JP2000206394A - Lens device, and electronic camera using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently drive-control lens frames in response to a required driving condition so as to reduce an electric power consumption. SOLUTION: This lens device is provided with plural lens frames inside a lens-barrel 1 moving in a storing section between a storing position bringing a storing condition and a photographing preparative position bringing a photographing condition and in a zoom section where the photographing preparative position is included and a power varying operation is executed, and holding a photographing optical system, a stepping motor 26 for moving the plural lens frames, and a drive control means 8 for drive-controlling the stepping motor 26 by the first driving mode at the time of an advancing operation for moving the plural lens frames from the storing position to the photographing preparative position and at the time of a storing operation for moving the lens frames from an optional position within the zoom section to the storing position, and for drive-controlling the stepping motor 26 by a second driving mode operated with an electric current lower than that in a first driving mode at the time of a zoom operation for moving the lens frames within the zoom section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens device and an electronic camera using the same, and more particularly, to a lens device for driving a retractable zoom lens with a stepping motor, and an electronic camera equipped with the lens device. In particular, the present invention relates to drive control of a lens frame in an electronic camera.

[0002]

2. Description of the Related Art In recent years, an electric image signal is generated by using a camera for taking a photograph or the like using a photographing film, an image pickup device or the like, and the image signal is recorded on a recording medium or the like. In electronic cameras and the like (hereinafter, both are collectively referred to as cameras and the like), it is desired to reduce the size of the camera body so that it is convenient to carry and use.

On the other hand, there is a demand for higher functions such as higher precision of an automatic focusing device (autofocusing device = AF device) and higher magnification of a zoom lens used as a photographing lens. .

Therefore, in a conventional camera or the like, various devices have been devised to achieve both miniaturization and high functionality of the camera body. For example, when the camera is not in use, a photographic lens barrel containing a plurality of lens barrels holding the photographic lens (also referred to as a zoom lens barrel when the photographic lens is a zoom lens) is placed inside the camera body. While using the camera to reduce the size of the camera when carrying it, the lens barrel is extended toward the front of the camera body when the camera is used, and a plurality of lens barrels in the lens barrel are moved to predetermined positions. In general, a device equipped with a so-called collapsible zoom lens device or the like that realizes a zooming operation (zoom operation) and an automatic focus adjustment operation (AF operation) by moving each of the zoom lens units has been put to practical use.

In this collapsible zoom lens apparatus and the like, a storage position where the lens frame is housed inside the camera body, and the lens frame are extended and projected so as to protrude from the front of the camera body. A storage section that moves between the shooting preparation position in a state in which the shooting is possible, and a movement section of the lens barrel during the shooting operation starting from the shooting preparation position,
That is, the lens frame is configured to be moved in two moving sections including a zoom section in which a predetermined lens barrel can move for the zoom operation.

When the moving section of the lens frame is configured to perform two different operations in a broad manner, that is, a zoom section (also referred to as a zoom area) mainly performing a zoom operation, and a lens barrel. And a storage section for storing in the camera body,
In both sections, the requirements required to drive the lens barrel differ.

In a normal case, the movement of the lens barrel in the zoom section is mainly performed for the photographing operation, so that a higher movement accuracy is required. On the contrary, high accuracy is not required in the storage section,
A faster operation is required, and it is necessary to quickly move the lens barrel (barrel) to the storage position by high-speed and reliable movement. For this reason, it is desirable to perform drive control of the lens barrel under drive conditions that are optimal for each moving section.

In consideration of such points, in the lens driving device disclosed in, for example, Japanese Patent No. 2702474, the driving speed of the zoom lens is changed between the zoom section and other sections. That is, in the zoom section, the drive speed of the zoom lens is controlled to be driven at a low speed, whereas in the non-zoom section, the control of driving the zoom lens at a high speed is performed.

According to this, the speed of the movement of the zoom lens in the non-zoom section is increased, so that the time required for switching the apparatus from the movable state to the housed state can be reduced.

[0010] Thus, the above-mentioned Patent No. 2702474
In the means disclosed in Japanese Patent Application Laid-Open No. H11-260, the driving conditions of the zoom lens in the zoom section and the other moving sections are changed by focusing on the driving speeds of the zoom lens required in the zoom section and the other moving sections. It is controlled as follows.

[0011]

However, in a normal collapsible zoom lens apparatus, in addition to the driving speed,
The following driving conditions may be required. In the normal case, in the storage section of the lens barrel, many means for operating at a relatively high speed by devising a mechanism such as a cam for moving the lens barrel are used. It is also conceivable that an unexpected external force is applied to a lens barrel or the like holding the lens barrel. Therefore, sufficient drive torque is required to execute drive control in the storage section in which the lens barrel is stored.

In the zoom section, movement in finer steps is indispensable in order to adjust the zoom magnification with high precision, and also to ensure that a predetermined lens barrel is positioned at a predetermined position. Therefore, higher-precision drive control is required.

Further, for example, in an electronic camera or the like,
Since it is necessary to operate an electric circuit and the like related to a photographing system that consumes relatively large power during the photographing operation, it is necessary to suppress power consumed by electric circuits other than the photographing system during the photographing operation.

Therefore, power consumption is relatively large, and a high power saving effect can be expected if the drive current for the zoom operation frequently used in the photographing operation can be reduced. Therefore, it can be said that reduction of the driving current for the zoom operation during the photographing operation is a function particularly desired in recent years.

Incidentally, as described above, an unintended unexpected external force is applied to the lens barrel or the like holding the lens barrel. For example, as shown in the schematic diagram of FIG. When F acts, the camera body 101
The lens frame 102 may move toward the inside of the camera, and may deviate from the original position where the front lens frame 102 is to be arranged.

Conventionally, a so-called closed-loop lens barrel drive system in which a position detecting encoder is provided on a lens barrel and a driving cam and this encoder and a driving DC motor are combined is adopted. The problem of the displacement caused by the external force F as described above has been solved. According to this, even if the position of the lens barrel changes due to external force or the like, the change in position can be detected by the encoder,
This can be corrected.

Examples of the lens barrel corresponding to the abnormal operation of the lens barrel include, for example, JP-A-6-347683, JP-A-7-218807, and JP-A-9-2302.
There is a technique disclosed in Japanese Patent Application Laid-Open No. 15-115, and all of these technical means detect an abnormal operation by using an encoder output for detecting the position of the lens barrel.

As a driving method of the lens barrel, a driving method using a stepping motor controlled by a driving pulse as a driving source is more costly than a combination of a DC motor and an encoder as described above. It is well-known that it is also advantageous from the top of the occupied space. For example, in the means disclosed in Japanese Patent Application Laid-Open No. 5-188267, a stepping motor is used as a driving source of a lens frame, and a photosensor is used as a detecting means for detecting a reference position (home position). I am trying to do it.

On the other hand, driving conditions such as a driving speed for driving a lens barrel and the like are closely related to a driving source such as a motor.
Therefore, in order to control the drive source while reliably adapting to various drive conditions, it is essential to limit the drive source. In a normal case, as a drive source of a lens barrel in a camera or the like, a stepping motor or the like that does not require a member such as an encoder has been more widely used than ever.

Here, a general method of driving a stepping motor will be briefly described. In general, a method of driving a stepping motor includes a one-phase excitation drive shown in FIG. 10, a two-phase excitation drive shown in FIG. 11, and a one-phase excitation drive shown in FIG.
There are various driving methods such as a two-phase excitation driving and a microstep driving (not shown).

The one-phase excitation drive is a drive type in which energization is alternately repeated in the A-phase and B-phase coils as shown in FIG. Therefore, while driving with low power consumption is possible,
The driving torque is characterized by a relatively low driving method.

In the case of two-phase excitation, the magnetic poles of the rotor move so as to face the middle between two adjacent magnetic poles of the stator. This is the same as in the case of phase excitation. This two-phase excitation is a drive type in which the A-phase and B-phase coils are energized simultaneously as shown in FIG. Therefore, in the case of two-phase excitation, it is necessary to always excite the stator to keep the motor stopped. From this, the two-phase excitation is 1
Although it requires more power consumption than phase excitation, it can be driven with a higher driving torque than one-phase excitation, and can achieve higher-speed movement.

In the case of the 1-2-phase excitation, the one-phase excitation and the two-phase excitation are repeated. For example, when the rotation starts from a position facing the magnetic pole of the stator, the next magnetic pole is started. The change causes the rotor to move to the middle between two adjacent magnetic poles, and the next change in the magnetic pole causes the rotor to move to a position facing the adjacent magnetic pole. As a result, the rotation amount obtained by one change of the magnetic pole of the stator is equivalent to a half rotation amount in the case of one-phase excitation or two-phase excitation.
Therefore, in the 1-2-phase excitation, the amount of rotation per magnetic pole change can be reduced as compared with the case of the 1-phase excitation or the 2-phase excitation, so that a finer drive can be performed and a higher In addition to the feature that high precision positioning accuracy can be ensured, there is an advantage that vibration and noise can be reduced.

The micro-step driving is a driving method capable of realizing an electrically fine step angle, and can secure a higher positioning accuracy than in the case of the 1-2-phase excitation. In addition, there is a feature that it can contribute to low vibration and low noise.

In the case where a stepping motor is used as described above, if the drive system of the stepping motor is controlled to be switched according to the required driving conditions, the lens barrel can be moved more efficiently. Extremely convenient.

In the inner focus type zoom lens barrel, the most important problem with respect to the displacement of the front lens barrel due to an external force is the positional relationship between the zoom lens and the focus lens. According to the focusing method often used in conventional silver halide cameras, the position of the focus lens is determined based on the position of the zoom lens and distance information obtained by distance measurement. Deviating from the original position is not allowed. Therefore, in the conventional means, it is indispensable to detect the position of the lens barrel by the encoder and to manage the position of the lens barrel so as to be always at a predetermined position.

Also, in a conventional electronic camera, video movie, or the like, a so-called contrast focusing method in which a focusing state is performed by detecting a high-frequency component of a signal acquired by an image sensor without depending on distance information is performed. It is generally used, but it is also known that the strictness is not required for the positional relationship between the zoom lens and the focus lens in the one using this focusing means.

However, in the conventional electronic camera or the like employing the contrast focusing method as described above, the photographing operation is not particularly hindered as long as the front lens frame is slightly displaced by external force or the like. Therefore, there is no need to provide an encoder. However, in the case of using a stepping motor as a drive source for moving the lens frame, if the amount of displacement of the front lens frame becomes larger than a certain value, it is necessary to correct the lens frame at the reference position. It can only be done when returning to (home position). For this reason, for example, when the front lens barrel of the lens frame of the camera used by the photographer during the shooting operation is significantly misaligned, the misalignment state is established. It is also conceivable that photographing is continued without knowing the information. Then, the following problem occurs.

That is, it is conceivable that the distance between the zoom lens and the focus lens is not the desired distance, and the moving focus lens collides with an adjacent zoom lens or the like during the execution of the focusing operation.

After the focusing operation is completed, the object distance is calculated based on the relationship between the position of the zoom lens and the position of the focus lens, and the information on the object distance is used as camera control information for controlling a flash device or the like. In the case of using, if the positional deviation is large, the error of the camera control information increases, which may degrade the image quality.

Because of the above-described problems, a zoom lens barrel having a front lens barrel provided in a conventional electronic camera or the like and having a movable front and rear movement is provided with a lens barrel drive structure using a stepping motor as a drive source. It is considered difficult to adopt a configuration that does not use an encoder.

The present invention has been made in view of the above points, and an object of the present invention is to quickly move a lens frame during a storage operation of moving the lens frame into the camera body. In addition to performing drive control to move the lens, and performing zoom control during the shooting operation, by performing drive control to move the lens barrel with higher accuracy, efficient drive control can be performed according to the required drive conditions. It is an object of the present invention to provide a lens device which can be realized and thereby contribute to reduction in power consumption of the entire device.

Further, the present invention is to optimally control the drive of a stepping motor used as a drive source for moving a lens frame in an electronic camera or the like, in accordance with a plurality of drive methods (drive modes). Accordingly, an object of the present invention is to provide an electronic camera which includes a lens device that can contribute to reduction in power consumption, and thereby can obtain both good usability and operability.

The present invention solves this displacement automatically by a displacement correction process even when a displacement of the lens frame on the subject side occurs due to an external force or the like applied to the lens frame. It is another object of the present invention to provide a camera having a small and low-cost zoom lens barrel that can continue shooting operation.

Further, according to the present invention, in an electronic camera capable of generating and recording moving image data and still image data, a zoom operation during a moving image shooting operation and a zoom operation during a still image shooting operation are performed. By controlling the driving in different driving modes, it is possible to suppress simultaneous recording of noise components such as driving noise of a motor and the like accompanying zoom driving during execution of a moving image photographing operation, and to suppress vibration to suppress a favorable moving image. An object of the present invention is to provide an electronic camera that can record data and can also record still image data comfortably.

[0036]

In order to achieve the above object, a lens device according to a first aspect of the present invention includes a lens position in a lens barrel, a storage position in a storage state, and a photographing preparation position in a photographable state. And a zoom section including the shooting preparation position and a zooming operation in which the zooming operation is performed, and a plurality of lens frames that hold a shooting optical system, and a stepping that moves the plurality of lens frames. A motor and a feeding operation for moving the plurality of lens frame from the storage position to the shooting preparation position, and a storage operation for moving the lens frame from an arbitrary position in the zoom section to the storage position. In a zoom operation for driving the stepping motor in a first drive mode and moving the lens barrel in the zoom section, the stepping motor is controlled to the above-described state. Characterized by comprising a drive control means for driving and controlling the second driving mode for operating at a lower current than the first drive mode.

According to a second aspect of the present invention, in the lens device according to the first aspect, the drive control means includes the first drive.
In the drive mode, the stepping motor is drive-controlled by two-phase excitation, and in the second drive mode, the stepping motor is drive-controlled by 1-2-phase excitation or micro-step drive.

The electronic camera according to the third aspect of the present invention
Electronic imaging means for photoelectrically converting a subject image formed by the imaging optical system to generate an image signal; and performing predetermined processing on the image signal generated by the electronic imaging means to obtain a predetermined form. In an electronic camera including an image processing unit for converting and a recording unit for recording an output from the image processing unit as image data,
Move to a storage section between a storage position where the lens barrel is stored and a shooting preparation position which is a position where shooting is possible and a zoom section where the zooming operation is performed including the shooting preparation position, A plurality of lens barrels for holding the shooting optical system,
A stepping motor for moving the plurality of lens barrels, a transmission unit for transmitting the driving force of the stepping motor to the lens barrel, and a feeding operation for moving the plurality of lens barrels from the storage position to the shooting preparation position And during a storage operation in which the lens frame moves from an arbitrary position in the zoom section to the storage position, the stepping motor is driven and controlled in a first drive mode, and the lens frame is moved in the zoom section. And a drive control means for driving and controlling the stepping motor in a second drive mode in which the stepping motor is operated at a lower current than the first drive mode during a zoom operation in which the stepping motor is moved.

According to a fourth aspect, in the electronic camera according to the third aspect, the drive control means controls the drive of the stepping motor by two-phase excitation in the first drive mode, and the second drive In the mode, the driving of the stepping motor is controlled by 1-2-phase excitation or micro-step driving.

According to a fifth aspect of the present invention, in the electronic camera according to the third aspect of the present invention, there is provided a control means for controlling not to supply power to the electronic imaging means during the extension operation and the storage operation of the lens barrel. Is further provided.

According to a sixth aspect, in the electronic camera according to the fifth aspect, the drive control means drives the stepping motor with a higher drive voltage in the first drive mode than in the second drive mode. It is characterized by controlling.

According to a seventh aspect of the invention, there is provided an electronic camera, comprising: an electronic imaging means for generating an image signal by photoelectrically converting a subject image formed by a photographic optical system; and an image signal generated by the electronic imaging means. An electronic camera including image processing means for performing predetermined processing on the image data to convert the image data into a predetermined form, and recording means for recording an output from the image processing means as image data. A lens frame that holds a plurality of lens frames that hold the photographing optical system, at least one lens frame protrudes from the front surface of the camera body and is driven forward and backward; and a pulse drive that moves the plurality of lens lens frames. A stepping motor; transmission means for transmitting the driving force of the stepping motor to the lens frame; and driving control of the stepping motor, the position of the lens frame being adjusted. And control means for controlling, characterized by comprising a plurality of position detecting means for detecting the zoom position of the lens barrel.

According to an eighth aspect of the present invention, in the electronic camera according to the seventh aspect, the transmitting means is a cam member, and the plurality of position detecting means detects displacement of the cam member to thereby form the lens mirror. The zoom position of the frame is detected.

According to a ninth aspect, in the electronic camera according to the seventh aspect or the eighth aspect, calculation means for calculating zoom position information from a drive pulse signal for driving the stepping motor; And a correcting means for correcting the zoom position information calculated by the calculating means in accordance with the outputs of the plurality of position detecting means.

According to a tenth aspect, in the electronic camera according to the eighth aspect, the cam member is a cam cylinder having a cam groove formed on a circumference of a cylindrical portion, and the plurality of position detecting means are It is characterized by being arranged along the circumferential direction on the circumference of the cylindrical portion of the cam cylinder.

According to an eleventh aspect, in the lens apparatus according to the second aspect, the drive control means drives the stepping motor at a higher drive frequency in the first drive mode than in the second drive mode. It is characterized by controlling.

According to a twelfth aspect, in the electronic camera according to the fourth aspect, the drive control means drives the stepping motor at a higher drive frequency in the first drive mode than in the second drive mode. It is characterized by controlling.

According to a thirteenth aspect, in the lens device according to the second aspect, the drive control means controls the drive of the stepping motor by two-phase excitation when the power is turned off. .

According to a fourteenth aspect, in the electronic camera according to the fourth aspect, the drive control means drives and controls the stepping motor by two-phase excitation when the power is turned off. .

An electronic camera according to a fifteenth aspect of the present invention comprises an electronic image pickup means for photoelectrically converting a subject image formed by a photographing optical system to generate an image signal, and an image signal generated by the electronic image pickup means. Image processing means for performing predetermined processing on the image data to convert the image data into a predetermined form; and recording means for recording an output from the image processing means as image data to generate and record moving image data and still image data. The electronic camera according to claim 1, wherein the storage section between the storage position where the lens barrel is stored in the lens barrel and the shooting preparation position where the shooting is possible includes the shooting preparation position. A plurality of lens barrels that move to a zoom section in which a zooming operation is performed and hold a photographing optical system; a stepping motor that moves the plurality of lens barrels; A transmitting means for transmitting the driving force of the lens frame to the lens frame, a feeding operation in which the plurality of lens frames move from the storage position to the photographing preparation position, and a position where the lens frame is at an arbitrary position in the zoom section. During the storage operation of moving from the camera to the storage position and during the shooting operation of the still image, the stepping motor is driven and controlled by the first drive mode, and during the zoom operation and the moving image in which the lens barrel moves within the zoom section. A drive control means for driving and controlling the stepping motor by a second drive mode for operating the stepping motor with a lower current than the first drive mode during an image capturing operation is provided.

According to a sixteenth aspect, in the electronic camera according to the fifteenth aspect, in the first drive mode, the drive control means controls the drive of the stepping motor by two-phase excitation, and controls the second drive. In the mode, the driving of the stepping motor is controlled by 1-2-phase excitation or micro-step driving.

According to a seventeenth aspect, in the electronic camera according to the fifteenth aspect, in the first drive mode, the drive control means controls the drive of the stepping motor by 1-2 phase excitation, and In the driving mode, the stepping motor is driven and controlled by micro-step driving.

An electronic camera according to an eighteenth aspect of the present invention provides an electronic camera which photoelectrically converts a subject image formed by a photographing optical system to generate an image signal, and converts an image signal generated by the electronic imager into an image signal. A lens barrel in an electronic camera including an image processing unit for performing predetermined processing on the image data to convert the output into a predetermined form; and a recording unit for recording an output from the image processing unit as moving image data or still image data. , A storage section between a storage position where the lens barrel is stored and a shooting preparation position which is a position where shooting is possible, and a zoom section where the zooming operation is performed including the shooting preparation position. And a plurality of lens frames for holding the photographing optical system, a stepping motor for moving the plurality of lens frames, and transmitting the driving force of the stepping motor to the lens frame. And a driving unit that controls the driving of the stepping motor in a first driving mode during a still image shooting operation, and operates the stepping motor at a lower current than the first driving mode during a moving image shooting operation. And a drive control means for performing drive control in the second drive mode.

According to a nineteenth aspect, in the electronic camera according to the eighteenth aspect, in the first drive mode, the drive control means controls the drive of the stepping motor by two-phase excitation, and controls the second drive. In the mode, the driving of the stepping motor is controlled by 1-2-phase excitation or micro-step driving.

According to a twentieth aspect, in the electronic camera according to the eighteenth aspect, in the first drive mode, the drive control means controls the drive of the stepping motor by one-two phase excitation, and In the driving mode, the stepping motor is driven and controlled by micro-step driving.

[0056]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. The following embodiments of the present invention exemplify an electronic camera (hereinafter abbreviated as a camera) configured to acquire an electric image signal using an image sensor or the like.

In the camera according to one embodiment of the present invention, the operation of the whole camera is controlled by a system controller 8 as control means as shown in the block diagram of FIG.
The system controller 8 includes a release switch (SW) 11 for generating a signal for instructing the start of photographing among a group of operation switches as operation means, and a zoom-up switch (SW) for generating a signal for instructing a zoom-up operation among zoom operations. SW) 9, a zoom-down switch (SW) 1 for similarly generating a signal for instructing a zoom-down operation.
0, a power switch (SW) 12 for generating signals for instructing start and stop of power supply (power-on signal and power-off signal) and the like are electrically connected. To be entered.

In this camera, when the start of photographing is instructed by the release switch 11, the subject image taken through the photographing optical system of the zoom lens barrel 1 is converted into an electric signal by the imager 2 which is an image pickup device. ,
In the imaging circuit 3, image processing such as sample hold is performed on the electric signal, and the output image signal is
The signal is converted into a digital signal by the A / D conversion circuit 4. Next, in the focusing circuit 7, contrast information for focusing driving of the photographing lens is extracted from a high frequency component of the digital image signal output from the A / D conversion circuit 4 and output to the system controller 8.

On the other hand, the image signal output from the A / D conversion circuit 4 is output to an image processing circuit 13 which is an image processing means. Is stored temporarily. The image signal stored in the memory 14 is transmitted to the display circuit 1 as needed.
The image data is output to a display means (hereinafter simply referred to as an LCD) 16 such as a liquid crystal display via the digital camera 5 and displayed as an image thereon. After being output to a compression / expansion circuit 19 and subjected to a compression process suitable for recording, it is output to a recording medium 18 such as a memory card or a flash memory via an interface (I / F) 17 as recording means. It is recorded in this. The image signal recorded in a compressed form on the recording medium 18 receives a predetermined instruction signal from a group of operation switches, and receives a predetermined instruction signal from an operation switch group.
After being subjected to a decompression process suitable for display here, the data is read into the memory 14 and then displayed on the LCD 16 via the display circuit 15.

In this embodiment, the imager 2
A block including the imaging circuit 3 and the like is an electronic imaging unit that photoelectrically converts a subject image formed by a photographing lens held by a plurality of lens barrels to generate an image signal. A block including at least the electronic imaging unit and formed by components such as the A / D conversion circuit 4 and the focusing circuit 7 is referred to as an imaging block.

The system controller 8 drives the focus motor 29 incorporated in the zoom lens barrel 1 via the focus motor drive circuit 6 and
(AF operation).

In the photographing operation, the release SW
When the zoom-up SW 9 or the zoom-down SW 10 is operated prior to the operation of the operation 11, the system controller 8 builds in the zoom lens barrel 1 via the zoom motor driving circuit 5 based on the input zoom operation instruction. Also, it serves as a drive control circuit that drives the zoom motor 26 to be operated and performs a zooming operation (zooming operation) of the photographing optical system.

A battery 42 serving as a drive power supply is electrically connected to the system controller 8 via a power supply circuit 41. The power supply circuit 41 supplies power to each internal circuit of the camera under the control of the system controller 8.

As shown in FIG. 1, the zoom lens barrel 1 includes a first lens group 22, a second lens group 23, and a third lens group 2.
A photographing optical system such as a fourth and fourth group lens 25 and a first group lens 22
, A zoom cam frame 27 for performing a zooming operation (zoom operation), a zoom motor 26 for driving the zoom cam frame 27, and photographing for performing a focusing operation (AF operation). A focus motor 29 for moving a predetermined lens group of the lens system in a direction along the optical axis O, an auxiliary frame 28 for holding the focus motor 29 and the like, and a photoreflector serving as position detecting means;
PR (A) 31 and photo reflector; PR (B) 32
And the like.

The zoom lens barrel 1 will be described in more detail. FIG. 2 is a perspective view illustrating a zoom lens barrel of the camera according to the present embodiment.

The zoom lens barrel 1 includes a fixed frame 30 for fixedly supporting the zoom lens barrel 1 on the front surface of a camera body (not shown), and a plurality of lens groups (22, 23, 24, 2).
5) and the like (not shown in FIG. 2; see FIG. 1), and a zoom motor 26 (not shown in FIG. 2) including a stepping motor or the like as a zoom drive source.
1) and a transmission means driven by the zoom motor 26, which is rotatably supported by a fixed frame 30 and includes a first group lens frame 21, a second group lens 23, a third group lens 24, an auxiliary frame 28, and the like. A zoom cam frame 27, which is a cam member that is supported so as to be able to advance and retreat in the direction along the optical axis O, and a focus motor 29 (see FIG. 1) that performs a focusing operation by moving the fourth lens group 25 (see FIG. 1) in the direction along the optical axis O. 2, not shown in FIG. 1), and the focus motor 29 and the like are attached.
A focus driving auxiliary frame 28 (not shown in FIG. 2) for supporting the fourth lens unit 25 so as to be able to advance and retreat in a direction along the optical axis O.
1) and two PR (A) 31, PR which are position detecting means for detecting the position of a cam pin engaged with the cam groove 27a of the zoom cam frame 27 by detecting the rotation state of the zoom cam frame 27. (B) 32 and the like.

The first lens group 22 is disposed closest to the subject, is disposed so as to protrude from the camera body toward the front during a shooting operation, and is held by the first lens group frame 21. The second group lens 23, the third group lens 24, the fourth group lens 25 as a focus lens, and the like
It is housed inside the zoom cam frame 27.

The above PR (A) 31 and PR (B) 32
Are arranged along the same circumferential direction on the outer peripheral surface of the fixed frame 30. These PR (A) 31 and PR (B)
At a predetermined position on the outer peripheral surface of the zoom cam frame 27 at a position facing each of the passage paths 32, a detection pattern (A) which is a reflection member along a direction orthogonal to the optical axis O is provided.
33 and the detection pattern (B) 34 are attached side by side. The detection pattern (A) 33 is formed so that the detection period is longer than the detection pattern (B) 34, and the length of the detection pattern (A) 33 is PR.
The interval is set to be longer than the interval between (A) 31 and PR (B) 32.

Therefore, when the reflected light of the detection pattern (A) 33 and the detection pattern (B) 34 is received by the PR (A) 31 and PR (B) 32, the PR (A) 31 and P
An output signal is detected from each of the R (B) 32. This makes it possible to detect the position of the zoom cam frame 27, that is, the position of the zoom lens barrel 1 when the zoom lens barrel 1 moves in the collapsed section and the zoom section (see FIG. 4).

The zoom cam frame 27 has a substantially cylindrical shape, and the first lens frame 21 is slidably fitted on the outer peripheral portion thereof. The zoom cam frame 27 is provided with a cam groove 27a having a predetermined shape at a predetermined position on the peripheral surface. The cam groove 27a is formed in the cam groove 27a toward the inner peripheral side of the first group lens frame 21. The protruding drive pin is fitted. Further, the first group lens frame 21 is provided with a protruding arm portion 30a of the fixed frame 30.
The optical axis O is defined by the linear guide groove provided on the
Is guided in a direction along the straight line. Accordingly, when the zoom cam frame 27 is rotated by the zoom motor 26, the first group lens frame 21 is driven forward and backward in the direction along the optical axis O in response to the rotation, and the zoom lens barrel is moved to the rearmost position ( It moves from the stowed position or the retracted position) to the extreme end position of the zoom section (the maximum telephoto position).

Then, inside the zoom cam frame 27,
The group lens 23, the third group lens 24, and the auxiliary frame 28 are held so as to be able to advance and retreat in the optical axis direction. 24, each member of the photographing system such as the auxiliary frame 28 moves in the direction along the optical axis O.

During the zoom operation, the focus motor 29 also moves integrally with the advance / retreat of the auxiliary frame 28, and at the same time, the focus motor 29 is driven to rotate in accordance with a predetermined tracking curve. Move to the focus position at each zoom position.

FIG. 3 is a conceptual diagram showing the extended positional relationship of each lens group in the zoom lens barrel of the present camera from the retracted position to the telephoto end position through the wide end position (also a photographing preparation position). FIG.

In FIG. 3, the retracted position is the position when the zoom lens barrel 1 is completely housed inside the camera body, and indicates the rearmost position of the retracted section. Wide end (position) and tele end (position)
Indicates the moving range of the zoom lens barrel 1 when the camera is in a photographable state, that is, both end positions in the zoom section. The extreme end position where the magnification of the photographing lens is closer to the wide angle is referred to as the wide end. The extreme end position is called the tele end. Note that the wide end is a photographing preparation position, and is also the frontmost end position in the collapsed section.

As shown in FIG. 3, when the zoom lens barrel 1 moves from the retracted position to the wide end (photographing preparation position), the first to fourth lens units 22 to 25 are extended to predetermined positions. The camera is ready for shooting.

In the section from the wide-angle end to the telephoto end, the first and third lens units 22 and 24 are extended and moved in the direction along the optical axis O to change the magnification (zoom operation).
Is made. In response to this, the fourth lens unit 25 is also extended and moved in the same direction within a predetermined range. This four-group lens 25
In FIG. 3, a focus adjustment operation (AF operation) is performed by moving within a range indicated by oblique lines, that is, within a focus movement range.

The extension position of the fourth group lens 25 is
It is determined by the subject distance and the magnification. That is, FIG.
As shown by the closest curve and the infinity curve in, the extension position of the fourth lens unit 25 for the same subject distance changes according to the magnification.

As described above, when the PR (A) 31 and the PR (B) 32 are arranged at positions facing the detection pattern (A) 33 and the detection pattern (B) 34, respectively, A) 33 and detection pattern (B)
The light reflected from the light receiving device 34 is received. In response, the PR (A) 31 and PR (B) 32 generate an ON signal. Therefore, based on the output signals of PR (A) 31 and PR (B) 32 and the rotation angle of zoom cam frame 27, it is detected whether zoom cam frame 27 is in the collapsed section or the zoom section. It has become.

FIG. 4 shows PR (A) 31 and PR (B) 3
FIG. 7 is a diagram showing an output signal of No. 2 and an area (zone) within a zoom section that can be detected by the output signal. That is, in the present embodiment, the arrangement of the PR (A) 31 / PR (B) 32 and the detection pattern (A) 33 / detection pattern (B) 34 is devised as described above, so that the PR (A) 31 And PR
By (B) 32, four areas (reference numerals Z1 to Z4 in FIG. 4) in the zoom section can be detected.

The camera according to the present embodiment has the above-described configuration, and, for example, an external force acts on the first lens group frame 21 which is one of the lens mirror frames protruding from the camera body. When the group lens frame 21 has largely moved toward the camera body, or the zoom motor 26 has largely lost synchronism due to an external force acting on the first lens frame 21 during zoom driving. In such a case, the original zoom position data stored in the system controller 8 in advance differs from the actually detected zoom position of the zoom cam frame 27. For example, when the drive instruction is issued by the system controller 8 and the zoom position should be at the telephoto end, and the actual zoom cam frame 27 is located at a position near the wide end, the instruction signal of the system controller 8 is output. The position data of the zoom cam frame 27 defined on the basis of PR (A) 31 and PR (B) 3
2 may differ from the zoom position of the zoom cam frame 27 detected.

Therefore, in such a case, the camera of the present embodiment drives the zoom motor 26 to rotate the zoom cam frame 27 so as to be retracted to a predetermined position at the wide end. If the position of the zoom cam frame 27 detected by the PR (A) 31 and PR (B) 32 is a collapsed section, the zoom cam frame 27 is extended to a predetermined position at the wide end. At the same time, the zoom position data of the system controller 8 is also rewritten to data indicating the wide end. Thus, when an external force or the like acts on the position of the zoom cam frame 27 to cause an abnormality, the position of the zoom cam frame 27 is corrected.

The operation of the camera having the above-described configuration according to the embodiment at the time of the photographing operation will be described below.

FIG. 5 is a flowchart showing a sequence of a photographing operation in the camera of this embodiment.

First, in step S11, the system controller 8 of the electronic camera checks the state of the power switch 12 in the operation switch group, and confirms that the power switch 12 has been turned on.
Move to the processing of.

In step S12, a subroutine of a photographing preparation process, that is, a process in which the zoom lens barrel 1 is extended from the retracted position to the photographing preparation position (the wide end position of the zoom section), and the present electronic camera is brought into a photographing preparation state (Lens extension processing) is executed.

Next, in step S13, the system controller 8 monitors the state of the output signal of the PR (B) 32. If an ON signal from the PR (B) 32 is detected, the system controller 8 proceeds to the next step S15. Proceed to. If no ON signal from PR (B) 32 is detected in step S13, the subroutine of the abnormality process in step S14 (see FIG. 8) is executed, and then the process proceeds to step S15.

In step S15, the system controller 8 rotates the zoom motor 26 in a predetermined direction (here, the normal rotation direction) via the zoom motor drive circuit 5 to rotate the zoom cam frame 27. Then, in response to this, a plurality of lens mirror frames such as the first lens frame 21 are moved along the optical axis O.
, And the zoom lens barrel 1 is extended accordingly. At this time, the drive of the zoom motor 26 is controlled by the system controller 8 by the two-phase excitation drive which is the first drive mode. Then, when the zoom lens barrel 1 moves to the shooting preparation position, PR (A) 31
Is turned on.

That is, the system controller 8 sets the PR
The state of the output signal of (A) 31 is monitored, and the above-described processing from step S15 is repeatedly executed until the ON signal from PR (A) 31 is detected in step S16. Then, in step S16 described above, PR
(A) When an ON signal from the terminal 31 is detected, the process proceeds to the next step S17. In this step S17,
The system controller 8 controls the power supply circuit 41,
Power supply to the photographing block is started (power of the photographing block is turned on).

When the power supply to the photographing block is started in this way, a state where actual photographing can be performed, that is, a photographing preparation state is completed. In this state, the photographer arbitrarily operates the operation switch group to execute a desired operation.

For example, the zoom processing subroutine in step S18 is executed by operating the zoom-up SW 9 or the zoom-down SW 10, whereby a desired zoom operation is performed (see FIG. 7).

At the time of this zoom operation, the following processing is performed. That is, the system controller 8 as drive control means controls the drive of the zoom motor 26 via the zoom motor drive circuit 5. At this time, the zoom motor 26 is operated at a lower current than in the first drive mode. The drive is controlled by a 1-2 drive mode, ie, 1-2-phase excitation drive or micro-step drive. And
By operating an operation switch different from those of the zoom-down SW 9 and the zoom-down SW 10, the zoom processing subroutine ends, and the camera returns to the photographing standby state (main routine) (return).

Here, the sequence of the zoom process is shown in FIG.
This will be described in more detail with reference to the flowchart of FIG.

As described above, when the sequence of the zoom process is started by the instruction signal from the zoom-up switch 9 or the zoom-down switch 10, first, in step S21, the output signal of the zoom switch, that is, the zoom-up switch 9 or the zoom-down switch 10 is turned on. It is determined whether the switch is off or on. If any switch is on, the process proceeds to step S22. If any switch is off, the process proceeds on step S30. .

In step S22, the zoom mode is entered. In the next step S23, the zoom motor 26
Starts pulse driving. Subsequently, in step S24, the output drive pulse value P is added or subtracted, and the count is incremented or decremented and stored.

Next, in step S25, the system controller 8 calculates zoom position data corresponding to the drive pulse value P stored in step S24.
This zoom position data is data indicating which position of the zoom lens barrel 1 is within its moving range (the range from the retracted position to the wide end position and the range from the wide end position to the tele end position). This corresponds to the rotation angle of the zoom cam frame 27. As described above, the system controller 8 functions as a calculation unit that calculates zoom position information (data) from the drive pulse value P (drive pulse signal) for driving the zoom motor 26 (stepping motor).

In step S26, the normal mode for judging the zoom position is entered. In the next step S27, the drive pulse value P described above and the pulse value corresponding to the original zoom position data stored in the system controller 8 in advance are set. Is compared.

The drive pulse of the zoom motor 26 basically corresponds to the actual zoom position unless step-out of the stepping motor or the like occurs.

Therefore, in step S27,
It is determined whether or not the drive pulse value P of the zoom motor 26 and the pulse value of the desired zoom position match with each other by PR.
(A) 31 and PR (B) 32 determine the output.

Note that this determination is based on PR (A) 31 or P (A) 31.
This is performed only when the on / off state of the output signal of the R (B) 32 is switched (zoom positions corresponding to the points indicated by reference numerals C1, C2, C3, and C4 in FIG. 4).

That is, PR (A) 31 and PR (B) 32
Are constantly monitored by the system controller 8, and the zoom positions are indicated by reference numerals C1, C2, C3,.
When the positions indicated by C4 are reached, the drive pulse value P of the zoom motor 26 at that time and the symbol C1
The drive pulse values corresponding to the zoom positions at C2, C3, and C4 are compared.

Here, if the drive pulse value P matches the pulse value corresponding to the original zoom position, it is determined that the state is normal, and the process proceeds to step S29. On the other hand, if the drive pulse value P does not match the pulse value corresponding to the original zoom position, the zoom cam frame 27 is considered to have been moved by the action of, for example, an external force during the zoom drive. It is determined that it is not in the proper state, and the process proceeds to step S28.

In step S28, the system controller 8 obtains the zoom position data stored therein,
Correction is performed so that the zoom position data is detected by PR (A) 31 and PR (B) 32. Here, the system controller 8 converts the zoom position information calculated during the zooming operation into PR (A) 31 and PR (B) 32.
(Position detecting means) plays the role of a correcting means for correcting in accordance with the output. Thereafter, the process proceeds to step S29.

Next, in step S29, when the zoom motor 26 is driven with a predetermined number of pulses or more, P
It is determined whether or not there are predetermined outputs of R (A) 31 and PR (B) 32. Here, PR (A) 31 and PR
(B) When it is determined that the predetermined output of 32 is output, the process returns to the step S21 described above.

On the other hand, PR (A) 31 and PR (B) 32
If the output does not reach the predetermined output, it is determined that some external force or the like is continuing to act on the first lens group 21, and the process proceeds to step S31. In this step S31, a subroutine for abnormality processing is called. .

On the other hand, if it is determined in step S21 that all the zoom switches are in the off state, the process proceeds to step S30 as described above. In this case, in step S30, if the zoom position has not changed from the time of the previous determination, the series of zoom processing sequence ends (return).

On the other hand, if it is determined in step S30 that the zoom position has changed from the time of the previous determination, it is determined that the first lens group frame 21 has moved due to some external force or the like. Conceivable. Therefore, the process proceeds to step S31, where a subroutine for abnormality processing is called.

Here, the details of the subroutine of the abnormal processing will be described with reference to the flowchart shown in FIG.

In step S41, the focus motor 29 is driven. Then, in step S42, the fourth lens unit (focus lens) 25 is moved to a predetermined infinity position. This operation is considered to be caused by the fact that the zoom lens is not at the normal extended position,
This is a process performed to prevent the fourth and fourth lens units 25 from interfering with each other.

Next, in step S43, the zoom motor 26 is rotated forward or backward to move the zoom cam frame 27 to a predetermined zoom position, that is, a predetermined position near the wide end. That is, if the zoom cam frame 27 is in the collapsed section before the driving of the zoom motor 26 in step S43, the zoom motor 26 is rotated forward to rotate the zoom cam frame 27 in a predetermined direction, and the wide end position is set. Let out. Similarly, when the zoom motor 26 is in the zoom section before driving, the zoom motor 2
By rotating the zoom cam frame 27 in a predetermined direction by rotating the zoom cam frame 27 in the reverse direction, the zoom cam frame 27 is retracted to the wide end position.

Next, in step S44, PR
By checking the output signals of (A) 31 and PR (B) 32, it is determined whether or not the zoom cam frame 27 has reached the wide end position. Here, if it is determined that the zoom cam frame 27 has reached the same position, the next step S4
The process proceeds to step S5, and if it is determined that the time has not reached, the process proceeds to step S46.

In step S46, the zoom motor 2
It is confirmed whether or not 6 has driven more than a predetermined number of pulses. Then, in this case, when it is confirmed that the drive has been performed for the predetermined number of pulses or more,
It is determined that the zoom operation cannot be performed normally for some reason, and a predetermined NG process is executed.
The NG process is a series of processes such as, for example, displaying a warning or the like to stop the photographing operation.

On the other hand, if it is determined in step S46 that the driving of the predetermined number of pulses has not yet been performed, the process returns to step S43, and the subsequent processes are repeated.

In step S45, an initialization process for storing the zoom position data as data corresponding to the wide end position is performed. Thus, a series of abnormal processing is completed, and a sequence of the zoom processing, that is, step S2 in FIG.
It returns to the process of 1.

The photographing process in step S19 in FIG. 5 is a process executed by operating the release SW11. For example, the AE operation and the AF operation performed by the first release operation, and the release performed by the second release operation. This is a subroutine at the time of the photographing operation including the operation. When a series of photographing operations is completed, the photographing process ends, and the camera returns to a photographing standby state (main routine) (return).

On the other hand, in step S20 of FIG.
By operating the power SW 12 to end the shooting state, a shooting end process (power-off process) for storing the lens barrel 1 inside the camera body is performed. The sequence of the photographing end processing will be described in detail below with reference to the flowchart of FIG.

In the camera according to the present embodiment, the system controller 8 constantly monitors the output signal of the power SW 12 when the photographing operation is possible. As shown in step S51 of FIG. Is determined whether or not the output signal is a power-off signal. Here, when the off signal of the power SW 12 is detected, a photographing end process is executed.

First, in step S52, the system controller 8 controls the power supply circuit 41 to stop power supply to the photographing block (power off). Next, step S5
In 3, the system controller 8 drives the zoom motor 26 to rotate in a predetermined direction (here, the reverse rotation direction) via the zoom motor drive circuit 5 to rotate the zoom cam frame 27. Then, in response to this, a plurality of lens frames such as the first lens frame 21 are retracted in the direction along the optical axis O,
Accordingly, the zoom lens barrel 1 moves in the storage direction. At this time, the drive of the zoom motor 26 is controlled by the system controller 8 by the two-phase excitation drive which is the first drive mode. When the zoom lens barrel 1 moves to the retracted position, the output signal of the PR (B) 32 is turned on.

That is, the system controller 8 sets the PR
(B) The output signal of 32 is monitored, and step S54 is performed.
, It is determined whether or not the output signal from PR (B) 32 is an ON signal. As described above, when the zoom lens barrel 1 reaches the retracted position and an ON signal is generated from the PR (B) 32, the system controller 8 receives the signal and controls the power supply circuit 41 to drive the zoom motor in step S55. Power supply to the circuit 5 and the like is stopped (power-off processing). Then, a series of sequences of the photographing end processing ends (end).

As described above, in the photographing end processing executed in response to the power-off signal generated by the operation of the power switch 12, the zoom lens barrel 1 is moved from an arbitrary position in the zoom section to a part of the zoom section and the collapsed section. After that, it moves to the retracted position. At this time, the zoom motor 26
Is driven and controlled by the first drive mode (two-phase excitation drive).

That is, the photographing end process is started when the photographer arbitrarily turns off the power SW 12 when the camera is in a state where the photographing operation can be executed. Therefore, the state of the zoom lens barrel 1 immediately before the power SW 12 is operated is at an arbitrary position in the zoom section.

However, when the photographing end processing is performed, it is necessary to store the zoom lens barrel 1 more quickly, and in this embodiment, the zoom lens barrel 1 is moved to an arbitrary position in the zoom section. The zoom motor 26 is also driven and controlled in the first drive mode (two-phase excitation drive) when moving in a zoom section from to the wide end position (shooting preparation position).

As described above, according to the above-described embodiment, during the execution of the zoom process during the photographing operation, the zoom lens barrel 1 is driven in the second drive mode (1-2-phase excitation drive or microstep drive). ), It is possible to secure higher positioning accuracy while suppressing power consumption.

Further, in the photographing end processing started in response to the power-off signal of the power SW 12, the first drive mode (two-phase excitation drive) is used even when the zoom lens barrel 1 moves within the zoom section. By controlling the drive, it is possible to drive with a higher torque than in the first drive mode, and even if an unexpected external force is applied to the moving zoom lens barrel 1, the lens mirror can be reliably driven. Cylinder 1
Can be stored. Then, at the time of the photographing end processing, the power supply to the photographing block is stopped in response to the power-off signal, so that the power consumption can be suppressed, and even if the battery voltage is depleted, the zoom can be reliably performed. The motor 26 can be driven.

As described above, in the electronic camera according to the present embodiment, the drive control is switched to the optimum drive control according to each moving section of the zoom lens barrel 1, and the zoom motor 26 is driven more efficiently. This can contribute to a reduction in power consumption of the entire camera.

Further, in the present embodiment, the two PRs for detecting the zoom position are connected to the zoom cam frame 27 without using a zoom encoder in spite of the configuration in which a stepping motor is applied as the motor for driving the zoom. In this configuration, the lens frame can be easily corrected even if the position of the lens frame becomes abnormal, and the camera itself can be reduced in size and cost. Can contribute. For example, 1 group lens frame 2
Even when the position of the zoom cam frame 27 is greatly displaced due to an external force or the like, or when the zoom motor 26 loses synchronism, the zoom cam frame 27 is temporarily moved to the reference wide end position. By doing so, the abnormal state as described above can be corrected.

In this electronic camera, since the focusing method is the contrast focusing method, the focusing operation for detecting the information of the high-frequency component of the subject image is performed immediately before the exposure operation. In the case where the displacement of the lens frame is small, the problem does not occur. Also, regarding the flash emission control, when the displacement of the lens frame is small, it goes without saying that there is no particular problem.

The drive control of the zoom motor 26 is performed by the supply voltage to the zoom motor drive circuit 5 during the execution of the photographing end processing, that is, in the first drive mode, by the drive voltage higher than that in the second drive mode. You may do it. In this case, it is easy to ensure a faster and more reliable storage operation.

Further, in the above-described embodiment, an electronic camera is described as an example. However, the present invention is not limited to this. For example, a camera using a silver halide film or an electronic moving image signal is used. The present invention can be easily applied to a video camera or the like that records on a recording medium such as a magnetic tape.

By the way, in the above embodiment,
First group lens 22 in zoom lens barrel 1 to be applied
Has a zoom optical system that is driven forward and backward between the wide end position and the tele end position. However, the present invention is not limited to this. For example, the present invention can be applied to a zoom lens barrel having a configuration in which the first lens unit does not advance or retreat between the wide-angle end and the telephoto end.

That is, in a zoom lens barrel in which the first lens unit does not move back and forth between the wide end and the tele end,
The cam groove for driving the first lens group frame provided on the zoom cam frame has a shape perpendicular to the lens optical axis between the wide end and the telephoto end. Therefore, even if an external force acts on the first group lens frame from the subject side, the first group lens frame itself is
It does not move in the optical axis direction due to the pressure angle of the cam groove.

However, when the stepping motor is being driven for zooming when an external force is applied, the friction generated between the cam groove of the zoom cam frame and the cam pins engaged with the cam groove due to the applied external force. The rotation of the zoom cam frame may not be performed smoothly due to an increase in the force, and the stepping motor may lose synchronism. Then, with the step-out of the stepping motor, the zoom cam frame largely shifts from the zoom position instructed by the system controller, causing a shift in the zoom position of the second lens group, the third lens group, the auxiliary frame, or the like. .

When such a shift occurs, a means for detecting a shift in the zoom position is provided in the same manner as in the above-described embodiment, so that an abnormality caused by an external force is recognized. The position of the frame may be corrected by temporarily moving the frame to the wide end position, and then the subsequent photographing processing may be executed. In this manner, even if the zoom lens barrel has a configuration in which the first lens unit does not move back and forth between the wide-angle end and the telephoto end, it is easy to eliminate the obstacle caused by the displacement of the first lens unit frame.

In recent years, various electronic cameras capable of handling moving images have been proposed, and various electronic cameras have been put to practical use.

That is, it is easy to configure the electronic camera shown in the above-described embodiment so that moving image data can be generated and recorded. Normally, when moving image data is recorded, it is common to simultaneously record audio data. Therefore,
At the time of moving image data recording operation, that is, at the time of moving image shooting operation, noise components such as noise components that cause deterioration of the image quality of the acquired moving image and noise components such as noise mixed with audio data recorded simultaneously with the moving image data Need to be minimized.
In the case of an electronic camera, these noise components are caused by, for example, vibration or driving noise generated by a driving motor.

Therefore, when the electronic camera of the above-described embodiment is configured to be able to generate and record moving image data, the drive control of the zoom motor 26 may be performed as follows.

As described above, during execution of the moving image shooting operation,
If the driving sound of the zoom motor is large due to zoom driving or the like, this is recorded as noise. On the other hand, during execution of the still image photographing operation, there is no problem in photographing itself even if some drive noise of the zoom motor is generated by the zoom drive.

Therefore, when performing a still image photographing operation, the zoom motor is driven and controlled by, for example, two-phase excitation (first drive mode). When performing a moving image photographing operation, the zoom motor is driven more than in the first drive mode. Drive control is performed by a drive control operating at a low current, for example, by 1-2-phase excitation or micro-step drive (second drive mode).

By performing such drive control,
At the time of moving image shooting operation, noise reduction and vibration reduction can be realized, so that image quality degradation of acquired moving image data and noise components such as noise are included in audio data recorded simultaneously with moving image data. That can be suppressed. In addition, during still image shooting operation, zoom drive can be performed more reliably and quickly, so that good operability can be ensured.

Alternatively, the drive of the zoom motor may be controlled by, for example, 1-2-phase excitation (first drive mode) when performing a still image photographing operation, for example. In this case, when performing the moving image shooting operation, drive control for operating the zoom motor with a lower current than in the first drive mode, that is, micro-step drive (second
Drive control).

In this way, noise and vibration can be reduced more than in the case described above.

[0141]

As described above, according to the present invention, the drive control for moving the lens barrel more quickly during the storing operation (moving end processing) for moving the lens barrel into the camera body. And at the time of a zoom operation (zoom processing) during a photographing operation, by performing drive control for moving the lens barrel with higher accuracy, efficient drive control according to each drive condition is performed. Accordingly, it is possible to provide a lens device that can contribute to a reduction in power consumption of the entire device.

Further, according to the present invention, the drive control of the stepping motor as a drive source for moving the lens frame in an electronic camera or the like is controlled by a plurality of drive methods (drive modes).
By performing optimally according to the above, it is possible to provide an electronic camera that can reduce power consumption and contribute to better usability and operability.

Further, according to the present invention, in an electronic camera capable of generating and recording moving image data and still image data, a zoom operation during a moving image shooting operation and a zoom operation during a still image shooting operation are performed. And drive control in different drive modes, it is possible to suppress simultaneous recording of noise components such as drive noise of a motor and the like accompanying the zoom drive during execution of the moving image shooting operation, and to reduce vibration. Thus, it is possible to provide an electronic camera that can record good moving image data while suppressing the image quality, and can also comfortably execute a shooting and recording operation of still image data.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a camera according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a zoom lens barrel of the camera shown in FIG.

FIG. 3 is a conceptual diagram showing a relationship between extended positions of respective lens groups when the zoom lens barrel of the camera shown in FIG.

4 is a diagram showing output signals of PR (A) 31 and PR (B) 32 in the camera shown in FIG. 1, a region (zone) in a zoom section which can be detected by the output signals, and a rotation angle of a zoom cam frame 27.

FIG. 5 is a flowchart showing a sequence of a shooting operation of the camera shown in FIG. 1;

FIG. 6 is a flowchart showing a sequence of a shooting end process of the camera shown in FIG. 1;

FIG. 7 is a flowchart showing a subroutine of a zoom process called in the shooting sequence of FIG. 5;

8 is a flowchart showing a subroutine of an abnormal process called in the photographing sequence of FIG. 5 or the zoom process of FIG. 7;

FIG. 9 is a schematic diagram showing a state in which an external force acts on a front lens barrel during photographing in a conventional camera.

FIG. 10 is a diagram illustrating one-phase excitation driving in a conventional general stepping motor.

FIG. 11 is a diagram illustrating two-phase excitation driving in a conventional general stepping motor.

FIG. 12 is a diagram illustrating a 1-2-phase excitation drive in a conventional general stepping motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Zoom lens barrel 2 ... Imager (electronic imaging means) 3 ... Imaging circuit (electronic imaging means) 4 ... A / D conversion circuit 5 ... Zoom motor drive circuit 6 ... Focus motor drive circuit 7 Focusing circuit 8 System controller (drive control means, control means, calculation means, correction means) 9 Zoom up switch (SW) 10 Zoom down switch (SW) 11 Release switch (SW) 12) Power switch (SW) 13 Image processing circuit (image processing means) 14 Memory 15 Display circuit 16 LCD (display means) 17 I / F (interface; recording means) 18 ... Recording medium 19... Compression / expansion circuit 21... First group lens frame 22... First group lens (photographing optical system) 23. Lens (photographing optical system) 25 Four-group lens (photographing optical system, focus lens) 26 Zoom motor (stepping motor) 27 Zoom cam frame (transmission means) 27a Cam groove (transmission means) 28 Auxiliary frame 29 Focus motor 30 Fixed frame 30a Projecting arm 31 PR (A) (photoreflector; position detecting means) 32 PR (B) (photoreflector; position detecting means) 41 ... Power supply circuit 42 ... Battery

Claims (20)

[Claims] 1. A zoom in which a variable magnification operation is performed including a storage section in a lens barrel between a storage position in a storage state and a shooting preparation position in a shooting enabled state, and the shooting preparation position. A plurality of lens barrels for moving the section and holding the photographing optical system; a stepping motor for moving the plurality of lens barrels; and moving the plurality of lens barrels from the storage position to the photographing preparation position. At the time of the extension operation and at the time of the storing operation of moving the lens barrel from an arbitrary position in the zoom section to the storing position, the stepping motor is moved to the first position.
During the zoom operation in which the drive control is performed in accordance with the drive mode of and the lens barrel is moved within the zoom section,
A lens control device, comprising: drive control means for driving and controlling the stepping motor in a second drive mode in which the stepping motor is operated at a lower current than the first drive mode. 2. The drive control means controls drive of the stepping motor by two-phase excitation in the first drive mode, and controls the stepping motor by one-two-phase excitation or micro-drive in the second drive mode. The lens device according to claim 1, wherein drive control is performed by step drive. 3. An electronic image pickup means for photoelectrically converting a subject image formed by a photographing optical system to generate an image signal,
Image processing means for performing predetermined processing on an image signal generated by the electronic imaging means to convert the image signal into a predetermined form; and recording means for recording an output from the image processing means as image data. In the electronic camera, the variable magnification including the storage section between the storage position in which the lens barrel is stored and the shooting preparation position which is a position where shooting can be performed, and the above-described shooting preparation position. A plurality of lens barrels that move to a zoom section where the operation is performed and hold the photographing optical system, a stepping motor that moves the plurality of lens barrels, and a driving force of the stepping motor is transmitted to the lens barrel. Transmitting means for moving the plurality of lens barrels from the storage position to the shooting preparation position; and moving the lens barrel upward from an arbitrary position in the zoom section. At the time of a storage operation of moving to the storage position, the stepping motor is driven and controlled by a first drive mode. At the time of a zoom operation at which the lens barrel moves within the zoom section, the stepping motor is controlled by the first drive mode. An electronic camera, comprising: drive control means for performing drive control in a second drive mode operating at a lower current. 4. In the first drive mode, the drive control means controls the drive of the stepping motor by two-phase excitation, and in the second drive mode, drives the stepping motor by one-two-phase excitation or micro-phase excitation. The electronic camera according to claim 3, wherein drive control is performed by step driving. 5. The electronic apparatus according to claim 3, further comprising control means for controlling not to supply power to said electronic imaging means at the time of extending and retracting the lens barrel. An electronic camera according to claim 1. 6. The electronic device according to claim 5, wherein the drive control means controls the drive of the stepping motor with a higher drive voltage in the first drive mode than in the second drive mode. camera. 7. An electronic imaging means for photoelectrically converting a subject image formed by a shooting optical system to generate an image signal,
Image processing means for performing predetermined processing on an image signal generated by the electronic imaging means to convert the image signal into a predetermined form; and recording means for recording an output from the image processing means as image data. An electronic camera, comprising: a plurality of lens barrels in the lens barrel and holding the photographing optical system, wherein at least one lens barrel projects from the front surface of the camera body and is driven forward and backward; A stepping motor of a pulse drive for moving the plurality of lens frames; a transmission unit for transmitting a driving force of the stepping motor to the lens frame; and a drive control of the stepping motor to control a position of the lens frame. An electronic camera comprising: a control unit that performs zooming; and a plurality of position detecting units that detect a zoom position of the lens barrel. 8. The apparatus according to claim 1, wherein said transmitting means is a cam member, and said plurality of position detecting means detects a zoom position of said lens barrel by detecting a displacement of said cam member. 8. The electronic camera according to 7. 9. A calculating means for calculating zoom position information from a driving pulse signal for driving the stepping motor, and the zoom position information calculated by the calculating means during a zooming operation according to outputs of the plurality of position detecting means. The electronic camera according to claim 7, further comprising: a correction unit configured to perform correction. 10. The cam member is a cam tube having a cam groove formed on the periphery of a cylindrical portion, and the plurality of position detecting means are arranged along a circumferential direction on the circumference of the cylindrical portion of the cam tube. 9. The electronic camera according to claim 8, wherein the electronic camera is arranged as follows. 11. The lens according to claim 2, wherein the drive control means controls the drive of the stepping motor with a higher drive frequency in the first drive mode than in the second drive mode. apparatus. 12. The electronic device according to claim 4, wherein the drive control means controls the drive of the stepping motor at a higher drive frequency in the first drive mode than in the second drive mode. camera. 13. The lens device according to claim 2, wherein the drive control means controls the drive of the stepping motor by two-phase excitation when the power is turned off. 14. The electronic camera according to claim 4, wherein said drive control means drives and controls said stepping motor by two-phase excitation when a power supply is turned off. 15. An electronic imaging means for generating an image signal by photoelectrically converting a subject image formed by an imaging optical system, and performing predetermined processing on the image signal generated by the electronic imaging means. An electronic camera that includes image processing means for converting the image data into a predetermined form, and recording means for recording the output from the image processing means as image data, and which can generate and record moving image data and still image data. A magnification change operation is performed including the storage section between the storage position where the lens barrel is stored in the lens barrel and the shooting preparation position which is a position where shooting is possible, and the shooting preparation position. A plurality of lens frames that move to a zoom section and hold a photographing optical system; a stepping motor that moves the plurality of lens frames; and a driving force of the stepping motor that is transmitted to the lens frame. Transmitting means for moving the plurality of lens barrels from the storage position to the shooting preparation position; and a storage means for moving the lens frame from an arbitrary position in the zoom section to the storage position. At the time of operation and at the time of photographing operation of a still image, the stepping motor is driven and controlled by the first drive mode. At the time of zoom operation at which the lens barrel moves within the zoom section and at the time of moving image photographing operation, the stepping motor is driven. An electronic camera, comprising: drive control means for performing drive control in a second drive mode that operates with a lower current than the first drive mode. 16. The drive control means controls the drive of the stepping motor by two-phase excitation in the first drive mode, and controls the drive of the stepping motor by one-two-phase excitation or micro-drive in the second drive mode. The electronic camera according to claim 15, wherein drive control is performed by step drive. 17. The drive control means drives and controls the stepping motor by 1-2 phase excitation in the first drive mode, and drives the stepping motor by micro-step drive in the second drive mode. The electronic camera according to claim 15, wherein the electronic camera is controlled. 18. An electronic imaging means for photoelectrically converting a subject image formed by an imaging optical system to generate an image signal, and performing predetermined processing on the image signal generated by the electronic imaging means. An electronic camera provided with an image processing means for converting the output from the image processing means into a predetermined form, and a recording means for recording an output from the image processing means as moving image data or still image data. The optical system moves to a storage section between a storage position where the frame is stored and a shooting preparation position which is a position where shooting is possible, and a zoom section including the shooting preparation position and in which a zooming operation is performed. A plurality of lens barrels for holding the system, a stepping motor for moving the plurality of lens barrels, a transmission means for transmitting the driving force of the stepping motor to the lens barrel, At the time of a shadow operation, the stepping motor is driven and controlled by a first drive mode. At the time of a moving image photographing operation, the stepping motor is driven by a second drive mode at a lower current than the first drive mode. An electronic camera, comprising: a drive control unit configured to: 19. The drive control means drives and controls the stepping motor by two-phase excitation in the first drive mode, and controls the stepping motor by one-two-phase excitation or micro-drive in the second drive mode. 19. The electronic camera according to claim 18, wherein drive control is performed by step driving. 20. The drive control means controls the drive of the stepping motor by 1-2 phase excitation in the first drive mode, and drives the stepping motor by micro-step drive in the second drive mode. The electronic camera according to claim 18, wherein the electronic camera is controlled.