JPH10136267A - Image input method/device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the change of a luminance value and to correspond to the slight deviation of a frequency from AC power by generating an image take-in timing signal based on the frequency of the greatest common measure of different commercial frequencies. SOLUTION: When a shutter start request is given from an image processing part 14, a driver 12 generates a charge discharge pulse to a CCD image pickup element 10 in synchronizing with the timing signal from a timer 11. The timing signal from the timer 11 is set to be integer-times of 50msec. Illumination generates a light quantity change at the period of 100Hz in the area of 50Hz and at the period of 120Hz in the area of 60Hz. For setting the device to be applicable for any areas, the image is taken in with time corresponding to the frequency of the greatest common measure of 100Hz and 120Hz or time which is integer-times of it as the period. Namely, time (50msec) corresponding to the period of 20Hz being the maximum common measure or time which is integer-times of it is set to be the period and the image is taken in.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image input method and an image input apparatus using a CCD image sensor as a solid-state image sensor.

[0002]

2. Description of the Related Art A CCD image sensor is used as a solid-state image sensor.
It has been used in a wide range of fields such as image input devices for personal computers and digital cameras.

This CCD image pickup device converts light energy into electric charges and accumulates them, and extracts the accumulated electric charges as pixel data constituting an image.

A CCD using such a CCD image pickup device
The camera has an electronic shutter corresponding to a shutter of a normal optical camera. This electronic shutter functions as a shutter by sweeping out the charge of all the pixels of the CCD image sensor and reading out the accumulated amount of charge until a certain time.

Further, the timing of sweeping out and reading out of electric charges can be arbitrarily controlled by giving respective pulses.

FIG. 4 shows a schematic configuration of a conventional image input device, which comprises a CCD image pickup device 1, a driver 2, a signal processing unit 3, an image processing unit 4, and the like.

In the image input device having such a configuration, if image input is continuously performed under illumination lit by an AC power supply such as a fluorescent lamp or an electric lamp, there is a periodic change in the amount of light that cannot be recognized by humans. Therefore, depending on the timing at which the shutter is released, there is a problem that a change in light occurs in the input image, which appears as a flicker in the read image.

FIG. 5A shows a change in the voltage of the AC power supply, and FIG. 5B shows a change in the amount of light of a fluorescent lamp or the like which is turned on by such an AC power supply. If the shutter is released arbitrarily under illumination having such a light amount change, a change in light occurs in the input image depending on the timing at which the shutter is released. In FIG. 5B, the shaded portion indicates the light amount corresponding to the shutter time (the time from when the electric charge is swept out to when the newly accumulated electric charge is read out). As can be seen from FIG. 5B, the amount of light varies depending on the timing at which the shutter is released.

As a technique for solving this, Japanese Patent Application Laid-Open No.
207286 (hereinafter referred to as a first conventional technique).
In the first prior art, the shutter time (the time from sweeping out the charge to reading out the newly accumulated charge as described above) is set to an integral multiple of a half cycle of the commercial AC power supply in Japan. That is. For example, when trying to correspond to an area of 50 KHz, 1
/ 100 seconds.

By setting the shutter time to an integral multiple of a half cycle of the commercial AC power supply, for example,
In the area of KHz, as shown in FIG. 6, the shutter time is 1/100 second (10 msec), which corresponds to one peak of the AC power supply waveform. Therefore, no matter what timing the shutter is released, the light amount for one peak can be obtained.

[0011]

There are 50 KHz regions and 60 KHz regions in the commercial AC power supply in Japan. In the first prior art, in order to correspond to an area of 50 KHz, the shutter time is set to an integral multiple of a half cycle of the frequency,
That is, the setting is made to be an integral multiple of 10 msec. However, there is a problem that it is not possible to cope with a region of 60 KHz as it is.

That is, in a region of 60 KHz, if the shutter time is set to an integral multiple of 10 msec, the image reading rate becomes NTSC (National T
There is no problem in the case of 60 sheets / sec, which is the same as elevision System Committee, but when reading at an arbitrary rate, the light amount changes depending on the shutter release timing.

Further, the first prior art has a problem that an optimum shutter time cannot be selected because the shutter time can be set only to an integral multiple of a half cycle of the frequency.

On the other hand, Japanese Patent Application Laid-Open No. 6-209427 (hereinafter referred to as "second prior art") discloses a technique which can be applied to different frequency regions. This second prior art is:
It is a method of reading the cycle of lighting from the captured image and releasing the shutter in phase with the lighting.
Complicated processing and configuration to read the lighting cycle are required,
There is a problem in miniaturization of the device, and there is also a problem that it leads to an increase in cost.

In addition to these conventional techniques, a method of performing a luminance correction so as to match the luminance of an image with a previously captured image by post-processing with respect to a change in light amount due to a cycle of illumination under an AC power supply. However, there is a problem that it is difficult to cope with a situation where the image to be photographed is suddenly changed (the time required to converge to an appropriate correction amount becomes long).

Accordingly, the present invention provides a simple method for capturing an image by an image input device using a solid-state imaging device under a fluorescent lamp or an electric lamp under an AC power supply. It is an object of the present invention to realize an image input method and an image input apparatus which can greatly reduce the change of the AC power and can cope with a slight shift of the frequency of the AC power supply.

[0017]

The image input method according to the present invention differs from the image input method using a solid-state image pickup device which captures an image as a light amount and converts it into charge information. An image capture timing signal is generated based on a frequency obtained as the greatest common divisor of the commercial frequency, and the image is captured based on the timing signal.

Further, the image input method of the present invention is characterized in that
As described in, in an image input method using a solid-state imaging device that captures an image as a light amount and converts it into charge information, an image capture timing signal based on a frequency obtained as the greatest common divisor of different commercial frequencies is used. Occurs and the image is captured by this timing signal.
It is characterized in that the captured image is subjected to luminance correction accompanying a change in light amount due to a frequency shift of each of the commercial frequencies.

Further, the image input method of the present invention is characterized in that
As described in, in an image input method using a solid-state imaging device that captures an image as a light amount and converts it into charge information, it corresponds to one cycle of 20 Hz obtained as the greatest common divisor of the commercial frequency of 50 Hz and 60 Hz. An image capture timing signal is generated at a period that is an integral multiple of the required time, and the image is captured using this timing signal.

The image input method according to the present invention is characterized in that:
As described in, in an image input method using a solid-state imaging device that captures an image as a light amount and converts it into charge information, it corresponds to one cycle of 20 Hz obtained as the greatest common divisor of the commercial frequency of 50 Hz and 60 Hz. A timing signal for capturing an image is generated at a period that is an integral multiple of the time required to capture the image.
It is characterized in that the captured image is subjected to luminance correction accompanying a change in light amount due to a frequency shift of each of the commercial frequencies.

In any one of the first to fourth aspects of the present invention, in the processing for capturing an image by the timing signal, a charge sweeping pulse is generated based on the timing signal, and the charge sweeping pulse is arbitrarily set from the charge sweeping pulse. A read pulse is generated after a predetermined time.

In the invention according to claim 2 or 4, the luminance correction processing accompanying a change in the amount of light due to a frequency shift of each commercial frequency includes a relationship between a change in luminance and a frequency shift of each commercial frequency. Is calculated, and luminance correction is performed based on the relationship.

The luminance correction is performed by comparing a change in the luminance of the image captured immediately before and a change in the luminance of the image captured this time with a value obtained from the relationship between the luminance change and the frequency shift. It is determined whether or not to perform the brightness correction based on the comparison result. When the brightness correction is performed, the brightness of the image captured this time is adjusted to the brightness of the image captured immediately before.

The image processing apparatus according to the present invention is characterized in that:
As described in, in an image input device using a solid-state imaging device that captures an image as a light amount and converts it into charge information, an image capture timing signal based on a frequency obtained as the greatest common divisor of different commercial frequencies is used. It is characterized by having timing signal generating means for generating, and driving means for outputting a signal for capturing an image to the solid-state imaging device based on the timing signal from the timing signal generating means.

Further, the image processing apparatus of the present invention has the following features.
As described in, in an image input device using a solid-state imaging device that captures an image as a light amount and converts it into charge information, an image capture timing signal based on a frequency obtained as the greatest common divisor of different commercial frequencies is used. Timing signal generating means for generating, driving means for outputting a signal for capturing an image to the solid-state imaging device based on the timing signal from the timing signal generating means, and an image captured by the solid-state imaging device Against
Brightness correction means for performing brightness correction accompanying a change in light amount due to a frequency shift of each of the commercial frequencies.

Further, the image processing apparatus of the present invention is characterized in that
As described in FIG. 0, in an image input device using a solid-state imaging device that captures an image as a light amount and converts it into charge information, one cycle of 20 Hz obtained as the greatest common divisor of 50 Hz and 60 Hz that are commercial frequencies is used. Timing signal generating means for generating a timing signal for capturing an image at a period of an integral multiple of the corresponding time, and a signal for capturing an image to a solid-state imaging device based on the timing signal from the timing signal generating means And a driving means for outputting

Further, the image processing apparatus of the present invention has the following features.
As described in 1, in an image input method using a solid-state imaging device that captures an image as a light amount and converts it into charge information, one cycle of 20 Hz obtained as the greatest common divisor of 50 Hz and 60 Hz that are commercial frequencies is used. Timing signal generating means for generating a timing signal for capturing an image at a period of an integral multiple of the corresponding time, and a signal for capturing an image to a solid-state imaging device based on the timing signal from the timing signal generating means Driving means for outputting the image, the image captured by the solid-state imaging device,
Brightness correction means for performing brightness correction accompanying a change in light amount due to a frequency shift of each of the commercial frequencies.

[0028] In the invention according to any one of claims 8 to 11, the image capturing process performed by the driving means generates a charge sweeping pulse based on a timing signal from the timing signal generating means. A read pulse is generated after a time arbitrarily set from the time of.

In the ninth or eleventh aspect of the present invention,
In the brightness correction processing performed by the brightness correction processing unit in accordance with the light quantity change due to the frequency shift, the brightness correction is performed based on the relationship of the brightness change with respect to the frequency shift of each commercial frequency.

[0030] The luminance correction is performed by calculating a change in luminance between the image captured immediately before and the image captured this time.
A comparison is made with a value obtained from a change in luminance with respect to the frequency shift, and it is determined whether or not to perform luminance correction based on the comparison result. When performing luminance correction, the luminance of the image captured this time is set to one. Try to match the brightness of the previously captured image.

As described above, in the present invention, the image capture timing signal is generated based on the frequency obtained as the greatest common divisor of different commercial frequencies, and the image capture is performed based on this timing signal. When imaging under fluorescent or electric lights in different areas,
In any frequency region, the amount of change in luminance for each image due to a change in light amount based on a periodic voltage change can be significantly reduced. In addition, since the image capturing timing is determined based on the frequency obtained as the greatest common divisor of the different commercial frequencies, the apparatus configuration and processing can be extremely simple.

In particular, as in Japan, 50 Hz and 60 Hz
50 Hz if there is a commercial frequency in some regions.
20Hz obtained as the greatest common divisor of Hz and 60Hz
A timing signal for capturing an image is generated at a period that is an integral multiple of the time (50 msec) corresponding to one period of the above, and a signal for capturing an image to the solid-state imaging device is output based on the timing signal. With this configuration, the amount of change in luminance for each image based on the periodic voltage change can be significantly reduced in any frequency region with a very simple device configuration and processing.

Further, in the processing for taking in an image in accordance with the timing signal, a charge sweeping pulse is generated based on the timing signal, and a readout pulse is generated after an arbitrarily set time from the charge sweeping pulse. Therefore, the shutter time can be set to an arbitrary length.

Further, since the brightness of the captured image is changed due to a change in the amount of light due to a shift in the frequency of each commercial frequency, even if there is a slight shift in the frequency of the commercial frequency, it is corrected. Can be absorbed.

In the brightness correction process, the relationship between the frequency shift of each commercial frequency and the change in brightness is determined, and the change in brightness between the image captured immediately before and the image captured this time is determined as described above. It is compared with a value obtained from the relationship between the frequency shift and the change in luminance, and it is determined whether or not to perform the luminance correction based on the comparison result. In this case, the amount of change in the luminance of each of the captured images can be suppressed to a very small value by a simple correction process.

[0036]

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 image input device according to an embodiment of the present invention. In general, a CCD image sensor 10 as a solid-state image sensor, a timer 11 as timing signal generating means, a driver 12. Signal processing unit 1
3, the image processing unit 14 and the like.

The timer 11 has a period of 50 msec or its n
The timing signal is generated at a cycle of twice (n is an integer). The value of 50 msec will be described later.

The driver 12 receives the timing signal from the timer 11 and generates a charge sweeping pulse for the CCD image pickup device 10. Based on the shutter time set by the image processing section 14, the driver 12 sets a fixed time after the charge sweeping. Later, a charge readout pulse is generated.

The signal processing unit 13 converts data output from the CCD image pickup device 10 into a format that can be handled by the image processing unit 14.

As described above, the image processing section 14 sets the shutter time, requests the driver 12 for a shutter start request, and simultaneously sets the shutter start request.
The image data output from 0 is converted into a data format that can be handled by an image display unit such as a television. The driver 1
When a shutter start request is issued from the image processing unit 14, the CCD 2 generates a charge sweeping pulse to the CCD imaging device 10 in synchronization with a timing signal from the timer 11 issued after the shutter start request.

Incidentally, the present invention is characterized in that the timing signal from the timer 11 is an integral multiple of 50 msec. Hereinafter, this will be described.

As described above, in Japan, the frequency of the AC power supply has an area of 50 Hz and 60 Hz. Therefore, illumination such as a fluorescent lamp or an electric light causes a light quantity change at a 100 Hz cycle (1/100 second cycle) in a 50 Hz area, and a 120 Hz cycle (1/12 cycle) in a 60 Hz area.
(0 second cycle). Figure 2
(A) and (b) show. FIG. 6A shows a change in light amount in a region of 50 Hz, and FIG. 6B shows a change in light amount in a region of 60 Hz.

The present invention is intended to be applicable to any of these two types of frequency regions, 100 Hz and 12 Hz.
The greatest common divisor of 0 Hz is obtained, and an image is taken in at a period corresponding to the frequency obtained as the greatest common divisor or a time that is an integral multiple of the time.

That is, since the greatest common divisor of 100 and 120 is 20, the time (50 msec) corresponding to the cycle of 20 Hz, which is the greatest common divisor, or an integral multiple thereof (100 msec, 150 msec, 200 msec,...). Such)
Is taken as a cycle. In addition,
In this embodiment, a description will be given assuming that the period is 50 msec.
In order to realize this, the timing signals t1, t2, t3,.
Output to 2. When a shutter request is issued from the image processing unit 14, the driver 12 outputs charge sweeping pulses p1, p2, p3,... To the CCD 10 in synchronization with a timing signal issued after the shutter start request. . An example of these timings is shown in FIG.
(D).

FIG. 2C shows timing signals t1, t2, t3,... Every 50 msec from the timer 11, and FIG. 2D shows charge extraction pulses p1, p2, p3,...

As described above, when the timing signal from the timer 11 is supplied to the driver 12 and a shutter start request is issued from the image processing unit 14 to the driver 12, a charge extraction pulse is output from the driver 12 to the CCD image pickup device 1.
Output to 0. As a result, the CCD imaging device 10 captures an image for a predetermined period of time. FIG. 11E shows the image capture timing at 50 Hz, and FIG. 11F shows the image capture timing at 60 Hz.
This is performed within the shutter time set by the image processing unit 14 (the time from when a charge sweep-out pulse is issued to when a charge readout pulse for reading out newly accumulated charge is issued).

In this case, the charge sweeping pulse is 5
Output every 0 msec. As described above, this 50 msec is a time corresponding to the greatest common divisor of 20 Hz of 100 Hz (period of change in the amount of light in the 50 Hz region) and 120 Hz (period of change in the amount of light in the region of 60 Hz). ) And (f), 5
In either case of 0 Hz or 60 Hz, the image acquisition operation is started from the position where the light quantity change always has the same phase. That is, since the image is always taken in from the part where the degree of the change of the light quantity is the same, the change in the light quantity between the taken pictures can be suppressed.

Note that the shutter time (the time from when the electric charge is swept to when the newly accumulated electric charge is read out) can be arbitrarily set to an optimum time.

Incidentally, the frequency of the AC power supply is 50 Hz.
Alternatively, in both cases of 60 Hz,
Often there is a gap. Therefore, even if the timer 11 generates a pulse every 20 Hz (50 msec) with high accuracy, it is not always possible to capture an image under the exact same light quantity.

In order to cope with this, a luminance correction process for correcting a deviation in luminance caused by a difference in light amount is performed.

FIG. 3 shows an example of a configuration to which a luminance correction process is added. In contrast to the configuration of FIG. 1, a luminance correction processing unit 15 is provided on the output side (or input side) of the image processing unit 14. I have. The other parts are the same as those in FIG. 1, and the same parts are denoted by the same reference numerals.

The brightness correction processing section 15 will be described below.

The frequency deviation of the AC power supply is, for example, 6
In the region of 0 Hz, the difference is at most 0.1% or less, and in reality, there is a slight shift of two digits after the decimal point, for example, 0.03%.

Now, when the reference frequency is 60 Hz, the maximum frequency deviation is 0.1%, and the period of the timing signal from the timer 11 (image capture period) is 50 ms.
Let it be ec. Also, by the voltage change of the AC power supply,
It is assumed that the luminance of a luminous body such as a fluorescent lamp or an electric lamp changes from 0% (turned off) to 100%.

As described above, when the cycle of the timing signal (image capture cycle) is 50 msec and the frequency shift is 0.1%, which is the maximum, the brightness is calculated as compared with the case where the frequency is just 60 Hz. (A maximum value when the shutter time is infinitely close to 0. The longer the shutter time is, the smaller the change amount becomes).
If the same is calculated for a case where the period of the timing signal from the timer 11 (image capturing period) is 100 msec, a change of about 6.3% occurs.

Therefore, according to the present invention, when the cycle of the timing signal is 50 msec, it is determined whether or not the difference α between the luminance of the immediately preceding image and the luminance of the currently acquired image is within 3%. If it is within%, it is considered that the same image has been captured, and the luminance of the image captured this time is adjusted to the luminance of the image captured immediately before. This processing is performed by the luminance correction processing unit 15.

Similarly, the period of the timing signal is 100 ms.
In the case of ec, it is determined whether or not the difference α between the brightness of the image captured immediately before and the brightness of the image captured this time is within 6.3%,
If it is within 6.3%, it is assumed that the same image has been captured, and a process of adjusting the luminance is performed. in this way,
An allowable value is obtained for each period (an integral multiple of 50 msec) of each timing signal when the frequency deviation is 0.1%, which is the maximum (for example, 3% for 50 msec, 10% for 10 msec).
(6.3% in case of 0 msec) Compare the difference between the brightness of the image captured immediately before and the brightness of the image captured this time and its permissible value. If the brightness difference α is within the permissible value, Assuming that the same image has been captured, a process is performed to match the luminance of the image captured this time with the luminance of the image captured immediately before. In practice, as mentioned above, the frequency shift is
Since it is often smaller than 0.1%, the amount of change in luminance when the same image is captured is very small, and the amount of luminance correction is small. In addition, since the minimum value of the luminance of the light emitter of a fluorescent lamp or an electric light is not 0%, the amount of change in the luminance due to the frequency shift (the difference between the luminance of the image captured immediately before and the luminance of the image captured this time). α) is a smaller value. Therefore, in practice, it is sufficient to set the allowable value to about 1.5% for 50 msec and about 3% for 100 msec.

In this example, the timing is set to 50 msec.
And 100 msec were explained, but 50 msec
As an integral multiple of 150 msec, 200 msec,
.. Can be similarly implemented by setting allowable values corresponding to each.

By performing such processing, a luminance shift due to a frequency shift can be absorbed, and the frequency shift does not affect the image brightness.
In addition, since the correction amount of the luminance is small, there is almost no influence on others.

As described above, according to the present invention, as described in the above-described embodiment, when capturing an image with a fluorescent light or an electric light,
In both the frequency regions of Hz and 60 Hz, the amount of change in luminance for each image due to a change in light amount based on a periodic voltage change can be significantly reduced. In addition, since the image capturing timing is determined based on the frequency obtained as the greatest common divisor of the different commercial frequencies, the apparatus configuration and processing can be extremely simple. Especially,
Since the timer 11 used in the present invention can be constituted only by a digital circuit, the design is easy, and the circuit scale of a gate array or the like can be extremely small. Further, it is possible to perform a luminance correction on the captured image in accordance with a change in the amount of light due to a frequency shift of each of the commercial frequencies by a simple process.

The processing program for performing the processing of the present invention can be stored in a storage medium such as a floppy disk, an optical disk, or a hard disk. The present invention includes those storage media. Alternatively, data may be obtained from a network.

[0063]

As described above, according to the present invention, an image capture timing signal is generated based on the frequency obtained as the greatest common divisor of different commercial frequencies, and the image is captured based on this timing signal. For example, as in Japan, 50Hz and 60H
When the commercial frequency of z is present in some regions, the amount of change in luminance for each image due to a change in light amount based on a periodic voltage change is significantly reduced in any frequency region when imaging is performed using a fluorescent lamp or electric light. be able to. Moreover, since the image capture timing is determined based on the frequency obtained as the greatest common divisor of different commercial frequencies,
The device configuration and its processing can be extremely simple.

In the processing for taking in an image by the timing signal, a charge sweeping pulse is generated based on the timing signal, and a readout pulse is generated after an arbitrarily set time from the charge sweeping pulse. Therefore, the shutter time can be set to an arbitrary length.

Further, since the brightness of the captured image is changed in accordance with the change in the amount of light due to the frequency shift of the respective commercial frequencies, even if the frequency of the commercial frequency is slightly shifted, Can be absorbed. Then, the brightness correction process obtains the relationship between the frequency shift and the brightness change of each commercial frequency, and determines the change in the brightness of the image captured immediately before and the brightness of the image captured this time by the frequency shift. And the value obtained from the relationship between the change in luminance and the value obtained from the comparison, it is determined whether or not to perform the luminance correction based on the comparison result.
Since the brightness of the image captured this time is adjusted to the brightness captured immediately before, the amount of change in the brightness of each captured image can be extremely small with simple correction.

As described above, according to the present invention, it is possible to reduce the amount of change in the luminance of each captured image in any frequency region when capturing an image with a fluorescent lamp or an electric light, and to achieve a very simple apparatus configuration and processing. Can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an image input device according to an embodiment of the present invention.

FIG. 2 is a view for explaining processing in the embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of the image input apparatus according to the embodiment of the present invention in which luminance correction based on a frequency shift is added.

FIG. 4 is a block diagram showing a schematic configuration of a conventional image input device.

FIG. 5 is a diagram illustrating a problem when an image is input by a solid-state imaging device under illumination lit by an AC power supply.

FIG. 6 is a diagram for explaining image capture timing in the first conventional technique.

[Description of Signs] 10 CCD imaging device 11 timer 12 driver 13 signal processing unit 14 image processing unit 15 brightness correction unit

Claims (14)

[Claims] In an image input method using a solid-state imaging device which captures an image as light quantity and converts it into charge information, an image capture timing signal is generated based on a frequency obtained as the greatest common divisor of different commercial frequencies. An image input method, wherein an image is captured by the timing signal. 2. An image input method using a solid-state image pickup device which captures an image as a light amount and converts it into charge information, wherein an image capture timing signal is generated based on a frequency obtained as the greatest common divisor of different commercial frequencies. An image input method, wherein an image is captured by the timing signal, and the captured image is subjected to luminance correction according to a change in light amount due to a frequency shift of each of the commercial frequencies. 3. An image input method using a solid-state image pickup device which captures an image as a light amount and converts it into charge information, wherein a time corresponding to one cycle of 20 Hz obtained as the greatest common divisor of 50 Hz and 60 Hz which are commercial frequencies. An image input method comprising: generating an image capture timing signal at a period that is an integral multiple of, and capturing an image by using the timing signal. 4. An image input method using a solid-state imaging device which captures an image as a light amount and converts it into charge information, wherein a time corresponding to one cycle of 20 Hz obtained as the greatest common divisor of 50 Hz and 60 Hz which are commercial frequencies. An image capture timing signal is generated at a cycle of an integral multiple of, and an image is captured by the timing signal. The captured image is subjected to a luminance correction associated with a change in the amount of light due to a frequency shift of each of the commercial frequencies. Image input method. 5. A process for capturing an image according to the timing signal includes generating a charge sweeping pulse based on the timing signal, and generating a read pulse after an arbitrarily set time from the charge sweeping pulse. The image input method according to any one of claims 1 to 4, wherein 6. A luminance correction process according to a light quantity change due to a frequency shift of each of the commercial frequencies, obtains a relation of a luminance change with respect to a frequency shift of each of the commercial frequencies, and calculates a luminance based on the relation. 5. The image input method according to claim 2, wherein the correction is performed. 7. The luminance correction is performed by comparing a change in luminance of an image captured immediately before and a change in luminance of an image captured this time with a value obtained from a relationship between a change in luminance with respect to the frequency shift. 7. The image according to claim 6, wherein it is determined whether or not to perform the brightness correction based on the comparison result, and when the brightness correction is performed, the brightness of the image captured this time is matched with the brightness of the image captured immediately before. input method. 8. An image input device using a solid-state image pickup device that captures an image as a light amount and converts it into charge information, wherein an image capture timing signal is generated based on a frequency obtained as the greatest common divisor of different commercial frequencies. An image input apparatus comprising: timing signal generating means; and driving means for outputting a signal for capturing an image to a solid-state imaging device based on a timing signal from the timing signal generating means. 9. An image input device using a solid-state imaging device that captures an image as a light amount and converts it into charge information, wherein an image capture timing signal is generated based on a frequency obtained as the greatest common divisor of different commercial frequencies. Timing signal generating means, driving means for outputting a signal for capturing an image to the solid-state imaging device based on the timing signal from the timing signal generating means, and driving the image captured by the solid-state imaging device An image input device, comprising: a luminance correction unit configured to perform luminance correction according to a change in light amount due to a frequency shift of each of the commercial frequencies. 10. An image input device using a solid-state imaging device that captures an image as a light amount and converts it into charge information, wherein a time corresponding to one cycle of 20 Hz obtained as the greatest common divisor of 50 Hz and 60 Hz that are commercial frequencies. A timing signal generating means for generating an image capturing timing signal at an integral multiple of a period; and outputting a signal for capturing an image to the solid-state imaging device based on the timing signal from the timing signal generating means. An image input device, comprising: driving means; 11. An image input method using a solid-state imaging device that captures an image as a light amount and converts it into charge information, wherein a time corresponding to one cycle of 20 Hz obtained as a greatest common divisor of 50 Hz and 60 Hz that are commercial frequencies. A timing signal generating means for generating an image capturing timing signal at an integral multiple of a period; and outputting a signal for capturing an image to the solid-state imaging device based on the timing signal from the timing signal generating means. An image input device, comprising: a driving unit; and a luminance correction unit that performs luminance correction on an image captured by the solid-state imaging device in accordance with a light amount change due to a frequency shift of each of the commercial frequencies. . 12. The image capturing process performed by the driving unit generates a charge sweeping pulse based on a timing signal from the timing signal generating unit, and generates a reading pulse after an arbitrarily set time from the charge sweeping pulse. The image input device according to claim 8, wherein the image is generated. 13. The brightness correction processing performed by the brightness correction processing unit in accordance with a light quantity change due to a frequency shift is performed by performing a brightness correction based on a relationship of a brightness change with respect to a frequency shift of each commercial frequency. The image input device according to claim 9 or 11, wherein: 14. The brightness correction is performed by comparing a change in brightness of an image captured immediately before and a change in brightness of an image captured this time with a value obtained from a relationship between a change in brightness with respect to the frequency shift. 14. The image according to claim 13, wherein it is determined whether or not to perform the luminance correction based on the comparison result, and when performing the luminance correction, the luminance of the image captured this time is matched with the luminance of the image captured immediately before. Input device.