Optical element holder
The optical element holder uses torsion springs and motor-controlled angle screws to address miniaturization and stability issues, achieving a compact and stable design for optical circuits.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-09-13
- Publication Date
- 2026-03-26
AI Technical Summary
Conventional optical element holders require larger external dimensions due to the use of compression coil springs or leaf springs, hindering miniaturization and integration density in optical circuits, especially for optical quantum computers.
An optical element holder utilizing torsion springs and rotating shafts within their windings, with adjustable angle screws controlled by motors, allowing for compact design and high stability.
The holder achieves miniaturization and high stability by using torsion springs, reducing dimensional changes and play in bearings, enabling a low optical axis height and enhanced angular stability.
Smart Images
Figure 2026053982000001_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an optical element holder for installing optical elements such as mirrors, beam splitters, and lenses in an optical path at a predetermined angle, and particularly to an optical element holder capable of adjusting the angle of an optical element with two axes in the rotational direction and the pitching direction.
Background Art
[0002] There have been many precedents for this type of optical element holder (mount).
Non-Patent Document 1
Non-Patent Document 2
[0003] Since these optical element holders have a so-called gimbal structure, they have the advantage of always being able to align the center of the optical element surface with the rotation center. In addition, they are equipped with biasing means for constantly biasing the frame holding the optical element toward the base side. Since they have a mechanism for abutting the tip of an adjustment screw inserted from the frame side against the surface of the base against this biasing force and finely adjusting the rotation angle of the frame, they also have the advantage of being able to stably hold the adjusted angle.
Disclosure of the Invention
Problems to be Solved by the Invention
[0004] Incidentally, in order to realize the optical quantum computer that has been attracting attention recently, it is necessary to construct an optical circuit in which a large number of optical elements are arranged at various angles. In such applications, not only is extremely high stability required, but further miniaturization of the optical element holder is also required in order to increase the integration density of the circuit. However, conventional optical element holders use compression coil springs or leaf springs as biasing means, which necessitates larger external dimensions to secure installation space.
[0005] This invention was devised to solve the above-mentioned problems of conventional optical element holders, and aims to realize an optical element holder that can be easily miniaturized by improving its structure. [Means for solving the problem]
[0006] To achieve the above objective, the optical element holder according to claim 1 comprises a subframe having an opening for mounting an optical element, a main frame that rotatably supports the subframe in the tilting direction, a base that rotatably supports the main frame in the rotational direction, a first angle adjustment screw that penetrates the main frame from the back to the front and whose tip abuts against one surface of the base, and a second angle adjustment screw that penetrates the main frame from the back to the front and whose tip abuts against one surface of the subframe, wherein the angle of the main frame is adjusted according to the amount of protrusion of the first angle adjustment screw. An optical element holder in which the angle of the subframe changes in accordance with the amount of protrusion of a second angle adjustment screw, wherein the base comprises an upper opening, a first torsion spring housed in the upper opening, and a first rotating shaft arranged within the winding of the first torsion spring, the tip of the first rotating shaft being fixed to the lower edge of the main frame, one arm of the first torsion spring being engaged with the base side and the other arm being engaged with the main frame side, thereby the torque of the first torsion spring acting when the main frame rotates.
[0007] The optical element holder according to claim 2 is the holder according to claim 1, further comprising a second rotating shaft disposed within one side of the main frame and a third rotating shaft disposed within the other side of the main frame, wherein the tip of the second rotating shaft is fixed to one side of the subframe and the third rotating shaft is fixed to the other side of the subframe, the second rotating shaft is inserted into the winding of the second torsion spring and the third rotating shaft is inserted into the winding of the third torsion spring, one arm of the second torsion spring and the third torsion spring are engaged with the main frame side and the other arm is engaged with the subframe side, so that torque is applied to the second torsion spring and the third torsion spring when the subframe rotates.
[0008] The optical element holder according to claim 3 is the holder according to claim 1 or 2, further characterized in that the bearing of the first rotating shaft is composed of a pair of angular bearings.
[0009] The optical element holder described in claim 4 is the holder of claim 1 or 2, further characterized in that the bearing of the first rotating shaft is composed of a pair of thrust bearings and a tubular spacer interposed between the two thrust bearings.
[0010] The optical element holder described in claim 5 is the holder of claim 1 or 2, further characterized in that the amount of protrusion of the first angle adjustment screw and the amount of protrusion of the second angle adjustment screw are controlled by the drive of an electric motor, respectively. [Effects of the Invention]
[0011] In the optical element holder according to this invention, a torsion spring is used as a biasing means for stabilizing the rotation angle of the main frame, as it requires less dimensional change in response to changes in the rotation angle compared to a compression spring, and the structure is provided to house the rotating shaft within its windings, thereby allowing the height of the optical element holder to be kept low. [Brief explanation of the drawing]
[0012] [Figure 1] This is a perspective view showing the front side of the optical element holder as observed from the upper right. [Figure 2] This is a perspective view showing the front side of the optical element holder as observed from the upper left. [Figure 3] This is a cross-sectional view of the back side of the optical element holder. [Figure 4] This is a cross-sectional view showing the first rotation axis of the optical element holder. [Figure 5] This is a perspective view showing the base of the optical element holder. [Figure 6] This is a perspective view showing the front side of an optical element holder, with the base and subframe omitted, as observed from the lower right. [Figure 7] This is a cross-sectional view showing the second rotation axis of the optical element holder. [Figure 8] This is a perspective view showing the front side of the optical element holder, with the main frame and motor unit omitted, as observed from the upper right. [Figure 9] This is a perspective view showing the back side of the optical element holder as seen from the lower right. [Figure 10] These are actual photographs of the optical element holder, taken from the upper right, showing both the front and back sides. [Figure 11] This is a cross-sectional view showing a modified example of the first bearing. [Best Mode for Carrying Out the Invention]
[0013] As shown in Figures 1 and 2, the optical element holder 10 comprises a support column 12, a base 14, a main frame 16, a subframe 18, a first motor unit 20, and a second motor unit 22.
[0014] As shown in Figure 3, which observes a cross-section of the optical element holder 10 from the rear side, the main frame 16 is formed in a roughly rectangular frame shape, and the tip of the first rotation shaft 24, which is located inside the base 14, is fixed (screwed and glued) to the center of the lower edge of the main frame 16. This first rotating shaft 24 is rotatably supported by a first bearing 26 composed of a pair of angular bearings 26a and 26b. The first bearing 26 is fixed to the bottom surface of the base 14.
[0015] As shown in FIG. 4, when the angular bearings 26a and 26b are inserted through the pipe portion 24a of the first rotating shaft 24 and the male screw of the convex portion 27a of the rear end cap portion 27 is screwed into the female screw in the pipe portion 24a, the first bearing 26 is clamped by the flange 24b of the first rotating shaft 24 and the flange portion 27b of the rear end cap portion 27 with a predetermined pressure. With the above structure, the main frame 16 is rotatable in the left - right direction with respect to the base 14 via the first rotating shaft 24.
[0016] As shown in FIG. 5, a first torsion spring (coil torsion spring) 32 is disposed in the upper surface opening portion 30 of the base 14, and the first rotating shaft 24 and the first bearing 26 are disposed within its winding. One arm 32a of this first torsion spring 32 is housed in the locking recess 34 on the base 14 side. Also, the other arm 32b of the first torsion spring 32 abuts against a pin 36 fixed to the lower side of the main frame 16 (FIG. 6). As a result, when the main frame 16 rotates, the torque of the first torsion spring 32 acts.
[0017] The sub - frame 18 is smaller than the main frame 16 but is also formed in a substantially rectangular frame shape and is disposed inside the main frame 16 (FIG. 3). An optical element (such as a mirror, beam splitter, lens, etc.) is fitted into the opening portion 38 of this sub - frame 18.
[0018] A through - hole 44 is formed in one side of the main frame 16, and a second rotating shaft 45, a second bearing 46 composed of a radial bearing, a rear end cap 50, and a second torsion spring 51 are housed in this through - hole 44.
[0019] As shown in Figure 7, the tip 45a of the second rotating shaft 45 is fixed (screwed and bonded) into a through hole (tapped hole) 52 formed in the side of the subframe 18. Furthermore, a connecting pipe portion 45b is formed at the rear end of the second rotating shaft 45. After the second bearing 46 is inserted through this connecting pipe portion 45b, the male thread of the protrusion 50a of the rear end cap 50 is screwed into the female thread inside the connecting pipe portion 45b. As a result, the second bearing 46 is sandwiched between the stepped portion 45c of the second rotating shaft 45 and the flange portion 50b of the rear end cap 50. In addition, the edge portion 46a of the second bearing 46 abuts against the stepped portion 44a of the through hole 44 of the main frame 16.
[0020] A through-hole 44 similar to the one described above is also formed on the other side of the main frame 16, and a third rotating shaft 54, a third bearing 56 made of a radial bearing, a rear end cap 50, and a third torsion spring 60 are housed in this through-hole 44.
[0021] The tip 54a of the third rotating shaft 54 is fixed (screwed and bonded) within a through hole (tapped hole) 52 formed in the side of the subframe 18. Furthermore, a connecting pipe portion 54b is formed at the rear end of the third rotating shaft 54. After the third bearing 56 is inserted through this connecting pipe portion 54b, the male thread of the protrusion 50a of the rear end cap 50 is screwed into the female thread inside the connecting pipe portion 54b. As a result, the third bearing 56 is sandwiched between the stepped portion 54c of the third rotating shaft 54 and the flange portion 50b of the rear end cap 50. In addition, the edge portion 56a of the third bearing 56 abuts against the stepped portion 44a of the through hole 44 of the main frame 16.
[0022] With the above configuration, the subframe 18 is rotatable in the tilting direction (up and down direction) relative to the mainframe 16 via the second rotation axis 45 and the third rotation axis 54.
[0023] One arm 51a of the second torsion spring 51, which is fitted onto the second rotating shaft 45, is housed in an engagement recess 57 of the main frame 16 (Figure 1), and the other arm 51b abuts against a pin 58 fixed to the lower right side of the subframe 18 (Figure 3).
[0024] Similarly, one arm 60a of the third torsion spring 60 fitted onto the third rotating shaft 54 is housed in an engagement recess 57 on the main frame 16 side (Figure 2), while the other arm 60b abuts against a pin 58 fixed to the lower left side of the subframe 18 (Figures 3 and 8).
[0025] As a result, when the subframe 18 rotates in the vertical direction, the torques of the second torsion spring 51 and the third torsion spring 60 act upon it. The second bearing 46 and the third bearing 56 are fitted with radial bearings. Generally, radial bearings have grooves in the raceways of the inner and outer rings that form arcs with a radius slightly larger than the radius of the rolling balls. This creates a small gap in the radial and thrust directions, resulting in play in the rotating shaft. Therefore, when the inner race is pressed by the flange portion 50b of the rear end cap 50, a gap is not created between it and the outer race (pre-pressure is applied), as shown in Figure 7, thereby suppressing rattle during rotation.
[0026] The first motor unit 20 and the second motor unit 22 are mounted on the lower rear side of the main frame 16, as shown in Figure 9.
[0027] The angle adjustment screw 62 of the first motor unit 20 penetrates the main frame 16 (Figure 6) and reaches the back surface of the contact plate 64 of the base 14 (Figure 1). When the knob 63 is rotated left or right, the amount of protrusion of the angle adjustment screw 62 from the main frame 16 increases or decreases, causing the main frame 16 to rotate by a predetermined amount in the left or right direction. During this rotation, the first torsion spring 32 generates a repulsive force, which stably fixes the position of the main frame 16 after the rotation.
[0028] Furthermore, the angle adjustment screw 66 of the second motor unit 22 penetrates the main frame 16 (Figure 6) and reaches the back surface of the contact plate 68 of the subframe 18 (Figure 2). When the knob 69 is rotated left or right, the amount of protrusion of the angle adjustment screw 66 from the main frame 16 increases or decreases, causing the subframe 18 to rotate a predetermined amount in the vertical direction. During this rotation, the second torsion spring 51 and the third torsion spring 60 generate repulsive forces, which stably fix the position of the subframe 18 after the rotation.
[0029] The first motor unit 20 and the second motor unit 22 are each equipped with a connector 68 for connecting cables, and by sending electrical signals through this connector 68, the amount of protrusion of the angle adjustment screws 62 and 66 can be remotely controlled via the built-in piezo motors.
[0030] As described above, a first torsion spring 32 is used as a biasing means for stabilizing the rotational position of the main frame 16, which requires less dimensional change in response to changes in rotational angle compared to a compression spring, and the structure is provided to house the first rotating shaft 24 within its windings, thereby enabling space saving and reduction of the optical axis height for the optical element holder 10.
[0031] Figure 10(a) is a photograph of the front side of the optical element holder 10, and Figure 10(b) is a photograph of the back side. As can be seen from the comparison with 70 one-yen coins placed for reference, the optical element holder 10 is formed to be extremely small overall, and its optical axis height is within 2 inches.
[0032] Furthermore, by employing a second torsion spring 51 and a third torsion spring 60 as biasing means for stabilizing the rotational position of the subframe 18, and by having a structure that houses the second rotating shaft 45 and the third rotating shaft 54 within their respective windings, the optical element holder 10 can be made smaller. Furthermore, because it is equipped with a structure that reduces play in the second bearing 45 and the third bearing 56, which are made of radial bearings, it can exhibit high angular stability.
[0033] The first rotating shaft 24 is supported by a first bearing 26 that is space-saving and has strong resistance to moment loads, achieved by strongly pre-pressuring a pair of angular bearings 26a and 26b in a back-to-back configuration, which are capable of simultaneously supporting radial and thrust loads. As a result, even though it is a cantilever bearing structure, play when rotating the main frame 16 is effectively suppressed. However, bearings other than angular bearings can also be used as bearings for the first rotating shaft 24.
[0034] For example, as shown in Figure 11, the bearing of the first rotating shaft 24 can be configured with a pair of thrust bearings 82a, 82b and a tubular spacer 84. In this case, a thrust bearing 82b, a tubular spacer 84, and a thrust bearing 82a are sequentially inserted onto a relatively long first rotating shaft 24 equipped with a flange 24a, and the threads formed at the ends are screwed into threaded holes 86 formed on the lower side of the main frame 16. As a result, each thrust bearing 82a, 82b is clamped between the flange 24a of the first rotating shaft 24 and the lower edge of the main frame 16 with a predetermined pressure via the tubular spacer 84, thereby effectively suppressing rattle during rotation. [Explanation of symbols]
[0035] 10 Optical element holder 12 pillars 14 Base 16 Mainframes 18 Subframes 20 First motor unit 22 Second Motor Unit 24 First axis of rotation 26 First bearing 30 Top opening of the base 32 First torsion spring 45 Second axis of rotation 46. Second bearing 51 Second torsion spring 54 Third axis of rotation 56 Third bearing 60 Third torsion spring 62 First angle adjustment screw 66. Second angle adjustment screw
Claims
1. A subframe having an opening for mounting optical elements, A main frame that supports the subframe so that it can rotate freely in the tilting direction, A base that supports the mainframe so that it can rotate freely in the rotational direction, A first angle adjustment screw that penetrates from the back to the front of the main frame, with its tip contacting one surface of the base, It includes a second angle adjustment screw that penetrates from the back to the front of the main frame, with its tip contacting one surface of the subframe, An optical element holder in which the angle of the main frame changes according to the amount of protrusion of the first angle adjustment screw, and the angle of the subframe changes according to the amount of protrusion of the second angle adjustment screw, The above base comprises an upper opening, a first torsion spring housed within the upper opening, and a first rotating shaft positioned within the windings of the first torsion spring. The tip of the first rotating shaft is fixed to the lower edge of the main frame. One arm of the first torsion spring is engaged with the base side, and the other arm is engaged with the main frame side. An optical element holder characterized in that the torque of the first torsion spring acts when the main frame rotates.
2. The main frame comprises a second rotation axis located within one side and a third rotation axis located within the other side, The tip of the second rotating shaft is fixed to one side of the subframe, and the third rotating shaft is fixed to the other side of the subframe. The second rotating shaft is inserted through the winding of the second torsion spring, and the third rotating shaft is inserted through the winding of the third torsion spring. One arm of the second torsion spring and the third torsion spring are engaged with the main frame side, and the other arm is engaged with the subframe side. The optical element holder according to claim 1, characterized in that the torque of the second torsion spring and the third torsion spring acts when the subframe rotates.
3. The optical element holder according to claim 1 or 2, characterized in that the bearing of the first rotating shaft is made up of a pair of angular bearings.
4. The optical element holder according to claim 1 or 2, characterized in that the bearing of the first rotating shaft is composed of a pair of thrust bearings and a tubular spacer interposed between the two thrust bearings.
5. The optical element holder according to claim 1 or 2, characterized in that the amount of protrusion of the first angle adjustment screw and the amount of protrusion of the second angle adjustment screw are controlled by the drive of an electric motor, respectively.