JP2017125988A - Accessory attachable to camera or interchangeable lens, and camera system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control system capable of preventing a zoom operation from stopping, the zoom operation likely to stop once noises cause a lowest driving voltage to go below a threshold value, the threshold value of a lowest driving voltage set by each lens so as to avoid an unstable operation, as a rotational load of a zoom ring differs from lens to lens, in an accessory attachable to an interchangeable lens configured to externally operating a zoom ring.SOLUTION: An imaging apparatus system includes a camera main body 1, an interchangeable lens 2 attachable to the camera main body 1 and an accessory 38 attachable to the interchangeable lens 2. The accessory 38 includes a drive part 34 capable of operating a zoom ring, a power supply unit 36, a detector configured to detect a voltage of the power supply unit 36, and a determination part configured to determine whether or not the power supply voltage has gone below a threshold value by a predetermined number of times. The determination part controls an operation stop by the accessory 38.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an accessory that can be attached to and detached from a camera and an interchangeable lens.

  Accessories that are detachable from cameras and interchangeable lenses are required to have high convenience. In particular, when a battery is used as a power source, the operation may become unstable due to the influence of a voltage drop.

  Patent Document 1 discloses a technique for detecting an voltage and stopping the operation when the voltage falls below a threshold value. Thereby, unstable operation can be avoided.

Japanese Patent Laid-Open No. 9-31002

  In an interchangeable lens for operating the zoom ring from the outside and a detachable accessory, the load for rotating the zoom ring of the interchangeable lens varies depending on the corresponding lens. The accessory is moved by a battery, and resetting may occur if the power supply voltage is low. Therefore, an unstable operation is prevented by providing a threshold value for each lens. When the technique described in Patent Document 1 is applied to an accessory for an interchangeable lens, unstable operation can be avoided.

  However, if the voltage drops below the threshold voltage even once due to the influence of noise or the like, the operation stops and it can be said that the convenience is poor.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a camera system including a camera capable of more accurately detecting a voltage at a voltage threshold and an accessory attachable / detachable to / from an interchangeable lens.

In order to achieve the above object, a camera system according to the present invention includes:
The camera body,
An interchangeable lens removable from the camera body;
In the imaging apparatus system comprising an accessory that is detachable from the interchangeable lens,
The accessory has a mechanism capable of operating a zoom ring of the interchangeable lens;
A power supply for supplying power to the accessory;
A detection unit for detecting a voltage of the power supply unit;
A determination unit for determining whether the voltage has fallen below a threshold value a predetermined number of times,
The determination unit controls the operation stop of the accessory.

  ADVANTAGE OF THE INVENTION According to this invention, the camera system containing the accessory which can attach or detach to an interchangeable lens and the camera which can make the voltage detection in a voltage threshold value more accurate can be provided.

It is a block diagram which shows the camera system which concerns on embodiment of this invention. It is a flowchart which shows a part of accessory operation | movement which concerns on embodiment of this invention. It is the figure which showed the voltage fluctuation by the time passage of a battery voltage. It is a flowchart which shows a part of accessory operation | movement which concerns on embodiment of this invention. It is the figure which showed the voltage fluctuation by the time passage of a battery voltage.

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

  FIG. 1 shows a configuration of a camera system including an interchangeable lens 2, an imaging device (hereinafter referred to as a camera body) 1 and an accessory 37 (hereinafter referred to as an accessory) according to an embodiment of the present invention.

  An electric circuit unit 3 provided in the camera body 1 includes an image sensor 4, a photometry unit 5, a focus detection unit 6, a shutter control unit 7, an image processing unit 8, a camera CPU 9, and a lens mounting detection unit. 10 and the camera side communication unit 11.

  The imaging element 4 is a photoelectric conversion element that converts a subject image formed by light that has passed through the interchangeable lens 2 into an electrical signal, and includes a CCD sensor or a CMOS sensor.

  The photometry unit 5 measures the amount of light (luminance) that has passed through the interchangeable lens 2 using the output from the image sensor 4.

  The focus detection unit (focus detection means) 6 calculates the focus state (defocus amount) of the interchangeable lens 2 using outputs from a plurality of focus detection pixels provided in the image sensor 4.

  The shutter control unit 7 controls the operation of a shutter (not shown) that opens and closes in order to control the exposure amount of the image sensor 4.

  The image processing unit 8 performs various processes on the output from the imaging pixels having a predetermined number of pixels provided in the imaging element 4 to generate an image. The various types of processing include processing using image processing information mounted on the interchangeable lens 2 and image processing information mounted on the camera body 1.

  The camera CPU 9 as the imaging device side control means controls the operation of the above-described imaging device 4 and each unit (5 to 8, 32 to 33). The camera CPU 9 can communicate with the lens CPU 26 as lens-side control means via the camera-side communication unit 11 and the lens communication unit 25 provided in the interchangeable lens 2. The camera CPU 9 calculates the aperture value and shutter time at the time of imaging based on the luminance obtained by the photometry unit 5, and transmits an aperture drive command including the aperture value to the lens CPU 26. Further, the camera CPU 9 calculates the drive direction and drive amount to the in-focus position of the focus lens 22 in the interchangeable lens 2 based on the defocus amount calculated by the focus detection unit 6. Then, a focus drive command including information on the drive direction and drive amount is transmitted to the lens CPU 26. That is, focus control of the imaging optical system provided in the interchangeable lens 2 is performed. From the calculation of the defocus amount (focus detection operation) by the focus detection unit 6 to the transmission (focus control) of the focus drive command to the lens CPU 26 by the camera CPU 9 is referred to as AF processing on the camera body 1 side.

  The lens mounting detection unit 10 includes a switch, a photodetector, and the like, detects that the interchangeable lens 2 is mounted on the camera body 1, and outputs a detection signal to the camera CPU 9. The camera CPU 9 communicates with the lens CPU 26 provided in the interchangeable lens 2 via the camera side communication unit 11 and the lens communication unit 25 (transmission unit, reception unit) provided in the interchangeable lens 2.

  In the camera body 1, a control system power supply 12, a drive system power supply 13, an imaging preparation switch (SW 1) 14, an imaging start switch (SW 2) 15, and an image recording unit 16 are also provided.

  The control system power supply 12 supplies power to a control system circuit that requires a stable voltage supply with relatively little power consumption, such as the image sensor 4, the photometry unit 5, the focus detection unit 6, the image processing unit 8, and the display means 33. Supply.

  The drive system power supply 13 supplies power to a drive system circuit that consumes a relatively large amount of power, such as the shutter control unit 7 and the interchangeable lens 2. When the imaging preparation switch (SW1) 14 is turned on by the user, the camera CPU 9 causes the photometry unit 5 to perform a photometry operation and causes the focus detection unit 6 to perform a focus detection operation.

  When the imaging start switch (SW2) 15 is turned on by the user, the camera CPU 9 performs the following operation assuming that an imaging instruction is input.

  First, the camera CPU 9 transmits an aperture driving command for driving the aperture 24 to the aperture value at the time of imaging to the lens CPU 26, and causes the shutter control unit 7 to perform shutter driving so that the imaging device 4 is activated at a predetermined shutter speed. To expose.

  Further, the camera CPU 9 causes the image processing unit 8 to generate a recording image from the output obtained from the image sensor 4 at this time. That is, the image pickup device 4 is used for acquiring a recording image and also used for calculating the defocus amount as described above. Thus, phase difference detection AF performed using an image sensor for acquiring a recording image is also referred to as imaging surface phase difference AF. This embodiment may be an image pickup apparatus that performs focus detection of an image pickup optical system by a phase difference detection method using an image pickup device (not shown).

  Further, the camera CPU 9 causes the image recording unit 16 to record a recording image on a recording medium (not shown) such as a semiconductor memory. A series of imaging operations including exposure, image generation, and recording is also referred to as release processing. Here, the image to be shot is a still image if the still image shooting mode is selected by a mode selection switch (not shown), and a moving image if the moving image shooting mode is selected. Alternatively, a recording start button for moving image shooting may be provided separately, and a moving image recording may be started when the button is pressed. Further, the user may be able to select the recording image quality by a recording image quality setting switch (not shown) on the camera body.

  The interchangeable lens 2 is provided with an imaging optical system composed of a variable power lens 21, a focus lens 22, a shake correction lens 23, and a diaphragm 24, and an electric circuit unit 20.

  The zoom lens 21 moves in the optical axis direction and changes the focal length of the imaging optical system.

  The focus lens 22 moves in the optical axis direction to perform focusing.

  The shake correction lens 23 moves in a direction orthogonal to the optical axis direction to reduce image shake due to camera shake such as camera shake.

  The aperture 24 has a variable aperture diameter (aperture value) and changes the amount of light according to the aperture diameter.

  The electric circuit unit 20 includes the lens communication unit 25 and the lens CPU 26 described above, a zoom drive unit 27, a focus drive unit 28, a shake correction drive unit 29, and an aperture drive unit 30.

  The camera CPU 9 and the lens CPU 26 communicate shooting information of the camera body, focus sensitivity information based on shooting conditions, a focus drive command, and the like via the camera side communication unit 11 and the lens communication unit 25.

  The lens CPU 26 outputs a focus drive signal to the focus drive unit 28 in accordance with a focus drive command received from the camera CPU 9 via the camera side communication unit 11 and the lens communication unit 25.

  The focus drive unit 28 includes an actuator such as a stepping motor, a vibration type motor, or a voice coil motor, and drives the focus lens 22 in accordance with a focus drive signal from the lens CPU 26. In this way, the focus lens 22 moves to the in-focus position. Driving from the order of the focus drive command to the focus position of the focus lens 22 is referred to as AF processing on the interchangeable lens 2 side.

  Further, the lens CPU 26 outputs an aperture drive signal to the aperture drive unit 30 in response to the aperture drive command. The aperture drive unit 30 includes an actuator such as a stepping motor, and drives the aperture 24 according to an aperture drive signal from the lens CPU 26.

  Further, the lens CPU 26 outputs a zoom drive signal for moving the zoom lens 21 at a zoom direction and a zoom drive speed according to an operation of a zoom operation ring (not shown) provided on the interchangeable lens 2 to the zoom drive unit 27. To do. The zoom drive unit 27 includes an actuator such as a stepping motor, and drives the variable magnification lens 21 in accordance with a zoom drive signal from the lens CPU 26.

  Further, the lens CPU 26 outputs a shake drive signal to the shake correction drive unit 29 based on a shake detection signal from a shake sensor (such as an acceleration sensor) (not shown) provided in the interchangeable lens 2. The shake correction drive unit 29 includes an actuator such as a voice coil motor, and drives the shake correction lens 23 according to a shake correction drive signal from the lens CPU 26.

  Further, the lens CPU 26 holds data including a voltage threshold value and the number of times used for communication with the accessory in a storage unit 31 constituted by a storage element such as an EEPROM or a flash ROM. The data is transmitted to the accessory CPU 35 via the lens communication unit 32 and the accessory communication unit 33. The storage unit 31 may be disposed inside the lens CPU 26.

  By correcting the defocus amount obtained by the focus detection using the focal position deviation information, the best image plane position of the imaging optical system matches the imaging plane of the image sensor 4 and the best focus is obtained. The best image plane position of the imaging optical system changes in accordance with the aberration (particularly spherical aberration) of the imaging optical system that varies depending on the position of the variable magnification lens 21, the focus lens 22, and the shake correction lens 23 and the aperture value of the diaphragm 24. Accordingly, the focal position deviation information also varies depending on the position of the variable power lens 21, the focus lens 22 and the shake correction lens 23 and the aperture value of the aperture 24.

  The lens CPU 26 can communicate with the accessory CPU 35 as an accessory-side control unit via the lens communication unit 32 and the accessory communication unit 33 provided in the accessory 38.

  The accessory 38 includes an accessory communication unit 33, a drive unit 34, an accessory CPU 35, a power supply unit 36, and a circuit unit 37. The power source unit 36 uses a battery as a power source.

  The accessory CPU 35 transmits and receives data through the lens CPU 26 and each communication unit. Further, the accessory CPU 35 drives the drive unit 34 by communication from a switch or lens (not shown) to rotate the zoom ring of the lens. Moreover, the process of detecting the voltage of the power supply part 36 and stopping operation | movement of an accessory is performed.

  Next, with reference to the flowchart of FIG. 2, the operation stop process of the accessory of the camera system according to the present embodiment will be mainly described. “S” in the figure is an abbreviation of steps indicating processing. The camera CPU 9, the lens CPU 26, and the accessory CPU 35, which are computers, operate according to an imaging device control program, an interchangeable lens, and an accessory control program, which are computer programs, respectively.

  <Step 100> A battery is inserted into the power source 36 or an accessory switch (not shown) is turned on.

  <Step 110> When power is supplied from the accessory power supply unit 36 to the drive unit 34 in Step 120 described later, the accessory CPU 35 detects the voltage. In order to prevent the circuit from being reset due to the low voltage, a threshold value is provided, and when the voltage falls below the threshold value, the accessory is stopped. When the load torque of the lens is large, a voltage drop is likely to occur. Therefore, there are cases where the remaining battery level is sufficient but falls below the threshold due to a voltage drop. Since it is not convenient to stop after the threshold value is lowered once, the accessory may be stopped when the threshold value is dropped a plurality of times. Therefore, the accessory CPU 35 communicates information regarding the threshold with the lens CPU 26 via the accessory communication unit 33, and sets the threshold and the number of times suitable for the load torque of the lens.

  <Step 120> The battery voltage is taken in by the accessory CPU 35 as the voltage of the power source 36. FIG. 3 shows a graph showing the voltage reading of the battery and the passage of time. The determination is made in steps 130 and 140 described later based on the prohibition voltage threshold and the number of times obtained in step 110.

  <Steps 130 and 140> When the voltage is below the forbidden voltage, the number of times the voltage is below the forbidden voltage is counted at Step 140, and when the number is below a predetermined number of times, the process proceeds to Step 160.

<Step 150> As the operation stop process, the operation of the drive unit is stopped.
As described above, an accessory with improved convenience for the user can be provided.

  Next, a second embodiment of the present invention will be described with reference to FIG. 1, FIG. 3, FIG. 4, and FIG.

  The configuration of the camera lens system of Example 2 is shown in FIG. The description of the configuration in FIG. 1 is omitted because it is the same as that of the first embodiment.

  With reference to the flowchart of FIG. 4, the operation stop process of the accessory of the camera system of the present embodiment will be mainly described. “S” in the figure is an abbreviation of steps indicating processing. The camera CPU 9, the lens CPU 26, and the accessory CPU 35, which are computers, operate according to an imaging device control program, an interchangeable lens, and an accessory control program, which are computer programs, respectively.

  <Step 100> A battery is inserted into the power source 36 or an accessory switch (not shown) is turned on.

  <Step 110> The accessory CPU 35 communicates with the lens CPU 26 via the accessory communication unit 33. With this communication, information about the load torque of the lens is communicated. Based on this information, the accessory CPU 35 sets a first threshold and a second threshold having a voltage lower than the first threshold as the voltage threshold. When the voltage falls below the second threshold, the stop process is started.

  <Step 120> When power is supplied from the accessory power supply unit 36 to the drive unit 34, the accessory CPU 35 detects the voltage. Sampling for a certain period and calculating the average value.

  <Steps 130 and 131> FIG. 5 shows the relationship between the battery voltage drop and the threshold value. If the average value detected in step 120 exceeds the first threshold value, it can be determined that the battery voltage is sufficiently stable or the load torque is small. For this reason, even if the second threshold value at which the stop process needs to be performed may be momentarily reduced, it is not necessary to stop the process immediately. Therefore, the stop process is performed only when the second threshold value is below a predetermined number of times. In FIG. 5, a portion surrounded by a circle is below the second threshold that needs to be stopped, but if it is below a predetermined number of times, the stop processing is not performed here. If the troop value detected in step 120 is below the first threshold, it can be determined that the battery voltage has dropped. In this case, since the battery voltage is decreasing, the stop process is performed by decreasing the number of times that the voltage may fall below the second threshold.

  <Step 140> If the voltage detected in step 120 falls below the second threshold value, the process proceeds to step 150. If not, read the battery voltage.

  <Step 150> Since it is determined in step 140 that the value has fallen below the second threshold value, it is determined whether or not the value falls below the second threshold value for a predetermined number of times set in step 131 or initially. If the predetermined number of times has been exceeded, the process proceeds to step 160 to stop the operation.

  As described above, an accessory with improved convenience for the user can be provided.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

1 camera body, 2 interchangeable lens, 3 electrical circuit section, 4 image sensor, 5 photometric section,
6 focus detection unit, 7 shutter control unit, 8 image processing unit, 9 camera CPU,
10 lens mounting detection unit, 11 camera side communication unit, 12 control system power supply,
13 drive system power supply, 14 imaging preparation switch (SW1),
15 imaging start switch (SW2), 16 image recording unit, 21 zoom lens,
22 focus lens, 23 shake correction lens, 24 aperture, 25 lens communication section,
26 lens CPU, 27 zoom drive unit, 28 focus drive unit,
29 shake correction drive unit, 30 aperture drive unit, 31 storage unit,
32 lens communication unit (accessory unit), 33 accessory communication unit, 34 drive unit,
35 accessory CPU, 36 power supply, 37 circuit, 38 accessory

Claims (4)

The camera body,
An interchangeable lens removable from the camera body;
In the imaging apparatus system comprising an accessory that is detachable from the interchangeable lens,
The accessory has a mechanism capable of operating a zoom ring of the interchangeable lens;
A power supply for supplying power to the accessory;
A detection unit for detecting a voltage of the power supply unit;
A determination unit for determining whether the voltage has fallen below a threshold value a predetermined number of times,
An image pickup apparatus system that controls the operation stop of the accessory by the determination unit. The imaging apparatus system according to claim 1, wherein the accessory includes a communication unit capable of communicating with the interchangeable lens. The imaging apparatus system according to claim 1, wherein the communication unit changes information regarding the threshold value determined by the determination unit. The imaging apparatus system according to any one of claims 1 to 3, wherein the communication unit makes the number of determinations made by the determination unit variable.