JP2003322788A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-performance, inexpensive and compact camera based on a concept thoroughly different from the conventional one. <P>SOLUTION: During a focusing operation, the renewal of an image based on image data obtained through a CCD3 at a real time is stopped (that is, the image is displayed based on information other than the image data obtained through the CCD3 at a real time), then, the image is brought into a frozen state (the display is performed in the different form), then, the photographer is prevented from having a sense of incompatibility even in the case the photographer views an image display part 8. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly to an electronic camera having an image display section such as a monitor.

[0002]

2. Description of the Related Art With the improvement of electronic technology, electronic cameras such as digital still cameras for converting captured images into digital data and storing the digital images have been developed and are already on the market.
The user can display the image captured by the electronic camera on the display of his / her personal computer, for example, and can print it through the printer, so that the application range is wide.

[0003]

By the way, there is a demand for downsizing and cost reduction in electronic cameras as well. However, additional functions such as the zoom function cannot be easily omitted because they have the effect of increasing the value of the product. In response to such a demand, there is an attempt to integrate a motor for zoom drive of a photographing optical system and a motor for focus drive, which are separately provided in a conventional electronic camera with a zoom function. . However, it was expected that such an attempt would have problems specific to electronic cameras.
This problem will be explained.

In a so-called silver halide camera, there is known a structure in which a driving force from a single motor is used to drive a photographing optical system for zooming and focusing.
1-174688). This is called the step zoom method, and the zoom position is set stepwise,
Since the focusing operation is performed between the adjacent zoom positions, there is an advantage that the zoom operation and the focusing operation can be performed only by providing one motor as a drive source. Therefore, it has been considered to incorporate such a step-zoom type configuration into an electronic camera.

However, in a general electronic camera,
In order for the photographer to confirm the subject, regardless of the operation of the release switch, if the power is turned on, an electronic image capable of displaying the subject image on the monitor based on the image data acquired via the image pickup device such as CCD. There is a finder function. Therefore, if the configuration of the step zoom method is simply incorporated in the electronic camera, the size of the angle of view changes with the movement of the taking lens when performing the focusing operation with the zoom position. Since the changed state is displayed on the monitor one by one by the electronic viewfinder function, there is a problem that a photographer viewing the monitor feels strange. In particular, JP-A-9-80291 and JP-A-9-189.
This problem becomes more noticeable when an optical system that changes the focal length in the focusing operation is used, as disclosed in Japanese Patent Laid-Open No. 844 and Japanese Patent Laid-Open No. 11-119083.

A similar problem is that the driving of the lens of the variable-magnification optical viewfinder used in some silver halide cameras and electronic cameras is performed in association with the driving of the taking lens. This can occur even if a configuration is adopted, but such a variable-magnification optical viewfinder is equipped with a clutch mechanism that disconnects the lens of the optical viewfinder from the drive of the shooting lens during focusing operation, so that the subject can be seen through the optical viewfinder. It is possible to prevent the photographer looking into the camera from feeling uncomfortable. However,
As long as the shooting lens is moved for focus drive, the subject image formed on the image sensor changes, so as long as the electronic viewfinder function is displayed, the image displayed on the monitor (view angle ) Will also change. Therefore, it is desired to solve this problem based on a completely different design concept from the conventional one.

The present invention has been made in view of the problems of the prior art, and it is an object of the present invention to provide a camera having a high function, a low cost and a compact structure, based on an idea completely different from the conventional art. To do.

[0008]

In order to achieve the above-mentioned object, the camera of the first aspect of the present invention is a photographing optical system having a plurality of lens groups, and an optical system for forming an image through the photographing optical system. An image pickup element that receives an image and outputs an image signal, a distance measuring means for obtaining a subject distance, and a motive power from a single drive source cause a specific lens group of the photographing optical system to move in the optical axis direction. Driving means for moving and driving for focusing operation and zooming operation based on the subject distance obtained in advance, and an image is displayed based on an image signal output from the image sensor. A camera having a display unit, wherein the display unit displays different images when the driving unit is driving for the zoom operation and when the driving unit is driving for the focusing operation. Display in a manner Therefore, even if the angle of view changes in the image displayed based on the image data obtained through the image sensor by the drive for the focusing operation, by displaying it in a different display mode, It is possible to prevent the photographer from feeling uncomfortable even when viewing the display unit. The distance measuring means is, for example, an active distance measuring device that projects infrared light toward a subject,
A passive ranging device in which the ranging device is separate from the photographing optical system.

Further, when the subject distance is obtained by the distance measuring unit, the sense of discomfort of the photographer can be further reduced unless the lens unit is moved by the driving unit.

Further, it has a release switch capable of outputting the first and second signals by an operation of an operator (for example, a photographer), and when the release switch outputs the first signal, the driving means is provided. When the object distance is obtained and the second signal is output without moving the photographing optical system according to (4), it is preferable to perform driving for the focusing operation by the driving unit.

A camera according to a second aspect of the present invention includes a photographing optical system having a plurality of lens groups, an image pickup device for receiving an optical image formed through the photographing optical system, and outputting an image signal.
Focusing operation for moving a specific lens group of the plurality of lens groups in the optical axis direction by power from a single drive source and searching for a focus position based on an image signal output from the image sensor. And a drive unit that performs drive for zooming operation, and a display unit that displays an image based on an image signal output from the image sensor, the display unit including: Since display is performed in different display modes when the drive unit is operating for the zoom operation and when performing the operation for the focusing operation, the drive for the focusing operation is performed. Even if the angle of view changes in the image displayed based on the image data obtained through the image pickup device, by displaying it in different display modes, the photographer can Possible so as not even to inspire a sense of discomfort if you are viewing the serial display unit. The "focusing operation for searching the in-focus position based on the image signal output from the image pickup device" is output from the image pickup device while moving at least one of the lens groups of the photographing optical system. This refers to an operation for obtaining an optimum in-focus position by processing and comparing a plurality of image signals. In such a configuration, the focusing operation takes a long time, so that the effect of the present invention is greater.

[0012] Further, by the operation of the operator, the first and second
When the release switch outputs the first signal, the drive means does not drive for the focusing operation, and when the release signal outputs the second signal. It is preferable that the driving means performs driving for focusing operation.

Further, it has a release switch capable of outputting the first and second signals by the operation of the operator, and when the release switch outputs the first signal, the driving means is for focusing operation. When the driving is performed and the second signal is output, it is preferable to capture the image signal (that is, image capturing for recording image data) without performing the focusing operation.

Further, when the display section displays a through image based on image data sequentially obtained through the image pickup device when the driving means is driving for zooming operation, the photographer can This is preferable because you can select your preferred angle of view.

Further, the display section responds to the image signal output from the image pickup device in order to display in the different display mode while the driving means is driving for the focusing operation. By using the image data that has been subjected to the predetermined processing, it is possible to perform display in different modes. "Predetermined processing" refers to the image signal obtained through the image sensor, monotone or sepia color change processing, mosaic processing, defocus processing, etc., "Focusing operation in progress", etc. The process of adding the image of the character may be used. Alternatively, it may be a process for obtaining an image based on a low resolution (low pixel) obtained by image processing in a control circuit or the like, and such an image is a visually normal subject when displayed on the display unit. Any image that is not recognized as the image of Further, for example, in the case of a camera that prepares thumbnail images for display, such thumbnail images may be displayed.

Further, the display section, when the driving means is driving for the focusing operation,
In order to display in the different display mode, it is preferable to use image data obtained by performing a predetermined process on the image signal output from the image sensor at a predetermined time. The image signal output from the image pickup device at a predetermined time refers to a signal other than an image signal obtained in real time for displaying a through image, for example, driving for the focusing operation is performed after the zoom operation is completed. It is preferable that the image signal is obtained from the image pickup element immediately before, but the image signal is not limited thereto.
However, if at least one of the lens groups (focusing lens) of the photographic optical system is kept at a position corresponding to the subject distance of 3 m, it is considered that focusing is possible in many cases of photographing. Therefore, as the reference position at the end of the zoom operation, image data is captured with at least one of the lens groups of the photographing optical system kept at such position, and an image is displayed on the display unit based on the image data. By stopping the update of the image during the subsequent focusing operation, it is possible to avoid the change in the angle of view of the image due to the focusing operation. The predetermined process also includes a process for displaying a normal image.

Further, the display section displays prestored image information without using the image output from the image pickup device when the driving means is driving for the focusing operation. You may. The image based on the information stored in advance may be, for example, a maker's logo, a trademark, an anime character, or a character image such as "Focusing is in progress".

Further, the display section, when the driving means is driving for the focusing operation,
The image may not be displayed. "Do not display image"
And, when the power supply to the display unit is stopped or the display unit has a backlight that illuminates the screen,
The process of stopping the power supply to the backlight or not supplying the image data itself to the display unit is not limited to this, but the display screen is covered with blinds and the photographer (operation (Person) cannot see the image.

Further, it is preferable that the driving means is provided with an alarm means for generating a warning sound when the driving operation is being performed for the focusing operation, because it is easy to call the photographer's attention.

Further, the driving means can perform the focusing operation and the zooming operation alternately or simultaneously in response to moving the specific lens group in the optical axis direction by driving the single driving source. It is preferable to have a plurality of regions. Such a method is known as a so-called step zoom method, and the effects of the present invention can be effectively exhibited.

Further, it is preferable to have an optical finder having an optical system different from that of the photographing optical system.

Further, it is preferable that the drive for the zoom operation and the drive for the focusing operation by the drive means are performed by operating different operation switches.

Further, when the driving means drives for the focusing operation by the operation switch, the display unit displays the different display, and when the driving for the focusing operation is finished, If an image is displayed on the display unit based on the latest image data obtained, a more user-friendly camera can be provided.

[0024]

DETAILED DESCRIPTION OF THE INVENTION A camera according to an embodiment of the present invention will be described in detail below with reference to the drawings. 1 is an external view showing an embodiment of a digital still camera 100 as an example of a camera to which the present invention is applied.
FIG. 1A is a front perspective view of the digital still camera 100, and FIG. 1B is a rear perspective view.

In FIG. 1, a digital still camera 10 is shown.
0 is provided with an image pickup unit 24 for picking up an image of a subject, an auxiliary light emitting unit 30 for emitting an auxiliary light to the subject, and an optical viewfinder 25 for confirming a composition including the subject when a photographer looks into the image. In addition, an image display unit 8 for displaying photographed images and the like, an information display unit (so-called status LCD) 26 for displaying photographing setting status, etc., and an operation SW (switch) 21 for setting and switching various functions, Further, a release switch 21a for performing shutter release is provided on the upper surface of the digital still camera 100. The detailed description of each component will be given together with the description of the functional configuration described later. In the present embodiment, the optical finder 25 is the lens unit 1
It has a different optical system.

FIG. 2 is a block diagram showing the functional structure of the digital still camera 100. In FIG. 2, a digital still camera 100 is a lens unit 1 (shown as a single unit in the drawing) which is a photographing optical system including at least a front lens group (first lens group) and a rear lens group (second lens group). , An aperture 24, an image pickup unit 24 including a CCD 3, an image pickup circuit 4, an A / D conversion circuit 5, a memory 6, a D / A conversion circuit 7, an image display unit 8, a recording memory 9, a compression / expansion circuit 1.
0, CPU 11, TG 12, AE / AF processing circuit 13,
The CCD driver 14, the diaphragm drive motor 15, the diaphragm drive motor drive circuit 16, the optical system drive motor 17, the optical system drive motor drive circuit 18, the battery 19, the EEPROM 20, the operation SW 21 including the zoom button ST which is a zoom switch,
Flash light emitting section 22, auxiliary light emitting section 3 as auxiliary light emitting means
0 (which can also be used as an auxiliary light emitting portion for AF and a red-eye reduction lamp), and a switching circuit 23. It should be noted that the lens unit 1 according to the present embodiment includes the first lens group and the second lens group.
Although it has a lens group, it goes without saying that more lens groups may be provided.

The image pickup unit 24 forms an image on the optical path of the lens unit 1 that captures an optical image of a subject, which will be described later, a diaphragm 2 that adjusts the light amount of the light flux that has passed through the lens unit 1, and the exposure. A CCD (Charge Co) that photoelectrically converts the optical image of the captured object
The image signal (analog signal), which is composed of an up-down device 3 and is photoelectrically converted, is output to the image pickup circuit 4. That is, the imaging unit 24 has a function as an imaging unit.

The image pickup circuit 4 performs various kinds of image processing such as sensitivity correction of the image signal input from the CCD 3 in synchronization with the timing signal input from the TG 12 to generate a predetermined image signal, and A / D-converts it. Output to the circuit 5. The A / D conversion circuit 5 converts the input image signal from an analog signal into a digital signal, and outputs the image data to the memory 6 or the AE / AF processing circuit 13 according to an instruction from the CPU 11.

The memory 6 is composed of a buffer memory and the like, and temporarily stores the input image signal. Further, when the memory 6 receives an image display instruction from the CPU 11,
The image display commanded image data is output to the A / A conversion circuit 7, and the D / A conversion circuit 7 performs analog conversion of the input image data and performs processing to adapt to output display, and the image display unit 8 The output is displayed. On the other hand, the memory 6
When an image recording instruction is received from the CPU 11, the image data (for example, J
(In PEG format), and the compression / expansion circuit 10 outputs the input image data to the recording memory 9.

The image display unit (also referred to as a display unit) 8 is a TF.
It is composed of a T (Thin Film Transistor) and the like, and outputs and displays the image signal input from the D / A conversion circuit 7. In addition, the display is not limited to the image, for example,
It may be a text screen such as a menu screen for selecting functions.

A recording memory 9 which is a recording unit is a recording memory composed of a semiconductor memory or the like, and the compression / expansion circuit 1
A recording medium having an image data recording area for recording image data input from 0. The recording memory 9 may be, for example, a built-in memory such as a flash memory, a removable memory card or a memory stick, or a magnetic disk such as a hard disk or a floppy (registered trademark) disk. It may be a recording medium or the like. That is, the recording memory 9 has a function as a recording unit.

Upon receiving an image read instruction from the CPU 11, the recording memory 9 outputs the read image data to the compression / expansion circuit 10, and the compression / expansion circuit 10 outputs the image data.
Performs the decompression process of the input image data to execute the memory 6
Output to.

The compression / expansion circuit 10 is a compression circuit for compressing the image data input from the memory 6 by a predetermined encoding method, and the input from the recording memory 9 for displaying the image data instructed to be read out on the screen. A decompression circuit for decoding and decompressing image data. That is, the compression / expansion circuit 10 has a function as a compression unit.

CPU (Central Process)
ing Unit) 11 reads various application programs related to shooting stored in the EEPROM 20 to a work area (not shown), executes various processing such as shooting processing according to the programs, and displays the processing result in the image display unit 8 or The information is displayed on the information display unit 26.

The CPU 11 has a release switch 21a.
The AE / AF processing circuit 13 is driven and controlled according to the half-pressing of (FIG. 1), the exposure condition is determined from the obtained photometric value, and the lens unit 1 is driven to the in-focus position detected by the AF processing. Then, the exposure process is executed in response to the full press of the release switch 21a, the generated image signal is subjected to the image process and the digital conversion, and temporarily stored in the memory 6,
The compression / expansion circuit 10 compresses the image data and outputs it to the recording memory 9.

TG (Timing Generato)
r) 12 generates a predetermined timing signal and outputs it to the image pickup circuit 4, the CPU 11, and the CCD driver 14.

An AE (Auto Exposure: automatic exposure control) / AF (Auto Focus: automatic focus control) processing circuit 13 detects an in-focus position and an AE processing circuit that executes an AE processing for detecting an appropriate exposure condition. AF
And an AF processing circuit that executes processing.
Each process is executed on the image data input from the A / D conversion circuit 5 according to an instruction from the CPU 11.

In the AE processing, the AE processing circuit performs arithmetic processing such as cumulative addition with respect to the brightness value of the input one screen or a predetermined area in the screen, and based on the processing result, it is possible to determine an appropriate value for actual exposure. The exposure condition is calculated and output to the CPU 11. On the other hand, the AF processing circuit calculates the AF evaluation value for the input one screen or a predetermined area in the screen in the AF processing, and the calculated result is calculated by the CPU 1
Output to 1.

This AF evaluation value has a characteristic that it becomes larger as the focus is improved.
When a graph is created with the F evaluation value on the vertical axis, a mountain with the in-focus point as the apex is formed. That is, the lens unit 1
By comparing the AF evaluation values obtained while moving the, the apex of the mountain, that is, the in-focus point can be obtained. The operation of obtaining the AF evaluation value in this way is called a search operation. The AF evaluation value is calculated by analyzing the frequency of the image data for one input screen or a predetermined area in the screen. In the frequency analysis, a band-pass filter is constructed by software, the integral value of the image signal intensity passed through this band-pass filter is calculated, and the calculation result is used as the AF evaluation value. That is, the AF evaluation value is
This is contrast (brightness / darkness) information, and is calculated by performing an operation for obtaining the intensity of a specific frequency included in the image.

Here, the AF processing by the CPU 11 and the AF processing circuit will be described. The CPU 11 drives and controls the optical system drive motor drive circuit 18 which is a drive means to move the second lens group of the lens unit 1 and gradually generate an image signal by the CCD 3 at each lens position. AE
The AF processing circuit 13 calculates an AF evaluation value for each image data input from the A / D conversion circuit 5, compares the AF evaluation values, detects the lens position that is the maximum AF evaluation value as the in-focus point, and causes the CPU 11 to do so. Output.

Upon receiving an instruction from the CPU 11, the CCD driver 14 drives and controls the CCD 3 in synchronization with the timing signal input from the TG 12. Specifically, the charge storage time of the CCD 3 is controlled according to the exposure adjustment control.

The diaphragm drive motor drive circuit 16 includes the CPU 1
The drive of the diaphragm drive motor 15 is controlled by an instruction from the control unit 1, and the diaphragm drive motor 15 drives the diaphragm 2. Further, the optical system drive motor drive circuit 18 controls the drive of the optical system drive motor 17 according to an instruction from the CPU 11, and the lens unit 1 is driven by the drive force of the optical system drive motor 17, whereby the first lens unit 1 of the lens unit 1 is driven. The first lens group and the second lens group move as described later.

The battery 19 is the digital still camera 100.
Is a power source that supplies power to each component, and, for example, a lithium battery or an alkaline dry battery is applied.

EEPROM (Electrically)
Erasable Programmable Re
The ad-only memory) 20 stores various application programs, processing programs, and the like related to image pickup of the digital still camera 100.

The operation SW (switch) 21 is provided with various operation switches such as a release switch 21a, a mode SW for switching functions and a menu SW for selecting settings. When each switch is operated, a signal is generated and output to the CPU 11. The release switch 2
The reference numeral 1a includes a two-stage switch including a half-press release switch for starting the AE and AF processes prior to the photographing operation and a full-press release switch for starting the actual exposure process.

The flash light emitting section 22 is a light emitting section that emits strobe light to the subject when the brightness of the surrounding environment detected at the time of photographing is insufficient, and the light emission timing, the light emission amount, etc. are controlled by the switching circuit 23. It

Next, a configuration for achieving the zooming operation and the focusing operation by the step zoom method will be described. FIG. 3 is a schematic configuration diagram showing the lens barrel of the camera and the drive configuration thereof according to the present embodiment.

In FIG. 3, 17 is an optical system drive motor which is drive-controlled by the CPU 11, 17a is a sun gear fixed to the output shaft of the optical system drive motor 17, and 41 is an output shaft of the optical system drive motor 17. The pinion gear is fixed, 42 is a Focus pulse plate held so as to rotate coaxially with the optical system drive motor 17, and 43 is a photo that optically detects a slit of the Focus pulse plate 42 and outputs a pulse according to the rotation of the motor. It is an interrupter.

44 is a gear train for decelerating and transmitting the power of the pinion gear 2 to the gear 45, 46 is a reference pulse plate held so as to rotate coaxially with the gear 45, and 47 is a reference pulse plate 46.
Is a photo interrupter which optically detects the slit of and outputs a pulse corresponding to the rotation of the gear 45.

Reference numeral 50 denotes a lens barrel, which includes a fixed barrel 59,
In this fixed barrel 59, a cam barrel 57 rotatable around the optical axis by a driving force from the gear 48 and a first lens group 51 (in the figure, a single lens group 51 engaged with a cam groove formed in the cam barrel 57). Although one lens is shown, multiple lenses may be used)
Group holder 56 for holding the second lens group 52 and second lens group 52
(A single lens is shown in the drawing, but a plurality of lenses may be used). Needless to say, this embodiment can be applied to a type having a multi-stage cam cylinder having a lens group in each of a plurality of cam cylinders having different diameters.

The fixed barrel 59 and the cam barrel 57 are helicoidally coupled, and the cam barrel 57 is connected to the optical system drive motor 1 via the sun gear 17a, the planet gear 62 and the cam barrel gear 57a.
By receiving power from 7 and rotating, it moves forward and backward with respect to the fixed barrel 59 in the optical axis direction. The first group holder 56 and the second group holder 58 are engaged with a cam groove (not shown) formed on the peripheral surface of the cam barrel 57, and the rotation of the cam barrel 57 causes the first lens group 51 and the first lens group 51 to move. The two lens groups 52 and 52 are respectively driven in the optical axis direction according to the cam groove (or may be a helicoid groove). CPU11
Controls all camera control operations.

In the above configuration, the Focus pulse plate 42 is
Since it is directly driven by the optical system drive motor 17, the photo interrupter 43 generates a Focus pulse (control pulse signal) which is a signal with a fine pitch to generate a CP pulse.
Input into U11.

On the other hand, the reference pulse plate 46 includes a gear train 44,
Since the motor is driven by the rotation of the motor that is decelerated by the gear 45, the photo interrupter 47 generates a reference pulse (reference pulse position) that is a signal of a coarse pitch, and the CPU
Enter in 11.

Next, drive control of the lens barrel 10 by the CPU 11 using the Focus pulse, the reference pulse and the absolute position signal will be described with reference to FIG.

In FIG. 4, T1 and T2 indicate movement loci when the first lens group 51 and the second lens group 52 are zoomed from f = 35 mm to f = 90 mm while maintaining the relationship of the afocal position.

Further, T3 is a movement locus of the second lens group 52 in the step zoom method when focusing is performed by the first lens group extension. Although the locus T3 is simplified in FIG. 4, the actual locus T3 is set to be different for each zoom position.

In the present embodiment, f = 35 mm by moving the first lens group 51 along the locus T1 and moving the second lens group 52 along the locus T3.
(WIDE), f = 50 mm (MIDDLE1), f =
70 mm (MIDDLE2), f = 80 mm (MIDD
LE3) and f = 90 mm (TELE) can be selectively set in five stages of zoom positions.

For example, when the shooting state of f = 50 mm is set in the zooming operation, first, the lens groups 51 and 52 are located at the switching point of the reference pulse (in this embodiment, the falling point may be the rising point) P1. Also stops at the position P2 on the WIDE side as the standby position. And at this time C
The PU 11 detects the switching of P1 and counts a predetermined number of Focus pulses, and the lens groups 51 and 52 are detected without error.
Stops at the standby position P2 and confirms it. And
In response to this confirmation, the Focus pulse counter is reset.

Here, such a standby position is similarly provided at each zoom position, and by counting a predetermined number of Focus pulses from the P1 switching, the zoom in which the lens groups 51 and 52 are selected is performed. It is possible to confirm whether the vehicle is stopped at the standby position corresponding to the position without error.

As a method for moving the lens groups 51 and 52 to the standby position, Fo is started from the time when the reference pulse is detected.
As a method of driving until the number of cus pulses reaches a predetermined number corresponding to the standby position, there is a method of detecting and driving the position based on a continuous signal. When the camera starts to operate due to the photographing operation of the photographer, the distance and brightness of the subject are measured, and then focusing drive is started.

At this time, based on the distance data, the number of Focus pulses to be driven (focusing target value) of the first lens group 51 from the time of detecting the switching point P1 of the reference pulse to be detected later is in the CPU 11. Called from memory.

The lens groups 51 and 52 are moved from the standby position P2 to T
It moves toward the ELE side, and the switching point P1 of the reference pulse
When the signal of is detected, the Focus pulse is counted from this detection time. Then, when the count number reaches the number of Focus pulses called from the memory earlier, the stop control of the lens groups 51 and 52 is performed.

Actually, since the inertia of the optical system drive motor 17 or the like has an influence, the brake control of the optical system drive motor 17 is performed a little before, and the count number is exactly F.
The lens groups 51 and 52 are stopped when the number of ocus pulses is reached. After that, the CPU 11 controls the imaging in response to the full press of the release switch SW21a.

When the image pickup control is completed, the CPU 11 resets the lens groups 51 and 52 to the original standby position P2. Here, the absolute position signal is detected again to confirm whether the lens groups 51 and 52 have returned to the standby position P2.

Here, using the optical system drive motor 17,
A mechanism for changing the angle of view of the optical finder 25 will be described. FIG. 5 is a schematic configuration diagram showing a mechanism for driving the taking lens and the lens group of the optical finder 25 in the camera of the present embodiment.

As shown in FIG. 5, the optical system drive motor 17
The gear 62 meshes with the output pinion gear (sun gear) 17a of. The gear 62 meshes with a cam cylinder gear 57 a formed on the peripheral surface of the cam cylinder 57, and also has a gear train 63.
The gear train 63 is engaged with the finder zoom cam 7
It meshes with the second cam gear 72a, and these are connected so that power can be transmitted. Cam grooves 72b and 72c are formed on the peripheral surface of the finder zoom cam 72, and each has a first groove.
Finder lens group 73, second finder lens group 74
Are engaged and are movable in the optical axis direction in accordance with the rotation of the finder zoom cam 72.

The cam gear 72a and the finder zoom cam 72 are connected via an electromagnetic clutch mechanism 72d, and the electromagnetic clutch mechanism 72d integrally rotates the cam gear 72a and the finder zoom cam 72 in response to a signal from the CPU 11. The power transmission state is changed to one in which the finder zoom cam 72 is not rotated even if the cam gear 72a is rotated.

Here, when the zoom operation is performed under the control of the CPU 11, the power from the gear 62 is transmitted to the cam barrel 57 and the viewfinder zoom cam 72 by bringing the electromagnetic clutch mechanism 72d into the power transmission state. It That is, the lens groups 51 and 52 are connected to each other via the cam barrel 57 as shown in FIG.
Is driven according to the cam diagram shown in FIG.
4 is driven.

In such a case, the zoom magnification of the lens unit 1 and the zoom magnification of the optical finder 25 change while always matching with each other by the rotation of the optical system drive motor 17. That is, the optical finder 25 has a variable magnification function. The shapes of the cam barrel 57 and the finder zoom cam 72 and the number of teeth of each gear of the transmission mechanism 60 are set to appropriate values in consideration of this operation.

On the other hand, when the focusing operation is performed, the power from the gear 62 is transmitted only to the cam barrel 57 and the finder zoom cam 72 does not rotate because the electromagnetic clutch mechanism 72d is in the power non-transmitted state. .
In this case, the lens groups 51 and 52 can be driven for the focusing operation via the cam barrel 57, but the first finder lens group 73 and the second finder lens group 74 do not move in the optical axis direction, and Even if the photographer is looking through the optical viewfinder 25. There is no feeling of strangeness.

FIG. 6 is a flow chart for explaining a photographing process executed by the digital still camera 100 to which the present invention is applied. In the present embodiment, the focusing operation is performed by so-called image plane AF. First, if the power switch (not shown) is turned on in step S101 of FIG. 6, the CPU 11 determines that the shooting mode is set, and the CPU 11 executes step S102.
, Regardless of the operation of the release switch 21a, CC
An image signal is fetched via D3, image processing is performed to obtain image data, and based on that, an image is displayed on the image display unit 8 in step S103.

Further, if it is determined in step S104 that the zoom button ST has been operated, the CPU 11 drives the zoom operation to any position in step S110 as described above (first lens group 51). And the second lens group 52 are moved in the optical axis direction), and in step S111, C
The image signal is taken in through the CD3, image processing is performed, and image data is obtained.
An image is displayed on the image display unit 8 in real time. That is, the photographer can observe the subject image (including the subject image displayed during zoom driving) in which the angle of view is changed by zoom driving. Then, step S11
3, the driving for the focusing operation is continued, but even if the image signal is fetched through the CCD 3 at this time, the image on the image display unit 8 is frozen, that is, the image is not updated in real time. Therefore, the photographer does not feel a sense of discomfort because he or she does not visually recognize the change in the angle of view of the image due to the focusing operation.
The frozen state of the image is C in step S115.
It continues until PU 11 detects the end of the focusing operation. After that, the flow returns to step S102.

Incidentally, at the time of operating the zoom button ST, without performing the focusing operation, after the photographer releases his / her finger from the zoom button ST, either the infinite position or the finite position is displayed.
It is also conceivable to forcibly move the lens unit 1. For example, if the lens unit 1 is forcibly moved to the reference position where the subject distance is 3 m, the probability of focusing on the main subject increases because of the depth of field,
Even if the image is frozen, there is less risk of problems. By not performing the focusing operation in this way,
It is possible to suppress changes in the angle of view of the subject image displayed on the image display unit 8 and also to suppress power consumption.

If it is determined in step S104 that the zoom button ST has not been operated, the CPU 11 determines in step S10.
5, the pressing signal (S of the first release switch 21a) (S
Wait for 1 signal) to be input. Here, if it is determined that the depression signal (S1 signal) of the first-stage release switch 21a is input, the CPU 11 proceeds to step S106.
AE processing is performed to determine appropriate exposure conditions, and step S
At 107, the inputting of the pressing signal (S2 signal) of the second-stage release switch 21a is waited for. If the CPU 11 determines that the push-down signal (S2 signal) of the second-stage release switch 21a has been input, the CPU 11 performs focusing drive in step S108.

Focusing drive at this time is AE
The AF processing circuit 13 moves the second lens group 52 of the lens unit 1 in a stepwise manner while processing and comparing a plurality of image data output from the CCD 3 to obtain an optimum focus position. Therefore, the angle of view of the subject image displayed on the image display unit 8 fluctuates during focusing drive. However, for example, even with a single-lens reflex camera, the image in the viewfinder may be momentarily invisible immediately after release. For example, this is an operation indicating that the release has been performed, and there is an advantage that no particular discomfort is felt. If the digital still camera 100 includes a so-called active distance measuring device or the like as a distance measuring unit, focusing drive may be performed based on the output (information regarding the focus position).

Thereafter, in step S109, the CPU 11
Receives the image signal through the CCD 3 and performs image processing to obtain image data, and based on that, step S11
At 6, the image data is recorded in the image storage memory 9. Here, the CPU 11 executes step S11.
7, a so-called post image is stored in the image storage memory 9
An image is displayed on the image display unit 8 based on the image data recorded in (i.e., new image data). After that, the flow is returned to step S101.

In the present embodiment, during the focusing operation, the update of the image based on the image data obtained in real time via the CCD 3 is stopped (that is, information other than the image data obtained in real time via the CCD 3 is stored. By displaying the image based on [through image display]),
Freeze image (display in different form)
However, the present invention is not limited to this, and based on the information stored in advance such as the EEPROM, the logo of the manufacturer different from the subject image, the trademark, the character of the animation, etc.
A character image such as "Focusing is in progress" or an icon may be displayed. Alternatively, in addition to monotone or sepia color change processing, mosaic processing, low resolution processing, defocus processing, etc. for the subject image, character information related to focusing such as "Focusing is in progress" (a kind of It is also possible to display a composite image that has been subjected to a process of adding (also referred to as an image) (that is, a predetermined image process).

Further, instead of or in addition to this, character information such as "Focusing is in progress" may be displayed on the reflective LCD 30 (FIG. 2) which is an information display unit, or a speaker (not shown). It is also possible to emit a warning sound such as a sound or voice related to the same purpose from (alarm means). Alternatively, in step S114, the power supply to the image display unit 8 is stopped, or when the image display unit 8 has a backlight that illuminates the screen, the power supply to the backlight is stopped, Alternatively, it is conceivable that the image is not displayed at all on the image display unit 8 by performing processing such as not supplying the image data itself to the image display unit.

When an image is displayed using the image display unit 8 having a number of pixels smaller than that of the CCD 3, the change in the angle of view of the displayed subject image due to the focusing drive is slight, and in such a case, during the focusing drive. A through image display may be performed.

FIG. 7 is a flow chart for explaining a photographing process executed by the digital still camera 100 according to the modification. This modification also performs the focusing operation by so-called image-plane AF, and only differences from the flowchart shown in FIG. 6 will be described.

The CPU 11 executes step S105 of FIG.
Then, the push signal (S1
Signal), and if it is determined that the depression signal (S1 signal) of the first-stage release switch 21a has been input, in step S106 ′, AE processing is performed to determine an appropriate exposure condition, In addition, focusing drive is performed. At this time, if the image display unit 8 is caused to perform a through image display (display based on image data obtained in real time), the angle of view of the displayed subject image changes according to the focusing operation, so When the image display unit 8 is visually recognized, there is a possibility that an uncomfortable feeling may occur. Therefore, similarly to the above-described embodiment, during the focusing operation, the image update is stopped by stopping the image update based on the image data obtained in real time via the CCD 3 (the image is displayed in a different state). Do). It should be noted that, similarly to the embodiment described above, it is of course possible to display in another different form.

After the processing of step S106 ', the CPU 11
Is the release switch 2 of the second stage in step S107.
It waits for the depression signal (S2 signal) of 1a to be input. Push-down signal (S2 signal) of the second-stage release switch 21a
If the CPU 11 determines that the
In 109, without further focusing drive, C
The image signal is taken in through the CD3, image processing is performed, and image data is acquired.
The image data is recorded in the image storage memory 9, and will be described below with reference to FIG.
The process is performed in the same steps as in the flowchart of FIG.

FIG. 8 is a flow chart for explaining a photographing process executed by the digital still camera 100 according to another modification. In this modification, a focusing operation is performed in response to a detection signal from a so-called active distance measuring device, and only different points from the flowchart shown in FIG. 6 will be described.

The CPU 11 executes step S105 of FIG.
Then, the push signal (S1
Signal), and if it is determined that the pressing signal (S1 signal) of the first-stage release switch 21a has been input, in step S106 ″, an active distance measuring device (not shown) (Good) is received to receive a distance measurement signal, and AE processing is performed to determine an appropriate exposure condition.

After the processing of step S106 ", the CPU 11
Is the release switch 2 of the second stage in step S107.
It waits for the depression signal (S2 signal) of 1a to be input. Push-down signal (S2 signal) of the second-stage release switch 21a
If the CPU 11 determines that the
At 108 ″, the lens unit 1 is driven to the position determined based on the signal from the active distance measuring device. In such a case, the subject image may be displayed in a frozen state or may be displayed as it is. After that, in step S109, the image signal is taken in through the CCD 3 to perform image processing to obtain image data, and based on that, the image data is recorded in the image storage memory 9 in step S116, and the flow chart of FIG. Processing is performed in the same steps as.

Although the present invention has been described above with reference to the exemplary embodiments, the present invention should not be construed as being limited to the above-described exemplary embodiments, but it goes without saying that appropriate modifications and improvements are possible. is there. For example, the image data captured at a predetermined focus position during the release operation or after the zoom setting can be used as the image data for recording.

[0087]

According to the present invention, it is possible to provide a camera having a high function, a low cost and a compact structure, based on a completely different idea from the conventional one.

[Brief description of drawings]

FIG. 1 is an external view showing an embodiment of a digital still camera 100 as an example of a camera to which the present invention is applied. FIG. 1A is a front perspective view of the digital still camera 100, and FIG. FIG. 4 is a rear perspective view.

FIG. 2 is a block diagram showing a functional configuration of a digital still camera 100.

FIG. 3 is a schematic configuration diagram showing a lens barrel of a camera and a drive configuration thereof according to the present embodiment.

FIG. 4 is a cam diagram for achieving a zoom operation and a focus operation according to the present embodiment.

FIG. 5 is a schematic configuration diagram showing a mechanism for driving a taking lens and a lens group of the optical finder 25 in the camera of the present embodiment.

FIG. 6 is a digital still camera 100 to which the present invention is applied.
6 is a flowchart illustrating a shooting process executed in step S6.

FIG. 7 is a flowchart illustrating a shooting process executed by a digital still camera according to a modification.

FIG. 8 is a flowchart illustrating a shooting process executed by a digital still camera according to another modification.

[Explanation of symbols]

8 Image display section 11 CPU 17 Optical system drive motor 30 Auxiliary light emitting unit 100 digital still camera 51 First lens group of lens unit 52 Second lens group of lens unit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/232 G03B 3/00 A // G03B 17/18 G02B 7/11 D H04N 101: 00 Z F term (Reference) 2H011 BA31 CA01 DA05 2H044 DA01 DA02 DA04 DB02 DC02 DE08 2H051 BA47 EB13 GA03 GA09 2H102 AA00 AA31 AA33 AA41 AA71 AB00 BA01 BA06 BA12 BA27 BB08 BB32 5C022 AA13 AB22 AB44 AB66 AC01 AC42 AC54 AC69 AC69

Claims (16)

[Claims] 1. An image pickup optical system having a plurality of lens groups, an image pickup device which receives an optical image formed through the image pickup optical system and outputs an image signal, and a measuring device for obtaining a subject distance. Distance means and a drive for a focusing operation based on the object distance obtained in advance by moving a specific lens group of the photographing optical system in the optical axis direction by power from a single drive source. A camera having: a drive unit that performs a drive for a zoom operation; and a display unit that displays an image based on an image signal output from the image sensor, wherein the display unit is configured such that the drive unit performs the zoom operation. A camera characterized in that display is performed in different display modes when driving is performed for operation and when driving is performed for the focusing operation. 2. The camera according to claim 1, wherein when the object distance is obtained by the distance measuring unit, the lens unit is not moved by the driving unit. 3. A release switch capable of outputting a first and a second signal in response to an operator's operation, and when the release switch outputs the first signal, the driving optical unit of the photographing optical system The camera according to claim 2, wherein when the subject distance is obtained without moving and the second signal is output, driving for the focusing operation by the driving unit is performed. 4. An image pickup optical system having a plurality of lens groups, an image pickup device for receiving an optical image formed through the image pickup optical system and outputting an image signal, and a single drive source. Driving for a focusing operation for moving a specific lens group of the plurality of lens groups in the optical axis direction by power to search for a focus position based on an image signal output from the image sensor, and zooming. A camera having: a driving unit that performs driving for operation; and a display unit that displays an image based on an image signal output from the image sensor, wherein the display unit includes the driving unit that performs the zoom operation. The camera is characterized in that the display is performed in different display modes when the operation is performed for the purpose and when the operation for the focusing operation is performed. 5. A release switch capable of outputting first and second signals in response to an operator's operation, and when the release switch outputs the first signal, the drive means is for focusing operation. 5. The camera according to claim 4, wherein when the second signal is output without driving, the driving unit performs driving for focusing operation. 6. A release switch capable of outputting first and second signals in response to an operator's operation, and when the release switch outputs the first signal, the driving means is for focusing operation. 5. When the second driving signal is output and the second signal is output, the image signal is captured without performing the focusing operation.
The camera described in. 7. The display unit displays a through image based on image data sequentially obtained through the image pickup device when the driving unit is driving for a zoom operation. The camera according to any one of claims 1 to 6. 8. The display unit responds to an image signal output from the image pickup device, in order to display in the different display mode when the driving unit is driving for the focusing operation. The camera according to claim 1, wherein image data that has been subjected to a predetermined process is used. 9. The display unit displays an image output from the image sensor at a predetermined time in order to display in the different display mode while the driving unit is driving for the focusing operation. The camera according to claim 1, wherein image data obtained by performing a predetermined process on a signal is used. 10. The display unit displays prestored image information without using an image output from the image pickup device when the driving unit is driving for the focusing operation. Claim 1 characterized by the above.
10. The camera according to any one of 9 to 9. 11. The camera according to claim 1, wherein the display unit does not display an image when the driving unit is driving for the focusing operation. 12. The apparatus according to claim 1, further comprising an alarm means for generating an alarm sound when the drive means is driving for the focusing operation.
Any one of the cameras 13. The driving means can perform a focusing operation and a zooming operation alternately or simultaneously in response to moving the specific lens group in the optical axis direction by driving the single driving source. The camera according to claim 1, wherein the camera has a plurality of regions. 14. The camera according to claim 1, further comprising an optical finder having an optical system different from the photographing optical system. 15. The drive for the zoom operation and the drive for the focusing operation by the drive means are:
15. The camera according to claim 1, wherein the camera is operated by operating different operation switches. 16. When a drive for a focusing operation is performed by the drive means by an operation switch, the display unit displays the different display, and when the drive for the focusing operation is finished, The camera according to any one of claims 1 to 15, wherein an image is displayed on the display unit based on the latest image data obtained.