Prism module manufacturing method, prism module and projection device

Abstract

A method for manufacturing a prism module includes the following steps: adjusting a predetermined temperature difference between a first prism and a second prism; and partially connecting an adhesive layer between the first prism and the second prism to provide a gap between the first prism and the second prism, wherein the adhesive layer includes an adhesive material and a plurality of spacers disposed within the adhesive material. The present invention also provides a prism module and a projection device having the prism module. The prism module and its manufacturing method of the present invention avoid interference issues within the prism module, thereby improving the image quality and reliability of the projection device of the present invention.

Description

Technical Field

[0001] The present invention relates to an optical element and a manufacturing method thereof, in particular to a prism module and a manufacturing method thereof, and a projection device having the prism module. Background Art

[0002] The projection device mainly includes an illumination system, a light valve and a projection lens. The illumination system is used to provide an illumination beam, the light valve is used to convert the illumination beam into an image beam, and the projection lens is used to project the image beam onto a screen to generate an image on the screen.

[0003] In conventional technology, some projection devices incorporate a prism module between the illumination system, light valve, and projection lens. This reflects the illumination beam generated by the illumination system toward the light valve, which then transmits the image beam generated by the light valve through the prism module to the projection lens. The prism module primarily consists of a first prism and a second prism bonded together by an adhesive layer, with an air gap between the first and second prisms. However, during operation, projection devices using this type of prism module can easily experience image beam interference variations within the prism module due to variations in the air gap, resulting in poor image quality.

[0004] This "Background" section is intended solely to facilitate understanding of the present invention. Therefore, the information disclosed in this section may contain information that is not generally known to those skilled in the art. Furthermore, the information disclosed in this section does not represent the problems to be solved by the present invention or one or more embodiments, nor does it imply that the information was known or understood by those skilled in the art prior to the filing of this application. Summary of the Invention

[0005] The present invention provides a method for manufacturing a prism module to improve the interference problem in the prism module.

[0006] The present invention provides a prism module to improve the interference problem.

[0007] The present invention provides a projection device to provide good image quality.

[0008] Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

[0009] To achieve one, some, or all of the above-mentioned objectives, or other objectives, the present invention provides a method for manufacturing a prism module, including the following steps: adjusting a predetermined temperature difference between a first prism and a second prism; and partially connecting the first prism and the second prism with an adhesive layer to provide a gap between the first prism and the second prism, wherein the adhesive layer includes an adhesive material and a plurality of spacers disposed within the adhesive material.

[0010] To achieve one, some, or all of the above-mentioned objectives, or other objectives, the present invention provides a prism module comprising a first prism, a second prism, and an adhesive layer. The first prism has a first surface. The second prism has a second surface opposite the first surface. The adhesive layer is partially connected between the first and second surfaces, and a gap is formed between the first and second surfaces. The adhesive layer comprises an adhesive material and a plurality of spacers disposed within the adhesive material.

[0011] To achieve one, some, or all of the above-mentioned objectives or other objectives, the projection device provided by the present invention includes an illumination system, a light valve, a projection lens, and the above-mentioned prism module. The illumination system can provide an illumination beam. The light valve is located in the transmission path of the illumination beam and can convert the illumination beam into an image beam. The projection lens is located in the transmission path of the image beam and can project the image beam. The prism module is disposed between the illumination system, the light valve, and the projection lens, wherein the first surface of the first prism of the prism module can reflect the illumination beam to the light valve, and the image beam is transmitted to the projection lens through the first surface and the second surface.

[0012] The prism module and its manufacturing method of the present invention utilize an adhesive layer with spacers, thereby making it easier to maintain a consistent gap between the first prism and the second prism, thereby avoiding interference within the prism module. Furthermore, the projection device of the present invention utilizes this prism module, resulting in better image quality.

[0013] In order to make the above and other objects, features and advantages of the present invention more clearly understood, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 FIG. 4 is a schematic diagram of a prism module according to an embodiment of the present invention.

[0015] Figure 2 FIG. 4 is a flow chart of a method for manufacturing a prism module according to an embodiment of the present invention.

[0016] Figure 3 yes Figure 2 Schematic diagram of step S2 in .

[0017] Figure 4 yes Figure 2 Schematic diagram of step S3 in .

[0018] Figure 5 yes Figure 4 An enlarged schematic diagram of the adhesive layer.

[0019] Figure 6 yes Figure 3 An enlarged schematic diagram of the adhesive layer.

[0020] Figure 7 FIG. 1 is a schematic diagram of a projection device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The foregoing and other technical aspects, features, and functions of the present invention are clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. Directional terms such as up, down, left, right, front, and back, used in the following embodiments, are intended solely to refer to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrative purposes only and are not intended to limit the present invention.

[0022] In order to reduce the interference variation produced by the prism module, the inventors of this case conducted in-depth research and found that it was related to the change in the distance between the first prism and the second prism of the prism module. Furthermore, when in the working state, the temperature of the first prism and the second prism will rise. The above temperature is higher than the temperature of manufacturing the prism module. The inconsistent temperature generates stress, which causes the image to have stripes. In addition, the temperature difference between the first prism and the second prism causes the two prisms to expand to different degrees, resulting in the inability to maintain a consistent distance between the first prism and the second prism. The present invention proposes an improvement solution for this, which will be described in detail below. In addition, the working state is defined as when the projection device is started and the light beam is irradiated on the prism module.

[0023] Figure 1 is a schematic diagram of a prism module according to an embodiment of the present invention. Figure 1 and Figure 7 The prism module 100 can be used in a projection device and includes a first prism 110, a second prism 120, and an adhesive layer 130. The first prism 110 has a first surface 111. The second prism 120 has a second surface 121 opposite to the first surface 111. The adhesive layer 130 is partially connected between the first surface 111 and the second surface 121, and a gap G is defined between the first surface 111 and the second surface 121. The adhesive layer 130 includes an adhesive material 131 and a plurality of spacers 132 disposed within the adhesive material 131. Air is contained in the gap G.

[0024] The first prism 110 and the second prism 120 are, for example, both triangular prisms, and the first surface 111 can be a rectangular surface of the first prism 110, and the second surface 121 can also be a rectangular surface of the second prism 120. In addition, the second prism 120 of this embodiment can also have a third surface 122 adjacent to the second surface 121, and the third surface 122 is provided with a light absorbing layer A. The light absorbing layer A is used to absorb stray light beams generated by the light valve of the projection device, so that when the projection device is operating, the temperature of the second prism 120 will be higher than that of the first prism 110. The light absorbing layer A includes, for example, a black coating layer, but this embodiment is not limited thereto. In addition, the third surface 122 can be a rectangular surface of the second prism 120, but this embodiment is still not limited thereto. According to another embodiment of the present invention, the first surface 111, the second surface 121, and the third surface 122 can be, for example, polished surfaces. According to another embodiment of the present invention, the first surface 111 , the second surface 121 , and the third surface 122 may include an optical film, such as an anti-reflection film.

[0025] The spacer 132 is located between the first surface 111 and the second surface 121 so that the gap G between the first surface 111 and the second surface 121 can maintain a consistent width. Further discussing the relationship between the spacer 132 and the adhesive layer 130, if the spacer 132 occupies too small a volume ratio of the adhesive layer 130, it will result in insufficient support force of the adhesive layer 130, which in turn will result in insufficient adhesion of the adhesive layer 130. Therefore, the spacer 132 of this embodiment may occupy approximately 0.7% to 11.3% of the volume of the adhesive layer 130 to balance the support strength and adhesion strength of the adhesive layer 130. The shape of the spacer 132 is, for example, granular, and the diameter D of each spacer 132 is, for example, between 3.5 μm and 12.0 μm, but the present invention is not limited thereto. In addition, the material of the spacer 132 may include silicon dioxide, a polymer, a metal, or a combination thereof, but the present invention is still not limited thereto. Incidentally, in this embodiment, the adhesive material 131 of the adhesive layer 130 may include ultraviolet curing adhesive (UV adhesive), thermosetting adhesive, or thermosetting ultraviolet curing adhesive (thermosetting UV adhesive), but other embodiments are not limited thereto. The minimum width of the gap G between the first surface 111 and the second surface 121 is equal to the diameter D of the spacer 132, for example, ranging from 3.5 μm to 12.0 μm.

[0026] Because the prism module 100 of this embodiment utilizes the adhesive layer 130 having the spacer 132, during operation of the projection device, even if the first prism 110 and the second prism 120 expand to different degrees due to temperature differences, the gap G between the first surface 111 and the second surface 121 can maintain a consistent width without causing a change in the air gap, thereby alleviating interference issues.

[0027] Furthermore, the inventors of this invention have discovered that the different degrees of thermal expansion of the first prism 110 and the second prism 120 can generate stress, potentially posing a risk of cracking the first prism 110 and the second prism 120. Furthermore, the adhesive layer 130 loses its adhesion at high temperatures. Therefore, when the first prism 110 and the second prism 120 expand differently, the adhesive layer 130 can pull against the first prism 110 and the second prism 120, potentially causing the first prism 110 and the second prism 120 to separate. To address this issue, the present invention further proposes a method for manufacturing a prism module.

[0028] Figure 2 FIG. 4 is a flow chart of a method for manufacturing a prism module according to an embodiment of the present invention. Figure 3 yes Figure 2 Schematic diagram of step S2 in . Please refer to Figure 2 and Figure 3 , the manufacturing method of the prism module includes the following steps. Step S1: Adjust the first prism 110 and the second prism 120 to have a predetermined temperature difference. In detail, adjust the temperature of the second prism 120 to be higher than the temperature of the first prism 110. Further, step S1 can be completed by heating the second prism 120 and / or cooling the first prism 110, wherein the aforementioned heating treatment can be performed by an oven, but this embodiment is not limited to this. The aforementioned predetermined temperature difference may be determined according to the temperature difference between the first prism 110 and the second prism 120 when they are in a working state, and the predetermined temperature difference of this embodiment is, for example, between 2°C and 80°C, but other embodiments are not limited to this. According to another embodiment of the present invention, the aforementioned predetermined temperature difference is preferably equal to the temperature difference between the first prism 110 and the second prism 120 when they are in a working state.

[0029] Next, step S2: An adhesive layer 130 is partially connected between the first prism 110 and the second prism 120, so that a gap G is formed between the first prism 110 and the second prism 120. The adhesive layer 130 includes an adhesive material 131 and a plurality of spacers 132 disposed within the adhesive material 131. The specific placement of the adhesive layer 130 can be adjusted according to the optical path and is not limited to the position shown in the figure. The adhesive layer 130 is positioned so as not to block the path of the light beam.

[0030] Because step S2 involves bonding the first prism 110 and the second prism 120 with the adhesive layer 130 while there is a predetermined temperature difference between the first prism 110 and the second prism 120, the adhesive layer 130 is less susceptible to being pulled by the first prism 110 and the second prism 120 during this temperature difference, and the first prism 110 and the second prism 120 are not at risk of breaking due to stress. This prevents the prisms from breaking due to stress caused by the temperature difference between the first prism 110 and the second prism 120 during operation. When the prism module 100a manufactured using the prism module manufacturing method of this embodiment is in operation, the stress to which the adhesive layer 130 is subjected can be less than 2200 kPa, or even less than 1100 kPa, thereby preventing the first prism 110 and the second prism 120 from separating from each other.

[0031] Figure 4 yes Figure 2 Schematic diagram of step S3 in . Figure 5 yes Figure 4 Please refer to the enlarged diagram of the adhesive layer. Figure 2 、 Figure 4 and Figure 5 , after step S2, the manufacturing method of the prism module may further include step S3: restoring the first prism 110 and the second prism 120 to the ambient temperature. This ambient temperature is lower than the temperature when the prism module 100a is in the working state. For example, the ambient temperature is, for example, about 20°C, and the working temperature in the working state may be between 60°C and 150°C. If the second prism 120 is heated in step S1, the second prism 120 will shrink due to the temperature drop during the process of returning to the ambient temperature; if the first prism 110 is cooled in step S1, the first prism 110 will expand due to the temperature rise during the process of returning to the ambient temperature. Therefore, in step S3, the adhesive layer 130 will be pulled and deformed due to the expansion of the first prism 110 and / or the contraction of the second prism 120; for example, Figure 4 The shape of the adhesive layer 130 shown is caused by the contraction of the second prism 120. However, since the ambient temperature is lower than the working temperature, the adhesive layer 130 at the ambient temperature has better adhesion than the adhesive layer 130 at the working temperature, even if Figure 5 As shown, even if the adhesive layer 130 is tilted due to stress, there is no risk of the first prism 110 and the second prism 120 being separated from each other.

[0032] Please refer to Figure 2 and Figure 5 , Figure 5The adhesive layer 130 shown may have a first adhesive surface A1 and a second adhesive surface A2, wherein the first adhesive surface A1 contacts the first surface 111, and the second adhesive surface A2 contacts the second surface 121. Figure 2 In step S2 and step S3, the overlap ratio of the first adhesive surface A1 and the second adhesive surface A2 will be different. The overlap ratio is defined as the ratio of the overlapping area of ​​the first adhesive surface A1 and the second adhesive surface A2 of the adhesive layer 130 along the normal direction of the first surface 111 of the first prism 110. Specifically, in step S3, the adhesive layer 130 is pulled and deformed due to the expansion of the first prism 110 and / or the contraction of the second prism 120. At this time, the overlap ratio between the first adhesive surface A1 and the second adhesive surface A2 is P1. In addition, please refer to Figure 2 and Figure 6 ,exist Figure 2 In step S2, the adhesive layer 130 is not pulled by the first prism 110 and the second prism 120. At this time, the overlap rate between the first adhesive surface A1 and the second adhesive surface A2 is P2, and P2 is greater than P1. The difference between P2 and P1 is, for example, approximately 0.1%, but other embodiments are not limited thereto. In addition, when in operation, due to the temperature difference between the first prism 110 and the second prism 120, the adhesive layer 130 is pulled and deformed to a lesser extent due to the expansion of the first prism 110 and / or the contraction of the second prism 120 than when it returns to ambient temperature. Therefore, the overlap rate between the first adhesive surface A1 and the second adhesive surface A2 is also greater than P1, so that the first prism 110 and the second prism 120 can effectively avoid interference problems.

[0033] Figure 7 This is a schematic diagram of a projection device according to an embodiment of the present invention. Figure 7 The projection device 200 includes an illumination system 210, a light valve 220, a projection lens 230, and the aforementioned prism module 100, wherein the prism module 100 may also be replaced with the aforementioned prism module 100a (shown in FIG. Figure 3 and Figure 4 The lighting system 210 can provide an illumination beam L1. The light valve 220 is located in the transmission path of the illumination beam L1 and can convert the illumination beam L1 into an image beam Li. The projection lens 230 is located in the transmission path of the image beam Li and can project the image beam Li out of the projection device 200. The prism module 100 is disposed between the lighting system 210, the light valve 220, and the projection lens 230. The first surface 111 of the first prism 110 of the prism module 100 can reflect the illumination beam L1 toward the light valve 220, while the image beam Li is transmitted to the projection lens 230 through the first surface 111 and the second surface 121. Furthermore, in the transmission path of the image beam Li, the prism module 100 is disposed between the light valve 220 and the projection lens 230.

[0034] The lighting system 210 may include a light source. Such light sources may include an ultrahigh-pressure mercury lamp (UHP lamp), a xenon lamp, a light-emitting diode (LED), or a laser diode (LD). Specifically, the number of ultrahigh-pressure mercury lamps and xenon lamps may be, for example, one. Alternatively, the number of light-emitting diodes or laser diodes may be one or more. For example, when there are multiple light-emitting diodes (or laser diodes), the light-emitting diodes (or laser diodes) may be arranged in a matrix. Furthermore, in embodiments where the light source includes a light-emitting diode or a laser diode, the lighting system 210 may further include a wavelength conversion element (e.g., a phosphor wheel). The wavelength conversion element may receive the excitation light beam provided by the laser diode and convert it into a color light of a different wavelength from the excitation light beam, thereby further forming an image.

[0035] In this embodiment, the light valve 220 is, for example, a digital micromirror device (DMD) to generate the image beam Li and the off-state beam Ls (referred to as the stray beam previously). Specifically, the image beam Li may first be incident on the first prism 110 and, after passing through the first surface 111 and the second surface 121, be emitted from the fourth surface 123 of the second prism 120 to the projection lens 230. Meanwhile, the off-state beam Ls may be incident on the light-absorbing layer A on the third surface 122 of the second prism 120. The adhesive layer 130 of the prism module 100 may be positioned offset from the light beam to prevent cracking of the adhesive layer 130 due to excessive temperature. In other embodiments, the light valve 220 may be a liquid crystal on silicon (LCoS) or liquid crystal display (LCD) panel. Furthermore, this embodiment does not limit the number of light valves 220. For example, other embodiments may adopt a single-chip LCD panel or a three-chip LCD panel structure, but are not limited thereto. The light paths of the image beam Li and the closed-state beam Ls may also vary depending on the type of the light valve 220 .

[0036] Projection lens 230, for example, includes one or more optical lenses, each of which may have the same or different refractive powers. For example, the optical lenses may include various non-planar lenses, such as biconcave lenses, biconvex lenses, concave-convex lenses, convex-concave lenses, plano-convex lenses, and plano-concave lenses, or any combination of these non-planar lenses. Alternatively, projection lens 230 may include a planar optical lens. The present invention does not impose any restrictions on the specific structure of projection lens 230.

[0037] Since the prism module 100 or 100 a used in the projection device of this embodiment can effectively avoid the problem of interference, it has better image quality.

[0038] In summary, the present invention has at least the following advantages:

[0039] 1. In the prism module and its manufacturing method of the present invention, the use of an adhesive layer with spacers makes it easier to maintain a consistent gap between the first prism and the second prism, thereby avoiding interference problems within the prism module and improving the image quality of the projection device of the present invention.

[0040] 2. In the manufacturing method of the prism module of the present invention, the first prism and the second prism are adhered to each other by an adhesive layer when there is a predetermined temperature difference between the first prism and the second prism. This can avoid the risk of the first prism and the second prism being broken or separated from each other during operation, thereby improving the reliability of the projection device of the present invention.

[0041] The above description is only a preferred embodiment of the present invention, and it cannot be used to limit the scope of implementation of the present invention. That is, all simple equivalent changes and modifications made in accordance with the claims of the present invention and the content of the invention description are still within the scope of the patent of the present invention. In addition, any embodiment or claim of the present invention is not required to achieve all the purposes, advantages or features disclosed by the present invention. In addition, the abstract and title are only used to assist in searching patent documents and are not used to limit the scope of rights of the present invention. In addition, the terms "first", "second", etc. mentioned in this specification or claims are only used to name the name of the element or to distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

[0042] Description of Reference Numerals

[0043] 100, 100a: Prism module

[0044] 110: First Prism

[0045] 111: first surface

[0046] 120: Second prism

[0047] 121: Second surface

[0048] 122: Third surface

[0049] 123: Fourth Surface

[0050] 130: Adhesive layer

[0051] 131: Rubber

[0052] 132: Interstitial

[0053] 200: Projection device

[0054] 210: Lighting System

[0055] 220: Light Valve

[0056] 230: Projection lens

[0057] A: Light-absorbing layer

[0058] A1: First adhesive surface

[0059] A2: Second adhesive surface

[0060] D: diameter

[0061] G: Gap

[0062] L1: illumination beam

[0063] Li: Image beam

[0064] Ls: Closed state beam

[0065] S1, S2, S3: steps.

Claims

1. A method for manufacturing a prism module, characterized in that: The method comprises: adjusting the first prism and the second prism to have a predetermined temperature difference; and An adhesive layer is used to partially connect the first prism and the second prism so that a gap exists between the first prism and the second prism, wherein the adhesive layer includes glue and a plurality of spacers disposed in the glue.

2. The method for manufacturing a prism module according to claim 1, wherein: The method of adjusting the first prism and the second prism to have the predetermined temperature difference includes: The second prism is heated and / or the first prism is cooled.

3. The method for manufacturing a prism module according to claim 2, wherein: The first prism has a first surface, the second prism has a second surface opposite to the first surface, the adhesive layer is partially connected between the first surface and the second surface, and the second prism also has a third surface adjacent to the second surface, and the third surface is provided with a light absorbing layer.

4. The method for manufacturing a prism module according to claim 1, wherein: The predetermined temperature difference is between 2°C and 80°C.

5. The method for manufacturing a prism module according to claim 1, wherein: After the step of locally connecting the first prism and the second prism using the adhesive layer, the method further includes: The first prism and the second prism are restored to ambient temperature.

6. The method for manufacturing a prism module according to claim 1, wherein: The adhesive material includes UV adhesive or thermosetting adhesive.

7. The method for manufacturing a prism module according to claim 6, wherein: The adhesive material includes thermosetting UV adhesive.

8. The method for manufacturing a prism module according to claim 1, wherein: The plurality of spacers occupy 0.7% to 11.3% of the volume of the adhesive layer.

9. The method for manufacturing a prism module according to claim 1, wherein: The materials of the plurality of spacers include silicon dioxide, high molecular polymer, metal or a combination thereof.

10. The method for manufacturing a prism module according to claim 1, wherein: A diameter of each of the plurality of spacers is between 3.5 μm and 12.0 μm.

11. A prism module, characterized in that: The prism module includes a first prism, a second prism, and an adhesive layer, wherein: The first prism has a first surface; The second prism has a second surface opposite to the first surface; and The adhesive layer is partially connected between the first surface and the second surface, and a gap is formed between the first surface and the second surface, wherein the adhesive layer includes an adhesive material and a plurality of gaps disposed in the adhesive material; The adhesive layer has a first adhesive surface and a second adhesive surface, the first adhesive surface contacts the first surface and the second adhesive surface contacts the second surface, when there is no temperature difference between the first prism and the second prism, the overlap rate between the first adhesive surface and the second adhesive surface is P1, when there is a temperature difference between the first prism and the second prism, the overlap rate between the first adhesive surface and the second adhesive surface is P2, and P2 is greater than P1.

12. The prism module according to claim 11, wherein: When the prism module is applied to a projection device and is in a working state, the stress borne by the adhesive layer is less than 2200 kPa.

13. The prism module according to claim 11, wherein: When the prism module is applied to a projection device and is in a working state, the stress borne by the adhesive layer is less than 1100 kPa.

14. The prism module according to claim 11, wherein: The materials of the plurality of spacers include silicon dioxide, high molecular polymer, metal or a combination thereof.

15. The prism module according to claim 11, wherein: The plurality of spacers occupy 0.7% to 11.3% of the volume of the adhesive layer.

16. The prism module according to claim 11, wherein: A diameter of each of the plurality of spacers is between 3.5 μm and 12.0 μm.

17. The prism module according to claim 11, wherein: The second prism further has a third surface adjacent to the second surface, and the third surface is provided with a light absorbing layer.

18. A projection device, characterized in that: The projection device includes an illumination system, a light valve, a projection lens, and a prism module. The illumination system is used to provide an illumination beam. The light valve is located in the transmission path of the illumination beam and is used to convert the illumination beam into an image beam. The projection lens is located in the transmission path of the image beam and is used to project the image beam. The prism module is disposed between the illumination system, the light valve, and the projection lens. The prism module includes a first prism, a second prism, and an adhesive layer. The first prism has a first surface; The second prism has a second surface opposite to the first surface; and The adhesive layer is partially connected between the first surface and the second surface, and a gap is formed between the first surface and the second surface, wherein the adhesive layer includes an adhesive material and a plurality of gaps disposed in the adhesive material; The first surface is used to reflect the illumination light beam to the light valve, and the image light beam is transmitted to the projection lens through the first surface and the second surface; The adhesive layer has a first adhesive surface and a second adhesive surface, the first adhesive surface contacts the first surface and the second adhesive surface contacts the second surface, when there is no temperature difference between the first prism and the second prism, the overlap rate between the first adhesive surface and the second adhesive surface is P1, when there is a temperature difference between the first prism and the second prism, the overlap rate between the first adhesive surface and the second adhesive surface is P2, and P2 is greater than P1.

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