JP2009204888A - Photographing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly vary power without a feeling of incongruity by reducing a sudden change in field angle when varying the power of a photographing apparatus. <P>SOLUTION: The photographing apparatus includes: a zoom lens unit 2 for varying power; a drive circuit 21 for driving the zoom lens unit 2; and a zooming means 16 for instructing to perform a variable power operation; and a zoom fixed speed/variable speed selection means 17 that can select either a fixed speed or a variable speed for zooming speed when the variable power operation is performed by the zooming means 16. The unit 2 also includes a zooming speed control means 14 which, when a fixed speed drive mode is selected by the zoom fixed speed/variable speed selection means 17, performs acceleration control so that the speed reaches a desired fixed speed in a predetermined time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photographing apparatus having a zoom drive mechanism.

  In recent years, due to demands for miniaturization and cost reduction, there are an increasing number of photographing apparatuses that electrically detect an operation by a zoom operation means, generate a zoom drive signal by a control CPU, and perform a zooming operation by an actuator. Such a mechanism does not require a mechanism for mechanically connecting the zoom operation means and the zoom lens unit directly. However, since the zoom acceleration operation directly affects the movement of the change in the angle of view, it is required to control the movement so that it does not feel strange.

  Japanese Patent Application Laid-Open No. 2004-228561 proposes that zoom operation characteristics during automatic zoom control such as a constant speed auto zoom function and a preset function can be changed, and an automatic zooming operation close to a manual operation by a user is realized.

  Similarly, during manual operation, it is necessary to improve the zoom operating characteristics, particularly the acceleration characteristics.

JP 2002-72047 A

  The zooming operation generally uses a zoom operation means that can detect a multi-stage state, such as a seesaw switch whose output changes depending on how the switch is pressed, or a ring mechanism that detects a rotation angle and a rotation speed. At that time, it is possible to switch between a variable speed drive mode that changes the zoom speed in conjunction with multi-step detection and a constant speed drive mode that controls to maintain a constant speed without interlocking with multi-step detection. An imaging device is known.

  In the case of such an imaging apparatus, the zoom speed can be manipulated in multiple stages in the variable speed drive mode. Therefore, the zoom operation means can be arbitrarily operated by the user adjusting the operation of the zoom operation means.

  In the constant speed drive mode, control is performed so as to reach a desired constant speed through an acceleration pattern based on table data as shown in FIG. 5, and VC1, VC2, and VC3 have a desired constant speed that can be selected. Represents. For example, when the speed of VC2 is selected, the speed of VC2 is reached through a stepwise acceleration pattern during a period from T0 to TC2. During the period from T0 to TC2 during which acceleration control is being performed, the speed determined by the table data is set, and therefore it is impossible to control the movement of the zoom. Accordingly, an inadvertent change in the angle of view occurs, and the user may feel uncomfortable.

  In view of the above problems, an object of the present invention is to smooth the change in the angle of view by controlling to reach a desired speed in a predetermined time when the constant speed driving mode of the zoom mechanism is selected. It is to provide a possible photographing apparatus.

  In order to achieve the above object, an imaging apparatus according to the present invention includes a zoom lens for zooming, an actuator for driving the zoom lens, a zoom operation means for instructing a zoom operation, and the zoom operation means. The zoom constant speed / variable speed selection means includes zoom constant speed / variable speed selection means and zoom speed control means capable of selecting whether the zoom speed is constant speed or variable speed during zooming operation. When the constant speed driving mode is selected by the above, the zoom speed control means performs linear acceleration control so as to reach the cloth bag speed in a predetermined time.

  According to the photographing apparatus of the present invention, by controlling to reach a desired speed in a predetermined time, it is possible to obtain a zoom function that smoothes the change in the angle of view at the time of zooming and does not cause a sudden change in the angle of view. It is done.

The present invention will be described in detail based on the embodiments shown in the drawings.
FIG. 1 shows a block circuit configuration diagram of the photographing apparatus. A fixed front lens unit 1 on the optical axis, a zoom lens unit 2 that moves in the optical axis direction to change the magnification, an aperture unit 3 that adjusts the amount of light, a fixed lens unit 4, and moves in the optical axis direction to adjust the focus. A focus lens unit 5 and an image sensor 6 are arranged.

  The output of the image sensor 6 composed of a photoelectric conversion element such as a CCD sensor or a CMOS sensor is connected to the control CPU 10 via the image sensor drive circuit 7 and the video signal processing circuit 8, and a video signal is externally transmitted from the video signal processing circuit 8. It is connected. The control CPU 10 incorporates focus control means 11, aperture control means 12, zoom control means 13, zoom speed control means 14, and zoom acceleration table storage means 15. The control CPU 10 is connected to outputs of the zoom operation means 16, the constant zoom / variable speed selection means 17, and the zoom speed selection means 18.

  The output of the control CPU 10 is transmitted to the zoom lens actuator 20 via the drive circuit 19 so as to drive the zoom lens unit 2. The actuator 20 includes a DC motor, a voice coil motor, a pulse motor, and the like. The output of the control CPU 10 is driven by a diaphragm actuator 22 comprising a DC motor or a pulse motor via a drive circuit 21, and the output of a diaphragm encoder 23 for detecting the position of the diaphragm unit 3 is controlled. It is connected to the CPU 10. Further, the output of the control CPU 10 is applied to a focus lens actuator 25 such as a DC motor, a voice coil motor, or a pulse motor via a drive circuit 24 to drive the focus lens unit 5.

  The light flux from the subject passes through the lens units 1, 2, 4, 5 and the aperture unit 3 and forms an image on the light receiving surface of the image sensor 6. The image sensor 6 accumulates the photoelectrically converted charge, and the image sensor driving circuit 7 reads the charge at a predetermined timing. The image sensor drive circuit 7 has an AD conversion function for converting an analog signal from the image sensor 6 into a digital signal. The signal output from the image sensor 6 via the image sensor drive circuit 7 is sent to the video signal processing circuit 8 and subjected to various processes such as predetermined amplification and gamma correction on the output signal from the image sensor 6. Generate a video signal. Then, the video signal is output to a display device such as an external liquid crystal display panel.

  Since the configuration diagram of FIG. 1 shows a case where a pulse motor is mounted, an encoder for detecting the position of the zoom lens unit 2 is omitted. The zoom lens actuator 20 is driven based on a command from the zoom control means 13 in the control CPU 10 via the drive circuit 19. The zoom control unit 13 can detect the position of the zoom lens unit 2 by performing pulse counting with an internal counter.

  The aperture control means 12 in the control CPU 10 drives the aperture actuator 22 via the drive circuit 21 based on the luminance information from the encoder 23 and the video signal processing circuit 8.

  1 has a four-group rear focus configuration, the focus lens unit 5 is interlocked with the zooming operation and needs to follow the cam locus. When performing the zooming operation, first, the zoom constant speed / variable speed selection means 17 selects the constant speed drive mode or the variable speed drive mode. The zoom speed selection means 18 selects the driving speed in the constant speed driving mode, and it is desirable that the selectable speed can be finely selected in the range from low speed to high speed in accordance with the use conditions.

  When the constant speed drive mode is selected, by operating the zoom operation unit 16, it is possible to perform a zooming operation at a speed selected by the zoom speed selection unit 18. When the variable speed mode is selected, the zoom speed of the zoom lens unit 2 is set by a command corresponding to the operation amount of the zoom operation means 16. As the zoom operation means 16, a seesaw switch whose output voltage changes depending on how it is pushed, a ring mechanism whose number of output pulses changes according to the rotation angle and rotation speed, and the like are used.

  The zoom acceleration table storage means 15 stores table data during zoom acceleration used when the variable speed mode is selected. As the zoom acceleration table storage unit 15, a rewritable electronic device such as an EEPROM or a flash ROM is preferably used.

  The zoom speed control means 14 calculates the acceleration speed in the constant speed mode, reads the acceleration speed table data stored in the zoom acceleration table storage means 15, or sets the speed selected by the zoom speed selection means 18. Control the zoom speed.

  FIG. 2A is an explanatory diagram of acceleration control by the zoom speed control means 14 in the embodiment. Similarly to FIG. 5, VC1, VC2, and VC3 represent desired constant speeds that can be selected by the zoom speed selection means 18. In this constant speed driving mode, acceleration driving is started at time T1, and the speed between times T1 and T2 is calculated so as to reach the speed selected at time T2, so that speeds VC1, VC2, and VC3 are obtained. Smooth acceleration can be realized. By performing such acceleration, a natural zooming operation can be performed without causing a sudden change in the angle of view.

  In FIG. 2A, the acceleration process in the constant speed drive mode is linearly changed. However, as shown in FIG. 2B, a curved element may be partially added at the inflection point. Good. In this way, when accelerating in a curved line, it takes time to calculate the speed at the time of acceleration, but it is possible to further smooth the movement at the start and end of acceleration.

  In the case of the variable speed driving mode, the driving is performed at a speed of, for example, VV1 to VV3 according to the operation amount of the zoom operation means 16 by the user as shown in FIG. In this case, the acceleration time is different from that in the constant speed driving mode. For example, in the case of the speed of VV1, the speed reaches VV1 through the acceleration interval of T0 to TV1. This is because it is impossible to predict the operation amount of the zoom operation means 16, and the reaching speed is unknown. Further, the acceleration speed is not calculated, but table data stored in the zoom acceleration table storage means 15 is used.

  If the acceleration speed is adjusted to the low speed side of VV1, for example, the time until it reaches the high speed side of VV3 becomes long, and if it is adjusted to the high speed side, the acceleration time on the low speed side becomes short. It is necessary to perform the acceleration processing used. Note that by increasing the amount of table data to be stored, the speed can be set finely and a smoother movement can be started.

  FIG. 4 is an operational flowchart of acceleration control in zoom operation processed by the control CPU 10 and its peripheral mechanisms.

(Step S <b> 1): It is detected whether the user has performed a zooming operation using the zoom operation means 16. When the zoom operation is not detected, the detection operation is repeated until the operation is performed, and when the zoom operation is detected, the process proceeds to the next step S2. In this embodiment, the detection of the zoom operation is repeatedly performed, but the same detection operation can be performed even if the interrupt function of the control CPU 10 is used.

(Step S2): Using the zoom constant speed / variable speed selecting means 17, it is detected whether or not the constant zoom speed driving mode is selected. If the constant speed drive mode is selected, the process proceeds to step S3. If the constant speed drive mode is not selected, that is, if the variable speed drive mode is selected, the process proceeds to step S13.

(Step S3): In the constant speed drive mode, the zoom speed selected by the zoom speed control means 14 is detected. The zoom speed selection means 18 is, for example, a dial switch or a button mechanism that can directly input numerical values, and the selected zoom speed is temporarily stored in the zoom speed control means 14.

(Step S4): The acceleration speed for reaching the zoom speed selected in Step S3 is calculated. The acceleration speed is calculated so as to reach the selected speed after a predetermined time.

(Step S5): In order to drive the zoom lens actuator 20, the zoom speed is set based on the acceleration speed calculated in Step S4.

(Step S6): The zoom control means 13 outputs a drive signal to drive the zoom lens unit 2, and drives the zoom lens actuator 20 via the drive circuit 19 to execute acceleration drive.

(Step S7): When the zoom operation is interrupted during the acceleration operation, a process for normally ending the scaling operation is performed. Whether or not the zoom operation has been completed is detected. If the zoom operation has been completed, the process proceeds to step S12 in order to stop the zooming operation even during acceleration. Subsequently, when the zoom operation is being performed, the process proceeds to the next step S8.

(Step S8): It is determined whether the acceleration operation has been completed. If the speed selected in step S3 has been reached, it is determined that the acceleration operation has ended, and the process proceeds to step S9. If the constant speed has not been reached, the process returns to step S4 to continue the acceleration operation, and the speed is calculated.
(Step S <b> 9): The zoom speed control unit 14 sets the selected desired constant speed in the zoom control unit 13.

(Step S10): The zoom control means 13 outputs a drive signal for moving the zoom lens unit 2, drives the zoom lens actuator 20 via the drive circuit 19, and executes the constant speed drive of the zoom lens unit 2. To do.

(Step S11): The zoom operation is determined. If the zoom operation is completed, the process proceeds to the next step S12. If the zoom operation is continued, the zooming operation is continued at a constant speed.

(Step S12): Stop processing of the zoom lens unit 2 is performed. From the viewpoint of the user, it is desirable that the actuator 20 is stopped simultaneously with the end of the zoom operation and the zooming is ended. However, in practice, a deceleration operation is required to reduce the step-out, overshoot, and stop noise of the actuator 20. Note that the deceleration operation may be omitted when the zoom speed is low.

(Step S13): In the variable speed drive mode, the zoom operation means 16 is used to detect the operation amount of the zoom lens unit 2 operated by the user.

(Step S14): The zoom speed control means 14 determines whether or not acceleration driving is completed. If the speed based on the zoom operation amount detected in step S13 has been reached, the acceleration process is terminated and the process proceeds to step S19. Further, if acceleration processing is necessary, the process proceeds to the next step S15.

(Step S15): In order to execute acceleration processing, acceleration speed data for variable speed control is read from the table data stored in the zoom acceleration table storage means 15.

(Step S16): The zoom speed control means 14 sets acceleration speed data in the zoom control means 13.

(Step S17): In order to move the zoom lens unit 2, the zoom control means 13 outputs a drive signal, drives the zoom lens actuator 20 via the drive circuit 19, and executes acceleration drive.

(Step S18): A speed based on the zoom operation amount detected in Step S13 is set in the zoom control means 13.

(Step S 19): The zoom control means 13 outputs a drive signal to move the zoom lens unit 2, and drives the zoom lens actuator 20 via the drive circuit 19. Thus, the zooming operation is performed at a speed corresponding to the amount operated by the user.

(Step S20): It is determined whether or not the zoom operation has ended. If the zoom operation has ended, the zoom stop process in step S12 is executed. If the user continues the zoom operation, the process returns to step S13 to check whether the zoom operation amount has changed.

  By executing the acceleration operation at the time of zooming as described above, the conventional acceleration can be performed in the variable speed drive mode. In the constant speed drive mode, acceleration is performed so that a desired speed is reached after a predetermined time. Therefore, the acceleration time does not become longer depending on the selected speed, and a smoother movement can be realized. Therefore, it is possible to obtain an imaging apparatus having a zoom function that does not cause a sudden change in the angle of view and does not cause a sense of discomfort.

It is a block circuit block diagram of the imaging device of an Example. It is explanatory drawing of the zoom acceleration operation | movement in constant speed drive mode. It is explanatory drawing of the zoom acceleration operation | movement in variable speed drive mode. It is an operation | movement flowchart figure of an Example. It is explanatory drawing of the zoom acceleration operation | movement in the conventional constant speed drive mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front lens unit 2 Zoom lens unit 3 Aperture unit 5 Focus lens unit 6 Imaging element 8 Video signal processing circuit 10 Control CPU
DESCRIPTION OF SYMBOLS 11 Focus control means 12 Aperture control means 13 Zoom control means 14 Zoom speed control means 15 Zoom acceleration table storage means 16 Zoom operation means 17 Zoom constant speed / variable speed selection means 18 Zoom speed selection means 19, 21, 24 Drive circuit 20 Zoom Lens actuator 22 Aperture actuator 23 Aperture encoder 25 Focus actuator

Claims (2)

  A zoom lens for zooming, an actuator for driving the zoom lens, a zoom operation means for instructing a zooming operation, and a zoom speed is set to a constant speed or a variable speed for zooming operation by the zoom operation means. A zoom constant speed / variable speed selection means and a zoom speed control means capable of selecting whether to perform the zoom when the constant speed drive mode is selected by the zoom constant speed / variable speed selection means. An imaging apparatus, wherein the speed control means performs linear acceleration control so as to reach a predetermined speed in a predetermined time.   Zoom acceleration table storage means for storing acceleration speed, and when the variable speed drive mode is selected by the zoom constant speed / variable speed selection means, the zoom speed control means is configured to store the zoom acceleration table from the zoom acceleration table storage means. The imaging apparatus according to claim 1, wherein variable speed control is performed by reading an acceleration speed.

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