JPH0555843B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field One and the other of optical devices that are attached to and detached from each other,
The present invention relates to a circuit opening/closing device in an optical system exchangeable optical device, which includes a driving member and a driven member that are connected and disconnected as they are attached and detached.

Conventional technology For example, in a single-lens reflex camera with interchangeable lenses that performs autofocus using TTL distance measurement, the camera body has an autofocus drive unit and its control system, and the interchangeable lens has an autofocus drive unit. Equipped with. The driving part and the driven part are connected and disconnected when the interchangeable lens is attached to and removed from the camera body, and it goes without saying that power must be reliably transmitted from the driving part to the driven part so that the autofocus function can be properly performed. Transmission efficiency also greatly affects the time required for autofocus, and is an important factor in reducing shooting time. However, in reality, if the interchangeable lens is not properly attached to the camera body, there may be a connection failure between the drive section and the driven section. It is possible that there is none.
In addition, even if the interchangeable lens is installed properly, the connection between the drive part and the driven part is not proper due to mount play, etc., so even if power is transmitted, the original transmission efficiency is considerably reduced, and automatic Sometimes it takes a long time to focus. These problems in photographing also impair the user's confidence in the optical equipment.

Conventionally, warning means for improperly attached interchangeable lenses have been known, such as in U.S. Pat. No. 4,130,358. Even if the problem of insufficient focus could be solved, there was no way to know that the connection between the drive part and the driven part was incorrect even though the attachment was sufficient, and shooting continued without correcting it. It left some flaws.

Purpose of the Invention The present invention reliably detects the inappropriateness of the connection state between the driving part and the driven part, gives a warning, and also responds to the suitability or unsuitability of the installed state of the optical equipment as a result of the above. It is an object of the present invention to provide a circuit switching device that can solve the conventional problems.

Features of the Invention The present invention includes a camera body having a driving member and a lens having a driven member, and the driving member and the driven member are connected to each other when the lens is attached to and removed from the camera body, and the driving member is attached to the driven member. In the interchangeable lens camera that connects and disconnects by taking a cutting position and a connecting position, the driving member includes a motor provided for driving the driving member, a motor drive control circuit for controlling the motor, and a motor provided for driving the driving member. When moving between the cutting position and the connecting position, in conjunction with the driving member, the motor drive control circuit corresponding to the cutting position is inactivated, and the motor corresponding to the connecting position is An object of the present invention is to provide a circuit opening/closing device characterized by comprising a switch that moves a drive control circuit to a position where it is ready for operation.

Example To explain the example, this example is an example in which two components of an optical device are detachably coupled and a driving force is transmitted from one of the components to the other. An example in which drive for autofocus is transmitted is shown below. FIG. 1 is a front view of the camera body 1, in which a body-side removable mount 3 is constructed in the center of a front cover 4 that protrudes from the front of the body 1. 7 is a positioning member release button. Reference numeral 10 denotes a tip positioning portion of a mount positioning member 9, which will be described later. The positioning portion 10 is inserted into a through hole formed in the detachable mount 3 from the inside, and a spring 8 (described later) is inserted in a direction protruding from the mount surface at all times. ) is energized. 13 is a drive shaft as a drive member provided on the body 1 side, which is connected to the first
Use as a drive shaft. The first drive shaft 13 has a sufficient distance from the inner diameter of the positioning portion 10 (mount positioning member 9). The reason for this is to absorb misalignment of the axis with the second drive shaft 60 on the side of the interchangeable lens 2, which will be described later, due to dimensional errors of parts, mounting errors between the camera body and the interchangeable lens, etc. 1st
In the figure, the distal end of the first drive shaft 13 is visible, and an engaging pawl 17 (noted by reference numeral in the drawing), which will be described later, is further formed on the distal end surface.

FIG. 2 is a simplified diagram showing the motor 22 and transmission gear train within the camera body 1. That is, for example, the motor 22 is disposed below the mirror 30, and the rotation thereof is transmitted to the gear 21 via the intermediate gear train 31 and the like, and further transmitted to the gear 19 fixed to the first drive shaft 13. 1 drive shaft 13 is rotated at a constant speed.

FIG. 3 is a view of the interchangeable lens 2 seen from the back side, that is, the side where it is attached to the camera body 1, and 54 is a lens-side detachable mount that is mounted on the detachable mount 3 on the camera body 1 side. Reference numeral 53 denotes a rear lens group installed inside. 64 is a mount positioning recess that opens to the outer periphery of the detachable mount 54;
When the positioning portion 10 of the side mount positioning member 9 is inserted, both are locked at that position.
A second drive shaft 60 is inserted into the through hole in the mount positioning recess 64 and has its tip facing the surface of the detachable mount 54, and is a driven member with respect to the first drive shaft 13.

FIG. 4 is a simplified diagram showing a transmission gear train inside the interchangeable lens 2. FIG. That is, a gear 66 fixed to the inner helicoid tube 58 (described later) that advances and retreats the inner tube 59 (described later) in which the lens group is fixed in the optical axis direction;
Gear 6 fixed to second drive shaft 60 and rotating together
5 are interlocked.

Figure 5 shows the camera body 1 explained above.
and interchangeable lens 2 are completely combined, and both drive shafts 1
3 and 60 are connected, and a protruding pin 63 formed in an engagement recess 62 at the tip of the second drive shaft 60 is connected to the engagement hole 18 formed in the engagement claw 17 at the tip of the first drive shaft 13. This shows that the motor 22 and the circuit switch from the motor drive control circuit 32 are on, that is, ready for operation.

In Fig. 5, the interchangeable lens 2 side is indicated by a code in the 50s or higher, and 52 is the front lens group;
3 is a rear lens group. These lens groups 52,
53 is fixed within the inner cylinder 59. Reference numeral 56 denotes an outer barrel of an interchangeable lens, and a second shaft, which is a driven shaft relative to the camera body 1 side, is connected between the outer barrel 56 and the inner barrel 59.
A drive shaft 60 and a lens feeding mechanism are provided. A bearing 61 is fixed to the outer cylinder 56, and one end of the second drive shaft 60 is supported on the bearing 61. is a gear fixed to the second drive shaft 60, and the gear 6
5 meshes with a gear 66 fixed to the middle helicoid cylinder 58. 55 is an outer helicoid cylinder. The outer helicoid tube 55 is fixed to the detachable mount 54 (see FIG. 7). 57 is a vertical ring that is rotatable.
This outer helicoid tube 55, middle helicoid tube 58,
The lens is extended in a straight line by receiving the rotational force of the gear 65 by the inner cylinder 59 and the linear key and keyway (none of which are shown) formed therein.

Reference numeral 51 denotes the optical axis of the lens, and a second drive shaft 60 arranged parallel to the optical axis 51 has its tip protruding from the through hole of the detachable mount 54 into the mount positioning recess 64. . An engagement recess 62 is formed on the end face of this tip, and corresponds to the engagement claw 17 of the first drive shaft 13 on the camera body 1 side.
Both 62 and 17 constitute a dog clutch.
Furthermore, a second drive shaft 6 is provided in the engagement recess 62.
A protruding pin 63 is formed to coincide with the axis of 0. This protruding pin 63 forms a pair with the engagement hole 18 formed in the engagement claw 17 of the first drive shaft 13.

Next, to explain the camera body 1 side, the removable mount 3 on the camera body 1 side, on which the interchangeable lens 2 is mounted, has a bayonet spring 6 on the back side, which ensures a loose connection when the interchangeable lens 2 is attached. There is. The positioning member release button 7, which partially projects from the front cover 4, is loosely fitted between the front cover 4 and the front base plate 5, and is always urged by a spring 8 in the direction of protrusion from the front cover 4. 23 is an engagement plate fixed to the positioning member release button 7, and the engagement plate 23 is engaged with the circumferential groove of the mount positioning member 9. Therefore, the positioning member release button 7 and the mount positioning member 9 are integrated. will be moved to. The mount positioning member 9 is formed in a cylindrical shape,
The distal end positioning portion 10 is fitted into the through hole of the body side removable mount 3, and the rear end portion is fitted onto the outer periphery of the bearing member 12 of the first drive shaft 13, so that it is held movably forward and backward. There is. The bearing member 12 is attached to a hole in the front base plate 5. Reference numeral 14 denotes a movable collar, which is slidably fitted onto the first drive shaft 13 and is always biased to the left in the figure by a spring 15. 33 is a collar fixed to the first drive shaft 13, and the movable collar 14 is attached to the collar 33.
By pressing against each other, the force of the spring 15 urges the first drive shaft 13 to the left in the figure. In this case, the movable flange 14 pushes the fixed flange 33 to the left in the figure, but at the end of its stroke, the movable flange 14 pushes the second inner diameter enlarged step 34 of the mount positioning member 9.
contact, and as a result, the contact pressure on the fixed collar 33 is released, so the first drive shaft 13 can rotate smoothly without being subjected to pressure from the spring 15. Regarding the relative positional relationship of the first drive shaft 13 with respect to the mount positioning member 9, the fixed collar 33 of the first drive shaft 13 is connected to the mount positioning member 9.
The position at which it abuts against the first inner diameter enlarged step 38 is the furthest to the left in the figure.

An engaging pawl 17 is formed at the tip of the first drive shaft 13 . The engagement claw 17 is fitted into the engagement recess 62 of the second drive shaft 60 on the side of the interchangeable lens 2.
It is formed to protrude from the end face. Furthermore, an engagement hole 18 is formed from the distal end surface of the engagement claw 17 in alignment with the axis of the first drive shaft 13 . The insertion hole 18 receives the protruding pin 63 of the second drive shaft 60 to accurately align the axes of the first drive shaft 13 and the second drive shaft 60.

35 is a drive circuit for driving the first drive shaft 13, which includes the motor 22 and the motor drive control circuit 3;
2. Switch 36, fixed electrode 27 and movable electrode 26
It consists of one switch, etc. The switch 36 is turned on and off in conjunction with, for example, a shutter release (not shown), and when the switch 36 is turned on while the fixed electrode 27 and the movable electrode 26 are in contact, the entire circuit 35 is turned on.
Motor drive is performed. 37 is a distance measuring circuit which uses the power supply in the drive circuit 35 as a common power supply;
The operation of the distance measuring circuit 37 is controlled by a switch consisting of the movable electrode 26 and another fixed electrode 37a which is slidably in contact with the movable electrode 26. Although the second fixed electrode 37a is formed to have a slightly wider width than the first fixed electrode 27,
This is a consideration so that only the distance measuring circuit can be turned on even when the drive circuit is off. That is, if the camera has a mechanism to display in-focus and out-of-focus states (e.g. in the viewfinder), an interchangeable lens without an autofocus arrangement (manual Even when a camera is equipped with a normal lens capable of focusing only, if the distance measuring circuit is activated, there is an advantage that focusing can be easily performed using the display mechanism. The reason why the second fixed electrode 37a is formed to be slightly wider is to operate only the distance measuring circuit 37 for this purpose. In this case, the movable electrode 26 is the fixed electrode 37a.
In order to make contact only with the lens, the depth of the positioning recess (64 in Fig. 5) for locking in the above-mentioned normal interchangeable lens is made smaller than that of an interchangeable lens with an autofocus mechanism (Fig. 5). Needless to say, it is necessary to form it slightly deeper.

Note that if an interchangeable lens whose distance measurement performance is not guaranteed by the distance measurement circuit 37 is attached, such as a super telephoto lens, there is a risk that inaccurate distance measurement will be performed and the distance measurement result will be displayed. Therefore, for lenses whose ranging performance is not guaranteed,
For example, if a protrusion is formed in the positioning recess, the first
The configuration may be such that the movable electrode 26 is swung through the drive shaft 13 so as not to come into contact with either of the two fixed electrodes 27, 37a. The distance measuring circuit 37 inputs the focus information of the subject to the motor drive control circuit 32, and thereby the motor drive control circuit 3
2 controls and drives the motor 22 in terms of rotation direction, rotation speed, etc. The rotation of the motor 22 is caused by the intermediate gear train 3.
1 (see FIG. 2), etc., to the gear 21 provided on the front base plate 5, and further to the first drive shaft 1.
3 to the fixed gear 19. As a result, the first drive shaft 13 is rotated by the required amount. 20 is gear 2
It is fixed to the front base plate 5 by a shaft 1. Reference numeral 27 denotes a fixed electrode provided at one end of the drive circuit 35, and a switch lever 24 that can swing about the fulcrum 25 with respect to the fixed electrode 27 is provided. The other end of the switch lever 24 is engaged with an annular groove 16 provided at the rear end of the first drive shaft 13. Therefore, the switch lever 24 is swung as the first drive shaft 13 moves back and forth, and the movable electrode 26 at the tip of the switch lever 24 comes into contact with the fixed electrode 27 at an appropriate swiveling position. The other end of the circuit 35 is connected to the switch lever 24 . The fixed electrode 27 and the movable electrode 26 are connected to each other by fitting the mount positioning member 9 into the mount positioning recess 64.
7 and the engagement recess 62 (see FIGS. 8 and 5). On the other hand, in a state where the mounting of the camera body 1 and the interchangeable lens 2 is not completed (see FIGS. 6 and 7), the movable electrode 26 and the fixed electrode 27 are located apart from each other.

Next, to explain the operation, the interchangeable lens 2 is pressed against the camera body 1 in the state shown in FIG. 6 against the pressure of the springs 8 and 15 (see FIG. 7).
When the interchangeable lens 2 is rotated, the interchangeable lens 2 reaches the position of the mount positioning member 9 of the camera body 1.
When the mount positioning recess 64 has been around, the positioning part 10 of the mount positioning member 9 automatically enters the positioning recess 64 due to the pressure of the springs 8 and 15 (see FIG. 8), and the interchangeable lens 2 is It is locked in a predetermined position relative to the camera body 1. At this point, the movable electrode 26 comes into contact with the fixed electrode 27 and enters the switch-on state.

On the other hand, at this point, the engagement pawl 17 of the first drive shaft 13 and the engagement recess 62 of the second drive shaft 60 are not necessarily engaged. FIG. 8 shows such a situation. In this state, the first drive shaft 13 can be retracted to the right in the drawing relative to the mount positioning member 9 against the pressure of the spring 15 while ensuring engagement between the mount positioning member 9 and the mount positioning recess 64.

As will be described later, when the motor 22 starts rotating, the first drive shaft 13 also starts rotating, and the moment the engagement claw 17 and the engagement recess 62 align, the spring 15 automatically engages the engagement recess 62. left in a bad state,
The driving force is transmitted to the interchangeable lens side (see Fig. 5). Of course, the insertion hole 18 and the protruding pin 63
The shafts 13 and 60 also fit together, and the axes of both shafts 13 and 60 coincide.

Now, in FIG. 5, close the switch 36,
When the signal from the distance measuring circuit 37 is input to the motor drive control circuit, the motor 22 rotates, and the signal from the distance measuring circuit 37 is input to the first drive shaft 1 via the intermediate gear train 31 and the gears 21 and 19.
3 rotates. The rotation of the first drive shaft 13 is transmitted to the second drive shaft 60 via the clutches 17 and 62.
Then, the middle helicoid tube 58 is further rotated via the gears 65 and 66. In response to this rotation, the optical systems 52 and 53 move in the direction of the optical axis 51. The optical system 5 receives the front focus and rear focus signals from the distance measuring circuit 37.
After the movement of the optical systems 52 and 53, the motor 22 is stopped due to focus detection by the distance measuring circuit 37, and the optical systems 52 and 53 are moved.
The camera also stops and the autofocus operation is completed. When removing the interchangeable lens 2, the mount positioning member 9 is moved back by pressing the positioning member release button 7, and at this time, the first drive shaft 13 is also moved back together with the first inner diameter enlarged step 38 of the member 9. Clutch 1
7,62 comes off. Therefore, by rotating the interchangeable lens 2 in the opposite direction, the interchangeable lens 2 can be removed.

FIG. 9 shows an embodiment in which a warning circuit 40 is provided.
41 is an oscillator, and 42 is a sounding body. A pair of switch pieces 43, 43 are provided opposite the rear end 7a of the positioning member release button 7, and are turned on and off as the release button 7 moves forward and backward in conjunction with the mount positioning member 9. It's getting old. That is,
When the interchangeable lens 2 is attached to the camera body 1,
If the positioning part 10 of the mount positioning member 9 has not yet fitted into the mount positioning recess 64, the positioning member release button 7 is in the retracted position as shown by the imaginary line, so the switch pieces 43, 4
3 closes and emits a warning sound. As shown by the solid line, the positioning portion 10 is located in the mount positioning recess 64.
When the button 7 is engaged, the switch pieces 43, 43 are opened, the circuit is opened, and the warning sound stops as the button 7 moves forward. Of course, when the interchangeable lens 2 is not attached, the button 7 is pushed forward by the spring 8, so the switch pieces 43, 43 are in an open state. That is, in this example, from the start of attaching the interchangeable lens 2 to the camera body 1, to the first
A warning will be issued until a proper connection between the drive shaft 13 and the second drive shaft 60 is secured.

In the above embodiment, for the sake of transmission efficiency, the driving member and the driven member are connected by the engagement of the linear groove 62 and the protrusion 17 on their abutting end faces, and this is done properly. Even if the groove 64 and the protrusion 17 are in the crossing direction, they are not actually engaged. The driving of the driving member is started to align the directions of the groove and the protrusion. However, depending on the type of clutch, such as a friction clutch, where matching of the connection direction is not a condition, this is not necessary, and the opening and closing of the switch closely corresponds to whether or not the connection is proper. become.

Effects According to the present invention, in an optical system exchangeable optical device, in which one and the other of optical devices that are attached to and detached from each other are provided with a driving member and a driven member that connect and disconnect as they are attached and detached, the driving member and the driven member are connected to each other. Since we have installed a switch that opens and closes the circuit depending on whether or not the drive and driven members are properly connected, it is possible to protect the driving and driven members from any problems that may occur due to not only improper mounting of each optical device but also mount backlash, etc. When there is a poor connection with the optical device, it is used to warn you or indicate that it cannot be driven, to reliably prevent failures and inconveniences due to the use of optical equipment with no connection or in a bad state, and to optimize the connection state. You can encourage people to do so.

[Brief explanation of the drawing]

FIG. 1 is a front view of a camera body according to an embodiment;
FIG. 2 is a simplified diagram showing the transmission mechanism configured inside the camera body according to the embodiment, FIG. 3 is a back view of the interchangeable lens according to the embodiment, and FIG. 4 is a diagram showing the transmission mechanism configured inside the interchangeable lens. A simplified diagram showing the mechanism. Figure 5 is a longitudinal sectional view of the interchangeable lens attached to the camera body. Figures 6 to 8 are longitudinal sectional views showing the process of attaching the interchangeable lens. Figure 9 is the warning circuit. FIG. 2 is a vertical cross-sectional view showing an example in which 1...Camera body, 2...Interchangeable lens, 7...
...Positioning member release button, 9...Mount positioning member, 13...First drive shaft, 17...Engagement claw, 3
2...Motor drive control circuit, 37...Distance measuring circuit, 40...Warning circuit, 60...Second drive shaft, 6
2... Engagement recess.

Claims (1)

[Scope of Claims] 1. Consisting of a camera body having a driving member and a lens having a driven member, the driving member and the driven member are interlocked with the attachment and detachment of the lens to the camera body, so that the driving member is attached to the driven member. In an interchangeable lens camera that connects and disconnects by switching between a disconnection position and a connection position, the drive member comprises: a motor provided for driving the drive member; a motor drive control circuit for controlling the motor; When moving between the cutting position and the connecting position, in conjunction with the driving member, the motor drive control circuit corresponding to the cutting position is inactivated, and the motor corresponding to the connecting position is A circuit opening/closing device comprising: a switch that moves a drive control circuit to and from a position where it is ready for operation;