This application claims the priority benefit of Taiwan application serial no. 111137617, filed on Oct. 4, 2022. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The invention relates to an elimination device, and more particularly, to a lens shift backlash elimination device.
The movement of a projection lens relative to a light valve may be achieved by a lens shift device. In general, in the design of the lens shift device, a gap is always reserved between the transmission shaft, between the worm and the worm gear, the cam transmission structure, the push transmission structure, and the screw and the nut structure, to avoid the components being too tight and causing inability to rotate or difficulty in rotating. However, if the gap is reserved, as long as the connection between the components is loose, a backlash is generated, thus causing the issue of idling components or the number of steps in the motor drive being not easy to control.
The invention provides a lens shift backlash elimination device that may eliminate or absorb backlash, so as to effectively avoid the idling of the active element or the incorrect number of steps in the motor drive.
A lens shift backlash elimination device of an embodiment of the invention includes a base, a transmission mechanism, and a lens. The transmission mechanism is disposed on the base and includes a first element, a second element, and an elastic element. The second element is mechanically connected to the first element. The elastic element is disposed between the first element and the second element, or abutted against the first element. The lens is mechanically connected to the transmission mechanism. The lens may be displaced relative to the base in a first direction.
A lens shift backlash elimination device of an embodiment of the invention includes a base, a transmission mechanism, and a lens. The transmission mechanism is disposed at the base and includes a first element and a second element. The second element is mechanically connected to the first element, and one of the first element and the second element has an elastic structure. The lens is mechanically connected to the transmission mechanism, and the lens may be displaced relative to the base in a first direction.
A lens shift backlash elimination device of an embodiment of the invention includes a base, a transmission mechanism, and a lens. The transmission mechanism is disposed on the base and includes a first element, a second element, and an elastic element. The first element is a moving element. The second element is a fixed element, and mechanically connected to the first element, but not acting with the first element. The elastic element is disposed between the first element and the second element. The lens is mechanically connected to the transmission mechanism, and the lens may be displaced relative to the base in a first direction.
Based on the above, in the design of the lens shift backlash elimination device of the invention, the elastic element is disposed between the first element and the second element, or abutted against the first element; or, one of the first element and the second element has the elastic structure; or, the elastic element is disposed between the first element (the moving element) and the second element (the fixed element). Thereby, the backlash error between the first element and the second element may be eliminated or absorbed, and the idling of the first element or the second element or the incorrect number of steps in the motor drive may be avoided.
In order to make the aforementioned features and advantages of the disclosure more comprehensible, embodiments accompanied with figures are described in detail below.
In general, in the design of a shift device, a gap is reserved between the transmission shaft, between the worm and the worm gear, the cam transmission structure, the push transmission structure, and the screw and the nut structure, for example, to avoid the components being too tight and causing inability to rotate or difficulty in rotating. If a gap is reserved, backlash occurs whenever there is looseness in the connection between the components. The following takes a lens shift device as an example to illustrate how a lens shift backlash elimination device of the invention eliminates or absorbs the backlash between the lens shift device in the transmission shaft, between the worm and the worm gear, the cam transmission structure, the push transmission structure, and the screw and the nut structure, but not limited thereto. As long as there is a backlash between the active element and the driven element or between the moving element and the fixed element in the shift device, the backlash may be eliminated or absorbed by the lens shift backlash elimination device of the invention.
In the invention, the active element refers to an element that may drive other parts to move; the driven element refers to an element that may be driven by the active element; the moving element refers to an element that may be moved or rotated; the fixed part refers to an element that is fixed (not moving or rotating). The moving plate refers to a plate-like element that may generate movement.
In detail, please refer to
In order to prevent the first element 220a (i.e., the screw) from moving in an axial direction X, a certain gap is reserved in the axial direction X of the first element 220a (i.e., the screw), and by disposing the elastic element 230a to be abutted against the second element 210a, the backlash error in the axial direction (i.e., between the first element 220a and the second element 210a) is absorbed by the design of micro-interference, to effectively avoid the idling of the moving elements or the incorrect number of steps in the motor drive.
Other embodiments of the invention are described below. It should be mentioned here that, the following embodiments adopt the reference numerals of the embodiment above and a portion of the content thereof, wherein the same reference numerals are used to represent the same or similar elements and descriptions of the same technical content are omitted. The omitted portions are as described in the embodiments above and are not repeated in the embodiments below.
More specifically, the first element 210b of the present embodiment is provided with a combining portion 212b, and the base 100 is provided with a protruding block 110, wherein an inner diameter L1 of the combining portion 212b is greater than an outer diameter L2 of the protruding block 110. That is, there is a gap between the combining portion 212b and the protruding block 110. At this time, an end 232b of an elastic element 230b of the present embodiment is fixed at the base 100, and another end 234b of the elastic element 230b is abutted against the combining portion 212b of the first element 210b. Here, the elastic element 230b is, for example, an elastic sheet or a coil spring, but not limited thereto.
In the present embodiment, to meet the motion requirements of the transmission mechanism 200b, a certain gap is reserved between the teeth of the first element 210b (i.e., the worm gear) and the teeth of the second element 220b (i.e., the worm). However, to avoid backlash, a gap (i.e., the gap between the combining portion 212b and the protruding block 110) is disposed in the direction in which the central axis of the first element 210b (i.e., the worm gear) is away from the second element 220b (i.e., the worm), and via the other end 234b of the elastic element 230b abutted against the first element 210b (i.e., the worm gear) to exert force to the left, the first element 210b (i.e., the worm gear) is pressed against the direction of the second element 220b (i.e., the worm), thereby absorbing the backlash error between the first element 210b (i.e., the worm gear) and the second element 220b (i.e., the worm) to effectively avoid the idling of the active element or the incorrect number of steps in the motor drive.
In another embodiment, a first element 210c′ may also have an elastic structure 230c′. Specifically, referring to
More specifically, the first element 210d of the present embodiment has a first inclined surface 212d, and the second element 220d has a second inclined surface 222d, wherein the first inclined surface 212d is in contact with the second inclined surface 222d. An end 232d of an elastic element 230d is fixed to the first element 210d or the base 100 via, for example, a screw S, and another end 234d of the elastic element 230d is in contact with the second element 220d. Here, the end 232d of the elastic element 230d is fixed on the first element 210d via, for example, the screw S, and the other end 234d of the elastic element 230d is in contact with the second element 220d. The elastic element 230d is, for example, a wave-shaped elastic sheet or a coil spring, but not limited thereto.
In the present embodiment, the gap between the first element 210b and the second element 220d is eliminated via the inclined cooperation between the first inclined surface 212d and the second inclined surface 222d between the first element 210d and the second element 220d, and via the arrangement of the elastic element 230d, the first element 210d and the second element 220d are in close contact with each other in a direction D4, thereby absorbing the backlash error between the first element 210d and the second element 220d to effectively avoid the idling of the active element or the incorrect number of steps in the motor drive. Here, the transmission mechanism 200d is, for example, a push transmission mechanism.
Further, in the present embodiment, the lens shift backlash elimination device further includes a moving plate 240e mechanically connected to the first element 210e. The moving plate 240e may be displaced relative to the base 100 in the direction D2 via the transmission mechanism 200e, and the lens 300 is disposed on the moving plate 240e. An end 232e of the elastic element 230e is fixed at one of the base 100 and the first element 210e, and another end 234e of the elastic element 230e is abutted against the other of the base 100 and the first element 210e. Here, the end 232e of the elastic element 230e is fixed to the first element 210e, and the other end 234e of the elastic element 230e is abutted against the base 100. The base 100 is provided with a blocking wall 120, and the elastic element 230e is fixed at a side of the screw portion 212e and in contact with the blocking wall 120. By disposing the transverse elastic element 230e on the first element 210e, the backlash error between the first element 210e and the second element 220e may be absorbed, thereby effectively preventing the active element from idling or the incorrect number of steps in the motor drive.
It should be mentioned that, via the operation of the transmission mechanism 200a of
Based on the above, in the design of the lens shift backlash elimination device of the invention, the elastic element is disposed between the first element and the second element, or abutted against the first element; or, one of the first element and the second element has the elastic structure; or, the elastic element is disposed between the first element (the moving element) and the second element (the fixed element). Thereby, the backlash error between the first element and the second element may be eliminated or absorbed, and the idling of the first element or the second element or the incorrect number of steps in the motor drive may be avoided.
Although the invention has been described with reference to the above embodiments, it will be apparent to one of ordinary skill in the art that modifications to the described embodiments may be made without departing from the spirit of the disclosure. Accordingly, the scope of the disclosure is defined by the attached claims not by the above detailed descriptions.
Number | Date | Country | Kind |
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111137617 | Oct 2022 | TW | national |