HK1102164A - Imaging device, imaging method and program - Google Patents

Description

Imaging device, imaging method, and program

Technical Field

The present invention relates to an imaging device, an imaging method, and a program suitable for a digital camera that performs flash imaging.

Background

In general, a digital camera is not limited to a silver salt camera, and in still image shooting in which a flash of an auxiliary light source is caused to emit light, a shooting operation is generally controlled so that if the flash is caused to emit light once for shooting, the next flash shooting cannot be performed until the charged state of a large-capacity capacitor for causing the flash to emit light after shooting reaches a light emission allowable amount.

Therefore, in a state where the battery of the power supply is consumed, once flash photography is performed, it takes time until flash photography can be performed next time, and a precious shutter opportunity is often missed.

In addition to the above situation, according to the present applicant, in order to image the subject at an appropriate luminance in order to reduce the influence on the battery life as much as possible, when the set shutter speed is slower than 1/60 seconds, ISO sensitivity is increased, strobe emission is not allowed, ISO sensitivity is maximized in accordance with the luminance of the subject, and when the shutter speed is also slower than 1/60 seconds, strobe emission is determined and sensitivity is determined. In the above processing, a technique is considered in which sensitivity is reduced when flash emission is a shooting condition, and at a time when the reaching distance of the flash does not become excessive with respect to the subject distance, the processing according to the flow is terminated in the processing when the shutter button is half-pressed, and sensitivity is determined (for example, patent document 1).

[ patent document 1] Japanese patent application laid-open No. 2005-204120

The technology described in the above patent document suppresses battery consumption by suppressing the emission driving of the flash when the sensitivity up to the maximum sensitivity that can be set can correspond to the brightness of the subject, but the problem of a high possibility of missing a shutter chance because it takes time to charge the flash when the battery is consumed and the shooting requiring flash emission is performed is not yet solved.

Disclosure of Invention

The invention provides an imaging apparatus, an imaging method, and a program capable of performing imaging without missing a shutter chance.

An imaging device according to an aspect of the present invention includes:

an imaging unit for imaging a subject;

an auxiliary light source for emitting a flash light having a predetermined brightness or higher in a predetermined charged state or higher by the charged electric power in synchronization with the image pickup by the image pickup device;

a determination unit that determines an amount of charge from a state of charge of the assist light source;

and a photographing control unit for increasing the photographing sensitivity of the photographing unit according to the charge amount and executing photographing using the auxiliary light source when the photographing unit photographs.

In addition, an imaging method of an imaging apparatus according to another aspect of the present invention is an imaging method of an imaging apparatus including an imaging unit that images an object and an auxiliary light source that flashes light with a predetermined luminance or higher in a predetermined charged state or higher by charged power in synchronization with imaging by an imaging device, the imaging method including the steps of:

a determination step of determining a charged amount from a charged state of the auxiliary light source;

and a photographing control step of increasing the photographing sensitivity of the photographing unit according to the amount of charge and performing photographing using the auxiliary light source when the photographing unit photographs.

Further, a program according to another aspect of the present invention is executed by a computer incorporated in an imaging apparatus, the imaging apparatus including: an imaging unit that images an object, and an auxiliary light source that flashes light having a predetermined brightness or higher in a predetermined charged state or higher by charged power in synchronization with imaging by an imaging means, the program including:

a determination step of determining a charged amount from a charged state of the auxiliary light source;

and a photographing control step of increasing the photographing sensitivity of the photographing unit according to the amount of charge and performing photographing using the auxiliary light source when the photographing unit photographs. Accordingly, photographing can be performed without missing a shutter opportunity.

Drawings

The drawings are briefly described as follows.

Fig. 1 is a block diagram showing a functional configuration of an electronic circuit of a digital camera according to embodiment 1 of the present invention.

Fig. 2 is a flowchart showing the procedure of the processing contents in the photographing mode of embodiment 1.

Fig. 3 is a diagram showing the charging characteristics of the large-capacity capacitor for a flash lamp of example 1.

Fig. 4 is a diagram showing the contents of a lookup table defining the presence or absence of strobe emission and ISO sensitivity corresponding to the amount of stored electricity in example 1.

Fig. 5 is a flowchart showing the procedure of the processing contents in the shooting mode of the digital camera according to embodiment 2.

Fig. 6 is a diagram showing the contents of a lookup table defining the presence or absence of strobe emission, ISO sensitivity, and shutter speed (S value) according to the amount of stored power in example 2.

Fig. 7 is a flowchart showing the procedure of the processing contents in the shooting mode of the digital camera according to embodiment 3.

Fig. 8 is a diagram showing the contents of a lookup table defining ISO sensitivity according to the stored electric energy and the subject distance in example 3.

Detailed Description

(example 1)

Embodiment 1 in the case of applying the present invention to a digital camera is described below with reference to the drawings.

Fig. 1 shows a conceptual configuration of an electronic circuit of the digital camera 10.

In the figure, in the monitoring state in the photographing mode, the positions of some lenses, specifically, the zoom lens and the focus lens in the photographing lens optical system 12 are appropriately moved by the driving of the motor (M) 11. The solid-state image pickup device CCD13 is disposed at an imaging position behind the photographing optical axis of the photographing lens optical system 12 via a mechanical shutter not shown.

The CCD13 is driven by a Timing Generator (TG)14 and a CCD driver 15 for scanning, and outputs a photoelectric conversion output corresponding to the light image formed in each timing period by 1 frame.

The photoelectric conversion output is obtained by an AGC/SH (Auto Gain Control/Sample Hold) circuit 16, which adjusts the Gain for each primary color component of RGB in accordance with the ISO sensitivity set at that time in the state of an analog value signal, samples and holds the adjusted Gain, and sends the adjusted Gain to an a/D converter 17.

The a/D converter 17 converts the image data of the hole into digital data according to the image size and image quality set at that time, and outputs the digital data to the color processing circuit 18.

The color processing circuit 18 performs color processing including pixel interpolation processing and γ correction processing on the digital pixel data, generates a luminance signal Y and color difference signals Cb and Cr of digital values, and outputs the signals to a dma (direct Memory access) controller 19.

The DMA controller 19 writes the luminance signal Y and the color difference signals Cb and Cr output from the color processing circuit 18 into a buffer in the DMA controller 19 at a time by using a composite synchronization signal, a memory write enable signal, and a clock signal from the color processing circuit 18, and performs DMA transfer to the DRAM21 used as the buffer via a DRAM interface (I/F) 20.

The control unit 22 is configured by a CPU, a nonvolatile memory such as a flash memory fixedly storing an operation program including flash emission and high sensitivity at the time of shooting described later, a RAM used as a work memory, and the like, and is responsible for controlling the operation of the entire digital camera, and after the DMA transfer of the luminance and color difference signals to the DRAM21 is completed, the luminance and color difference signals are read out from the DRAM21 through the DRAM interface 20, and written into the VRAM24 through the VRAM controller 23.

The digital video encoder 25 reads the luminance and color difference signals from the VRAM24 periodically by the VRAM controller 23, generates a video signal based on the data, and outputs the video signal to the display unit 26.

The display unit 26 is configured by a color liquid crystal panel with a backlight and a drive circuit, which are disposed on the back surface of the housing of the digital camera 10, and operates as an electronic viewfinder during the shooting mode, displays an image based on the image information obtained from the digital video encoder 25 at that time, and displays the image selected during the playback mode in real time.

In a so-called through image display state in which the display unit 26 displays an image at that time in real time as a monitor image, if a shutter button constituting a part of the key input unit 27 is operated at a timing at which still image shooting is desired, a trigger signal is generated.

The control unit 22 stops DMA transfer of the 1-picture brightness and color difference signals obtained from the CCD13 to the DRAM21 at that time, drives the mechanical shutter and the CCD13, not shown, at a shutter speed according to appropriate exposure conditions again, obtains 1-picture startup and color difference signals, transfers the signals to the DRAM21, stops the route, and shifts to a memory storage state.

In the stored state, the control unit 22 reads out 1 frame of luminance and color difference signals written in the DRAM21 through the DRAM interface 20 in units of basic blocks called vertical 8 pixels × horizontal 8 pixels for each component of Y, Cb, and Cr, writes the read out signals in the JPEG (joint photographic coding experts group) circuit 28, and encodes the read signals by data compression processing such as ADCT (Adaptive discrete cosine Transform) or huffman coding of entropy coding scheme by the JPEG circuit 28.

Then, the obtained encoded data is read out from the JPEG circuit 28 as a data file of 1 image size, and written into the memory 29 as a storage medium of the digital camera 1 or a memory card 30 removably attached to the digital camera 10.

Then, the control unit 22 restarts the route from the CCD13 to the DRAM21 in accordance with the compression processing of the luminance and color difference signals for 1 frame and the writing of the full-compressed data into the built-in memory 29 or the memory card 30.

Here, the built-in memory 29 and the memory card 30 are memory means for writing and reading various data including image data of still images, with priority given to the memory card 30. That is, the memory unit writes and reads data into and from the internal memory 29 in a state where the memory card 30 is removed from the digital camera 10 and does not exist, and writes and reads data into and from the memory card 30 in a state where the memory card 30 is attached.

The control unit 22 is connected to the key input unit 27, the audio processing unit 31, and the strobe drive unit 32.

The key input unit 27 is constituted by the shutter button, the power button, the zoom button, the shooting mode button, the playback mode button, the cursor button, the setting button, the menu button, the macro button, and the flash button, and signals associated with these buttons are directly transmitted to the control unit 22.

The audio processing unit 31 has an audio source circuit such as a PCM audio source, and digitizes an audio signal input from a microphone unit (MIC)33 disposed on the front surface of the frame of the digital camera 10 at the time of audio recording, performs data compression according to a predetermined data file format, for example, MP3(Moving Picture coding expert group-1 audio layer3) standard, generates an audio data file, transmits the audio data file to the built-in memory 29 or the memory card 30, decompresses and simulates the audio data file read from the built-in memory 29 or the memory card 30 at the time of audio reproduction, and drives a speaker unit (SP)34 provided on the back side of the digital camera 10 similarly to the display unit 26 to perform sound amplification.

The flash drive unit 32 charges a large-capacity capacitor, not shown, for a flash when a still image is captured, and drives a flash light emitting unit 35 including a xenon discharge tube or the like under the control of the control unit 22.

However, when a moving image is selected instead of a still image in the shooting mode, a series of operations such as continuously acquiring the above-mentioned still image data from 30[ frames/second ] at the time of first operating the shutter button, compressing the data by the JPEG circuit 28, storing the data in the internal memory 29 or the memory card 30, and the like are performed, and the still image data file is collectively reset as a motion JPEG data file (AVI file) at the time of 2 nd operating the shutter button or at the time of elapse of a predetermined time limit, for example, 30 seconds.

In the reproduction mode, the control unit 22 selectively reads out the image data stored in the built-in memory 29 or the memory card 30, expands the compressed image data by the JPEG circuit 28 in a procedure completely reverse to the procedure of data compression in the shooting mode, holds the expanded image data in the DRAM21 through the DRAM interface 20, stores the holding content of the DRAM21 in the VRAM24 through the VRAM controller 23, periodically reads out the image data from the VRAM24, generates a video signal, and reproduces the video signal on the display unit 26.

When the selected image data is not a still image but a moving image, reproduction of each still image data constituting the selected moving image file is performed continuously in time at a predetermined frame rate, and at the time of ending reproduction of the last still image data, reproduction display is performed using only the still image data located at the head until an instruction to perform reproduction next time.

The operation of the described embodiment is explained below.

In the digital camera 10, as in the case of other general cameras, the shutter button has an operation stroke of 2 stages, and performs a photographing operation based on the operation of the 1 st stage, which is an operation state generally called half-press, in which the Autofocus (AF) process and the Automatic Exposure (AE) process are performed to lock respective process values, and then performs an operation of the second stage, which is an operation state generally called full-press, in which the operation logic of main photographing based on the AF value and the AE value is performed.

Fig. 2 shows the contents of processing executed when still image shooting is executed in the shooting mode, and at this point in time, simple AF processing and AE processing are executed with convergence at a predetermined frame rate, for example, 30[ frame/second ], and by continuously driving CCD13 at a high shutter speed in consideration of the frame rate, processing is repeatedly executed to determine whether or not key input unit 27 is half-pressed (step S02) while maintaining a through image display state in which content shot by CCD13 is displayed by display unit 26 (step S01), and waiting for the shutter key to be half-pressed.

When the shutter key is half-pressed, it is judged in step S02 that the shutter key is pressed, the focusing lens in the photographing lens optical system 12 is moved to the center of the image obtained at that time, and the focusing lens is locked (AF lock), and the electronic sound of the "tic …" is reproduced by sound with the speaker unit 34, thereby notifying the user that AF lock is performed (step S03).

At the same time, an appropriate exposure value is acquired from the state where the focus position is locked, the diaphragm value and the shutter speed are set from the exposure value, the lock is temporarily performed (step S04), and it is repeatedly determined whether the shutter button is fully pressed (step S05) or half pressed (step S06), so that the state where the shutter button is fully pressed or half pressed is released while locking the respective states of AF and AE is waited for.

Note that, from the AE value temporarily locked in step S04, when the emission of the strobe light emission unit 35 is necessary, the charging of the capacitor, not shown, is started immediately by the strobe drive unit 32.

It should be noted that the capacitor, not shown, is not limited to be charged at the timing when AE is temporarily locked (step S04), and may be charged at the timing when the shooting mode is switched or after flash emission, for example, for forced emission.

When the half-press operation of the shutter button is released, it is judged in step S06 that it is not reached to the main shooting, and the process returns to the process from step S01.

Further, if the shutter key is fully pressed from the state where the AF value and the AE value are locked, it is judged at step S05, and then it is judged from the AE value locked at the previous step S04 whether or not light emission of the flash light emission section 35 is necessary (step S07).

When it is determined that there is external light of a sufficient amount to the subject that does not require the emission of the strobe light-emitting unit 35, the emission of the strobe light-emitting unit 35 is not performed, and imaging is performed in accordance with the AF value and the AE value locked in steps S03 and S04 (step S08), and after image data obtained by imaging is compressed and is then quickly recorded in the internal memory 29 or the memory card 30 (step S09), the process returns to the process from step S01 in preparation for the next imaging.

When it is determined in step S07 that the emission of the strobe light-emitting unit 35 is necessary, the strobe drive unit 32 checks the state of charge of the capacitor (C), not shown, for the emission of the strobe light-emitting unit 35 at that time, and outputs information indicating the result to the control unit 22 (step S10).

Fig. 3 shows the charging characteristics of the capacitor based on the flash driving section 32 for driving the flash light emission section 35. Here, when the voltage applied to the xenon discharge tube constituting the flash light emission unit 35 is 220V by the amount of charge charged in the capacitor, the flash light emission unit 35 can be flash-driven, and if 330V is reached, the full charge of the upper limit value is achieved, and the charged state is maintained.

The state of charge of the capacitor at this time is checked to determine whether or not the state of charge is a state of charge in which light emission by the strobe light emitting unit 35 is possible, and whether or not the voltage is 220V or more is determined (step S11).

When it is determined that the stroboscopic light-emitting unit 35 can emit light, ISO sensitivity, specifically, the amplification factor of the image signal with respect to the analog value in the AGC/SH circuit 16 is set in accordance with the charging state at the time of the examination (step S12), and the stroboscopic light-emitting unit 35 is caused to emit light by the amount of light that can be emitted at that time, and photography is performed (step S13).

Fig. 4 shows the contents of the lookup table referred to by the control unit 22 at this time, and when the voltage of the capacitor is 220V to 330V, the ISO sensitivity is set in stages in the range of 1600 to 50, and imaging is performed.

Then, in step S13, if the image capturing is performed by emitting the strobe light emitting section 35 based on the amount of light that can be emitted at that time, the image data obtained by the image capturing is compressed and then quickly recorded in the built-in memory 29 or the memory card 30 (step S09), and the process returns to the process from step S01 in preparation for the next image capturing.

In step S11, when it is determined that the state of charge of the capacitor of the flash drive unit 32 is a state in which light emission by the flash light emission unit 35 is not possible and it is determined that the voltage is lower than 220V, the ISO sensitivity is set to the maximum value (1600 in fig. 4) (step S14), and light emission by the flash light emission unit 35 is not performed, and imaging is performed (step S15).

Then, the image data obtained by the shooting is compressed and then promptly recorded in the built-in memory 29 or the memory card 30 (step S09), and the process returns to the process from step S01 in preparation for the next shooting.

Even if the capacitor for causing the flash light emission unit 35 of the auxiliary light source to emit light is not in a fully charged state, if light emission is possible, it is determined that the ISO sensitivity is set to be improved immediately, and the operation is shifted to a shooting operation accompanied by light emission of the flash light emission unit 35.

Further, when the capacitor for causing the strobe light emitting unit 35 to emit light is far from the fully charged state and it is determined that light emission is not possible, the ISO sensitivity is set to the maximum value, strobe light emission is not performed, and the image capturing operation is shifted to the image capturing operation.

In the above-described embodiment, the determination of whether or not the flash can emit light and the setting of the ISO sensitivity corresponding to the charging state are both determined by referring to the look-up table stored in the nonvolatile memory in the control unit 22 together with the operation program.

Accordingly, high sensitivity of photographing can be realized quickly with a simple circuit configuration, and stored contents can be easily rewritten according to individual differences of components constituting the digital camera 10, upgrade of products, and customization by a user.

(example 2)

Embodiment 2 when the present invention is applied to a digital camera is described below with reference to the drawings.

The conceptual configuration of the electronic circuit of the digital camera 10 according to embodiment 2 is basically the same as that shown in fig. 1, and the same reference numerals are used for the same portions, and illustration and description thereof are omitted.

In example 2, the photographing lens optical system 12 or the CCD13 has a camera-shake correction function, and specifically, there is a method of displacing the photographing optical axis of the photographing lens optical system 12 or a method of moving the photographing range in the photographing region of the CCD 13.

Further, an acceleration sensor is provided for detecting displacement in a frequency range of 5 to 50Hz in 2 directions orthogonal to the respective photographing optical axes of the photographing lens optical system 12, not shown in fig. 2, and in a state where the camera shake correction mode deviates from a setting difference, the camera shake correction function is activated in accordance with the acceleration sensor, thereby eliminating the influence of camera shake and obtaining clear image data.

Next, the operation of the embodiment will be described.

In the digital camera 10, as in the case of other general cameras, the shutter button has an operation stroke of 2 stages, and performs a photographing operation based on the operation of the 1 st stage, which is an operation state generally called half-press, in which the Autofocus (AF) process and the Automatic Exposure (AE) process are performed to lock respective process values, and then performs an operation of the second stage, which is an operation state generally called full-press, in which the operation logic of main photographing based on the AF value and the AE value is performed.

Fig. 5 shows the contents of processing executed when still image shooting is executed in the shooting mode, and at this point in time, simple AF processing and AE processing are executed with convergence at a predetermined frame rate, for example, 30 frames/second, and by continuously driving CCD13 at a high shutter speed in consideration of the frame rate, processing is repeatedly executed to maintain a through image display state in which the display unit 26 displays the contents shot by CCD13 (step S21), and to determine whether or not the key input unit 27 is half-pressed (step S22), and wait for the shutter key to be in the half-pressed state.

Then, if the shutter key is half-pressed, it is judged in step S22 that the focus lens in the photographing lens optical system 12 is moved to the center of the image obtained at that time, and the focus lens is locked (AF lock), and the electronic sound of the "tic …" is amplified and played by the speaker unit 34, thereby notifying the user that AF lock is performed (step S23).

At the same time, an appropriate exposure value is acquired from the state where the focus position is locked, the diaphragm value and the shutter speed are set from the exposure value, the lock is temporarily performed (step S24), it is repeatedly determined whether the shutter button is fully pressed (step S25), whether the shutter button is still half pressed (step S26), and the state where the shutter button is fully pressed or half pressed is released while waiting for the respective states of AF and AE to be locked.

Note that, from the AE value temporarily locked in step S24, when light emission from the flash light emission unit 35 is necessary, charging of a capacitor, not shown, is immediately started by the flash drive unit 32.

Note that the capacitor, not shown, is not limited to be charged at the timing when AE is temporarily locked (step S24), and may be charged at the timing when the shooting mode is switched to or after flash emission, for example, for forced emission.

When the half-press operation of the shutter button is released, it is judged in step S26 that it is not reached to the main shooting, and the process returns to the process from step S21.

Further, if the shutter key is fully pressed from the state where the AF value and the AE value are locked, it is judged at step S25, and then it is judged from the AE value locked at the previous step S24 whether or not light emission of the flash light emission section 35 is necessary (step S27).

When it is determined that there is external light of a sufficient amount to the subject that does not require the emission of the strobe light-emitting unit 35, the emission of the strobe light-emitting unit 35 is not performed, and imaging is performed in accordance with the AF value and the AE value locked in steps S23 and S24 (step S28), and after image data obtained by imaging is compressed and is then quickly recorded in the internal memory 29 or the memory card 30 (step S29), the process returns to the process from step S21 in preparation for the next imaging.

When it is determined in step S27 that the emission of the strobe light-emitting unit 35 is necessary, the strobe drive unit 32 checks the state of charge of the capacitor (C), not shown, for causing the strobe light-emitting unit 35 to emit light at that time, and outputs information indicating the result to the control unit 22 (step S30).

Fig. 3 shows the charging characteristics of the capacitor based on the flash driving section 32 for driving the flash light emission section 35. Here, when the voltage applied to the xenon discharge tube constituting the flash light emission unit 35 is 220V by the amount of charge charged in the capacitor, the flash light emission unit 35 can be flash-driven, and if 330V is reached, the full charge of the upper limit value is achieved, and the charged state is maintained.

The state of charge of the capacitor at this time is checked to determine whether or not the state of charge is a state of charge in which light emission by the strobe light emitting unit 35 is possible, and whether or not the voltage is 220V or more is determined (step S31).

When it is determined that the stroboscopic light-emitting unit 35 can emit light, ISO sensitivity, specifically, the amplification factor of the image signal with respect to the analog value in the AGC/SH circuit 16 is set in accordance with the charging state at the time of the examination, the shutter speed is set as necessary (step S32), and the stroboscopic light-emitting unit 35 is caused to emit light with the amount of light that can be emitted at that time, and imaging is performed (step S33).

When it is determined that the stroboscopic light-emitting unit 35 can emit light, the stroboscopic light-emitting unit 35 may be caused to emit light by the amount of light that can be emitted at that time, without setting the ISO sensitivity, and imaging may be performed. Further, it is possible to determine whether or not the strobe light-emitting unit 35 is fully charged without determining whether or not it is able to emit light.

Fig. 6 shows the contents of the lookup table referred to by the control unit 22 at this time, and when the voltage of the capacitor is 220V to 330V, ISO sensitivity is set in stages in the range of 1600 to 50, and when the voltage of the capacitor is 290V to 330V in the higher range, imaging is performed in stages in the range of 1/15 seconds to 1/60 seconds.

Then, in step S33, if the image capturing is performed by emitting the strobe light emitting section 35 based on the amount of light that can be emitted at that time, the image data obtained by the image capturing is compressed and then quickly recorded in the built-in memory 29 or the memory card 30 (step S29), and the process returns to the process from step S21 in preparation for the next image capturing.

In step S31, when it is determined that the state of charge of the capacitor of the flash drive unit 32 is a state in which light emission by the flash light emission unit 35 is not possible, and in this case, is a state lower than 220V, the camera shake correction mode by the photographing lens optical system 12 or the CCD13 is automatically ON-set (step S34), the ISO sensitivity is set to the maximum value (1600 in this case, as shown in fig. 6), the shutter speed (S value) for proper exposure at the ISO sensitivity is further set (step S35), and photographing is performed without light emission by the flash light emission unit 35 (step S36).

Then, the image data obtained by the shooting is compressed and then promptly recorded in the built-in memory 29 or the memory card 30 (step S29), and the process returns to the process from step S01 in preparation for the next shooting.

Thus, when the strobe light emitting unit 35 of the auxiliary light source cannot emit light, the camera-shake correction mode is automatically set, the ISO sensitivity is set to the maximum value, and the shutter speed for obtaining proper exposure is set to perform photographing.

In the above-described embodiment, the determination of whether or not the flash can emit light corresponding to the charging state, the ISO sensitivity, and the setting of the shutter speed in a partial range are determined by referring to the lookup table stored together with the operation program in the nonvolatile memory in the control unit 22.

Accordingly, high sensitivity of photographing can be realized quickly with a simple circuit configuration, and stored contents can be easily rewritten according to individual differences of components constituting the digital camera 10, upgrade of products, and customization by a user.

(example 3)

Embodiment 3 in the case of applying the present invention to a digital camera is described below with reference to the drawings.

The conceptual configuration of the electronic circuit of the digital camera 10 according to embodiment 3 is basically the same as that shown in fig. 1, and the same reference numerals are used for the same portions, and illustration and description thereof are omitted.

The operation of the embodiment is explained below.

In the digital camera 10, as in the case of other general cameras, the shutter button has an operation stroke of 2 stages, and performs a photographing operation based on the operation of the 1 st stage, which is an operation state generally called half-press, in which the Autofocus (AF) process and the Automatic Exposure (AE) process are performed to lock respective process values, and then performs an operation of the second stage, which is an operation state generally called full-press, in which the operation logic of main photographing based on the AF value and the AE value is performed.

In the present embodiment, when performing flash photography by the flash light emission unit 35, the effective photographing distance to the subject is, for example, 10m, and when photographing a subject existing in the range of 10m to infinity (∞), a reflected light amount sufficient for photographing cannot be obtained, and an effect of emission by flash light cannot be expected, so that photography using the flash light emission unit 35 is not performed.

Fig. 7 shows the contents of processing executed when still image shooting is executed in the shooting mode, and at this point in time, simple AF processing and AE processing are executed with convergence at a predetermined frame rate, for example, 30 frames/second, and by continuously driving CCD13 at a high shutter speed in consideration of the frame rate, processing is repeatedly executed to maintain a through image display state in which the display unit 26 displays the contents shot by CCD13 (step S41), and to determine whether or not the key input unit 27 is half-pressed (step S42), and wait for the shutter key to be in the half-pressed state.

Then, if the shutter key is half-pressed, it is judged in step S42 that the focus lens in the photographing lens optical system 12 is moved to the center of the image obtained at that time, and the focus lens is locked (AF lock), and the electronic sound of the "tic …" is amplified and played by the speaker unit 34, thereby notifying the user that AF lock is performed (step S43).

At the same time, an appropriate exposure value is acquired from the state where the autofocus position is locked, the aperture value and the shutter speed are set from the exposure value, the lock is temporarily performed (step S44), it is repeatedly determined whether the shutter button is fully pressed (step S45), whether the shutter button is still half pressed (step S46), and the state where the shutter button is fully pressed or half pressed is released while waiting for the respective states of AF and AE to be locked.

Note that, from the AE value temporarily locked in step S44, when light emission from the flash light emission unit 35 is necessary, charging of a capacitor, not shown, is immediately started by the flash drive unit 32.

Note that the capacitor, not shown, is not limited to be charged at the timing when AE is temporarily locked (step S44), and may be charged at the timing when the shooting mode is switched to or after flash emission, for example, for forced emission.

When the half-press operation of the shutter button is released, it is judged in step S46 that it is not reached, and the process returns to the process from step S41.

Further, if the shutter key is fully pressed from the state where the AF value and the AE value are locked, it is judged at step S45, and then it is judged from the AE value locked at the previous step S44 whether or not light emission of the flash light emission section 35 is necessary (step S47).

When it is determined that there is external light of a sufficient amount to the subject that does not require the emission of the strobe light-emitting unit 35, the emission of the strobe light-emitting unit 35 is not performed, and imaging is performed in accordance with the AF value and the AE value locked in steps S43 and S44 (step S48), and after image data obtained by imaging is compressed and is then quickly recorded in the internal memory 29 or the memory card 30 (step S49), the process returns to the process from step S01 in preparation for the next imaging.

When it is determined in step S47 that the emission of the strobe light-emitting unit 35 is necessary, the strobe drive unit 32 checks the state of charge of the capacitor (C), not shown, for causing the strobe light-emitting unit 35 to emit light at that time, and outputs information indicating the result to the control unit 22 (step S50).

Fig. 3 shows the charging characteristics of the capacitor based on the flash drive section 32 for flash-driving the flash light emission section 35. Here, when the voltage applied to the xenon discharge tube constituting the flash light emission unit 35 is 220V by the amount of charge charged in the capacitor, the flash light emission unit 35 can be flash-driven, and if 330V is reached, the full charge of the upper limit value is achieved, and the charged state is maintained.

The state of charge of the capacitor at this point in time is checked, and it is determined whether or not the distance from the AF value locked in the above-described step S43 to the object is within a range (10m to infinity (∞)) in which the effect by stroboscopic light emission cannot be expected (step S51).

Here, when the distance to the subject is long and it is determined that the effect of strobe emission cannot be expected, all elements other than the strobe including ISO sensitivity are set to high sensitivity (step S52), and imaging is performed without emission of the strobe emission unit 35 (step S53).

Then, the image data obtained by the shooting is compressed and then promptly recorded in the built-in memory 29 or the memory card 30 (step S49), and the process returns to the process from step S01 in preparation for the next shooting.

When it is determined in step S51 that the distance to the subject is within the range in which the effect by stroboscopic light-emitting can be expected, it is determined in step S50, as a result of the check of the charged state, whether or not the charged state is a charged state in which sufficient light-emitting by the stroboscopic light-emitting unit 35 can be performed, and it is determined whether or not the charged state is 220V or more (step S54).

When it is determined that the stroboscopic light-emitting unit 35 is capable of emitting light, ISO sensitivity, specifically, the amplification factor of the image signal with respect to the analog value in the AGC/SH circuit 16 is set in accordance with the distance from the subject in accordance with the charged state at the time of the examination (step S56), and the stroboscopic light-emitting unit 35 is caused to emit light at the amount of light capable of emitting light at that time, and photography is performed (step S57).

Fig. 8 shows the contents of the lookup table referred to by the control unit 22 at this time, and when the voltage of the capacitor is 220V to 330V, ISO sensitivity is set in stages in a range of 1600 to 50 from the AF value, and imaging is performed.

Then, in step S57, if the image capturing is performed in which the strobe light emitting unit 35 emits light based on the amount of light that can be emitted at that time, the image data obtained by the image capturing is compressed and then stored in the internal memory 29 or the memory card 30 (step S49), and the process returns to the process from step S41 in preparation for the next image capturing.

In step S54, when it is determined that the state of charge of the capacitor of the strobe driver 32 is a state in which light emission by the strobe light emitting unit 35 is not possible, that is, a state below 220V, all elements other than the strobe light including ISO sensitivity are set to high sensitivity (step S58), and imaging is performed without light emission by the strobe light emitting unit 35 (step S59).

Then, the image data obtained by the shooting is compressed and then promptly recorded in the built-in memory 29 or the memory card 30 (step S49), and the process returns to the process from step S41 in preparation for the next shooting.

In this way, even in a charged state in which light emission is originally impossible, the flash is caused to emit light even if it is insufficient, and forced photography is performed by increasing the sensitivity of the respective elements automatically set at the same time, so that it is possible to give priority to the user's photographic intention and to reliably perform photography without missing a shutter opportunity.

In embodiments 1 to 3, the ISO sensitivity, specifically, the amplification factor when the analog image signal is amplified by the AGC/SH circuit 16 corresponds to the high sensitivity of the image capturing, but the present invention is not limited to this, and the image capturing method may be performed by a pixel addition method in which information between adjacent pixels is added to expand the dynamic range of the pixels.

Further, the image processing apparatus can be performed by a pixel addition method based on a plurality of images in which a plurality of image data acquired by a plurality of temporally successive exposures are added by pixels [ ].

In this case, since image data with high sensitivity is obtained from image data obtained by multiple exposures, even if a motion correction operation is performed when the subject moves violently, "vibration" is inevitably generated in the image, and in order to perform good imaging, the subject is limited to a small amount of movement, but more natural and high-quality image data can be obtained.

The present invention is not limited to the above-described embodiments, and various modifications and implementations can be made without departing from the scope of the invention.

The embodiments described above include inventions in various stages, and various inventions can be extracted by appropriate combinations of a plurality of constituent elements described. For example, even if several constituent elements are deleted from all the constituent elements described in the embodiments, at least one of the problems described in the section of the problem to be solved by the invention can be solved, and when at least one of the effects described in the section of the effect of the invention is obtained, the structure in which the constituent element is deleted can be extracted as the invention.

Claims (9)

1. A kind of camera device is disclosed, which comprises a camera body,

comprises the following steps:

an imaging unit that images an object;

an auxiliary light source for emitting a flash light having a predetermined brightness or higher in a predetermined charged state or higher by the charged power in synchronization with the image pickup by the image pickup device;

a determination unit that determines a charged amount from a charged state of the assist light source; and

and an imaging control unit that increases the imaging sensitivity of the imaging unit in accordance with the charge amount and executes imaging using the auxiliary light source when the imaging unit performs imaging.

2. The image pickup apparatus according to claim 1, wherein:

the photographing control means increases the photographing sensitivity of the photographing means according to the determination by the determination means, and performs photographing using the auxiliary light source by changing the shutter speed.

3. The image pickup apparatus according to claim 1, wherein:

the determination means includes means for determining whether or not light emission of a predetermined luminance or higher is possible from a charged state of the auxiliary light source;

the photographing means corresponds to photographing in a hand shake correction mode;

the photographing control means sets the photographing means to the camera shake correction mode and executes photographing by changing a shutter speed when the determination means determines that the light emission is not possible.

4. The image pickup apparatus according to claim 1, wherein:

the imaging control means increases the imaging sensitivity of the imaging means in accordance with the determination by the determination means and the subject distance, and executes imaging using the auxiliary light source.

5. The image pickup apparatus according to claim 1, wherein:

the imaging control unit uses a lookup table in which an increase amount of the imaging sensitivity of the imaging unit corresponding to a charging stage of the auxiliary light source is stored in advance.

6. The image pickup apparatus according to claim 1, wherein:

the imaging control means increases the imaging sensitivity by a pixel addition method of adding information of adjacent pixels.

7. The image pickup apparatus according to claim 1, wherein:

the imaging control means performs image addition of adding a plurality of image data acquired by the imaging means through temporally continuous multiple exposures in the same pixel unit, thereby acquiring image data with improved sensitivity.

8. A photographing method of an image pickup apparatus, the image pickup apparatus comprising: an imaging unit that images an object; and an auxiliary light source for emitting a flash light having a brightness equal to or higher than a predetermined brightness in a predetermined charged state or higher by the charged power in synchronization with the image pickup by the image pickup unit,

the photographing method of the photographing apparatus includes:

a determination step of determining a charged amount from a charged state of the auxiliary light source; and

and a photographing control step of increasing the photographing sensitivity of the photographing section according to the charged amount and performing photographing using the auxiliary light source when the photographing section performs photographing.

9. A program executed by a computer built in an image pickup apparatus, the image pickup apparatus comprising: an imaging unit that images an object; and an auxiliary light source for emitting a flash light having a brightness equal to or higher than a predetermined brightness in a predetermined charged state or higher by the charged power in synchronization with the image pickup by the image pickup unit,

the program includes:

a determination step of determining a charged amount from a charged state of the auxiliary light source; and

and a photographing control step of increasing the photographing sensitivity of the photographing section according to the charged amount and performing photographing using the auxiliary light source when the photographing section performs photographing.