JPS6251454B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a so-called built-in extender type optical system,
In other words, it relates to an optical system in which the focal length range is changed by inserting and removing a variable power lens group into the basic main lens system without changing the overall length and back focus of the lens system. This invention relates to a mechanism for inserting and removing a magnification lens group into and from a main lens system.

Figure 1 shows a conventional example of this. 1 is an assembly frame (or housing), 2 is a shaft rotatably supported by the frame 1, and 3 (Figure 3) is an assembly integrally attached to the shaft 2. A lens barrel 5 containing a zoom lens group 4 is inserted into the hole 31 of the annular lens barrel holding member which is connected and supported, and a flange 51 formed on the outer periphery of the lens barrel 5 is screwed 52 to the member 3. By doing so, the lens barrel 5 is attached to and supported by the member 3. 6 is a tension coil spring, and a pin 8 is provided on a hardware 7 that is integrated with the frame 1;
A pin 9 provided on the lens barrel holding member 3 is stretched between both pins 8 and 9. 10 is a gear integrally attached to the rotating shaft 2, 11 is an operating member shaft rotatably supported by the frame 1, and 12 is an operating member integrated with the shaft (the figure shows a lever, even if it is a dial) good), 1
A gear 3 is integrally attached to the shaft 11 and meshes with the gear 10 of the lens barrel holding member shaft 2.

The figure shows that when the operating member 12 is rotated in the forward direction (in the direction of arrow a), the lens barrel holding member 3 rotates to the right within the frame 1 about the shaft 2 and hits the stopper 14. A variable power lens group inserted state (hereinafter referred to as a lens group inserted state) in which the optical axis 0 of the variable power lens group 4 is held coaxially with the optical axis of the main lens system (not shown) by being pressed against the stopper 14. shows.

In this state, when the operating member 12 is reversely rotated against the spring 6 (in the direction of arrow b), the barrel holding member 3 holds the shaft 2 via the shaft 11, gear 13, gear 10, and shaft 2. It rotates to the left of the frame 1 at the center, and after passing the spring full extension point (dead point) during the rotation, it actively rotates to the left within the frame by the tension of the spring 6, and the stopper 1
5, and the tension of the spring 6 causes the stopper 1 to
5 is maintained in the state indicated by the chain line, that is, the state in which the variable power lens escapes from the optical path of the main lens system (hereinafter referred to as the lens group escape state).

To return to the lens group insertion state again, press operation member 1.
2 should be rotated in the forward direction. That is, as a result of this operation, the lens barrel holding member 3 rotated to the right within the frame around the shaft 2 via the shaft 11, gear 13, gear 10, and shaft 2, and exceeded the spring full extension point in the middle of the rotation. Thereafter, it is actively rotated clockwise by the tensile force of the spring 6 and hits the stopper 14, and is pressed against the stopper 14 by the spring 6 to enter the lens group insertion state shown by the solid line in FIG.

The stopper 14, which receives the lens barrel holding member 3 rotated to the right, is made of a rigid material with no elasticity in order to ensure accurate insertion of the lens barrel 5, that is, the lens group 4 into the main lens system. On the other hand, the stopper 15 that receives the lens barrel holding member 3 that has escaped from the main lens system is made of a shock absorbing material such as rubber, since the receiving position of the member 3 does not require strict precision as in the case of the stopper 14 described above.

In the above configuration, when the lens group is inserted, the lens barrel holding member 3 is pressed against the stopper 14 by the spring 6 and is kept in a stationary state, but in an environment where quite severe vibrations and shocks are applied, For example, when used in a moving automobile or helicopter, the lens barrel holding member 3 often swings relatively easily around the shaft 2 against the tensile force of the spring 6 due to severe vibrations and shocks. Optical axis 0 of variable magnification lens group 4
is displaced little by little with respect to the optical axis of the main lens system and is not constant.

If the tensile force of the spring 6 is made stronger, the spring 6 becomes more resistant to vibrations, etc., but a large force is required to rotate the operating member 12. In addition, the impact shock on the stopper 14 or 15 of the lens barrel holding member 3 when switching between inserting and removing the lens groups becomes stronger, causing a loud switching noise and causing loosening of the assembly screws of various parts of the optical system. .

In addition, if a locking mechanism that is operated separately from the operating member 12 is provided in order to hold the lens barrel holding member 3 immovably when the lens group is inserted, the locking mechanism can be locked after the forward rotation of the operating member 12 when the lens group is inserted. It is necessary to operate the mechanism to lock it, and when the lens group is released, it is necessary to perform an operation to unlock the lock mechanism before operating the operating member 12, resulting in extremely poor operability and lack of speed.

In the present invention, the inserted state of the lens group is similarly locked by a locking mechanism, and the locking and unlocking are performed using an operating member 12 for switching the insertion and removal of the lens group 4.
By interlocking, the objective is to achieve good operability by sequentially inserting the lens group → locking or unlocking → retracting the lens group just by operating the operating member 12 in the forward and reverse directions. .

A detailed explanation will be given below based on the embodiments shown in the figures.

2 to 4 show the first embodiment, and the lens group insertion/removal mechanism is the same as that shown in FIG. 1, with the addition of a locking mechanism using a cam.

That is, cams 16 and 17 are provided on the lens barrel holding member mounting shaft 2 and the operating member shaft 11, respectively. Both cams 16 and 17 are arranged so that when the variable power lens group 4 is coaxially inserted into the main lens system in the solid line state shown in FIG. They are integrally fixed to the shafts 2 and 11 at such angles that the upper surface of the projecting portion of the cam 17 on the operating member shaft side 11 comes into contact with the lower surface of the tension member. Cam 1 in the diagram
6 and 17 (FIG. 3) show gears manufactured in one piece with gears 10 and 13, respectively.

Also, in order to cut the edges of the gears 13 and 10 when the lens group is inserted, one tooth on each of the gears 13 and 10 that is in meshing relationship when the lens group is inserted is shaved off 13 as shown in FIG. ₁ ,10 ₁
There is.

Furthermore, a torsion coil spring 19 is fitted to the outer periphery of the bearing sleeve 18 (FIG. 3) of the operating member shaft 11, and one end of the torsion coil spring 19 is engaged with the metal fitting 7 integrated with the frame 1, and the other end is engaged with the gear 13, thereby making the gear 13, The entire shaft 11, cam 17, and operating member 12 are always biased in the positive rotation direction (direction a). 20 is a bearing holding fitting for the shaft 2.

When the operating member 12 is rotated in the forward direction, the lens barrel holding member 3 rotates to the right of the frame around the shaft 2 and hits the stopper 14, as described in FIG.
Although the lens group is inserted into the lens group by being pressed against the stopper ₁₄ by the force _of Correspondingly, both gears 1
3 and 10 are cut, and the lens barrel holding member 3 continues to rotate clockwise around the shaft 2 due to the tensile force of the spring 6, and comes into contact with the stopper 14. and the operating member 12
When you release your hand, the operating member 12, shaft 11, gear 13, and cam 17 all continue to rotate by one gear tooth due to the biasing force of the torsion coil spring 19, and the projecting portion of the cam 17 moves toward the cam 16 on the shaft 2 side. The cam 16 is pressed against the lower surface of the protrusion as shown in the second figure.

In this state, even if the lens barrel holding member 3 tries to rotate leftward around the shaft 2 against the tensile force of the spring 6 due to the action of severe vibrations, the cam 17 in contact with the cam 16 gets stuck. The rotation is blocked. That is, the rotation of the lens barrel holding member 3 is locked. The lock becomes more rigid as the contact angle of the cam 17 with respect to the cam 16 is designed to be tighter.

When the operating member 12 is rotated in the reverse direction (in the b direction) in order to move the variable magnification lens group 4 out of the main lens system, the gear 13 and the gear 10 move to the toothless portion 13 ₁ , as described above.
10 Since the edges are cut in response to ₁ , the operating member 1
2, at the beginning of the reverse rotation, the operating member 12, the shaft 11,
The gear 13 and the cam 17 rotate in advance against the torsion coil spring 19 by one tooth of the gear, and the cam 1
7 separates from the lower surface of the cam 16 and becomes unlocked. Next, when the operation member 12 is subsequently rotated in the reverse direction, the gear 13 and the gear 10 are brought into mesh with each other, and the lens barrel holding member 3 is rotated to escape to the left of the frame around the shaft 2.

That is, by simply rotating the operating member 12 in the forward and reverse directions, the lock can be released → the lens group can be withdrawn, or the lens group can be inserted →
Locking is performed in a series, making it extremely easy to operate.

5 and 6 show a second embodiment, and the lens group insertion/removal mechanism is substantially the same as that shown in FIG. 1, with the addition of a locking mechanism using a lock pin.

That is, the gear 13 is rotatably provided on the operating member shaft 11, the surface cam 21 is provided integrally with the shaft 11, and the circular arc elongated hole 23 is formed in the surface cam 21 with a pipon 22 integrally implanted in the gear 13. The gear 13 and the surface cam 21 are brought into contact with each other. Then, one end is attached to the metal fitting 7 that is integrated with the frame 1, and the other end is attached to the surface cam 2.
The torsion coil spring 19 locked to the surface cam 2
1. The entire shaft 11 and operating member 12 are always biased in the forward rotation operating direction (direction a).

On the other hand, in addition to the gear 10 fixed to the shaft 2, the lens barrel holding member mounting shaft 2 is provided with a slide member 24 that is freely movable along the shaft 2, and a lock pin 25 is attached to the slide member 24 on the gear 10 side. The lock pin 2
A lock pin engagement hole 26 into which the lock pin 5 is inserted is provided. 27 is a spring that constantly presses the slide member 24 toward the gear 10, and 28 is a slide guide pin that prevents the slide member 24 from rotating, which is implanted in the hardware 7.

FIG. 5 shows that the lens group is inserted into the main lens system by forward rotation of the operation member 12, and the thin part of the surface cam 21 is positioned relative to the slide member 24, and the lock pin 25 is inserted into the receiving hole 26 of the gear 10. This shows a state in which the lens group has been inserted and the inserted state is locked.
At this time, the pin 22 of the gear 13 is located on the left end side of the circular arc elongated hole 23 of the surface cam 21, as shown in FIG.

In this state, when the operating member 12 is rotated in the reverse direction (direction b) in order to release the variable power lens group from the main lens system, the shaft 11 and the surface cam 21 are rotated accordingly.
rotates, but the gear 13 does not rotate until the surface cam 21 rotates and the right end of the elongated hole 23 hits the pin 22. Due to this rotation of the surface cam 21, the slide member 24 is pushed along the shaft 2 in the direction away from the gear 10 against the pressure spring 27 by the thick part of the surface cam 21, and as a result, the lock pin 25 is moved away from the gear 10. It comes out of the receiving hole 26, and the lock of the gear 10, that is, the lock of the lens barrel holding member 3 is released. Then, by the subsequent reverse rotation operation of the operating member 12, the elongated hole 21 of the surface cam 21 is opened.
After the left end of the gear 13 hits the pin 22 of the gear 13, the gear 13 rotates together with the surface cam 21. This causes the gear 10 and the shaft 2 to rotate, and the mirror is rotated in the same way as in the example in Figs. The barrel holding member 3 rotates to the left of the frame around the shaft 2, resulting in the lens group relief state shown by the chain line in FIGS. 1 and 2.
After that, when you release your hand from the operating member 12, the operating member 12 returns and rotates by the length of the elongated hole 23 due to the force of the torsion coil spring 19, and the left end of the elongated hole 23 is connected to the gear 10.
It comes into contact with the pin 22 of.

When the operating member 12 is rotated in the forward direction from this state, the gear 13 immediately rotates together with the surface cam 21, and as a result, the gear 10,
The lens barrel holding member 3 rotates to the right of the frame around the shaft 2 via the shaft 2, and finally hits the stopper 14.
The lens group is then pressed against the stopper 14 by the spring 6, thereby entering the lens group insertion state. Shortly before the lens group is inserted, the thin part of the surface cam 21 is positioned on the slide member 24, and the slide member 24 slides along the shaft 2 in the direction of the gear 10 by the pressing force of the spring 28.
The tip of the lock pin 25 touches the side of the gear 10.
Next, when the lens barrel holding member 3 comes into contact with the stopper 14, the hole 26 of the gear 10 engages with the lock pin 24.
The locking pin 24 falls into the hole 26 at a position corresponding to the hole 26, and is locked.

As described above, the present invention provides a lens system in which magnification is changed by inserting and removing the variable power lens group 4 into and from the main lens system in conjunction with forward and reverse rotational operations of the operating member 12. A mechanism is provided for locking the variable power lens group inserted into the main lens system at that position when the variable power lens group inserted into the main lens system is positioned coaxially with the main lens system by the positive rotation operation of (1) Since the variable power lens group is released in conjunction with the initial rotation of the reverse rotation operation of the operation member, and is released in conjunction with the subsequent rotation of the operation member, so that the variable magnification lens group escapes from the main lens system. When the lens group is inserted, it is locked and the coaxial relationship between the main lens system and the inserted variable power lens group is maintained even if it is subjected to severe vibrations or shocks.

(2) Just by rotating the operating member 12 in the forward and reverse directions, the lock can be released → the lens group can be withdrawn, or the lens group can be inserted →
Locking is performed in a series, making it extremely easy to operate.

(3) A weak tension coil spring 6 is sufficient. Therefore, strong force is not required for operation. The impact of the lens barrel holding member 3 against the stopper 14 or 15 during switching can be reduced, and switching noise and loosening of the assembly screws can be suppressed.

This is an effective improvement for this type of lens system.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional front view of the conventional example, Figures 2 to 4
The drawings show the first embodiment of the present invention, Fig. 2 is a longitudinal sectional front view, Fig. 3 is a cross-sectional side view, Fig. 4 is an explanatory diagram of gear meshing, and Figs. 5 and 6 are a second embodiment. FIG. 5 is a cross-sectional side view, and FIG. 6 is an explanatory diagram of the relationship between the gear engagement and the pin and the circular arc elongated hole. 1 is an assembly frame, 2 is a rotating shaft, 3 is a lens barrel holding member,
4 is a variable magnification lens group, 5 is its lens barrel, 6 is a tension coil spring, 10 and 13 are gears, 11 is a shaft of an operating member, 16 and 17 are locking cams, 21 is a surface cam,
24 is a slide member, 25 is a lock pin, and 26 is a lock pin receiving hole.

Claims (1)

[Scope of Claims] 1. In a variable magnification lens device in which the variable magnification lens group is inserted into a position that satisfies a coaxial relationship with the main lens system by forward rotation of an operating member, and removed from the optical path by reverse rotation. A first shaft for rotating a holding member that holds the variable power lens group and a second shaft driven by the operating member are connected by a gear train, and the gear train connects the main lens system and the variable power lens system. The main lens system and the variable power lens group are configured so that they are disengaged from each other when they satisfy a coaxial relationship, and a first cam is provided on the first shaft, and a main lens system and a variable power lens are provided on the second shaft. A second cam is provided to prevent the rotation of the first cam when the lens group for use in the camera satisfies a coaxial relationship, and is biased in a direction equivalent to positive rotation, so that the variable power lens can be rotated by positive rotation of the operating member. When the group is inserted in a position that satisfies the coaxial relationship with the main lens system, the first
The interlock between the axis of A variable power lens system in which a first cam is free to rotate and a first shaft and a second shaft are linked to allow a variable power lens group to escape. 2. In a variable power lens device in which the variable power lens group is inserted into a position that satisfies a coaxial relationship with the main lens system by forward rotation of the operating member, and removed from the optical path by reverse rotation, the variable power lens a rotation shaft that rotates a holding member that holds the group; a first gear that rotates the rotation shaft;
The cam member, which is rotated by the operating member and has a cam surface and is biased in the direction equivalent to forward rotation, transmits power to the first gear, so it can rotate independently within the free movement range, but outside this range, the cam A second gear engages and interlocks with the member and is rotatably supported, and is biased toward the cam surface of the cam member and slides in response to the cam lift to engage and separate from the first gear. and a slide member having an engaging portion that rotates, and the cam member rotates independently of the second gear within the free movement range of the second gear by reverse rotation of the operating member, and the cam surface slides the slide member. The cam member and the second gear rotate in conjunction with each other from the time when the engagement with the first gear is cut off and the end of the free movement range is reached, the rotation shaft is rotated via the first gear, and the holding member is rotated to move the variable power lens group out of the optical path, while the cam member is rotated in the forward direction in conjunction with the second gear to position the variable power lens group at a position that satisfies the coaxial relationship. The cam member rotates independently of the second gear within the free movement range, and locking is achieved by allowing the slide member to slide until the engaging portion of the slide member engages with the first gear. Lens system.