Blade driving device

Abstract

To provide a blade driving device having improved durability.SOLUTION: The blade driving device includes a base plate 13 having a first support shaft and a second support shaft 61 arranged in parallel with each other. The blade drive device is attached to the base plate and has a blade that opens and closes the opening of the base plate. The blade driving device has a driving rotor 38 rotatably attached to the first supporting shaft and provided with an arm connected to the blade. The blade driving device has a first braking plate 51 rotatably attached to the first support shaft and having a pair of wall parts arranged on the moving locus of the arm across the arm. The blade driving device has a second braking plate 67 rotatably attached to the second support shaft and connected to the first braking plate. The blade driving device has a friction plate 66 which is provided in contact with the second braking plate and gives frictional resistance to the second braking plate.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a blade drive device. [Background technology]

[0002] The camera has a focal plane shutter that controls the exposure of the image sensor and film. The focal plane shutter also has a brake member that slides against the drive member that drives the blades (see Patent Document 1). By using the brake member to suppress the movement of the drive member, the blades connected to the drive member can be stopped gently. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-221744 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a structure in which the brake member is in sliding contact with the drive member, there is a risk that the drive member and the blade member may be worn out. For this reason, there is a need to improve the durability of the blade drive device by suppressing wear on the components that make up the blade drive device. [Means for solving the problem]

[0005] According to the present disclosure, a blade drive device has a base plate with a first support shaft and a second support shaft arranged parallel to each other. The blade drive device is attached to the base plate and has blades that open and close an opening in the base plate. The blade drive device has a drive rotor rotatably attached to the first support shaft and having an arm connected to the blade. The blade drive device has a first brake plate rotatably attached to the first support shaft and having a pair of wall portions arranged on either side of the arm on the movement trajectory of the arm. The blade drive device has a second brake plate rotatably attached to the second support shaft and connected to the first brake plate. The blade drive device has a friction plate that is provided in contact with the second brake plate and applies frictional resistance to the second brake plate. [Effects of the Invention]

[0006] According to the present disclosure, the durability of the blade drive device can be improved. [Brief explanation of the drawings]

[0007] [Figure 1A] FIG. 1A is a perspective view showing a blade drive device according to an embodiment of the present disclosure. [Figure 1B] FIG. 1B is a perspective view showing a blade drive device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is an exploded perspective view showing the structure of the blade drive device. [Figure 3] FIG. 3 is an exploded perspective view showing the structure of a drive unit and a brake unit provided in the blade drive device. [Figure 4] FIG. 4 is an exploded perspective view showing the structure of a brake unit provided in the blade drive device. [Figure 5] FIG. 5 is an exploded perspective view showing the mounting structure of the magnet rotor to the brake unit. [Figure 6] FIG. 6 is an exploded perspective view showing the mounting structure of the magnet rotor to the blade set. [Figure 7A]FIG. 7A is a diagram showing the operating state of the blade set and the magnet rotor. [Figure 7B] FIG. 7B is a diagram showing the operating state of the blade set and the magnet rotor. [Figure 8A] FIG. 8A is a diagram showing a magnet rotor and a brake unit. [Figure 8B] FIG. 8B is a diagram showing the magnet rotor and the brake unit. [Figure 9A] FIG. 9A is a diagram showing a magnet rotor and a brake unit. [Figure 9B] FIG. 9B is a diagram showing the magnet rotor and the brake unit. [Figure 10] FIG. 10 is a view showing the magnet rotor and the brake unit as viewed from the direction of arrow X in FIG. 8A. [Figure 11] FIG. 11 is a diagram illustrating an example of the configuration of the control unit. [Figure 12] FIG. 12 is a flowchart showing an example of a procedure for executing blade opening / closing control. [Figure 13] FIG. 13 is a flowchart showing an example of a procedure for executing blade opening / closing control. [Figure 14] FIG. 14 is a diagram showing a connection state of the voltage data adjusting device to the blade driving device. [Figure 15] FIG. 15 is a flowchart showing an example of a procedure for performing the adjustment work of the reference voltage data. [Figure 16] FIG. 16 is a diagram illustrating another example of the configuration of the control unit. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, identical or substantially identical configurations and elements will be designated by the same reference numerals and repeated description will be omitted.

[0009] <Outline of the blade drive device> 1A and 1B are perspective views showing a blade drive device 10 according to an embodiment of the present disclosure. FIG. 1A shows the blade drive device 10 with the opening 11 open, and FIG. 1B shows the blade drive device 10 with the opening 11 closed. The illustrated blade drive device 10 is a focal plane shutter incorporated into a camera such as a digital camera, and is also called a shutter device. As shown in FIG. 1A, by moving the blade set 12 to the open position, the opening 11 can be opened to allow light to shine on an imaging element or film (not shown). On the other hand, as shown in FIG. 1B, by moving the blade set 12 to the closed position, the opening 11 can be closed to block light directed toward the imaging element or film (not shown).

[0010] <Structure of the blade drive device> The structure of the blade drive device 10 will now be described. Fig. 2 is an exploded perspective view showing the structure of the blade drive device 10. Fig. 3 is an exploded perspective view showing the structures of the drive unit 30 and brake unit 50 provided in the blade drive device 10, and Fig. 4 is an exploded perspective view showing the structure of the brake unit 50 provided in the blade drive device 10.

[0011] As shown in Fig. 2, the blade drive device 10 includes a base plate 13 having an opening 11, a base cover 15 having an opening 14 and attached to the base plate 13, and a blade set 12 disposed between the base plate 13 and the base cover 15. The blade set 12 includes four blades 16, 17, 18, and 19, and a pair of link levers 20 and 21 connected to the blades 16 to 19. A support pin 22 attached to the base plate 13 is inserted into the through hole 20a of the link lever 20, and a support pin 23 attached to the base plate 13 is inserted into the through hole 21a of the link lever 21. In other words, the blades 16 to 19 constituting the blade set 12 are attached to the base plate 13 via the support pins 22 and 23. The blades 16 to 19 are also called curtains or blades.

[0012] <Drive unit structure> As shown in Fig. 2, the base plate 13 has a drive unit 30 for driving the blade set 12. As shown in Fig. 3, the drive unit 30 has a core 33 consisting of a pair of core pieces 31 and 32, a coil 34 wound around the core 33, and a control unit 36 ​​consisting of a flexible printed circuit board 35 and a microcontroller 80 (described later) and the like. The base plate 13 also has a plate main body 13a having an opening 11, and a bracket 13b attached to the plate main body 13a with an attachment screw 37. The core 33 and the flexible printed circuit board 35 are attached to the bracket 13b of the base plate 13.

[0013] The drive unit 30 has a magnet rotor (drive rotor) 38 disposed between the core pieces 31 and 32. A support pin 39 is attached to the bracket 13b of the base plate 13, and the magnet rotor 38 is rotatably attached to this support pin 39. The tip of the support pin 39 is inserted into a support pin 22 attached to a through hole 40 in the plate body 13a. In other words, the base plate 13 is provided with a first support shaft 41 made up of the support pins 22 and 39, and the magnet rotor 38 is rotatably attached to this first support shaft 41.

[0014] <Brake unit structure> As shown in FIG. 2, the base plate 13 has a brake unit 50 for braking the blade set 12. As shown in FIG. 4, the brake unit 50 has a first brake plate 51 rotatably attached to the base plate 13 via a support pin 22. The first brake plate 51 has a small-diameter plate portion 53 with a through-hole 52 into which the support pin 22 is inserted, and a large-diameter plate portion 54 with a diameter larger than that of the small-diameter plate portion 53. The large-diameter plate portion 54 has a rotor-accommodating recess 55 cut out in a substantially U-shape, an open sidewall portion 56 provided at one end of the rotor-accommodating recess 55, and a closed sidewall portion 57 provided at the other end of the rotor-accommodating recess 55. The large-diameter plate portion 54 also has a lever portion 58 extending radially outward, and a pin-accommodating groove 59 formed in the lever portion 58. The first brake plate 51 is formed using a resin material such as polyacetal or polyamide.

[0015] The brake unit 50 has a support pin 61 inserted into a through-hole 60 of the base plate 13, a collar 62 attached to the support pin 61, and a torsion coil spring 63 attached to the collar 62. The brake unit 50 also has an adjustment screw 64 that passes through the collar 62 and the torsion coil spring 63 and is attached to a screw hole 61b of the support pin 61. The brake unit 50 also has a leaf spring 65, a washer 66, a second brake plate 67, and a washer 68. The leaf spring 65, washer 66, second brake plate 67, and washer 68 are sandwiched between the flange 61a of the support pin 61 and the flange 62a of the collar 62. The second brake plate 67 also has a connecting pin 67a received in the pin receiving groove 59 of the first brake plate 51 and an engagement piece 67b on which the torsion coil spring 63 is hooked.

[0016] As described above, the base plate 13 is provided with a support pin (second support shaft) 61, and the second brake plate 67 is rotatably attached to this support pin 61. In addition, a leaf spring (elastic member) 65, a washer (friction plate) 66, and an adjustment screw 64 are attached to the support pin 61. The distance between the flange 61a of the support pin 61 and the flange 62a of the collar 62 can be adjusted by adjusting the amount that the adjustment screw 64 is fastened to the support pin 61. In other words, by adjusting the amount that the adjustment screw 64 is fastened, the compression amount of the leaf spring 65 can be adjusted, and the pressing force of the washer 66 against the second brake plate 67 can be adjusted. The second brake plate 67 is formed using a metal material such as steel or a copper alloy.

[0017] FIG. 5 is an exploded perspective view showing the mounting structure of the magnet rotor 38 relative to the brake unit 50, and FIG. 6 is an exploded perspective view showing the mounting structure of the magnet rotor 38 relative to the blade set 12. As shown in FIG. 5, the magnet rotor 38 has a rotor body 70 made of a permanent magnet and rotor arms (arms) 71 extending radially outward from the rotor body 70. The lower end of the magnet rotor 38 is housed in the rotor housing recess 55 of the first braking plate 51. A connecting pin 72 is provided at the tip of the rotor arm 71, and this connecting pin 72 is inserted into the through hole 20b of the link lever 20 that constitutes the blade set 12. In other words, as shown in FIG. 6, the rotor arm 71 of the magnet rotor 38 is connected to the blades 16 to 19 via the connecting pin 72 and the link lever 20.

[0018] As shown in Fig. 5, an arc-shaped opening 75 that accommodates the rotor arm 71 is formed in the base plate 13. An open-side stopper surface 76 is provided at one end of the opening 75, and a close-side stopper surface 77 is provided at the other end of the opening 75. The first braking plate 51 also has a pair of walls that sandwich the rotor arm 71, namely, an open-side wall portion 56 and a close-side wall portion 57. As shown in Fig. 8A (described later), the open-side wall portion 56 and the close-side wall portion 57 of the first braking plate 51 are arranged on the movement locus α of the rotor arm 71 so that the rotor arm 71 comes into contact with them.

[0019] <Blade and magnet rotor operation> Next, the operation of the blade set 12 and the magnet rotor 38 will be described. Figures 7A and 7B are diagrams showing the operating states of the blade set 12 and the magnet rotor 38. Figure 7A shows a state in which the opening 11 is opened by the blades 16 to 19 of the blade set 12, that is, a state in which the blade set 12 and the magnet rotor 38 have moved to the open position. Figure 7B shows a state in which the opening 11 is closed by the blades 16 to 19 of the blade set 12, that is, a state in which the blade set 12 and the magnet rotor 38 have moved to the closed position. Note that in Figures 7A and 7B, an example of the imaging element 110 is shown using a two-dot chain line.

[0020] 7A, magnet rotor 38 is disposed between core pieces 31 and 32, and rotor body 70 of magnet rotor 38 is magnetized to a north pole and a south pole. As will be described later, control unit 36 ​​including microcontroller 80 can switch between energizing and de-energizing coil 34, and can switch the direction of current flow through coil 34. In other words, control unit 36, which controls the energization state of coil 34, can magnetize core piece 31 to a south pole and core piece 32 to a north pole, or can magnetize core piece 31 to a north pole and core piece 32 to a south pole.

[0021] 7A, when core piece 31 is magnetized to the south pole and core piece 32 is magnetized to the north pole, magnet rotor 38 rotates in the direction of arrow OP1 toward the open position, and blades 16-19 move in the direction of arrow OP2 toward the open position. Note that when blades 16-19 move to the open position, control unit 36 ​​cuts off the power supply to coil 34. In this way, even when power supply to coil 34 is cut off, magnet rotor 38 continues to be attracted to core pieces 31 and 32, so blades 16-19 are held in the open position.

[0022] 7B, when core piece 31 is magnetized to the north pole and core piece 32 is magnetized to the south pole, magnet rotor 38 rotates in the direction of arrow CL1 toward the closed position, and blades 16-19 move in the direction of arrow CL2 toward the closed position. Note that when blades 16-19 move to the closed position, control unit 36 ​​cuts off the power supply to coil 34. In this way, even when power supply to coil 34 is cut off, magnet rotor 38 continues to be attracted to core pieces 31 and 32, so blades 16-19 are held in the closed position.

[0023] As shown in FIG. 5, two light-shielding walls 78 are provided on the rotor body 70 of the magnet rotor 38, and as shown in FIG. 3, a position sensor 79 is provided on the bracket 13b of the base plate 13, sandwiching the light-shielding walls 78. For example, a photointerrupter, which is a transmission-type photosensor, can be used as the position sensor 79. The position sensor 79 is connected to the flexible printed circuit board 35. This allows the control unit 36 ​​to determine the rotational position of the magnet rotor 38, i.e., the movement positions of the blades 16 to 19, based on the detection signal from the position sensor 79. Furthermore, the control unit 36 ​​can detect positions P1, P2, and P3 of the blade set 12 shown in FIG. 7A based on the detection signal output from the position sensor 79. In other words, the control unit 36 ​​can detect the timing when the edge 16x of the blade 16 (hereinafter referred to as the blade edge 16x) passes through positions P1, P2, and P3.

[0024] <Blade group braking status> When the blade set 12 is moved to the closed position or the open position, the blade set 12 is moved at high speed, and therefore it is necessary to brake the blade set 12 near the closed position or the open position. For this reason, the blade drive device 10 according to one embodiment of the present disclosure has a brake unit 50 for braking the blade set 12. The braking of the blade set 12 by the brake unit 50 will be described below.

[0025] Figures 8A, 8B, 9A, and 9B are views showing the magnet rotor 38 and the brake unit 50. Figures 8A and 8B show the process of the magnet rotor 38 moving from the closed position to the open position. Meanwhile, Figures 9A and 9B show the process of the magnet rotor 38 moving from the open position to the closed position. Also, Figure 10 is a view showing the magnet rotor 38 and the brake unit 50 from the direction of arrow X in Figure 8A.

[0026] <Braking near the open position> 8A, when the magnet rotor 38 is stopped in the closed position, the side surface 71a of the rotor arm 71 contacts the close-side wall portion 57 of the first braking plate 51, and the side surface 71a of the rotor arm 71 contacts the close-side stopper surface 77 of the base plate 13. At this time, the open-side wall portion 56 of the first braking plate 51 is positioned closer to the rotor arm 71 than the open-side stopper surface 76 of the base plate 13. Here, when the magnet rotor 38 is rotated in the direction of arrow OP1, which is the open side, the side surface 71b of the rotor arm 71 contacts the open-side wall portion 56 when it reaches position Po1. Subsequently, when the side surface 71b of the rotor arm 71 moves to position Po2, the side surface 71b of the rotor arm 71 contacts the open-side stopper surface 76 and stops.

[0027] 8B , when the magnet rotor 38 moves toward the open position, the rotor arm 71 comes into contact with the first brake plate 51 before the magnet rotor 38 reaches the open position. The rotor arm 71 then rotates the first brake plate 51 in the direction of arrow OP3 until the magnet rotor 38 reaches the open position. Furthermore, because the second brake plate 67 is connected to the first brake plate 51, the rotor arm 71 rotates the second brake plate 67 in the direction of arrow OP4 via the first brake plate 51. In this way, when the magnet rotor 38 rotates from the closed position to the open position, the rotor arm 71 comes into contact with the open side wall portion 56, which is one of the pair of walls, and rotates the first brake plate 51 and the second brake plate 67 toward the open side.

[0028] As shown in FIG. 10 , the leaf spring 65 biases the washer 66 toward the second braking plate 67. As shown in FIG. 8B , the engagement piece 65a of the leaf spring 65 is attached to the base plate 13, restricting rotation of the leaf spring 65 relative to the support pin 61. That is, when the second braking plate 67 rotates in the direction of arrow OP4, the second braking plate 67 slides relative to the washer 66, and the washer 66 applies frictional resistance to the second braking plate 67. This increases the rotational resistance of the second braking plate 67, allowing the magnet rotor 38 to be stopped smoothly together with the second braking plate 67, and the blade set 12 to be stopped smoothly in the open position. The second braking plate 67 also slides relative to the washer 68, and the washer 68 also applies frictional resistance to the second braking plate 67.

[0029] 8B and 10, the second braking plate 67 is provided with an engagement piece 67b extending upward. Furthermore, the torsion coil spring 63 of the brake unit 50 has an end 63a hooked on the engagement piece 67b and an end 63b hooked on the base plate 13. Therefore, as shown by arrow Fs1 in FIG. 8B, the spring force of the torsion coil spring 63 acts to urge the second braking plate 67 to rotate in the direction of arrow OP4, i.e., toward the open side. In other words, the torsion coil spring 63 is attached so as to bias the second braking plate 67 toward the open side. This allows the torsion coil spring 63 to assist the movement of the blade set 12, even when the magnet rotor 38 is stopped by the brake unit 50, and ensures that the blade set 12 moves to the open position.

[0030] The timing at which the side surface 71a of the rotor arm 71 contacts the close side wall portion 57 of the first braking plate 51, i.e., the timing at which braking starts, can be set appropriately according to the camera specifications. For example, as shown in Fig. 7A, braking may start after the blade edge 16x reaches the lower end 110a of the imaging element 110, or before the blade edge 16x reaches the lower end 110a of the imaging element 110. Braking may also start when the blade edge 16x reaches the lower end 110a of the imaging element 110.

[0031] <Braking near the closed position> 9A, when the magnet rotor 38 is stopped in the open position, the side surface 71b of the rotor arm 71 contacts the open side wall portion 56 of the first braking plate 51, and the side surface 71b of the rotor arm 71 contacts the open side stopper surface 76 of the base plate 13. At this time, the close side wall portion 57 of the first braking plate 51 is positioned closer to the rotor arm 71 than the close side stopper surface 77 of the base plate 13. Here, when the magnet rotor 38 is rotated in the direction of arrow CL1, which is the close side, the side surface 71a of the rotor arm 71 contacts the close side wall portion 57 when it reaches position Pc1. Subsequently, when the side surface 71a of the rotor arm 71 moves to position Pc2, the side surface 71a of the rotor arm 71 contacts the close side stopper surface 77 and stops.

[0032] 9B , when the magnet rotor 38 moves toward the closed position, the rotor arm 71 comes into contact with the first brake plate 51 before the magnet rotor 38 reaches the closed position. The rotor arm 71 then rotates the first brake plate 51 in the direction of arrow CL3 until the magnet rotor 38 reaches the closed position. Furthermore, because the second brake plate 67 is connected to the first brake plate 51, the rotor arm 71 rotates the second brake plate 67 in the direction of arrow CL4 via the first brake plate 51. In this way, when the magnet rotor 38 rotates from the open position to the closed position, the rotor arm 71 comes into contact with the close-side wall portion 57, which is one of a pair of walls, and rotates the first brake plate 51 and the second brake plate 67 toward the closed side.

[0033] When the second braking plate 67 rotates in the direction of arrow CL4, the second braking plate 67 slides against the washer 66, and therefore frictional resistance can be applied to the second braking plate 67 from the washer 66. This increases the rotational resistance of the second braking plate 67, and therefore the magnet rotor 38 can be stopped gently together with the second braking plate 67, and the blade set 12 can be stopped gently in the closed position. Note that the second braking plate 67 also slides against the washer 68, and therefore frictional resistance is also applied to the second braking plate 67 from the washer 68. Furthermore, as shown by arrow Fs1 in FIG. 9B , the spring force of the torsion coil spring 63 acts to suppress rotation of the second braking plate 67 in the direction of arrow CL4, i.e., toward the closed side.

[0034] In this way, when the blade set 12 is moved to the closed position, frictional resistance is applied to the second braking plate 67 from the washers 66, 68, and spring force is applied from the torsion coil spring 63 in a direction to stop rotation. As a result, when the release switch 103 described below is pressed to close the opening 11 of the blade drive device 10, the frictional resistance and spring force can stop the magnet rotor 38 smoothly and quickly. In other words, even if the movement speed of the blades 16 to 19 is increased, the noise generated when the rotor arm 71 comes into contact with the close-side stopper surface 77 can be suppressed.

[0035] The timing at which the side surface 71b of the rotor arm 71 contacts the open side wall portion 56 of the first braking plate 51, i.e., the timing at which braking starts, can be set appropriately according to the camera specifications. For example, as shown in Fig. 7B, braking may start after the blade edge 16x reaches the upper end 110b of the imaging element 110, or before the blade edge 16x reaches the upper end 110b of the imaging element 110. Braking may also start when the blade edge 16x reaches the upper end 110b of the imaging element 110.

[0036] <Summary> As explained above, the base plate 13 is provided with the first support shaft 41 made up of the support pins 22 and 39, as well as with a support pin (second support shaft) 61 arranged parallel to the first support shaft 41. The magnet rotor 38 is rotatably attached to the first support shaft 41, and the first braking plate 51 is rotatably attached to the first support shaft 41. Furthermore, the second braking plate 67 connected to the first braking plate 51 is rotatably attached to the support pin (second support shaft) 61.

[0037] In this way, by arranging the magnet rotor 38 and the first braking plate 51 coaxially, it is possible to suppress sliding between the side surfaces 71a, 71b of the rotor arm 71 and the wall portions 56, 57 of the first braking plate 51. In other words, the side surfaces 71a, 71b of the rotor arm 71 and the wall portions 56, 57 of the first braking plate 51 do not move relative to each other in the radial direction of the first support shaft 41, so it is possible to suppress wear of the rotor arm 71 and the first braking plate 51. This makes it possible to increase the durability of the blade drive device 10.

[0038] Furthermore, a second braking plate 67 is attached to a support pin (second support shaft) 61 that is different from the first support shaft 41, and a washer (friction plate) 66 is brought into contact with this second braking plate 67. This allows the washer 66, leaf spring 65, etc. to be arranged away from the magnet rotor 38, thereby achieving a reduction in size of the blade drive device 10. In other words, if the leaf spring 65, washer 66, and second braking plate 67, etc. are arranged coaxially with the first support shaft 41, the leaf spring 65, washer 66, and second braking plate 67 are stacked on the magnet rotor 38. In this way, when the various components are stacked on the magnet rotor 38, the thickness dimension of the blade drive device 10 increases, but by arranging the washer 66, leaf spring 65, etc. away from the magnet rotor 38, a reduction in thickness, i.e., a reduction in size of the blade drive device 10 can be achieved. Furthermore, since the adjustment screw 64 can be arranged away from the magnet rotor 38, the adjustment screw 64 can be easily installed while avoiding interference with the core 33 arranged near the magnet rotor 38.

[0039] Furthermore, since the first brake plate 51 that contacts the rotor arm 71 and the second brake plate 67 that contacts the washer (friction plate) 66 are separated, it is possible to improve the quietness and durability of the brake unit 50. That is, by forming the first brake plate 51 from a resin material, it is possible to reduce the noise when the rotor arm 71 contacts the first brake plate 51. Furthermore, by forming the second brake plate 67 from a metal material, it is possible to improve the wear resistance of the second brake plate 67 that contacts the washer (friction plate) 66.

[0040] Furthermore, in order to reduce the contact noise of the rotor arm 71 against the first brake plate 51 while increasing the wear resistance of the brake plates, the material of the first brake plate 51 needs to be softer than the material of the second brake plate 67. That is, by forming the first brake plate 51 using a material softer than the second brake plate 67, the noise generated when the rotor arm 71 contacts the first brake plate 51 can be reduced. Furthermore, by forming the second brake plate 67 using a material harder than the first brake plate 51, the wear resistance of the second brake plate 67, which contacts the washer (friction plate) 66, can be increased. Note that both the first brake plate 51 and the second brake plate 67 may be made of a metal material, or both the first brake plate 51 and the second brake plate 67 may be made of a resin material. Furthermore, for example, a Rockwell hardness test, a Vickers hardness test, or a Barcol hardness test can be used as a hardness test for the material.

[0041] <Control unit> Next, the control unit 36 ​​of the blade drive device 10 will be described. Fig. 11 is a diagram showing an example of the configuration of the control unit 36. As shown in Fig. 11, the control unit 36 ​​has a microcontroller 80 equipped with a processor 81 and a main memory 82. The microcontroller 80 has a power supply IC 83 such as a low dropout regulator IC, and a D / A converter 85 with a built-in non-volatile memory 84. The control unit 36 ​​also has a motor driver 86 that controls the current flowing through the coils 34. The motor driver 86 has a bridge circuit 87 connected to the coils 34, and a drive circuit 88 that controls the switching elements SW1 to SW4 of the bridge circuit 87. The control unit 36 ​​also has a position sensor 79 that detects the position of the magnet rotor 38, a temperature sensor 89 that detects the temperature of the blade drive device 10, and a gyro sensor 90 that detects the attitude of the blade drive device 10.

[0042] The control unit 36 ​​also includes an operational amplifier 91 that connects the microcontroller 80 and the motor driver 86. The operational amplifier 91 outputs a feedback voltage to the microcontroller 80 based on the potential difference between the reference voltage input from the D / A converter 85 and the input voltage input from the bridge circuit 87. The microcontroller 80 then adjusts the PWM signal output to the drive circuit 88 based on the feedback voltage. That is, the current value flowing through the bridge circuit 87, i.e., the rotational torque of the magnet rotor 38, can be controlled based on the reference voltage from the D / A converter 85, thereby controlling the movement speed of the blades 16 to 19. The blades 16 to 19 are also called curtains, and the blade speed, which is the movement speed of the blades 16 to 19, is sometimes called the curtain speed. Reference voltage data, which is data on the reference voltage, is stored in the nonvolatile memory 84 of the D / A converter 85.

[0043] 11, when blade drive device 10 is incorporated into camera 100, control unit 36 ​​is connected to camera control unit 101 of camera 100. When power switch 102 or release switch 103 of camera 100 is operated, operation signals of power switch 102 or release switch 103 are input from camera control unit 101 to microcontroller 80. Position information (open position, closed position) of blade set 12 is input from microcontroller 80 to camera control unit 101.

[0044] Furthermore, temperature information and attitude information of the blade drive device 10 are also input from the microcontroller 80 to the camera control unit 101. For example, when the temperature of the blade drive device 10 rises, the blade speed decreases, so the camera control unit 101 corrects the readout timing of the image sensor 110, etc., based on the temperature information of the blade drive device 10. Furthermore, when the attitude of the blade drive device 10 changes, the blade speed is affected by gravity, so the camera control unit 101 corrects the readout timing of the image sensor 110, etc., based on the attitude information of the blade drive device 10.

[0045] <Blade opening / closing control> The blade opening / closing control for moving the blade set 12 of the blade drive device 10 to the open position or the closed position will now be described. Figures 12 and 13 are flowcharts showing an example of the execution procedure for the blade opening / closing control. The flowcharts shown in Figures 12 and 13 are connected to each other at the point indicated by the symbol A.

[0046] As shown in FIG. 12, the microcontroller 80 proceeds to step S10 and determines whether the power switch 102 of the camera 100 is ON. If the microcontroller 80 determines in step S10 that the power switch 102 is ON, the microcontroller 80 proceeds to step S11 and reads reference voltage data from the non-volatile memory 84. The microcontroller 80 proceeds to step S12 and outputs an open signal to the motor driver 86 to rotate the magnet rotor 38 to the open side, and outputs a reference voltage from the D / A converter 85 based on the reference voltage data. As a result, as shown by arrows OP1 and OP2 in FIG. 7A, the magnet rotor 38 rotates toward the open position, and the blade set 12 moves toward the open position. The blade speed at this time is a blade speed corresponding to the reference voltage.

[0047] As shown in Fig. 12, after starting the movement of the blade set 12 in step S12, the microcontroller 80 proceeds to step S13 and determines whether the blade edge 16x passes through position P1 (see Fig. 7A). If the microcontroller 80 determines in step S13 that the blade edge 16x has not passed through position P1, the microcontroller 80 returns to step S12 and continues to energize the coil 34. On the other hand, if the microcontroller 80 determines in step S13 that the blade edge 16x has passed through position P1, the microcontroller 80 proceeds to step S14 and stops energizing the coil 34. As a result, the blade set 12 stops at the open position, and the opening 11 is opened, as shown in Fig. 7A.

[0048] As shown in FIG. 13, the microcontroller 80 proceeds to step S15 and determines whether the power switch 102 is ON. If the microcontroller 80 determines in step S15 that the power switch 102 is ON, the microcontroller 80 proceeds to step S16 and determines whether the release switch 103 is pressed. If the microcontroller 80 determines in step S15 that the release switch 103 is pressed, that is, that the release switch 103 is ON, the microcontroller 80 proceeds to step S17. In step S17, the microcontroller 80 outputs a close signal to the motor driver 86 to rotate the magnet rotor 38 to the close side, and outputs a reference voltage from the D / A converter 85 based on the reference voltage data. As a result, as shown by arrows CL1 and CL2 in FIG. 7B, the magnet rotor 38 rotates toward the close position, and the blade set 12 moves toward the close position. The blade speed at this time is a blade speed corresponding to the reference voltage.

[0049] As shown in Fig. 13, after starting the movement of the blade set 12 in step S17, the microcontroller 80 proceeds to step S18 and determines whether the blade edge 16x passes through position P3 (see Fig. 7A). If the microcontroller 80 determines in step S18 that the blade edge 16x has not passed through position P3, the microcontroller 80 returns to step S17 and continues to energize the coil 34. On the other hand, if the microcontroller 80 determines in step S18 that the blade edge 16x has passed through position P3, the microcontroller 80 proceeds to step S19 and stops energizing the coil 34. As a result, the blade set 12 stops at the closed position, and the opening 11 is closed, as shown in Fig. 7B.

[0050] As shown in Fig. 13, the microcontroller 80 proceeds to step S20 and determines whether a predetermined time has elapsed since the blade set 12 moved to the closed position. If the microcontroller 80 determines in step S20 that the predetermined time has elapsed, the microcontroller 80 proceeds to step S21 and outputs an open signal to the motor driver 86 to rotate the magnet rotor 38 to the open side, and outputs a reference voltage from the D / A converter 85 based on the reference voltage data. As a result, as shown by arrows OP1 and OP2 in Fig. 7A, the magnet rotor 38 rotates toward the open position, and the blade set 12 moves toward the open position. The blade speed at this time is a blade speed corresponding to the reference voltage.

[0051] 13, after starting the movement of the blade set 12 in step S21, the microcontroller 80 proceeds to step S22 and determines whether the blade edge 16x passes through position P1 (see FIG. 7A). If the microcontroller 80 determines in step S22 that the blade edge 16x has not passed through position P1, the microcontroller 80 returns to step S21 and continues to energize the coil 34. On the other hand, if the microcontroller 80 determines in step S22 that the blade edge 16x has passed through position P1, the microcontroller 80 proceeds to step S23 and stops energizing the coil 34. As a result, the blade set 12 stops at the open position, and the opening 11 is opened, as shown in FIG. 7A.

[0052] <Reference voltage data adjustment work> As described above, the blade speed, which is the movement speed of the blades 16 to 19, is determined according to the reference voltage data stored in the nonvolatile memory 84. However, for mass-produced blade drive devices 10, even if the same reference voltage data is used for each blade drive device, variations in the blade speed of mass-produced blade drive devices generally occur. For this reason, in order to make the blade speed of mass-produced blade drive devices uniform, it is necessary to adjust the reference voltage data stored for each blade drive device.

[0053] The following describes the adjustment of the reference voltage data that is carried out in the inspection process when manufacturing the blade drive device 10. Fig. 14 is a diagram showing the connection status of the voltage data adjusting device 120 to the blade drive device 10, and Fig. 15 is a flowchart showing an example of the procedure for performing the adjustment of the reference voltage data. The adjustment of the reference voltage data shown in Fig. 15 is performed by the voltage data adjusting device 120.

[0054] As shown in FIG. 14, in the inspection process when manufacturing the blade drive device 10, a voltage data adjusting device 120 is communicatively connected to the blade drive device 10. The voltage data adjusting device 120 is made up of a microcontroller, a power supply circuit, etc. (not shown). The voltage data adjusting device 120 transmits reference voltage data and a release signal to the microcontroller 80 of the blade drive device 10. The release signal is an operation signal that is output when the release switch 103 described above is pressed. The microcontroller 80 of the blade drive device 10 also transmits the blade speed to the voltage data adjusting device 120. The microcontroller 80 calculates the blade speed based on a passing signal of positions P1, P2, and P3 of the blade edge 16x, which is output by the position sensor 79.

[0055] As shown in FIG. 15, the voltage data adjusting device 120 proceeds to step S30 and transmits an initial value of reference voltage data to the blade drive device 10. The initial value of the reference voltage data is a minimum value that signifies the lower limit voltage of the adjustable range. The voltage data adjusting device 120 also proceeds to step S31 and transmits a release signal to the blade drive device 10, and then proceeds to step S32 and receives the blade speed from the blade drive device 10. Next, the voltage data adjusting device 120 proceeds to step S31 and determines whether the blade speed is within a predetermined reference range. If the voltage data adjusting device 120 determines in step S33 that the blade speed is outside the reference range, it proceeds to step S34 and adds a predetermined value to the reference voltage data to update the reference voltage data, and then proceeds to step S35 and transmits the updated reference voltage data to the blade drive device 10.

[0056] After transmitting the updated reference voltage data in step S35, the voltage data adjusting device 120 again proceeds to steps S31 to S33, where it transmits a release signal to the blade drive device 10, receives the blade speed from the blade drive device 10, and determines whether this blade speed is within the reference range. That is, the voltage data adjusting device 120 gradually increases the reference voltage data until the blade speed falls within the reference range. Then, when the voltage data adjusting device 120 determines in step S33 that the blade speed is within the reference range, it proceeds to step S36 and writes the current reference voltage data to the non-volatile memory 84 of the blade drive device 10. Furthermore, the voltage data adjusting device 120 proceeds to step S37, where it generates a two-dimensional code including the current reference data, and imprints this two-dimensional code on the blade drive device 10 using a laser or the like.

[0057] In this way, by adjusting the reference voltage data so that the blade speed falls within the reference range, it is possible to make the blade speed of mass-produced blade drive devices 10 approximately uniform. This makes it possible to stabilize the performance of the camera 100 incorporating the blade drive device 10. Also, since there is no need to adjust the blade speed in the camera 100, it becomes easier to incorporate the blade drive device 10 into the camera 100. Furthermore, even when replacing the blade drive device 10 in the camera 100, it is possible to easily replace the blade drive device 10 because the blade speed is approximately uniform before and after replacement.

[0058] <Modification> In the example shown in Fig. 11, the reference voltage is output using a D / A converter 85, but this is not limited to this. Here, Fig. 16 is a diagram showing another configuration example of the control unit 36. As shown in Fig. 16, the control unit 36 ​​of the blade drive device 10 has a microcontroller 131 equipped with a processor 81 and a main memory 82. The microcontroller 131 has a digital potentiometer 133 with a built-in non-volatile memory 132. In addition, the control unit 36 ​​has an operational amplifier 91 that connects the microcontroller 131 and the motor driver 86.

[0059] The operational amplifier 91 outputs a feedback voltage to the microcontroller 131 based on the potential difference between the reference voltage input from the digital potentiometer 133 and the input voltage input from the bridge circuit 87. The microcontroller 131 then adjusts the PWM signal output to the drive circuit 88 based on the feedback voltage. That is, the value of the current flowing through the bridge circuit 87, i.e., the rotational torque of the magnet rotor 38, can be controlled based on the reference voltage from the digital potentiometer 133, and the blade speed can be controlled. Reference voltage data, which is data on the reference voltage, is stored in the nonvolatile memory 132 of the digital potentiometer 133.

[0060] <Other variations> The present disclosure is not limited to the above-described embodiment and can be modified in various ways without departing from the spirit and scope of the present disclosure. The illustrated blade drive device 10 is a so-called electronic front-curtain shutter that controls the end of exposure of the image sensor 110 by closing the rear-curtain blade set 12, but is not limited to this. For example, the blade drive device may be one that includes the rear-curtain blade set 12 and the front-curtain blade set. Even in such a blade drive device, the rear-curtain blade set 12 can be braked using the brake unit 50 described above, and the front-curtain blade set can be braked using the brake unit 50 described above.

[0061] In the illustrated example, four blades 16-19 are used to open and close the opening 11, but this is not limiting. For example, the opening 11 may be opened and closed using one blade, two or three blades, or five or more blades. In addition, in the above description, the leaf spring 65 is used as the elastic member that biases the washer 66, but this is not limiting, and a compression coil spring, rubber, or the like may also be used as the elastic member. In addition, in the above description, a low dropout regulator IC is used as the power supply IC 83, but this is not limiting, and a DC / DC converter may also be used as the power supply IC 83.

[0062] The present technology can be configured as follows. [1] a base plate including a first support shaft and a second support shaft arranged parallel to each other; a blade attached to the base plate and configured to open and close an opening in the base plate; a drive rotor rotatably mounted on the first support shaft and including an arm connected to the blade; a first braking plate rotatably attached to the first support shaft and including a pair of wall portions disposed on a movement path of the arm with the arm sandwiched therebetween; a second brake plate rotatably attached to the second support shaft and connected to the first brake plate; a friction plate provided in contact with the second brake plate and applying frictional resistance to the second brake plate; having Blade drive device. [2] In the blade drive device described in [1], the drive rotor is rotatable between an open position where the blades are moved to open the opening and a closed position where the blades are moved to close the opening, When the drive rotor rotates from the open position to the closed position, the arm contacts one of the pair of wall portions to rotate the first brake plate and the second brake plate toward the closed side, When the drive rotor rotates from the closed position to the open position, the arm contacts the other of the pair of wall portions to rotate the first brake plate and the second brake plate toward the open side. Blade drive device. [3] In the blade drive device according to the above [1] or [2], the first braking plate is made of a resin material, The second braking plate is made of a metal material. Blade drive device. [4] In the blade drive device described in any one of [1] to [3], the material of the first brake plate is softer than the material of the second brake plate; Blade drive device. [5] In the blade drive device described in any one of [1] to [4], an elastic member attached to the second support shaft and biasing the friction plate toward the second brake plate; Blade drive device. [6] In the blade drive device described in [5] above, an adjusting screw attached to the second support shaft for compressing the elastic member; Blade drive device. [7] In the blade drive device described in [2], a torsion coil spring attached to the second support shaft and biasing the second brake plate toward the open side; Blade drive device. [Explanation of symbols]

[0063] 10...blade drive device, 11...opening, 13...base plate, 16, 17, 18, 19...blade, 38...magnet rotor (drive rotor), 41...first support shaft, 51...first brake plate, 56...open side wall portion (wall portion), 57...closed side wall portion (wall portion), 61...support pin (second support shaft), 63...torsion coil spring, 64...adjustment screw, 65...leaf spring (elastic member), 66...washer (friction plate), 67...second brake plate, 71...rotor arm (arm), α...movement trajectory

Claims

1. a base plate including a first support shaft and a second support shaft arranged parallel to each other; a blade attached to the base plate and configured to open and close an opening in the base plate; a drive rotor rotatably mounted on the first support shaft and including an arm connected to the blade; a first braking plate rotatably attached to the first support shaft and including a pair of wall portions disposed on a movement path of the arm with the arm sandwiched therebetween; a second brake plate rotatably attached to the second support shaft and connected to the first brake plate; a friction plate provided in contact with the second brake plate and applying frictional resistance to the second brake plate; having Blade drive device.

2. The blade drive device according to claim 1, the drive rotor is rotatable between an open position where the blades are moved to open the opening and a closed position where the blades are moved to close the opening, When the drive rotor rotates from the open position to the closed position, the arm contacts one of the pair of wall portions to rotate the first brake plate and the second brake plate toward the closed side, When the drive rotor rotates from the closed position to the open position, the arm comes into contact with the other of the pair of wall portions to rotate the first brake plate and the second brake plate toward the open side. Blade drive device.

3. The blade drive device according to claim 1, the first braking plate is made of a resin material, The second braking plate is made of a metal material. Blade drive device.

4. The blade drive device according to claim 1, the material of the first brake plate is softer than the material of the second brake plate; Blade drive device.

5. The blade drive device according to claim 1, an elastic member attached to the second support shaft and biasing the friction plate toward the second brake plate; Blade drive device.

6. The blade drive device according to claim 5, an adjusting screw attached to the second support shaft and compressing the elastic member; Blade drive device.

7. The blade drive device according to claim 2, a torsion coil spring attached to the second support shaft and biasing the second brake plate toward the open side; Blade drive device.

Images