Abstract:
A control apparatus configured to control a control target in response to an operation by a user includes a first operation member configured to control the control target at a speed corresponding to an operation amount given by a user per unit time, a second operation member that is disposed in a position simultaneously operable by one and the same finger as the first operation member configured to control the control target at a predetermined speed in response to the operation by the user, and a control member configured to prioritize the operation of the first operation member over that of the second operation member when the first operation member and the second operation member are simultaneously operated.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a control apparatus, for example, for controlling focus adjustment of an imaging apparatus performed by an operator, and an imaging apparatus equipped with the control apparatus. 
   2. Description of the Related Art 
   Conventionally, most imaging apparatuses such as a still camera and a video camera include a manual focus (MF) function of manually performing focus adjustment on an object. However, since resolution of an image is increased along with recent increase of a number of pixels of an image sensor and a high definition system, focus adjustment has to be more finely tuned when a focus is manually adjusted. 
   Conventionally, as an operation unit for the MF operation, a key switch that executes a key operation, a touch panel, and a rotation member such as a focus ring, a dial or a wheel have been produced. 
   Since only two kinds of operation amount, namely on and off, can be input by the key operation, the focus can be easily shifted at one stroke by continuously pressing the key. However, it is bothersome to perform fine focus adjustment since minute manipulation needs to be repeated for that purpose. 
   A ring, a wheel or the like can change the operation amount by a rotation amount and a rotation speed, so that they are suitable for the fine focus adjustment. However, if an amount of focus change responding to the operation amount is set small so as to enable the fine focus adjustment, the operation amount increases when the focus needs to be widely shifted. Consequently, it becomes difficult to quickly perform focus adjustment. 
   Accordingly, an ease-of-use operation unit is provided which includes both a key for rough focus adjustment and a wheel for fine focus adjustment and has advantages of both devices. 
   On the other hand, a recent imaging apparatus has been miniaturized in order to enhance portability. Thus, it is required to dispose a key and a wheel in an area as small as possible. Japanese Patent Application Laid-Open No. 10-148751 discusses an information input apparatus which includes a wheel and a key disposed within the wheel to decrease an area where the wheel and the key are disposed and enables performing of two types of operations with one finger. 
   The information input apparatus discussed in Japanese Patent Application Laid-Open No. 10-148751 enables one finger (e.g., right hand thumb) to operate both the key and the wheel. In this apparatus, in order to prevent making an unintentional operation by mistake, when any one of the key and the wheel is operated, another operation is neglected. 
   However, application of the above-described information input apparatus to the above-described MF operation causes a following problem. That is, if the key is unnoticeably operated by mistake at the same time that the wheel is operated to finely adjust focus, the operation of the wheel is neglected, so that an object is greatly out of focus and an MF operation cannot be performed as intended. 
   As described above, along with miniaturization of an imaging apparatus, a key and a wheel tend to be disposed within a small and narrow region. Thus, the above-described problem frequently occurs and operability of the MF becomes greatly impaired. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a control apparatus and an imaging apparatus which can make both fine and rough adjustments of an MF, and perform the MF operation intended by an operator even if a key and a wheel are simultaneously operated by mistake. 
   According to an aspect of the present invention, a control apparatus configured to control a control target in response to an operation by a user includes a first operation member configured to control the control target at a speed corresponding to an operation amount given by the user per unit time, a second operation member that is disposed in a position simultaneously operable by one and the same finger as the first operation member, configured to control the control target at a predetermined speed in response to the operation by the user, and a control member configured to prioritize the operation of the first operation member over that of the second operation member when the first operation member and the second operation member are simultaneously operated. 
   Further features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the invention and, together with the description, serve to explain the principles of the invention. 
       FIG. 1  is a diagram illustrating an example configuration of an imaging apparatus according to a first exemplary embodiment of the present invention. 
       FIG. 2  is a diagram illustrating a relation in arrangement between an operation wheel and an operation key in  FIG. 1 . 
       FIG. 3  is a diagram illustrating details of the operation key in  FIG. 2 . 
       FIG. 4  is a flowchart illustrating procedures of a simultaneous operation of the operation wheel and the operation key executed by the imaging apparatus in  FIG. 1 . 
       FIG. 5  is a flowchart illustrating procedures of MF processing (MF operation) performed in step S 111  of the flowchart in  FIG. 4 . 
       FIG. 6  is a diagram illustrating an example configuration of an imaging apparatus according to a second exemplary embodiment of the present invention. 
       FIG. 7  is a flowchart illustrating procedures of mode changeover processing executed by the imaging apparatus in  FIG. 6 . 
       FIG. 8  is a flowchart illustrating procedures of a simultaneous operation of the operation wheel and the operation key executed by the imaging apparatus in  FIG. 6 . 
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
   Various exemplary embodiments, features, and aspects of the invention will be described in detail below with reference to the drawings. 
   First Exemplary Embodiment 
     FIG. 1  is a diagram illustrating an example configuration of an imaging apparatus (camera) according to a first exemplary embodiment of the present invention. 
   In  FIG. 1 , the imaging apparatus includes a first stationary lens unit  101 , a zoom lens  102  for changing a magnification, a diaphragm  103 , and a second stationary lens unit  104 . 
   The imaging apparatus further includes a focus lens  105  (a focus adjustment lens unit of an image optical system) equipped with a focus adjustment function, an image sensor  106 , a camera signal processing circuit  107 , a monitor device  108 , a recording apparatus  109 , a focus drive source  110  for driving the focus lens  105 , a camera microcomputer  111 , and a pulse generation circuit  112 . The imaging apparatus further includes an operation wheel (a first operation member)  113  and an operation key (second operation member)  114 . 
   The camera signal processing circuit  107  converts an output signal of the image sensor  106  into a signal corresponding to the monitor device  108  having a display function and the recording apparatus  109 . The monitor device  108  displays a video signal which is converted by the camera signal processing circuit  107 , and has an information display function of displaying information such as image capture information and operation information. The recording apparatus  109  records a moving image and a still image and uses a magnetic tape and a semiconductor memory as a recording medium. 
   The camera microcomputer  111  controls the focus drive source  110  in response to an operation amount of the operation wheel  113  and the operation key  114 , and controls an output signal of the camera signal processing circuit  107 . 
   The camera microcomputer  111  is connected with the operation wheel  113  and the operation key  114  to move the focus lens  105  in a closest distance direction or an infinity distance direction. An operator can perform the MF operation by operating the operation wheel  113  or the operation key  114 . 
   The operation wheel  113  is connected with the pulse generation circuit  112  for generating a pulse in response to its rotation amount, rotation speed, and rotation direction. The camera microcomputer  111  detects a pulse generated when the operation wheel  113  is operated, and determines a drive direction and a drive speed of the focus lens  105  in response to a detected pulse. 
   The operation key  114  has a switch mechanism that allows a press operation (a switch mechanism capable of determining on and off states of input). The camera microcomputer  111  drives the focus drive source  110  to move the focus lens  105  in the closest distance direction or the infinity distance direction in response to a pressed switch. 
   In the operation wheel  113 , the operation amount by which a control amount of the control target focus lens  105  is input, is variable. Further, the operation amount of the operation key  114  is fixed. 
     FIG. 2  is a diagram illustrating the arrangement of the operation wheel  113  and the operation key  114  in  FIG. 1 . 
   In the present exemplary embodiment, the operation wheel  113  is disposed to a side of the monitor device  108  such as a liquid crystal display. The monitor device  108  is attached to the main body of the imaging apparatus by hinges or the like. The monitor device  108  has a mechanism that can open leftward. The operation wheel  113  is provided at a position where an operator can operate with his/her left thumb when holding the main body by the right hand (shown in dot-dash lines). 
   The operation wheel  113  has a rotation mechanism having a rotation axis in a direction orthogonal to the monitor device  108 . In the present exemplary embodiment, the operation wheel  113  is configured to drive the focus lens  105  in the infinity distance direction when the operation wheel  113  is rotated rightward and in the closest distance direction when the operation wheel  113  is rotated leftward. 
   The correspondence between the rotation direction of the operation wheel  113  and the drive direction of the focus lens  105  may be changed over as required. 
   Further, the operation key  114  is disposed inside the operation wheel  113 . As shown in  FIG. 3 , the operation key  114  includes operation key switches  114   a,    114   b,    114   c  and  114   d  and the input position of these keys are displaced at 90 degree angles each other in a cross direction, and an operation key switch  114   e  located in a center part. The operation key  114  can be operated with the left thumb when the operator is holding the main body of the imaging apparatus with the right hand similar to the operation wheel  113 . 
   The present exemplary embodiment is configured such that when the operation key switch  114   b  is pressed, the focus lens  105  is driven in the infinity distance direction. When the operation key switch  114   d  is pressed, the focus lens  105  is driven in the closest distance direction. In the present exemplary embodiment, the MF operation is performed using only the operation key switches  114   b  and  114   d  in a horizontal direction. 
   However, as an embodiment different from the present exemplary embodiment, the MF operation may also be performed using the operation key switches  114   a  and  114   c  in a vertical direction. The MF operation may be changed over to other operations such as an auto-focus (AF) function of automatically adjusting the focus by pressing the operation key switch  114   e  in the center part. 
     FIG. 4  is a flowchart illustrating procedures of a simultaneous operation of the operation wheel  113  and the operation key  114  executed by the imaging apparatus in  FIG. 1 . 
   More specifically, in the flowchart of  FIG. 4 , an input of the operation wheel  113  is prioritized when the operation wheel  113  and the operation key  114  are simultaneously operated. 
   In  FIG. 4 , first, in step S 101 , the camera microcomputer  111  determines whether the operation wheel  113  is operated and a signal change is present. If the signal change is present (YES in step S 101 ), the processing proceeds to step S 102 . If the signal change is not present (NO in step S 101 ), the processing proceeds to step S 105 . 
   In step S 102 , the camera microcomputer  111  determines whether a flag indicating the operation of the operation key  114  is off. If the flag is off, which indicates that the operation key  114  is not operated (YES in step S 102 ), the processing proceeds to step S 103 . If the flag is on, which indicates that the operation key  114  is operated (NO in step S 102 ), the processing proceeds to step S 109 . 
   In step S 103 , the camera microcomputer  111  sets a flag indicating that the operation wheel  113  is operated on. In step S 104 , the camera microcomputer  111  sets time Tk during which an input operation from the operation key  114  is disabled. Then, the processing proceeds to step S 109 . 
   In step S 105 , the camera microcomputer  111  determines whether the operation key  114  is operated and a signal change is detected. If the signal change is detected (YES in step S 105 ), the processing proceeds to step S 106 . If the signal change is not detected (NO in step S 105 ), the processing proceeds to step S 109 . 
   In step S 106 , the camera microcomputer  111  determines whether a flag indicating the operation of the operation wheel  113  is off. If the flag is off, which indicates that the operation wheel  113  is not operated (YES in step S 106 ), the processing proceeds to step S 107 . If the flag is on, which indicates that the operation wheel  113  is operated (NO in step S 106 ), the processing proceeds to step S 109 . 
   In step S 107 , the camera microcomputer  111  sets a flag on which indicates that the operation key  114  is operated. The processing proceeds to step S 108 . In step S 108 , the camera microcomputer  111  sets time Th during which an input operation from the operation wheel  113  is disabled. Then, the processing proceeds to step S 109 . 
   Herein, the time Th during which the input operation from the operation wheel  113  is disabled is set to a smaller value than the time Tk set in step S 104 . An input signal from key operation is continuously in an on-state during the key is pressed. On the other hand, as to an input signal from wheel operation, the time Th during which the input operation from the operation wheel  113  is disabled needs to be set to a small value since a pulse signal is only intermittently transmitted even during the wheel is rotated. 
   Further, when chattering which repeats intermittence of an input signal due to a noise or the like, occurs during the input operation of the operation key  114 , the time Tk is set to receive the input operation from the operation key  114 . The time Tk during which the input operation from the operation key  114  is disabled is set longer than the time Th during which the input operation from the operation wheel  113  is disabled, so that the operation of the operation wheel  113  is prioritized over the operation of the operation key  114 . 
   In step S 109 , the camera microcomputer  111  determines whether the time Tk or the time Th set in step S 104  or step S 108  is zero. If it is not zero (NO in step S 109 ), in step S 110 , the camera microcomputer  111  decrements the time Tk or the time Th. Then, the processing proceeds to step S 111 . 
   In step S 109 , if the time Tk or the time Th is zero (YES in step S 109 ), in step S 112 , the camera microcomputer  111  sets the flag indicating that the operation wheel  113  is operated and the flag off which indicates that the operation key  114  is operated. Then, the processing ends. 
   In step S 111 , the camera microcomputer  111  drives the focus lens  105  and executes the MF operation in response to the operation of the operation wheel  113  or the operation key  114 . Then, the processing ends. The camera microcomputer  111  executes these flows of the processing for every predetermined time, for example, by synchronizing with a vertical synchronizing signal of a video picture. 
     FIG. 5  is a flowchart illustrating procedures of the MF processing (the MF operation) performed in step S 111  in  FIG. 4 . 
   In  FIG. 5 , in step S 201 , the camera microcomputer  111  sets the drive speed of the focus lens  105 . When the input of the operation wheel  113  is received, the camera microcomputer  111  sets the drive speed corresponding to the rotation speed of the operation wheel  113 . Further, if the input of the operation key  114  is received, the camera microcomputer  111  sets a predetermined fixed speed. Here, the drive speed of the focus lens  105  is set by the key operation to a larger value than the drive speed set by the wheel operation to enable a rough adjustment of the MF. 
   In step S 202 , the camera microcomputer  111  determines whether the drive direction of the focus lens  105  is in the infinity distance direction. 
   In the present exemplary embodiment, as described above, when the operation wheel  113  is rotated rightward or the operation key  114  is operated in a right direction, the camera microcomputer  111  sets the focus lens  105  to be driven in the infinity distance direction. Further, when the operation wheel  113  is rotated leftward or the operation key  114  is operated in a left direction, the camera microcomputer  111  sets the focus lens  105  to be driven in the closest distance direction. 
   If a drive direction command of the focus lens  105  is in the closest distance direction (NO in step S 202 ), the processing proceeds to step S 203 . If the drive direction command of the focus lens  105  is in the infinity distance direction (YES in step S 202 ), the processing proceeds to step S 204 . In step S 203 , the camera microcomputer  111  drives the focus lens  105  in the closest distance direction by the focus drive source  110 . Instep S 204 , camera microcomputer  111  drives the focus lens  105  in the infinity distance direction by the focus drive source  110 . 
   If the processing is performed as described above, the MF operation that prioritizes the wheel operation can be performed even if the operation wheel  113  for fine adjustment and the operation key  114  for rough adjustment are simultaneously operated by mistake. As a result, an operator can perform an intended MF operation without causing an object to be greatly out of focus. 
   Second Exemplary Embodiment 
     FIG. 6  is a diagram illustrating a configuration of an imaging apparatus according to a second exemplary embodiment of the present invention. 
   The imaging apparatus according to the second exemplary embodiment includes a mode changeover switch  115  for changing over a control target by the wheel operation and the key operation in addition to the configuration of the imaging apparatus in the first exemplary embodiment. Other configurations are similar to the first exemplary embodiment and are denoted with the same reference numeral. 
     FIG. 7  is a flowchart illustrating procedures of mode changeover processing to be executed by the imaging apparatus shown in  FIG. 6 . 
   In  FIG. 7 , in step S 301 , the camera microcomputer  111  determines whether the mode changeover switch  115  is turned on. If the mode changeover switch  115  is not turned on (NO in step S 301 ), the processing proceeds to step S 302 . If the mode changeover switch  115  is turned on (YES in step S 301 ), the processing proceeds to step S 303 . 
   In step S 302 , the camera microcomputer  111  executes the processing for prioritizing the operation wheel input (processing in the simultaneous operation (1)) according to the first exemplary embodiment shown in  FIG. 4 . Further, in step S 303 , the camera microcomputer  111  executes a menu operation (processing in the simultaneous operation (2)) of executing shift of a menu item or selection of a menu item. The detail of the menu operation mode is described below. 
     FIG. 8  is a flowchart illustrating procedures of the simultaneous operation of the operation wheel  113  and the operation key  114  executed by the imaging apparatus shown in  FIG. 6 . 
   More specifically,  FIG. 8  is the flowchart when both the operation wheel  113  and the operation key  114  are operated in the menu operation mode. Steps S 401  to S 412  respectively correspond to steps S 101  to S 112  of the first exemplary embodiment shown in  FIG. 4 . Thus, the similar processing shall be executed. 
   However, in the second exemplary embodiment, in order to receive the operation which is earlier operated between the wheel operation and the key operation in priority to the other operations, a transition destination of determination in step S 402  is different from the first exemplary embodiment. 
   In step S 402 , the camera microcomputer  111  determines whether a flag indicating the operation of the operation key  114  is off. If the flag is off, which indicates that the operation key  114  is not operated (YES in step S 402 ), the processing proceeds to step S 403 . If the flag is on, which indicates that the operation key  114  is operated (NO in step S 402 ), the processing proceeds to step S 405 . 
   In step S 405 , the camera microcomputer  111  determines whether a signal change by the key operation is detected. If the signal change is detected (YES in step S 405 ), the processing proceeds to step S 406 . 
   If the signal change by the key operation is not detected (NO in step S 405 ), the processing proceeds to step S 409 . In step S 402  and step S 406 , the camera microcomputer  111  determines each operation state of the operation wheel  113  and the operation key  114  to enable exclusively disabling of the other operation. Thus, the camera microcomputer  111  receives an input that is earlier operated. 
   Further, in step S 104  and step S 108  of the first exemplary embodiment shown in  FIG. 4 , the time Tk during which the input operation from the operation key  114  is disabled and the time Th during which the input operation from the operation wheel  113  is disabled are set to Tk&gt;Th. However, in the processing of the second exemplary embodiment shown in  FIG. 8 , in order to make each priority equal, Tk′ and Th′ set in step S 404  and step S 408  are set to Tk′=Th′. 
   In step S 411 , the camera microcomputer  111  executes the menu operation such as a menu selection in response to the operation of the operation wheel  113  or the operation key  114 . Then, the processing ends. In the menu operation, the camera microcomputer  111  executes changeover of the transfer direction of the menu item corresponding to the rotation direction of the operation wheel  113  or transfer of the menu item corresponding to the input position of the operation key  114 . The camera microcomputer  111  executes these flows of the processing for every predetermined time, for example by synchronizing with a vertical synchronizing signal of a video picture similar to the first exemplary embodiment. 
   When the processing is performed as described above, the changeover can be carried out between a mode of prioritizing the wheel operation and a mode of prioritizing the operation earlier operated. If the latter mode is selected, an operator can perform the menu operation without being aware which operation unit is operated. 
   The description according to the present exemplary embodiment, the MF operation mode (first mode) is set as the mode of prioritizing the wheel operation and the menu operation mode (second mode) is set as the mode of prioritizing the operation which is earlier operated. However, the setting is not limited to these two modes. Image capture information, for example, exposure compensation of an object, selection of focusing points or the like may be set. Further, the present invention can be applied to zoom control instead of focus control. In this case, a control target is not a focus lens but a zoom lens. 
   While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications, equivalent structures, and functions. 
   This application claims priority from Japanese Patent Application No. 2007-197496 filed Jul. 30, 2007, which is hereby incorporated by reference herein in its entirety.