JP2019110369A - Imaging apparatus - Google Patents

Abstract

To provide an imaging apparatus capable of performing a focus follow-up with high responsibility over wide imaging region on an imaging surface.SOLUTION: An imaging apparatus includes: imaging means; a driving instruction means of outputting a plurality of driving target value in accordance with a plurality of signals from one part of an imaging region different in the imaging means; and driving means of moving one part of the imaging region to a prescribed position of an optical axial direction on the basis of the plurality of driving target values from the driving instruction means. In the imaging apparatus, a plurality of combinations of one part of the plurality of imaging regions and each driving instruction means corresponded to them and the driving means is provided. One part of the plurality of imaging regions is a different region from a whole imaging region, and the position of the optical axis direction is independently determined.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging device such as a camera and a video, and more particularly to a high response of a drive mechanism provided in the imaging device.

  In recent years, the usage of cameras has diversified, and a highly convenient photographing device adapted to photographing of various scenes and objects is required.

  Patent Document 1 discloses a highly mobile autofocus mechanism that follows an object moving at high speed.

Unexamined-Japanese-Patent No. 7-248522 gazette

  So far, technology development has been made with the main aim of following an object moving at high speed in a certain direction. However, the motion of the subject and the motion of shooting are various, and the elemental technology for keeping track of the subject whose distance changes frequently in the entire imaging region is still insufficient. Therefore, an object of the present invention is to realize a technology capable of following the focus with high responsiveness over a wide imaging area on the imaging surface.

In order to achieve the above object, the imaging apparatus of the present invention has the following configuration.
· Imaging means · Drive instructing means for outputting a plurality of drive target values corresponding to a plurality of signals from a part of the imaging area in the imaging means · A part of the imaging area in the optical axis direction based on the plurality of drive target values A photographing device is configured by a combination of driving means which moves to a predetermined position.

  According to the present invention, it is possible to follow the focus with high responsiveness over a wide imaging area on the imaging surface.

FIG. 1 is a block diagram of an imaging apparatus according to a first embodiment of the present invention. FIG. 2 is a diagram for explaining a drive mechanism and a control block in the imaging device of the first embodiment of the present invention. 7 is a drive flowchart of the photographing device according to the first embodiment of the present invention. FIG. 8 is a block diagram of an imaging apparatus according to a second embodiment of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

Example 1
FIG. 1A is a block diagram in the case of driving an imaging device in the optical axis direction to perform focusing, and a camera having a photographing lens barrel 102 having a lens 103 as an optical means and an imaging device 105 as an imaging means The main body 104 configures an imaging device.

  In FIG. 1A, signal processing units 107a, 107b, and 107c, which are drive instruction units extracted and illustrated from the camera main body 104 for the purpose of explanation, are cascaded to which imaging signals from the imaging element 105 are simultaneously input. The signal processing means 107a, 107b and 107c are connected and take out only necessary signals from their inputs and process them, and output drive target values to a plurality of control means 108a, 108b and 108c such as drivers.

  The signals required by the signal processing means 107a, 107b, 107c correspond to, for example, the portions 109a, 109b, 109c of different imaging areas in the entire imaging area of the imaging device 105 shown in FIG. 1b.

  As described above, the control units 108a, 108b, and 108c are drive units 106a that are drive units that independently move to a plurality of predetermined positions in the optical axis direction for each of the portions 109a, 109b, and 109c of the respective imaging regions. , 106b, 106c are driven and controlled. As shown in FIG. 1B, in this case, each drive mechanism 106a is disposed at a position closest to the part 109a of the imaging region among the three locations in the vicinity of the imaging element 105, and similarly, the drive mechanism 106b is The drive mechanism 106c is disposed closest to the part 109b of the imaging area, and the drive mechanism 106c is disposed closest to the part 109c of the imaging area.

  Further, for example, a part 109a of the imaging area, the signal processing means 107a, the control means 108a, and the drive mechanism 106a form one combination, which is a combination 1, and the range of individual combinations is shown in FIG. Indicated by dashed line as A. Similarly, the part 109b of the imaging area, the signal processing means 107b, the control means 108b and the drive mechanism 106b are combination 2, the part 109c of the imaging area, the signal processing means 107c, the control means 108c and the drive mechanism 106c are combination 3, In the imaging apparatus of the embodiment, a plurality of (in this case, three) combinations are provided. The range of combination 2 and combination 3 is not shown.

  The signal of the release button 110 provided on the camera body 104 is also input to the signal processing means 107a, 107b and 107c, and when the photographer operates the release button, the signal processing means 107a, 107b and 107c are the drive targets described above. The values are output to the control means 108a, 108b, 108c, and the imaging device 105 starts driving for focus adjustment. As shown in FIG. 1B, at this time, the positions of the portions 109a, 109b and 109c in the optical axis direction of the imaging region are independently determined by the three drive means of the drive mechanisms 106a, 106b and 106c. Ru.

  Therefore, the position of the image pickup device 105 is determined by movement in the Z direction which is the optical axis direction, tilting, and a combination thereof.

  For example, when the distances to a plurality of subjects projected onto the portions 109a, 109b, and 109c of the imaging region are equal and the focus detection states of the portions 109a, 109b, and 109c are equal, imaging is performed according to the signals. The element 105 is driven in the Z direction in the optical axis 101 direction. When the distances to the plurality of subjects are different and the focus detection states from the portions 109a, 109b, and 109c of the imaging area are different, the imaging device 105 moves in the Z-axis direction according to the signal and The imaging surface of the imaging device 105 is tilted with respect to the orthogonal plane. Therefore, it is possible to focus on the subject projected on a part of each imaging area.

  In addition, when the distance between the imaging device and each of the subjects imaged in the portions 109a, 109b, and 109c of the imaging region is large, the mutual difference between the plurality of drive target values becomes large. In that case, the difference between the plurality of drive target values is controlled to be within a predetermined amount in order to prevent the inclination of the imaging element 105 from the optical axis to become large and control becomes difficult. Note that this predetermined amount changes depending on the photographing condition of the optical means. The photographing conditions include the aperture value of the optical unit, the shutter speed, and the focal length of the optical unit due to the change in the brightness of the reflected light from the subject.

  FIG. 2A is a view for explaining the periphery of the drive mechanisms 106a, 106b, 106c (106b is not shown) in FIG.

  The drive mechanism 106a will be described with reference to FIG. 2A, and the description of the drive mechanisms 106b and 106c will be omitted because they have the same structure.

  The drive mechanism 106a includes a rotor 201a, a vibrator 203a, a piezoelectric member 204a, a pressure spring 205a, and a position detection unit 206a. The rotor 201 a, which is a friction member fixed to the imaging element 105, has a contact surface on a circular arc centered on a point 209 near the optical axis of the imaging device 105.

The vibrator 203a has a dowel 202a formed of the same member. The dowel 202a is ultrasonically vibrated by the vibration of the piezoelectric member 204a by the voltage applied from the control means a (108a). Therefore, the vibrator 203a and the rotor 201a perform relative motion by the dowel 202a being pressurized and brought into contact with the contact surface of the rotor 201a by the pressure of the pressure spring 205a. Here, since the vibrator 203a is fixed to the main body of the imaging apparatus via the pressure spring 205a, the imaging element 105 to which the rotor 201a is fixed is driven to move.
The position detection means 206a detects the displacement in the Z direction of the part 109a (FIG. 1b) of the imaging area of the imaging device 105, and outputs a position detection signal to the control means 108a.

  Due to the vibration of the dowel 202a, the rotor 201a is displaced in the positive direction of the Z axis as shown in FIG. 2B, for example.

  The position detection means 206a outputs a signal corresponding to the displacement of the part 109a of the imaging area of the imaging device 105 to the control means 108a, and the control means 108a produces an error between the displacement signal and the target value signal from the signal processing means 107a. Feedback drive control is performed by applying a voltage as a drive voltage to the piezoelectric member 204a.

  For example, as shown in FIG. 2B, the focus of a part 109a of the imaging area of the imaging device 105 is analyzed by the signal processing means 107a, and in the case of a front pin state, a target value for correcting the front pin is sent to the control means 108a. Output. The control means 108a drives the piezoelectric member 204a based on the target value, and the rotor 201a is driven in the positive direction of the Z axis.

At this time, the focus of a part 109c of the imaging area of the imaging device 105 is analyzed by the signal processing means 107c, and in the case of the back pin state, a target value for correcting the back pin is output to the control means 108c. The control means 108a drives the piezoelectric member 204a based on the target value, and the rotor 201c is driven in the negative direction of the Z axis.
Therefore, as shown in FIG. 2B, the imaging device 105 is inclined with respect to a plane orthogonal to the optical axis, and corrects the defocus of a part of each imaging region.

  In the case where both the portions 109a and 109c of the imaging area are in the front pin state, as shown in FIG. 2C, the signal processing unit 107a and the signal processing unit 107c output target values for correcting the front pin to the control unit 108a. Do. The control means 108a and the control means 108c drive the piezoelectric members 204a and 204c in the positive direction of the Z axis based on the target values.

  At this time, the focus of a part 109c of the imaging area of the imaging device 105 is analyzed by the signal processing means 107c, and in the case of the back pin state, a target value for correcting the back pin is output to the control means 108c. The control means 108a drives the piezoelectric member 204a based on the target value.

  As described above, the drive mechanism 106 is driven by the contact between the rotor 201 and the dowel 202, and is driven with high responsiveness because there is no mechanism of the transmission system between the drives. In addition, since signal processing is performed independently for each part of each imaging area of the imaging device and drive control is performed independently, output of the drive target value can also be performed at high speed, and highly accurate correction drive can be performed. .

  FIG. 3 is a drive flowchart of the image pickup element described in FIGS. 1 and 2, and a description will be given by omitting a photographing apparatus sequence not related to the present invention.

  This flowchart starts when the main power of the imaging apparatus is turned on. In step # 301, the imaging device 105 takes in an image signal, and outputs the image signal obtained from the part 109a, 109b, 109c of each imaging region of the imaging device 105 to the corresponding signal processing means 107a, 107b, 107c. Do.

  At step # 302, each signal processing means 107a, 107b, 107c processes the input image signal to detect the focus state of the main subject in the part 109a, 109b, 109c of each imaging area.

  In step # 303, this step is repeated and the process waits until the photographer presses the release button of the photographing apparatus halfway. When the release button is pressed halfway, in step # 304, the signal processing means 107a, 107b and 107c control the drive target values of the image sensor 105 for each of the parts 109a, 109b and 109c of the respective imaging areas. The image pickup device starts focus adjustment driving.

  At step # 305, it is judged whether or not the position of the image pickup element detected by the position detection means 206a, 206b, 206c is in the vicinity of the drive target value. If not, the process returns to step # 304 to drive the image pickup element again. If yes, the process returns to step # 302 and the signal processing means 107a, 107b, 107c detect the next focus state.

  In this manner, image signals obtained from the imaging device are divided into parts of the imaging region by a plurality of signal processing means and processed in parallel, and provided for each part of the imaging region of the imaging device with the obtained drive target value. A combination of a plurality of means is configured in parallel so that the drive means can be independently driven and controlled for each part of the imaging region.

With this configuration, the processing time is shorter than in a system in which signals from the entire imaging region in the related art are integrated, and then divided into drive target values for each region and output to the drive unit.
Accordingly, the time for moving the imaging means from the photographing to the predetermined position is shortened, and the responsiveness of the autofocusing operation becomes high. By executing the highly responsive operations independently and in parallel, it is possible to obtain an in-focus image over a wide imaging area of the imaging surface with high responsiveness.

Example 2
FIG. 4 is a side view showing a second embodiment of the present invention. The driving means in the first embodiment is a driving mechanism for relative movement due to the contact between the ultrasonic vibrator and the friction member, whereas in this embodiment, the driving means is based on the electromagnetic driving force by the magnet and the coil. Descriptions are omitted except for necessary parts for the other parts.

  The image pickup device 105 is pivotally supported by the arm portion 403o of the holding ring 403 about the rotation center 209, and the holding ring 403 is a guide shaft 404a fixed to the photographing lens barrel at the end portions 403a and 403b. It is supported so as to be slidable in the Z-axis direction at 404 b. Permanent magnets 401a, 401b, and 401c (each permanent magnet is disposed at three locations as in FIG. 2 and the permanent magnet 401c is not shown) are provided in the imaging element 105, and opposing coils 402a, 402b, and 402c (each coil Are arranged in three places as in FIG. 2, and the coil 402c is not shown) is fixed to the photographing lens barrel.

  Therefore, when the same amount of current in phase is applied to the coils 402a, 402b and 402c, the permanent magnets 401a, 401b and 401c all receive the same force in the Z axis direction which is the optical axis, and the imaging device 105 in the longitudinal direction of the Z axis It is driven. When different amounts of current are applied to the coils 402a, 402b, and 402c, the imaging element 105 receives driving force around the rotation center 209, and also receives driving force in the Z-axis direction. When a current of reverse phase is applied to any one of the coils 402a, 402b, and 402c, the imaging element 105 receives driving force around the rotation axis.

  Position detection means 206a, 206b, 206c (each position detection means is arranged at three locations as in FIG. 2, and the position detection means 206c is not shown) detects the displacement in the Z axis direction which is the optical axis of the imaging element 105, The position detection signal is output to the corresponding control means 108a, 108b. The signal processing means 107a, 107b performs feedback control of the coils 402a, 402b in relation to the position detection signals of the position detection means 206a, 206b and the focusing target value from the control means 108a, 108b.

  As described above, in the present embodiment, even if the electromagnetic driving force by the magnet and the coil is used, the same function as the first embodiment is performed. That is, image signals obtained from the imaging device are divided into portions for each imaging region by a plurality of signal processing means and processed in parallel, and driving provided for each portion of the imaging region of the imaging device with the obtained driving target value A combination of a plurality of means is configured in parallel so that the means can be driven and controlled independently for each part of the imaging region.

  With this configuration, the processing time is shorter than in a system in which signals from the entire imaging region in the related art are integrated, and then divided into drive target values for each region and output to the drive unit. Accordingly, the time for moving the imaging means from the photographing to the predetermined position is shortened, and the responsiveness of the autofocusing operation becomes high. By executing the highly responsive operations independently and in parallel, it is possible to obtain an in-focus image over a wide imaging area of the imaging surface with high responsiveness.

  The present invention is applicable not only to digital cameras and videos but also to industrial cameras intended for factories and surveillance.

102 shooting barrel camera body 104 camera body 105 image pickup element 107 signal processing means 108 control means

Claims (6)

Imaging means,
Drive instructing means for outputting a drive target value corresponding to a signal from a part of the imaging area of the imaging means;
An imaging apparatus comprising a drive unit configured to move a part of the imaging area to a position in a predetermined optical axis direction based on the drive target value.
A plurality of combinations of the drive instruction means and the drive means are provided, each corresponding to a part of the imaging area.
Some of the plurality of imaging regions are different from each other in the entire imaging region,
An image pickup apparatus characterized in that the positions in the optical axis direction are independently determined. The imaging apparatus according to claim 1, wherein a signal from the imaging unit is cascade-connected to the plurality of drive instruction units. The driving means is disposed at three locations in the vicinity of the imaging means, and is disposed at a position closest to a part of the imaging area of the corresponding imaging means. Shooting device. The imaging apparatus includes an optical unit for guiding a light beam from a subject to the imaging unit, and a difference between a plurality of drive target values is within a predetermined amount, and the predetermined amount changes according to the imaging condition of the optical unit. The imaging device according to claim 3. The driving means comprises a vibrator for ultrasonically vibrating and a friction member having a contact surface in contact with the vibrator, the friction member is fixed to the imaging means, and the contact surface is an optical axis of the imaging means The photographing device according to claim 1, wherein the photographing device has an arc shape centering on a point on the vicinity. The imaging device according to claim 1, wherein the driving unit uses an electromagnetic driving force by a magnet and a coil.