JP2003111089A - Control method of solid-state imaging device and image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method of a solid-state imaging device and an image reader that can enhance a processing speed of reading operation for a color original image. SOLUTION: In the image reading operation for one color original image, a CCD area sensor continuously execute charge storage process sequentially for each of RGB light beams. Further, in the R and G photoelectric charge transfer processes executed respectively synchronously with an execution timing of G and B photoelectric charge transfer processes, the stored electric charges by the R and G photoelectric charge transfer processes are sequentially transferred by each line, and in this case, the electric charges are not transferred for the number of lines (P lines) among upper and lower end non-use parts at the outside of image projection areas among all lines. Moreover, in the B photoelectric charge transfer process whose execution is started after the end of B photoelectric charge storage processes, the stored electric charges by the B photoelectric charge storage process are sequentially transferred by each line and in this case, the electric charges are not transferred for an upper end non use part (N lines) at the outside of the image projection area among all lines.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a solid-state image sensor and an image reading apparatus for obtaining information for reproducing a color original image by light from a light source that transmits or reflects the color original image.

[0002]

2. Description of the Related Art Conventionally, as an image reading apparatus for finally reading a color original image formed on a photographic film as image signal data, a color original image is irradiated with light from a light source composed of an LED or the like. , The color original image is reproduced by receiving the light transmitted or reflected from the original color image by the solid-state image pickup device which converts (photoelectrically converts) the optical image of the object into an electric signal and outputs it as an image signal. It is known that various kinds of attribute information such as color and density are obtained.

Usually, in such an image reading apparatus, a CCD type optical sensor (hereinafter referred to as a CCD sensor) is mainly used as a solid-state image pickup device. This CCD sensor has a light receiving section that accumulates electric charges according to the amount of light received for each pixel,
In the image reading operation by this CCD sensor, the light receiving unit receives the light transmitted or reflected from the color original image. A charge accumulation step of accumulating charges according to the amount of received light and a charge transfer step of transferring and outputting the charges accumulated in the charge accumulation step by the transfer unit are performed.

In the charge accumulating step, the light emitted from the light source transmits or reflects the color original image, and then the CCD.
All the pixels on the light-receiving surface of the sensor are irradiated, and as a result, a projection area carrying a color original image is formed on the light-receiving surface of the CCCD sensor. This projection area depends on the size of the original color image and is usually CC
The area of this projection region is smaller than the light receiving area of the D sensor. In the charge transfer process, the CCD
Since the accumulated charges in the entire light receiving surface of the sensor, that is, in all the pixels in the light receiving section are sequentially transferred, the processing time of this charge transfer, that is, the image reading time in the CCD sensor is
It will be determined by the total number of pixels of the CD sensor.

As a result, in a solid-state image pickup device such as a CCD sensor used in a conventional image reading device, in order to improve the efficiency of image reading processing, for example, the technique disclosed in Japanese Patent Laid-Open No. 5-56357. As described above, various techniques have been proposed to shorten the overall image reading time by increasing the charge transfer execution timing in the CCD sensor to a plurality of times.

[0006]

By the way, in the image reading apparatus as described above, as a reading operation of the color original image by the CCD sensor, for one color original image, the RGB color coordinates included in the color original image are included. System and CMY
It is generally practiced to finally obtain read image data for one color original image by continuously executing the charge accumulation process and the charge transfer process for each color based on the color system. . Here, for example, as shown in FIG. 5A, after the charge accumulating step corresponding to R color light (R photocharge accumulating step; required time T _aR ) is performed, the charge accumulating step corresponding to G color light (G _Photocharge accumulation step; required time T _aG ) and charge accumulation step corresponding to B color light (B photocharge accumulation step;
The required time T _aB ) is sequentially executed, and the charge transfer process (R photocharge transfer process; required time T _tR = T _aG ) corresponding to the R color light is executed in synchronization with the execution of the G photocharge accumulation process. Further, in synchronization with the execution of the B photocharge accumulation process, a charge transfer process corresponding to G color light (G photocharge transfer process; required time T
_tG = T _aB ), and then the charge transfer step (B photocharge transfer step; required time T _tB ) corresponding to the B color light is executed. In this case, finally, the required time RT of the reading operation for one color original image is the required time T _aR of the R photocharge storage step, the required time _Tag of the G photocharge storage step (or the R photocharge transfer step). Required time T _tR ), the required time T _{aB for} the B photocharge storage step (or the required time T _{tG for} the G photocharge transfer step), and the required time T _{tB for} the B photocharge transfer step.

As described above, in the conventional image reading apparatus, it is possible to efficiently obtain the received light data separately for each color of R, G and B, and to shorten the image reading time.

However, as described above, since the projection area formed on the light receiving surface of the CCD sensor and carrying the color original image is narrower than the area of all pixels on the light receiving surface,
In the charge transfer step, the charge transfer of the light receiving area outside the projection area and unrelated to the color original image is also performed. This makes it difficult to say that the image reading operation is performed sufficiently efficiently, particularly in the reading operation of the color original image for obtaining the received light data separately for each color described above.
There is room for further speeding up the image reading processing time.

The present invention has been made in view of the above circumstances, and an object thereof is to obtain a solid-state image pickup device control method and an image reading apparatus in which the processing speed of the reading operation of a color original image is improved. And

[0010]

According to a first aspect of the present invention, a plurality of elements are regularly arranged in the vertical and horizontal directions, respectively.
A solid-state imaging device having a light-receiving element for receiving and photoelectrically converting the irradiation light that is emitted from a light source to a color original image and transmitted or reflected the color original image, and a transfer unit for transferring the charge accumulated in the light-receiving element. As an image reading operation for photoelectrically reading the color original image as a two-dimensional image by using the charge accumulation step of receiving the irradiation light for a predetermined time on the light receiving surface of the solid-state image sensor including the array of the light receiving elements. After that, the charges stored in the light receiving elements in the charge storing step are sequentially transferred to the subsequent stage via the transfer unit for each line corresponding to one row in the vertical or horizontal direction in the array of the light receiving elements. A method for controlling a solid-state image sensor for executing a charge transfer step of transferring to an external device, wherein when the image reading operation is continuously executed a plurality of times, the charge transfer step is performed in synchronization with the execution of the charge transfer step. The next charge accumulation step is executed, and in the charge transfer step, the charge transfer for the number of lines corresponding to the outside of the carrying area of the color original image formed on the light receiving surface of the solid-state imaging device by the irradiation light is performed. It is characterized by not performing.

According to the first aspect of the present invention, a plurality of light beams are regularly arranged in the vertical and horizontal directions, respectively, and the irradiation light which is emitted from the light source to the color original image and is transmitted or reflected by the color original image is received. By using a solid-state image sensor having a light-receiving element that performs photoelectric conversion and a transfer unit that transfers the charge accumulated in the light-receiving element, a predetermined time is set on the light-receiving surface of the solid-state image sensor that is an array of the light-receiving elements. After performing the charge accumulating step of receiving the irradiation light, the charges accumulated in the light receiving element in the charge accumulating step correspond to the light receiving elements for one column in the vertical or horizontal direction in the array of the light receiving elements. In the execution control of the image reading operation for photoelectrically reading the color original image as a two-dimensional image, the charge transfer process of sequentially transferring the charges to the external device at the subsequent stage via the transfer unit is executed line by line. When executing image reading operation a plurality of times continuously, in synchronization with the execution of the charge transfer process, and executes the next charge accumulation process. That is, since the charge transfer process corresponding to the previous charge storage process is executed in synchronization with the execution timing of each charge storage process, each process can be efficiently executed. Further, in each charge transfer step, charge transfer is not performed by the irradiation light for the number of lines corresponding to the outside of the carrying region of the color original image formed on the light receiving surface of the solid-state imaging device. As a result, the time required for each charge transfer step can be shortened, and as a result, the processing time of the entire image reading operation can be shortened.

According to a second aspect of the present invention, in the first aspect of the invention, when the image reading operation is continuously executed a plurality of times, the first charge accumulation step is performed in synchronization with the first charge accumulation step. The present invention is characterized in that an idle transfer step of transferring charges accumulated in the light receiving element as invalid charges through the transfer section is executed.

According to the second aspect of the invention, when the image reading operation is continuously executed a plurality of times, the charges accumulated in the light receiving element are invalidated in synchronization with the first execution of the charge accumulation step. By executing the idle transfer process of transferring the charges as the charges through the transfer unit, it is possible to remove the charges that have not been transferred and remain in the charge transfer process of the image reading operation performed immediately before as invalid charges. It is not necessary to perform a special process for clearing the residual charge, and each charge storage process and charge transfer process can be efficiently performed.

According to a third aspect of the present invention, a light source for irradiating a color original image with light of a plurality of kinds of wavelengths and a plurality of light sources arranged regularly in the vertical and horizontal directions are arranged from the light source to the color original image. A solid-state image sensor having a light-receiving element that receives and photoelectrically converts the irradiation light that is emitted to and transmitted through the color original image, and a transfer unit that transfers the charge accumulated in the light-receiving element; As an image reading operation for photoelectrically reading the color original image as a two-dimensional image by using, a charge accumulating step of receiving the irradiation light for a predetermined time on the light receiving surface of the solid-state image sensor including the array of the light receiving elements is executed. After that, the charges accumulated in the light receiving element in the charge accumulating step are sequentially passed through the transfer unit for each line corresponding to one row in the vertical or horizontal direction in the array of the light receiving elements. Image reading control means for controlling to execute the charge transfer step of transferring to the external device of the stage, and when the image reading operation is continuously executed a plurality of times, in synchronization with the execution of the charge transfer step, In the charge transfer step, the charge transfer step is performed for the number of lines corresponding to the outside of the carrying area of the color original image formed on the light receiving surface of the solid-state image sensor by the irradiation light. Process control means for controlling not to perform.

According to the invention described in claim 3, the light source comprises:
The color original image is irradiated with light of plural kinds of wavelengths.
In addition, the solid-state image pickup device is regularly arranged in a plurality of columns in the vertical and horizontal directions, and a light-receiving device that receives and photoelectrically converts the irradiation light that has transmitted or reflected the color original image, and is stored in the light-receiving device. And a transfer unit that transfers charges. As an image reading operation for photoelectrically reading the color original image as a two-dimensional image by using this solid-state image sensor, the image reading control means causes the light-receiving surface of the solid-state image sensor, which is an array of the light-receiving elements, to perform the predetermined time. After performing the charge storage step of receiving the irradiation light, the charge stored in the light receiving element in the charge storage step is stored in one line corresponding to one row in the vertical or horizontal direction in the array of the light receiving elements. The charge transfer process of sequentially transferring the charges to the external device at the subsequent stage via the transfer unit is controlled. Further, when this image reading operation is continuously executed a plurality of times, the process control means executes the charge transfer process corresponding to the previous charge storage process in synchronization with the execution timing of each charge storage process. As a result, each process can be efficiently executed. Further, the process control means, in each charge transfer process,
The irradiation light is controlled so as not to perform the electric charge transfer for the number of lines corresponding to the outside of the carrying region of the color original image formed on the light receiving surface of the solid-state imaging device. As a result, the time required for each charge transfer step can be shortened, and as a result, the processing time of the entire image reading operation can be shortened.

According to a fourth aspect of the present invention, in the invention according to the third aspect, the process control means further includes the first charge accumulation step when the image reading operation is continuously executed a plurality of times. In synchronism with the execution of step 1, an idle transfer step of transferring the charges accumulated in the light receiving element as invalid charges through the transfer section is executed.

According to the fourth aspect of the present invention, when the process control means further executes the image reading operation a plurality of times in succession, the light receiving element is synchronized with the first execution of the charge accumulation step. By executing the idle transfer step of transferring the electric charge accumulated in the electric charge as an invalid electric charge through the transfer unit, the electric charge remaining without being transferred in the electric charge transfer step of the image reading operation executed immediately before is regarded as an invalid electric charge. Since it can be removed, it is not necessary to perform a special process for clearing the residual charges in the charge transfer process, and each charge storage process and charge transfer process can be efficiently executed.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, the image reading apparatus 10 according to the present embodiment provides R (red) light and G (color) light for a color original image formed on a photographic film 16, respectively.
An RGB LED array 14 including three types of LED groups that emit three colors of light (green) light and B (blue) light, and an LED drive circuit 1 that drives the RGB LED array 14.
2 and. In the RGB LED array 14, R light, G
It is possible to separately emit light of each color of light and B light, and the color balance, light distribution, etc. of the emitted R light, G light, B light are appropriately adjusted in advance.

Further, along the optical axis C of the RGBLED array 14, from the position near the RGBLED array 14 in order,
Lens 18 for focusing the transmitted light from photographic film 16
And a CCD that converts the color original image into an electric signal and outputs it as a read image signal of a two-dimensional image by receiving the R, G, and B color lights emitted from the RGB LED array 14 and transmitted through the photographic film 16. An area sensor 20 (details of which will be described later) is arranged.

The CCD area sensor 20 has R light and G light.
An analog circuit 22 is connected to each of the light and the B light, and each analog circuit 22 has an analog / digital (A /
D) The converters 24 are respectively connected. As a result, each color light of R light, G light, and B light emitted from each LED group is converted into C light.
When the CD area sensor 20 receives the light, the read image signal corresponding to each color light output from the CCD area sensor 20 is sequentially transmitted to the corresponding analog circuit 22 and A / D converter 24. ing.

The above analog circuit 22 and A / D
As for the converter 24, as described above, R light, G light, B light
It is not limited to the configuration including three sets for each color of light,
It may be configured to include one set that can be shared for each color light of R light, G light, and B light.

FIG. 2 shows a schematic configuration of a control system of the image reading apparatus 10 according to this embodiment. The controller 26 as the main control unit of the image reading operation in the image reading apparatus 10 according to the present embodiment controls the LED drive circuit 12, the A / D converter 24, and the CCD area sensor 20. CCD driver 2
8 is connected. The controller 26 includes a process control unit 26A (details will be described later) that controls the start and end timings of each process of the charge storage process and the charge transfer process.

The LED driving circuit 12 sequentially turns on the R light, G light, and B light LED groups in the RGB LED array 14 to divide the R light, G light, and B light into respective color lights, and then the photographic film 16 is provided. RGBLED to illuminate
The array 14 can be controlled. By this,
The transmitted light from the photographic film 16 for each color light can be received by the CCD area sensor 20. Further, the CCD that receives the transmitted light from the photographic film 16 for each color light
The read image signal corresponding to each color light output from the area sensor 20 is input to the controller 26 via the A / D converter 24.

As shown in FIG. 3, the CCD area sensor 20 is arranged with K pieces and J pieces (K and J are natural numbers) respectively in the arrow X direction and the arrow Y direction to form all pixels on the light receiving surface. A plurality of (K × J) photodiode units 20A (hereinafter, referred to as
PD unit 20A), and a plurality of PDs
In the section 20A, a vertical transfer path 20B for shifting and transferring the electric charge accumulated in each PD section 20A of the row is provided for each row of J arranged in the arrow Y direction.
Further, the CCD area sensor 20 is provided with a horizontal transfer path 20C for transferring and outputting charges transferred from the above-mentioned vertical transfer paths 20B provided in all K columns.

The operation of each part of the CCD area sensor 20 is performed by the controller 26 by the CCD driver 28.
It is designed to be controlled via. Specifically, the light transmitted through the color original image on the photographic film 16 is converted into the above-mentioned C
During the light receiving operation in which the CD area sensor 20 receives light, in each PD unit 20A, the transmitted light from the color original image is transmitted for a predetermined time in a state in which unnecessary charges remaining in each PD unit 20A are cleared and charge can be stored. (Charge accumulation time) By receiving light, charges are accumulated according to the amount of received light.
Further, the electric charge accumulated in each PD section 20A is shift-transferred to each vertical transfer path 20B and held therein.
Is newly set to a light receiving state in which charges can be stored. The operation up to this point is referred to as a charge storage step in this embodiment.

In the CCD area sensor 20, a charge transfer process is executed subsequent to the charge storage process. In this charge transfer step, the charge held in each vertical transfer path 20B is treated as one line for the pixel group corresponding to the K PD units 20A arranged in the arrow X direction in FIG. ~ J), the charges held in each vertical transfer path 20B corresponding to each line are sequentially transferred to the horizontal transfer path 20C in the direction of arrow A in FIG. 3, and further to the horizontal transfer path 20C. Is output in the direction of arrow B in FIG. In the present embodiment, in each PD unit 20A shown in FIG. 3, the line consisting of PD (1,1) to PD (1, K) is the first line, PD, along the arrow X direction in FIG. The line consisting of (2,1) to PD (2, K) is the second line, and so on.
A line composed of PD (J, K) is referred to as a Jth line.

In this way, in the image reading apparatus 10 according to the present embodiment, the R light from the RGB LED array 14
The G light and the B light are separately emitted, and the CCD area sensor 20 separately obtains the read image signal for each of the R, G, and B colors for one color original image. As a result, in the image reading operation performed under the control of the controller 26, the process control section 26A included in the controller 26 causes the charge accumulation process and charge in the CCD area sensor 20 via the CCD driver 28. The start and end timings of the transfer process are controlled so that each process is continuously executed by distinguishing each color of R, G, and B.

In the image reading operation, first, the photographic film 16 is conveyed by a conveying means (not shown), stopped at a predetermined frame position, and the color original image recorded on each image frame of the photographic film 16 is preliminarily prepared. The controller 26 calculates various reading conditions such as the charge accumulation time based on the size and density of the original image of each image frame read (pre-scan), and each image frame is calculated according to the calculated reading conditions. The original color image is scanned for fine scanning. Here, the R light, G emitted from the RGB LED array 14
The photographic film 16 is irradiated with the respective colored lights of light and B light for a predetermined time respectively, and the transmitted light from the photographic film 16 is C
As shown in FIG. 4, when the light is received by the light receiving surface of the CD area sensor 20, that is, all pixels, R light, G
An image projection area A corresponding to the original color image is formed in the light-receiving surface area of the CCD area sensor 20 for each of the colored lights of light and B light. As a result, the CCD area sensor 20
The number of lines of the unused portion other than the image projection area A formed on the light receiving surface is previously recognized and set as the reading condition based on the image size.

The time required for the charge accumulation process of each color light depends on the reading conditions, for example, RGBLED.
It can be variably set by adjusting the light amount of the array 14.

Next, the operation of this embodiment will be described. In the image reading device 10 according to the present embodiment, the image reading operation is executed as follows under the control of the controller 26.

First, the photographic film 1 is produced by the above-mentioned conveying means.
In a state where 6 is conveyed in a direction orthogonal to the normal direction of the light receiving surface of the CCD area sensor 20, the LED drive circuit 12
The RGB LED array 14 is driven, and R is output from each LED group.
Light of each color of light, G light, and B light is sequentially emitted.

R emitted from the RGB LED array 14
Light of each color of light, G light, and B light is applied to the photographic film 16 for a predetermined time respectively, and the transmitted light from the photographic film 16 is received by the light receiving surface of the CCD area sensor 20, that is, all pixels, As shown in FIG.
An image projection area A corresponding to the original color image is formed in the light-receiving surface area of the CCD area sensor 20 for each of the light rays of G, G, and B. In the present embodiment, the number of unused partial lines other than the image projection area A on the light receiving surface of the CCD area sensor 20 described above is as shown in FIG.
With respect to the image projection area A on the light receiving surface of the CCD area sensor 20, the number of lines of the unused portion (lower end unused portion) located on the first line side is set to M (M is a natural number), and is set to the J line side. Let N (N is a natural number) be the number of lines of the unused portion (upper unused portion) located.

FIG. 5B shows an execution sequence of the charge accumulation step and the charge transfer step corresponding to the R, G, and B color lights in this image reading operation.

First, the R color light is applied to the photographic film 16 for a predetermined time, and the transmitted light from the photographic film 16 is received by the CCD area sensor 20, whereby a charge accumulating process (R light charge accumulation) corresponding to the R color light is performed. Process) is started (t _{0 in} FIG. 5). In this R photocharge accumulation step, the charge corresponding to the amount of light received is accumulated in each PD section 20A of all the pixels of the CCD area sensor 20 by the transmitted light from the photographic film 16 during the required time _taR , and each PD unit 20A
All the electric charges accumulated in are vertically transferred and held in each vertical transfer path 20B.

At the time point when the R photocharge accumulation process is completed (t _{1 in} FIG. 5), the charge accumulated in the R photocharge accumulation process is transferred and output. Charge transfer step) is started.

In this R photocharge transfer process, each vertical transfer path 2 of the CCD area sensor 20 is used in the R photocharge storage process.
The charges held in 0B are sequentially transferred to the horizontal transfer path 20C for each line from the first line side and output. At this time, the bottom unused portion (for M lines) and the top unused portion (for N lines) outside the image projection area A shown in FIG.
On the other hand, when the number M of lines at the lower end unused portion is greater than or equal to the number N of lines at the upper end unused portion (M ≧ N), N lines from the final J line side out of all lines (1 to J). When the number M of lines at the lower end unused portion is less than the number of lines N at the upper end unused portion (M <N), the transfer process is completed with the remaining number. The transfer process ends with leaving M lines from the J-th line side.

That is, here, when the number M of lines at the lower end unused portion is greater than or equal to the number of lines N at the upper end unused portion (M ≧ N), from the first line of all lines (1 to J). will be only to transfer the accumulated charges corresponding to up to the (J-N) line, the total transfer time in this case, when the transfer time for one line and T _0, T ₀ ×
(J-N).

On the other hand, when the number M of lines at the lower end unused portion is less than the number of lines N at the upper end unused portion (M <N),
Of all the lines (1 to J), from the first line to the (J-
Will be performed only transfer the accumulated charge corresponding to up to M) lines, the total transfer time in this case, when the transfer time for one line and T _0, the _{T 0 × (J-M)} .

As a result, the required time t _tR (= T ₀ ×) obtained by shortening the R photocharge transfer step by Δt _P (= T ₀ × P) as compared with the conventional required time T _tR. (JP))
Can be run with. The variable P is P = N when M ≧ N, and P = M when M <N.

Further, the execution start time of the above-mentioned R photocharge transfer step is started.
Imming (t in FIG. 5)₁), Corresponding to G color light
The charge storage process (G photocharge storage process) is started. In addition,
The required time t of the G photocharge accumulation step at this time_aGIs the above R
Required time t for photocharge transfer process _tRSet equal to
Done (t_aG= T_tR).

Next, when the G photocharge accumulation step is completed (t _{2 in} FIG. 5), the charges accumulated in the G photocharge accumulation step are transferred and output, which corresponds to the G color light. The process (G photocharge transfer process) is started.

In this G photocharge transfer process, the CCD is used in the G photocharge storage process as in the R photocharge storage process described above.
The charges held in each vertical transfer path 20B of the area sensor 20 are sequentially transferred to the horizontal transfer path 20C from the first line side for each line and output. At this time, the lower end unused portion (for M lines) outside the image projection area A shown in FIG.
And when the number M of lines at the lower end unused portion is equal to or larger than the number of lines N at the upper end unused portion (M ≧ N) with respect to the upper end unused portion (N lines), among all lines (1 to J) , The accumulated charges corresponding to the first line to the (JN) line are transferred, and the total transfer time in this case is
If the transfer time for one line is T ₀ , T ₀ × (J
-N).

On the other hand, when the number M of lines at the lower end unused portion is less than the number of lines N at the upper end unused portion (M <N),
Of all the lines (1 to J), from the first line to the (J-
Performed only transfer the accumulated charge corresponding to up to M) lines, the total transfer time in this case, when the transfer time for one line and T _0, the _{T 0 × (J-M)} .

As a result, the required time t _tG (= T ₀ ×) which is reduced by Δt _P (= T ₀ × P) in the G photocharge transfer step compared with the conventional required time T _tG. (JP))
Can be run with. The variable P is P = N when M ≧ N, and P = M when M <N.

Also, the execution start time of the above-mentioned G photocharge transfer step is started.
Imming (t in FIG. 5)₂), Corresponding to B color light
The charge accumulation step (B photocharge accumulation step) is started. In addition,
The time t required for the B photocharge storage step at this time_aBIs the above G
Required time t for photocharge transfer process _tGSet equal to
Done (t_aB= T_tG).

Next, at the time point when the B photo electric charge accumulating step is completed (t _{3 in} FIG. 5), the charge accumulated in the B photo electric charge accumulating step is transferred and outputted, which corresponds to the B color light. The process (B photocharge transfer process) is started.

In this B photocharge transfer step, B photocharge accumulation
Each vertical transfer path 2 of the CCD area sensor 20 in the process
The charge held in 0B is applied to the first line for each line.
From the side, it is transferred to the horizontal transfer path 20C and output,
At this time, the bottom end unused outside the image projection area A shown in FIG.
All lines (1 to J) are added to the number N of lines for use
Then, transfer process leaving N lines from the final J line side
Ends (t in FIG. 5) _Four). That is, here
Of the Inns (1 to J), the 1st line to the (JN) th line
Only the accumulated charge corresponding to the
And the total transfer time in this case is for one line.
Transfer time of T₀Then, T₀X (J-N).

As a result, the B photocharge transfer step can be executed in the required time t _tB which is shortened by Δt _N (= T ₀ × N) as compared with the conventional required time T _tB. it can.

By executing the charge accumulation step and the charge transfer step corresponding to each color light as described above, the accumulated charge (residual charge) remaining without being transferred in the charge transfer step of each color light is transferred as follows. 4 in the charge transfer process of FIG.
Since it can be performed corresponding to the transfer to the unused partial line outside the image projection area A shown in (3), the read image data can be appropriately obtained without being affected by the residual charge. In addition, by shortening the time required for the charge transfer process of each color light as described above, as a result, Δt (= 2Δt _P + Δt _N compared to the conventional required time RT in the moving image reading operation for one color original image). ), The moving image reading operation for one color original image can be executed with the required time RTn shortened, and the processing speed of the apparatus can be improved.

Further, in the present embodiment, the idle transfer process is executed in synchronization with the execution of the R photocharge storage process. In this idle transfer process, the charges retained in each vertical transfer path 20B of the CCD area sensor 20 are retained in all lines (1 to 1).
J) is sequentially transferred line by line as invalid charges and transferred to the horizontal transfer path 20C and output. The total line transfer time t _{tE at} this time is the transfer time for one line T _0.
Then, T ₀ × J (= t ₁ −t ₀ ), which is set to be equal to the required time _taR of the R photocharge accumulation step. As a result, after the B photoelectric charge transfer step in the previous image reading operation is completed, the upper end unused portion (N outside the image projection area A shown in FIG. 4 that remains without being transferred to each vertical transfer path 20B (N The charge corresponding to the line) can be cleared as an invalid charge. As a result, the image reading operation can be efficiently and continuously executed.

As described above, according to the image reading apparatus of the present embodiment, in the image reading operation for one color original image, the CCD area sensor sequentially performs the charge accumulation process and the charge transfer for each of the RGB color lights. When the read image signal is obtained for each of the RGB colors by continuously performing the steps, it is determined based on the number of lines of the unused portion in the light receiving surface area of the CCD area sensor in the charge transfer step of each color light. By reducing the transfer time for the number of lines without performing the charge transfer for the number of lines, it is possible to reduce the time required for the moving image reading operation for one color original image, and to increase the processing speed of the apparatus. Can be improved.

[0053]

As described above, according to the present invention, when the image reading operation is continuously executed a plurality of times, the next charge accumulation step is executed in synchronization with the execution of the charge transfer step, and the charge transfer step is performed. In the process, the time required for the charge transfer process is shortened by not performing the charge transfer by the number of lines corresponding to the outside of the carrying area of the color original image formed on the light receiving surface of the solid-state image sensor by the irradiation light from the light source. Therefore, there is an excellent effect that it is possible to obtain the solid-state image sensor control method and the image reading apparatus in which the processing speed of the color original image reading operation is improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a schematic configuration of an image reading apparatus according to an embodiment of the present invention.

FIG. 3 is a diagram showing a schematic configuration of part of a CCD area sensor according to the present embodiment.

FIG. 4 is a diagram for explaining an image projection area on a light receiving surface of the CCD area sensor according to the present embodiment.

5A is a diagram for explaining an execution sequence of a charge storage process and a charge transfer process of a CCD area sensor according to a conventional technique, and FIG. 5B is a charge of the CCD area sensor according to the present embodiment. It is a figure for explaining the execution sequence of an accumulation process and a charge transfer process.

[Explanation of symbols]

10 Image reading device 14 RGB LED array (light source) 20 area CCD sensor (solid-state image sensor) 20A Photodiode part (light receiving element) 20B Vertical transfer path (transfer section) 20C horizontal transfer path (transfer section) 26 controller (image reading control means) 26A Process control unit (process control means)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/335 H04N 1/04 DF term (reference) 5B047 AA05 AB04 BB04 BC11 CA05 CA07 CA14 CA23 CB09 CB12 5C024 AX02 CX51 DX01 EX01 GX03 GY01 GZ36 HX23 5C051 AA01 BA02 DA06 DB01 DB08 DB29 DB31 DC03 DE01 EA01 FA04 5C065 AA07 BB41 BB46 CC01 DD02 GG18 5C072 AA01 BA03 CA05 EA08 FA08 FB08 RA06 RA08 RA06 FB08 RA06 FB08 RA08 FB08 RA06 FB08 RA06 FB08 RA06 FB08 RA06 FB08 RA06 FB08 RA06 FB08

Claims (4)

[Claims] 1. A light-receiving element, which is arranged regularly in the vertical and horizontal directions, respectively, and which receives the light emitted from a light source to a color original image and transmits or reflects the color original image, and photoelectrically converts the light. As the image reading operation for photoelectrically reading the color original image as a two-dimensional image using a solid-state imaging device having a transfer unit that transfers charges accumulated in the light-receiving device, the solid-state imaging including an array of the light-receiving devices is performed. After performing the charge accumulation step of receiving the irradiation light on the light receiving surface of the element for a predetermined time, the charges accumulated in the light receiving element in the charge accumulation step are arranged in one row in the vertical or horizontal direction in the array of the light receiving elements. Minute for each line corresponding to the light-receiving element,
A method of controlling a solid-state image sensor for executing a charge transfer step of transferring to a subsequent external device via the transfer unit, wherein the charge transfer step is executed when the image reading operation is continuously executed a plurality of times. In synchronization with the next charge accumulation step, in the charge transfer step, the line corresponding to the outside of the carrying area of the color original image formed on the light receiving surface of the solid-state imaging device by the irradiation light. A method for controlling a solid-state image sensor, which does not transfer charges for several minutes. 2. When the image reading operation is continuously executed a plurality of times, the electric charge accumulated in the light receiving element is treated as an invalid electric charge in synchronization with the first execution of the electric charge accumulating step. 2. The method for controlling a solid-state image pickup device according to claim 1, wherein an idle transfer step of transferring via the CPU is executed. 3. A light source for irradiating a color original image with light of a plurality of types of wavelengths, and a plurality of light sources arranged regularly in the vertical and horizontal directions, and the light source irradiates the color original image to the color original image. A light-receiving element that receives and irradiates photoelectrically the irradiated light that has passed through or is reflected by,
A solid-state image sensor having a transfer unit that transfers charges accumulated in the light-receiving element, and an image reading operation for photoelectrically reading the color original image as a two-dimensional image using the solid-state image sensor, After performing a charge accumulation step of receiving the irradiation light for a predetermined time on the light receiving surface of the solid-state imaging device formed of an array, the charge accumulated in the light receiving element in the charge accumulation step is stored in the array of the light receiving elements. An image reading control unit that controls to execute a charge transfer step of sequentially transferring to a subsequent external device via the transfer unit for each line corresponding to one row of light receiving elements in the vertical or horizontal direction; When the reading operation is continuously performed a plurality of times, the next charge accumulation step is performed in synchronization with the execution of the charge transfer step, and the charge transfer step is performed by the irradiation light. Image reading apparatus and a process control means for controlling so as not to charge transfer of the number of lines corresponding to the outside supporting area of said color original image to be formed on the light receiving surface of the solid-state imaging device. 4. The process control means further, when performing the image reading operation a plurality of times in succession, synchronizes the charges accumulated in the light receiving element in synchronization with the first execution of the charge accumulation process. The image reading apparatus according to claim 3, wherein an idle transfer step of transferring the charges as invalid charges through the transfer unit is executed.