JP6207188B2 - Imaging device - Google Patents

Description

  The present invention relates to an optical apparatus such as a lens-integrated camera and an interchangeable lens.

  The lens barrel of the compact still camera is configured so that it can be retracted and extended by an actuator, and an annular gap for reducing a frictional load is provided between the lens barrel and the fixed exterior. In order to prevent foreign matters such as water and dust from entering the gap, Patent Document 1 proposes to provide an elastic seal member between the lens barrel and the fixed exterior.

JP 2001-42407 A

  In Patent Document 1, the elastic seal member is in contact with the lens barrel via a lip portion inclined with respect to a plane orthogonal to the optical axis, and the driving load (frictional force) received from the lip portion differs depending on the driving direction of the lens barrel. . If the power supplied to the actuator is set so as to generate a driving force that can overcome a large driving load, an excessive driving force is generated when driving in the direction of a small driving load. turn into.

  An object of the present invention is to provide an optical apparatus that can prevent intrusion of foreign matter and reduce power consumption.

The optical apparatus of the present invention seals the first member, the second member moved relative to the first member, and the gap between the first member and the second member. A sealing member that stops, and a biasing means that applies a biasing force to at least one of the first member and the second member, wherein the second member is a second member with respect to the first member. The driving load applied by the sealing member in a second direction opposite to the first direction when the sealing member is moved in the first direction is such that the second member applies the second to the first member. The energizing means is larger than the driving load applied to the first direction when the sealing member is moved in the direction of the first member. driving force required to move the direction, the biasing force to reduce than the biasing force is zero added by said biasing means Fs is an urging force applied to the second member in the first direction, F3a is a driving load when the second member is driven in the first direction with respect to the first member, when the F3b the driving load when the second member is driven in the second direction relative to the first member, 0 <Fs <F3a-F3b conditional expression is satisfied and characterized Rukoto To do.

  ADVANTAGE OF THE INVENTION According to this invention, the optical device which can prevent invasion of a foreign material and can reduce power consumption can be provided.

It is sectional drawing of the retracted state and extended state of the optical apparatus of this invention. Example 1 It is a partial expanded sectional view explaining operation | movement of the optical instrument shown in FIG. Example 1 It is a graph which shows the urging | biasing force of the spring shown in FIG. Example 1 It is a flowchart which shows operation | movement of the optical apparatus shown in FIG. Example 1 It is sectional drawing of the retracted state of the optical apparatus of this invention. (Example 2) It is a flowchart which shows operation | movement of the optical apparatus shown in FIG. (Example 2) It is a graph which shows the power consumption of the optical apparatus shown in FIG. (Example 2) It is sectional drawing which shows the modification of the 1st packing of the optical instrument shown in FIG.1 and FIG.5. (Examples 1 and 2)

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following embodiments, the optical apparatus of the present invention is configured as a lens-integrated imaging device (digital still camera), but may be configured as a lens device that is detachably mounted from the imaging device body.

  FIG. 1A is a cross-sectional view taken along a plane that passes through the optical axis indicated by the alternate long and short dash line and is parallel to the optical axis when the imaging apparatus 100 according to the first embodiment is in the retracted state. FIG. 1B is a cross-sectional view taken along a plane that passes through the optical axis and is parallel to the optical axis when the imaging apparatus 100 is in the extended state.

  Reference numeral 101 denotes a single lens (imaging optical system), which is fixed to the first lens barrel 102. An optical image of the subject is formed on the imaging surface of the image sensor 114.

  Reference numeral 102 denotes a first lens barrel, which includes a cylindrical outer peripheral portion 102 a made of a smooth surface with small irregularities that comes into contact with the first packing 103. The outer peripheral portion 102 a has a surface parallel to the optical axis of the lens 101. The optical axis of the lens 101 is a central axis of the first lens barrel 102 and is parallel to the following first direction and second direction. When considering the first member and the second member moved relative to the first member, the first lens barrel 102 corresponds to the second member, and the second lens barrel 104 is the first member. This corresponds to one member.

  On the outer periphery of the first lens barrel 102, cylindrical cam followers 102b extending radially about the optical axis are provided at three locations that are equal in the circumferential direction when viewed from the optical axis direction. The first lens barrel 102 is supported in a state where the cam follower 102b is engaged with the rectilinear groove 105a and the cam groove 106a.

  Reference numeral 103 denotes a first packing, which is an elastic seal member (sealing member) formed of an elastic material such as silicon rubber. The first packing 103 has a cylindrical shape, and is fixed to the second lens barrel 104 and the guide tube 105 by being sandwiched in the optical axis direction.

  Here, when the first lens barrel 102 is moved in the retracted direction with respect to the second lens barrel 104, a driving load (frictional force) applied to the first packing 103 in the extending direction opposite to the retracted direction is applied. Let F3a. Further, a driving load (friction force) applied to the first packing 103 in the retracted direction when the first lens barrel 102 is moved in the extending direction with respect to the second lens barrel 104 is defined as F3b. Then, as will be described later, F3a is larger than F3b.

  Further, the retracting direction is a direction (first direction) in which at least a part of the first lens barrel 102 is accommodated in the optical apparatus as the first lens barrel 102 moves. The extension direction is a direction (second direction) in which at least a part of the first lens barrel 102 is exposed to the outside of the optical device by moving the first lens barrel 102.

  The first packing 103 is provided to prevent foreign matters such as water and dust from entering between the first lens barrel 102 and the second lens barrel 104. The first packing 103 has a lip portion 103a that contacts the outer peripheral portion 102a regardless of the position of the first lens barrel 102 in the optical axis direction. The lip portion 103a will be described later.

  Reference numeral 104 denotes a second lens barrel that is provided around the first lens barrel 102 and is fixed to the guide tube 105. The second lens barrel 104 includes a cylindrical outer peripheral portion 104 a made of a smooth surface with small irregularities that comes into contact with the second packing 107. The outer peripheral portion 104a has a surface parallel to the optical axis of the lens 101, and the second packing 107 moves in the optical axis direction with respect to the outer peripheral portion 104a.

  Reference numeral 105 denotes a guide tube, which is provided with three straight grooves 105a that are parallel to the optical axis penetrating in the radial direction and engage with the cam follower 102b in the circumferential direction at three locations that are equal in the circumferential direction when viewed from the optical axis direction. ing. Cylindrical cam followers 105b extending radially around the optical axis are provided on the outer periphery at three locations that are equal in the circumferential direction when viewed from the optical axis direction. The guide tube 105 is supported with the cam follower 105b engaged with the rectilinear groove 109b.

  Reference numeral 106 denotes a cam cylinder, which is fitted to the guide cylinder 105 and is supported so as to be rotatable about the optical axis and limited in movement in the optical axis direction. The inner periphery is a spiral groove centered on the optical axis dug in the radial direction at three locations even in the circumferential direction when viewed from the optical axis direction, and is engaged with the cam follower 102b in a direction parallel to the optical axis. A mating cam groove 106a is provided. Cylindrical cam followers 106b extending radially around the optical axis are provided on the outer periphery at three locations that are uniform in the circumferential direction when viewed from the optical axis direction. The cam cylinder 106 is supported in a state where the cam follower 106b is engaged with the rectilinear groove 110a and the cam groove 109a.

  Reference numeral 107 denotes a second packing, which is an elastic seal member (sealing member) formed of an elastic material such as silicon rubber. The second packing 107 has a cylindrical shape, and is fixed to the front cover 108 and the stationary ring 109 by being sandwiched in the optical axis direction.

  Here, when the second lens barrel 104 is moved in the retracted direction with respect to the front cover 108, a driving load that the second packing 107 applies in the extending direction is F3a. A driving load applied by the second packing 107 in the retracted direction when the second lens barrel 104 is moved in the extending direction with respect to the front cover 108 is defined as F3b. Then, as will be described later, F3a is larger than F3b.

  The second packing 107 is provided to prevent foreign matters such as water and dust from entering between the second lens barrel 104 and the front cover 108. The second packing 107 includes a lip portion 107a that contacts the outer peripheral portion 104a regardless of the position of the second lens barrel 104 in the optical axis direction. The lip portion 107a will be described later.

  Reference numeral 108 denotes a front cover, which is watertightly fixed to the casing 115 using an O-ring (not shown). When considering the first member and the second member moved relative to the first member, the second lens barrel 104 corresponds to the second member, and the front cover 108 is the first member. Corresponding to In this case, the front cover 108 is fixed (stationary) while the second lens barrel 104 moves. Further, the retracting direction is a direction (first direction) in which at least a part of the second lens barrel 104 is accommodated in the optical apparatus as the second lens barrel 104 moves. The extension direction is a direction (second direction) in which at least a part of the second lens barrel 104 is exposed to the outside of the optical device by moving the second lens barrel 104.

  Reference numeral 109 denotes a fixed ring, which is fixed to the housing 115. A cam groove 109a which is a spiral groove centered on the optical axis penetrating in the radial direction and is engaged with the cam follower 106b in a direction parallel to the optical axis at three positions equal to the circumferential direction when viewed from the optical axis direction. It has. The inner circumference is provided with three straight grooves 109b that are parallel to the optical axis dug in the radial direction and engage with the cam follower 105b in the circumferential direction at three locations that are equal in the circumferential direction when viewed from the optical axis direction. Yes.

  Reference numeral 110 denotes a drive ring, which is fitted to the fixed ring 109 and is supported so as to be rotatable about the optical axis and limited in movement in the optical axis direction. The inner circumference is provided with three straight grooves 110a that are parallel to the optical axis dug in the radial direction and engage with the cam follower 106b in the circumferential direction at three locations that are equal in the circumferential direction when viewed from the optical axis direction. Yes. A gear portion 110b to which the rotation of the pinion 111 is transmitted is formed on the outer periphery over a predetermined length in the circumferential direction.

  A pinion 111 is fixed to the rotating shaft of the motor 112. A gear portion that meshes with the gear portion 110b in the circumferential direction of the rotation shaft of the motor 112 is formed on the outer periphery.

  Reference numeral 112 denotes a motor (actuator), which is a driving means fixed to the housing 115. The rotating shaft can be rotationally driven by a drive signal output from a control circuit (control means) (not shown).

  Reference numeral 113 denotes a spring (biasing means), which is composed of two coil springs arranged evenly in the circumferential direction as viewed from the optical axis. Both ends are fixed to the first lens barrel 102 and the housing 115, and the first lens barrel 102 and the housing 115 are brought closer to the optical axis direction regardless of the position of the first lens barrel 102 in the optical axis direction. Generate a biasing force.

  The spring 113 of the present embodiment applies a biasing force to the first lens barrel 102, but the biasing means is the first lens barrel (second member) 102 and the second lens barrel (first lens). It is sufficient to apply a biasing force to at least one of the members.

  The spring 113 applies a biasing force such that the driving force necessary to move the first lens barrel 102 in the retracted direction with respect to the second lens barrel 104 is smaller than that when the biasing force is zero. As a result, driving in the retracted direction is assisted by the spring 113, so that power consumption is reduced.

  The spring 113 includes a driving force necessary to move the first lens barrel 102 in the retracted direction with respect to the second lens barrel 104 and a feeding direction of the first lens barrel 102 with respect to the second lens barrel 104. The biasing force is applied so as to reduce the difference between the driving force required to move to the position when the biasing force is zero. Thereby, even if the electric power supplied to the motor 112 is set so as to generate a driving force that overcomes a large driving load, waste of the driving force when driving in the direction of a small driving load can be reduced. In this embodiment, the absolute value of the driving force of the motor 112 is constant regardless of the driving direction of the first lens barrel.

  The urging means is two coil springs in this embodiment, but three or more coil springs that are equally arranged in the circumferential direction when viewed from the optical axis, or a spiral-shaped 1 centered on the optical axis. You may comprise by one coil spring and you may comprise by other elastic members, such as rubber | gum and a leaf | plate spring. A configuration in which a magnetic urging force in the optical axis direction is generated by a magnet and a magnetic body may be used.

  In the present embodiment, the urging force by the spring 113 acts between the first lens barrel 102 and the second lens barrel 104, but the urging force by the urging means is the second lens barrel 104 and the front cover 108. You may act between.

  Reference numeral 114 denotes an image sensor, which is fixed to the housing 115. The imaging element 114 includes a light receiving surface (imaging surface) orthogonal to the optical axis, and is composed of a CCD sensor or a CMOS sensor that outputs an analog image signal by photoelectrically converting the structure formed by the light of the lens 101.

  Reference numeral 115 denotes a housing, which is configured to be watertight so as to fix and store each member and prevent foreign matters from entering. In order to cope with a change in the volume of the imaging apparatus 100 accompanying the movement of the first lens barrel 102, it is desirable to provide a ventilation means that can ensure air permeability while maintaining water tightness.

  Hereinafter, the operation of the imaging apparatus 100 in the present embodiment will be described.

  In this embodiment, by driving the motor 112, the first lens barrel 102 and the second lens barrel 104 are moved in the optical axis direction with respect to the housing 115, and the retracted state shown in FIG. 1 (b) can be held in the extended state and the state in between.

  Consider a case in which the motor 112 is driven in the first direction in order to extend the first lens barrel 102 in the retracted state shown in FIG. When the motor 112 is driven, the pinion 111 fixed to the rotation shaft rotates, and the drive ring 110 connected to the pinion 111 and the gear portion 110b rotates around the optical axis.

  Since the rectilinear groove 110a and the cam follower 106b are engaged in the circumferential direction, the cam ring 106 rotates about the optical axis as the drive ring 110 rotates. Since the cam follower 106b is engaged with the cam groove 109a in a direction parallel to the optical axis, the cam ring 106 moves in the optical axis direction along the spiral cam groove 109a. Since the cam follower 105b and the rectilinear groove 109b are engaged in the circumferential direction, the rotation of the guide tube 105 is restricted. Further, the guide tube 105 moves in the optical axis direction as the cam ring 106 moves. Therefore, the second lens barrel 104 fixed to the guide tube 105 does not rotate and moves in the optical axis direction.

  Since the cam follower 102b and the rectilinear groove 105a are engaged in the circumferential direction, the rotation of the first lens barrel 102 is restricted. Since the cam follower 102b is engaged with the cam groove 106a in a direction parallel to the optical axis, the first lens barrel 102 moves in the optical axis direction along the spiral cam groove 106a. Therefore, the first lens barrel 102 does not rotate and moves in the optical axis direction.

  As a result, the first lens barrel 102 and the second lens barrel 104 can move to the extended state shown in FIG. 1B in the direction in which the lens 101 and the image sensor 114 are separated (the extended direction). is there. Similarly, when the motor 112 is driven in a second direction opposite to the first direction, the first lens barrel 102 and the second lens barrel 104 are arranged in a direction in which the lens 101 and the image sensor 114 approach (retraction direction, collapsible direction). In the direction), it is possible to move to the retracted position shown in FIG.

  By holding the lens 101 fixed to the first lens barrel 102 at an arbitrary position, the collapsing operation for shortening the overall length of the imaging apparatus 100 and the size of the image formed on the imaging element 114 are arbitrarily changed. Zoom operation is possible. In the present embodiment, the state shown in FIG. 1 (b) where the first lens barrel 102 is most extended is the tele end, and the state shown in FIG. 1 (a) and the intermediate state shown in FIG. 1 (b) is the wide end. Such an optical system is used.

  In this embodiment, the minute gap in the optical axis direction of each drive transmission portion is rattled by the urging force of the spring 113, and the first lens barrel 102 and the lens 101 can be driven with high accuracy. Is possible. The drive transmission units include the guide cylinder 105 and the cam ring 106, the fixed ring 109 and the drive ring 110, the cam follower 102b and the cam groove 106a, the cam follower 106b and the cam groove 109a, and the like. In the present embodiment, high accuracy of zooming and reduction of power consumption are achieved by the spring 113. Therefore, the number of parts of the imaging device 100 can be reduced and the size can be reduced.

  Hereinafter, the first packing 103 and the second packing 107 in the present embodiment will be described. FIG. 2 is a partially enlarged cross-sectional view of a plane that passes through the optical axis of the imaging apparatus 100 and is parallel to the optical axis. FIG. 2A is a cross-sectional view showing the shape of the first packing 103.

  The first packing 103 has a lip portion 103a extending toward the optical axis on the inner periphery, and the lip portion 103a is a plane orthogonal to both the retracting direction and the feeding direction in which the first lens barrel 102 moves. The gap is sealed with an inclination. The inner diameter D1 (the diameter of the tip of the lip portion 103a) of the first packing 103 is configured to be smaller than the outer diameter D2 (the outer peripheral portion 102a) of the first lens barrel 102. Therefore, the first lens barrel 102 is inserted while expanding the inner diameter of the first packing 103 against the elasticity of the lip portion 103a. The outer peripheral portion 102a and the lip portion 103a are in close contact with each other over the entire circumference, and foreign matter from between the first lens barrel 102 and the second lens barrel 104 can be prevented. When the difference in diameter between D1 and D2 is 2 × d, the amount of bending (charge amount) in the radial direction of the lip 103a is represented by d. Further, let Fc be the radially inner charging force acting on the first lens barrel 102 when the charge amount is d.

  The extending direction of the lip portion 103a and the outer peripheral portion 102a of the first lens barrel 102 are not orthogonal to each other in the cross section (surface including the optical axis) shown in FIG. 2, but have a predetermined angle (extending angle). In FIG. 2, the lip portion 103 a extends in a third direction indicated by a one-dot chain line from the fixed side fixed to the second lens barrel 104 to the contact side in contact with the first lens barrel 102. Yes. The extension value when viewed from the direction toward the lens 101 from the image sensor 114 (viewed from the right side in the figure), which is the absolute value of the angle formed by the retracted direction and the alternate long and short dash line, is θ in the figure. The extension angle when viewed from the direction from the lens 101 toward the image sensor 114 (viewed from the left side in the figure), which is the absolute value of the angle formed by the one-dot chain line with the extension direction, is (180 ° − θ). Θ is set to be smaller than (180 ° −θ) ((180 ° −θ) is larger than θ), and the lip portion 103a is configured so that the extension angle on the image sensor 114 side is a narrow angle. Has been. As a result, when the first lens barrel 102 moves in the optical axis direction, foreign matter outside the imaging device 100 (left side in the figure) is unlikely to enter the inside, and inside the imaging device 100 (right side in the figure). Some foreign matter is easily discharged to the outside. Further, when pressure is applied from the outside, a force is generated in a direction in which the lip portion 103a is pressed against the outer peripheral portion 102a. Therefore, for example, water can be prevented from entering when water pressure is applied from the outside.

  The first packing 103 has been described above. Similarly, the second packing 107 can prevent foreign matter from entering between the second lens barrel 104 and the front cover 108. Since the shapes of the first packing 103 and the second packing 107 are the same except for the diameter (the diameter of the second packing 107 is large), detailed description of the second packing 107 is omitted.

  In this embodiment, since the inside is sealed by the first packing 103, the second packing 107, the front cover 108, and the housing 115, the first lens barrel 102 and the second lens barrel 104 are arranged in the optical axis direction. Even if it moves to, it can prevent the entrance of foreign matter from the outside.

  Hereinafter, the force acting on the first lens barrel 102 and the first packing 103 when the first lens barrel 102 is driven in the optical axis direction will be described.

  FIG. 2B is a cross-sectional view showing the force acting on the first lens barrel 102 and the first packing 103 when the first lens barrel 102 is driven in the retracting direction (the direction of the white arrow in the figure). is there.

  F1a is a driving force acting on the first lens barrel 102 in the driving direction (retraction direction). If the driving force transmitted in the optical axis direction from the cam ring 106 is Fd, and the biasing force in the retracting direction by the spring 113 is Fs, the driving force F1a is expressed by the following equation.

F1a = Fd + Fs (1)
F2a is a vertical drag acting radially inward with respect to the first lens barrel 102. As described above, the charging force Fc on the inner side in the radial direction acts on the first lens barrel 102 by the charging of the lip portion 103a. Further, when the first lens barrel 102 is driven in the retracting direction, the compressive force Fta acts in the direction opposite to the extending direction of the lip portion 103a (the Fta arrow direction in the figure), and the lip portion 103a extends. Deformation (dotted line shape in the figure) to reduce the length. A force in the same direction as the charge force Fc (inward in the radial direction) acts on the first lens barrel 102 by the reaction force of Fta. These resultant forces are the vertical drag F2a.

  F3a is a driving load acting on the first lens barrel 102 in a direction opposite to the driving direction by friction. When the friction coefficient between the lip portion 103a and the outer peripheral portion 102a is μ, the driving load F3a is expressed by the following equation.

F3a = μF2a (2)
Therefore, the sum of forces F4a acting in the driving direction (feeding direction) with respect to the first lens barrel 102 is expressed by the following equation.

F4a = F1a−F3a = Fd + Fs−μF2a (3)
FIG. 2C is a cross-sectional view showing the force acting on the first lens barrel 102 and the first packing 103 when the first lens barrel 102 is driven in the feeding direction (the direction of the white arrow in the figure). is there.

  F1b is a driving force acting on the first lens barrel 102 in the driving direction (feeding direction). If the driving force in the optical axis direction transmitted from the cam ring 106 is Fd, and the biasing force in the retraction direction by the spring 113 is Fs, the driving force F1b is expressed by the following equation.

F1b = Fd−Fs (4)
F <b> 2 b is a normal force acting radially inward with respect to the first lens barrel 102. As described above, the charging force Fc on the inner side in the radial direction acts on the first lens barrel 102 by the charging of the lip portion 103a. In addition, when the first lens barrel 102 is driven in the extending direction, a tensile force Ftb acts in the extending direction of the lip portion 103a (the Ftb arrow direction in the figure), and the lip portion 103a has a long extension length. It is deformed so as to be (dotted line shape in the figure). A force in the direction (in the radial direction) to cancel the charge force Fc acts on the first lens barrel 102 by the reaction force of Ftb. These resultant forces are the normal force F2b.

  F3b is a driving load that acts on the first lens barrel 102 in a direction opposite to the driving direction by friction. When the friction coefficient between the lip portion 103a and the outer peripheral portion 102a is μ, the driving load F3b is expressed by the following equation.

F3b = μF2b (5)
Therefore, the sum of forces F4b acting in the driving direction (feeding direction) with respect to the first lens barrel 102 is expressed by the following equation.

F4b = F1b-F3b = Fd-Fs- [mu] F2b (6)
Hereinafter, the sum of forces acting in the driving direction on the first lens barrel 102 will be described.

  As described above, when driven in the retracting direction (collapse direction), a force in the same direction (radially inward) as the charge force Fc acts on the first lens barrel 102. Further, when driven in the extending direction, a force in the direction (radially outward) that cancels the charge force Fc acts on the first lens barrel 102. Since the charge amount Fc does not change depending on the driving direction, the normal force acting radially inward is greater in the retraction direction.

F2a> F2b (7)
From Equations (2), (5), and (7), the driving load F3a when driven in the retracting direction is larger than the driving load F3b when driven in the extending direction.

F3a = μF2a> μF2b = F3b (8)
Here, a case where the urging force Fs = 0 by the spring 113 is considered. When driving in the retracting direction, the sum F4a ′ of the forces acting on the first lens barrel 102 in the driving direction, and acting on the first lens barrel 102 in the driving direction when driven in the retracting direction. The sum of forces F4b ′ is expressed by the following equation.

F4a ′ = Fd−μF2a (9)
F4b ′ = Fd−μF2b (10)
In this embodiment, the urging force Fs generated by the spring 113 is generated in the retraction direction, and the urging force Fs is set so that the following conditional expression is satisfied.

0 <Fs <F3a−F3b (= μF2a−μF2b) (11)
At this time, the magnitude relation of the sum of the forces acting in the driving direction with respect to the first lens barrel 102 is expressed by the following inequality. That is, when the driving force Fd is constant, the minimum value of the sum of the forces acting in the driving direction on the first lens barrel 102 is smaller in this embodiment than when the biasing force Fs = 0 of the spring 113 is set. It will be big.

F4b ′>F4a> F4a ′ (12)
F4b ′>F4b> F5a ′ (13)
Sums F4a, F4b, F4a ′, and F4b ′ of forces acting in the driving direction with respect to the first lens barrel 102 can be considered as driving margins. The imaging apparatus 100 needs to determine the performance and driving conditions of the motor 112 so that the driving margin is equal to or greater than the necessary driving margin. The necessary drive margin is determined in consideration of disturbances to the movable part and various variations such as component dimensions and motor output. Further, when the drive margin varies depending on the drive direction, the smaller drive margin must be equal to or greater than the required drive margin.

  When there is no spring 113 (when urging force Fs = 0), the minimum value of the sum of the forces acting in the driving direction on the first lens barrel 102 is small. In other words, since the drive margin is small, there is a risk that the imaging device 100 may increase in size and the power consumption of the motor 112 may increase as the motor 112 increases in size in order to ensure the necessary drive margin.

  In this embodiment, the urging force Fs generated by the spring 113 is generated in the retraction direction, and the minimum value of the sum of the forces acting on the first lens barrel 102 in the driving direction is increased as compared with the case where the spring 113 is not provided. Yes. That is, since the drive margin is large, the imaging device 100 can be downsized and the power consumption of the motor 112 can be reduced.

  The urging force Fs is preferably set to the following value.

Fs = (μF2a−μF2b) / 2 (14)
At this time, the magnitude relation of the sum of the forces acting in the driving direction with respect to the first lens barrel 102 is expressed by the following inequality. That is, it is possible to eliminate the difference in drive margin depending on the drive direction and optimize the performance and drive conditions of the motor 112.

F4a ′> F4a = F4b> F4b ′ (15)
The force acting on the first lens barrel 102 and the first packing 103 has been described above, but the shapes of the second lens barrel 104 and the second packing 107 are the same except for the diameter. Therefore, since the force acting on the second lens barrel 104 and the second packing 107 can be considered in the same manner, detailed description of the second packing 107 is omitted.

  FIG. 3 is a graph showing the biasing force of the spring 113 in this embodiment. The horizontal axis is the position of the first lens barrel 102 in the optical axis direction, the right side is the telephoto side (feeding side) and the left side is the retracting side (retracting side). The vertical axis represents the biasing force of the spring 113 in the retracting direction.

  The urging force of the spring 113 is the weakest at the retracted position where the entire length is the shortest, and the urging force is within the range of Equation 11. The urging force of the spring 113 is strongest at the tele end position where the entire length of the spring 113 is the longest, and the urging force is within the range of Equation 11.

  In the present embodiment, as shown in FIG. 3A, the urging force of the spring 113 has the relationship of Formula 14 at the wide end that is intermediate between the retracted position and the tele end. In this case, the average of the urging force in the range from the retracted position to the telephoto end is expressed by Equation 14. Therefore, when the lens position moves to an arbitrary position, the performance and driving conditions of the motor 112 can be optimized as a whole, and the power consumption of the imaging device 100 can be reduced.

  Further, as shown in FIG. 3B, the urging force of the spring 113 may be in the relationship of Expression 14 at the middle position between the wide end and the tele end. In this case, the average of the urging forces in the range from the wide end to the tele end, which is most frequently driven at the time of shooting, has the relationship of the formula (14). Therefore, it is possible to optimize the performance and driving conditions of the motor 112 as a whole at the time of shooting, and the power consumption of the imaging apparatus 100 can be reduced.

  Hereinafter, the operation of the imaging apparatus 100 in the present embodiment will be described.

  FIG. 4 is a flowchart of the imaging apparatus 100 in the present embodiment, where “S” represents a step.

  When the power of the imaging apparatus 100 is turned on in S101, the control circuit drives the motor 112 in S102, and the first lens barrel 102 is extended to the wide end position. When the zoom operation is performed in S103, the drive direction is selected in S104. If the driving direction is the tele side (the feeding side), the first lens barrel 102 is driven to the tele side in S105. If the drive direction is the wide side (retraction side), the first lens barrel 102 is driven to the wide side in S106. In S107, the presence / absence of the zoom operation is determined again. If there is a zoom operation, the process returns to S104, and if there is no zoom operation, the process proceeds to S108. In S108, it is determined whether or not there is a power OFF operation. If there is no power OFF operation, the process returns to S107. In S109, the control circuit drives the motor 112, and the first lens barrel 102 is retracted to the retracted position. In S110, the imaging apparatus 100 is turned off.

  As described above, the imaging apparatus 100 can generate the urging force of the spring 113 in the retraction direction, reduce the difference in driving margin depending on the driving direction, and optimize the performance and driving conditions of the motor 112. Therefore, power consumption can be reduced.

  Further, by holding the lens 101 at an arbitrary position, a focus operation that arbitrarily changes the focal point of an image formed on the image sensor 114 may be possible. The imaging apparatus 100 is not limited to a two-stage collapsible configuration in which the first and second lens barrels are retracted as in the present embodiment, and may be a one-stage collapsible or a three-stage or more retracted configuration.

  FIG. 5 is a cross-sectional view of a plane that passes through the optical axis indicated by the alternate long and short dash line and is parallel to the optical axis when the imaging apparatus 200 according to the second embodiment is in the retracted state. In the present embodiment, the drive control of the motor 112 by the control means 213 is different from the first embodiment in that there is no spring 113. The control circuit constituting the control means 213 is arranged at a position that is not actually visible in FIG. 5, but is shown by a broken line for convenience. Hereinafter, the difference between the imaging apparatus 200 and the first embodiment will be described. 5 corresponds to the case where 100 is added to the reference numeral shown in FIG. 1, and the structure is substantially the same as that of the first embodiment.

  Hereinafter, the force acting on the first lens barrel 202 and the first packing 203 when the first lens barrel 202 is driven in the optical axis direction will be described.

  When considering the first member and the second member moved relative to the first member, the first member corresponds to the second lens barrel 204, and the second member is the first member. Although it corresponds to the lens barrel 202, it can be extended to the second lens barrel 204 and the front cover 208 as in the first embodiment.

  The first packing 203 functions as a sealing member that seals the gap between the first lens barrel 202 and the second lens barrel 204. Here, when the first lens barrel 202 is moved in the retracted direction (first direction) with respect to the second lens barrel 204, the driving load applied by the first packing 203 in the feeding direction is defined as F3a. In addition, a driving load applied by the first packing 203 in the retracted direction when the first lens barrel 202 is moved in the feeding direction (second direction) with respect to the second lens barrel 204 is defined as F3b. Then, like Example 1, F3a is larger than F3b.

  The motor (actuator) 212 functions as a driving unit that moves the first lens barrel 202 relative to the second lens barrel 204. The control unit 213 controls driving of the motor 212. The control means 213 moves the first lens barrel 202 in the retracted direction with respect to the second lens barrel 204 rather than moving the first lens barrel 202 in the extension direction with respect to the second lens barrel 204. The driving force of the driving means is increased.

  The control means 213 of the present embodiment uses the driving voltage Va of the motor 212 when the driving direction of the first lens barrel 202 is the retracting direction (collapsed direction, first direction), and the driving direction is the extending direction (second The driving voltage Vb of the motor 212 is increased. When the driving voltage is large, the driving force in the optical axis direction of the first lens barrel 202 also increases. The driving force in the optical axis direction transmitted from the cam ring 106 when the first lens barrel 202 is driven in the retracting direction is Fda, and the cam ring when the first lens barrel 202 is driven in the retracting direction. When the driving force transmitted in the optical axis direction 106 is Fdb, the following inequality is established.

Fda> Fdb (16)
As in the first embodiment, the frictional force μF2a when the first lens barrel 202 is driven in the retracting direction is larger than the frictional force μF2b when the first lens barrel 202 is driven in the retracting direction. There will be.

  In the present embodiment, when the first lens barrel 202 is driven in the retracting direction, the driving force Fda in the optical axis direction transmitted from the cam ring 206 can ensure a predetermined margin with respect to the frictional force μF2a. The driving voltage Va of the motor 212 is set to Further, when the first lens barrel 202 is driven in the extending direction, the motor 212 can ensure a predetermined margin for the driving force Fdb transmitted from the cam ring 206 in the optical axis direction with respect to the frictional force μF2b. Drive voltage Vb is set. Therefore, compared with the case where the drive voltage of the motor 212 is set in accordance with the maximum drive load, the drive voltage when driving in the feeding direction can be reduced, and the power consumption of the motor 212 can be reduced.

  In particular, it is desirable to set the driving voltage so that the driving forces Fda and Fdb have the following relationship.

Fda−Fdb = μF2a−μF2b (17)
At this time, the sum F4a of the force acting in the driving direction when driven in the retraction direction with respect to the first lens barrel 202 is equal to the sum F4b of the force acting in the driving direction when driven in the drawing direction. It is possible to optimize the margin for the frictional force.

  The force acting on the first lens barrel 202 and the first packing 203 has been described above, but the shapes of the second lens barrel 204 and the second packing 207 are the same except for the diameter. Accordingly, the force acting on the second lens barrel 204 and the second packing 207 can be considered in the same manner, and thus the detailed description of the second packing 207 is omitted.

  FIG. 6 is a flowchart for explaining the operation of the imaging apparatus 200, where “S” represents a step. When the zoom operation of the imaging apparatus 200 is performed in S201, the drive direction is selected in S202. If the drive direction is the tele side (feeding side) in S202, the control circuit sets the drive voltage of the motor 212 to Vb in S203. In S204, the first lens barrel 202 is driven to the tele side. If the drive direction is the wide side (retraction side) in S202, the control circuit sets the drive voltage of the motor 212 to Va in S205. In S206, the first lens barrel 102 is driven to the wide side. In S207, the zoom operation of the imaging apparatus 200 is completed.

  FIG. 7 is a graph showing the relationship between the driving force, driving voltage, driving power and time of the image pickup apparatus 200 in this embodiment. The horizontal axis is time. A retracting release operation (from the retracted position to the wide end) is performed from time T1 to T2, and a tele-feeding operation (from the wide end to the tele end) is performed from time T3 to T4, with the pause time in between. In addition, the first lens barrel 202 is driven in a sequence of a wide retracting operation (from the tele end to the wide end) from time T5 to T6 and a retracting operation (from the wide end to the retracted position) from time T7 to T8.

  FIG. 7A shows the relationship between time and the driving force (vertical axis) acting on the first lens barrel 202. A solid line C is a driving force, and a dotted line D is a driving load. In this embodiment, the driving voltage is set so that a margin of 1.5 times the driving force with respect to the driving load (friction force) can be secured. Since the driving load μF2b in the retracting release and tele-feeding operation is smaller than the driving load μF2a in other operations, the driving voltage can be lowered by that amount to reduce the driving force.

  FIG. 7B shows the relationship between time and the driving voltage of the motor 212. The solid line A is the drive voltage of this embodiment, and the dotted line B is the drive voltage when the drive voltage of the motor 212 is set according to the maximum drive load. In this embodiment, the driving voltage Vb in the retracting release and tele-feeding operation is made smaller than the driving voltage Va in other operations, and the driving force is lowered from Fda to Fdb.

  FIG. 7C shows the relationship between time and the power of the imaging apparatus 100. The solid line A is the power of this embodiment, and the dotted line B is the power when the drive voltage of the motor 212 is set according to the maximum drive load. In the present embodiment, the power Wb in the retracting release and tele-feeding operation is smaller than the power Wa of other operations, so that the shaded portion is compared with the case where the driving voltage of the motor 212 is set according to the maximum driving load. The power consumption of the range can be reduced.

  Even when the sequence other than the sequence shown in FIG. 7 is used, power is consumed in the feeding direction between power ON and power OFF, so that the power consumption is higher than when the driving voltage of the motor 212 is set according to the maximum driving load. Can be reduced.

  As described above, in the imaging apparatus 200, the control circuit controls the driving voltage of the motor 212 according to the driving direction so that the driving force of the first lens barrel 202 becomes necessary and sufficient, thereby reducing power consumption. be able to.

  The control circuit may increase the driving force of the motor 212 by changing at least one of the voltage, current, or power applied to the motor 212 instead of the driving voltage of the motor 212. Further, the driving force of the motor 212 may be increased by changing the rotation speed of the motor 212 or the gear ratio of a gear unit (not shown) that transmits the driving force from the motor 212. The imaging apparatus 200 may include a plurality of drive circuits having different drive conditions for the motor 212, and the control unit 213 may switch the drive circuit according to the drive direction.

  FIG. 8 is a cross-sectional view showing a first packing 303 as a modified example of the first packing 103 shown in the first and second embodiments. The first packing 303 is an elastic member having a first lip portion 303 a and a second lip portion 303 b, and is fixed to the second lens barrel 304.

  The inner diameter of the first packing 303 (the diameter of the tip of the lip 103a) is smaller than the outer diameter of the first lens barrel 302 (the outer periphery 302a). Therefore, the first lens barrel 302 is inserted while expanding the inner diameter of the first packing 303 against the elasticity of the lip portion 303a. Therefore, the outer peripheral portion 302a of the first lens barrel and the first lip portion 303a are in close contact with each other, and foreign matter can be prevented from entering the gap between the first lens barrel 302 and the second lens barrel 304. can do.

  In addition, a second lip portion 303 b that comes into contact with the inner peripheral portion 304 b of the second lens barrel 304 is provided. The outer diameter of the first packing 303 (the diameter of the tip of the lip portion 303b) is configured to be smaller than the inner diameter (inner peripheral portion 304b) of the second lens barrel 304. Therefore, the first packing 303 is inserted while compressing the outer diameter of the first packing 303 against the elasticity of the second lip portion 303b. Therefore, the inner peripheral portion 304b and the second lip portion 303b are in close contact with each other over the entire periphery, and foreign matter can be prevented from entering the gap between the first lens barrel 302 and the second lens barrel 304.

  The first lip portion 303a is configured such that the extension angle on the image sensor 314 side is a narrow angle. As a result, when the first lens barrel 302 moves in the optical axis direction, the foreign matter outside the imaging device 100 (left side in the figure) is unlikely to enter the inside, and inside the imaging device 100 (right side in the figure). Some foreign matter is easily discharged to the outside.

  The second lip portion 303b is also configured such that the extension angle on the image sensor 314 side is a narrow angle. Thereby, when pressure is applied from the outside, a force in a direction in which the first lip portion 303a is pressed against the outer peripheral portion 302a and a force in a direction in which the second lip portion 303b is pressed against the inner peripheral portion 304b are generated. Therefore, for example, water can be prevented from entering when water pressure is applied from the outside. For this reason, it is preferable that the first packing 303 has a Y-shaped cross section.

  Since the first lip portion 303a is configured such that the extension angle on the image sensor side (not shown) is a narrow angle, the sum of the forces acting in the driving direction with respect to the first lens barrel 302 is driven. It depends on the direction. In this embodiment, it is possible to reduce the difference in the drive margin depending on the driving direction by the biasing force by the spring (not shown), and to optimize the performance and driving conditions of the motor (not shown), thereby reducing the power consumption. Can do.

  As mentioned above, although the preferable Example of this invention was described, this invention is not limited to these Examples, A various deformation | transformation and change are possible within the range of the summary.

  The optical apparatus of the present invention can be applied to uses of optical apparatuses such as a lens-integrated camera and an interchangeable lens.

DESCRIPTION OF SYMBOLS 102 ... 1st lens-barrel (2nd member), 103 ... 1st packing (sealing member), 104 ... 2nd lens-barrel (1st member), 113 ... Coil spring (biasing means), F3a, F3b ... Drive load, Fs ... Biasing force

Claims (12)

A first member;
A second member that is moved relative to the first member;
A sealing member for sealing a gap between the first member and the second member;
Biasing means for applying a biasing force to at least one of the first member and the second member;
Have
When the second member is moved in the first direction with respect to the first member, the driving load applied by the sealing member in a second direction opposite to the first direction is the first load Greater than the driving load applied by the sealing member in the first direction when the two members are moved in the second direction relative to the first member;
The biasing means is configured so that a driving force required to move the second member relative to the first member in the first direction is less than that when the biasing force is zero. Add power ,
Driving when the biasing force applied to the second member by the biasing means in the first direction is Fs, and the second member is driven in the first direction with respect to the first member. When the load is F3a and the driving load when the second member is driven in the second direction with respect to the first member is F3b,
0 <Fs <F3a-F3b
Optics conditional expression that is characterized Rukoto be satisfied.   The biasing means includes a driving force required to move the second member in the first direction relative to the first member, and the second member relative to the first member. The optical apparatus according to claim 1, wherein the urging force is applied so that a difference in the case where the urging force is zero with respect to a driving force necessary for moving in the second direction is reduced. A cam groove having a cam groove and driven to rotate;
The second member has a cam follower that engages with the cam groove of the cam ring, and is driven by the cam ring.
The optical apparatus according to claim 1, wherein the urging unit urges the second member in the first direction with respect to the cam ring. The first direction is a direction in which at least a part of the second member is accommodated in the optical apparatus by moving the second member,
The second direction, of the claims 1 to 3, wherein the second member is at least part of the second member by moving a direction which is exposed to the outside of the optical instrument The optical apparatus according to any one of the above. A lens for forming an optical image of the subject;
The second member is a first lens barrel to which the lens is fixed,
Wherein the first member is an optical device according to any one of claims 1 to 4, characterized in that a second barrel disposed about said first barrel. Said first member, said while the second member moves, the optical device according to any one of claims 1 to 4, characterized in that it is fixed. The sealing member is an elastic member having a lip portion inclined with respect to a plane orthogonal to both the first direction and the second direction in which the second member moves, and the first member Fixed to
The optical device according to any one of claims 1 to 6 wherein the lip portion is characterized by contacting the second member. The lip portion includes a third axis extending from a fixed side fixed to the first member to a contact side contacting the second member on a plane perpendicular to the plane including the central axis of the second member. The absolute value of the angle formed by the first direction and the third direction is smaller than the absolute value of the angle formed by the second direction and the third direction. The optical apparatus according to claim 7. The sealing member is an elastic member having a first lip portion and a second lip portion, and is fixed to the first member.
The first lip portion and the second lip portion are inclined with respect to a plane orthogonal to both the first direction and the second direction in which the second member moves to seal the gap. And
The said 1st lip part contacts the said 2nd member, The said 2nd lip part contacts the said 1st member, The any one of Claims 1 thru | or 6 characterized by the above-mentioned. Optical equipment. The optical apparatus according to claim 9 , wherein the sealing member has a Y-shaped cross section. The optical device according to any one of claims 1 to 10, characterized in that an imaging apparatus. The optical device according to any one of claims 1 to 10, characterized in that a lens device detachably attached to the imaging apparatus.