Lens barrel and optical device
By detecting the reference position of the lens frame in the optical system and adjusting the reset driving conditions, the problem of lens frame collision during reset driving is solved, and a faster and safer reset process is achieved.
Patent Information
- Application Number
- CN202411563050.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-11-10
- Filing Date
- 2024-11-05
- Publication Date
- 2025-05-13
AI Technical Summary
In optical systems with overlapping moving regions, how to avoid collisions between moving lens frames during reset drive, especially when using open loop control methods.
By setting a detection unit to detect the reference position of each moving lens frame, and adjusting the reset driving conditions based on the detection output, it is ensured that each lens frame will not collide during reset. The specific method includes using an optical circuit breaker to detect the reference position and adjusting the movement speed and direction of each lens frame according to the detection results.
It effectively avoids collisions between moving lens frames during reset drive, shortens the time spent on reset drive, and improves the stability and safety of the system.
Smart Images
Figure CN119986945A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a lens barrel and an optical device. Background Art
[0002] Image capturing devices such as digital cameras and video cameras (optical devices) perform magnification (zooming) and focus adjustment (focusing) by moving a movable lens frame holding a lens in the optical axis direction using a driving force from a driving source. A stepping motor, a voice coil motor (VCM) composed of a magnet and a coil, and the like are called a driving mechanism (driving source) for moving the movable lens frame.
[0003] Generally, in the case where the moving lens frame is driven by a driving force from a driving source (such as a stepping motor, etc.), a reference position of the moving lens frame on the optical axis (this reference position becomes a driving origin) is set, and the moving lens frame moves from this position. At this time, the reference position of the moving lens frame on the optical axis is determined, and as a position determination driving control method to be used to drive the moving lens frame later, a so-called open-loop control method is generally used.
[0004] The open loop control method does not require a detection device to detect the position on the optical axis of the mobile lens frame every moment. In addition, the open loop control method has the advantage of being simpler and smaller than a control system in which the control system is set as a closed loop control method.
[0005] However, in an open-loop control method using a driving source such as a stepping motor, when positioning the moving lens frame, it is necessary to make the driving start position of the stepping motor and the driving start position of the moving lens frame the same. Therefore, the moving lens group must be returned to a specific reference position on the optical axis before starting the positioning drive control. Therefore, a drive for detecting whether the moving lens frame has been positioned at the reference position (reset position) is also necessary. The drive for determining the reset position is called a reset drive (or reset control).
[0006] In addition, in the case of closed-loop control, a combination of a first detection element that detects a reference position and a second detection element that outputs an incremental pulse signal (for example, a GMR element) is often used for control, or a single detection element that can detect an absolute position is used for control.
[0007] Conventionally, there is known a lens control device which uses a single reference position detection unit (common photo interrupter) to detect the reference position of a zooming moving lens frame and a focusing moving lens frame and performs drive control on the two moving lens frames. This lens control device is shown in Japanese Patent No. 3384133.
[0008] In recent years, optical systems have become more complex, and an optical type having an overlapping area (overlap) in the moving areas of a plurality of moving lens frames at the time of zooming and at the time of focusing has been proposed.
[0009] In the optical type with overlap, it is necessary to avoid collision between the moving lens frames at the time of resetting and at the time of normal driving.
[0010] Japanese Unexamined Patent Application First Publication No. 2010-210868 discloses an example in which collision between moving lens frames is avoided by resetting and driving a plurality of moving lens frames in a predetermined order.
[0011] Japanese Unexamined Patent Application First Publication No. 2013-3352 discloses an example of using a grey code pattern and a brush as a means for detecting an absolute value and using a GMR as a relative detection unit. Therefore, detailed detection can be performed, thereby avoiding collision between moving lens frames at the time of reset drive even in an optical system with overlap. Summary of the invention
[0012] According to one aspect of an embodiment of the present application, a lens barrel comprises: a first movable lens frame and a second movable lens frame, wherein there is an overlapping area in the moving range of the first movable lens frame and the moving range of the second movable lens frame; a driving unit, which is configured to move the first movable lens frame along the optical axis direction and to move the second movable lens frame along the optical axis direction; a detection unit, which is configured to detect a reference position of the first movable lens frame and a reference position of the second movable lens frame; and a control unit, which is configured to perform a reset drive, in which the first movable lens frame moves to the reference position of the first movable lens frame and the second movable lens frame moves to the reference position of the second movable lens frame; wherein the control unit changes the reset drive conditions for the first movable lens frame or the second movable lens frame based on the output from the detection unit.
[0013] Further features of the present disclosure will become apparent from the following description of example embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 is an exploded perspective view of the lens barrel according to the first embodiment.
[0015] Figure 2 is a cross-sectional view of the lens barrel (when the object distance at the wide-angle end is infinite)
[0016] Figure 3 is a cross-sectional view of the lens barrel (when the object distance at the telephoto end is infinite).
[0017] Figure 4 : is a view showing the relationship between the locus of moving the lens frame and the output of the photo interrupter in the first embodiment.
[0018] Figure 5 : is a view showing the relationship between the locus of moving the lens frame and the output of the photo interrupter in the second embodiment.
[0019] Figure 6 : is a view showing the relationship between the locus of moving the lens frame and the output of the photo interrupter in the third embodiment. DETAILED DESCRIPTION
[0020] The embodiments of the present disclosure will be explained below with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments described below. It should be noted that for each of the drawings, the same reference numerals represent the same components or elements, and their descriptions are omitted.
[0021] (First embodiment: lens barrel and optical device)
[0022] The lens barrel 100 constitutes a part of a camera (optical device) such as a lens interchangeable camera, a compact digital camera, etc. The lens barrel 100 is used by being mounted (in a fixed or detachable manner) on a camera body K not shown.
[0023] Figure 1 is an exploded perspective view of the lens barrel according to the first embodiment.
[0024] Figure 2 is a cross-sectional view of the lens barrel (when the object distance at the wide-angle end is infinite)
[0025] Figure 3 is a cross-sectional view of the lens barrel (when the object distance at the telephoto end is infinite).
[0026] The lens barrel 100 is provided with a first group of lenses L1 to a fourth group of lenses L4. At least two groups of lenses among the first group of lenses L1 to the fourth group of lenses L4 are held by a moving lens frame. That is, the second group unit 101 including the second group of lenses L2 and the third group unit 102 including the third group of lenses L3 are moving lens frames that are driven (moved) when zooming or when focusing. On the contrary, the first group unit 105 including the first group of lenses L1 and the fourth group unit 106 including the fourth group of lenses L4 are fixed units.
[0027] The second group unit (first moving lens frame) 101 is driven along the optical axis O by a first stepping motor 103 . In addition, the third group unit (second moving lens frame) 102 is driven along the optical axis O by a second stepping motor 104 .
[0028] The second group unit 101 is driven at the time of zooming (zoom lens frame).
[0029] The third group unit 102 is driven both at the time of zooming and at the time of focusing (zoom lens frame and focus frame).
[0030] The second group unit 101 is provided with an aperture unit 108 , an anti-vibration unit 109 , and a zoom lens. The mass of the second group unit 101 is greater than the mass of the third group unit 102 .
[0031] The second group unit 101 has a reference position P in its moving range (optical axis O), and the third group unit 102 also has a reference position P in its moving range (optical axis O). The reference position P is a position that becomes a reference (starting point) when zooming or when focusing. For example, the second group unit 101 has two reference positions, a reference position P1 (first reference position) and a reference position P2 (second reference position). The third group unit 102 has one reference position, namely, a reference position P3 (third reference position).
[0032] The lens barrel 100 is provided with a plurality of photo interrupters 130 for detecting reference positions P (P1, P2, and P3). For example, the lens barrel 100 is provided with two photo interrupters (first detection units), namely, a photo interrupter 131 and a photo interrupter 132, so as to detect two reference positions, namely, a reference position P1 and a reference position P2, of the second group unit 101. In addition, the lens barrel 100 is provided with a photo interrupter 133 (second detection unit) so as to detect the one reference position P3 of the third group unit 102.
[0033] The lens barrel 100 is provided with a base cylinder 107 which holds the first group unit 105 and the fourth group unit 106 .
[0034] The first stepper motor 103 and the third group unit 102 are fixed to the lens barrel 100 .
[0035] The base column 107 holds the ends of two guide rod pairs (four legs) that guide the second group unit 101 and the third group unit 102. The other ends of the four legs of the guide rods are held by the fourth group unit 106. In addition, the base unit 107 holds a control substrate (control unit) J.
[0036] Furthermore, there are an external unit and a mounting member (both not shown), which make it possible to communicate with the camera body K fixed to the base cylinder 107 and to attach and detach the camera body K.
[0037] The photo interrupters 130 are mounted on the flexible printed circuit board 110 and fixed on the base column 107. The flexible printed circuit board 110 is connected to the control substrate J and realizes the function of transmitting the control signal and the driving power to the first stepper motor 103 and the like.
[0038] The rotational force is converted into a linear movement force by the combination of the lead screw and the rack, and the second group unit 101 and the third group unit 102 are driven (moved) along the optical axis O. The second group unit 101 has a light blocking unit 121, and the third group unit 102 has a light blocking unit 122. When the second group unit 101 and the third group unit 102 move (advance or retreat) along the optical axis O, the light blocking units 121 and 122 allow the detection light of the photo interrupter 130 to pass through or block the light.
[0039] The photo interrupter 130 detects the reference position P (P1, P2, P3, etc.) by switching between light transmission and light blocking. Also, the photo interrupter 130 detects the timing of switching between light transmission and light blocking.
[0040] In addition, the photo interrupters 130 not only detect switching between light transmission and light blocking, they also detect zones (areas) in the moving range by distinguishing between light transmission and light blocking states. A zone is an area that has divided the moving areas M1 and M2 with the reference position P as a boundary.
[0041] The detection of the zone by the photo interrupter 130 is performed based on the output voltage of the photo interrupter 130. Hereinafter, the light-transmitting state in which the output voltage is low is referred to as low, and the light-blocking state in which the output voltage is high is referred to as high.
[0042] In the second group unit 101, the reference positions P1 and P2 are detected by the photo interrupter 131 and the photo interrupter 132. The photo interrupter 131 and the photo interrupter 132 combine their respective light-transmitting and light-blocking states and can detect a maximum of four zones and three switching timings.
[0043] For example, three zone detections (zones A to C to be described below) and two switching timings (reference positions P1 and P2) are used in the control.
[0044] In the third group unit 102, the reference position P3 is detected by the photo interrupter 133. The photo interrupter 133 can detect two zones and one switching timing.
[0045] For example, in the present embodiment, two zone detections (zones D and E to be described below) and one switching timing (reference position P3) are used in the control.
[0046] [Reset drive]
[0047] Next, description will be given of the reset drive after the lens barrel 100 is mounted on the camera body K. The reset drive is performed based on a command from the control substrate J.
[0048] Figure 41 is a diagram showing the relationship between the trajectory of the moving lens frame (the second group unit 101 and the third group unit 102) and the output of the photo interrupter 130 (photo interrupters 131, 132, and 133) in the first embodiment. The positions of the second group unit 101 and the third group unit 102 may be such that a surface 101B of the second group unit 101 on the image capturing side is associated with the third group unit 102, and a surface 102B of the third group unit 102 on the object side is associated with the second group unit 101 (refer to Figure 3 ).
[0049] Figure 4 The left figure in FIG. 1 shows the zoom and focus tracks of the second group unit 101 and the third group unit 102. The vertical axis is the distance from the image capturing surface, and the horizontal axis is the zoom parameter. The zoom parameter corresponds to the zoom position. The zoom position represents the position that has been standardized as the linear movement of the second group unit 101 from wide angle to telephoto. For the wide angle end, the zoom parameter is 0, and for the telephoto end, the zoom parameter is 1.
[0050] Figure 4 The right diagram of shows the switching positions of the outputs of the photo interrupters 131, 132, and 133. The switching positions of the outputs of the photo interrupters 131, 132, and 133 correspond to the reference positions P1, P2, and P3.
[0051] The area (region) where the second group cell 101 exists and the area (region) where the third group cell 102 exists are defined in the following manner.
[0052] If the second group cells 101 exist in zone A (abbreviated ZA), zone A is a region where the output of the photo interrupter 132 is low and the output of the photo interrupter 131 is high.
[0053] If the second group cell 101 exists in a zone B (abbreviated ZB), the zone B is a region where the output of the photo interrupter 132 is high and the output of the photo interrupter 131 is high.
[0054] If the second group cell 101 exists in zone C (abbreviated ZC), zone C is an area where the output of the photo interrupter 132 is high or low and the output of the photo interrupter 131 is low. The output of the photo interrupter 132 switches between high and low in zone C, and therefore does not contribute to detection of zone C.
[0055] If the third group cell 102 exists in a zone D (abbreviated ZD), the zone D is a region where the output of the photo interrupter 133 is low.
[0056] If the third group cell 102 exists in a zone E (abbreviated ZE), the zone E is a region where the output of the photo interrupter 133 is high.
[0057] The switching position of the zone A and the zone B is a reference position P2 and is detected by the photo interrupter 132 .
[0058] The switching position of the zone B and the zone C is a reference position P1 and is detected by the photo interrupter 131 .
[0059] The switching position of the area D and the area E is the reference position P3 and is detected by the photo interrupter 133 .
[0060] The switching positions (reference positions P1 and P2 ) of the photo interrupters 131 and 132 are positioned so as to divide the moving region M1 of the second group unit 101 into three regions (eg, approximately three equal parts).
[0061] The switching position (reference position P3 ) of the photo interrupter 133 is positioned so as to divide the moving region M2 of the third group unit 102 into two regions (eg, approximately two equal parts).
[0062] There is a region where the movement region M1 of the second group unit 101 and the movement region M2 of the third group unit 102 overlap (overlap region: overlap OL).
[0063] It should be noted that in the present embodiment, in the movement area M1 and the movement area M2 , the distance of the overlap OL is greater than the distance of the area of the non-overlap OL.
[0064] The zones are arranged such that when the second group of cells 101 are in zone C, the third group of cells 102 cannot be in zone D (it must be in zone E).
[0065] In addition, the reference position P2 is located outside the range of the overlap OL (outside the overlap area), and the reference position P1 is located within the range of the overlap OL (within the overlap area).
[0066] Therefore, even if the second group cell 101 and the third group cell 102 have an overlap OL in their respective movement areas M1 and movement areas M2 , the time taken for the reset drive can be shortened.
[0067] In addition, the reference position P3 is set within the range of the overlap OL. Therefore, even if the second group unit 101 and the third group unit 102 have the overlap OL in their respective movement areas M1 and M2, the time taken for the reset drive can be shortened.
[0068] However, it is necessary to make the distance of the moving area M1 or the moving area M2 smaller than half the distance of the overlap OL.
[0069] In addition, it is also arranged so that the distance of the area E is shorter than the distance of the area D. Therefore, the moving speed of the third group unit 102 in the area E can be reduced, and the time taken for the reset drive (reset time) can be adjusted (extended).
[0070] The second group of units 101 is driven by 1 to 2 phases, wherein the maximum speed of the first stepper motor 103 is 1600 pps (pulses per second), wherein 1 pulse is 10 μm.
[0071] The third group of units 102 is driven by 1 to 2 phases, wherein the maximum speed of the second stepper motor 104 is 3000 pps, wherein 1 pulse is 10 μm.
[0072] The mass of the third group of cells 102 is lighter than that of the second group of cells 101 , and therefore the maximum speed of the third group of cells 102 is set to be faster than the maximum speed of the second group of cells 101 .
[0073] As described above, the reset drive is an operation of detecting the reference positions P1 , P2 , and P3 of the second group unit 101 and the third group unit 102 before image capturing by moving the second group unit 101 and the third group unit 102 .
[0074] Next, the specific operations occurring during the reset drive will be described in terms of processing and the like.
[0075] (Case 1)
[0076] When the second group unit 101 exists in the area A, it starts moving toward the area B (image capturing side) at a maximum speed of 1600 pp. The second group unit 101 moves toward the switching point where the photo interrupter 132 switches from low to high (reference position P2).
[0077] When the third group cell 102 exists in the zone D, the third group cell 102 starts to move toward the zone E at a maximum speed of 3000 pps, and when the third group cell 102 exists in the zone E, the third group cell 102 starts to move toward the zone D at a maximum speed of 3000 pps. That is, the third group cell 102 moves toward the switching position (reference position P3) of the photo interrupter 133.
[0078] That is, even if the second group unit 101 moves toward the image capturing side at a maximum speed of 1600 pps, the third group unit 102 will move toward the image capturing side at a maximum speed of 3000 pps. Although the second group unit 101 and the third group unit 102 move in the same direction, the second group unit 101 will not catch up with the third group unit 102, thus avoiding a collision between the second group unit 101 and the third group unit 102.
[0079] On the contrary, even if the second group unit 101 moves from the area A to the reference position P2 on the image capturing side, the third group unit 102 will only move from the area E to the reference position P3 on the object side. Although the second group unit 101 and the third group unit 102 move in a direction approaching each other, they will both stop at positions separated from each other, thereby avoiding a collision between the second group unit 101 and the third group unit 102. In particular, the reference position P2 is located outside the range of the overlap OL, and therefore, there is no risk of the second group unit 101 and the third group unit 102 colliding, and both the second group unit 101 and the third unit 102 can be moved at their respective maximum speeds.
[0080] (Case 2)
[0081] When the second group unit 101 is in the zone B, it starts to move toward the zone A (toward the object side) at a maximum speed of 1600 pps. The second group unit 101 moves to the position (reference position P2) where the photo interrupter 132 switches from high to low.
[0082] When the third group unit 102 is in zone D, it starts moving toward zone E at a maximum speed of 3000 pps, and when the third group unit 102 is in zone E, it starts moving toward zone D at a maximum speed of 3000 pps. That is, the third group unit 102 moves toward the switching position (reference position P3) of the photo interrupter 133.
[0083] That is, even if the second group unit 101 moves from the area B to the object side at a maximum speed of 1600 pps, the third group unit 102 moves from the area D to the image capturing side at a maximum speed of 3000 pps. The second group unit 101 and the third group unit 102 move in a direction away from each other, thereby avoiding a collision between the second group unit 101 and the third group unit 102.
[0084] On the contrary, even if the second group unit 101 moves from the area B to the second reference position P2, the third group unit 102 will only move from the area E to the reference position P3 on the object side. Although the second group unit 101 and the third group unit 102 move in the same direction, they will both stop at different positions, thus avoiding a collision between the second group unit 101 and the third group unit 102. In particular, the reference position P2 is located outside the range of the overlap OL, thus, there is no risk of the second group unit 101 and the third group unit 102 colliding, and the second group unit 101 and the third group unit 102 can be moved at their respective maximum speeds.
[0085] (Case 3)
[0086] When the second group unit 101 is in zone C, it starts moving toward zone B (object side) at a maximum speed of 1600 pps. The second group unit 101 moves toward a position (reference position P1) where the photo interrupter 131 switches from low to high.
[0087] The third group unit 102 must be in zone E, so it starts to move toward the switching position (reference position P3) of the photo interrupter 133. At this time, the movement is performed by reducing the speed to 1600 pps. In addition, after a predetermined time has passed, the movement speed of the third group unit 102 increases to 2400 pps.
[0088] That is, even if the second group of cells 101 moves from zone C to the object side at a maximum speed of 1600 pps, the third group of cells 102 will move from zone E to the object side at the same speed (1600 pps). Although the second group of cells 101 and the third group of cells 102 move in the same direction, the third group of cells 102 will not catch up with the second group of cells 101, thus avoiding a collision between the second group of cells 101 and the third group of cells 102. In addition, when a state is reached in which a collision between the second group of cells 101 and the third group of cells is physically avoided (wherein it is impossible for the third group of cells 102 to catch up with the second group of cells 101), the moving speed of the third unit 102 will increase.
[0089] The following will describe in detail the moving speed of the third group unit 102. The distance between the reference position P1 and the reference position P3 is X1 (mm), and the distance of the zone C is X2 (mm). X2 (mm) is the distance from the moving end of the overlap OL side of the second group unit 101 to the first reference position P1.
[0090] The maximum speed of the second group of units 101 is V1 (mm / s), and the maximum speed of the third group of units 102 is V2 (mm / s). The time difference between the second group of units 101 and the third group of units 102 when they start to move is Δt (s).
[0091] The above-mentioned predetermined time is the time t(s) during which the third group unit 102 cannot catch up with the second group unit 101. In other words, it is the time t(s) at which the moving speed of the third group unit 102 is updated.
[0092] The time t (s) can be obtained using the following formula (1):
[0093] t=(X2-X1) / V1-Δt…(1)
[0094] Specifically, X1=3.5 mm, X2=6.5 mm, V1=16 mm / s, V2=24 mm / s, and Δt=0 s.
[0095] Then the time t=0.1875 (s).
[0096] When the second group of cells 101 are in zone C and the third group of cells 102 are in zone E, the reset drive starts (activates), and after about 0.19 seconds, the speed of the third group of cells 102 will change from V1 to V2.
[0097] That is, the third group unit 102 moves at a low speed (V1) until the second group unit 101 moves past the position corresponding to the reference position P3 from the moving end (end point) of the zone C. In addition, if the time t (s) taken for the second group unit 101 to move past the reference position P3 elapses, the speed of the third group unit 102 is changed to the speed (V2).
[0098] Therefore, the time taken for the reset drive can be shortened while avoiding collision between the second group of cells 101 and the third group of cells 102 .
[0099] At the start time of the reset drive, although the precise positions of the second group cell 101 and the third group cell 102 are unclear, it is possible to detect the area (region) where the second group cell 101 and the third group cell 102 exist. That is, at the start time of the reset drive, it is possible to identify which of the cases 1 to 3 exists.
[0100] Herein, the moving speed of the third group cells 102 is set (made different) based on the zone where the second group cells 101 and the third group cells 102 exist and the moving directions of the second group cells 101 and the third group cells 102 .
[0101] In this way, at the time of reset drive, the second group unit 101 and the third group unit 102 move simultaneously. The moving speed (reset drive condition) changes according to the area where the second group unit 101 and the third group unit 102 exist and the moving direction of the second group unit 101 and the third group unit 102. At the time of reset drive, when the second group unit 101 and the third group unit 102 move in a direction away from each other, and when they move in a direction approaching each other, the reset drive condition changes. In particular, in the case where there is a possibility that the second group unit 101 and the third group unit 102 collide at the time of reset drive, the moving speed of the unit (the third group unit 102) with a faster moving speed is reduced.
[0102] Therefore, even if the second group unit 101 and the third group unit 102 move simultaneously, a collision between the second group unit 101 and the third group unit 102 at the time of reset driving can be avoided.
[0103] It should be noted that in case 3, Δt≠0s can also be made. In other cases (case 1 and case 2), it is also possible to switch to Δt=0s. For example, it can be set so that Δt=0.1s is always made. That is, in any case, the start timing of the third group of cells 102 at the time of reset drive can be changed (later). That is, the start timing (reset drive condition) of the second group of cells 101 and the third group of cells 102 can be made different from each other.
[0104] However, preferably, Δt(s) is a shorter time than the time taken to complete the reset drive (movement) of the second group unit 101. When the second group unit 101 moves, the third group unit 102 will start to move. That is, preferably, the second group unit 101 and the third group unit 102 move simultaneously.
[0105] Therefore, the time taken to perform the reset drive can also be shortened.
[0106] As described above, according to the lens barrel 100 of the present embodiment, by using a simple structure, the collision between the moving lens frames (the second group unit 101 and the third group unit 102) during the reset drive can be quickly avoided. In this way, the collision between the moving lens frames during the reset drive can be avoided at a low cost.
[0107] (Second embodiment)
[0108] Figure 5 1 is a view showing the relationship between the locus of moving the lens frame (the second group unit 101 and the third group unit 102 ) and the output of the photo interrupter 130 (photo interrupters 131 , 132 , 133 , and 134 ) in the second embodiment.
[0109] The photo interrupter (second detection unit) 134 is added, and the reference position (fourth reference position) P4 of the third group unit 102 is set to the zone F (abbreviation ZF). At this time, the reference position P4 is located outside the range of the overlap OL.
[0110] It should be noted that the specific operations, processing, etc. occurring during the reset drive are the same as those of Cases 1, 2, and 3 in the first embodiment described above. The second embodiment differs from the first embodiment in that there is another Case 4.
[0111] In case 4, the following operations, processes, etc. are performed.
[0112] (Case 4)
[0113] If the third group of cells 102 is present in zone E, the third group of cells 102 will start moving toward the switching position (reference position P4) of the photo interrupter 134 at a maximum speed of 3000 pps.
[0114] The second group of cells 101 exists in any one of the zones A to C and will start moving toward the reference position P1 or the reference position P2 at a maximum speed of 1600 pps.
[0115] That is, the third group unit 102 moves toward the object at a maximum speed of 3000 pps and reaches the reference position P4. Therefore, even if the second group unit 101 moves in any direction at a maximum speed of 1600 pps, a collision between the second group unit 101 and the third group unit 102 can be avoided.
[0116] Therefore, the time taken for the lens barrel 100 according to the second embodiment to perform the reset drive can be further shortened.
[0117] (Third embodiment)
[0118] Figure 6 1 is a view showing the relationship between the locus of moving the lens frame (the second group unit 101 and the third group unit 102 ) and the output of the photo interrupter 130 (the photo interrupters 131 and 133 ) in the third embodiment.
[0119] In the third embodiment, the photo interrupter 132 is separated from the configuration of the lens barrel 100, and the reference position P2 and the area A of the second group unit 101 are removed.
[0120] It should be noted that the specific operations, processing, etc. that occur during the reset drive are the same as those of Cases 2 and 3 of the first embodiment described above.
[0121] However, the third embodiment differs from the first embodiment in a portion of the operation that occurs in case 2. In case 2 of the third embodiment, the second group unit 101 begins moving from zone B toward the reference position P1 at a maximum speed of 1600 pps.
[0122] At this time, even if the second group unit 101 moves from the area B to the image capturing side at a maximum speed of 1600pps, the third group unit 102 will move from the area D to the image capturing side at a maximum speed of 3000pps. Therefore, the second group unit 101 will not catch up with the third group unit 102, and thus, a collision between the second group unit 101 and the third group unit 102 is avoided. On the contrary, even if the second group unit 101 moves from the area B to the reference position P1, the third group unit 102 will only move from the area E to the reference position P3 on the object side. Although the second group unit 101 and the third group unit 102 move in a direction approaching each other, they will both stop at different positions, and thus, a collision between the second group unit 101 and the third group unit 102 is avoided.
[0123] Therefore, the time taken for the lens barrel 100 according to the third embodiment to perform the reset drive can be further shortened.
[0124] <Other embodiments>
[0125] The driving unit is not limited to the stepping motor (STM). For example, a driving mechanism such as an oscillation actuator (ultrasonic motor), a voice coil motor (VMC), etc. may also be used.
[0126] The detection unit is not limited to the photo interrupter. For example, the detection unit may count pulses of a stepping motor and detect the movement amount and movement direction of the moving lens frame (the second group unit 101 and the third group unit 102).
[0127] The base cylinder 107 is not limited to the case where it is fixed to the lens barrel 100. For example, the base cylinder 107 may also move in the optical axis direction O while holding the second group unit 101 and the third group unit 102.
[0128] Although the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the present disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
[0129] This application claims the benefit of Japanese Patent Application No. 2023-191914 (November 10, 2023), which is hereby incorporated by reference in its entirety.
Claims
1. A lens barrel, comprising: a first movable lens frame and a second movable lens frame, wherein there is an overlapping area in a moving range of the first movable lens frame and a moving range of the second movable lens frame; a driving unit, wherein the driving unit is configured to move the first movable lens frame along the optical axis direction and to move the second movable lens frame along the optical axis direction; a detection unit configured to detect a reference position of the first moving lens frame and a reference position of the second moving lens frame; and a control unit configured to perform a reset drive in which the first movable lens frame moves to a reference position of the first movable lens frame and the second movable lens frame moves to a reference position of the second movable lens frame; Wherein the control unit changes a reset driving condition for the first moving lens frame or the second moving lens frame based on an output from the detection unit.
2. The lens barrel according to claim 1, wherein: The control unit causes the first moving lens frame and the second moving lens frame to move simultaneously.
3. The lens barrel of claim 1, wherein: The reset driving condition is the moving speed or the start timing.
4. The lens barrel of claim 1, wherein: The control unit is configured to change a reset driving condition of the second moving lens frame, and wherein a moving speed of the second moving lens frame is higher than a moving speed of the first moving lens frame.
5. The lens barrel of claim 1, wherein: The control unit is configured to change the reset driving condition of a second movable lens frame, wherein a moving range of the second movable lens frame is smaller than a moving range of the first movable lens frame.
6. The lens barrel of claim 1, wherein: the detecting unit is configured to detect in which region of a plurality of regions the first and second moving lens frames exist, wherein the plurality of regions are divided by positioning a reference position on boundaries of the plurality of regions; and The control unit is configured to change the reset driving condition based on an area where the first moving lens frame and the second moving lens frame exist.
7. The lens barrel of claim 1, wherein: The detection unit comprises: a first detecting unit configured to detect a first reference position and a second reference position of the first movable lens frame; and A second detection unit, wherein the second detection unit is configured to detect a third reference position of the second movable lens frame; The first reference position and the third reference position exist in the overlapping area.
8. The lens barrel of claim 1, wherein: The detection unit comprises: a first detecting unit configured to detect a first reference position and a second reference position of the first movable lens frame; and A second detection unit, wherein the second detection unit is configured to detect a third reference position and a fourth reference position of the second movable lens frame; The first reference position and the third reference position exist in the overlapping area.
9. The lens barrel of claim 1, wherein: The detection unit includes: a first detecting unit configured to detect a first reference position of the first movable lens frame; and A second detection unit, wherein the second detection unit is configured to detect a third reference position of the second movable lens frame; The first reference position and the third reference position exist in the overlapping area.
10. The lens barrel of claim 1, wherein: The control unit is configured to: change the moving speed of the second moving lens frame when a time t calculated using the formula given below has elapsed from the start time of the first moving lens group; t = (X2-X1) / V1-Δt The condition is, X: distance between the first position of the first moving lens frame and the third position of the second moving lens frame X2: distance from the moving end of the first moving lens frame to the first reference position V1: Moving speed of the first moving lens frame Δt: the difference between the start time of the first moving lens frame and the start time of the second moving lens frame.
11. The lens barrel of claim 1, wherein: The movement range is set so that the overlapping area has a greater distance than the area of the non-overlapping area.
12. The lens barrel of claim 1, wherein: The drive unit is a stepper motor.
13. The lens barrel of claim 1, wherein: The detection unit is configured to be capable of detecting a movement amount and a movement direction of the first movable lens frame and a movement amount and a movement direction of the second movable lens frame.
14. The lens barrel of claim 1, wherein: The lens barrel is configured to further include a base cylinder configured to hold the first movable lens frame and the second movable lens frame and to move along the optical axis direction.
15. The lens barrel of claim 1, wherein: At least one of the first moving lens frame and the second moving lens frame is a zoom lens frame.
16. The lens barrel of claim 1, wherein: At least one of the first moving lens frame and the second moving lens frame is a focusing lens frame.
17. An optical device comprising: A lens barrel, the lens barrel comprising: a first movable lens frame and a second movable lens frame, wherein there is an overlapping area in the moving range of the first movable lens frame and the moving range of the second movable lens frame; a driving unit, the driving unit is configured to move the first movable lens frame along the optical axis direction and to move the second movable lens frame along the optical axis direction; a detection unit, the detection unit is configured to detect a reference position of the first movable lens frame and a reference position of the second movable lens frame; and a control unit, the control unit is configured to perform a reset drive, in which the first movable lens frame moves to the reference position of the first movable lens frame and the second movable lens frame moves to the reference position of the second movable lens frame; wherein the control unit changes the reset drive condition for the first movable lens frame or the second movable lens frame based on an output from the detection unit; and A camera body to which the lens barrel is fixedly or removably mounted.