JP2008268361A - Photographing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To take a photograph while the brightness of a main subject is balanced with that of a background as a photographer intends in stroboscopic photography. <P>SOLUTION: An upper limit value setting part 33a sets the upper limit value of the emitted light quantity of a stroboscopic device 34 based on an operation signal from a cursor operation button 23. An emitted light quantity setting part 33 acquires an AE evaluated value and photographic sensitivity information, and sets the initial value X of the emitted light quantity based on them. Furthermore, the emitted light quantity setting part 33 sets the emitted light quantity to the upper limit value when the initial value X is larger than the upper limit value, and sets the emitted light quantity to the initial value X when the initial value X is equal to or under the upper limit value. A system controller 30 controls exposure based on the AE evaluated value and the photographic sensitivity, and also controls the stroboscopic device 34 based on the set value of the emitted light quantity. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging apparatus including an imaging means for imaging subject light that has passed through a photographing lens capable of changing a focal length by photoelectric conversion, and a strobe device that emits strobe light toward the subject.

  In recent years, photographing apparatuses such as digital cameras have been widely used. The digital camera includes a solid-state imaging device (for example, a CCD image sensor) that captures a subject image by photoelectric conversion, and records image data obtained by the solid-state imaging device on a recording medium such as a memory card. In such a digital camera, shooting is performed by setting an exposure value for shooting the main subject with appropriate exposure based on image data obtained by the solid-state imaging device.

However, in a scene where the luminance difference between the main subject and the background is large, there is a problem that overexposure causes overexposure and underexposure causes blackout. In order to solve such problems, an exposure correction amount for reducing overexposure or underexposure is calculated based on a luminance frequency distribution of image data obtained by imaging with a set exposure value, and this exposure correction There is known a digital camera that performs photographing with an exposure value corrected by the amount (see, for example, Patent Document 1). There is also known a digital camera that adjusts the amount of strobe light according to the subject distance in order to prevent overexposure or underexposure during strobe shooting (see, for example, Patent Document 2). Furthermore, a digital camera that amplifies the insufficient gain when the amount of strobe light is insufficient is also known (see, for example, Patent Document 3).
JP 2006-157348 A JP 2006-98786 A JP 2001-169178 A

  However, the digital camera described in Patent Document 1 has a problem in that it cannot prevent overexposure or underexposure during strobe shooting because it does not consider the control of the amount of light during strobe shooting. In addition, the digital camera described in Patent Document 2 only changes the amount of strobe light according to the subject distance, and cannot balance the brightness balance between the main subject and the background as intended by the photographer. There's a problem. Further, in the digital camera described in Patent Document 3, the shortage of the strobe light amount is adjusted by the amplification of the imaging signal, but there is a similar problem because the strobe light amount is not controlled.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an imaging device capable of imaging the brightness balance of the main subject and the background as intended by the photographer during flash photography. And

  In order to solve the above-described problems, an imaging apparatus according to the present invention includes an imaging lens having a zoom lens and a focus lens, imaging means for imaging subject light transmitted through the imaging lens by photoelectric conversion, and strobe light toward the subject. A stroboscope that irradiates the subject with light, and a photometric means for measuring subject brightness, a zoom position detecting means for detecting a zoom position of the zoom lens, and a focus for detecting a focus position of the focus lens. A position detection unit; a shooting sensitivity setting unit that sets a shooting sensitivity based on the zoom position and the in-focus position; and a first amplification that amplifies an imaging signal output from the imaging unit with a gain corresponding to the shooting sensitivity. And setting the light emission amount of the strobe device on the basis of the subject brightness and the photographing sensitivity, and setting the light emission amount Is larger than a preset upper limit value of the flash emission amount, a light emission amount setting means for changing the set value to the upper limit value, and controlling exposure based on the subject brightness and the photographing sensitivity, and And a control means for controlling the strobe device based on a set value.

  It is preferable that an upper limit value switching operation unit that switches the upper limit value is provided, and the light emission amount setting unit sets the upper limit value based on an operation signal acquired from the upper limit value switching operation unit.

  Further, the luminance value of the image data obtained by converting the imaging signal into a digital signal is calculated, and the insufficient gain value is calculated by comparing the luminance value with a preset target luminance value. It is preferable to include a calculating unit and a second amplifying unit that amplifies the signal level of the image data based on the insufficient gain value.

  In addition, when the imaging instruction input means for inputting the imaging instruction is acquired and the imaging instruction is acquired from the imaging instruction input means, the control means is a first before the signal level is amplified by the second amplification means. It is preferable to record both the image data and the amplified second image data on the recording means.

  Further, the image processing apparatus further includes display means for displaying an image, and the first image data before the signal level is amplified by the second amplifying means and the second image data after the amplification are recorded before or on the recording means. Later, the control means controls the display means to display a selection screen in which the first and second image data are arranged side by side and an image to be recorded or erased is selected. It is preferable to execute a recording process or an erasing process of the image data corresponding to the selected image based on the selection result.

  In addition, when only the first image data is recorded in the recording unit, it is preferable that the control unit controls the second amplifying unit to generate the second image data.

  Furthermore, it comprises determination means for determining whether or not the light emission amount is larger than a predetermined light emission amount, and when the light emission amount is larger than the predetermined light emission amount, the control means controls the strobe device to perform before the main light emission. It is preferable that pre-light emission for preventing red-eye is performed and the pre-light emission is not performed when the light emission amount is equal to or less than the predetermined light emission amount.

  In addition, a normal setting mode in which the light emission amount is set without setting the upper limit value and an upper limit value setting mode in which the upper limit value is set, and the photographing process is executed in the upper limit value setting mode. Preferably, the control means controls the display means to display the presence / absence of strobe light emission, the light emission amount, and the presence / absence of pre-light emission for preventing red eyes.

  According to the photographing apparatus of the present invention, when the setting value of the light emission amount set based on the subject brightness and the photographing sensitivity is larger than the upper limit value of the strobe light emission amount, the setting value is changed to the upper limit value. Photographers can balance the brightness of the main subject with the background because the amount of light emitted is close to no emission, and the background of the subject can be emphasized. Can be taken as intended.

  Further, since the photographer can set the upper limit value appropriately by operating the upper limit value switching operation means, it is possible to capture an image that matches the brightness balance between the main subject and the background.

  Further, since the signal level of the image data can be amplified to correct the insufficient gain, it is possible to correct the brightness balance between the main subject and the background after the imaging process. Also, since the two image data before and after the correction of the insufficient gain are recorded, it is possible to simultaneously photograph two images having different brightness balances between the main subject and the background.

  Further, since the image to be recorded or deleted is selected from the two images before and after the correction of the insufficient gain at the time of shooting or after shooting, the image data corresponding to the selected image is recorded and erased. Only the image data suitable for the image can be left in the recording means. For this reason, the recording area of the recording means can be used effectively.

  In addition, when only the first image data is recorded in the recording means, the second image data is generated by the second amplifying means, so that it is possible to obtain image data in which the insufficient gain is corrected after photographing.

  Pre-flash that prevents red-eye is performed only when the flash device's flash output is greater than the predetermined flash output, so unnecessary pre-flash can be prevented to reduce power consumption and reduce time loss during shooting. .

  Before the shooting process is executed in the upper limit setting mode, the presence / absence of strobe light emission, the light emission amount, and the presence / absence of pre-light emission to prevent red-eye are displayed, so that it is possible to prevent photographing not intended by the photographer .

  A digital camera (photographing apparatus) 10 shown in FIG. 1 has a lens barrel 12 having a photographing lens (see FIG. 2) 40 on the front surface of a camera body 11, a strobe light emission window (not shown), and a viewfinder objective window. (Not shown). A power button 13 and a shutter button 14 are provided on the upper surface of the camera body 11. The shutter button 14 is a two-stage press button. When the shutter button 14 is half-pressed and the first-stage switch is turned on, the digital camera 10 performs shooting preparation processing such as focus adjustment and exposure adjustment. Further, when the shutter button 14 is fully pressed and the second-stage switch is turned on, the photographing process is executed.

  A finder eyepiece window 15, an LCD 16 that is a display means for displaying an image, and an operation unit 17 including a plurality of operation buttons are provided on the back surface of the camera body 11. The LCD 16 displays a through image, a reproduced image, various menu screens, and the like.

  The operation unit 17 includes a mode switching button 21, a zoom operation button 22, a cursor operation button 23, a MENU / OK button 24, a cancel button 25, and a display button 26. The mode switching button 21 is slid when switching between the shooting mode and the playback mode. The zoom button 22 is pressed when changing the focal length of the photographic lens 40.

  The cursor operation button 23 can be operated by pressing each of the upper, lower, left, and right parts, and is operated when the cursor is moved up, down, left, and right in the menu screen, or when the playback image is sequentially forwarded and backwards in the playback mode. . Further, by pressing the “right” of the cursor operation button 23 in the shooting mode, the light emission mode of the strobe device (see FIG. 2) 63 can be switched. As the light emission mode, for example, an AUTO light emission mode, a red-eye reduction light emission mode, a forced light emission mode, a light emission inhibition (natural) mode, a slow sync mode, and the like are set. The AUTO light emission mode has a normal setting mode in which the light emission amount is set based on the subject brightness and the photographing sensitivity, and an upper limit value setting mode in which an upper limit value of the light emission amount can be set. In the upper limit setting mode, when the set value of the light emission amount set based on the subject brightness and the photographing sensitivity is larger than the upper limit value, this upper limit value is set as the light emission amount.

  The MENU / OK button 24 is disposed at the center of the cursor button 23, and is pressed when displaying a menu screen on the LCD 16 or when selecting an item. The cancel button 25 is pressed to stop various setting operations in the menu screen or return to the previous screen. The display button 26 is pressed when the LCD 16 is switched on and off.

  A recording media slot 27 is provided on the side surface of the camera body 11. The recording medium slot 27 is detachably loaded with a recording medium (for example, a memory card) 28 that is a recording means for recording image data.

  Next, the electrical configuration of the digital camera 10 will be described with reference to FIG. The digital camera 10 includes a system controller 30 that is a control unit that controls each unit in the camera body 11. In the system controller 30, a ROM 31, a RAM 32, and a light emission amount setting unit 33 are provided.

  The ROM 31 stores a control program for controlling each unit in the camera body 11, various control data, and the like. The RAM 32 temporarily stores work data. The system controller 30 controls each unit based on these programs and various control data. The system controller 30 is connected to a shutter button 14, an operation unit 17, and a strobe device 34 that irradiates a subject with strobe light. The system controller 30 controls each unit based on operation signals input from the shutter button 14 and the operation unit 17.

  The light emission amount setting unit 33 includes an upper limit value setting unit 33a for setting an upper limit value of the light emission amount. The light emission amount setting unit 33 sets the light emission amount of the strobe device 34 based on the subject brightness and the photographing sensitivity, and when the light emission amount setting value is larger than the upper limit value set by the upper limit value setting unit 33a. Then, the set value of the light emission amount is changed to the upper limit value.

  Based on the light emission amount setting value, the system controller 30 controls the strobe device 34 to adjust the light emission amount. The cursor operation button 23 is an upper limit value switching operation means, and the above-described upper limit value can be changed by operating the cursor operation button 23. The upper limit setting unit 33a sets an upper limit based on this operation signal. Further, when adjusting the light emission amount, it may be adjusted by changing the charging time of the main capacitor, or may be adjusted by providing a plurality of main capacitors and selectively using them.

  The lens barrel 12 described above includes a photographic lens 40. The photographing lens 40 is a lens whose focal length can be changed, and includes a zoom lens 41, a diaphragm 42, and a focus lens 43. The zoom lens 41 is moved in the optical axis direction of the photographing lens 40 by a zoom pulse motor 44. The aperture 42 is driven by an iris motor 45 to change the aperture diameter, and adjusts the amount of subject light incident on a light receiving surface of a CCD image sensor (hereinafter simply referred to as a CCD) 48 described later. Further, the focus lens 43 is moved along the optical axis direction by the focus pulse motor 46.

  Each motor 44 to 46 is connected to a motor driver 47. The motor driver 47 is connected to the system controller 30 and transmits drive pulses to the motors 44 to 46 based on an instruction from the system controller 30. Each motor 44-46 is rotationally driven by this drive pulse.

  The system controller 30 is zoom position detection means for detecting the zoom position of the zoom lens 41, and detects the zoom position by counting the number of drive pulses of the zoom pulse motor 44. For example, the number of pulses is added when the zoom lens 41 is moved toward the tele end, and the number of pulses is subtracted when the zoom lens 41 is moved toward the wide end. Similarly, the system controller 30 detects the position of the focus lens 43 based on the number of focus pulses obtained by counting the number of pulses of the focus pulse motor 46.

  A CCD 48 is disposed behind the photographing lens 40. The CCD 48 includes a light receiving surface on which light receiving elements (photodiodes) are two-dimensionally arranged. The CCD 48 photoelectrically converts subject light that has passed through the photographing lens 40 and formed an image on the light receiving surface, and a signal corresponding to the amount of light. Accumulate charge. The signal charge accumulated in each light receiving element is sequentially read out as a voltage signal (imaging signal) corresponding to the amount of charge based on a pulse applied from the CCD driver 49.

  The imaging signal output from the CCD 48 is input to the analog signal processing unit 50. The analog signal processing unit 50 includes a correlated double sampling circuit (CDS) 50a, an auto gain control amplifier (AMP) 50b, and an A / D converter 50c.

  The CDS 50a removes amplifier noise and reset noise caused by the CCD 48 from the imaging signal. The AMP 50b is an amplifying unit that amplifies the imaging signal. The system controller 30 acquires shooting sensitivity information from a shooting sensitivity setting circuit 61, which will be described later, controls the AMP 50b, and amplifies the imaging signal with a gain corresponding to the shooting sensitivity. Further, the A / D converter 50c converts an imaging signal that is an analog signal into image data of a digital signal.

  A timing generator (TG) 51 gives a timing signal to the CCD driver 49 and the analog signal processing unit 50 in accordance with an instruction from the system controller 30, and the circuits are synchronized by this timing signal. The electronic shutter speed (exposure time) of the CCD 48 is determined by the timing signal (clock pulse) input from the TG 51. That is, the system controller 30 controls the exposure by changing the aperture value of the aperture 42 and the exposure time of the CCD 48.

  An image input controller 52 is connected to the analog signal processing unit 50. The image input controller 52 is connected to the SDRAM 54 via the bus 53, and stores image data for one screen in the SDRAM 54. In addition to the image input controller 52 and the SDRAM 54, the bus 53 includes a digital signal processing circuit 55, a compression / decompression processing circuit 56, an LCD driver 57, a media controller 58, an AE detection circuit 59, an AF detection circuit 60, and a photographing sensitivity setting circuit 61. And an insufficient gain calculation circuit 62 are connected.

  The digital signal processing circuit 55 performs predetermined signal processing such as gradation conversion processing, contour enhancement processing, noise reduction processing, white balance correction processing, and YC conversion processing on the image data stored in the SDRAM 54. When displaying a through image, image data having a lower resolution than that at the time of shooting is stored in the SDRAM 54, and the above-described signal processing is performed on the low-resolution image data. Thereafter, the system controller 30 controls the LCD driver 57 to display the image data subjected to signal processing on the LCD 16 as a through image.

  When the shutter button 14 described above is pressed halfway and the first-stage switch is turned on, photographing preparation operations such as AE control and AF control described later are performed. When the shutter button 14 is pressed halfway down (fully pressed), the main exposure is performed on the CCD 48 with the exposure value set by the AE control.

  At this time, the above-described SDRAM 54 stores image data having a higher resolution than that of the through image, and the above-described signal processing is performed on the image data. The image data subjected to the signal processing is compressed in a predetermined compression format (for example, JPEG format) by the compression / decompression processing circuit 56. After the compression process, the image data is recorded on the recording medium 28 by the media controller 58.

  In the reproduction mode, the image data read from the recording medium 28 by the media controller 58 is decompressed by the compression / decompression processing circuit 56 and displayed on the LCD 16 as a reproduced image.

  The AE detection circuit 59 is a photometric means for measuring the subject brightness based on the image data stored in the SDRAM 54 when the shutter button 14 is half-pressed, and detects an AE evaluation value with an optimum exposure value. The AE evaluation value is output to the system controller 30. The AF detection circuit 60 is an integrating unit that extracts high-frequency components of image data and integrates the high-frequency components. When the shutter button 14 is half-pressed and the focus lens 43 is moved in the optical axis direction, An AF evaluation value that is an integrated value of high-frequency components of image data stored in the SDRAM 54 is sequentially calculated, and this AF evaluation value is output to the system controller 30.

  The system controller 30 sets the aperture diameter of the diaphragm 42 and the electronic shutter speed of the CCD 48 based on the AE evaluation value. Further, the system controller 30 sequentially acquires the AF evaluation value at each position of the focus lens 43, determines the position of the focus lens 43 at which the AF evaluation value is maximum (peak) as the in-focus position, and sets the focus position to this in-focus position. The focus lens 43 is moved. The in-focus position detection unit includes an AF detection circuit 60 and a system controller 30.

  The photographing sensitivity setting circuit 61 is photographing sensitivity setting means for setting photographing sensitivity based on the current focal length of the photographing lens 40 and the in-focus position of the focus lens 43, and is photographed when the shutter button 14 is half-pressed. Sensitivity is set and photographing sensitivity information is output to the system controller 30.

  As shown in FIG. 3, zoom position information that is focal length information and the number of focus pulses as a focus position are input to the shooting sensitivity setting circuit 61. Based on these, an optimum shooting sensitivity is set, and this shooting sensitivity is set. Sensitivity information (ISO 400, 800, 1600, etc.) is output to the system controller 30. In the present embodiment, a case where selection is made from three shooting sensitivities will be described as an example.

  The photographing sensitivity setting circuit 61 stores a table shown in Table 1 below. This table shows distance selection parameters A and B for each zoom position (Z1 to Z10). The distance selection parameters A and B are set by the number of focus pulses. As shown in FIG. 4, the distance selection parameters A and B are the Far end (the number of focus pulses: 0) and the Near end of the focus lens 43. The distance parameter A is set to the Far end side with respect to the distance parameter B.

  The photographing sensitivity setting circuit 61 acquires information on the zoom position (Z1 to Z10) and information on the number of focus pulses from the system controller 30, and selects distance selection parameters A and B corresponding to the current zoom position. Thereafter, the imaging sensitivity setting circuit 61 sets the number of focus pulses at the in-focus position to any range of the Far end side from the distance selection parameter A, the distance selection parameters A and B, and the Near end side from the distance selection parameter. Determine if there is.

  The shooting sensitivity setting circuit 61 sets the shooting sensitivity to a high sensitivity when it is far from the distance selection parameter A, and sets the shooting sensitivity to a medium sensitivity when it is between the distance selection parameters A and B. If it is closer to the Near end than the selected parameter, the imaging sensitivity is set to a low sensitivity. Thereafter, the shooting sensitivity setting circuit 61 outputs the set shooting sensitivity information to the system controller 30.

  The deficient gain calculation circuit 62 is deficient gain value calculation means for calculating deficient gain values of image data based on the image data stored in the SDRAM 54 at the time of shooting processing. As shown in FIG. 5, the insufficient gain calculation circuit 62 receives the integration data for each divided area and the pixel number data in one area, and calculates and outputs an insufficient gain value.

  Hereinafter, the configuration of the insufficient gain calculation circuit 62 will be described. As shown in FIG. 6, the insufficient gain calculation circuit 62 includes a luminance data conversion unit 62a, a weighted average processing unit 62b, a luminance level calculation unit 62c, and a gain value calculation unit 62d. The luminance data conversion unit 62a receives the integrated data for each divided area and the area size data. The integrated data for each divided area is R / G / B integrated data for each area obtained by dividing the image data into a predetermined number, and the area size data is the pixel number data in the divided area. In this embodiment, the case where image data is divided into 64 parts will be described as an example, but the number of divisions can be changed as appropriate. Further, the system controller 30 may calculate R / G / B integrated data for each area, or the AE detection circuit 59 may calculate the integrated data.

  The luminance data conversion unit 62a acquires R (i), G (i), and B (i) that are integrated data for each divided area, and calculates the luminance data Y (i) of each area according to Equation 1 below. . The luminance data conversion unit 62a outputs the luminance data Y (i) to the weighted average processing unit 62b.

  Thereafter, the weighted average processing unit 62b performs weighted average processing on the luminance data Y (i). That is, the weighted average processing unit 62b assumes that there is a main subject in the center of the screen and weights the luminance data Y (i) of each area using the weighting coefficient table shown in FIG. The average value Yk of the luminance data Y (i) is calculated by the following formula 2. The weighted average processing unit 62b outputs the average value Yk to the luminance level calculation unit 62c.

  An average value Yk and pixel count data in one area are input to the luminance level calculation unit 62c. The luminance level calculation unit 62c calculates the luminance level Yp per pixel according to the following mathematical formula 3. The luminance level calculation unit 62c outputs the luminance level Yp to the insufficient gain value calculation unit 62d.

  The deficient gain value calculation unit 62d calculates the deficient gain value (crct_gain) by the following mathematical formula 4, and outputs the deficient gain value (crct_gain) to the digital signal processing circuit 55.

  Further, the digital signal processing circuit 55 includes an insufficient gain adjusting unit 55a that is a signal level adjusting means. The insufficient gain adjusting unit 55a adjusts the gain of the image data stored in the SDRAM 54 based on the insufficient gain value (crct_gain).

  The operation of the digital camera 10 having the above configuration will be described. First, the light emission mode setting method will be described with reference to the flowchart of FIG. When the “right” of the cursor operation button 23 is pressed by the user, the system controller 30 sets the light emission modes to “AUTO light emission mode”, “red-eye reduction mode”, “forced light emission” every time this operation signal is acquired. Set in the order of “Mode”, “Flash Off Mode”, and “Slow Sync Mode”. Further, when the above-described operation signal is acquired in the state set to “slow sync mode”, it is set again to “AUTO flash mode”.

  Next, the light emission amount upper limit setting process will be described with reference to the flowchart of FIG. When the “right” of the cursor operation button 23 is pressed and set to “AUTO flash mode”, the system controller 30 determines whether “up” or “down” of the cursor operation button 23 is pressed. To do. If it is determined that the pressing operation has been performed, the system controller 30 controls the LCD driver 57 to display, for example, the upper limit value setting screen 70 shown in FIG. 10 on the LCD 16, and the upper limit value can be changed by these pressing operations. Selected. When it is determined that the pressing operation is not performed, the determination process is repeatedly performed until the pressing operation is performed.

  Further, the system controller 30 determines whether or not the MENU / OK button 24 has been pressed. If it is determined that the pressing operation has not been performed, the process returns to the process of determining whether “up” or “down” has been pressed. If it is determined that a pressing operation has been performed, the upper limit setting unit 33a is controlled to set an upper limit, and the upper limit setting process is terminated.

  Next, with reference to a flowchart of FIG. 11, a photographing process of the digital camera 10 when the light emission mode is set to “AUTO light emission mode” will be described. When the power of the digital camera 10 is turned on and the photographing mode is set, a through image is displayed on the LCD 16 and the system controller 30 determines whether or not the shutter button 14 is half-pressed. When it is determined that the shutter button 14 is not half-pressed, the standby state is maintained until the shutter button 14 is half-pressed.

  When it is determined that the shutter button 14 is half-pressed, the system controller 30 controls the AE detection circuit 59 to execute the photometric process. The AE detection circuit 59 outputs the AE evaluation value to the system controller 30. The system controller 30 calculates the AF exposure value based on the AE evaluation value, and sets the aperture diameter of the diaphragm 42 and the electronic shutter speed of the CCD 48. With this exposure setting, imaging is performed by the CCD 48 and image data is taken into the SDRAM 54.

  At this time, the system controller 30 controls the motor driver 47 to move the focus lens 43 between the Far end and the Near end, and controls the AF detection circuit 60 to execute the AF process. The AF detection circuit 60 calculates an AF evaluation value for each position of the focus lens 43, and sequentially outputs the AF evaluation value to the system controller 30.

  The system controller 30 sequentially acquires AF evaluation values from the AF detection circuit 60, determines a position (number of focus pulses) at which the AF evaluation value is maximum (peak), and determines this position as a focus position of the focus lens 43. Detect as. Thereafter, the system controller 30 executes photographing sensitivity setting processing.

  Next, imaging sensitivity setting processing will be described with reference to the flowchart of FIG. The system controller 30 outputs zoom position information (Z1 to Z10) indicating the current position of the zoom lens 41 and in-focus position information (number of focus pulses) of the focus lens 43 to the photographing sensitivity setting circuit 61.

  When the photographing sensitivity setting circuit 61 acquires the zoom position information and the focus position information, the imaging sensitivity setting circuit 61 refers to the table shown in Table 1 and sets the number of focus pulses of the distance selection parameters A and B corresponding to the current zoom position. For example, when the zoom position is Z6, the distance selection parameter A is set to 10 and the distance selection parameter B is set to 18.

  Thereafter, the imaging sensitivity setting circuit 61 determines whether or not the number of focus pulses at the focus position is greater than the distance selection parameter B. When it is determined that the distance is larger than the distance selection parameter B, the photographing sensitivity setting circuit 61 sets the photographing sensitivity to a low sensitivity (for example, ISO 400). If it is determined that the distance selection parameter B is equal to or less than the distance selection parameter B, the imaging sensitivity setting circuit 61 determines whether the focus pulse number is smaller than the distance selection parameter A.

  When it is determined that the distance is smaller than the distance selection parameter A, the photographing sensitivity setting circuit 61 sets the photographing sensitivity to high sensitivity (for example, ISO 1600). If it is determined that the distance selection parameter A is greater than or equal to the distance selection parameter A, the imaging sensitivity setting circuit 61 sets the imaging sensitivity to medium sensitivity (for example, ISO 800). The system controller 30 acquires the shooting sensitivity information from the shooting sensitivity setting circuit 61 and ends the shooting sensitivity setting process. Thereafter, the system controller 30 executes a process for setting the light emission amount and the exposure value.

  Next, the setting process of the light emission amount and the exposure value will be described with reference to FIG. In the following description, a case where the upper limit value can be set in three ways of “large” (100%), “medium” (50%), and “small” (25%) will be described. First, the light emission amount setting unit 33 acquires an AE evaluation value and photographing sensitivity information, and sets an initial setting value (hereinafter simply referred to as an initial value) X of the light emission amount based on these values. Thereafter, the system controller 30 determines whether or not the upper limit value is set to “large”.

  When it is determined that “large” is set, the upper limit value is set to 100%. That is, in this case, the normal light emission mode is set, and the light emission amount setting unit 33 proceeds to the process of setting the light emission amount to the initial value and setting the exposure value.

  When it is determined that the upper limit value is not set to “large”, it is determined whether or not the upper limit value is set to “medium”. When it is determined that the upper limit value is set to “medium”, the upper limit value is set to 50% (A), the upper limit value A is compared with the initial value X, and the upper limit value A is set to the initial value X. It is judged whether it is larger than.

  When it is determined that the upper limit value A is larger than the initial value X, the light emission amount is set to the initial value X, and the process proceeds to a process for setting the exposure value. If it is determined that the upper limit value is equal to or less than the initial value X, the light emission amount is set to the upper limit value A, and the process proceeds to a process for setting the exposure value.

  When it is determined that the upper limit value is not set to “medium”, the upper limit value is set to 25% (B), the upper limit value B is compared with the initial value X, and the upper limit value B is set to the initial value X. It is judged whether it is larger than. When it is determined that the upper limit value B is larger than the initial value X, the light emission amount is set to the initial value X, and the process proceeds to a process for setting the exposure value. When it is determined that the upper limit value B is equal to or less than the initial value X, the light emission amount is set to the upper limit value B, and the process proceeds to a process for setting the exposure value.

  After the light emission amount is set, the exposure value is set. In this exposure value setting, the system controller 30 sets the exposure value based on the AE evaluation value, the photographing sensitivity, and the light emission amount, and the setting process of the light emission amount and the exposure value is completed.

  After completing the setting process of the light emission amount and the exposure value, the system controller 30 determines whether or not the shutter button 14 has been fully pressed. If it is determined that the button is not fully pressed, the standby state is maintained until the button is fully pressed. If it is determined that the shutter button 14 has been fully pressed, the system controller 30 controls the aperture diameter of the aperture 42 and the electronic shutter speed of the CCD 48 based on the exposure value setting, and the flash device 34 emits light. The amount is controlled to cause the CCD 48 to execute an imaging process.

  At this time, the system controller 30 controls the AMP 50b to amplify the imaging signal output from the CCD 48 with a gain corresponding to the imaging sensitivity. Thereafter, high-resolution image data obtained by converting the imaging signal into a digital signal is stored in the SDRAM 54.

  Thereafter, the system controller 30 controls the digital signal processing circuit 55, the compression / decompression processing circuit 56, and the media controller 58 to perform various signal processing and compression processing on the image data, and then stores the image data on the recording medium 28. Is recorded, and the photographing process is terminated.

  In the above description of the photographing process, an example in which only normal image data that has not been subjected to the insufficient gain adjustment by the insufficient gain adjustment unit 55a has been described. However, two image data before and after gain adjustment are recorded below. It may be recorded on the medium 28.

  With reference to the flowchart of FIG. 14, a description will be given of imaging processing when recording both image data that has been subjected to insufficient gain adjustment and normal image data that has not been subjected to insufficient gain adjustment. The process until it is determined that the shutter button 14 is fully pressed is the same as when only normal image data is recorded, and only the process after the shutter button 14 is fully pressed will be described.

  The system controller 30 determines whether or not the shutter button 14 is fully pressed. If it is determined that the shutter button 14 is not fully pressed, the system controller 30 is in a standby state until it is fully pressed. If it is determined that the shutter button 14 has been fully pressed, the system controller 30 controls the aperture diameter of the aperture 42 and the electronic shutter speed of the CCD 48 and the amount of light emitted from the strobe based on the exposure value setting. Then, the CCD 48 is caused to execute an imaging process.

  At this time, the system controller 30 controls the AMP 50b to amplify the imaging signal output from the CCD 48 with a gain corresponding to the imaging sensitivity. Thereafter, high-resolution image data obtained by converting the imaging signal into a digital signal is stored in the SDRAM 54.

  Thereafter, the system controller 30 controls the digital signal processing circuit 55, the compression / decompression processing circuit 56, and the media controller 58 to perform various signal processing and compression processing on normal image data, and then the image data (First image data) is recorded on the recording medium 28.

  Further, the system controller 30 outputs the integrated data for each of the 64 divided areas and the pixel count data for one area to the insufficient gain calculation circuit 62. The deficient gain calculation circuit 62 acquires the integrated data and the pixel number data, and the luminance data conversion unit 62a calculates the luminance data Y (i) based on the integrated value for each RGB, and the luminance data Y ( i) is output to the weighted average processing unit 62b. The weighted average processing unit 62b weights the luminance data Y (i) of each area, calculates an average value Yk of the luminance data Y (i), and uses the average value Yk as the luminance level calculation unit 62c. Output to.

  The luminance level calculation unit 62c calculates the luminance level Yp per pixel based on the average value Yk and the number of pixels in one area, and outputs the luminance level Yp per pixel to the insufficient gain calculation unit 62d. The insufficient gain value calculation unit 62d calculates an insufficient gain value (crct_gain) and outputs the insufficient gain value (crct_gain) to the digital signal processing circuit 55. The insufficient gain adjustment unit 55a adjusts the insufficient gain of the high-resolution image data stored in the SDRAM 54 based on the insufficient gain value (crct_gain).

  Thereafter, the system controller 30 controls the digital signal processing circuit 55, the compression / decompression processing circuit 56, and the media controller 58 to perform various signal processing and compression processing on the image data in which the insufficient gain is adjusted. This image data (second image data) is recorded on the recording medium 28, and the photographing process is terminated.

  In the above description of the photographing process, the case where two image data are recorded has been described as an example. However, before the image data is recorded, a recording image selection screen on which two images are displayed side by side is displayed on the LCD 16 and recorded. The image may be recorded on the recording medium 28 by letting the user select an image and only the image data corresponding to the selected image.

  Next, the image erasing process when the digital camera 10 is in the playback mode will be described with reference to the flowchart of FIG. When the mode switching button 21 is operated to set the reproduction mode, the system controller 30 determines whether or not the image data to be reproduced is image data that has been subjected to insufficient gain adjustment by the insufficient gain adjustment 55a.

  If it is determined that the image is a gain-adjusted image, the process proceeds to a process for displaying an erased image selection screen. If it is determined that the image data is not the image data with insufficient gain adjustment (normal image data), the system controller 30 controls the LCD driver 57 to display the normal image without gain adjustment on the LCD 16. Display.

  Furthermore, the system controller 30 determines whether or not an instruction for adjusting the insufficient gain has been acquired. This determination is performed based on the selection result by displaying on the LCD 16 a selection screen for selecting whether or not to perform the insufficient gain adjustment, for example.

  If it is determined that an instruction for adjusting the insufficient gain has not been acquired, the erased image selection process is terminated. If it is determined that the instruction for adjusting the insufficient gain is acquired, the system controller 30 controls the insufficient gain adjusting unit 55a to perform the insufficient gain adjustment on the normal image data, and displays the erased image selection screen. Proceed to processing.

  In the process of displaying the erased image selection screen, the system controller 30 controls the LCD driver 57 to display the erased image selection screen. For example, as shown in FIG. 16, on this erased image selection screen 80, a normal image 81 and an image 82 that has been subjected to insufficient gain adjustment are displayed side by side, and a selection erase icon 83 and a two-image erase icon are displayed. 84, a left icon 85, a right icon 86, an OK icon 87, and a cancel icon 88 are displayed. In the erased image selection screen 80, a selection operation is performed by operating the cursor operation button and the MENU / OK button 23.

  For example, when the erased image selection icon 83 is selected by the cursor operation button 23, the left icon 85 and the right icon 86 can be selected, and the erased image is selected. Thereafter, when the OK icon 87 is selected and the MENU / OK button 24 is further pressed, the image data corresponding to the selected image is erased from the recording medium 28. For example, when the left icon 85 is selected, the image data corresponding to the normal image 81 is deleted, and when the right icon 86 is selected, the image data corresponding to the image subjected to the insufficient gain adjustment is deleted. The

  Further, when the MENU / OK button 24 is pressed with the two-image deletion icon 84 selected and the OK icon 87 selected, the image data corresponding to the two images are deleted. When the cancel icon 88 is selected and the MENU / OK button 24 is pressed, the selection so far is canceled and the initial state is restored.

  The system controller 30 determines whether or not at least one of the normal image 81 and the image 82 with the insufficient gain adjusted is selected. This determination is made based on the selection result on the erased image selection screen 80. If it is determined that no image is selected, the erased image selection process is terminated.

  If it is determined that an image has been selected, the system controller 30 controls the media controller 58 to erase the image data corresponding to the selected image from the recording medium 28, and ends the erased image selection process.

  In the description of the image erasing process, the erasing of the image in the playback mode has been described. However, the image erasing process may be performed in the transfer mode in which the image data is transferred to the outside of the digital camera 10. In this case as well, when only the normal image data is recorded, the lacking gain adjustment process may be performed on the normal image data to display the erased image selection screen.

  Next, with reference to the flowchart of FIG. 17, a photographing process in the case of performing pre-flash for preventing red eyes will be described. Since the shooting sensitivity setting process is the same as the above-described shooting process, detailed description thereof is omitted.

  When the photographing sensitivity setting process is completed, the system controller 30 performs a light emission amount and exposure value setting process. Hereinafter, the setting process of the light emission amount and the exposure value will be described with reference to the flowchart of FIG. First, the light emission amount setting unit 33 sets the initial value of the light emission amount and the pre-light emission amount E. Thereafter, the processing up to setting the light emission amount of the strobe device is the same as the light emission amount and exposure value setting processing, and detailed description thereof is omitted.

  After the light emission amount of the strobe device 34 is set, the system controller 30 determines whether or not the light emission amount setting value is larger than the pre-light emission amount E. When it is determined that the pre-emission amount E is less than or equal to the pre-emission amount E, the system controller 30 sets the pre-emission to “none” and proceeds to a process of setting an exposure value.

  When it is determined that the set value of the light emission amount is larger than the predetermined light emission amount E, the system controller 30 sets the pre-light emission to “present” and proceeds to a process for setting the exposure value. In the process of setting the exposure value, the system controller 30 sets the exposure value based on the AE evaluation value, the shooting sensitivity, and the light emission amount, and ends the light emission amount and exposure value setting process.

  Next, the system controller 30 determines the presence or absence of strobe light emission. In the case of no flash emission, as shown in FIG. 19A, the process proceeds to a determination process as to whether or not the shutter button 14 has been fully pressed while only the light emission mode mark 91 is displayed in the through image 90. .

  When there is strobe light emission, the system controller 30 determines the presence or absence of pre-light emission. When the pre-flash is present, as shown in FIG. 19B, the flash mode mark 91, the flash mark 92 indicating the flash device 34, the pre-flash mark 93, and the flash amount 94 are displayed in the through image 90. Further, when there is no pre-emission, the pre-emission mark is not displayed and the emission mark 92, the pre-emission mark 93, and the emission amount 94 are displayed in the through image 90 as shown in FIG. Thereafter, the process proceeds to a process of determining whether or not the shutter button 14 has been fully pressed.

  The system controller 30 determines whether or not the shutter button 14 has been fully pressed. If it is not fully pressed, the determination process is repeated by entering a standby state. If it is determined that the button has been fully pressed, the system controller 30 sequentially executes an imaging process, a compression process, and an image data recording process, and ends the imaging process.

  In the above embodiment, the case where the focus lens is detected by the contrast method while moving the focus lens has been described as an example. However, the present invention is not limited to this. For example, an active method, a passive method, etc. You may detect the focus position of a focus lens using a ranging means. In this case, distance selection parameters A and B indicating the shooting distance may be used for each zoom position (Z1 to Z10) as shown in Table 2 below instead of the table shown in Table 1 above.

  In the above-described embodiment, the case where the photographing sensitivity is selected from three types of low sensitivity (ISO 400), medium sensitivity (ISO 800), and high sensitivity (ISO 1600) has been described as an example. Or you may select from four or more imaging sensitivity.

  Furthermore, in the above-described embodiment, the case where the upper limit value of the light emission amount can be set in three ways has been described as an example. However, the present invention is not limited to this, and it may be possible to set two ways or more than four ways.

  In the above embodiment, the case where the light emission amount setting unit and the upper limit value setting unit are provided in the system controller has been described as an example. However, the light emission amount setting unit and the upper limit value setting unit may be provided outside the system controller. The setting process and the upper limit setting process may be executed by a program.

  Furthermore, in the above embodiment, the case where the pulse motor is used as the motor for driving the zoom lens and the focus lens has been described as an example. However, the present invention is not limited to this, and a DC motor may be used. In this case, an encoder may be provided to detect the position of the lens.

  In the above embodiment, the case where a CCD image sensor is used as the solid-state imaging device has been described as an example. However, the present invention is not limited to this. For example, a CMOS image sensor may be used.

  Further, although cases have been described with the above embodiment as examples where the present invention is applied to a digital camera, the present invention is not limited to this. For example, the present invention may be applied to a mobile phone with a camera or a digital video camera.

It is a perspective view which shows the structure of a digital camera. It is a block diagram which shows the electric constitution of a digital camera. It is explanatory drawing which shows the input / output data of an imaging sensitivity setting circuit. It is explanatory drawing which shows a distance selection parameter. It is explanatory drawing which shows the input-output data of an insufficient gain calculation circuit. It is a block diagram which shows the structure of an insufficient gain calculation circuit. It is explanatory drawing which shows the weighting coefficient for every area. It is a flowchart explaining the setting method of light emission mode. It is a flowchart explaining the setting process of the upper limit of light emission amount. It is explanatory drawing which shows an upper limit setting screen. It is a flowchart explaining an imaging | photography process. It is a flowchart explaining the setting process of imaging sensitivity. It is a flowchart explaining the setting process of light emission amount. It is a flowchart explaining the imaging | photography process in the case of recording two image data before and after adjustment of an insufficient gain. 10 is a flowchart for describing image data erasing processing in a reproduction mode. It is explanatory drawing explaining the erased image selection screen. It is a flowchart explaining the imaging | photography process including pre light emission. It is a flowchart explaining the setting process of the light emission amount and exposure value including the setting of pre light emission. It is explanatory drawing explaining the display of a light emission mark, a pre light emission mark, and light emission amount.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Digital camera 23 Cursor operation button 28 Recording medium 30 System controller 33 Light emission amount setting part 33a Upper limit setting part 34 Strobe device 40 Shooting lens 41 Zoom lens 43 Focus lens 48 CCD
50b AMP
54 SDRAM
55 Digital Signal Processing Circuit 55a Insufficient Gain Control Unit 59 AE Detection Circuit 60 AF Detection Circuit 61 Shooting Sensitivity Setting Circuit 62 Insufficient Gain Calculation Circuit 70 Upper Limit Setting Screen 80 Erase Image Selection Screen 90 Through Image 92 Light Emission Mark 93 Pre Light Emission Mark 94 Light Emission Quantity mark

Claims (8)

In a photographing apparatus comprising a photographing lens having a zoom lens and a focusing lens, an imaging means for photographing subject light transmitted through the photographing lens by photoelectric conversion, and a strobe device that irradiates strobe light toward the subject.
Metering means for metering subject brightness;
Zoom position detecting means for detecting the zoom position of the zoom lens;
A focus position detecting means for detecting a focus position of the focus lens;
Photographing sensitivity setting means for setting photographing sensitivity based on the zoom position and the in-focus position;
First amplification means for amplifying an imaging signal output from the imaging means with a gain corresponding to the imaging sensitivity;
Based on the subject brightness and the shooting sensitivity, the flash amount of the strobe device is set, and when the set value of the flash amount is larger than a preset upper limit value of the flash amount, the set value is A light emission amount setting means for changing to an upper limit value;
An imaging apparatus comprising: control means for controlling exposure based on the subject brightness and the imaging sensitivity, and controlling the strobe device based on the set value.   The upper limit switching operation means for switching the upper limit is provided, and the light emission amount setting means sets the upper limit based on an operation signal acquired from the upper limit switching operation means. The imaging device described. Insufficient gain value calculation means for calculating a luminance value of image data obtained by converting the imaging signal into a digital signal and calculating an insufficient gain value by comparing the luminance value with a preset target luminance value When,
The imaging apparatus according to claim 1, further comprising: a second amplifying unit that amplifies a signal level of the image data based on the insufficient gain value.   When a photographing instruction input unit for inputting a photographing instruction is provided and the photographing instruction is acquired from the photographing instruction input unit, the control unit includes a first image before the signal level is amplified by the second amplification unit. 4. The photographing apparatus according to claim 3, wherein both the data and the amplified second image data are recorded on a recording means. A display means for displaying an image;
Before or after recording the first image data before the signal level is amplified by the second amplifying means and the second image data after amplification on the recording means, the control means The first and second image data are arranged side by side to display a selection screen on which an image to be recorded or deleted is selected, and the selected image is handled based on the selection result on the selection screen. 5. The photographing apparatus according to claim 1, wherein a recording process or an erasing process of image data is executed.   6. The control unit according to claim 5, wherein when only the first image data is recorded at the time of shooting, the control unit controls the second amplification unit to generate the second image data. Shooting device.   And determining means for determining whether or not the light emission amount is larger than a predetermined light emission amount. When the light emission amount is larger than the predetermined light emission amount, the control means controls the strobe device to make red eyes before the main light emission. The photographing apparatus according to claim 1, wherein pre-light emission for preventing is performed, and the pre-light emission is not performed when the light emission amount is equal to or less than the predetermined light emission amount.   A normal setting mode in which the light emission amount is set without setting the upper limit value, and an upper limit value setting mode in which the upper limit value is set, and before the photographing process is executed in the upper limit value setting mode Further, the control means controls the display means to display the presence / absence of strobe light emission, the light emission amount, and the presence / absence of pre-light emission for preventing red eyes. The imaging device according to item.

Images