JPH02139511A - Automatic focus adjusting device - Google Patents

Abstract

PURPOSE:To make a photographic lens reach a focusing position in a short time by detecting an overshoot quantity by a specific counter after a brakes operates, and reversing the motor by the counted value. CONSTITUTION:When a distance ring 9 rotates, pulses corresponding to the angle of the rotation are generated by an ADR switch 40 and counted by and ADR counter in a CPU. Here, the brake which is driven by the specific number of pulses by a focus detecting means operates. Then when the lens position exceeds a specific position, the ADR counter counts the overshoot quantity and the driving motor is reversed by the counted number of the pulses. Therefore, the photographic lens is moved back immediately by the overrun quantity, so the focusing is performed in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an automatic focus adjustment device, specifically a camera, etc., in which a photographic lens driving motor is driven based on the output of a focus detection means to move the photographic lens toward a focusing position. This invention relates to an automatic focus adjustment device that performs focus adjustment.

In this type of conventional automatic focusing device, a motor drives the photographing lens at high speed in order to perform a focusing operation at a reasonably high speed. Therefore, even if you apply the brakes at the target position, the brakes will pass the target position and go over the target position again.
An operation is performed in which the drive is performed again after a distance of llll. In addition, the 4pj distance means integrates the photocurrent of the light receiving element and performs complicated calculations based on the integrated value, which requires a considerable amount of time. Therefore, it takes a considerable amount of time for the photographing lens to reach the in-focus position. There was a problem that it took a while.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic focus adjustment device that eliminates the above-mentioned conventional problems and allows a photographic lens to reach a focusing position in a short time.

Hereinafter, the present invention will be explained based on illustrated embodiments.

1 to 4 are a perspective view, a rear view, a side view, and a schematic cross-sectional view of a lens barrel having an automatic focus adjustment device showing one embodiment of the present invention.

1 to 4, a zoom ring 2 is rotatably provided on a fixed frame 1 of a lens barrel, and the rotation of the zoom ring 2 causes a pin 4.5 to engage with a cam groove of a cam barrel 3. It moves in the direction along the optical axis O. The bottle 4 is installed in a cylindrical body 7 that is helicoidally screwed together with the front lens frame 6, and the bottle 5 is installed in the rear group lens frame 8. Therefore, when the zoom ring 2 is rotated, the front group lens frame 6 and the rear group lens frame 8 move along the optical axis 0 according to the shape of the cam groove so that the focal length changes from wide angle to telephoto. Front group lens frame 6
A distance ring 9 is screwed together with a helicoid screw, so that when the distance ring 9 is rotated, the front group lens frame 6 rotates and moves along the optical axis 0. At this time, fixed frame 1
The distance is displayed in an index window 18 provided in the outer cylinder 1a according to the rotation of the distance ring 9. An aperture ring 10 is provided near the rear end of the fixed frame 1, and rotation of the aperture ring 10 causes an aperture stage setting lever 11 (see Figure 2) to rotate, thereby determining the number of aperture stages. . The aperture blades 12 provided in the rear group lens frame 8 are stopped down by an aperture lever 13, which is controlled by the camera.

A case 14 is provided integrally with the outer tube 1a of the fixed frame 1 at the lower part of the main body of the lens barrel. A mode selector switch 15 is provided on one outer surface of the case 14, and switching between P and F is possible by switching the switch 15.
, (power focus), OFF (power off),
SIN, AF (single autofocus), SEQ
, AF (Sea Fence Auto Focus) and BAT
.

Each mode of C (battery check) can be selected. An operation plate 17 having two upper and lower operation buttons 16A and 16B is provided between the case 14 and the outer tube 1a of the fixed frame 1 on the same outer surface, that is, at a middle height position that is easy to operate with this lens barrel. It is being Operation button 16A
, 16B are for P, F, UP which, when the mode selector switch 15 is in the P, F position, presses these buttons 16A, 16B to rotate the distance ring 9 toward the short distance side by the motor, respectively. , P to rotate to the far side
, F, and DN, and when the mode selector switch 15 is in the SIN, AF, SEQ, and AP positions, these buttons 16A.

16B is an operation button for AF 5TAT (focus start) which rotates the distance ring 9 to the focusing position, regardless of which button is pressed, and the operation buttons are shared between the PF mode and the AF mode. It has a simple operability and appearance.

An in-focus trigger socket 19 is provided on the opposite side surface of the case 14. One trigger socket is connected to the photographing lens 2 of the front group lens frame 6 by rotating the distance ring 9.
This socket 19 is used to take out this focusing signal to the outside when the lens reaches the in-focus position.A motor drive device or winder is connected to the socket 19 by a cord, and the focus signal is used to output the focusing signal to the outside. etc. can be triggered. Further, a sound switch 21 is provided on the back of the case 14, and when the switch 21 is turned upward, the switch is turned on and various warnings are emitted by sound, and the warning sound is muted. If you wish to do so, switch to the lower silent side and turn off the switch. A signal bin 22 is provided on the mounting surface of the fixed frame 1 of the lens barrel for identifying the camera and transmitting a release signal when the camera is attached to a dedicated camera.

As shown in FIG. 4, a flexible substrate 26 having a motor 23, IC chips 24, 25, etc. is housed inside the case 14.

The motor 23 is meshed and connected to the outer periphery of the distance ring 9 through a gear train 27, and the rotation of the motor 23 rotates the distance ring 9, thereby driving the photographing lens 20. At a predetermined position above the rear part of the case 14, a focus sensor 28 made of a CCD is mounted on the flexible substrate 26. Light that passes through the photographing lens 20, is reflected by a half mirror 30 of a prism 29, passes through the prism 29, and is further reflected by a reflection mirror 31 is guided to the light receiving surface of the focus sensor 28. The light receiving surface of this sensor 28 is located at a position conjugate with the film surface. Therefore, the Δ-1 distance is performed by the TTL incident light.

Four brush-shaped contact pieces 32 to 35 are attached to the fixed frame 1 surrounded by the case 14, and the contact pieces are wired to the board 26. The contact pieces 32 to 35 are the fifth
As shown in the figure, it comes into sliding contact with the rear outer periphery of the distance ring 9. A conductive pattern 37 is formed on the rear outer periphery of the distance ring 9.

The conductive pattern 37 has two strips 37 as shown in the figure.
a, 37b, and a comb tooth portion 37c continuous to the band portion 37b. Contact pieces 32 to 35 are contact pieces for zone 1, zone 2, common, and ADR (address), respectively. Therefore, contact pieces 32 and 34, and 33 and 34 are contact pieces for zone 1, zone 2, common, and ADR (address), respectively. A second zone switch 38,39 is formed, and the contacts 35 and 34 form an ADR switch 40. Contact piece 32
34 indicates that when the distance ring 9 is at a rotational position corresponding to the intermediate distance zone, each of the contact pieces 32 to 35 is connected to the strip portion 3 at a position PO of the conductive pattern 37, for example.
7a, insulating section 9a, and band-shaped section 37b.

It faces the comb tooth portion 37c. Since the contact pieces 34 and 35 always come into contact with the strip portion 37b and the comb tooth portion 37c when the distance ring 9 is rotated, the ADR switch 40 is turned on and off for each IADR when the distance ring 9 is rotated. The state of contact between the contact pieces 32 and 33 with the conductive pattern 37 differs depending on the rotational position of the distance ring 9, and when the distance ring 9 reaches the closest position, the contact pieces 32 and 3
3 is a position P on the conductive pattern 37 common to the contact piece 34.
n, so at the same position zone switch 3839
are both on, and at the above position PO, the first zone switch 38 is on and the second zone switch 39 is off. Further, when the distance ring 9 is rotated to a position immediately before reaching the infinite position, the contact pieces 32 to 35 correspond to the position Pr, and the strip portion 37a is formed at the same position. do not have.

Therefore, both zone switches 38 and 39 are off at the same position. Further, when the distance ring 9 is rotated to the infinite position, the contact pieces 32 to 35 correspond to the position Pω, and although the strip portion 37a does not exist at the same position, the insulating portion 9a
Since the conductive part 37d integrated with the strip part 37b is formed at the extended position, the first zone switch 38
is off and the second three zone switches are on. Eventually, the zone switches 38 and 39 cause the distance ring 9 to
The rotational position of the zone switch 38 and 39 can be gray-coded, and the ON of the zone switches 38 and 39 can be set to 0. If off is 1, then
The zone signal is (00) for the zone at the closest position Pn, and (01) for the zone at the position Po.

Since the coded signals are divided into four coded signals (11) in the zone of the far position Pr and (10) in the zone of the infinite position P-, the rotational position state of the distance ring 9 can be determined by reading these signals. It is determined. In this lens barrel, when the zone switch is in the zone of the above position Po, the rotation of the motor is maintained at high speed, and when the zone switch reaches the zone of the above position Pr from the same state, the motor is made to rotate at a low speed, and when the zone switch is in the zone of the above position Pr, the motor is kept at a high speed. When this happens, the motor stops rotating. Also,
The rotation of the motor also stops when the zone at the position Po reaches the zone at the position Pn. By slowing the rotation of the motor in the far position Pr zone, the distance ring 9 will smoothly stop in the infinitely far position Poo zone, and will stop immediately before colliding with the stopper. Note that, similarly to the far position Pf', the motor may be rotated at a low speed even before reaching the zone from the position Po to the close position Pn, but the frequency of use is particularly high at the infinite position POO.
The effect is great.

Further, a brush-shaped contact piece 41 is provided on the outer periphery of the zoom ring 2 in a portion surrounded by the case 14.
As shown in an enlarged view in FIG. 6, a zoom information detector 42 is configured together with a conductive pattern 45 formed on a zoom substrate 44 that is integrated with the case 14. The conductive pattern 45 includes an integrated conductive part 45a that contacts the contact piece 41 and the zoom ring 2 regardless of the rotation angle, and a conductive part 45b that is divided into multiple parts in the moving direction so that the position can be determined according to the rotation angle. Each of the conductive parts 45b is composed of a resistive part 45c connected to each other by a resistor, and each of the conductive parts 45b is connected to the contact piece 45c.
The pattern is slanted so that either side can always come into contact with 1. This zoom information detector 42 is connected to the zoom ring 2
This is to ensure that distance adjustment is performed normally no matter what rotational position the zoom information detector 42 has.

The aperture ring 46 integrated with the aperture lever 13 has a shape shown in FIG.
^) As shown in (13), a substrate 48 having a conductive pattern 47 is integrally fixed, and when the aperture lever 13 is not narrowed down, the substrate 48 is fixed as shown in FIG. Among the extending fixed contact pieces 49 and 50, at least one contact piece 49 comes into contact with the insulating part of the board 48 to create a non-conducting state between the contact pieces 49 and 50, but even if the aperture lever 13 is slightly When the aperture ring 46 rotates in the direction of the arrow as shown in FIG. 7(B), the substrate 4
8 also moves together with the ring 46, so the contact piece 49.5
0 both come into contact with the conductive pattern 47 and become electrically conductive.

That is, the contact pieces 49 and 50 constitute an aperture interlocking switch 51 for detecting the start of aperture reduction, and the switch 5
1, it is possible to detect whether the lens barrel is attached to the camera before photographing or during photographing.

The aperture interlocking switch 51 is used to prevent the photographic lens from being driven during release, and to prevent the necessary light from entering the focus sensor 28 when the aperture is closed, which can cause malfunctions. This is to do so.

In addition to the above-mentioned configuration, the lens barrel is configured to have various functions, which will be described in more detail with reference to the drawings from FIG. 8 onwards.

FIG. 8 is a circuit diagram of an electric circuit constructed within the case 14 of the lens barrel. This electric circuit includes a power supply circuit 60, a CPU (central processing unit) 61, and a
An oscillation circuit 62 externally attached to the PU 61, an A/D converter 63 connected to the CPU 6 via a pass line, the focus sensor 28 that sends a CCD output to the A/D converter 63, and an A/D converter. The zoom information 1 detector 42 connected to the input terminal I2 of the A/D converter 63 and the input terminal 1. A battery voltage detection circuit 64 connected to the battery voltage detection circuit 64, a motor drive circuit 65 connected to the output terminals 07 to 0□0 of the CPU 61, and an input terminal I of the CPU 61
The switch circuit 66 connected to t~■8 and the CPU 61
A warning display circuit 67 connected to the output terminals 0□ to 03 of the CPU 1lil, a power holding circuit 68 connected to the output terminal 04 of the CPU 1lil, and an in-focus trigger circuit 69 connected to the (I 10) terminal of the CPU 61. It mainly consists of a sound generation circuit 70 connected to the output terminal 05 of the CPU 61 and an ADH switch circuit 71 connected to the input terminal 110 of the CPU 61.

The power supply circuit 60 includes a power switch 74, a battery 75, transistors 76 to 82, and a phototransistor 83.
, DC/DC converter 84, diode 85.86,
87 to 8 capacitors, 90 choke coils, 92 resistors
-99 and switches 100-102. The terminal 103 is for guiding a release signal from the camera body, and corresponds to the signal pin 22 described above. terminal 1
04 is a terminal for supplying a power supply voltage of -5V to the CPU 61 and the circuit connected to this CPU 61; terminal 10;
5 is a terminal for supplying a power supply voltage of -3 to -4.5V to the motor drive circuit 65, battery voltage detection circuit 64, etc.

The operation of this power supply circuit 60 is as shown in the flowchart shown in FIG. The power switch 74 is linked to the mode changeover switch 15 shown in FIG. 1, and when the changeover switch 15 is changed to a mode position other than OFF, the power switch 74 is turned on. After this, transistor 78. When any of the switches 100 to 102 is turned on, the transistors 79 and 80 are also turned on, the DC/DC converter 84 is activated, and a power supply voltage is generated at the terminals 104 and 105. The transistor 78 is turned on when a release signal is introduced from the camera to the terminal 103. The switch 100 switches the mode changeover switch 15 to BAT,
The switches 101 and 102, which are turned on when set to the C (battery check) mode position, are switches that operate in conjunction with the operation buttons 16A and 16B shown in FIG. 1, respectively. Note that when the release signal from the camera is guided to the terminal 103, the transistor 7
6 turns on, the transistor 78 turns on. At this time, transistors 81 and 82 turn on, and a REL (release) signal is introduced to the input terminal 3 of the CPU 61.

When the power supply voltage is supplied to the CPU 61 from the power supply circuit 60, the CPU 61 is reset and then starts a program. At this time, in order to prevent the CPU 61 from malfunctioning due to noise when the power is turned on, the power holding circuit 68 is activated after a certain wait time. In the power supply holding circuit 68, when an "L" signal is issued from the output terminal 04 of the CPU 61 through the resistor 106, the transistor 107 is turned on, and the LED (light emitting diode) 109 of the photocoupler 108 emits light. LED
When 109 emits light, the phototransistor 83 of the power supply circuit 60 receives this light and turns on the phototransistor 83, which turns on the transistor 77. When transistor 77 is turned on, the initially turned on transistor 78 . Even when the switches 100 to 102 are turned off, the transistors 79 and 80 are kept on, and power continues to be supplied thereafter. Note that the power supply holding circuit 6
Reference numeral 116 in 8 is a resistance.

The oscillation circuit 62 includes a crystal oscillator 110° oscillation capacitors 111, 11.2. It consists of a power-on reset capacitor 113. Further, the A/D converter 63 is connected between the CPU 61 and the I10 terminal by a pass line, and is operated by the system clock from the CPU 61. This A/D converter 63
leads the signal corresponding to the focal length information from the zoom information detector 42 and the battery monitor voltage VBAT from the battery voltage detection circuit 64 to the input terminal 11°I2 and A/D converts them. The battery voltage detection circuit 64 uses variable resistors 114 and 115 to set the voltage vBAT according to the battery 75. The A/D converter 63 A/D converts the output of the focus sensor 28, and sends a CCD drive clock and a COD control signal to the focus sensor 28 to drive and control the sensor 28.

The motor drive circuit 65 is connected to the motor 23. transistor 1
17-124, diode 125.126, resistor 127
138, and is driven and controlled by the output of the CPU 61. Describing the operation of this motor drive circuit 65, when the output terminal 07.09 of the CPU 61 becomes "below level", the transistors 117 and 124 are turned on, so at this time the transistors 119 and 122 are turned on and the motor 23 is When the output terminal 08"10 becomes "L" level, transistors 118, 123 are turned on, transistors 120, 121 are turned on, and the motor 23 is turned on as described above. The distance ring 9 is rotated toward the long distance by rotating in the opposite direction. Further, when the output terminals O8 and O9 both go to "L" level while the motor 23 is rotating, the transistors 118 and 124 are turned on, which turns on the transistors 120 and 122, thereby applying a brake to the remoter 23. That is, at this time, a back electromotive force is applied between both terminals of the motor 23 by the transistor 120 and the diode 126, or the transistor 122 and the diode 125, and the motor 23 suddenly comes to a halt.

The switch circuit 66 is connected to the input terminal 11 of the CPU 61.
, 12, 14 to I8, respectively.
It consists of groups 1 to 147. Switches 141 and 142 are mode switches for determining each mode state other than OFF of the mode 9 changeover switch 15 shown in FIG.

P, F, , SIN by turning on and off 142
, AF, SEQ, AF, BAT, and C mode states are determined. Switches 143 and 144 are switches that are closed by operating buttons 16A and 16B shown in FIG. 1, respectively. Further, the switches 145146 are respectively connected to the first and second switches shown in FIG. Second zone switch 38.3
It is 9. Furthermore, the switch 147 is shown in FIG. 7(A) above.
, is the aperture interlocking switch 51 shown in (B).

The warning display circuit 67 includes transistors 151 to 153;
It consists of LEDs 154-156 and resistors 157-162. For each transistor 151 to 153, the output terminals 01, 02, 03 of the CPU 61 are "L".

Each LE turns on when the level is reached, and at this time each LE
D154 to D156 enter the display state by emitting light. 1st
The LED 154 displays a warning about the movement of the subject, and if the subject is moving so fast that the focusing operation cannot follow the movement of the subject, the LED 154 lights up to warn the user. Further, the second LED 155 is used to display a warning about the short distance limit, and when the photographic lens approaches the subject too much and the distance Il&:Bw1 becomes impossible, this LED 155 emits light at the extreme position. Third
LEDI 56 is for low contrast warning display, and when the contrast of the subject is extremely low and it becomes difficult to adjust the distance, this LED
D156 emits light. In addition, the first and second LEDs 1
When 54 and 155 are turned on at the same time, a low light warning is issued. That is, the background is very dark and the focus sensor 28
If a sufficient amount of light is not incident on the lens, accurate focusing will not be possible. 2nd LED
154 and 155 both emit light to warn the user. In this way, the warning display circuit 67
48 warnings are displayed from 54 to 156. These warning displays are internal displays that the user can see when looking through the camera's viewfinder.

The in-focus trigger circuit 69 includes a changeover switch 164, a transistor 165. Resistors 166 to 168 and contact 19a of in-focus trigger socket 19 shown in FIG. 3 above,
19b. In-focus trigger socket 19
Since the in-focus trigger cord 170 is connected to the contacts 19a and 19b by inserting it into one of the sockets, the motor trigger circuit 171 of the winder is connected through the trigger cord 170. The changeover switch 164 is switched to the contact 164a side when the trigger cord 170 is not inserted into the socket 19.
When the trigger code 170 is inserted, the trigger code 17
The changeover switch 164 is switched to the contact 164b side by the tip of the plug 0, and the transistor 165 is connected to the terminal (I
lo). The switching state of this changeover switch 164 is detected by the CPU 61.

Therefore, when the winder is connected by the trigger code 170, the transistor 165 is turned on in the focused state, and at this time, the trigger code 17
When the LED 173 of the 0 photocapsule 172 emits light, the phototransistor 174 is turned on, and then the transistors 175 and 176 are turned on, the winder's motor trigger circuit 171 is activated, and the winder releases the shutter and winds the winder. Note that the reference numeral 177 in the trigger code 170 is a resistor.

The above-mentioned oscillation circuit 70 includes a transistor 180. PCV (piezo ceramic vibrator) 181 and resistor 182,
It consists of 183. Transistor 180 is CPU6
When an "L" level signal is led from the output terminal 05 of the PCV 1, the PCV] 81 is activated and generates a warning sound. This warning sound can also be prevented from sounding by using the sound switch 21 shown in FIG. 2 above. In this case, the sound switch 21 connected to the input terminal 19 of the CPU 61 will be opened.

The ADR switch circuit 71 is the AD switch circuit 71 shown in FIG.
It consists of an R switch 40, a resistor 185 to 187°, a chattering prevention capacitor 188, and a waveform shaping comparator 189, and the output terminal of the comparator 189 is C
It is connected to the input terminal 110 of the PU 61. The input terminal '10 is the ADR counter 1 configured in the CPU 61.
It has 90 input terminals. Therefore, when the distance ring 9 rotates, the ADR switch 40 is
When each ADH is turned on and off, the ADR counter 190 counts the number of pulses (ADH) corresponding to the rotation angle of the distance ring 9, and the amount of rotation of the distance ring 9 is counted by the counter 1.
90.

As described above, the main electric circuit inside the case 14 of the lens barrel is configured.

Next, a more detailed operation of the electric circuit of the lens barrel will be explained in accordance with a program installed in the CPU 61, with reference to the flowcharts shown in FIG. 10 and subsequent figures. First, when the mode selector switch 15 on the lens barrel is set to a mode other than OFF, the power switch 74 is turned on as described above, and at this time the CPU 61 is powered on as shown in FIG. The circuit goes into reset state,
As a result, the CPU 61 is initialized and all flags are cleared. After waiting to prevent malfunction until the power supply stabilizes, the power supply holding state is entered and the LED 109 of the power supply holding circuit 68 is turned on.

Thereafter, a system clock is supplied from the output terminal 06 of the CPU 61 to the input terminal I4 of the A/D converter 63. Thereafter, it is determined which mode has been selected by the mode changeover switch 15. By turning on and off the mode switches 141 and 142 of the switch circuit 66, the BAT and C modes are (00), the P and F modes are (01), and the S IN and AF modes are (10).
, SEQ, AF mode corresponds to code (11), so BAT.

If in C mode, battery check BCHKl, P
, F, mode, power focus operation POWE
If the mode is R, SIN, or AF mode, the routine goes to AFSINI or SEQ for single AF1 operation, and if it is AF mode, the routine goes to AFS-EQ for sequence AF operation. below,
The operation will be explained for each mode.

(1) When in BAT, C (battery check) mode.

When in the BAT or C mode, the CPU 61 first performs the INBATT operation, as shown in FIG. That is, the monitor voltage VBA from the battery voltage detection circuit 64
The A/D converted result of T is taken into the CPU 61. After this, the above voltage ■ and a certain constant voltage V,
, VL (V, ,>VL)BAT is compared, and if the voltage VBAT is higher than the voltage II that can be driven sufficiently, the sound generation circuit 70 emits a continuous sound, and the voltage V is lower than the voltage VH mentioned above. The minimum voltage V is required to drive the AT lower; if it is higher, it will emit an intermittent sound. By listening to the sound generation state at this time, the user can know whether the voltage of the battery 75 is sufficient or whether it is time to replace the battery 75. When the monitor voltage VBAT is VBAT less vL, there is a risk of malfunction, so the power is turned off at this time.

This power-off is performed when the level of the output terminal 04 of the CPU 61 becomes H, the power supply holding circuit 68 becomes inactive, and the LED 109 stops emitting light.

(2) When in P, F, (power focus) mode.

When in the P, F mode, as is clear from FIG. 10, the routine goes to the POWER routine shown in FIG. 12, so the battery check BCHK2 operation is performed first. The operation of this battery check BCHK2 is as shown in FIG. 16. After the operation of INBATT, the battery check BCHK2 compares the monitor voltage
If BAT SvL TE13AT +・, the power is turned off as in the above BAT, C mode, and if vBA, r>■, then the voltage ■ and V
Compare VII〉VBAT 13^T
11, that is, if V L < V BAT < V o , set the DUTY flag to 1,
``If I≦VBAT, clear the DUTY flag and return.

After this, returning to FIG. 12, it is determined whether or not the P, F, UP operation buttons 16A, P, F, DN operation buttons I[iB are pressed. First, switch 1
43 (P, F, UP) is on, switch 144 (
P, F, DN) are off, the distance ring 9 rotates in the near direction, so it is determined whether the close range position Pn has been reached as shown in FIG. (referred to as a limit). When the near limit is reached, the limit warning LMTAL shown in Fig. 15 is activated.
M is performed. As shown in the sound generation PCV2 routine of FIG. 34, the limit warning LMTALM activates the sound generation circuit 70 if the sound switch 21 is turned on.
After the PCV 181 emits a warning sound in the oscillation 2 mode, it waits and returns to A1. At this time, a warning display is also performed by emitting light from the LED 155 shown in FIG. 8 above.

If the near limit has not been reached, the pronunciation P shown in Figure 33
When the CVI routine is entered and the sound switch 21 is turned on, the sound generation circuit 70 is activated and the PCV 18 is activated.
1 makes a beep sound in the sound mode of oscillation 1. If the sound switch 21 is off, it returns without producing a sound. After this, the direction flag is cleared and the motor drive MDRI
The routine moves to V1 (see Figure 27), where the motor is driven by IADH over a short distance, and after that, the count number N is set in the ADR counter 190, and then the switch 143 is turned on or off again. A determination is made. If it is off, it returns to AI, and if it is on, after a wait, a count of (N-1) is performed, which is N
It is repeated until it becomes -0. If it becomes N-0, it is again determined whether the limit is near or not. That is,
If the switch 143 is turned off before it reaches N-0, it will return to Al, and even if it reaches N-0, the switch 143 will not turn off.
If continues to be on, the next near limit is determined. After this, if the near limit is reached, the above-mentioned limit warning LMTALM occurs, and if the near limit has not been reached, the motor drive MDRIVI is followed by a wait, and then P and F.

While the UP is being performed, the motor drive MDRI V 1 is operated until reaching the near limit.

Now, to describe the operation of the motor drive MDRIVI, as shown in Fig. 27, the battery check BCHK
2 is performed, it is determined whether the direction flag is 1 (infinite) or 0 (close). If the direction flag is 1, the far direction drive MDI routine (second
(See Figure 8). If the direction flag is 0, AD
It is determined whether the output of the R switch circuit 71 (hereinafter referred to as ADR output) is at H level. If the ADR output is at L level, the motor brake will be applied if it is at the near limit, but if it is not at the near limit, the near direction I will be applied.
After the operation of ADR drive MDSI (see Figure 29), A11
Return to If the ADR output is at H level, at this time,
The above MDSI operation is repeated until the ADH output reaches L level. When the ADR output reaches the L level, the motor brake is applied, and after a wait, the motor returns.

Regarding the near direction IADR drive MDSI, as shown in FIG. 29, first, the motor drive flag is inverted, and it is determined whether the motor drive flag is at H level or not. Assuming that the motor drive flag is currently at H level, for example,
The motor 23 is driven in the near direction, waits, and then turns off and returns. And in TS27 diagram, AD
This MDSI operation is repeated until the H output reaches the L level, so in the second operation, the motor drive flag is set to L level.
level and the motor is braked.

Then, it is determined whether the DUTY flag is 1 or O. If it is 1, then VII>vBAT, so the motor is turned off after 2 waits, and if it is 0, VII≦vBA
Since it is T, the motor is turned off after one wait.

That is, the on/off duty ratio of the motor is changed in accordance with the voltage of the battery 75 to vary the time during which the brake is applied. In the end, MDRI V in Figure 12 above
In operation 1, the motor repeats on and off operations in the near direction in the MDSI to drive for IADR.

In other words, by performing the above-mentioned operations, when the P, F, and UP pushbuttons 16A in FIG. , each time the operation is performed, a sound is generated in the form of oscillation 1.

When the push button 16A is continuously pressed, the distance #l
The ring 9 will rotate continuously. When the near limit is reached, the signal is issued in the form of oscillation 2 to warn the user of the near limit, and at the same time the motor is braked to stop the rotation of the distance M ring 9.

Next, returning to FIG. 12 again, switch 143°144,
That is, when P, F, UP, P, F, and DN are all off, if the REL (release) signal is being led, it returns to A1, and if it is not being led, it is in the power-off state. When switch 143 is off, switch 14
4 is on, the distance ring 9 rotates in the far direction, so the routine moves to the infinite limit check FLCHK1 shown in FIG.

In FLCHKI shown in FIG. 13, a long distance limit (hereinafter referred to as a long limit) is first determined. If the far limit is reached, the above-mentioned limit warning LMTALM is executed, or if the far limit has not been reached, a sound is generated in the mode of oscillation 1 by the operation of the PCVI, and the direction flag is set to the infinite direction (1
).

After this, the program operation of the motor drive MDRIV1 is started. As shown in FIG. 28, the operation of the MDRI V 1 at this time is a program operation of the far open drive MDI, so first it is determined whether or not the ADR output is at the L level. If the ADR output is at H level and reaches the far limit, the brake operation BRKI will be performed.
If the return point has not been reached, the far direction IADR drive MD
After the operation of S2 (see FIG. 30), return to A1°. A
When the DR output is at H level, after the far direction LADR drive MDS2, when the ADH output goes to H level, it is determined whether it is the far limit or not. If not, A
The operation of the MDS2 is performed until the DH output reaches the L level, and the brake operation is performed when the ADR output reaches the L level.

In this way, after the above MDRIV1 operation, the A
A count number N is set in the DR counter 190. After this, if the switch 144 is off, it returns to A1, and if the switch 144 is on, it waits and returns to (N-1).
is counted, and this is repeated until it reaches N-0.

If N-0, as shown in FIG. 14, the far limit is determined, and if it is the far limit, the above LMTALM
If a warning is issued and the far limit has not been reached, as long as the switch 144 is on, the MDRIVI and then wait operations are repeated until the far limit is reached.

Therefore, the pushbuttons 16B of P, F, and DN in FIG.
When operating , the distance ring 9 rotates by a small angle in the long distance direction when operated singly, and generates sound in the manner of oscillation 1 each time it is operated. When the push button 16B is kept pressed, the distance ring 9 will rotate continuously. When the far limit is reached, a sound is generated in the mode of oscillation 2 to warn the user of the far limit, and at the same time, the motor is braked to stop the distance # ring 9.

Now, regarding the far direction IADR drive MDS2 in the far direction open drive MDI, as shown in FIG. A determination is made. When the motor drive flag is at H level, the motor 23 is driven in the far direction, and after waiting, the motor 23 is turned off.

When the motor drive flag is at L level, the motor 23 is braked. At this time, if the DUTY flag is 1, the motor 23 is turned off after two waits, and if it is O, the motor 23 is turned off after one wait. That is, even in the case of this far-open drive, the time during which the brake is applied differs depending on the state of the battery monitor voltage 13AT.

(3) When in SIN, AF (single autofocus) mode.

In the SIN, AF mode, as is clear from FIG. 10, the AFSINI program operation shown in FIG. 17 is performed. In AFSINI, after battery check BCHK2, it is determined whether the REL signal is on or off.
If it is on, the power is turned off after the operation of AFSIN2 shown in FIG. 18, and if the REL signal is off, the AFSTAT pushbuttons 16A, 16B,
If the switches 143, 144 are off, the power is off, and if either the AFSTAT switches 143, 144 are on, the power is turned off after the AFS IN2 operation.

The operation of AFSIN2 is as shown in FIG.
After the operation of FSIN3 (see FIG. 20), it is determined whether the LL (low light) flag is 1 or 0, and if it is low light (=1), the first LED 1 of the W notification display circuit 67 is
54 and the second LED 155 are both turned on and a low light warning is displayed. If it is not low light (-0)
, it is determined whether the AF status flag is 0 or not. If the AF status flag is not 0, that is, if any one of the short distance flag, subject movement flag, and low contrast flag is 1, the PCV2 warning operation is performed and the short distance warning, subject movement warning, and low contrast flag are activated. Contrast 2 notification is performed by firing η and returns.

These warnings are also issued by the warning display circuit 67. If the AF status flag is O, the PCVI sound generation operation is performed and the user is informed that it is normal, and the process returns after the WIND operation.

The operation of WIND is as shown in Figure 19.
or a motor drive device) is connected, an output that turns on the winder is generated.

Now, to describe the operation of AFSIN3(7) in FIG. 18, as shown in FIG. 20, after the RETRY flag is cleared, the AF small loop AF count number is set. Thereafter, after the AF status flag is cleared, a routine AF operation for distance measurement is performed. As is clear from FIG. 31, this AF program operation involves loading the result of A/D conversion of the CCD output from the focus sensor 28 into the CPU 61 (INCCD),
We will convert this into an algorithm and perform a low contrast test. After this, return to Figure 20, and if the contrast is low, subtract 1 from the AF small loop count and return to A5, repeat this process, and when the AF small loop count becomes 0, the low contrast warning display will be displayed. It is done. This warning display is made by the LED 156.

If the contrast is not low, the ADH operation shown in FIG. 32 is performed. As is clear from FIG. 32, this ADR operation involves taking in the A/D conversion result from the zoom information detector 42 into the CPU 61 (INZOOM).
, and calculates how many ADRs the motor 23 (range ring 9) should be driven in consideration of this zoom factor. If the ADR value thus calculated is smaller than a certain maximum value MAX, the ADR value is left unchanged, but if the ADR value>MAX, this ADR value is forcibly set to ADR value - MAX. After this, a comparison is made between the ADR value and the PCALL value. The PCALL value is a threshold for determining whether autofocus is in an extremely accurate distance measurement state. If the amount of movement from the focus plane is Δd, then the PCALL value is the number of pulses required to move this Δd. be. ADR<PCA
If it is LL, low-speed pulse driving of the motor is performed by MDRIV8 shown in FIG. ADR≧PCALL
If so, the RETRY flag is 0 at the time of the first allJ distance calculation, so after the RETRY flag is set at this time, the process goes to A3 shown in Figure 21, where the current ADR value is stored, and the later-described value shown in Figure 24 is stored. The motor is driven at high speed by MDRIV4. Then, subtract 1 from the AF small loop count number, return to A4, and use A4 again based on distance measurement AF.
A DR value is calculated. After this, the RETRY flag is set to 1, so go to 5IN32. Repeating these operations, this time A D
A comparison is made between H11n and the previous ADR value. This time AD
If the R value≧the previous ADR value, it means that the focusing operation of the photographic lens cannot follow the subject movement speed at this time, so the subject movement flag is set and a warning display of the subject movement is performed. This warning display of subject movement is performed by emitting light from an LED 154 in a warning display circuit 67 in FIG.

If the current ADR value is 1 ADR value, the current ADR value is memorized, and the above M
Repeat the operations from DRIV4 onwards.

Note that the determination of the warning display for subject movement is not necessarily limited to comparing the current ADR value and the previous ADR value as described above, but, for example, comparing the previous ADR value X (1/2) and the current ADR value. After comparison, if the current ADR value is not within 5096 of the previous ADR value, the above warning may be displayed.

Now, to describe the motor low-speed pulse drive MDRI V8 in the AFS IN3 routine,
As shown in FIG. 22, after performing battery check BCHK2, it is determined whether the ADR value is 0 or not. If the ADR value is -0, the AF status flag is cleared, and if the ADR value is -0, the AF status flag is cleared. If not, ADR counter 1
Set the above ADR value to 90. After this, if the direction flag is 0 (close direction), the motor 23 is driven in the short distance direction, and if the direction flag is 1 (infinite direction), the FDR is driven.
It moves to the IVI routine and is driven in the far direction. The IADR pulse from the ADR switch 71 is manually subtracted by hardware from the ADR value set in the ADR counter 190 by driving the motor 23. If the direction flag is 0 and the near limit is reached, motor 2
After the brake is applied to 3 and the ADR value becomes -0, the process returns to A7 and the AF status flag is cleared. At this time, if the ADR value is O, the short distance flag of the AF status flags is set, and the LED 155 of the warning display circuit 67 displays a short distance warning.

When the direction flag is 1 and the mode shifts to FDRIVI (far open drive), this FDRIVI is as shown in Fig. 23. If it is at the far limit, the motor is braked, and after a wait, the motor is braked, as shown in Fig. 22 above. Return to A7 inside and A
The F status flag is cleared. If the far limit has not been reached, the motor is driven in the far direction, and after waiting, if the remaining ADR value is 5ADR or more, it returns to A9 in Fig. 22, and is driven further in the far direction, and the remaining 4AD
When reaching R, the motor is braked, and after a wait, A8 is reached. Then, the motor is driven in the far direction until the count ends, and the remaining ADR value is 2ADR, IAD
When R is reached, the brake is applied in the same way each time, and the motor is driven by low-speed pulses. When the ADR value set in the ADR counter 190 finishes counting, the motor brake is activated. After the wait, if the shot has gone beyond the predetermined position, the amount of this shot is set in the ADR counter 190, the direction flag is inverted, and the process shifts to motor drive of II and MDRIV8.

Furthermore, during the operation of MDRIV8, even when the direction flag is O and the motor is driven in the near direction, the process shifts to A6 in FIG. The motor is driven in the near direction until it reaches 4 ADR, and when the remaining 4 ADR is reached, the motor is intermittently braked and decelerated, and stops at the end of the count. At this time, if there is an over amount, the direction flag is similarly inverted and the MDRIV
8 is performed.

Regarding the operation of the motor-driven MDRI V4 shown in FIG. 21, as shown in FIG. The counter 190 is set. The P-minus value is a value calculated by taking into account overshoot. + value. As a result, if the set value of the ADR counter 190 is not 0, the direction flag is determined, and when the direction flag is 0 (closest direction), the motor is driven in the near direction. The motor is driven in the near direction and the ADR counter 19
When the set value of 0 becomes 0, a brake operation BRKI shown in FIG. 26 is performed, and the motor 23 is braked to stop the lens drive. The set value of counter 190 is 0
Even if it does not reach the limit, if it reaches the near limit, the motor will be braked at this time as well. Further, when the direction flag is 1 (infinite direction), the program proceeds to the far direction limit check DLEFTI program operation.

The operation of the far direction limit check DLEFTI is as follows.
As shown in the figure, it is first determined whether the far limit is reached, and if the far limit is reached, the brake BRKI is operated, but if the far limit is not reached, the low speed zone (position P in Fig. 5) is performed. It is determined by the gray-coded signals from the zone switches 38 (145) and 39 (146) whether the motor is in the low speed zone or not. When the speed reaches the low speed zone, the motor 23 is braked by moving to the far-direction drive of the IADH of MDRIVI, and returns to Alo after a wait.Then, the value set in the counter 190 becomes O. Then, the operation of B RK 1 is performed and the rotation of the motor 23 is stopped. Therefore, when the photographing lens is driven in the infinity direction and reaches the above "iPr" zone,
The lens drive shifts from a high speed state to a low speed state and brakes are applied, resulting in a smooth stopping state at position POo.

(4) When in SEQ, AF (Sea fence autofocus) mode.

In the SEQ, AF mode, as is clear from FIG. 10, the AFSEQ routine shown in FIG. 35 is performed. In AFSEQ, battery check BC
After HK2, it is determined whether the REL signal is on or off, and if it is on, the operation shifts to AFSIN2 (see FIG. 18).

That is, in this SEQ and AF mode, when a release signal from the camera is input, SIN.

AF mode operation is performed. When the REL signal is off or after the above AFSIN2 operation is performed, the AF status flag is cleared and AFSTAT
When either of the switches 143, 144 is turned on, the AFS IN5 (see FIG. 20) is operated. After this, it is checked whether all the AF status flags are cleared, that is, whether the low contrast, close distance, limb movement, and low contrast flags are cleared. If they are cleared, it is determined that the focus is OK. After the determination is made, the PCVI operation, that is, the sound of oscillation mode 1 is performed to notify the user that the focus has been achieved, and the WIND operation is performed. After this, it returns to Al1, so while either of the switches 143, 144 is turned on, the focusing operation is performed continuously, and the sound is generated each time the focus is achieved, and if the winder is connected, Trigger output is sent sequentially to the winder.

When both the AFSTAT switches 143 and 144 are turned off, the above-mentioned focus OK check is performed, and if the focus is OK, it is determined whether the REL signal is on or off, and if the same signal is off, the power is turned off. leading to off. After turning off the switches 143 and 144, if the focus is not OK, the PCV2 operates, that is, the sound of oscillation mode 2 is performed to warn the user and the power is turned off.

As described above, according to the present invention, the following excellent effects are exhibited.

That is, after the brake is activated, the lens drive motor is rotated in the reverse direction by the number of pulses counted by the overshoot detection means, and the lens drive motor is rotated in the reverse direction by the number of pulses counted by the overshoot detection means, and
Since the photographic lens is returned immediately, the photographic lens can reach the in-focus position in a short time. Therefore, it is possible to provide an automatic focus adjustment device that eliminates the conventional drawbacks.

[Brief explanation of the drawing]

1 to 4 are respectively a perspective view, a back view, a side view, and a schematic cross-sectional view of a lens barrel having an automatic focus adjustment device showing one embodiment of the present invention, and FIG. 1 is a perspective view of the distance ring in Figure 1, Figure 6 is a perspective view of the zoom information detector in Figure 4 above, and Figures 7 (A) and (B) are the aperture interlocking switch in Figure 4 above. 8 is a front view of the lens barrel shown in FIG. 1 above, and FIG. 9 is a diagram of the power supply circuit shown in FIG. 8 above, respectively. Flowchart Showing Operation FIGS. 10 to 35 are flowcharts showing the program operation of the CPU in FIG. 8 above. 15 (141, 142)...Mode selection switch (
mode switch) 11iA, 16B (143, 144)...
Operation buttons 38, 39...Zone switch (G21 generation member) 20......Photographing lens 21...
......Sound switch 22.103...
・・・Relise River Signal Pin 23・・・・・・・・・・・・
·motor

Claims (1)

[Claims] Focus detecting means; a motor for driving a photographing lens; a pulse generating means for generating pulses proportional to the amount of drive accompanying the driving of the motor; a brake means for applying a brake to the motor when a number determined by the output of the focus detection means is reached; an overshoot detection means for counting the number of pulses generated after the brake means is activated; An automatic focus adjustment device comprising: overshoot correction means for correcting overshoot by rotating the motor in reverse by the number of pulses counted by the shoot detection means.