WO2024138696A1

WO2024138696A1 - Optical module and projection apparatus using same

Info

Publication number: WO2024138696A1
Application number: PCT/CN2022/144195
Authority: WO
Inventors: 张锦
Original assignee: 成都九天画芯科技有限公司
Priority date: 2022-12-30
Filing date: 2022-12-30
Publication date: 2024-07-04

Abstract

An optical module and a projection apparatus. The optical module comprises: a first optical assembly (1) and a second optical assembly (2) having the same structure as that of the first optical assembly (1), wherein the first optical assembly (1) and the second optical assembly (2) abut against each other and are arranged in a mirror symmetry manner; the first optical assembly (1) comprises: a first collimating light source (11), a second collimating light source (12) and a first light combining structure (13), wherein optical axes of the first collimating light source (11) and the second collimating light source (12) are perpendicular to each other, the first light combining structure (13) is arranged on light emergent surfaces of the first collimating light source (11) and the second collimating light source (12), and included angles between the first light combining structure (13) and the optical axes of the first collimating light source (11) and the second collimating light source (12) are both first preset angles; and emergent light of the first optical assembly (1) and emergent light of the second optical assembly (2) are parallel to each other in the same direction.

Description

Optical module and projection device using the same

Technical Field

The present invention relates to the field of optical technology, and in particular to an optical module and a projection device using the same.

Background technique

With the development of technology, people have put forward higher requirements on the portability of consumer electronic products. Small size and light weight have become an important development direction of the electronics market. Based on this, in optical devices such as projectors, AR (augmented reality), VR (virtual reality), etc., higher design requirements are put forward for the design of optical systems.

In optical devices such as projectors, AR, and VR, it is often necessary to combine multiple colors of light according to functional requirements. Currently, when combining multiple colors of light, various combined filters, x-cubes, x plates, etc. are used. However, these methods have disadvantages such as large size, difficult processing, and high assembly difficulty.

Traditional light combination uses the x-cube method to combine RGB colors into white light.

Referring to FIG1, the existing three-color X-type merging prism (also called x-cube) uses a square X-combined prism, the contact surface in the middle is orthogonal, and the coating is glued. It is common to synthesize white light with RGB red, green and blue light. The filter film on one side reflects blue light and transmits red and green light, and the other side reflects red light and transmits blue and green light. When the RGB three-color light is input into the X-cube from their respective incident surfaces, as shown in the figure, white light is emitted on the surface. It is necessary to shoot at the corresponding filter film at an incident angle of 45°, and the relative aperture of the particles is small. That is, the current use of X-CUBE for light combination, that is, from the light source to the incident surface, a certain optical path and a number of optical devices need to be placed to achieve the corresponding function. When two adjacent X-CUBEs combine light, there is always a surface with limited space due to the optical path, which is a limiting factor affecting the application of this X-CUBE.

Based on the defects of the current three-color prism, some people have proposed the idea of using a double prism for merging, such as the patent number 202111277059.1. This technology, when integrated, requires a light source that has been converged and narrowed, that is, it is an abstract light source; to generate such a light source, sufficient optical path and a certain number of optical devices, as well as the light source itself, are required. In other words, in order to implement this optical path, in addition to the prism assembly, a light source system with optical devices and optical path is also required. In addition, the light from the light source is projected onto the inclined surface, and the filter film transmits the light to the incident surface; the filter film on the surface of the incident surface reflects the light from the light source and projects the light back onto the inclined surface. The filter film on the inclined surface reflects the light and emits it from the exit surface. In other words, this patent requires a complex filter film design; the process difficulty increases, and the cost will be relatively high; reflection from multiple surfaces also leads to a large amount of energy loss.

Secondly, since the optical path of the surface light source is long, the relative aperture of the surface light source is required to be higher, or the other two light sources need to achieve equal optical paths or consistent phases through phase delay plates, etc. The increase in components leads to an increase in costs.

In addition, it can be seen from the above existing technologies that the commonly used light source distribution schemes for LED projectors are reflector cup distribution and lens distribution, but these methods are based on the collection efficiency and light distribution problems under a single light source and one illuminated area. Generally speaking, there are still problems in terms of light source power and multiple illumination areas that cannot be realized, or the cost is high and the design is difficult.

technical problem

The present invention provides an optical module and a projection device using the same, which can overcome the technical problem of complex structure in the prior art.

Technical Solutions

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

An optical module includes: a first optical component and a second optical component, the structure of the first optical component is consistent with the structure of the second optical component, the first optical component and the second optical component are abutted and arranged in mirror symmetry, the first optical component includes: a first collimated light source, a second collimated light source and a first light-combining structure, the optical axes of the first collimated light source and the second collimated light source are perpendicular to each other, the first light-combining structure is arranged on the light-emitting surfaces of the first collimated light source and the second collimated light source, and the first angles between the first collimated light source and the optical axis of the first collimated light source and the optical axis of the second collimated light source are both first preset angles, and the emergent light rays of the first optical component and the second optical component are parallel and in the same direction.

In an optional manner, the second optical component includes: a third collimated light source, a fourth collimated light source and a second light-combining structure, the optical axes of the third collimated light source and the fourth collimated light source are perpendicular to each other, the second light-combining structure is arranged on the light-emitting surfaces of the third collimated light source and the fourth collimated light source, and the angles between the second light-combining structure and the optical axes of the third collimated light source and the fourth collimated light source are both the first preset angle, one end of the first light-combining structure is connected to one end of the second light-combining structure and are perpendicular to each other, the second collimated light source and the third collimated light source are located in the same horizontal plane, and the light-emitting surfaces of the first collimated light source and the fourth collimated light source are opposite.

In an optional manner, the first collimated light source includes: a first light source and a first collimating element arranged on the light exit surface of the first light source, the second collimated light source includes a second light source and a second collimating element arranged on the light exit surface of the second light source, the third collimated light source includes a third light source and a third collimating element arranged on the light exit surface of the third light source, and the fourth collimated light source includes a fourth light source and a fourth collimating element arranged on the light exit surface of the fourth light source.

In an optional manner, the first optical component also includes: a first reflector for reflecting the light of the fourth light source, the second optical component also includes a second reflector for reflecting the light of the first light source, the first reflector and the second reflector are mirror-symmetrical, the first reflector is arranged on the side of the first light source away from the second light source, the second reflector is arranged on the side of the fourth light source away from the third light source, the angle between the first reflector and the optical axis of the first light source and the angle between the second reflector and the optical axis of the fourth light source are both second preset angles, and the second preset angle is 0°~16°.

In an optional manner, the first preset angle is 43°~46°, and/or the second preset angle is 0°~15°.

In an optional manner, the first light-combining structure includes an isosceles right-angle prism, the second light-combining structure includes a second isosceles right-angle prism, the first isosceles right-angle prism includes two first sub-isosceles right-angle prisms with two right-angled sides stacked together, the second isosceles right-angle prism includes two second sub-isosceles right-angle prisms with two right-angled sides stacked together, and the hypotenuses of the first isosceles right-angle prism and the second isosceles right-angle prism are stacked together.

In an optional manner, the first light-combining structure and the second light-combining structure are both right-angle prisms, and the first light-combining structure and the second light-combining structure form a rectangular structure.

In an optional manner, the first light-combining structure and the second light-combining structure are both dichroic lenses to reflect blue light and transmit green light and red light.

In an optional manner, the second light source and the third light source are red-green mixed light sources, and the first light source and the fourth light source are blue light sources; or,

The first light source, the second light source, the third light source and the fourth light source are all blue light sources. A first optical conversion film is respectively arranged between the second light source and the second collimating element and between the third light source and the third collimating element to convert blue light into red and green mixed light.

In an optional manner, the first light-combining structure and the second light-combining structure are both dichroic lenses to reflect green light and transmit blue light and red light.

In an optional manner, the second light source and the third light source are red and blue mixed light sources, and the first light source and the fourth light source are green light sources; or

The first light source, the second light source, the third light source and the fourth light source are all blue light sources. A second optical conversion film is arranged between the second light source and the second collimating element, and between the third light source and the third collimating element, respectively, to convert blue light into red and blue mixed light. A third conversion film is arranged between the first light source and the first collimating element, and between the fourth light source and the fourth collimating element, to convert blue light into green light.

In an optional manner, the first light-combining structure and the second light-combining structure are both dichroic lenses to reflect red light and transmit blue light and green light.

In an optional manner, the first collimating element, the second collimating element, the third collimating element and the fourth collimating element are one of a first lens group or a first microlens array.

In an optional embodiment, the optical module also includes a fixed bracket, which is a square frame, the first light source is fixed to an inner wall of the square frame, the second light source and the third light source are fixed to the upper side wall of the square frame, and the fourth light source is fixed to another inner wall of the square frame opposite to the inner wall.

In an optional manner, bosses are respectively provided at both ends of the upper side wall of the square frame, which are respectively used to fix one end of the first light-combining structure and the second light-combining structure, and the other ends of the first light-combining structure and the second light-combining structure are fixedly connected by a connecting member.

In an optional manner, the optical structure further includes a second lens group or a second microlens array disposed on a side of the connecting member away from the boss.

In an optional manner, a polarization separation component is further provided between the lenses of the second lens group; and/or a stop is further provided on a side of the second lens group away from the second light source.

In an optional manner, a heat sink is respectively disposed between the first light source and the side wall, between the second light source and the third light source and the upper side wall, and between the fourth light source and the other side wall.

An embodiment of the present invention further provides a projection device, which includes: a liquid crystal screen and the above optical module.

Beneficial Effects

Compared with the prior art, the present invention has the following beneficial effects: a first optical component and a second optical component are arranged in a mirror-like manner to achieve collimation and convergence of light, and the light of the first optical component and the second optical component are aggregated together, which has a simple structure and can also increase the light-emitting area and improve the utilization rate of light.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. The drawings described below are only drawings corresponding to some embodiments of the present invention.

FIG1 is a diagram of an existing light combining method;

FIG2 is a structural block diagram of an optical module provided by an embodiment of the present invention;

FIG3 is a schematic diagram showing a partial structure of an optical module provided by an embodiment of the present invention;

FIG4 is a schematic diagram showing a partial structure of an optical module provided by an embodiment of the present invention;

FIG5 is a schematic diagram showing a partial structure of an optical module provided by an embodiment of the present invention;

FIG. 6 is a schematic diagram showing a light combining structure of an optical module provided by an embodiment of the present invention.

Best Mode for Carrying Out the Invention

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

The directional terms mentioned in the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", "top" and "bottom", are only for reference to the orientation of the drawings. The directional terms used are used to illustrate and understand the present invention, not to limit the present invention.

The terms "first", "second", etc. in the present invention are used for descriptive purposes only and should not be understood as indicating or implying relative importance, and should not be used as a limitation on the order of precedence.

In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Embodiment 1:

Please refer to Figure 1, a preferred embodiment of the present invention provides a structural schematic diagram of an optical module, which includes: a first optical component 1 and a second optical component 2, wherein the specific structure of the first optical component 1 is consistent with that of the second optical component 2, and the first optical component 1 and the second optical component 2 are arranged in mirror symmetry, and the outgoing light rays of the first optical component 1 and the second optical component 2 are parallel and in the same direction.

In an embodiment of the present invention, a first optical component and a second optical component are arranged in a mirror-like manner to achieve collimation and convergence of light. The light of the first optical component and the second optical component are aggregated together, the structure is simple, and the light-emitting area can be increased, thereby improving the utilization rate of light.

Embodiment 2:

In a preferred embodiment of the present invention, as shown in FIG2 , the first optical component 1 includes: a first collimated light source 11, a second collimated light source 12 and a first light-combining structure 13, wherein the optical axes of the first collimated light source 11 and the second collimated light source 12 are perpendicular to each other. As shown in FIG2 , the first light-combining structure 13 is arranged on the light-emitting surfaces of the first collimated light source 11 and the second collimated light source 12, and the angles between the first collimated light source 11 and the optical axes of the second collimated light source 12 are both first preset angles.

See Figure 2, the second optical component 2 includes: a third collimated light source 21, a fourth collimated light source 22 and a second light-combining structure 23, wherein the optical axes of the third collimated light source 21 and the fourth collimated light source 22 are perpendicular to each other, the second light-combining structure 23 is arranged on the light-emitting surfaces of the third collimated light source 21 and the fourth collimated light source 22, and the angles between the second light-combining structure 23 and the optical axes of the third collimated light source 21 and the fourth collimated light source 22 are both the first preset angles, further, one end of the first light-combining structure 13 is connected to one end of the second light-combining structure 23 and are perpendicular to each other, further, the second collimated light source 12 and the third collimated light source 22 are located in the same horizontal plane, and the light-emitting surfaces of the first collimated light source 11 and the fourth collimated light source 21 are arranged opposite to each other, as shown in Figure 2. In this embodiment, the first preset angle can be 43°~46°, and more preferably, the first preset angle is 45°. In this embodiment, the angle between the first light-combining structure 13, the second light-combining structure 23 and the optical axis of the light source is set to 45°, which can avoid the transmission and reflection of the light-combining structure from shifting toward short-wavelength light to a certain extent, thereby avoiding color deviation.

It should be noted that the first collimated light source 11, the second collimated light source 12, the third collimated light source 21 and the fourth collimated light source 22 can be ordinary light sources that are collimated and converged by collimating optical elements.

In a preferred embodiment of the present invention, the first collimated light source 11 includes: a first light source 111 and a first collimating element 112 disposed on the light exit surface of the first light source 111; the second collimated light source 12 includes: a second light source 121 and a second collimating element 122 disposed on the light exit surface of the second light source 121; the third collimated light source 21 includes: a third light source 211 and a third collimating element 212 disposed on the light exit surface of the third light source 211; the fourth collimated light source 22 includes: a fourth light source 221 and a fourth collimating element 222 disposed on the light exit surface of the fourth light source 221. The first light source 111, the second light source 121, the third light source 211 and the fourth light source 221 are array-distributed LED chips, and the size of the LED chips may be 2*2, 3*3 or 4*4 (in mm), which is not limited here. Preferably, the size is 4*4. The LED chip is a single-sided light source. In the optical module, the second light source 121 and the third light source 211 can form a larger surface light source. In this embodiment, the first collimating element 112, the second collimating element 122, the third collimating element 211 and the fourth collimating element 222 are preferably aspheric free-form mirrors, which are used to converge the light, that is, the light can be shaped into a square or rectangle, and a nearly rectangular light spot is formed on the light-emitting surface. The size of the light spot satisfies b>0.85a, wherein a represents the long side size of the rectangular light spot, and b represents the short side size of the rectangular light spot. The fixing method of the LED chip can adopt the existing fixing method, which is not limited here.

As shown in Figures 3 to 5, in a preferred embodiment of the present invention, the optical module also includes: a fixed bracket 3, the fixed bracket 3 is a square frame (rectangular or square frame), the first light source 111 is arranged on a side wall of the fixed bracket 3 (such as the left side wall), the second light source 121 and the third light source 211 are both arranged on the upper side wall of the fixed bracket 3, and the fourth light source 221 is arranged on the other inner side wall of the fixed bracket 3 opposite to the left side wall (such as the right side wall).

In a preferred embodiment of the present invention, the first optical component 1 further includes: a first reflector 14 for reflecting the fourth light source 22, and the second optical component 2 further includes: a second reflector 24 for reflecting the light of the first light source 11, the first reflector 14 and the second reflector 24 are arranged in mirror symmetry, the first reflector 14 is arranged on the side of the first light source 111 away from the second light source 121, and the angle between the first reflector 14 and the optical axis of the first light source 111 is a second preset angle, the second reflector 24 is arranged on the side of the fourth light source 221 away from the third light source 211, the second preset angle is 0°~16°, and further, the second preset angle can be 0~15°. In this embodiment, preferably, the second preset angle is 15°.

In this embodiment, a divergence angle a of the light coming out of the lens is defined, and the optimal angle of the divergence angle is 15 degrees.

Define the angle between the reflector and the LCD screen (or the optical axis of the first light source 111) as β, then the reflector will reflect large-angle light (such as light with a divergence angle a) onto the LCD screen. The angle β can be obtained using the following formula:

(52.5°+a/2)>β>a+30°. Since 0°≤a≤16°, 30°＜β＜60.5°. It should be noted that the reflector can select an existing reflector structure, and there is no limitation on this here. The second preset angle is 15°, which can effectively solve the problem of light interference.

In this embodiment, during the subsequent application of the optical module, the light after collimation will still have a certain divergence angle α, and the divergence angle α is controlled to be approximately 0°~16°. In this embodiment, according to experiments, if the angle between the light and the dichroic lens increases from 10 degrees to 70 degrees, the impact on the wavelength of the light will exceed 100nm, which is likely to cause a large change in color. On the other hand, too large an angle is not easy to be collected to illuminate the LCD screen; the divergence angle α is controlled to be no more than 16°; when the light passes through the light combining structure, the wavelength drift of the light will not exceed 30nm. Even if the color changes, it is not easy to be captured intuitively by the eyes, which can avoid visual deviations caused by color changes.

In a preferred mode of the present embodiment, bosses (15 and 25) are respectively provided at both ends of the upper side wall of the square frame, see Figures 3, 4 and 5, the boss 15 is used to fix the first light-combining structure 13, the boss 25 is used to fix the second light-combining structure 23, the second light source 12 and the third light source 21 are fixed to the upper side wall of the square frame, see Figure 2, the first light source 111 is arranged on the left side wall of the fixed square frame, the fourth light source 211 is fixed to the right side wall of the square frame, one end of the first light-combining structure 13 is fixed to the boss 15, and the other end is connected to one end of the second light-combining structure 23, the other end of the second light-combining structure 23 is fixed to the boss 25, the first light-combining structure 13 and the second light-combining structure 23 are fixedly connected by a connecting member 4, the connecting member can be a snap-fitting member, or other structures that can realize the fixed connection function, which is not limited here. The first light-combining structure 13 and the second light-combining structure 23 are perpendicular to each other, an angle between the first light-combining structure 13 and the upper side wall is 45°, and an angle between the second light-combining structure 23 and the upper side wall is also 45°.

In a preferred embodiment of the present invention, the optical structure further comprises a second lens group 5 or a second microlens array disposed on a side of the connector 4 away from the boss 15 (i.e., the upper side wall). In a preferred solution of this embodiment, the lens in the lens group is an aspheric lens with a diameter of 19 mm and a height of 18 mm. In this embodiment, the distance between the first lens group and the second lens group can be 20 to 50 mm.

In a preferred embodiment of the present invention, the second lens group 5 includes a plurality of aspheric lenses arranged in parallel, and a polarization separation component is arranged between the plurality of aspheric lenses for performing polarization conversion.

In a preferred embodiment of the present invention, see FIG. 4 , a stop 6 is further provided on the side of the second lens group 5 away from the second light source 121 (i.e., the upper side wall) to intercept light with a large divergence angle, for example, light with a divergence angle greater than 16° can be intercepted, so that after the light is reflected, the angle between the light and the vertically downward optical axis is also equal to the divergence angle, thereby avoiding the formation of stray light. In this embodiment, the setting of the stop 6 can cut off large-angle light to avoid the formation of stray light.

In a preferred embodiment of the present invention, a heat sink 7 is provided between the first light source 111 and the left side wall, between the second light source 121 and the third light source 211 and the upper side wall, and between the fourth light source 221 and the right side wall. In this embodiment, the light source is directly provided on the heat sink 7, and the heat is transferred out through the heat sink, which can solve the heat dissipation problem, protect the light source to a certain extent, and improve the service life of the light source.

In a preferred embodiment of the present invention, the first light combining structure 13 and the second light combining structure 23 are both right-angle prisms, and the two right-angle prisms form a rectangular structure. In the present embodiment, the two right-angle prisms are both isosceles right-angle prisms.

In another preferred embodiment of the present invention, the first light-combining structure 13 is a first isosceles right-angle prism, the second light-combining structure 23 is a second isosceles right-angle prism, the first isosceles right-angle prism includes two first sub-isosceles right-angle prisms with two right-angle sides stacked, the second isosceles right-angle prism includes two second sub-isosceles right-angle prisms with two right-angle sides stacked, and the hypotenuses of the first isosceles right-angle prism and the second isosceles right-angle prism are stacked. That is, the first light-combining structure 13 and the second light-combining structure 23 are combined to form an X-CUBE light-combining prism. As shown in FIG6 .

Preferably, the first light-combining structure 13 and the second light-combining structure 23 are both dichroic lenses, which can reflect blue light and transmit red light and green light.

In a preferred embodiment of the present invention, the first light source 111, the second light source 121, the third light source 211 and the fourth light source 212 are all blue light sources, and a first optical conversion film (not shown in the figure) is respectively arranged between the second light source 121 and the second collimating element 122, and between the third light source 211 and the third collimating element 212 to convert blue light into red and green mixed light. Among them, the first optical conversion film can be a quantum dot conversion film with red and green quantum dot materials added, or an optical conversion film with red and green phosphor materials added, which is not limited here. Among them, the blue light emitted by the first light source 111 is collimated by the first collimating element 112, and then reflected through the first photosynthetic structure 113. The blue light emitted by the second light source 121 and the third light source 211 is collimated and converged by their respective collimating elements, and then transmitted through the first photosynthetic structure 13 and the second photosynthetic structure 23 respectively. The blue light emitted by the fourth light source 221 is collimated and converged by the fourth collimating element 222, and then reflected through the second light combining structure. The light of the first light source 111, the second light source 121, the third light source 211, and the fourth light source 221 is finally converged together, and the red light, blue light and green light are combined to emit white light.

In a variation of this embodiment, the second light source 121 and the third light source 211 are red and green mixed light sources, and the first light source 111 and the fourth light source 221 are blue light sources.

In another preferred embodiment of the present invention, the first light combining structure 13 and the second light combining structure 23 are both dichroic lenses that can reflect green light and transmit blue light and red light, the second light source 121 and the third light source 211 are red and blue mixed light sources, and the first light source 111 and the fourth light source 221 are green light sources;

In a variation of the present embodiment, the first light source 111, the second light source 121, the third light source 211 and the fourth light source 221 are all blue light sources, and a second optical conversion film (not shown in the figure) is respectively arranged between the second light source 121 and the second collimating element 122, and between the third light source 211 and the third collimating element 212 to convert blue light into red and blue mixed light, and a third optical conversion film (not shown in the figure) is arranged between the first light source 111 and the first collimating element 112, and between the fourth light source 221 and the fourth collimating element 222. As shown), to convert blue light into green light, wherein the second optical conversion film can be a quantum dot film doped with red quantum dots, or a phosphor layer doped with red phosphor, wherein the doping ratio of the red quantum dots or the red phosphor can be determined according to the actual light ratio. Generally speaking, the doping ratio will be relatively low, so that a part of the blue light that does not hit the red quantum dots or the red phosphor is directly emitted, and when it hits the red quantum dots or the red phosphor, it will be converted into red light, thereby obtaining a red and blue mixed light, and the third optical conversion film can be a green light conversion film to convert the incident blue light into green light.

In another preferred embodiment of the present invention, both the first light-combining structure 13 and the second light-combining structure 23 are dichroic lenses to reflect red light and transmit blue light and green light.

Furthermore, the first light source 111 and the fourth light source 221 are red light sources, and the second light source 121 and the third light source 211 are blue-green mixed color light sources.

In a variation of the present embodiment, the first light source 111, the second light source 121, the third light source 211 and the fourth light source 221 are all blue light sources, and a fourth optical conversion film (not shown in the figure) is respectively arranged between the first light source 111 and the first collimating element 112, and between the fourth light source 221 and the fourth collimating element 222 to convert blue light into red light, and a fifth optical conversion film (not shown in the figure) is arranged between the second light source 121 and the second collimating element 122, and between the third light source 211 and the third collimating element 212 to convert Blue light is converted into blue-green mixed light, wherein the fourth optical conversion film can be a red light conversion film, which can directly convert blue light into red light, and the fifth optical conversion film can be a quantum dot film doped with green quantum dot material, or a phosphor layer doped with green phosphor material, wherein the incorporation ratio of the green quantum dots or green phosphors can be determined according to the actual light ratio. Generally speaking, the incorporation ratio will be relatively low, so that a part of the blue light that has not hit the green quantum dots or green phosphors is directly emitted, and will be converted into green light when it hits the green quantum dots or green phosphors, thereby obtaining a blue-green mixed light.

Specifically, the blue light emitted by the first light source 111 passes through the fourth optical conversion film to obtain red light, and the red light is incident on the first collimating element 112 for light collimation and convergence, and then is incident on the first light combining structure 13 for red light reflection, and finally emitted vertically and horizontally; the blue light emitted by the second light source 121 and the third light source 211 passes through the fifth optical conversion film to convert the blue light into blue-green light, and then passes through the second collimating element 122 and the third collimating element 212 respectively for light convergence and collimation, and is emitted to the corresponding first The light combining structure 13 and the second light combining structure 23 project light, and finally emit it vertically to the horizontal plane; the blue light emitted by the fourth light source 221 passes through the fourth optical conversion film to obtain red light, and then enters the fourth light combining structure 23 to reflect the red light, and finally emits it vertically to the horizontal plane, and then the light emitted by the first light source 111, the second light source 121, the third light source 211, and the fourth light source 221 is converted, collimated, transmitted or reflected, and then emitted in the direction of the optical axis of the first light source 111, so as to achieve the mixing of blue-green light and red light, and finally emit white light. In this embodiment, preferably, the mixing ratio of the blue light, red light, and green light can be 1:3:8, and the color temperature of this mixing ratio is higher, and it has a relatively balanced white balance.

It should be noted that a corresponding optical conversion film may be provided on the side of the corresponding collimating element away from the corresponding light source. For example, an optical conversion film may be provided on the side of the first collimating element 112 away from the first light source 111 to achieve light conversion. This is not limited here.

In the embodiment of the present invention, a first optical component and a second optical component are arranged in a mirror-like manner to achieve collimation and convergence of light. The light of the first optical component and the second optical component are aggregated together to increase the light-emitting area and improve the utilization rate of light.

Secondly, setting up mutually perpendicular light-combining structures to reflect or transmit light can effectively achieve the mixing of RGB light. By mixing multiple light sources, the difficulty of making circuit substrates for RGB light sources can be reduced, and the effect of evenly mixing light sources is improved without producing color spots. Since the RGB light sources have different sensitivities to temperature, they can be driven by different colors, and the heat dissipation of light sources of specific colors can be considered separately, thereby maintaining better lighting effects.

Furthermore, by arranging reflectors below the first light source and the fourth light source, the central light can be increased, the edge light can be reduced, interference can be avoided, and the luminous brightness and uniformity can be improved.

Furthermore, using multiple light sources to collimate an LCD screen reduces the demand for optical extension of a single light source and improves the utilization rate of the light source.

Based on the above embodiments, the present invention further proposes a projection device, which includes a liquid crystal screen and an optical module. The optical module is applied to the projection device, and the liquid crystal screen is arranged on the light-emitting surface of the optical module. The specific structure, working principle and technical effects brought about by the optical module are consistent with the description of the above embodiments and will not be repeated here.

In this embodiment, when RGB light sources are used, the wavelength of the R light source is 620nm, the wavelength of the G light source is 560nm, and the wavelength of the B light source is 455nm. The distance from the RB light source to the display screen is 45mm, and the distance from the G light source to the display screen is 55mm. The LCD screen can use an existing LCD screen, and there is no limitation on this.

In summary, although the present invention has been disclosed as above in terms of preferred embodiments, the above preferred embodiments are not intended to limit the present invention. A person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

An optical module, characterized in that it includes: a first optical component and a second optical component, the structure of the first optical component is consistent with the structure of the second optical component, the first optical component and the second optical component are abutted and arranged in mirror symmetry, the first optical component includes: a first collimated light source, a second collimated light source and a first light-combining structure, the optical axes of the first collimated light source and the second collimated light source are perpendicular to each other, the first light-combining structure is arranged on the light-emitting surfaces of the first collimated light source and the second collimated light source, and the angles between the first light-combining structure and the optical axes of the first collimated light source and the second collimated light source are both first preset angles, and the emergent light rays of the first optical component and the second optical component are parallel and in the same direction.
The optical module according to claim 1 is characterized in that the second optical component includes: a third collimated light source, a fourth collimated light source and a second light-combining structure, the optical axes of the third collimated light source and the fourth collimated light source are perpendicular to each other, the second light-combining structure is arranged on the light-emitting surfaces of the third collimated light source and the fourth collimated light source, and the angles between the second light-combining structure and the optical axes of the third collimated light source and the fourth collimated light source are both the first preset angle, one end of the first light-combining structure is connected to one end of the second light-combining structure and are perpendicular to each other, the second collimated light source and the third collimated light source are located in the same horizontal plane, and the light-emitting surfaces of the first collimated light source and the fourth collimated light source are opposite.
The optical module according to claim 1 or 2 is characterized in that the first collimated light source includes: a first light source and a first collimating element arranged on the light emitting surface of the first light source, the second collimated light source includes a second light source and a second collimating element arranged on the light emitting surface of the second light source, the third collimated light source includes a third light source and a third collimating element arranged on the light emitting surface of the third light source, and the fourth collimated light source includes a fourth light source and a fourth collimating element arranged on the light emitting surface of the fourth light source.
The optical module according to claim 3 is characterized in that the first optical component also includes: a first reflector for reflecting the light of the fourth light source, the second optical component also includes a second reflector for reflecting the light of the first light source, the first reflector and the second reflector are mirror-symmetrical, the first reflector is arranged on the side of the first light source away from the second light source, the second reflector is arranged on the side of the fourth light source away from the third light source, the angle between the first reflector and the optical axis of the first light source and the angle between the second reflector and the optical axis of the fourth light source are both second preset angles, and the second preset angle is 0~16.
The optical module according to claim 4, characterized in that the first preset angle is 43~46, and/or the second preset angle is 0~15.
The optical module according to any one of claims 2 to 5 is characterized in that the first light-combining structure includes an isosceles right-angle prism, the second light-combining structure includes a second isosceles right-angle prism, the first isosceles right-angle prism includes two first sub-isosceles right-angle prisms with two right-angle sides stacked, the second isosceles right-angle prism includes two second sub-isosceles right-angle prisms with two right-angle sides stacked, and the hypotenuses of the first isosceles right-angle prism and the second isosceles right-angle prism are stacked.
The optical module according to any one of claims 2 to 5 is characterized in that the first light-combining structure and the second light-combining structure are both right-angle prisms, and the first light-combining structure and the second light-combining structure form a rectangular structure.
The optical module according to any one of claims 2 to 5 is characterized in that the first light-combining structure and the second light-combining structure are both dichroic lenses to reflect blue light and transmit green light and red light.
The optical module according to claim 8, characterized in that the second light source and the third light source are red-green mixed light sources, and the first light source and the fourth light source are blue light sources; or,

The first light source, the second light source, the third light source and the fourth light source are all blue light sources. A first optical conversion film is respectively arranged between the second light source and the second collimating element and between the third light source and the third collimating element to convert blue light into red and green mixed light.
The optical module according to any one of claims 2 to 5 is characterized in that the first light-combining structure and the second light-combining structure are both dichroic lenses to reflect green light and transmit blue light and red light.
The optical module according to claim 10, characterized in that the second light source and the third light source are red and blue mixed light sources, and the first light source and the fourth light source are green light sources; or

The first light source, the second light source, the third light source and the fourth light source are all blue light sources. A second optical conversion film is arranged between the second light source and the second collimating element, and between the third light source and the third collimating element, respectively, to convert blue light into red and blue mixed light. A third conversion film is arranged between the first light source and the first collimating element, and between the fourth light source and the fourth collimating element, to convert blue light into green light.
The optical module according to any one of claims 2 to 5 is characterized in that the first light-combining structure and the second light-combining structure are both dichroic lenses to reflect red light and transmit blue light and green light.
The optical module according to claim 12, characterized in that the first light source and the fourth light source are red light sources, and the second light source and the third light source are blue-green mixed light sources; or

The first light source, the second light source, the third light source and the fourth light source are all blue light sources. A fourth optical conversion film is respectively arranged between the first light source and the first collimating element and between the fourth light source and the fourth collimating element to convert blue light into red light. A fifth optical conversion film is arranged between the second light source and the second collimating element and between the third light source and the third collimating element to convert blue light into blue-green mixed light.
The optical module according to claim 2, characterized in that the first collimating element, the second collimating element, the third collimating element and the fourth collimating element are one of a first lens group or a first microlens array.
The optical module according to claim 3 is characterized in that the optical module also includes a fixed bracket, the fixed bracket is a square frame, the first light source is fixed to an inner wall of the square frame, the second light source and the third light source are fixed to the upper side wall of the square frame, and the fourth light source is fixed to another inner wall of the square frame opposite to the inner wall.
The optical module according to claim 15 is characterized in that bosses are respectively provided at both ends of the upper side wall of the square frame, which are respectively used to fix one end of the first light-combining structure and the second light-combining structure, and the other ends of the first light-combining structure and the second light-combining structure are fixedly connected by a connecting member.
The optical module according to claim 15 is characterized in that the optical structure also includes a second lens group or a second microlens array arranged on a side of the connecting member away from the boss.
The optical module according to claim 17 is characterized in that a polarization separation component is further provided between the lenses of the second lens group; and/or a stop is further provided on the side of the second lens group away from the second light source.
The optical module according to claim 15 is characterized in that a heat sink is respectively arranged between the first light source and the side wall, between the second light source and the third light source and the upper side wall, and between the fourth light source and the other side wall.
A projection device, characterized in that it comprises a liquid crystal screen and the optical module according to any one of claims 1 to 19, wherein the liquid crystal screen is arranged on a light emitting surface of the optical module.