JP2019124966A - Lens barrel and camera system - Google Patents

Abstract

To provide a lens barrel and camera system that can perform suitable focus adjustment control.SOLUTION: A lens barrel comprises: a drive unit 36 that can drive a focus adjustment optical system 32 in an optical axis direction; an acquisition unit 37 that acquires position information on the focus adjustment optical system 32; a drive range limitation unit 37 that judges whether to limit a drive range of the focus adjustment optical system 32, and limits the drive range of the focus adjustment optical system 32 on the basis of a result of the judgement; a transmission/reception unit 39 that performs transmission/reception of a signal between the lens barrel and a camera body 2; and a control unit 37 that when the drive range of the focus adjustment optical system 32 is limited by the drive range limitation unit 37, controls the transmission/reception unit 37 so as to transmit the location information on the focus adjustment optical system 32 to the camera body 2 in a method different from a case where the range of the focus adjustment optical system 32 is not limited thereby.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lens barrel and a camera system.

  2. Description of the Related Art Conventionally, in a lens-interchangeable imaging device, a technique is known in which the position of a focusing optical system provided in a lens barrel is detected by a position detection device such as an encoder and the detected position is transmitted to a camera body. (See, for example, Patent Document 1).

Unexamined-Japanese-Patent No. 2006-162411

  However, in the prior art, since the position of the focusing optical system is transmitted to the camera body on the basis of the drive range in which the focusing optical system can be mechanically driven, the camera body has a mechanical focusing optical system. It is possible to grasp the positional relationship of the focusing optical system in the drive range that can be driven in a dynamic manner, but limited, for example, when the driving range of the focusing optical system is limited in order to shorten the time required for focusing. There is a problem that the positional relationship of the focusing optical system in the driving range can not be grasped.

  The problem to be solved by the present invention is to provide a lens barrel and a camera system capable of suitable focusing control.

  The present invention solves the above-mentioned subject by the following solution means. Although the following description will be made with reference to the reference numerals corresponding to the drawings showing the embodiments of the present invention, these reference numerals are for the purpose of facilitating the understanding of the present invention and in the spirit of limiting the invention. Absent.

  [1] A lens barrel according to the present invention includes a drive unit (36) capable of driving a focusing optical system (32) in the optical axis direction, and an acquisition unit (37) for acquiring position information of the focusing optical system A driving range limiting unit (37) for limiting the driving range of the focusing optical system, a transmitting / receiving unit (39) for transmitting / receiving a signal to / from the camera body, and the focusing optics by the driving range limiting unit. When the drive range of the system is limited, the transmission and reception are performed so as to transmit positional information of the focus adjustment optical system to the camera body in a format different from the case where the drive range of the focus adjustment optical system is not limited. And a control unit (37) for controlling the unit.

  [2] In the invention relating to the focusing device, the acquisition unit (37) is, as position information of the focusing optical system (32), information on the number of segments set in the optical axis direction, and the information The information of the section in which the focusing optical system exists is acquired, and the drive range limiting unit (37) limits the sections that can be driven by the focusing optical system among the sections set in the optical axis direction. The drive range of the focusing optical system is limited, and the control unit (37) performs the limited drive when the drive range of the focusing optical system is limited by the drive range limiting unit. The number of divisions corresponding to the range is calculated as the number of restriction divisions, and the information of the number of restriction divisions as the position information of the focusing optical system and the information of the division in which the focusing optical system in the restriction division exists And the camera It can be configured to control the transceiver unit (39) to be sent to di.

  [3] In the invention relating to the focusing device, when the driving range of the focusing optical system (32) is limited by the driving range limiting portion (37), the control part (37) may Information on the number of the restriction divisions, information on at least one of the division numbers corresponding to the nearest end divisions of the restriction divisions and the division numbers corresponding to the divisions at the infinity end, as position information of the focusing optical system, and The transmission / reception unit (39) may be controlled to transmit information of a section number corresponding to a section in which the focusing optical system exists to the camera body (2).

  [4] In the invention relating to the focusing device, when the driving range of the focusing optical system (32) is limited by the driving range limiting part (39), the control part (37) may The focusing optical system exists in the case where one of the section number at the near end and the section number at the infinite end among the restricted sections is set to zero as the information of the section number in which the focusing optical system exists. The information on the division number to be transmitted may be transmitted to the transmission / reception unit (39).

  [5] A camera system according to the present invention comprises the lens barrel and a camera body.

  According to the present invention, it is possible to provide a lens barrel and a camera system capable of suitable focusing control.

FIG. 1 is a block diagram showing a camera according to the present embodiment. FIG. 2 is a diagram showing the relationship between the drivable range of the focus lens and the position (segmented position) of the focus lens detectable by the encoder. FIG. 3 is a view showing the relationship between the drivable range of the focus lens and the position (segment position) of the focus lens detectable by the encoder when the drivable range of the focus lens is limited. FIG. 4 is a front view showing an imaging surface of the imaging device shown in FIG. FIG. 5 is a front view schematically showing the arrangement of the focus detection pixels 222a and 222b by enlarging the portion V of FIG. FIG. 6 is a front view showing one of the imaging pixels 221 in an enlarged manner. FIG. 7A is an enlarged front view of one of the focus detection pixels 222a, and FIG. 7B is an enlarged front view of one of the focus detection pixels 222b. FIG. 8 is a cross-sectional view showing one of the imaging pixels 221 in an enlarged manner. FIG. 9A is an enlarged sectional view showing one of the focus detection pixels 222a, and FIG. 9B is an enlarged sectional view showing one of the focus detection pixels 222b. FIG. 10 is a cross-sectional view taken along the line XX in FIG.

  Hereinafter, embodiments of the present invention will be described based on the drawings.

  FIG. 1 is a main part configuration diagram showing a digital camera 1 according to an embodiment of the present invention. The digital camera 1 (hereinafter simply referred to as the camera 1) of the present embodiment is composed of a camera body 2 and a lens barrel 3, and the camera body 2 and the lens barrel 3 are detachably coupled by a mount unit 4 There is.

  The lens barrel 3 is an interchangeable lens that is detachable from the camera body 2. As shown in FIG. 1, the lens barrel 3 incorporates a photographing optical system including lenses 31, 32, 33 and a diaphragm 34.

  The lens 32 is a focus lens, and can move in the direction of the optical axis L1 to adjust the focal length of the imaging optical system. The focus lens 32 is provided so as to be movable along the optical axis L1 of the lens barrel 3, and its position is adjusted by the focus lens drive motor 36 while its position is detected by the encoder 35.

  The specific configuration of the moving mechanism along the optical axis L1 of the focus lens 32 is not particularly limited. For example, a rotary cylinder is rotatably inserted into a fixed cylinder fixed to the lens barrel 3, and a helicoid groove (helical groove) is formed on the inner peripheral surface of the rotary cylinder, and the focus lens 32 is fixed. The end of the lens frame is fitted in the helicoid groove. Then, by rotating the rotary cylinder by the focus lens drive motor 36, the focus lens 32 fixed to the lens frame moves rectilinearly along the optical axis L1.

  As described above, the focus lens 32 fixed to the lens frame moves rectilinearly in the direction of the optical axis L1 by rotating the rotary cylinder with respect to the lens barrel 3, but the focus lens drive motor 36 as its drive source is a lens The lens barrel 3 is provided. The focus lens drive motor 36 and the rotary cylinder are connected by, for example, a transmission composed of a plurality of gears, and when the drive shaft of the focus lens drive motor 36 is rotationally driven in either direction, it is transmitted to the rotary cylinder with a predetermined gear ratio. Then, when the rotary cylinder rotates in any one direction, the focus lens 32 fixed to the lens frame moves rectilinearly in any direction of the optical axis L1. When the drive shaft of the focus lens drive motor 36 is driven to rotate in the reverse direction, the gears constituting the transmission also rotate in the reverse direction, and the focus lens 32 moves rectilinearly in the direction opposite to the optical axis L1. .

  The position of the focus lens 32 is detected by the encoder 35. As described above, the position of the focus lens 32 in the direction of the optical axis L1 is correlated with the rotation angle of the rotary cylinder, and therefore can be determined by detecting the relative rotation angle of the rotary cylinder with respect to the lens barrel 3, for example.

  The encoder 35 according to the present embodiment detects a rotation of a rotating disk connected to the rotational drive of the rotating cylinder by an optical sensor such as a photo interrupter and outputs a pulse signal according to the number of rotations, or a fixed cylinder An encoder pattern (electrode pattern) on the surface of the flexible printed wiring board provided on either one of the rotating cylinder and the brush contact provided on the other is brought into contact, and the moving amount of the rotating cylinder (optical axis even in the rotation direction) It is possible to use one that detects a change in the contact position according to any of the directions) by a detection circuit.

  The focus lens 32 can move in the direction of the optical axis L1 from the end on the camera body side (also referred to as the near end) to the end on the subject side (also referred to as the infinite end) by rotation of the rotary cylinder described above. it can.

Here, FIG. 2 is a diagram showing the relationship between the drivable range in which the focus lens 32 can be driven and the position (segmented position) of the focus lens 32 that can be detected by the encoder 35. In the present embodiment, as shown in FIG. 2, the drive range in which the focus lens 32 can be driven is divided into, for example, 21 sections of D _{0 to} D ₂₀ . That is, in the present embodiment, the number N of division divisions, which is the number of division positions of the focus lens 32 detectable by the encoder 35, is 21, and each division D _{0 to} D ₂₀ is close to the infinity end Section numbers N _D are set to 0 to 20 in order from the end side. That is, the section D ₀ at the near end is set to the section number N _D = 0, and the section D ₁ adjacent to the closest side is set to the section number N _D = 1. Further, the segment D ₂₀ at the infinite distance end has a segment number N _D = 20, and the segment D ₁₉ next to the infinite distance side has a segment number N _D = 19. Note that FIG. 2 exemplifies a scene in which the current position of the focus lens 32 is located within D ₁₁ (section number N _D = 11).

Then, in the present embodiment, the encoder 35 detects the position of the section where the focus lens 32 is currently located, and the section number N _D of the section where the focus lens 32 is currently located (for example, in the example shown in FIG. Send N _D = 11) to the lens control unit 37.

  The aperture 34 is configured to adjust the aperture diameter centered on the optical axis L1 in order to limit the light amount of the light flux passing through the imaging optical system and reaching the imaging device 22 and to adjust the blur amount. Adjustment of the aperture diameter by the aperture stop 34 is performed, for example, by transmitting an appropriate aperture diameter calculated in the automatic exposure mode from the camera control unit 21 via the lens control unit 37. Further, the set aperture diameter is input from the camera control unit 21 to the lens control unit 37 by the manual operation by the operation unit 28 provided in the camera body 2. The aperture diameter of the diaphragm 34 is detected by a diaphragm aperture sensor (not shown), and the lens controller 37 recognizes the current aperture diameter.

The lens memory 38, as information on the position of the focus lens 32 detectable by the encoder 35 shown in FIG. partition number _{N D_F} (e.g., in the example shown in FIG. 2, divided division number _{N D_F} = 0) and of the near end of the partition number _{N d_n} (e.g., in the example shown in FIG. 2, divided division number _N d_N = 20) It stores information. Incidentally, the partition number N _{d_n} the infinity end of the partition number N _{D_F} and the closest end, which is stored in the lens memory 38, in the driving range that can focus lens 32 is mechanically driven, the infinity end and It indicates the position of the section at the near end. That is, when the drivable range of the focus lens 32 described later is limited (for example, in the case shown in FIG. 3 described later), the positions of the sections at the infinity end and the near end may be different.

The lens control unit 37, the encoder 35 receives the division number N _D of the current lens position _(partition number N _D of the current position of the focus lens _32), the segment number N _D of the received current lens position, the lens memory 38 The camera communication of the camera body 2 via the lens communication unit 39 as position information of the focus lens 32, together with the number N of division divisions _stored , the division number N _{D_N} at the near end, and the division number N _{D_F} on the infinity side. The information is transmitted to the unit 29, and the information is finally transmitted to the camera control unit 21 described later.

Further, the lens control unit 37 limits the drivable range in which the focus lens 32 can be driven based on, for example, a signal from the camera body 2 in order to shorten the time required to adjust the focus of the focus lens 32, for example (range limit ). Specifically, when the lens control unit 37 receives a signal for limiting the drivable range from the camera control unit 21, the lens control unit 37 can operate the camera within the drive range in which the focus lens 32 can be mechanically driven. The drivable range of the focus lens 32 is limited so that the focus lens 32 can be driven only in the drive range determined by the control unit 21. For example, in the example illustrated in FIG. 3, the lens control unit 37 divides the six divisions of D _{10 to} D _{15 in} the drive range corresponding to the division of 21 of D _{0 to} D ₂₀ where the focus lens 32 can be mechanically driven. The range corresponding to the six divisions of D _{10 to} D ₁₅ is limited as the drivable range so that the focus lens 32 can be driven only in the range corresponding to f.

As described above, when the drive range in which the focus lens 32 can be driven is limited, the lens control unit 37 sets the division corresponding to the limited drivable range as the restriction division, and the division number N _{D of the} current lens position. In addition to the above, the number N of the restriction divisions, the division number N _{D_N} of the division located at the near end in the restriction division, and the division number N _{D_F} on the infinity side of the division located at the nearest end in the restriction division The position information of the focus lens 32 is transmitted to the camera body 2 via the lens communication unit 39. For example, in the example shown in FIG. 3, as shown in Table 1, the division number D _n of the current lens position, 11, the number of restriction divisions 6, and the division of divisions positioned at infinity end in the restriction division Transmit 10 to the camera body 2 via the lens communication unit 39 as the position information of the focus lens 32. The number 10 is the number N _{D_F} , and 15 is the number N _{D_N} of the section located at the closest end in the restricted section. Do. The method of transmitting the position information of the focus lens 32 by the lens control unit 37 will be described later.

  Furthermore, the lens control unit 37 controls the entire lens barrel 3 such as driving the focus lens 32 and adjusting the aperture diameter by the diaphragm 34 based on the command from the camera control unit 21 in addition to the transmission of the data. Do.

  The lens communication unit 39 is configured to be able to exchange signals with the camera communication unit 29 of the camera body 2 via the camera control unit 21 and the electric signal contact unit 41 provided in the mount unit 4. The lens communication unit 39 is a communication interface of the lens barrel 3, and the camera communication unit 29 is a communication interface of the camera body 2. The lens control unit 37 of the lens barrel 3 and the camera control unit of the camera body 2 21 perform data communication with each other using these communication interfaces. In the present embodiment, two types of data communication, hotline communication and command data communication, are executed in combination between the lens communication unit 39, which is a communication interface, and the camera communication unit 29. Therefore, structurally, the communication line performing the hotline communication and the communication line performing the command data communication are provided separately.

  Hot-line communication is communication that is executed every first predetermined cycle (in this embodiment, for example, one millisecond) shorter than the cycle for performing command data communication. In the present embodiment, for data for controlling the lens barrel 3 such as a drive command for the focus lens 32 (drive pulse for the focus lens 32), data transmission / reception is performed by hotline communication.

On the other hand, the command data communication is communication executed every second predetermined cycle (in the present embodiment, for example, 16 milliseconds) longer than the cycle of performing hotline communication. The current position of the lens barrel 3 such as the position data of the focus lens 32 described above (division number N, segment number N _{D_N} at the near end, segment number N _{D_F} on the infinity side, and segment number N _D of the current lens position) Data transmission / reception is performed by command data communication for data indicating the status of

  On the other hand, in the camera body 2, an imaging element 22 for receiving the light flux L1 from the imaging optical system is provided on a planned focal plane of the imaging optical system, and a shutter 23 is provided on the front surface thereof. The imaging device 22 is configured of a device such as a CCD or a CMOS, converts the received light signal into an electric signal, and sends it to the camera control unit 21. The photographed image information sent to the camera control unit 21 is sequentially sent to the liquid crystal drive circuit 25 and displayed on the electronic viewfinder (EVF) 26 of the observation optical system, and the release button (provided in the operation unit 28) When the full depression (not shown) is performed, the photographed image information is recorded in the camera memory 24 which is a recording medium. The camera memory 24 can use any of a removable card type memory and a built-in type memory. Details of the structure of the imaging device 22 will be described later.

  The camera body 2 is provided with an observation optical system for observing an image captured by the image sensor 22. The observation optical system of the present embodiment includes an electronic viewfinder (EVF) 26 composed of a liquid crystal display element, a liquid crystal drive circuit 25 for driving the same, and an eyepiece lens 27. The liquid crystal drive circuit 25 reads the photographed image information picked up by the image pickup device 22 and sent to the camera control unit 21, and drives the electronic viewfinder 26 based on this. Thus, the user can observe the current captured image through the eyepiece 27. A liquid crystal display may be provided on the back surface of the camera body 2 or the like instead of or in addition to the above observation optical system according to the optical axis L2, and a photographed image may be displayed on the liquid crystal display.

A camera control unit 21 is provided in the camera body 2. The camera control unit 21 receives position information of the focus lens 32 from the lens control unit 37 via the camera communication unit 29 and the lens communication unit 39 (that is, the number N of divisional divisions, division number N _{D —} N of the near end, infinite distance side of the partition number N _{D_F,} and which receives the partition number N _D) various lens information such as the current lens position, and transmits information such as the defocus amount and the aperture diameter to the lens control unit 37. In addition, as described above, the camera control unit 21 reads out the pixel output from the imaging device 22 and generates image information by performing predetermined information processing on the read out pixel output as necessary, and the generated image information Are output to the liquid crystal drive circuit 25 and the memory 24 of the electronic viewfinder 26. Further, the camera control unit 21 controls the entire camera 1 such as correction of image information from the image pickup device 22 and detection of a focusing state of the lens barrel 3, an aperture adjusting state, and the like.

  Further, in addition to the above, the camera control unit 21 detects the focus state of the photographing optical system by the phase detection method based on the pixel data read from the imaging device 22 and detects the focus state of the photographing optical system by the contrast detection method. I do. A specific focus state detection method will be described later.

  The operation unit 28 is an input switch for a photographer such as a shutter release button to set various operation modes of the camera 1, and can switch between an auto focus mode and a manual focus mode. The various modes set by the operation unit 28 are sent to the camera control unit 21, and the operation of the entire camera 1 is controlled by the camera control unit 21. Further, the shutter release button includes a first switch SW1 which is turned on when the button is half pressed, and a second switch SW2 which is turned on when the button is fully pressed.

  Next, the image sensor 22 according to the present embodiment will be described.

  FIG. 4 is a front view showing the imaging surface of the imaging element 22, and FIG. 5 is a front view schematically showing the arrangement of the focus detection pixels 222a and 222b by enlarging a portion V of FIG.

  As shown in FIG. 5, in the imaging device 22 of the present embodiment, a plurality of imaging pixels 221 are two-dimensionally arranged on a plane of an imaging surface, and a green pixel G having a color filter transmitting a green wavelength region And a red pixel R having a color filter transmitting the red wavelength region and a blue pixel B having a color filter transmitting the blue wavelength region are what is called a Bayer arrangement. That is, two green pixels are arranged on one diagonal line in adjacent four pixel groups 223 (a dense square lattice array), and one red pixel and one blue pixel are arranged on the other diagonal line. The imaging element 22 is configured by repeatedly arranging the pixel group 223 two-dimensionally on the imaging surface of the imaging element 22 in units of the pixel group 223 in which the Bayer arrangement is performed.

  The arrangement of the unit pixel groups 223 may be, for example, a close hexagonal lattice arrangement, as well as the close square lattice shown in the drawing. Further, the configuration and arrangement of the color filter are not limited to this, and an arrangement of complementary color filters (green: G, yellow: Ye, magenta: Mg, cyan: Cy) can also be adopted.

  FIG. 6 is an enlarged front view showing one of the imaging pixels 221, and FIG. 8 is a cross-sectional view. One imaging pixel 221 includes a microlens 2211, a photoelectric conversion unit 2212, and a color filter (not shown), and as shown in the cross-sectional view of FIG. 2212 is fabricated, and a microlens 2211 is formed on the surface. The photoelectric conversion unit 2212 is shaped so as to receive the imaging light flux passing through the exit pupil (for example, F1.0) of the imaging optical system by the microlens 2211 and receives the imaging light flux.

  In addition, focus detection pixel arrays 22a, 22b, and 22c in which focus detection pixels 222a and 222b are arranged instead of the imaging pixels 221 described above at the center of the imaging surface of the imaging element 22 and at three positions symmetrical with respect to the center. Is provided. Then, as shown in FIG. 5, in one focus detection pixel row, a plurality of focus detection pixels 222a and 222b are arranged adjacent to each other and alternately arranged in one horizontal row (22a, 22c, 22c). There is. In the present embodiment, the focus detection pixels 222a and 222b are densely arranged without providing a gap at the positions of the green pixel G and the blue pixel B of the imaging pixel 221 in Bayer arrangement.

  The positions of the focus detection pixel arrays 22a to 22c shown in FIG. 4 are not limited to the illustrated positions, but may be one or two, or may be disposed at four or more positions. it can. Further, at the time of actual focus detection, the photographer manually selects the desired focus detection pixel row as the focus detection area from the plurality of arranged focus detection pixel rows 22a to 22c by manually operating the operation unit 28. It can also be done.

  FIG. 7A is an enlarged front view showing one of the focus detection pixels 222a, and FIG. 9A is a cross-sectional view of the focus detection pixel 222a. 7B is an enlarged front view showing one of the focus detection pixels 222b, and FIG. 9B is a cross-sectional view of the focus detection pixel 222b. The focus detection pixel 222a includes a micro lens 2221a and a semicircular photoelectric conversion unit 2222a as shown in FIG. 7A, and as shown in the cross sectional view of FIG. The photoelectric conversion portion 2222a is formed on the surface of the semiconductor circuit substrate 2213, and the micro lens 2221a is formed on the surface. Further, as shown in FIG. 7B, the focus detection pixel 222b is composed of a micro lens 2221b and a photoelectric conversion portion 2222b, and as shown in the cross sectional view of FIG. The photoelectric conversion portion 2222b is formed on the surface of the circuit board 2213, and the micro lens 2221b is formed on the surface. Then, as shown in FIG. 5, these focus detection pixels 222a and 222b are arranged adjacent to each other and alternately in a horizontal row, to form focus detection pixel rows 22a to 22c shown in FIG.

  The photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b have shapes that receive light beams passing through a predetermined area (for example, F2.8) of the exit pupil of the photographing optical system by the micro lenses 2221a and 2221b. Be done. Further, no color filter is provided in the focus detection pixels 222a and 222b, and the spectral characteristics thereof are obtained by integrating the spectral characteristics of the photodiode performing photoelectric conversion and the spectral characteristics of the infrared cut filter (not shown). ing. However, one of the same color filters as the imaging pixel 221, for example, a green filter may be provided.

  Although the photoelectric conversion units 2222a and 2222b of the focus detection pixels 222a and 222b shown in FIGS. 7A and 7B are semicircular, the shape of the photoelectric conversion units 2222a and 2222b is not limited thereto. And other shapes, for example, an oval shape, a rectangular shape, and a polygonal shape.

  Here, a so-called phase difference detection method for detecting the focus state of the photographing optical system based on the pixel outputs of the focus detection pixels 222a and 222b described above will be described.

  FIG. 10 is a cross-sectional view taken along the line XX in FIG. 5, and the focus detection pixels 222a-1, 222b-1, 222a-2, 222b-2 arranged in the vicinity of the photographing optical axis L1 and adjacent to each other have exit pupils. It shows that light beams AB1-1, AB2-1, AB1-2, AB2-2 emitted from the distance measuring pupils 351, 352 of 350 are respectively received. In FIG. 10, among the plurality of focus detection pixels 222a and 222b, only those located in the vicinity of the photographing optical axis L1 are illustrated. However, other focus detection pixels other than the focus detection pixels shown in FIG. Similarly, the light beams emitted from the pair of distance measuring pupils 351 and 352 are also received.

  Here, the exit pupil 350 is an image set at the position of the distance D in front of the microlenses 2221 a and 2221 b of the focus detection pixels 222 a and 222 b disposed on the planned focal plane of the imaging optical system. The distance D is a value uniquely determined according to the curvature of the micro lens, the refractive index, the distance between the micro lens and the photoelectric conversion part, and the like, and this distance D is referred to as a distance measurement pupil distance. Further, the ranging pupils 351 and 352 refer to images of the photoelectric conversion units 2222a and 2222b respectively projected by the micro lenses 2221a and 2221b of the focus detection pixels 222a and 222b.

  In FIG. 10, the arrangement direction of the focus detection pixels 222a-1, 222b-1, 222a-2, 222b-2 coincides with the arrangement direction of the pair of distance measurement pupils 351, 352.

  In addition, as shown in FIG. 10, the microlenses 2221a-1, 2221b-1, 2221a-2, 2221b-2 of the focus detection pixels 222a-1, 222b-1, 222a-2, 222b-2 are photographing optical systems. It is placed near the planned focal plane of. The shape of each of the photoelectric conversion units 2222a-1, 2222b-1, 2222a-2, 2222b-2 disposed behind the microlenses 2221a-1, 2221b-1, 2221a-2, 2221b-2 is The light is projected onto the exit pupil 350 separated by the distance measurement distance D from the lenses 2221a-1 and 2221b-1, and 2221a-2 and 2221b-2, and the projected shapes form distance measurement pupils 351 and 352.

  That is, on the exit pupil 350 located at the distance measurement distance D, the microlenses and photoelectric conversion units in each focus detection pixel are matched so that the projection shapes (distance measurement pupils 351, 352) of the photoelectric conversion units of each focus detection pixel match. The relative positional relationship of is determined, whereby the projection direction of the photoelectric conversion unit at each focus detection pixel is determined.

  As shown in FIG. 10, the photoelectric conversion unit 2222a-1 of the focus detection pixel 222a-1 is formed on the microlens 2221a-1 by the light beam AB1-1 which passes through the distance measurement pupil 351 and is directed to the microlens 2221a-1. Output a signal corresponding to the intensity of the image being Similarly, the photoelectric conversion unit 2222a-2 of the focus detection pixel 222a-2 passes through the distance measurement pupil 351, and the intensity of the image formed on the microlens 2221a-2 by the light beam AB1-2 directed to the microlens 2221a-2. Output a signal corresponding to

  In addition, the photoelectric conversion unit 2222b-1 of the focus detection pixel 222b-1 passes through the distance measurement pupil 352, and the intensity of the image formed on the microlens 2221b-1 by the light beam AB2-1 directed to the microlens 2221b-1 Output the corresponding signal. Similarly, the photoelectric conversion unit 2222b-2 of the focus detection pixel 222b-2 passes through the distance measurement pupil 352, and the intensity of the image formed on the microlens 2221b-2 by the light beam AB2-2 directed to the microlens 2221b-2. Output a signal corresponding to

  Then, a plurality of the two types of focus detection pixels 222a and 222b described above are linearly arranged as shown in FIG. 5, and the output of the photoelectric conversion units 2222a and 2222b of each focus detection pixel 222a By combining the output groups corresponding to each of the focus detection pupils 352 and the focus detection pupil 352, the intensities of a pair of images formed on the focus detection pixel array by the focus detection light beams passing through the focus detection pupil 351 and the focus detection pupil 352, respectively. Data on the distribution is obtained. Then, by performing image shift detection calculation processing such as correlation calculation processing or phase difference detection processing on the intensity distribution data, it is possible to detect an image shift amount by a so-called phase difference detection method.

  Then, a conversion operation according to the distance between the center of gravity of the pair of distance measuring pupils is performed on the obtained image shift amount to obtain the current focal plane with respect to the planned focal plane (the focal point corresponding to the position of the microlens array on the planned focal plane). The deviation of the focal plane in the detection area can be determined.

  The calculation of the image shift amount by the phase difference detection method and the calculation of the defocus amount based on this are executed by the camera control unit 21.

  Further, the camera control unit 21 reads the output of the imaging pixel 221 of the imaging element 22, and calculates the focus evaluation value based on the read pixel output. The focus evaluation value can be obtained, for example, by extracting the high frequency component of the image output from the imaging pixel 221 of the imaging device 22 using a high frequency transmission filter. It can also be determined by extracting high frequency components using two high frequency transmission filters having different cutoff frequencies.

  Then, the camera control unit 21 sends a drive signal to the lens control unit 37 to drive the focus lens 32 at a predetermined sampling interval (distance) to obtain a focus evaluation value at each position, and the focus evaluation value is maximum. The focus detection by the contrast detection method is performed to obtain the position of the focus lens 32 as the in-focus position. It should be noted that, for example, when the focus evaluation value is calculated while driving the focus lens 32, the in-focus position is further lowered twice after the focus evaluation value rises twice. It can obtain | require by performing calculations, such as an interpolation method, using the focus evaluation value of.

Further, in the present embodiment, when performing camera focus detection by the contrast detection method, the camera control unit 21 receives positional information of the focus lens 32 received from the lens barrel 3 (that is, the division number N, the closest end). partition number _{N d_n,} based infinity side of the partition number _{N D_F,} and partition number _{N D)} of the current lens position, it performs focus detection. For example, in the case where the camera control unit 21 determines that the in-focus position does not exist near the infinite distance end when the focus lens 32 is positioned near the infinite distance end, the camera control unit 21 drives the focus lens 32 to the infinite distance end By driving the focus lens 32 to the near side without moving the lens, the time required for focus detection can be shortened.

  Next, transmission processing of position information of the focus lens 32 executed by the lens control unit 37 will be described in detail based on an example of a scene shown in FIG.

  Although the example shown in FIG. 3 exemplifies a scene in which the drivable range of the focus lens 32 is limited, an example of such a scene is, for example, to reduce the time required for focusing. The camera control unit 21 transmits, to the lens control unit 37, a signal indicating that the focus control process of the focus lens 32 is performed around the in-focus position detected in the previous focus adjustment process. There are cases where the drivable range is limited by the camera control unit 37 based on this signal.

  Further, the present invention is not limited to the above-described situation. For example, when the close-up shooting mode for shooting a flower or the like is selected by the photographer, driving of the focus lens 32 from the camera control unit 21 to the lens control unit 37 is performed. The driveable range of the focus lens 32 may be limited to the near side by transmitting a signal for limiting the possible range to the near side, or a photographing mode for photographing a landscape etc. by the photographer When the camera control unit 21 transmits to the lens control unit 37 a signal for limiting the drivable range of the focus lens 32 to the infinity side, the drivable range of the focus lens 32 is selected. May be limited to the infinity side. Further, the lens control unit 37 may be configured to determine whether to limit the drivable range. When a signal for limiting the drivable range of the focus lens 32 is transmitted from the camera control unit 21 to the lens control unit 37, the signal is transmitted to the lens control unit 37 by command data communication.

For example, in the scene example illustrated in FIG. 3, the lens control unit 37 corresponds to the drive range (D _{0 to} D ₂₀ divisions) in which the focus lens 32 can be mechanically driven based on the signal transmitted from the camera control unit 21. of the range) that _sets a range corresponding to 6 section of the D 10 _{to D 15} as a driving range. Then, the lens control unit 37 sets segments corresponding to the drive range which is restricted to (6 section of the D ₁₀ to D ₁₅₎ as a limited segment, calculates the number of the restriction classified as 6. In addition, the lens control unit 37 acquires, from the encoder 35, 11 that is the section number of the section in which the current focus lens 32 exists.

Then, in the scene example shown in FIG. 3, as shown in Table 1, the lens control unit 37 sets 11 as the division number D _n of the current lens position, 6 as the number of restriction divisions, and infinite distance in the restriction divisions. As the position information of the focus lens 32, the lens communication unit 39 is used as the position information of the focus lens 32, which is 10 which is the division number N _{D_F} of the division located at the end and 15 which is the division number N _{D_N} of the division located at the near end Then, the information is transmitted to the camera communication unit 29 of the camera body 2 and the information is finally transmitted to the camera control unit 21.

Thereby, even when the drivable range of the focus lens 32 is limited, the lens control unit 37 can cause the camera control unit 21 to appropriately grasp the position of the focus lens 32 in the drivable range of the focus lens 32. . That is, in the example of the scene shown in FIG. 3, the camera control unit 21 divides the section of the present lens position into 11 which is the section number D _n of the lens position, 6 which is the number of restricted sections, and the section located at infinity in the restricted section. 10 is a number N _{D_F,} 15 and a partition number N _{d_n} sections located closest end in the restricted segment, by receiving the position information of the focus lens 32, a focus lens in the limited driving range The positional relationship of 32 can be specified. As a result, in the example of the scene shown in FIG. 3, it can be determined that the focus lens 32 is positioned near the infinite end.

On the other hand, in the related art, as shown in FIG. 3, even when the drivable range of the focus lens 32 is limited, as shown in Table 2, the section in which the current focus lens 32 exists In addition to 11, which is the division number corresponding to the drive range in which the focus lens 32 can be driven mechanically, 21 which is the division number corresponding to the infinitely far end, 0 which is the division number _{ND_F} of the infinitely far end, and the division number of the closest end 20, which is N _{D —} N, was transmitted as position information of the focus lens 32. Therefore, the camera control unit can not grasp the positional relationship of the focus lens 32 in the limited drivable range, and in the example of the scene shown in FIG. 3, for example, the focus lens 32 is positioned near the center of the drive range. There was a case that it was judged that it was wrong.

  Therefore, conventionally, when the focus adjustment of the focus lens 32 is performed, the focus adjustment is performed based on the incorrect position of the focus lens 32. As a result, it may take time to perform the focus adjustment. On the other hand, in the present embodiment, even when the drivable range of the focus lens 32 is limited, the positional relationship of the focus lens 32 in the limited drivable range (for example, the focus lens in the example shown in FIG. 3) 32 can be grasped in the vicinity of the infinite distance end, so that focusing can be properly performed based on the position of the focusing lens 32, and as a result, it is necessary for focusing. The effect of shortening the time can be obtained. In the present embodiment, transmission of the focus lens position from the lens control unit 37 to the camera control unit 21 is performed by command data communication.

As described above, in the present embodiment, when the drivable range of the focus lens 32 is limited, the number N of the limited sections corresponding to the limited drivable range as the position information of the focus lens 32, and the restricted category The section number N _{D_F} of the section located at the infinite distance end, the section number N _{D_N} of the section located at the near end in the restricted section, and the section where the focus lens 32 exists in the restricted section, the position of the focus lens 32 The information is transmitted to the camera body 2 as information. Thus, in the present embodiment, the position of the focus lens 32 in the limited drivable range can be appropriately grasped by the camera body 2, whereby the focus lens 32 can be determined based on the position information of the focus lens 32. The appropriate focus adjustment etc. can be performed.

  The embodiments described above are described to facilitate the understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents that fall within the technical scope of the present invention.

For example, in addition to the above-described embodiment, the data capacity of the division number N, the number N _{D_N} of the near end, the number N _{D_F of} the infinity side, and the number N _D of the current lens position is 1 byte In order to reduce the size to 255), the data volume may be compressed and the compressed data may be transmitted from the lens control unit 37 to the camera control unit 21.

Further, in the embodiment described above, for example, in the scene example shown in FIG. 3, 11 of the section number D _n of the current lens position, 6 which is the number of restricted sections, and the section located at infinity end in the restricted section 10 is a partition number N _{D_F,} 15 and a partition number N _{d_n} sections located closest end in the limit indicator, as the position information of the focus lens 32 has been illustrated the structure to be transmitted to the camera body 2, Not limited to this configuration, for example, the segment number N _{D — F} of the segment located at the infinite end in the restricted segment is offset to 0, and accordingly, the segment number N of the segment located at the closest end in the restricted segment by _{D_N} and offset the partition number D _n of the current lens position, as shown in Table 3, and 6 is the number of limit classification, be located in the infinity end in limited segment A configuration in which 0 corresponding to the division, 5 corresponding to the division located at the closest end in the restricted division, and 1 corresponding to the division of the current lens position are transmitted to the camera body 2 as position information of the focus lens 32 It may be In this case, since the data volume to be transmitted to the camera body 2 can be reduced, the positional information of the focus lens 32 can be transmitted to the camera body 2 without performing the above-described compression processing.

Further, in the above embodiment, as the position data of the focus lens 32, division division number N, the closest end of the partition number N _{d_n,} infinity side of the partition number N _{D_F,} and partition number N _D of the current lens position ( Although the configuration in which the compressed one is included is transmitted to the camera control unit 21 of the camera body 2 is exemplified, when the drivable range is limited to the infinity side, the number N of division divisions and the present lens Only the division number N _{D of the} position (including the one after compression) may be transmitted. Alternatively, in a limited driving range, infinite sections located end section number N _{D_F} and partition number N _{d_n} sections located closest _end, and, the current lens position partition number N _{D (after} compression ) May be transmitted. By reducing the number of data to be transmitted in this manner, it is possible to further reduce the communication load at the time of data transmission. In the above-described embodiment, one of the near-side segment number N _{D_N} and the infinity-side segment number N _{D_F} is set to be zero. Absent.

DESCRIPTION OF SYMBOLS 1 digital camera 2 camera main body 21 camera control part 22 imaging element 221 imaging pixel 222a, 222b focus detection pixel 29 camera communication part 3 lens barrel 32 focus lens 36 focus lens drive motor 37 Lens control unit 38 ... lens memory 39 ... lens communication unit

Claims (5)

A driving unit capable of driving the focusing optical system in the optical axis direction;
An acquisition unit configured to acquire position information of the focusing optical system;
A drive range limiting unit for limiting a drive range of the focusing optical system;
A transmitting / receiving unit for transmitting / receiving a signal to / from the camera body;
When the drive range of the focusing optical system is limited by the drive range limiting unit, positional information of the focusing optical system is different from that in the case where the drive range of the focusing optical system is not limited. A control unit configured to control the transmission / reception unit to transmit data to the camera body. The lens barrel according to claim 1, wherein
The acquisition unit acquires, as position information of the focusing optical system, information of the number of sections set in the optical axis direction and information of a section in which the focusing optical system is present,
The drive range limiting unit limits the drive range of the focusing optical system by limiting the sections which can be driven by the focusing optical system among the sections set in the optical axis direction,
When the drive range of the focusing optical system is limited by the drive range limiting unit, the control unit calculates the number of segments corresponding to the limited drive range as the number of limited segments, The transmission / reception unit is controlled to transmit, to the camera body, information on the number of the limited sections and information on a section in which the focused optical systems exist in the limited sections as position information of the focusing optical system. A lens barrel characterized by The lens barrel according to claim 2, wherein
When the drive range limiting unit limits the drive range of the focusing optical system, the control unit may use information on the number of the limited sections as position information of the focusing optical system, Information of at least one of the section number corresponding to the section at the near end and the section number corresponding to the section at the infinite end, and the information on the section number corresponding to the section in which the focusing optical system exists, the camera body A lens barrel that controls the transmission / reception unit so as to transmit the image data. In the lens barrel according to claim 3,
The control unit, when the drive range limiting unit limits the drive range of the focusing optical system, determines the closest end of the limited sections as the information of the section number in which the focusing optical system exists. Lens barrel characterized in that information on the division number in which the focusing optical system is present is transmitted to the transmission / reception unit when any one of the division number of and the division number of the infinite distance end is set to zero. .   A camera system comprising the lens barrel according to any one of claims 1 to 4 and a camera body.

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