Light machine illumination system and laser projection equipment

Abstract

The utility model provides an optical machine illumination system and laser projection equipment, and relates to the technical field of laser display. According to the optical machine illumination system, the first face of the first prism is arranged to be the curved face, the first face is used for collecting the illumination light beam and adjusting the incident angle of the illumination light beam entering the second face to replace a lens, materials and space of the lens are saved, and the system size and the number of optical elements can be effectively reduced; and miniaturization of the equipment is facilitated. Meanwhile, by adding the second prism, the propagation path of the light beam is prolonged, so that the projection light beam and the non-projection light beam can be separated, and the contrast ratio is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of laser display, and more specifically, to an optical mechanical lighting system and a laser projection device. Background Art

[0002] With the continuous development of science and technology, laser projection equipment is increasingly used in people's work and life. Users' requirements for laser projection equipment are also getting higher and higher, and they prefer integrated and high-contrast equipment.

[0003] In related technologies, such as Figure 1 As shown, the optical path of the optomechanical lighting system is an inclined optical path, and the plane reflector 104 is used to deflect the illumination light beam. Although the length of the optomechanical lighting system (in the optical axis direction of the light homogenizing component 101) is reduced, the thickness of the optomechanical lighting system is also increased. In order to cooperate with the optomechanical lighting system, other components in the entire optical engine system need to be rearranged, which leads to an increase in the volume and thickness of the entire laser projection equipment. Utility Model Content

[0004] The exemplary embodiments of the present application provide an optical mechanical illumination system and a laser projection device to solve the problem of how to reduce the volume of the system.

[0005] This application provides the following technical solutions:

[0006] In a first aspect, the present application provides an optical-mechanical lighting system, comprising:

[0007] A first prism, comprising a first surface, a second surface and a third surface, wherein the first surface is a curved surface, and is used to converge the illumination light beam and adjust the incident angle of the illumination light beam to the second surface;

[0008] a light valve, located on one side of the third surface and arranged toward the third surface;

[0009] a second prism located on one side of the second surface, the second prism comprising a fourth surface and a fifth surface connected to the fourth surface, the fourth surface is opposite to the second surface, and the fifth surface is located on a side of the fourth surface away from the second surface;

[0010] The illumination light beam enters the first prism through the first surface and is incident on the second surface at a first angle. The illumination light beam totally reflected by the second surface is emitted from the third surface to the light valve. The illumination light beam reflected by the light valve becomes a projection light beam. The projection light beam is emitted after passing through the third surface, the second surface, the fourth surface and the fifth surface. The first angle is greater than or equal to a first preset angle.

[0011] In a second aspect, the present application further provides a laser projection device, comprising: a light source system, an imaging system, and any one of the above-mentioned optical-mechanical illumination systems;

[0012] The light source system is used to provide an illumination beam to the optical mechanical illumination system;

[0013] The optical mechanical illumination system is used to modulate the illumination light beam provided by the light source system into a projection light beam and then emit it to the imaging system;

[0014] The imaging system is used for imaging the projection light beam and then emitting it to a projection screen.

[0015] It can be seen from the above technical solutions that the optical mechanical lighting system provided by the present application, by setting the first surface of the first prism as a curved surface, uses the first surface to converge the illumination light beam and adjusts the incident angle of the illumination light beam to the second surface, so as to replace a lens, thereby saving the material and space of the lens, and can effectively reduce the system volume and the number of optical components, which is more conducive to realizing miniaturization of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the implementation methods in the embodiments of the present application or the related technologies, the following is a brief introduction to the drawings required for use in the embodiments or the related technology descriptions. Obviously, the drawings described below are some embodiments of the present application, and a person skilled in the art can also obtain other drawings based on these drawings.

[0017] Figure 1 It is a structural schematic diagram of an optical mechanical lighting system in the related art;

[0018] Figure 2 for Figure 1 Total irradiance diagram of the luminous flux on the light exiting surface of the total internal reflector;

[0019] Figure 3 A schematic diagram of the structure of an optical-mechanical lighting system provided in an embodiment of the present application;

[0020] Figure 4 A schematic diagram of the structure of another optical-mechanical lighting system provided in an embodiment of the present application;

[0021] Figure 5 A schematic diagram of the structure of another optical-mechanical lighting system provided in an embodiment of the present application;

[0022] Figure 6 A schematic diagram of the structure of another optical-mechanical lighting system provided in an embodiment of the present application;

[0023] Figure 7 A schematic diagram of the structure of a prism provided in an embodiment of the present application;

[0024] Figure 8 A schematic diagram of the structure of another prism provided in an embodiment of the present application;

[0025] Fig. 9 A schematic diagram of the structure of another optical-mechanical lighting system provided in an embodiment of the present application;

[0026] Fig.10 A schematic diagram of the structure of another prism provided in an embodiment of the present application;

[0027] Fig.11 A schematic diagram of the modulation principle of a light valve provided in an embodiment of the present application;

[0028] Fig.12 A schematic diagram of the structure of another optical-mechanical lighting system provided in an embodiment of the present application;

[0029] Fig.13 for Figure 1 A side view of the light path incident on the bottom side of the optomechanical illumination system is shown;

[0030] Fig.14 for Figure 1 A top view of the light path incident on the bottom edge of the optomechanical illumination system is shown;

[0031] Fig.15 A schematic diagram of the incident direction of a light beam when incident from the bottom edge provided in an embodiment of the present application;

[0032] Fig.16 for Figure 1 A side view of the light path of the optomechanical illumination system with oblique edge incidence is shown;

[0033] Fig.17 for Figure 1 A top view of the light path of the optomechanical illumination system with oblique edge incidence is shown;

[0034] Fig.18 A schematic diagram of the incident direction of a light beam when incident at an oblique edge provided in an embodiment of the application;

[0035] Fig.19 A schematic diagram of a light spot at the first surface provided in an embodiment of the application;

[0036] Fig. 20 A schematic diagram of a light spot at a light valve receiving surface provided in an embodiment of the present application;

[0037] Fig.21 A schematic structural diagram of a laser projection device provided in an embodiment of the application. DETAILED DESCRIPTION

[0038] In order to make the purpose and implementation method of the present application clearer, the exemplary implementation method of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0039] It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their ordinary and common meanings.

[0040] The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to all the components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0041] In related technologies, such as Figure 1 As shown, the optical machine illumination system includes a light homogenizing component 101, a first lens 102, a second lens 103, a plane reflector 104, a third lens 105, a total internal reflection prism 106 and a light valve 4. After the illumination light beam is emitted from the light homogenizing component 101, it passes through the first lens 102 to the second lens 103 vertically arranged along the direction of the system optical axis, and the plane reflector 104 reflects the illumination light beam to change the propagation direction of the illumination light beam. The illumination light beam with the changed propagation direction is incident on the third lens 105, and then vertically emitted from the third lens 105 to the total internal reflection prism 106, and then reflected from the total internal reflection prism 106 to the light valve 4, and then emitted from the light valve 4 to the imaging system. The optical path of the optomechanical lighting system is an inclined optical path, and the plane reflector 104 is used to deflect the illumination light beam. Although the length of the optomechanical lighting system (in the optical axis direction of the light homogenizing component 101) is reduced, the thickness of the optomechanical lighting system is also increased. In order to cooperate with the optomechanical lighting system, other components in the entire optical engine system need to be rearranged, which leads to an increase in the volume and thickness of the entire laser projection equipment.

[0042] Furthermore, the light valve 4 generally includes a plurality of array-arranged digital micromirrors (DMDs). By adjusting the deflection angle of the digital micromirrors, it is controlled whether the light beam reflected by the digital micromirrors is used for projection imaging. The light beam used for projection imaging is the projection light beam, also called "On light", and the light beam not used for projection imaging is the non-projection light beam, also called "Off light". Figure 2 As shown, due to the small deflection angle of the digital micromirror, the On light and Off light of the digital micromirror will overlap partially. The overlapping Off light is transmitted to the imaging system, causing the black field to become brighter, thereby reducing the contrast and affecting the user's subjective experience.

[0043] In order to solve the above technical problems, an embodiment of the present application provides an optomechanical lighting system and a laser projection device, wherein the optomechanical lighting system includes: a first prism, including a first surface, a second surface and a third surface, the first surface being a curved surface, for converging an illumination light beam and adjusting the incident angle of the illumination light beam incident on the second surface; a light valve, located on one side of the third surface and arranged toward the third surface; a second prism, located on one side of the second surface, the second prism including a fourth surface and a fifth surface connected to the fourth surface, the fourth surface being opposite to the second surface, and the fifth surface being located on the side of the fourth surface away from the second surface; wherein the illumination light beam enters the first prism through the first surface and is incident on the second surface at a first angle, the illumination light beam totally reflected by the second surface is emitted from the third surface to the light valve, the illumination light beam reflected by the light valve becomes a projection light beam, and the projection light beam is emitted after passing through the third surface, the second surface, the fourth surface and the fifth surface; the first angle is greater than or equal to the first preset angle. Therefore, by setting the first surface of the first prism as a curved surface, using the first surface to converge the illumination beam and adjust the incident angle of the illumination beam to the second surface, instead of a lens, the material and space of the lens are saved, the system volume and the number of optical elements can be effectively reduced, and it is more conducive to miniaturization of the device. At the same time, by adding a second prism, the propagation path of the light beam is extended, so that the projection beam and the non-projection beam can be separated, thereby improving the contrast.

[0044] The following is an exemplary description of the optical mechanical lighting system and laser projection equipment provided in the embodiments of the present application in conjunction with the accompanying drawings.

[0045] In some embodiments, Figure 3 As shown, the optomechanical illumination system includes: a first prism 1 , a second prism 2 and a light valve 4 .

[0046] The first prism 1 includes a first surface 11, a second surface 12 and a third surface 13 connected end to end. The first surface 11 is a curved surface, and the function of the curved surface is similar to that of a lens, which converges the illumination light beam incident on the first surface 11 and adjusts the incident angle of the illumination light beam incident on the second surface to achieve the regulation of the angle and shape of the light beam. The embodiment of the present application does not limit the surface type of the curved surface, including all types of curved surfaces known to those skilled in the art, such as spherical surfaces, aspherical surfaces or free-form surfaces. In some embodiments, the third surface 13 is parallel to the light valve 4, and the second surface 12 is an inclined surface.

[0047] The light valve 4 is located on one side of the third surface 13 of the first prism 1 and is disposed toward the third surface 13. The light valve 4 is used to receive the illumination beam emitted from the third surface 13 and adjust its propagation direction, such as reflecting the illumination beam, and the beam reflected by the light valve enters the first prism again.

[0048] The second prism 2 is located on the second surface 12 of the first prism 1 . The second prism 2 includes a fourth surface 21 and a fifth surface 22 connected to the fourth surface 21 . The fourth surface 21 is opposite to the second surface 12 . The fifth surface 22 is located on the side of the fourth surface 21 away from the second surface 12 .

[0049] The illumination light beam enters the first prism 1 through the first surface 11 and is incident on the second surface 12 at a first angle i. The illumination light beam totally reflected by the second surface 12 is emitted from the third surface 13 to the light valve 4. The illumination light beam reflected by the light valve 4 becomes a projection light beam. The projection light beam is emitted after passing through the third surface 13, the second surface 12, the fourth surface 21, and the fifth surface 22. The first angle i is greater than or equal to the first preset angle, which is equal to the first critical angle arcsin(1 / n1), where n1 represents the refractive index of the first prism 1. When the incident angle of the illumination light beam on the second surface 12 (i.e., the first angle i) is greater than the critical angle arcsin (1 / n1), the total reflection condition is met, the illumination light beam is reflected to the receiving surface of the light valve 4, and after being processed by the light valve 4, the illumination light beam becomes a projection light beam, and the projection light beam enters the first prism 1 through the third surface 13 and is merged into the second surface 12. The incident angle of the projection light beam on the second surface 12 is less than the critical angle, and total reflection does not occur. The projection light beam enters the second prism 2 through the second surface 12 and the fourth surface 21, and is emitted from the fifth surface 22 of the second prism 2.

[0050] The optical-mechanical illumination system provided in the present application, by setting the first surface 11 of the first prism 1 as a curved surface, utilizes the first surface 11 to converge the illumination light beam and adjust the incident angle of the illumination light beam to the second surface, so as to replace a lens, thereby saving the material and space of the lens, being able to effectively reduce the system volume and the number of optical components, and being more conducive to realizing miniaturization of the equipment.

[0051] In some embodiments, the light valve includes a digital micromirror, and the light valve is configured to control the digital micromirror to rotate a first deflection angle, so that an illumination light beam incident on the digital micromirror is converted into a projection light beam, and control the digital micromirror to rotate a second deflection angle, so that the illumination light beam incident on the digital micromirror is converted into a non-projection light beam. The specific optical path process is as follows: Figure 4 shown.

[0052] Among them, the illumination light beam enters the first prism 1 through the first surface 11 and is incident on the second surface 12. The illumination light beam totally reflected by the second surface 12 is emitted from the third surface 13 to the light valve 4. When the light valve 4 controls the digital micromirror to rotate the first deflection angle, the illumination light beam incident on the digital micromirror is converted into a projection light beam (i.e., on light), and the projection light beam is emitted after passing through the third surface 13, the second surface 12, the fourth surface 21, and the fifth surface 22; when the light valve 4 controls the digital micromirror to rotate the second deflection angle, the illumination light beam incident on the digital micromirror is converted into a non-projection light beam (i.e., off light), and the non-projection light beam is emitted after passing through the third surface 13, the second surface 12, the fourth surface 21, and the fifth surface 22. Since the first deflection angle is not equal to the second deflection angle, the projection light beam and the non-projection light beam emitted from the light valve 4 have different emission angles, and the projection light beam and the non-projection light beam propagate along different paths, which are different from each other. Figure 1 Compared with only one total internal reflection prism 106, by adding the second prism 2, the propagation path of the light beam is extended, the projection beam and the non-projection beam are emitted from different positions of the fifth surface 22, and the distance between the two emission positions is increased, so that the projection beam and the non-projection beam can be separated, thereby improving the contrast.

[0053] In some embodiments, Figure 5 As shown, there is a gap between the second surface 12 of the first prism 1 and the fourth surface 21 of the second prism 2, and the refractive index of the medium filled in the gap is less than the refractive index of the first prism 1. This arrangement ensures that the transmission path of the illumination light beam incident on the second surface 12 is from the light-dense medium to the light beam medium, and when the incident angle of the illumination light beam on the second surface 12 (i.e., the first angle i) is greater than or equal to the first preset angle, the illumination light beam is totally reflected on the second surface 12.

[0054] In some embodiments, the gap between the second surface 12 and the fourth surface 21 is filled with air, the refractive index of air is equal to 1, and the first prism 1 is made of a material with a refractive index greater than 1, such as glass. Exemplarily, the first prism 1 is made of H-K9L glass material, whose refractive index is 1.5168, which is greater than the refractive index of air.

[0055] In some embodiments, the width of the gap between the second surface 12 and the fourth surface 21 is in the range of [3 μm, 5 μm].

[0056] In some embodiments, Figure 6 As shown, the second prism 2 also includes a sixth face 23, which connects the fourth face 21 and the fifth face 22; the optical mechanical lighting system also includes: a third prism 3, which includes a seventh face 31, an eighth face 32 and a ninth face 33 connected in end to end order, the seventh face 31 is opposite to the second face 12, and the eighth face 32 is opposite to the sixth face 23.

[0057] The light valve 4 includes a digital micromirror, and the light valve 4 is configured to control the digital micromirror to rotate at a first deflection angle, so that the illumination light beam incident on the digital micromirror is converted into a projection light beam, and the projection light beam passes through the third surface 13, the second surface 12 and the seventh surface 31 to enter the third prism 3, and is incident on the eighth surface 32 at a second angle, which is less than the second preset angle, and the projection light beam incident on the eighth surface 32 passes through the eighth surface 32, the sixth surface 23 and the fifth surface 22 and then is emitted. The light valve 4 is also configured to control the digital micromirror to rotate at a second deflection angle, so that the illumination light beam incident on the digital micromirror is converted into a non-projection light beam, and the non-projection light beam passes through the third surface 13, the second surface 12 and the seventh surface 31 to enter the third prism 3, and is incident on the eighth surface 32 at a third angle, which is greater than or equal to the second preset angle, and the non-projection light beam incident on the eighth surface 32 is emitted from the ninth surface 33 after being totally reflected.

[0058] The second preset angle is equal to the second critical angle arcsin(1 / n3), wherein n3 represents the refractive index of the third prism 3 .

[0059] The optical path of the illumination light beam incident on the light valve 4 is the same as that described above and will not be described again. This embodiment only explains the optical path after the light valve.

[0060] When the light valve 4 controls the digital micromirror to rotate to the first deflection angle, the illumination light beam incident on the digital micromirror is converted into a projection light beam (i.e., on light), and the projection light beam enters the third prism 3 through the third surface 13, the second surface 12, and the seventh surface 31 and is incident on the eighth surface 32. The incident angle of the projection light on the eighth surface 32 is less than the second preset angle, and total reflection does not occur. The lens light beam is emitted after passing through the eighth surface 32, the sixth surface 23, and the fifth surface 22.

[0061] When the light valve 4 controls the digital micromirror to rotate to the second deflection angle, the illumination light beam incident on the digital micromirror is converted into a non-projection light beam (i.e., Off light), and the non-projection light beam enters the third prism 3 through the third surface 13, the second surface 12, and the seventh surface 31 and is incident on the eighth surface 32. The incident angle of the non-projection light beam on the eighth surface 32 is greater than the second preset angle, and the non-projection light beam is totally reflected on the eighth surface 32 and emitted from the ninth surface 33.

[0062] In this way, by adding the third prism 3, the projection light beam can pass through the eighth surface 32 of the third prism 3 and finally be emitted from the fifth surface 22 of the second prism 2, while the non-projection light beam is totally reflected at the eighth surface 32 of the third prism 3, transmitted in a direction away from the second prism 2, and finally be emitted from the ninth surface 33 of the third prism 3. The fifth surface 22 and the ninth surface 33 are respectively located in different orientations, and the non-projection light beam does not overlap with the projection light beam, thereby improving the contrast.

[0063] In some embodiments, Figure 7As shown, the first surface 11 is a convex surface, which protrudes toward the first prism 1 and away from the third prism 3 .

[0064] In some embodiments, Figure 8 As shown, the first surface 11 is a concave surface, which is concave in the direction from the first prism 1 to the third prism 3 .

[0065] In some embodiments, the first surface 11 includes one of a spherical surface, an aspherical surface, and a free-form surface.

[0066] The first surface 11 is used to converge the illumination light beam incident on the first surface 11 and adjust the incident angle of the illumination light beam incident on the second surface, and its curvature will affect the incident angle and spot shape of the illumination light beam on the second surface 12. The curvature of the first surface 11 is not limited in the embodiment of the present application, and the first surface 11 and the lens located in front of the first prism are used to adjust the angle and shape of the light beam to meet the incident condition of the light valve 4.

[0067] In some embodiments, Fig. 9 As shown, there are gaps between the second surface 12 of the first prism 1 and the fourth surface 21 of the second prism 2, and between the eighth surface 32 of the third prism 3 and the sixth surface 23 of the second prism 2, and the refractive index of the medium filling the gaps is less than the refractive index n1 of the first prism 1 and less than the refractive index n3 of the third prism 3.

[0068] Such an arrangement ensures that the transmission path of the illumination light beam incident on the second surface 12 is from the light-dense medium into the light beam medium, and when the incident angle of the illumination light beam on the second surface 12 (i.e., the first angle i) is greater than the first preset angle, the illumination light beam is totally reflected on the second surface 12, and the transmission path of the non-projection light beam incident on the eighth surface 32 is from the light-dense medium into the light beam medium, and when the incident angle of the non-projection light beam on the eighth surface 32 (i.e., the third angle) is greater than the second preset angle, the non-projection light beam is totally reflected on the eighth surface 32.

[0069] In some embodiments, the gap is filled with air, and the refractive index of air is equal to 1. The first prism 1 and the third prism 3 can be made of a material with a refractive index greater than 1, such as glass.

[0070] In some embodiments, the first prism 1 and the third prism 3 are prisms of the same material, that is, the refractive index n1 of the first prism 1 is equal to the refractive index n3 of the third prism, and correspondingly, the first critical angle arcsin (1 / n1) is equal to the second critical angle arcsin (1 / n3).

[0071] In some embodiments, the first prism 1 , the second prism 2 , and the third prism 3 are prisms made of the same material.

[0072] Exemplarily, the first prism 1 , the second prism 2 and the third prism 3 are all made of the same glass material, such as H-K9L glass, whose refractive index is 1.5168, and the first critical angle and the second critical angle are both equal to 41.25°.

[0073] In some embodiments, the width D1 of the gap satisfies: 3 μm≤D1≤5 μm.

[0074] In some embodiments, Figure 3-10 As shown in any of the figures, the fifth surface 22 is parallel to the receiving surface of the light valve.

[0075] In this way, the fifth surface is arranged to be parallel to the receiving surface of the light valve, which mainly plays a role in compensating the optical path difference, so that the optical path of the projection light beam from the light valve 4 to the fifth surface 22 is consistent.

[0076] The receiving surface of the light valve 4 faces the third surface 13 of the first prism 1, and the receiving surface is parallel to the plane where the light valve 4 is located, and does not represent the reflection surface of the digital micromirror in the light valve 4. For example, Figure 3-6 As shown in any of the figures, the light valve 4 is placed horizontally, that is, the receiving surface is placed horizontally, and the receiving surface is arranged parallel to the fifth surface 22 .

[0077] For example, Fig.12 As shown, the optical machine illumination system further includes a light homogenizing component 101, a first lens 102, a second lens 103 and a plane reflector 104 arranged in sequence. The light homogenizing component 101 can be a light pipe or a fly-eye lens. The light homogenizing component 101, the first lens 102 and the second lens 103 have the same optical axis. After the illumination beam is emitted from the light homogenizing component 101, the first lens 102 and the second lens 103 adjust the angle and shape of the illumination beam, the plane reflector 104 reflects the beam to change the propagation direction of the illumination beam, and the illumination beam after the direction change is emitted to the first surface 11 of the first prism 1, and the first surface 11 further adjusts the angle and shape of the beam, and the illumination beam is totally reflected by the second surface 12 to the light valve 4, and the light valve 4 can control the digital micromirror to rotate the first deflection angle to convert the illumination beam into a projection beam, and the projection beam is emitted from the fifth surface 22 of the second prism 2, and the light valve can also control the digital micromirror to rotate the second deflection angle to convert the illumination beam into a non-projection beam, and the non-projection beam is totally reflected on the eighth surface 32 of the third prism 3 and emitted from the ninth surface. Thus, the optical mechanical lighting system can separate the projection beam and the non-projection beam, so that the two do not overlap, thereby improving the contrast.

[0078] In some embodiments, the absolute value of the first deflection angle is equal to the absolute value of the second deflection angle, and the incident angle of the illumination light beam entering the light valve 4 is equal to twice the absolute value of the first deflection angle.

[0079] The surface of the light valve 4 facing the third surface 13 is its receiving surface, which is parallel to the plane where the light valve 4 is located, and does not represent the reflection surface of the digital micromirror in the light valve 4. The angle between the main light of the illumination light beam and the normal of the receiving surface is the incident angle of the illumination light beam entering the light valve 4. The digital micromirror includes an on state (On state), a flat state (Fkat state) and an off state (Off state), and the corresponding rotation angles are: a first deflection angle, 0°, and a second deflection angle. When the digital micromirror is in the flat state, the reflection surface of the digital micromirror is parallel to the receiving surface of the light valve 4.

[0080] For example, Fig.11 As shown, when the digital micromirror is in a flat state, the corresponding rotation angle is 0°. When the digital micromirror is adjusted to an open state, the digital micromirror is rotated 12° clockwise (i.e., the first deflection angle is +12°). When the digital micromirror is adjusted to a closed state, the digital micromirror is rotated 12° counterclockwise (i.e., the second deflection angle is -12°). The illumination beam emitted by the light source system is controlled to be incident on the light valve 4 at -24°. If the light valve 4 controls the digital micromirror to rotate the first deflection angle of +12°, so that the digital micromirror is in an open state, the angle between the illumination beam and the normal of the digital micromirror is reduced by 12°, i.e., the incident angle of the illumination beam on the reflection surface of the digital micromirror is reduced from 24° to 12°. Since the emission angle is equal to the incident angle, the projection beam after reflection by the digital micromirror is emitted from the 0° direction, i.e., the projection beam is emitted in a direction perpendicular to the plane where the light valve 4 is located. The projection beam is transmitted to the imaging system for projection imaging. If the light valve controls the digital micromirror to rotate to the second deflection angle of -12°, so that the digital micromirror is in the closed state, the angle between the illumination beam and the normal of the digital micromirror increases by 12°, that is, the incident angle of the illumination beam on the reflection surface of the digital micromirror increases from 24° to 36°. Since the emission angle is equal to the incident angle, the non-projection beam reflected by the digital micromirror is emitted from the 48° direction. The emission directions of the non-projection beam and the projection beam are different. The non-projection beam is transmitted to the black field and does not overlap with the projection beam, thereby improving the contrast. When the digital micromirror is in the flat state, the angle between the illumination beam and the normal of the digital micromirror is 24°, the emission angle is equal to the incident angle, and the beam reflected by the digital micromirror is emitted from the 24° direction, which is between the non-projection beam and the projection beam.

[0081] In some embodiments, the illumination beam is incident on the light valve in two ways: bottom edge incident and oblique edge incident. Figure 13-15 As shown, the illumination light beam is incident on the light valve 4 in a bottom edge incident manner, and the incident light is incident along the bottom edge of the light valve 4. Figure 16-18 As shown, the illumination light beam is incident on the light valve 4 in a bevel incident manner, and the incident light is incident along the diagonal (eg, 45°) direction of the light valve 4. The contrast index of the bevel incident is better than the contrast index of the bottom edge incident.

[0082] Among them, the deflection angle of the digital micromirror corresponding to the bottom edge incidence mode is larger, and the deflection angle of the digital micromirror corresponding to the oblique edge incidence mode is smaller. The deflection angle of the digital micromirror has a certain influence on the degree of separation of the projection beam and the non-projection beam. The larger the deflection angle, the greater the distance between the projection beam and the non-projection beam, and the higher the contrast.

[0083] In some embodiments, the light valve 4 comprises a bevel-incidence light valve.

[0084] In this way, the illumination light beam emitted from the third surface 13 of the first prism 1 enters the bevel-incident light valve in a bevel-incident manner, and the illumination light beam is incident along the diagonal direction of the bevel-incident light valve. Compared with the bottom-incident light valve, the optical mechanical illumination system has a higher contrast. Exemplarily, the size of the bevel-incident light valve is 10.368 mm×5.832 mm, and the size of a single digital micromirror is 5.4 μm×5.4 μm.

[0085] In some embodiments, the absolute value of the first deflection angle is equal to 14.5°.

[0086] The rotation angle of the digital micromirror includes a first rotation angle and a second rotation angle, the first rotation angle and the second rotation angle are opposite numbers to each other, the absolute value of the first rotation angle and the absolute value of the second rotation angle are equal, and the first rotation angle is equal to the second rotation angle. DMD Indicates the absolute value of the first rotation angle or the absolute value of the second rotation angle. Combined with the above, the illumination beam must meet the incident condition of the light valve 4: γ = 2 × θ DMD , where γ represents the incident angle of the illumination light beam entering the light valve 4.

[0087] θ DMD =14.5°, then the incident angle γ of the illumination light beam entering the light valve 4 is equal to 29°. Considering the existence of system error, the incident angle γ of the illumination light beam entering the light valve 4 only needs to meet the requirement of 29°±0.5°.

[0088] In some embodiments, Figure 5 As shown, the illumination beam is incident on the second surface 12 at a first angle i, and after being totally reflected by the second surface 12 , the illumination beam is incident on the third surface 13 . The incident angle of the illumination beam on the third surface 13 is θ, and the illumination beam is incident on the light valve 4 through the third surface 13 .

[0089] The material of the first prism 1 is H-K9L glass, the refractive index n1 is 1.5168, and the first angle i satisfies: i≥arcsin(1 / n1)=41.25°;

[0090] In this embodiment, the deflection angle θ of the digital micromirror is DMD=14.5°, the incident angle β of the illumination beam on the third surface 13 can be calculated according to the law of refraction, as follows:

[0091] θ DMD =14.5°;

[0092] sin(θ DMD ) = sinθ × n1;

[0093] After calculation, β = 9.5°;

[0094] According to the formula α=i-β, the angle α between the second surface 12 and the third surface 13 is calculated, and α≥31.74°. At this time, the illumination light beam is totally reflected at the second surface 12. Exemplarily, it is determined that α=33.2470°.

[0095] In some embodiments, Fig.10 As shown, the output angle of the non-projection light beam after reflection by the digital micromirror is θ1; the non-projection light beam enters the first prism 1 through the third surface 13, and the non-projection light beam is refracted on the third surface 13, and the refraction angle is θ2; the non-projection light beam enters the third prism 3 through the second surface 12 and is incident on the eighth surface 32 at a third angle θ3, and the non-projection light beam incident on the eighth surface 32 is totally reflected to the ninth surface 33 and then emitted.

[0096] In this embodiment, the calculation of the angle α between the second surface 12 and the third surface 13 can refer to the above, and will not be repeated here. The specific process of determining the angles of the second prism 2 and the third prism 3 is as follows:

[0097] The non-projection light beam is totally reflected at the eighth surface 32. The material of the third prism 3 is the same as that of the first prism 1, which is also H-K9L glass. Then the refractive index n3 is 1.5168. According to the law of total reflection:

[0098] θ3=θ3'=arcsin(1 / n3)=41.25°;

[0099] θ2=arcsin(sin(θ1) / n);

[0100] θ1=4θ DMD -θ;

[0101] Among them, θ DMD is the deflection angle of the digital micromirror. In this embodiment, θ DMD =14.5°; θ is the opening angle of the illumination beam incident on the light valve 4, that is, the angle between the main ray and the marginal ray in the illumination beam, which is related to the system F / #, θ=arcsin(1÷2F#). Take F / #=2.8 as an example for calculation.

[0102] According to the geometric relationship, it can be obtained that the inclination angle of the eighth surface 32 of the third prism 3 is θ4, and its minimum value θ 4min for:

[0103] θ 4min =θ3-θ2=12.06°;

[0104] θ5 is equal to the angle α of the first prism 1, that is, θ5=α=33.2470°.

[0105] In addition, the angle setting of the third prism 3 also needs to satisfy that the projection light beam can completely pass through the eighth surface 32, and no total reflection occurs on the eighth surface 32. In this case, the following conditions must be met:

[0106] θ1=θ=arcsin(1÷2F#)=10.29°;

[0107] θ2=arcsin(sin(θ1) / n)=6.76°;

[0108] According to the geometric relationship, it can be obtained that the inclination angle of the eighth surface 32 of the third prism 3 is θ4, and its maximum value θ 4max for:

[0109] θ 4max =θ3-θ2=34.49°;

[0110] Therefore, the value range of θ4 is: 12.06°<θ4<34.49°.

[0111] In addition, after the non-projection light beam is totally reflected by the eighth surface 32, the reflected light beam should be as parallel to the second surface 12 of the first prism 1 as possible. This arrangement can minimize the probability of the non-projection light beam entering the imaging system after being scattered or reflected by the structural member. Therefore, according to the geometric relationship, it is obtained that:

[0112] θ6=180°-θ3-θ3'-θ4-θ5;

[0113] The included angle between the seventh face 31 and the ninth face 33 in the third prism 3 can be obtained based on the fact that the sum of the interior angles of a triangle is equal to 180°.

[0114] Since the fifth surface 22 of the second prism 2 is parallel to the receiving surface of the light valve 4, θ4′=θ4;

[0115] According to the geometric relationship, we can get: θ7 = 180° - θ4 - θ5;

[0116] Similarly, the included angle between the fourth face 21 and the fifth face 22 in the second prism 2 can be obtained based on the fact that the sum of the interior angles of a triangle is equal to 180°.

[0117] Exemplarily, θ4=23.3°, θ5=α=33.2470°, θ6=23.3°, θ7=123.45°.

[0118] In some embodiments, the size of the first prism 1 can be determined according to the light spot incident on the first surface.

[0119] Exemplarily, the aperture of the first surface is used as a size index of the first prism 1, and the aperture of the first surface 11 can be calculated according to the following trigonometric law:

[0120] tanα = aperture of the first surface ÷ aperture of the third surface;

[0121] sinα = aperture of the first surface ÷ aperture of the second surface;

[0122] The size of the light spot can be checked through professional software, for example, Fig.19 As shown, the maximum spot aperture = 10.3551 + 9.3551 = 19.7102 mm, a 1 mm margin is reserved on each side of the aperture of the first surface, and the aperture of the first surface should be larger than the corresponding spot aperture, therefore, the aperture of the first surface 11 is determined to be 21.8 mm.

[0123] Similarly, the aperture of the seventh surface can be determined according to the spot size of the non-projection light beam on the seventh surface of the third prism 3, and then the apertures of the eighth and ninth surfaces can be determined according to the trigonometric law mentioned above.

[0124] In some embodiments, the optical mechanical illumination system meets the following conditions: F#=2.8, the size of the light valve is 10.368mm×5.832mm, the incidence mode is bevel incidence, the light spot on the light valve incident surface must meet the following conditions: root mean square radius <0.3mm, geometric radius <0.7mm, the light spot formed by the illumination beam at the light valve is as follows: Fig. 20 As shown. The relative illumination of the incident surface of the light valve is greater than 96%. The maximum chief ray angle of different fields of view is 29.4269° and the minimum is 28.5476°, which meets the requirement that the incident angle of the chief ray of the illumination beam on the light valve is 29°±0.5°.

[0125] Based on the above implementation, an embodiment of the present application also provides a laser projection device, which includes: a light source system, an imaging system and any one of the above optical-mechanical illumination systems, which has corresponding beneficial effects and will not be described here to avoid repetition.

[0126] The light source system is used to provide an illumination beam to the optomechanical illumination system; the optomechanical illumination system is used to modulate the illumination beam provided by the light source system into a projection beam and then emit it to the imaging system; the imaging system is used to image the projection beam and then emit it to the projection screen. The imaging system includes a projection lens.

[0127] For example, Fig.21 As shown, the laser projection device includes a light source system (not shown in the figure), an imaging system 200 and an optical-mechanical illumination system, and the optical-mechanical illumination system includes a light-homogenizing component 101, a first lens 102, a second lens 103, a plane reflector 104, a first prism 1, a second prism 2, a third prism 3 and a light valve 4. The light-homogenizing component 101, the first lens 102 and the second lens 103 are coaxial, the plane reflector 104 is located on the light-emitting side of the second lens 103, and the plane reflector 104 deflects and refracts the illumination light beam emitted by the second lens 103 to the first surface 11 of the first prism 1, and the deflection angle is about 90°. Such a configuration is conducive to reducing the length of the optical-mechanical illumination system in the optical axis direction of the light-homogenizing component 101. The first surface 11 further regulates the angle and shape of the light beam. The illumination light beam is totally reflected by the second surface 12 to the light valve 4. The light valve 4 can control the digital micromirror to rotate at the first deflection angle to convert the illumination light beam into a projection light beam. The projection light beam is emitted from the fifth surface 22 of the second prism 2 and finally incident on the imaging system 200. The light valve 4 can also control the digital micromirror to rotate at the second deflection angle to convert the illumination light beam into a non-projection light beam. The non-projection light beam is totally reflected at the eighth surface 32 of the third prism 3, transmitted in a direction away from the imaging system 200, and finally emitted from the ninth surface. As a result, the optical mechanical illumination system can separate the projection light beam and the non-projection light beam so that the two do not overlap, thereby improving the contrast.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0129] For the convenience of explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations can be obtained. The selection and description of the above embodiments are to better explain the principles and practical applications, so that those skilled in the art can better use the embodiments and various different variations of the embodiments suitable for specific use considerations.

Claims

1. An optical mechanical lighting system, characterized in that: include: A first prism, comprising a first surface, a second surface and a third surface, wherein the first surface is a curved surface, and is used to converge the illumination light beam and adjust the incident angle of the illumination light beam to the second surface; a light valve, located on one side of the third surface and arranged toward the third surface; a second prism located on one side of the second surface, the second prism comprising a fourth surface and a fifth surface connected to the fourth surface, the fourth surface is opposite to the second surface, and the fifth surface is located on a side of the fourth surface away from the second surface; The illumination light beam enters the first prism through the first surface and is incident on the second surface at a first angle. The illumination light beam totally reflected by the second surface is emitted from the third surface to the light valve. The illumination light beam reflected by the light valve becomes a projection light beam. The projection light beam is emitted after passing through the third surface, the second surface, the fourth surface and the fifth surface. The first angle is greater than or equal to a first preset angle.

2. The optical mechanical lighting system according to claim 1, characterized in that: The second prism further includes a sixth surface, and the sixth surface connects the fourth surface and the fifth surface; the optical mechanical lighting system further includes: A third prism comprises a seventh face, an eighth face and a ninth face connected end to end, wherein the seventh face is opposite to the second face, and the eighth face is opposite to the sixth face; Wherein, the light valve includes a digital micromirror, and the light valve is configured to control the digital micromirror to rotate a first deflection angle, so that the illumination light beam incident on the digital micromirror is converted into a projection light beam, and the projection light beam enters the third prism through the third surface, the second surface and the seventh surface, and is incident on the eighth surface at a second angle, and the second angle is less than a second preset angle, and the projection light beam incident on the eighth surface is emitted after passing through the eighth surface, the sixth surface and the fifth surface; The light valve is also configured to control the digital micromirror to rotate to a second deflection angle, so that the illumination light beam incident on the digital micromirror is converted into a non-projection light beam, and the non-projection light beam enters the third prism through the third surface, the second surface and the seventh surface, and is incident on the eighth surface at a third angle, and the third angle is greater than or equal to the second preset angle, and the non-projection light beam incident on the eighth surface is totally reflected and then emitted from the ninth surface.

3. The optical mechanical lighting system according to claim 2, characterized in that: The absolute value of the first deflection angle is equal to the absolute value of the second deflection angle, and the incident angle of the illumination light beam entering the light valve is equal to twice the absolute value of the first deflection angle.

4. The optical mechanical lighting system according to claim 3, characterized in that: The light valve comprises a bevel-incident light valve; and / or, The absolute value of the first deflection angle is equal to 14.5°.

5. The optical mechanical lighting system according to claim 2, characterized in that: The first prism, the second prism and the third prism are prisms made of the same material.

6. The optical mechanical lighting system according to claim 2, characterized in that: There is a gap between the second surface and the fourth surface, and between the eighth surface and the sixth surface; The refractive index of the filling medium in the gap is smaller than the refractive index of the first prism and smaller than the refractive index of the third prism.

7. The optical mechanical lighting system according to claim 6, characterized in that: The width D1 of the gap satisfies: 3 μm≤D1≤5 μm.

8. The optical mechanical lighting system according to claim 2, characterized in that: The first surface protrudes in a direction of the first prism away from the third prism; or, The first surface is recessed toward the first prism and toward the third prism.

9. The optical mechanical lighting system according to any one of claims 1 to 8, characterized in that: The fifth surface is parallel to the receiving surface of the light valve.

10. A laser projection device, characterized in that: include: A light source system, an imaging system, and an optomechanical illumination system as claimed in any one of claims 1 to 9; The light source system is used to provide an illumination beam to the optical mechanical illumination system; The optical mechanical illumination system is used to modulate the illumination light beam provided by the light source system into a projection light beam and then emit it to the imaging system; The imaging system is used for imaging the projection light beam and then emitting it to a projection screen.

Images