JP2005130027A - Imaging device, imaging method, program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device capable of improving a time lag at photographing while reducing a correction error due to differences of photographing conditions to the utmost. <P>SOLUTION: The imaging device includes: an imaging element (14) capable of generating first image data or part of data of the first image data for obtaining the first image data through photoelectric conversion in a non exposure state and generating second image data through photoelectric conversion in an exposure state; a storage means (56) for storing correction data for correcting the second image data; and a correction means (20) for comparing the first image data with the correction data and generating the second image data corrected by the correction processing on the basis of the comparison result. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an imaging apparatus, an imaging method, a program, and a storage medium that can capture, record, and reproduce still images and moving images, for example.

  2. Description of the Related Art Conventionally, electronic cameras that use a memory card having a solid-state memory element as a recording medium and record / reproduce a still image or a moving image captured by a solid-state image sensor such as a CCD or a CMOS image sensor are already on the market. In this electronic camera, it is possible to switch between a single shooting mode in which shooting is performed frame by frame each time the shutter button is pressed, and a continuous shooting mode in which shooting is performed continuously while the shutter button is held down.

  In addition, when imaging using a solid-state imaging device, dark image data read from the imaging device after charge accumulation is performed in the same manner as in the main shooting without exposing the imaging device, and the charge is obtained with the imaging device exposed. Dark noise correction processing can be performed by performing arithmetic processing using the actual captured image data read from the image sensor after accumulation.

  That is, it is possible to obtain a high-quality image by correcting the captured image data with respect to image quality degradation such as pixel current loss due to dark current noise generated in the image sensor or minute scratches inherent to the image sensor.

  In particular, dark current noise increases with the charge accumulation time and the temperature rise of the image sensor. Therefore, when performing exposure at long seconds or exposure at high temperatures, a large image quality improvement effect can be obtained by dark correction processing. Dark noise correction processing is a useful function for users of electronic cameras.

  However, in the dark noise correction process described above, dark image data must be acquired in addition to the captured image data, so that an image sensor such as an electronic camera has a large release time lag and may miss a valuable photo opportunity. Further, in the case of continuous shooting, there is a problem that the shooting interval between the first frame and the second frame becomes longer by the time for acquiring dark image data, and the shooting frame interval cannot be made uniform.

Therefore, correction data for correcting image data is stored in advance under shooting conditions where the dark current generated in the image sensor is small and circuit noise is dominant, such as when shooting at short seconds, and this correction data is stored in advance. There is an image pickup apparatus that corrects photographed image data using.
JP-A-11-158562 JP-A-11-313791 JP-A-06-205301 JP 62-107589 A JP 08-05571 A

  However, due to the difference between the environment when the correction data was calculated and the environment when the image was actually taken, there was an error in the correction data stored in advance, and there was a problem that the captured image data could not be corrected accurately. ing.

  As described above, as a method of correcting dark noise (such as dark current of an image sensor), a method of correcting using dark image data and captured image data, and a captured image using correction data stored in advance. There are methods for correcting data, but each of these correction methods has a problem of a large release lime lag and a problem of correction errors caused by changes in photographing conditions.

  SUMMARY An advantage of some aspects of the invention is that it provides an imaging apparatus, an imaging method, a program, and a storage medium that can improve a time lag during imaging while reducing correction errors due to differences in imaging environments as much as possible.

  The imaging apparatus according to the first invention of the present application generates a part of data for obtaining the first image data from the first image data or the first image data by photoelectric conversion in a non-exposure state, Image sensor capable of generating second image data by photoelectric conversion in an exposure state, storage means for storing correction data for correcting second image data, first image data and correction data And a correction means for generating second image data corrected by a correction process based on the comparison result.

  The imaging method according to the second invention of the present application generates the first image data or a part of the first image data for obtaining the first image data by photoelectric conversion by the imaging element in the non-exposure state. A first step of generating second image data by photoelectric conversion by an image sensor in an exposed state, correction data for correcting the first image data and the second image data, and And a third step of generating second image data corrected by a correction process based on the comparison result.

  The program according to the third invention of the present application generates first image data or partial data for obtaining first image data out of the first image data by photoelectric conversion by an image sensor in a non-exposure state. A first step, a second step of generating second image data by photoelectric conversion by an image sensor in an exposure state, and correction data for correcting the first image data and the second image data. Comparing and causing the computer to execute a third step of generating the second image data corrected by the correction processing based on the comparison result.

  Here, the above program can be recorded on a recording medium.

  According to the first to third aspects of the present invention, the first image data and the correction data are compared, and the second image data corrected by the correction process based on the comparison result is generated, whereby the imaging apparatus The correction can be performed in consideration of the error of the correction data caused by the difference in the photographing conditions. That is, when the environment when the correction data is obtained differs greatly from the environment when the second image data is obtained, the correction process is performed in consideration of the first image data in addition to the correction data. Compared to a case where correction processing based on correction data is simply performed, image quality degradation caused by a difference in shooting conditions can be suppressed.

  In addition, by generating a part of the first image data to obtain the first image data by the image sensor, the data can be obtained in a shorter time than when the first image data is generated. Can be generated. As a result, the time until the second image data is generated can be shortened (release time lag is reduced), and the user can be prevented from missing a photo opportunity.

  Here, the correction means corrects the correction data based on the first image data, corrects the second image data based on the corrected correction data, or compares the first image data and the correction data. Based on the result, the second image data corrected by the correction data can be corrected. As a result, an image with suppressed image quality deterioration can be obtained.

  Here, image quality degradation can be suppressed by performing correction processing on at least one of gain, offset, and inclination.

  On the other hand, a control means for controlling the driving of the image sensor is provided, and the control means drives the image sensor according to the shooting conditions to generate the first image data. When the first image data is generated, When the first image data and the second image data corrected by the correction process based on the correction data are generated and the first image data is not generated, the second image data corrected by the correction process based on the correction data is generated. Can be generated.

  That is, it is determined whether or not the first image data is to be generated based on shooting conditions (for example, shooting environment such as shutter speed or imaging sensitivity when shooting, and temperature), and correction according to the determination result. By performing the processing, it is possible to suppress the image quality deterioration of the second image data using the correction data corresponding to the shooting conditions.

  Here, when the first image data is generated, correction processing taking the first image data into consideration is performed, and correction cannot be made with only correction data stored in the storage unit due to a change in photographing conditions. In addition, it is possible to perform a correction process corresponding to a change in photographing conditions. When the first image data is not generated, the time until the second image data is generated can be shortened by omitting the time for generating the first image data.

  The correction data can be data corresponding to one of the first image data and a part of the data, and the data corresponding to the part of the data reduces the storage capacity of the storage means. be able to. Further, by storing correction data under a specific environment in advance (for example, at the manufacturing stage of the image pickup apparatus), when the image pickup apparatus is in a specific environment, the correction data stored in advance is used. Correction processing can be performed easily.

  Here, the correction data corresponding to a part of the data is data obtained by projecting the first image data with respect to the specific direction of the image sensor, so that the correction data is converted into the circuit configuration of the image sensor. Corresponding data can be obtained.

  Examples of the present invention will be described below.

  A camera system (imaging device) that is Embodiment 1 of the present invention will be described with reference to the drawings. The camera system according to the present embodiment includes a camera body and a lens device that is detachably attached to the camera body.

  FIG. 1 is a block diagram showing the configuration of the camera system in this embodiment. In the figure, reference numeral 100 denotes a camera body, and 300 denotes a lens device that is detachably attached to the camera body 100.

  First, the configuration of the camera body 100 will be described.

  A shutter 12 has a plurality of light shielding blades and controls the amount of light incident on the image plane. An image sensor 14 such as a CCD or CMOS image sensor converts an optical image (subject image) formed by a photographing optical system in the lens apparatus 300 into an electric signal and accumulates charges, and accumulates accumulated charges (image data). ) Is output. The system control circuit (control unit) 50 controls driving of the image sensor 14 (charge accumulation and charge signal readout) via the image sensor driving unit 14a.

  Reference numeral 16 denotes an A / D converter that converts an analog signal output from the image sensor 14 into a digital signal. A timing generation circuit 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16 and the D / A converter 26, and is controlled by the memory control circuit 22 and the system control circuit 50.

  Reference numeral 20 denotes an image processing circuit (correction means) that performs predetermined pixel interpolation processing and color conversion processing on the data output from the A / D converter 16 or the data output from the memory control circuit 22. The image processing circuit 20 performs a predetermined calculation process using the image data captured as necessary, and outputs the calculation result to the system control circuit 50.

  The system control circuit 50 performs TTL (through-the-lens) AF (autofocus) processing, AE (automatic exposure) processing, and EF (flash dimming) processing based on the calculation result from the image processing circuit 20. Do. The image processing circuit 20 performs predetermined arithmetic processing using the captured image data, and performs TTL AWB (auto white balance) processing based on the obtained arithmetic result.

  Since the camera body 100 of the present embodiment is provided with a focus detection unit 42 and a photometry unit 46 as will be described later, the system control circuit 50 uses a focus detection unit instead of the output of the image processing circuit 20. AF processing, AE processing, and EF processing can also be performed based on the outputs of 42 and the photometry unit 46.

  Further, AF processing, AE processing, and EF processing are performed based on the outputs of the focus detection unit 42 and the photometry unit 46, and AF processing, AE processing, and EF processing are performed based on the output of the image processing circuit 20. May be performed. For example, after performing AF processing by the phase difference detection method based on the output of the focus detection unit 42, AF processing by the contrast detection method can be performed based on the output of the image processing circuit 20.

  A memory control circuit 22 controls operations in the A / D converter 16, the timing generation circuit 18, the image processing circuit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression circuit 32. .

  The image data output from the A / D converter 16 is written into the image display memory 24 or the memory 30 via the image processing circuit 20 and the memory control circuit 22 or directly via the memory control circuit 22.

  Reference numeral 28 denotes an image display unit comprising a TFT type LCD. Display image data written in the image display memory 24 is output to the image display unit 28 via the D / A converter 26, and an image captured by the image sensor 14 is displayed on the image display unit 28. By sequentially displaying the captured image data on the image display unit 28, an electronic viewfinder function can be realized.

  The system control circuit 50 can control ON / OFF of the display in the image display unit 28. If the display is turned OFF, the power consumption of the camera body 100 can be significantly reduced.

  Reference numeral 30 denotes a memory for storing still image data and moving image data captured by the image sensor 14, and has a storage capacity sufficient to store a predetermined number of still image data and a predetermined time of moving image data. doing. Therefore, even in continuous shooting or panoramic shooting in which a plurality of still images are continuously shot, it is possible to write a large amount of images to the memory 30 at high speed. The memory 30 can also be used as a work area for the system control circuit 50.

  Reference numeral 32 denotes a compression / decompression circuit that compresses and decompresses image data by adaptive discrete cosine transform (ADCT) or the like. The image data stored in the memory 30 is read and subjected to compression processing or decompression processing. Is written into the memory 30.

  A shutter control unit 40 controls driving of the shutter 12 based on an output from the system control circuit 50. A focus detection unit 42 detects the focus adjustment state of the photographing optical system by receiving subject light that has passed through the lens device 300. Here, the focus detection unit 42 is disposed such that the light receiving surface is conjugate with the light receiving surface of the image sensor 14. The system control circuit 50 controls the driving of the focus lens, as will be described later, based on the output of the focus detection unit 42.

  Reference numeral 44 denotes a temperature sensor, which detects the ambient temperature in the shooting environment (the ambient temperature of the camera system) and outputs the detection result to the system control circuit 50. Here, if the temperature in the image sensor 14 is detected by the temperature sensor 44, it is possible to more accurately predict a change in the dark current of the image sensor 14 due to a change in the shooting environment.

  Reference numeral 46 denotes a photometry unit for performing AE processing, which measures subject luminance by receiving subject light that has passed through the lens apparatus 300. The measurement result is output to the system control circuit 50, and the system control circuit 50 calculates an exposure value (aperture value and shutter speed) based on the measurement result.

  The system control circuit 50 performs drive control of the shutter 12 via the shutter control unit 40 based on the calculated exposure value, and performs drive control of the diaphragm 312 via the aperture control unit 340 described later.

  The photometry unit 46 receives light emitted from an illumination unit 48 (to be described later) and reflected by the subject, and the output of the photometry unit 46 at this time is used for EF processing. Reference numeral 48 denotes an illumination unit that irradiates the subject with illumination light, and has an AF auxiliary light projecting function and a flash light control function.

  In the present embodiment, exposure control is performed based on the output of the photometry unit 46. However, based on the image data captured by the image sensor 14 and processed by the image processing circuit 20, video is captured. You may make it perform exposure control by a TTL system. Further, exposure control may be performed based on the measurement result by the photometry unit 46 and the calculation result by the image processing circuit 20.

  Reference numeral 50 denotes a system control circuit that controls the overall operation of the camera body 100, and includes a known CPU, an internal memory, and the like. A memory 52 stores constants, variables, programs, and the like for operating the system control circuit 50.

  An information output unit 54 informs the photographer of the operating state of the camera system, a specific message, and the like with characters, images, voices, and the like according to the execution of the program in the system control circuit 50. The display unit (for example, LCD , LEDs, lamps) and sound generating elements (for example, speakers). One or a plurality of information output units (liquid crystal display unit, speakers, etc.) 54 are provided in the vicinity of the operation unit provided in the camera body 100 and at a position where the photographer can easily see.

  Here, the information displayed by the information output unit (display unit) 54 is also displayed in the optical viewfinder 104 described later.

  Among the contents displayed on the information output unit (display unit) 54, those displayed on the LCD etc. include single shooting / continuous shooting display, self-timer display, compression rate display, recording pixel number display, and recording number display. , Remaining shot number display, shutter speed display, aperture value display, exposure compensation display, illumination display, red-eye reduction display, macro shooting display, buzzer setting display, watch battery remaining display, battery remaining display, error display , Information display with a plurality of digits, attachment / detachment state display of recording media 200 and 210 (to be described later), attachment / detachment state display of the lens apparatus 300, communication I / F operation display, date / time display, display indicating connection state with an external computer and so on.

  Among the contents displayed on the information output section (display section) 54, the contents displayed in the optical viewfinder 104 include an in-focus display, a shooting preparation completion display, a camera shake warning display, an illumination charge display, and an illumination charge completion display. , Shutter speed display, aperture value display, exposure correction display, recording medium writing operation display, and the like.

  Further, among the contents displayed on the information output unit (display unit) 54, the ones displayed by the LEDs and the like include, for example, in-focus display, photographing preparation (focus adjustment operation, photometric operation, etc.) completion display, camera shake warning display, and the like. Illumination charging display, illumination charging completion display, recording medium writing operation display, macro shooting setting notification display, secondary battery charging display, and the like.

  In addition, among the display contents in the information output unit (display unit) 54, what is displayed by lighting of a lamp or the like includes, for example, a self-timer notification lamp. This self-timer notification lamp can also be used as AF auxiliary light.

  Reference numeral 56 denotes a non-volatile memory (storage means) that can electrically erase and record data, and stores a program and the like to be described later. As the nonvolatile memory 56, an EEPROM or the like is used.

  Specifically, the nonvolatile memory 56 stores various parameters, setting values such as ISO sensitivity, setting mode, and one-dimensional correction data used when performing horizontal dark shading correction. The one-dimensional correction data is created at the time of adjustment in the production process of the camera body 100 and is written in the nonvolatile memory 56.

  As a method of creating the one-dimensional correction data, for example, dark image data (first image data, 2) obtained by performing dark photographing (accumulation of charge of the image sensor 14 in a non-exposure state and reading of the accumulated charge). For example, there is a method in which data for one horizontal line (or data for one vertical line) of the image sensor 14 composed of regularly arranged pixels is used as one-dimensional correction data by projecting the (dimensional data). .

  As the correction data, dark image data obtained in the production process of the camera body 100 may be stored as two-dimensional data (data in the horizontal and vertical directions of the image sensor 14) as they are.

  Here, some image pickup devices 14 have a small fixed pattern noise in the vertical direction and need only be corrected in the horizontal direction.

  The cause of the generation of fixed pattern noise is that there is a large difference (variation) in the readout path where the signal of the pixel portion reaches the final output stage when the signal is read out from the circuit system of the image sensor 14. FIG. 2 is a diagram illustrating mixing of fixed pattern noise in the horizontal and vertical directions of the image sensor 14. The fixed pattern noise in the horizontal direction depends on the difference between the readout path of the vertical line a and the readout path of the vertical line b in the figure. Also, the fixed pattern noise in the vertical direction depends on the difference between the readout path of the horizontal line c and the readout path of the horizontal line d in the figure.

  For example, as shown in FIG. 2, an image sensor is used in which each horizontal line shares a readout circuit, and noise that is mixed when transferring the signal of each horizontal line to the common readout circuit by devising a circuit layout or the like. In this case, the fixed pattern noise in the vertical direction is reduced, and it is not necessary to correct the captured image data (second image data) in the vertical direction.

  In the camera body 100 using such an image sensor 14, the fixed pattern noise can be removed by correcting the captured image data using the one-dimensional correction data in the horizontal direction of the image sensor 14. When an image sensor with a small fixed pattern noise in the horizontal direction is used, the fixed pattern noise can be removed by correcting the captured image data using the one-dimensional correction data in the vertical direction of the image sensor.

  Reference numerals 60, 62, 64, 66, 68 and 70 are operation units for inputting various operation instructions to the system control circuit 50, such as switches, dials, touch panels, pointing by line-of-sight detection, and voice recognition units. Of these, it is composed of one or more combinations. Details of these operation units are shown below.

  Reference numeral 60 denotes a mode dial switch, which is operated by the photographer to switch the shooting mode. Here, the above shooting modes include automatic shooting mode, program shooting mode, shutter speed priority shooting mode, aperture priority shooting mode, manual shooting mode, depth of focus priority (depth) shooting mode, portrait shooting mode, landscape shooting mode. , Close-up shooting mode, sports shooting mode, night scene shooting mode, panoramic shooting mode, and the like.

  Reference numeral 62 denotes a shutter switch (SW1), which is turned on when a shutter button (not shown) provided in the camera body 100 is half-pressed, and performs AF processing, AE processing, and AWB for the system control circuit 50. Instructs the start of a shooting preparation operation such as processing or EF processing.

  A shutter switch (SW2) 64 is turned on when a shutter button (not shown) is fully pressed. Thereby, the SW 2 causes the system control circuit 50 to write the signal read from the image sensor 14 to the memory 30 via the A / D converter 16 and the memory control circuit 22. A series of processing operations such as a development process using calculation in the memory control circuit 22, a recording process in which image data is read from the memory 30, compressed by the compression / decompression circuit 32, and written to the recording media 200 and 201. Instruct to start.

  Reference numeral 66 denotes a reproduction switch, which instructs to start a reproduction operation for reading out image data recorded in the memory 30 or the recording media 200 and 210 and displaying it on the image display unit 28.

  68 is a single-shot / continuous-shot switch, and when SW2 is turned on, a single-shot shooting mode in which one frame is shot and the camera is in a standby state, or a plurality of consecutive shots while SW2 is on. It is possible to instruct the system control circuit 50 to set a continuous shooting mode in which continuous shooting is performed.

  Reference numeral 69 denotes an ISO sensitivity setting switch. The system control circuit 50 can set the ISO sensitivity by changing the gain setting in the image sensor 14 or the image processing circuit 20 based on the output signal from the ISO sensitivity setting switch 69.

  An operation unit 70 includes various buttons, switches, a touch panel, and the like. The operation unit 70 includes a menu button, a set button, a macro button, a multi-screen playback page break button, a lighting setting button, a single shooting / continuous shooting / self-timer switching button, a menu movement + (plus) button, a menu movement− ( There are a (minus) button, a playback image shift + (plus) button, a playback image-(minus) button, a shooting image quality selection button, an exposure correction button, and a date / time setting button. In addition, a selection / switch button for setting selection and switching of various functions when performing shooting and playback in panorama mode, etc., and a determination for setting and executing various functions when performing shooting and playback in panorama mode and the like / Execution button, image display ON / OFF switch for setting ON / OFF of display on the image display unit 28, and quick review ON / OFF switch for setting a quick review function for automatically reproducing captured image data immediately after shooting. Further, a compression mode that is a switch for selecting a compression rate at the time of image compression (for example, compression by the JPEG method) or for selecting a CCD RAW mode in which the signal of the image sensor 14 is digitized and recorded on a recording medium. Playback switch that can set each function mode such as switch, playback mode, multi-screen playback / erase mode, PC connection mode, etc. AF processing starts when SW1 is turned on, There is an AF mode setting switch capable of setting a one-shot AF mode that keeps a focused state and a servo AF mode that continues AF processing while SW1 is in an ON state.

  In addition, a rotary dial switch can be used in place of the plus button and the minus button, and in this case, a numerical value and a function can be selected by a simple operation such as rotating the rotary dial switch.

  Reference numeral 72 denotes a power switch, which can be switched between power-on and power-off modes of the camera body 100. Also, the power on and power off settings of various attached devices such as the lens device 300 mounted on the camera main body 100, the external strobe mounted on the camera main body 100, and the recording media 200 and 210 can be switched.

  A power control unit 80 includes a power detection circuit, a DC-DC converter, a switch circuit that switches a block to be energized, and the like. The power supply control unit 80 detects whether or not a power supply unit 86 to be described later is attached to the camera body 100, the type of the power supply unit 86, and the remaining amount of the battery in the power supply unit 86. Based on the above, the DC-DC converter is controlled, and a necessary voltage is supplied to each part including the recording media 200 and 210 for a necessary period.

  Reference numerals 82 and 84 denote connectors, 86 denotes a primary battery such as an alkaline battery or lithium battery, a secondary battery such as a NiCd battery, NiMH battery, or Li battery, an AC adapter, or the like.

  90 and 94 are interfaces with the recording media 200 and 210 such as a memory card and a hard disk, 92 and 96 are connectors for connecting to the recording media 200 and 210, and 98 is a recording medium 200 for each of the connectors 92 and 96. , 210 is a recording medium attachment / detachment detection unit for detecting whether or not 210 is attached.

  In the present embodiment, two interfaces (90, 94) and connectors (92, 96) for communicating with the recording media 200, 210 are provided. It may be equipped with a number of systems.

  Further, as interfaces and connectors of different standards, those conforming to standards such as PCMCIA cards and CF (Compact Flash (registered trademark)) cards may be used.

  Further, when the interfaces 90 and 94 and the connectors 92 and 96 are configured using a standard conforming to a PCMCIA card or a CF card, a LAN card, a modem card, a USB card, an IEEE 1394 card, a P1284 card, a SCSI card, a PHS, etc. By connecting various communication cards such as communication cards, it is possible to transfer image data and management information attached to the image data to and from peripheral devices such as other computers and printers.

  Reference numeral 104 denotes an optical viewfinder, and a subject light flux reflected by the mirror (quick return mirror) 130 and the mirror 132 obliquely provided on the photographing optical path is guided to the optical viewfinder 104. Accordingly, the photographer can observe the subject image by looking into the optical viewfinder 104 without using the electronic viewfinder function of the image display unit 28.

  In the optical viewfinder 104, some of the information displayed by the information output unit 54, for example, in-focus display, camera shake warning display, illumination charge display, shutter speed display, aperture value display, and exposure correction display are displayed. It has come to be.

  Here, the mirror 130 is movable between a position obliquely provided on the photographing optical path (mirror down position) and a position retracted from the photographing optical path (mirror up position) by a mirror driving mechanism (not shown). When obliquely arranged on the optical path, the imaging light beam is guided to the optical viewfinder 104 side as described above, and when it is retracted from the imaging optical path, the imaging light beam is received by the image sensor 14. The mirror 132 that guides the light beam from the mirror 130 to the optical viewfinder 104 can be configured as a quick return mirror or a half mirror that transmits part of the light beam and reflects the rest.

  A communication unit 110 has various communication functions such as RS232C, USB, IEEE1394, P1284, SCSI, modem, LAN, and wireless communication. Reference numeral 112 denotes a connector for connecting the camera body 100 to another device by the communication unit 110 or an antenna for performing wireless communication.

  Reference numeral 120 denotes an interface for performing communication between the camera body 100 and the lens apparatus 300. Reference numeral 122 denotes a connector that electrically connects the camera body 100 and the lens apparatus 300. A lens attachment / detachment detection unit 124 detects whether the lens device 300 is attached to the camera mount 106 and / or the connector 122.

  In the camera system of the present embodiment, control signals, status signals, data signals, and the like can be transmitted between the camera body 100 and the lens apparatus 300 via the connector 122 and a connector 322 described later. Currents of various voltages can be supplied from the side to the lens device 300 side. The connector 122 may be configured to enable not only electrical communication but also optical communication, voice communication, and the like.

  Reference numeral 200 denotes a recording medium such as a memory card or a hard disk. The recording medium 200 includes a recording unit 202 composed of a semiconductor memory, a magnetic disk, or the like, an interface 204 with the camera body 100, and a connector 206 for connecting with the camera body 100. Reference numeral 210 denotes a recording medium such as a memory card or a hard disk, similar to the recording medium 200. The recording medium 210 includes a recording unit 212 composed of a semiconductor memory, a magnetic disk, or the like, an interface 214 with the camera body 100, and a connector 216 for connecting with the camera body 100.

  Next, the configuration of the lens apparatus 300 attached to the camera body 100 will be described.

  Reference numeral 306 denotes a lens mount for mechanically coupling the lens apparatus 300 to the camera body 100 (camera mount 106). The lens mount 306 has various functions for electrically connecting the lens device 300 to the camera body 100.

  Reference numeral 310 denotes a photographic lens, which is shown as one lens in FIG. 1, but actually includes a plurality of lens groups. Some of these multiple lens groups (zoom lens and focus lens) move in the optical axis direction to change the focal length of the photographic optical system or bring the photographic optical system into focus. can do.

  Reference numeral 312 denotes a diaphragm, which adjusts the amount of light incident on the image plane (image sensor 14) by changing the opening area of the light passage opening. Reference numeral 320 denotes an interface for performing communication between the lens apparatus 300 and the camera body 100. Reference numeral 322 denotes a connector that electrically connects the lens apparatus 300 to the camera body 100.

  A diaphragm control unit 340 controls driving of the diaphragm 312 based on an instruction from the lens control circuit 350. Here, the system control circuit 50 calculates an exposure value (aperture value and shutter speed) based on the output of the photometry unit 46, and the calculation result is sent to the lens control circuit 350 via the interfaces 120 and 320 and the connectors 122 and 322. Output to. Then, the lens control circuit 350 outputs a signal for driving the aperture 312 to the aperture control unit 340 in accordance with the exposure value (aperture value) information sent from the system control circuit 50.

  In this embodiment, the exposure value is calculated by the system control circuit 50. However, the photometric result of the photometry unit 46 is output to the lens control circuit 350, and the exposure value is calculated by the lens control circuit 350. You may do it.

  A focus control unit 342 controls the driving of the focus lens in the photographing lens 310 based on an output from the lens control circuit 350. Here, the system control circuit 50 detects the focus adjustment state of the photographing optical system based on the output from the focus detection unit 42 and the image processing circuit 20 as described above, and outputs the detection result to the lens control circuit 350. . The lens control circuit 350 outputs a signal for driving the focus lens to the focus control unit 342 so that the photographing optical system is brought into focus based on the input detection result.

  A zoom control unit 344 controls the driving of the zoom lens in the photographing lens 310 based on the output from the lens control circuit 350. Reference numeral 350 denotes a lens control circuit that controls the overall operation of the lens apparatus 300.

  The lens control circuit 350 includes a memory for storing operation constants, variables, programs, etc., identification information such as a number unique to the lens apparatus 300, management information, function information such as an open aperture value, a minimum aperture value, a focal length, It also has a non-volatile memory function for holding current and past set values.

  An operation in the camera system having the above-described configuration will be described. 3, 4, and 5 are flowcharts showing the shooting operation processing procedure of the camera system. This processing program is stored in a storage medium such as the nonvolatile memory 56, loaded into the memory 52, and executed by the CPU in the system control circuit 50.

  Upon power-on such as battery replacement, the system control circuit 50 initializes flags, control variables, and the like, and performs necessary initial settings for each part of the camera system (camera body 100 and lens device 300) (step S101). . The system control circuit 50 determines the setting state of the power switch 72, and determines whether or not the power is set to the OFF state by the power switch 72 (step S102).

  Here, when the power switch 72 is set to the power OFF, the driving in the information output unit (display unit) 54 and the image display unit 28 is stopped (set to a non-display state). Then, necessary parameters, setting values and setting modes including flags and control variables are recorded in the nonvolatile memory 56, and the power supply control unit 80 cuts off the power supply to each part of the camera body 100 including the image display unit 28. After performing the predetermined end process (step S103), the process returns to step S102.

  On the other hand, when the power switch 72 is set to the power ON, the system control circuit 50 has a problem in the operation of the camera system due to the remaining battery capacity and the operation status of the power supply 86 via the power control unit 80. It is determined whether or not (step S104). If it is determined that there is a problem, a control signal is output to the information output unit 54 to give a predetermined warning by displaying an image or outputting a sound (step S105), and then the process of step S102. Return to.

  On the other hand, when it is determined that the state of the power source 86 is satisfactory for the operation of the camera system, the system control circuit 50 determines the setting state of the mode dial switch 60, and the mode dial switch 60 enters the shooting mode. It is determined whether it is set (step S106). When the mode dial switch 60 is set to a mode other than the shooting mode, the system control circuit 50 executes a process according to the selected mode (step S107), and after the execution, the process of step S102. Return to.

  On the other hand, when the mode dial switch 60 is set to the shooting mode, it is determined whether or not the recording medium 200 or 201 is attached to the camera body 100 based on the output of the recording medium attachment / detachment detection unit 98. . The management information of the image data recorded on the recording medium 200 (or / and the recording medium 201) attached to the camera main body 100 and the operation state of the recording medium 200 (201) are the operations of the camera main body 100, in particular. It is determined whether there is a problem in the recording / reproducing operation of the image data with respect to the recording medium (step S108).

  If it is determined that there is a problem with the above operation, a predetermined warning is given by displaying an image or outputting sound in the information output unit 54 (step S105), and the process returns to step S102.

  On the other hand, if it is determined in step S108 that there is no such problem, the system control circuit 50 determines the setting state of the single / continuous shooting switch 68 (step S109). Here, when the single shooting mode is set, the single shooting flag is set (step S110), and when the continuous shooting mode is set, the continuous shooting flag is set (step S111). .

  It should be noted that the single shooting / continuous shooting switch 68 continuously captures a single frame when SW2 is turned on and is in a standby state, and continuously while SW2 is turned on. It is possible to switch and set the continuous shooting mode to continue shooting. Here, the states of the single shooting flag and the continuous shooting flag are stored in the internal memory of the system control circuit 50 or the memory 52.

  The system control circuit 50 outputs information (display, audio output, etc.) set in the camera system by outputting a control signal to the information output unit 54 (step S112). Here, when the image display switch of the image display unit 28 is in the ON state, various setting information in the camera system may be output (display, audio output, etc.) using the image display unit 28.

  In FIG. 4, the system control circuit 50 determines whether or not SW1 is in an ON state (step S113). If SW1 is in an OFF state, the process returns to step S102. On the other hand, when SW1 is in the ON state, the system control circuit 50 detects the focus adjustment state of the photographing optical system based on the output of at least one of the focus detection unit 42 and the image processing circuit 20, and the detection result The focus lens in the photographing lens 310 is driven via the lens control circuit 350 and the focus control unit 342 based on the above. As a result, the photographing optical system is brought into a focused state. Further, the subject brightness is detected based on the output of at least one of the photometry unit 46 and the image processing circuit 20, and the exposure value (aperture value and shutter speed) is calculated based on the detection result (step 114). Detailed description of the focus adjustment process and the photometry process in step 114 will be described later.

  In step S115, the system control circuit 50 reads one-dimensional correction data used for horizontal dark shading correction, which will be described later, from the nonvolatile memory 56, and stores this one-dimensional correction data in a predetermined area of the memory 30 in the vertical direction of the image sensor 14. Then, the correction data is developed by repeating the same number of lines as the actual image.

  Then, the system control circuit 50 determines the sensitivity set in the camera system based on the output from the ISO sensitivity switch 69. And it is discriminate | determined whether the setting sensitivity by the ISO sensitivity setting switch 69 is less than ISO800 (step S116). The reason for this determination is that the exposure amount is small at ISO 800 or higher, and image quality degradation due to dark current noise generated in the image sensor 14 or pixel defects due to minute flaws inherent to the image sensor 14 is conspicuous. In this embodiment, ISO 800 is used as a determination criterion, but ISO 1600 may be used as a determination criterion.

  If it is determined in step S116 that the ISO is 800 or more, the process proceeds to step S120. If it is determined that it is less than ISO 800, it is further determined whether or not the set sensitivity is less than ISO 400 (step S116). S117).

  If the temperature is lower than ISO 400, the process proceeds to step S123. If the temperature is higher than ISO 400, whether or not the ambient temperature Temp of the camera system is lower than 28 ° C. based on the output from the temperature sensor 44. Is discriminated (step S118). If the temperature is less than 28 ° C., the process proceeds to step S123. If the temperature is 28 ° C. or more (that is, if Temp is high and the dark current changes), the shutter speed determined in step S114. It is determined whether or not Tv is less than 1 second (step S119).

  Here, when Tv is less than 1 second, the process proceeds to step S123, and when Tv is 1 second or more (that is, when the dark current changes due to long exposure), the process of step S120 is performed. Migrate to

  In this embodiment, as the determination criteria in steps S116 to S119, the set sensitivity is ISO800, ISO400, the ambient temperature Temp is 28 ° C., and the shutter speed Tv is 1 second. These reference values are the characteristics of the image sensor 14. It can be set appropriately depending on the situation. In other words, these criteria (ISO sensitivity, Temp, Tv) are assumed to be the conditions under which the captured image data cannot be satisfactorily corrected with the correction data stored in advance due to the increase in dark current noise of the image sensor 14. can do.

  Here, the dark current noise generated in the image sensor 14 increases as the charge accumulation time and the temperature of the image sensor 14 rise. Therefore, when performing exposure at a long time or exposure at a high temperature, the nonvolatile memory The correction corresponding to the increased dark current noise cannot be performed only by using the correction data stored in advance in 56. For this reason, the captured image must be corrected using correction data corresponding to changes in dark current noise.

  In this embodiment, in order to make correction data stored in advance correspond to changes in dark current noise, the correction data correction flag is set to 1 when none of the conditions in steps S116 to S119 is satisfied ( Step S120). On the other hand, if any of the conditions in steps S116 to S119 is satisfied, the correction data correction flag is not set (step S123).

  Next, the system control circuit 50 determines the setting state of the single shooting flag and the continuous shooting flag (step S121). If the single shooting flag is set, the system control circuit 50 proceeds to the process of step S124, and the continuous shooting flag is set. If it is set, the process proceeds to step S122.

  In step S122, with the shutter 12 closed, charge accumulation in the image sensor 14 and readout of the accumulated charge (dark capture) are performed, and the read data (dark image data (on the entire screen of the image sensor 14) is read. The correction data stored in advance is corrected based on a part of the data obtained by the charge accumulation. Here, details of the dark capturing process in step S122 will be described later (FIG. 10).

  The correction data is corrected using a part of the dark image data obtained by the dark capture processing, and the shot image data is corrected based on the corrected correction data. It is possible to suppress deterioration in image quality due to a change in dark current noise generated in the image sensor 14 in accordance with shooting conditions such as setting conditions.

  Then, the system control circuit 50 determines whether or not SW2 is in an ON state (step S124). If SW2 is in an OFF state, the system control circuit 50 determines whether or not SW1 is in an ON state (step S124). S125). Here, when SW1 is in the ON state, the processes of Step S124 and Step S125 are repeated, and when SW1 is in the OFF state, the process proceeds to Step S102.

  In step S124, when SW2 is in the ON state, the system control circuit 50 determines whether or not there is an image storage buffer area capable of storing captured image data in the memory 30 by communication with the memory 30 (step S124). Step S126 in FIG. If it is determined that there is no area in the image storage buffer area of the memory 30 where new image data can be stored, the information output unit 54 issues a predetermined warning (warning by display or sound output). Perform (step S127), and return to the process of step S102.

  As a case where new image data cannot be stored, for example, immediately after the maximum number of image data that can be stored in the image storage buffer area of the memory 30 is generated by continuous shooting, it is read from the memory 30. The first image data to be written to the storage media 200 and 210 is still unrecorded in the storage media 200 and 210, and one image data cannot be written in the image storage buffer area of the memory 30. It is.

  In addition, when the captured image data is compressed and stored in the image storage buffer area of the memory 30, the image data storage is performed in consideration of the fact that the amount of compressed image data varies depending on the compression mode setting. Whether or not the possible area is on the image storage buffer area of the memory 30 is determined in the process of step S126.

  If it is determined in step S126 that there is an image storage buffer area in the memory 30 that can store the captured image data, the system control circuit 50 drives the aperture 312 and the shutter 12 to capture the subject luminous flux. The element 14 is exposed. Then, an imaging signal (image data) generated by photoelectric conversion in the imaging device 14 and accumulated for a predetermined time is read from the imaging device 14, and the A / D converter 16, the image processing circuit 20, and the memory control circuit 22 are read. Or a process (imaging process) for writing in a predetermined area of the memory 30 via the memory control circuit 22 or directly from the A / D converter 16 (step S128). Details of this photographing process will be described later.

  When the photographing process in step S128 is completed, the system control circuit 50 checks the setting state of the correction data correction flag stored in the internal memory or the memory 52 (step S129). If the correction data correction flag is not set to 1, the process proceeds to step S132. On the other hand, when the correction data correction flag is set to 1, the system control circuit 50 determines the state of the single / continuous shooting flag stored in the internal memory or the memory 52 (step S130). If the continuous shooting flag is set, the process proceeds to step S132.

  When the continuous shooting flag is set, the dark capturing process is performed prior to the execution of the continuous shooting in the above-described step S122. Therefore, the dark capturing process in step S131 is not performed and will be described later. The developing process in step S132 is performed. That is, in this embodiment, when continuous shooting is performed, the dark capturing process is performed before the first image is captured, and the dark capturing process is not performed in the subsequent capturing. As a result, the shooting interval in the continuous shooting can be made substantially constant, and the shooting interval varies depending on the dark capturing process during the continuous shooting, thereby preventing the photographer from feeling uncomfortable.

  On the other hand, if it is determined in step S130 that the single-shot flag is set, the noise component such as dark current of the image sensor 14 is kept for a predetermined time (with the shutter 12 closed) as in the process in step S122. In some cases, dark capture processing is performed to store the noise image signal that has been stored for the same time as the actual shooting (step S131), and the process proceeds to step S132. Details of the dark capturing process in step S131 will be described later.

  The system control circuit 50 reads a part of image data written in a predetermined area of the memory 30 via the memory control circuit 22 and performs WB (white balance) integration calculation processing, OB (optical) necessary for development processing. (Black) integration calculation processing is performed, and these calculation results are stored in the internal memory or the memory 52 of the system control circuit 50.

  Then, the system control circuit 50 uses the memory control circuit 22 and, if necessary, the image processing circuit 20 to read the captured image data written in a predetermined area of the memory 30 and reads the internal memory or the memory 52 of the system control circuit 50. Are used to perform various development processes including an AWB (auto white balance) process, a gamma conversion process, and a color conversion process (step S132).

  In this development processing, as shown in FIG. 6, horizontal dark shading correction data developed in step S115 (data obtained by developing one-dimensional correction data stored in advance in the vertical direction of the image sensor 14) or step S122 (or step S122). A dark correction calculation process for canceling dark current noise and the like of the image sensor 14 is also performed by performing a subtraction process on the captured image data obtained in step S128 using the correction data corrected in the dark capturing process of S131). Done.

  In this embodiment, when the correction data correction flag is not set in step S123, the dark capturing process is performed because the dark correction calculation process is performed using the correction data stored in advance in the nonvolatile memory 56. The captured image data can be corrected without any image quality deterioration due to dark current noise or fixed pattern noise generated in the image sensor 14.

  When the correction data correction flag is set, the correction data stored in advance is corrected using a part of the dark image data obtained by the dark capturing process, as will be described later. Since the dark correction calculation process is performed using the correction data, it is possible to suppress deterioration in image quality due to dark current noise or fixed pattern noise generated in the image sensor 14 that has changed under the shooting conditions.

  Next, the system control circuit 50 reads the image data written in a predetermined area of the memory 30, and the compression / decompression circuit 32 performs image compression processing corresponding to the mode set for the read image data. In step S133, the compressed image data is written in an empty area of the image storage buffer area of the memory 30.

  Then, the system control circuit 50 reads the image data stored in the image storage buffer area of the memory 30, and the read image data is sent via the interface 90 (or interface 94) and the connector 92 (or connector 96). A recording process for writing to the recording medium 200 (or the recording medium 210) such as a memory card or a compact flash (registered trademark) card is started (step S134).

  This recording start process is executed each time new photographed image data (image data that has undergone the processes in steps S132 and S133) is written in the empty area of the image storage buffer area of the memory 30.

  Note that while the captured image data is being written to the recording medium 200 (or the recording medium 201), the information output unit 54 is driven to indicate that the recording operation is in progress to indicate that the recording operation is in progress. To output information indicating that For example, the LED in the information output unit 54 can be blinked.

  Here, when the recording process of writing the photographic image data to the recording medium is completed, a series of processes relating to one image is completed.

  On the other hand, the system control circuit 50 determines whether or not SW1 is in an ON state (step S135). If SW1 is in the OFF state, the process returns to step S102. On the other hand, when SW1 is in the ON state, the state of the single / continuous shooting flag stored in the internal memory of the system control circuit 50 or the memory 52 is determined (step S136).

  If the single shooting flag is set, the process returns to step S135, and the processes of step S135 and step S136 are repeated until SW1 is turned off. On the other hand, if the continuous shooting flag is set in step S136, the process returns to step S124 to prepare for the next shooting in order to perform continuous shooting.

  Next, the procedure of the focus adjustment / photometry process in step S114 described above will be described with reference to FIG.

  In the focus adjustment / photometry processing, the aperture control unit 340 and the focus control unit 342 receive control signals from the system control circuit 50 via the interface 120, the connector 122, the connector 322, the interface 320, and the lens system control circuit 350. Is done by.

  First, the system control circuit 50 starts focus adjustment processing of the photographing optical system using the image sensor 14, the focus detection unit 42, and the focus control unit 342 (step S201).

  In step S202, the system control circuit 50 controls the driving of the diaphragm 312 and the mirror 130, so that the light incident on the photographing lens 310 is converted into the diaphragm 312, the lens mounts 306 and 106, the mirror 130, and the distance measuring sub-mirror (FIG. (Not shown) to enter the focus detection unit 42. Then, the system control circuit 50 determines whether or not the photographing optical system is in focus based on the output of the focus detection unit 42, and keeps the focus detection unit 42 until the photographing optical system is in focus. The photographing lens 310 (focus lens) is driven using the focus control unit 342 while detecting the focus adjustment state of the photographing optical system (step S202, step S203).

  If it is determined in step S203 that the imaging optical system is in focus, the system control circuit 50 selects a focus detection area in focus from a plurality of focus detection areas provided in the shooting screen. The focus adjustment data and / or setting parameters are stored in the internal memory of the system control circuit 50 or the memory 52 together with the data relating to the determined focus detection area (step S204).

  Next, the system control circuit 50 starts an AE (automatic exposure) process using the photometry unit 46 (step S205). The system control circuit 50 controls the driving of the diaphragm 312 and the mirror 130 to thereby convert the light incident on the photographing lens 310 into the diaphragm 312, the lens mounts 306 and 106, the mirrors 130 and 132, and a photometric lens (not shown). Then, the light is incident on the photometry unit 46. Then, the system control circuit 50 measures the exposure state of the image formed as an optical image based on the output of the photometry unit 46, and performs photometry processing until it is determined that the exposure (AE) is appropriate (step S206). , S207).

  If it is determined in step S207 that the exposure (AE) is appropriate, the system control circuit 50 stores the photometric data and / or setting parameters in the internal memory or the memory 52 of the system control circuit 50 (step S207A). ).

  The system control circuit 50 determines the aperture value (Av value) and the shutter speed (Tv value) according to the exposure (AE) result detected by the photometric processing in step S206 and the shooting mode set by the mode dial switch 60. ) Is determined.

  Here, the system control circuit 50 determines the charge accumulation time in the image sensor 14 in accordance with the determined shutter speed (Tv value), and performs imaging processing with the determined charge accumulation time. In the dark capturing process, charge accumulation is performed in a time shorter than the charge accumulation time.

  Next, the system control circuit 50 determines whether or not it is necessary to irradiate the subject with illumination light based on the measurement data obtained by the photometry processing in step S206 (step S208). If necessary, an illumination flag is set and charging for irradiating illumination light is performed until charging is completed (steps S209 and S210). Then, when the charging in the illumination unit 48 is completed, this process is terminated and the process returns to the main process.

  Next, the procedure of the photographing process in step S128 of FIG. 5 will be described using the flowcharts shown in FIGS.

  The system control circuit 50 moves the mirror 130 to the mirror-up position by controlling the drive of a mirror drive unit (not shown) (step S301), and the photometry stored in the internal memory of the system control circuit 50 or the memory 52. Based on the data, the diaphragm 312 is driven to a predetermined diaphragm value via the diaphragm controller 340 (step S302). Here, communication between the system control circuit 50 and the aperture control unit 340 is performed via the interface 120, the connector 122, the connector 322, the interface 320, and the lens control circuit 350.

  The system control circuit 50 performs the charge clear operation of the image sensor 14 via the image sensor drive unit 14a (step S303), and then starts charge accumulation in the image sensor 14 (step S304). Then, the system control circuit 50 opens the shutter 12 via the shutter control unit 40 (step S305), and starts exposure of the image sensor 14 (step S306).

  And it is discriminate | determined whether the illumination flag is set, ie, it is necessary to drive the illumination part 48 and to irradiate illumination light (step S307), and when illumination light is required, it is illumination. The unit 48 is driven (light emission) (step S308).

  The system control circuit 50 waits for the exposure of the image sensor 14 to end based on the photometric data in step S206 of FIG. 7 (step S309), and when the exposure ends, closes the shutter 12 via the shutter control unit 40 (step S309). S310), the exposure of the image sensor 14 is terminated.

  Further, the system control circuit 50 drives the aperture 312 to the open aperture value via the aperture controller 340 (step S311), and moves the mirror 130 to the mirror down position via the mirror driver (not shown). (Step S312).

  Then, the system control circuit 50 determines whether or not the set charge accumulation time has elapsed (step S313). When the set charge accumulation time has elapsed, after the charge accumulation of the image sensor 14 is finished. (Step S314) A charge signal (captured image data) is read from the image sensor 14, and the captured image data is read via the A / D converter 16, the image processing circuit 20 and the memory control circuit 22, or the A / D converter. 16 is directly written into a predetermined area of the memory 30 via the memory control circuit 22 (step S315). When the series of processes described above is completed, the present process is terminated and the process returns to the main process.

  Next, the procedure of the dark capturing process in step S122 of FIG. 4 and step S131 of FIG. 5 will be described using the flowchart shown in FIG.

  The system control circuit 50 performs the charge clearing operation of the image sensor 14 via the image sensor driver 14a (step S401), and then starts the charge accumulation of the image sensor 14 with the shutter 12 closed (step S402). .

  Then, the system control circuit 50 determines whether or not a predetermined charge accumulation time has elapsed (step S403), and when the charge accumulation time has elapsed, after completing the charge accumulation of the image sensor 14 (step S404). ), A charge signal (a part of dark image data) is read out from the image sensor 14, and a part of the dark image data is read via the A / D converter 16, the image processing circuit 20 and the memory control circuit 22, or A / Data is written directly into the predetermined area of the memory 30 from the D converter 16 via the memory control circuit 22 (step S405).

  In this embodiment, charge accumulation is performed in a part of the image sensor 14 (one horizontal line or one vertical line), and the accumulated charge signal is read out. However, the charge accumulation is performed on the entire screen of the image sensor 14. It is also possible to read out the accumulated charge signal.

  In step S406, as shown in FIG. 6, the correction data stored in advance and a part of the dark image data are compared. If they match (the gain, the offset, and the inclination match), the correction data is not corrected. Exit this process. On the other hand, if the correction data and part of the dark image data do not match, the correction data is corrected based on the dark image data (step S407).

  That is, when the dark image data has a gain shift with respect to the correction data, gain correction is performed on the correction data. If the dark image data has an offset error with respect to the correction data, the correction data is offset. Further, when the dark image data is tilted with respect to the correction data, tilt correction is performed on the correction data.

  The corrected data is used when the development process is performed in a state in which the photographing process is executed first and the photographed image data is read from the image sensor 14 and written in the memory 30.

  By performing development processing using the corrected correction data, the captured image data is corrected for image quality degradation such as dark current noise generated in the image sensor 14 and pixel defects due to scratches inherent to the image sensor 14. It is possible. Thereafter, this process is terminated and the process returns to the main process.

  FIG. 11 is a diagram illustrating a flow of a photographing operation in the camera system of the present embodiment. As shown in FIG. 5A, when the correction data correction flag is set, when single shooting is performed, the SW (1) is turned on so that the AF (autofocus) operation and the AE (automatic exposure) are performed. ) Operation is performed and SW2 is turned on, so that the dark capturing process is performed after the photographing operation is performed.

  Also, as shown in FIG. 6A, when the correction data correction flag is set and the continuous shooting is performed, the SW1 is turned on to turn on the AF (autofocus) operation and AE ( (Automatic exposure) operation is performed, followed by dark capture processing. Then, when the SW2 is turned on, a plurality of shootings are continuously performed while the SW2 is turned on.

  On the other hand, when the correction data correction flag is not set and correction (horizontal dark shading correction) is performed using previously stored correction data, as shown in FIG. In any of the shootings, dark capture processing is not performed, and AF (autofocus) operation and AE (automatic exposure) operation are performed when SW1 is turned on, and then shooting is performed when SW2 is turned on. Is called.

  As described above, in the camera system according to the present embodiment, when the horizontal dark shading correction data stored in advance is selected and corrected, it is not necessary to perform the dark capturing process, and thus the shutter release time lag associated with the dark capturing process is eliminated. The release time lag prevents the photographer from missing a photo opportunity.

  Further, noise that does not change depending on shooting conditions, such as fixed pattern noise corresponding to the circuit system noise of the image sensor 14, can be corrected with correction data stored in advance. If the amount changes depending on the shooting conditions (including the shooting environment), such as image quality degradation such as pixel current loss due to dark current noise that occurs or minute flaws inherent to the image sensor, the correction data stored in advance In some cases, it cannot be corrected. In this case, whether or not the amount to be corrected differs from the previously stored horizontal dark shading correction data based on the shooting conditions such as ISO sensitivity, shutter speed, and ambient temperature in order to correct the changed noise. Judge whether or not. If the correction data is different from the correction data, a dark capturing process is performed, and the correction data is corrected using a part of the obtained dark image data, thereby preventing the image quality from deteriorating.

  Further, when the image sensor 14 has a fixed pattern noise that is small in one of the horizontal direction and the vertical direction of the image sensor and does not need to be corrected, correction data stored in advance is, for example, one-dimensional By using the horizontal dark shading correction data, the processing becomes simple and the memory for storing the correction data can be reduced.

  The above is the description of the camera system according to the first embodiment of the present invention. However, the present invention is not limited to the configuration of the present embodiment, and the function described in the claims or the present embodiment has been described. Any configuration that can achieve the functions of the configuration is applicable.

  In this embodiment, as shown in FIG. 6, correction data stored in advance is corrected, and the captured image data is corrected based on the corrected correction data. On the other hand, correction can be performed using correction data stored in advance, and correction can be performed based on a difference between correction data stored in advance and dark image data.

  In this embodiment, when horizontal dark shading correction is performed, the correction data is expanded in the memory 30 (step S115 in FIG. 4). However, image data is captured from the image sensor 14 without performing this expansion process. However, it is also possible to perform correction so that correction data is subtracted from the captured image data sequentially.

  Furthermore, in the present embodiment, the expansion process of the horizontal dark shading correction data is performed after the switch SW1 is turned on, but the correction data may be expanded when the camera system is turned on.

  The correction data is one-dimensional data in the horizontal direction of the image sensor, but may be one-dimensional data or two-dimensional data in the vertical direction. In addition, as shown in FIG. 12, both horizontal and vertical one-dimensional data are stored in the correction data development process, as shown in FIG. At the time of development, dark shading in both horizontal and vertical directions can be corrected by adjusting the correction amount for each line using one-dimensional data in the vertical direction.

  FIG. 12 is a diagram illustrating correction of captured image data using one-dimensional data in both the vertical and horizontal directions. In this case, even if the vertical direction is not stored as one-dimensional correction data, it is stored as a mathematical formula, and when developing the one-dimensional data in the horizontal direction, this formula is applied to dark the vertical direction. You may make it correct | amend shading.

  In this embodiment, the correction data is created at the time of adjustment in the production process of the camera body 100 and stored in the nonvolatile memory 56. However, the user or the like performs dark shooting (dark capturing process) at an arbitrary time. It is also possible to create the image data obtained by performing projection operations and store the created correction data.

  Furthermore, the charge accumulation time of the photographing process and the charge accumulation time of the dark capturing process can be made equal, and the photographing is performed as long as sufficient data (dark image data) for correcting dark current noise or the like is obtained. The charge accumulation time may be different from the charge accumulation time of the processing.

  In addition, during the execution of the dark capturing process in step S122 of FIG. 4 and step S131 of FIG. 5, the photographing operation cannot be performed, so the information output unit 54 and / or the image display unit 28 causes the camera body 100 to be busy. Information indicating that it is in a state can also be output (display or audio output).

  In the present embodiment, the case where the photographing operation is performed by moving the mirror 130 between the mirror up position and the mirror down position is shown. However, the mirror 130 is configured as a half mirror, and the photographing operation is performed without moving the mirror 130. May be performed.

  Furthermore, the recording media 200 and 210 are not only memory cards such as PCMCIA cards and compact flash (registered trademark), hard disks, but also micro DAT, magneto-optical disks, optical disks such as CD-R and CD-RW, DVDs and the like. It may be composed of a phase change optical disk or the like. Furthermore, the recording media 200 and 210 may be composite media in which a memory card and a hard disk are integrated. In this case, a part of the composite medium may be detachable.

  In this embodiment, the recording media 200 and 210 are separated from the camera body 100 and can be arbitrarily connected. However, any or all of the recording media remain fixed to the camera body 100. Also good. Further, the camera main body 100 may be configured such that a single or a plurality of recording media 200 and 210 can be connected.

  It goes without saying that the present invention can also be applied to a case where the present invention is achieved by supplying software program codes for realizing the functions of the above-described embodiments to a system or apparatus. In this case, the program code itself realizes the novel function of the present invention, and the program itself and the storage medium storing the program constitute the present invention.

  In this case, the program codes shown in the flowcharts of FIGS. 3 to 5 and FIGS. 7 to 10 can be stored in a ROM that is a storage medium. The storage medium for supplying the program code is not limited to the ROM, and for example, a flexible disk, a hard disk, a nonvolatile memory card, or the like can be used.

  In this embodiment, the camera system including the camera body 100 and the lens device 300 has been described. However, the present invention can also be applied to a camera in which the lens device is integrated. In this case, the lens control circuit 350 in the lens apparatus 300 is not necessary, and the overall operation of the camera is controlled by the system control circuit 50.

1 is a block diagram illustrating a configuration of a camera system that is Embodiment 1. FIG. It is a figure which shows mixing of the fixed pattern noise in a horizontal and vertical direction. It is a flowchart which shows the imaging | photography operation processing procedure of a camera system. It is a flowchart which shows the imaging | photography operation processing procedure of a camera system. It is a flowchart which shows the imaging | photography operation processing procedure of a camera system. It is a figure which shows correction | amendment of the picked-up image data by a part of horizontal dark shading correction data or dark image data. It is a flowchart which shows a focus adjustment and photometry processing procedure. It is a flowchart which shows an imaging | photography process procedure. It is a flowchart which shows an imaging | photography process procedure. It is a flowchart which shows a dark taking-in process procedure. FIG. 6 is a diagram illustrating a flow of photographing operation of the camera system in Embodiment 1. It is a figure which shows correction | amendment of the picked-up image data by the correction data in the horizontal direction and vertical direction of an image pick-up element.

Explanation of symbols

14 Image sensor 44 Temperature sensor 50 System control circuit 56 Non-volatile memory 60 Mode dial 62 SW1
64 SW2
69 ISO sensitivity setting switch 100 Camera body

Claims (12)

The first image data or a part of the first image data for obtaining the first image data is generated by photoelectric conversion in the non-exposure state, and the second is obtained by photoelectric conversion in the exposure state. An image sensor capable of generating image data of
Storage means for storing correction data for correcting the second image data;
An image pickup apparatus comprising: a correction unit that compares the first image data and the correction data and generates the second image data corrected by a correction process based on the comparison result.   2. The correction unit according to claim 1, wherein the correction unit corrects the correction data based on the first image data, and corrects the second image data based on the corrected correction data. Imaging device.   2. The imaging according to claim 1, wherein the correction unit corrects the second image data corrected by the correction data based on a comparison result between the first image data and the correction data. apparatus. Control means for controlling driving of the image sensor;
The control means drives the image sensor according to shooting conditions to generate the first image data,
When the first image data is generated, the correction unit generates the second image data corrected by a correction process based on the first image data and the correction data, and the first image data is generated. 4. The imaging apparatus according to claim 1, wherein when the data is not generated, the second image data corrected by the correction process based on the correction data is generated. 5.   5. The imaging apparatus according to claim 1, wherein the correction data is data corresponding to one of the first image data and the partial data. 6.   The imaging apparatus according to claim 5, wherein the correction data corresponding to the partial data is data obtained by projecting the first image data with respect to a specific direction of the imaging element. A first step of generating first image data or partial data for obtaining the first image data out of the first image data by photoelectric conversion by an image sensor in a non-exposure state;
A second step of generating second image data by photoelectric conversion by the imaging device in an exposed state;
A third step of comparing the first image data and correction data for correcting the second image data, and generating the second image data corrected by a correction process based on the comparison result; An imaging method characterized by comprising:   In the third step, the correction data is corrected based on the first image data, and the second image data is corrected based on the corrected correction data. The imaging method described.   The said 3rd step correct | amends the said 2nd image data corrected by the said correction data based on the comparison result of the said 1st image data and the said correction data, The said 2nd image data are corrected. Imaging method. In the first step, the first image data is generated according to shooting conditions,
In the third step, when the first image data is generated, the second image data corrected by a correction process based on the first image data and the correction data is generated, and the first image data is generated. 10. The imaging method according to claim 7, wherein when the image data is not generated, the second image data corrected by the correction process based on the correction data is generated. 11. A first step of generating first image data or partial data for obtaining the first image data out of the first image data by photoelectric conversion by an image sensor in a non-exposure state;
A second step of generating second image data by photoelectric conversion by the imaging device in an exposed state;
A third step of comparing the first image data and correction data for correcting the second image data, and generating the second image data corrected by a correction process based on the comparison result; A program that causes a computer to execute.   A recording medium comprising the program according to claim 11.

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