consumption.

Description of drawings

Below in conjunction with accompanying drawing, the specific embodiment of the present utility model is described in further detail;

Fig. 1 shows a schematic diagram of a speckle elimination device.

Figure 2 shows a schematic diagram of a laser light source.

Detailed ways

In order to illustrate the utility model more clearly, the utility model will be further described below in conjunction with preferred embodiments and accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present utility model.

As shown in FIG. 1 , the speckle elimination device provided by this embodiment includes a controller 10 and a liquid crystal panel 20 located on the laser beam exit optical path, and the controller 10 applies different voltage values to different positions of the liquid crystal panel 20 at different times. The deflection voltage whose voltage value changes with time, so that the deflection directions of the liquid crystals 201 (which can be understood as liquid crystal molecules) at different positions in the liquid crystal panel 20 are different and the deflection directions of the liquid crystals 201 at each position change with time. Those skilled in the art can understand that the controller 10 applies deflection voltages with different voltage values to different positions of the liquid crystal panel 20 at different times, and the voltage values vary with time. The voltage values of the deflection voltages applied to different positions of the panel 20 are different, and the voltage values of the deflection voltages respectively applied to different positions of the liquid crystal panel 20 by the controller 10 vary with time. Wherein, the changes of the deflection voltages applied by the controller 10 to different positions of the liquid crystal panel 20 can be regular changes or random changes, and the changes of the deflection voltages respectively applied by the controller 10 to different positions of the liquid crystal panel 20 can be The same may also be different.

The deflection directions of the liquid crystal 201 at different positions are different under the action of different deflection voltages. Since the liquid crystal 201 has birefringence characteristics, the refractive index of the liquid crystal in different deflection states is different, and the phase information of the laser beam incident on the liquid crystal 201 will be different. It changes with the deflection direction of the liquid crystal 201. In the speckle elimination device provided in this embodiment, the controller 10 applies deflection voltages with different voltage values to different positions of the liquid crystal panel 20 at different times and whose voltage values change with time, so that the deflection of the liquid crystal 201 at different positions in the liquid crystal panel 20 The directions are different and the deflection direction of each liquid crystal 201 changes with time. That is to say, since the deflection directions of the liquid crystals 201 at different positions in the liquid crystal panel 20 are different, the phase delays of the laser beams incident on the liquid crystals 201 at different positions are also different, and there will be no interference between the laser beams in the laser beams, so The laser speckle phenomenon of the incident laser beam is also eliminated. In addition, the variation of the deflection direction of the liquid crystal 201 at each position with time further enhances the effect of eliminating the laser speckle phenomenon of the incident laser beam. Those skilled in the art can understand that the variation of the applied deflection voltage with time is limited to the input voltage range of the liquid crystal panel 20, that is, although the applied deflection voltage varies with time, the variation cannot exceed the limit. range, otherwise the liquid crystal panel 20 will be damaged.

The principle of eliminating laser speckle in this embodiment is further described below through the function formula: the wave function of the laser is: where A is the amplitude function of the wave function, is the phase function of the wave function; the total self-coherent wave function is: For a small-sized spot, the amplitude of the spot is approximately equal, that is, A _xi = A _yj , and the rotation angle of the liquid crystal at each position is different, so the phases of each position are different and arranged randomly, then Because the phases in the X direction and the Y direction are random, the coherence function after the overall addition is 0 when used. This eliminates the laser speckle phenomenon of the incident laser beam.

In practice, the liquid crystal panel 20 includes a first substrate 202, a second substrate 203, and a liquid crystal 201 disposed between the first substrate 202 and the second substrate 203. The first substrate 202 is provided with first electrodes 2021 and 2022, the second substrate 203 is provided with a second electrode 2031 opposite to the first electrode 2021 and a second electrode 2032 opposite to the first electrode 2022, and the controller 10 applies a first deflection voltage to the first electrode 2021 and the second electrode 2031 And apply a second deflection voltage to the first electrode 2022 and the second electrode 2032 . Those skilled in the art can understand that this structure is only an example where the controller 10 applies deflection voltages with different voltage values to two different positions of the liquid crystal panel 20 and whose voltage values vary with time. The deflection voltages with different voltage values applied to two or more different positions of the same and whose voltage values change with time are similar, and will not be repeated here.

In specific implementation,

An optional manner is that the controller 10 respectively applies deflection voltages in the form of sine waves to different positions of the liquid crystal panel 20 . Take the example shown in FIG. 1, that is, the controller 10 applies a deflection voltage in the form of a sine wave to the upper and lower positions of the liquid crystal panel 20 respectively. Use methods such as making two sine waves have a phase difference. In this way, deflection voltages with different voltage values and time-varying voltage values can be applied to different positions of the liquid crystal panel 20, and at the same time, the voltage value of the deflection voltage is easy to modulate and control;

Another optional way is that the controller 10 alternately applies the deflection voltages of the first voltage value and the second voltage value to different positions of the liquid crystal panel 20 respectively, which can also meet the requirements of applying voltages to different positions of the liquid crystal panel 20 respectively. The deflection voltage whose value is different (for example, by making the period length of the deflection voltage of the first voltage value and the deflection voltage of the second voltage value applied to different positions is different or the timing is not synchronized, etc.) and the voltage value changes with time, and at the same time, the deflection voltage The voltage value is also easy to modulate and control. Further, the first voltage value or the second voltage value is 0V, which can reduce energy consumption without affecting the effect of dispersing speckles. Further, the controller 10 respectively applies the deflection voltage of the first voltage value and the deflection voltage of the second voltage value to different positions of the liquid crystal panel 20 for 0.5-1 ms, and alternately applies the first voltage value in a period of 0.5-1 ms and the second voltage value can guarantee the effect of dissipating speckle.

As shown in Figure 2, this embodiment also provides a laser light source, including a laser 30 emitting laser light and the above-mentioned speckle elimination device, the laser beam emitted by the laser 30 can eliminate the laser speckle phenomenon after passing through the liquid crystal panel 20, further, On the laser beam emitting optical path between the laser 30 and the liquid crystal panel 20 , the laser light source further includes a collimating lens 40 for converting the divergent laser beam emitted by the laser 30 into a parallel laser beam.

This embodiment also provides a laser projection system, including the above-mentioned laser light source.

In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the utility model and simplifying the Describes, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the present invention. Unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be interpreted in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, It can also be an electrical connection; it can be a direct connection, or an indirect connection through an intermediary, or an internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model according to specific situations.

It should also be noted that in the description of the utility model, relative terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply There is no such actual relationship or order between these entities or operations. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

Obviously, the above-mentioned embodiments of the present utility model are only examples for clearly illustrating the present utility model, rather than limiting the implementation of the present utility model. For those of ordinary skill in the art, on the basis of the above description It is also possible to make other changes or changes in different forms. All the implementation modes cannot be exhausted here. All obvious changes or changes that belong to the technical solutions of the present invention are still within the scope of protection of the present invention. .

Claims (8)

1. A speckle elimination device is characterized in that it comprises a controller and a liquid crystal panel positioned on the laser beam exit optical path, and the controller applies a deflection voltage that voltage value is different and voltage value varies with time to different positions of the liquid crystal panel respectively , so that the deflection directions of the liquid crystals at different positions in the liquid crystal panel are different and the deflection directions of the liquid crystals at each position change with time. 2. The speckle elimination device according to claim 1, wherein the liquid crystal panel comprises a first substrate, a second substrate, and a liquid crystal disposed between the first substrate and the second substrate, and the first substrate is provided There are a plurality of first electrodes at different positions, the second substrate is provided with a plurality of second electrodes opposite to the first electrodes, and the controller applies a deflection voltage to the first electrodes at different positions and the opposite second electrodes respectively . 3 . The speckle elimination device according to claim 1 , wherein the controller applies a deflection voltage in the form of a sine wave to different positions of the liquid crystal panel. 4 . 4. The speckle elimination device according to claim 1, wherein the controller alternately applies the deflection voltages of the first voltage value and the second voltage value to different positions of the liquid crystal panel. 5. The speckle elimination device according to claim 4, wherein the first voltage value or the second voltage value is 0V. 6. The speckle elimination device according to claim 4, wherein the controller applies the deflection voltage of the first voltage value and the deflection voltage of the second voltage value to different positions of the liquid crystal panel for a period of 0.5 -1ms. 7. A laser light source, comprising a laser emitting a laser beam, characterized in that it further comprises the speckle elimination device according to any one of claims 1-6. 8. A laser projection system, comprising the laser light source according to claim 7.