JP2006186451A - Electronic camera, noise reducing apparatus, noise reduction control program and noise reducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately reduce noises, coping with a noise generation time and noise generating condition. <P>SOLUTION: A sound processing block 32 has a microphone amplifier 321, subtractor 322, AD converter 323, audio interface 324, current waveform detecting circuit 325, waveform compositing circuit 326, and pseudo motor sound generating circuit 327. The circuit 325 detects the waveform of a current to be supplied to a zoom motor, and outputs the waveform to the circuit 326. The circuit 327 generates a pseudo motor sound, and the circuit 326 composites the current waveform with the pseudo motor sound and outputs a composite waveform obtained by the composition to the subtractor 322. The subtractor 322 subtracts a composite waveform to be inputted from the circuit 326 from the sound waveform to be inputted from the microphone amplifier 321, the sound waveform after subtraction is inputted into a CPU 13 and encoded, and then, the sound waveform is recorded in the external memory 25 together with motion image data. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic camera that reduces noise generated by the operation of an operating means such as a mounted motor, a noise reduction device for reducing noise, a noise reduction control program, and a noise reduction method.

Conventionally, for example, in a camera that records sound at the time of photographing together with a photographed image, a noise reduction device is installed to prevent noise from being mixed into the recorded sound by reducing noise generated with the operation of the zoom motor. Things have been proposed. This noise reduction device attenuates the sound level detected by the microphone to a certain level during the operation of the zoom key, thereby preventing the operation noise of the zoom motor that operates during the operation of the zoom key from being recorded ( For example, see Patent Document 1).
JP-A-6-292048

  However, there is an inevitable time lag at the time of start until the user starts operating the zoom key and the zoom motor circuit is turned on to actually start the rotation of the zoom motor. In addition, a time lag at the end is inevitably caused until the zoom motor circuit is turned off and the switch of the zoom motor circuit is turned off and the zoom motor actually stops rotating. Therefore, if the sound level detected by the microphone is attenuated to a certain level during the operation of the zoom key as in the prior art described above, the sound level is reduced even though the operation noise of the zoom motor is not generated. Although the sound is attenuated to a certain level and the necessary sound is missing or the operation noise of the zoom motor is generated, the sound level attenuation is canceled and the operation noise is recorded. In addition, the rotation speed of the zoom motor is not necessarily constant during operation, and may change, and noise also changes accordingly. Therefore, depending on the level of sound to be attenuated, necessary sound may be lost or noise may be recorded.

  The present invention has been made in view of such conventional problems, and an electronic camera, a noise reduction device, a noise reduction control program, and a noise capable of accurately reducing noise corresponding to the generation time and generation state of noise. The object is to provide a reduction method.

  In order to solve the above-mentioned problem, in the electronic camera according to the first aspect of the present invention, there is provided an image pickup means for picking up a moving image, a detection means for detecting surrounding sounds when picked up by the image pickup means, and an image pickup by the image pickup means. Recording means for recording a moving image and sound detected by the detecting means, operating means driven by current, and pseudo-noise generating means for generating pseudo-noise of noise generated by the operation of the operating means And a synthesized waveform generating means for generating synthesized waveform noise by synthesizing the pseudo noise with the current waveform for driving the operating means, and a voice detected by the detecting means for detecting the synthesized waveform noise generated by the synthesized waveform generating means. Subtracting means for subtracting.

  In other words, since the operating means is driven by current, its operation depends on the current waveform, and the generation state of noise generated by the operation also depends on the current waveform. Therefore, if the synthetic waveform noise is generated by synthesizing the pseudo noise with the current waveform that drives the operating means, the time during which the synthesized waveform noise is generated is the operation of the operating means and the generation of the noise generated by this operation. Matches time accurately. Even if the operation means changes during operation, the current waveform that drives the operation means changes accordingly, so that pseudo noise is synthesized with the current waveform that drives the operation means. If the combined waveform noise is generated, the generated combined waveform noise coincides with the change in the operation of the operating means and the change in the noise generated along with the change in the operation with high accuracy.

  Therefore, if the synthesized waveform noise that matches the noise occurrence time with high accuracy and the noise change with high accuracy is subtracted from the sound detected by the detection means, the noise is not generated from the operation means. However, subtraction is not performed, and subtraction is not performed even though noise is generated, and it is possible to accurately reduce noise corresponding to the time and state of occurrence of noise.

  In the electronic camera according to the second aspect of the present invention, the operating means is a zoom motor for driving a lens. In the case of a zoom motor, lime lag or lime lag is likely to occur before the rotation is completely stopped before the rotation starts due to inertia, so in consideration of this lime lag, the motor actually starts from the time when the motor actually starts rotating. It is possible to reduce noise with high accuracy in the time until the rotation is stopped.

  According to a third aspect of the present invention, there is provided a noise reduction apparatus comprising: a detection means for detecting surrounding sound; and a predetermined operation means driven by current. A pseudo noise generating means for generating a pseudo noise of noise generated in accordance with the operation of the operating means, and a composite waveform for generating a synthetic waveform noise by synthesizing the pseudo noise with a current waveform for driving the operating means. Generating means, and subtracting means for subtracting the synthesized waveform noise generated by the synthesized waveform generating means from the sound detected by the detecting means.

  Therefore, as described above, the synthesized waveform noise that accurately matches the noise generation time and also accurately matches the noise change can be subtracted from the sound detected by the detecting means, and noise is generated from the operating means. Subtraction is not performed regardless of whether or not noise is generated, but subtraction is not performed even if noise is generated, and noise can be reduced accurately according to the noise generation status. It becomes.

  According to a fourth aspect of the present invention, there is provided a noise reduction apparatus further comprising recording means for recording the sound detected by the detection means. Therefore, it is possible to record sound with reduced noise with high accuracy.

  In the noise reduction device according to the invention described in claim 5, the operating means is a motor. In the case of a motor, a lime lag is likely to occur before the rotation is completely stopped due to inertia, so this lime lag is taken into consideration, so this motor actually starts rotating from the time when the motor actually starts rotating. It is possible to reduce noise with high accuracy in the time up to the point of stopping.

  In the noise reduction device according to the sixth aspect of the present invention, the combined waveform generating means adds and synthesizes the current waveform and the pseudo noise. Therefore, when the current value of the current waveform is zero, the combined waveform noise is not generated from the combined waveform generating means, and the combined waveform noise is generated from the time when it exceeds zero. On the other hand, since the operating means is driven by current as described above, its operation depends on the current waveform. Therefore, if the combined waveform generation means generates synthetic waveform noise by adding and synthesizing pseudo noise to the current waveform that drives the operating means, the time during which the combined waveform noise is generated corresponds to the operation of the operating means and the accompanying operation. It matches the generation time of the generated noise accurately. Even if the operation means changes during operation, the current waveform that drives the operation means changes accordingly, so pseudo noise is integrated into the current waveform that drives the operation means. If the combined waveform noise is generated, the generated combined waveform noise coincides with the change in the operation of the operation means and the change in the noise generated along with the change in the operation with high accuracy.

  In the noise reduction device according to the invention of claim 7, when the current waveform for driving the operating means is detected and the current value is zero, the pseudo noise generating means and the combined waveform generating means And control means for turning off at least one of the subtracting means. Therefore, when the operation time of the operation means is short during the operation of the apparatus in which the noise reduction apparatus is mounted, the time for which the pseudo noise generation means, the combined waveform generation means, and the subtraction means are maintained off. It becomes relatively long, and power consumption can be reduced.

  In the noise reduction control program according to the eighth aspect of the present invention, the computer includes a computer that includes a detection unit that detects ambient sound and a predetermined operation unit that is driven by current. Pseudo-noise generating means for generating pseudo-noise of noise generated by the operation of the means, synthesized waveform generating means for generating synthesized waveform noise by synthesizing the pseudo-noise with a current waveform for driving the operating means, and It is made to function as a subtracting means for subtracting the synthesized waveform noise generated by the synthesized waveform generating means from the sound detected by the detecting means. Therefore, when the computer executes processing according to this program, the same effects as those of the third aspect of the invention can be obtained.

  In the invention according to claim 9, there is provided a noise reduction method in a device comprising detection means for detecting ambient sound and predetermined operation means driven by electric current, wherein the operation of the operation means is performed. A pseudo-noise generation step for generating pseudo-noise of noise generated along with the above, a synthetic waveform generation step for generating synthetic waveform noise by synthesizing the pseudo-noise with a current waveform for driving the operating means, and generation of the synthetic waveform A subtracting step of subtracting the synthesized waveform noise generated in the step from the sound detected by the detecting means. Therefore, by performing the processing according to the described steps, the same effects as those of the third aspect of the invention can be achieved.

  As described above, according to the electronic camera of the present invention, the synthesized waveform noise is generated by synthesizing the pseudo noise generated from the pseudo noise generating means with the current waveform for driving the operating means to generate the synthesized waveform noise. It is possible to accurately match the remaining time with the operation of the operation means and the generation time of noise generated by this operation. Further, even if the operation means changes during operation, the current waveform for driving the operation means changes accordingly, so that the current waveform for driving the operation means is changed from the pseudo noise generation means. By synthesizing the generated pseudo noise to generate synthesized waveform noise, the generated synthesized waveform noise is accurately matched with the change in operation of the operating means and the change in noise generated with this change in operation. be able to. Therefore, no noise is generated from the operating means by subtracting the synthesized waveform noise that accurately matches the noise generation time and the noise change accurately from the sound detected by the detecting means. Regardless of whether subtraction is performed or noise is generated, subtraction is not performed, and it is possible to accurately reduce noise corresponding to the time and state of noise generation. . Therefore, the sound with reduced noise can be recorded with the moving image with high accuracy.

  Further, according to the noise reduction device according to the present invention, similarly, by subtracting the synthesized waveform noise that accurately matches the noise generation time and also accurately matches the noise change from the sound detected by the detecting means. The subtraction is not performed even though no noise is generated from the operation means, or the subtraction is not performed even though the noise is generated. Corresponding noise can be reduced.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram illustrating a circuit configuration of a digital camera 10 according to an embodiment of the present invention. The digital camera 10 has general functions such as AE, AWB, and AF. That is, the lens block 11 includes an optical system such as a zoom lens and a focus lens, and a drive mechanism for driving the optical system, and the optical system includes a zoom motor 12 ( It is driven in the optical axis direction by a DC motor. A motor driver 16 is connected to a CPU 13 that controls the entire digital camera 10 via a bus 14 and a timing generator (TG) 15. The motor driver 16 is connected to a timing generator 15 according to a command from the CPU 13. The zoom motor 12 is driven based on the generated timing signal. At this time, the current waveform supplied to the zoom motor 12 (the voltage of the current waveform of the motor driver 16) is input to the audio processing block 32 described later. The strobe 17 is also driven by a timing signal generated by the timing generator 15. Although not shown, actually, a focus motor and a motor driver for driving the focus lens, a mechanical shutter, a mechanical aperture, a driving mechanism for driving them, and the like are provided.

  The digital camera 10 has a CCD 18 as an image sensor. The CCD 18 is disposed on the optical axis of the lens block 11, and the subject is imaged on the light receiving surface of the CCD 18 by the lens block 11. The CCD 18 is driven by a vertical and horizontal driver 19 based on a timing signal generated by the timing generator 15 in accordance with a command from the CPU 13, and outputs an analog imaging signal corresponding to the optical image of the subject to the unit circuit 20. The unit circuit 20 includes a CDS circuit that removes noise included in the output signal of the CCD 18 by correlated double sampling, an A / D converter that converts an imaging signal from which noise has been removed into a digital signal, and the like. The converted imaging signal is output to the image processing unit 21.

  The image processing unit 21 performs processing such as pedestal clamping on the input image pickup signal, converts it into a luminance (Y) signal and a color difference (UV) signal, and performs image processing such as auto white balance, contour enhancement, and pixel interpolation. Perform digital signal processing to improve quality. The YUV data converted by the image processing unit 21 is sequentially stored in the SDRAM 22 and, in the REC through mode, is converted into a video signal every time one frame of data (image data) is accumulated, and the backlight (BL) The image is sent to a liquid crystal monitor (LCD) 23 having 24 and displayed on the screen as a through image.

  In the still image shooting mode, with the shutter key operation as a trigger, the CPU 13 switches the through image shooting mode from the through image shooting mode to the still image shooting mode with respect to the CCD 18, the vertical and horizontal drivers 19, the unit circuit 20, and the image processing unit 21. Switching is instructed, and the image data obtained by the photographing process in the still image photographing mode and temporarily stored in the SDRAM 22 is compressed by the CPU 13 and finally recorded in the external memory 25 as a still image file of a predetermined format. The In the movie recording mode, a plurality of image data sequentially stored in the SDRAM 22 is sequentially compressed by the CPU 13 between the first shutter key operation and the second shutter key operation, and recorded in the external memory 25 as a moving image file. Is done. The still image file and the moving image file recorded in the external memory 25 are read out and expanded by the CPU 13 in accordance with the user's selection operation in the PLAY mode, and expanded on the SDRAM 22 as YUV data, and then displayed on the liquid crystal monitor 23. Is done.

  The flash memory 26 stores various programs for causing the CPU 13 to control the respective units, for example, various programs such as a program for controlling AE, AF, and AWB, and a moving image shooting program used in the movie recording mode. .

  The digital camera 10 also includes a key input unit 27 including a plurality of operation keys and switches such as a power switch, a mode selection key, a shutter key, and a zoom key, a rechargeable battery 28 such as a nickel metal hydride battery, and the power of the battery 28. Power supply control circuit 29 for supplying the power to each unit, and a microcomputer 30 for controlling them. The microcomputer 30 constantly scans the key input unit 27 for operation of the operation key, and when a user operates any operation key, sends an operation signal corresponding to the operation content to the CPU 13. . The zoom key is a seesaw type key having a “+” part and a “−” part.

  The digital camera 10 also has a recording function for recording ambient sounds in the movie recording mode, and the CPU 13 has a speaker (SP) 33 and a microphone (MIC) via an audio processing block 32. 34 is connected. In the movie recording mode, the audio processing block 32 processes the audio waveform input from the microphone 34 and inputs the audio waveform data to the CPU 13. Then, the CPU 13 compresses the audio waveform data input from the audio processing block 32 between the first and second shutter key operations in the movie recording mode, and a moving image with audio including the compressed audio data and the compressed moving image data. A file is generated and recorded in the external memory 25. The moving image file with sound recorded in the external memory 25 is reproduced by the speaker 33 after the sound data is converted into a sound waveform by the sound processing block 32 when the moving image data is reproduced in the PLAY mode. Note that the timing of performing the audio recording is not limited to the time of moving image shooting, and may be during the recording operation in the still image shooting mode with audio, or during the recording operation in the recording mode or the after-recording mode.

  FIG. 2 is a block diagram showing details of the audio processing block 32 in the first embodiment of the present invention. As shown in the figure, the sound processing block 32 connected to the microphone 34 and the CPU 13 is provided with a microphone amplifier (MIC AMP) 321, a subtracter 322, an AD converter (ADC) 323, and an audio interface 324. A current waveform detection circuit 325, a waveform synthesis circuit 326, and a pseudo motor sound generation circuit 327 are provided. The microphone amplifier 321 amplifies the sound waveform input from the microphone 34 and inputs it to the subtractor 322. The current waveform detection circuit 325 detects the current waveform a (voltage of the current waveform of the motor driver 16) supplied to the zoom motor 12 shown in FIG. 3A and outputs it to the waveform synthesis circuit 326. The pseudo motor sound generation circuit 327 is a circuit that constantly generates the pseudo motor sound b having the waveform shown in FIG. The pseudo motor sound b is the same as or approximate to the noise obtained by detecting and analyzing the noise generated when the zoom motor 12 is rotated in a quiet environment in the manufacturer of the digital camera 10. It has a constant frequency.

  The waveform synthesis circuit 326 integrates and synthesizes the current waveform a shown in FIG. 3A and the pseudo motor sound b shown in FIG. The composite waveform c shown is output to the subtractor 322. The subtractor 322 subtracts the synthesized waveform c input from the waveform synthesis circuit 326 from the speech waveform input from the microphone amplifier 321. The subtracted audio waveform is converted into digital data by the AD converter 323, input to the CPU 13 via the audio interface 324, encoded, and recorded in the external memory 25 together with the moving image data.

  FIG. 4 is a circuit diagram showing details of the A portion composed of the zoom motor 12 and the motor driver 16 in FIG. As shown in the figure, the motor driver 16 has a circuit in which switches 1, 2 and switches 3, 4 connected in series are connected in parallel. The zoom motor 12 includes switches 1, 2, and switches 3, 4 are connected in parallel. When the “+” side of the zoom key is operated, the switches 1 and 4 are turned on, whereby the zoom motor 12 is rotated forward, and when the “−” side is operated, the switches 2 and 3 are turned on. Thus, the zoom motor 12 is configured to reverse. Further, the current waveforms in the on state of the switches 1 and 4 and the on state of the switches 2 and 3 are extracted from between the switches 2 and 4 and the ground and supplied to the current waveform detection circuit 325.

  In the present embodiment having the above-described configuration, when the user sets the movie recording mode and performs the first shutter key operation, the CPU 13 starts recording and recording based on the moving image shooting program. Are sequentially recorded in the external memory 25. On the other hand, ambient sounds are detected by the microphone 34, input to the CPU 13 via the microphone amplifier 321, the subtractor 322, the AD converter 323, and the audio interface 324, and sequentially recorded in the external memory 25.

  At this time, if the user is shooting a moving image without operating the zoom key, the current waveform a is not generated, and the current waveform is not output from the current waveform detection circuit 325. Therefore, even if the waveform synthesis circuit 326 performs integration, the output is zero, so that the synthesized waveform c is not output from the waveform synthesis circuit 326 to the subtracter 322. Therefore, the subtractor 322 does not perform subtraction, and the sound detected by the microphone 34 is recorded in the external memory 25 as it is. At this time, since the zoom motor 12 is not operating, noise generated along with the operation of the zoom motor 12 is not recorded together with the sound.

  When the user operates the zoom key, in the motor driver 16, the switches 1, 4 or the switches 2, 3 are turned on and current from the power source 29 starts to be supplied to the zoom motor 12. At this time, the supply current waveform a to the zoom motor 12 rises with a time lag Δt as shown in FIG. Input to the circuit 326. Then, the waveform synthesis circuit 326 integrates and synthesizes the pseudo motor sound b with the current waveform a rising with this time lag Δt to generate a synthesized waveform c, and outputs this synthesized waveform c to the subtractor 322. The subtractor 322 subtracts the synthesized waveform c from the voice waveform input from the microphone 34 via the microphone amplifier 321 and outputs the result to the AD converter 323.

  Therefore, in the subtractor 322, the synthesized waveform c is subtracted from the voice waveform input from the microphone 34 from the time when the current waveform a rises with a time lag Δt. The time when the current waveform a rises with a time lag Δt is the time when the zoom motor 12 starts to rotate and the time when noise is generated due to the rotation of the zoom motor 12, so the composite waveform c is subtracted from this time. As a result, the subtraction start time of the synthesized waveform c can be accurately matched with the noise generation time.

  If the current waveform a changes during the rotation of the zoom motor 12 as shown in FIG. 3A, the composite waveform c also changes accordingly as shown in FIG. Therefore, in the subtractor 322, the audio waveform input from the microphone 34 is subtracted by the synthesized waveform c that changes with the change of the current waveform a. Since the rotation of the zoom motor 12 also changes with the change in the current waveform a, the noise generated with the change in the rotation of the zoom motor 12 also changes. Therefore, the subtractor 322 subtracts the synthesized waveform c, which changes with the change of the current waveform a, from the speech waveform, so that noise can be accurately reduced according to the change of noise.

  When the zoom lens in the lens block 11 moves to the limit position or when the user stops the operation of the zoom key, the motor driver 16 turns on the switches 1 and 3 or turns off all the switches 1 to 4, for example. To do. As a result, the zoom motor 12 is braked, and the current waveform “a” drops and eventually reaches the zero level. When the current waveform a starts to decrease, the rotation of the zoom motor 12 also decreases, so that the noise generated with the decrease in the rotation of the zoom motor 12 also decreases. Therefore, in the subtractor 322, the synthesized waveform c that changes as the current waveform a decreases is subtracted from the speech waveform, so that noise can be accurately reduced according to noise reduction. Further, when the current waveform a reaches the zero level, the zoom motor 12 stops, so that noise accompanying the operation of the zoom motor 12 also stops. When the current waveform a reaches zero level, the output of the current waveform a from the current waveform detection circuit 325 to the synthesis circuit 326 also becomes zero level, and the output from the synthesis circuit 326 also becomes zero level. The output of the combined waveform c from the combining circuit 326 to the subtracter 322 is also zero level, and the subtracter 322 does not perform subtraction. Therefore, the end of subtraction in the subtracter 322 can be matched with the end of noise with high accuracy.

Therefore, it is possible to reduce the noise by subtraction by matching the noise generation time and the generation end time with the rotation of the zoom motor 12 to match the noise generation time with high accuracy, and also accurately match the noise change. Thus, noise reduction by subtraction can be performed.
Note that when the user performs the second shutter key operation, the storage of the image data and audio data in the external memory 25 is stopped.

  (Second Embodiment)

  FIG. 5 is a block diagram showing details of the audio processing block 32 in the second embodiment of the present invention. This embodiment is different from the first embodiment shown in FIG. 2 only in that an on / off control circuit 328 is provided. Therefore, the same parts are denoted by the same reference numerals and description thereof is omitted. The on / off control circuit 328 turns off the subtraction function and waveform synthesis circuit 326 of the subtractor 322 and the pseudo motor sound generation circuit 327 when the current waveform a input from the current waveform detection circuit 325 is zero level. And a control circuit that is turned on when the zero level is exceeded.

  In the present embodiment having the above-described configuration, when the user sets the movie recording mode and performs the first shutter key operation, the CPU 13 starts recording and recording based on the moving image shooting program. Are sequentially recorded in the external memory 25. On the other hand, ambient sounds are detected by the microphone 34, input to the CPU 13 via the microphone amplifier 321, the subtractor 322, the AD converter 323, and the audio interface 324, and sequentially recorded in the external memory 25.

  At this time, if the user is shooting a moving image without operating the zoom key, the current waveform a is not generated, and the current waveform is not output from the current waveform detection circuit 325. Therefore, the on / off control circuit 328 turns off the subtraction function of the subtractor 322, the waveform synthesis circuit 326, and the pseudo motor sound generation circuit 327. Therefore, the power consumption accompanying the subtraction function of these subtracters 322 and the operation of the waveform synthesis circuit 326 and the pseudo motor sound generation circuit 327 is prevented. Therefore, the subtractor 322 does not perform subtraction, and the sound detected by the microphone 34 is recorded in the external memory 25 as it is. At this time, since the zoom motor 12 is not operating, noise generated along with the operation of the zoom motor 12 is not recorded together with the sound.

  When the user operates the zoom key, in the motor driver 16, the switches 1, 4 or the switches 2, 3 are turned on and current from the power source 29 starts to be supplied to the zoom motor 12. At this time, the supply current waveform a to the zoom motor 12 rises with a time lag Δt as shown in FIG. The signal is input to the circuit 326 and the on / off control circuit 328. Then, the on / off control circuit 328 turns on the subtraction function of the subtractor 322, the waveform synthesis circuit 326, and the pseudo motor sound generation circuit 327. Therefore, the waveform synthesizing circuit 326 generates a synthesized waveform c by integrating and synthesizing the pseudo motor sound b with the current waveform a that has risen with the time lag Δt, and outputs the synthesized waveform c to the subtractor 322. The subtractor 322 subtracts the synthesized waveform c from the speech waveform input from the microphone 34 via the microphone amplifier 321 and outputs the result to the AD converter 323.

  Therefore, in the subtractor 322, the synthesized waveform c is subtracted from the voice waveform input from the microphone 34 from the time when the current waveform a rises with a time lag Δt. The time when the current waveform a rises with a time lag Δt is the time when the zoom motor 12 starts to rotate and the time when noise is generated due to the rotation of the zoom motor 12, so the composite waveform c is subtracted from this time. As a result, the subtraction start time of the synthesized waveform c can be accurately matched with the noise generation time.

  Then, when the zoom lens in the lens block 11 moves to the limit position or when the user stops operating the zoom key and the current waveform a reaches the zero level, the zoom motor 12 stops, so that the zoom motor 12 operates. The accompanying noise also stops. When the current waveform a reaches zero level, the output of the current waveform a from the current waveform detection circuit 325 to the synthesis circuit 326 also becomes zero level, and the on / off control circuit 328 includes the subtraction function and waveform of the subtractor 322. The synthesis circuit 326 and the pseudo motor sound generation circuit 327 are turned off. Therefore, the end of subtraction in the subtracter 322 can be matched with the end of noise with high accuracy.

  (Modification of the second embodiment)

  In the second embodiment, as in the first embodiment, an integration circuit that integrates and synthesizes with the current waveform a is used as the waveform synthesis circuit 326 as in the first embodiment. However, in the second embodiment, since the on / off control circuit 328 is used, even if the addition circuit for adding and synthesizing with the current waveform a is used as the waveform synthesis circuit 326. Similar effects can be obtained.

(Other embodiments)
(1) In the embodiment described above, the current waveform a is detected by the current waveform detection circuit 325 provided in the voice processing block 32, the pseudo motor sound b is generated by the pseudo motor sound generation circuit 327, and the waveform synthesis is performed. The synthesized waveform c is generated by the circuit 326, and the subtractor 322 performs subtraction. However, without providing these in the audio processing block 32, the flash memory 26 stores a program for realizing the functions of these circuits by the processing of the CPU 13, and the CPU 13 executes the processing according to this program, so that The detection of the waveform a, the generation of the pseudo motor sound b and the synthesized waveform c, and the subtraction of the synthesized waveform c may be performed.

  (2) Although the case where the present invention is applied to the noise reduction processing of the zoom motor 12 has been described in the embodiment, the rotation of the AF motor that drives the focus lens provided in the lens block 11 and the focus lens You may make it apply to the noise reduction process of the noise which arises with the drive of this. In this case, the motor driver 16 in FIG. 2 may be a driver for driving the AF motor, and the pseudo motor sound generation circuit 327 may generate the pseudo motor sound of the AF motor. Moreover, you may make it apply to the noise reduction process of not only a DC motor but a stepping motor.

  (3) In addition, when the shutter and the diaphragm mechanism are driven with a current waveform, or in a camera having a hard disk driven with a current waveform, the present invention can be applied by performing the same replacement. Furthermore, the present invention can be applied not only to cameras but also to various devices having a hard disk driven by a current waveform, various recording devices, and the like.

1 is a block diagram illustrating an electrical configuration of a digital camera to which an embodiment of the present invention is applied. It is a block diagram which shows the detail of the audio | voice processing block in the 1st Embodiment of this invention. (A) is a current waveform, (B) is a pseudo motor sound waveform, and (C) is a waveform diagram showing a combined waveform. It is a circuit diagram which shows the detail of the A section in FIG. It is a block diagram which shows the detail of the audio | voice processing block in the 2nd Embodiment of this invention.

Explanation of symbols

10 Digital Camera 11 Lens Block 12 Zoom Motor 13 CPU
16 Motor driver 25 External memory 26 Flash memory 27 Key input unit 32 Audio processing block 33 Speaker 34 Microphone 321 Microphone amplifier 322 Subtractor 323 AD converter 324 Audio interface 325 Current waveform detection circuit 326 Waveform synthesis circuit 327 Pseudo motor sound generation circuit 328 ON・ Off control circuit a Current waveform b Pseudo motor sound c Composite waveform

Claims (9)

An imaging means for capturing a video;
Detecting means for detecting surrounding sounds at the time of imaging by the imaging means;
Recording means for recording the moving image picked up by the image pickup means and the sound detected by the detection means;
Operating means driven by current;
Pseudo-noise generating means for generating pseudo-noise of noise generated with the operation of the operating means;
Synthesized waveform generating means for generating synthesized waveform noise by synthesizing the pseudo noise with the current waveform for driving the operating means;
An electronic camera comprising: subtracting means for subtracting the synthesized waveform noise generated by the synthesized waveform generating means from the sound detected by the detecting means.   2. The electronic camera according to claim 1, wherein the operating means is a zoom motor for driving a lens. A noise reduction device arranged in a device having detection means for detecting ambient sound and predetermined operation means driven by current,
Pseudo-noise generating means for generating pseudo-noise of noise generated with the operation of the operating means;
Synthesized waveform generating means for generating synthesized waveform noise by synthesizing the pseudo noise with the current waveform for driving the operating means;
A noise reduction apparatus comprising: subtracting means for subtracting the synthesized waveform noise generated by the synthesized waveform generating means from the sound detected by the detecting means.   4. The noise reduction apparatus according to claim 3, further comprising recording means for recording the voice detected by the detection means.   5. The noise reduction device according to claim 3, wherein the operating means is a motor.   6. The noise reduction apparatus according to claim 3, 4 or 5, wherein the combined waveform generating means is configured to integrate and combine the current waveform and the pseudo noise.   Control means for detecting a current waveform for driving the operating means and turning off at least one of the pseudo noise generating means, the combined waveform generating means, and the subtracting means when the current value is zero. The noise reduction device according to claim 3, wherein the noise reduction device is a noise reduction device. A computer having a device including a detection unit that detects ambient sound and a predetermined operation unit that is driven by a current.
Pseudo-noise generating means for generating pseudo-noise of noise generated with the operation of the operating means;
Synthesized waveform generating means for generating synthesized waveform noise by synthesizing the pseudo noise with the current waveform for driving the operating means;
A noise reduction control program for causing a synthetic waveform noise generated by the synthetic waveform generating means to function as a subtracting means for subtracting from a voice detected by the detecting means. A noise reduction method in a device comprising detection means for detecting ambient sound and predetermined operation means driven by current,
A pseudo-noise generating step for generating pseudo-noise of noise generated with the operation of the operating means;
A combined waveform generating step of generating the combined waveform noise by combining the pseudo noise with the current waveform that drives the operating means;
And a subtracting step of subtracting the synthesized waveform noise generated in the synthesized waveform generating step from the sound detected by the detecting means.

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