JP2000187153A - Automatic focusing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arbitarily set the movement range of a focusing lens group and to vary the movement range according to circumstances. SOLUTION: In this automatic focusing device, the lens group is moved within a first focus range when the starting position of the lens group is within the first focus range (a). The lens group is moved in a second focus range when the starting position is within the second focus range (b) and when the starting position is in a third focus range (c), the group is moved within the third focus range. When the starting position is in the remote limit position and if an object is on an end point at infinity side, the lens group is moved within the first focus range (a). If the body to be photographed is on the short distance end point side, the lens group is moved within the second focus range (b). When the starting position is on the short side limit position, if the object is on the end point at infinity side, the lens group is moved within the second focus range (b). If the object is on the short distance end point side, the lens group is moved within the third focus range (c).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an automatic focusing device having a focus limiter function for controlling a moving range of a focusing lens group.

[0002]

2. Description of the Related Art Conventionally, a super-telephoto lens which can be exchanged for a camera body has a larger lens extension than other interchangeable lenses. Therefore, if the focusing lens group is always movable over the entire range, the range that the focusing lens group can follow is too large in the automatic focusing operation, and the time required to obtain a focused state may be too long. So, as such an interchangeable lens,
There is a lens provided with a so-called focus limiter for limiting a moving range of a focusing lens group.

In a conventional focus limiter, when a focus limiter switch is turned in an interchangeable lens, a restricting member projects to a position where the restricting member can interfere with a supporting member of the focusing lens group, so that the moving range of the focusing lens group is limited. (For example,
JP-A-63-70519).

[0004]

As described above, the conventional focus limiter can limit the moving range of the focusing lens group only within a predetermined range, and can operate the restricting member to change the moving range. By,
The movement range that has already been determined must be released.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens movement control device capable of arbitrarily setting a movement range of a focusing lens group and easily changing the movement range.

[0006]

According to a first aspect of the present invention, there is provided a first automatic focusing apparatus, comprising: a defocus calculating means for obtaining a defocus amount based on a subject image; and a focusing lens group of a photographing lens according to the defocus amount. Lens moving means for moving along the optical axis, position detecting means for detecting the position of the focusing lens group, focus area setting means for setting a plurality of focus areas within a movable range of the focusing lens group, and a focusing lens A focus area selecting unit that selects one from a plurality of focus areas according to a position at which the group starts moving.

It is preferable that the focus area setting means sets the focus area using the subject distance obtained by the distance measuring operation.

When the position at which the focusing lens group starts moving coincides with a boundary position defining a plurality of focus areas, the focus area selecting means selects one of the plurality of focus areas according to the distance to the subject. It is preferable to select one.

The focus area setting means may set the focus area based on the number of pulses and the distance code generated according to the amount of movement of the focusing lens group.
In this case, it is preferable that the focus area setting unit corrects the number of pulses when the number of pulses does not match the distance code.

The focus area setting means may include a focus area release means for permitting the focusing lens group to move beyond the focus area.

[0011] The focus area setting means may have a photometric switch. In this configuration, the focusing lens group moves within one focus area while the photometry switch is in the on state, and is switched to the off state after the photometry switch is switched to the off state when the end point of the focus area is reached. Accordingly, the focusing lens group moves to a focus area adjacent to one focus area.

[0012] A second automatic focusing apparatus according to the present invention comprises:
Defocus calculating means for obtaining a defocus amount based on a subject image; lens moving means for moving a focusing lens group of a photographing lens along an optical axis according to the defocus amount; and position detection for detecting a position of the focusing lens group Means, a first limit position relatively close to the infinity end point and a relatively close distance end point between the infinity end point and the short distance end point which are the end points of the movable range of the focusing lens group. By dividing by the second limit position, a first focus area between the end point at infinity and the first limit position, and a second focus area between the first and second limit positions And a focus area setting means for defining a third focus area between the second limit position and the short distance end point, and the focusing lens group moves. Depending on the position at the start, first, it is characterized in that it comprises a focus area selecting means for selecting one from the second and third focus area.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an electrical configuration of a camera provided with an automatic focusing apparatus according to an embodiment of the present invention.

This camera is a single-lens reflex camera, and includes a camera body 100 and an interchangeable lens (photographing lens) 200 that is detachable from the camera body 100. In the camera body 100, a pentaprism 102 constituting a part of the finder optical system is disposed above the quick return mirror 101, and has passed through a plurality of lens groups 201 and 202 provided in the interchangeable lens 200. The light beam passes through the quick return mirror 101 and the pentaprism 1
In addition to being guided to the eyepiece of the finder optical system via 02, the light enters the photometric sensor 103. The lens group 20
The light beams that have passed through 1, 202 are reflected by a sub-mirror 104 attached to the lower surface of the quick return mirror 101, and guided to a focus detection sensor 300 provided below the quick return mirror 101, which is a focus detection device.

Each circuit provided in the camera body 100 includes a camera control circuit (CPU) 110 having a microcomputer.
Is controlled by The camera control circuit 110 is connected to the peripheral circuit 120. The peripheral circuit 120 includes, in addition to the photometric sensor 103, a motor drive circuit 121, an exposure mechanism 12
2. The aperture mechanism 123 is connected. The motor drive circuit 121 is provided for driving a mirror motor 124 that changes the tilt angle of the quick return mirror 101 and for driving a hoist motor 125 that winds up a film. The exposure mechanism 122 drives a shutter (not shown), and the aperture mechanism 123 adjusts the opening of the aperture (not shown).

A motor drive circuit 130 is connected to the camera control circuit 110. The motor drive circuit 130 is AF
The motor 131 is driven by the AF motor 131.
Is connected to a gear block 132. The gear block 132 is connected to a gear block 203 provided in the interchangeable lens 200 via a joint mechanism (not shown). The lens group 20 is controlled by the gear block 203.
Reference numerals 1 and 202 are movable in the optical axis direction, whereby the in-focus state of the subject image is adjusted. That is, these lens groups 201 and 202 are focusing lens groups. On the other hand, the output shaft of the AF motor 131 has an encoder 13
The pulse signal output from the encoder 133 is connected to a counter 1 provided in the camera control circuit 110.
The number of movements of the lens is obtained by counting by 11.

The peripheral circuit 120 is provided with a D / A converter 126, and a voltage signal VAGC for determining an output level of the focus detection sensor 300 is input to the focus detection sensor 300 via the D / A converter 126. Is done. Video signal (VIDEO) output from focus detection sensor 300
Is input to the A / D converter 112 of the camera control circuit 110 and is used to drive the lens groups 201 and 202 to perform focus adjustment.

The camera control circuit 110 has a limit temporary release switch 140, an automatic manual (AF / MF) switch 141, a release switch 142, a photometry switch 143, a main switch 144, and a focus limit switch (electric switch) 147. Is connected. Automatic manual (AF / MF) switch 141
Is provided to determine whether the focus adjustment is performed manually or automatically. The release switch 142 is turned on by fully depressing the shutter button 139, thereby executing a shooting operation. The photometry switch 143 is turned on by half-pressing the shutter button, thereby starting the focus adjustment operation. The main switch 144 is a switch for permitting the operation of the camera. The focus limit switch 147 is provided with a focus area, and
02 is used to control the movable range. The limit temporary release switch 140 is connected to the lens groups 201, 2
An operation is performed to release the moving range 02, that is, the focus area.

The camera control circuit 110 includes a display device 14
5 and a nonvolatile memory (EEPROM) 146 are connected. The display device 145 is provided for displaying a shooting mode, a shutter speed, and the like. EEPRO
Various data are stored in M146.

In the interchangeable lens 200, a lens control circuit (lens CPU) 204 for communicating information unique to the interchangeable lens with the camera body 100 for control of automatic focusing (AF) and the like is provided. . The lens control circuit 204 is connected with a focus limit switch (electrical changeover switch) 211, a distance switch 212, and a limit temporary release switch 211b. The focus limit switch 211 is provided for selecting a focus area similarly to the focus limit switch 147 in the camera body 100. Distance switch 2
Reference numeral 12 is provided for detecting the positions of the lens groups 201 and 202, and is configured by a conductive pattern of a brush 252 and a code plate 251 described later with reference to FIG. The temporary limit release switch 211b is operated to release the focus area similarly to the temporary limit release switch 140.

FIG. 2 shows the structure of the interchangeable lens 200. The lens barrel includes a first support tube 221 and a second support tube 2
22 and these support cylinders 221 and 222
3 are integrally connected. These support cylinders 2
A manual operation ring 224 is rotatably provided on the outer peripheral surfaces of the first and second support tubes 222 and 222. The manual operation ring 224 is rotatably supported on the inner peripheral surface of the second support cylinder 222.
25 are integrally connected. That is, the manual operation ring 224 and the rotary cylinder 225 are rotatable relative to the support cylinders 221 and 222 around the optical axis X. The rotating cylinder 225 is connected to the gear block 203 (see FIG. 1). Therefore, when the AF motor 131 rotates,
The rotary cylinder 225 rotates via the gear block 203.

A helicoid 226 is formed on the inner peripheral surface of the first support cylinder 221, and the helicoid 226 is
27 is in mesh with a helicoid 228 formed on the outer peripheral surface. An engagement pin 229 is fixed to the cam ring 227, and the engagement pin 229 is connected to a guide groove 230 formed in the rotary cylinder 225.
Is engaged. The guide groove 230 extends linearly parallel to the optical axis X.

Therefore, when the AF motor 131 or the manual operation ring 224 is rotated, the rotary cylinder 225 is rotated, so that the engagement pin 229 is pushed against the side surface of the guide groove 230, and the cam ring 227 is rotated about the optical axis. I do.
Also, since the cam ring 227 and the first support cylinder 221 are connected via helicoids 226 and 228, the cam ring 2
27 is displaced along the optical axis X. That is, the AF motor 1
The cam ring 227 is displaced along the optical axis while rotating around the optical axis by the rotation of the 31 or the manual operation ring 224.

The first lens holding cylinder 231 extends over substantially the entire length of the interchangeable lens 200. A holding section 232 for the first lens group is formed inside the first lens holding cylinder 231, and the first lens group 201 is attached to the holding section 232. A rectilinear guide groove 233 extending parallel to the optical axis X is formed on the outer peripheral surface of the rear part of the first lens holding cylinder 231. On the other hand, an annular wall 234 is provided at the rear end of the second support cylinder 222, and a projection 235 formed on the inner peripheral edge of the annular wall 234 engages with the linear guide groove 233 of the first lens holding cylinder 231. ing. Therefore, the first lens holding cylinder 231 does not rotate around the optical axis but moves linearly along the optical axis X.

The first lens holding cylinder 231 has a cam ring 227
Is inserted inside. The cam ring 227 is in sliding contact with the outer peripheral surface of the first lens holding barrel 231 and is relatively rotatable around the optical axis.
7 moves integrally in the optical axis direction. Therefore, when the AF motor 131 or the manual operation ring 224 is rotated, the cam ring 227 moves along the optical axis X while rotating around the optical axis, and the first lens group 201 is displaced in the optical axis direction.

The second lens holding cylinder 231 has a second
The lens holding cylinder 236 is provided, and the second lens group 202 is attached to the second lens holding cylinder 236.
A pin 237 is fixed to the second lens holding cylinder 236, and a cam follower 238 is provided on an outer peripheral surface of the pin 237. On the other hand, the circumferential cam hole 241 formed in the cam ring 227 and the axial cam hole 242 formed in the first lens holding cylinder 231 overlap each other, and the pin 237 is inserted into these cam holes 241 and 242. Is engaged. The circumferential cam hole 241 is inclined with respect to the circumferential direction of the cam ring 227, and the axial cam hole 242 extends parallel to the optical axis X.

Therefore, when the AF motor 131 or the manual operation ring 221 is rotated, the first lens group 201 moves along the optical axis X by rotating the cam ring 227 in the optical axis direction while rotating. At the same time, the cam follower 238, the second lens holding cylinder 231 and the second lens group 202 are also displaced along the optical axis X. Thereby, focus adjustment is performed.

The lens groups 201 and 20 are provided on the annular wall 234.
2 is provided with a code plate 251 for generating a signal relating to the position in the optical axis direction. The code plate 251 extends annularly around the optical axis X similarly to the annular wall 234, and a brush 252 attached to the rotary cylinder 225 slides on the surface thereof.

A mount 2 for attaching the interchangeable lens 200 to the camera body 100 is provided on the rear side of the annular wall 234.
53 are provided. The terminal member 2 is mounted on the mount 253.
The terminal member 254 and the code board 251 are connected by a flexible printed wiring board 255. Further, a contact pin 256 is provided on the mount 253, and the contact pin 256 is in contact with the terminal member 254.
The contact pin 256 can contact a contact pin (not shown) provided on a mount (not shown) of the camera body 100, whereby the interchangeable lens 200 and the camera body 10 can be contacted.
Communication is performed during 0.

FIG. 3 is a view showing the code board 251, the terminal member 254, and the flexible printed wiring board 255. Conductive patterns 261 to 264 are formed on the surface of the code plate 251 along four circumferences. The conductive pattern 261 formed on the outermost periphery and extending over about 270 degrees is connected to the ground. Conductive pattern 2 inside
62 corresponds to the signal of the least significant bit, and the further inner conductive pattern 263 corresponds to the signal of the second bit. The innermost conductive pattern 264 corresponds to the third bit signal.

When the brush 252 is in contact with the conductive pattern, the bit signal corresponding to the conductive pattern is "0", and when not, the bit signal is "1". For example, the brush 25
2 is located, the signal of “010” is
51.

The code plate 251 has a lens control circuit 20
4 are attached. The lens control circuit 204 stores information unique to the lens 100, such as an open F value, a minimum F value, and a focal length.

Table 1 below shows the relationship between the distance information Dv 'corresponding to the current positions of the lens groups 201 and 202 and the distance codes.

The distance code is determined by the brush 252 and the code plate 2.
This is represented by the on / off state of the distance switch 212 (see FIG. 1) constituted by the 51 conductive patterns 261 to 264 (see FIG. 3). The distance switch 212 is the first
To SW3, SW3 and SW3. The first switch SW1 is formed by the second conductive pattern 262 and the brush 252 from the outermost circumference, the second switch SW2 is formed by the third conductive pattern 263 and the brush 252 from the outermost circumference, and the third switch SW3 is formed by the innermost circumference. It is constituted by the conductive pattern 264 and the brush 252.
When the brushes 252 are in contact with the conductive patterns 262 to 264, the switches SW1, SW2, and SW3 are turned on to generate a signal of “0”, and when not, they are turned off and set to “1”. Signal is generated. The first switch SW1 is a signal of the least significant bit and the second switch SW
2 corresponds to the signal of the second bit, and the third switch SW3 corresponds to the signal of the third bit.

FIG. 4 is a flowchart of a main routine for controlling the operation of the camera. The main routine is executed by the camera control circuit 110 and is started by setting the main switch 144 (FIG. 1) to the ON state.

In step S101, system initialization is performed, and initialization such as setting various parameters relating to the operation control of the camera to initial values is performed.
In step S102, a power down process is performed, and a process necessary to suppress power consumption of the battery is performed. In step S103, the photometric switch 143 (FIG. 1)
Is switched to the ON state. Step S10 when the photometry switch 143 is not on.
Returning to step 2, when the photometry switch 143 is in the ON state, the process proceeds to step S104, and power is supplied to each circuit and the like in the camera body 100 (FIG. 1) and the interchangeable lens 200 (FIG. 1). That is, each circuit is in an operable state when the photometry switch 143 is turned on.

Next, a VDD loop constituted by steps S105 to S117 is executed. Step S1
At 05, a timer for measuring the loop time starts. The loop time is a length of time during which AF (automatic focus adjustment) processing should be continued, and is described later in step S111.
Is checked in

In step S106, the switching state of each switch is checked. In step S107, lens communication is performed, and predetermined data is transmitted and received to and from the interchangeable lens 200. In step S108, A
E (automatic exposure) calculation processing is performed, and a shutter speed, an aperture value, and the like are obtained. In step S109, a display process is performed, and the display device 145 displays a shutter speed, an aperture value, and the like.

In step S110, a subroutine of the AF process (FIGS. 6 to 8) is executed, and automatic focus adjustment is performed. In step S111, it is determined whether the loop time has elapsed since the timer was started in step S105. When the loop time has not elapsed, step S110 is executed again. On the other hand, when the loop time has elapsed, it is determined in step S112 whether the photometry switch 143 is on. When the photometry switch 143 is kept on, the power hold flag is cleared to 0 in step S118, and the process returns to step S105, and the above-described processing is executed again. That is, the AF process is continuously performed until the loop time elapses, but after the loop time elapses, if the photometry switch 143 is on, the photometry is newly performed, and the shutter speed and the aperture value are changed. .

In step S112, the photometric switch 1
When it is determined that the switch 43 is not in the ON state, that is, when the shutter button is released, steps S113 and thereafter are executed.

In step S113, it is determined whether the power hold flag is "1". The initial value of the power hold flag is set to 0 in step S101. Therefore, when step S113 is executed for the first time, the process proceeds to step S114, the power hold timer is started, and the power hold flag is set to 1 in step S115.

In step S116, it is determined whether or not the power hold time has elapsed, that is, whether or not a predetermined time has elapsed since the start of the power hold timer in step S114. When step S116 is performed for the first time, the power hold time has not elapsed, so the process returns to step S105. And step S10
Steps S112 to S113 are performed when the photometry switch 143 is in the OFF state after execution of steps S112 to S112.
Move to In this case, since it is determined in step S113 that the power hold flag is 1, step S11
4. Step S115 is skipped, and step S116 is executed. If the power hold time elapses during such processing, the power hold flag is reset to 0 in step S117, and the process returns to step S102.

As described above, when a certain period of time elapses after the photometry switch 143 is turned off, the power down process is executed, and the power consumption of the battery is suppressed.

FIG. 5 is a diagram showing a range in which the lens groups 201 and 202 can move in the automatic focusing operation, that is, a focus area. The focus area is defined by an end point at infinity (∞ end), a far limit position, a near limit position, and a near end point (near end).

The lens groups 201 and 202 constitute a focusing lens, and are movable between an infinity end point and a close distance end point by a limit determined by an axial length of the interchangeable lens 200. The far limit position and the near limit position are determined by a focus limit switch 147 as described later.
Alternatively, it can be set by manipulating 211 (FIG. 1), and can be set at any position between the infinity end point and the short distance end point. In the example illustrated in FIG. 5, the far-side limit position is a position where the number of pulses output from the encoder 133 when the lens groups 201 and 202 start moving from the end point at infinity is 500. , The distance information Dv ′ obtained via the code plate 251 (FIGS. 2 and 3) is “4”. The near-side limit position is a position where the number of pulses output from the encoder 133 when the lens groups 201 and 202 start moving from the end point at infinity is 1000. At this position, the distance information Dv ′ is “ 1 ". The end point at infinity is pulse number 0
, And corresponds to the distance information Dv ′ “7”. The short-distance end point corresponds to the pulse number 1500, and the distance information Dv ′ “0”
Corresponding to That is, this pulse number is absolute position information from the end point at infinity (hereinafter, referred to as the position pulse number).
The number of position pulses and the distance information Dv 'are constantly monitored (managed) by the camera control circuit 110.

The present embodiment is configured such that the range in which the lens groups 201 and 202 can move is determined according to the positions (start positions) of the lens groups 201 and 202 when the automatic focus adjustment is started. I have. For example, when the start positions of the lens groups 201 and 202 are within the first focus area (a), that is, between the end point at infinity and the far-side limit position, the lens groups 201 and 202 move only within the first focus area. I do. Similarly, the lens group 20
1, 202 move only in the second focus area when the start position is in the second focus area (b), that is, between the far-side limit position and the near-side limit position, and the start position is shifted to the third focus area. When it is within the focus area (c), that is, between the near-side limit position and the short-range end point, it moves only within the third focus area.

On the other hand, when the start position is at the far limit position and the subject is at the end point at infinity, the lens groups 201 and 202 move only within the first focus area (a), and If you are on the near end point,
The lens groups 201 and 202 are in the second focus area (b)
Move only within. On the other hand, when the start position is just at the near-side limit position and the subject is on the end point at infinity, the lens groups 201 and 202 move only within the second focus area (b), and If it is on the distance end point side, the lens groups 201 and 202 move only within the third focus area (c).

Next, referring to FIGS. 6 to 8 and FIG.
The AF processing routine executed in step S110 of FIG. 4 will be described. In step S201, it is determined whether the photometry switch 143 is on. A
When the F processing routine is executed, the photometry switch 143 is normally set to the ON state, but if it is OFF, the step S202 is executed. That is, the AF lock flag and AF
The NG flag, the driving direction inversion flag, and the limit initialization flag are reset to 0, respectively, and this routine ends.

In step S201, the photometric switch 1
If it is determined that the switch 43 is in the ON state, the process proceeds to step S2
03 is performed, and it is determined whether the AF lock flag is 1 or not. The AF lock flag is set to 1 in step S210 when the taking lens is set to the in-focus state, and in this case, this routine ends. On the other hand, when the AF lock flag is not 1, step S204 and the subsequent steps are performed to perform the focus adjustment operation.

In step S204, FIG. 9 and FIG.
The limit input check processing routine shown in (1) is executed, and in the limit position input mode, the lens groups 201 and 2
02 is positioned at the end point at infinity (∞ end) as the initial position. In step S205, the lens groups 201 and 202
Is the position (start position) at which the camera starts moving, that is, the distance information Dv ′ corresponding to the distance code information obtained from the code plate 251 (FIGS. 2 and 3).
10 RAMs.

In step S206, the focus detection sensor 3
At 00, the charge signal is accumulated (integrated), and the generated video signal is supplied to the camera control circuit 110.
Is input to Then, a defocus calculation is performed based on the video signal, and a defocus amount including the driving direction of the lens is obtained. That is, step S206
Then, a ranging operation is performed. In step S207, it is determined whether the result of the calculation performed in step S206 is valid, that is, whether the in-focus position of the photographing lens has been obtained. When the calculation result is valid, steps S208 and subsequent steps are executed, and the focus adjustment operation is performed.

In step S208, step S206
Is compared with a predetermined range obtained by the calculation. In step S209, it is determined whether or not the defocus amount is within a predetermined range. When the defocus amount is within the predetermined range, the lens groups 201 and 202 are considered to be at the in-focus position. The flag is set to 1. In step S211, FIG.
Then, a limit input check processing routine shown in FIG. 10 is executed. That is, in the limit position input mode, the number of pulses from the end point at infinity and the distance information obtained from the code plate 251 correspond to the lens group 201,
As data indicating the position of 202, the camera control circuit 11
0, and the AF processing routine ends.
On the other hand, when it is determined in step S209 that the defocus amount is not within the predetermined range, step S2 is performed.
Proceed to 21.

In step S221, the lens groups 201, 2
It is determined whether or not the rotation direction of the gear of the gear block 203 for moving the 02 is opposite to the previous direction. Steps S222 and S223 are executed in order to remove the error of the backlash which occurs when the gear of the gear block 203 rotates in the reverse direction to the previous time. Step S22
In step 2, a backlash calculation is performed, and the amount of backlash, that is, the amount of gear rotation required to remove the backlash, is obtained. In step S223, step S22
The gear is rotationally driven by the backlash amount obtained in (2).

On the other hand, when it is determined in step S221 that the rotation direction of the gear is the same as the previous direction,
Step S224 is executed, and it is determined whether the AFNG flag is “1”. The AFNG flag is set in step S235 when the focus adjustment operation has not been performed normally and the lens group 201 or 202 has reached the limit position within the movable range.
Is set to 1. In this case, since the focus adjustment operation is not possible, this routine ends immediately. On the other hand, when the AFNG flag is 0, step S2
Steps S22 and S223 are skipped.

After step S223 or S224, drive pulse calculation is performed in step S225. That is, the number of drive pulses required to move the lens groups 201 and 202 by the amount of defocus calculated in step S206 and focus the image is obtained. In step S226, the AF motor 131 is driven, and the driving of the lens groups (focusing lenses) 201 and 202 starts.

In step S227, overlap integration is performed. That is, while the lens groups 201 and 202 are being driven, charge signals are accumulated in the focus detection sensor 300, and based on the video signal generated thereby, a defocus calculation is performed as in step S204. , A defocus amount is required. In step S228, similarly to step S205, it is determined whether the calculation result in step S227 is valid. When the calculation result is valid, the drive pulse calculation is performed in step S229 as in step S225, but when the calculation result is not valid, step S229 is performed.
Is skipped. A situation where the result of this calculation is not valid occurs, for example, when the contrast of the subject suddenly disappears.

Next, in step S230, a focus limit processing routine shown in FIGS. 12 and 13 is executed, and a focus limit check is performed.
That is, it is determined whether or not the lens groups 201 and 202 are at the limit position of the movable range (for example, the far-side limit position). When the lens groups 201 and 202 are at the limit positions, the focus limit flag is set to 1, and when not, the focus limit flag is set to 0. In the focus limit processing routine, further processing is performed, which will be described later.

In step S231, it is determined whether or not the focus limit flag is "1". When the focus limit flag is 0, it is determined in step S232 whether or not the lens groups 201 and 202 are located at an infinity end point or a short distance end point. The detection of this end point is performed by determining whether or not a pulse signal is output from the encoder 133. When the pulse signal is no longer output, the lens groups 201 and 202 are located at the infinity end point or the near distance end point. Is considered to be

If it is determined in steps S231 and S232 that the focus limit flag is 0 and that the lens groups 201 and 202 are not located at the infinity end point or the short distance end point, step S233 is executed and the lens group 201, It is determined whether the driving of 202 has been completed. This is performed by detecting whether or not the lens groups 201 and 202 have been driven by the number of pulses obtained in step S229. Lens group 201,
If the driving of the motor 202 has not been completed, step S227
Then, the above-described processing is executed again, and when the driving is completed, this routine ends.

If it is determined in step S231 or S232 that the focus limit flag is 1 or that the lens groups 201 and 202 are located at the infinity end point or the short distance end point, step S234 is performed.
Then, the driving of the AF motor 131 is stopped and the lens group 2
01 and 202 are stopped. In step S235, the AFNG flag indicating that the focus adjustment operation is impossible is set to 1. In step S236, a limit input check routine is executed. In the limit position input mode, the number of pulses (minimum value or maximum value) from the infinity end point and the code plate 251 from the infinity end point or near distance end point in the case of the infinity end point or the short distance end point The obtained distance information is stored in the RAM of the camera control circuit 110 as data indicating the positions of the lens groups 201 and 202 at that time, and this routine ends.

On the other hand, if it is determined in step S207 that the calculation result is not valid, steps S241 and subsequent steps are executed, the lens groups 201 and 202 are driven, and the in-focus position is obtained. First, in step S241, AFN
It is determined whether or not the G flag is 1. This routine ends when the AFNG flag is 1,
When the G flag is 0, lens driving (search driving) is started in step S242. That is, the lens groups 201 and 202 are moved from the current position toward the short distance end point.

In step S243, search integration is performed, and the contents are the same as in step S227. That is, while the lens groups 201 and 202 are being driven, a video signal is generated by the focus detection sensor 300, and a defocus calculation is performed to obtain a defocus amount in the same manner as in step S206. Step S244
Then, it is determined whether or not the calculation result of step S243 is valid. If the operation result is valid, step S
Move to 229.

If it is determined in step S244 that the calculation result is not valid, step S245 is executed, and a focus limit check is performed as in step S230. If it is determined in step S246 that the focus limit flag is not 1, and if it is determined in step S247 that the lens groups 201 and 202 are not located at the end points, the process returns to step S243. That is, as long as the lens groups 201 and 202 are within the movable range, the search integration is repeatedly executed.

During the search integration, the focus limit flag is determined to be 1 or the lens group 20
When it is determined that 1, 202 has reached the end point, the process proceeds to step S248, and it is determined whether the drive direction inversion flag is 1. The driving direction reversal flag indicates that the lens group 2
It is set to 1 when the moving directions of 01 and 202 are reversed. When step S248 is executed for the first time, the driving direction inversion flag is 0, so step S249 is executed, and the driving direction inversion flag is set to 1;
Step S250 is executed and the lens groups 201, 202
Are reversed. That is, the lens group 201,
Step 202 starts moving toward the end point at infinity.
43 is executed again.

If it is determined in step S244 that the operation result is valid while the loop including steps S243 to S250 is being executed, the process proceeds to step S229. When the process proceeds from step S246 or S247 to step S248, the driving direction reversal flag is determined to be 1, so that the process proceeds to step S234, and a process of stopping lens driving is executed. Then, step S235
, The AFNG flag is set to 1, and a limit input check routine is executed in step S236, and this routine ends.

As described above, in the search drive, the lens group 20
Reference numerals 1 and 202 make one reciprocation within the movable range, during which the in-focus position is detected. The movable range of the lens groups (focusing lenses) 201 and 202 will be described later.

FIGS. 9 and 10 show steps S2 of FIG.
10 is a flowchart of a limit input check processing routine executed in steps S041, S211 and step S236 of FIG.

In step S301, it is determined whether the limit input mode has been set. When the limit input mode has not been set, this routine ends without performing substantially any operation. When the limit input mode is set, step S302 and subsequent steps are executed.

The limit input mode is set by operating the focus limit switch 147 or 211 (FIG. 1). FIG. 11 shows a focus limit switch 211 provided on the interchangeable lens 200. The focus limit switch 211 includes a rotatable rotation operation unit 211a and a rotation operation unit 211a.
And a limit temporary release switch 211b provided at a central portion of the first position and displaceable in the axial direction. On the surface of the interchangeable lens 200, a mark M1 indicating a focus limit permission mode for limiting a movement range of the lens groups 201 and 202, a mark M2 indicating a far-side input mode for inputting a far-side limit position of the movement range, Mark M3 indicating the near-side input mode for inputting the near-side limit position of the range
And a mark M4 indicating the full mode in which the movement range of the lens groups 201 and 202 is not limited. By rotating the rotary operation unit 211a, the index 2 provided on the surface thereof
By aligning 11c with mark M2 or M3,
The limit input mode is set. The focus limit permission mode is released by pressing the limit temporary release switch 211b.

In step S302, lens communication is performed. That is, the camera control circuit 110 and the interchangeable lens 2
Data communication is performed between the lens group 201 and the lens control circuit 204, and a distance code indicating the current position of the lens groups 201 and 202 is input to the camera control circuit 110 via the code plate 251 and the brush 252.

In step S303, it is determined whether or not the AF lock flag is 1, that is, whether or not the in-focus state has been obtained. When the in-focus state is obtained, the AF lock flag is set to 1 in step S210 in FIG. If the AF lock flag is 1, the process proceeds to step S
If the AF lock flag is not 1, the process from step S311 is performed.

In step S304, it is determined whether or not the far side input mode has been set. In the far side input mode, the mark 211c of the focus limit switch is marked M
It is set by adjusting to 2. When the far-side input mode is set, in step S305, the number of pulses from the infinity end point (current lens position), that is, the encoder when the lens groups 201 move from the infinity end point to the current position. The number of pulses output from the camera control circuit 1
10 RAMs. That is, the AF operation is performed, the focusing lens is focused on an arbitrary object distance, and the photographing lens position (the number of pulses) at this time is stored in the memory (RAM) as the far-side limit position. Next, in step S306, the distance information Dv 'indicating the current positions of the lens groups 201 and 202 is stored in the RAM of the camera control circuit 110 as the far limit position, and this routine ends. Thus, the far limit position is
The determination is made based on the subject distance obtained by the distance measuring operation in step S206 in FIG.

On the other hand, when the near-side input mode is set by setting the index 211c of the focus limit switch to the mark M3, step S3
04, the process advances to step S307, where the number of pulses from the end point at infinity is set as the near-side limit pulse number, and the camera control circuit 1
10 RAMs. That is, the AF operation is performed, the focusing lens is set to the in-focus state at an arbitrary object distance, and the lens position (the number of pulses) at that time is stored in the memory (RAM) as the near-side limit position. Next, in step S308, the lens groups 201, 2
02 is stored in the RAM of the camera control circuit 110 as the near-side limit position, and the routine ends. That is, the near limit position is also determined based on the subject distance obtained by the distance measuring operation, similarly to the far limit position.

When it is determined in step S303 that the AF lock flag is 0, step S311 is executed, and it is determined whether the AFNG flag is 1. The AFNG flag is set to 1 in step S235 in FIG. 8 when the focus adjustment operation has not been performed smoothly.

When it is determined in step S311 that the AFNG flag is 0, that is, when the in-focus state has not been obtained but the focus adjustment operation is being performed smoothly, the process proceeds from step S311 to step S312. In step S312, it is determined whether the limit initialization flag is “1”. When the photometry switch 143 is in the off state, the limit initialization flag is set in step S2 in FIG.
In 02, it is set to 0. When the limit initialization flag is 1, this routine ends. When the limit initialization flag is 0, steps S313 and S31 are executed.
4 is executed. In step S313, the lens group 20
1, 202 are moved to the end point at infinity, and step S
At 314, the limit initialization flag is set to 1, and this routine ends. That is, the lens groups 201 and 20
Reference numeral 2 moves to the end point at infinity to initialize the number of pulses from the end point at infinity only when the photometry switch is first turned on in the limit position input mode.

If it is determined in step S311, that the AFNG flag is 1, that is, if the in-focus state has not been obtained and the focus adjustment operation has not been performed smoothly, the process proceeds from step S311 to step S315. In step S315, it is determined whether the far side input mode is set.

When the far-side input mode is set, it is determined in step S316 whether or not the lens groups 201 and 202 are located at the end points at infinity. Lens group 2
When 01 and 202 are not located at the infinity end points, this routine ends. However, when they are located at the infinity end points, in step S317, (0) is set as the far-side limit pulse number in the camera control circuit. 110 is stored in the RAM. Next, in step S318, the lens group 201,
Distance information Dv ′ indicating the infinity position of 202 is stored in the RAM of the camera control circuit 110, and this routine ends.

On the other hand, when it is determined in step S315 that the near-side input mode is set, step S319 is executed to determine whether or not the lens groups 201 and 202 are located at the short distance end points. You. When the lens groups 201 and 202 are not located at the short-distance end points, this routine ends. When the lens groups 201 and 202 are located at the short-distance end points, the maximum value of the hexadecimal number (F
FFFh) is stored in the RAM of the camera control circuit 110. Next, in step S321, the lens groups 201, 2
02 is stored in the RAM of the camera control circuit 110, and the routine ends.

Therefore, when the limit input check routine is executed in step S204 of FIG.
Steps S301 to S303 and S311 to S314 are executed. When the limit input check routine is executed in step S211, steps S301 to S301
After step 304 is executed, steps S305 and S306 or steps S307 and S308 are executed. Step S23
When the limit input check routine is executed in step 6, steps S301 to S303 and step S31
1 and S315 are executed in this order, and step S
Steps 316 to S318 or S319 to S321 are executed.

FIG. 12 and FIG. 13 show steps S in FIG.
9 is a flowchart of a focus limit check processing routine executed in step S245 of FIG. 230 and FIG. The focus limit process will be described with reference to FIGS.

At step S401, the focus limit flag is set to 0. In step S402, it is determined whether the lens groups 201 and 202 are being driven. When the lens groups 201 and 202 are not being driven, that is, when they are stationary, this routine ends immediately. On the other hand, when the lens groups 201 and 202 are being driven, step S403 and subsequent steps are executed.

At step S403, lens communication is performed. That is, the camera control circuit 110 and the interchangeable lens 20
Data communication is performed with the lens control circuit 204 of 0, a distance code indicating the current position of the lens groups 201 and 202 is input to the camera control circuit 110 via the code plate 251 and the brush 252, and the distance information (Dv ')
And stored in memory. A command signal or the like indicating a focus limit permission mode set by operating the focus limit switch 211 is input to the camera control circuit 110.

In step S404, it is determined whether the focus limit permission mode has been set. When the focus limit permission mode is not set,
This routine ends immediately.

Therefore, in step S231 in FIG.
It is determined that the focus limit flag is 0, and the process proceeds to step S232. That is, the lens groups 201 and 20
Steps S234 to S236 are executed if 2 is located at the infinity end point or near distance end point, and step S233 is executed if it is not located at infinity end point or near distance end point. In step S233, the lens group 201,
When it is determined that the driving of the 202 has not been completed, the process returns to step S227, and the focus adjustment operation is continued. As described above, when the focus limit permission mode is not set, the process proceeds from step S231 to step S232, so that the lens groups 201 and 202 can move between the infinity end point and the near distance end point, and move beyond the focus area. It is possible to move.

The point that the focus limit flag is determined to be 0 in step S246 in FIG. 8 and the process proceeds to step S247 is the same as that in step S231, and the operation in step S246 will be omitted in the following description. .

On the other hand, when it is determined in step S404 that the focus limit permission mode has been set, step S405 is executed. That is, it is determined whether or not the limit temporary release switch 211b is on. If the limit temporary release switch 211b is on, the focus limit processing routine ends.

Therefore, in this case, step S2 in FIG.
At 31, it is determined that the focus limit flag is 0 and the process proceeds to step S232, and the same processing as when it is determined at step S404 that the focus limit permission mode is not set is performed.

When it is determined in step S405 that the limit temporary release switch 211b is in the off state, the process from step S406 is executed, and the lens group 2
Focus limit processing for limiting the movement range of 01 and 202 is performed.

In step S406, the lens group 201,
Position (start position) at which 202 starts moving;
That is, it is determined whether or not the distance information obtained via the code plate 251 (FIGS. 2 and 3) is closer to the far end point than the far limit position. When the start position is closer to the far end point than the far limit position, the process proceeds to step S407, and when the start position is not the far limit position,
Proceed to step S412. Note that this focus limit processing routine is performed by using the value of the distance information Dv 'shown in FIG.
Processing is performed based on 0) at the short distance end point.

In steps S407 to S411, processing is performed when the lens groups 201 and 202 are located in the first focus area (a). In step S407, it is determined whether or not the lens groups 201 and 202 are driven in a direction from the long-distance end point to the short-distance end point (arrow A1). This routine ends when the lens groups 201 and 202 are driven in the direction from the near end point to the far end point (arrow A2). Therefore, in step S231 in FIG. 7, it is determined that the focus limit flag is 0, and the process proceeds to step S232.

On the other hand, if it is determined in step S407 that the lens groups 201 and 202 are being driven in the direction from the long-distance end point to the short-distance end point (arrow A1), step S408 is executed, and the infinite-distance end point is executed. The number of position pulses counted from the point is the far-side limit pulse number (500)
It is determined whether or not this is the case. When the number of pulses from the end point at infinity is smaller than the number of limit pulses on the far side, that is, when the lens groups 201 and 202 are within the focus area (a), this routine ends.

Therefore, in step S231 in FIG.
It is determined that the focus limit flag is 0 and the process proceeds to step S232, and the lens group 201,
If the lens 202 is not located at the infinity end point or the close distance end point, and the driving of the lens groups 201 and 202 has not been completed, a loop including steps S227 to S233 is executed, and the focus adjustment operation is continued. You. During the execution of this loop, if it is determined in step S233 that the lens groups 201 and 202 have moved by the amount calculated in step S229, the AF processing routine ends.

On the other hand, when it is determined in step S408 that the number of position pulses from the end point at infinity is equal to or greater than the number of far-side limit pulses, the lens groups 201 and 202 move beyond the far-side limit position and move to the second focus area. It is possible that (b) has been entered. Therefore, in step S409,
It is determined whether or not the distance information (Dv ') obtained from the code plate 251 is equal to or less than the far-side limit position (4). It is determined that the focus area (b) has been reached, the focus limit flag is set to 1 in step S411, and this routine ends.

Therefore, in step S231 in FIG.
Since it is determined that the focus limit flag is 1, the process proceeds to step S234 in FIG. 8, and the lens groups (focusing lenses) 201 and 202 are forcibly stopped.

On the other hand, when it is determined in step S409 that the distance information is larger than the far limit position, that is, the number of pulses from the end point at infinity indicates the second focus area (b). When the distance information indicates the first focus area (a), it is considered that an error is accumulated in the pulse number, and in step S410, the pulse number (for example, 550) from the end point at infinity is on the far side. The number of pulses is corrected to the limit pulse number (500), and this routine ends. As a result, the focus limit flag is maintained at 0, so that the lens groups 201 and 202 can move further to the far limit position.

If it is determined in step S406 that the start position is not on the far end point from the far limit position, the flow advances to step S412 to determine whether the start position is on the far end point position from the near limit position. Is determined. When the start position is not on the far end point (in the area C), the process proceeds to step S421, and when the start position is on the far end point, that is, when the start position is between the far limit position and the near limit position (area B
In), the process proceeds to step S425.

In steps S421 to S423, processing is performed when the lens groups 201 and 202 are located in the first focus area (c). In step S421, it is determined whether or not the lens groups 201 and 202 are driven in a direction (arrow A3) from the long-distance end point to the short-distance end point. When the lens groups 201 and 202 are being driven in the direction from the long-distance end point to the short-distance end point (arrow A3), this routine ends. Therefore, in step S231 of FIG. 7, it is determined that the focus limit flag is 0, and the process proceeds to step S232, where step S22 is performed.
A loop consisting of 7 to S233 is executed.

On the other hand, when it is determined in step S421 that the lens groups 201 and 202 are driven in the direction from the short distance end point to the long distance end point (arrow A4), step S422 is executed, and the infinite distance end point is executed. It is determined whether the number of pulses counted from the point is equal to or less than the near-side limit pulse number (1000). When the number of pulses from the end point at infinity is larger than the number of near-side limit pulses, that is, when the lens groups 201 and 202 are within the focus area (c), this routine ends. Therefore, in step S231 of FIG. 7, it is determined that the focus limit flag is 0, and the process proceeds to step S232, where
A loop consisting of 227 to S233 is executed.

On the other hand, when it is determined in step S422 that the number of pulses from the end point at infinity is equal to or less than the near-side limit pulse number, the lens groups 201 and 202 exceed the near-side limit position and move to the second focus area ( It is possible that b) has been entered. Therefore, in step S423, it is determined whether or not the distance information (Dv ') obtained from the code plate 251 is equal to or greater than the near-side limit position (1). If the information matches the second focus area (b), it is determined that the lens groups 201 and 202 are within the second focus area (b). Then, in step S411, the focus limit flag is set to 1, and this routine ends.

Therefore, in step S231 in FIG.
Since it is determined that the focus limit flag is 1, the process proceeds to step S234 in FIG.
202 is stopped.

On the other hand, when it is determined in step S423 that the distance information is smaller than the near limit position, that is, the number of pulses from the end point at infinity indicates the second focus area (b). When the distance information indicates the third focus area (c), it is considered that an error has been accumulated in the pulse number, and in step S424, the pulse number (for example, 950) from the end point at infinity is closer to the near side. This routine is terminated after the number of pulses is replaced by the limit pulse number (1000). As a result, the focus limit flag is set to 0
, The lens groups 201 and 202 can be further moved to the near-side limit position.

If it is determined in step S412 that the start position is closer to the far end point than the near limit position, that is, if it is determined that the start position is within the second focus area (b), step S425 is performed. Proceed to. In step S425, the lens groups 201 and 202
Is moving in the direction from the infinity end point to the short distance end point (the direction of arrow A5).

When the lens groups 201 and 202 are moving in the direction of arrow A5, it is determined in step S426 whether or not the start position is the near-side limit position.
When it is determined that the start position is the near-side limit position, this routine ends.

Therefore, in step S231 in FIG.
It is determined that the focus limit flag is 0, and the flow advances to step S232 to execute a loop including steps S227 to S233. That is, in this case, since the lens groups 201 and 202 are moving in the direction of the arrow A5, the subject is on the near end point side, and the start position is the near-side limit position. The focus adjustment operation is performed in the area (c).

When it is determined in step S426 that the start position is not the near limit position, that is, when it is determined that the start position is in the far limit position or the second focus area (b), step S42 is performed.
At 7, it is determined whether the number of pulses from the end point at infinity is equal to or greater than the near-side limit pulse number (1000). When the number of pulses from the end point at infinity is smaller than the number of near-side limit pulses, this routine ends. Therefore, FIG.
In step S231, it is determined that the focus limit flag is 0, and the flow advances to step S232 to execute a loop including steps S227 to S233.

If the lens groups 201 and 202 reach the near limit position during this execution, the focus limit processing routine is executed in the order of steps S426, S427 and S428, and the distance information (Dv ') is stored in the near limit position ( If 1) has been reached, the focus limit flag is set to 1 in step S411, and the process ends. Therefore, in the processing routine A, the process proceeds from step S231 to step S234. That is, in this case, the lens group 20
Reference numerals 1 and 202 perform a focus adjustment operation in the second focus area (b).

When it is determined in step S427 that the number of pulses from the end point at infinity is equal to or larger than the number of near-side limit pulses, the lens groups 201 and 202 move beyond the near-side limit position to the third focus area (c). May have entered. In this case, if it is determined in step S428 that the distance information (Dv ') obtained from the code plate 251 is equal to or smaller than the near-side limit position (1), the lens group 20
1, 202 are determined to be within the third focus area (c), the focus limit flag is set to 1 in step S411, and this routine ends.

Therefore, in step S231 in FIG.
Since it is determined that the focus limit flag is 1, the process proceeds to step S234 in FIG.
202 is stopped.

On the other hand, when it is determined in step S428 that the distance information is larger than the near-side limit position, that is, the number of pulses from the end point at infinity indicates the third focus area (c). When the distance information indicates the second focus area (b), it is considered that an error is accumulated in the pulse number, and in step S424, the pulse number (for example, 1050) from the infinity end point is closer to the near side. This routine is terminated after the number of pulses is replaced by the limit pulse number (1000). As a result, the focus limit flag is maintained at 0, so that the lens groups 201 and 202 can move further to the near-side limit position.

On the other hand, when it is determined in step S425 that the lens groups 201 and 202 are moving in the direction from the short distance end point to the infinity end point (the direction of arrow A6),
Step S414 is executed, and it is determined whether the start position is the far-side limit position. When the start position is the far-side limit position, this routine ends.

Therefore, in step S231 in FIG.
It is determined that the focus limit flag is 0, and the flow advances to step S232 to execute a loop including steps S227 to S233. That is, in this case, since the lens groups 201 and 202 are moving in the direction of the arrow A6, the subject is at the end point at infinity, and the start position is the far-side limit position. A focus adjustment operation is performed in the focus area (a).

When it is determined in step S414 that the start position is not at the far limit position, that is, when it is determined that the start position is within the near limit position or the second focus area (b), step S41 is performed.
At 5, it is determined whether the number of pulses from the end point at infinity is equal to or less than the far-side limit pulse number (500). This routine ends when the number of pulses from the end point at infinity is larger than the number of limit pulses on the far side, that is, when the lens groups 201 and 202 are within the focus area (b).
Therefore, in step S231 in FIG. 7, it is determined that the focus limit flag is 0, and step S232 is performed.
Proceed to.

On the other hand, when it is determined in step S415 that the number of pulses from the infinity end point is equal to or smaller than the far-side limit pulse number, the lens groups 201 and 202 move beyond the far-side limit position to perform the first focus. There is a possibility that the vehicle has entered the area (a). In this case, step S416 is executed, and the distance information (Dv ′) obtained from the code plate 251
Is greater than or equal to the far-side limit position (4). If the distance information is equal to or greater than the far limit position, it is determined that the lens groups 201 and 202 are within the first focus area (a), the focus limit flag is set to 1 in step S411, and this routine ends. I do.

Therefore, in step S231 in FIG.
Since it is determined that the focus limit flag is 1, the process proceeds to step S234 in FIG.
202 is stopped.

When the start positions of the lens groups 201 and 202 are in the near-side limit position or the second focus area (b) and the subject is on the far end point side, the lens groups 201 and 202 are in the second focus position. While in the area (b), the focus limit processing routine proceeds to step S42.
5, S414, and S415 are executed in this order, and the processing ends. Therefore, in the AF processing routine, steps S227 to S2
A loop consisting of 33 is executed.

If the lens groups 201 and 202 reach the far-side limit position during this execution, the focus limit processing routine executes steps S425, S414, S415,
The processing is executed in the order of S416. If the distance information is equal to or greater than the far-side limit position (4), the focus limit flag is set to 1 in step S411, and the process ends. Therefore, in the AF processing routine, the process proceeds from step S231 to step S234. That is, in this case, the lens group 20
Reference numerals 1 and 202 perform a focus adjustment operation in the second focus area (b).

When it is determined in step S415 that the distance information is smaller than the near-side limit position, that is, the number of pulses from the end point at infinity indicates the first focus area (a), but the distance information indicates the first focus area (a). When the focus area (b) of FIG. 2 is indicated, it is considered that an error is accumulated in the pulse number, and step S410 is executed, and the pulse number (for example, 450) from the end point at infinity is set to the far-side limit pulse. This routine is replaced with the number (500) and the routine ends. As a result, the lens groups 201 and 202 can move further to the far limit position.

Now, in step S411, the focus limit flag is set to 1, and the lens groups 201, 2
02 stops, and the ANFG flag is set to 1 (step S235 in FIG. 8). Therefore, if the photometry switch is kept on, the AF processing routine proceeds to steps S201, S203 to S209, S221, and S224.
And the processing is terminated. The limit input processing routine is executed in steps S301 to S303, S311, S315, and S301.
The processing is executed in the order of 319, and the processing ends. In the main routine of FIG. 4, a loop including steps S105 to S112 is repeatedly executed, and the lens groups 201 and 202 maintain a stopped state. When the metering switch is turned off,
When the AFNG flag is cleared to 0 in step S202 of FIG.
In the processing routine, the processing after step S204 is executed again to control the driving of the lens groups 201 and 202. In this state, when the driving of the lens groups 201 and 202 is started next, the lens groups 201 and 202 are located at either the far limit position or the near limit position at that time. The focus area in which the lens groups 201 and 202 move is determined based on the lens driving direction.

For example, assume that the lens groups 201 and 202 are in the first focus area (a) and the subject is approaching the camera. Since the lens groups 201 and 202 move to the far limit position and stop at the far limit position, steps S401 to S409 and S411 are performed.
Is executed, and the focus limit flag is set to 1. Here, if the user turns off and turns on the photometry switch once, the AFNG flag is cleared to 0 in step S202 of the AF processing routine, and then, in the next processing of the AF processing routine, the process proceeds from step 241 to step 242. In step S230, a focus limit check processing routine is executed. That is,
When the focus limit flag is cleared to 0 and the focus limit check processing routine is executed again,
Steps S401 to S406, S412, S425 to S
427 is executed and the processing ends. Therefore, the focus limit flag remains at 0.

Thereafter, when the focus limit processing routine is executed again, steps S401 to S406, S
412, S425 to S427 are performed in this order, and the lens groups 201 and 202 are driven in the second focus area (b). Then, as long as the lens groups 201 and 202 reach the near-side limit position and the focus limit flag is not set to 1 (in this case, steps S427, S428,
(Executed in the order of S411), and is driven in the second focus area (b).

As described above, when the photometric switch is turned off once and then turned on again with the lens groups 201 and 202 stopped at one of the far limit position and the near limit position,
The focus area in which the lens groups 201 and 202 are driven is changed to an area adjacent to the area that has been driven so far. In other words, when the lens group is driven in the second focus area (b), the lens group 201, 202 is changed to the first focus area (a) when moving in the direction of the end point at infinity. When moving in the direction of the end point, the focus area is changed to the third focus area (c). In addition, during the lens driving, the limit temporary release switch 221b
While the is pressed, the lens groups 201 and 202 can be driven in all areas.

That is, even if the lens reaches a preset limit position and stops when the focusing lens is moving in the direction of focusing by the AF operation, the user can temporarily switch the photometric switch. By turning on and off again, the focus area of the focusing lens can be easily moved to an adjacent focus area according to the moving direction. As a result, even if the subject is in the shooting range outside the set focus area, it is possible to quickly switch to an appropriate focus area in accordance with the distance to the subject by simply operating the photometric switch. Shooting is possible without missing.

In place of the photometric switch, for example, AF
An operation start switch may be provided so that the focus area is switched by the switch.
On the other hand, the photometry switch is often designed so that the execution of the photometry operation and the AF operation is started by the ON operation thereof, and is a member that is most frequently operated when using the camera. That is, the present embodiment is configured to switch the focus area in association with the operation of the photometry switch, and it is not necessary to provide a special operation member such as an AF operation start switch, and the operation can be performed quickly. it can.

As described above, according to the present embodiment, the range of the focus limit can be set arbitrarily, and the limit range can be switched according to the situation.

[0125]

As described above, according to the present invention, the range of movement of the focusing lens group can be set arbitrarily, and the range of movement of the focusing lens group can be easily changed. A movement control device can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an electric configuration of a camera including an automatic focusing apparatus according to an embodiment of the invention.

FIG. 2 is a cross-sectional view illustrating a configuration of an interchangeable lens.

FIG. 3 is a plan view showing a code board, a terminal member, and a flexible printed wiring board.

FIG. 4 is a flowchart of a main routine for controlling the operation of the camera.

FIG. 5 is a diagram illustrating a focus area in which a lens group can move in an automatic focus adjustment operation.

FIG. 6 is a flowchart of an AF processing routine.

FIG. 7 is a flowchart of an AF processing routine.

FIG. 8 is a flowchart of an AF processing routine.

FIG. 9 is a flowchart of a limit input check processing routine.

FIG. 10 is a flowchart of a limit input check processing routine.

FIG. 11 is a plan view showing a focus limit switch provided on the interchangeable lens.

FIG. 12 is a flowchart of a focus limit processing routine.

FIG. 13 is a flowchart of a focus limit processing routine.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 Camera body 140, 211b Focus limit temporary release switch 200 Interchangeable lenses 201, 202 Lens group

Claims (8)

[Claims] A defocus calculating unit for obtaining a defocus amount based on a subject image; a lens moving unit for moving a focusing lens group of a photographing lens along an optical axis according to the defocus amount; Position detecting means for detecting the position of the focusing lens group, a focus area setting means for setting a plurality of focus areas within the movable range of the focusing lens group, according to the position when the focusing lens group starts moving, An automatic focus adjustment device comprising: a focus area selecting unit that selects one of the plurality of focus areas. 2. The automatic focusing apparatus according to claim 1, wherein said focus area setting means sets said focus area using a subject distance obtained by a distance measuring operation. 3. When the position at which the focusing lens group starts to move coincides with a boundary position defining the plurality of focus areas, the focus area selecting means determines a distance to the subject. The automatic focusing apparatus according to claim 1, wherein one of the plurality of focus areas is selected. 4. The focus area setting unit according to claim 1, wherein the focus area setting unit sets the focus area based on a number of pulses and a distance code generated according to an amount of movement of the focusing lens group. Automatic focusing device. 5. The automatic focusing apparatus according to claim 4, wherein the focus area setting means corrects the number of pulses when the number of pulses does not match the distance code. 6. The automatic focusing apparatus according to claim 1, wherein said focus area setting means includes a focus area release means for permitting said focusing lens group to move beyond said focus area. . 7. A state in which the focus area setting means has a photometric switch, and the focusing lens group moves within one focus area while the photometric switch is on, and reaches an end point of the focus area. 2. The automatic focusing apparatus according to claim 1, wherein the focusing lens group moves to a focus area adjacent to the one focus area by switching the photometric switch to an on state after being switched to an off state. Focus adjustment device. 8. A defocus calculating unit for obtaining a defocus amount based on a subject image; a lens moving unit for moving a focusing lens group of a photographing lens along an optical axis according to the defocus amount; And a first limit position relatively close to the infinity end point, between the infinity end point and the short distance end point, which are the end points of the movable range of the focusing lens group. By dividing by the second limit position relatively close to the near end point,
A first focus area between the end point at infinity and the first limit position, a second focus area between the first and second limit positions, and a position near the second limit position. A focus area setting unit that defines a third focus area between distance end points; and a focus area setting unit that moves from the first, second, and third focus areas according to a position at which the focusing lens group starts moving. An automatic focus adjustment device comprising: a focus area selection unit that selects one of the focus areas.