JP6080834B2 - Interchangeable lens and camera system - Google Patents

Description

  The present invention relates to an interchangeable lens and a camera system including the interchangeable lens and a camera body.

  Patent Document 1 discloses a camera system in which when an interchangeable lens is mounted on a camera body, both communicate to exchange information and initialize a lens in parallel. Here, “lens initialization” means that the zoom lens or the focus lens is moved to a predetermined position.

JP-A-11-64956

  Patent Document 1 speeds up the activation of the camera system by parallel processing. However, before parallel exchange of information between the interchangeable lens and the camera body (that is, before recognizing the specifications and functions of each other), Initialization will be performed. This may cause some problems.

  For example, if the initialization of the lens is started before the camera power supply is completely started up, the initialization of the lens may fail. In addition, when the lens is initialized earlier than expected or does not need to be initialized, the lens starts an unintended operation, which may cause the camera system to malfunction. Furthermore, if the initialization of the lens and the activation of the camera body and other processes are performed at the same time, the camera system may run out of power and the camera body may be stopped or reset. These problems are particularly likely to occur when a new specification interchangeable lens is attached to an old camera body that does not support it.

  Accordingly, an exemplary object of the present invention is to provide an interchangeable lens and a camera system that can normally initialize an optical element included in a photographing optical system.

  The interchangeable lens of the present invention is detachable from the camera body, a photographing optical system that forms an optical image of an object, and a control unit that performs initialization to move an optical element included in the photographing optical system to a predetermined position; The control means is capable of communicating with the camera body when the interchangeable lens is mounted on the camera body, and the control means transmits identification information of the camera body to the camera. If a signal for starting the initialization is received from the camera body before a predetermined time, which is a time during which the camera body consumes a predetermined amount or more of power, is received from the camera body, the initial The initialization is started after receiving a signal for starting the initialization, and the initialization is started before the predetermined time elapses after receiving the identification information of the camera body from the camera body. If it does not receive a signal to be characterized by starting the initialization after the predetermined time has elapsed.

  ADVANTAGE OF THE INVENTION According to this invention, the interchangeable lens and camera system which can initialize normally the optical element contained in an imaging optical system can be provided.

It is a block diagram of the camera system of this embodiment. It is an operation principle diagram of the focus unit and the position detection unit shown in FIG. It is a flowchart which shows the lens initialization control by the lens microcomputer shown in FIG. Example 1 It is a flowchart which shows the process of the camera microcomputer corresponding to FIG. Example 1 It is a flowchart which shows the lens initialization control by the lens microcomputer shown in FIG. (Example 2)

  FIG. 1 is a block diagram of a camera system as an imaging system according to the first embodiment. The camera system includes an interchangeable lens 1 and a camera body 10 as an imaging device to which the interchangeable lens 1 is detachably mounted.

  The interchangeable lens 1 and the camera body 10 are mechanically coupled by a mount (not shown), and are electrically connected to each other via a lens contact 9 of the interchangeable lens 1 and a camera contact 14 of the camera body 10. The communication mode is not limited to electricity only, and other means such as optical communication may be used. The interchangeable lens 1 and the camera body 10 can exchange information such as their identification numbers, specifications, and functions through communication. Further, power is supplied from the camera body 10 to the interchangeable lens 1 via the lens contact 9 and the camera contact 14.

  The interchangeable lens 1 has a photographing optical system composed of a plurality of optical lens units, and forms an optical image of an object. The photographing optical system includes a focus lens 2, a zoom lens, a correction lens for camera shake correction, a diaphragm, and the like. In FIG. 1, only the focus lens 2 is shown for simplicity. The focus lens 2, the zoom lens, and the like are actually composed of a plurality of lenses and are unitized.

  The focus lens 2 is moved in the direction of the optical axis OA by the focus unit 3 to perform focus adjustment, and the zoom lens (magnification lens) is moved in the direction of the optical axis to change the focal length. The correction lens is moved in a direction orthogonal to the optical axis to correct image blur. The “perpendicular direction” only needs to have a component orthogonal to the optical axis, and may be moved obliquely with respect to the optical axis. The diaphragm adjusts the amount of light incident on an image sensor (not shown) of the camera body 10.

  The focus unit 3 holds the focus lens 2 movably in the optical axis direction during automatic focus adjustment (AF).

  The interchangeable lens 1 further includes a motor unit 4, a driver circuit 5, a position detection unit 6, a zoom position detection unit 7, and a lens microcomputer 8.

  The motor unit 4 is an actuator that moves the focus unit 3. As an example, the motor unit 4 is an electromagnetic stepping motor that is driven and controlled by the voltage supplied from the driver circuit 5, and a member that converts the rotational force of the motor into the moving force of the focus unit 3 is incorporated therein. . The driver circuit 5 converts the excitation signal from the lens microcomputer 8 into power and supplies it to the motor unit 4. The motor unit 4 and the driver circuit 5 function as driving means for driving the focus lens 2.

  The position detection unit 6 detects the position of the focus unit 3. As an example, a part of the focus unit 3 is cut out, and the position detection unit 6 is configured as a photo interrupter composed of a light emitting element and a light receiving element, and the optical path of the photo interrupter can pass through the notch. The lens microcomputer 8 acquires a signal level that changes depending on whether light from the light-emitting element of the photo interrupter reaches the light-receiving element or is blocked.

  FIG. 2 is an operation principle diagram of the focus unit 3 and the position detection unit 6. The movement range of the focus unit 3 is limited to the range between the close end 30 and the infinite end 31, and the focus unit 3 is controlled to stop when it moves to either end. Each end is determined by the amount of movement from the origin position A.

  The center of the optical path of the photo interrupter 32 as the position detection unit 6 passes through the origin position A, and the light shielding plate 33 that moves integrally with the focus unit 3 is configured to cross the optical path of the photo interrupter 32. The light shielding plate 33 blocks the optical path of the photo interrupter 32 while the focus unit 3 is moving on the close side, and is exposed while moving on the infinite side.

  This makes it possible to determine whether the focus unit 3 is on the near side or the infinite side. Since the absolute position of the focus unit 3 is specified at the origin position A where the signal of the photo interrupter 32 changes, the lens microcomputer 8 stores a predetermined amount starting from the origin position A. The position detection unit 6 of the present embodiment is a relative position detection unit that detects the position of the focus unit 3 based on the relative distance from the origin position A as described above, and does not include an encoder that detects the absolute distance. As a result, the position detection unit 6 can be downsized.

  For example, the lens microcomputer 8 stores the time when the signal of the photo interrupter 32 is changed (the time when it passes through the origin position A) as 10,000 steps. When the focus unit 3 moves to the closest side, it decrements from 10,000 steps, and increments when it moves to the infinite side. For example, the lens microcomputer 8 recognizes the close end 30 as 5000 steps and the infinite end 31 as 15000 steps, and stops the focus unit 3.

  If the origin position A is not known, the amount of movement of the focus unit 3 is not known, and the focus unit 3 moves beyond the close end 30 or the infinite end 31 and collides with other members to cause the focus unit 3, the motor unit 4 or The other member may be damaged.

  Therefore, it is necessary to specify the origin position A before the focus unit 3 is moved (before the user operates the switch 13), and the interchangeable lens 1 is attached to the camera body 10 when the origin position A is specified. This is performed when the power of a camera (not shown) is turned on. A series of controls for specifying the origin position A is called focus reset control, and is performed as part of initialization of the optical element. In the initialization of the optical element, the focus lens 2 is moved to a predetermined position with reference to the origin position A.

  In the initialization of the optical elements, other optical elements (zoom lens, correction lens, diaphragm) other than the focus lens 2 included in the photographing optical system are also moved to a predetermined position. In the initialization of the diaphragm, the diaphragm blades constituting the diaphragm are moved to a predetermined position, and the diaphragm aperture is set to a predetermined value. However, since initialization of these other optical elements is the same as that of the focus lens 2, only the focus lens 2 will be described here. In addition, the initialization of the focus lens 2 of the present embodiment includes the specification of the origin position A, but the initialization of the optical element may or may not include the specification of the origin position.

  The focus reset control is a system mounted on a relatively new interchangeable lens, and the camera body 10 has a new specification corresponding to the old specification not corresponding to the focus reset control. For the interchangeable lens 1, it is necessary to initialize the optical element normally regardless of which type of camera body is mounted.

  In this respect, it is conceivable that the lens microcomputer 8 determines the start timing of initialization of the optical element, but since a power supply circuit including a battery or the like is generally provided in the camera device, a problem occurs. there is a possibility.

  For example, if the initialization of the optical element of the interchangeable lens 1 is performed simultaneously with the activation of the camera body or the charging of power for strobe light emission, the camera system may become insufficient in power and the camera body may be stopped or reset.

  Therefore, when the interchangeable lens 1 is attached to a camera body that does not support focus reset control, it is necessary to initialize the optical element so that the interchangeable lens 1 does not overlap the power consumption period of the camera body. On the other hand, when the interchangeable lens 1 is attached to the camera body that supports focus reset control, the camera body controls the initialization timing of the optical element of the interchangeable lens so that it does not overlap the power consumption period of the camera body. There is a need. Since the camera body controls the initialization timing of the optical element, the start-up of the camera system can be speeded up.

  The zoom position detection unit 7 electrically detects the change state when the zoom magnification (not shown) moves and the optical magnification changes. Normally, in zooming (when zooming), it is necessary to change not only the magnification but also the focus state of the subject.

  The lens microcomputer 8 is configured by a microcomputer such as a CPU (processor), and is a control unit that controls each component inside the interchangeable lens 1. The lens microcomputer 8 performs control so that the focus unit 3 is moved according to the zoom state detected by the zoom position detection unit 7 and the in-focus state is maintained. Hereinafter, this series of control is referred to as “computer zoom control” (CZ control).

  The lens microcomputer 8 of the interchangeable lens 1 of this embodiment corresponds to CZ control. The lens microcomputer 8 has functions such as a communication circuit (communication means) for performing communication between the interchangeable lens 1 and the camera body 10, reset exception processing, A / D, timer, input / output port, ROM, and RAM. Have The communication circuit communicates with the camera body 10 including lens identification information, a lens operation permission command, and the like. Furthermore, the lens microcomputer 8 performs drive control of optical elements such as the focus unit 3 and a diaphragm (not shown) using various control information obtained via the communication circuit.

  The camera body 10 includes a focus detection unit 11, a camera microcomputer 12, various switches (SW) 13 that give instructions regarding shooting, an image sensor that photoelectrically converts an optical image formed by the shooting optical system, and the like.

  The focus detection unit 11 is a focus detection unit that performs focus detection from the amount of deviation of the current position of the focus unit 3 with respect to the distance to the subject. The focus detection method is not limited to a contrast method or a phase difference method.

  The camera microcomputer 12 is composed of a microcomputer such as a CPU (processor), and is a control means for controlling each component inside the camera body 10. The camera microcomputer 12 has functions such as a communication controller for communicating with the lens microcomputer 8, an A / D, a current detector, a timer, a power supply switch to the lens, an input / output port, a ROM, and a RAM. Have.

  The lens microcomputer 8 and the camera microcomputer 12 exchange various data by a clock synchronous serial communication function, and each has an input terminal, an output terminal, and a synchronous clock input terminal. In synchronization with the clock signal, information in units of 1 byte (8 bits) is exchanged by one communication.

  The switch 13 notifies the camera microcomputer 12 of an AF start instruction, an imaging start instruction, and the like from the user. At the time of AF, the camera microcomputer 12 acquires information on the amount of focus shift of the subject image from the focus detection unit 11 in accordance with the operation of the switch 13, and based on the information from the lens microcomputer 8, The amount of movement is calculated and transmitted to the lens microcomputer 8.

  When the lens microcomputer 8 receives an instruction to move the focus unit 3 from the camera microcomputer 12, it issues an energization instruction to the driver circuit 5 to drive the motor unit 4 and move the focus unit 3.

  The movement amount of the focus unit 3 is counted each time the energized phase of the stepping motor in the motor unit 4 is switched. When the movement amount specified by the camera microcomputer 12 is moved, the driving of the motor unit 4 is stopped. Stop moving. There is generally a 1-2 phase drive method as a stepping motor drive method, but the movement of the focus unit 3 is counted at the timing when the energized phase is switched between 1 phase energization, 2 phase energization, 1 phase energization, and so on. It is equivalent to the amount. Here, the minimum unit of the movement amount is a step amount.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 3 is a flowchart showing initialization control by the lens microcomputer 8 according to the first embodiment. “S” is an abbreviation for “step”. The flowchart shown in FIG. 3 can be embodied as a program for causing a computer to realize the function of each step.

  When the interchangeable lens 1 is attached to the camera body 10, the lens microcomputer 8 determines whether the camera microcomputer 12 is a camera with a new specification corresponding to the focus reset control (hereinafter also referred to as “new camera”). It is determined whether information has been received (S101).

  Here, “camera information” is identification information of the camera body 10, and the identification information includes not only the identification number of the camera body 10 but also additional information (information such as attached accessories). In S <b> 101, the lens microcomputer 8 also transmits information about the interchangeable lens 1 to the camera body 10. Such information includes identification information of the interchangeable lens 1, and this identification information includes information that the optical element of the interchangeable lens 1 needs to be initialized.

  If the camera body 10 is a new camera (Y in S102), it waits until an initialization command is received from the camera microcomputer 12 (N in S104), and if it is an old camera (N in S102), a predetermined time elapses. (N in S103). The “old camera” means a case where the camera body 10 is an old specification camera that does not support the focus reset control. The new specification may be a specification in which the camera body 10 transmits an initialization command to be described later, and the old specification may be a specification in which the camera body 10 does not transmit an initialization command to be described later.

  The “predetermined time” in S103 is a different value for each camera body stored in the lens microcomputer 8, and is a period during which power of a predetermined amount or more of the camera body 10 is consumed. As a result, the initialization of the optical element of the interchangeable lens 1 (here, it is simply the “lens initialization” in the figure because it is the initialization of the focus lens 2) does not overlap the power consumption period of the camera body 10. can do.

  For example, the “predetermined time” in S103 is a power-on period of the camera body 10. If the camera body 10 is performing power charging for strobe light emission (this information is included in the camera information in S101), the predetermined time is a period until the power charging ends. Of course, the period is not limited to the period required for power activation or strobe charging, but may be any period in which any optical member of the camera body 10 consumes more than a predetermined amount of power.

  The lens microcomputer 8 can determine whether a predetermined time stored in the lens microcomputer 8 has elapsed by measuring time with a timer (not shown) or counting clock signals.

  The “initialization command” in S104 is a first signal that is issued after the camera body 10 ends the power consumption period and causes the interchangeable lens 1 to start initialization of the optical element.

  When an initialization command is received (Y in S104) or when a predetermined time has elapsed (Y in S103), the lens microcomputer 8 starts lens initialization (S105) and waits until the initialization is completed (N in S106). ). When initialization is completed (Y in S105), normal processing such as AF is performed (S107). Thereafter, if reinitialization is necessary (Y in S108), the process returns to S101, and if not necessary, the process returns to S107.

  An example of reinitialization (or refocus reset control) in S108 will be described. In FIG. 2, the origin position A is set to 10000 steps as an example, and the signal of the photo interrupter 32 is switched at a position where the moving amount of the focus unit 3 is 10000 steps. However, if the motor unit 4 (stepping motor) steps out and the rotation amount of the motor deviates from the electrical excitation phase, the step amount also deviates and the signal of the photo interrupter 32 is not switched at 10,000 steps. In this case, since the focus unit 3 may move beyond the close end 30 and the infinite end 31, reinitialization is executed in S108, and refocus reset control for setting the origin position A to 10000 steps is performed.

  In this embodiment, it is determined whether the camera is a new camera or an old camera in S102, but this determination is not always necessary. For example, instead of S102, the lens microcomputer 8 determines whether or not an initialization command has been received from the camera microcomputer 12 within the predetermined time of S103. If received, the process proceeds to S105. You may move to.

  FIG. 4 is a flowchart showing processing of the camera microcomputer 12 corresponding to the processing of the lens microcomputer 8 shown in FIG. The flowchart shown in FIG. 4 can be embodied as a program for causing a computer to realize the function of each step.

  FIG. 4A shows processing when the camera body 10 is a new camera. In the figure, when the interchangeable lens 1 is attached to the camera body 10, the camera microcomputer 12 receives information from the lens microcomputer 8 (S201) and simultaneously transmits camera information. Thereby, the lens microcomputer 8 can recognize that the camera body 10 is a new camera (Y in S102).

  Next, the camera microcomputer 12 determines whether or not all information has been received from the lens microcomputer 8 (S202). If received, the camera microcomputer 12 sends an operation permission signal (second signal) to the lens microcomputer 8 after the power consumption period of the camera body 10 ends. Signal) is transmitted (S203).

  The “operation permission signal” is effective when the interchangeable lens 1 can be operated alone, and includes electric zooming and camera shake correction (not shown). When the operation permission command is received, since the interchangeable lens 1 is in a state where it can operate independently, initialization can also be started.

  Next, the camera microcomputer 12 performs normal operation as a camera (S204), and if it is determined from the lens information received in S201 that the optical element of the interchangeable lens 1 needs to be initialized (Y in S205), the initialization command Is transmitted (S206). By this communication, the interchangeable lens 1 starts initialization. If initialization is unnecessary (N in S205), the process proceeds to S204.

  As described above, the present embodiment does not immediately transmit the initialization command in S203, but transmits the initialization command only when the initialization is required in S205 (S206). Thereby, it is possible to prevent the camera system from malfunctioning by transmitting an initialization command to the interchangeable lens 1 that does not require initialization and starting the operation that the interchangeable lens 1 does not intend.

  FIG. 4B shows processing when the camera body 10 is an old camera. In the figure, when the interchangeable lens 1 is attached to the camera body 10, the camera microcomputer 12 receives information from the lens microcomputer 8 (S201) and simultaneously transmits camera information. Thereby, the lens microcomputer 8 can recognize that the camera body 10 is an old camera (N in S102).

  Next, the camera microcomputer 12 determines whether all the information has been received from the lens microcomputer 8 (S202). If received, the camera microcomputer 12 transmits an operation permission signal to the lens microcomputer 8 after the power consumption period of the camera body 10 ends. (S203). Next, the camera microcomputer 12 performs a normal operation as a camera (S204).

  FIG. 5 is a flowchart illustrating lens initialization control by the lens microcomputer 8 according to the second embodiment. “S” is an abbreviation for “step”. The flowchart shown in FIG. 5 can be embodied as a program for causing a computer to realize the function of each step. FIG. 5 differs from FIG. 3 in that it has S109, and is the same in other points, so only the differences will be described.

  In the first embodiment, in the case of an old camera, S105 is executed after a predetermined time has elapsed after receiving camera information (N in S103). In other words, the camera body 10 cannot shoot until a predetermined time elapses, and the subject may be missed from the field of view. Therefore, in this embodiment, the time until the initialization is started is shortened.

  If the camera body 10 is an old camera (N in S102) and the predetermined time has elapsed, the process proceeds to S105. If the predetermined time has not elapsed (N in S103), an operation permission command is received from the camera microcomputer 12 (S104). Y), the process proceeds to S105. If the predetermined time has not elapsed (N in S103) and no operation permission signal has been received from the camera microcomputer 12 (N in S104), the process returns to S103. As a result, when the operation permission signal is received before the predetermined time elapses, the initialization start time can be advanced.

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

  According to the present invention, the lens initialization is normally performed regardless of the specifications of the interchangeable lens attached to the camera body. In addition, when an interchangeable lens is attached to a new camera, a system with faster startup can be constructed.

  The interchangeable lens can be applied to a camera system including an interchangeable lens and a camera body.

DESCRIPTION OF SYMBOLS 1 ... Interchangeable lens, 2 ... Focus lens (optical element), 8 ... Lens microcomputer, 10 ... Camera body

Claims (8)

It can be attached to and detached from the camera body.
A photographing optical system for forming an optical image of an object;
An interchangeable lens having control means for performing initialization to move an optical element included in the photographing optical system to a predetermined position,
The control means can communicate with the camera body when the interchangeable lens is attached to the camera body,
The control means starts the initialization before a predetermined time, which is a time during which the camera body consumes a predetermined amount of power or more, after receiving identification information of the camera body from the camera body. If the signal to be received is received from the camera body, the initialization is started after receiving the signal to start the initialization,
If the signal for starting the initialization is not received before the predetermined time has elapsed since the identification information of the camera body is received from the camera body, the initialization is performed after the predetermined time has elapsed. An interchangeable lens characterized by starting.   The interchangeable lens according to claim 1, wherein the predetermined time is set for each model of the camera body.   The interchangeable lens according to claim 1, wherein the initialization includes an operation of specifying an origin position of the optical element.   The exchange according to any one of claims 1 to 3, wherein the control means transmits identification information including information indicating that the optical element needs to be initialized to the camera body. lens.   The optical element includes a focus lens that is moved when the focus is adjusted, a zoom lens that is moved when the focal length is changed, a correction lens that is moved when the image blur is corrected, and a diaphragm for adjusting the amount of light. The interchangeable lens according to claim 1, comprising at least one.   The control means includes at least one of when the interchangeable lens is attached to the camera body, when the power of the camera body with the interchangeable lens is turned on, and when re-initialization is necessary. The interchangeable lens according to claim 1, wherein the optical element is initialized.   A camera system comprising the interchangeable lens according to any one of claims 1 to 6 and a camera body.   When the identification information received from the interchangeable lens includes information indicating that the optical element needs to be initialized, the camera body sends a signal for starting the initialization to the interchangeable lens. The camera system according to claim 7, wherein the transmission is performed.