JPH05313053A - Electric drive mechanism - Google Patents

Abstract

PURPOSE:To realize electric drive mechanism of desirable operability capable of reflecting the intention of a photographer by the high speed performance and low speed stability of electric driving without making the photographer feel uncomfortable by getting operation, performed for focusing or zooming through the electric driving of a lens group, close to the manual operating sensation. CONSTITUTION:Electric drive mechanism is provided with a driving means 1 for driving a lens group electrically, an operating member 2 operable in both directions with a neutral position as a border, a first detecting means 3 for detecting the operating direction of the operating member 2, a second detecting means 4 for detecting the operating quantity of the operating member 2, a third detecting means 5 for detecting the operating speed of the operating member 2, and a control means 6 for selecting the driven direction of the lens group by the first detecting means 3 and determining the driven speed of the lens group on the basis of the operating quantity and speed of the operating member outputted from the second and third detecting means 4, 5 so as to drive the lens group electrically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive speed adjustment of an apparatus having a function of focusing or zooming a lens group by electric driving, and is used for a still camera or a video camera.

[0002]

2. Description of the Related Art Conventionally, it has been known to provide a mechanism for electrically driving a lens group and an operating member that can be operated in both directions with a neutral position sandwiched therebetween, and to control the direction and speed of driving the lens group based on the operating direction and operation amount. It is proposed by Kai 62-272215.

[0003]

In the above-mentioned prior art, the driving speed of the lens group is determined only by the operation amount of the operation member, and if the operation amount is large, the driving speed is high, and if the operation amount is small, the driving speed is low. Because it is possible, it is thought that focusing and zooming can be done easily and easily. However, when actually operating the product, there was a great deal of discomfort, and it was not possible to drive the camera as intended by the photographer.

Now, let us consider a focusing or zooming method by a manual operation before such an electrically driven still camera or video camera is put on the market. When a large image change is desired, the operation amount of each operation member is increased, and when a small change is required, the operation amount is rotated small.
Further, if this operation is performed at a high speed, the image changes quickly, and if it is performed at a low speed, it becomes slow. That is, the photographer only has to operate the intended image change amount and change speed in parallel with the operation member, the operation amount of the operation member corresponds to the image change amount, and the operation speed corresponds to the image change speed. It was

However, in the conventional electric drive, the operation amount of the operating member corresponds to the image change speed. Therefore, when a photographer familiar with manual operation is used, for example, the image change amount is increased at a low speed. When the operating member is rotated with the intention of performing the operation, it first starts to rotate slowly from the intention of low speed. However, since there is an intention to increase the amount of change in the image, it may rotate at a slow speed to the maximum angle. It was Therefore, with this operation, the change speed of the image reaches the maximum controllable speed, and the intention of the photographer is not reflected, which causes a great discomfort.

Further, in order to increase the agility of the electric drive, when the operation range of the operation member is set to a narrow rotation range from 10 degrees to 15 degrees, the image change from low speed to maximum speed can be adjusted within this range. Requires a delicate turning operation and requires a lot of training before shooting, and if this is not done, the operation cannot be performed as intended and there is a problem that the operability is dissatisfied.

The present invention has been made in view of the above points, and an object of the present invention is to bring an operation for focusing or zooming by electrically driving the lens group closer to a manual operation feeling so that a photographer Another object of the present invention is to provide an electric drive device having good operability, which can reflect the intention of the photographer due to the high speed and low speed stability of the electric drive without giving a feeling of strangeness.

[0008]

In order to solve the above-mentioned problems, in the electric drive device according to the present invention, as shown in the block diagram of FIG. , Operation member 2 that can be operated in both directions from the neutral position
And a first detecting means 3 for detecting the operating direction of the operating member.
And second detection means 4 for detecting the operation amount of the operation member,
A third detecting means 5 for detecting the operating speed of the operating member, and a driving direction of the lens group is selected by the first detecting means 3 and an operation output by the second and third detecting means 4, 5 is performed. The control means 6 determines the drive speed of the lens group based on the operation amount and the operation speed of the member and electrically drives the lens group.

Here, when the operating amount of the operating member is operated in the increasing direction, the control means 6 performs a calculation in which the operating amount and the operating speed are both proportional to the driving speed, and accelerates and drives the lens group. It is preferable that the means is

When the operation amount of the operating member is operated in the restraining direction (direction approaching the neutral position), the control means 6
It is preferable that the operation amount is proportional to the driving speed, and the operation speed is inversely proportional to the calculation to perform deceleration driving of the lens group.

[0011]

The operation of the present invention will be described below with reference to the block diagram of FIG. 1 when the electrically driven lens group is a zoom lens group. The operation member 2 can be operated in both directions across the neutral position as shown by the arrow. The first detection means 3 detects the operation direction of the operation member 2. Also, the second
The detection means 4 detects the operation amount of the operation member 2. Further, the third detecting means 5 detects the operating speed of the operating member 2. By the output from the first detecting means 3, when the operating member 2 is rotated clockwise, it is set to the telephoto side, and when it is rotated counterclockwise, it is set to the wide angle side by the control means 6 by the control means 6 to drive the zoom lens group. 1 is controlled. At the same time, the drive speed of the lens group is determined based on the operation amount and the operation speed of the operation member output from the second and third detecting means 4 and 5, and the operation of the drive means 1 is controlled. The driving unit 1 electrically drives a lens group that is movable by zooming with an actuator (for example, a motor) to change the focal length of the photographing lens.

In the present invention, if the control means 6 is operated so that the operation amount of the operation member is increased, the operation amount and the operation speed are both proportional to the drive speed. The change of the operation amount and the operation speed due to the rotation of the operation member becomes a smooth change of the drive speed, so that the drive means 1 can be acceleration-controlled. With such a configuration, for example, when the operation member 2 is rotated with the intention of making a large amount of image change at a low speed, first, the operation member 2 is slowly rotated from the intention of a low speed, and the amount of change of the image is increased. Therefore, when the vehicle is rotated at a slow speed to the maximum angle as it is, the drive speed calculation of the control means 6 increases the speed as the operation amount increases.
Finally, the driving means 1 is controlled at a driving speed equal to or lower than the medium speed. Further, when the operation member is rotated at a high speed with the intention of changing the image at a high speed, the speed is rapidly increased as the operation amount is increased by the drive speed calculation of the control means 6, and finally the speed is increased. The drive means 1 is controlled by reaching the maximum controllable speed. In this way, when the operation member is slowly rotated, the drive control is performed so as to gently accelerate according to the operation amount, and when the operation member is rotated at high speed, the drive control is performed so as to rapidly accelerate according to the operation amount. The intention is reflected and the photographer does not feel uncomfortable.

Further, the lower the operating speed of the operating member 2 is, the more the maximum driving speed is suppressed, and the control means 6 acts so that the speed change per unit operating amount becomes slow, so that the rotating range of the operating member 2 is narrowed. Even if it was set, the intended drive speed could be obtained without delicate turning operation, and the operability was improved without impairing the high speed and low speed stability, which are advantages of electric drive.

Next, when the operation amount of the operation member is operated in the restraining direction, the control means 6 performs a calculation in which the operation amount has a proportional relationship with the drive speed and the operation speed has an inverse proportional relationship. Then, the change of the operation amount and the operation speed due to the rotation of the operation member becomes a smooth drive speed change, and the drive means 1 can be decelerated and controlled. In this way, when the zoom operation ring is slowly rotated, the drive control is performed so as to gradually decelerate according to the operation amount, and when the zoom operation ring is rotated at high speed, the drive control is performed so as to rapidly decelerate according to the operation amount. The intention of the photographer can be reflected.

In the above description, the case where the electrically driven lens group is the zoom lens group has been described. However, even if the electrically driven lens group is the focusing lens group, if the electric drive lens group has the same structure, the electrically operated focusing drive device having the same function. Can be

[0016]

EXAMPLE An electric drive zoom lens will be described below as an example of the present invention. FIG. 2 shows an external configuration of an electrically driven zoom lens barrel L to which the present invention is applied.

Reference numeral 10 denotes a manual focus ring for adjusting the focus position by manually extending or retracting a lens group movable for the purpose of focusing.

Reference numeral 11 denotes an autofocus (hereinafter abbreviated as AF) and manual focus (hereinafter abbreviated as MF) changeover switch knob. If the switch is on the AF side, the lens group that is movable for the purpose of focusing is an autofocus drive mechanism (not shown). ), The manual focus ring 10 allows manual focus position adjustment on the MF side.

Reference numeral 12 denotes a zoom operation ring, which can be rotated in both left and right directions with the neutral position being sandwiched by the outer periphery of the lens barrel L. Further, when the hand is released, the zoom operation ring automatically returns to the left and right neutral positions.
It is operated to instruct the direction and speed of the electric zoom by turning. The details will be described later.

Next, FIG. 3 shows an electrically driven zoom lens barrel L.
FIG. 3 is a block circuit diagram built in the. In the figure, μCOM is a microcomputer for controlling a focus motor, a zoom motor, and a data communication with a camera body (not shown) built in the lens barrel L. The names and functions of each part will be described below.

MP + is a power supply for driving the focus motor and the zoom motor, and MP- is a ground for the power supply for driving. VCC is a power source other than the one for driving the motor.
Is the ground for the power supply. SCK is a clock terminal for inputting a data communication clock from the camera body side, S
I is a serial input terminal for inputting data from the camera body side, and SO is a serial output terminal for outputting data on the lens side to the camera body side.

AMSW is a switch that works in conjunction with the AF and MF switching stitch knob 11 described above, and inputs the selection of AF operation or MF operation to the terminal AM of the microcomputer.
When the AF operation is selected, a control signal indicating a motor driving direction and a driving speed is output to the terminal MD1 of the microcomputer according to an instruction of communication data with the camera body. If the MF operation is selected, the communication data informs the camera body that AF is prohibited.

DR1 is a motor control circuit for driving the focus motor, and controls the operating direction and operating speed of the focus motor M1 in accordance with a control signal given from the microcomputer μCOM. In addition, according to the motor braking signal and the motor stop signal given from the microcomputer μCOM,
Both ends of the focus motor M1 are short-circuited or the applied voltage is cut off.

M1 is a focus motor that drives a focus lens group (not shown) to adjust the focus position.

The ENC is an encoder that interlocks with the zoom operation ring 12 to instruct the driving direction and speed of zooming.

DR2 is a motor control circuit for driving the zoom motor, and controls the operating direction and operating speed of the zoom motor M2 in accordance with a control signal given from the microcomputer μCOM. Further, both ends of the zoom motor M2 are short-circuited or the applied voltage is cut off in accordance with a motor braking signal and a motor stop signal provided from the microcomputer μCOM.

M2 is a zoom motor that drives a zoom lens group (not shown) to adjust the focal length.

Here, the zoom operation ring will be described in detail.

FIG. 4 is a sectional view of the zoom operation ring 12 of FIG. The operation ring 12 is held by springs 22 and 23 so as to be rotatable left and right, and further, the four-leg brush 20 is fixed, and the brush is in contact with the cord plate 21. The brush 20 and the code plate 21 form an encoder ENC for instructing the driving direction and speed of zooming.

FIG. 5 is a development view of the encoder ENC which is interlocked with the zoom operation ring 12. Since the zoom operation ring 12 automatically returns to the neutral position when the hand is released, the brush 20 is at the stop position of the cord plate 21. When the zoom operation ring 12 is rotated in the clockwise direction, the brush 20 moves the code plate 21 to the telephoto side, and when the rotation is further continued, the process proceeds to and finally ends in. When the zoom operation ring 12 is rotated counterclockwise, the brush 20 moves the code plate 21 to the wide angle side,
When the rotation is further continued, the process advances to and finally ends in. The code plate 21 is provided with four conductive patterns,
The conductive pattern COM is grounded, and the other conductive pattern EC
2, EC1 and EC0 are respectively connected to the power supply VCC through a resistor.
It is connected to the. Therefore, when the contact piece of the brush 20 comes into contact with any one of the conductive patterns EC2, EC1, and EC0, the conductive pattern COM and the conductive patterns EC2 and EC0.
One of the EC0 and the EC0 that is in contact with the brush 20 is short-circuited by the brush 20, and the signal output becomes “Low”. In addition, the non-contact signal output becomes "High". The conductive patterns EC2, EC1 of the encoder ENC,
The output of EC0 is connected to the microcomputer μCOM.

The microcomputer μCOM receives the conductive pattern signal output from the encoder ENC and outputs the signal to the microcomputer μC.
By searching the data table 1 provided in the ROM area of the OM, the operation direction and operation amount of the operation member 12 can be known. Here, Table 1 shows the relationship between the rotation operation of the zoom operation ring 12 and the data table 1 for obtaining the operation direction (DIR) and the operation amount (STP) from the encoder ENC signal.

[0032]

[Table 1]

The conductive pattern of the encoder ENC is the output E.
C2 to EC0 are provided so as to be a gray code. When the zoom operation ring 12 is not rotated, it is in the neutral position, and the encoder signals EC2 to EC0 become "111" and are input to the microcomputer μCOM. Microcomputer μCO
M searches the ROM table 1 from the encoder signal, the operation direction (DIR) of the operation ring is "0", and the operation amount (STP)
Know that is "0". In this case, manipulated variable (STP)
"0" means that the zoom operation ring 12 is not rotating, and therefore the zoom motor M2 is stopped.

When the zoom operation ring 12 is rotated clockwise, the zoom operation ring 12 is set to the telephoto side, and the encoder signals EC2 to EC0 are set to "1".
10 ”is input to the microcomputer μCOM. The microcomputer μCOM searches the ROM table 1 from the encoder signal and finds that the operation direction of the operation ring is“ 1 ”and the operation amount is“ 1 ”. When the direction (DIR) is “1”, it means that the zoom operation ring 12 has been turned to the telephoto side.
When the operation amount (STP) is "1", it means that the zoom operation ring has been rotated by a small amount. When the rotation is further continued, the position becomes the telephoto side, and the encoder signals EC2 to EC0 become "100" and are input to the microcomputer μCOM. The microcomputer μCOM searches the ROM table data from the encoder signal and knows that the manipulated variable (STP) has changed from "1" to "2". In this case, the operation amount (STP) being "2" means that the zoom operation ring 12 has been rotated by a medium degree. And finally it becomes a termination at the telephoto side, and encoder signals EC2-EC0
Becomes “101” and is input to the microcomputer μCOM.
The microcomputer μCOM searches the ROM table 1 from the encoder signal, and knows that the manipulated variable (STP) has changed from "2" to "3". In this case, the operation amount (STP) "3" indicates that the zoom operation ring 12 has been largely rotated.

Further, when the zoom operation ring 12 is rotated counterclockwise, it becomes the telephoto side, and the encoder signals EC2 to EC
0 becomes “011” and is input to the microcomputer μCOM. The microcomputer μCOM searches the ROM table 1 from the encoder signal, and the operation direction (DIR) of the operation ring is "0".
Know that the manipulated variable (STP) is "1". In this case, the operation direction (DIR) being "0" means that the zoom operation ring has been rotated to the wide angle side, and the operation amount (STP) is "1".
Indicates that the zoom operation ring has been rotated a small amount. When the rotation is further continued, the wide-angle side is reached, and finally the wide-angle side ends. The description of the turning operation to the wide-angle side is omitted because it overlaps with the description on the telephoto side.

The microcomputer μCOM knows the operation direction (DIR) and the operation amount (STP) of the zoom operation ring 12, and at the same time,
The manipulated variable (STP) changes from "0" to "1" and becomes "1".
From "2" to "2" or from "2" to "3" is measured. The measured time is RO
By comparing with the data table 2 provided in the M area, the operation speed (SPD) of the operation member 12 can be known. Here, from the time between the change points of the encoder ENC signal due to the rotation operation of the zoom operation ring 12, the operation speed (SP
Table 2 shows the relationship of the data table 2 for obtaining D).

[0037]

[Table 2]

The zoom operation ring 12 is rotated and the operation amount (ST
The time between the changing points of P) is compared with the ROM table 2, and if the time is 300 ms or more, the operating speed SP
Know that D is "1". 200ms or more 300m
If the time is less than s, the operation speed (SPD) is known to be "2". Also, if the time is less than 200 ms, it is known that the operation speed (SPD) is "3". In this case, the operation speed (SPD) "1" indicates that the zoom operation ring 12 is slowly rotated, "2" indicates medium rotation, and "3" indicates that it is rotated at high speed.

Items to be considered when determining the operation speed will be described. At the time when the zoom operation ring 12 is rotated a small amount from the intermediate position and moved to the telephoto side or the wide angle side, the operation direction (D
Although the IR) and the operation amount (STP) can be known, the operation speed becomes indefinite because the time between the change points of the operation amount cannot be measured. Therefore, the operation speed (SPD) is set to "1" by assuming that the rotation speed of the operation ring has not increased so much at the initial stage of the rotation of the zoom operation ring. Further, by setting in this way, it is possible to prevent the zoom motor M2 from rapidly rotating at high speed from the start of rotation.

The microcomputer μCOM knows the operation direction (DIR) and operation amount (STP) of the zoom operation ring 12 and the operation speed (SPD). Next, drive control of the zoom motor will be described. Operation amount (STP)
Is 0, it means that there is no rotation of the zoom operation ring, so the following motor drive control is not performed. However, if the operation amount has already become “0” during zoom motor drive control, a braking signal is output to the zoom motor control circuit DR2 to stop zooming drive.

Operation direction (DIR) when the operation amount is other than "0"
When the value is "0", a control signal is output to the motor control circuit DR2 so that the zoom lens group is driven to the wide angle side, and when it is "1", the zoom lens group is driven to the telephoto side. The drive speed (DSP) at this time is determined by the calculation of Expression 1 from the operation amount (STP) and the operation speed (SPD).

DSP = STP × SPD (Formula 1) The drive speed (DSP) calculated by Formula 1 is the zoom motor M
2 does not indicate the actual motor rotation speed (DRP), the drive speed (DSP) to the motor rotation speed (D
RP), but in this embodiment, the PWM control method is used to drive at a constant speed. Therefore, in order to obtain the energization time (TON) and the pause time (TOFF) required for the PWM control, the data table 3 in Table 3 is used. Are provided in the ROM area.

[0043]

[Table 3]

FIG. 6 shows a PWM (frequency modulation) control signal for driving at a constant speed. By outputting the control signal with the duty ratio based on the energization time (TON) and the rest time (TOFF) obtained from the drive speed (DSP), the target motor rotation speed can be obtained. One cycle of pulse is 1ms,
When the maximum drive speed is 8000 rpm, it is continuously energized and 480
It indicates that the control signal is output at a duty of 60% at 0 rpm and 20% at 1600 rpm.

The motor control circuit DR2 is a microcomputer μCOM
When a drive control signal is applied from the zoom motor M2, the zoom motor M2 is rotated in the instructed direction and speed to drive the zoom lens group and adjust the focal length.

In the above, from the left and right neutral positions where the zoom operation ring 12 is not rotated to the direction in which the operation amount is increased, for example, to the telephoto side, further to, or to the wide angle side, and further from, to. Drive control of the zoom lens group when the rotary operation is performed is described. FIG. 7 shows a rotary operation and a motor rotation when the zoom operation ring is slowly operated toward the telephoto side and FIG. 8 is a high speed operation in the same direction. The relationship between the number and the amount of movement of the zoom lens group is shown. In the figure, a solid line a shows the relationship between the rotational operation (angle, speed) and the motor rotation speed (DRP), and the amount of movement of the lens at this time is shown by a chain line e. A broken line b shows the case where the rotation of the zoom operation ring is stopped midway and the position is held, and the amount of movement of the lens is shown by a chain line f. The broken line c and the alternate long and short dash line g show the case where the position is held. As you can see from the figure,
When the zoom operation ring is slowly rotated, it is gradually accelerated according to the operation amount, and when it is rotated at high speed, it is rapidly accelerated according to the operation amount. Although the relationship diagram when the zoom operation ring is rotated at a medium speed is omitted, drive control is performed at a medium acceleration according to the operation amount. That is, the drive speed of the zoom lens group is determined by the operation amount and the operation speed of the operation ring.

On the other hand, when the zoom operation ring 12 has already been rotated clockwise or counterclockwise and the zoom motor M2 is rotationally driven, the operation amount is suppressed from the current position of the zoom operation ring 12 (to the neutral position). The drive control of the zoom lens group when the zoom operation ring is rotated from the telephoto side to the side or from the wide angle side to the side will be described. The purpose of the turning operation in the restraining direction is to reduce the zooming drive speed. In order to reflect this intention in driving the zoom motor, Expression 1 described above is transformed into Expression 2, and the operation amount (STP) and the operation speed (SPD) at this time are modified.
Then, the driving speed (DSP) is calculated by the calculation formula of Formula 2.

DSP = STP × (SPDpls + SPDmin−SPD) (Equation 2) SPDpls: Operation speed when the operation amount is rotated in the increasing direction.

SPDmin: The minimum value of the operating speed. However, if (SPDpls + SPDmin−SPD) ≦ 0, the solution in parentheses is calculated as “1”.

When the zoom operation ring is operated in the direction in which the operation amount is suppressed, it is sufficient to calculate the drive speed (DSP) by adopting the expression 2 as the drive speed calculation expression as described above. The control is all the same as when the zoom operation ring is rotated in the increasing direction. FIG. 9 shows the relationship between the rotational operation, the motor rotation speed, and the movement amount of the zoom lens group when the zoom operation ring is slowly operated to the intermediate position and FIG. 10 is operated at high speed in the same direction. In the figure, a solid line a shows the relationship between the rotational operation (angle, speed) and the motor rotation speed (DRP), and the amount of movement of the lens at this time is shown by a chain line e. The broken line b shows the case where the zoom operation ring is operated from the middle position to the intermediate position direction, and the movement amount of the lens is shown by the alternate long and short dash line f. The broken line c and the alternate long and short dash line g show the case where the operation is performed from the middle position toward the intermediate position. As you can see from the figure,
When the zoom operation ring is slowly rotated, the drive speed is controlled to be gradually decelerated according to the operation amount, and when the zoom operation ring is rotated at high speed, the zoom operation ring is rapidly decelerated according to the operation amount. Although the relationship diagram when the zoom operation ring is rotated at a medium speed is omitted, drive control is performed at a moderate deceleration according to the operation amount. That is, the drive speed of the zoom lens group is determined by the operation amount and the operation speed of the operation ring.

7 to 10 have been described by showing the relationship diagrams when the zoom operation ring is operated from the telephoto side and in the range, the operation rings in the figures are shown when operating from the wide angle side and in the range. Since the position may be replaced with and the telephoto side and the wide-angle side of the lens movement amount scale column may be replaced with each other, a new description will be omitted here.

Next, the operation of the microcomputer μCOM built in the lens barrel L will be described with reference to the flow charts of FIGS. 15, 16, 17 and 18. First, when the power supply VCC is supplied by the control of the camera body, a clock oscillator (not shown) is activated to clear the RAM area and set the input / output terminals in # 40 in FIG. In step # 41, a free-run timer 1 for measuring time (hereinafter referred to as timer 1) is started. The timer 1 continuously counts at a constant cycle, and the count value can be taken out without stopping. Then, in order to receive the instruction data from the camera body and to transmit the lens information to the camera side, the 3-wire serial communication mode in which communication is performed through the terminals SCK, SI, SO is set (# 42), and the communication data is transmitted. At some time, the permission flag is set to execute the communication interrupt process (# 43).

FIG. 18 shows a flow chart of this serial communication interrupt. If there is no lens information counter (ANC) in # 100, the data received from the camera body is set as the instruction data (CMD) in the RAM area (# 103). When it is determined that the instruction data (CMD) is the lens information request in # 104, the information number "12" is set in the lens information counter (ANC) in # 105, and the process proceeds to # 101. In # 101, the first lens information is first set in the serial register (SIO), the lens information counter (ANC) is decremented, and the process returns to the main flow (# 101 to # 102). Here, since the lens information counter (ANC) is "11", in the next communication interrupt, the determination of # 100 proceeds to # 101,
The second lens information is set in the serial register (SIO), the lens information counter ANC is decremented, and the process returns to the main flow (# 101 to # 102). Similarly, # 100 to # 102 are repeated until the lens information counter (ANC) runs out.

If the instruction data (CMD) is not the lens information request in # 104, it is determined in # 106 whether or not the AF mode is set. In the AF mode, the instruction data (CM
If it is determined that D) is the feeding drive request, # 10
At 8, the feed signal is output to the motor control output terminal MD1. If it is determined in # 109 that the instruction data (CMD) is the renormalization drive request, the output terminal M is output in # 110.
The renormalization signal is output to D1. # 108 and # 110
When the focus motor M1 starts driving at, the motor driving flag M1F is set at # 111 and the process returns to the main flow.

If it is not AF mode in # 106, # 112
If the focus motor drive request is received, the process is invalidated. If it is determined in # 112 that the instruction data (CMD) is the focus motor stop request, # 113
Then, a brake signal is output to the M1 motor control output terminal MD1, a stop signal is output after 50 ms has elapsed, the motor driving flag M1F is reset, and the process returns (# 114 to #).
116).

When it is determined in # 117 that the instruction data (CMD) is the standby request, the interrupt of the timer 2 described later is prohibited in # 118, the focus motor M1 and the zoom motor M2 are stopped, and each drive flag is set. M1F, M
2F is reset, the counting operation of timers 1 and 2 is stopped, and then the mode is shifted to the standby mode (# 119 to # 1).
24). During the standby mode, the clock oscillator (not shown) is stopped to reduce the current consumption. When the next communication is started from the camera body side in this state, the clock oscillator is restarted, the counting operation of the timer 1 is restarted at # 125, and the process returns to the main flow.

When it is determined in # 117 that the standby request is not issued, that is, because the request is outside the processing range of the lens microcomputer, the request is invalid and the process returns to the main flow.

Here, returning to FIG. 15 again, the description will be continued.
If the AM terminal input is "High" level at # 44, #
The AF mode flag AFF is set at 48 and the process proceeds to step # 49. If it is at the "LOW" level, the AF mode flag AFF is reset at # 45. At this time, if the driving flag M1F of the focus motor M1 indicates driving, a stop signal is output to the output terminal MD1 to output the focus motor. Of the power supply is stopped (# 46 to # 47). In # 49, the conductive pattern signal output from the encoder ENC is input and the data table 1 (see Table 1) provided in the ROM area is searched from this encoder data to operate the operation member 12 and the operation direction (DIR). The quantity (STP) is determined (# 50). If the operation amount (STP) is "0" in # 51, it means that the zoom operation ring 12 is not rotated, and therefore the process proceeds to # 60. Zoom motor M2 at this point
If is not driving, proceed to # 66. Also, # 6
If it is 0 and the driving flag M2F indicates driving, # 61.
Interrupts the timer 2 by prohibiting, outputs a brake signal to the M2 motor control output terminal MD2, outputs a stop signal after 50 ms, and resets the motor driving flag M2F (# 62 to # 65). Operation amount (STP) in # 66
Is stored in the operation amount (LSTP) last time, the process returns to # 44, and the above processing is repeated until the turning operation is performed.

When it is determined in # 51 that the operation ring has been rotated to any position, the process proceeds to # 52. # 52
The previous operation amount (LSTP) and the current operation amount (STP) are compared with each other. If they match, the operation ring 12 is stopped at any position, so the process returns to step # 44, and the above operation is performed until the turning operation is performed. The process of is repeated.

Next, at # 52, if the previous operation amount (LSTP) and the current operation amount (STP) do not match, the operation amount (S
TP) changes from "0" to "1" and changes from "1" to "2"
It also indicates that each change point is changed from "2" to "3". As the time when this change point is detected, the count value of the timer 1 is stored at the change point time (T1) (# 53). In # 54, the previous manipulated variable (LSTP) is "
If the rotation is from other than 0 ", the previous change point time T2 is subtracted from the change point time (T1) in # 57 to obtain the time (T3) between the change points, and then the change point time (T1). ) Is stored at the last change point time (T2) .At # 59, the data table 2 (see Table 2) provided in the ROM area is searched from the time (T3) between the change points, and the operation member 12 of the operation member 12 is searched. You can know the operation speed.

On the other hand, if the previous operation amount (LSTP) and the current operation amount (STP) match in # 52, the current time T
1 was stored at the previous time T2, and the operation speed (SPD) was set to "
1 "is stored (# 55 to # 56) and the process proceeds to # 67 in FIG. 16. The meaning of these steps # 54 to # 56 is that the zoom operation ring 12 is slightly rotated from the intermediate position to the telephoto side or the wide angle side. At the time of moving to the side, the operation direction (DIR) and the operation amount (STP) of the zoom operation ring 12 can be known by the method described above, but the time between the change points of the operation amount cannot be measured, Therefore, the operation speed (SPD) is set to "1" by assuming that the rotation speed of the operation ring has not increased so much at the initial rotation of the zoom operation ring. By setting in this way, it is possible to prevent the zoom motor M2 from rapidly rotating at high speed from the start of rotation.

The microcomputer μCOM knows the operation direction (DIR) of the zoom operation ring 12, the operation amount (STP), and the operation speed (SPD). In # 67, the previous operation amount (LSTP) is compared with the current operation amount (STP), and if the operation amount of the operation ring is increased,
The drive speed (DSP) at this time is determined by the calculation of Expression 1 from the operation amount (STP) and the operation speed (SPD) (#
69).

If the operation amount of the operation ring is operated in a direction in which the operation amount is suppressed (direction toward the neutral position), the drive speed (DSP) at this time is calculated from the operation amount (STP) and the operation speed (SPD). Determined by the operation of Equation 2 (# 6
8). The purpose of the turning operation in the restraining direction is to reduce the zooming drive speed. In order to reflect this intention in the drive of the zoom motor, Expression 1 described above is modified into Expression 2.

Driving speed calculated by equations 1 and 2 (DSP)
Does not indicate the actual motor speed (DRP) of the zoom motor M2. In this embodiment, the PWM control method is used to drive at a constant speed, so the data table 3 (see Table 3) provided in the ROM area from the drive speed (DSP).
By searching for the energization time (T
ON) and pause time (TOFF) are obtained, and a control signal is output at this duty ratio, so that the target motor speed can be obtained.

At # 71, the manipulated variable (STP) is stored in the previous manipulated variable (LSTP) to prepare for the next change point comparison.
If the operation direction (DIR) indicates the telephoto side in # 72,
The telephoto side drive signal is output to the M2 motor control output terminal MD2 (# 73), and if the wide angle side is indicated, the wide angle side drive signal is output to the M2 motor control output terminal MD2 (# 74),
M2 motor driving flag M2F and motor energizing flag O
Set NF (# 75- # 76). If the pause time (TOFF) is "0" in # 77, continuous energization is indicated. Therefore, the processing related to PWM control is skipped and the process returns to # 44.
The above process is repeated. If the energization time (TON) is available, the PWM speed control timer 2 is energized (TON).
Is stored, the counting operation is started, and the interrupt of the timer 2 is enabled (# 78 to # 80). And it returns to # 44 and repeats the above-mentioned processing.

FIG. 17 shows a flowchart of the timer 2 interrupt for executing the PWM speed control. # 85 with timer 2
Stop counting operation. If the M2 motor energization flag ONF indicates energization at # 86, the process proceeds to # 93, where M
2 Stop signal is output to the motor control output terminal MD2, and M2
The motor ON flag ONF is reset, the timer 2 stores the pause time (TOFF), then the counting operation is started, and the process returns to the main flow (# 93 to # 9).
6). If the M2 motor energization flag ONF is not energized in # 86 and the operation direction (DIR) indicates the telephoto side in # 87, the telephoto side drive signal is output to the M2 motor control output terminal MD2 (# 88). ), M indicates the wide-angle side
The wide-angle side drive signal is output to the 2-motor control output terminal MD2 (# 89), the M2 motor energization flag ONF is set, the energization time (TON) is stored in the timer 2 to start the counting operation, and the main flow is executed. Return (# 9
0- # 92).

In the above-described example, when the zoom operation ring is operated in the direction in which the operation amount is suppressed, the zoom is performed by calculating the drive speed (DSP) by using the equation 2 as the drive speed calculation formula. The drive control is performed such that when the operation ring is slowly rotated, the speed is gradually reduced according to the operation amount, and when the operation ring is rotated at high speed, the speed is rapidly reduced according to the operation amount. However, in addition to such deceleration control, if it is desired to perform drive control so as to rapidly decelerate in any case, it is possible to adopt Equation 3 in which the portion related to the operation speed is deleted from Equation 2.

DSP = STP (Equation 3) When Equation 3 is viewed independently, it is confused with the conventional method because the drive speed (DSP) is determined only by the manipulated variable (STP). However, since the possible value of the manipulated variable (STP) is in the range of "2" to "0", the maximum value of the drive speed (DSP) is also "2", so the motor operating speed is rapidly reduced to 2400 rpm or less. You have control.

In this embodiment, the code plate pattern of the encoder ENC interlocking with the zoom operation ring 12 is divided into left and right parts, and the operation amount (STP) and the operation speed (SPD) are detected from the positional relationship. However, the number of divisions is not limited to this, and the present invention can be implemented if the number of divisions is at least two. Further, the pattern is divided into a large number, or a variable resistor and a brush are provided instead of the code plate, and the manipulated variable (STP) and the manipulated speed (SPD) are detected from the voltage value output from the resistor. Good.

Further, if the number of divisions is increased, the number of variable operation amounts and operation speeds detected increases, and the drive speed (DSP) calculated from this is also divided into a large number. Therefore, a large number of ROM areas must be provided with the data table 3 of Table 3 for converting the drive speed (DSP) into the energization time (TON) and the quiescent time (TOFF) of PWM control. here,
If the energization time (TON) and the dwell time (TOFF) are obtained by calculation from the drive speed (DSP) as in the equation 4, the data table 3 need not be provided in the ROM area.

TON = (DSP + 1) × 100 (Equation 4) TOFF = 1000-TON If the operation of Equation 4 is performed, the same value as the data table 3 of Table 3 can be obtained for the motor rotation speed. By the way, the rotation speed (DRP) and energization time (TO
N) and the dwell time (TOFF), the same value can be obtained by Equation 4
Is an example and is not limited to this value.

In this embodiment, the PWM (frequency modulation) control signal has been described as a method of outputting the constant speed drive control signal to the motor control circuit DR2 according to the motor rotation speed (DRP). There are various control methods for high-speed driving, and it is not necessary to limit to PWM control.

The above description applies the electric drive device of the present invention to zooming, and the focus is adjusted by manually operating the manual focus ring 10. Further, if the present invention is applied to this as well, an encoder that interlocks with the focus ring 10 is provided, detection and control are incorporated in the microcomputer μCOM, and a drive control signal is output to the motor control circuit DR1. When M is rotated clockwise, the focus position can be adjusted by the motor M1 to the payout side, and when it is rotated counterclockwise, the focus position can be adjusted to the payout side.

Further, the zoom operation ring 12 is arranged on the outer periphery of the lens barrel L and has a structure capable of rotating in both left and right directions with the neutral position interposed therebetween, but such arrangement and structure can be variously modified. For example, FIG. 11 shows a structure in which a zoom operation ring 30 is arranged on the back surface of the right shoulder of the camera body so that the right thumb can be used to perform zoom operations, and the zoom operation ring 30 can be rotated in both left and right directions with the neutral position sandwiched as indicated by the arrow. As shown in FIG. 12, the operation direction, the operation amount, and the operation speed are detected by the outputs of the brush 31 and the code plate 32 which are interlocked with the operation ring 30. FIG. 13 shows a structure in which the zoom operation switch 33 is arranged on the grip portion of the camera body and can be pushed down in both the left and right directions with the neutral position sandwiched as shown by the arrow in FIG. , 35 to detect the operation direction, the operation amount, and the operation speed. Further, the operation switch 33 may be divided into left and right parts so that the switch contact pieces 34 and 35 can be operated independently. However, in this case, since there is a possibility that the right and left are operated simultaneously, it is necessary to consider driving control by the detection output of the switch contact piece on the side where the operation direction is previously detected.

[0075]

According to the present invention, as described above, the drive speed is determined based on the operation amount and the operation speed of the operation member,
Since the lens group is driven and controlled, if the zoom operation ring is slowly turned, it will gradually accelerate according to the operation amount,
By rotating at a high speed, it is possible to rapidly accelerate according to the operation amount, and the effect of allowing the photographer to feel the sense of incongruity by reflecting the intention of the photographer by approaching the feeling of manual operation.

Further, the control means controls the maximum drive speed as the operation speed of the operating member is suppressed to a lower value, and the control means operates so that the speed change per unit operation amount becomes slower. Even if it is set narrow, the intended drive speed can be obtained without a delicate turning operation, and the operability is improved without impairing the high speed and low speed stability which are advantages of the electric drive.

When the operation amount of the operating member is operated in the increasing direction, the control means performs a calculation in which the operation amount and the operating speed are both proportional to the drive speed. There is an effect that the change of the operation amount and the operation speed due to the rotation can be drive-controlled with a smooth change of the drive speed.

Further, when the operation amount of the operation member is operated in the restraining direction, the control means performs a calculation in which the operation amount is in proportion to the drive speed and the operation speed is in inverse proportion. Therefore, the driving means can be controlled to be decelerated while the driving amount is smoothly changed by the change of the operation amount and the operation speed due to the rotation of the operation member. In this way, when the zoom operation ring is slowly rotated, the drive is controlled to gradually decelerate according to the operation amount, and when the zoom operation ring is rotated at high speed, the drive control is performed so as to rapidly decrease according to the operation amount. There is an effect that the intention of the person is reflected.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a configuration diagram showing an external configuration of an electrically driven zoom lens barrel as one embodiment of the present invention.

FIG. 3 is a block circuit diagram of a zoom lens barrel.

4 is a cross-sectional view of the zoom operation ring shown in FIG.

FIG. 5 is a development view of an encoder that interlocks with a zoom operation ring.

FIG. 6 is a timing chart of a PWM control signal for driving at a constant speed.

FIG. 7 is a relationship diagram showing an operation when the operation amount of the operation ring is rotated in an increasing direction.

FIG. 8 is a relationship diagram showing an operation when the operation amount of the operation ring is rotated in an increasing direction.

FIG. 9 is a relationship diagram showing an operation when the operation amount of the operation ring is rotated in the suppression direction.

FIG. 10 is a relationship diagram showing an operation when the operation amount of the operation ring is rotated in the suppression direction.

FIG. 11 is a perspective view showing a modified example of the operation ring.

FIG. 12 is an exploded perspective view showing a main part of FIG.

FIG. 13 is a perspective view showing a modified example of the operation ring.

14 is a cross-sectional view showing the main parts of FIG.

FIG. 15 is a flow chart showing the operation of a microcomputer.

FIG. 16 is a flowchart showing the operation of the microcomputer.

FIG. 17 is a flowchart showing the operation of the microcomputer.

FIG. 18 is a flowchart showing the operation of the microcomputer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Driving means 2 Operation member 3 1st detection means 4 2nd detection means 5 3rd detection means 6 Control means

Claims (3)

[Claims] 1. A drive means for electrically driving a lens group, an operation member operable in both directions with a neutral position as a boundary, a first detection means for detecting an operation direction of the operation member, and an operation amount of the operation member. Second detecting means, third detecting means for detecting the operating speed of the operating member, and the first detecting means to select the driving direction of the lens group, and output from the second and third detecting means. An electric drive apparatus comprising: a control unit that determines a drive speed of a lens group based on an operation amount and an operation speed of an operation member to be operated and electrically drives the lens group. 2. The control means, when the operation amount of the operation member is operated in an increasing direction, performs a calculation in which both the operation amount and the operation speed are in proportion to the drive speed, and accelerates and drives the lens group. The electric drive device according to claim 1, wherein: 3. When the operation amount of the operation member is operated in the restraining direction, the control means performs a calculation in which the operation amount has a proportional relationship with the drive speed and the operation speed has an inverse proportional relationship,
The electric drive device according to claim 1, wherein the lens group is driven to decelerate.