JPH0980521A - Camera apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect accurate angular velocity without causing resonance even in the case of incorporating an ultrasonic motor causing vibration near to the excitation frequency of an angular velocity sensor in the same lens barrel. SOLUTION: This camera apparatus is equipped with a vibration source 30 causing image blurring and a shake detection means 31 detecting the occurrence of the image blurring, and constituted so that the detection means 31 may be arranged at the position of the node of a standing wave generated in the camera apparatus by the vibration of the vibration source 30. Then, it is equipped with the vibration source 30 and the detection means 31 and constituted so that the vibration source 30 may be arranged near a leading edge in the longitudinal direction of the camera apparatus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera device optimal as a camera having an image blur correction function.

[0002]

2. Description of the Related Art Shake (camera shake, etc.) generated in a still camera, a video camera, etc. is detected by a sensor such as an angular velocity sensor, and a correction optical system is moved in a direction opposite to the detected shake direction to cause image blurring. A camera device for correction is known (Japanese Patent Laid-Open No. 2-183217). The sensor detects the spatial movement of the optical axis at an angular velocity, calculates the amount of movement of the correction optical system based on the angular velocity, and controls driving.

The sensor for detecting the angular velocity is roughly constructed as follows. The angular velocity sensor is composed of a piezoelectric ceramic oscillator for excitation and a piezoelectric ceramic oscillator for detection.When the oscillator for excitation resonates, a signal corresponding to this vibration is output from the oscillator for detection. It is being output. When this oscillator rotates, a component corresponding to the Coriolis force is output from the detection oscillator in a form including the output signal at the time of resonance. The output of the Coriolis component is extracted from this output and amplified.

On the other hand, the camera has a vibrator other than the angular velocity sensor. For example, a clock circuit (ceramic or crystal oscillator) of a microcomputer, a coil of a DC / DC converter, an oscillation circuit of an ultrasonic motor or the like can be used. In particular, an object having a large energy and having an oscillation frequency close to or vibrating at an integer multiple frequency is likely to affect the oscillation of the angular velocity sensor and resonate easily. The frequency of the vibrator for excitation of the angular velocity sensor is often around 25 KHz, and an ultrasonic motor having a close oscillation frequency and large energy is likely to resonate with this frequency. Further, in the case of a method of correcting the image blur correction by dividing it into two axes (for example, the X axis and the Y axis), at least two angular velocity sensors are required, but the angular velocity sensors do not resonate with each other at their vibration frequencies. The frequencies for excitation are made different from each other on two axes.

When correcting the blurring of the optical axis by the correction optical system,
Since the correction optical system is arranged in the taking lens, it is more convenient to mount the angular velocity sensor and its signal processing circuit, drive circuit, etc. in the taking lens in terms of circuit mounting. On the other hand, an ultrasonic motor has come to be used as an actuator for autofocus in the photographing lens. The ultrasonic motor applies ultrasonic waves of a frequency (20 KHz or higher) higher than the audible range of humans to the piezoelectric body to create a traveling wave utilizing piezoelectric vibration, and presses the rotor under pressure to the stator, It is a motor that moves and rotates by an elliptical motion. Like the angular velocity sensor, this motor is also fixed to the lens barrel. The autofocus optical system is driven by the rotation of this motor. The angular velocity sensor is not directly fixed to the lens barrel with screws or the like in order to make it difficult to be affected by the ultrasonic motor and other vibrating bodies, and is mounted with a shock absorbing member interposed therebetween.

[0006]

When another vibrating body vibrates at a frequency close to the excitation frequency of the angular velocity sensor, the vibration energy resonates with the vibration of the angular velocity sensor and causes an error when detecting the Coriolis force. There was a risk that
If the shock absorber is sandwiched too much to suppress this effect, the response of the response deteriorates, and the frequency characteristics of the entire control system shift to the delay side. If the shock absorbing material is not used or the usage thereof is minimized in order to minimize the delay of the frequency response, there arises a problem of how to make it difficult to be affected by the vibration from other vibrators.

The present invention has been made in view of the above problems, and does not resonate with each other even when an ultrasonic motor that causes a vibration close to the excitation frequency of an angular velocity sensor is incorporated in the same lens barrel. The purpose is to detect the angular velocity with high accuracy.

[0008]

In order to achieve this object, a first aspect of the present invention relates to a vibration source (30) which causes image blur.
And shake detection means (31) for detecting the occurrence of image blur, and the shake detection means (31) is arranged at the node of the standing wave generated in the camera device by the vibration of the vibration source (30). Is configured to. A second invention comprises a vibration source (30) that causes image blur and a shake detection unit (31) that detects the occurrence of the image blur, and the vibration source ( 30).

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block connection diagram showing an embodiment of a camera device according to the present invention.

In FIG. 1, a battery 3 is provided inside the camera body 1 and power is supplied to the inside of the camera and the taking lens. The camera body 1 and the taking lens 2 are connected by electrical contacts 8, 9, 10, 11, and 12 for making an electrical connection. The electrical contact 8 is a contact for supplying power to the taking lens 2 from the battery 3 in the body via the power supply control switch 6 which is a semiconductor switch. The electrical contact 9 connects the output of the DC / DC converter 5 in the camera body 1 to the photographing lens 2
Is a contact for supplying power to. The electrical contacts 10 are the CPU 4 in the camera body 1 and the master CP in the taking lens 2.
It is a contact group for performing communication of U14. Electrical contact 11
Is connected to the negative terminal of the battery 3 in the camera body 1
It is a contact point of the ND (ground) line. Electrical contact 12
Is a GND line that is grounded to the hardware of the camera body 1.

The switches 7a and 7b are switches which are turned on in the first stroke and turned on in the second stroke of the release button of the camera, respectively. Switch 7a is ON
Then, the L level is input to the HAN terminal of the body CPU 4. When the switch 7b is turned on, the L level is input to the RLS terminal of the body CPU 4. Camera body 1
The CPU4, which controls the internal control of the camera, controls the DC / D in the camera body 1 by inputting the L level to the HAN terminal.
The C converter 5 is activated and controlled, and power is supplied to the master CPU 14 and the electrically rewritable non-volatile memory (EEPROM) 15 in the taking lens 2 through the contact 9. When the master CPU 14 outputs a power supply request signal for the electrical contact 8 to the CPU 4 in the camera body 1 via the electrical contact 10, the battery 3 in the camera body 1 causes the semiconductor switch 6 controlled by the CPU 4 and the electrical contact 8. Power is supplied to the DC / DC converter 17 in the taking lens 2 via the image pickup lens 2.

When the power of the electrical contact 9 is supplied, the master CPU 14 activates the DC / DC converter 17. D
The C / DC converter 17 includes a constant voltage regulator 18,
Power is supplied to the slave CPU 20, the motor drivers 21 and 24. The constant voltage regulator 18 supplies power to the shake detection circuit and analog processing circuit block (analog circuit) 19. In the analog processing circuit 19, since the dynamic range of the signal component is wide, the power supply of the processing circuit must also have a low noise level. When the output of the DC / DC converter 17 is directly used, the noise level is not sufficiently low due to the characteristic that this power supply is a switching power supply. Therefore, the constant voltage regulator circuit 18
Is supplied to the power supply of the circuit that performs analog processing via.

The master CPU 14 monitors the voltage of the electrical contact 6 at the AN2 terminal 27. When the value of this voltage is below a predetermined value, a warning is issued or control is stopped. The resistor 13 is a low resistance inserted so that the potential difference with the contact 12 does not become large when the motors 22 and 25 rotate and a large current flows into the contact 11.

The switches 16a and 16b are 2
A bit setting switch for selecting the image blur correction control mode. When the switch 16a is ON, the L level is input to the D1 terminal of the in-lens CPU 14. When the switch 16b is ON, the CPU 14 inside the lens
The L level is input to the D2 terminal of. With this setting, the mode is selected as follows. D1 D2 correction mode ――――――――――――――――――――――――――――― L H Mode for performing correction operation only during exposure H L Other than during exposure Mode to perform correction operation H H Mode to perform no correction operation

The shake amount detected by the analog circuit 19 is analog-processed and input to the master CPU 14. When the switch 7a in the camera body 1 is turned on in the state where the image blur correction mode is set to the mode for performing the correction operation other than during the exposure (only the switch 16b is turned on), the master CPU 14 causes the analog processed data to be processed. Based on the above, the amount to drive the motors 22 and 25 is calculated and transmitted to the slave CPU 20. Slave CPU2
0 outputs the amount to drive to MD21 and MD24, and drives the motors 22 and 25. Motor 22
Reference numerals 25 and 25 convert rotational movement into linear movement and drive a correction optical system (not shown). The deviation from the control amount is known by the feedback pulse from the position detection circuits 23 and 26 that detect the position of the correction optical system by the rotation of the motors 22 and 25, for example, the photo interrupter element.

The image blur correction mode is set to a mode in which the correction operation is performed only during exposure (switch 16a).
Switch 7b in the camera body 1 is ON.
In that case, the correction optical system is driven only during the exposure. The master CPU 14 monitors the voltage of the electrical contact 6 at the AN2 terminal 27. When the value of this voltage is below a predetermined value, a warning is issued or control is stopped.
The resistor 13 is a low resistance inserted so that the potential difference with the contact 12 does not become large when the motors 22 and 25 rotate and a large current flows into the contact 11.

In FIG. 3, an image pickup optical system (not shown) is provided in the image pickup lens 2, and the function is shared by each block of the optical system. The optical system driven for autofocus is an ultrasonic motor 30 as an actuator.
Is used for the drive actuator of the image blur correction optical system.
C motors (22 and 25) are used. Inside the taking lens 2, there are a master CPU 14 that controls the autofocus actuator and a slave CPU 20 that controls the image blur correction actuator. Further, the angular velocity sensor 31 for detecting the angular velocity for image blur correction has two
There are two axes (X axis and Y axis) correction. Further, a power supply circuit (not shown) for supplying power to the photographing lens 2
Equipped. The master CPU 14 controls communication with the camera body 1 and control of the power supply circuit in the taking lens 2.

2 to 3 are conceptual views in which the taking lens 2 is attached to the camera body 1 and is regarded as one rigid body. Assuming that this camera is an ideal uniform rigid body, and assuming that the ultrasonic motor 30 that is the main vibration source is located at the center of the rigid body, this rigid body has a finite length instead of an infinite length, so the ends are fixed. An odd-numbered standing wave is generated, which is the end and the position of the ultrasonic motor 30 is the antinode, and the end of the rigid body is the node. FIG. 2 schematically shows a state in which a first-order standing wave is generated, FIG. 3 is a third-order standing wave, and FIG. 4 is a fifth-order standing wave. In the case of FIG. 2, in order to arrange the angular velocity sensor 31, the position A has the smallest vibration energy and is hardly affected. In the case of FIG. 3, when the angular velocity sensor 31 is arranged, the position C has the smallest vibration energy and is hardly affected. In the case of FIG. 4, the angular velocity sensor 3
In order to dispose 1, the position B has the smallest vibration energy and is hardly affected. It is to be noted that the fixed end (the end of the camera) of the rigid body has a small effect in common in FIGS.

In FIGS. 2 and 3, the vibration source called the ultrasonic motor 30 is located at the center of the rigid body. Under this condition, the primary standing wave is generated. The first-order standing wave has the largest amplitude (energy) and is easily affected by vibration. The influence can be reduced by arranging the angular velocity sensor 31 at the node of the standing wave, but this is when the camera is assumed to be a uniform rigid body, and in reality, the position of the center of gravity is changed by the movement of the correction optical system. As a result, the uniform rigid body is affected by changing conditions. As one method of reducing this effect, it is necessary to prevent low-order standing waves from being generated in the rigid body as much as possible. For that purpose, the position of the ultrasonic motor 30, which is the antinode of the standing wave, is not placed in the center of the rigid body as shown in FIGS. 5 and 6. By arranging in this way, in the case of FIG. 5, a standing wave of only the third order is generated, and if the angular velocity sensor 31 is arranged at the position A at this time, the influence of vibration can be minimized. When the ultrasonic motor 30 is arranged at the position shown in FIG. 6, a fifth-order standing wave is generated, and by disposing the angular velocity sensor 31 at the position C, the influence of vibration can be minimized.
On the contrary, when the position of the vibration source is extremely located at the end of the rigid body,
Although the order of the standing wave further increases and the amplitude also decreases, the area corresponding to the node becomes smaller and any point on the rigid body is accompanied by some vibration.

As described above, the angular velocity sensor is arranged at the position corresponding to the node of the vibration standing waveform during vibration when the ultrasonic motor, which is apt to resonate with the angular velocity sensor and has a bad influence, is fixed to the lens barrel. . As another method, the installation position of the ultrasonic motor, which is the source of large vibration energy, is set to be near the end of the camera, which is regarded as a rigid body. As a result, even when the vibrating body is fixed in the camera equipped with the sensor for detecting the angular velocity, the angular velocity sensor can be firmly fixed with screws or the like, and the delay of the frequency characteristic of the image blur correction control system can be prevented. It can be minimized and accurate image blur correction can be realized.

Although the present invention has been described with reference to the embodiments, various modifications can be made according to the technical idea of the present invention. For example, in the above-described embodiments, the camera device having the image blur correction function has been described, but the shake detection means or the vibration source is arranged at a position where the influence of vibration from the vibration source on the shake detection means is reduced. From the idea, the present invention is not limited to the case of correcting the image blur, and the present invention can be applied to a camera that prohibits photographing when the image blur is detected or a camera that notifies that the image blur is detected. .

[0027]

As described above, according to the camera device of the present invention, the shake detecting means is arranged at the position of the node of the standing wave generated in the camera device by the vibration of the vibration source, or the longitudinal direction of the camera device. Since the vibration source is arranged near the tip of the direction, it is possible to reduce the influence of vibration from the vibration source to the shake detection means, and this makes it possible to reduce the ultrasonic motor that causes vibration close to the excitation frequency of the angular velocity sensor. Even when they are incorporated in the same lens barrel, they do not resonate with each other, and it is possible to detect the angular velocity with high accuracy.

[Brief description of drawings]

FIG. 1 is a block connection diagram showing an embodiment of a camera device according to the present invention.

FIG. 2 is a conceptual diagram showing an embodiment of a camera device according to the present invention.

FIG. 3 is a conceptual diagram showing an embodiment of a camera device according to the present invention.

FIG. 4 is a conceptual diagram showing an embodiment of a camera device according to the present invention.

FIG. 5 is a conceptual diagram showing an embodiment of a camera device according to the present invention.

FIG. 6 is a conceptual diagram showing an embodiment of a camera device according to the present invention.

[Explanation of symbols]

 1 camera body 2 taking lens 4 CPU 5 DC / DC converter 6 semiconductor switch for power supply 7 two-stage release button 14 master CPU 15 non-volatile memory 16 image blur correction mode setting switch 17 DC / DC converter in lens 18 constant voltage output Circuit 19 Analog processing circuit 20 Slave CPU 21 Image blur correction motor driver 22 Image blur correction motor 23 Motor rotation detection circuit 24 Image blur correction motor driver 25 Image blur correction motor 26 Motor rotation detection circuit 30 Ultrasonic motor 31 Square Acceleration sensor

Claims (6)

[Claims] 1. A vibration source that causes image blurring, and a shake detection unit that detects the occurrence of image blurring, wherein a vibration of the vibration source causes a standing wave at a node position of a standing wave generated in a camera device. A camera device comprising the shake detection means. 2. The camera device according to claim 1, wherein the shake detecting means is an angular velocity sensor. 3. The camera device according to claim 1, wherein the vibration source is an ultrasonic motor. 4. A vibration source that causes image blurring, and a shake detection unit that detects the occurrence of image blurring, wherein the vibration source is disposed near a longitudinal end portion of the camera device. Characteristic camera device. 5. The camera device according to claim 4, wherein the shake detecting means is an angular velocity sensor. 6. The camera device according to claim 4, wherein the vibration source is an ultrasonic motor.