Lens barrel and imaging apparatus

Abstract

To provide a lens barrel that can be reduced in size and accurately hold a lens.SOLUTION: An imaging apparatus comprises: a first lens and a second lens; a first lens frame that holds the first lens and a second lens frame that holds the second lens; and a first guide bar that supports the first lens frame movably in an optical axis direction. The first lens frame has a sleeve part that includes a first hole part and a second hole part engaged with the first guide bar, and an opening formed between the first hole part and the second hole part. The second lens frame is provided with a third hole part that is engaged with the first guide bar. When the first guide bar is engaged with the first hole part and second hole part of the first lens frame and the third hole part of the second lens frame, the first guide bar determines the positions in an optical axis orthogonal direction of the first lens frame and the second lens frame, and the third hole part of the second lens frame is arranged in the opening of the sleeve part.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a lens barrel and an imaging device. [Background technology]

[0002] Conventionally, in order to realize a high-image-quality zoom lens, in addition to a movable zoom lens and a focus lens, a means is known that includes a fixed lens for refracting light to improve imaging performance. In addition, generally, a hole for positioning with respect to the housing is provided in the lens frame that holds the fixed lens, and the fixed lens frame is positioned by first engaging the hole with a positioning boss provided on the housing.

[0003] However, such a positioning structure requires space for the positioning boss provided on the housing, and the overall size of the lens barrel tends to become large. On the other hand, to improve image quality, it is preferable to reduce the relative positional deviation between the center of the fixed lens and the center of the zoom lens, that is, to hold the lens with high precision. However, when the fixed lens frame is positioned by the positioning boss provided on the housing, the positioning structure is different from that of a zoom lens that is movable while being engaged and positioned with a guide bar, and therefore the centers of the two lenses are likely to be misaligned relative to each other.

[0004] Patent Document 1 discloses a configuration in which, when the lens holding frame is retracted into the drive head side of the drive motor, a position detection pulse plate attached to the screw part of the drive motor and the lens holding frame overlap in the radial direction. Patent Document 2 discloses a configuration in which a notch is provided in the outer shape of the aperture unit, so that a part of the lens drive motor head is positioned inside the outer shape of the aperture unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-006465 A [Patent Document 2] JP 2018-180322 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when attempting to apply the conventional technologies disclosed in Patent Documents 1 and 2 to a lens holding structure that enables high-precision lens holding while being compact, even if it is possible to achieve compactness, it becomes difficult to hold the lens with high precision.

[0007] SUMMARY OF THE PRESENT EMBODIMENT In view of the above circumstances, an object of the present invention is to provide a lens barrel that is compact and capable of holding a lens with high precision. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, an imaging device as one aspect of the present invention comprises a first lens and a second lens, a first lens frame that holds the first lens and a second lens frame that holds the second lens, and a first guide bar that supports the first lens frame movably in the optical axis direction, wherein the first lens frame has a sleeve portion including a first hole portion and a second hole portion that engage with the first guide bar and an opening formed between the first hole portion and the second hole portion, and the second lens frame is provided with a third hole portion that engages with the first guide bar, and when the first guide bar is engaged with the first hole portion and the second hole portion of the first lens frame and the third hole portion of the second lens frame, the first guide bar positions the first lens frame and the second lens frame in a direction perpendicular to the optical axis, and the third hole portion of the second lens frame is positioned within the opening of the sleeve portion. Effect of the Invention

[0009] According to the present invention, it is possible to provide a lens barrel that is compact and has a highly accurate lens holding structure. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of an imaging device according to an embodiment. [Diagram 2] 1 is an exploded perspective view showing a configuration of a zoom lens barrel according to an embodiment of the present invention. [Diagram 3] 1 is a block diagram of an imaging device according to an embodiment. [Figure 4] 4A and 4B are diagrams illustrating details of a movable lens frame and a fixed lens frame according to the embodiment. [Diagram 5] This is a detailed view showing the movable lens frame and the fixed lens frame engaged with two guide bars. [Figure 6] 13 is a diagram showing a state in which a hole portion of a fixed lens frame is disposed in an opening portion of a sleeve portion of a movable lens frame. FIG. [Figure 7] 13 is a diagram showing a state in which the fixed lens frame is fastened to the rear fixed frame with screws. FIG. [Figure 8] 13 is a diagram showing a state in which the zoom position of the movable lens frame is at the WIDE end position. FIG. [Figure 9] 13 is a diagram showing a state in which the zoom position of the movable lens frame is at the TELE end position. FIG. [Figure 10] This figure shows the state in which two guide bars, a fixed lens frame, an aperture unit, and a movable lens frame are assembled into the rear fixed frame, and then inserted into the rear fixed frame and the fixed lens frame is fastened. [Figure 11] FIG. 11 is a partially enlarged view of the state shown in FIG. [Figure 12] 11 is a diagram showing a state in which the rear fixed frame is removed from the state shown in FIG. 10. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiment for carrying out the present invention will be described in detail with reference to the attached drawings. The embodiment described below is one example of a means for realizing the present invention, and should be appropriately modified or changed depending on the configuration of the device to which the present invention is applied and various conditions, and the present invention is not limited to the following embodiment.

[0012] <Embodiment 1> 1 is a configuration diagram of an imaging device according to this embodiment. The imaging device according to this embodiment is configured to include a cover 2, a dome cover 3, a zoom lens barrel 4, an imaging element unit 5, and a pan-tilt rotation unit 6. In this embodiment, the imaging device is configured as a network camera. More specifically, in this embodiment, the imaging device is configured as a network surveillance camera.

[0013] The imaging element unit 5 holds an imaging element and is attached to the zoom lens barrel 4. The pan-tilt / rotation unit 6 holds the zoom lens barrel 4 so that it can rotate in the pan, tilt, and rotation directions. The dome cover 3 is sandwiched between the cover 2 and the pan-tilt / rotation unit 6 and fastened to the imaging device by multiple fastening screws 1.

[0014] 2 is an example of an exploded perspective view of the zoom lens barrel 4 according to this embodiment. The zoom lens barrel 4 according to this embodiment has four lens groups. Lens 9 is a fixed group that is fixed (unmoving) in the optical axis direction. Zoom lens (first lens) 13 is a movable lens that moves in the optical axis direction to perform a magnification change operation. Focus lens 22 moves in the optical axis direction to perform a focusing operation.

[0015] The fixed lens frame 8 is fixed to a front fixed frame (front fixed cylinder) 10 with screws 7. The front fixed frame 10 is coupled to a rear fixed frame (rear fixed cylinder) 24 with screws (not shown).

[0016] The guide bar (second guide bar) 11, the guide bar (first guide bar) 12, the guide bar 19, and the guide bar 20 are fixed in a state where they are sandwiched between the front fixed frame 10 and the rear fixed frame 24.

[0017] The movable lens frame (first lens frame) 14 holds the zoom lens 13, and is supported by the guide bar 12 so as to be movable in the optical axis direction. The U-shaped groove on the movable lens frame 14 engages with the U-shaped groove on the guide bar 11, thereby restricting the rotation of the movable lens frame 14 around the guide bar 12, i.e., around the optical axis.

[0018] The rack 15 is fixed to the moving lens frame 14 while being biased in the optical axis direction and rotation direction by a rack spring (not shown). The rack 15 is screwed into a threaded portion of a stepping motor 25, and moves in the optical axis direction together with the moving lens frame 14 by rotation of the threaded portion.

[0019] The aperture unit 16 is fixed by screws (not shown) to a fixed lens frame (second lens frame) 17 that holds a fixed lens (second lens) 18, and adjusts the amount of incident light entering the zoom lens barrel 4 by changing the aperture diameter to a number of states.

[0020] The movable lens frame 21 holds a focus lens 22, and is supported by the guide bar 19 so as to be movable in the optical axis direction. The U-shaped groove on the movable lens frame 21 engages with the U-shaped groove on the guide bar 20, thereby restricting the rotation of the movable lens frame 21 around the guide bar 19, i.e., around the optical axis.

[0021] The rack 23 connected to the moving lens frame 21 is fixed to the moving lens frame 21 while being biased in the optical axis direction and rotation direction by a rack spring (not shown). The rack 23 is screwed into a threaded portion of a stepping motor 26, and moves in the optical axis direction together with the moving lens frame 21 by the rotation of the threaded portion.

[0022] Filter moving frame 28 holds infrared cut filter 29 and glass member 30, and is supported by guide bar 32 so as to be movable in the optical axis direction. The U-shaped groove on filter moving frame 28 engages with the U-shaped groove on guide bar 35, thereby restricting rotation of filter moving frame 28 around guide bar 32, i.e., around the optical axis.

[0023] The rack 31 connected to the filter moving frame 28 is fixed to the filter moving frame 28 while being biased in the optical axis direction and rotation direction by a rack spring (not shown). The rack 31 is screwed into the threaded portion of the stepping motor 27, and moves together with the filter moving frame 28 in a direction perpendicular to the optical axis by rotation of the threaded portion. By retracting the infrared cut filter 29 from the optical path, it is possible to photograph the subject even at night.

[0024] The sensor holder 33 holds the imaging element unit 5 using an imaging element screw (not shown), and is fixed to the rear fixing frame 24 by a screw 34.

[0025] The origin position of the movement of the moving lens frames 14 and 21 in the optical axis direction is detected using a detector such as a photointerrupter (not shown) soldered to an FPC (flexible printed circuit board) (not shown). The FPC is connected to the aperture unit 16, stepping motors 25, 26, 27, and photodetectors (not shown), and activates each of them when current is applied.

[0026] The photodetector is disposed on the moving area of ​​the moving lens frames 14, 21. The positions of the moving lens frames 14, 21 are controlled by the output of the photodetector and the number of drive pulses of the stepping motors 25, 26. Each of the lenses, the lens 9, the zoom lens 13, the fixed lens 18, and the focus lens 22, functions as an imaging lens.

[0027] 3 is a configuration block diagram of an imaging device in this embodiment. The imaging device is composed of a camera 36 installed outdoors, for example, and an operation unit (information processing device) 37 that operates the camera 36. The camera 36 and the operation unit 37 are communicatively connected via a communication means 38. The camera 36 and the operation unit 37 may constitute an imaging system.

[0028] Camera 36 has a control unit 39, a pan driving unit 40, a tilt driving unit 41, a rotation driving unit 42, a zoom lens driving unit 43, a focus lens driving unit 44, an aperture driving unit 45, and a switching driving unit 46. Camera 36 further has a first detection unit 47, a second detection unit 48, a first storage unit 49, a second storage unit 50, a first calculation unit 51, a second calculation unit 52, a third detection unit 53, a third storage unit 54, and a third calculation unit 55.

[0029] The control unit 39 includes a CPU, a memory (storage unit), a signal processing unit, etc., and is composed of at least one computer. The control unit 39 performs overall control of the operation of the camera 36, ​​etc., according to a program stored in the memory. Specifically, the control unit 39 controls the pan, tilt, rotation, etc., operations of the camera 36 according to a control signal (control command) output (transmitted) in response to an operation (input) from the operation unit 37.

[0030] The pan driving unit 40 controls the imaging direction of the camera 36 (pan control). The pan driving unit 40 is connected to the control unit 39. The pan driving unit 40 includes a driving mechanism such as a motor and a speed reducing mechanism. The pan driving unit 40 changes the direction (imaging direction) of the camera 36 (changes the attitude) by driving the driving mechanism based on a control signal (control command) output in response to an operation from the operation unit 37 and received via the control unit 39. The imaging direction that can be changed by the pan driving unit 40 is the pan direction (horizontal direction). In addition, the pan driving unit 40 has a sensor capable of detecting an angle. The sensor detects the pan angle of the camera 36 and also functions as a pan angle detection means. In addition, the detection result detected by the sensor of the pan driving unit 40 is transmitted to the control unit 39.

[0031] The tilt drive unit 41 controls the imaging direction of the camera 36 (tilt control). The tilt drive unit 41 is connected to the control unit 39. The tilt drive unit 41 includes a drive mechanism such as a motor and a speed reducer mechanism. The tilt drive unit 41 changes the orientation (imaging direction) of the camera 36 (changes the attitude) by driving the drive mechanism based on a control signal (control command) output in response to an operation from the operation unit 37 and received via the control unit 39. The imaging direction that can be changed by the pan drive unit 40 is the tilt direction (vertical direction). The tilt drive unit 41 also has a sensor capable of detecting an angle. The sensor detects the tilt angle of the camera 36 and also functions as a tilt angle detection means. The detection result detected by the sensor of the tilt drive unit 41 is transmitted to the control unit 39.

[0032] The rotation drive unit 42 controls the imaging direction of the camera 36 (rotation control). The rotation drive unit 42 is connected to the control unit 39. The rotation drive unit 42 includes a drive mechanism such as a motor and a speed reducer. The rotation drive unit 42 changes the orientation (imaging direction) of the camera 36 (changes the attitude) by driving the drive mechanism based on a control signal (control command) output in response to an operation from the operation unit 37 and received via the control unit 39. The imaging direction that can be changed by the pan drive unit 40 is the rotation direction. In addition, the rotation drive unit 42 has a sensor capable of detecting an angle. The sensor detects the rotation angle of the camera 36 and also functions as a rotation angle detection means. In addition, the detection result detected by the sensor of the rotation drive unit 42 is transmitted to the control unit 39.

[0033] The zoom lens driving unit 43 controls the position of the zoom lens 13 by moving the moving lens frame 14 holding the zoom lens 13 in the optical axis direction. The zoom lens driving unit 43 is configured with a driving mechanism such as a stepping motor, and in this embodiment, the stepping motor 25 functions as the zoom lens driving unit 43. The zoom lens driving unit 43 is connected to the control unit 39. The zoom lens driving unit 43 changes the position of the zoom lens by driving the stepping motor 25 based on a control signal (control command) output in response to an operation from the operation unit 37 and received via the control unit 39. The zoom lens driving unit 43 also has a first detection unit 47. The first detection unit 47 detects the number of drive pulses of the stepping motor 25. The detection result detected by the first detection unit 47 is also transmitted to the control unit 39.

[0034] The focus lens driving unit 44 controls the position of the focus lens 22 by moving the moving lens frame 21 holding the focus lens 22 in the optical axis direction. The focus lens driving unit 44 is configured with a driving mechanism such as a stepping motor, and in this embodiment, the stepping motor 26 functions as the focus lens driving unit 44. The focus lens driving unit 44 is connected to the control unit 39. The focus lens driving unit 44 changes the position of the focus lens by driving the stepping motor 26 based on a control signal (control command) output in response to an operation from the operation unit 37 and received via the control unit 39. The zoom lens driving unit 43 also has a second detection unit 48. The second detection unit 48 detects the number of drive pulses of the stepping motor 26. The detection result detected by the second detection unit 48 is also transmitted to the control unit 39.

[0035] The aperture driver 45 changes the aperture diameter between a plurality of states to adjust the amount of incident light entering the zoom lens barrel 4. In this embodiment, the aperture unit 16 functions as the aperture driver 45.

[0036] The switching drive unit 46 controls the switching between the infrared cut filter 29 and the glass member 30. The switching drive unit 46 is connected to the control unit 39. The switching drive unit 46 switches between the infrared cut filter 29 and the glass member 30 by driving a drive mechanism (not shown) based on a control signal (control command) that is output in response to an operation from the operation unit 37 and received via the control unit 39. The switching drive unit 46 also has detection means constituted by a sensor or the like that detects the position of the filter moving frame 28 that holds the infrared cut filter 29. The detection result detected by the detection means is transmitted to the control unit 39.

[0037] The first memory unit 49 stores the number of drive pulses of the stepping motor 25. The first memory unit 49 is connected to the control unit 39. The second memory unit 50 stores the number of drive pulses of the stepping motor 26. The second memory unit 50 is connected to the control unit 39. In addition, the control unit 39 can read out the information stored in the first memory unit 49 and the second memory unit 50 at any time.

[0038] The first calculation unit 51 calculates the number of drive pulses of the zoom lens driving unit 43 to drive to a predetermined position, based on the detection result by the first detection unit 47 and the number of drive pulses of the stepping motor 25 stored in the first storage unit 49. The first calculation unit 51 is connected to the control unit 39. The second calculation unit 52 calculates the number of drive pulses of the focus lens driving unit 44 to drive to a predetermined position, based on the detection result by the second detection unit 48 and the number of drive pulses of the stepping motor 26 stored in the second storage unit 50. The second calculation unit 52 is connected to the control unit 39.

[0039] The third detection unit 53 detects the drive arm position from the brightness difference of the aperture. The third detection unit 53 is connected to the control unit 39. The third memory unit 54 stores a preset rotation angle position of the drive arm. The third memory unit 54 is connected to the control unit 39. The third calculation unit 55 calculates the difference based on the detection result of the drive arm position detected by the third detection unit 53 and the rotation angle position of the drive arm stored in the third memory unit 54. The third calculation unit 55 is connected to the control unit 39.

[0040] Based on the calculation result of the third calculation section 55, the control section 39 drives the diaphragm blades held by the drive arm using the diaphragm drive section 45, so that an optimal amount of light is incident on the image sensor in the image sensor unit 5.

[0041] The operation unit 37 includes a CPU 101, a ROM 102, a RAM 103, a display unit 104, an operation unit 105, and a communication unit 106.

[0042] CPU 101 is a central processing unit that is composed of at least one computer and executes various processes by reading out control programs stored in ROM (Read-Only Memory) 102. ROM 102 is a non-volatile memory that stores programs for camera 36 and operation unit 37, other programs (control programs) required for other controls, and various data.

[0043] The RAM (Random Access Memory) 103 is a volatile memory, and is used as a temporary storage area such as the main memory and work area of ​​the CPU 101. The RAM 103 also temporarily stores various data such as image and video data. The display unit 104 is composed of a display device such as a monitor or a display, and displays images and videos captured by the camera 36, ​​for example.

[0044] The operation unit 105 is composed of input devices such as a keyboard and a mouse. By operating the operation unit 105, it is possible to instruct the pan, tilt and rotation operations of the camera 36, ​​the opening and closing of the aperture blades in the aperture unit 16, and the switching of the infrared cut filter. While checking the image captured by the camera 36 on the screen of the display unit 104, the operator can operate the operation unit 105 to capture the subject at a desired shooting magnification and display it on the display unit 104. The communication unit 106 performs communication processing such as transmitting a control signal (control command) to the camera 36 via a network by wire or wirelessly.

[0045] Although not shown, the operation unit 37 has a storage device. The storage device stores various data, various programs, etc. The storage device is, for example, a non-volatile storage device such as a HDD, a flash memory, or an SD card. The storage device is used as a permanent storage area for the OS, various programs, various data, etc., and is also used as a short-term storage area for various data, etc.

[0046] The functions and processes of the camera 36 and the operation unit 37 are realized by the CPU 101 reading out a program stored in the ROM 102 or a storage device and executing this program. As another example, the CPU 101 may read out a program stored in a recording medium such as an SD card instead of the ROM 102 or the like.

[0047] In this embodiment, the operation unit 37 executes each process of the camera 36 and the operation unit 37 using one processor (CPU 101) and one memory (ROM 102), but other configurations are also possible. For example, each process of the camera 36 and the operation unit 37 can be executed by cooperating multiple processors, multiple RAMs, ROMs, and storage devices. Also, some of the processes may be executed using hardware circuits. Also, functions and processes of the imaging device may be realized using a processor other than a CPU. Also, for example, a GPU (Graphics Processing Unit) may be used instead of a CPU.

[0048] Fig. 4 is a diagram showing an example of details of the movable lens frame 14 and the fixed lens 18. Fig. 4(A) is a diagram showing an example of details of the movable lens frame 14 that holds the zoom lens 13 as viewed from the imaging surface side (imaging element side). The movable lens frame 14 in this embodiment is provided with a sleeve portion 59 that engages with the guide bar 12.

[0049] A first hole 60 and a second hole 61 for engaging with the guide bar 12 are provided on the side surface of the sleeve portion 59. The first hole 60 is provided toward the imaging surface side of the sleeve portion 59, and the second hole 61 is provided toward the object side of the sleeve portion 59. Furthermore, the sleeve portion 59 has an opening 64 between the first hole 60 and the second hole 61. The opening 64 is an opening portion of the sleeve portion 59 formed between the first hole 60 and the second hole 61 when viewed from the inside in a direction perpendicular to the optical axis OA.

[0050] The sleeve portion 59 is connected to the rack 15, and is screwed with a screw portion (thread portion, not shown) of the stepping motor 25, thereby allowing the zoom lens 13 to move linearly in the direction of the optical axis OA.

[0051] 4(B) is a detailed view of the fixed lens frame 17 that holds the fixed lens 18, as viewed from the imaging surface side. The fixed lens frame 17 has a hole portion (third hole portion) 62 for engaging with the guide bar 12, and an elongated hole portion (fourth hole portion) 63 for engaging with the guide bar 11. The hole portion 62 can regulate the position of the fixed lens frame 17 in a vertical plane (in a plane perpendicular to the optical axis OA) relative to the optical axis OA. The elongated hole portion 63 is provided to regulate the rotation direction of the fixed lens frame 17 relative to the optical axis OA.

[0052] Fig. 5 is a detailed view showing the state in which the movable lens frame 14 and the fixed lens frame 17 are simultaneously engaged with the guide bars 11 and 12. Note that Fig. 5 is also a perspective view showing the state in which the movable lens frame 14 and the fixed lens frame 17 are simultaneously engaged with the guide bars 11 and 12 as viewed from the imaging surface side.

[0053] 5, by engaging the movable lens frame 14 and the fixed lens frame 17 with the guide bar 11 and the guide bar 12, the hole 62 of the fixed lens frame 17 is fitted into the opening 64 provided in the sleeve portion 59 (the hole 62 fits into the opening 64). Then, by engaging the guide bar 12 with the movable lens frame 14 and the fixed lens frame 17, the two lens frames (movable lens frame 14, fixed lens frame 17) are simultaneously positioned in a plane perpendicular to the optical axis OA or in a direction perpendicular to the optical axis OA, with the guide bar 12 as a reference. Note that engaging the guide bar 12 with the movable lens frame 14 and the fixed lens frame 17 refers to a state in which the guide bar 12 is engaged with the first hole 60 and the second hole 61 of the movable lens frame 14 and the hole 62 of the fixed lens frame 17, respectively.

[0054] Also, similar to the guide bar 12, by engaging the guide bar 11 with the moving lens frame 14 and the fixed lens frame 17, the rotation (rotational position) of the two lens frames around the optical axis is restricted in a plane perpendicular to the optical axis OA or in a direction perpendicular to the optical axis. That is, the moving lens frame 14 and the fixed lens frame 17 are positioned by the guide bar 11 in a state in which the rotation around the optical axis is restricted by the guide bar 11. Incidentally, engaging the guide bar 11 with the moving lens frame 14 and the fixed lens frame 17 refers to a state in which the U-groove on the guide bar 11 is engaged with the U-groove on the moving lens frame 14, and the guide bar 11 is engaged with the elongated hole portion 63 of the fixed lens frame.

[0055] Furthermore, by engaging the guide bars 11 and 12 with the moving lens frame 14 and the fixed lens frame 17, the hole 62 of the fixed lens frame 17 is placed (disposed) in the opening 64 (within the opening) of the sleeve portion 59.

[0056] Then, by engaging the guide bar 11 and the guide bar 12 with the movable lens frame 14 and the fixed lens frame 17, the first hole 60 and the second hole 61 of the sleeve portion 59 and the hole 62 of the fixed lens frame 17 are arranged to overlap when viewed from the optical axis OA direction. Therefore, both the lens frames of the movable lens frame 14 and the fixed lens frame 17 are positioned by the same guide bar (guide bar 12). With this configuration, it is possible to reduce the outer shape of the zoom lens barrel 4 in the radial direction (the direction perpendicular to the optical axis).

[0057] Furthermore, since both the moving lens frame 14 and the fixed lens frame 17 are positioned by the same guide bar (guide bar 12), it is possible to reduce the relative positional deviation between the center of the zoom lens 13 and the center of the fixed lens 18. This makes it possible to improve the decentering accuracy, which is important for high image quality.

[0058] 6 is a diagram showing a state in which the hole 62 of the fixed lens frame 17 is arranged in the opening 64 of the sleeve portion 59 of the moving lens frame 14. FIG. 6(A) is a side view of a state in which the hole 62 of the fixed lens frame 17 is arranged in the opening 64 of the sleeve portion 59 of the moving lens frame 14. FIG. 6(B) is a diagram seen from the XX cross section of FIG. 6(A), and is a diagram of the moving lens frame 14 seen from the imaging surface side in the state of FIG. 6(A). Specifically, it is a diagram (front view) of a state in which the hole 62 of the fixed lens frame 17 is incorporated in the opening 64 of the sleeve portion 59 of the moving lens frame 14 seen from the imaging surface side to the object side in the optical axis direction.

[0059] In this manner, in this embodiment, the hole portion 62 of the fixed lens frame 17 is engaged with the guide bar 12 with a clearance secured with respect to the sleeve portion 59 so as not to interfere with the sleeve portion 59 of the movable lens frame 14.

[0060] Therefore, even if the movable lens frame 14 moves in the direction of the optical axis OA, it can move without interfering with the fixed lens frame 17. In this way, since the positions of the zoom lens 13 and the movable lens frame 14, which change the zoom magnification, can be changed, a zoom lens can be realized.

[0061] 7 is a diagram showing a state in which the fixed lens frame 17 is fastened to the rear fixed frame 24 with screws (not shown). Specifically, this is a state in which the hole portion 62 of the fixed lens frame 17 is fitted into the opening portion 64 of the sleeve portion 59 of the moving lens frame 14. Furthermore, this is a diagram showing a state in which the lens assembly in a state in which it is engaged with the guide bars 11 and 12 is further fitted into the rear fixed frame 24, and the fixed lens frame 17 is fastened to the rear fixed frame 24 with screws (not shown).

[0062] In this way, the fixed lens frame 17 is held at a fixed position relative to the rear fixed frame 24, but the movable lens frame 14 is movable in the direction of the optical axis OA.

[0063] Figure 8 is a diagram showing a state in which the zoom position of the movable lens frame 14 is at the WIDE end position. Figure 8(A) is an example of a side view showing a state in which the zoom position of the movable lens frame 14 is at the WIDE end position. Figure 8(B) is a diagram seen from the YY cross section of Figure 8(A), and is a diagram of the movable lens frame 14 seen from the object side in the state of Figure 8(A).

[0064] Fig. 9 is a diagram showing a state where the zoom position of the moving lens frame 14 is at the TELE end position. Fig. 9(A) is an example of a side view showing a state where the zoom position of the moving lens frame 14 is at the TELE end position. Fig. 9(B) is a diagram seen from the ZZ cross section of Fig. 9(A), and shows the moving lens frame 14 seen from the object side in the state of Fig. 9(A). Note that Figs. 8 and 9 omit the components on the object side, including the front fixed frame 10.

[0065] In Fig. 8, the zoom position of the movable lens frame 14 engaged with the guide bars 11 and 12 is held at the WIDE end position. The hole 62 of the fixed lens frame 17 inserted (placed) in the opening 64 of the sleeve portion 59 of the movable lens frame 14 is fixed to the rear fixed frame 24, so the fixed lens frame 17 does not move in the direction of the optical axis OA. Even if the movable lens frame 14 moves in the direction of the optical axis OA, the hole 62 of the fixed lens frame 17 is located inside (inside) the opening 64 of the sleeve portion 59 of the movable lens frame 14, so there is no interference between the movable lens frame 14 and the fixed lens frame 17.

[0066] 9, the zoom position of the moving lens frame 14 engaged with the guide bars 11 and 12 is held at the TELE end position. The hole 62 of the fixed lens frame 17 inserted (placed) in the opening 64 of the sleeve portion 59 of the moving lens frame 14 is fixed to the rear fixed frame 24, so the fixed lens frame 17 does not move in the direction of the optical axis OA. Even if the moving lens frame 14 moves in the direction of the optical axis OA, the hole 62 of the fixed lens frame 17 is placed inside the opening 64 of the sleeve portion 59 of the moving lens frame 14, so there is no interference between the moving lens frame 14 and the fixed lens frame 17.

[0067] In this way, when the moving lens frame 14 moves in the direction of the optical axis OA in accordance with the zoom magnification, the hole 62 of the fixed lens frame 17 is already inside the opening 64 of the sleeve portion 59 of the moving lens frame 14. In other words, because the hole 62 of the fixed lens frame 17 is located so as to straddle the sleeve portion 59 of the moving lens frame 14, interference between the moving lens frame 14 and the fixed lens frame 17 is avoided.

[0068] With this configuration, the space for arranging components is more efficient in terms of the external size of the zoom lens barrel 4, and the zoom lens barrel 4 in this embodiment can be made smaller in the radial direction. As described above, the moving lens frame 14 and the fixed lens frame 17 engage with the guide bar 12, so that the moving lens frame 14 and the fixed lens frame 17 are positioned in a plane perpendicular to the optical axis OA or in a direction perpendicular to the optical axis OA. This makes it possible to suppress misalignment of the two lens frames (moving lens frame 14, fixed lens frame 17) relative to the guide bar 12.

[0069] FIG. 10 is a diagram showing the state in which two guide bars, the fixed lens frame 17, the aperture unit 16, and the moving lens frame 14 are assembled in the rear fixed frame 24 and the fixed lens frame 17 is inserted into the rear fixed frame 24 and fastened. FIG. 10(A) shows the rear fixed frame 24 assembled with the guide bars 11 and 12, the fixed lens frame 17, the aperture unit 16, and the moving lens frame 14. The fixed lens frame 17 is fastened to the rear fixed frame 24 with screws not shown in FIG. 10. FIG. 10(B) is a diagram seen from the SS cross section of FIG. 10(A), and is a diagram of the moving lens frame 14 seen from the object side in the state of FIG. 10(A). FIG. 11 shows a partially enlarged view P in FIG. 10(B).

[0070] The area cut out and surrounded by the dotted line in Fig. 11 is the range in which there are first hole portion 60 and second hole portion 61 through which guide bar 12 of movable lens frame 14 passes. As shown in Fig. 11, part of the outer periphery of outer portion 65 of aperture unit 16 fits into opening 64 of sleeve portion 59 so as to overlap with the range in which there are first hole portion 60 and second hole portion 61 through which guide bar 12 of movable lens frame 14 passes when viewed from the object side in the optical axis OA direction.

[0071] In this manner, by arranging the outer portion 65 of the aperture unit 16 so that it fits inside the opening 64 of the sleeve portion 59 provided in the movable lens frame 14, it is possible to further reduce the size of the zoom lens barrel 4 in the radial direction.

[0072] Fig. 12 is a diagram showing a state in which the rear fixing frame 24 has been removed from the state shown in Fig. 10. Fig. 12(A) is an example of a side view showing a state in which the rear fixing frame 24 has been removed from Fig. 10(A). Fig. 12(B) is an example of a perspective view (assembly perspective view) of Fig. 12(A).

[0073] The wall portion 66 in which the first hole portion 60 for passing the guide bar 12 of the movable lens frame 14 is provided is shown by the dotted circle range to be equivalent to the extension of the lens holding portion that holds the zoom lens 13.

[0074] As described above, the zoom lens barrel 4 in this embodiment has a photodetector (not shown), such as a photointerrupter, and the photodetector is held by the rear fixed frame 24. In addition, a fin portion (plate portion, light shielding portion) 68 that blocks light irradiated from the photodetector is provided near the second hole portion 61 of the moving lens frame 14 through which the guide bar 12 passes.

[0075] In this embodiment, the fin portion 68 is a plate member that blocks light from the photodetector. In this manner, the photodetector can detect the position of the moving lens frame 14 using the fin portion 68.

[0076] A wall portion 66 (which may be considered as a part of the first hole portion 60) in which the fin portion 68 and the first hole portion 60 through which the guide bar 12 of the movable lens frame 14 pass is formed across the outer shape portion 65 of the aperture unit 16. In other words, when viewed in a direction perpendicular to the optical axis, the plate portion (fin portion 68) that blocks the photodetector and a part of the hole portion 62 of the fixed lens frame 17 overlap (overlap).

[0077] The above-mentioned configuration improves space efficiency in the radial direction of the zoom lens barrel 4. In this manner, in this embodiment, both the movable lens frame 14 and the fixed lens frame 17 are positioned in a plane perpendicular to the optical axis OA or in a direction perpendicular to the optical axis OA, using the same guide bar as a reference. This makes it possible to reduce the size of the zoom lens barrel 4 in the radial direction, while suppressing misalignment of two or more lens frames relative to the guide bar 12, and to provide a zoom lens barrel with high image quality.

[0078] As described above, in this embodiment, it is possible to provide a zoom lens barrel (lens barrel) that is smaller in size than conventional lens barrels and has a structure that allows for highly accurate lens holding.

[0079] Although the preferred embodiments of the present invention have been described above using examples and drawings, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

[0080] The disclosure of this embodiment includes the following configuration.

[0081] (Configuration 1) A first lens and a second lens; a first lens frame that holds the first lens and a second lens frame that holds the second lens; a first guide bar that supports the first lens frame so as to be movable in the optical axis direction; the first lens frame has a sleeve portion including a first hole portion and a second hole portion that engage with the first guide bar, and an opening portion formed between the first hole portion and the second hole portion; the second lens frame is provided with a third hole portion that engages with the first guide bar, when the first guide bar is engaged with the first hole portion and the second hole portion of the first lens frame and the third hole portion of the second lens frame, the first guide bar positions the first lens frame and the second lens frame in a direction perpendicular to the optical axis, and the third hole portion of the second lens frame is disposed within the opening portion of the sleeve portion. A lens barrel characterized by:

[0082] (Configuration 2) A second guide bar is provided to restrict rotation of the first lens around the optical axis. The lens barrel described in configuration 1, wherein the first lens frame and the second lens frame are positioned by the first guide bar while rotation around the optical axis is restricted by the second guide bar.

[0083] (Configuration 3) A second guide bar is further provided to restrict rotation of the first lens around the optical axis. the second lens frame is provided with a fourth hole portion that engages with the second guide bar, 3. The lens barrel according to configuration 1 or 2, wherein rotation of the second lens frame about the optical axis is restricted by engaging the second guide bar with the fourth hole portion.

[0084] (Configuration 4) The lens barrel described in any one of configurations 1 to 3, characterized in that when viewed from the optical axis direction, the first hole portion of the first lens frame overlaps with the second hole portion, and the third hole portion of the second lens frame overlaps with the first hole portion of the first lens frame.

[0085] (Configuration 5) the first hole portion is provided on an imaging surface side of the sleeve portion in the optical axis direction, 5. The lens barrel according to any one of configurations 1 to 4, wherein the second hole is provided on the object side of the sleeve portion in the optical axis direction.

[0086] (Configuration 6) A second guide bar is further provided to restrict rotation of the first lens around the optical axis. 6. The lens barrel according to any one of configurations 1 to 5, further comprising a fixed frame that holds the first guide bar and the second guide bar.

[0087] (Configuration 7) a diaphragm unit fixed to the second lens frame; The lens barrel described in any one of configurations 1 to 6, characterized in that when the first guide bar is engaged with the first hole portion and the second hole portion of the first lens frame and the third hole portion of the second lens frame, a part of the aperture unit enters the opening.

[0088] (Configuration 8) a photodetector for detecting a position of the first lens frame; 8. The lens barrel according to any one of configurations 1 to 7, wherein the first lens frame is provided with a light blocking portion that blocks light from the photodetector.

[0089] (Configuration 9) 9. The lens barrel according to configuration 8, wherein the light blocking portion and a part of the third hole portion overlap when viewed from a direction perpendicular to the optical axis.

[0090] (Configuration 10) An imaging element; 10. An imaging device comprising the lens barrel according to any one of claims 1 to 9. [Explanation of symbols]

[0091] 11 Guide bar 12 Guide bar 14 Moving lens frame 17 Fixed lens frame 59 Sleeve section 60 First hole 61 Second hole 62 Hole 64 Opening

Claims

1. A first lens and a second lens; a first lens frame that holds the first lens and a second lens frame that holds the second lens; a first guide bar that supports the first lens frame so as to be movable in the optical axis direction; the first lens frame has a sleeve portion including a first hole portion and a second hole portion that engage with the first guide bar, and an opening portion formed between the first hole portion and the second hole portion, the second lens frame is provided with a third hole portion that engages with the first guide bar, when the first guide bar is engaged with the first hole portion and the second hole portion of the first lens frame and the third hole portion of the second lens frame, the first guide bar positions the first lens frame and the second lens frame in a direction perpendicular to the optical axis, and the third hole portion of the second lens frame is disposed within the opening portion of the sleeve portion. A lens barrel characterized by:

2. A second guide bar is provided to restrict rotation of the first lens around the optical axis.

2. The lens barrel according to claim 1, wherein the first lens frame and the second lens frame are positioned by the first guide bar in a state in which rotation about an optical axis is restricted by the second guide bar.

3. A second guide bar is provided to restrict rotation of the first lens around the optical axis. the second lens frame is provided with a fourth hole portion that engages with the second guide bar, 2. The lens barrel according to claim 1, wherein rotation of the second lens frame about the optical axis is restricted by engaging the second guide bar with the fourth hole.

4. The lens barrel according to claim 1 , wherein, when viewed in the optical axis direction, the first hole and the second hole of the first lens frame overlap with each other, and the third hole of the second lens frame overlap with each other.

5. the first hole portion is provided on an imaging surface side of the sleeve portion in an optical axis direction, The lens barrel according to claim 1 , wherein the second hole is provided on an object side of the sleeve portion in the optical axis direction.

6. A second guide bar is provided to restrict rotation of the first lens around the optical axis.

2. The lens barrel according to claim 1, further comprising a fixed frame for holding the first guide bar and the second guide bar.

7. a diaphragm unit fixed to the second lens frame; 2. The lens barrel according to claim 1, wherein when the first guide bar is engaged with the first hole portion and the second hole portion of the first lens frame and the third hole portion of the second lens frame, a portion of the aperture unit enters the opening.

8. a photodetector for detecting a position of the first lens frame; The lens barrel according to claim 1 , wherein the first lens frame is provided with a light blocking portion that blocks light from the photodetector.

9. 9. The lens barrel according to claim 8, wherein the light blocking portion and a part of the third hole portion overlap each other when viewed from a direction perpendicular to the optical axis.

10. An imaging element; An imaging device comprising the lens barrel according to claim 1 .

Images