JP2004112529A - Camera and camera system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a photographing preparation operation is delayed, if the transmission/reception of information for the optical characteristic of a photographing lens used for image processing is performed from the photographing lens to a camera during the photographing preparation operation. <P>SOLUTION: A camera 40 comprises a detachable lens device 10 equipped with a storage means 31 for storing information about the optical characteristic of a photo-optical system. The camera 40 is provided with an image processing means 62 for conducting correction processing for an image signal outputted from an imaging device 52 using the information about the optical characteristic of the photo-optical system; and a control means 51 for conducting a photographing preparation sequence including a photometry operation and a focus alignment control of the photo-optical system, and then conducting a photographing sequence to carry out the correction processing of the image signal outputted from the imaging device 52 by the image processing means 62 and to record the result into a recording medium. As for the control means 51, the information about the optical characteristics stored in the storage means 31 is transmitted to the lens device 10 after the completion of the photographing preparation sequence. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a camera that processes an image obtained by an image sensor.
[0002]
[Prior art]
The above-mentioned camera, a so-called digital camera, basically converts an optical image formed by a photographing lens into a photoelectric conversion by an image pickup device such as a CCD (Charge Coupled Device) and performs image processing on an image signal as an output thereof. It is stored in a recording medium such as a memory card.
[0003]
Among such digital cameras, there are also digital cameras with interchangeable lenses. In an interchangeable lens camera system, lenses having various focal lengths can be freely combined and used according to the shooting conditions, and a shooting lens for a lens interchangeable camera using a film can be used in many cases.
[0004]
As described above, in a digital camera that can use various photographing lenses, a photographed image is generated by the inherent optical characteristics of the photographing lens, such as distortion (distortion aberration), shading (peripheral dimming), and chromatic aberration of magnification of the photographing lens. May not be the image intended by the photographer.
[0005]
"Distortion" refers to an aberration in which an image of an object projected through a photographic lens does not have a similar shape to the object, but is distorted, for example, in a straight line. This means that the light amount decreases in the portion and the image becomes darker. The term “chromatic chromatic aberration of magnification” means that when light from a subject is decomposed into a plurality of color lights and formed on an image forming surface, the refractive index varies depending on the wavelength. Appears as a difference in magnification and causes color shift. If there is such an aberration or the like, an image of the subject cannot be accurately captured.
[0006]
As a solution to the above-mentioned problem, Patent Literature 1 discloses a circuit for storing information on optical characteristics of a photographing lens, such as distortion information and shading information, in the photographing lens. The information on all the optical characteristics stored in the circuit is sent to the camera, and the image signal obtained from the image pickup device is corrected using the information on the optical characteristics in the camera, and the high-quality image is stored in the memory. Camera systems have been proposed.
[0007]
Further, in Patent Document 2, a circuit for storing a shading correction coefficient in a photographing lens is provided, and a camera reads the stored correction coefficient in the process of A / D converting an analog image signal obtained from an image sensor. Accordingly, a camera system that performs shading correction has been proposed.
[0008]
Further, in Patent Document 3, a storage circuit for storing information relating to chromatic aberration of magnification or distortion is provided in a taking lens, and a camera reads information from the storage circuit and corrects an image signal from an image pickup device to obtain a high-quality image. A camera system that stores in a memory has been proposed.
[0009]
Further, in Japanese Patent Application Laid-Open No. H11-163, the photographing lens is provided with a storage circuit that stores comprehensive spectral characteristic data of the photographing lens and the camera, and the camera transmits a readout command of the comprehensive spectral characteristic data to the photographing lens side, so that photographing is performed. There is also disclosed a camera system in which a lens transmits the stored total spectral characteristic data to the camera upon receiving the data, and the camera controls the white balance based on the received total spectral characteristic data.
[0010]
[Patent Document 1]
JP-A-2-123879
[Patent Document 2]
JP-A-6-197266
[Patent Document 3]
JP-A-6-292207
[Patent Document 4]
Japanese Patent Publication No. 7-83481
[0011]
[Problems to be solved by the invention]
In the camera systems proposed in each of the above publications, information on optical characteristics of a photographing lens represented by distortion, shading, chromatic aberration of magnification, and the like is stored in advance in a storage circuit provided in the photographing lens for each photographing lens. Accesses the storage circuit of the taking lens to read information, or sends all the information stored in the storage circuit of the taking lens to the camera when the taking lens is attached to the camera, and stores it. Have been.
[0012]
By the way, in the digital camera system of the interchangeable lens type, it is necessary to perform an autofocus operation or a photometric operation as an image pickup preparation operation at a timing intended by a photographer, but a quick shooting property is required. For this reason, if transmission / reception of information on the optical characteristics of the imaging lens used for image processing from the imaging lens to the camera is performed during the imaging preparation operation, the imaging preparation operation may be delayed, which may hinder quick shooting.
[0013]
Further, as the pixel pitch of the image sensor becomes smaller, a more accurate autofocus operation is required, so that a large amount of information about the optical characteristics of the photographing lens sent from the photographing lens to the camera may be required. In this case, the communication load when transmitting and receiving information on the optical characteristics of the photographing lens increases, so that it is necessary to further prevent the autofocus operation and the photometry operation from being affected.
[0014]
In addition, some of the information on the optical characteristics of the photographing lens changes in accordance with the focusing position, zooming position, and photometric value of the photographing lens. There must be.
[0015]
An object of the present invention is to provide a camera and a camera system capable of improving the quality of an image obtained by an image sensor without hindering an autofocus operation and a photometric operation.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in a camera which is detachable from a lens device provided with a storage unit for storing information on optical characteristics of a photographing optical system and which can communicate with the lens device, An image sensor that photoelectrically converts a subject image formed by the optical system; an image processing unit that corrects an image signal output from the image sensor by using information related to optical characteristics of a photographing optical system; After performing an imaging preparation sequence including focusing control of the imaging optical system, a control unit that performs an imaging sequence of correcting an image signal output from the imaging element by an image processing unit and recording the image signal on a recording medium is provided. Then, after the imaging preparation sequence is completed, the control unit causes the lens device to transmit the information on the optical characteristics stored in the storage unit.
[0017]
For example, in response to an instruction to start the imaging sequence by the imaging operation member after the end of the imaging preparation sequence, the lens device is caused to transmit information regarding the optical characteristics, or the charge accumulation in the imaging device in the imaging sequence is started. Sometimes, the lens device is made to transmit information on optical characteristics.
[0018]
As a result, the communication of information on the optical characteristics of the photographing optical system does not affect the photometric operation, focusing control, and the like in the imaging preparation sequence, and performs high-quality imaging by performing a correction process according to the optical characteristics of the photographing optical system. An image (recorded image) can be obtained.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows the configuration of a lens-interchangeable digital camera system according to an embodiment of the present invention. The camera system includes a photographing lens 10 and a digital camera 40. The taking lens 10 is a zoom lens that is detachable from the camera 40.
[0020]
In the photographic lens 10 of the present embodiment, a photographic optical system for forming a subject image includes four groups of lenses 11, 12, 13, and 14. The lens 12 is a lens for zooming, and the lens 13 is a lens for focusing. Also, an aperture unit 15 is arranged in the photographing optical system.
[0021]
A light beam from a subject (not shown) is guided to a movable mirror 41 in a camera 40 via lenses 11 and 12, an aperture unit 15 and lenses 13 and 14. Further, a zoom encoder 17, a focus encoder 18, and an aperture encoder 20 for detecting the positions of the lenses 12 and 13 and the aperture state of the aperture unit 15 are provided in the photographing lens 10, and are connected to a lens control circuit 21. Have been.
[0022]
The lens control circuit 21 is connected to a zoom drive circuit 24 for driving a zoom motor 25, a focus drive circuit 26 for driving a focus motor 27, and an aperture drive circuit 28 for driving an aperture motor 29. It operates according to a control signal from the control circuit 21.
[0023]
Further, a lens switch input circuit 30 and a nonvolatile memory (EEPROM) 31 are connected to the lens control circuit 21.
[0024]
Further, the lens control circuit 21 is provided with a communication controller 21a for communicating with the camera 40 via the communication line 32 and the communication contact 33.
[0025]
The lens control circuit 21 controls the zoom motor 25 via the zoom drive circuit 24 to drive the lens 12. The initial position and the stop position of the lens 12 are detected by counting pulse signals output from the zoom encoder 17 according to the movement of the lens 12. Then, the zoom motor 25 is feedback-controlled using the detected position information.
[0026]
Further, the lens control circuit 21 controls the focus motor 27 via the focus drive circuit 26 to drive the lens 13. The initial position and the stop position of the lens 13 are detected by counting pulse signals output from the focus encoder 18 according to the movement of the lens 13. Then, feedback control of the focus motor 27 is performed using the detected position information.
[0027]
Further, the lens control circuit 21 controls the operation of the aperture unit 15 via the aperture drive circuit 28. The initial state and the aperture position of the aperture unit 15 are detected by counting pulse signals output from the aperture encoder 20 according to the operation state of the aperture unit 15. Then, the aperture motor 29 is feedback-controlled using the detected operation state information.
[0028]
In this manner, the lens control circuit 21 controls the zoom drive circuit 24, the focus drive circuit 26, and the aperture drive circuit 28 based on the outputs of the zoom encoder 17, the focus encoder 18, and the aperture encoder 20, and performs the overall control. Performs various calculations and other processes necessary for the operation. The lens control circuit 21 communicates with the camera 40 as needed via the communication controller 21 a, the communication line 32, and the communication contact 33 to reflect the control of each circuit in the photographing lens 10 and a photographing lens described later. The information is transmitted to the information camera 40 indicating information on the optical characteristics of the camera 10 and the state of the photographing lens 10.
[0029]
The non-volatile memory 31 stores information on the optical characteristics of the photographic optical system unique to the photographic lens 10, specifically, information on distortion, information on shading, information on chromatic aberration of magnification, and the like. Is stored in accordance with. Note that the information regarding the unique optical characteristics of the photographing lens 10 may be any information as long as the information is used for a correction process in an image processing process of an image captured by the camera 40.
[0030]
The non-volatile memory 31 also stores information on optical characteristics necessary for focusing control that is different from or partially overlaps with the information on optical characteristics used in the above-described image processing.
[0031]
The information indicating the state of the photographing lens 10 is information such as the state of various lens switches, the lens position obtained through the encoders, and the aperture state.
[0032]
The lens switch input circuit 30 transmits the state of a switch (not shown) provided on the taking lens 10 to the lens control circuit 21. In the present embodiment, a switch provided on the photographing lens 10 has a zoom selection switch for setting the zoom state to tele, middle, and wide, and when the photographer operates the zoom selection switch, The lens control circuit 21 detects the operation via the lens switch input circuit 30 and controls the zoom motor 25 via the zoom drive circuit 24 to move the lens 12 so as to attain the selected zoom state.
[0033]
Next, the configuration of the camera 40 will be described. The subject light that has passed through the taking lens 10 is incident on a movable mirror 41 whose central portion is a half mirror. On the center rear side of the movable mirror 41, a sub-mirror 42 that reflects a light beam transmitted through the movable mirror 41 is provided. The light beam reflected downward by the sub-mirror 42 is separated into two light beams by the separator optical system 43, and two images are formed on a pair of CCD line sensors 44. The separator optical system 43 and the CCD line sensor 44 constitute a focus detection unit for detecting the focus adjustment state (focus detection) of the photographing optical system.
[0034]
The signal photoelectrically converted and output by the CCD line sensor 44 is input to a focus detection circuit 57. The focus detection circuit 57 detects a phase difference between the two images formed on the pair of CCD line sensors 44, and detects the detection result. Is input to the camera control circuit 55. The camera control circuit 55 calculates the amount of defocus (the amount of defocus) of the imaging optical system based on the input signal representing the phase difference. That is, focus detection is performed by the phase difference detection method. Then, the camera control circuit 55 transmits information indicating the calculated defocus amount to the lens control circuit 21 via the communication controller 55a, the communication line 65, and the communication contact 66 provided in the camera control circuit 55.
[0035]
The lens control circuit 21 obtains a drive amount of the lens 13 (that is, the focus motor 27) necessary for obtaining focus based on the received information of the defocus amount, and drives the focus motor 27 by the drive amount. I do. Thereby, automatic focusing control is performed.
[0036]
In the present embodiment, the case where the defocus amount information is transmitted from the camera control circuit 55 to the lens control circuit 21 is described. The driving amount of the lens 13 may be determined based on the information, and information on the determined driving amount may be transmitted to the lens control circuit 21. In this case, the camera control circuit 55 captures the optical characteristic information of the photographing lens 10 necessary for calculating the driving amount of the lens 13 by initial communication at the time when the photographing lens 10 is mounted on the camera 40, and stores it in a memory (FIG. (Not shown).
[0037]
On the other hand, a focusing plate 46, a pentaprism 47, and an eyepiece optical system 48 that constitute a finder optical system are arranged on the optical path of the object mirror reflected by the movable mirror 41. Further, behind the movable mirror 41, a shutter 50, an optical low-pass filter 51, and an image sensor 52 are arranged. The imaging element 52 is configured by a CCD, a CMOS sensor, or the like, and photoelectrically converts a subject image formed on a light receiving surface and outputs an image signal. The image sensor 52 is driven and controlled by an image processing circuit 62 that has received an imaging command from a camera control circuit 55.
[0038]
When the movable mirror 41 moves up and the shutter 50 opens, a subject image is formed on the image sensor 52, and the accumulation of electric charges in the image sensor 52 is started. Then, when the charge accumulation ends, the shutter 50 closes.
[0039]
A mirror drive circuit 56, a line sensor drive circuit 57, a focus detection circuit 69, a shutter drive circuit 58, a photometric sensor drive circuit 59, an image processing circuit 62, and a strobe circuit 63 are connected to the camera control circuit 55. It controls the operation of the circuit. Further, a shutter detection circuit 61 and a switch input circuit 64 are connected to the camera control circuit 55.
[0040]
The mirror drive circuit 56 drives the movable mirror 41 to move forward and backward with respect to the imaging optical path. When the movable mirror 41 is in the photographing optical path, the subject light flux is guided to the finder optical system, and when the movable mirror 41 retreats from the photographing optical path, the subject light flux is guided to the image sensor 52.
[0041]
The line sensor driving circuit 57 drives the line sensor 44. The shutter drive circuit 58 drives a shutter 50 for controlling the amount of light received by the image sensor 52. Further, a photometric sensor 60 for measuring the brightness of the subject is provided near the ender prism 47 and the eyepiece optical system 48. The photometric sensor 60 is driven by a photometric sensor drive circuit 59. The output from the photometric sensor 60 is input to the camera control circuit 55, and the camera control circuit 55 calculates the brightness of the subject light based on the input signal. The shutter detection circuit 61 detects the open / closed state of the shutter 50.
[0042]
The image processing circuit 62 converts the image signal (analog signal) output from the image sensor 52 into a digital signal, and then performs the above-described correction processing using the information on the optical characteristics of the photographing lens 1. An image corresponding to the image signal on which the correction process has been performed is recorded on a recording medium (not shown) detachably mounted on the camera 40 (semiconductor memory, magnetic disk, optical disk, or the like). Details of the image processing circuit 62 will be described later.
[0043]
The strobe circuit 63 drives a light emitting unit (not shown) for illuminating the subject. The switch input circuit 64 detects the state of various operation switches provided on the camera 40 and inputs a detection signal to the camera control circuit 55.
[0044]
As an operation switch on the camera 40 side, there is a release switch. The release switch outputs a SW1ON signal for starting an imaging preparation operation sequence described later by a one-step pressing operation, and outputs a SW2ON signal for starting an imaging sequence described later by a further pressing operation.
[0045]
As an operation switch on the camera 40 side, there is a mode switch, and by operating this mode switch (in accordance with the number of operations), the camera control circuit 55 sets the imaging mode (aperture priority mode, shutter speed priority mode, program mode, etc.). Set.
[0046]
Further, the camera 40 is provided with a power supply 68. The power supply 68 supplies power to each circuit in the camera 40 and also supplies power to the photographing lens 10 via the communication contact 66.
[0047]
FIG. 2 shows a configuration of the image processing circuit 62 described above. The image processing circuit 62 includes a control unit 71, an A / D conversion unit 72, an image processing unit 73, a buffer memory unit 74, an external recording unit 75, and a correction value memory unit 76. You. The image processing unit 73, the buffer memory unit 74, the external recording unit 75, and the correction value memory unit 76 are connected by a common data bus 77, and have a configuration in which data can be exchanged. Further, the operations of the A / D conversion section 72, the image processing section 72, the buffer memory section 74, the external recording section 75, and the correction value memory section 76 are controlled by the control section 71 which has received a control signal from the camera control circuit 55. You. The control unit 71 also controls the driving of the image sensor 52.
[0048]
In FIG. 2, an analog image signal output from the image sensor 52 is converted into a digital signal by an A / D converter 72 and input to an image processor 73. The control unit 71 causes the correction value memory unit 76 to temporarily store information (hereinafter, referred to as correction data) regarding the optical characteristics of the photographing lens 10 transmitted from the photographing lens 10 side. The image processing unit 73 performs various correction processes such as distortion correction, shading correction, and color correction on the digital image signal input from the A / D conversion unit 72 using the correction data stored in the correction value memory unit 76. And performs processing such as image compression.
[0049]
Then, the image signal processed by the image processing unit 73 is stored in the buffer memory unit 74, and further transferred to the external recording unit 75, and the recording medium detachably attached to the camera 40 described above. Recorded in.
[0050]
Next, the operation of the camera 40 (mainly the camera control circuit 55) in the present embodiment will be described with reference to the flowchart of FIG. When a power switch (not shown) is turned on, the camera control circuit 55 starts operating.
[0051]
[Step (shown as S in the figure) 101]
The camera control circuit 55 determines whether or not the SW1ON signal has been input from the switch input circuit 64. If the input has been made, the process proceeds to the next step 102 to enter an imaging preparation sequence. If not, the process returns to step 101.
[0052]
[Step 102]
If SW1 is ON, the camera control circuit 55 activates the photometric sensor driving circuit 59, and outputs the output from the photometric sensor 60 and the F number of the photographing lens 10 (the F number of the lens control circuit 21 according to the ON of the power switch). (Obtained in the initial communication), the shutter speed and the aperture value used in the imaging sequence described later are determined.
[0053]
[Step 103]
Next, the camera control circuit 55 activates the line sensor drive circuit 57 and the focus detection circuit 69, and calculates a defocus amount based on an output obtained from the focus detection circuit 69.
[0054]
[Step 104]
The camera control circuit 55 transmits information indicating the defocus amount calculated in step 103 to the lens control circuit 21 as a focus drive command.
[0055]
[Step 105]
When the camera control circuit 55 receives from the lens control circuit 21 that the driving of the lens 13 has been completed, the camera control circuit 55 calculates the defocus amount again based on the output from the focus detection circuit 69, and calculates the defocus amount. It is determined whether or not it is within a predetermined allowable range (that is, whether or not focus has been achieved). If it is not focused, the process returns to step 101 again, and if it is focused, the process proceeds to the next step 106. The imaging preparation sequence ends with this in-focus determination.
[0056]
[Step 106]
After the imaging preparation sequence ends, the camera control circuit 55 determines whether or not the SW2ON signal has been input from the switch input circuit 64. If it has not been input, the process returns to step 101. If it has been input (if the start of the imaging sequence is instructed), the process enters the imaging sequence and proceeds to step 107.
[0057]
[Step 107]
The camera control circuit 55 transmits, to the lens control circuit 21, a communication command requesting transmission of correction data relating to the optical characteristics of the photographing lens 10 used for image processing in the image processing circuit 62. Here, the correction data requested to be transmitted by the communication command may be a part of the various correction data described above, or may be data corresponding to the aperture value determined in step 102 or the positions of the lenses 12 and 13. Good. Thus, the amount of transmission and reception of the correction data can be suppressed to a necessary minimum. In this case, the communication command may be different depending on the type of correction data requested, or may include information indicating the aperture value determined in step 102.
[0058]
The camera control circuit 55 receives the correction data transmitted from the lens control circuit 21 having received the communication command, and stores the correction data in the correction value memory unit 76 (see FIG. 2) in the image processing circuit 62.
[0059]
[Step 108]
Next, the camera control circuit 55 transmits an aperture drive command for driving the aperture unit 15 to the aperture value determined in step 102 to the lens control circuit 21.
[0060]
[Step 109]
Next, the camera control circuit 55 causes the movable mirror 41 to perform an up operation through the mirror driving circuit 56.
[0061]
[Step 110]
Next, the camera control circuit 55 operates the shutter 50 through the shutter drive circuit 58 at the shutter speed determined in step 102. In addition, at the same time as the shutter opening operation, the control unit 71 of the image processing circuit 62 starts the charge accumulation by the photoelectric conversion in the image sensor 52.
[0062]
[Step 111]
When the operation of the shutter 50 is completed (the charge accumulation in the image sensor 52 is completed), the camera control circuit 55 transmits a command to drive the aperture unit 15 to the open state to the lens control circuit 21.
[0063]
[Step 112]
Next, the camera control circuit 55 causes the movable mirror 41 to perform a down operation through the mirror drive circuit 56, and then returns to step 101.
[0064]
In the present embodiment, a case has been described in which the photographing lens 10 is requested to transmit correction data necessary for image processing in response to the start of the imaging sequence (input of SW2ON) and receives the correction data. When a plurality of types of correction data are requested, a command for requesting transmission of all types of correction data may be transmitted in step 107, and the correction data may be collectively received. The correction data may be requested or received at any timing until the operation of step 109 is completed.
[0065]
Next, the operation of the taking lens 10 (mainly the lens control circuit 21) will be described with reference to the flowchart of FIG.
[0066]
When the power supply from the camera 40 is started, the lens control circuit 21 is activated. From step 201 onward, the lens control circuit 21 analyzes a switch operation on the photographing lens 10 and an instruction transmitted from the camera control circuit 55. A drive control process for the lens and the like and an information transmission process are performed according to the result.
[0067]
[Step 201]
The lens control circuit 21 determines whether or not a signal (zoom selection signal) from a zoom selection switch for changing the focal length is input from the lens switch input circuit 30. If it has been input, the process proceeds to step 202, and if it has not been input, the process proceeds to step 203.
[Step 202]
The lens control circuit 21 compares the zoom state (tele, middle, or wide) corresponding to the zoom selection signal from the zoom selection switch with the current zoom state. The lens 12 (zoom motor 25) is driven so as to be in a corresponding zoom state. Thereafter, the process returns to step 201.
[0068]
[Step 203]
The lens control circuit 21 determines whether or not the command transmitted from the camera control circuit 55 is a command to request transmission of correction data relating to optical characteristics of the photographing lens 10 used for image processing. If it is a correction data transmission request command, the process proceeds to step 204; otherwise, the process proceeds to step 205.
[0069]
[Step 204]
When the lens control circuit 21 determines that the command is a request for transmission of correction data, the lens control circuit 21 further analyzes which type of correction data the transmission request command requires, and determines whether the correction data stored in the non-volatile memory 31 is correct. The requested correction data is transmitted to the camera control circuit 55. Thereafter, the process returns to step 201.
[0070]
[Step 205]
The lens control circuit 21 determines whether the command transmitted from the camera control circuit 55 is a focus drive command. If it is a focus drive command, the process proceeds to step 206; otherwise, the process proceeds to 207.
[0071]
[Step 206]
The lens control circuit 21 relates to the defocus amount information included in the focus drive command and the optical characteristics of the photographing lens 10 necessary for determining the drive amount of the lens 13 (focus motor 27) stored in the nonvolatile memory 31. The drive amount of the lens 13 (focus motor 27) is calculated based on the information (as described above, information that is different from or partially overlapped with the correction data used for image processing), and the focus motor corresponding to the calculated drive amount is calculated. 27 is performed. Thereafter, the process returns to step 201.
[0072]
[Step 207]
The lens control circuit 21 determines whether the command transmitted from the camera control circuit 55 is an aperture drive command. If it is an aperture drive command, the flow proceeds to step 208; otherwise, the flow proceeds to step 209.
[0073]
[Step 208]
The lens control circuit 21 drives the aperture unit 15 according to the aperture drive command so that the aperture value is included in the command. Thereafter, the process returns to step 201.
[0074]
[Step 209]
Here, processing corresponding to instructions other than the above-described instructions and processing for lens control are performed, and the process returns to step 201.
[0075]
As described above, according to the present embodiment, at the start timing of the imaging sequence after the imaging preparation sequence of the camera 40 ends (in response to the input of the SW2ON signal), the image signal acquired in the imaging sequence is Since the correction data relating to the optical characteristics unique to the photographing lens 10 used for the image processing is transmitted and received, the camera control circuit 55 increases the load for requesting and receiving the correction data in the imaging preparation sequence. A high-quality captured image (recorded image) can be obtained without any influence on the focusing control and the photometric operation (i.e., without delay of the imaging preparation sequence).
[0076]
In the present embodiment, the case where the transmission / reception timing of the correction data between the camera and the lens is set as the start timing of the imaging sequence is described. However, the timing of starting the charge accumulation in the imaging element 52 may be set. Further, after the end of the imaging preparation sequence, the request and the reception of the correction data may be performed without waiting for the input of SW2ON (that is, before entering the imaging sequence).
[0077]
In addition, when the correction data is only data corresponding to the positions of the lenses 12 and 13 that perform zooming and focusing, the correction data may be requested and received when the positions of the lenses 12 and 13 are determined. .
[0078]
【The invention's effect】
As described above, according to the present invention, the communication of the information on the optical characteristics of the imaging optical system does not affect the photometric operation, focusing control, and the like in the imaging preparation sequence. A high-quality captured image (recorded image) that has been subjected to the correction processing can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a digital camera system according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of an image processing circuit of the digital camera system.
FIG. 3 is a flowchart showing an operation of a camera control circuit 55 of the digital camera system.
FIG. 4 is a flowchart showing an operation of a lens control circuit of the digital camera system.
[Explanation of symbols]
10 Shooting lens
11-14 lens
15 Aperture unit
17 Zoom encoder
18 Focus encoder
20 Aperture encoder
21 Lens control circuit
24 Zoom drive circuit
26 Focus drive circuit
28 Aperture drive circuit
30 Lens switch input circuit
31 Non-volatile memory
40 camera
41 Movable mirror
42 submirror
43 Separator optical system
44 line sensor
50 shutter
51 Optical low-pass filter
52 Image sensor
62 Image processing circuit

Claims (5)

A camera that is detachable from a lens device including a storage unit that stores information on optical characteristics of a photographing optical system and is capable of communicating with the lens device,
An image sensor that photoelectrically converts a subject image formed by the imaging optical system;
Image processing means for correcting the image signal output from the image sensor using information on the optical characteristics of the imaging optical system,
After performing an imaging preparation sequence including a photometric operation on a subject and focusing control of the imaging optical system, an imaging sequence in which an image signal output from the imaging element is corrected by the image processing unit and recorded on a recording medium is performed. A camera for transmitting information on the optical characteristics stored in the storage unit to the lens device after the end of the imaging preparation sequence. An imaging operation member for instructing the start of the imaging sequence,
2. The apparatus according to claim 1, wherein the control unit causes the lens device to transmit information on optical characteristics stored in the storage unit in response to an instruction to start the imaging sequence by the imaging operation member. 3. camera. The control means causes the lens device to transmit information on the optical characteristics stored in the storage means when the charge accumulation in the image pickup device is started in the image pickup sequence. 2. The camera according to 1. 4. The image processing apparatus according to claim 1, wherein the image processing unit includes at least one of information on distortion, information on shading, and information on chromatic aberration of magnification as information on optical characteristics used for image processing. Camera described. 5. A camera comprising: the camera according to claim 1; and a lens device removably mounted on the camera, the lens device including storage means for storing information on optical characteristics of a photographing optical system. Characterized camera system.

Images