JP2015125313A - Dust-proof and drip-proof structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve decrease in operability caused by dust-proof and drip-proof processing with a dust seal.SOLUTION: In a range where a barrel moves in thrust direction, an outer periphery of the barrel in contact with a dust seal is provided with an inclination having the diameter increasing in a direction toward a lip of the dust seal.

Description

  The present invention relates to a dustproof / drip-proof structure for a lens unit of an imaging apparatus, and more particularly to a dustproof / drip-proof structure for an eyepiece.

  There is an eyepiece unit that is electrically connected to an imaging device, displays an image captured by the imaging device on a built-in display unit, and scales the image with a lens unit so that an operator can visually recognize the image.

  In general, the eyepiece unit has a structure in which an operator can adjust the position of the lens unit in the optical axis direction according to his diopter. Thereby, the lens unit provided in the eyepiece unit is movable in the optical axis direction.

  On the other hand, since a commercial imaging apparatus and its accessories are used in a harsh environment where dust and drip proof is required, a dust and drip proof structure is required.

  When the dustproof / splashproof structure is applied to the movable part of the lens unit of the above eyepiece unit, the lens unit moves in the thrust direction as described above.

  A structure using a dust seal is known as a dust-proof / drip-proof structure that moves in the thrust direction (see Patent Document 1 and Patent Document 2). Can be realized.

JP 2003-294154 A JP 2009-250310 A

  Usually, the dust seal has a lip shape on only one side to ensure dustproof and dripproof properties.

  The resistance to the moving lens unit differs between the direction toward the lip and the direction toward the lip. More specifically, it has been found that when the lens moves in the direction toward the lip, the resistance force applied to the lens unit is greater than when the lens moves in the direction toward the lip.

  When a difference in resistance force occurs in the moving direction when the lens moves, for example, in the case of a mechanism in which an operator manually moves the lens unit in the optical axis direction, this is recognized as a difference in operational feeling.

  In addition, when the lens unit is moved electrically, such as with a motor, a necessary driving force difference occurs, and the motor does not have enough driving force to drive the lens unit in the direction toward the lip. sell.

  A structure as shown in FIGS. 3 and 4 is known as a structure for reducing the resistance difference due to the moving direction of the lens unit.

  Each of the structures shown in FIGS. 3 and 4 is such that the lip portion of the dust seal is increased so that the lip shape has no difference in the direction of resistance during thrust movement.

  In the structure shown in FIGS. 3 and 4, the resistance force during the thrust movement is larger than that of the dust seal having a lip on one side.

  Therefore, the operation force when manually operating the lens unit is increased.

  In addition, when the lens unit is electrically operated, the required driving force becomes large, and it is necessary to increase the size of the motor. As a result, the structure shown in FIGS. 3 and 4 is not desirable as a dust / drip proof against the thrust movement of the lens unit.

  Therefore, when realizing a dust-proof / drip-proof structure against the thrust movement of the lens unit, use a dust seal with a small frictional force that has a lip only on one side, and reduce the direction difference in the resistance force of the dust seal. It is preferable to take a structure.

  The first feature of the present invention is that the lens barrel comes into contact with the dust seal at the outer peripheral portion for the dust-proof and drip-proof effect. In the diopter adjustment range, the outer periphery of the lens barrel has an inclination such that the outer shape increases in the direction of the lip of the dust seal in the range where the lens barrel contacts the dust seal when moving in the thrust direction.

  Moreover, the magnitude | size of the said inclination is an inclination which does not impair the function by a dust seal.

  According to the present invention, it is possible to provide a dust-proof / drip-proof structure of a lens barrel that has a small directional difference in resistance due to a dust seal and high operability.

A perspective view of an eyepiece unit in which the present invention is implemented AA 'sectional view of an eyepiece unit in which the present invention is implemented 1 is a perspective view of an optical function unit of an eyepiece unit in which the present invention is implemented. 1 is an exploded perspective view of an optical function unit of an eyepiece unit in which the present invention is implemented. A perspective view of a dust seal in which the present invention is implemented Side view of a lens embodying the present invention Optical function section BB 'cross section of the present invention C section enlarged view of the optical function section BB 'cross section of the present invention Explanatory drawing of the preceding case (1) Explanatory drawing of the previous case (Part 2)

  FIG. 1a is an external perspective view of the eyepiece unit 1 in the embodiment of the present invention, and FIG. 1b is a cross-sectional view of the eyepiece unit 1 cut along a straight line AA ′.

  In the external part of the eyepiece unit 1 according to the present invention, a diopter adjustment operation unit 11 that is operated by an operator to adjust the diopter, an eyepiece unit 12 for an operator to observe the display panel, a housing 13, and the eyepiece unit. 1 and a connection cable 14 with a connector for electrically connecting an imaging apparatus main body (not shown).

  Next, the function of the eyepiece unit 1 will be described with reference to FIG. FIG. 1 b is a cross-sectional view of the eyepiece unit 1 taken along the line AA ′. However, the case 13 of the eyepiece unit 1 is partially omitted.

  The eyepiece unit 1 receives an image being photographed from the imaging device main body via the connection cable 14 and displays the image on the display unit 3 via a substrate (not shown). Then, the image displayed on the display unit 3 is enlarged by the lens unit 22 and is recognized by the operator.

  The lens unit 22 is slidably engaged with the lens guide 21. The lens guide 21 has fastening portions 214 to 217 shown in FIG. 2b and is fastened to the housing 13 with screws.

  The housing 13 has an opening 131 provided so that the display unit 3 and the lens closest to the display unit 3 can be cleaned, and the protective cover 15 seals the opening 131. It is fastened with a screw (not shown) to a fastening part 132 provided on the housing 13.

  Further, a dust seal 28 is installed between the lens guide 21 and the lens unit 22, and a lip portion 281 of the dust seal 28 extends between the lens guide 21 and the lens unit 22 from the display unit 3 and the lens unit 22. It plays a function to prevent dust and water droplets from entering.

  2a is a perspective view of the optical function unit 2 in the embodiment of the present invention, FIG. 2b is an exploded view of the optical function unit 2, FIG. 2c is a perspective view of the dust seal 28, FIG. 2d is a side view of the lens unit 22, and FIG. Sectional drawing when the optical function part 2 is cut | disconnected by straight line BB 'in FIG. 2a. A straight line B-B ′ is a horizontal straight line passing through the center of the optical axis of the lens unit 22.

  FIG. 2f is an enlarged view of part C of FIG. 2e. The configuration of the optical function unit 2 will be described with reference to FIGS. 2A and 2B, the optical function unit 2 is inserted into a lens guide 21, a lens unit 22, the diopter adjustment operation unit 11, and a groove 213 provided in the lens guide 21, and the diopter adjustment operation unit 11. The lens unit 22 is inserted into a restriction pin 23 fastened to a screw portion (not shown), a groove portion 211 provided in the lens guide 21, and a cam groove 111 provided in the diopter adjustment operation portion 11. The lens unit 22 is not shown by being inserted into a cam pin 24 fastened to a screw portion that is not provided, a groove portion 212 provided in the lens guide 21, and a cam groove 112 provided in the diopter adjustment operation portion 11. The cam pin 25 is fastened to the screw portion.

  A cam pin provided in the lens guide 21 and not shown in FIG. 2b, and a cam pin provided in the diopter adjustment operation part 11 and inserted into a cam groove 113 and fastened to a screw part (not shown) of the lens unit 22. 26, a wave washer 27 that is installed between the lens guide 21 and the diopter adjustment operation unit 11 to shift the diopter adjustment operation unit 11 and generate a rotational torque, and the lens guide 21 and the lens unit. 22 and a dust seal 28 provided to realize a dustproof / dripproof function.

  The cam grooves 111, 112, and 113 provided in the diopter adjustment operation unit 11 are used to rotate the diopter adjustment ring 11 that occurs when an operator rotates the diopter adjustment operation unit 11. The lens unit 22 has a function of converting into a straight movement through 24-26.

  In this embodiment, there are three cam grooves, but the present invention is not limited to the case where the number of cam grooves is three.

  As shown in FIG. 2 b, the groove portions 211 to 212 of the lens guide 21 are straight advance grooves, and the groove portions 211 and 212 move straight when the lens unit 22 rotates when the diopter adjustment operation portion 11 is rotated. It has a function of restricting the movement so as not to rotate. Another groove (not shown) through which the cam pin 26 is inserted also has the same function as the groove portions 211 to 212.

  Like the diopter adjustment operation unit 11, in this embodiment, there are three grooves, but the present invention is not limited to the case where the number of cam grooves is three.

  The groove 213 has a function of regulating the position and the rotation amount of the diopter adjustment operation unit 11. That is, the linear movement amount of the lens unit 22 is regulated by the groove portion 213.

  As shown in FIG. 2c, the dust seal 28 uniformly has a lip portion 281 on one side, which is in contact with the outer peripheral portion of the lens unit 22 and imparts a dustproof / dripproof effect.

  The dust seal 28 has the lip 281 only on one side. This is to reduce the frictional force that the lens unit 22 receives from the dust seal 28. As shown in FIG. 2D, the lens unit 22 has an inclined portion 221.

  The lens unit 22 length direction range L of the inclined portion 221 is determined when the lens unit 22 moves within a range in which the lens unit 22 can move straight when the diopter adjustment operation unit 11 is operated by an operator. Is slightly larger than the range of the dust seal 28 that passes through the lip 281. By making the range slightly larger, it is possible to absorb variations in processing.

  In the outer periphery of the lens unit 22, the maximum diameter is D1 and the minimum diameter is D2, but the portion where the diameter is D1 and the portion where the diameter is D2 are continuously connected by the inclined portion 221. Even when the diameter is D1 or D2, the dust-proof / drip-proof function of the lip portion 281 of the dust seal 28 is not impaired. That is, the dust-proof / drip-proof function by the lip portion 281 of the dust seal 28 is not impaired at any place of the inclined portion 221 having a diameter between D1 and D2.

  2e and 2f, the outer periphery of the lens guide 21 and the lens unit 22, the lip portion 281 of the dust seal 28, the inclined portion 221 of the lens unit 22, the diopter adjustment operation portion 11 and the lens The outer peripheral portions of the units 22 are in a sliding relationship.

  When an operator rotates the diopter adjustment operation unit 11, the cam pins 111 to 113, the cam pins 24 to 26, the grooves 211, 212, and the third groove are restricted by the restriction pin 23 and the groove 213. In such a range, the lens unit 22 moves linearly while sliding with the respective parts.

  In FIG. 2f, F1 'is a frictional force received from the lip portion 281 of the dust seal 28 when the lens unit 22 is moved in the right direction in FIG. 2f, and F2' is moved in the left direction in FIG. 2f. Is a frictional force received from the lip portion 281 of the dust seal 28, and F2 'is larger than F1'. In addition, θ is an angle formed by a portion where the lip portion 281 and the lip portion 281 of the lens unit 22 are in contact with each other.

  The frictional force that the lens unit 22 receives from the lip portion 281 is generated by the vertical drag between the lip portion 281 and the lens unit 22, and the direction in which the lens unit 22 is generated is opposite to the direction in which the lens unit 22 moves in the horizontal direction. Become.

  Since the lip portion 281 contacts the inclined portion of the lens unit 22, the angle θ is smaller than when the lip portion contacts a horizontal portion of the lens unit. Therefore, the frictional force F2 ′ can be reduced as compared with the case where the lens unit is not inclined.

  Therefore, the direction difference of the operation force for the operator to operate the diopter adjustment operation unit 11 is reduced, and the operability is improved.

  The present invention has been described in the embodiment in which the present invention is applied to the lens portion of the eyepiece unit. However, the present invention can be applied to structures other than the eyepiece unit as long as equivalent effects can be obtained.

1. Eyepiece unit 11. Diopter adjustment operation units 111 to 113. Cam groove 12. Eye cup13. Eyepiece unit housing 131. 15. Opening for cleaning optical system Connector for connection with imaging device main body 15. Protective cover Optical function unit 21. Lens guides 211 to 213. Groove 22. Lens 221. Lens inclined part 23. Restriction pin 24. Cam pin 25. Cam pin 26. Cam pin 27. Wave washer 28. Dust seal 281. Lip part θ. Angle formed by the contact portion between the lip 281 and the lens unit 22

Claims (3)

A lens barrel that holds the lens;
A dust seal that comes into contact with the outer periphery of the lens barrel and adds a dustproof and dripproof effect;
The dust seal is a dust-proof / drip-proof structure having a lip that comes into contact with the lens barrel at one place.
The outer periphery of the lens barrel has an inclined portion whose outer shape increases in a direction toward the lip of the dust seal. The dust-proof / drip-proof structure according to claim 1, wherein the inclined portion is formed in a range in contact with the lip portion of the dust seal within a range in which the lens barrel is movable. The dust-proof / drip-proof structure according to claim 1, wherein the slope has an amount of slope that does not impair the function of the dust seal.