Optical device and imaging device

Abstract

To provide an optical device which is advantageous in terms of a compact size, for example.SOLUTION: Provided is a lens device 100 comprising a fixed front lens barrel 1 and a fixed rear lens barrel 3 and having, in the fixed front lens barrel 1 and fixed rear lens barrel 3, first to fourth movable lens groups L1-L4, first to fourth actuators 10-40 that respectively drive the first to fourth movable lens groups L1-L4 along an optical axis O, a diaphragm unit 5 that adjusts light, and a fifth actuator 50 that drives the diaphragm unit 5. The fifth actuator 50 and a second actuator 20 that is longest in a direction along the optical axis O among the first to fourth actuators 10-40 that are arranged closer to the image plane side than the diaphragm unit 5, are arranged in quartered and mutually different regions around the optical axis O.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an optical device and an imaging device. [Background technology]

[0002] In lens barrels used in optical devices such as video cameras, zooming and focusing are performed by driving a moving frame that holds the lens with an actuator in a direction along the optical axis, and the amount of light is adjusted by driving multiple blades of the aperture diaphragm unit with an actuator.

[0003] Patent Document 1 discloses a lens barrel having three actuators that respectively drive three lens group movement frames, an actuator that drives an aperture, and an actuator that drives an anti-vibration lens. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-101606 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the lens barrel of Patent Document 1, the aperture unit and the fourth lens group drive motor are arranged in series along the optical axis. Here, the fourth lens group drive motor is the longest in the direction along the optical axis among the actuators closer to the image side than the aperture unit. Therefore, by arranging the fourth lens group drive motor in series with the aperture unit, the lens barrel becomes larger in the direction along the optical axis.

[0006] An object of the present invention is to provide an optical device that is advantageous in terms of, for example, compactness. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides an optical device having a housing and including within the housing a plurality of lens groups, a plurality of lens group driving units each driving the plurality of lens groups in a direction along an optical axis, an adjustment member that adjusts light, and an adjustment member driving unit that drives the adjustment member, wherein the adjustment member driving unit and the lens group driving unit that is longest in a direction along the optical axis among the plurality of lens group driving units arranged on the image side of the adjustment member are arranged in different regions in a region divided into four equal parts around the optical axis. Effect of the Invention

[0008] According to the present invention, for example, it is possible to provide an optical device which is advantageous in terms of its small size. [Brief description of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a lens device 100 according to an embodiment. [Diagram 2] 1 is an exploded perspective view (object side) of a drive unit 101 in an embodiment. [Diagram 3] 2 is an exploded perspective view (image surface side) of a drive unit 101 in the embodiment. [Figure 4] 2 is a diagram showing the arrangement of actuators in a plane perpendicular to the optical axis O in the embodiment. FIG. [Diagram 5] 2 is a diagram showing the arrangement of actuators in a direction along an optical axis O in the embodiment. FIG. [Figure 6] FIG. 1 is a schematic diagram showing a configuration example of an imaging device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view of a lens device 100 (optical device) according to an embodiment of the present invention. The direction in which the optical axis O extends is the optical axis direction, the side of a fixed lens unit L0 described below is the object side, and the side of a second fixed holding frame F5 described below is the image surface side. A photographing light beam from the object side passes through a plurality of lens groups (optical elements) described below and is imaged on an imaging unit (not shown).

[0011] The lens device 100 has a front fixed barrel 1, a middle fixed barrel 2, a rear fixed barrel 3, a first fixed holding frame F0, and a second fixed holding frame F5, which constitute a housing. In addition, the housing is provided with a plurality of lens groups, a plurality of actuators that drive the plurality of lens groups in a direction along the optical axis O, an adjustment member that adjusts light, and an adjustment member drive unit (described later) that drives the adjustment member. The plurality of lens groups are configured by a variable magnification optical system (zoom lens system) that includes four movable lens groups, each of which includes at least one optical element. The plurality of actuators include four actuators that drive the four lens groups, respectively. An IR unit 7 (Infrared unit), a polarizing filter, a wavelength selection filter, a soft focus filter, and the like are provided as adjustment members that adjust light. Alternatively, an aperture unit 5 (aperture diaphragm) and an ND unit 6 (Neutral Density unit, filter) are provided as adjustment members that adjust the amount of light.

[0012] The fixed lens unit L0 includes at least one optical element, is fixed to the first fixed holding frame F0, and is immovable in the optical axis direction. The lens groups include a first moving lens group L1, a second moving lens group L2, a third moving lens group L3, and a fourth moving lens group L4. The first moving lens group L1, the second moving lens group L2, and the fourth moving lens group L4 can be moved in the optical axis direction to change the magnification of the optical system.

[0013] The second moving lens group L2 is composed of the 2a lens group L2a and the 2b lens group L2b, and is a unit that can perform not only the magnification change function but also the image blur correction of the optical system. The 2b lens group L2b is an image stabilization unit that is shifted in a direction perpendicular to the optical axis O of the photographing optical system to reduce image blur. The third moving lens group L3 can perform the correction of the image plane fluctuation caused by the magnification change and the focus adjustment function by moving in the optical axis direction.

[0014] The first fixed holding frame F0 holds the fixed lens unit L0. The first moving holding frame F1 holds the first moving lens group L1 so that it can move in the optical axis direction. The second moving holding frame F2a holds the 2a lens group L2a so that it can move in the optical axis direction, and the vibration-proof moving frame F2b holds the 2b lens group L2b. The vibration-proof moving frame F2b is attached to the second moving holding frame F2a so that it can move in a direction perpendicular to the optical axis. The third moving holding frame F3 holds the third moving lens group L3 so that it can move in the optical axis direction. The fourth moving holding frame F4 holds the fourth moving lens group L4 so that it can move in the optical axis direction.

[0015] The front fixed barrel 1 holds a first fixed holding frame F0 at the front end (object side) of the front fixed barrel 1, and fixes the fixed lens unit L0 in a predetermined position via the first fixed holding frame F0. In addition, the rear end (image surface side) of the front fixed barrel 1 is connected to the rear fixed barrel 3.

[0016] The central fixed barrel 2 holds an aperture unit 5 that adjusts the amount of light passing through multiple lenses, and the rear end of the central fixed barrel 2 is connected to the rear fixed barrel 3. The aperture unit 5 adjusts the amount of light by moving the aperture blades in a plane perpendicular to the optical axis O using an adjustment member drive unit in order to change the aperture diameter of the optical system.

[0017] The front end of the rear fixed barrel 3 is fixed to the front fixed barrel 1 and the central fixed barrel 2, and the rear end of the rear fixed barrel 3 is coupled to the second fixed holding frame F5. The rear fixed barrel 3 also holds a lens drive unit, which will be described later.

[0018] The second fixed holding frame F5 has its front end fixed to the rear fixed lens barrel 3, and houses the ND unit 6, the IR unit 7, and an imaging element (not shown).

[0019] If the amount of light is adjusted only by changing the area of ​​the aperture using the aperture unit 5, the aperture becomes smaller when shooting a high-brightness subject, and optical performance deteriorates due to the phenomenon of light diffraction. To prevent such deterioration of optical performance, the amount of light is reduced using a filter using the ND unit 6. The IR unit 7 is configured with a mechanism that places an infrared light cut filter that cuts out near-infrared light in front of the optical axis of the image sensor when used in the visible light range, and removes the infrared light cut filter when used in the near-infrared light range.

[0020] Components of the drive unit 101 according to the embodiment will be described in detail below with reference to Fig. 2 and Fig. 3. Fig. 2 is an exploded perspective view of the drive unit 101 according to the embodiment as seen from the object side, and Fig. 3 is an exploded perspective view of the drive unit 101 according to the embodiment as seen from the image plane side.

[0021] The first guide bar G1 is held at both ends by a front fixed lens barrel 1 and a rear fixed lens barrel 3 (not shown), and the second guide bar G2 is held at both ends by the front fixed lens barrel 1 and a central fixed lens barrel 2. The first moving holding frame F1 is supported by the first guide bar G1 and the second guide bar G2 so as to be movable in the optical axis direction.

[0022] The third guide bar G3 and the fourth guide bar G4 are held at their respective ends by the central fixed lens barrel 2 and the rear fixed lens barrel 3. The second movable holding frame F2a is supported by the third guide bar G3 and the fourth guide bar G4 so as to be movable in the optical axis direction.

[0023] The fifth guide bar G5 and the sixth guide bar G6 are held at their respective ends by the central fixed lens barrel 2 and the rear fixed lens barrel 3. The third movable holding frame F3 is supported by the fifth guide bar G5 and the sixth guide bar G6 so as to be movable in the optical axis direction.

[0024] Both ends of the seventh guide bar G7 and the eighth guide bar G8 are held by the central fixed lens barrel 2 and the rear fixed lens barrel 3. The fourth movable holding frame F4 is supported by the seventh guide bar G7 and the eighth guide bar G8 so as to be movable in the optical axis direction.

[0025] Next, the configuration of the first actuator 10 (lens group driving unit) that moves the first moving and holding frame F1 will be described. The first actuator 10 is a stepping motor, and drives the first moving and holding frame F1 in the optical axis direction by being driven by a motor unit 11. A lead screw 12 is formed on the output shaft of the motor unit 11.

[0026] The motor unit 11 is fixed to the rear fixed barrel 3 via a support member 13. A rack 14 attached to the first moving holding frame F1 meshes with the lead screw 12. Therefore, when the motor unit 11 is energized and the lead screw 12 rotates, the first moving holding frame F1 is driven in the optical axis direction via the rack 14.

[0027] The rattle between the rack 14 and the first moving holding frame F1 in the optical axis direction is reduced by the biasing force of the torsion coil spring 15. When the motor unit 11 is not energized (de-energized state), the first moving holding frame F1 has a self-holding force because the rack 14 and the lead screw 12 are engaged with each other.

[0028] The reset 16 is a zoom reset for detecting the reference position of the first movable holding frame F1, and is a photointerrupter for detecting switching between a light-shielding state and a light-transmitting state caused by movement in the optical axis direction of a light-shielding portion 17 formed on the first movable holding frame F1. The reset 16 is fixed to the front fixed barrel 1 via a substrate (not shown).

[0029] The scale 18 is a reflective film scale constituting an optical position detection encoder, and is held by the first moving holding frame F1. The sensor head 19 is a photo IC chip incorporating a light source equipped with an LED chip and a circuit that processes the signal of the reflected light from the light source reflected by the scale 18, and is fixed via a substrate (not shown) to a position of the rear fixed lens barrel 3 facing the scale 18. By using a signal from the sensor head 19, the first moving holding frame F1 can detect the amount of movement from a predetermined reference position (reset 16).

[0030] Next, the configuration of the second actuator 20 (the longest lens group driving unit) that moves the second moving and holding frame F2a will be described. The basic configuration of the second actuator 20 is similar to that of the first actuator 10. The second actuator 20 is a stepping motor, and drives the second moving and holding frame F2a in the optical axis direction by being driven by a motor unit 21. A lead screw 22 is formed on the output shaft of the motor unit 21.

[0031] The motor unit 21 is fixed to the rear fixed barrel 3 via a support member 23. A rack 24 attached to the second moving and holding frame F2a meshes with the lead screw 22. Therefore, when the motor unit 21 is energized and the lead screw 22 rotates, the second moving and holding frame F2a is driven in the optical axis direction via the rack 24.

[0032] The rattle between the rack 24 and the second moving holding frame F2a in the optical axis direction is reduced by the biasing force of the torsion coil spring 25. In a state where no electricity is applied to the motor unit 21 (non-energized state), the second moving holding frame F2a has a self-holding force because the rack 24 and the lead screw 22 are engaged with each other.

[0033] The reset 26 is a zoom reset for detecting the reference position of the second movable holding frame F2a, and is a photointerrupter for detecting switching between a light-shielding state and a light-transmitting state caused by movement in the optical axis direction of a light-shielding portion 27 formed on the second movable holding frame F2a. The reset 26 is fixed to the rear fixed barrel 3 via a substrate (not shown).

[0034] The scale 28 is a reflective film scale constituting an optical position detection encoder, and is held by the second moving holding frame F2a. The sensor head 29 is a photo IC chip incorporating a light source equipped with an LED chip and a circuit for signal processing of the reflected light reflected from the light source by the scale 28, and is fixed via a substrate (not shown) to a position of the rear fixed lens barrel 3 facing the scale 28. By using a signal from the sensor head 29, the second moving holding frame F2a can detect the amount of movement from a predetermined reference position (reset 26).

[0035] Next, a description will be given of the configuration of the third actuator 30 (lens group drive unit) that moves the third moving holder frame F3. The third actuator 30 is a voice coil motor, and is made up of a drive coil 31, a drive magnet 32, and a yoke member 33 for closing the magnetic flux.

[0036] The drive coil 31 is attached to the third moving support frame F3. The drive magnet 32 ​​is provided within a yoke member 33, and the yoke member 33 is attached to the rear fixed barrel 3.

[0037] When the drive coil 31 is energized, a Lorentz force is generated between the drive magnet 32 ​​and the drive coil 31 due to the repulsion of magnetic lines of force. The Lorentz force at this time drives the third moving and holding frame F3 in the optical axis direction. When the drive coil 31 is not energized (non-energized state), no driving force is generated to the third moving and holding frame F3, and the third moving and holding frame F3 has no self-holding force.

[0038] The scale 34 is a reflective film scale constituting an optical position detection encoder, and is held by the third movable holding frame F3. The sensor head 35 is a photo IC chip incorporating a light source equipped with an LED chip and a circuit for signal processing of the reflected light reflected from the light source by the scale 34, and is fixed via a substrate (not shown) to a position of the rear fixed lens barrel 3 facing the scale 34. By using a signal from the sensor head 35, the third movable holding frame F3 can detect the amount of movement from a predetermined reference position.

[0039] Next, the configuration of the fourth actuator 40 (lens group driving unit) that moves the fourth moving and holding frame F4 will be described. The basic configuration of the fourth actuator 40 is similar to that of the first actuator 10. The fourth actuator 40 is a stepping motor, and drives the fourth moving and holding frame F4 in the optical axis direction by being driven by a motor unit 41. A lead screw 42 is formed on the output shaft of the motor unit 41.

[0040] The motor unit 41 is fixed to the rear fixed barrel 3 via a support member 43. A rack 44 attached to the fourth moving holder frame F4 meshes with the lead screw 42. Therefore, when the motor unit 41 is energized and the lead screw 42 rotates, the fourth moving holder frame F4 is driven in the optical axis direction via the rack 44.

[0041] The rattle between the rack 44 and the fourth moving holding frame F4 in the optical axis direction is reduced by the biasing force of the torsion coil spring 45. When the motor unit 41 is not energized (de-energized state), the fourth moving holding frame F4 has a self-holding force because the rack 44 and the lead screw 42 are engaged with each other.

[0042] The reset 46 is a zoom reset for detecting the reference position of the fourth movable holding frame F4, and is a photointerrupter for detecting switching between a light-shielding state and a light-transmitting state caused by movement in the optical axis direction of a light-shielding portion 47 formed on the fourth movable holding frame F4. The reset 46 is fixed to the rear fixed barrel 3 via a substrate (not shown).

[0043] The scale 48 is a reflective film scale constituting an optical position detection encoder, and is held by the fourth movable holding frame F4. The sensor head 49 is a photo IC chip incorporating a light source equipped with an LED chip and a circuit that processes the signal of the reflected light reflected from the light source by the scale 48, and is fixed via a substrate (not shown) to a position of the rear fixed lens barrel 3 facing the scale 48. By using a signal from the sensor head 49, the third movable holding frame F3 can detect the amount of movement from a predetermined reference position (reset 46).

[0044] Next, the configuration of the aperture unit 5 will be described. The aperture unit 5 is driven by a fifth actuator 50 (adjustment member driving section), which is a stepping motor or a DC motor. The aperture unit 5 is made up of a plurality of aperture blades (not shown) and a plurality of components connected from the aperture blades to the fifth actuator 50. When the fifth actuator 50 is driven, the plurality of aperture blades advance and retreat in the radial direction, making it possible to adjust the amount of light.

[0045] The arrangement of the actuators according to the embodiment will be described in detail below with reference to Fig. 4 and Fig. 5. Fig. 4 is a diagram showing the positional relationship of the actuators according to the embodiment when viewed from the object side. Fig. 5 is a diagram showing the positional relationship of the actuators according to the embodiment when viewed from a direction perpendicular to the vertical plane B in Fig. 4.

[0046] As shown in FIG. 4, when the lens device 100 is divided by a horizontal plane A and a vertical plane B perpendicular to the horizontal plane A with respect to the optical axis O, the lens device 100 is divided into four regions. In this case, each actuator for driving the first to fourth moving holding frames F1 to F4, which are the four moving members, is disposed in each region. In particular, the third actuator 30 is configured by a voice coil motor and uses a magnet having a strong magnetic force, so that it is preferable to dispose the actuators as far apart as possible from each other in order to prevent magnetic interference with other actuators. Meanwhile, the fifth actuator 50 of the aperture unit 5 is disposed in the same region as the fourth actuator 40. Note that, although FIG. 4 illustrates a case in which there are four actuators, the number of actuators may be three or five or more. In the embodiment, the first, second and fourth actuators 10, 20 and 40 are stepping motors, respectively, and the third actuator is a voice coil motor. However, at least one of the plurality of actuators may include a stepping motor, and at least another of the plurality of actuators may include a voice coil motor.

[0047] As described above, the first actuator 10 drives the first moving and holding frame F1 in the optical axis direction, but as shown in Fig. 5, the first moving and holding frame F1 is arranged on the object side of the aperture unit 5. The second actuator 20 similarly drives the second moving and holding frame F2a in the optical axis direction, but the second moving and holding frame F2a is arranged on the image plane side of the aperture unit 5. In addition, the third actuator 30 and the fourth actuator 40 are also arranged on the image plane side of the aperture unit 5.

[0048] When the lens device 100 is divided into four regions on a plane perpendicular to the optical axis O, the fifth actuator 50 must be disposed in the same region (in series) as one of the actuators. Therefore, depending on which actuator the fifth actuator 50 is disposed in, the device may become large.

[0049] Since the first actuator 10 is the longest actuator in the optical axis direction among all the actuators, for example, if the fifth actuator 50 and the first actuator 10 are arranged in the same region, the device will become larger, especially on the object side. The same is true if the fifth actuator 50 and the second actuator 20 are arranged in the same region. Since the second actuator 20 is the longest actuator in the optical axis direction among all the actuators arranged on the image plane side of the aperture unit 5, and has the longest moving distance, the device will become larger, especially on the image plane side.

[0050] Therefore, the fifth actuator 50 and the second actuator 20, which is the longest in the direction along the optical axis O among the multiple actuators arranged closer to the image surface side (image side) than the aperture unit 5, are arranged in different regions from each other in a region obtained by dividing the circumference of the optical axis O into four equal parts. Moreover, the fourth actuator 40 is the second longest in the optical axis direction among the actuators arranged closer to the image surface side than the aperture unit 5. Therefore, by arranging the fifth actuator 50 and the fourth actuator 40 in the same region, it is possible to suppress an increase in size of the device on the image surface side compared to the case where they are arranged in the same region as the second actuator 20.

[0051] In addition, in the optical axis direction, the fifth actuator 50 and the first actuator 10, which is one of a plurality of actuators arranged closer to the object side than the aperture unit 5, are not arranged in the same region. In other words, the fifth actuator 50 and the first actuator 10 are arranged in parallel, and are arranged at diagonal positions inside the substantially rectangular rear fixed barrel 3. By arranging them in this way, the four corners of the internal space of the substantially rectangular rear fixed barrel 3 can be effectively utilized, making it possible to suppress an increase in the size of the device in the diametrical direction.

[0052] Further, a plurality of (four) actuators are arranged in mutually different regions in the region obtained by dividing the circumference of the optical axis O into four equal parts, and two of the plurality of actuators are arranged to overlap each other in the direction along the optical axis O. As shown in FIG. 5, a portion C of the plurality of actuators is arranged to overlap each other in the direction along the optical axis O. In other words, they are all arranged in parallel and substantially parallel to the optical axis O. By arranging them in this manner, the internal space of the rear fixed barrel 3 can be effectively utilized, and therefore it is possible to prevent the device from becoming large in the optical axis direction. Therefore, according to the embodiment, it is possible to provide an optical device that enables miniaturization.

[0053] In the embodiment, the second actuator 20 is configured to be the longest in the optical axis direction on the image plane side relative to the aperture unit 5, but if another actuator is the longest, it is sufficient to avoid arranging that actuator and the fifth actuator 50 in the same region. Note that the fifth actuator 50 drives the aperture unit 5 that adjusts the amount of light, but it may also drive the ND unit 6 instead of the aperture unit 5. Furthermore, the fifth actuator 50 may also drive the IR unit 7 that adjusts light, a polarizing filter, a wavelength selection filter, a soft focus filter, etc.

[0054] In the embodiment, the region is divided by a horizontal plane A and a vertical plane B perpendicular to the horizontal plane A and the optical axis O. Meanwhile, the rear fixed barrel 3, whose cross section perpendicular to the optical axis O is substantially rectangular, has a bottom surface and a top surface facing each other, and two side surfaces facing each other. The region obtained by dividing the circumference of the optical axis O into four equal parts may be a region obtained by dividing the circumference of the optical axis O by a first surface passing through the optical axis O and perpendicular to the bottom surface, and a second surface passing through the optical axis O and perpendicular to the first surface, and the lens device 100 can be defined into four regions. When divided into four regions in this way, at least one or more of the multiple actuators are disposed in each region. By dividing the four equally, the distance between the actuators can be secured to a certain degree, which is effective when using actuators for which magnetic interference is a concern. In the embodiment, the number of lens moving groups is four, but even if the number of lens moving groups is increased, a similar effect can be expected by providing a region according to the number of moving groups.

[0055] (Examples) 6 is a schematic diagram showing a configuration example of a camera device 1000 (imaging device) using a lens device 100 to which the present invention is applied. The imaging device includes the lens device 100 and a camera body 1000a having an image sensor 1000b that captures an image of an object formed by the lens device 100. The imaging device may also be configured such that the lens device 100 is detachably attached to the camera body 1000a of the camera device 100.

[0056] The disclosure of this embodiment includes the following configuration. (Configuration 1) The device has a housing, In the housing, A plurality of lens groups; a plurality of lens group driving units configured to drive the plurality of lens groups in directions along an optical axis; An adjustment member for adjusting light; an adjustment member driving unit that drives the adjustment member, an optical device characterized in that the adjustment member drive unit and the lens group drive unit that is the longest in a direction along the optical axis among the multiple lens group drive units arranged on the image side of the adjustment member are arranged in different regions from each other in a region that divides a circumference around the optical axis into four equal parts. (Configuration 2) The housing has a bottom surface and a top surface opposed to each other, and two side surfaces opposed to each other, The optical device described in configuration 1, characterized in that the area around the optical axis is divided into four equal parts by a first surface that passes through the optical axis and is perpendicular to the bottom surface, and a second surface that passes through the optical axis and is perpendicular to the first surface. (Configuration 3) The optical device described in configuration 1 or 2, characterized in that two of the plurality of lens group driving units arranged in different regions of a region divided into four equal parts around the optical axis are arranged so as to overlap each other in a direction along the optical axis. (Configuration 4) The optical device according to any one of configurations 1 to 3, characterized in that four of the lens group driving units are arranged in four equal regions around the optical axis. (Configuration 5) 5. The optical device according to any one of configurations 1 to 4, wherein the adjustment member adjusts the amount of light. (Configuration 6) 6. The optical device according to any one of configurations 1 to 5, wherein the adjustment member includes an aperture stop or a filter. (Configuration 7) the plurality of lens groups includes four movable lens groups; 7. The optical device according to any one of configurations 1 to 6, wherein the plurality of lens group driving sections include four lens group driving sections that drive the four lens groups, respectively. (Configuration 8) 8. The optical device of any one of configurations 1 to 7, wherein at least one of the plurality of lens group driving units includes a stepping motor, and at least one other of the plurality of lens group driving units includes a voice coil motor. (Configuration 9) 9. The optical device according to any one of configurations 1 to 8, wherein the adjustment member drive unit includes a stepping motor or a DC motor. (Configuration 10) 10. An imaging device comprising: the optical device according to any one of configurations 1 to 9; and an imaging element that captures an image formed by the optical device. [Explanation of symbols]

[0057] 1 Front fixed barrel (housing) 3 Rear fixed barrel (housing) 5 Aperture unit (aperture diaphragm, adjustment member) 6 ND unit (filter, adjustment parts) 10 First actuator (lens group drive unit) 20 Second actuator (longest lens group actuator) 30 Third actuator (lens group drive unit) 40 Fourth actuator (lens group drive unit) 50 Fifth actuator (adjustment member drive unit) 100 Lens device (optical device) L1 First moving lens group L2 Second moving lens group L3 Third moving lens group L4 Fourth moving lens group O optical axis

Claims

1. First to fourth lens groups; first to fourth drive units that move the first to fourth lens groups in directions along the optical axis, respectively; a diaphragm member whose opening diameter is variable; a fifth driving unit that changes the opening diameter, An optical device characterized in that the longest driving unit in a direction along the optical axis among the first to fourth driving units that are arranged closer to the image side than the aperture member and the fifth driving unit are arranged in different regions among four equal regions centered on the optical axis.

2. A housing that holds the first to fourth lens groups, the diaphragm member, and the first to fifth drive units, the housing including a bottom surface and a top surface that face each other, and two side surfaces that face each other; 2. The optical device according to claim 1, wherein the area around the optical axis is divided into four equal parts by a first surface that passes through the optical axis and is perpendicular to the bottom surface, and a second surface that passes through the optical axis and is perpendicular to the first surface.

3. The optical device according to claim 1, characterized in that two of the first to fourth driving units arranged in different regions of a region equally divided into four around the optical axis are arranged so as to overlap each other in a direction along the optical axis.

4. 2. The optical device according to claim 1, wherein four of the first to fourth drive units are arranged in regions that are equal in size to four around the optical axis.

5. An optical device as described in claim 1, characterized in that the fifth driving unit is arranged in the same area as one of the first to fourth driving units.

6. An optical device as described in Claim 5, characterized in that the first to fourth lens groups are arranged in order from the object side to the image side, and the fourth driving unit is arranged in the same area as the fifth driving unit.

7. An optical device as described in Claim 6, characterized in that the fifth driving unit is positioned closer to the optical axis than the fourth driving unit.

8. An optical device as described in Claim 1, characterized in that when the optical device is in its normal position, the fifth driving unit is located in the upper left area.

9. 2. The optical device according to claim 1, wherein at least one of the first to fourth drive units includes a stepping motor, and at least one other of the first to fourth drive units includes a voice coil motor.

10. 2. The optical device according to claim 1, wherein the fifth driving unit includes a stepping motor or a DC motor.

11. 11. An imaging device comprising: the optical device according to claim 1; and an imaging element for capturing an image formed by the optical device.

Images