JPH07240864A - Electronic video camera - Google Patents

Abstract

PURPOSE:To provide the electronic video camera having a silencing means silencing effectively a motor drive sound noise without increase in the weight, the size and the cost. CONSTITUTION:A motor drive sound noise from any or two of an iris motor 9, a zoom motor 10 and a focus motor 11 is picked up by a motor drive sound noise microphone 23, which converts the picked-up motor drive sound noise into a pickup signal and it is outputted to an MSCNT section 20. A phase inverting circuit 21 of the MSCNT section 20 inverts a phase of the pickup signal to generate a phase inversion signal. The phase inversion signal is amplified by an amplifier 22 and the amplified signal is given to a speaker 24, by which the signal is reproduced as a phase inversion sound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic video camera for converting a reflected light image from a subject into an image signal, and particularly for driving a driving mechanism such as a lens focusing mechanism or a zooming mechanism or a shutter opening / closing mechanism. The present invention relates to an electronic video camera equipped with the drive motor.

[0002]

2. Description of the Related Art Conventionally, some electronic video cameras have a shutter opening / closing mechanism for mechanically opening / closing a shutter, a focusing mechanism for operating a lens, a driving mechanism such as a zooming mechanism, and such a driving mechanism. Generally, it is configured to operate with a drive motor as power.

In the electronic video camera as described above, a motor driving sound is generated by driving the driving motor. If the level of the motor drive sound outside the camera is high,
In an electronic video camera equipped with a recording function, the motor drive sound becomes noise, which deteriorates the sound quality, and even in an electronic video camera not equipped with the recording function, the quality is deteriorated. In order to solve these problems, measures have conventionally been taken to reduce the level of motor drive noise outside the camera by using a soundproof structure for the camera chassis or using a high-priced, low-noise drive motor. Was there.

In Japanese Utility Model Application Laid-Open No. 2-4149, noise inside the duct is picked up by a microphone, its output is passed through a digital filter to make the noise input characteristic reverse, and its output is amplified by an amplifier to produce the inside of the duct. There is disclosed a speaker device for electronic muffling that lowers a noise level by driving a speaker having an opening disposed therein. However, the muffling speaker device disclosed in Japanese Utility Model Laid-Open No. 2-4149 is for muffling noise from a blower of an air conditioner such as a hall, and the electronic muffling device having such a principle is applied to an electronic video camera. There was no case.

[0005]

However, when the soundproof structure is used for the chassis of the camera, there is a problem that the structure of the camera becomes complicated and the camera body becomes heavy or large. Further, when a low noise type drive motor is used for the drive mechanism, there arises a problem that the manufacturing cost of the camera increases.

In order to solve the above problems, an object of the present invention is to provide an electronic video equipped with a sound deadening means capable of effectively muting a motor driving sound and suppressing an increase in weight, an increase in size and an increase in cost. To provide a camera.

[0007]

In order to solve the above problems, the first means of the present invention comprises a drive motor for driving a drive mechanism such as a focusing mechanism, a zooming mechanism, a shutter opening / closing mechanism of a shutter. In the electronic video camera described above, a silencer is provided which silences the motor driving sound by generating a phase inversion sound whose phase is opposite to that of the motor driving sound when the driving motor is driven.

Further, in the second means, the muffling means is
It is characterized in that a phase inversion circuit for outputting a phase inversion signal in which the phase of the pickup signal obtained by electrically picking up the motor driving sound is inverted is provided.

Further, in a third means, the muffling means is
A phase inversion circuit that outputs a phase inversion signal whose phase is inverted from that of the pickup signal obtained by electrically picking up the motor driving sound, and the phase inversion sound based on the phase inversion signal from the phase inversion circuit. And a speaker for generating

Further, in a fourth means, the muffling means is
A phase inversion circuit that outputs a phase inversion signal in which the phase is inverted from the pickup signal obtained by electrically picking up the motor drive sound, and the phase inversion signal from the phase inversion circuit that is adjacent to the drive motor. And a speaker that generates the phase inversion sound based on the speaker.

[0011]

According to the first means described above, in an electronic video camera equipped with a drive motor for driving a drive mechanism such as a focusing mechanism, a zooming mechanism, and a shutter opening / closing mechanism, a motor drive sound is generated when the drive motor is driven. By providing a muffling means for silencing the motor driving sound by generating a phase reversing sound whose phase is reversed, the motor driving sound and the phase reversing sound are muted by overlapping the phase reversing sound with the motor driving sound.

Further, according to the second means, the muffling means is provided with a phase inversion circuit for outputting a phase inversion signal whose phase is inverted from the pickup signal obtained by electrically picking up the motor driving sound. Thus, even if the motor driving sound changes with time, the phase inversion circuit outputs the phase inversion signal corresponding to the change in the motor driving sound.

Further, according to the third means, a phase inverting circuit for outputting a phase inversion signal whose phase is opposite to that of a pickup signal obtained by electrically picking up the motor driving sound by the muffling means, and this phase By including a speaker that generates a phase inversion sound based on the phase inversion signal from the inversion circuit, even if the motor drive sound changes over time, the speaker outputs a phase inversion sound corresponding to the change in the motor drive sound. Occur.

Further, according to the fourth means, a phase inverting circuit for outputting a phase inversion signal having a phase inverted from the pickup signal obtained by electrically picking up the motor driving sound by the muffling means, and the drive motor. And a speaker that generates a phase inversion sound based on the phase inversion signal from the phase inversion circuit adjacent to the speaker, even if the motor drive sound changes with time, the speaker responds to the change in the motor drive sound. It is possible to generate a phase inversion sound and superimpose the phase inversion sound on the motor drive sound at a position close to the drive motor that is the sound source.

[0015]

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

FIG. 1 is a block diagram showing the configuration of an embodiment of the electronic video camera of the present invention. 1 is an imaging lens, 2
Is an image pickup device configured by a CCD (charge coupled device) or the like, which converts a reflected light image from a subject formed by the image pickup lens 1 into an analog image signal, and 3 gain-controls an electric signal from the image pickup device 2. AGC section (automatic gain control section), 4 is an A / D conversion section for converting an analog image signal into a digital image signal, 5 is a process processing section for processing the digital signal, 6 is a memory for temporarily storing the digital image signal, 7 Is a memory card as a recording medium, and the memory card 7 is detachably attached to the camera body.

Further, 8 is a CPU (central processing unit) for controlling the entire apparatus, 9 is an iris motor (not shown), and an iris motor for adjusting the opening and closing of the shutter, and 10
Is a zoom motor for zooming, 11 is a focus motor for automatically adjusting the focus, 12 is a voice microphone for picking up external sound together with image capturing, 13 is pulse code modulation of the analog signal from the voice microphone 12 A
It is a DPCM section (pulse code modulation section).

Reference numeral 20 is an MSCNT section (motor sound control section), and the MSCNT section 20 is a phase inversion circuit 21.
And an amplifier 22. 23 is an iris motor 9,
A motor drive sound microphone that picks up the motor drive sound of the zoom motor 10 and the focus motor 11, and 24 is a speaker close to the iris motor 9, the zoom motor 10, and the focus motor 11.

Next, the recording operation for moving images and sounds by the electronic video camera of this embodiment will be described.

The light flux from the subject enters from the image pickup lens 1 and is imaged on the image pickup surface of the image pickup device 2. The image sensor 2 converts the optical signal into an analog image signal, and the analog image signal is input to the A / D conversion unit 4 via the AGC unit 3,
It is converted into a digital image signal in the A / D converter 4.

The converted digital image signal is compressed in the process processing section 5 and written in the memory card 7. At this time, the shutter is held open, and the iris motor 9 is driven by the light amount adjustment signal from the CPU 8 to adjust the opening of the iris. Also zoom motor
A focus motor 11 is driven by a magnification change signal from the CPU 8 to change the magnification of the optical system including the imaging lens 1, and a focus motor 11 is driven by a focus adjustment signal from the CPU 8 to adjust the focus.

Here, the iris motor 9 and the zoom motor
When driven, the focus motor 11 and the focus motor 11 each generate a motor driving sound. If these motor driving sounds are not muted or soundproofed, these motor driving sounds will be picked up by the audio microphone 12 along with the external sound and recorded as noise during voice recording.

In the present embodiment, there is provided a muffling means that utilizes the property that, when a phase-inverted sound, the phase of which is inverted with respect to a certain sound, is superimposed on each other, they cancel each other out. Is composed of an MSCNT unit 20, a motor driving sound microphone 23, and a speaker 24.

The motor drive sound from any one motor of the iris motor 9, zoom motor 10 or focus motor 11 or the motor drive sound from two or more motors is picked up by the motor drive sound microphone 23 to drive the motor. The sound microphone 23 converts the picked-up motor drive sound into a pick-up signal, and the MSCNT unit 20
Output to.

The phase inverting circuit 21 in the MSCNT unit 20
Generates a phase inversion signal by inverting the phase of the pickup signal. This phase inversion signal is amplified by the amplifier 22 and input to the speaker 24, and is reproduced by the speaker 24 as a phase inversion sound. At this time, the amplifier 22 amplifies the phase inversion signal so that the volume of the phase inversion sound becomes equal to the volume of the motor driving sound. This prevents the motor driving sound from being muted and leaking to the outside of the camera and being picked up by the voice microphone 12.

Since the sound deadening means of this embodiment has a simple structure and a small number of parts, the increase in the weight and cost of the camera body due to the provision of the sound deadening means of this embodiment is slight.

Further, in the present embodiment, the motor driving sound from the iris motor 9, the zoom motor 10 and the focus motor 11 is picked up by the common motor driving sound microphone 23, and the phase inversion sound is output from one speaker 24. Although generated, of course, in order to independently pick up the respective motor drive sounds from the iris motor 9, the zoom motor 10 and the focus motor 11, three motor drive sound microphones 23 are provided close to the respective motors. Further, in order to generate independent phase inversion sounds for the iris motor 9, the zoom motor 10 and the focus motor 11, it is possible to provide three speakers 24 close to the respective motors.

[0028]

As described above, according to the first means of the present invention, the motor driving sound and the phase reversing sound are eliminated by the phase reversing sound overlapping with the motor driving sound.
Since the motor driving sound can be effectively silenced, and the silencing means is composed of electrical or electronic parts, the silencing means can be made lightweight and compact.

Further, according to the second means, even when the motor drive sound changes with time, the phase inversion circuit outputs the phase inversion signal corresponding to the change in the motor drive sound, so that the motor drive sound Since the phase inversion signal can be changed according to changes in sound quality and volume, even if the number of motors to be driven and the number of rotations change, for example, the phase is inverted by the speaker with respect to the actual motor drive sound. It is possible to generate a phase-inverted sound.

Further, according to the third means, even if the motor driving sound changes with time, the speaker generates a phase inversion signal corresponding to the change in the motor driving sound, so that the sound quality of the motor driving sound is improved. Since the phase-inverted sound can be changed according to the change in volume, for example, even if the number of motors to be driven, the number of rotations, etc., change, the phase that is inverted by the speaker with respect to the actual motor-driven sound The reversing sound can be generated and the motor driving sound can be surely silenced.

Further, according to the fourth means, even when the motor driving sound changes with time, the speaker produces a phase inversion sound corresponding to the change in the motor driving sound and is close to the driving motor which is the sound source. By making it possible to superimpose the phase inversion sound on the motor drive sound at the specified position, the phase inversion signal can be changed according to the change in the sound quality and volume of the motor drive sound, and the motor near the drive motor, which is the sound source, can be changed. Since the drive sound can be muted, for example, even when the number of motors to be driven, the number of rotations, etc., changes, the speaker produces a phase-reversed sound whose phase is inverted with respect to the actual motor-driving sound. It is possible to mute the motor drive sound and effectively mute the motor drive sound.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of an electronic video camera of the present invention.

[Explanation of symbols]

9 ... Iris motor, 10 ... Zoom motor, 11 ... Focus motor, 20 ... MSCNT section (motor sound control section), 21 ... Phase inversion circuit, 22 ... Amplifier,
23… Motor drive sound microphone, 24… Speaker.

Claims (4)

[Claims] 1. A focusing mechanism, a zooming mechanism,
In an electronic video camera equipped with a drive motor for driving a drive mechanism such as a shutter opening / closing mechanism, when the drive motor is driven, a phase inversion sound having a phase opposite to that of the motor drive sound is generated to mute the motor drive sound. An electronic video camera, which is provided with a sound deadening means. 2. The silencer includes a phase inversion circuit that outputs a phase inversion signal having a phase inverted from a pickup signal obtained by electrically picking up the motor drive sound. Item 1. The electronic video camera according to item 1. 3. A phase inverting circuit that outputs a phase inverting signal whose phase is opposite to the phase of a pickup signal obtained by electrically picking up the motor driving sound, and the phase inverting circuit from the phase inverting circuit. The electronic video camera according to claim 1, further comprising: a speaker that generates the phase-inverted sound based on a phase-inverted signal. 4. A phase inversion circuit that outputs a phase inversion signal whose phase is inverted from a pickup signal obtained by electrically picking up the motor drive sound, the noise reduction means being adjacent to the drive motor. The electronic video camera according to claim 1, further comprising: a speaker that generates the phase inversion sound based on the phase inversion signal from the phase inversion circuit.