JP2013157891A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the operational performance related to zoom adjustment.SOLUTION: A blade member 56 includes: a blade 56a that has an air gap OP1 formed with a gap corresponding to an angle of θ1 in a rotational direction and rotates along with a shaft 52 transmitting torque to a zoom lens 12 and a lens driving system 54; and a blade 56b that has an air gap OP2 formed with a gap corresponding to an angle of θ2 in a rotational direction and rotates at rotational speed corresponding to the rotational speed of the blade 56a. A low-speed PI sensor 58a, a high-speed PI sensor 58b, and a selector 60 detect light output from one main surface side of the blade member 56 at the other main surface side of the blade member 56 corresponding to any one position of the blade 56a and the blade 56b. A zoom motor 50 and a motor control circuit 62 controls the rotation of the shaft 52 in reference to the detection result of the low-speed PI sensor 58a and the high-speed PI sensor 58b. A CPU 38 changes the output position of light detected like this depending on an operation mode.

Description

  The present invention relates to an electronic camera, and more particularly to an electronic camera that adjusts a zoom magnification of an image representing a scene.

  An example of a control device used in this type of camera is disclosed in Patent Document 1. According to this background art, the rotating drum is rotated by the drive motor incorporating the rotation detecting element. The rotational speed of the drive motor is controlled by the PI control means. The PI control means controls the rotational speed by inputting the measured value of either the pulse train frequency measuring means or the pulse interval measuring means from the rotation detecting element. Input switching of each measuring means is performed by the switching means. The switching means outputs the measured value of the pulse train frequency measuring means to the PI control means if the set value is in the high speed range, and the measured value of the pulse interval measuring means if the set value is in the low speed range. A pulse interval measuring unit suitable for the low speed region is used, and a pulse train frequency measuring unit suitable for the high speed region is used.

JP 7-68096 A

  However, in the background art, when the motor rotates at a high speed, there is a possibility that the pulse may be missed by shortening the pulse generation interval. In addition, when the motor rotates at a low speed, there is a possibility that a sufficient number of measurement values cannot be obtained due to an increase in the pulse generation interval. For this reason, when such a control device is used for zoom adjustment of an electronic camera, accurate adjustment cannot be realized, and the operation performance may be deteriorated.

  Therefore, a main object of the present invention is to provide an electronic camera capable of enhancing the operation performance related to zoom adjustment.

  An electronic camera according to the present invention (10: reference numeral corresponding to the embodiment; the same applies hereinafter) has a gap formed at first intervals in the rotation direction and transmits a torque to the zoom mechanism (12, 54). A first blade (56a, 56c1) that rotates in accordance with the rotation of (52) and a second space that has a gap formed at a second interval in the rotation direction and rotates at a rotational speed corresponding to the rotational speed of the first blade. A blade member (56, 56c) having blades (56b, 56c2), a signal output from one main surface side of the blade member corresponding to the position of one of the first blade and the second blade, Detection means (58a to 58d, 60) for detecting on the other main surface side, control means (62, 50) for controlling the rotation of the shaft with reference to the detection result of the detection means, and output of signals detected by the detection means Changing means (S29 to S31, S35) for changing the position according to the operation mode is provided.

  Preferably, the detection means detects the first signal emitted from the one main surface side of the first blade on the other main surface side of the first blade, and one of the second blades. Second detection means (58b, 58d) for detecting the second signal emitted from the main surface side on the other main surface side of the second blade is included.

  Preferably, the second interval is larger than the first interval, the operation mode includes a low-speed drive mode and a high-speed drive mode, and the changing unit sets the output position of the signal detected by the detection unit corresponding to the low-speed drive mode. First position changing means (S31) for changing to the position of one blade, and second position changing means (S35) for changing the output position of the signal detected by the detecting means to the position of the second blade corresponding to the high speed driving mode. )including.

  More preferably, first request means (S33) for requesting low speed rotation to the control means corresponding to the low speed drive mode, and second request means (S37) for requesting high speed rotation to the control means corresponding to the high speed drive mode. Is further provided.

  More preferably, the low-speed driving mode corresponds to the moving image capturing mode, and the high-speed driving mode corresponds to the still image capturing mode.

  Preferably, an operation button (40zm) for switching the operation mode is further provided.

  Preferably, the first blade (56c1) and the second blade (56c2) form a shape in which the other is positioned around one and rotate integrally.

  Both the first blade and the second blade rotate with the rotation of the shaft that transmits torque to the zoom mechanism. The rotation speed of the second blade corresponds to the rotation speed of the first blade.

  However, since the gap formed in the rotation direction of the second blade is different from the gap formed in the rotation direction of the first blade, the change appearing in the detection result corresponding to the position of the second blade is also the first. This is different from the change appearing in the detection result corresponding to the position of one blade. The rotation of the shaft is controlled with reference to one of the two detection results, which differs depending on the operation mode. Thereby, the operation performance regarding the zoom adjustment is improved.

  The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

It is a block diagram which shows the basic composition of one Example of this invention. It is a block diagram which shows the structure of one Example of this invention. FIG. 3 is a block diagram showing a configuration of a driver applied to the embodiment in FIG. 2; (A) is an illustration figure which shows an example of the blade | wing applied to FIG. 2 Example, (B) is an illustration figure which shows an example of the other blade | wing applied to FIG. 2 Example. (A) is an illustration figure which shows the waveform of the detection result output from a low speed PI sensor, (B) is an illustration figure which shows the waveform of the detection result output from a high speed PI sensor. It is a flowchart which shows a part of operation | movement of CPU applied to the FIG. 2 Example. It is a flowchart which shows a part of other operation | movement of CPU applied to the FIG. 2 Example. It is an illustration figure which shows an example of the blade | wing applied to another Example. FIG. 9 is a block diagram illustrating a configuration of a driver applied to the embodiment in FIG. 8;

Embodiments of the present invention will be described below with reference to the drawings.
[Basic configuration]

  Referring to FIG. 1, the electronic camera of this embodiment is basically configured as follows. The blade member 1 has a gap formed at a first interval in the rotation direction and a first blade rotating with a rotation of a shaft transmitting torque to the zoom mechanism and a gap formed at a second interval in the rotation direction. And a second blade (56b, 56c2) that rotates at a rotational speed corresponding to the rotational speed of the first blade. The detection means 2 detects the signal output from the one main surface side of the blade member on the other main surface side of the blade member corresponding to the position of either the first blade or the second blade. The control unit 3 controls the rotation of the shaft with reference to the detection result of the detection unit. The changing unit 4 changes the output position of the signal detected by the detecting unit 3 according to the operation mode.

  Both the first blade and the second blade rotate with the rotation of the shaft that transmits torque to the zoom mechanism. The rotation speed of the second blade corresponds to the rotation speed of the first blade.

However, since the gap formed in the rotation direction of the second blade is different from the gap formed in the rotation direction of the first blade, the change appearing in the detection result corresponding to the position of the second blade is also the first. This is different from the change appearing in the detection result corresponding to the position of one blade. The rotation of the shaft is controlled with reference to one of the two detection results, which differs depending on the operation mode. Thereby, the operation performance regarding the zoom adjustment is improved.
[Example]

  Referring to FIG. 2, the digital camera 10 of this embodiment includes a zoom lens 12, a focus lens 14, and an aperture unit 16 that are respectively driven by drivers 20a to 20c. The optical image that has passed through these members is irradiated onto the imaging surface of the image sensor 18 and subjected to photoelectric conversion. Thereby, a charge corresponding to the optical image is generated.

  When the power is turned on, the CPU 38 instructs the driver 20d to repeat the exposure operation and the charge readout operation in order to execute the moving image capturing process under the imaging task. In response to a vertical synchronization signal Vsync periodically generated from an SG (Signal Generator) (not shown), the driver 20d exposes the imaging surface and reads out the charges generated on the imaging surface in a raster scanning manner. From the image sensor 18, raw image data based on the read electric charges is periodically output.

  The preprocessing circuit 22 performs processing such as digital clamping, pixel defect correction, and gain control on the raw image data output from the image sensor 18. The raw image data subjected to these processes is written into the raw image area 26 a of the SDRAM 26 through the memory control circuit 24.

  The post-processing circuit 28 reads the raw image data stored in the raw image area 26a through the memory control circuit 24, and performs color separation processing, white balance adjustment processing, and YUV conversion processing on the read raw image data. The YUV format image data generated thereby is written into the YUV image area 26 b of the SDRAM 26 by the memory control circuit 24.

  The LCD driver 30 repeatedly reads out the image data stored in the YUV image area 26b through the memory control circuit 24, and drives the LCD monitor 32 based on the read image data. As a result, a real-time moving image (through image) representing the scene captured on the imaging surface is displayed on the monitor screen.

  An evaluation area is assigned to the imaging surface. The evaluation area is divided into 16 in each of the horizontal direction and the vertical direction, and an evaluation area is formed by 256 divided areas. In addition to the above-described processing, the preprocessing circuit 22 shown in FIG. 2 executes simple RGB conversion processing that simply converts raw image data into RGB data.

  The AE evaluation circuit 34 integrates RGB data belonging to the evaluation area among the RGB data generated by the preprocessing circuit 22 every time the vertical synchronization signal Vsync is generated. As a result, 256 integral values, that is, 256 AE evaluation values, are output from the AE evaluation circuit 34 in response to the vertical synchronization signal Vsync.

  In addition, the AF evaluation circuit 36 extracts high-frequency components of RGB data belonging to the same evaluation area from the RGB data output from the preprocessing circuit 22, and generates the extracted high-frequency components every time the vertical synchronization signal Vsync is generated. Integrate into. As a result, 256 integral values, that is, 256 AF evaluation values, are output from the AF evaluation circuit 36 in response to the vertical synchronization signal Vsync.

  The CPU 38 executes a simple AE process based on the output from the AE evaluation circuit 34 in parallel with the moving image capturing process, and calculates an appropriate EV value. The aperture amount and the exposure time that define the calculated appropriate EV value are set in the drivers 20c and 20d, respectively. As a result, the brightness of the through image is appropriately adjusted.

  When the shutter button 40sh provided in the key input device 46 is half-pressed, the CPU 38 executes a strict AE process based on the output of the AE evaluation circuit 34 under the imaging task, and calculates the optimum EV value calculated thereby. The aperture amount and the exposure time to be defined are set in the drivers 20c and 20d, respectively. As a result, the brightness of the through image is adjusted strictly. The CPU 38 also executes AF processing based on the output from the AF evaluation circuit 36 under the imaging task, and sets the focus lens 14 to the in-focus point through the driver 20b. This improves the sharpness of the live view image.

  When the shutter button 40sh is fully pressed, the CPU 38 executes a still image capturing process and a recording process under the imaging task. One frame of raw image data at the time when the shutter button 40sh is fully pressed is captured into the still image area 26c of the SDRAM 26 by the still image capturing process. The captured raw image data of one frame is read from the still image area 26c by the memory I / F 42 activated in association with the recording process, and is recorded on the recording medium 44 in a file format.

  When the recording process is completed, the through image is displayed again on the monitor screen, and the operation of the shutter button 40sh is awaited.

  On the other hand, when the zoom button 40zm provided on the key input device 46 is operated, the CPU 38 moves the zoom lens 12 in the optical axis direction through the driver 20a under a zoom control task executed in parallel with the imaging task. . As a result, the magnification of the through image and the recorded image changes.

  The driver 20a is configured as shown in FIG. The zoom motor 50 generates torque according to the control of the motor control circuit 62, and the generated torque is transmitted to the lens driving system 54 through the rotation of the shaft 52. The lens driving system 54 drives the zoom lens 12 using the transmitted torque.

  A blade member 56 is attached to the shaft 52. The blade member 56 includes blades 56 a and 56 b that spread in a direction orthogonal to the extending direction of the shaft 52. The blades 56 a and 56 b rotate with the rotation of the shaft 52. As shown in FIG. 4A, in the rotation direction of the blades 56a, fan-shaped gaps OP1 having a central angle θ1 and fan-shaped shielding portions SH1 having the same central angle θ1 are alternately formed. As shown in FIG. 4B, in the rotational direction of the blade 56b, fan-shaped gaps OP2 having a central angle of θ2 and fan-shaped shielding portions SH2 having the same central angle of θ2 are alternately formed. Here, the angle θ2 is larger than the angle θ1.

  The low speed PI sensor 58a emits light from one main surface side of the blade 56a, and detects the emitted light on the other main surface side of the blade 56a. The high-speed PI sensor 58b emits light from one main surface side of the blade 56b, and detects the emitted light on the other main surface side of the blade 56b.

  The low speed PI sensor 58 a and the high speed PI sensor 58 b output the respective detection results to the motor control circuit 62 through the selector 60. The selector 60 selects the output of either the low speed PI sensor 58a or the high speed PI sensor 58b based on the operation position of the zoom button 40zm.

  While the shaft 52 is rotating, the detection result output from the low speed PI sensor 58a is represented by the waveform shown in FIG. On the other hand, since the air gap is formed in the blade 56b at a larger interval than the blade 56a, the detection result output from the high-speed PI sensor 58b has a longer detection time and detection interval, and has a waveform shown in FIG. expressed.

  When the operation position of the zoom button 40zm is set to “Z_1”, the rotation of the shaft 52 is controlled as follows. “Z_1” is an operation position for instructing low-speed driving of the zoom lens 12, and the rotational speed of the shaft 52 is also reduced. For this reason, the selector 60 selects the output of the low-speed PI sensor 58a in order to obtain a large number of pulses within a certain period and perform high-precision control. The motor control circuit 62 grasps the current rotation speed of the shaft 52 based on the output of the low speed PI sensor 58a, and controls the torque generated by the zoom motor 50 so that the zoom lens 12 is driven at a low speed.

  When the operation position of the zoom button 40zm is set to “Z_2”, the rotation of the shaft 52 is controlled as follows. “Z — 2” is an operation position for instructing high-speed driving of the zoom lens 12, and the rotational speed of the shaft 52 is also increased. Therefore, the selector 60 selects the output of the high-speed PI sensor 58b in order to prevent missing pulses. The motor control circuit 62 grasps the current rotation speed of the shaft 52 based on the output of the high-speed PI sensor 58b, and controls the torque generated by the zoom motor 50 so that the zoom lens 12 is driven at high speed.

  When the operation position of the zoom button 40zm is set to “Z_0”, the motor control circuit 62 stops driving the zoom motor 50.

  The CPU 38 executes a plurality of tasks in parallel including the imaging task shown in FIG. 6 and the zoom control task shown in FIG. Note that control programs corresponding to these tasks are stored in the flash memory 46.

  Referring to FIG. 6, in step S1, a moving image capturing process is executed. As a result, a through image representing a scene is displayed on the LCD monitor 32. In step S3, it is determined whether or not the shutter button 40sh is half-pressed, and as long as the determination result is NO, the simple AE process is repeatedly executed in step S5. The brightness of the through image is appropriately adjusted by the simple AE process.

  When the determination result is updated from NO to YES, the strict AE process and the AF process are executed in steps S7 and S9, respectively. As a result of the strict AE process and the AF process, the brightness and sharpness of the through image are strictly adjusted.

  In step S11, it is determined whether or not the shutter button 40sh has been fully pressed. If the determination result is NO, it is determined in step S13 whether or not the half-pressed state of the shutter button 40sh has been released. If the determination result of step S13 is NO, it will return to step S11, and if the determination result of step S13 is YES, it will return to step S3.

  When the determination result in step S11 is updated from NO to YES, still image capturing processing and recording processing are executed in steps S15 and S17. One frame of image data at the time when the shutter button 40sh is fully pressed is captured into the still image area 26c by the still image capturing process. The captured one-frame image data is read from the still image area 26c by the memory I / F 42 activated in association with the recording process, and is recorded in the recording medium 44 in a file format. When the process of step S17 is completed, the process returns to step S3.

  Referring to FIG. 7, in step S21, the arrangement of the zoom lens 12 is initialized, and in step S23, the operation position of the zoom button 40zm is detected. In step S25, it is determined whether or not the detected operation position indicates “Z — 0”. If the determination result is YES, driving of the zoom motor 50 is stopped in step S27. When the process of step S27 is completed, the process returns to step S23.

  If the determination result in step S25 is NO, it is determined in step S29 whether or not the operation position detected in step S23 indicates “Z_1”. If the determination result in step S29 is YES, the process proceeds to step S39 via steps S31 and S33. If the determination result in step S29 is NO, the process proceeds to step S39 via steps S35 and S37.

  In step S31, the output of the low speed PI sensor 58a is selected by the selector 60, and in step S33, the motor control circuit 62 is requested to control the zoom motor 50 such that the zoom lens 12 is driven at low speed.

  In step S35, the selector 60 selects the output of the high-speed PI sensor 58b. In step S37, the motor control circuit 62 is requested to control the zoom motor 50 so that the zoom lens 12 is driven at high speed.

  In step S39, the zoom motor 50 is activated. When the process of step S39 is completed, the process returns to step S23.

  As can be seen from the above description, the blade member 56 has a gap OP1 formed in the rotation direction at an interval corresponding to the angle θ1, and rotates the shaft 52 that transmits torque to the zoom lens 12 and the lens drive system 54. The blade 56a rotates with the blade 56a, and the blade 56b has a gap OP2 formed in the rotation direction at an interval corresponding to the angle θ2 and rotates at a rotation speed corresponding to the rotation speed of the blade 56a. The low-speed PI sensor 58a, the high-speed PI sensor 58b, and the selector 60 correspond to the position of one of the blades 56a and 56b with respect to the light output from the one main surface side of the blade member 56. Detect on the surface side. The zoom motor 50, the selector 60, and the motor control circuit 62 control the rotation of the shaft 52 with reference to the detection result of the low speed PI sensor 58a and the detection result of the high speed PI sensor 58b. The CPU 38 changes the output position of light detected by the low speed PI sensor 58a, the high speed PI sensor 58b, and the selector 60 according to the operation mode.

  Both the blades 56 a and 56 b rotate with the rotation of the shaft 52 that transmits torque to the zoom lens 12 and the lens driving system 54. The rotational speed of the blade 56b corresponds to the rotational speed of 56a.

  However, since the interval of the gap OP2 formed in the rotation direction of the blade 56b is different from the interval of the gap OP1 formed in the rotation direction of the blade 56a, the change appearing in the detection result corresponding to the position of the blade 56b is also changed. This is different from the change appearing in the detection result corresponding to the position of. The rotation of the shaft 52 is controlled with reference to one of the two detection results, which differs depending on the operation mode. Thereby, the operation performance regarding the zoom adjustment is improved.

  In this embodiment, two blades 56a and 56b having different gaps are attached to the shaft 52, and the low speed PI sensor 58a and the high speed PI sensor 58b are installed so as to sandwich the respective blades. However, one blade 56c shown in FIG. 8 may be used for the driver 20a.

  The blade 56c is configured by two regions, an outer region 56c1 and an inner region 56c2. A gap OP1 is formed at an interval corresponding to the angle θ1 in the rotation direction of the outer region 56c1, and a gap OP2 is formed at an interval corresponding to the angle θ2 in the rotation direction of the inner region 56c2.

  When such a blade 56c is used, the driver 20a is configured as shown in FIG. The low speed PI sensor 58c emits light from one main surface side of the outer region 56c1, and detects the emitted light on the other main surface side of the outer region 56c1 of the blade 56a. The high-speed PI sensor 58d emits light from one main surface side of the inner region 56c2, and detects the emitted light on the other main surface side of the inner region 56c2. Other operations of the low speed PI sensor 58c and the high speed PI sensor 58d are the same as those of the low speed PI sensor 58a and the high speed PI sensor 58b described above.

  In this embodiment, the selection of the output of the selector 60 and the control of the torque generated by the zoom motor 50 are changed according to the operation position of the zoom button 40zm. However, these may be changed according to the imaging mode.

  In this case, the selector 60 selects the output of the low-speed PI sensor 58a or 58c corresponding to the moving image capturing mode, and the motor control circuit 62 causes the zoom lens 12 to be driven at low speed with the torque generated by the zoom motor 50. It is sufficient to control them. Further, in this case, the selector 60 selects the output of the high-speed PI sensor 58b or 58d corresponding to the still image capturing mode, and the motor control circuit 62 causes the zoom lens 12 to drive the torque generated by the zoom motor 50 at high speed. Control may be performed so that

  In this embodiment, the digital camera is used for the explanation. However, the present invention can also be applied to a personal computer, a mobile phone terminal, a smartphone, or the like.

DESCRIPTION OF SYMBOLS 10 ... Digital camera 12 ... Zoom lens 20a ... Driver 38 ... CPU
40zm ... Zoom button

Claims (7)

A first blade having a gap formed at a first interval in the rotation direction and having a gap formed at a second interval in the rotation direction; and a first blade rotating with rotation of a shaft transmitting torque to the zoom mechanism; A blade member having a second blade rotating at a rotation speed corresponding to the rotation speed of the first blade,
Detecting means for detecting a signal output from one main surface side of the blade member on the other main surface side of the blade member corresponding to one of the positions of the first blade and the second blade;
An electronic camera comprising: control means for controlling rotation of the shaft with reference to a detection result of the detection means; and change means for changing an output position of a signal detected by the detection means in accordance with an operation mode.   The detecting means detects the first signal emitted from the one main surface side of the first blade on the other main surface side of the first blade, and the one main surface side of the second blade. The electronic camera according to claim 1, further comprising second detection means for detecting the emitted second signal on the other main surface side of the second blade. The second interval is greater than the first interval;
The operation modes include a low speed driving mode and a high speed driving mode,
The changing means includes a first position changing means for changing an output position of a signal detected by the detecting means to a position of the first blade corresponding to the low speed driving mode, and a signal detected by the detecting means. 3. The electronic camera according to claim 1, further comprising a second position changing unit that changes an output position to a position of the second blade corresponding to the high-speed driving mode. The apparatus further comprises first request means for requesting the control means to rotate at a low speed corresponding to the low speed drive mode, and second request means for requesting the control means to rotate at a high speed corresponding to the high speed drive mode. 3. The electronic camera according to 3. The low-speed drive mode corresponds to a moving image capturing mode,
The electronic camera according to claim 3 or 4, wherein the high-speed driving mode corresponds to a still image capturing mode.   The electronic camera according to claim 1, further comprising an operation button for switching the operation mode.   The electronic camera according to claim 1, wherein the first blade and the second blade form a shape in which the other is positioned around one of the first blade and rotate integrally.

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