JPS62131217A - Power focusing device - Google Patents

Abstract

PURPOSE:To execute more speedily and precisely power focusing operation by setting up the operation to two stages, i.e. rapid rough movement and slow fine movement. CONSTITUTION:A power focusing operation ring is arranged on the exchange lens barrel fitting part or the exchange lens barrel side of a camera body and a switch opening/closing projection part 4a, a position regulating click groove 7, etc., are formed on a switch ring 4 interlocking with the operation ring. Switches 9a, 9b having a pair of movable armature groups for switch speed are opened/closed by the projection part 4a and a click spring 8 is engaged with the click groove to execute the power focusing operation. Consequently, power focusing to be driven in the lens extruding direction and the lens drawing-in direction rapidly (rough movement) and slowly (fine movement) with operating sense similar to manual operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power focusing device for a camera, and more particularly to a power focusing operation device for a camera that performs focusing four weeks by power drive.

C. Prior Art Recently, autofocus has become common even in negative-eye reflex cameras, and power focus has been adopted (see, for example, Japanese Patent Laid-Open No. 84818/1983). In this case, the power focus switch is located on the side of the photographic lens barrel, and it does not provide the same operational feel as when rotating the distance ring of a conventional manual photographic lens. This is configured so that when you press the speed adjustment switch or the changeover switch mentioned above, it will move by the minimum rotation angle of one address, and if you keep pressing the same switch for a certain period of time, it will rotate continuously at a constant speed. Because there is. Therefore, if the speed of power focusing is increased, the minimum rotation angle will increase, and the accuracy of focus adjustment will decrease accordingly. Also,
If the minimum rotation angle is set small in an attempt to achieve this accuracy, there is a problem in that the speed of the focal week 1 week becomes slow.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned points, and it is possible to operate the operation member of a power focus device with a feeling similar to that of the operation ring of a conventional manual focus. It is formed into a ring shape.

Further, this power focus operation is increased to two speed modes: high speed (coarse movement) and low speed (fine movement), so that focusing can be performed quickly and accurately.

[Means and effects for solving the problem] An annular power focus operation ring is provided on the interchangeable lens barrel attachment part of the camera body or on the side of the interchangeable lens barrel, and a switch ring that interlocks with this operation ring is provided. A protrusion for opening/closing the switch and a click groove for regulating the position are provided, and the protrusion opens and closes the switch having a pair of movable contact pieces for speed switching, and a click spring is engaged with the click groove. This allows you to perform power focus operations.

Therefore, when performing a power focus operation using a power focus device configured in this way, the high-speed (coarse movement) and low-speed (fine movement) driving of the lens in the extending and retracting directions can be performed with the same operational feeling as conventional manual operation. This makes power focus possible.

[Example] Although the power focus device of the present invention can be applied to a camera without an autofocus function, there is no problem in applying it to a camera that does not have an autofocus function. Since the present invention is used for manual operation as an auxiliary means for focusing when autofocus is not activated, the present invention will be described with reference to the case where it is applied to an autofocus camera with interchangeable lenses. Therefore, first, the outline of the autofocus device will be explained below in section 111.

FIG. 3 is a schematic block diagram of an electric circuit of an autofocus device for a camera to which the power focus device of the present invention is applied. Data is exchanged between the AFCPU 30, which is a central processing unit for autofocus, and the MAINCPU 20, which is a main processing unit for exposure adjustment, etc., through a serial communication line.

The direction of communication is controlled by a serial control line, which is a bidirectional communication line.

The contents of this communication include lens data of the interchangeable lens, absolute distance information, absolute distance count information, and the like. In addition, the model line is battery check mode (BAT-C),
Power focus mode F (P, F,), single
It is designed to decode information on a series of operation parts such as autofocus mode (SIN, AP) and Sea Fence autofocus mode (SEQ, AF).

The AFENA line is the line that controls the start and stop of autofocus and power focus.
The EOFAF line indicates the end of operation in autofocus and power focus modes, and indicates that it is possible to shift to exposure sea fencing.

The lens is driven by decoding and driving an autofocus morph control signal by the bipolar IC 40, and rotating the autofocus morph 51, which drives the lens, in forward and reverse directions. This rotation of the motor 51 is taken into the bipolar IC 40 by the photointerrupter 41 attached to the autofocus morph drive member, and the waveform is shaped and taken into the AFCPU 30 via the address line as an address signal. SLAMP 42 controls the autofocus auxiliary light, and turns on the autofocus auxiliary light when the object has low brightness and low contrast. Further, the AFOKLED 31 indicates that the subject is in focus, and the AFNGLED 32 indicates that the subject is out of focus.

A1 of the human power port of MArNCPU20. A2゜A3.
A4 has a pair of switches 24a, a switch 22 (hereinafter referred to as PFUP) for power focus up for lens extension, a switch 23 (hereinafter referred to as PFDN) for power focus down for lens retraction.

Power focus for high speed drive consisting of 24b
A speed switch 24 (hereinafter referred to as PFSPEED) is connected, and its information is sent from the MAINcPU 20 to the AFCPU 3Q via the model line and decoded. And is this AFCPU30 the above switch? ! 'Depending on the state of F22, 23, and 24, control signals for performing each power focus operation are output.

The relationship between each of these switches 22, 23, 24 and the power focus is shown in Table 1 below.

(*Can be either on or off) Switch 22 is a lens extension direction switch that changes the focal length of the lens from an infinity position to a close range position, and switch 23 changes the focal length of the lens from a close range position to an infinity position. The switch 24 is a switch for the lens retraction direction to be operated, and the switch 24 is a switch for high-speed driving and is composed of a pair of switches, a switch 24a for the lens extension direction and a switch 24b for the retraction direction.

The movement of the focusing lens is detected by the address generation section of the bipolar IC 40 using the photo ink converter 41, and this signal is manually inputted to the AFCPU 30 as an address signal after waveform shaping.

The AFCPU 30 sends a control signal for the autofocus motor 51 to the bipolar IC 40, which controls the forward and reverse rotation of the motor 51 at high speed.

It is designed to control low speed drive and stop.

Next, the outline of the autofocus motor drive section 50 will be explained in the fourth section.
This will be explained based on the diagram. The bipolar IC 40 is connected to the decode section 52 and the driver section 53 via the drive power sources V no, F 7 ,
IQ,,Q2. Q3. Q4 and diode 54.55
It consists of a forward/reverse switching circuit. The autofocus motor 51 is driven and controlled by a control signal from the AFCPU 30 via the bipolar IC 40.

Diode 54.55 is transistor Q2 or Q3
autofocus motor 5 respectively when turned on.
This is to apply a back electromotive force to 1 and apply the brakes to bring it to a sudden stop.

The above autofocus motor 51 during power focus
The high-speed and low-speed operations during normal rotation and reverse rotation will be explained using the timing chart of FIG.

The same motor 51 has two high speed (coarse movement) and low speed (fine movement) motors in the direction of extending the lens and the direction of retracting the lens.
It is designed to be driven at high speed. For example, when driving at high speed in the lens extending direction, transistor Q,
, Q3 are on, transistor Q2. Due to the control signal that turns off transistor Q4, current flows from the drive power supply VDD to transistor Q and motor 51. Through the transistor Q3, the motor 51 performs high-speed drive in the lens extending direction. At this time, when the transistor Q2 is turned on by the control signal from the AFCPU 30, the motor 51
is a transistor Q1. A back electromotive force is applied via Q2 and the diode 54, and the motor 51 suddenly stops. The current to the transistors Q, Q3 is controlled in the same way in the case of low speed driving, but the AF is controlled so that the driving time t3 is shorter than the driving time t in the case of high speed driving.
This is performed by performing arithmetic processing so that the duty ratio T of the control signal of the CPU 30 is controlled. In exactly the same way, drive control in the lens retraction direction is also performed by transistor Q2. This is carried out under the control of a control signal from a similar AFC CPU 30 on the Q4 side.

Next, the operation of the power focusing device of the present invention will be explained based on the flowchart of FIG.

When the mode selector switch (not shown) is selected to power focus mode, the PFU in the lens extending direction is
P switch 22. It is determined whether the PFDN switch 23 in the lens retraction direction is on or off. Now, PFU
Assuming that the P switch 22 is on and the PFDN switch 23 is off, then the PFSP for high-speed drive control
It is determined whether the EED switch 24 is on or off, and when the switch 24 is on, as shown in Fig. 4.5, the transistor Q3 is on and the transistor Q is on for a time t, and the transistor Q2 is on for a time t2. A control signal with a duty ratio such as
0 to the AF motor drive unit 5 via the bipolar IC 40.
0, and the autofocus motor 51 is driven in normal rotation at high speed. Further, when the PFSPEED switch 24 is off, the transistor Q3 is on, the transistor Q1 is on for a time t3, and the transistor Q2 is on.
The autofocus motor 51 is controlled to be driven at a low speed with a duty ratio of ON for time t4. In exactly the same way, in the lens retracting direction, the reverse drive control of the autofocus motor 51 at two high and low speeds is performed by selective manual control signals from the PFDN switch 23 and the PFSPEED switch 24.

Next, an embodiment of the operation section of the power focus device of the present invention will be described based on FIGS. 1 and 2. Similar to the conventional manual distance ring, the operation ring 3 of the present invention includes a ring-shaped ring disposed on the interchangeable lens mounting portion 5 of the camera body 1 (see FIG. 1(A)), and an interchangeable lens barrel. 2
There is also one that is arranged in a ring shape on the side (see Fig. 1(B)). The operating ring 3 is formed so as to be able to rotate together with the switch ring 4 shown in FIG. This switch ring 4 is connected to the MAIN CPU 20
Input port A 1. A2, A3. Movable contact piece J of switch 9 connected to A4! ￥9 al,
9 a2゜9a3 and 9bl, 9b2. 9b3
A switch opening/closing protrusion 4a for bringing the switch into contact and separation, and a reciprocating protrusion 4b that engages with the spring member 6 in a direction making a 90° angle with the protrusion 4a are provided on its periphery. A two-stage click groove 7 for position regulation is formed on the periphery on the side opposite to the portion 4a, and is formed of an annular member with an opening for a photographing optical path in the center. The switch 9 has a pair of mounting parts 9a.

9b, movable contact groups 9a1 to 9a3. 9bl to 9b3, the inner contact pieces 9al and 9bl that engage with the protrusion 4a of the switch ring 4 are straight elastic conductive contact pieces, and the inner contact pieces 9a2. 9 b2
and outer contact piece 9 a3. 9 b3 is formed from an elastic conductive contact piece RT which is short in length and has a curved contact portion at its tip. And a pair of mounting parts 9
a, 9b to input port A of the MAIN CPU 20
1°A2. A3. Connection lines are wired on each A4. The contact pieces 9al and 9a2 are connected to P in the lens extending direction.
The FUP switch 22 is formed, and the contact pieces 9a2 and 9a3 similarly form the PFSPEED switch 24a in the lens extension direction. Also, the contact piece 9b on the mounting part 9b side
l, 9b2. 9b3 also forms a PFDN switch 23 and a PFSPEED switch 24b in the lens retracting direction, respectively.

Further, the spring member 6 that engages with the reciprocating protrusion 4b of the switch ring 4 is formed by winding the center part into a coil shape, and this part is attached to a stationary member (not shown).
The protrusion 4b is sandwiched between the two ends 6a and 6b.

In general, the force of the spring portion 4A6 does not act on the protrusion 4b because the intermediate portion comes into contact with an immovable stopper member 6c that is slightly wider than the protrusion 4b. Furthermore, the click lt7 has the same click groove 7 at the tip.
The click spring 8, which has a bent portion matching the shape of the click spring 8, is fixed to a fixed member (not shown) of the interchangeable lens barrel 2 or the interchangeable lens mounting portion 5 so as to be engaged with the click spring 8.

Next, the operation of the switch ring 4 and switch 9 will be explained. First, when the operating ring 3 is not operated, the switch ring 4 is in the state shown in FIG. 2(A). That is, the switch ring 4 is in a state where the click spring 8 falls into the click groove 7 and is locked. Therefore, since both ends 6a and 6b of the spring member 6 are in contact with the stopper member 6c at this time, no force is applied to the protrusion 4b of the switch ring 4. Also, in this state, switch 9
Contact piece 9 al, 9 a2. 9 a3 and 9b
l, 9b2゜9b3 are not in contact and PF
UP switch 22. PFDN switch 23 and P
The FSPEED switches 24 are each in an off state.

When the operator manually rotates the operating ring 3 in the direction of the arrow in Fig. 1, the state shown in Fig. 2 (B) is achieved, the motor 51 rotates forward at low speed, and the lens is finely adjusted in the feeding direction. be done. That is, the switch ring 4 also rotates in the direction of the arrow, and the click spring 8 climbs over the first notch step 7a of the click groove 7 and stops when it is in contact with the second notch step 7b.
At this time, the protrusion 4b of the switch ring 4 pushes the one end 6a of the spring member 6, thereby charging the spring member, and the protrusion 4a of the switch ring 4
Push the contact piece 9al to make contact with the contact piece 9a2, and press PFUP.
switch 22 is turned on. Therefore, the lens will be moved slightly. When the force applied to the operating ring 3 is removed in this state, the switch ring 4 returns to the state shown in FIG. 2(A) due to the reciprocating elastic action of the spring member 6.

Next, when the operating ring 3 is rotated in the direction of the arrow by applying further force from the state shown in FIG. 2(B), the click spring 8
passes over the second cut step 7b of the click groove 7. The protrusion 4b of the switch ring 4 is a stopper.
It comes into contact with 0H and its rotation is restricted. At this time, the contact pieces 9 al, 9 a2 . 9 All a3 are in contact. Therefore, the P FUP switch 22 is turned on, the PFSPEED switch 24 is also turned on, the autofocus mask 51 rotates forward at high speed, and the lens is coarsely adjusted in the extending direction. When the force applied to the operating ring 3 is removed from this state, the reciprocating elasticity of the spring member 6 applied to the protrusion 4b of the switch ring 4 causes the operating ring 3 and the switch ring to move as shown in FIG. 2(B). The state returns to the state shown in FIG. 2(A).

When the operating ring 3 is rotated in the clockwise direction opposite to the arrow, the contact piece 9bl on the opposite side performs exactly the same operation.
, 9b2. 9b3. Click iM 7 and the other end 6b side of the spring member 6, and the PFDN switch 2
3 and turn on the PFSPEED switch 24,
The lens will be operated in the renormalization direction.

In this way, by controlling the force and direction that the operator applies to the operating ring 3, the first stage of low-speed fine adjustment and the second stage of high-speed ↑■ coarse adjustment can be performed using different forces from the spring member 6. Since the switch ring 4 is actuated by the switch ring 4, the power focus operation can be performed at approximately the same interval as the operation ring in the case of conventional manual operation.

In the above embodiment, the operation ring performs low-speed fine adjustment in the first stage operation and high-speed coarse adjustment in the second stage operation; Of course, the coarse adjustment may be performed in the second stage, and the fine adjustment at a low speed may be performed in the second stage operation.

[Effects of the Invention] As described above, since power focusing can be performed in stages of high-speed coarse movement and low-speed fine movement, the operation can be performed more quickly and accurately.

Further, since the coarse and fine adjustment switch is arranged on the circumference 1 of the lens barrel or lens mounting portion, the power focus can be adjusted with almost the same operational feel as the distance ring of a conventional interchangeable lens.

[Brief explanation of drawings]

':j 3 is a schematic block diagram showing the configuration of an autofocus device in which the power focus device of the present invention is used, and FIG. 4 is an autofocus of the autofocus device shown in FIG. 3 above. A schematic electrical circuit diagram for explaining the morph drive section, FIG. 5 is a time chart for explaining the operation of the bridge circuit of the autofocus morph drive section shown in FIG. 4, and FIG. 6 is a diagram of the present invention. 3 is a flowchart showing the operation of the power focus device. 1... Camera body 2...
......Interchangeable lens barrel 3...
・・Power focus operation ring 4・・・・・・・・・
... Switch ring (operation member that generates the first and second signals) 5 ... ... ... Interchangeable lens mounting member 50
...... Autofocus morph drive unit 51.
・・・・・・・・・Auto focus motor 1st (B) 2nd 5th 1st 'thousand' and direction Q4゜FF

Claims (3)

[Claims] (1) A lens drive motor that adjusts the focus of the photographic lens, an operating member that generates first and second signals, and a control signal that generates a control signal to finely drive the motor in response to the first signal. , a motor drive control circuit that generates a control signal to coarsely drive the motor in response to the second signal. (2) Claim 1, wherein the operating member is an annular member that is rotatable on the circumference of the lens barrel.
Power focus device as described in section. (3) The power focus device according to claim 1, wherein the operating member is provided on a body mount portion of a camera body.