JP2009290351A - Imaging apparatus, two-dimensional scanning device, noise reduction method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce noise sound due to the operation of an image element without deteriorating sound quality. <P>SOLUTION: The imaging device part 120 of a digital camera 1 includes the imaging device 121 for performing scanning in a two-dimensional direction and transferring charges and a drive part 122 for driving the imaging device 121. The drive part 122 reduces the noise sound due to the charge transfer operation of the imaging device 121 by controlling the charge transfer operation of the imaging device 121 by control by a control part 210 which controls the digital camera 1. In this case, the drive part 122 spreads the cycle of the charge transfer operation by inserting a random time interval between V transfer and H transfer in the imaging device 121. Thus, the generation cycle of power ripples which bring the vibrations of a capacitor is spread, the peak of a noise level at a specified frequency declines and the noise sound is reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging device, a two-dimensional scanning device, a noise reduction method, and a program, and more particularly, to an imaging device, a two-dimensional scanning device, a noise reduction method, and a program that are suitable for moving image capturing with audio recording.

  Digital imaging devices such as digital still cameras (hereinafter referred to as “digital cameras”) are widely used. Many digital cameras are generally equipped with not only a still image capturing but also a moving image capturing function, and it is possible to easily capture a moving image without using a video camera.

  A CCD (Charge Coupled Device) is often used as an image sensor (image sensor) used in such a digital camera. When imaging moving images, an image sensor such as a CCD sends charges accumulated in a two-dimensionally arranged imaging region (for example, n rows and n columns) to the vertical transfer path for each frame, The vertical transfer (V transfer) that transfers (shifts) one row at a time in the vertical direction of the vertical transfer path, and the charge (for 1 row and n columns) sent to the horizontal transfer path by V transfer from the end of the vertical transfer path The horizontal transfer (H transfer) sweeping out in the horizontal direction is repeated for n rows at a predetermined cycle (for example, 8 KHz).

  Here, in the charge transfer in which the charge in the imaging region is output from the image sensor, a current may suddenly flow at a predetermined cycle when the charge in the transfer path is shifted. Thus, the sudden load fluctuation that occurs causes so-called power supply ripple. When power supply ripple occurs, the output capacitor voltage in the driver power supply of the image sensor decreases, so the output capacitor may vibrate. In such a case, the entire board may vibrate, and so-called “sound of the capacitor” may be generated.

  When moving image imaging as described above is performed, sound recording is usually performed, so that vibration sound generated from the capacitor may be recorded as noise sound (so-called “keen sound”). That is, when an image sensor (CCD or the like) that performs charge transfer by scanning in a two-dimensional direction is used, noise noise may be generated due to the charge transfer operation.

In a device that performs voice recording, a notch filter is generally used to reduce noise generated by the device (for example, Patent Document 1). That is, the frequency of the noise sound generated from a specific device is stored in advance, and the noise sound is removed by attenuating the specific frequency component in the input / output audio data with the notch filter.
JP 2008-52059 A

  However, since the frequency component of the noise sound caused by the device varies from device to device, the frequency component attenuated by the notch filter needs to have a certain width. For this reason, noise components can be attenuated, but frequency components that are not noise may be attenuated. As a result, there is a problem that sound quality deteriorates.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an imaging device, a two-dimensional scanning device, a noise reduction method, and a program that can reduce noise without reducing sound quality. And

In order to achieve the above object, an imaging apparatus according to the first aspect of the present invention provides:
In an imaging device using an imaging device that performs charge transfer by scanning in a two-dimensional direction,
Drive means for driving the image sensor so that the period of horizontal transfer and vertical transfer in the image sensor is diffused;
It is characterized by that.

In the imaging apparatus,
It is desirable that the driving unit diffuses the cycle by inserting a random time interval between horizontal transfer and vertical transfer in the image sensor.

In the imaging apparatus,
It is desirable that the driving unit determines the time interval for insertion based on the frame rate of the captured image.

In order to achieve the above object, a two-dimensional scanning apparatus according to the second aspect of the present invention provides:
A two-dimensional scanning device that performs horizontal and vertical movements,
Drive means for driving the two-dimensional scanning device so that the period of horizontal operation and vertical operation is diffused;
It is characterized by that.

In the above two-dimensional scanning device,
The driving unit preferably diffuses the period by inserting a random time interval between a horizontal operation and a vertical operation in the two-dimensional scanning device.

  The two-dimensional scanning device can be an image sensor.

In order to achieve the above object, a noise reduction method according to a third aspect of the present invention includes:
A noise reduction method for reducing noise caused by load fluctuation of a voltage generated at a constant cycle,
Diffusing the timing of the current change that causes the load fluctuation of the voltage,
It is characterized by that.

In order to achieve the above object, a program according to the fourth aspect of the present invention is:
In a computer that controls an image pickup apparatus using an image pickup element that performs charge transfer by scanning in a two-dimensional direction,
Realizing the function of driving the image sensor so that the period of horizontal transfer and vertical transfer in the image sensor is diffused;
It is characterized by that.

  According to the present invention, it is possible to reduce noise without reducing sound quality.

  Embodiments according to the present invention will be described below with reference to the drawings. In the present embodiment, a case where the present invention is realized by a digital still camera (hereinafter referred to as a digital camera) is illustrated. The digital camera 1 according to the present embodiment is assumed to have a function that a general digital still camera has, and at least includes a moving image imaging function accompanied by audio recording.

  FIG. 1 is a block diagram showing a configuration of a digital camera 1 according to an embodiment of the present invention. The schematic configuration of the digital camera 1 according to the present embodiment includes an imaging unit 100, a data processing unit 200, an interface (I / F) unit 300, and the like as illustrated.

  The imaging unit 100 is a part that performs an imaging operation of the digital camera 1, and includes an optical device 110, an imaging element unit 120, and the like as illustrated, and operates under the control of the control unit 210 described later.

  The optical device 110 includes, for example, a lens, a diaphragm mechanism, a shutter mechanism, and the like, and performs an optical operation related to imaging. That is, the operation of the optical device 110 collects incident light and adjusts optical elements related to the angle of view, focus, exposure, and the like, such as focal length and aperture.

  The image sensor unit 120 includes an image sensor (image sensor) that generates an electrical signal corresponding to the incident light collected by the optical device 110. A more detailed configuration of the image sensor unit 120 will be described with reference to FIG. As illustrated, the image sensor unit 120 according to the present embodiment includes an image sensor 121 and a drive unit 122 that drives the image sensor 121.

  The image sensor 121 according to the present embodiment uses an image sensor (two-dimensional scanning device) of a system that transfers charges by scanning in a two-dimensional direction. As an example of such an image sensor, in this embodiment, the image sensor 121 is configured by a CCD (Charge Coupled Device).

  Here, the image sensor 121 that is a two-dimensional scanning device sends charges accumulated in a two-dimensionally arranged imaging region (for example, n rows and n columns) to the vertical transfer path for each frame, The vertical transfer (V transfer) that transfers (shifts) one row at a time in the vertical direction of the vertical transfer path, and the charge (for 1 row and n columns) sent to the horizontal transfer path by V transfer from the end of the vertical transfer path It is assumed that the horizontal transfer (H transfer) sweeping out in the horizontal direction is repeated for n rows at a predetermined cycle (for example, 8 KHz).

  The drive unit 122 is a drive circuit that drives such an image sensor 121, and drives and controls the image sensor 121 in accordance with a control signal from the control unit 210. In the present embodiment, the charge transfer operation as described above is controlled by the drive control by the drive unit 122.

  Here, the drive unit 122 according to the present embodiment diffuses the horizontal transfer and vertical transfer periods (for example, 8 KHz) in order to reduce noise noise caused by the charge transfer operation in the image sensor 121 described above. Such drive control is performed. In the present embodiment, noise noise is reduced by controlling the charge transfer operation of the image sensor 121 so that a random time interval is inserted between horizontal transfer and vertical transfer. Details of this operation will be described later.

  By such an operation of the image sensor unit 120, the image sensor 121 performs photoelectric conversion, and an electric signal generated in response to light reception is output to the data processing unit 200. Since the digital camera 1 according to the present embodiment has a moving image capturing function, the image sensor unit 120 sequentially outputs an electric signal generated by continuous light reception to generate an image signal for a moving image. Shall be output.

  The data processing unit 200 processes the electrical signal generated by the imaging operation by the imaging unit 100 to generate digital data indicating the captured image, and performs image processing on the captured image. As shown in FIG. 1, the data processing unit 200 includes a control unit 210, an image processing unit 220, an image memory 230, an image output unit 240, a storage unit 250, an external storage unit 260, and the like.

  The control unit 210 includes, for example, a processor such as a CPU (Central Processing Unit), a main storage device (memory) such as a RAM (Random Access Memory), and the like. Each part of the digital camera 1 is controlled by executing the stored program. Further, in the present embodiment, by executing a predetermined program, a function related to each process described later is realized by the control unit 210.

  The image processing unit 220 includes, for example, an ADC (Analog-Digital Converter), a buffer memory, an image processing processor (a so-called image processing engine), and the like. Based on the signal, digital data indicating a captured image is generated.

  That is, when the analog electric signal output from the image sensor unit 120 is converted into a digital signal by the ADC and sequentially stored in the buffer memory, the image processing engine performs a so-called development process on the buffered digital data. Adjust image quality and compress data.

  In the case of moving image capturing, moving image data having a predetermined frame rate is generated by the operation of the image processing unit 220. In this case, the image signal output from the image sensor unit 120 is converted into moving image data by making a frame image at a timing corresponding to a predetermined frame rate. In addition, when moving image imaging is performed, the image processing unit 220 performs audio data processing together with image data processing. That is, as with a normal moving image capturing function, audio is recorded together with an image, and moving image data is generated by combining audio data input from the audio input / output unit 320 with moving image data. In this case, for example, moving image data generation based on an encoding standard such as H.264 / AVC is performed.

  The image memory 230 includes, for example, a storage device such as a RAM or a flash memory, and temporarily stores captured image data generated by the image processing unit 220, image data processed by the control unit 210, and the like.

  The image output unit 240 includes, for example, an RGB signal generation circuit and the like, converts the image data expanded in the image memory 230 into an RGB signal and the like, and outputs the RGB signal to a display screen (a display unit 310 to be described later).

  The storage unit 250 includes a storage device such as a ROM (Read Only Memory) or a flash memory, and stores programs and data necessary for the operation of the digital camera 1. In the present embodiment, it is assumed that, for example, sound source data of audio to be output is stored in the storage unit 250 in addition to an operation program executed by the control unit 210 and the like, parameters and arithmetic expressions necessary for processing.

  The external storage unit 260 includes a storage device that can be attached to and detached from the digital camera 1 such as a memory card, and stores image data captured by the digital camera 1.

  The interface unit 300 has a configuration related to an interface between the digital camera 1 and its user or an external device, and includes a display unit 310, an audio input / output unit 320, an operation unit 330, and the like as shown in FIG. .

  The display unit 310 includes, for example, a liquid crystal display device, and displays and outputs various screens necessary for operating the digital camera 1, a live view image (finder image) at the time of shooting, a captured image, and the like. In the present embodiment, display output of a captured image or the like is performed based on an image signal (RGB signal) from the image output unit 240.

  The audio input / output unit 320 includes, for example, a microphone, a speaker, an audio codec device, and the like. The audio input / output unit 320 collects audio from the outside of the digital camera 1 to generate digital audio data, and audio when reproducing moving image data. Is output. In this case, the audio codec device performs audio data generation and audio reproduction based on an encoding method such as ADPCM (Adaptive Differential Pulse Code Modulation).

  The operation unit 330 includes various buttons configured on the outer surface of the digital camera 1, generates an input signal corresponding to an operation by the user of the digital camera 1, and inputs the input signal to the control unit 210. As buttons constituting the operation unit 330, for example, a shutter button for instructing a shutter operation, a mode button for designating an operation mode of the digital camera 1, a cross key and a function button for performing various settings, and the like Is included.

  Here, in the present embodiment, the control unit 210 executes the operation program stored in the storage unit 250 to realize each process described later. In this case, the functions realized by the control unit 210 are implemented. This will be described with reference to FIG.

  FIG. 3 is a functional block diagram illustrating functions realized by the control unit 210. Here, a functional configuration necessary for realizing a function of reducing noise caused by the charge transfer operation of the image sensor 121 is shown. In this case, as illustrated, the control unit 210 functions as a recording operation processing unit 211, a noise sound processing unit 212, and the like.

  The recording operation processing unit 211 controls the imaging unit 100, the image processing unit 220, and the audio input / output unit 320 to perform processing related to the recording operation in the digital camera 1. That is, when the digital camera 1 is operating in a mode for capturing a still image, control necessary for capturing a still image is performed, and when the digital camera 1 is operating in a mode for capturing a moving image, Perform the control required for imaging. Alternatively, when the digital camera 1 is operating in a mode for recording only sound, control necessary for sound recording is performed.

  When the recording operation executed by the recording operation processing unit 211 includes audio recording, the noise sound processing unit 212 controls the image capturing unit 100 to reduce the generation of noise sound due to the charge transfer operation of the image sensor 121. Let More specifically, the drive unit 122 of the image sensor unit 120 is controlled to drive the horizontal and vertical transfer cycles of the image sensor 121 to be diffused.

  The above is the function realized by the control unit 210. In the present embodiment, each function described above is realized by a logical process performed by the control unit 210 executing a program. These functions are, for example, ASIC (Application Specific Integrated Circuit). Or an integrated circuit). In this case, among the functions shown in FIG. 3, the functions related to image processing may be realized by the image processing unit 220. Further, the function related to the noise sound processing unit 212 may be realized by the drive unit 122 of the image sensor unit 120.

  The configuration of the digital camera 1 described above is a configuration necessary for realizing the present invention, and a configuration used for a basic function and various additional functions as a digital camera is provided as necessary. .

  The operation of the digital camera 1 having such a configuration will be described below. In the present embodiment, such an operation to reduce noise noise is performed when performing an operation accompanied by voice recording so that noise noise due to the charge transfer operation in the image sensor 121 is not recorded. The “noise noise reduction process” executed by the digital camera 1 in this case will be described with reference to the flowchart shown in FIG. This “noise noise reduction process” is started when a mode related to a recording operation is selected from various modes of the digital camera 1. As the recording operation of the digital camera 1, for example, still image capturing, moving image capturing, voice recording (voice memo), and the like are assumed.

  That is, when the user of the digital camera 1 desires one of the recording operations, a mode for executing the recording operation is selected by operating the operation unit 330 or the like. In response to such an operation, each function as shown in FIG. 3 is realized by the control unit 210, and processing is started.

  When the process is started, the recording operation processing unit 211 performs control according to the recording operation selected by the user. That is, the imaging unit 100 and the audio input / output unit 320 are controlled to perform a recording operation such as an imaging operation. At this time, the recording operation processing unit 211 notifies the noise sound processing unit 212 of the recording operation to be performed.

  The noise sound processing unit 212 determines the recording operation to be executed in response to the notification from the recording operation processing unit 211. In the present embodiment, it is determined whether or not the recording operation to be performed involves audio recording. That is, when the recording operation to be performed is moving image imaging, it is determined that the recording operation is accompanied by audio recording. Also, when a voice recording operation that does not involve an imaging operation, such as a voice memo, is performed, it is determined that the recording operation involves voice recording. On the other hand, in the case of still imaging, it is determined that the recording operation does not involve voice recording.

  When it is determined by such determination operation that the recording operation to be performed involves voice recording (step S101: Yes, or step S101: No, step S102: Yes), the noise sound processing unit 212 is Then, the drive unit 122 of the image sensor unit 120 is controlled to perform control for reducing the generation of noise noise caused by the charge transfer operation of the image sensor 121 (step S104 (the operation of step S103 will be described later)). Here, before explaining the charge transfer control to be performed, the principle of generation of noise noise caused by the charge transfer operation of the image sensor 121 will be described with reference to FIG.

  As described above, the imaging device 121 according to the present embodiment is an imaging device (such as a CCD) that transfers charges by two-dimensional scanning, and is in a two-dimensionally arranged imaging region (for example, n rows and n columns). The accumulated charge is sent to the vertical transfer path for each frame, and further, the vertical transfer (V transfer) for transferring (shifting) the charge by one row in the vertical direction of the vertical transfer path, and V from the end of the vertical transfer path The horizontal transfer (H transfer) that sweeps out the charges (one row and n columns) sent to the horizontal transfer path by the transfer in the horizontal direction is repeated for n rows at a predetermined cycle (for example, 8 KHz). .

  Timing charts for such a transfer operation are shown in FIGS. 5 (a) and 5 (b). FIG. 5A is a timing chart showing the operation timing of H transfer, and FIG. 5B is a timing chart showing the operation timing of V transfer. As shown in the figure, the V transfer and the H transfer of the image sensor 121 are executed at a constant cycle. In this embodiment, it is assumed that the cycle of such charge transfer operation is 8 KHz.

  Here, a power supply circuit (not shown) serving as an operating power supply is connected to the image sensor 121 that performs such an operation. Timing charts showing changes in the driver current and the driver voltage when the power supply circuit drives the image sensor 121 are shown in FIG. 5C and FIG. 5D, respectively. These timing charts correspond to the respective timing charts shown in FIGS. 5A and 5B in time series.

  As shown in FIG. 5C, when a charge transfer operation is performed in the image sensor 121, the driver current increases at the timing when the H transfer is executed. In response to such a change in current, as shown in FIG. 5D, a rapid load fluctuation occurs between the V transfer and the H transfer in the driver voltage. That is, a sudden power load is applied in the operation cycle of the charge transfer operation (8 kHz in this example), and a power ripple is generated. When such a power supply ripple with a constant period (8 KHz) is generated, the capacitor of the power supply circuit vibrates, and the entire board vibrates to generate noise noise. The frequency of the noise sound at this time is the generation period (8 KHz) of the power supply ripple.

  FIG. 7A is a graph showing the noise level of noise sound generated based on such a principle. As shown in the figure, the noise sound generated by the power supply ripple caused by the charge transfer operation of the image sensor 121 has a pinpoint peak at the frequency of the power supply ripple, that is, the frequency of the charge transfer operation in the image sensor 121 (8 KHz). It becomes a characteristic that appears. Such a noise component having a large peak easily reaches human hearing and becomes an unpleasant noise sound (so-called “keen sound”).

  As described above, when the frequency of the noise component is concentrated on a specific frequency and the peak is large, it is easily recognized as a noise sound. Therefore, if the noise component can be diffused so as not to concentrate on a specific frequency, the generated noise sound will be difficult to recognize.

  Therefore, in the present invention, by controlling the charge transfer operation of the image sensor (two-dimensional scanning device), the frequency component of noise noise (that is, the generation period of the power supply ripple) is diffused to reduce noise noise. The principle of such control and noise noise reduction will be described with reference to FIG. FIG. 6 is a timing chart showing the operation timing of H transfer and V transfer when the charge transfer operation according to the application of the present invention is controlled. FIG. 6A shows the operation timing of H transfer, and FIG. b) shows the operation timing of V transfer.

  As shown in the figure, in this embodiment, the noise sound processing unit 212 controls the drive unit 122 so that a random time interval is inserted between the V transfer and the H transfer. To control. That is, when V transfer and H transfer are set as one set of charge transfer operation, a time interval which becomes a waiting time (wait) is provided between V transfer and H transfer in each set, and this time interval is set in each set. Control differently.

  For example, as shown in FIG. 6, a 0.1 KHz weight is inserted between the first set of V and H transfers, and a 0.2 KHz weight is inserted between the second set of V and H transfers. Perform an action like inserting. Here, when the operation cycle of V transfer and H transfer is 8 KHz, by inserting such a weight, the operation cycle of each set is spread as 8.1 KHz, 8.2 KHz. .

  Here, since the wait is inserted before the H transfer performed immediately after the V transfer, the start timing of the H transfer is not constant. That is, the load fluctuation of the voltage generated in response to the change of the current for H transfer also occurs at the spread timing.

  As described above, the noise sound generated by the vibration of the capacitor is characterized in that the noise component of a specific frequency has a large peak because the power supply ripple is generated at a constant frequency. When the generation period of the power supply ripple is diffused, as shown in FIG. 7B, the frequency component of the generated noise sound spreads without concentrating on a specific frequency, so that the peak decreases. As described above, when the noise level peak decreases, it is difficult for the auditory to recognize even if a noise sound is generated, and thus the noise sound is reduced.

  That is, it is possible to effectively reduce the noise sound resulting from the charge transfer operation of an imaging device or the like that performs two-dimensional scanning by spreading the operation cycle of the two-dimensional transfer operation. With this method, the noise sound is reduced by directly controlling the charge transfer operation that is the cause of the noise sound. Therefore, unlike the method of attenuating the noise component with a notch filter, it is effective without reducing the sound quality. Noise noise can be reduced.

  Here, the time interval inserted as a weight can be set according to the processing of the recording operation being performed. In other words, inserting a wait increases the time required for charge transfer, but the wait time is set in a range where the increased time does not affect the recording operation process. For example, if a moving image is being captured, the wait time can be set based on the frame rate of the moving image. For example, if charge transfer for one frame is performed with one set of V transfer and H transfer, the range in which the charge transfer time for one frame does not become longer than the time for one frame based on the frame rate. The wait time can be determined by.

  Therefore, in the “noise sound reduction process” shown in FIG. 4, when it is determined that the recording operation to be performed is moving image capturing (step S <b> 101: Yes), the noise sound processing unit 212 uses the frame rate for moving image capturing. The wait time is set based on (Step S103), and the charge transfer operation is controlled (Step S104). As a result, noise noise can be reduced without degrading the moving image quality.

  By performing such charge transfer control (step S104) until the recording operation is completed (step S105: No), it is possible to operate so as not to record noise sound resulting from the charge transfer operation of the image sensor 121. . And this process is complete | finished with completion | finish of a recording operation (step S105: Yes).

  If the recording operation is not accompanied by voice recording such as still image capturing (step S101: No, step S102: No), the processing is terminated without performing the operation related to noise noise reduction as described above. That is, it is possible to prevent the noise sound from being recorded by performing the noise sound reduction operation only when performing a recording operation accompanied by audio recording.

  As described above, by applying the present invention as in the above-described embodiment, it is possible to reduce noise sound resulting from the operation of a two-dimensional scanning device such as an image sensor without deteriorating sound quality.

  In other words, noise noise is reduced by controlling the charge transfer operation that is the cause of noise noise, so it does not affect the recorded audio signal, unlike conventional methods that remove the generated noise later. . For this reason, sound quality deterioration due to attenuation to frequency components other than noise does not occur.

  In this case, the noise sound is reduced by diffusing the operation period of the two-dimensional scanning. The diffusion of the operation period is performed by inserting a random wait time between each scanning operation of the two-dimensional scanning. Since this can be realized, noise noise can be reduced by relatively easy drive control.

  The said embodiment is an example and the application range of this invention is not restricted to this. That is, various applications are possible, and all embodiments are included in the scope of the present invention.

  For example, in the above-described embodiment, an example in which noise noise caused by the charge transfer operation of the image sensor used in the imaging device is shown. However, if noise noise is generated due to the operation by two-dimensional scanning, Noise sound can be reduced by applying the present invention to an arbitrary two-dimensional scanning device, not limited to an image sensor. For example, a display device that rewrites a screen by repeating horizontal scanning and vertical scanning can be a two-dimensional scanning device, and noise noise can be reduced by applying the present invention to such a device. Can be planned.

  Further, in the above embodiment, when performing a recording operation accompanied by audio recording, the noise sound is reduced by controlling the charge transfer operation so that the noise sound is recorded. You may always perform the operation | movement which reduces the noise sound as mentioned above, without performing. That is, even when a still image is captured without sound being recorded, by controlling the charge transfer operation of the image sensor (two-dimensional scanning device), noise noise heard by the user when using the digital camera 1 is reduced. be able to.

  When the noise noise reduction method according to the present invention is used, the noise sound characteristics can be changed by setting the wait time. In other words, when the wait time is short, the frequency spread range is narrow, so that the noise characteristic is “high peak but narrow frequency band”. On the other hand, when the wait time is long, the range in which the frequency is spread is widened, resulting in a noise characteristic that “the frequency band is wide but the peak is low”. That is, by adjusting the setting value of the wait time, it is possible to easily perform the optimum noise reduction even when the noise characteristic varies depending on the apparatus. Therefore, unlike the conventional method using a notch filter, a wider band is not removed in order to absorb the difference in characteristics of each product.

  In addition, the setting of the wait time to be inserted can be arbitrarily adjusted by, for example, the user of the product, as well as being settable by the manufacturer of the product. Thereby, for example, even if the noise characteristics change due to the aging of the product or the like, the optimum noise reduction can be achieved by adjusting the wait time.

  Note that the direct sound source of the noise sound exemplified in the above embodiment is capacitor vibration, and such capacitor vibration is caused by voltage load fluctuation (power supply ripple) generated at a constant period. The cause of the occurrence of the power supply ripple is exemplified by an increase in current that occurs in a fixed cycle in the image sensor (two-dimensional scanning device). The vibration frequency of the capacitor is also diffused, and noise noise can be reduced. Therefore, even when a two-dimensional scanning device such as an image sensor is not used, if noise noise is generated due to voltage load fluctuations due to a constant current change, as illustrated in the above embodiment. Noise noise can be reduced by diffusing the generation timing of the current change by a method (such as insertion of wait time).

  In the case where the present invention is realized by an imaging apparatus such as the digital camera 1 exemplified in the above embodiment, each function of the control unit 210 can be provided in addition to the provision of the configuration and functions according to the present invention in advance. By applying a program that realizes the same function as the above, it is possible to make an existing imaging device function as the imaging device according to the present invention.

  In the above embodiment, a digital still camera having a moving image capturing function is shown as an example of the image capturing apparatus. However, the form of the image capturing apparatus is arbitrary and can be realized by a single digital still camera. The present invention may be applied to various electronic devices (for example, a digital video camera, a mobile phone, etc.) having the same imaging function.

  Even in such a case, by applying the program, an existing apparatus can be caused to function as the imaging apparatus according to the present invention.

  The application method of such a program is arbitrary. For example, the program can be applied by being stored in a storage medium such as a CD-ROM or a memory card, or can be applied via a communication medium such as the Internet.

It is a block diagram which shows the structure of the digital camera concerning embodiment of this invention. It is a block diagram which shows the structure of the image pick-up element part shown in FIG. It is a functional block diagram which shows the function implement | achieved by the control part shown in FIG. It is a flowchart for demonstrating the "noise sound reduction process" concerning embodiment of this invention. It is a figure for demonstrating the generation principle of the noise sound resulting from the charge transfer operation | movement of an image pick-up element, (a) shows the operation timing of H transfer, (b) shows the operation timing of V transfer, (c). Represents a change in the driver current during the charge transfer operation, and (d) represents a change in the driver voltage during the charge transfer operation. It is a figure for demonstrating the principle of noise sound reduction by this invention, (a) shows the operation | movement timing of H transfer when a random time interval is inserted, (b) is a random time interval inserted. The operation timing of V transfer in the case of It is a graph for demonstrating the difference of the noise sound when not applying this invention and when applying this invention, (a) shows the relationship between the noise level when not applying this invention, and a frequency. (B) shows the relationship between the noise level and the frequency when the present invention is applied to reduce noise noise.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Digital camera, 100 ... Image pick-up part, 110 ... Optical apparatus, 120 ... Image pick-up element part, 121 ... Image pick-up element (two-dimensional scanning apparatus), 122 ... Drive part, 200 ... Data processing part, 210 ... Control part, 211 ... Recording operation processing unit, 212 ... noise sound processing unit, 220 ... image processing unit, 230 ... image memory, 240 ... image output unit, 250 ... storage unit, 260 ... external storage unit, 300 ... interface unit, 310 ... display unit, 320 ... voice input / output unit, 330 ... operation unit

Claims (8)

In an imaging device using an imaging device that performs charge transfer by scanning in a two-dimensional direction,
Drive means for driving the image sensor so that the period of horizontal transfer and vertical transfer in the image sensor is diffused;
An imaging apparatus characterized by that. The driving means diffuses the period by inserting a random time interval between horizontal transfer and vertical transfer in the image sensor,
The imaging apparatus according to claim 1. The drive means determines a time interval for insertion based on the frame rate of the captured image.
The imaging apparatus according to claim 2. A two-dimensional scanning device that performs horizontal and vertical movements,
Drive means for driving the two-dimensional scanning device so that the period of horizontal operation and vertical operation is diffused;
A two-dimensional scanning device. The driving means diffuses the period by inserting a random time interval between a horizontal operation and a vertical operation in the two-dimensional scanning device;
The two-dimensional scanning device according to claim 4. The two-dimensional scanning device is an image sensor.
The two-dimensional scanning apparatus according to claim 4 or 5, wherein A noise reduction method for reducing noise caused by load fluctuation of a voltage generated at a constant cycle,
Diffusing the timing of the current change that causes the load fluctuation of the voltage,
The noise reduction method characterized by the above-mentioned. In a computer that controls an image pickup apparatus using an image pickup element that performs charge transfer by scanning in a two-dimensional direction,
Realizing the function of driving the image sensor so that the period of horizontal transfer and vertical transfer in the image sensor is diffused;
A program characterized by that.

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