JPH1010406A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain pleasant operability and natural zooming effect by realizing smooth zoom start and sure zoom stop. SOLUTION: This device is provided with a ring member 1301 concentrically provided with respect to a lens optical axis, a detecting means detecting variation in accordance with the rotation of the member 1301, a control means controlling at least the moving/stopping of a variable power lens group in an optical axis direction based on the detection result of the detecting means, and an inhibiting means inhibiting the variable power lens group from being stopped during a predetermined period even if the rotation of the member 1301 is stopped. The zoom lens is inhibited from being stopped for the predetermined period even through the rotation of the member 1301 is stopped, so that the zooming operation is prevented from being repeatedly driven/stopped even though the detection of the rotation is hard to be performed because the member 1301 rotates at a slow speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device,
In particular, the present invention relates to an imaging device having a function of manually moving a lens.

[0002]

2. Description of the Related Art A conventional interchangeable lens system used for an imaging device such as a video camera will be described with reference to a block diagram of FIG. In a conventional zoomable lens unit, a variable power lens 802 and a correction lens 803 are mechanically connected by a cam, and when a variable power operation is performed manually or electrically, the variable power lens 802 and the correction lens 803 are used. And move together.

Generally, the zoom lens 802 and the correction lens 803 are called a zoom lens. In such a lens system, the front lens 801 is a focusing lens, and performs focusing by moving in the optical axis direction. Light that has passed through these lens groups is imaged on the imaging surface of the imaging element 804, photoelectrically converted into an electric signal, and output as a video signal.

This video signal is sampled and held by the CDS / AGC 805 and then amplified to a predetermined level.
The data is converted into digital video data by the A / D converter 806. Thereafter, the signal is input to a process circuit of the camera, converted into a standard television signal, and input to a bandpass filter 807 (hereinafter, BPF).

The BPF 807 extracts a high-frequency component from the video signal and extracts only a signal corresponding to a portion set in the focus detection area on the screen by the gate circuit 808.
The peak hold circuit 809 performs peak hold at intervals synchronized with an integral multiple of the vertical synchronization signal to generate an AF evaluation value.

The AF evaluation value is obtained by
The motor driving direction is determined so that the focusing speed according to the degree of focusing and the AF evaluation value increase in the main body AF microcomputer 810, and the speed and direction of the focus motor are transmitted to the lens microcomputer 811. .

[0007] The lens microcomputer 811 is
As instructed by 10, the rotation speed and the rotation direction of the motor 813 are controlled via the motor driver 812, and the focus adjustment is performed by moving the focus lens 801 in the optical axis direction.

The microcomputer 810 of the main body controls the zoom lens 802 and the zoom lens 802 according to the operation state of the zoom switch 818.
The driving direction and the driving speed of the lens unit 803
The zoom lens 802 is sent to the zoom motor driver 814 in the control unit 6 to drive the zoom lenses 802 and 803 by controlling the zoom motor 815 to obtain a zooming effect. The camera body 817 can detach the lens unit 816, and the shooting range is expanded by connecting another lens unit.

On the other hand, in the integrated camera for consumer use, in order to enable downsizing and photographing up to the front of the lens, the mechanical connection between the variable power lens 802 and the correction lens 803 by a cam is stopped, and the correction lens is removed. Is previously stored in the microcomputer as lens cam data.

A so-called inner focus type lens system, in which the correction lens 803 is driven in accordance with the stored lens cam data and the focus is also adjusted by the correction lens 803, has become mainstream. It has the advantages of cost reduction, simplification of the system, and reduction in size and weight of the lens barrel.

FIG. 10 shows a simple structure of a conventionally used inner focus type lens system. In FIG. 10, reference numeral 901 denotes a fixed first lens group; 902, a second lens group for performing zooming; 903, an aperture; 904, a fixed third lens group; A fourth lens group (hereinafter, referred to as a focus lens) 906 having a so-called competition function for correcting movement of a focal plane due to zooming, and 906, an imaging surface of an imaging element.

In the lens system configured as shown in FIG. 10, since the fourth lens group 905 has both a competing function and a focus adjusting function, even if the focal lengths are equal, the fourth lens group 905 can focus on the imaging surface 906. The position of the fourth lens group 905 varies depending on the subject distance.

That is, when the subject distance is changed at each focal length, the position of the fourth lens group 905 for focusing on the image pickup surface 906 is plotted continuously as shown in FIG. Become. During zooming, if the trajectory shown in FIG. 11 is selected according to the subject distance and the fourth lens group 905 is moved along the trajectory, zooming without blurring becomes possible.

By the way, in the front lens type lens system, an independent compensating lens is provided for the variable power lens, and the variable power lens and the compensating lens are connected by a mechanical cam ring.

Therefore, for example, when a knob for manual zoom is provided on this cam ring to change the focal length manually, no matter how fast the knob is moved, the cam ring rotates to follow the change, and Since the magnification lens and the compensating lens move along the cam groove of the cam ring, if the focus lens is in focus, the above operation does not cause blur.

On the other hand, in the control of the inner focus type lens system, a plurality of trajectory information shown in FIG. 11 is stored in some form (the trajectory itself or a function using the lens position as a variable). Generally, a locus is selected according to the positions of the focus lens and the variable power lens, and zooming is performed while following the selected locus.

Furthermore, in order to read out the position of the focus lens with respect to the position of the variable power lens from the storage element and apply it to lens control, it is necessary to read out the position of each lens with some accuracy. In particular, as is clear from FIG. 11, when the variable power lens moves at a constant speed or a speed close thereto, the inclination of the locus of the focus lens changes every moment due to a change in the focal length.

This indicates that the moving speed and the moving direction of the focus lens change every moment. In other words, the actuator of the focus lens must have an accurate speed response from 1 Hz to several hundred Hz.

As an actuator that satisfies the above-mentioned requirements, it is becoming common to use a stepping motor for the focus lens group of the inner focus lens system. The stepping motor rotates while being completely synchronized with a stepping pulse output from a microcomputer for lens control or the like, and a stepping angle per pulse is constant.
It is possible to obtain high speed response, stopping accuracy and position accuracy.

Further, when a stepping motor is used, since the rotation angle with respect to the number of stepping pulses is constant,
The step pulse can be used as it is as an increment type encoder, and there is an advantage that no special position encoder needs to be added.

As described above, in the case where the zooming operation is to be performed while keeping the focus by using the stepping motor, the trajectory information shown in FIG. It is necessary to read locus information according to the position or moving speed of the variable power lens, and move the focus lens based on the information.

FIG. 12 is a diagram for explaining an example of a conventionally known trajectory tracking method. In FIG. _{12, Z 0, Z 1,} Z 2, ··· Z 6 shows a zoom lens _{position, a 0, a 1, a} 2, ··· a 6 and b _{0,
b 1, b 2, ··· b} 6 is a representative trace stored in the microcomputer. Also, p ₀ , p ₁ , p ₂ ,... P
Reference numeral ₆ denotes a trajectory calculated based on the two trajectories.

The formula for calculating the locus is described below. p (n + 1) = | p (n) -a (n) | / | b (n) -a (n) | * | b (n + 1) -a (n + 1) -a (n + 1) | + a (n + 1)… (1)

According to the equation (1), for example, in FIG. 12, when the focus lens is at p ₀ , p ₀ is a line segment b
The ₀ -a ₀ to determine the specific which internally divides the line segment b ₁ in accordance with the ratio
A point which internally divides the -a ₁ is set to p _1. This p ₁ -p ₀
And position difference, from the variator lens is the time required to move to Z ₀ to Z _1, is seen moving speed of the focus lens for maintaining focus.

Next, a description will be given of a case where the stop position of the variable power lens is not limited only to the boundary possessing the stored representative trajectory data. FIG. 13 is a diagram for explaining an interpolation method in the position direction of the variable power lens.
2 is extracted, and a variable-power lens is arbitrarily selected.

In FIG. 13, the ordinate and the abscissa indicate the focus lens position and the lens position, respectively. The representative trajectory position (focus lens position with respect to the variable power lens) stored in the lens control microcomputer is represented by the variable power lens. Position Z
_{0, Z 1 ··· Z k-} 1, Z k ··· and Z _n, a focus lens position at that time by the object _{distance, a 0, a 1, ···} a k-1, a k ··· a _n b _0, b _1, is set to _{··· b k-1, b k} ··· b n.

Now, if the zoom lens position is at Z _x not on the zoom boundary and the focus lens position is P _x ,
a _x, when determining the _{b x, a x = a k} - (z k - z x) * (a k - a k-1) / (Z k -Z k-1) ... (2) b x = b _k - and made _{- (b k-1 b k} ) / (Z k -Z k-1) ... (3) - (z k z x) *.

That is, according to the internal division ratio obtained from the current zoom lens position and two zoom boundary positions sandwiching the current zoom lens position (for example, Z _k and Z _{k-1 in} FIG. 13), the stored value is stored.
13, representative locus data (in FIG. 13, a _k , a _k−1 , b _k ,
a _x , b _x can be obtained by internally dividing the same subject distance out of b _k−1 ) by the internal division ratio.

Then, according to the internal division ratio obtained from a _x , p _x , b _x , the stored four representative data (in FIG. 13,
_{a k, a k-1,} b k, of b _k-1), p _k by internally dividing those same focal length (1) in the internal ratio as equation the p _k-1 You can ask.

At the time of zooming from wide to tele, the following focus position _pk and the current focus position p _x
The moving speed of the focus lens for maintaining the focus can be determined from the time required for the variable power lens to move from Z _{x to} Z _k . Further, from the time of zooming to wide from the telephoto and follow destination focus position p _k-1 and the positional difference between the current focus position p _x, zooming lens and the time required to move to the Z _x ~Z _k-1, The moving speed of the focus lens for keeping the focus is known. A trajectory following method as described above has been proposed.

As described above, in the inner focus type lens, a stepping motor is combined as an actuator to reduce the size and simplify the drive transmission system. In addition, since the stepping pulse supplied to the stepping motor can be easily generated in the microcomputer for lens control, by counting the number of stepping pulses output by the microcomputer for lens control itself,
There is an advantage that the position of the lens can be accurately known without specially providing an encoder or the like for detecting the lens position.

By the way, in a front lens type lens system, a general “rotating a zoom ring fitted to a lens barrel moves a zoom lens mechanically connected to the zoom ring to perform zooming. (1) The lens moves in proportion to the amount of rotation. (2) Therefore, it is excellent in that smooth zooming from rough adjustment to fine adjustment can be performed.

However, in the lens system of the inner focus type, (a) all the movable lenses are arranged in the lens barrel. (A) If the lens is rotated by a mechanically connected cam ring or the like without using a control circuit, an error occurs between the count value of the drive pulse of the stepping motor and the actual lens position. (C) It is difficult to mechanically couple the zoom ring and the lens and move the lens by external force, for example, because the drive transmission system having a simple structure is not suitable for mechanical manual operation. Yes, it is difficult to achieve manual zoom operability with a front lens type lens system.

In particular, in the interchangeable lens system described with reference to FIG. 9, depending on the lens to be mounted, the holding of the camera is in the form of holding the lens barrel. If it is necessary to look away from the viewfinder and look for the zoom operation switch on the main body for adjustment, there is a problem that it causes a camera shake or hinders smooth shooting.

On the other hand, there has been proposed a system in which an encoder is fitted to a lens barrel and a zoom lens is moved by electrically detecting a rotation direction and a rotation speed of the encoder. Here, a zoom ring that is not mechanically connected to a zoom lens is hereinafter referred to as a zoom ring. Regarding the zoom ring 1301,
The configuration will be described in detail with reference to FIGS.

In FIG. 14, reference numeral 1301 denotes a rotary encoder fitted to a lens barrel; 1302, a comb-shaped structure of an encoder having a light reflecting portion and a light transmitting portion;
Numerals 303 and 1304 denote light emitting / receiving elements having a light emitting unit 1306 and a light receiving unit 1307, respectively.
The state of the output signal changes depending on whether or not the reflected light is received (the light emitting unit 130 surrounded by a broken line in FIG. 14).
FIG. 15 is an enlarged view of FIG. ).

When the encoder 1301 is rotated, the output signals of the light emitting and receiving elements 1303 and 1304 are respectively shown in FIG.
6 (a) or (b). Emitter / receiver element 1
The positional relationship between 303 and 1304 is determined so that the phases of the two output signals are shifted by an appropriate amount. The rotational speed is detected based on the period of change of the output signal, and the rotational direction is determined based on the phase relationship between the two signals. It is a mechanism to detect.

That is, FIG. 16A shows an output waveform when the rotating member is operated in the forward rotation direction, and FIG. 16B shows an output waveform when the rotating member is operated in the reverse rotation direction. The output signals of the light emitting and receiving elements 1303 and 1304 are taken in, and the driving direction and the driving speed of the lens are determined according to the state of the signals.

An encoder as shown in FIG. 14 to FIG. 16 is provided, and a lens actuator such as a stepping motor is driven according to the rotation of the ring. It is possible to maintain a feeling of operation similar to that described above and perform a zooming operation with the power zoom.

[0040]

However, in the front lens type manual zoom lens system, as in the prior art, the moving amount of the variable power lens with respect to the operating amount of the zoom ring is mechanically determined. If the priority is given to the operation amount of the zoom ring required to move from the end to the telephoto end, the zoom lens movement is sensitive to zoom ring operation, and the angle of view changes rapidly when the zoom lens starts moving. It was unsightly. Conversely, if smooth movement is prioritized, the amount of operation of the zoom ring required to move the variable power lens increases, making it difficult to use.

In a front lens type electric zoom or an inner focus type zoom (even in the case of a zoom ring operation, an electric zoom), it is often difficult for a photographer to operate the zoom operation member before the zoom lens starts moving. did not understand. For this reason, the zoom lens may not move when you want to zoom, or conversely, the angle of view may suddenly change when you want to zoom slowly,
There was a problem of missing a photo opportunity.

In particular, in the case of an interchangeable lens type camera, the photographing posture is such that the lens unit is held, so that the zoom lens may be moved by slightly touching the zoom operation member provided on the lens unit. there were.
If the play of the operating member is increased or the load is increased to prevent this, there has been a problem that fine tuning cannot be performed.

Further, in the zooming by the zoom ring 1301 shown in FIG. 14, when the zoom ring 1301 is slowly rotated, the encoder 1303 is rotated for half a cycle of the comb-shaped structure 1302 even if the zoom ring is rotated.
Since the output waveforms of 1304 and 1304 do not change, it may be erroneously determined that no operation has been performed.

At this time, the zoom lens repeatedly moves and stops at the changing cycle of the encoder output waveform, resulting in unnatural zooming that is unclear on the photographing screen or zooming from the wide end to the telephoto end. Ring 13
01 had to be operated many times.

Further, the photographer's intention to zoom may differ depending on the photographing situation. For example, while recording is stopped, the angle of view should be adjusted as quickly as possible. On the other hand, at the time of recording, we want to make use of the zooming effect in painting, so we want to reproduce the movements of the operating members that we operate with zooming from the ultra-low speed to the variable speed zoom.

However, in the front lens type zoom of the conventional example, since the operation member and the movement of the zoom lens are mechanically fixed, it is not possible to satisfy all photographer's requirements. Further, even with an inner focus type zoom, it has been extremely difficult to realize a zoom function that can simultaneously satisfy the above-mentioned requirements only by recognizing the operation state of the operation member.

In view of the above-mentioned problems, the present invention realizes a smooth zoom start and a reliable zoom stop,
An object is to provide a comfortable operability and a natural zooming effect.

[0048]

According to the present invention, there is provided an imaging apparatus comprising: a ring member provided concentrically with respect to a lens optical axis of a lens unit; and a detecting means for detecting an amount of change accompanying rotation of the ring member. A control unit that controls at least movement / stop of the zoom lens group in the optical axis direction based on the detection result of the detection unit, wherein the zooming is performed for a predetermined period even after the rotation of the ring member is stopped. It is characterized in that a prohibiting means for prohibiting stopping of the lens group is provided.

Another feature of the present invention is that
A ring member provided concentrically with respect to the lens optical axis, detection means for detecting an amount of change accompanying rotation of the ring member, and a moving direction and a moving speed of the variable power lens group based on the detection means output. And control means for moving and stopping the variable power lens group in the optical axis direction, and determining the response of the variable power lens group movement to the detection result of the detecting means. A change means for changing between the start of the movement and the movement of the movement is provided.

Another feature of the present invention is that a ring member provided concentrically with respect to the optical axis of the lens, a detecting means for detecting an amount of change accompanying rotation of the ring member, Control means for determining the moving direction and moving speed of the variable power lens group based on the output of the means, and for controlling the movement / stop of the lens group in the optical axis direction. It is characterized in that a changing means for changing the responsiveness of the movement of the zoom lens group according to the shooting state is provided.

Another feature of the present invention is that the changing means changes the moving speed of the zoom lens group with respect to the output of the detecting means.

Another feature of the present invention is that the changing means permits the movement of the variable power lens group.
The present invention is characterized in that the reference amount of the change due to the rotation of the ring member to be prohibited is changed.

Another feature of the present invention is that the lens unit is detachable from the image pickup apparatus main body and is replaceable.

[0054]

Since the present invention has the above technical means, even if the rotation of the ring member provided concentrically with respect to the optical axis of the lens is stopped, the stop of the zoom lens is prohibited for a predetermined period. Even when rotation is difficult to detect due to low rotation speed, it is possible to prevent the inconvenience of repeating the driving / stopping of the zoom operation, and it is possible to perform natural and smooth zooming.

According to another feature of the present invention, it is possible to change the responsiveness of the movement of the zoom lens to the operation state of the ring member according to the start and the movement of the zoom lens or the shooting state. Thus, it is possible to prevent a sudden change in the angle of view at the start of zooming, and to appropriately set the operability of the ring member and the characteristics of the zoom operation according to the intention of the photographer. This makes it possible to obtain optimal and comfortable operability and a zooming effect according to the shooting situation.

According to another feature of the present invention, since the change in the response is changed by the moving speed of the zoom lens, it is possible to perform a slow-starting zooming in response to the operation of the ring member. Because it is difficult to know how much to operate the zoom operation member to move the zoom lens group, the zoom lens does not move when you want to zoom, and conversely, the angle of view changes suddenly when you want to zoom slowly. Then, it is possible to prevent the problem of missing a photo opportunity.

According to another feature of the present invention, the change of the responsiveness is performed by changing the reference amount of the rotation amount of the ring member for permitting / prohibiting the start of the movement of the zoom lens. Even in a photographing posture in which a lens unit of a lens-type camera or the like is held, it is possible to prevent a malfunction in which the zoom lens moves only by touching the ring member a little. It is not necessary to mechanically adjust, and it is possible to realize a zoom function that satisfactorily responds to delicate ring operations.

[0058]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, an embodiment in which the present invention is applied to an interchangeable lens output will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the imaging apparatus according to the present invention. As shown in FIG. 1, the light from the subject is transmitted to the fixed first lens group 10.
1. A second lens group 102 (hereinafter, referred to as a zoom lens) for performing zooming, an aperture 103, a fixed third lens group 104, a focus adjustment function, and a competing function for correcting movement of a focal plane due to zooming. The fourth lens group 105 having both
(Hereinafter referred to as a focus lens), the red component of the three primary colors is on a red image sensor 106 such as a CCD, the green component is on a green image sensor 107 such as a CCD, and the blue component is C.
Each image is formed on a blue image sensor 108 such as a CD.

The zoom ring described in the prior art described above is
Reference numeral 301 denotes an encoder unit, and reference numeral 1303 denotes an encoder unit. 106, 107, 10 for each color component passing through the lens
8 are photoelectrically converted, amplified by amplifiers 109, 110, and 111 to optimal levels, respectively, input to a camera signal processing circuit 112, and converted into a standard television signal. , To the AF signal processing circuit 113.

AF generated by AF signal processing circuit 113
The evaluation value is read out by the data reading program 115 in the main body microcomputer 114 and transferred to the lens microcomputer 116. Further, the main body microcomputer 114 reads the operation states of the zoom switch 130 and the AF switch 131 and sends them to the lens microcomputer 116.

In the lens microcomputer 116, when the AF switch 131 is off and the zoom ring 1301 is rotating or the zoom switch 130 is pressed according to information from the main body microcomputer 114, the computer zoom program 119 executes the zoom ring 1301 The lens microcomputer 11 is driven in the telephoto or wide direction depending on the rotation direction of the zoom lens or the direction in which the zoom switch 130 is pressed.
6, lens cam data 120 stored in advance
Is sent to the zoom motor driver 122 based on

As a result, the zoom motor 121 operates to drive the variable power lens 102, and at the same time, a signal is sent to the focus motor driver 126 to operate the focus motor 125 and move the focus compensating lens 105. Performs the magnification operation.

When the AF switch 131 is on and the zoom ring 1301 is rotating or the zoom switch 130 is pressed, it is necessary to keep the in-focus state. Therefore, the computer zoom program 119 is stored in the lens microcomputer. Referring to not only the lens cam data 120 stored in advance but also the AF evaluation value signal sent from the main body microcomputer 114, the zooming operation is performed while maintaining the position where the AF evaluation value becomes maximum.

When the zoom ring 1301 is rotating and the zoom switch 130 is pressed, the operability similar to that of the front lens type lens can be realized by giving priority to the zoom ring 1301. .

When the AF switch 131 is on and the zoom ring 1301 is not rotating or the zoom switch 130 is not pressed, the AF program 117
Sends a signal to the focus motor driver 126 so that the AF evaluation value signal sent from the main body microcomputer 114 is maximized, and moves the focus compensation lens 105 via the focus motor 125 to perform an automatic focus adjustment operation.

Next, the AF signal processing circuit 11 will be described with reference to FIG.
3 will be described. The red (R), green (G), and blue (B) CCD outputs amplified by the amplifiers 108, 109, and 110 to the optimal lenses are output from the A / D converters 206, 207, and 207 in the camera signal processing circuit 112. At 208, the digital signals are converted to digital signals, respectively, and sent to the camera signal processing unit. At the same time, the signals are appropriately amplified by the amplifiers 209, 210, and 211, respectively. Thereafter, the signals are added by the adder 208 and sent to the AF signal processing circuit 113 as a luminance signal S5 for automatic focus adjustment.

The luminance signal S5 for automatic focus adjustment is input to a gamma circuit 213, where it is gamma-converted by a predetermined gamma curve to produce a signal S6 in which low luminance components are emphasized and high luminance components are suppressed. .

The gamma-converted signal S6 is input to the TE-LPF 214, which is an LPF having a high cut-off frequency, and the FE-LPF 215, which is an LPF having a low cut-off frequency, and is determined by the microcomputer 114 via the microcomputer interface 253. The low-frequency component is extracted by each filter characteristic, and the TE-LPF 214 output signal S
7 and the FE-LPF 215 output signal S8.

The signal S7 and the signal S8 are selected by a switch 216 by a LineE / 0 signal which is a signal for identifying whether the horizontal line is an even number or an odd number, and is input to a high-pass filter (hereinafter, HPF) 217. .

That is, the even-numbered line outputs the signal S7 to the HPF2
The odd line passes the signal S8. HPF2
In step 17, only high-frequency components are extracted from the odd / even filter characteristics determined by the main microcomputer 114 through the microcomputer interface 253, and the absolute value circuit 218 is extracted.
The positive signal S9 is generated by converting the absolute value into. The positive signal S9 is supplied to the peak hold circuits 225, 226,
227 and the line peak hold circuit 231.

The frame generation circuit 254 generates an L frame signal, a C frame signal, and an R frame signal as gate signals for focus adjustment at positions in the screen as shown in FIG. The peak hold circuit 225 receives an L frame signal output from the frame generation circuit 254 and a Line / 0 signal that is a signal for identifying whether the horizontal line is an even number or an odd number.

Then, as shown in FIG. 3, the peak hold circuit 225 is initialized at each location of the upper left LR1 which is the head of the focus adjustment L frame, and the even number designated through the microcomputer interface 253 from the microcomputer 114 of the main body. The signal S9 in each frame of either the line or the odd line is peak-held, and the data transfer signal IR1 (see FIG. 3)
The peak hold value in the frame is transferred to the buffer 228 with
Generate a TE / FE peak evaluation value.

Similarly, the C frame signal and the LineE / 0 signal output from the frame generation circuit 254 are input to the peak hold circuit 226, and the peak hold CR 226 at the top left of the focus adjustment C frame shown in FIG. The hold circuit 226 is initialized, and the signal S9 in each frame of either the even-numbered line or the odd-numbered line designated from the main body microcomputer 114 through the microcomputer interface 253 is peak-held, and the data transfer signal IR1 is stored in the buffer 229 in the frame. Is transferred to generate a TE / FE peak evaluation value.

Similarly, the peak hold circuit 227
The R frame signal output from the frame generation circuit 254 and LineE /
0 signal is input, the peak hold circuit 227 is initialized at the upper left RR1 which is the head of the focus adjustment R frame shown in FIG. 3, and the even line or the odd line specified from the main microcomputer 114 through the microcomputer interface 253. The peak hold value in the frame is transferred to the buffer 230 by the data transfer signal IR1 to generate the TE / FE peak evaluation value.

The signal S9 and the L frame signal, the C frame signal, and the R frame signal output from the frame generation circuit 254 are input to the line peak hold circuit 231 and are initialized at a horizontal start point in each frame. The one-line peak value of the signal S9 in the frame is held.

Integrating circuits 232, 233, 234, 23
5, 236 and 237 have a line peak hold circuit 2
At the same time as the output of Line 31 and the LineE / 0 signal for identifying whether the horizontal line is an even number or an odd number, the integrating circuits 232 and 235 output the frame generating circuit output L frame signal and the integrating circuits 233 and 236 to the integrating circuits 232 and 235, respectively. , A frame generation circuit output C frame signal, and the integration circuits 234 and 237 receive a frame generation circuit output R frame signal.

The integration circuit 232 initializes the integration circuit 232 at the upper left LR1, which is the head of the L frame for focus adjustment, and outputs the output of the line peak hold circuit to the internal register immediately before the end of the even line in each frame. The peak hold value is transferred to the buffer 238 with the data transfer signal IR1 to generate a line peak integration evaluation value.

The integration circuit 233 initializes the integration circuit 233 at each location of the upper left CR1 which is the head of the focus adjustment C frame, and outputs the line peak hold circuit output immediately before the end of the even-numbered line in each frame. The value is added to the internal register, and the peak hold value is transferred to the buffer 239 with the data transfer signal IR1 to generate a line peak integral evaluation value.

The integration circuit 234 initializes the integration circuit 234 at the top left RR1, which is the head of the R frame for focus adjustment,
Immediately before the end of each frame, the output of the line peak hold circuit is added to the internal register, the peak hold value is transferred to the buffer 240 by the data transfer signal IR1, and the line peak integration evaluation value is generated.

The integration circuits 235, 236, and 237 perform addition of the data of the odd lines, respectively, instead of the addition of the data of the even lines by the integration circuits 232, 233, and 234, respectively. Then, the respective results are transferred to the buffers 241, 242, and 243.

The signal S7 is supplied to the peak hold circuit 2
19, 220, 221 and line maximum value hold circuit 2
44 and the line minimum value hold circuit 245. The peak hold circuit 219 includes a frame generation circuit 25
Four outputs of the L frame signal are input, and the peak hold circuit 219 is initialized at the top left LR1 which is the head of the L frame,
The signal S7 in each frame is peak-held. Then, the peak hold result is transferred to the buffer 222 by the data transfer signal IR1, and a Y peak evaluation value is generated.

Similarly, the C frame signal output from the frame generation circuit 254 is input to the peak hold circuit 220, and the peak hold circuit 220 is initialized by the upper left CR1, which is the head of the C frame, to perform initialization. The signal S7 is peak-held, the peak-hold result is transferred to the buffer 223 with the data transfer signal IR1, and a Y-peak evaluation value is generated.

Further, similarly, the peak hold circuit 221
, An R frame signal output from the frame generation circuit 254 is input, and the HR1 at the top left of the R frame,
1, the signal S7 in each frame is peak-held, the peak-hold result is transferred to the buffer 224 with the data transfer signal IR1, and a Y-peak evaluation value is generated.

The L frame signal, the C frame signal, and the R frame signal output from the frame generation circuit 254 are input to the line maximum value hold circuit 244 and the line minimum value hold circuit 245, and at the horizontal start point in each frame. Initialized, the maximum value and the minimum value of one line of the signal S7 in each frame are held.
The maximum value and the minimum value held by these are input to the subtractor 246, and a (maximum value-minimum value) signal S10 is calculated, and the peak hold circuits 247, 248, 249
Is input to

The L frame signal output from the frame generation circuit 254 is input to the peak hold circuit 247, and the peak hold circuit 247 is initialized by the upper left LR1 which is the head of the L frame, and the signal S10 in each frame is converted. The peak hold is performed, the peak hold result is transferred to the buffer 250 with the data transfer signal IR1, and the Max-Min evaluation value is generated.

Similarly, the C frame signal output from the frame generation circuit 254 is input to the peak hold circuit 248, and the peak hold circuit 248 is initialized by the upper left CR1, which is the top of the C frame, and Peak hold the signal S10,
The peak hold result is transferred to the buffer 251 by the data transfer signal IR1, and a Max-Min value is generated.

Further, similarly, the peak hold circuit 249
Is supplied with an R frame signal output from the frame generation circuit 254, and the HR1 at the top left, which is the head of the R frame,
9, the signal S10 in each frame is peak-held, the peak transfer result is transferred to the buffer 252 by the data transfer signal IR1, and the Max-Min evaluation value is generated.

At each location of the data transfer signal IR1, buffers 222, 223, 224, 228, 229, 23
0, 238, 239, 240, 241, 242, 24
3, 250, 251, and 252, an interrupt signal is sent from the frame generation circuit 254 to the main microcomputer 114 at the same time.

The main body microcomputer 114 receives the interrupt signal, and through the microcomputer interface 253, buffers 222, 223, 224, 228, 229, 23
0, 238, 239, 240, 241, 242, 24
Each data in 3, 250, 251 and 252 is read by the end of the lower frame until the next data is transferred to the buffer and transferred to the lens microcomputer 116.

As described above, FIG. 3 is a diagram for explaining the timing in the AF signal processing circuit 113. The outer frame is an effective image screen of the output of the image sensor 106, 107, 108. The inner three divided frames are gate frames for focus adjustment, and the signals of the left L frame, the center C frame, and the right R frame are output from the frame generation circuit 254. A reset signal is output for each of the L, C, and R frames at the start positions of these frames to generate LR1, CR1, and RR1, and reset the integration circuit, peak hold circuit, and the like.

At the end of the frame, the data transfer signal IR1
Is generated, and each integrated value and peak hold value are transferred to each buffer. The scanning of the even field is indicated by a solid line, and the scanning of the odd field is indicated by a dotted line. In both the even field and the odd field, the even line selects the TE_LPF output, and the odd line selects the FE_LPF output.

Next, the TE / FE peak evaluation value in each frame,
The following describes how the microcomputer performs the automatic focusing operation using the TE line peak integrated evaluation value, the FE line peak integrated evaluated value, the Y peak evaluated value, and the Max-Min evaluated value.

The TE / FE peak evaluation value is an evaluation value representing the degree of focusing, and is a peak hold value, so that it is relatively less dependent on the subject and less affected by camera shake, etc. Optimal. Although the TE line peak integral evaluation value and the FE line peak integral evaluation value also indicate the degree of focus,
Since it is a stable evaluation value with little noise due to the integration effect, it is optimal for direction determination.

Further, both the peak evaluation value and the line peak integration evaluation value are optimal in the vicinity of the focus because TE extracts a higher frequency component, whereas the FE is optimal in the case of a large blur far from the focus. is there.

Since the Y peak evaluation value and the Max-Min evaluation value do not depend much on the degree of focusing and depend on the subject,
It is optimal for grasping the situation of the subject in order to reliably perform the focus degree determination, the restart determination, and the direction determination.

That is, it is determined whether the subject is a high luminance subject or a low illuminance subject based on the Y peak evaluation value, the contrast is determined based on the Max-Min evaluation value, and the TE / FE peak evaluation value and the TE line peak integration evaluation value are determined. , The optimal control is performed by predicting and correcting the size of the peak of the FE line peak integrated evaluation value.

The evaluation values are transferred from the camera body 128 to the lens unit 127,
The automatic focus adjustment operation is performed by the AF program 117 in the lens microcomputer 116 of FIG.

Next, the lens unit 127 will be described with reference to FIG.
The algorithm of the automatic focus adjustment operation in the lens microcomputer 116 will be described. First start (A1),
The hill-climbing control (A2) is performed by controlling the speed at the level of the TE or FE peak, and controlling the direction mainly using the TE line peak integrated evaluation value near the top of the mountain and the FE line peak integrated evaluation value at the foot of the mountain. .

Next, the peak of the mountain (A3) is determined based on the absolute value of the TE or FE peak evaluation value or the variation of the TE line peak integral evaluation value, and the hill is climbed so that the TE and FE peak evaluation values become maximum. It performs control, stops at the highest point, and enters the restart standby (A4).

In the restart standby, the system detects that the level of the TE or FE peak evaluation value has decreased, and restarts (A5). In this automatic focusing operation loop, TE / FE
The degree of speed control using the peak, the absolute level of the judgment of the top of the mountain, the amount of change in the TE line peak integrated evaluation value, and the like are larger than those of the subject using the Y peak evaluation value and the Max-Min evaluation value. And a decision is made based on this.

Next, a method for smoothly starting a zoom operation in response to a zoom ring operation and realizing a smooth zoom operation even with a slow zoom ring operation, which is a feature of the present embodiment, will be described. This will be described with reference to the flowcharts of FIGS.

FIG. 5 is a flowchart for detecting rotation of the zoom ring 1301 performed in the lens microcomputer 116. FIG. 6 is a flowchart of a zoom operation performed in the lens microcomputer 116.

The processing in FIG. 5 detects the time required for the lens microcomputer 116 to rotate the zoom ring 1301 in the rotation direction and the unit rotation angle, and is an interrupt processing routine in the microcomputer. The triggering factor of the interrupt is the switching point of the output waveform voltage of the ring rotation detection encoder 1303, and the rising edge and the falling edge of the output of the ring rotation detection encoder 1303 shown in FIGS. 16A and 16B are detected. And an interrupt occurs,
The processing of FIG. 5 is executed. (On the other hand, the processing in FIG. 6 is performed in synchronization with the vertical synchronization signal.)

As shown in the figure, first, the interrupt processing is started in the first step S501, and then the interrupt processing is started in the step S5.
In 02, it is determined whether the "rotation flag" is 0 or not. If the result of this determination is that the flag is cleared, the "rotation flag" is set in step S503, the interrupt number counter C0 and the waiting time counter C1 are cleared, and the current timer value is stored in the memory T1.

Here, the timer value is a free-running counter generally provided in a microcomputer or the like, and is a counter that is counted at a period obtained by dividing the system clock of the microcomputer.

The “rotation flag” is the zoom ring 130.
Reference numeral 1 denotes a flag indicating rotation, which is used to determine whether the ring has been rotated in the processing of FIG. 6, and is cleared every time the processing of FIG. 6 is performed several times. That is, the “rotation flag” indicates whether or not the zoom ring 1301 has been rotated within an integral multiple of one vertical synchronization period, which is the processing cycle of FIG.

After step S503, step S506 is executed.
It is determined whether the current interrupt is the rising edge or the falling edge of the output of the encoder 1303. If the interrupt is the rising edge, the process proceeds to step S507.
It is determined whether the output signal of 304 is "L".

If the result of the determination in step S507 is true,
Since the combination of the two outputs is as shown in FIG.
A ring flag indicating that the rotation direction of the zoom ring 1301 is the forward rotation direction is set (step S50).
9), and terminate the process (step S511).

On the other hand, in step S507, the encoder 13
If the output 04 is “H”, the combination of the two outputs is the case of FIG.
Is determined to be the reverse rotation direction, and the ring flag is cleared (step S510).

If the output of encoder 1303 is a falling edge as a result of the determination in step S506, the output signal of encoder 1304 is determined in step S508, and if "L", the process proceeds to step S510. If "H", the process proceeds to step S509 to set a ring flag.

After the processing of FIG. 5 is completed, before the rotation flag is cleared in the processing of FIG.
When the rotation of 01 is performed, an interrupt occurs again, and the processing of FIG. 5 is performed. At this time, since the rotation flag has already been set in step S502, step S504 is performed.
Is performed.

In step S504, the number-of-interrupts counter C0 is incremented, and the current timer value is stored in the memory T2. Then, in step S505, the difference between the previous and current timer values is calculated (T2−T1), and the difference is divided by the interrupt counter value C0 to obtain the time required to rotate a half cycle of the comb-shaped structure 1302 of the zoom ring 1301. Is stored in the memory ΔT, and the processing from step S506 is performed.

When an interrupt occurs again while the rotation flag is set, the interrupt counter C0 is incremented, the memory T2-memory T1 has a rotation time of one cycle of the comb-shaped structure 1302, and the memory ΔT has a half cycle. This indicates the average time required for rotation.

As described above, by executing the zoom ring rotation detection routine shown in FIG. 5, the ring operation rotation amount indicated by the counter value C0, the ring operation rotation speed indicated by the memory ΔT, the ring rotation direction indicated by the ring flag, and the rotation flag It is possible to obtain information on the presence or absence of a ring operation represented by.

During the rotation of the zoom ring, while the processing of FIG. 5 is being performed, the processing of FIG. 6 is performed in synchronization with the vertical synchronization signal.
First, the process is started in the first step S601, and mutual communication with the main microcomputer 114 is performed in a step S602.

As described above, the main body microcomputer 114 sends information such as information on the zoom switch 130 on the camera body 128 side, key information of AF on / off, and AF evaluation value. The encoder 1303 determines whether or not the rotation flag is set so as to give priority to the zoom ring operation on the lens unit side, and determines the operation state of the zoom switch 130 obtained through communication when the ring operation is not performed in a clear state. While moving the zoom lens according to the operation state, the focus lens is operated in accordance with the cam locus tracing method described in the related art (step S).
622, step S623, step S624, step S625, step S626) and step S627, this process ends.

If the AF is ON at the time of the zoom operation, the zoom operation is performed while performing the focus correction with reference to the AF evaluation value as described above. If it is determined in step S603 that the rotation flag has been set, that is, the rotation of the zoom ring 1301 has occurred before the period of an integral multiple of the vertical synchronization (here, the period of the integral multiple of the vertical synchronization is referred to as a zoom control period for convenience), In step S604, it is first determined whether or not the interrupt counter C0 is cleared.

As a result of the determination, the interrupt counter C
If 0 is clear, in step S605, it is determined whether the current rotation of the zoom ring 1301 is continuing the low-speed rotation or starting from the rotation stop state. When the interrupt number counter C0 is cleared, it is determined that the memory T1-memory T2 is larger than a predetermined value α on the assumption that the comb teeth of the comb-shaped structure portion 1302 are not rotated by half a cycle in the current rotation.

At the time of low-speed rotation in which the ring continuously rotates over the past several V synchronization periods, the memory T2 stores the timer value of the previous rotation (about several times before the zoom control cycle). Since the timer value for the current rotation (within one zoom control cycle) is stored in the memory T1 (step S504 in FIG. 5) (step S504 in FIG. 5), the memory T1-memory T2 The value is a small value to some extent.

On the other hand, if the rotation is started from the ring rotation stop state, the time at which the memory T2 was last updated will be several tens of cycles before the zoom control cycle, so
1- The memory T2 has a large value. Therefore, by examining the values of the memory T1 and the memory T2, it is possible to determine whether the operation is from the rotation stop state or the continuous low speed rotation state, and the switching threshold value for the determination is the predetermined value α.
It is.

Actually, since the memory T1 and the memory T2 at the time of low-speed rotation are determined from the relationship between the comb tooth pitch of the zoom ring and the rotation speed at which the photographer slowly rotates, α is determined based on the value. I have.

If it is determined in step S605 that the rotation has not been performed continuously, the flow advances to step S618 to stop the zoom operation. If the ring rotation is being performed continuously, the difference value between the memory T1 and the memory T2 is stored in the memory ΔT in step S606.

On the other hand, if the interrupt counter C0 is not 0 in step S604, the process proceeds to step S505 in FIG.
Using the memory ΔT (average rotation time per half cycle of the comb teeth of the zoom ring) determined in step (1), the processing shifts from step S607.

Next, in step S607, it is determined whether the zoom lens has already been driven. When the zoom is stopped, it is determined in step S611 whether or not the interrupt counter C0 is larger than a predetermined value N.

If the counter value C0 is equal to or smaller than the predetermined value N, it is possible that the zoom ring 1301 was touched by mistake. Therefore, in this case, the process proceeds to step S618, and the zoom drive is not performed. Also, a predetermined value N
If it is larger, the photographer intentionally uses the zoom ring 13
In step S612, the start flag is set in order to start the zoom drive, and the zoom speed Zsp at the start of the zoom drive is set in step S614.

The zoom speed at the start of driving is controlled by the zoom ring 13 so that the angle of view changes slowly.
A low zoom speed is calculated according to the operation rotation speed of 01. Here, Zsp = (Zspstart * ΔT m
in) / ΔT, and Zspstart is the zoom lens movement start speed according to each focal length set so that the zoom image magnification change changes slowly and smoothly. The photographer rotates the zoom ring 1301 at the highest speed. Is set so that the image magnification change is relatively smooth even when the image is displayed.

.DELTA.Tmin is the time required for the half cycle of the comb teeth (the half cycle of the comb teeth) determined by the pitch of the comb teeth and the rotation load of the zoom ring 1301 when the photographer rotates the ring at the highest speed. (The minimum time required). That is, when the photographer rotates the ring at the highest speed (ΔT min
= ΔT), Zsp = Zspstart.

On the other hand, if it is determined in step S607 that zoom driving has already been performed, step S608 is executed.
To determine whether or not the start flag has been set. If the start flag has been set, that is, if the driving of the zoom has just started, the interrupt counter C0 is set in step S609.
Is smaller than or equal to a predetermined value M. As a result of this determination,
If the value is equal to or smaller than the predetermined value M, the process proceeds to step S614 to determine a low zoom speed at the start of zoom driving.

If the interrupt counter C0 is larger than the predetermined value M in step S609, the flow advances to step S610 to perform the zoom operation at the normal driving speed, and the start flag is cleared. Then, in step S613, a zoom speed corresponding to the ring operation during normal operation is calculated.

Here, Zsp = (Zspmax * ΔT
min) / ΔT, and Zspmax is the maximum zoom lens moving speed in a range where the focus motor performing the competing operation at each focal length does not lose synchronism. ΔT min is the maximum speed when the photographer rotates the ring at the highest speed. The time required for the half cycle of the comb teeth determined by the pitch of the comb teeth of the zoom ring 1301 and the rotation load (the minimum time required for the half cycle of the comb teeth)
It is.

That is, when the photographer rotates the ring at the maximum speed (ΔT min = ΔT), Zsp = Zspm
ax, and the zoom lens moves at the highest possible speed for the focal length. Step S608
If it is determined that the start flag is clear, the flow directly goes to step S613.

Steps S07 to S
In the processing routine that reaches step 613 and step S614, the amount of rotation and the rotation speed of the zoom ring operation are detected by monitoring the number-of-interrupts counter C0 and the average rotation time ΔT per half cycle of the comb teeth, and detect the ring operation. To enable optimal zoom operation.

As a result, effects such as prevention of malfunction when the photographer accidentally touches the zoom ring 1301, prevention of a sudden change in the angle of view at the start of zooming, and enhancement of the interlocking between the ring operation and the image magnification change are obtained. It becomes possible.

The processing routine of steps S615, S616, and S617 is processing for setting the moving direction of the zoom lens according to the rotating direction of the zoom ring. First, in step S615, it is determined whether the ring flag is set, and it is determined whether the rotation direction of the zoom ring 1301 is forward rotation or reverse rotation.

If the result of this determination is that the ring flag is set and in the forward rotation state, the flow advances to step S616 to drive the zoom lens in the wide direction. Step S61
If it is determined in step S5 that the rotation direction of the zoom ring 1301 is reverse rotation, the zoom lens is driven in the telephoto direction in step S617. As described above, the focus lens is also driven to correct the focal plane in accordance with the movement of the zoom lens. Step S616, step S617,
After step S618, in any case, step S619
To the processing routine to determine the above-described zoom control cycle.

The processing routine consisting of steps S619, S620 and S621 is a processing for resetting the rotation flag at a cycle of an integral multiple of the vertical synchronization. In step S619, it is determined whether or not the waiting time counter C1 is larger than a predetermined value β. If true, the rotation flag is cleared in step S620. If not, step S6
In step 21, C1 is incremented, and the process ends (step S627).

When the process goes through step S621, the rotation flag remains set even when the present process is performed next time. Therefore, the process goes through step S619 again and waits for a predetermined value β. The rotation flag will be cleared.

That is, the rotation flag is reset at a cycle β times the vertical synchronization (the above-described zoom control cycle). Therefore, when the zoom driving is performed, the process goes through steps S615, S616, and S617. Even if the ring 1301 stops rotating, the zoom operation is continued.

Therefore, even if the encoder output does not change for a half cycle of the comb teeth of the zoom ring 1301, the zoom is not stopped, so that even if the period during which the encoder output does not change during the low-speed rotation operation is long to some extent, it is smooth and natural. It is possible to perform a proper zoom operation.

Another effect when the zoom control cycle is set to an integral multiple of the vertical synchronization is as follows. As described above, the predetermined value α is determined from the relationship between the comb tooth pitch of the zoom ring 1301 and the rotation speed at which the photographer slowly rotates, and the low-speed rotation and the stop are determined as described above. In order to detect rotation, it is necessary to reduce the pitch of the comb teeth and increase the resolution for detecting the rotation angle.

However, the pitch of the comb teeth is limited due to the structure of the mechanism, and a predetermined value α that can always distinguish low-speed rotation from non-rotation may not be determined. On the other hand, by increasing β, even at the time of low-speed rotation, FIG.
Since the process of FIG. 5 can be performed before the rotation flag is cleared in step S620, the counter C0 can be set to C0 ≠ 0, and it can be determined in step S605 of FIG.

Therefore, it is not necessary to determine the predetermined value α severely, and it is not necessary to form the comb tooth pitch with high precision, and it is possible to provide the zoom ring function at relatively low cost. This has the effect of reliably determining whether the zoom ring 1301 is rotating at a low speed or stopped.

However, if the value of the predetermined value β is too large, the rotation flag is not cleared during that period, so that it is determined that the rotation of the zoom ring 1301 has already stopped, but the ring is still rotating. Then the zoom lens continues to move. This depends on the comb pitch of the zoom ring 1301.

For example, the predetermined value β <12 (0.
If it is within about 2 seconds), there is no discrepancy between the zoom ring operation and the change of the zooming screen. Therefore, it is desirable to determine the predetermined value α so that low-speed rotation and stop can be reliably distinguished within this range.

Although the moving speed of the zoom movement by the main body zoom key is not specified here, it may be a fixed speed of a predetermined speed, or the zoom key may have a structure in which the output voltage changes by pressing the operation. If it is a type, the speed may be a multi-step speed according to the pressing. Further, in the present embodiment, an interchangeable lens system has been described as an example, but an imaging device in which a lens unit and a camera unit are integrated may be used.

As described above, by executing the processing routine of FIG. 6, the low-speed rotation and the stop of the rotation of the zoom ring 1301 can be reliably distinguished, so that a smooth and natural zoom operation can be realized. Become like

Further, by switching the responsiveness of the zoom operation to the operation of the zoom ring 1301 between the start of the zoom drive and during the drive, a sudden change in the angle of view at the start of the zoom, a feeling of inconsistency between the ring operation and the zoom movement, etc. Malfunction can be prevented, and comfortable zoom operability can be realized.

(Second Embodiment) Next, one of the features of the image pickup apparatus of the present invention, the changing means for changing the responsiveness of the zoom operation to the zoom ring operation, is changed according to the shooting state. An example of operating the means will be described.

FIG. 7 is a diagram showing the configuration of the second embodiment of the present invention, and the same components as those in FIG. 1 are denoted by the same reference numerals. The imaging device in FIG. 7 has a recording device for photographed images and a photographing mode setting function (a so-called program mode function). In the present embodiment, the imaging device has an exposure control function in a program mode. Hereinafter, this will be described in detail with reference to the drawings.

The light from the subject passes through the lens group of the lens unit and has three image pickup devices 106, such as CCDs.
7, 108. After being photoelectrically converted, the signals are amplified to optimal levels by amplifiers 109, 110, and 111, respectively, input to a camera signal processing circuit 112 and converted into a standard television signal, and at the same time, an AF signal processing circuit 113 and an AE signal. The data is input to the processing circuit 706.
A method of generating an AF evaluation value in the AF signal processing circuit 113,
The usage and use are as described in the first embodiment.

The photometric signal generated by the AE signal processing circuit 706 is sent to an exposure control section 704 in the microcomputer 114 for use in exposure control. On the other hand, the exposure control unit 704 sends to the AE signal processing circuit 706 a command for photometry area control for mainly performing photometry in only a part of the screen.

Further, the exposure control section 704 controls the CCD driving circuit 70 so that the exposure state of the photometric signal becomes a desired state.
5 to control the accumulation time of the image sensors 106, 107, and 108, the gains of the amplifiers 109, 110, and 111, and the aperture drive command in the aperture control unit 709 in the lens microcomputer 116.
And the amount of light passing through the aperture 103 is controlled in a loop.

In controlling the aperture 103, the aperture control unit 709 drives the IG meter 123 by sending a signal to the iris driver 124 via the motor control unit 118 in accordance with the aperture drive command sent from the main body. The state of the stopped aperture 103 is detected by the encoder 129. Then, the output signal of the encoder 129 is transferred to the exposure control unit 704 in the microcomputer 114 of the main body through the aperture control unit 709.

The exposure control section 704 also controls the program mode with emphasis on exposure control. The photographer operates the program mode switching SW unit 701 to control parameters such as an aperture mechanism, an amplifier such as an AGC, and an electronic shutter according to a mode to be selected, thereby realizing an optimal exposure state for a subject or a shooting situation. I have.

In particular, when the program mode is the manual mode, the manual exposure setting switch set by the photographer is set.
The exposure state as set is reproduced according to the state of the unit 702.

On the other hand, the standard television signal generated by the camera signal processing circuit 112 is amplified by an amplifier 707 to an optimum level, and then sent to a magnetic recording / reproducing device 708. Recording of the photographed video is performed by the microcomputer 11 according to the state of the REC switch unit 703 operated by the photographer.
4 is performed by sending a recording start command to the magnetic recording device 708.

Note that, in addition to the information described in the first embodiment, aperture control information, selected program mode information, and REC- ON information and the like are sent.

Next, the AF signal processing circuit 70 will be described with reference to FIG.
6 will be described in detail. Amplifiers 109, 110, 1
The red (R), green (G), and blue (B) CCD outputs respectively amplified to the optimum levels at 11 are converted into digital signals by A / D converters 206, 207, and 208, respectively.
At the same time as being sent to the camera signal processing unit, they are given to the amplifiers 209, 210 and 211, respectively, and are appropriately amplified. Thereafter, the addition is performed by the adder 212 to generate a luminance signal S5.

The luminance signal S5 is supplied to the AF signal processing circuit 1
13 and input to the AE signal processing circuit 706. The input luminance signal S5 is divided into an average photometric signal S10 for detecting the entire video area and a center-weighted photometric signal S11 for detecting only the center of the video area, and weighting is performed by weighting circuits 1401 and 1403, respectively. . The photometric evaluation value S1 is added by the adder 1404.
2 is sent to the exposure control calculation unit 1407 in the exposure control unit 704 of the main body microcomputer 114.

Here, a gate circuit 1 for performing center-weighted photometry
The control of the ON / OFF timing and the weighting ratio of 402 is performed based on the information of the exposure control calculation unit 1407. Hereinafter, the exposure control operation will be described by taking exposure control in the program mode as an example.

The control parameters for determining the exposure include an aperture mechanism, an AGC, an electronic shutter, and the like. Data in which each parameter is set for each program mode according to the subject and shooting conditions are looked up in the exposure control unit 704. LUT1 (1412) corresponding to program mode 1, LUT2 (1413) corresponding to program mode 3, LUT3 (1414) corresponding to program mode 3, and LUT4 (1415) corresponding to program mode 4 for each program mode as a table It is prepared as.

Further, in the exposure control section 704, the LUT data control section 1411 calls the data of the look-up table corresponding to the program mode set by the program mode switch SW701, and controls each parameter based on this data, thereby controlling the program. Mode becomes possible.

For example, when the movement of the subject is fast, the electronic shutter control unit 1409 sets the electronic shutter for controlling the accumulation time of the image pickup element in preference to the high speed.
By controlling the CCD drive circuit 705, a so-called “sport mode” can be performed in which shooting with excellent dynamic resolution can be performed.

An aperture drive command is passed from the aperture control unit 1410 to the lens microcomputer 116 so that the aperture mechanism is prioritized to the open side, and exposure control is performed using other parameters, whereby the depth of the subject becomes shallow and the effect of blurring the background is obtained. For example, a so-called “portrait mode” suitable for photographing, etc., can be performed, and photographing optimal for a photographing situation can be realized. Also, AGC
The control unit 1408 supplies A to the amplifiers 109, 110, and 111.
It sends out GC information.

Further, in the AE signal processing circuit 706,
By controlling the photometric distribution by setting a detection area and a detection position of a video signal for exposure control set by a gate pulse control circuit 1405 that operates based on a signal provided from the gate timing generator 1406, a more optimal distribution is obtained. Enables shooting.

For example, the so-called average photometry for detecting the entire image area in the screen and controlling the exposure so that this detection signal is at a constant level, or detecting only the central portion of the image area in the screen, It is possible to perform center-weighted photometry for controlling exposure so that is at a constant level.

The AE signal processing circuit 706 weights the detection data of the entire image area and the detection data of the center-weighted area by weighting circuits 1401 and 1403, respectively, and adds detection data obtained by adding each data at a fixed ratio. By performing exposure control based on the data, it is possible to perform exposure control by photometry combining average photometry and center-weighted photometry. By changing the setting of each weighting ratio in each program mode according to the subject and the shooting situation, more optimal exposure control can be performed by taking advantage of the respective photometry.

For example, if the main subject is illuminated by a spotlight and the surroundings are dark or the subject is backlit, the weight of the center-weighted photometry is increased and the ratio with the average photometry is adjusted, so that only the main subject is used. It is also possible to perform well-balanced and appropriate exposure control for subjects such as the surrounding background.

The main microcomputer 114 to the lens microcomputer 1
The lens microcomputer 116 changes the responsiveness of the operation to the zoom ring rotation operation in accordance with the shooting state information such as the program mode information and the REC information passed to the camera 16.

As described in the first embodiment, the responsiveness is changed by changing the zoom movement speed or changing the reference amount of the zoom ring operation amount for determining whether the zoom movement is permitted or prohibited to the photographing state. It is done by changing accordingly. The change of the responsiveness can be realized by making the determination routine of step S607 described in FIG. 6 of the first embodiment a determination routine of the shooting state.

A description will be given of what kind of responsivity the zoom operation should be performed according to the photographing state. For example, there are many cases where the photographer intends to operate the zoom ring 1301 during recording of a captured image and during recording stop. When the recording is stopped, the angle of view to be recorded is adjusted as quickly as possible so as not to miss a photo opportunity. Therefore, the zoom ring operation is mainly used for adjusting the angle of view.

Therefore, at the time of stopping recording, it is sufficient to control the zoom ring operation amount so as to be sensitive and responsive and to quickly perform the zoom operation. On the other hand, at the time of recording, the zoom ring operation is often performed to create a picture using the zooming effect rather than adjusting the angle of view, so the zoom speed does not need to be so fast, so the photographer can adjust the rotation amount and rotation. By operating the ring while changing the speed, it is necessary to be able to perform the zoom operation of your choice.

Therefore, at the time of recording, in order to integrate the ring operation and the zoom operation and improve the operability, zoom control may be performed so that the ring rotation amount and the rotation speed are faithfully reproduced in the zoom operation.

Also, for example, when the manual mode is set in the program mode, the photographer wants to set the photographing conditions voluntarily. Therefore, even with a delicate zoom ring operation, the photographer does not accidentally touch the ring. , Often intentional.

Therefore, it is desirable that the ring rotation amount for inhibiting the zoom movement for preventing the malfunction be set as small as possible. On the other hand, in the auto mode, it is more effective to prevent the malfunction at the start of zooming by setting the ring rotation amount for inhibiting the zoom movement to a relatively large value.

However, if the ring rotation amount exceeds the prohibition determination amount, the photographer wants to obtain a zooming effect. Therefore, once the zoom operation is performed, it responds to a subtle ring operation as in the manual mode. It is desirable to do.

When the effect of blurring the background of the subject, such as the portrait mode, is aimed at, the effect is lost on the wide side where the focal length is short. If the zoom operation is started sensitively to the operation and the ring is rotated in the wide direction, the hysteresis for starting the zoom in response to the ring operation is set to be relatively large.

[0179]

According to the present invention, as described above, according to the present invention, a ring member is provided concentrically with respect to the lens optical axis,
Even if the rotation of the ring member is stopped, the stop of the zoom lens is prohibited for a predetermined period, so even if the rotation detection is difficult due to the low rotation of the ring member,
It is possible to prevent the inconvenience that the zoom operation repeats driving / stopping, and thereby it is possible to perform natural and smooth zooming, thereby realizing comfortable shooting.

According to another feature of the present invention, the responsiveness of the movement of the zoom lens to the operating state of the ring member is changed according to the start and the movement of the zoom lens or the shooting state. Therefore, it is possible to prevent a sudden change in the angle of view at the start of zooming, and to appropriately set the operability of the ring member and the characteristics of the zoom operation according to the intention of the photographer. This makes it possible to obtain optimal and comfortable operability and a zooming effect according to the shooting situation.

Further, according to another feature of the present invention, the change of the response is changed by the moving speed of the zoom lens, so that zooming in which the ring member is operated at a slow start can be performed. Therefore, you do not know how much you need to operate the zoom operation member to move the zoom lens, and you want to zoom but the zoom lens does not move, or conversely, you want to zoom slowly but suddenly change the angle of view By doing so, it is possible to prevent the problem of missing a photo opportunity.

According to another feature of the present invention, the response is changed by changing the reference amount of the rotation amount of the ring member for permitting / prohibiting the start of the movement of the zoom lens. Even in a shooting posture in which a lens unit of an interchangeable lens type camera or the like is held, it is possible to prevent a malfunction in which the zoom lens is moved by just touching the ring member a little. Accordingly, it is not necessary to mechanically adjust the play or load of the ring member, and it is possible to realize a zoom function that satisfactorily responds to a delicate ring operation.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an imaging device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an AF signal processing circuit.

FIG. 3 is a diagram illustrating a gate signal for focus adjustment generated by a frame generation circuit.

FIG. 4 is a flowchart illustrating an algorithm of an automatic focus adjustment operation.

FIG. 5 is a flowchart illustrating a zoom operation.

FIG. 6 is a flowchart illustrating a zoom operation performed in the lens microcomputer.

FIG. 7 is a block diagram illustrating a configuration of an imaging device according to a second embodiment.

FIG. 8 is a block diagram illustrating an AF signal processing circuit in detail.

FIG. 9 is a block diagram showing a conventional example of an interchangeable lens system.

FIG. 10 is a diagram showing a simple configuration of a conventionally used inner focus type lens system.

FIG. 11 is a diagram showing a state in which the position of a fourth lens group for focusing on an imaging surface when the subject distance is changed is continuously plotted.

FIG. 12 is a diagram for explaining an example of a conventional trajectory tracking method.

FIG. 13 is a view for explaining an interpolation method in the direction of the position of the variable power lens.

FIG. 14 is a perspective view schematically showing a zoom ring.

FIG. 15 is a diagram showing details of a light projecting unit of a zoom ring.

FIG. 16 is a diagram showing output signals from the light emitting and receiving elements.

[Explanation of symbols]

 Reference Signs List 101 first lens group 102 second lens group 103 aperture 104 third lens group 105 fourth lens group 106 image sensor for red 107 image sensor for green 108 image sensor for blue 109 red amplifier 110 green amplifier 111 Blue amplifier 112 Camera signal processing circuit 113 AF signal processing circuit 114 Body microcomputer 115 Data reading program 116 Lens microcomputer 117 AF program 118 Frame generation circuit

Claims (6)

[Claims] 1. A ring member provided on a concentric circle with respect to a lens optical axis of a lens unit, detection means for detecting a change amount accompanying rotation of the ring member, and at least a detection result based on a detection result of the detection means. A control means for controlling the movement / stop of the variable power lens group in the optical axis direction, wherein a prohibiting means for prohibiting the stop of the variable power lens group for a predetermined period after the rotation of the ring member is stopped is provided. An imaging device characterized in that: 2. A ring member provided concentrically with respect to a lens optical axis, detection means for detecting an amount of change accompanying rotation of the ring member, and movement of the variable power lens group based on the output of the detection means. Determine the direction and moving speed,
Control means for moving / stopping the variable-magnification lens group in the optical axis direction, wherein the response of the variable-magnification lens group movement to the detection result of the detecting means is determined when the movement of the variable-magnification lens group starts. An image pickup apparatus, further comprising a change unit that changes between a moving state and a moving state. 3. A ring member provided concentrically with respect to the lens optical axis, detecting means for detecting an amount of change accompanying rotation of the ring member, and movement of the zoom lens group based on the output of the detecting means. Determine the direction and moving speed,
Control means for controlling the movement / stop of the lens group in the optical axis direction, wherein a change means for changing the responsiveness of the movement of the variable magnification lens group to the detection result of the detection means in accordance with a shooting state is provided. An imaging device characterized in that: 4. The imaging apparatus according to claim 2, wherein the changing unit changes a moving speed of the variable power lens group with respect to an output of the detecting unit. 5. The apparatus according to claim 2, wherein the change unit changes a reference amount of a change amount accompanying rotation of a ring member for permitting / prohibiting movement of the variable power lens group. An imaging device according to item 13. 6. The imaging apparatus according to claim 1, wherein the lens unit is detachable from the imaging apparatus main body and is replaceable.