JP2010026010A - Imaging apparatus and photographic lens - Google Patents

Abstract

An imaging apparatus capable of detecting the amount and direction of movement of a photographic lens even when a photographic lens equipped with a pulse encoder that outputs a single-phase pulse signal is attached.
In a two-phase lens, a moving amount and a moving direction of a focus lens are represented by two pulse signals having different phases. The single-phase lens represents a movement amount and a movement direction of a focus lens (not shown) using a pulse signal that represents the movement amount and a signal that represents the movement direction. In order to support these two types of photographing lenses, the communication unit 125 on the camera body side includes two types of pulse counters. The communication unit 125 switches between two types of pulse counters according to the type of the photographing lens 200 attached to the camera body 100, and processes a signal passing through the second transmission path with an appropriate pulse counter.
[Selection] Figure 2

Description

  The present invention relates to an imaging apparatus system including an imaging apparatus such as a digital single-lens reflex camera and an interchangeable photographic lens.

  In general, an imaging apparatus system including an interchangeable imaging lens and an imaging apparatus to which the imaging lens can be attached is configured so that the imaging apparatus can detect the movement amount and the movement direction of the optical system of the imaging lens. . For example, a photographing lens that outputs a two-phase pulse signal according to the movement of the optical system is known. This two-phase pulse signal is a signal that represents the amount of movement of the optical system by the number of pulses and the direction of movement of the optical system by a phase difference. On the other hand, for reasons such as cost reduction, there are photographing lenses that output only a single-phase pulse signal that is not two-phase. This photographing lens outputs only a pulse signal that represents the amount of movement of the optical system by the number of pulses.

  When an imaging lens that outputs a single-phase pulse signal is attached to the imaging apparatus instead of an imaging lens that outputs a two-phase pulse signal, the imaging apparatus cannot detect the moving direction of the optical system.

The invention according to claim 1 is an imaging apparatus in which a photographic lens can be detachably attached, and a receiving unit that receives a signal output from the photographic lens attached to the imaging apparatus, and the photographic lens, It is a first imaging lens that outputs a two-phase pulse signal that represents the movement amount and movement direction of the photographing lens, or a single-phase pulse signal that represents the movement amount of the photographing lens, and the movement of the photographing lens A determination unit that determines whether the second imaging lens outputs a direction signal that is a direction signal that is different from a pulse signal that represents the movement amount; and the determination unit determines the first imaging lens as the first imaging lens. If the lens is determined to be a photographic lens, the movement amount and direction of the photographic lens are detected from the two-phase pulse signal, and the determination means determines the photographic lens as the second photographic lens. If it is determined that, from the pulse signal of the single-phase and the direction signal, which is an imaging apparatus characterized by comprising a detecting means for detecting a moving amount and the moving direction of the photographing lens.
According to a sixth aspect of the present invention, a predetermined photographing lens having a first lens side terminal and a second lens side terminal for outputting a two-phase pulse signal representing a moving amount and a moving direction of the photographing lens is attached and detached. When the predetermined photographing lens is attached, the first camera side terminal to which the first lens side terminal is connected, and the predetermined photographing lens are attached. And a second camera side terminal to which the second lens side terminal is connected. A photographic lens that can be attached to an imaging apparatus in the same manner as the predetermined photographic lens. A signal connected to the third lens side terminal for outputting a single-phase pulse signal representing the moving amount of the photographing lens and a signal representing the moving direction of the photographing lens by a signal level. Output 4 and the lens-side terminal of a photographic lens, characterized in that it comprises a.

  According to the present invention, the imaging apparatus can be used in an optical system regardless of whether the imaging lens that outputs a single-phase pulse signal and direction signal or the imaging lens that outputs a two-phase pulse signal is attached to the imaging apparatus. The amount and direction of movement can be detected.

-First embodiment-
With reference to FIGS. 1-2, 1st Embodiment to which this invention is applied is described about a camera body and a photographic lens. FIG. 1 is a perspective view showing a camera body 100 of a single-lens reflex camera to which the present invention is applied and a photographing lens 200 attached to the camera body 100. FIG. FIG. The camera body 100 is provided with a control circuit 101 that controls each part of the camera body 100, an imaging unit 102, a release button 104, a camera side lens mount 108, and a recording medium mounting portion 100a. The recording medium 11 is inserted and attached to the recording medium mounting portion 100a.

  Reference numeral 105 denotes a photographic optical path for guiding a subject image from the photographic lens 200 to the imaging unit 102, 106 denotes a main mirror, and 107 denotes a camera-side diaphragm interlocking lever for driving the diaphragm of the photographic lens 200. . In the present embodiment, the diaphragm of the photographing lens 200 is described as being driven by the diaphragm interlocking lever 107 on the camera body side. However, the present invention is not limited to this, and a diaphragm driving actuator (for example, an ultrasonic motor) is incorporated in the photographing lens 200. ) And the diaphragm may be driven by this actuator. The camera side lens mount 108 is an attachment portion to which the photographing lens 200 is detachably attached to the camera body 100. The camera side lens mount 108 includes a connection unit 109 having a plurality of terminals including a terminal for performing communication with the photographing lens 200 side and a terminal for supplying power to the photographing lens 200 side, and the photographing lens 200. And a mechanical switch (not shown) for detecting the attachment / detachment.

  As shown in FIG. 2, the camera body 100 includes a distance measuring sensor 121, a photometric sensor 122, a monitor 123, a release switch 124, a communication unit 125, a light emitting device control unit 126, and a light emitting device 127. Is provided. The distance measuring sensor 121 is a sensor that outputs focusing information indicating a focusing state on a subject of the photographing optical system. The photometric sensor 122 is a sensor that outputs a photoelectric conversion signal for photometric processing corresponding to the brightness of the subject image.

  The monitor 123 is a monitor for displaying an image obtained by shooting, various information related to shooting, and the like, and is provided on the back surface of the camera body 100 using, for example, a liquid crystal display device. The release switch 124 outputs a release operation signal to the control circuit 101 in conjunction with the release button 104. The release operation signal includes a half-press operation signal corresponding to a half-press operation of the release button and a full-press operation signal corresponding to a full-press operation pressed deeper than the half-press operation. The communication unit 125 communicates with the photographing lens 200 attached to the camera body 100. The light emitting device control unit 126 is a control unit that controls the illumination light irradiated to the subject by controlling the light emission of the light emitting device 127, and a photometric sensor (not shown) that detects the brightness of the subject light via the photographing lens 200. have.

  The imaging unit 102 is integrally provided with the imaging element 2 and an optical filter (not shown) disposed on the front surface of the imaging element 2. The imaging device 2 is configured by a CCD image sensor or the like that is a device that converts a subject image into an electrical image signal. The image sensor 2 captures an image of subject light that has passed through the photographing lens 200 and outputs an image signal (analog image signal). The recording medium 11 is a storage medium that can be attached to and detached from the camera body 100, such as a memory card, and stores image data that has been subjected to predetermined processing by the control circuit 101 as will be described later.

  As shown in FIG. 1, the photographing lens 200 is provided with a lens side mount 201, a plurality of optical lenses (not shown) for forming a subject image on the imaging surface of the imaging device 2, and a control circuit 205. ing. Reference numeral 203 denotes a lens-side aperture interlocking lever that is driven by the camera-side aperture interlocking lever 107. The lens side mount 201 includes a connection unit 202 having a plurality of terminals including a terminal for communication with the camera body 100 side and a terminal for receiving power supply from the camera body 100 side, and a camera side lens mount. A pressing portion (not shown) that presses the mechanical switch provided at 108 is provided.

  As shown in FIG. 2, the photographing lens 200 is provided with a lens side blur correction device (lens side VR device) 210, a lens driving device 220, and a communication unit 240. The lens side VR device 210 is a device for correcting blurring of an optical image due to shake of the photographing lens 200 and the camera body 100 to which the photographing lens 200 is attached. The lens-side VR device 210 includes an acceleration sensor (lens-side acceleration sensor) 210 a for detecting a change in posture of the photographing lens 200 (amount of blur of the photographing lens 200), and a blur of a subject image on the imaging surface of the image sensor 2. A blur correction optical system (not shown) that corrects the image and a drive device (not shown) that drives the blur correction optical system are provided. The lens driving device 220 drives a focus lens (not shown) to advance and retreat in the optical axis direction in response to an instruction from the control circuit 205. In the present embodiment, the subject side in the optical axis direction is defined as “front”, and the camera body side is defined as “rear”. The photographing lens 200 is provided with a focus ring (not shown) for manual focus adjustment, and the user can manually focus. The communication unit 240 communicates with the camera body 100 to which the photographing lens 200 is attached.

  When the photographing lens 200 is attached to the camera side lens mount 108 of the camera body 100, the lens side diaphragm lever 203 and the camera side diaphragm interlocking lever 107 come into contact with each other. The lens side aperture lever 203 is driven by the camera side aperture interlocking lever 107 and controlled to a predetermined aperture value at the time of shooting. When the photographing lens 200 is attached to the camera-side lens mount 108 of the camera body 100, the connection part 202 of the photographing lens 200 and the connection part 109 of the camera body 100 are connected. When the photographic lens 200 is attached to the camera side lens mount 108 of the camera body 100, a mechanical switch (not shown) provided on the camera side lens mount 108 is pressed by a pressing portion (not shown) provided on the camera side lens mount 108. Pressed.

  As shown in FIG. 2, the control circuit 101 of the camera body 100 includes an AFE (Analog Front End) circuit 131, an A / D conversion circuit 132, a driver 133, a timing generator (TG) 134, and an image processing circuit 135. An image compression circuit 136, a main CPU 137, a buffer memory 138, and a display image creation circuit 139.

  The timing generator (TG) 134 generates a timing signal in response to an instruction sent from the main CPU 137 and supplies the timing signal to each of the driver 133, the AFE circuit 131, and the A / D conversion circuit 132. The driver 133 generates a drive signal necessary for the image sensor 2 to capture an image using the timing signal, and supplies the generated drive signal to the image sensor 2. The AFE circuit 131 performs analog processing (such as gain control) on the photoelectric conversion signal output from the image sensor 2. The A / D conversion circuit 132 converts the imaging signal after analog processing into a digital signal.

  The main CPU 137 receives a signal output from each block, performs a predetermined calculation, and outputs a control signal based on the calculation result to each block. The image processing circuit 135 is configured as an ASIC, for example, and performs image processing on the digital image signal input from the A / D conversion circuit 132. For image processing, for example, grouping processing for detecting subject brightness, contrast, and the like corresponding to each predetermined area on the image sensor 2, contour enhancement and color temperature adjustment (white balance adjustment) for the image signal from the image sensor 2 ) Processing, image correction processing described later based on lens parameter information, format conversion processing for the image signal, and the like.

  The image compression circuit 136 performs image compression processing on the image signal processed by the image processing circuit 135 at a predetermined compression ratio using the JPEG method. The display image creation circuit 139 creates display data for displaying the captured image on the monitor 123.

  In the recording medium 11 mounted on the recording medium mounting unit 100a, the image file including the data of the captured image and the information thereof is recorded according to an instruction from the main CPU 137. The image file recorded on the recording medium 11 can be read by an instruction from the main CPU 137. The buffer memory 138 temporarily stores data before and after image processing and in the middle of image processing, stores an image file before recording on the recording medium 11, and stores an image file read from the recording medium 11. Used for.

  Further, the control circuit 101 of the camera body 100 includes a memory 141. The memory 141 is a memory including a ROM for storing a control program, various setting values set in advance, and a RAM for a work area. The main CPU 137 accesses the memory 141, executes a control program, and performs various controls.

  The control circuit 205 of the photographing lens 200 includes a main CPU 231 and a memory 232. The main CPU 231 inputs a signal output from each block, performs a predetermined calculation, and outputs a control signal based on the calculation result to each block. The memory 232 is a memory including a ROM for storing control programs, various setting values set in advance, and a RAM for a work area. The ROM of the memory 232 stores lens parameter information of the taking lens 200.

  Next, lens parameters will be described. The lens parameter is data representing the characteristics of the photographing lens 200, and includes, for example, data representing the optical characteristics of the photographing lens 200 and data representing characteristics other than the optical characteristics of the photographing lens 200. Examples of data representing the optical characteristics of the taking lens 200 include a lateral chromatic aberration parameter, an axial chromatic aberration parameter, a coma aberration parameter, a distortion aberration parameter, a peripheral light attenuation parameter, a γ value parameter, a white balance parameter, a contour correction parameter, There are parameters relating to vignetting, parameters relating to the amount of defocus due to the aperture value, and the like. These data are respectively stored in the ROM 232 as correction amount data for performing correction on the camera body side.

  Examples of data representing characteristics other than the optical characteristics of the photographic lens 200 include, for example, data relating to the amount of image plane movement per one lens drive command pulse from the camera body side, and data relating to play (mechanical play) of the lens drive system (drive). Information relating to the focus adjustment of the taking lens 200, such as (quantity difference information), and the like, each of which is stored in the ROM 232. In addition to these data, there is lens type data to be described later. Lens type data is also stored in the ROM 232 in the same manner as other data.

  Next, communication between the camera body 100 and the photographing lens 200 will be described. There are two types of transmission paths between the camera body 100 and the taking lens 200. One transmission path is a first transmission path for transferring control information such as a lens movement instruction between the camera body 100 and the photographing lens 200. The other transmission path is a second transmission path for transmitting to the camera body 100 the movement amount and movement direction of a focus lens (not shown) included in the photographing lens 200. Both types of transmission lines can be used by connecting the terminals included in the connection unit 109 and the terminals included in the connection unit 202.

  The signal passing through the second transmission path is different depending on the type of the taking lens 200. There are two types of photographic lenses 200 attached to the camera body 100, and these two types of photographic lenses output signals representing the amount and direction of movement of the focus lens transmitted by the second transmission path in different ways. In the following description, one of the two types of photographing lenses is referred to as a “two-phase lens” and the other is referred to as a “single-phase lens”. Each photographing lens holds data representing its own lens type in the ROM 232.

  In the two-phase lens, a movement amount and a movement direction of a focus lens (not shown) are represented by two pulse signals having different phases. One of the two pulse signals is delayed from the other pulse signal when the focus lens moves forward, and advances from the other pulse signal when the focus lens moves backward. Therefore, the camera body 100 can know the moving direction of the focus lens by examining the phase difference between the two pulse signals.

  In the two-phase lens, the movement amount of the focus lens is represented by the number of pulses. The two-phase lens outputs a number of pulses corresponding to the amount of movement of the focus lens. Therefore, the camera body 100 can know the amount of movement of the focus lens by counting the rise and fall of the two pulse signals output from the two-phase lens.

  The single-phase lens represents the movement amount and movement direction of a focus lens (not shown) using a pulse signal that represents the movement amount and a signal that represents the movement direction. The pulse signal representing the amount of movement represents the amount of movement of the focus lens by the number of pulses as in the case of the two-phase lens. The signal representing the movement direction represents the movement direction by changing the signal level between when the focus lens moves to one side and when the focus lens moves to the other side.

  In order to support these two types of photographing lenses, the communication unit 125 on the camera body side includes two types of pulse counters. The communication unit 125 switches between two types of pulse counters according to the type of the photographing lens 200 attached to the camera body 100, and processes a signal passing through the second transmission path with an appropriate pulse counter.

  Next, the communication unit 125 on the camera body side will be described.

  FIG. 3 is a block diagram illustrating main components of the communication unit 125. Terminals Xc, Yc, and Zc are terminals included in the connecting portion 109 provided on the camera side lens mount 108. When the photographing lens 200 is attached to the camera body 100, the terminals included in the photographing lens 200 (details will be described later). Connected).

  The terminals Xc and Yc correspond to the above-described second transmission path, and signals representing the movement amount and movement direction of a focus lens (not shown) provided in the photographing lens 200 are input. Signals input to the terminals Xc and Yc are converted into numerical values inside the communication unit 125 and sent to the main CPU 137 as numerical values representing the moving amount and moving direction of the focus lens. The amount of movement of the focus lens is represented by the absolute value of the difference between this value and the value before the focus lens moves. The moving direction of the focus lens is represented by the sign of the difference between this value and the value before the focus lens moves.

  The terminal Zc corresponds to the first transmission path described above, and is a terminal for performing so-called serial communication between the camera body 100 and the photographing lens 200. The camera body 100 issues various control instructions to the photographing lens 200 by transmitting control information from the terminal Zc.

  The communication unit 125 includes a control circuit 150, a two-phase counter 151, a single-phase counter 152, an interrupt controller 153, a switch 154, and a switch 155. The control circuit 150 performs serial communication with the photographing lens 200 using the terminal Zc.

  The two-phase counter 151 and the single-phase counter 152 convert signals input to the terminals Xc and Yc into numerical values. Only one of these two counters operates at the same time. Which one operates is controlled by the main CPU 137.

  When a single-phase lens is attached to the camera body 100, the main CPU 137 controls the switch 154 to connect the terminal Yc and the interrupt controller 153. The main CPU 137 further controls the switch 155 to connect the output of the single-phase counter 152 and the output of the communication unit 125. As a result, the single-phase counter 152 operates and the two-phase counter 151 does not operate.

  On the other hand, when the two-phase lens is attached, the main CPU 137 controls the switch 154 to connect the terminal Yc and the two-phase counter 151. The main CPU 137 further controls the switch 155 to connect the output of the two-phase counter 151 and the output of the communication unit 125. As a result, the two-phase counter 151 operates and the single-phase counter 152 does not operate.

  When the two-phase counter 151 receives two pulse signals having different phases, the two-phase counter 151 outputs a result of pulse counting. The two-phase counter 151 reverses the polarity of the count according to which of the two pulse signals is delayed.

  The single-phase counter 152 receives one pulse signal and outputs the result of pulse counting. Counting is performed in either positive or negative direction, and the positive / negative of the count can be changed from the outside of the single-phase counter 152.

  The interrupt controller 153 receives one signal. When the signal level of the input signal changes, the main CPU 137 is interrupted. In response to this interrupt, the main CPU 137 reverses the sign of the single-phase counter 152. If the terminal Yc is not connected to the interrupt controller 153 by the switch 154, the interrupt controller 153 does nothing.

  Next, the communication unit on the photographing lens side will be described. As described above, the photographing lens 200 includes two types, a two-phase lens and a single-phase lens. These two types of photographic lenses differ in the configuration of the communication unit. Hereinafter, the communication unit of the two-phase lens is referred to as a communication unit 240a, and the communication unit of the single-phase lens is referred to as a communication unit 240b.

  FIG. 4 is a block diagram showing a communication unit on the photographing lens side and its peripheral components. FIG. 4A shows the communication unit 240a and its peripheral components in the two-phase lens, and FIG. 4B shows the communication unit 240b and its peripheral components in the single-phase lens. Hereinafter, the configuration of the communication unit in each case will be described in order.

  First, the communication unit 240a and its periphery in the two-phase lens will be described with reference to FIG. The communication unit 240a includes terminals Xa, Ya, and Za, and a control circuit 241a. The two-phase lens includes a lens driving device 220a, a main CPU 231a, and photo interrupters 250a and 251a.

  Terminals Xa, Ya and Za included in communication unit 240a are connected to terminals Xc, Yc and Zc included in communication unit 125 on the camera body side shown in FIG. The control circuit 241a transmits and receives control information to and from the camera body 100 through the terminal Za.

  The main CPU 231a is connected to a control circuit 241a and a lens driving device 220a included in the communication unit 240a. When the camera body 100 transmits control information including an instruction to move a focus lens (not shown) from the terminal Zc, the control information is transmitted to the main CPU 231a by the control circuit 241a via the terminal Za. The main CPU 231a that has received the control information controls the lens driving device 220a based on the control information to move the focus lens.

  The photo interrupters 250a and 251a output a number of pulses corresponding to the amount of movement when the lens driving device 220a moves a focus lens (not shown). These two photo interrupters are configured to output pulse signals that are 90 degrees out of phase.

  When the focus lens advances forward, the pulse signal output by the photo interrupter 250a is output with a delay of 90 degrees compared to the output of the photo interrupter 251a. On the other hand, when the focus lens advances backward, the pulse signal output from the photo interrupter 250a is output 90 degrees ahead of the output of the photo interrupter 251a.

  The photo interrupter 250a outputs a pulse signal to the terminal Ya and the main CPU 231a. Similarly, the photo interrupter 251a outputs a pulse signal to the terminal Xa and the main CPU 231a.

  Next, the communication part and its periphery in a single phase lens are demonstrated using FIG.4 (b). In the case of a single-phase lens, unlike the two-phase lens, the photo interrupter has only a photo interrupter 251b connected to the terminal Xb and the main CPU 231b. Further, the terminal Yb is configured to output the signal output from the main CPU 231b to the camera body 100 as it is.

  Similar to the case of the two-phase lens, the photo interrupter 251b outputs a number of pulses corresponding to the amount of movement when the lens driving device 220b moves a focus lens (not shown). When the main CPU 231b controls the lens driving device 220b to advance the focus lens forward, the main CPU 231b outputs a signal having a signal level corresponding to High to the terminal Yb. On the other hand, when the focus lens is advanced backward, a signal having a signal level corresponding to Low is output to the terminal Yb.

  Next, signals output to the terminals Xc and Yc and the count value output from the communication unit 125 on the camera body side will be described using specific examples. Hereinafter, an example of a signal output from the two-phase lens and a count value output from the two-phase counter 151 will be described first, and then an example of a signal output from the single-phase lens and a count value output from the single-phase counter 152 will be described. Will be explained.

  FIG. 5 is a diagram illustrating signals output from the two-phase lens. FIG. 5A shows an example in which the count value increases, and FIG. 5B shows an example in which the count value decreases. That is, the example of FIG. 5B shows a signal when the focus lens (not shown) is moved in the direction opposite to the example of FIG.

  In FIG. 5A, the signal at the terminal Xa changes from L (Low) to H (High) at time T51, and the signal at the terminal Ya changes from L to H at time T52 later than that. As described above, when the signal at the terminal Ya is output later than the signal at the terminal Xa, the two-phase counter 151 increases the count value in accordance with the change in the signal.

  On the other hand, in FIG. 5B, the signal at the terminal Ya changes from L to H at time T53, and the signal at the terminal Xa changes from L to H at time T54 later than that. As described above, when the signal at the terminal Xa is output later than the signal at the terminal Ya, the two-phase counter 151 decreases the count value in accordance with the change in the signal.

  FIG. 6 is a diagram illustrating a signal output from the single-phase lens. FIG. 6A shows a signal to the single-phase counter 152, and FIG. 6B shows a signal output from the single-phase lens.

  The single-phase counter 152 has two types of operation modes, an increase mode and a decrease mode. In the increase mode, the count value is increased according to the change in the signal at the terminal Xb. In the decrease mode, the count value is decreased according to the change in the signal at the terminal Xb. FIG. 6A shows the counter value when the single-phase counter 152 is in the increment mode. At this time, the single-phase counter 152 increases the count value in accordance with the change in the signal at the terminal Xb.

  The signal at the terminal Yb is input to the interrupt controller 153 as shown in FIG. When the interrupt controller detects that the signal level of the input signal has changed, it generates an interrupt to the main CPU 137. The main CPU 137 that has detected the interrupt changes the operation mode of the single-phase counter 152 to an operation mode different from the current operation mode.

  FIG. 6B is a diagram illustrating signals output from the terminals Xb and Yb by the single-phase lens. At times T61 and T62, the signal level of the terminal Yb is H. Therefore, the single-phase counter 152 is in the increase mode, and the count value increases due to a change in the signal at the terminal Xb. On the other hand, at time T63 and T64, the signal level of the terminal Yb is L. At this time, the single-phase counter 152 is in a decrement mode, and the count value is decremented by a change in the signal at the terminal Xb.

  Next, specific processing contents of the camera body 100 will be described with reference to the drawings. FIG. 7 is a flowchart showing processing of the camera body 100 regarding attachment and removal of the photographing lens 200. First, in step S1, it is determined whether or not the taking lens 200 is attached, and step S1 is repeated until an affirmative determination is made. When the photographing lens 200 is attached, an affirmative determination is made, and the process proceeds to step S2.

  In step S2, an inquiry is made as to whether the attached photographing lens 200 is a two-phase lens or a single-phase lens by communication through the terminal Zc. As a result of the inquiry, the main CPU 137 receives data representing the lens type stored in the ROM 232 of the photographing lens 200 through the terminal Zc. In step S3, a branching process based on the lens type obtained in step S2 is performed. If the lens type is a two-phase lens, the process proceeds to step S4. If the lens type is a single phase lens, the process proceeds to step S7.

  In step S4, the switch 154 is switched to the two-phase counter side, and in step S5, the switch 155 is switched to the two-phase counter side. Thereby, the two-phase counter 151 becomes effective. In step S6, it is determined whether the taking lens 200 has been removed. If the photographic lens is not removed, the process of step S6 is repeated until the photographic lens is removed. On the other hand, if a positive determination is made in step S6, the process returns to step S1, and step S1 is repeated until the photographic lens is attached again.

  In step S7, the switch 154 is switched to the interrupt controller side, and in step S8, the switch 155 is switched to the single-phase counter side. As a result, the single-phase counter 152 and the interrupt controller 153 are enabled. In step S9, it is determined whether or not an interrupt by the interrupt controller 153 has occurred. If an interrupt has occurred, an affirmative determination is made, and processing proceeds to step S10. In step S10, the operation mode of the single-phase counter is changed to a mode different from the current mode, and the process proceeds to step S11. That is, the operation mode of the single-phase counter is switched to the decrease mode if the current operation mode is the increase mode, and to the increase mode if the current operation mode is the decrease mode. On the other hand, if a negative determination is made in step S9, the process proceeds to step S11.

  In step S11, it is determined whether or not the taking lens 200 has been removed. If the photographic lens has not been removed, a negative determination is made in step S11, and the process returns to step S9. On the other hand, if a positive determination is made in step S11, the process returns to step S1, and step S1 is repeated until the photographic lens is attached again.

  According to the camera body and the photographing lens according to the first embodiment described above, the following operational effects can be obtained.

(1) When the photographing lens 200 is attached to the camera body 100, the main CPU 137 inquires about the lens type through the communication unit 125 and determines whether the lens is a two-phase lens or a single-phase lens. If it is determined that the lens is a two-phase lens, a two-phase counter is used. If a single-phase lens is determined, a single-phase counter is used to perform pulse counting of signals output from the photographing lens 200 to the terminals Xc and Yc. Get the count value. The difference between the count value before movement of the focus lens and the count value after movement is calculated, and the movement amount of the focus lens is detected from the absolute value of the difference, and the movement direction of the focus lens is detected from the sign of the difference. Thereby, the movement amount and movement direction of the focus lens can be detected regardless of which of the two types of photographing lenses with different output signals is attached.

(2) The signal output from the photographic lens 200 is input to the terminals Xc and Yc regardless of whether the signal is a two-phase lens or a single-phase lens. Thereby, it is not necessary to provide an additional terminal in order to cope with a plurality of types of photographing lenses.

  In the first embodiment described above, two types of pulse counters are prepared for two types of photographing lenses. In the second embodiment described in detail below, only two-phase counters are used and two types of photographing lenses are supported.

-Second embodiment-
FIG. 8 is a block diagram illustrating main components of the communication unit 325 included in the camera body according to the present embodiment. The communication unit 325 includes a control circuit 350, a two-phase counter 351, a switch 354, a switch 355, a delay circuit 356, and a switch 357.

  The control circuit 350 performs serial communication with the photographing lens 200 using the terminal Zd, similarly to the control circuit 150 included in the communication unit 125 in the first embodiment. The two-phase counter 351 operates in the same manner as the two-phase counter 151 in the first embodiment.

  Unlike the first embodiment, the communication unit 325 outputs only the output of the two-phase counter 351 as a count value. That is, the communication unit 325 includes only one type of pulse counter. The correspondence to the two types of photographing lenses is performed by processing the inputs to the two-phase counter 351 by the switches 354, 355 and 357 and the delay circuit 356.

  The signal input to the terminal Xd is directly input to the input terminal D of the switch 357. The signal at the terminal Xd is also input to the delay circuit 356. The delay circuit 356 outputs a signal obtained by delaying the input signal by a predetermined time. An output signal of the delay circuit 356 is input to the switch 355.

  On the other hand, the signal input to the terminal Yd is input to the switch 354. The switch 354 inputs the signal of the terminal Yd to either the switch 355 or the input terminal F of the switch 357. The switch 355 inputs either the output of the delay circuit and the output of the switch 354, that is, the signal of the terminal Yd, to the input terminal E of the switch 357.

  The switch 357 is a switch having three input terminals D, E and F and two output terminals G and H. When the signal input from the input terminal F is other than L, the switch 357 outputs the signal of the input terminal D to the output terminal G and the signal of the input terminal E to the output terminal H as it is. The same applies when no signal is input to the input terminal F.

  When the signal input from the input terminal F is L, the switch 357 replaces and outputs the above output signals. That is, the signal of the input terminal E is output from the output terminal G, and the signal of the input terminal D is output from the output terminal H as it is.

  When the two-phase lens is attached to the camera body, the main CPU connects the terminal B and the switch 355 by controlling the switch 354, and controls the switch 355 to output the switch 354 and the input terminal of the switch 357. F is connected. That is, when the two-phase lens is attached, the signal of the terminal Yd is input to the input terminal E of the switch 357. Since nothing is input to the input terminal F of the switch 357, the signal at the terminal Xd and the signal at the terminal Yd are input as they are to the two-phase counter.

  When a single-phase lens is attached to the camera body, the main CPU connects the terminal Yd and the input terminal F of the switch 357 by controlling the switch 354, and controls the switch 355 to delay the circuit 356 and the switch 357. To the input terminal E. That is, when the single-phase lens is attached, the output of the delay circuit 356 is input to the input terminal E of the switch 357 and the signal of the terminal Yd is input to the input terminal F of the switch 357. As a result, the signal at the terminal Xd and the signal output from the delay circuit 356 are input to the two-phase counter while being switched according to the signal at the terminal Yd.

  FIG. 9 is a diagram illustrating an example of an input signal to the two-phase counter when a single-phase lens is attached. Since the signal at the terminal Yd is H at first, the switch 357 outputs the signal at the input terminal D from the output terminal G and the signal at the input terminal E from the output terminal H. The output terminal G is an input A to the two-phase counter in FIG. 9, and the output terminal H is an input B to the two-phase counter in FIG.

  At time T91, the signal at the terminal Xd appears as it is at the input A to the two-phase counter. The delay circuit 356 outputs the signal at the terminal Xd at time T92 delayed by a predetermined time, and the output of the delay circuit 356 appears at the input B to the two-phase counter.

  Since the signal at the terminal Yd becomes L at time T93, the switch 357 switches the output signal. That is, the signal of the input terminal D is output from the output terminal H, and the signal of the input terminal E is output from the output terminal G. Thus, from time T93, the signal at the terminal Xd appears at the input B to the two-phase counter, and the output of the delay circuit 356 appears at the input A to the two-phase counter.

  As described above, the communication unit 325 performs pulse counting corresponding to the two types of photographing lenses, and outputs the same as the count value in the first embodiment.

  According to the camera body and photographing lens according to the second embodiment described above, the following operational effects can be obtained in addition to the operational effects obtained with the camera body and photographing lens according to the first embodiment.

(1) The pulse signal input from the single-phase lens and another pulse signal obtained by adding a delay to the pulse signal are input to the two-phase counter. Further, these two pulse signals are exchanged by a switch that operates based on a signal indicating the moving direction of the focus lens. That is, one of the two pulse signals input to the two-phase counter is either advanced or delayed from the other based on the signal indicating the moving direction. Thereby, it is possible to deal with two types of photographing lenses without having to prepare two pulse counters.

  The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.

(1) Instead of using a single-phase counter and an interrupt controller, a single-phase counter that switches between increasing and decreasing depending on the signal level of a signal input separately from a pulse signal may be used in order to support a single-phase lens. . In this case, the signal input to the interrupt controller is directly input to the single-phase counter as described above.

(2) The photographing lens may generate a pulse signal by a member other than the photo interrupter.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

1 is a perspective view showing a camera body 100 of a single-lens reflex camera to which the present invention is applied and a photographing lens 200 attached to the camera body 100. FIG. FIG. 2 is a block diagram illustrating configurations of a camera body 100 and a photographing lens 200. 3 is a block diagram illustrating main components of a communication unit 125. FIG. It is a block diagram which shows the communication part 240 by the side of a photographic lens, and its surrounding component. It is a figure which shows the signal which a two phase lens outputs. It is a figure which shows the signal which a single phase lens outputs. 5 is a flowchart showing processing of the camera body 100 related to attachment and removal of the photographing lens 200. It is a block diagram which shows the main components of the communication part 325 with which a camera body is provided. It is a figure which shows the example of the input signal to a 2 phase counter when a single phase lens is attached in 2nd Embodiment.

Explanation of symbols

100 Camera body 200 Shooting lens 125, 325 Communication unit (camera body side)
137 Main CPU (Camera body side)
231, 231a, 231b Main CPU (photographing lens side)
240, 240a, 240b Communication unit (photographing lens side)

Claims (6)

An imaging device to which a photographic lens can be detachably attached,
Receiving means for receiving a signal output from the photographing lens attached to the imaging device;
Whether the photographic lens is a first photographic lens that outputs a two-phase pulse signal that represents a movement amount and a movement direction of the photographic lens, or a single-phase pulse signal that represents a movement amount of the photographic lens; A determination means for determining whether the second photographing lens outputs a direction signal different from a pulse signal representing the movement amount, which is a signal representing the movement direction of the photographing lens;
When the determination unit determines that the photographic lens is the first photographic lens, the movement amount and the movement direction of the photographic lens are detected from the two-phase pulse signals, and the determination unit detects the photographic lens as the photographic lens. When it is determined that it is the second photographing lens, detection means for detecting a moving amount and a moving direction of the photographing lens from the single-phase pulse signal and the direction signal;
An imaging apparatus comprising: The imaging device according to claim 1,
The receiving means includes a first input terminal and a second input terminal,
When the first imaging lens is attached to the imaging device, the first input terminal receives one of the two-phase pulse signals, and the second input terminal receives the two-phase pulse signals. Receive the other of
When the second imaging lens is attached to the imaging apparatus, the first input terminal receives a pulse signal indicating the movement amount, and the second input terminal receives a signal indicating the movement direction. An imaging device characterized by receiving. The imaging device according to claim 1 or 2,
The imaging device detects whether the moving direction of the photographing lens is a first direction or a direction opposite to the first direction from the signal level of the direction signal. In the imaging device according to any one of claims 1 to 3,
The detection means includes
Two-phase counting means for performing pulse counting by switching between count-up and count-down based on the phase difference between the two-phase pulses;
Switching between counting up and counting down based on a signal representing the moving direction, and single-phase counting means for performing pulse counting using a pulse signal representing the moving amount,
When the determination means determines the first photographic lens, pulse counting is performed using the two-phase counting means,
When the determination unit determines the second photographic lens, an image pickup apparatus that detects a moving amount of the photographic lens by performing pulse counting using the single-phase counting unit. In the imaging device according to any one of claims 1 to 3,
The detection means includes
Phase difference pulse output means for outputting a phase difference pulse signal obtained by adding a predetermined phase difference based on the direction signal to the single phase pulse signal;
A third input terminal and a fourth input terminal, and counting up based on a phase difference between a pulse signal input to the third input terminal and a pulse signal input to the fourth input terminal; And two-phase counting means for performing pulse counting by switching between countdown and
When the determination means determines the first photographing lens, one of the two-phase pulses is input to the third input terminal, and the other of the two-phase pulses is input to the fourth input terminal,
When the determination means determines the second photographic lens, by inputting the single-phase pulse signal to the third input terminal and the phase difference pulse signal to the fourth input terminal, An image pickup apparatus that detects a moving amount of the photographing lens. Attachment means for detachably attaching a predetermined photographic lens having a first lens side terminal and a second lens side terminal for outputting a two-phase pulse signal representing a movement amount and a movement direction of the photographic lens When,
A first camera side terminal to which the first lens side terminal is connected when the predetermined photographing lens is attached;
A second camera side terminal to which the second lens side terminal is connected when the predetermined photographing lens is attached;
A photographic lens that can be attached to an imaging device comprising the same as the predetermined photographing lens,
A third lens-side terminal connected to the first camera-side terminal and outputting a single-phase pulse signal representing the amount of movement of the photographic lens;
A fourth lens side terminal that is connected to the second camera side terminal and outputs a signal representing the moving direction of the photographing lens by a signal level;
A photographic lens comprising:

Images