JP2012088642A - Image pickup apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve insufficient light intensity when performing an electronic front curtain imaging after performing a shift movement in a case where a TS lens is mounted on an image pickup device including an electronic front curtain shutter.SOLUTION: This image pickup apparatus includes: shift amount component calculation means that determine a shift direction by rotating, by revolving means, at least a part of a photographic lens about an optical axis and calculates a shift amount component H in a shutter travel direction out of the shift amount of shift means; calculation means of an emission pupil distance P for calculating a corrected emission pupil distance P based on photographic lens information and the shift amount component H; and electronic front curtain scan calculation means for calculating a scanning pattern of an electronic front curtain scan based on the calculated corrected emission pupil distance P.

Description

  The present invention relates to an imaging apparatus, and more particularly to an imaging apparatus that performs an imaging operation using a mechanical shutter and an electronic shutter together and a control method thereof.

  Some conventional single-lens reflex digital cameras perform an imaging operation using both a mechanical shutter and an electronic shutter.

  In this case, a mechanical shutter is configured as a rear curtain, and photographing is performed by driving an electronic shutter that performs an operation for starting charge accumulation in an image sensor prior to the running of the rear curtain.

  In addition, when performing an imaging operation using an electronic shutter, for example, in an imaging device using a CMOS sensor, first, the accumulated charge amount of the pixel is set to zero for each pixel or for each region (for example, each line) composed of a plurality of pixels. Reset scanning is performed.

  Thereafter, by performing scanning for reading out a signal after a predetermined time has elapsed for each pixel or area for which reset scanning has been performed, an imaging operation using an electronic shutter can be realized.

  Hereinafter, such an imaging operation is referred to as electronic front curtain scanning.

  In Patent Document 1, when exposure of an image sensor is controlled using both an electronic shutter and a mechanical shutter, first, for each pixel in the traveling direction of the mechanical shutter, or for each area (for example, each line) composed of a plurality of pixels of the image sensor. The pixel is reset (scanning to reduce the accumulated charge amount of the pixel to zero), and charge accumulation is started.

  Then, after a predetermined time has elapsed, the light to the image sensor is sequentially shielded by the trailing shutter of the mechanical shutter, and then readout scanning is performed to sequentially read out the charges accumulated in each pixel.

  Therefore, it is disclosed that the electronic front curtain scanning of the electronic shutter is adapted to the running characteristics of the rear curtain of the mechanical shutter.

  Hereinafter, such a configuration of electronic front curtain scanning of the electronic shutter and rear curtain traveling of the mechanical shutter is referred to as an electronic front curtain shutter.

  In Patent Document 2, a single-lens reflex type digital camera can generally replace a photographic lens. However, when a photographic lens having a shift mechanism (hereinafter referred to as a “shift lens”) is used, a shutter depending on the shift amount is used. The shift amount component in the traveling direction is different, and the light shielding position on the imaging surface by the mechanical shutter changes.

  In particular, when the exposure time from when the electronic front curtain is scanned to when the light is shielded by the mechanical shutter is short, exposure unevenness occurs in the shutter traveling direction according to the focal length, exit pupil position, and the like of the mounted photographic lens.

  Accordingly, it is disclosed that the scanning pattern for the electronic front curtain is set according to the shift amount component in the shutter traveling direction.

Japanese Patent Laid-Open No. 11-41523 JP 2007-053742 A

  The electronic front curtain shutter disclosed in the above-mentioned Japanese Patent Application Laid-Open No. H10-260260 performs a reset scan and a charge accumulation start scan on the image sensor prior to the rear curtain travel of the mechanical shutter, and performs a charge readout scan after the rear curtain travel.

  Therefore, it is disclosed that the electronic front curtain scanning of the electronic shutter is adapted to the running characteristics of the rear curtain of the mechanical shutter.

  However, the distance in the optical axis direction between the electronic front curtain that scans the image sensor and the rear curtain of the mechanical shutter is longer than that of the mechanical shutter of the front curtain and rear curtain.

  For this reason, when a photographic lens having a shift mechanism is used, an error occurs between the position of the light-shielding blade of the rear curtain and the light-shielding position on the image sensor, and uneven exposure occurs.

  In addition, in the above-mentioned Japanese Patent Application Laid-Open No. 2005-228867, when a photographing lens having a shift mechanism is used in a single-lens reflex type camera that performs an image pickup operation of an electronic front curtain shutter, a scanning pattern for electronic front curtain scanning based on the shift amount. It is disclosed that exposure unevenness is reduced by setting.

  However, with respect to the setting method of the scanning pattern of the electronic front curtain scanning, it is necessary to store a plurality of scanning patterns, and the capacity of the information storage unit of the camera is required.

  Further, no consideration is given to revolving that rotates at least a part of the photographing lens with respect to the optical axis with respect to the image sensor.

  Therefore, if the scanning pattern of the electronic front curtain scan is set according to the shift amount without considering revolving, exposure unevenness in the shutter traveling direction that does not occur originally will occur.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electronic front curtain scanning correction method capable of reducing exposure unevenness in the shutter traveling direction when a photographing lens having a revolving mechanism and a shift mechanism is used. .

  An image sensor composed of a plurality of pixels, an information storage unit for storing a plurality of coefficients for calculating the corrected exit pupil distance P, shutter means for shielding the image sensor, and start of shielding of the image sensor by the shutter means Prior to this, at least a part of the photographing lens unit is shifted in a direction perpendicular to the optical axis, and the electronic front curtain scanning unit that sequentially resets the pixels of the image sensor in the traveling direction of the shutter unit and starts charge accumulation. In the imaging device used by mounting the detachable lens unit having a shift unit that rotates, and a revolving unit that rotates at least a part of the lens unit including the shift unit about the optical axis, the photographing is performed by the revolving unit. Rotate at least part of the lens around the optical axis, determine the shift direction, and A shift amount component calculating means for calculating a shift amount component H in the shutter travel direction of the step shift amount, a corrected exit pupil distance calculating means for calculating a corrected exit pupil distance P based on individual lens information, and the calculation An image pickup apparatus and a control method comprising electronic front curtain scanning calculation means for calculating electronic front curtain scanning based on the corrected exit pupil distance P.

  According to the present invention, when a photographing lens having a revolving mechanism and a shift mechanism is attached to a single-lens reflex type camera having an electronic front curtain shutter, the calculation coefficient of the corrected exit pupil distance P determined based on photographing lens information The corrected exit pupil distance P optimum for the individual information of the lens is calculated from the shift amount component H based on the shift amount and the revolving angle. Then, a scanning pattern of electronic front curtain scanning is calculated based on the corrected exit pupil distance P. From the above, it is possible to reduce the exposure unevenness in the shutter running direction without storing a large amount of the corrected exit pupil distance P for each shift amount and revolving angle.

1 is a block diagram showing a configuration of an imaging system in an embodiment. The front view which looked at the image sensor and shutter in an embodiment from the photographic subject side. 6A and 6B illustrate a change in a charge accumulation region according to a positional relationship between a shift lens and a shutter. The figure which shows the relationship between the scanning curve of the electronic front curtain in the different shift amount, and the running curve of a mechanical rear curtain. 6 is a flowchart illustrating a shooting operation of the imaging apparatus according to the embodiment. The block diagram which shows the function structure for calculating the correction | amendment exit pupil distance P in order to determine the scanning pattern of the electronic front curtain scan in embodiment. The flowchart which shows the process which determines the correction | amendment exit pupil distance P in 1st Embodiment. The figure for demonstrating the shift amount component of the shutter traveling direction in 1st Embodiment. The flowchart which shows the process which determines the calculation coefficient of the correction | amendment exit pupil distance P in 1st Embodiment. The flowchart which shows the process which determines the correction | amendment exit pupil distance P in 2nd Embodiment. The flowchart which shows the process which determines the calculation coefficient of the correction | amendment exit pupil distance P in 2nd Embodiment. The flowchart which shows the process which determines the correction | amendment exit pupil distance P in 3rd Embodiment. The flowchart which shows the process which determines the calculation coefficient of the correction | amendment exit pupil distance P in 3rd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing a configuration of an imaging system according to the first embodiment of the present invention.

  The imaging system according to the first embodiment includes a camera main body 100 that is an imaging device, and a detachable lens unit 101 that is attached to the camera main body 100 and serves as an imaging optical unit.

  First, the configuration in the lens unit 101 will be described.

  Reference numeral 114 denotes a photographic lens, which is represented as one lens in FIG. 1, but actually includes a plurality of lenses such as a focus lens and a zoom lens.

  The lens CPU 115 controls the driving of the photographing lens 114 via the lens driving circuit 116 and also drives the diaphragm 117a via the diaphragm driving circuit 117 to control the diaphragm according to the subject brightness during the photographing operation.

  A lens shift mechanism 118 moves at least a part of the lens unit 101 including at least one lens of the photographing lens 114 in a predetermined direction orthogonal to the optical axis of the lens unit 101.

  By operating an operation unit (not shown) provided in the lens shift mechanism 118, at least a part of the lens unit 101 can be shifted.

  The shift amount is detected by the shift amount detection circuit 119 and sent to the lens CPU 115.

  Reference numeral 120 denotes a revolving mechanism. By operating an operation unit (not shown) provided in the revolving mechanism 120, at least a part of the lens unit 101 can be rotated.

  The rotation angle (hereinafter referred to as “revolving angle”) is detected by the revolving angle detection circuit 121 and sent to the lens CPU 115.

  By the rotation by the revolving mechanism 120 and the shift by the lens shift mechanism 118, at least a part of the lens unit 101 can be shifted to an arbitrary position on a plane orthogonal to the optical axis.

  The lens CPU 115 can communicate with a camera CPU 113 in the camera body 100 described later via a communication contact 122 on the lens unit 101 side and a communication contact 123 on the camera body 100 side.

  The lens CPU 115 notifies the lens information in response to a request from the camera CPU 113 via the communication contacts 122 and 123.

  The photographing lens information is, for example, individual information of the lens unit 101, aperture value, focal length, focal position (focus position), photographing distance, exit pupil distance, lens shift mechanism shift direction, shift amount, and revolving angle. is there.

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

  When the imaging apparatus is in a non-photographing state (the state shown in FIG. 1), a part of the subject light flux that has passed through the photographing lens 114 and the diaphragm 117 of the lens unit 101 is reflected by the mirror 102 located in the photographing optical path. The light is reflected and guided to the finder optical unit 103.

  Thus, the photographer can observe the subject image via the finder optical unit 103.

  When a release button (not shown) to be described later is pressed to shift from the non-photographing state to the photographing state, the mirror 102 is retracted from the photographing optical path.

  As a result, the subject light flux from the lens unit 101 travels to the image sensor 104 constituted by a CMOS sensor, CCD, or the like.

  Each pixel of the image sensor 104 photoelectrically converts the subject optical image formed by the lens unit 101 according to the amount of light while being exposed, and accumulates the obtained charges.

  A scanning clock (horizontal drive pulse) or a predetermined control pulse is supplied from the pulse generation circuit 107 to the image sensor 104.

  Of the scanning clock generated by the pulse generation circuit 107, the vertical scanning clock is modulated to a predetermined clock frequency by the vertical drive modulation circuit 108 and input to the image sensor 104.

  The vertical drive modulation circuit 108 determines the scanning pattern of the electronic front curtain.

  The pulse generation circuit 107 also outputs a clock signal to a signal processing circuit 109 described later.

  A mechanical shutter 105 is disposed on the object side (lens side) with respect to the image sensor 104.

  The mechanical shutter 105 has a rear curtain composed of a plurality of light shielding blades (hereinafter referred to as “mechanical rear curtain”), and shields the image sensor 104 from light.

  The camera CPU 113 controls driving of the mechanical shutter 105 via the shutter driving circuit 106.

  The signal processing circuit 109 performs image processing by performing double correlation sampling processing (CDS), gain (AG) processing, and predetermined processing (color processing, gamma correction, etc.) on the signal read from the image sensor 104. Generate data.

  The generated image data is output to the display device 151 via the image display circuit 110 and displayed as a photographed image or recorded in the image recording circuit 111.

  The switch unit 112 is a switch for controlling ON / OFF of the main power supply, a switch operated to set shooting conditions, and a switch (release button) operated to start a shooting preparation operation and a shooting operation. including.

  A shooting preparation operation (photometry operation, focus adjustment operation, etc.) is started by half-pressing the release button (switch SW1 is turned ON).

  Further, a photographing operation (exposure of the image sensor 104, reading of a charge signal, and recording of image data obtained by processing the charge signal on a recording medium) is started by a full press operation (ON of the switch SW2).

  The camera CPU 113 performs an operation according to the operation of the switch unit 112.

  The information storage unit 150 stores a plurality of types of coefficients of an expression for calculating a corrected exit pupil distance P as described later.

  The camera body 100 according to the present embodiment having the above-described configuration is an electronic tip that is an electronic shutter that sequentially resets the pixels of the image sensor 104 and starts charge accumulation instead of the front curtain that is normally configured by a plurality of light shielding blades. An electronic front curtain shutter with curtain and mechanical rear curtain is adopted.

  The exposure control of the image sensor 104 is performed using an electronic front curtain shutter.

  FIG. 2 is a front view showing a state in which the image sensor 104 and the mechanical rear curtain are observed from the lens side along the optical axis direction, and the electronic front curtain scanning and mechanical mechanism after shooting is started by pressing the release button. This shows the state when the trailing curtain is running.

  An arrow 1 indicates the scanning direction of the electronic front curtain and the traveling direction of the mechanical rear curtain.

  Note that the subject image formed on the imaging surface of the image sensor 104 by the photographing lens 114 is inverted upside down.

  Therefore, by performing electronic front curtain scanning from the lower side to the upper side of the imaging surface as shown in FIG. 2, the electronic front curtain scan and the mechanical rear curtain travel from the upper part of the image to the lower part of the image.

  In FIG. 2, reference numeral 2 denotes an image pickup surface of the image pickup element 104, 3 denotes a mechanical rear curtain of the mechanical shutter 105, and a state where the mechanical rear curtain 3 blocks a part of the image pickup surface 2 is shown.

  Reference numeral 4 denotes a line (reset line) on which reset scanning is performed in the image sensor 104.

  The reset scanning is to make the accumulated charge amount of the pixels on the reset line 4 zero, and the reset line 4 corresponds to the tip of the electronic front curtain.

  A region 6 formed by a slit between the reset line 4 and the tip 5 of the mechanical rear curtain 3 is a region (charge accumulation region) where charge accumulation by exposure is performed in the image sensor 104.

  The charge storage area 6 moves in the direction of the arrow 1 as the electronic front curtain and the mechanical rear curtain 3 travel.

  The time from when the reset line 4 passes, that is, from when the pixel is reset to when the light is blocked by the mechanical rear curtain 3, is the charge accumulation time due to pixel exposure.

  As described above, since the reset line 4 scans in the direction of the arrow 1 and charge accumulation of each line is started, the charge accumulation start timing is different for each line of the image sensor 104.

  In the example shown in FIG. 2, the charge accumulation operation is performed at the earliest timing on the lowermost line on the imaging surface 2, and the charge accumulation operation is performed at the latest timing on the uppermost line.

  The movement of the reset line 4 from the lower part to the upper part of the imaging surface 2 is controlled by the vertical drive modulation circuit 108 as described later with reference to FIGS. 4 (a) and 4 (b).

  The movement pattern of the reset line 4 is referred to as a “scanning pattern”. This scanning pattern can be said to indicate the timing at which reset scanning is performed for each line of the image sensor 104.

  The information storage unit 150 stores a plurality of calculation coefficients for the corrected exit pupil distance P for executing such a scanning pattern.

  The camera CPU 113 selects one of these, and controls the vertical drive modulation circuit 108 so that the reset line 4 moves based on the selected coefficient formula and the information of the lens CPU 115.

  Details of the processing for determining the coefficient of the expression for the exit pupil distance P will be described later.

  FIG. 3 is a cross-sectional view showing the relationship between the photographing lens 114, the mechanical shutter 105, and the image sensor 104 in the present embodiment.

  In FIG. 3, the shutter travel of (a) and (b) is upward, and the lens 114a indicated by the solid line is at the reference optical axis position without being shifted (the shift amount is zero). 114 is shown.

  A lens 114b indicated by a broken line indicates the photographing lens 114 in the case where the lens 114b is shifted by the shift amount y from the reference optical axis position in the same direction as the traveling direction of the mechanical shutter 105.

  Reference numeral 105-1 denotes a shutter base plate, and 105-2 denotes a shutter blade presser.

  FIG. 3A shows a state in which the electronic front curtain shutter starts to open in the photographing operation.

  The slit width C indicates the width of a region where the light beam that has passed through the lens 114a having a shift amount of zero is limited by the line shielded by the line 105-3 and the reset line 4 and enters the imaging surface 2.

  The slit width D is a width of a region in which the light beam transmitted through the lens 114b whose shift amount is y is limited by the line that is shielded by the mechanical rear curtain 105-3 and the reset line 4, and is incident on the imaging surface 2. Is shown.

  At the timing of FIG. 3A, the slit width D is larger than the slit width C.

  Therefore, when the electronic front curtain and the mechanical rear curtain are driven under the same conditions, the exposure amount when the lens 114b is located in the region indicated by the slit width D is larger than the exposure amount when the lens 114a is located. .

  Therefore, when the scanning pattern of the reset scanning of the electronic front curtain is set so that proper exposure can be obtained at the position of the lens 114a, when the shutter is opened, the exposure is overexposed when the image is taken at the position of the lens 114b. Will end up.

  FIG. 3B shows a state in the latter half of the photographing operation (near the end of photographing).

  The slit width C ′ is defined as the width of the region where the light beam transmitted through the lens 114a having a shift amount of zero is limited by the line that is shielded by the mechanical rear curtain 105-3 and the reset line 4, and is incident on the imaging surface 104. Show.

  The slit width D ′ indicates the width of the region where the light beam transmitted through the lens 114b with the shift amount y is formed by the line shielded by 105-3 and the reset line 4 and is incident on the imaging surface 104. ing.

  At the timing shown in FIG. 3B, the slit width D 'is larger than the slit width C', as in the state where the shutter starts to be opened shown in FIG.

  Therefore, when the electronic front curtain and the mechanical rear curtain are driven under the same conditions, the exposure amount at the position of the lens 114b is larger than the exposure amount at the position of the lens 114a in the region indicated by the slit width D ′. Become.

  Therefore, if the scanning pattern of the electronic front curtain scan is set so that proper exposure can be obtained at the position of the lens 114a, the exposure will be over when the image is taken at the position of the lens 114b.

  Further, since the amount of overexposure is not constant between the beginning of opening of the shutter and the end of opening, it varies, and as a result, uneven exposure (so-called vertical exposure unevenness) occurs at the top and bottom of the image. ) Will occur.

  In FIG. 4A, reference numeral 12 represents a traveling pattern of the mechanical rear curtain, and represents a state in which the speed gradually increases from the start of traveling.

  Reference numeral 11 denotes a scanning pattern of electronic front curtain scanning.

  The distance in the time direction between the scanning pattern 11 and the scanning pattern 12 represents the exposure time of each line of the image sensor.

  In FIG. 4A, the exposure time is substantially the same from the bottom to the top of the image sensor.

  When the focal length and exit pupil distance of the shift lens are sufficiently long (for example, 500 mm or more), appropriate exposure can be obtained with a scanning pattern having substantially the same shape as the running curve of the mechanical rear curtain.

  As described above, in the case of the lens 114b at the position shifted by the shift amount y in the same direction as the traveling direction of the mechanical shutter 105, the exposure is over.

  Specifically, in the shutter control as shown in FIG. 4A, overexposure occurs particularly at the lower part of the imaging surface (= upper part of the image), and a small amount of overexposure occurs at the upper part of the imaging surface (= lower part of the image). Become.

  Therefore, it is necessary to correct the scanning pattern 11 of the electronic front curtain to the scanning pattern 11b of FIG. 4B so as to shorten the exposure time of each part of the imaging surface and reduce the exposure unevenness.

  On the other hand, in contrast to the above, in the case of a lens at a position shifted in the direction opposite to the traveling direction of the mechanical shutter 105, setting the scanning pattern of the electronic front curtain scanning without the shift amount particularly lowers the imaging surface. Is underexposed and the upper part of the imaging surface is underexposed.

  Therefore, as shown in FIG. 4C, the scanning pattern 11 of the electronic front curtain is changed to a scanning pattern as shown in FIG. 4C so as to lengthen the exposure time and reduce the exposure unevenness in each part of the imaging surface. It is necessary to correct to 11c.

  An outline of the imaging operation in the first embodiment of the imaging system having the above configuration will be described with reference to the flowchart of FIG. 5 while following the operation of the camera.

  Note that the process shown in FIG. 5 is a process executed mainly by the camera CPU 113.

  When the first stroke of the release button in the switch unit 112 (so-called half-pressed state) is detected (switch SW1 is turned on), the process proceeds from S101 to S102.

  In S102, the camera CPU 113, through the communication contacts 122 and 123, such as individual information of the mounted lens, aperture value, focal length, exit pupil distance, shooting distance, shift amount of the lens shift mechanism, revolving angle of the revolving mechanism, etc. Control is performed so that lens information is acquired from the lens CPU 115.

  In step S103, a lens aperture value is determined based on information from a photometric sensor (not shown) and ISO sensitivity setting.

  In step S104, subject distance information is acquired by a distance measuring unit (not shown), and the shooting distance of the lens unit 101 is determined.

  In S105, the shutter speed is determined by subject brightness, aperture value, ISO sensitivity setting, etc., and the process proceeds to S106.

  In S106, a corrected exit pupil distance P is determined in order to calculate a scanning pattern for electronic front curtain scanning based on the lens information acquired so far.

  Note that the process of determining the corrected exit pupil distance P performed in S106 will be described later in detail with reference to FIGS.

  Then, after determining the corrected exit pupil distance P in S106, the process proceeds to S107, and reset scanning of the electronic front curtain is calculated.

  When the second stroke of the release button, that is, when the release button is fully pressed (switch SW2 is turned on) is detected, the mirror 102 is raised (retracted from the photographing optical path) in S109.

  In S110, the electronic front curtain scanning drive calculated based on the corrected exit pupil distance P in S107 is started.

  In step S <b> 111, the mechanical rear curtain is driven and controlled, and the image sensor 104 is sequentially shielded from light.

  Finally, in S112, the mirror 102 is lowered and the mechanical shutter 105 is charged, and a series of shutter control sequences associated with photographing is completed, and the process returns to S101.

  Next, the process of determining the corrected exit pupil distance P performed in S106 will be described with reference to FIGS.

  FIG. 6 is a block diagram relating to control of electronic front curtain scanning according to the first embodiment.

  The information collecting unit 113a of the camera CPU 113 collects the individual information 101a of the lens mounted as described above, the aperture value 101b, the photographing distance 101c, the exit pupil distance 101d, the shutter time 106a, and the like.

  Further, the shift amount 101e of the lens shift mechanism and the revolving angle 101f of the revolving mechanism are collected.

  At this time, the shift amount 101e and the revolving angle 101f may be collected by operating an operation unit (not shown) provided in the camera body 100.

  Then, among the collected information, the shift amount 101e and the revolving angle 101f are passed to the shift amount component calculation unit 113b, and the individual lens information 101a, the aperture value 101b, the photographing distance 101c, and the exit pupil distance 101d are corrected to the corrected exit pupil distance calculation coefficient. It is passed to the setting unit 113c.

  In 113b, the shift amount component H in the shutter running direction or the reverse direction is calculated from the shift amount after the revolving rotation.

  The process of calculating the shift amount component H in the shutter travel direction or in the reverse direction of the shift amount will be described later with reference to FIG.

  Then, the shift amount component H obtained by the calculation is passed to the corrected exit pupil distance calculation unit 113d.

  Although the camera CPU 113 performs the calculation of the shift amount component in the shutter travel direction in the first embodiment, the lens CPU 115 may perform the calculation.

  The corrected exit pupil distance calculation coefficient setting unit 113c calculates the corrected exit pupil distance P from among the plurality of calculation coefficients stored in the information storage unit 150 based on the individual information of the lens unit among the acquired information. The coefficients A, B, C, and D of the equation are acquired and passed to the corrected exit pupil distance calculation unit 113d.

The corrected exit pupil distance calculation unit 113d stores a polynomial expression such as P = AH ³ + BH ² + CH + D using the calculation coefficient of the shift amount component H and the corrected exit pupil distance P as variables.

  Then, the corrected exit pupil is calculated using the shift amount component H acquired from the shift amount component calculator 113b and the calculation coefficients A, B, C, and D of the corrected exit pupil distance P acquired from the corrected exit pupil distance calculation coefficient setting unit 113c. The distance P is calculated and passed to the electronic front curtain scanning calculation unit 113e.

  The electronic front curtain scanning calculation unit 113e calculates a scanning pattern for electronic front curtain scanning based on the corrected exit pupil distance P obtained by the calculation, and passes it to the vertical drive modulation circuit control unit 113f.

  The vertical drive modulation circuit control unit 113f controls the vertical drive modulation circuit 108 to perform the electronic front curtain scan calculated based on the corrected exit pupil distance P calculated by the electronic front curtain scan calculation unit 113e.

  Next, FIG. 7 is a flowchart showing the correction exit pupil distance P determination process (S106).

  First, in S401, individual information of the mounted lens unit 101, aperture information, lens information such as focal length, photographing distance, exit pupil distance, and shutter time are collected.

  Further, the shift amount of the lens shift mechanism and the revolving angle of the revolving mechanism are collected, and the process proceeds to S402.

  In S402, the shift amount component H in the shutter running direction or in the reverse direction is calculated from the shift amount after the revolving rotation.

  Next, in S403, when the shift amount component is 0 or in S404, the shutter time is slower than the predetermined value (the shutter time is longer than the predetermined value). Proceeding to S407, a standard exit pupil distance corresponding to the lens individual information is determined, and then proceeding to S107.

  If neither is satisfied, the process proceeds to S405, the calculation coefficient of the corrected exit pupil distance P is determined according to the individual information of the lens, and the process proceeds to S406.

  The process of determining the calculation coefficient of the corrected exit pupil distance P according to the individual information of the lens in S405 will be described later.

  In S406, the correction exit pupil distance P optimum for the individual lens information, lens shift, and revolving state is calculated using the calculation coefficient of the shift amount component H and the corrected shooter pupil distance P, and the process proceeds to S107.

  The standard exit pupil distance is substantially equal to the traveling pattern 12 of the mechanical rear curtain, such as the scanning pattern 11 in FIG. 4A (exposure of each line of the image sensor from the start to the end of shooting). Time is almost the same).

  The conditions described above are for the following reasons.

  First, the exposure unevenness caused by the shift amount is particularly large when the shutter slit width is narrow at high speed as described above.

  Therefore, in the first embodiment, the corrected exit pupil distance P is calculated in the shutter time range in which the shutter time is long (for example, 1/8 second or less) and exposure unevenness can be sufficiently ignored. I do not do it.

  This condition is not essential, and the corrected exit pupil distance P may be calculated regardless of the shutter speed.

  Next, of the shift amount after the revolving rotation, the shift amount component H in the shutter running direction or in the reverse direction will be described with reference to FIG.

  FIG. 8 is a diagram schematically illustrating at least a part of the revolving angle and the shift amount of the lens unit 101 according to the first embodiment.

  In FIG. 8, the intersection of the X axis and the Y axis is the optical axis, and the Y axis and the traveling direction of the shutter coincide.

  θ represents a revolving angle, S represents a shift amount, and L represents a position shifted by S in the direction of the revolving angle θ.

In this case, the shift amount component H in the shutter running direction, that is, the Y-axis direction is H = Scos θ
Can be calculated. (S402)
Next, the process of determining the calculation coefficient of the corrected exit pupil distance P according to the individual information of the lens in S405 will be described with reference to FIG.

  FIG. 9 is a flowchart showing the calculation coefficient determination process (S405) of the corrected exit pupil distance P in the first embodiment.

  First, in S501, the lens individual information acquired in S401 is determined.

  The lens unit 101 is a detachable lens. For example, in FIG. 9, it is determined in S501 whether the individual information of the lens of the lens unit 101 is the TS lens 1, and in this case, the process proceeds to S502.

  In S502, a calculation coefficient of the corrected exit pupil distance P optimum for the individual lens information determined in S501 is determined, and the process proceeds to S406.

  If it is determined that the individual information of the lens in S501 is not the TS lens 1, the process proceeds to S601, the attached lens is determined, the flow similar to S501 and S502 is performed, and then the process proceeds to S406.

  As described above, according to the first embodiment, the shift amount component H in the shutter traveling direction or the reverse direction is calculated using the revolving angle and the shift amount.

  Next, when the coefficient for calculating the corrected exit pupil distance P is determined according to the individual information of the lens, the corrected exit pupil is corrected by the polynomial based on the shift amount component H and the coefficient for calculating the corrected exit pupil distance P. The distance P is calculated.

  Then, by calculating the scanning pattern of the electronic front curtain scanning based on the calculated corrected exit pupil distance P, it is possible to reduce the shift unevenness in the shutter travel direction according to the shift amount component H and the individual lens information.

  Next, a second embodiment of the present invention will be described with reference to FIGS.

  The configuration of the imaging system in the second embodiment is the same as that described with reference to FIG. 1 in the first embodiment, and the flowchart showing the shooting operation in FIG. 5 and the corrected injection in FIG. Since the block diagram showing the functional configuration for calculating the pupil distance P is the same, the description thereof is omitted here.

  FIG. 10 is a flowchart showing the process of determining the corrected exit pupil distance P in the second embodiment.

The difference from the process described with reference to FIG. 7 in the first embodiment is that a determination process based on aperture value information is added to a process for determining a calculation coefficient of the corrected exit pupil distance P according to individual lens information. . (S410)
FIG. 11 is a flowchart showing the calculation coefficient determination process (S410) of the corrected exit pupil distance P in the second embodiment.

The difference from the process described with reference to FIG. 9 in the first embodiment is that a determination process based on aperture value information is added. (S503 to S512)
Here, the process (S410) for determining the calculation coefficient of the corrected exit pupil distance P based on the individual lens information and the aperture value information according to the second embodiment will be described with reference to FIG.

  For example, in S501, it is determined whether the individual lens information is the TS lens 1. When the acquired individual information of the lens is the TS lens 1, the process proceeds to S503.

  In S503, the aperture value information of the lens unit is acquired, and the process proceeds to S504.

  After S504, the aperture value is set to FNo. 1, FNo. 2, FNo. 3, FNo. Judgment is made using a threshold value of 4, and the calculation coefficient of the corrected exit pupil distance P is determined accordingly.

In S504, the aperture value information is FNo. Determine if it is less than 1.
If the condition is satisfied, the process proceeds to S505, and the calculation coefficients of the corrected exit pupil distance P are acquired from the information storage unit 150 such that A = A ₁ , B = B ₁ , C = C ₁ , D = D _1. , The process proceeds to S406.

  If the condition is not satisfied, the process proceeds to S506.

  In S506, the aperture value information is FNo. 1 or more FNo. Judge whether it is less than 2.

If the condition is satisfied, the process proceeds to S507, and the calculation coefficient of the corrected exit pupil distance P is acquired from the information storage unit 150 such that A = A ₂ , B = B ₂ , C = C ₂ , D = D _2. , The process proceeds to S406.

  If the condition is not satisfied, the process proceeds to S508.

  In S508, the aperture value information is FNo. 2 or more FNo. Judge whether it is less than 3.

If the condition is satisfied, the process proceeds to S509, and the calculation coefficient of the corrected exit pupil distance P is acquired from the information storage unit 150 such that A = A ₃ , B = B ₃ , C = C ₃ , D = D _3. , The process proceeds to S406.

  If the condition is not satisfied, the process proceeds to S510.

  In S510, the aperture value information is FNo. 3 or more FNo. Judge whether it is less than 4.

If the condition is satisfied, the process proceeds to S511, and the calculation coefficient of the corrected exit pupil distance P is acquired from the information storage unit 150 such that A = A ₄ , B = B ₄ , C = C ₄ , D = D _4. , The process proceeds to S406.

If the condition is not satisfied, the process proceeds to S512. In S512, the aperture value information is FNo. The calculation coefficient of the corrected exit pupil distance P is acquired from the information storage unit 150 such that A = A ₃ , B = B ₃ , C = C ₃ , D = D _3, and the process proceeds to S406.

  The determination of the calculation coefficient of the corrected exit pupil distance P based on the aperture value has been described above. However, the present invention is not limited to this, and the calculation coefficient of the dedicated corrected exit pupil distance P is stored in all aperture values, and the corrected exit A calculation coefficient of the pupil distance P may be determined.

  Note that, as described above, the flowchart is a calculation coefficient determination process for the corrected exit pupil distance P when the individual lens information is the TS lens 1, and therefore, a plurality of processes in S503 to S512 are performed according to the individual lens information. Have.

  As described above, according to the second embodiment, the shift amount component H in the shutter traveling direction or the reverse direction is calculated using the revolving angle and the shift amount.

  Thereafter, the calculation coefficient of the corrected exit pupil distance P is determined according to the individual lens information and the aperture value, thereby calculating the shift amount component H and the corrected exit pupil distance according to the individual lens information and the aperture value. Exposure unevenness in the shutter travel direction can be reduced.

  Next, a third embodiment of the present invention will be described with reference to FIGS.

  The configuration of the imaging system in the third embodiment is the same as that described with reference to FIG. 1 in the first embodiment. The flowchart showing the shooting operation in FIG. 5 and the corrected injection in FIG. Since the block diagram showing the functional configuration for calculating the pupil distance P is the same, the description thereof is omitted here.

  FIG. 12 is a flowchart showing the determination process (S106) of the corrected exit pupil distance P in the third embodiment.

In the process described with reference to FIG. 10 in the second embodiment, the determination process based on the shooting distance information is added to the process of determining the calculation coefficient of the corrected exit pupil distance P according to the individual lens information and the aperture value information. It is different. (S420)
FIG. 13 is a flowchart showing a process for determining the calculation coefficient of the corrected exit pupil distance P in the third embodiment.

  The process described with reference to FIG. 11 in the second embodiment is a process for determining the calculation coefficient of the corrected exit pupil distance P based on the individual lens information and the aperture value information, and a determination process based on the shooting distance information. It is different to have added.

Other than that, it is the same as the processing of FIG.
Note that the process shown in FIG. 13 is a process executed mainly by the camera CPU 113.

  Here, with respect to the process of determining the calculation coefficient of the corrected exit pupil distance P based on the individual lens information, the aperture value information, and the photographing distance information, the calculation coefficient determination process of the corrected exit pupil distance P is described with reference to FIG. explain.

  First, in S501 to S503, the same processing as in the second embodiment is performed, and then the process proceeds to S513.

  In S513, the shooting distance information Z is acquired from 113a, and the process proceeds to S514.

  In S514, the shooting distance is determined based on the shooting distance information Z acquired in S513 based on thresholds such as shooting distances M1, M2, and M3.

  In the case of Z <M1, the process proceeds to S515, and the calculation coefficient determination process for the corrected exit pupil distance P is performed as in FIG. If M1 ≦ Z ≦ M2, the process proceeds to S524, and the calculation coefficient determination process for the corrected exit pupil distance P is performed as in FIG. 11 of the second embodiment.

  Alternatively, if M2 <Z, the process proceeds to S533, and the calculation coefficient determination process for the corrected exit pupil distance P is performed in the same manner as in FIG.

  As described above, according to the third embodiment, the shift amount component H in the shutter traveling direction or the reverse direction is calculated using the revolving angle and the shift amount.

  After that, by determining the calculation coefficient of the corrected exit pupil distance P according to the individual information of the lens, the aperture value, and the shooting distance, the shutter according to the shift amount component H, the individual information of the lens, the aperture value, and the shooting distance. Exposure unevenness in the running direction can be reduced.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

2 Imaging surface 3 Mechanical rear curtain 4 Reset line 5 Mechanical rear curtain tip 100 Camera body 101 Interchangeable lens 101a Lens individual information 101b Aperture value 101c Imaging distance 101d Exit pupil distance 101e Shift amount information 101f Revolving angle information 104 Imaging element 105 Mechanical shutter 106 Shutter drive circuit 106a Shutter time 107 Pulse generation circuit 108 Vertical drive modulation circuit 109 Signal processing circuit 110 Image display circuit 111 Image recording circuit 112 Switch unit 113 Camera CPU
113a Information collection unit 113b Shift amount component calculation unit 113c Correction exit pupil distance calculation coefficient setting unit 113d Correction exit pupil distance calculation unit 113e Electronic front curtain calculation unit 113f Vertical drive modulation circuit control unit 114 Shooting lens 115 Lens CPU
116 Lens drive circuit 117 Aperture drive circuit 118 Lens shift mechanism 119 Shift amount detection circuit 120 Revolving mechanism 121 Revolving angle detection circuit 122 Lens side communication contact 123 Camera side communication contact 150 Information storage unit

Claims (5)

  An image sensor (104) composed of a plurality of pixels, a central processing unit (113), an information storage unit (150) for storing information on the calculation coefficient of the corrected exit pupil distance P, and a shutter for shielding the image sensor And a vertical drive modulation circuit (108) for sequentially resetting the pixels of the image sensor in the traveling direction of the shutter means and controlling the start of charge accumulation prior to the start of light shielding of the image sensor by the shutter means. And a shift means (118) for shifting at least a part of the photographing lens unit in a direction perpendicular to the optical axis, and a revolving means for rotating at least a part of the lens unit including the shift means about the optical axis. In the imaging device used by attaching the detachable lens unit having (120), the lens information (115) Imaging apparatus characterized by having an electronic front curtain scanning calculating means for calculating a scanning pattern of the electronic front curtain scanning (113e) by Zui.   The imaging apparatus according to claim 1, wherein the lens information (115) includes individual information of the lens, a revolving angle, a shift amount, an aperture value, shooting distance information, and all or a plurality of exit pupil distances. .   The electronic front curtain scanning calculating means (113e) calculates a shift amount component H in the shutter traveling direction from the revolving information and shift information of the lens unit, and calculates the corrected exit pupil distance P for each individual information of the photographing lens. Is obtained from the information storage unit (150), the corrected exit pupil distance P is calculated based on the calculated shift amount component H and the calculation coefficient of the corrected exit pupil distance P, and based on the calculated corrected exit pupil distance P. 2. The imaging apparatus according to claim 1, wherein a scanning pattern of the electronic front curtain is calculated.   The electronic front curtain scanning calculation means (113e) calculates a shift amount component H in the shutter running direction from the revolving information and shift information of the lens unit, and a corrected exit pupil distance P based on the aperture value for each piece of individual information of the photographing lens. Is calculated from the information storage unit (150), the corrected exit pupil distance P is calculated based on the calculated shift amount component H and the calculated exit pupil distance P, and the calculated corrected exit pupil distance is calculated. 2. The imaging apparatus according to claim 1, wherein a scanning pattern of the electronic front curtain is calculated based on P. The electronic front curtain scanning calculation means (113e) calculates a shift amount component H in the shutter running direction from the revolving information and shift information of the lens unit, and corrects and emits the light according to the aperture value and shooting distance for each piece of individual information of the photographing lens. The calculation coefficient of the pupil distance P is acquired from the information storage unit (150), the corrected exit pupil distance P is calculated based on the calculated shift amount component H and the calculated calculation coefficient of the corrected exit pupil distance P, and the calculated correction is performed. The imaging apparatus according to claim 1, wherein a scanning pattern of the electronic front curtain is calculated based on the exit pupil distance P.