CN117311067A - Projection optical machine - Google Patents

Abstract

The application provides a projection ray apparatus, include: lens, diaphragm, display device, light source and refractive element. The lens includes a lens rear group and a lens front group. The diaphragm is arranged between the rear lens group and the front lens group, and is provided with a light inlet and a light outlet. The display device is arranged on one side of the rear lens group, which is far away from the front lens group, and is used for modulating and reflecting light. The light source is arranged at one side of the light inlet of the diaphragm. The refraction element is arranged at the light inlet of the diaphragm and is positioned on the light-emitting path of the light source, and light rays emitted by the light source enter the light inlet of the diaphragm after passing through the refraction element, pass through the rear lens group, are modulated and reflected by the display device, and then sequentially pass through the rear lens group, the light-emitting opening of the diaphragm and the front lens group to emit. The light splitting prism of the traditional optical machine design is omitted, the rear intercept of the lens is reduced, and the size of the projection optical machine is reduced.

Description

Projector

Technical field

The present application relates to the technical field of projection equipment, specifically to a projection light machine.

Background technique

The current projection light machine consists of three parts: light source, light machine, and lens. The light source part is responsible for providing uniform illumination light. The light machine part usually passes through a Total Internal Reflection (TIR) prism or Refraction Total Reflection (Refraction Total). Internal Reflection (RTIR) prism to achieve splitting of incident and emergent light. This prism will increase the overall volume of the optical machine, increase the lens back focus, and increase the burden of lens design.

Contents of the invention

The embodiment of the present application proposes a projection light machine to solve the above technical problems.

The embodiments of the present application achieve the above objectives through the following technical solutions.

This application provides a projection light machine, including: a lens, an aperture, a display device, a light source and a refractive element. The lens includes the rear lens group and the front lens group. The diaphragm is arranged between the rear lens group and the front lens group, and the diaphragm is provided with a light entrance and a light exit. The display device is disposed on the side of the rear lens group away from the front lens group, and is used to modulate and reflect light. The light source is arranged on the light entrance side of the diaphragm. The refractive element is arranged at the light entrance of the diaphragm and is located on the light path of the light source. The light emitted by the light source enters the light entrance of the diaphragm after passing through the refractive element. After passing through the lens, group, modulated and reflected by the display device, and then emitted through the lens rear group, the light outlet of the diaphragm, and the lens front group in sequence.

In one implementation, the display device is LCoS.

In one embodiment, the aperture includes an outer ring part for shielding light and an inner ring part for transmitting light, the light entrance and the light exit are both located in the inner ring part, and the The light entrance is located on one side of the light exit.

In one embodiment, the projection light machine further includes a polarizing plate, and the polarizing plate is disposed between the lens rear group and the display device.

In one embodiment, the projection light machine further includes a 1/4 wave plate, the 1/4 wave plate is disposed between the polarizing plate and the display device, and the 1/4 wave plate has a fast The angle between the axis and the polarizer is 45 degrees.

In one implementation, the display device is a DMD.

In one embodiment, the diaphragm includes an outer ring part for light shielding and an inner ring part for light transmission, the light entrance is provided on the outer ring part, and the light exit is provided with the On the inner circle part.

In one embodiment, the light entrance is tangent to the light exit.

In one embodiment, the lens is a telecentric lens.

In one embodiment, the refractive element is a mirror.

The projection light machine provided in the embodiment of the present application sets an aperture with a light entrance and a light exit between the rear lens group and the front lens group, so that the light emitted by the light source enters from the light entrance of the aperture and passes through the lens. The rear group enters the display device, and after being modulated and reflected by the display device, it passes through the rear group of the lens, the light outlet of the diaphragm, and the front group of the lens. This application utilizes the area multiplexing of the lens diaphragm to achieve light splitting and combining, eliminating the need for the dichroic prism of traditional optical engine design, and reducing the lens back intercept and reducing the size of the projection light engine.

Description of the drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

FIG. 1 is a schematic structural diagram of a projection light machine according to an embodiment of the present application.

FIG. 2 is a schematic structural diagram of a projection light machine provided by another embodiment of the present application.

Figure 3 is a schematic diagram of the structure and working principle of an aperture in another embodiment of the present application.

FIG. 4 is a schematic diagram of the working principle of a lens in another embodiment of the present application.

FIG. 5 is a schematic structural diagram of a projection light machine provided in yet another embodiment of the present application.

Figure 6 is a schematic diagram of the working principle of the DMD provided in yet another embodiment of the present application.

Reference signs: projection light engine 1, lens 10, lens rear group 110, lens front group 120, diaphragm 20, light entrance 210, light exit 220, display device 30, light source 40, refractive element 50, polarizer 60, 1/4 wave plate 70.

Detailed ways

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and cannot be understood as limiting the present application.

In order to enable those in the technical field to better understand the solution of the present application, the technical solution in the embodiment of the present application will be clearly and completely described below in conjunction with the drawings in the embodiment of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the scope of protection of this application.

Referring to FIG. 1 , this application provides a projection light machine 1 including: a lens 10 , an aperture 20 , a display device 30 , a light source 40 and a refractive element 50 .

The lens 10 includes a rear lens group 110 and a front lens group 120 . It can be understood that the lens 10 can be divided into two parts with the aperture 20 as the boundary. The part close to the display device 30 is called the rear lens group 110 , and the other part is called the front lens group 120 .

The aperture 20 is disposed between the rear lens group 110 and the front lens group 120. The aperture 20 is provided with a light entrance 210 and a light exit 220. The aperture 20 can be used to block large-angle stray light.

The display device 30 is disposed on a side of the rear lens group 110 away from the front lens group 120 for modulating and reflecting light. In this application, the display device 30 may be a Liquid Crustal On Silicon (LCoS) or a Digital Micromirror Device (DMD). The light source 40 is disposed on one side of the light entrance 210 of the diaphragm 20. The light source 40 is used to emit light. The light source 40 can be a laser light source 40, a laser fluorescent light source 40, a light-emitting diode (Light-Emitting Diode, LED) light source 40, etc. . In addition, the light source 40 can also be uniformized through compound eyes, square rods, diffractive optical elements (Diffractive Optical Elements, DOE) and other devices, so that the brightness uniformity at different angles is better. It should be noted that this application does not require light source 40 Make specific assumptions about the technology and form.

The refractive element 50 is disposed at the light entrance 210 of the aperture 20 and is located on the light path of the light source 40. The light emitted by the light source 40 passes through the refractive element 50 and then enters the incident light of the aperture 20. The port 210 passes through the rear lens group 110 , is modulated and reflected by the display device 30 , and then exits through the rear lens group 110 , the light outlet 220 of the diaphragm 20 and the front lens group 120 in sequence. In some embodiments, the refractive element 50 may be a mirror, a prism, etc., which is not limited here.

The projector 1 provided in the embodiment of the present application disposes the diaphragm 20 with the light entrance 210 and the light exit 220 between the rear lens group 110 and the front lens group 120, so that the light emitted from the light source 40 can pass through the diaphragm 20. The light enters the entrance 210 , passes through the rear lens group 110 , enters the display device 30 , and after being modulated and reflected by the display device 30 , passes through the rear lens group 110 , the light outlet 220 of the diaphragm 20 , and the front lens group 120 . This application uses the area multiplexing of the diaphragm 20 of the lens 10 to realize splitting and combining light, removes the dichroic prism of the traditional optical machine design, and reduces the back intercept of the lens 10, solving the problem that the optical machine part in the prior art is usually passed through A TIR prism or RTIR prism is used to split the incident and emitted light. This prism will increase the volume of the optical machine, increase the back focus of the lens 10, and increase the burden of the lens 10 design.

Please refer to FIG. 2 . As another embodiment of the present application, in this embodiment, the projector 1 includes: a lens 10 , an aperture 20 , a display device 30 , a light source 40 and a refractive element 50 . In this embodiment, the display device 30 is LCoS.

The positional relationship of the lens 10 , the diaphragm 20 , the display device 30 , the light source 40 and the refractive element 50 may be the same as that in the first embodiment, and will not be described again here. In this embodiment, the projector 1 may further include: a polarizing plate 60 , which is disposed between the lens rear group 110 and the display device 30 . The polarizing plate 60 may also be attached to the display device. 30, the polarizing plate 60 realizes polarization of the incident light and analysis of the reflected light.

Further, in some embodiments, the projector 1 may further include: a 1/4 wave plate 70 , the 1/4 wave plate 70 is disposed between the polarizing plate 60 and the display device 30 . The angle between the fast axis of the 1/4 wave plate 70 and the polarizing plate 60 is 45 degrees. The above 1/4 wave plate 70 is arranged in such a way that the light without LCoS phase modulation is absorbed and passes through the LCoS. Modulated light can pass through to improve the contrast of the LCoS.

In this embodiment, LCoS is used as the display device 30. LCoS is a new type of silicon-based liquid crystal display device. It modulates the polarization of incident light by controlling the orientation of liquid crystal molecules and realizes the display function of a specific picture. Intensity-modulated LCoS uses polarizing devices such as polarizing plates 60 and polarizing beam splitter (PBS) prisms to inject light with a specific polarization direction into the LCoS, and after modulation by the LCoS, the polarization direction of the image light is deflected. While the polarization direction of other light remains unchanged, the image light can be separated by using the polarizing device again and injected into the lens 10 .

The diaphragm 20 in this embodiment includes an outer ring part for light shielding and an inner ring part for light transmission. The light entrance 210 and the light exit 220 are both located in the inner ring part, and the entrance The light port 210 is located on one side of the light outlet 220 . On the aperture 20, the surface distribution of the light corresponds to the angular distribution of the emitted light on the LCoS, and the angular distribution of the aperture 20 corresponds to the surface distribution of the LCoS (that is, the light emitted by each pixel will be at a certain location at the aperture 20. angle of incidence). It should be noted that the surface distribution of light refers to placing a screen at a certain point in the light path, and the intensity distribution on the screen is the surface distribution. The angular distribution of light refers to the intensity distribution of incident light at different angles on a certain plane. Equivalently, it can be considered that the light entering/exiting this plane freely propagates to infinity, and the distribution at infinity is the angular distribution.

Please also refer to Figure 3. Based on this characteristic of the aperture 20, if illumination light is incident at a point on the left side of the aperture 20, after passing through the lens rear group 110, the light will be incident on the LCoS from a specific angle. After reflection by the LCoS, the light rays emerging from the LCoS will converge on the symmetrical point on the right side of the aperture 20 .

It should be noted that the lens 10 in this embodiment is a telecentric lens 10 . The telecentric lens 10 means that light at different angles passing through the center point of the aperture 20 will eventually enter/exit the display device 30 approximately perpendicularly. ,As shown in Figure 4. When using the telecentric lens 10, since the main ray is perpendicular to the display device 30, the incident light and the exit light are symmetrical with respect to the main ray, and the incident point and the exit point on the aperture 20 are symmetrical with respect to the center of the aperture 20.

Please refer to Figure 5. As another embodiment of the present application, this embodiment provides a projection light machine 1. The projection light machine 1 also includes: a lens 10, an aperture 20, a display device 30, a light source 40 and a refractive element 50. . In this embodiment, the display device 30 adopts DMD.

The positional relationship of the lens 10 , the diaphragm 20 , the display device 30 , the light source 40 and the refractive element 50 is the same as that in the first embodiment, and will not be described again here.

The diaphragm 20 includes an outer ring part for shielding light and an inner ring part for transmitting light. The light entrance 210 is provided on the outer ring part, and the light outlet 220 is provided on the inner ring part. superior.

Unlike ordinary reflectors, DMD reflection does not follow the usual reflection laws. Since the ON state of the digital micromirror has a specific angle, the relationship between the light cone angles of the input light and the output light is shown in Figure 6. According to the angle of the micromirror, the central angle of the light cone angle of the ON state and the IN state can be obtained. And the exit angle corresponding to each incident light.

Furthermore, in some embodiments, the light entrance 210 is tangent to the light exit 220 . The above arrangement of the light entrance 210 and the light exit 220 can reduce the overall size of the aperture 20 and further reduce the size of the projector 1 volume of.

In this embodiment, the light rays passing through the center point of the aperture 20 at different angles will eventually enter/exit the DMD approximately perpendicularly, as shown in FIG. 4 . Since the telecentric characteristic will provide the same exit and entrance angles for different field of view points, making it possible to split light at the aperture 20 , the telecentric lens 10 can be selected as the lens 10 in this embodiment.

The projection light in this embodiment is emitted from the light source 40 from the light entrance 210 of the diaphragm 20 to the rear lens group 110, passes through the rear lens group 110 and is projected on the DMD, where the light is deflected. Finally, it passes through the rear lens group 110 again and converges at the light outlet 220 of the diaphragm 20. After the light exits through the light outlet 220, it continues to pass through the front lens group 120 and then is projected out, thereby realizing a complete imaging process. This application uses the area multiplexing of the diaphragm 20 of the lens 10 to realize splitting and combining light, removes the dichroic prism of the traditional optical machine design, and reduces the back intercept of the lens 10, solving the problem that the optical machine part in the prior art is usually passed through A TIR prism or RTIR prism is used to split the incident and emitted light. This prism will increase the volume of the optical machine, increase the back focus of the lens 10, and increase the burden of the lens 10 design.

Descriptions of the terms "some embodiments," "other embodiments," and the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this application, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples described in this application unless they are inconsistent with each other.

The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the foregoing embodiments. The recorded technical solutions are modified, or some of the technical features are equivalently replaced; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of this application, and shall be included in this application. within the scope of protection.

Claims (10)

1. A projection light engine, comprising:

a lens including a lens rear group and a lens front group;

the diaphragm is arranged between the rear lens group and the front lens group, and is provided with a light inlet and a light outlet;

the display device is arranged on one side of the rear lens group, which is far away from the front lens group, and is used for modulating and reflecting light;

the light source is arranged at one side of the light inlet of the diaphragm; and

the light emitted by the light source passes through the refraction element and then enters the light inlet of the diaphragm, passes through the lens rear group, and then sequentially passes through the lens rear group, the light outlet of the diaphragm and the lens front group after being modulated and reflected by the display equipment.

2. The projection engine of claim 1, wherein the display device is an LCoS.

3. The projection light engine of claim 2, wherein the diaphragm includes an outer ring portion for shielding light and an inner ring portion for transmitting light, the light inlet and the light outlet are both located at the inner ring portion, and the light inlet is located at one side of the light outlet.

4. The projection light engine of claim 3, further comprising: and the polaroid is arranged between the lens rear group and the display device.

5. The projection light engine of claim 4, further comprising: the 1/4 wave plate is arranged between the polaroid and the display device, and the included angle between the fast axis angle of the 1/4 wave plate and the polaroid is 45 degrees.

6. The projection engine of claim 1, wherein the display device is a DMD.

7. The projection light engine of claim 1, wherein the diaphragm includes an outer ring portion for shielding light and an inner ring portion for transmitting light, the light inlet is disposed on the outer ring portion, and the light outlet is disposed on the inner ring portion.

8. The projection light engine of claim 7, wherein the light entrance is tangential to the light exit.

9. The projection engine of claim 1, wherein the lens is a telecentric lens.

10. The projection light engine of any one of claims 1-9, wherein the refractive element is a mirror.