JP2000249908A - Focusing device for electronic image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the focusing device of an electronic image pickup device which can be adapted to the wide-ranging conditions of an object. SOLUTION: When such a condition that the object is dark and the like is satisfied in the case of automatic focusing processing, a more precise focusing position is calculated by turning on a lamp device 101 according to a vertical synchronizing signal related to a CCD 5 and the electric charge accumulating action of the CCD 5 or the prescribed moving amount of a focusing lens 3 so that the proper automatic focusing processing is executed. Thus, the focusing device of the electronic image pickup device which can be adapted to the wide- ranging conditions of the object can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focus adjusting device for an electronic imaging device, and more particularly to a focus adjusting device for an electronic imaging device that adjusts the focus of a photographing optical system based on an image sensor signal.

[0002]

2. Description of the Related Art Hitherto, various automatic focusing devices provided with illumination means for illuminating a subject have been proposed.
Japanese Patent Publication No. 2797 also discloses a contrast detection type focus adjustment device that controls the lighting of LED auxiliary light to perform focus detection.

[0003]

However, in the focus adjusting device of the electronic imaging device proposed in Japanese Patent Application Laid-Open No. Hei 9-312779, an LED is used as an auxiliary light as an auxiliary light, and as an auxiliary light for focusing. There was a limit to the distance at which the lighting effect could be exhibited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a focus adjusting device of an electronic image pickup apparatus which uses a lamp having a large amount of light as a light source and can adapt to a wide range of subject conditions. .

[0005]

According to a first aspect of the present invention, there is provided a focus adjusting apparatus for an electronic imaging apparatus, comprising:
A charge storage type two-dimensional image sensor disposed on an image forming surface of a photographing optical system; and a drive circuit for driving the image sensor. The focus adjustment of the photographing optical system is performed based on a signal from the image sensor. In electronic photography devices,
A light projection unit using a lamp as a light source for smoothly performing focus adjustment under a predetermined subject condition; and an arithmetic control unit for determining a light emission timing of the light projection unit, wherein the arithmetic control unit includes: Under a predetermined subject condition, the light emitting means is turned on at least during the focus adjustment driving of the photographing optical system.

In order to achieve the above object, a second aspect of the present invention is provided.
The focus adjusting device of the electronic imaging device according to the first aspect, wherein the arithmetic control unit starts lighting of the light projecting unit prior to the focus adjustment of the photographing optical system unit in the first electronic imaging device. And

[0007] In order to achieve the above object, a third aspect of the present invention is provided.
The focus adjusting device of the electronic imaging device includes a charge storage type two-dimensional image sensor disposed on an image forming surface of a photographing optical system, a driving circuit for driving the image sensor, and an image forming position of the photographing optical system. An optical system driving unit that performs pulse driving so as to change, and an electronic photographing apparatus that performs focus adjustment of the photographing optical system based on a signal from the image sensor during driving of the photographing optical system, Detecting means for detecting the position or the amount of movement of the photographing optical system, light emitting means using a lamp as a light source for smoothly performing focus adjustment under predetermined object conditions, and controlling the light emitting timing of the light emitting means Computing control means for calculating a contrast value for evaluating a focus adjustment state of the photographing optical system, wherein the computing control means controls the photographing optical system while projecting the light projecting means. When performing the point adjustment, the optical system position in the cycle is associated based on the pre-driving optical system position, the number of driving pulses during non-light projection, and the value obtained by multiplying the number of driving pulses during light projection by a predetermined coefficient. It is characterized in that the contrast value is obtained.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an electronic image pickup apparatus according to a first embodiment of the present invention.

As shown in FIG. 1, an electronic image pickup apparatus 1 includes a zoom lens 2 and a focus lens 3 as an image pickup optical system.
After passing through these lenses, the light beam passes through the stop 4 to form a subject image on the CCD 5 as a solid-state image sensor.

The signal photoelectrically converted by the CCD 5 is input to an imaging circuit 6, which generates a video signal. The video signal is converted into a digital video signal (image data) by an A / D converter 7. And temporarily stored in the memory 8.

The image data stored in the memory 8 is read out at a predetermined screen rate (for example, 1/30 second), and is read out from the D / A
After being converted into an analog video signal by the converter 9, a subject image is displayed on a liquid crystal display element (abbreviated as LCD) 10.

When a recording operation is performed by operating one of the operation switches 24, the image data in the memory 8 is compressed by the compression circuit of the compression / expansion circuit 11, and then the recording data is recorded. Stored in the memory 12.

When a reproducing operation is performed, the data compressed and stored in the recording memory 12 is expanded by the compression / expansion circuit 11 and temporarily stored in the memory 8, and the image data is stored in the D / D memory. After being converted into an analog video signal by the A converter 9, a reproduced image is displayed on a liquid crystal display (LCD) 10.

The image data A / D converted by the A / D converter 7 is input to an auto exposure processing circuit (abbreviated as AE processing circuit) 13 and an auto focus processing circuit (abbreviated as AF processing circuit) 14. The AE processing circuit 13 calculates an AE evaluation value corresponding to the brightness of the subject by, for example, integrating the luminance values of the image data for one frame (one screen), and
Output to PU15.

The AF processing circuit 14 extracts a high-frequency component of the luminance component of the image data for one frame (one screen) by a high-pass filter or the like, and calculates a cumulative addition value to thereby obtain a high-frequency contour. An AF evaluation value corresponding to the component amount or the like is calculated and output to the CPU 15.

A predetermined timing signal synchronized with the screen rate is input from a timing generator (abbreviated as a TG circuit) 16 to the CPU 15, and the CPU 15 performs various control operations in synchronization with the timing signal.

The timing signal of the TG circuit 16 is also input to the imaging circuit 6, and performs processing such as separation of color signals in synchronization with the signal.

The TG circuit 16 controls the CCD driver 17 to drive the CCD 5 at a predetermined timing.

The CPU 15 controls the first, second and third motor drive circuits 18, 19 and 20, respectively, so that the first and second motors 21, 22 and 23 control the aperture 4, The drive of the focus lens 3 and the zoom lens 2 is controlled.

That is, the CPU 15 uses the AE evaluation value
The first motor drive circuit 18 is controlled to rotate the first motor 21 to adjust the aperture amount of the aperture 4 to an appropriate value, that is, to perform automatic exposure control.

The CPU 15 controls the second motor drive circuit 19 based on the AF evaluation value to control the second motor 2
2 is rotationally driven to obtain an AF evaluation value from the AF processing circuit 14. Based on the obtained AF evaluation value, the CPU 15 drives the focus lens 3 to the lens position where the value becomes the maximum, and sets the focus state, that is, performs autofocus.

Further, a focus lens position detecting circuit 31 is provided near the second motor 22. The focus lens position detection circuit 31 is provided with the second motor 2
The number of rotations is detected and the detection signal is sent to the CPU 15. The CPU 15 can know the position or the amount of movement of the focus lens 3 from the detection signal.

In this embodiment, when the AF evaluation value is obtained and the focus position is set, the screen rate (for example, 1/30) when the CCD 5 captures one frame (one screen) of the subject.
Per second) and the focus lens 3
The focus lens 3 is moved by a predetermined feed amount within a movable range in the optical axis direction.

In this embodiment, as a means for performing this autofocus, a hill-climbing autofocus (abbreviated as hill-climbing AF) is employed as shown in FIG. 2 according to the brightness of the subject.

In the present embodiment, a well-known method is used for the auto-focusing process according to the hill-climbing method, which will be briefly described below. As shown in FIG. 2, AF is performed for each lens position at predetermined equal intervals (in the figure, every four steps).
An evaluation value is obtained, and an autofocus processing operation is performed based on the AF evaluation value characteristic curve obtained thereby. That is, the in-focus position is calculated based on the obtained AF evaluation value and the current photographing lens position. CPU 15 is the second motor 2
2 is driven to move the focus lens 3 to the calculated focus position. As a method for obtaining the in-focus position (maximum AF evaluation value), a known method, for example, a method such as a quadratic approximation method is used. The details will be described later.

Further, the present invention is not limited to the above-described method of obtaining an AF evaluation value for each lens position at predetermined regular intervals (see FIG. 2). An approximation characteristic curve may be obtained from the AF evaluation value at a small number of evaluations by using a method such as the above-described quadratic approximation method, and the autofocus process may be performed. In this process, the autofocus process can be realized more quickly.

Zoom UP which is one of the operation switches 24
When the switch is operated, the CPU 15 receives the operation signal and controls the third motor drive circuit 20 to rotate the third motor 23 to drive the zoom lens 2 to the enlargement side.

The CPU 15 is connected to, for example, an electrically rewritable and non-volatile EEPROM 25 as a read-only memory.
The ROM 25 stores a program for performing various controls and the like via the CPU 15, data used for performing various operations, and the like. The ROM 25 reads the program when the power of the electronic imaging apparatus 1 is turned on. Used and used.

Note that the CPU 15 detects the voltage of the battery 26 and, when detecting that the voltage has dropped below a predetermined value, uses the LCD 10 to determine whether the battery 26 is low or to charge or replace the battery. Prompt display.

On the other hand, the electronic imaging device 1 of the present embodiment
A built-in lamp device 101 is provided as a light source device in addition to a normal flash device used for photographing. The lamp device 101 serves as a light projecting unit, and emits a large amount of light compared to a light emitting unit such as an LED.
And a light emission control circuit 28 that controls the light emission (lighting, extinguishing) of the light emitting lamp unit 27 under the control of the CPU 15. The lamp device 101 is controlled by the CPU 15
When the auxiliary light is required during the autofocus process, the light is appropriately turned on, thereby contributing to the optimization of the autofocus process. Details will be described later.

Next, a description will be given of a photographing sequence in the electronic image pickup apparatus of the present embodiment having such a configuration.

FIG. 4 is a flowchart showing a photographing sequence of the electronic image pickup apparatus of the first embodiment. CP
U15 first controls the AE processing circuit 13 to perform automatic exposure processing (AE processing, step S1), and then waits for pressing of a first release switch, which is one of the operation switches 24 (step S2). Here, when the first release switch is turned on, it is determined based on the AE evaluation value calculated by the AE processing circuit 13 whether or not the darkness requires auxiliary light for performing the autofocus processing (step S3). ).

If it is determined in step S3 that the brightness is sufficient to perform the autofocus process, the normal autofocus process is performed (step S3).
5).

Here, normal auto focus processing will be described with reference to FIG. FIG. 5 is a flowchart illustrating a subroutine of a normal autofocus process in the electronic imaging apparatus according to the first embodiment.

The CPU 15 first sets the focus lens 3
Is once moved to an infinity position (step S11). At this time, the CPU 15 drives the second motor 22 via the second motor drive circuit 19 to
To move. Next, the CPU 15 sets the unit drive amount SP of the focus lens 3 (step S12). In this embodiment, the unit drive amount SP is the second drive amount SP.
The drive pulse applied to the motor 22 corresponds to four steps.

Thereafter, the CPU 15 moves the focus lens 3 in the close direction by the unit drive amount SP (step S13). The detection of the lens position of the focus lens 3 is detected by a focus lens position detection circuit 31 provided near the second motor 22 and can be determined by the CPU 15.

When the focus lens 3 moves by the unit drive amount SP, the CPU 15 drives the AF processing circuit 14 to acquire an AF evaluation value (step S14).

This AF evaluation value is obtained over all evaluation points until the focus lens 3 reaches the closest position, and is temporarily stored together with the lens position of the focus lens 3 (steps S15 and S16).

Then, the in-focus position is calculated from the acquired AF evaluation value and the position of the focus lens 3 in the following steps (steps S17, S18, S19). That is, first, the AF evaluation value and the lens position are substituted into predetermined parameters as described below (step S1).
7).

The lens position at which the maximum AF evaluation position was obtained → X2 The lens position immediately before X2 → X1 The lens position immediately after X2 → X3 The AF evaluation position at X1 → Y1 The maximum AF evaluation position → Y2 X3 Next, an approximation of the contrast curve is obtained from the obtained value by a known method, for example, a method such as quadratic approximation (step S18), and the lens position XF at which the contrast curve becomes maximum is obtained. And set this as the in-focus position (step S
19).

For example, a simultaneous equation such as Y1 = aX1 ＾ 2 + bX1 + c Y2 = aX2 ＾ 2 + bX2 + c Y3 = aX3 ＾ 2 + bX3 + c is obtained. Obtain the maximum value of.

The CPU 15 moves the focus lens 3 to the in-focus position XF thus obtained (step S20). When the autofocus process is completed in this way, the process returns to the main routine.

Returning to FIG. 4, after the above-mentioned autofocus processing, the action as the first release switch is released (step S6), and when the second release switch is turned on (step S7), that is, for example, the first release switch is turned on. When the second release switch is turned on with the switch on, the CPU 15 drives predetermined circuits to perform a shooting operation (step S8).

On the other hand, in step S3, when it is determined from the AE evaluation value calculated by the AE processing circuit 13 that the darkness requires auxiliary light in performing the autofocus processing, the auxiliary light autofocus processing is performed. Perform (Step S4).

Here, the auxiliary light autofocus processing will be described with reference to FIGS. FIG. 6 is a flowchart illustrating a subroutine of auxiliary light autofocus processing in the electronic imaging apparatus according to the first embodiment, and FIG. 7 is a timing chart illustrating a timing of emitting a lamp in the auxiliary light autofocus processing. It is.

In the flowchart shown in FIG.
15 first gives an instruction to the light emission control circuit 28 to turn on the light emission lamp unit 27 (step S10).
1). As a result, the light emitting lamp unit 27 is turned on. CP
U15 executes the autofocus processing subroutine shown in FIG. 5 at the same time as the lighting of the light emitting lamp unit 27 (see FIG. 7) (step S102). That is, the same process as the normal auto focus process is performed, and the light emitting lamp unit 27 is turned off when the process is completed (Step S
103), returning to the main routine.

Returning to FIG. 4, after the auxiliary light autofocusing process in step S4, the action as the first release switch is released (step S6), and the second switch is released.
When the release switch is turned on (step S7), that is, for example, when the second release switch is turned on while the first release switch is turned on, the CPU 1
Reference numeral 5 drives predetermined circuits to perform a shooting operation (step S8).

As described above, in the first embodiment, as shown in FIG. 7, the lighting of the lamp device 101 is started almost simultaneously with the autofocus processing (denoted by AF in the figure).
It is characterized by terminating.

As described above, according to the electronic imaging apparatus of the first embodiment, at the time of autofocus processing,
Since the lamp device 101 is operated as needed when the subject is darker than a predetermined condition, there is an effect that it is possible to adapt to a wide range of subject conditions.

The rising of the light emission is slow with respect to the strobe light or the like, but the change in the light amount is small in a stable period, and the lamp can emit light for a long time, so that it can be adapted to a wider range of subject conditions.

Next, an electronic imaging apparatus according to a second embodiment of the present invention will be described. The configuration of the electronic imaging device according to the second embodiment is the same as that of the electronic imaging device according to the first embodiment as far as shown in the block diagram of FIG. 1. As far as the flowchart of FIG. 4 is concerned, it is the same as the first embodiment. Only the operation related to the auxiliary light autofocus processing in step S4 of the photographing sequence shown in FIG. 4 is different. Therefore, only the differences from the first embodiment will be described here, and detailed descriptions of other configurations and operations will be omitted.

Hereinafter, the auxiliary light autofocus processing in the second embodiment will be described with reference to FIGS. FIG. 8 is a flowchart showing a subroutine of an auxiliary light autofocus process in the electronic imaging apparatus according to the second embodiment. FIG. 9 is a timing chart showing a timing at which a lamp is emitted in the auxiliary light autofocus process. It is.

The photographing sequence in the electronic image pickup apparatus according to the second embodiment is the same as the flowchart shown in FIG. 4, but the auxiliary light autofocus processing in step S4 is as shown in the flowchart in FIG. That is, when the CPU 15 determines that the auxiliary light is necessary in step S3 (see FIG. 4), the CPU 15 gives an instruction to the light emission control circuit 28 to turn on the light emission lamp unit 27 before executing the autofocus process (step S3). S20
1). As a result, the light emitting lamp unit 27 is turned on.

Thereafter, the CPU 15 operates a timer or the like to confirm that a predetermined time has elapsed (step S2).
02), the subroutine of the autofocus process shown in FIG. 5 is executed (step S203). That is,
The same process as the normal auto focus process is performed, and at the end of the process, the light emitting lamp unit 27 is turned off (step S204), and the process returns to the main routine.

Returning to FIG. 4, after the auxiliary light autofocus processing in step S4, the action as the first release switch is canceled (step S6), and the second release switch is released.
When the release switch is turned on (step S7), for example, while the first release switch is kept on, 2
When the nd release switch is turned on, the CPU 15 drives predetermined circuits to perform a photographing operation (step S8).

As described above, in the second embodiment, as shown in FIG. 9, the lighting of the lamp device 101 is started before the execution of the auto focus process (denoted as AF in the figure). I do. Generally, since a light source device such as a lamp requires a predetermined time to reach a state in which a stable light amount is supplied,
In the present embodiment, the lighting is started before the auto-focus processing in order to heat up.

As described above, according to the electronic imaging apparatus of the second embodiment, in addition to the effects of the first embodiment, more accurate autofocus processing is performed by taking into account the remaining heat time of the lamp. obtain.

Next, an electronic imaging apparatus according to a third embodiment of the present invention will be described. The configuration of the electronic imaging apparatus according to the third embodiment is the same as that of the electronic imaging apparatus according to the first embodiment as far as shown in the block diagram of FIG. As far as the flowchart of FIG. 4 is concerned, it is the same as the first embodiment. Only the operation related to the auxiliary light autofocus processing in step S4 of the photographing sequence shown in FIG. 4 is different. Therefore, only the differences from the first embodiment will be described here, and detailed descriptions of other configurations and operations will be omitted.

Hereinafter, the auxiliary light autofocus processing in the third embodiment will be described with reference to FIG. FIG. 10 is a flowchart showing a subroutine of an auxiliary light autofocus process in the electronic imaging apparatus according to the third embodiment.

The photographing sequence in the electronic image pickup apparatus according to the third embodiment is the same as the flowchart shown in FIG. 4, but the auxiliary light autofocus processing in step S4 is as shown in the flowchart in FIG. That is, the CPU 15 first moves the focus lens 3 to the infinity position once as in the normal autofocus processing (step S301). Next, the CPU 15 sets the predetermined drive amount SP of the focus lens 3 (step S302). In the present embodiment, the predetermined drive amount SP is set to eight steps of the drive pulse applied to the second motor 22.

Thereafter, the CPU 15 waits for detection of a rising pulse of the vertical synchronizing signal VD (step S30).
3), when the rising pulse is detected, a predetermined process is performed;
That is, processing performed for each vertical synchronization signal, for example, key scan, power reduction check, TG setting, and the like are performed (step S304).

When these predetermined processes are completed, the CPU 15
Moves the focus lens 3 in the closest direction by the predetermined drive amount SP (step S305). The movement of the focus lens 3 is performed without stopping. In addition,
The detection that the focus lens 3 has been moved by the drive amount SP is detected by the focus lens position detection circuit 31 provided near the second motor 22 and can be determined by the CPU 15.

When the focus lens 3 moves by the predetermined driving amount SP, the CPU 15
Is instructed to light the light emission control circuit 28 (step S306). As a result, the light emitting lamp unit 27 is turned on.

In step S306, the CPU 15 drives the AF processing circuit 14 to acquire an AF evaluation value simultaneously with the lighting of the light emitting lamp unit 27 (step S307).
Note that the method of acquiring the AF evaluation value is the same as the method in the normal auto-focus processing described above, and a detailed description thereof will be omitted.

The CPU 15 further includes a light emitting lamp 27
Is turned on to calculate the lens position of the focus lens 3 at the moment when the AF evaluation value is obtained (step S308). This lens position is provided by a detection signal from the focus lens position detection circuit 31.

Thereafter, steps S303 to S3
The operation at 08 is performed until the AF evaluation value reaches the closest position, and the AF evaluation value is obtained over all the corresponding evaluation points and stored together with the lens position of the focus lens 3 at the moment of lighting (steps S309 and 310).

Then, the in-focus position is calculated from the acquired AF evaluation value and the position of the focus lens 3 (steps S311, S312, S313).

The CPU 15 moves the focus lens 3 to the focus position thus obtained (step S3).
14) After that, return to the main routine.

As described above, in the third embodiment, each time the focus lens 3 moves by approximately SP, the ramp device 10 is moved.
1 is turned on (however, during the charge accumulation period of the CCD 5), and the AF evaluation value at the lens position at the moment of this lighting is acquired. Then, a focus position is obtained from the AF evaluation value and the lens position.

As described above, according to the electronic imaging apparatus of the third embodiment, in addition to exhibiting the same effects as those of the first embodiment, the electronic imaging apparatus can be used without stopping the focus lens 3 without stopping. Since an accurate AF evaluation value using light can be obtained, there is an effect that quick and accurate autofocus processing can be performed.

Next, an electronic imaging apparatus according to a fourth embodiment of the present invention will be described. The configuration of the electronic imaging apparatus according to the fourth embodiment is the same as that of the electronic imaging apparatuses of the first and third embodiments as far as shown in the block diagram of FIG. The imaging sequence is the same as in the first and third embodiments as far as shown in the flowchart of FIG. Only the lens position calculation process during the auxiliary light autofocus process is different. Therefore, only the differences from the third embodiment will be described here, and detailed descriptions of other configurations and operations will be omitted.

Hereinafter, the lens position calculation processing during the auxiliary light autofocus processing according to the fourth embodiment will be described with reference to FIGS. FIG. 11 is a flowchart illustrating a subroutine for calculating a lens position of a focus lens in the auxiliary light autofocus processing in the electronic imaging apparatus according to the fourth embodiment.
5 is a timing chart showing timings for turning on a lamp device in the auxiliary light autofocus processing.

As in the third embodiment, the auxiliary light autofocus processing in the electronic imaging apparatus according to the fourth embodiment is performed by turning on the lamp device 101 and calculating the AF evaluation value for each vertical synchronization signal VD. Then, the lens position of the focus lens 3 is calculated. However, the lighting timing of the lamp device 101 is always performed during the charge accumulation period of the CCD 5, but is not necessarily controlled to be at equal intervals.

On the other hand, the driving pulse of the second motor 22 is also
Control is not performed so that the number of outputs is the same for each vertical synchronization signal VD. The CPU 1 for calculating the AF evaluation value and the like
The calculation of 5 is performed for each vertical synchronization signal VD and at least while the drive pulse of the second motor 22 is not output.

Therefore, accurately calculating the lens position of the focus lens 3 related to the lighting of the lamp device 101 is indispensable for accurate calculation of the in-focus position.

Under such circumstances, in the fourth embodiment, a lens calculation process as shown in FIG. 11 is performed.

That is, the period is set as follows: the period of the vertical synchronizing signal VD → the lighting period of the tv lamp device 101 → the operation time relating to the trAF evaluation value → tc (steps S500, S501, S5).
02).

Further, the CPU 15 proceeds to the next step S50.
In 3, the AFSP * (driving rate) → tm, where AFSP is the number of steps that move during one vertical synchronization signal VD.

Then, the CPU 15 determines whether or not tm <tv− (tr + tc) (step S 504).
If "s", the process proceeds to step S05, and if "No", the process proceeds to step S506.

In step S505, assuming that the lens position of the focus lens 3 before the arbitrary vertical synchronizing signal VD is AFPOS0, the following is established: AFPOS0 + AFSP → AFPOS1.

In step S506, AFPOS0 + AFSP- (tr / drive rate) * 1 /
2 → AFPOS1.

After the calculations in steps S505 and S506, the CPU 15 determines in step S507 that A
FPOS0 is updated to be AFPOS0 + AFSP → AFPOS0.

Thus, for example, in the example of FIG. 12A, since the motor drive does not start during the lighting period of the lamp device 101, the current lens position of the focus lens 3 becomes "4".

In the example of FIG. 12B, since the motor drive takes half the lighting period of the lamp device 101, the current lens position of the focus lens 3 is "9".

In the example of FIG. 12C, since the motor drive is entirely performed during the lighting period of the lamp device 101, the current lens position of the focus lens 3 is "6".

As described above, the lens position of the focus lens 3 corresponding to the lighting of the lamp device 101 can be grasped, and the AF evaluation value at this lens position can be obtained.
The in-focus position can be known using the same method as described above.

As described above, according to the fourth embodiment, in addition to exhibiting the same effects as those of the first embodiment,
Since the lens position of the focus lens 3 according to the lighting of the lamp device 101 can be accurately grasped, there is an effect that accurate autofocus processing can be performed.

[0089]

As described above, according to the present invention, it is possible to provide a focus adjusting device of an electronic image pickup device which can adapt to a wide range of subject conditions.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating an AF evaluation value characteristic used in an autofocus process by a hill-climbing method employed in the electronic imaging apparatus according to the first embodiment.

FIG. 3 is a diagram showing AF evaluation value characteristics used in another autofocusing process by a hill-climbing method employed in the electronic imaging apparatus of the first embodiment.

FIG. 4 is a flowchart showing a shooting sequence in the electronic imaging device of the first embodiment.

FIG. 5 is a flowchart illustrating a subroutine of a normal autofocus process in the electronic imaging apparatus according to the first embodiment.

FIG. 6 is a flowchart illustrating a subroutine of an auxiliary light autofocus process in the electronic imaging apparatus according to the first embodiment.

FIG. 7 is a timing chart showing a timing at which a lamp emits light in an auxiliary light autofocus process in the electronic imaging apparatus according to the first embodiment.

FIG. 8 is a flowchart illustrating a subroutine of an auxiliary light autofocus process in the electronic imaging apparatus according to the second embodiment of the present invention.

FIG. 9 is a timing chart showing a timing at which a lamp is emitted in an auxiliary light autofocus process in the electronic imaging apparatus according to the second embodiment of the present invention.

FIG. 10 is a flowchart showing a subroutine of an auxiliary light autofocus process in the electronic imaging device according to the third embodiment of the present invention.

FIG. 11 is a flowchart illustrating a subroutine for calculating a lens position of a focus lens in an auxiliary light autofocus process in an electronic imaging apparatus according to a fourth embodiment of the present invention.

FIG. 12 is a timing chart showing a timing of turning on a lamp device in an auxiliary light autofocus process in an electronic imaging apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic imaging device 2 ... Photographing lens 3 ... Focus lens 5 ... CCD 13 ... AE processing circuit 14 ... AF processing circuit 15 ... CPU 16 ... TG circuit 19 ... 2nd motor drive circuit 22 ... 2nd motor 26 ... Battery 27: Light-emitting unit 28: Light-emitting control circuit 101: Lamp device

Claims (3)

[Claims] A charge storage type two-dimensional image sensor disposed on an image forming surface of a photographing optical system; and a drive circuit for driving the image sensor. The photographing optical system is based on a signal from the image sensor. An electronic photographing apparatus for adjusting the focus of a subject, comprising: a light projecting means using a lamp as a light source for smoothly performing focus adjustment under a predetermined subject condition; and an arithmetic control means for determining a projecting timing of the light projecting means. And an electronic imaging device, characterized in that the arithmetic and control unit turns on the light emitting unit at least during a focus adjustment drive of the imaging optical system under a predetermined subject condition. Focus adjustment device. 2. A focus adjusting device for an electronic image pickup apparatus according to claim 1, wherein said arithmetic control means starts turning on said light projecting means before adjusting the focus of said photographing optical system means. . 3. A two-dimensional charge storage type image sensor disposed on an image plane of a photographing optical system, a driving circuit for driving the image sensor, and a pulse for changing an image forming position of the photographing optical system. An optical system driving means for driving, the electronic photographing apparatus for adjusting the focus of the photographing optical system based on a signal from the image sensor during driving of the photographing optical system, wherein the position of the photographing optical system or Detecting means for detecting the amount of movement; light emitting means using a lamp as a light source for smoothly performing focus adjustment under predetermined subject conditions; controlling the light emitting timing of the light emitting means; Calculation control means for calculating a contrast value for evaluating the focus adjustment state of the system, wherein the calculation control means adjusts the focus of the photographing optical system while projecting the light projecting means. Determining the contrast value by associating the optical system position in the cycle with the optical system position before driving, the number of driving pulses during non-light projection, and the value obtained by multiplying the number of driving pulses during light projection by a predetermined coefficient. A focus adjustment device for an electronic imaging device.