JP2004102113A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus which can realize a focusing sensitivity with adequate operability in the case of a manual focusing operation. <P>SOLUTION: The imaging apparatus is provided with a focusing ring such that manual focusing operation can be made. In rotating the focusing ring, the focal length changes but if a focus evaluation value is large like in a curve Cb indicating the relation between the respective focal lengths and the actual moving quantity of the focusing lens, and more particularly if the value exceeds Pmax, the actual moving quantity of the focusing lens is suppressed. The actual moving quantity of the focusing lens per unit displacement volume of the focusing ring is thereby decreased when the ring is moved closer to a focusing position and therefore the focusing can be eventually performed with high accuracy. Consequently, the adequate operability and the focusing sensitivity in the manual focusing operation can be realized. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an imaging device that changes a lens arrangement of a photographing lens according to a displacement of an operation member due to an operation input.
[0002]
[Prior art]
In a conventional imaging apparatus, for example, when a focus ring is rotated to perform a manual focus operation, the ease of a focus operation becomes a problem.
[0003]
In order to improve the operability of this focusing operation, in addition to setting an appropriate operation torque, the focusing sensitivity for the focusing operation, that is, the setting of the amount by which the optical system (focus lens) is actually moved, is set. It becomes important.
[0004]
For example, Patent Literature 1 discloses a technique in which, when a focus ring is manually operated, an operation torque can be set to a desired value by using a valve for adjusting an air flow rate.
[0005]
Patent Document 2 discloses a technique in which the focusing sensitivity is constant irrespective of the focal length or the aperture value of the taking lens.
[0006]
[Patent Document 1]
JP-A-7-199035
[Patent Document 2]
JP-A-7-274053
[0007]
[Problems to be solved by the invention]
However, in the technology described in Patent Document 1, the operation torque is constant regardless of the focus position during manual focus operation. Therefore, when the operation torque is set to an excessively large, the focus is quickly changed from the defocus state. When moving to the position, the focus ring is heavy and the focusing is not good, and there is a problem that it takes time to miss a photo opportunity. On the other hand, if the operation torque is set to an excessively small value, the focus ring is too light and excessively operated to excessively move the in-focus position when the focus is changed from the defocus state to the in-focus state at once.
[0008]
Furthermore, in the technique of Patent Document 2, since a complicated mechanism is employed for torque control, the lens barrel becomes large and heavy, making it difficult to perform a good photographing operation, and it is difficult to perform a delicate focusing operation near the in-focus position. The operability is not always good.
[0009]
The present invention has been made in view of the above problems, and has as its object to provide an imaging apparatus capable of achieving appropriate operability and focusing sensitivity in a manual focus operation.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is an imaging apparatus having an imaging lens and an imaging unit, wherein (a) a lens arrangement relating to the imaging lens according to displacement of an operation member by an operation input (B) changing means for changing the operation load of the operating member in response to the operation input; (c) detecting means for detecting the degree of focusing in the imaging unit for each lens arrangement; and (d). Control means for increasing the operation load in accordance with an increase in the degree of focusing.
[0011]
The invention according to a second aspect is the imaging apparatus according to the first aspect, further comprising: (e) an electric circuit having a motor rotated in conjunction with the displacement of the operation member, wherein the changing unit includes: (B-1) means for changing the operation load by changing characteristics of the electric circuit.
[0012]
According to a third aspect of the present invention, in the imaging device according to the first or second aspect of the present invention, (f) a press-contact member for press-contacting the operation member is further provided, and the changing means includes (b-2) The apparatus further includes means for changing the operation load by changing a pressing force of the pressing member on the operation member.
[0013]
Further, the invention according to claim 4 is an image pickup apparatus having a photographing lens and an image pickup section, wherein (a) means for changing a lens arrangement of the photographing lens according to displacement of an operation member by operation input; (B) changing means for changing a change amount of the lens arrangement per unit displacement amount in the operation member; (c) detecting means for detecting a degree of focusing in the imaging unit for each lens arrangement; Control means for reducing the amount of change in the lens arrangement per unit of displacement in accordance with an increase in the degree of focusing.
[0014]
According to a fifth aspect of the present invention, in the image pickup apparatus according to the fourth aspect of the present invention, (e) means for changing an operation load of the operation member in response to the operation input, and (f) a response to an increase in the degree of focusing. Means for increasing the operation load.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
<First embodiment>
<Main components of imaging device>
FIG. 1 and FIG. 2 are perspective views showing an imaging device 1A according to the first embodiment of the present invention. FIGS. 1 and 2 show three axes X, Y, and Z orthogonal to each other to clarify the azimuth relationship.
[0016]
The imaging device 1A is configured as a digital camera, and includes a camera body 10 having a box shape and a photographing lens 11. The imaging lens 11 is provided with a focus ring 12.
[0017]
The photographing lens 11 has a lens system that can be driven along the direction of the optical axis LA, and by moving the lens system in the direction of the optical axis, a subject image formed on an image sensor 15 (described later). Is achieved.
[0018]
The focus ring 12 has a cylindrical shape, and can be rotated in the direction RD about the optical axis LA. When the photographer operates the focus ring 12, a plurality of lenses in the photographing lens 11 move, and the focus state of the subject changes.
[0019]
A shutter button 13 is provided on the upper surface of the imaging device 1A. The shutter button 13 is a button for giving a photographing instruction to the imaging device 1A by performing a pressing operation by a photographer when photographing a subject.
[0020]
On the back surface of the imaging device 1B, a display unit 14 configured by, for example, a liquid crystal display is provided. The display unit 14 performs a live view display in which the subject is displayed in a moving image mode before the main shooting, that is, a live view display, and displays an image or the like that is shot when the shutter button 13 is instructed to shoot.
[0021]
FIG. 3 is a diagram illustrating functional blocks of the imaging device 1A.
[0022]
The imaging device 1A includes an imaging element 15 provided in the back of the imaging lens 11 having a focus lens 11a and a zoom lens 11b, a signal processing circuit 16 connected to the imaging element 15 so that data can be transmitted, and a transmission to the signal processing circuit 16. And an image processing unit 17 to be connected as possible. Further, the imaging device 1 </ b> A includes a control unit 18 and a memory 19 that are connected to the image processing unit 17 so that transmission is possible.
[0023]
The imaging element 15 is configured by, for example, a charge coupled device (CCD), and converts a subject image formed by the imaging lens 11 into an electric signal.
[0024]
The signal processing circuit 16 is a part that performs gain control, sample hold, and A / D conversion on an analog image signal output from the image sensor 15 to generate a digital signal.
[0025]
The image processing unit 17 performs image processing such as color correction and gradation correction on image data output from the signal processing circuit 16. The image data subjected to the image processing by the image processing unit 17 is temporarily stored in the memory 19 and then recorded in the memory card 9 which is detachable from the imaging device 1A. When displaying the actually photographed image, the image data stored in the memory 19 or the memory card 9 is converted by the image processing unit 17 and displayed on the display unit 14.
[0026]
The control unit 18 has a CPU and a memory, and is a part that performs overall control of the imaging device 1A. In addition, the control unit 18 has an evaluation value calculation unit 18a that detects the degree of focusing in the image sensor 15 for each lens arrangement of the photographing lens 11 based on the image data stored in the memory 19. The evaluation value calculation unit 18a calculates a focus evaluation value (focus evaluation value), which is a sum of absolute values of differences between adjacent pixels, as an index of the degree of focus.
[0027]
The imaging apparatus 1A includes A / D converters 21 to 23 and D / A converters 24 and 25, and further includes a position detector (potentiometer) 26 for detecting a rotation angle of the focus ring 12. Further, the imaging device 1A includes a focus lens drive motor 27 and a zoom lens drive motor 28 for driving the focus lens 11a and the zoom lens 11b, and a position detector for detecting the lens positions of the focus lens 11a and the zoom lens 11b. 31 and 32 are provided.
[0028]
The position detector 26 acquires information on the relative rotation angle of the focus ring 12 with respect to the camera body 10 and outputs the information to the A / D converter 21.
[0029]
The drive motors 27 and 28 are actuators for changing the lens positions of the zoom lens 11a and the zoom lens 11b, respectively, and are driven by motor drive circuits 33 and 34 connected to the D / A converters 24 and 25, respectively.
[0030]
The position detectors 31 and 32 acquire lens position information of the zoom lens 11a and the zoom lens 11b, respectively, by connecting to the rotation shafts of the drive motors 27 and 28, and output the information to the A / D converters 22 and 23, respectively.
[0031]
The operation of the focus lens 11a when the photographer operates the focus ring 12 in the imaging apparatus 1A having the above configuration will be described.
[0032]
<Operation of Focus Lens 11a>
In the imaging device 1A, when the photographer performs focusing in a photographing preparation stage of live view display on the display unit 14, the focus adjustment is performed by an operation of rotating the focus ring 12 in the direction RD. At the time of this manual focus operation, the lens position of the focus lens 11a is moved by operating the focus ring 12, and this operation will be described in detail below.
[0033]
When the focus ring 11a is operated in the direction RD, the rotation angle information of the focus ring 11a detected by the position detector 26 is converted into a digital signal by the A / D converter 21 and input to the control unit 18. The control unit 18 calculates the amount of movement of the focus lens 11a based on the rotation angle information. Then, the control unit 18 sends a drive signal corresponding to the calculated movement amount of the focus lens 11a to the focus motor drive circuit 33 via the D / A converter 24, and moves the focus lens 11a by this movement amount. By such an operation, the lens arrangement of the photographing lens 11 changes according to the displacement of the focus ring 12 (operation member) due to the operation input, and the focus can be adjusted.
[0034]
Here, the amount by which the focus lens 11a actually moves (the actual movement amount) is controlled by the following equation (1).
[0035]
(Focus lens / actual moving distance) = (focus lens / temporary moving distance) × (moving distance coefficient) (1):
The temporary movement amount of the focus lens on the right side of the above equation (1) is calculated as a value proportional to the movement amount (rotation amount) of the focus ring 12 as shown in FIG.
[0036]
As shown in FIG. 5, when the focus evaluation value calculated by the evaluation value calculation unit 18a is Pmin to Pmax, as shown in FIG. It is set to decrease as the focus position is approached. Furthermore, when the focus evaluation value is equal to or less than Pmin, the movement amount coefficient is maintained at the maximum “1”. When the focus evaluation value is equal to or more than Pmax, the movement amount coefficient is maintained at the minimum αmin. Is set to
[0037]
FIG. 6 is a diagram illustrating the relationship between the focal length, the focus evaluation value, and the actual movement amount of the focus lens 11a. In the figure, the relationship between the focal length and the focus evaluation value is indicated by a solid line Ca, and the relationship between the focal length and the actual movement amount of the focus lens 11a is indicated by a chain line Cb.
[0038]
When the focus ring 12 is rotated, the focal length changes because the lens position moves. However, when the focus evaluation value is large, as indicated by the dashed-dotted line Cb, particularly when the focus evaluation value exceeds Pmax, the actual focal length of the focus lens 11a is increased. Since the amount of movement is suppressed, the actual amount of movement of the focus lens 11a decreases when the focus lens 11a approaches a focused state.
[0039]
By the operation of the focus lens 11a as described above, the actual movement amount of the focus lens 11a is set to the product of the temporary movement amount of the focus lens and the movement amount coefficient as described above. Of the focus lens 11a, that is, the change amount of the lens arrangement can be changed. Then, by reducing the amount of movement of the focus lens 11a per unit displacement amount in accordance with the increase in the focus evaluation value (the degree of focusing), the focus lens 11a has a large focus evaluation value at the lens position of the focus lens 11a. Position adjustment, that is, focusing, can be performed with higher accuracy. That is, when the focus is likely to be achieved, the control resolution of the focus lens 11a can be increased.
[0040]
Therefore, in the imaging apparatus 1A, appropriate operability and focusing sensitivity can be realized at the time of a manual focus operation.
[0041]
Note that the relationship between the amount of movement of the focus ring 12 and the provisional amount of movement of the focus lens 11a is not necessarily the relationship shown in FIG. 4, but may be the relationship shown in FIG. It is sufficient if the temporary movement amount of the focus lens 11a increases as the movement amount increases.
[0042]
Further, the relationship between the focus evaluation value and the movement amount coefficient is not necessarily the relationship shown in FIG. 5, but the relationship between the focus evaluation value and the relationship shown in FIG. 9 and FIG. It is sufficient if the relationship is such that the quantity coefficient decreases.
[0043]
<Second embodiment>
<Main components of imaging device>
The imaging device 1B according to the second embodiment of the present invention has the same appearance as the imaging device 1A shown in FIG. 1 and FIG.
[0044]
FIG. 11 is a diagram illustrating functional blocks of the imaging device 1B.
[0045]
The imaging device 1B has a configuration similar to the functional blocks of the imaging device 1A shown in FIG. 3, but differs in that a control load generator 35 and a D / A converter 36 are added.
[0046]
FIG. 12 is a diagram for explaining the configuration of the control load generator 35.
[0047]
The control load generator 35 includes a main body 35a and a press-contact member 35b.
[0048]
The main body 35a has, for example, an actuator using a piezoelectric element or the like and a pressure sensor, and is configured to be capable of pressure control.
[0049]
The press contact member 35b is pressed by the main body 35a against the side surface of the gear 12g (parallel hatched portion) inside the focus ring 12.
[0050]
With such a configuration of the control load generator 35, the frictional force between the pressing member 35b and the gear 12g changes by changing the pressing force of the pressing member 35b against the side surface of the gear 12g by the main body 35a. Thus, when the photographer operates the focus ring 12, the control unit 18 sends a control signal relating to the pressing force to the control load generator 35 via the D / A converter 36, so that the load torque ( Control load) can be changed.
[0051]
<Operation of Focus Lens 11a>
In the image pickup apparatus 1B, as in the first embodiment, when the photographer performs focusing in a photographing preparation stage in which live view is displayed on the display unit 14, focus adjustment is performed by rotating the focus ring 12 in the direction RD. Is performed. During this manual focus operation, the load torque (control load amount) of the focus ring 12 changes. This operation will be described in detail below.
[0052]
FIG. 13 is a diagram illustrating a relationship between the focus evaluation value and the control load amount.
[0053]
When the focus evaluation value calculated by the evaluation value calculation unit 18a is Pmin to Pmax, the control load amount (operation load) increases as the focus evaluation value increases, that is, as the focus evaluation value approaches. Is set. Further, when the focus evaluation value is equal to or less than Pmin, the control load is maintained at the minimum torque Tmin, and when the focus evaluation value is equal to or more than Pmax, the control load is maintained at the maximum torque Tmax. Is set. Then, a control signal corresponding to the control load amount calculated by the control unit 18 is transmitted to the control load generator 35 via the D / A converter 36, and the load torque of the focus ring 12 is adjusted.
[0054]
By the operation of the focus lens 11a as described above, when the focus evaluation value is large, that is, when focusing is close, the load torque of the focus ring 12 can be relatively increased. In other words, by increasing the operation load on the focus ring 12 in accordance with the increase in the degree of focus, it is possible to prevent the photographer from inadvertently turning the focus ring 12 and to prevent the focus point from passing due to excessive rotation. Thus, more accurate control of the focus lens 11a becomes possible.
[0055]
Therefore, also in the imaging device 1B, as in the first embodiment, appropriate operability and focusing sensitivity can be realized in the manual focus operation.
[0056]
The configuration shown in FIG. 12 is not essential for the control load generator 35, and may be a control load generator 35r having a configuration described below.
[0057]
FIG. 14 is a diagram for explaining the control load generator 35r.
[0058]
The control load generator 35r includes an electric circuit CT having a motor 35c and a variable resistor 35e electrically connected to the motor 35c via a wiring 35d.
[0059]
The motor 35c is configured such that a gear 35f provided on a rotating shaft thereof is meshed with a gear 12g (parallel hatched portion) inside the focus ring 12, and is rotated in conjunction with the displacement of the focus ring 12. Further, the motor 35c functions as a generator that generates electric power from a terminal by forced rotation.
[0060]
The variable resistor 35e is configured so that its resistance value can be changed by a control signal from the control unit 18. The variable resistor 35e consumes the power output by the motor 35c rotated by the focus ring 12, but the power amount can be changed by changing the resistance value of the variable resistor 35e.
[0061]
With such a configuration of the control load generator 35r, by changing the resistance value of the variable resistor 35e and changing the characteristics of the electric circuit CT, the load torque required to rotate the gear 35f of the motor 35c changes. Thus, when the photographer operates the focus ring 12, the control unit 18 sends a control signal to the control load generator 35r via the D / A converter 36 to thereby control the load torque of the focus ring 12 linked to the gear 35f. (Control load amount) can be changed.
[0062]
Also in this case, if the control load (operation load) of the focus ring 12 is controlled as shown in FIG. 13, appropriate operability and focus sensitivity can be realized during manual focus operation.
[0063]
Further, in the imaging apparatus having the above-described control load generator 35r, in addition to the function of driving the focus lens 11a by the photographer's operation on the focus ring 12, the focus lens 11a is driven by the focus lens drive motor based on the focus evaluation value. Even when the function of automatically driving the focus is added at 27, the increase in the number of components can be suppressed to a minimum.
[0064]
<Modification>
Regarding the imaging device, a configuration in which the actual movement amount of the focus lens 12 is controlled based on the focus evaluation value as in the first embodiment, and a configuration in which the load torque is controlled based on the focus evaluation value as in the second embodiment. May be used.
[0065]
In each of the above embodiments, it is not essential to use a member that is rotated and operated, such as a focus ring, and an operation member that is linearly operated may be used.
[0066]
The imaging device in each of the above embodiments is not necessarily configured as a digital camera, but may be configured as a silver halide camera having a focus ring and an evaluation value calculation unit.
[0067]
【The invention's effect】
As described above, according to the first to fifth aspects of the present invention, since the operation load on the operation member is increased in accordance with the increase in the degree of focusing, appropriate operability and focus sensitivity can be realized.
[0068]
In particular, according to the second aspect of the present invention, since the operation load is changed by changing the characteristics of an electric circuit having a motor rotated in conjunction with the displacement of the operation member, the operation load can be easily changed.
[0069]
According to the third aspect of the present invention, since the operation load is changed by changing the pressing force of the pressing member against the operation member, the operation load can be easily changed.
[0070]
According to the fourth and fifth aspects of the present invention, since the amount of change in the lens arrangement per unit displacement amount of the operation member is reduced in accordance with the increase in the degree of focusing, appropriate operability and focusing sensitivity are obtained. realizable.
[0071]
In particular, in the invention of claim 5, since the operation load on the operation member is increased in accordance with the increase in the degree of focusing, more excellent operability and focus sensitivity can be realized.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an imaging device 1A according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing an imaging device 1A.
FIG. 3 is a diagram showing functional blocks of an imaging device 1A.
FIG. 4 is a diagram illustrating a relationship between a focus ring movement amount and a focus lens temporary movement amount.
FIG. 5 is a diagram illustrating a relationship between a focus evaluation value and a movement amount coefficient.
FIG. 6 is a diagram illustrating a relationship between a focal length, a focus evaluation value, and an actual movement amount of a focus lens.
FIG. 7 is a diagram illustrating a relationship between a focus ring moving amount and a focus lens temporary moving amount.
FIG. 8 is a diagram illustrating a relationship between a focus ring moving amount and a focus lens temporary moving amount.
FIG. 9 is a diagram illustrating a relationship between a focus evaluation value and a movement amount coefficient.
FIG. 10 is a diagram illustrating a relationship between a focus evaluation value and a movement amount coefficient.
FIG. 11 is a diagram illustrating functional blocks of an imaging device 1B according to a second embodiment of the present invention.
FIG. 12 is a diagram for explaining a configuration of a control load generator 35.
FIG. 13 is a diagram illustrating a relationship between a focus evaluation value and a control load amount.
FIG. 14 is a diagram illustrating a configuration of a control load generator 35r.
[Explanation of symbols]
1A, 1B Imaging device 11 Imaging lens 11a Focus lens 12 Focus ring 18 Control unit 18a Evaluation value calculation unit 26 Position detector (potentiometer)
27 Focus lens drive motors 35, 35r Control load generator 35a Body 35b Pressure contact member 35c Motor 35e Variable resistance

Claims (5)

An imaging device having a shooting lens and an imaging unit,
(A) means for changing a lens arrangement of the photographing lens according to a displacement of an operation member by an operation input;
(B) changing means for changing an operation load of the operation member in response to the operation input;
(C) detecting means for detecting the degree of focusing in the imaging unit for each lens arrangement;
(D) a control unit configured to increase the operation load in accordance with an increase in the degree of focusing. The imaging device according to claim 1,
(E) an electric circuit having a motor rotated in conjunction with the displacement of the operation member,
Further comprising
The changing means,
(B-1) means for changing the operation load by changing characteristics of the electric circuit;
An imaging device comprising: In the imaging device according to claim 1 or 2,
(F) a pressing member for pressing against the operating member;
Further comprising
The changing means,
(B-2) means for changing the operation load by changing the pressing force of the pressing member against the operation member;
An imaging device, further comprising: An imaging device having a shooting lens and an imaging unit,
(A) means for changing a lens arrangement of the photographing lens according to a displacement of an operation member by an operation input;
(B) changing means for changing a change amount of the lens arrangement per unit displacement amount in the operation member;
(C) detecting means for detecting the degree of focusing in the imaging unit for each lens arrangement;
(D) control means for decreasing a change amount of the lens arrangement per unit displacement amount according to an increase in the degree of focusing;
An imaging device comprising: The imaging device according to claim 4,
(E) means for changing an operation load of the operation member in response to the operation input;
(F) means for increasing the operation load according to an increase in the degree of focusing;
An imaging device, further comprising:

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