JP2003084192A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a focusing time in a camera. SOLUTION: As for a focusing digital camera 100, when a photographing recording operation is designated by a second SW 210b before finishing photometry and focusing operations started with an operation of depressing a first SW 210a, the focusing operation is immediately stopped by a CPU 11 after finishing the photometry operation, and a focus lens in an image pickup optical system 1 is stopped at a prescribed position by a second motor driving circuit 17, and the photographing recording operation of the object is started.

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 a camera having a focus adjusting function.

[0002]

2. Description of the Related Art Recently, in digital cameras, AF
As an (Auto Focus) method, an image pickup element used for shooting is used, the focusing lens is sequentially moved, and each focus state is evaluated to find the optimum position of the focusing lens. Imaging plane AF is common. This image plane AF type digital camera has a new A
Since it is not necessary to prepare means for F, it is relatively inexpensive and is advantageous for downsizing a digital camera.

Further, it has a normal distance mode function and a macro (short distance) mode function. In the normal distance mode, a pan focus system (fixed focus system) for fixing the lens at the hyperfocal position is used, and in the macro mode. There are known cameras that can select a shooting mode according to a shooting distance, such as a shooting surface AF method, and a camera that can select AF priority and release priority.

[0004]

However, since the imaging surface AF method is a method of searching for an optimum focus position by sequentially moving the lens, it is compared with other AF methods (active distance measuring method and passive phase difference method). Therefore, it takes a lot of time to adjust the focus, which may cause an inconvenience of missing a photo opportunity.

In a camera in which the shooting mode can be selected according to the shooting distance, it is troublesome for the user to select the mode, and when the user forgets to select the mode, the shot image becomes out of focus. There was something that happened.
Also, when shooting in the normal distance mode, if there is sufficient time for focus adjustment, it is natural that it is better to shoot with the AF method than to shoot with the pan-focus method using the depth of field. there were. In a camera in which AF priority and release priority can be selected, in the case of AF priority, there is a risk of missing a shutter opportunity, but there is a problem that in release priority, a shutter opportunity can be captured but the focus is out of focus. there were.

An object of the present invention is to shorten the focusing time of the camera.

[0007]

The invention according to claim 1 is
In a focus-adjustable camera, prior to photographing and recording, first switch means for designating the start of photometry and focus adjustment, second switch means for designating the start of photographing and recording operation, and the first switch means. When the photographing and recording operation is designated by the second switch means before the start of the photometry and focus adjustment operations that have started, the focus adjustment operation is immediately stopped after the photometry and the photographing lens is stopped at a predetermined position. And a control means for starting the photographing and recording operation.

According to the first aspect of the invention, the time required from the designation of the photographing / recording operation by the second switch means to the actual photographing / recording operation is shortened, and the user does not miss the photo opportunity. You can shoot without stress.

According to a second aspect of the present invention, in the first aspect of the invention, the control means determines a predetermined position at which the photographing lens should stop in accordance with the subject brightness.

According to the second aspect of the present invention, the stop position of the photographing lens is determined according to the brightness of the subject.
A clear image can be taken.

According to a third aspect of the present invention, in a camera capable of focus adjustment, first switch means for designating the start of photometry and focus adjustment and second display for designating the start of the recording / recording operation prior to recording / recording. If the photographing / recording operation is designated by the second switch means before the end of the photometric and focus adjustment operations started by the switch means and the first switch means, the driving amount of the photographing lens per step To continue focus adjustment, and after the focus adjustment is completed,
And a control means for starting a photographing / recording operation.

According to a fourth aspect of the present invention, in the third aspect of the invention, the control means sets the photographing lens drive amount per step in focus adjustment from the drive amount before designation by the second switch means. It is characterized by making it larger.

According to the invention described in claims 3 and 4, the second
The time required from the designation of the shooting / recording operation by the switch means to the actual shooting / recording operation can be minimized, and the user does not miss a photo opportunity. Further, since the actual photographing / recording operation is performed after the focus adjustment is completed, a clear image can be photographed.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

[First Embodiment] FIGS. 1 and 2 are views for explaining a first embodiment of a digital camera 100 to which the present invention is applied. First, the configuration will be described.

FIG. 1 is a block diagram showing the internal structure of a digital camera 100 to which the present invention is applied. As shown in FIG. 1, the digital camera 100 includes an image pickup optical system 1, a diaphragm shutter unit 2, a CCD 3, an image pickup circuit 4, an A / D conversion unit 5, a memory 6, a D / A conversion unit 7, an image display unit 8, Compression / decompression means 9, recording memory 10, CPU 11, TG
(Timing generator) 12, AE / AF processing means 13, CCD driver 14, first motor drive circuit 15,
Aperture shutter drive motor 16, second motor drive circuit 1
7, focus motor 18, battery 19, EEPROM2
0, operation SW 21, switching circuit 22, auxiliary light emitting section 23.

The image pickup optical system 1 is provided with a focus lens group or the like for properly forming a subject image on the CCD 3, and the diaphragm shutter 2 has an exposure adjusting function for adjusting the amount of light flux passing through the image pickup optical system 1. The image pickup optical system 1 and the aperture shutter 2 are housed in the lens barrel.

The CCD (Charged Coupled Device) 3 is
The optical image signal of the subject image input from the imaging optical system 1 is converted into an electric signal. The image pickup circuit 4 performs various image processing such as color signal separation on the electric signal input from the CCD 3 in synchronization with the timing signal input from the TG 12 to generate a predetermined color image signal.

The A / D conversion means 5 converts the image signal (analog signal) generated by the image pickup circuit 4 into a digital signal (image data). The memory 6 is for A / D at the time of shooting.
When the image data input by the conversion unit 5 or the image data stored in the recording memory 10 is reproduced, the image data subjected to the expansion processing by the compression / expansion unit 9 is temporarily stored.

The D / A conversion means 7 displays the subject image in real time on the image display section 8 (shooting mode),
At the time of reproduction display (reproduction mode) of the image data stored in the recording memory 10, the image data temporarily stored in the memory 6 is read out and converted into an analog signal, and also converted into an image signal of a form suitable for reproduction output. .

The image display unit 8 is an LCD (Liquid Crystal).
Display), an EL (ElectroLuminescence) display, etc., and screen display is performed based on the analog image signal input by the D / A conversion means 7. The image display unit 8 has a function as a finder that continuously displays images captured by the CCD 3 in the shooting mode.

The compression / expansion means 9 reads the image signal temporarily stored in the memory 6 at the time of recording the image data in the recording memory 9 and stores it in the recording memory 10 and the compression means for performing the compression processing. When the reproduced image data is reproduced, there is provided decompression means for performing a decompression process for setting the optimum form for reproduction and display of the image data.

The recording memory 10 has a recording medium (not shown) and stores image data compressed by the compression / expansion means 9. Examples of this recording medium include a magnetic recording medium such as a hard disk and a semiconductor memory.

CPU (Central Processing Unit) 11
Performs various control operations in synchronization with the timing signal input from the TG 12 according to the control program for the digital camera stored in the EEPROM 20.
Specifically, the CPU 11 immediately interrupts the focus adjustment and moves the focus lens to a predetermined position to perform the image recording and recording when the image capturing and recording operation is specified by the operation SW 21 before the end of the photometry and the focus adjustment. The photographing process 1 for starting the operation is executed (see FIG. 2). The CPU 11 has a function as a control unit in claims 1 and 2.

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

The AE / AF processing means 13 automatically adjusts the focus of the lens in the photographing optical system 1 to the photographing object based on the digital image signal inputted from the A / D converting means 5. (AF) processing and automatic exposure adjustment (AE: Auto Exposure) processing for automatically adjusting the exposure of the CCD 3 according to the brightness of the object to be photographed are executed.

In the AF process, a high-pass filter extracts a high-frequency component of image data for one screen or a predetermined part in the screen, calculates an AF evaluation value by a calculation process such as cumulative addition, and outputs the AF evaluation value to the CPU 11. . In the AE process, arithmetic processing such as cumulative addition is performed on the brightness value of the image data for one screen, the AE condition at the time of actual exposure is calculated, and the calculated AE condition is output to the CPU 11.

The CCD driver 14 controls the driving of the CCD 3 in synchronization with the timing signal input from the TG 12.

The first motor drive circuit 15 drives and controls the aperture shutter drive motor 16 based on the aperture shutter drive signal input from the CPU 11. The aperture shutter drive motor 16 drives the aperture shutter 2 based on the control signal input from the first motor drive circuit 15.

The second motor drive circuit 17 drives and controls the focus motor 18 based on the focus drive signal input from the CPU 11. Focus motor 18
Drives the focus lens in the imaging optical system 1 based on a control signal input from the second motor drive circuit 17.

The battery 19 supplies electric power to each part constituting the digital camera 100. EEPROM (Electric
ally Erasable Programmable Read-Only Memory) 20
Is an electrically rewritable read-only memory, C
Various control programs executed by the PU 11 and data used for various operations are stored in advance.

An operation SW (SWitch) 21 is a main power SW for designating the power supply to the digital camera 100, a reproduction SW for designating the reproduction operation of the image data stored in the recording memory 10, and a photographing operation (recording operation). ) Has a release SW 210 etc. for designating the start of the above. Release SW210
Has a 1st release SW 210a that specifies the start of the AF operation and the AE operation prior to the shooting operation, and a 2nd release SW 210b that specifies the start of the exposure processing.
The 1st release SW 210a is the first in claim 1.
2nd release S
W210b has a function as a second switch means in claim 1.

The switching circuit 22 is responsive to a fill light control signal input from the CPU 11 to fill the fill light emitting section 23.
ON / OFF control of the flash light emission and the amount of light emission are controlled, and the auxiliary light emitting section 23 emits the auxiliary light under the control of the switching circuit 22.

Next, the operation of the first embodiment will be described. The photographing process 1 executed in the digital camera 100 will be described with reference to the flowchart in FIG.

First, when the power of the digital camera 100 is turned on and the position of at least one focus lens in the image pickup optical system 1 is detected by a photoelectric method, the CPU 1
Based on this detection result, 1 confirms whether or not the focus lens is in the initial position (step S1).

If the focus lens is not at the initial position in step S1 (step S1; NO), C
The PU 11 causes the second motor drive circuit 17 to move the focus lens to the initial position (step S2),
If the focus lens is in the initial position (step S
1; YES), the process proceeds to step S3 described later.

When the focus lens is at the initial position (step S1; YES, or step S2), the CPU 11
Is ON / OFF of 1st SW210a of operation SW21
The state is confirmed (step S3). If the state is the OFF state (step S3; NO), the process returns to step S1, and if the state is the ON state (step S3; YES), the second motor drive circuit 17 sets the focus lens to a predetermined position. To position A (step S4). Here, the predetermined position A is preferably a lens position focused on infinity, for example.

When the focus lens is moved to the predetermined position A, the AE / AF processing means 13 performs photometry at this position to determine the exposure amount at the time of photographing (step S5).
Next, the CPU 11 operates the second SW21 of the operation SW21.
Check the ON / OFF state of 0b (step S7), and
If in the FF state (step S7; NO), step S
8, the AF operation is started, and if it is in the ON state (step S7; YES), the process proceeds to step S15 described later.

In the AF operation, first, the CPU 11
The focus lens is set to 1 by the second motor drive circuit 17.
It is moved by a step (step S8), and the AE / AF processing means 13 performs AF on the imaging surface at the position A.
The (imaging) evaluation value is acquired (step S9), and this AF evaluation value data is temporarily stored in a RAM (Random Access Memory) not shown together with the position data of the focus lens.

In the CPU 11, the 1st SW 210a is turned off.
When the N and 2nd SW 210b are in the OFF state, the operations (AF operations) of steps S6 to S9 are repeated, and among the AF evaluation values calculated at each focus lens position,
It is confirmed whether or not there is a value (maximum value) corresponding to the in-focus lens position (step S10).

When the maximum AF evaluation value is detected from the AF evaluation values calculated in the AF operation (steps S6 to S9) at each focus lens position (step S10; YES), the CPU 11 drives the second motor. The circuit 17 moves the focus lens to a position corresponding to this maximum evaluation value (step S11), and ends the AF operation.

Next, the CPU 11 checks the state of the 1st release SW 210a again (step S12),
If it is in the OFF state (step S12; NO), it returns to step S1, and if it is in the ON state (step S12; Y).
(ES) Confirm the state of the second release SW 210b (step S13).

In step S13, if the second release SW 210b is in the OFF state (step S13;
If NO), the CPU 11 returns to step S12, and if it is in the ON state (step S13; YES), starts the exposure operation (step S14).

In step S7, the CPU 11 sets A
Before detecting the maximum F evaluation value, 2ndSW210b
When the ON state is detected (step S7; YES), it is determined from the photometric result of step S5 whether or not the subject brightness is the brightness required for flashing (step S1).
5).

In step S15, if it is determined from the photometric result that the subject brightness is the brightness (high brightness) that does not require flash (step S15; NO), C
The PU 11 causes the second motor drive circuit 17 to move the focus lens to a predetermined position B (step S1).
6), the exposure operation is started (step S14), and the main photographing process 1 ends. Here, the predetermined position B is preferably a hyperfocal position (pan focus position).

On the other hand, in step S15, it is determined from the photometric results that the subject brightness is the brightness (low brightness) required for flashing (step S15; YE).
S), the CPU 11 causes the second motor drive circuit 17 to
The focus lens is moved to a predetermined position C (step S17), the exposure operation is started (step S14),
The main photographing process 1 is ended. Here, it is preferable that the predetermined position C is closer to the position B (hyperfocal position).

As described above, according to the digital camera 100 of the first embodiment, when the exposure operation is designated by the user pressing the 2ndSW 210b before the end of the photometry and the focus adjustment, the focus adjustment is immediately performed. And the focus lens is moved to the preset lens stop position (position B or position C) to start the exposure operation, so the time required from the pressing operation of the 2nd SW 210b to the actual shooting / recording is shortened. By being able to do so, the user does not miss a photo opportunity, and it is possible to perform stress-free photography. Therefore, the first
The digital camera 100 according to the embodiment is particularly effective for shooting with a wide-angle lens having a short focal length.

[Second Embodiment] A second embodiment of the digital camera 100 to which the present invention is applied will be described below.
This will be described with reference to FIGS. 1 and 3.

The internal configuration diagram of the digital camera 100 according to the second embodiment is the same as that of the first embodiment shown in FIG.
Since it is the same as that shown in FIG. 2, its illustration is omitted, and the configuration description of each part will be described only regarding the points different from the first embodiment.

The CPU 11 executes various control operations in synchronization with the timing signal input from the TG 12, according to the control program for the digital camera stored in the EEPROM 20. Specifically, the CPU 11 increases the drive step of the focus lens for focus adjustment to a value larger than usual when the shooting recording operation is designated by the operation SW 21 before the end of the photometry and the focus adjustment, and the focus adjustment operation. And the shooting process 2 for starting the shooting / recording operation when the focus adjustment is completed (see FIG. 3).
The CPU 11 has a function as a control unit in claims 3 and 4.

Next, the operation of the second embodiment will be described. The photographing process 2 executed in the digital camera 100 will be described with reference to the flowchart of FIG.

First, when the power of the digital camera 100 is turned on and the position of at least one focus lens in the image pickup optical system 1 is detected by the photoelectric method, the CPU 1
Based on this detection result, 1 confirms whether or not the focus lens is at the initial position (step T1).

In step T1, if the focus lens is not in the initial position (step T1; NO), C
The PU 11 causes the second motor drive circuit 17 to move the focus lens to the initial position (step T2),
If the focus lens is in the initial position (step T
1; YES), the process proceeds to step T3 described later.

When the focus lens is at the initial position (step T1; YES, or step T2), the CPU 11
Is ON / OFF of 1st SW210a of operation SW21
After confirming the state (step T3), if it is in the OFF state (step T3; NO), the process returns to step T1, and if it is in the ON state (step T3; YES), the second motor drive circuit 17 sets the focus lens to a predetermined position. To position A (step T4). Here, the predetermined position A is preferably a lens position focused on infinity, for example.

When the focus lens is moved to the predetermined position A, the AE / AF processing means 13 performs photometry at this position to determine the exposure amount at the time of photographing (step T5).
Next, the CPU 11 operates the second SW21 of the operation SW21.
Check the ON / OFF state of 0b (step T7), and
In the FF state (step T7; NO), step T
If it is in the ON state by moving to 8 and starting the AF operation (step T7; YES), it moves to step T15 described later.

In the AF operation, first, the CPU 11
The focus lens is set to 1 by the second motor drive circuit 17.
It is moved by a step (step T8), and the AE / AF processing means 13 performs AF on the imaging surface at the position A.
The (imaging) evaluation value is acquired (step T9), and the AF evaluation value data is temporarily stored in a RAM (not shown) together with the position data of the focus lens.

In the CPU 11, the first SW 210a is turned off.
When the N and 2nd SW 210b are in the OFF state, the operation (AF operation) of steps T6 to T9 is repeated, and the AF evaluation value calculated at each focus lens position includes:
Check if there is a value (maximum value) corresponding to the in-focus lens position.

When the maximum AF evaluation value is detected from the AF evaluation values calculated in the AF operation (steps T6 to T9) at each focus lens position (step T10; YES), the CPU 11 drives the second motor. The circuit 17 moves the focus lens to a position corresponding to this maximum evaluation value (step T11), and ends the AF operation.

Next, the CPU 11 checks the state of the 1st release SW 210a again (step T12),
If it is in the OFF state (step T12; NO), the process returns to step T1, and if it is in the ON state (step T12; Y).
ES) Confirm the state of the second release SW 210b (step T13).

At step T13, if the second release SW 210b is in the OFF state (step T13;
If NO), the CPU 11 returns to step T12, and if it is in the ON state (step T13; YES), starts the exposure operation (step T14) and ends the main photographing process 2.

When the CPU 11 detects the ON state of the second SW 210b before detecting the maximum value of the AF evaluation value (step T7; YES), the second motor drive circuit 17 causes the movement amount of the focus lens based on the movement amount of the focus lens in step S8. The focus lens is moved one step with a large movement amount (step T15), and the AE / AF processing means 13 causes
An AF evaluation value on the imaging surface at this lens position is acquired (step T15). Here, the large movement amount in step T15 is preferably 2 to 3 times the one-step movement amount in step T8.

The CPU 11 temporarily stores the AF evaluation value data obtained in step T16 in the RAM (not shown) together with the position data of the focus lens until the maximum AF evaluation value is detected (step T17). The AF operation of steps T15 to T16 is repeated.

When the maximum value is detected from the AF evaluation values calculated in the AF operation (steps T15 to T16) at each focus lens position (step T17; YE).
S), the CPU 11 causes the second motor drive circuit 17 to
The focus lens is moved to the position corresponding to this maximum evaluation value (step T18), the exposure operation is started (step T14), and the main photographing process 2 is ended.

As described above, according to the digital camera 100 of the second embodiment, if the exposure operation is designated by the user pressing the 2ndSW 210b before the end of the photometry and the focus adjustment, the focus adjustment is performed. The focus lens driving step is set to be larger than usual (2 to 3 times the normal step) to continue the focus adjustment operation, and the exposure operation is started when the focus adjustment is completed.
Since the time required from the pressing operation of b to the actual shooting / recording can be minimized, it is possible for the user not to miss a photo opportunity, and it is possible to shoot a clear image. Therefore, the digital camera 100 according to the second embodiment is particularly effective for shooting with a telephoto lens having a long focal length.

The contents described in each of the above embodiments can be changed as appropriate without departing from the spirit of the present invention. For example, the digital camera 100 to which the present invention is applied
The first embodiment is suitable for a wide-angle system with a short focal length at the time of shooting, and a second lens for a telephoto system with a long focal length.
Since the embodiment is suitable, when the zoom lens covers a wide-angle system to a telephoto system, the first and second embodiments can be selectively used according to the focal length at the time of shooting.

[0066]

According to the first aspect of the present invention, the time required from the designation of the photographing / recording operation by the second switch means to the actual photographing / recording operation is shortened, and the user does not miss the photo opportunity. You can shoot without stress.

According to the second aspect of the present invention, a clear image can be taken by determining the stop position of the taking lens according to the subject brightness.

According to the invention described in claims 3 and 4, the second
The time required from the designation of the shooting / recording operation by the switch means to the actual shooting / recording operation can be minimized, and the user does not miss a photo opportunity. Further, since the actual photographing / recording operation is performed after the focus adjustment is completed, a clear image can be photographed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an internal configuration of a camera 100 to which the present invention has been applied.

FIG. 2 is a flowchart showing a shooting process 1 executed by the camera 100 according to the first embodiment.

FIG. 3 is a flowchart showing a shooting process 2 executed by the camera 100 according to the second embodiment.

[Explanation of symbols]

1 Imaging optical system 2 Aperture shutter section 3 CCD 4 Imaging circuit 5 A / D conversion means 6 memory means 7 D / A conversion means 8 Image display section 9 compression / decompression means 10 Memory for recording 11 CPU 12 TG (timing generator) 13 AE / AF processing means 14 CCD driver 15 First motor drive circuit 16 aperture shutter drive motor 17 Second motor drive circuit 18 Focus motor 19 batteries 20 EEPROM 21 Operation SW 210 Release SW 210a 1st release SW 210b 2nd release SW 22 Switching circuit 23 Auxiliary light emitting unit 100 digital camera

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/232 G02B 7/11 N // H04N 101: 00 G03B 3/00 AF term (reference) 2H002 AB01 BB03 BB05 BB06 BB07 FB21 FB22 FB84 GA54 HA05 JA07 2H011 CA24 DA00 DA01 2H044 DA01 DB02 DC01 DC02 DE01 2H051 EB03 EB20 FA49 5C022 AA13 AB03 AB15 AB28 AB40 AC03 AC32 AC42 AC54 AC73 AC74

Claims (4)

[Claims] 1. A focus-adjustable camera, comprising: first switch means for designating the start of photometry and focus adjustment prior to shooting and recording; second switch means for designating the start of shooting and recording operation; Before the end of the photometry and focus adjustment operations started by the first switch means, by the second switch means,
When the shooting and recording operation is specified, the focus adjustment operation is immediately stopped after the photometry, and the shooting lens is stopped at a predetermined position.
A camera comprising: a control unit that starts a shooting and recording operation. 2. The camera according to claim 1, wherein the control means determines a predetermined position at which the taking lens should stop in accordance with subject brightness. 3. A focus adjustable camera, comprising: first switch means for designating the start of photometry and focus adjustment, second switch means for designating the start of shooting and recording operation, prior to shooting and recording; Before the end of the photometry and focus adjustment operations started by the first switch means, by the second switch means,
When the photographing / recording operation is designated, the drive amount of the photographing lens per step is changed to continue the focus adjustment, and the photographing / recording operation is started after the end of the focus adjustment. A camera to do. 4. The camera according to claim 3, wherein the control means makes the drive amount of the photographing lens per step in focus adjustment larger than the drive amount before the designation by the second switch means.