JP2001230970A - Image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device for picking up a suitable image, regardless of the position of an object. SOLUTION: Corresponding to the range rank of the object (from a deciding part 310), a read mode (from a reading part 330) and an exposure value rank set by a user, as needed (from a deciding part 320), an output command part 300 determines a read number and selects one set of image pickup conditions from among an image pickup condition table 410. In the quantity of light to be emitted, the need for light emission (from a deciding part 340) is considered additionally. The image pickup conditions are set so that an (auto-) exposure value, a gain and the light emission quantity can be increased, corresponding to the enlargement of the distance rank and an aperture (contour emphasis) processing level can be lowered corresponding to the increase of the gain. Therefore, the lightness of the image becomes suitable, and noise is suppressed as well independently of the excess or deficiency of stroboscopic light caused by a distance. White balance control is made by an ordinary mode in the case of distance rank L and is suitably performed, corresponding to the color temperature of a light source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an image pickup apparatus. In particular, the present invention relates to an imaging apparatus in which imaging conditions change according to the distance from a subject.

[0002]

2. Description of the Related Art A digital camera is generally provided with a strobe in order to compensate for a shortage of light quantity at the time of image pickup. An image of a subject is taken after obtaining sufficient brightness by the light emission of the strobe.

[0003] The amount of light emitted from the strobe is adjusted so that an image with just the right brightness can be obtained when the distance from the subject to the digital camera is within a certain range. However, when the subject is placed on a close position (macro position), the amount of light becomes excessive, and the image may be cut off.

[0004] On the other hand, when the subject is located far away, the strobe light may not reach sufficiently, so that the light quantity may be insufficient and the image may be lost. Further, in a digital camera having a function of adjusting a white balance, it is generally set that white balance adjustment for strobe light is performed when a strobe is used. However, in such a setting, the control of the strobe light is weak at a long distance, and the white balance of the image is shifted.

As described above, there has been a problem that an appropriate image cannot be obtained depending on the position of a subject even if a strobe is used. A technique for solving such a problem is disclosed in Japanese Patent Application Laid-Open No. 8-271595. This technique is directed to a camera using a silver halide film, and prevents image skipping by limiting the amount of strobe light emitted from a subject at a macro position.

[0006]

However, it is clear that this technique is not aimed at solving the problem when the position of the subject is far. Even if the light amount is limited in the macro position, light emission is performed in a short time, and it is difficult to make fine adjustments. Therefore, the limited amount of light is not always appropriate, and an image may be cut off.

Accordingly, an object of the present invention is to provide an imaging device capable of solving the above problems. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous embodiments of the present invention.

[0008]

That is, according to a first aspect of the present invention, there is provided a distance sensor for grasping a distance to a subject, a luminous body for reinforcing reflected light from the subject by emitting light,
An image receiving unit that accumulates the reflected light as image information, an exposure control unit that controls exposure to the image receiving unit, a sensitivity adjustment unit that adjusts sensitivity to the reflected light, and controls the exposure control unit and the sensitivity adjustment unit. A control unit that performs control based on an imaging condition relating to the brightness of the image information in accordance with the distance.

In a second aspect of the present invention, the control section includes: a distance determination section that outputs a comparison result obtained by comparing the distance with a distance determination reference; and wherein the imaging condition according to the comparison result is An imaging condition setting unit to be set.

In a third aspect of the present invention, the imaging condition includes the sensitivity as a parameter, and the sensitivity is increased or decreased according to the comparison result.

According to a fourth aspect of the present invention, the imaging conditions are as follows:
An exposure value that is increased or decreased according to the comparison result and provided to the exposure control unit is included as a parameter.

According to a fifth aspect of the present invention, in the imaging condition setting unit, the first sensitivity adjustment processing for the light emitter and the second sensitivity for a light source in an environment where the subject is placed are provided. One of the adjustment processing contents is input according to the distance, and the sensitivity adjustment unit adjusts the sensitivity according to the one selected from the first and second sensitivity adjustment processing contents. Thus, the color temperature is corrected.

A sixth aspect of the present invention further comprises a sharpness adjustment unit for performing a sharpness adjustment process for adjusting the sharpness of the image information, wherein the imaging condition setting unit includes the imaging condition as a parameter. Then, a degree of the sharpness adjustment processing corresponding to the distance is set, and the sharpness adjustment unit performs the sharpness adjustment processing according to the degree.

According to a seventh aspect of the present invention, in the imaging condition setting unit, a light emission amount is included in the imaging condition as a parameter, and a light emission amount according to the distance is set. It emits light that matches.

The above summary of the present invention does not list all of the necessary features of the present invention, and a sub-combination of these features may also be an invention.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to embodiments of the present invention. However, the following embodiments do not limit the invention according to the claims and are described in the embodiments. Not all combinations of features are essential to the solution of the invention.

FIG. 1 is a block diagram illustrating the configuration of a digital camera 10 having a function of changing imaging conditions such as sensitivity in accordance with a distance. First, a general configuration and functions of the digital camera 10 will be described, as a characteristic configuration for realizing such functions will be described in detail with reference to FIG.

The digital camera 10 mainly includes an imaging unit 20, an imaging control unit 40, a processing unit 60, a display unit 100, and an operation unit 110.

The image pickup unit 20 includes a mechanical member and an electric member related to image pickup and image formation. Imaging unit 20
First, an imaging lens 22 that captures and processes a video,
An aperture 24, a shutter 26, an optical LPF (low-pass filter) 28, a CCD 30, and an image signal processing unit 32 are included. The imaging lens 22 includes a focus lens, a zoom lens, and the like. With this configuration, the subject image is
Image on the light receiving surface of. Charges are accumulated in each sensor element (not shown) of the CCD 30 according to the amount of light of the formed subject image (hereinafter, the charges are referred to as “accumulated charges”). The accumulated charge is read out to a shift register (not shown) by a read gate pulse, and is sequentially read out as a voltage signal by a register transfer pulse.

Since the digital camera 10 generally has an electronic shutter function, a mechanical shutter such as the shutter 26 is not essential. In order to realize the electronic shutter function, the CCD 30 is provided with a shutter drain via a shutter gate. When the shutter gate is driven, accumulated charges are swept out to the shutter drain. By controlling the shutter gate, the time for accumulating the electric charges in each sensor element, that is, the shutter speed can be controlled.

A voltage signal output from the CCD 30, that is, an analog signal is color-separated into R, G, and B components by an image signal processing unit 32, and a white balance is adjusted first.
Subsequently, the imaging signal processing unit 32 performs gamma correction, sequentially A / D converts the R, G, and B signals at necessary timing, and obtains digital image data (hereinafter, simply referred to as “digital image data”) obtained as a result. ) Is output to the processing unit 60.

The imaging unit 20 further includes a finder 3
4 and a strobe 36. The finder 34 may be equipped with an LCD (not shown). In this case, various information from the main CPU 62 and the like described later can be displayed in the finder 34. The strobe 36 functions by emitting light when energy stored in a capacitor (not shown) is supplied to the discharge tube 36a.

The imaging control unit 40 includes a zoom drive unit 4
2. It has a focus drive unit 44, an aperture drive unit 46, a shutter drive unit 48, an imaging system CPU 50 that controls them, a distance measurement sensor 52, and a photometry sensor 54. The driving units such as the zoom driving unit 42 each have a driving unit such as a stepping motor. When a release switch 114 described later is pressed, the distance measurement sensor 52 measures the distance to the subject, and the photometry sensor 54 measures the brightness of the subject. The measured distance data (hereinafter simply referred to as “distance measurement data”) and the subject luminance data (hereinafter simply referred to as “photometry data”) are sent to the imaging system CPU 50. Imaging system CPU 50
Controls the zoom drive unit 42 and the focus drive unit 44 to adjust the zoom magnification and focus of the imaging lens 22 based on imaging information such as the zoom magnification specified by the user.

The image pickup system CPU 50 controls the R of one image frame.
The aperture value and the shutter speed are determined based on the integrated value of the digital signal of GB, that is, the AE information. According to the determined values, the aperture driving unit 46 and the shutter driving unit 48 adjust the aperture amount and open and close the shutter 26, respectively.

The imaging system CPU 50 controls the emission of the strobe light 36 based on the photometric data, and at the same time adjusts the aperture of the aperture 24. When the user instructs the capture of an image, the CCD 30 starts to accumulate electric charges, and the accumulated electric charges are output to the imaging signal processing unit 32 after a lapse of a shutter time calculated from the photometric data.

The processing unit 60 includes the digital camera 10
The main C that controls the whole, especially the processing unit 60 itself
PU 62 and memory control unit 6 controlled by PU 62
4, a YC processing unit 70, an optional device control unit 74, a compression / decompression processing unit 78, and a communication I / F unit 80. Main C
The PU 62 is connected to the imaging CPU 5 by serial communication or the like.
Necessary information is exchanged with 0. Main CPU6
The second operation clock is provided from a clock generator 88. The clock generator 88 also provides clocks having different frequencies to the imaging system CPU 50 and the display unit 100, respectively.

The main CPU 62 is provided with a character generator 84 and a timer 86. The timer 86 is backed up by a battery and always counts the date and time.
From the count value, information relating to the imaging date and time and other time information are provided to the main CPU 62. The character generation unit 84 generates character information such as a shooting date and time and a title, and the character information is appropriately combined with the captured image.

The memory control unit 64 includes a nonvolatile memory 66
And the main memory 68. Non-volatile memory 66
Is constituted by an EEPROM (electrically erasable and programmable ROM) or a flash memory, and stores data to be retained even when the power of the digital camera 10 is off, such as setting information by a user and adjustment values at the time of shipment. ing. The non-volatile memory 66 may have a main CP
A boot program or a system program of U62 may be stored.

On the other hand, the main memory 68 is generally a DRAM
And a relatively inexpensive and large-capacity memory. The main memory 68 has a function as a frame memory for storing data output from the imaging unit 20, a function as a system memory for loading various programs, and a function as a work area. The nonvolatile memory 66 and the main memory 68 exchange data with each unit inside and outside the processing unit 60 via the main bus 82.

The YC processing section 70 performs YC conversion on the digital image data, and outputs a luminance signal Y and a color difference (chroma) signal B-
Generate Y, RY. The luminance signal and the color difference signal are temporarily stored in the main memory 68 by the memory control unit 64.
The compression / decompression processing unit 78 sequentially reads out the luminance signal and the color difference signal from the main memory 68 and compresses them. The data thus compressed (hereinafter simply referred to as “compressed data”) is written to a memory card, which is a type of the optional device 76, via the optional device control section 74.

The processing unit 60 further includes an encoder 72
With. The encoder 72 receives a luminance signal and a color difference signal, converts them into a video signal (NTSC or PAL signal), and outputs the video signal from a video output terminal 90. When a video signal is generated from data recorded in the optional device 76, the data is first supplied to the compression / decompression processing unit 78 via the optional device control unit 74. Subsequently, the data subjected to the necessary expansion processing by the compression / expansion processing unit 78 is converted into a video signal by the encoder 72.

The optional device control section 74 generates a necessary signal between the main bus 82 and the optional device 76, performs logical conversion, or converts voltage according to the signal specifications recognized by the optional device 76 and the bus specifications of the main bus 82. And so on. The digital camera 10 may include, for example, a PCM as an optional device 76 in addition to the above-described memory card.
A standard CIA-compliant standard I / O card may be supported. In that case, the optional device control unit 74
It may be constituted by an IA bus control LSI or the like.

The communication I / F unit 80 is provided for the digital camera 10
Communication specifications supported by, for example, USB, RS-23
It performs control such as protocol conversion according to specifications such as 2C and Ethernet. The communication I / F unit 80 includes a driver IC as necessary, and communicates with an external device including a network via a connector 92. In addition to such standard specifications, data may be exchanged with an external device such as a printer, a karaoke machine, a game machine, or the like by a unique I / F.

The display unit 100 includes an LCD monitor 10
2 and an LCD panel 104. These are the LCD driver monitor driver 106, panel driver 10
8 respectively. LCD monitor 102
Is provided on the back of the camera with a size of, for example, about 2 inches, and displays a current imaging / reproduction mode, a zoom magnification for imaging / reproduction, a battery level, a date / time, a screen for setting a mode, a subject image, and the like. . The LCD panel 104 is, for example, a small black-and-white LCD provided on the upper surface of the camera and has an image quality (FINE).
/ NORMAL / BASIC etc.), information such as strobe light emission / light emission inhibition, standard number of images that can be captured, number of pixels, and battery capacity are simply displayed.

The operation unit 110 includes mechanisms and electric members necessary for the user to set or instruct the operation of the digital camera 10 and its mode. The power switch 112 determines whether the power of the digital camera 10 is turned on or off. The release switch 114 has a two-stage pressing structure of half pressing and full pressing. As an example, AF and AE are locked by pressing halfway, captured images are taken by pressing fully, and are recorded in the main memory 68, the optional device 76, etc. after necessary signal processing, data compression, and the like.

The operation unit 110 may receive settings using a rotary mode dial, a cross key, or the like in addition to these switches, and these are collectively referred to as a function setting unit 116 in FIG. Examples of operations or functions that can be specified by the operation unit 110 include “file format”, “special effects”, “printing”, “determine / save”, and “display switching”. The zoom switch 118 determines a zoom magnification.

The main operation of the above configuration is as follows.

First, the power switch 112 of the digital camera 10 is turned on, and power is supplied to each part of the camera. The main CPU 62 reads the state of the function setting unit 116 to determine whether the digital camera 10 is in the imaging mode or the reproduction mode.

When the camera is in the imaging mode, the main C
The PU 62 monitors the half-pressed state of the release switch 114. When the half-pressed state is detected, the main CPU 62
Obtains photometry data and distance measurement data from the photometry sensor 54 and the distance measurement sensor 52, respectively. The imaging control unit 40 operates based on the obtained data, and the focus and the aperture of the imaging lens 22 are adjusted. Once the adjustment is complete,
Characters such as "standby" are displayed on the LCD monitor 102 to inform the user of the fact, and then the release switch 114 is fully pressed.

When the release switch 114 is fully depressed, the shutter 26 is closed after a predetermined shutter time, and the charge stored in the CCD 30 is discharged to the image signal processing unit 32. The digital image data generated as a result of the processing by the imaging signal processing unit 32 is output to the main bus 82. The digital image data is temporarily stored in the main memory 68, thereafter processed by the YC processing unit 70 and the compression / decompression processing unit 78, and recorded in the optional device 76 via the optional device control unit 74. The recorded image is displayed on the LCD monitor 102 in a frozen state for a while, so that the user can know the captured image. Thus, a series of imaging operations is completed.

On the other hand, when the digital camera 10 is in the playback mode, the main CPU 62 reads the last captured image from the main memory 68 via the memory control unit 64,
This is displayed on the LCD monitor 102 of the display unit 100. When the user instructs “forward” or “reverse” in the function setting unit 116 in this state, images captured before and after the currently displayed image are read and displayed on the LCD monitor 102.

Next, a configuration and a function for determining the imaging condition according to the distance will be described.

FIG. 2 is a block diagram illustrating in detail a portion related to a function of determining an imaging condition relating to brightness of an image according to a distance from the configuration illustrated in FIG. The imaging system CPU 50 includes an imaging condition setting unit 200, an imaging condition output command unit 300, a nonvolatile memory 400, and a white balance adjustment condition output unit 500. With this configuration, the CPU 50 determines an imaging condition based on distance measurement data and the like obtained from the distance measurement sensor 52. The contents will be described below.

The distance measurement data obtained from the distance measurement sensor 52 is output to the subject distance rank determination unit 310. The distance measurement sensor 52 may obtain the distance measurement data by directly measuring the distance to the subject, or may obtain the distance measurement data by, for example, back-calculating the distance from the setting state of the focus ring provided in the digital camera 10. Rank judgment unit 3
10 ranks the distance from the subject based on the distance measurement data.

FIG. 3 is a schematic diagram exemplifying a state of ranking. The distance includes a distance rank M at which an appropriate image can be captured by the emission of the strobe light 36, a distance rank S smaller than the distance rank (corresponding to a case where the subject is at the macro position), and a distance rank at which the strobe light is insufficient. L
Classified as

The classification is performed by the rank determination unit 310 shown in FIG.
Accordingly, the distance x from the digital camera 10 to the subject 12 and the reference distances Lmin, Lmax (Lmin <
Lmax). Here, the distance Lmin is a distance between the excess state of the strobe light and the appropriate amount state, and the distance Lmax is a distance between the appropriate amount state and the insufficient amount state.

Further, the imaging condition output command unit 300 shown in FIG.
The mode set in the function setting unit 116 is read by the mode reading unit 330. At the same time, the exposure value rank determination unit 320 causes the exposure control unit 58 to read the aperture value and shutter speed set by the user through manual operation, calculate the exposure value, and determine the rank. The judgment of the rank of the exposure value is shown in FIG.
May be performed in the same manner as the distance ranking exemplified in (1).

The light emission necessity judging section 340 judges the necessity of light emission of the strobe 36 based on the photometry data from the photometry sensor 54. The output command unit 300 outputs an imaging condition according to a distance rank, a mode, an exposure value rank, and necessity of light emission from an imaging condition table 410 stored in the nonvolatile memory 400.

FIG. 4 is a schematic diagram illustrating the contents of the imaging condition table 410. The imaging condition table 410 includes distance ranks S to
L and a table for associating the exposure value rank at the time of manual operation with the imaging conditions, and more specifically, exposure (aperture value and shutter speed), sensitivity (gain and white balance (WB)), sharpness (aperture processing level) , And light emission (light emission amount).

The contents of these parameters are obtained by variously changing the contents of the parameters with respect to the distance from the subject, and examining in advance what state is considered to be optimal. The parameters other than the sharpness of these parameters directly affect the brightness of the image. On the other hand, sharpness is defined as one of the parameters in order to counter the increase in noise with an increase in the sensitivity for determining the brightness of an image. That is, it can be said that the sharpness is an indirect parameter necessary for setting the brightness of the image as desired.

In brief, the imaging condition table 410 is created so that the exposure value, the gain, and the light emission amount during the automatic operation increase as the distance increases. Regarding the exposure, the aperture 24 is set to be open and the shutter speed is set to be slow as the distance increases. With the above-described configuration, it is possible to correct the excess or shortage of the light amount from the strobe 36, which becomes serious depending on the degree of the distance, and to secure the brightness of the image.

Also, the aperture processing level is set to be lower as the gain is larger. This is because the noise of the image increases (the image becomes rough) as the gain increases, and the degree of the edge enhancement processing (aperture processing) is reduced in order to reduce the noise.

The exposure value at the time of the manual operation corresponds to the provision of a mode for permitting the setting of the exposure by the manual operation. By setting a plurality of types of imaging conditions to be selectable even within the same distance rank, it becomes possible to read out imaging conditions (especially gain) suitable for the exposure value set by manual operation.

How to output the imaging condition from the imaging condition table 410 based on the result of the rank determination and the like will be described later.

As illustrated in FIG. 2, the imaging condition setting unit 200 includes an exposure condition setting unit 210 having an aperture value setting unit 212 and a shutter speed setting unit 214, and a light emission condition setting unit having a light emission amount setting unit 222. 220, a gain setting section 232 and a white balance adjustment condition setting section 234
And a sharpness condition setting unit 240 having an aperture processing level setting unit 242. The contents of the parameters of the imaging conditions read from the imaging condition table 410 are input to the corresponding components.

More specifically, an aperture value and a shutter speed are input to the aperture value setting unit 212 and the shutter speed setting unit 214, respectively, and have a function of holding these. Then, these contents are respectively described in the exposure control unit 5.
The control is provided to an aperture driving unit 46 and a shutter driving unit 48 provided in the control unit 8 so as to perform control according to the contents thereof. However,
Such processing is performed when the exposure setting is performed automatically (automatically). When the setting of the exposure is specified by a manual operation, the mode reading unit 330 gives an instruction to the exposure condition setting unit 210 to prohibit the setting from being changed, as illustrated in FIG. As a result, the exposure state set by the user is maintained.

The gain setting unit 232 holds the input gain while maintaining the gain adjustment unit 60 of the sensitivity adjustment unit 600.
2 to determine the gain of the CCD 30 with respect to the accumulated charge. The gain adjuster 602 amplifies the accumulated charge based on the given gain.

The aperture processing level setting section 242 holds the input aperture processing level and outputs it to the sharpness adjustment section 620 provided in the imaging signal processing section 32. The sharpness adjustment unit 630 includes an aperture processing unit 622,
The aperture processing unit 622 performs a process of enhancing the contour according to the given aperture processing level.

The light emission amount setting section 222 holds whether the inputted light emission amount is “R” (suppressed), “N” (normal) or “0” (no light emission) (FIG. 4), and 36
Is controlled by the light emission control unit 36b. Specifically, the light emission amount setting unit 222 sets the light emission amount of the strobe light 36 to “0” in response to the input of the light emission amount “0”, and instructs the light emission control unit 36b to prohibit light emission. When the light emission amount is "R", a light emission amount lower than that in the normal mode is set, and the light emission amount of the strobe 36 is reduced by the light emission control unit 36b than in the normal mode. Such suppression is achieved by further shortening the light emission time. When the light emission amount is “N”, a normal light emission amount is set.

In the white balance adjustment condition setting section 234, the white balance is adjusted in the strobe mode (ST).
Alternatively, a designation as to which of the normal mode (N) is to be performed is input (FIG. 4). Here, the strobe mode and the normal mode are modes used in a conventional digital camera. In the conventional digital camera, the strobe mode is forcibly selected when the strobe 36 is to be fired, and the normal mode is selected when the strobe 36 is not to be fired.

On the other hand, in the digital camera 10 of the present embodiment, as shown in FIG. 4, even when the strobe light is emitted, the normal mode is selected in the case of the distance rank L. I have. Accordingly, even in the case of the distance rank L, when the light from the light source under the environment where the subject such as the sun or a fluorescent lamp is placed is stronger than the light from the strobe 36, the color of the ambient light White balance adjustment suitable for temperature can be performed.

Of course, if the color temperature determination unit 510 determines that the strobe light is the most dominant when the strobe light is preliminarily emitted, even if the distance rank is “L”, the strobe light is not used. The white balance is adjusted. Therefore, it can be said that the strobe light is one of the light sources of the environment where the subject is placed.

A specific method for setting the adjustment conditions according to the white balance adjustment mode will be described.
In response to the input of the “strobe mode”, the adjustment condition setting unit 234 reads the adjustment condition for strobe light from the white balance (WB) adjustment condition table 440 stored in the nonvolatile memory 400 by the white balance adjustment condition reading unit 520. Is read and held.

On the other hand, when the “normal mode” is input, by reading the setting state of the function setting section 116, the white balance adjustment condition should be automatically judged and read by the light source, or selected by the user. It is determined whether the adjusted adjustment condition for the light source should be read.

In the former case, the adjustment condition setting unit 234 causes the color temperature determination unit 510 to function, and automatically determines the color temperature of the light source based on the RGB signals obtained from the CCD 30. The adjustment condition reading unit 520 reads the adjustment condition from the adjustment condition table 440 based on the determination result and outputs the adjustment condition to the adjustment condition setting unit 234. In the latter case, the white balance manual setting mode reading section 530 is made to function, and the function setting section 116 is used to read which light source mode is set by the user. The adjustment condition reading unit 520 reads an adjustment condition suitable for the color temperature of the light source from the adjustment condition table 440 based on the result of the reading, and outputs the adjustment condition to the adjustment condition setting unit 234.

The adjustment condition setting unit 234 holds the adjustment conditions input as described above, and provides the adjustment conditions to the white balance adjustment unit 604 provided in the sensitivity adjustment unit 600. The white balance adjustment unit 604 performs white balance adjustment based on the input adjustment conditions. The adjustment of the white balance is to adjust the gain of each of the color components RGB, and can be said to be fine adjustment of the sensitivity corresponding to the color temperature.

As described above, an image having appropriate brightness is obtained by performing imaging based on the input imaging conditions. In the following, a description will be given of a processing procedure when imaging is performed using the digital camera 10.

FIG. 5 shows a digital camera 1 according to the present embodiment.
9 is a flowchart illustrating a processing procedure when imaging is performed using 0. First, in step S10, processing for imaging is started. Next, in step S12, the digital camera 10 accepts an input by the user for setting the mode in the function setting unit 116 in FIG. If the user desires that the imaging condition is automatically set according to the distance, the user selects the sensitivity adjustment mode. If it is desired to manually set only the exposure condition even in the sensitivity adjustment mode, the exposure condition is set to the manual mode.

Next, in step S14, distance measurement and photometry are performed by the distance measurement sensor 52 and the photometry sensor 54 in FIG. Using the photometric data thus obtained, it is determined in step S16 whether or not light emission by the strobe 36 is necessary. If "NO" is determined, it is determined that a sufficient light amount can be obtained without using the strobe 36, and the process shifts to step S20. On the other hand, if "YES" is determined, the process proceeds to step S30.

In step S30, the mode reading section 330 in FIG. 4 determines whether or not the sensitivity adjustment mode has been set. If it is determined to be "YES", it is necessary to adjust the sensitivity so as to correspond to strobe light that is either excessive, appropriate, or insufficient according to the distance from the subject, and the process proceeds to step S32. On the other hand, if “NO” is determined, it is determined that there is no need to adjust the sensitivity according to the distance, and the process shifts to step S20.

In step S32, whether the setting of the exposure condition is performed by manual operation or automatic processing is determined based on the setting in step S12. When it is determined to be "auto (A)", the process proceeds to step S34, and when it is determined to be "manual (M)", the process proceeds to step S36.

In steps S20, S34 and S36, the imaging conditions are read out by the imaging condition output command unit 300 in FIG. In each step, depending on which mode is selected by the user, it is determined whether the output of each component of the output command unit 300 is adopted or ignored for reading out the imaging condition. Depending on the combination of adoption and ignorance, the imaging conditions to be read out change. The system will be described below.

In the case of step S20, the mode reading unit 3
In response to reading that the mode is not the sensitivity adjustment mode in step 30 (step S30), the determination results of the subject distance rank determination unit 310 and the exposure value rank determination unit 320 are ignored. Then, the output command unit 300 outputs the imaging conditions (exposure, sensitivity, sharpness, and light emission conditions) of the readout number 5 in FIG. 4 to the imaging condition setting unit 200 as default conditions that do not depend on the distance.

At this time, the light emission amount is “0” or “N”.
Which one is output depends on the determination result of the light emission necessity determination unit 340. That is, “N” is output when it is determined that light emission is necessary, and “0” is output when it is determined that light emission is unnecessary. Similarly, the white balance (W
As for the adjustment in B), the normal mode (N) is output when it is determined that light emission is unnecessary, and the strobe mode (ST) is output when it is determined that light emission is necessary. The selection process regarding the adjustment of the light emission amount and the white balance is performed in step S
34 and S38 are also common.

On the other hand, in step S34, it is determined that the imaging condition should be read out based on the distance from the subject and that the exposure condition should be set by automatic processing. The determination result of the unit 320 is ignored, and the results of the subject distance rank determination unit 310 and the light emission necessity determination unit 340 are used. In this case, based on the determination result of the subject distance rank determination unit 310, the imaging condition of the readout number 2 in the case of the distance rank S, the imaging condition of the readout number 5 in the case of the distance rank M, and the imaging condition of the readout number 5 in the case of the distance rank L Are the imaging conditions of readout number 8, respectively.

In step S36, the user sets the exposure condition. The user may manually input the desired aperture value and shutter speed to the exposure control unit 58 in FIG. In this way, the user's favorite exposure setting is received when the aperture value and the shutter speed as the specifications in the imaging condition table 410 cannot obtain the desired depth of focus of the user, or when "blur" occurs.
Is considered in some cases.
Although not described in detail here, it is also possible to adopt a configuration in which the user sets only one of the aperture value and the shutter speed. In this case, the remaining one is automatically set based on the aperture priority AE or the shutter speed priority AE.

In a succeeding step S38, reading of the imaging conditions based on the distance from the subject and the input exposure conditions is performed. As can be understood by referring to the imaging condition table 410 in FIG. 4, the gain is changed according to the exposure value rank. With such a configuration, for example, even when the user sets a short shutter speed in order to eliminate “blur”, it is possible to secure the brightness of the image by increasing the gain.

In step S38, in response to the mode reading section 330 reading that the sensitivity adjustment mode and the exposure condition setting are in the manual mode, the subject distance rank determining section 310 and the exposure value rank determining section The imaging conditions are read out in consideration of all the results of the light emission necessity determination unit 320 and the light emission necessity determination unit 340.

In this case, the readout number is determined based on the distance rank and the exposure value rank (manual). For example, in the case of the distance rank S and the exposure value rank EXR3, the imaging condition of the read number 3 is read.

Here, in accordance with the fact that the exposure has already been set by the user, the exposure conditions (aperture value and shutter speed) of the imaging conditions must be ignored. Therefore, the mode reading unit 330 outputs a signal for prohibiting the setting change to the imaging condition setting unit 200 (specifically, the exposure condition setting unit 210).

In step S40 following steps S20, S34 and S38, the user determines whether or not the imaging conditions are appropriate. This is shown in Figure 1 by preliminary imaging.
This can be done by capturing an image on the LCD monitor 102 of the camera. The user observes the displayed image and checks brightness, depth of focus, blur, and the like.
Then, when it is determined that the imaging conditions are appropriate (YES), the imaging may be performed in step S50 under the imaging conditions. Thereafter, in step S70, the process ends.

On the other hand, if it is determined that the imaging conditions are inappropriate (NO), the user determines in step S60 whether to continue the imaging process. For example, if it is determined that insufficient sunshine cannot be compensated for by changing the imaging conditions, it may be determined that the process is terminated (NO).

However, if the user does not like the image when the default value is adopted as the imaging condition (step S20), there is still room for obtaining a desired image by selecting the sensitivity adjustment mode. I have.
In such a case, it is determined that the imaging process is continued (YES). In step S62, re-input of the mode setting is accepted, and the user can perform imaging under a new imaging condition by changing the setting of the sensitivity adjustment mode and the setting of the exposure condition.

With the configuration of the present embodiment described above, it is possible to select an imaging condition suitable for the distance from the subject. Thus, an image having appropriate brightness can be obtained regardless of the position of the subject. Specifically, when the subject belongs to the distance rank S, it is possible to avoid the “jump” of the image by suppressing the gain and the light emission amount.

Further, when the subject belongs to the distance rank L, the shortage of the light quantity of the strobe light 36 can be compensated for by increasing the gain in particular, and "crushing" of the image can be avoided. Also, it is possible to prevent an increase in noise due to an increase in gain by suppressing the aperture processing. Furthermore, even in the case of the distance rank L,
By setting the white balance adjustment in the normal mode, it is possible to perform adjustment suitable for the color temperature of the light source illuminating the subject.

Although the configuration of FIG. 2 has been described above, the above-described effects cannot be achieved only by such a configuration. For example, in FIG. 2, the white balance adjustment unit 604 and the aperture processing unit 622 provided in the imaging signal processing unit 32 are replaced with the processing unit 6 in FIG.
It is also possible to prepare for zero. Further, the imaging system CPU 5
0 has a non-volatile memory 400 as illustrated in FIG. 2, but the non-volatile memory 66 in FIG.
It is also possible to store 10.

Further, in the example of FIG. 2, as apparent from the imaging condition output command unit 300, the photometric data from the photometric sensor 54 is used only to determine whether or not light emission is required (see FIG. 2). Light emission necessity determination unit 340). But,
It is also possible to adopt a configuration in which the level of the imaging condition changes according to the level of the photometric data. This is similar to the exposure value at the time of manual operation in the imaging condition table 410 in FIG.
This can be realized by further subdividing each distance rank by the rank of photometric data. In this case, the imaging condition output command unit 300 must be provided with a component for ranking photometric data according to its level.

Further, in FIG. 4, the distance rank and the exposure value rank are each classified into three. However, for example, it is possible to finely change the imaging conditions by increasing the classification. Here, the distance rank M is an area in which an image can be appropriately picked up by the emission of the strobe light 36, and the distance ranks S and L are areas that require adjustment for performing an appropriate image pickup. Therefore, it is more efficient to subdivide the adjustment in the distance ranks S and L than the distance rank M.

As described above, the digital camera 10 for achieving the function of changing the imaging condition according to the distance is used.
It can be understood that the configuration has a considerable degree of freedom.

Although the present invention has been described using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. Various changes or improvements can be added to the above embodiment. It should be noted that such modified or improved embodiments may be included in the technical scope of the present invention.
It is clear from the description of the claims.

[0091]

As is apparent from the above description, according to the present invention, it is possible to obtain an appropriate strobe image according to the distance to the subject.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a digital camera 10 according to an embodiment.

FIG. 2 is a block diagram illustrating in detail a configuration of a portion related to a function of selecting an imaging condition according to a distance to a subject in the configuration of FIG.

FIG. 3 is a schematic view illustrating a determination of a distance rank.

FIG. 4 is a diagram exemplifying a configuration of an imaging condition table 410.

FIG. 5 is a flowchart illustrating a processing procedure of imaging by the digital camera 10.

[Explanation of symbols]

 Reference Signs List 10 digital camera 20 imaging unit 24 aperture 26 shutter 30 CCD 32 imaging signal processing unit 36 strobe 46 aperture driving unit 48 shutter driving unit 50 imaging system CPU 52 distance measurement sensor 58 exposure control unit 116 function setting unit 200 imaging condition setting unit 310 subject Distance rank determination unit 600 Sensitivity adjustment unit 620 Clarity adjustment unit

Continued on the front page F term (reference) 2H002 AB04 BB06 BB07 CD04 CD05 FB32 GA28 GA33 JA07 2H053 AA05 AB08 AD06 AD07 AD08 BA52 DA03 DA04 5C022 AA13 AB12 AB15 AB17 AB19 AB27 AC42 AC69

Claims (7)

[Claims] 1. A distance sensor for grasping a distance to a subject, a luminous body for reinforcing reflected light from the subject by emitting light, an image receiving body for accumulating the reflected light as image information, and an exposure for the image receiving body. An exposure control unit that controls the sensitivity, a sensitivity adjustment unit that adjusts the sensitivity to the reflected light, and an imaging device that includes a control unit that controls the exposure control unit and the sensitivity adjustment unit. An imaging apparatus that performs control based on imaging conditions related to the brightness of the image information. 2. The control unit, comprising: a distance determination unit that outputs a comparison result obtained by comparing the distance with a distance determination criterion; and an imaging condition setting unit that sets the imaging condition according to the comparison result. The imaging device according to claim 1, comprising: 3. The imaging apparatus according to claim 2, wherein the imaging condition includes the sensitivity as a parameter, and the sensitivity is increased or decreased according to the comparison result. 4. The imaging apparatus according to claim 2, wherein the imaging condition includes, as a parameter, an exposure value which is increased or decreased in accordance with the comparison result and provided to the exposure control unit. 5. The image capturing condition setting unit includes: a first sensitivity adjustment processing content for the light emitting body; and a second sensitivity adjustment processing content for a light source in an environment where the subject is placed. Either one is input according to the distance, and the sensitivity adjustment unit adjusts the sensitivity according to the one selected from the first and second sensitivity adjustment processing contents, so as to adjust the color temperature. The imaging device according to claim 2, wherein the correction is performed. 6. A clarity adjustment unit for performing clarity adjustment processing for adjusting clarity with respect to the image information, wherein the imaging condition setting unit includes a parameter in the imaging condition as a parameter, and according to the distance. The imaging apparatus according to claim 3, wherein a degree of the sharpness adjustment processing is set, and wherein the sharpness adjustment unit performs the sharpness adjustment processing according to the degree. 7. The imaging condition setting section includes a light emission amount that is included as a parameter in the imaging condition and is set according to the distance, and the light emitter emits light corresponding to the light emission amount.
An imaging device according to claim 1.