Optical actuator and image forming apparatus

Abstract

To provide an optical actuator.SOLUTION: An optical actuator includes: a base that has an attachment surface; a light-transmissive plate that is located above the attachment surface; a frame that is provided at an outer edge of the light-transmissive plate, and that has recesses relative to the attachment surface so that the attachment surface has a plurality of arrangement areas relative to the frame; a plurality of holding parts that are located respectively in the arrangement areas to be connected between the base and the frame; and a plurality of actuation members that are located respectively in the arrangement areas and are arranged to cause the frame to reciprocate relative to the attachment surface.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an optical actuator and an image forming apparatus. [Background technology]

[0002] A projector is a display device for generating a large screen. The image formation principle of a projector is that an image forming element converts an illumination beam from a light source module into an image beam, and then a projection lens projects the image beam onto a screen or a wall.

[0003] In order to improve the pixel quality of the projection screen, an optical actuator is disposed between the image-forming element and the projection lens of some projectors, and the pixel is appropriately shifted back and forth by the vibration of the optical actuator, so that the pixel grain on the projection screen is less noticeable. Specifically, the light from the light source module is modulated by the image-forming element, and then passes through the optical actuator and is transmitted to the projection lens.

[0004] However, conventional optical actuators are relatively large, and when applied to projection lenses with certain focal lengths (e.g., projection lenses with short back focal lengths), there is always a problem of structural interference due to the limited space between the prism and the projection lens, making them unable to be used.

[0005] Therefore, providing an optical actuator and an image forming apparatus capable of solving the above problems is currently one of the important research and development issues. Summary of the Invention [Problem to be solved by the invention]

[0006] In view of this, one object of the present disclosure is to provide an optical actuator and an image forming apparatus capable of solving the above problems. [Means for solving the problem]

[0007] In order to achieve the above object, according to one embodiment of the present disclosure, an optical actuator includes a base having a mounting surface, a light-transmitting plate located above the mounting surface, a frame provided on an outer edge of the light-transmitting plate, the frame having a recess in the mounting surface such that the mounting surface has a plurality of placement areas relative to the frame, a plurality of holding portions each located in the placement areas so as to be connected between the base and the frame, and a plurality of actuating members each located in the placement areas and arranged to move the frame back and forth relative to the mounting surface.

[0008] In one or more embodiments of the present disclosure, the retaining portion and the actuating member located in one of the placement regions are aligned in a normal direction to the mounting surface.

[0009] In one or more embodiments of the present disclosure, the actuating member is arranged to reciprocate the frame along a direction normal to the mounting surface.

[0010] In one or more embodiments of the present disclosure, the placement areas are located at the four corners of the base, respectively.

[0011] In one or more embodiments of the present disclosure, two of the actuating members are arranged along a first diagonal direction and the other two are arranged along a second diagonal direction, and the first diagonal direction and the second diagonal direction are perpendicular to each other.

[0012] In order to achieve the above object, according to one embodiment of the present disclosure, an image forming device includes an image forming element, a base having a mounting surface, a translucent plate located above the mounting surface, a frame provided on the outer edge of the translucent plate, the frame having a recess relative to the mounting surface such that the mounting surface has a plurality of placement areas relative to the frame, an optical actuator including a plurality of holding portions each located in the placement areas so as to be connected between the base and the frame, and a plurality of actuating members each located in the placement areas and arranged to move the frame back and forth relative to the mounting surface, and a plurality of prisms optically combined between the image forming element and the translucent plate.

[0013] In one or more embodiments of the present disclosure, the retaining portion and the actuating member located in one of the placement regions are aligned in a normal direction to the mounting surface.

[0014] In one or more embodiments of the present disclosure, the actuating member is arranged to reciprocate the frame along a direction normal to the mounting surface.

[0015] In one or more embodiments of the present disclosure, the placement areas are located at the four corners of the base, respectively.

[0016] In one or more embodiments of the present disclosure, two of the actuating members are arranged along a first diagonal direction and the other two are arranged along a second diagonal direction, and the first diagonal direction and the second diagonal direction are perpendicular to each other.

[0017] In one or more embodiments of the present disclosure, a first diagonal edge direction extends through two of the placement regions, and a second diagonal edge direction extends through the other two of the placement regions.

[0018] In one or more embodiments of the present disclosure, the image-forming element has longitudinal and transverse directions that are parallel to a first diagonal direction and a second diagonal direction, respectively.

[0019] In one or more embodiments of the present disclosure, the base further has a side connected to the mounting surface, the side connected to two of the placement areas, and the prisms include a first prism located between the image-forming element and the translucent plate, and a second prism located partially between the image-forming element and the first prism and extending to one side of the side to form a gap with the side.

[0020] In one or more embodiments of the present disclosure, one of the retaining portions has a first fixed end and a second fixed end, and is fixed to the base and the frame via the first fixed end and the second fixed end, respectively.

[0021] In one or more embodiments of the present disclosure, each of the retaining portions includes two ribs, both ends of each of which are connected to a first fixed end and a second fixed end, respectively, and protrude in opposite directions between the first fixed end and the second fixed end. Effect of the Invention

[0022] In summary, in the optical actuator and image forming device of the present disclosure, by concentrating the holding portion and the actuating member on multiple arrangement areas of the mounting surface of the base, the area of ​​the mounting surface can be reduced, and the volume occupied by the optical actuator in the image forming device can be effectively reduced, thereby effectively increasing the applicability of projection lenses with various focal lengths to the image forming device of the present disclosure.

[0023] The above is intended to describe the problems that the invention aims to solve, the means for solving the problems, and the effects of the invention, and specific details of the present disclosure will be described in detail in the following embodiments and related drawings. [Brief description of the drawings]

[0024] The following description of the accompanying drawings will make the above and other objects, features, advantages and embodiments of the present disclosure more comprehensible. [Figure 1] FIG. 1 is an exploded view illustrating an image forming apparatus according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an exploded view showing some elements of an image forming apparatus according to one embodiment of the present disclosure. [Diagram 3] FIG. 3 is a side view showing the element in FIG. [Figure 4] FIG. 4 is a front view showing the optical actuator in FIG. [Diagram 5] 5 is another front view of the optical actuator of FIG. 4 with the suspension bracket removed. [Figure 6] FIG. 5 is a front view showing the hanging bracket in FIG. [Figure 7] FIG. 3 is an exploded view showing the operating member in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, several embodiments of the present disclosure will be described with reference to the drawings, and many actual details will be described in the following description for clarity. However, the reader should understand that these actual details are not intended to limit the present invention. That is, in some embodiments of the present invention, these actual details are not necessary. In addition, in order to simplify the drawings, some conventional structures and elements are simply and diagrammatically shown in the drawings.

[0026] Please refer to FIG. 1 and FIG. 2. FIG. 1 is an exploded view showing an image forming apparatus 100 according to an embodiment of the present disclosure. FIG. 2 is an exploded view showing some elements of the image forming apparatus 100 according to an embodiment of the present disclosure. As shown in FIG. 1 and FIG. 2, in this embodiment, the image forming apparatus 100 is exemplified as a projector, but the present disclosure is not limited thereto. The image forming apparatus 100 includes a case 110 and a plurality of elements provided in the case 110. As an example, the image forming apparatus 100 includes a projection lens 120, a light source module (not shown), an image forming element 130, an optical actuator 200, and a plurality of prisms. The light source module is arranged to generate an illumination beam. The prism is optically combined between the light source module and the image forming element 130, and is optically combined between the image forming element 130 and the optical actuator 200. The illumination beam from the light source module passes through the prism before reaching the image forming element 130. The image forming element 130 is positioned to convert the illumination beam into an image beam which is sequentially passed through a prism, an optical actuator 200 and a projection lens 120 and projected onto a screen.

[0027] In some embodiments, the image forming element 130 is a digital micro mirror device (DMD), but the present disclosure is not limited thereto. Specifically, when a pixel represents an image, the corresponding micro mirror device of the image forming element 130 projects the image beam converted from the illumination beam to the outside of the case 110 through the prism, the optical actuator 200, and the projection lens 120 in sequence. When a pixel does not represent an image, the corresponding micro mirror device of the image forming element 130 shifts from the optical actuator 200 to the prism and prevents the beam from being projected to the outside of the case 110 through the projection lens 120.

[0028] As shown in FIG. 2, in this embodiment, the optical actuator 200 includes a base 210, a light-transmitting plate 220, a frame 230, a hanging bracket 240, and a plurality of actuating members 250. The base 210 has a mounting surface 212a. The light-transmitting plate 220 is located above the mounting surface 212a. The frame 230 is provided on the outer edge of the light-transmitting plate 220 and has a recess with respect to the mounting surface 212a such that the mounting surface 212a has a plurality of arrangement regions 212b with respect to the frame 230. The hanging bracket 240 includes a plurality of holding portions 241. The holding portions 241 are each located in the arrangement region 212b so as to be connected between the base 210 and the frame 230. The actuating members 250 are each located in the arrangement region 212b and are arranged to reciprocate the frame 230 with respect to the mounting surface 212a. In detail, the function of the hanging bracket 240 is to suspend the frame 230 at a certain distance above the mounting surface 212a to maintain parallelism, and ensure a certain movement space and elastic reset ability when the actuating member 250 reciprocates the frame 230. The prism is optically synthesized between the image-forming element 130 and the light-transmitting plate 220.

[0029] From the above-mentioned structural arrangement, it can be clearly seen that since both the holding portion 241 and the actuating member 250 are respectively concentrated in multiple arrangement areas 212b of the mounting surface 212a of the base 210, the area of ​​the mounting surface 212a can be reduced, and the volume occupied by the optical actuator 200 in the image forming apparatus 100 can be effectively reduced.

[0030] As shown in FIG. 2, in this embodiment, the base 210 includes a bottom plate 211 and a circuit board 212. The circuit board 212 is provided on the bottom plate 211 (for example, in a form of being locked by a screw). The bottom plate 211 is located on the side of the base 210 facing the image forming element 130. The circuit board 212 is located on the side of the base 210 away from the image forming element 130. The mounting surface 212a is the surface of the circuit board 212 away from the bottom plate 211. In some embodiments, the material of the bottom plate 211 includes metal, which can improve the rigidity of the entire base 210 and support the circuit board 212. The bottom plate 211 and the circuit board 212 have an openwork structure to pass the image beam converted by the image forming element 130.

[0031] Please refer to FIG. 3, which is a side view showing the element in FIG. 2. As shown in FIG. 2 and FIG. 3, in this embodiment, the base 210 further has a side surface 212c connected to the mounting surface 212a. The side surface 212c is connected to two of the arrangement areas 212b (for example, the two arrangement areas 212b located on the right side and the lower side in FIG. 2 and adjacent to the prism). That is, the side surface 212c is a surface facing the prism of the circuit board 212. The prism includes a first prism 141 and a second prism 142. The first prism 141 is located between the image forming element 130 and the light-transmitting plate 220. The second prism 142 is partially located between the image forming element 130 and the first prism 141, and extends to one side of the side surface 212c to form a gap G with the side surface 212c. Since the holding portion 241 and the actuating member 250 are concentrated in the arrangement region 212b of the mounting surface 212a, the edge of the frame 230 of the optical actuator 200 that is close to the second prism 142 can be closer to the side surface 212c of the base 210. This can effectively reduce the distance between the optical actuator 200 and the image forming element 130 without structural interference between the optical actuator 200 and the second prism 142, thereby achieving the purpose of effectively increasing the applicability of the projection lenses 120 with various focal lengths to the image forming device 100 of the present disclosure.

[0032] 3, in this embodiment, the bottom plate 211 of the base 210 has a side surface 211a adjacent to the second prism 142, and the side surface 211a is inclined with respect to the side surface 212c and is substantially parallel to the surface of the second prism 142 facing the optical actuator 200. This allows the distance between the optical actuator 200 and the image forming element 130 to be further reduced.

[0033] 2 and 3, in this embodiment, the holding portion 241 and the actuating member 250 located in the same arrangement region 212b are arranged in the normal direction N of the mounting surface 212a, so that the action direction of the actuating member 250 and the corresponding elastic reset direction of the holding portion 241 also move along the same normal direction N. As can be seen from this, each set of the holding portion 241 and the actuating member 250 actually operates in the same arrangement region 212b on the mounting surface 212a. Therefore, there are many places around the frame 230 of the optical actuator 200 where a space for retraction is provided.

[0034] Please refer to Figures 4 and 5. Figure 4 is a front view of the optical actuator 200 in Figure 3. Figure 5 is another front view of the optical actuator 200 in Figure 4, and the hanging bracket 240 is removed. As shown in Figures 4 and 5, in this embodiment, the placement areas 212b are located at the four corners of the base 210, respectively. Specifically, the mounting surface 212a of the base 210 is substantially rectangular and has four corners. Since the frame 230 has recesses for the four corners of the mounting surface 212a, the mounting surface 212a has four placement areas 212b for the frame 230, and the lower two placement areas 212b are closer to the edge of the base 210.

[0035] 5, in this embodiment, the frame 230 having a recess relative to the mounting surface 212a has a substantially octagonal outer edge contour, but the present disclosure is not limited thereto. In practical application, the frame 230 may have a circular outer edge contour.

[0036] As shown in FIG. 5, in this embodiment, the frame 230 of the optical actuator 200 includes an underframe 231 and a plurality of fixed plates 232. The light-transmitting plate 220 is supported by the underframe 231. The fixed plates 232 are fixed to the underframe 231 and abut different edges of the light-transmitting plate 220, respectively, so as to clamp the light-transmitting plate 220. In particular, as shown in FIG. 5, there are four fixed plates 232. The light-transmitting plate 220 has an outer edge contour that is substantially octagonal. Two fixed plates 232 are located at diagonal corners of the light-transmitting plate 220.

[0037] Please refer to FIG. 6, which is a front view showing the hanging bracket 240 in FIG. 4. As shown in FIG. 4 and FIG. 6, in this embodiment, the hanging bracket 240 further includes a parallel connection strip 242. The parallel connection strip 242 is frame-shaped and connects the holding parts 241 in parallel. By connecting the holding parts 241 in parallel by the parallel connection strip 242, the hanging bracket 240 can be made into a single structure, and the installation of the hanging bracket 240 can be made more convenient. Each of the holding parts 241 has a first fixed end 241a and a second fixed end 241b. The first fixed end 241a and the second fixed end 241b are spaced apart from each other by a certain distance so that the structure is connected and maintains structural elasticity. The first fixed end 241a is located at one end of the holding part 241 away from the parallel connection strip 242. The second fixed end 241b is located at the connection point between the holding part 241 and the parallel connection strip 242. The holding portion 241 is fixed to the base 210 via a first fixed end 241a (for example, to the bottom plate 211 of the base 210 so as to be locked by a screw). The holding portion 241 is fixed to the frame 230 via a second fixed end 241b (for example, to the fixed plate 232 of the frame 230 so as to be locked by a screw). In this way, the suspension bracket 240 can be connected between the base 210 and the frame 230.

[0038] In some embodiments, whether the holding portion 241 is located within the arrangement region 212b is determined based on whether the first fixed end 241a is located within the arrangement region 212b. As shown in Figures 4 and 6, the first fixed ends 241a of the four holding portions 241 are located within the four arrangement regions 212b, respectively, and therefore, it is confirmed that the holding portions 241 are located within the four arrangement regions 212b, respectively.

[0039] As shown in FIG. 6, in this embodiment, each of the holding parts 241 includes two ribs. Both ends of each of the ribs are connected to the first fixed end 241a and the second fixed end 241b, respectively, and protrude in opposite directions between the first fixed end 241a and the second fixed end 241b. More specifically, the two ribs are symmetrical with the connection lines between the first fixed end 241a and the second fixed end 241b extending to both sides, so that the holding part 241 is formed as a symmetrical butterfly wing structure. It should be noted that the ribs are thinner than the parallel connecting strips 242, and therefore are more easily elastically deformed. Meanwhile, the parallel connecting strips 242 are coarser than the ribs, and therefore the rigidity and stability of the entire hanging bracket 240 can be increased.

[0040] In practical applications, the hanging bracket 240 may omit the parallel connecting strips 242. That is, the hanging bracket 240 may only include the holding portions 241 separated from each other.

[0041] 2. You may refer to FIG. 7, which is an exploded view showing the actuating member 250 in FIG. 2. As shown in FIG. 2 and FIG. 7, in this embodiment, the actuating member 250 includes a coil 251, a magnetic conductive member 252, and a magnet 253. The coil 251 is fixed to the base 210 so as to be electrically connected to the circuit board 212. The conductor of the coil 251 is wound substantially parallel to the mounting surface 212a. The magnetic conductive member 252 is fixed to the frame 230 and partially enters the space surrounding the coil 251 (for example, enters along the normal direction N shown in FIG. 3). The magnet 253 is fixed to the magnetic conductive member 252, and its magnetic force can be conducted to the magnetic conductive member 252. According to the left-hand rule, when the left hand is placed in a magnetic field and the magnetic field line is inserted perpendicular to the center of the hand, the direction of the thumb perpendicular to the four fingers is the direction of the Lorentz force when the four fingers represent the direction of movement of a positive charge. As can be seen from this, by passing currents in different directions through the coil 251, it is possible to apply a Lorentz force reciprocatingly to the magnetic conductive member 252 along the normal direction N. This allows the operating member 250 to move the frame 230 reciprocatingly along the normal direction N relative to the mounting surface 212a.

[0042] As shown in FIG. 2, in this embodiment, two of the actuating members 250 (i.e., the upper actuating member 250 and the lower actuating member 250 in FIG. 2) are arranged along a first diagonal end direction DA1. The other two of the actuating members 250 (i.e., the left actuating member 250 and the right actuating member 250 in FIG. 2) are arranged along a second diagonal end direction DA2. The first diagonal end direction DA1 and the second diagonal end direction DA2 are perpendicular to each other. More specifically, the arrangement area 212b, the holding portion 241 and its first fixed end 241a, second fixed end 241b, and the actuating member 250 are all provided in the first diagonal end direction DA1 or the second diagonal end direction DA2. The first diagonal direction DA1 extends through the two upper and lower arrangement areas 212b in FIG. 2, and the second diagonal direction DA2 extends through the two left and right arrangement areas 212b in FIG. 2. These actuating members 250 may be operated sequentially according to timing. When these actuating members 250 are operated sequentially, the optical axis of the light-transmitting plate 220 may be swung toward different orientations. This can generate a pixel shift effect on the image beam passing through the light-transmitting plate 220, and the resolution of the screen can be improved after the signal is synchronized. For example, the resolution, which is originally 1920*1080, can be improved to 3840*2160, but the present disclosure is not limited thereto.

[0043] 2, in this embodiment, the image-forming element 130 has a vertical axis direction AL and a horizontal axis direction AW. The vertical axis direction AL and the horizontal axis direction AW are parallel to the first diagonal end direction DA1 and the second diagonal end direction DA2, respectively. This arrangement allows the image beam of the image-forming element 130 in the on-state to effectively pass through the light-transmitting plate 220 and generate a predetermined pixel shift effect on the image beam.

[0044] As can be clearly seen from the above detailed description of the specific embodiments of the present disclosure, in the optical actuator and image forming device of the present disclosure, the holding portion and the actuating member are both concentrated in multiple arrangement areas on the mounting surface of the base, thereby reducing the area of ​​the mounting surface and effectively reducing the volume occupied by the optical actuator in the image forming device, thereby effectively increasing the applicability of projection lenses with various focal lengths to the image forming device of the present disclosure.

[0045] The present invention has been disclosed above based on the embodiments, but the above embodiments do not limit the present invention, and a person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention is based on that defined in the appended claims. [Explanation of symbols]

[0046] 100 Image forming device 110 cases 120 Projection Lens 130 Image forming element 141 First Prism 142 The Second Prism 200 Optical Actuator 210 Base 211 Bottom plate 211a, 212c side 212 Circuit Board 212a Mounting surface 212b Placement area 220 Translucent plate 230 frames 231 Underframe 232 Fixing plate 240 Lifting bracket 241 Holding part 241a First fixed end 241b Second fixed end 242 parallel connection strips 250 Operating member 251 Coil 252 Magnetically conductive materials 253 Magnet AL Vertical axis direction AW Horizontal axis direction DA1 First diagonal direction DA2 Second diagonal direction G Gap N normal direction

Claims

1. a base having a mounting surface; a light-transmitting plate located above the mounting surface; a frame provided on an outer edge of the light-transmitting plate and having a recess with respect to the mounting surface such that the mounting surface has a plurality of placement areas with respect to the frame; a plurality of holding portions each located in the arrangement area so as to be connected between the base and the frame; a plurality of actuating members each positioned in the arrangement area and arranged to reciprocate the frame relative to the mounting surface; 1. An optical actuator comprising:

2. The optical actuator according to claim 1 , wherein the holding portion and the actuating member located in one of the arrangement regions are aligned in a normal direction to the attachment surface.

3. The optical actuator of claim 2 , wherein the actuating member is arranged to reciprocate the frame along the normal direction relative to the mounting surface.

4. The optical actuator according to claim 1 , wherein the placement areas are located at four corners of the base, respectively.

5. 5. The optical actuator according to claim 1, wherein among the plurality of actuating members, two are arranged along a first diagonal end direction and the other two are arranged along a second diagonal end direction, and the first diagonal end direction and the second diagonal end direction are perpendicular to each other.

6. An image forming element; an optical actuator including: a base having a mounting surface; a light-transmitting plate located above the mounting surface; a frame provided on an outer edge of the light-transmitting plate and having a recess relative to the mounting surface such that the mounting surface has a plurality of placement regions relative to the frame; a plurality of holding portions each located in the placement regions so as to be connected between the base and the frame; and a plurality of operating members each located in the placement regions and arranged to reciprocate the frame relative to the mounting surface; a plurality of prisms optically combined between the image forming element and the light-transmitting plate; An image forming apparatus comprising:

7. 7. The image forming apparatus according to claim 6, wherein the holding portion and the operating member located in one of the arrangement areas are arranged in a normal direction to the attachment surface.

8. 8. The image forming apparatus according to claim 7, wherein the operating member is disposed so as to reciprocate the frame along the normal direction relative to the mounting surface.

9. The image forming apparatus according to claim 6 , wherein the arrangement areas are located at four corners of the base, respectively.

10. 7. The image forming apparatus according to claim 6, wherein among the plurality of actuating members, two are arranged along a first diagonal end direction and the other two are arranged along a second diagonal end direction, and the first diagonal end direction and the second diagonal end direction are perpendicular to each other.

11. 11. The image forming apparatus according to claim 10, wherein the first diagonal direction extends through two of the placement areas, and the second diagonal direction extends through the other two of the placement areas.

12. 11. The image forming apparatus according to claim 10, wherein the image forming element has vertical and horizontal axis directions parallel to the first diagonal direction and the second diagonal direction, respectively.

13. 13. The image forming device of claim 12, wherein the base further has a side connected to the mounting surface, the side connected to two of the placement areas, and the plurality of prisms include a first prism positioned between the image forming element and the translucent plate, and a second prism positioned partially between the image forming element and the first prism and extending to one side of the side to form a gap with the side.

14. 14. An image forming apparatus according to claim 10, wherein one of the plurality of holding portions has a first fixed end and a second fixed end, and is fixed to the base and the frame via the first fixed end and the second fixed end, respectively.

15. 15. The image forming apparatus of claim 14, wherein each of the plurality of retaining portions includes two ribs, both ends of each of the ribs being connected to the first fixed end and the second fixed end, respectively, and protruding in opposite directions between the first fixed end and the second fixed end.

Images