JPH07123221A - Device and method for reading picture - Google Patents

Abstract

PURPOSE:To transfer quickly R, G, B picture data for one line to a host computer. CONSTITUTION:A timing control circuit 21 drives a lighting device 5 via a lighting drive circuit 5 allowing the device 5 to emit R, G, B light. R, G or B data by line read by a CCD 8 are ADD-converted by an A/D converter circuit 9 and the resulting data are transferred to RAM 23 via a bus changeover circuit 22 and stored therein. The timing control circuit 21 controls the lighting device 6, the CCD 8 and the A/D converter circuit 9. A CPU 1 applies DMA transfer to the picture data stored in the RAM 23 via a DMA controller 24 and stored therein. The CPU 1 processes the R, G, B picture data by one line stored in the RAM 3 and transfers the processed data to a host computer 13 when the processing is finished. The processing by the CPU 1 is made in parallel while the timing control circuit 21 reads the R, G, B picture data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an image reading apparatus and method suitable for illuminating each line and capturing R, G, or B image data line by line.

[0002]

2. Description of the Related Art FIG. 6 shows an example of the configuration of a conventional image reading apparatus. The CPU 1 controls each unit according to a program stored in the ROM 2 and executes an image reading operation. RAM3 is CP
Data and the like necessary for the U1 to execute various processes are stored at any time. The interface control circuit 4 is connected to the host computer 13, outputs the read data to the host computer 13, and supplies a command from the host computer 13 to the CPU 1.

The illumination drive circuit 5 is controlled by the CPU 1 to drive the illumination device 6 so that R, G for an original (not shown) can be read.
Alternatively, the light of B is illuminated. CCD drive circuit 7 is CC
D8 is driven to read the original. The image data output from the CCD 8 is input to the A / D conversion circuit 9 and A
After the D / D conversion, it is supplied to the RAM 3 and stored therein.

The motor drive circuit 10 is controlled by the CPU 1 at a predetermined timing and drives the motor 11 to move an original document (not shown) line by line. The timer 12 constantly performs a timekeeping operation and outputs time information to C
It is being supplied to PU1.

Next, the operation will be described with reference to the flowchart of FIG. 7 and the timing chart of FIG. First, in step S11, the measurement of the R light illumination time is started and the R light illumination is started. That is, the CPU 1 supplies the line start trigger signal (FIG. 8A) to the motor drive circuit 10 to drive the motor 11. As a result, the original document (not shown) is moved to the position of the first reading line. Then, the CPU 1 controls the illumination drive circuit 5 to cause the illumination device 6 to generate R light and irradiate the document. At this time, the CPU 1 causes the timer 12 to
Control to start measuring the exposure time of the R light.

As a result, the R light is illuminated on the document (FIG. 8B), and the CCD 8 accumulates the light corresponding to the R image for one line.

Then, in step S12, the process waits until the illumination time of the R light is completed. When the illumination time of the R light has elapsed, the process proceeds to step S13, the illumination of the R light is terminated, and the R data is stored. It is A / D converted and written in the RAM 3. That is, the CPU 1 controls the CCD 8 via the CCD drive circuit 7 (FIG. 8 (e)), outputs the R image signal captured in the CCD 8 to the A / D conversion circuit 9, and
After D conversion, it is supplied to the RAM 3 and stored therein.

Next, in step S14, the CPU 1
The illumination device 6 is driven via the illumination drive circuit 5 to illuminate the document with G light. Then, the timer 12 is caused to start measuring the illumination time of the G light. As a result, the document is illuminated with the G light (FIG. 8C), and the CCD 8 captures an image corresponding to the G light.

In step S15, the process waits until the end of the G light illumination time is detected. When the end of the G light illumination time is detected, the process proceeds to step S16 to end the G light illumination. After the image data captured in the CCD 8 is A / D converted by the A / D conversion circuit 9, the RAM 3
And store it (FIG. 8 (e)).

Further, in step S17, the illumination device 6 is driven through the illumination drive circuit 5 to illuminate the original with B light. Then, the timer 12 starts measuring the illumination time of the B light. As a result, the image of B light is captured by the CCD 8 (FIG. 8D).

In step S18, the process waits until the end of the B light illumination time is measured, and when the end of the B light illumination time is measured, the process proceeds to step S19 to end the B light illumination. . And B taken in CCD8
The image corresponding to the light of A / D is converted into A / D by the A / D conversion circuit 9.
It is converted, supplied to RAM3, and stored (FIG. 8).
(E)).

In this way, when the data of R, G and B for one line is stored in the RAM 3, step S
In step 20, the CPU 1 processes the data stored in the RAM 3, and when the processing is completed, the CPU 1 proceeds to step S21 to transfer the processed data to the host computer 13 as an external device. That is, CPU1
Processes the image data stored in the RAM 3, and then transfers the processed data to the host computer 13 via the interface control circuit 4.

After the data for one line is transferred to the host computer 13 in this way, the CPU 1 sends a line start trigger signal (see FIG. 8) to the motor drive circuit 10.
(A)) is supplied and the motor 11 is driven to move the document by one line. Then, the same processing is performed on the moved new line.

A summary of the above processing is shown in FIG. That is, R light is illuminated on a predetermined line, the R image is A / D converted, and is taken into the RAM 3. Similarly, following that, G image data and B
Image data is sequentially loaded into the RAM 3. R, G
When the image data of B and B are fetched, the CPU 1
Processes the data, and when the processing is completed, transfers the data to the host computer 13. Then, after moving the document by one line further, the same process is executed for a new line.

As described above, the original can be read by one CPU 1 and a low-cost apparatus can be realized.

[0016]

However, in the above-mentioned conventional apparatus, as shown in FIG.
After the image data for one line of B is fetched, the data is processed and the processed data is transferred to an external device. After the transfer is completed, the document is moved by one line and the same process is repeated for a new line.

As a result, the time for exposing R, G, and B, the time for A / D converting each color data and storing it in the RAM 3, and the time for processing the data for one line stored in the RAM 3 are set. , The processed data to the host computer 1
The time required to transfer the data for one line to the host computer 13 was required to be the total of the time for transferring the data to No. 3 and the time for moving the document by one line. Therefore,
There is a problem that it takes a long time to transfer the data for one line to the host computer 13. Further, when the data cannot be transferred at high speed due to the capability of the interface control circuit 4, there is a problem that the transfer time becomes longer.

The present invention has been made in view of such a situation, and it is possible to more quickly read and transfer image data.

[0019]

An image reading apparatus according to a first aspect of the present invention includes an illumination unit for illuminating an original document (for example, the illumination device 6 in FIG. 1) and R, G of the original document illuminated by the illumination unit. Alternatively, a reading unit (for example, CCD 8 in FIG. 1) for sequentially reading B images and a conversion unit (for example, A / D in FIG. 1) for A / D converting the image signal output by the reading unit.
D conversion circuit 9), first storage means (for example, RAM 23 in FIG. 1) for temporarily storing the image data A / D converted by the conversion means, and image data from the conversion means to the first storage means. Control means (for example, the timing control circuit 21 in FIG. 1) for controlling the transfer of the image data, and a second storage means (for example, in FIG. 1) for storing the image data transferred from the first storage means.
RAM 3) and the transfer of the image data from the first storage means to the second storage means, and when the reading means is reading the original, the image data stored in the second storage means is processed. Processing means (eg CP of FIG. 1)
U1) are provided.

Further, in the image reading method according to the second aspect, an image of any one of R, G, and B colors of a predetermined one line of the original is read, and the signal of the read image is A
A / D-converted and A / D-converted image data is temporarily stored in the first memory, and an image signal of any one of R, G, and B colors is A / D-converted and stored in the first memory. During the stored period, the operation of reading the image of the other color of R, G, or B is started, and the image data of all the colors of R, G, and B for one line is stored in the first memory. When remembered,
The image data of all colors of R, G, and B for one line is transferred to the second memory, and when the transfer of the image data to the second memory is completed, the reading line of the original is changed to When the reading line is changed, the image data stored in the second memory is processed, and the image of the changed line of the document is read during the period in which the image data stored in the second memory is processed. It is characterized by starting.

After processing the image data stored in the second memory, it is possible to transfer the processed image data to an external device while the changed line of the document is being read. .

[0022]

The image reading apparatus according to claim 1,
And the image reading method according to claim 2,
In the period in which the R, G, or B light is illuminated, the image data of the color illuminated immediately before is A / D converted,
It is captured. Therefore, more rapid processing is possible.

[0023]

1 is a block diagram showing the construction of an embodiment of an image reading apparatus of the present invention, in which parts corresponding to those in FIG. 6 are designated by the same reference numerals. In this embodiment, in addition to the CPU 1, the timing control circuit 21
Are provided as separate circuits, and the illumination drive circuit 5,
The CCD drive circuit 7 and the A / D conversion circuit 9 are controlled by the timing control circuit 21.
On the other hand, the motor drive circuit 10 is controlled by the CPU 1.

Further, a bus switching circuit 22 is provided and RA
The bus connected to M23 is the A / D conversion circuit 9 or R
One of AM3 is switched to be connected. In addition, a DMA controller (DMAC) 2
4 transfers data from the RAM 23 to the RAM 3 (DMA
Transfer) is designed to control. The timer 12
Can be provided as necessary also in this embodiment. Other configurations are the same as those in FIG.

FIG. 2 shows a configuration example of the timing control circuit 21. As shown in the figure, in this embodiment, an overall control circuit 31 is provided, the overall control circuit 31 is controlled by the CPU 1, and the R light illumination control circuit 3 is provided.
2, G light illumination control circuit 33, and B light illumination control circuit 3
4 is controlled. R light illumination control circuit 3
2, G light illumination control circuit 33, and B light illumination control circuit 3
4 controls the lighting drive circuit 5, and the lighting device 6
Then, R light, G light, or B light is generated to illuminate the document.

The overall control circuit 31 includes a CCD control circuit 35, an A / D timing control circuit 36, and a RAM.
Each of the control circuits 37 is controlled.
The CCD control circuit 35 controls the CCD drive circuit 7,
The D conversion timing control circuit 36 controls the A / D conversion circuit 9. In addition, the RAM control circuit 37
Has a built-in address switching circuit, and RAM2
It is designed to control the writing of data to the data.

Next, the operation will be described with reference to the flowchart of FIG. 3 and the timing chart of FIG. First, in step S1, the CPU 1 executes R,
A process of setting the illumination time of each light of G and B in the timing control circuit 21 is executed. That is, the timing control circuit 21
When the illumination time of each light of R, G, B is input from the CPU 1, the overall control circuit 31 of FIG. 3 sets these values to the R light illumination control circuit 32, the G light illumination control circuit 33, or the B light illumination. It is supplied to the control circuit 34 and stored therein.

Next, in step S2, the CPU 1 sends the line start trigger signal (FIG. 4A) to the overall control circuit 31.
Supply to. When this signal is input, the overall control circuit 31 executes the R, G, and B image data fetching processing as follows, independently of the instruction from the CPU 1.

That is, the overall control circuit 31 first controls the R light illumination control circuit 32 and drives the illumination device 6 via the illumination drive circuit 5 to illuminate the document with R light (FIG. 4).
(B)). As a result, only the exposure time of this R light, CCD
The image of R will be accumulated in 8. Then, the R-light illumination control circuit 32 sets the R-light illumination control circuit 32 to the R-light illumination control circuit 32 set in step S1.
The illumination of the R light is terminated at the timing when the light exposure time has elapsed.

This end signal is supplied to the G light illumination control circuit 33. When the G light illumination control circuit 33 receives the input of the end signal, the G light illumination control circuit 33 transmits the illumination device 6 via the illumination drive circuit 5.
Is driven to generate G light and illuminate the document. As a result, the image corresponding to the G light starts to be accumulated in the CCD 8 (FIG. 4C).

On the other hand, the overall control circuit 31 controls the CCD control circuit 35 when the R light illumination control circuit 32 finishes the illumination of the R light, drives the CCD 8 through the CCD drive circuit 7, and causes the CCD 8 to operate. The captured R image signal is read and output to the A / D conversion circuit 9 (FIG. 4 (e)).
Further, the overall control circuit 31 controls the A / D conversion circuit 9 via the A / D timing control circuit 36 to A / D convert the image signal of R input from the CCD 8.

Furthermore, the overall control circuit 31 is a RAM
The control circuit 37 is controlled to cause the bus switching circuit 22 to switch buses. That is, the bus of the RAM 23 is connected to the A / D conversion circuit 9. The R image data output from the A / D conversion circuit 9 is supplied to the R data address of the RAM 23 designated by the address switching circuit incorporated in the RAM control circuit 37 and stored therein (FIG. 4).
(E)).

In this way, the G light illumination control circuit 33 continues to illuminate the G light as it is even during the period when the R image data is transferred to the RAM 23. And
When the G light illumination time set in step S1 has elapsed, the G light illumination control circuit 33 ends the illumination of the G light. This end signal is supplied to the B light illumination control circuit 34. The B-light illumination control circuit 34 controls the illumination device 6 via the illumination drive circuit 5 when the end signal is input,
B light is generated to illuminate the document (FIG. 4 (d)).

In this way, when the illumination of B light is started, the overall control circuit 31 drives the CCD drive circuit 7 via the CCD control circuit 35 to A / D the image data of G taken in the CCD 8. It is supplied to the conversion circuit 9. And
The A / D conversion circuit 9 is controlled via the A / D timing control circuit 36, and the G image data input from the CCD 8 is A / D converted.

At this time, the RAM control circuit 37 is
The G image data output from the A / D conversion circuit 9 is designated by specifying the G address of the RAM 23, and the bus switching circuit 22
It is stored in the address for G of the RAM 23 via (FIG. 4 (e)).

As described above, the G image data is RA
The B light illumination control circuit 34 continues to illuminate the B light even during the period when the light is transferred to M23. When the B light illumination time set in step S1 has elapsed,
The B light illumination control circuit 34 ends the illumination of the B light. When the illumination of B light is completed, the CCD control circuit 35
The CCD 8 is controlled via the drive circuit 7 so that the B image data fetched so far is read out, and the A / D conversion circuit 9
To supply.

The A / D conversion circuit 9 is controlled by the A / D timing control circuit 36 to A / D convert the input B image signal.
It is D-converted and transferred to the RAM 23 via the bus switching circuit 22. At this time, the RAM control circuit 37 causes the RAM 23 to
Specify the address of the B data. Therefore, the image data of B is transferred and stored in a predetermined address of the RAM 23 (FIG. 4 (e)).

As described above, the R, G and B image data for one line is stored in the RAM 23, and the processing is controlled by the timing control circuit 21 which is hardware independent from the CPU 1. It

On the other hand, returning to FIG. 3, in step S2, after the line start trigger signal is output to the overall control circuit 31, the process proceeds to step S3, and the CPU 1 stores 1 in the RAM 3.
It is determined whether or not R, G, B data for the line is stored. In the present case, since the data of the first line of the document is read and stored in the RAM 23,
No data is stored in the RAM 3 yet. Therefore,
In this case, the process proceeds to step S6, and it is determined whether the A / D conversion of the B data is completed. If the A / D conversion of the B data is not yet completed, the process waits until it is completed, and when the conversion is completed, the process proceeds to step S7, and the image data stored in the RAM 23 is transferred to the RAM 3 in the D format.
The MA is transferred.

That is, at this time, the CPU 1 outputs a control signal to the DMA controller 24 to manage the bus by the DMA.
Hand over to the controller 24. In addition, the bus switching circuit 22
The bus connected to the RAM 23 to the RAM
Connect to 3. The DMA controller 24 is the CPU 1
After taking control of the bus from
The R, G and B image data for one line stored therein is DM-stored in the RAM 3 via the bus switching circuit 22.
A is transferred. After this transfer is completed, the DMA controller 24 transfers the bus management to the CPU 1 again.

When the second and subsequent lines are being read, the RAM 3 is read in step S3.
Then, it is determined that the image data for one line read immediately before is stored. Therefore, in this case, the process proceeds from step S3 to step S4, and the CPU 1
Processes the image data stored in the RAM 3.
As this processing, data averaging, edge enhancement processing, etc. can be considered. Alternatively, the host computer 1
In response to the command from 3, the process of emphasizing a predetermined component among the R, G, B components can be considered.

After the above processing is completed, the process proceeds to step S5, and the data transfer processing to the external device is executed. That is, the CPU 1 supplies the processed data stored in the RAM 3 to the interface control circuit 4 via the bus and further transfers the data to the host computer 13.

In this way, after transferring the processed data stored in the RAM 3 to the host computer 13,
The process proceeds to step S6 and waits until the A / D conversion process of the last B image data of the image data of the line currently being processed is completed, and when the process is completed, it is stored in the RAM 23 as described above. One line of R, G, B
The image data of is transferred to the RAM 3 by DMA. Then, when this DMA transfer is completed, the CPU 1 drives the motor 11 via the motor drive circuit 10 to set the original to 1
Move only the line. Then, the reading operation of the moved new line is executed in the same manner as in the case described above.

The above operation is summarized as shown in FIG. That is, the timing control circuit 21 causes the illumination device 6 to sequentially illuminate the document with R, G, and B lights.
Then, while the G light is being exposed, the already captured R image data is A / D converted,
23, and store. Similarly, while the B exposure is being performed, the image data of the G light captured in the CCD 8 immediately before that is A / D converted, and the RAM 23
Transfer to and store. Since the B exposure is the last exposure, when the exposure is completed, the data is transferred from the CCD 8 to the RAM 23 and stored therein.

In this way, the timing control circuit 21
After the image data of each color of R, G, B is fetched into the RAM 23 under the control of 1, the CPU 1 stores the image data of R, G, B for one line stored in the RAM 23. It is transferred to the RAM 3 and stored. After this transfer is completed, the motor 11 is controlled via the motor drive circuit 10 to move the document by one line. Then, while the timing control circuit 21 is executing the read operation for the new line, the CPU 1
When the image data of R, G, B for one line stored in the memory 3 is processed and the processing is completed, the data is transmitted via the interface control circuit 4 to the host computer 13
Transfer to.

As described above, since the control by the CPU 1 is executed in parallel while the control by the timing control circuit 21 is being performed, one line of R, G, B data is transferred to the host computer 13. It takes less time.

For example, even if the data transfer rate slows down due to the capability of the interface control circuit 4, if it is within the total exposure time of R, G, and B, the host computer 13 is actually The time required to transfer the image data for one line is not delayed.

In the above description, the R, G or B light is generated to illuminate the original document. However, the original document is illuminated with white light and the R, G and B filters are switched to change the R, G and B filters.
It is also possible to obtain G and B image data.

[0049]

As described above, according to the image reading apparatus of the first aspect, the control means for controlling the transfer of the image data from the converting means to the first storing means and the second storing means are stored. Since the processing means for processing the image data is configured separately, it is possible to quickly transfer the image data with a simple configuration without increasing the cost so much.

Further, according to the image reading method of the second aspect, the reading of the image of the new line is performed in parallel while the image data stored in the second memory is being processed. It is possible to quickly read and transfer image data.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of an image reading apparatus of the present invention.

FIG. 2 is a block diagram showing a configuration of a timing control circuit 21 of the embodiment shown in FIG.

FIG. 3 is a flowchart illustrating the operation of the embodiment of FIG.

FIG. 4 is a timing chart explaining the operation of the embodiment of FIG.

5 is a timing chart explaining the operation of the embodiment of FIG.

FIG. 6 is a block diagram showing a configuration of an example of a conventional image reading apparatus.

FIG. 7 is a flowchart illustrating an operation of the example of FIG.

FIG. 8 is a timing chart illustrating the operation of the example of FIG.

9 is a timing chart explaining the operation of the example of FIG.

[Explanation of symbols]

 1 CPU 2 ROM 3 RAM 4 Interface control circuit 5 Lighting drive circuit 6 Lighting device 7 CCD drive circuit 8 CCD 9 A / D conversion circuit 10 Motor drive circuit 11 Motor 12 Timer 13 Host computer 21 Timing control circuit 22 Bus switching circuit 23 RAM 24 DMA controller

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[Procedure amendment]

[Submission date] June 7, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

Next, the operation will be described with reference to the flowchart of FIG. 7 and the timing chart of FIG. First, in step S11, the measurement of the R light illumination time is started and the R light illumination is started. That is, the CPU 1 controls the illumination drive circuit 5, and the illumination device 6
The R light is generated and is irradiated on the document. At this time, the CPU 1 also controls the timer 12 to start measuring the exposure time of the R light.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

This end signal is sent from the R light illumination control circuit 32.
To the G light illumination control circuit 33. Upon receiving the input of the end signal, the G light illumination control circuit 33 drives the illumination device 6 via the illumination drive circuit 5 to generate G light and illuminate the document. As a result, the CCD 8 has G
The image corresponding to the light of light begins to be accumulated (Fig. 4
(C)).

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction content]

In this way, the G light illumination control circuit 33 continues to illuminate the G light as it is even during the period when the R image data is transferred to the RAM 23. And
When the G light illumination time set in step S1 has elapsed, the G light illumination control circuit 33 ends the illumination of the G light. This end signal is supplied from the G light illumination control circuit 33 to the B light illumination control circuit 34. B light illumination control circuit 34
When this end signal is input, controls the illumination device 6 via the illumination drive circuit 5 to generate the light of B and illuminate the document (FIG. 4 (d)).

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7]

Claims (3)

[Claims] 1. An illumination unit for illuminating a document, and R, G of the document illuminated by the illumination unit.
Alternatively, a reading unit for sequentially reading B images, a conversion unit for A / D converting the image signal output by the reading unit, and a first storage unit for temporarily storing the image data A / D converted by the conversion unit Storage means, control means for controlling transfer of image data from the conversion means to the first storage means, second storage means for storing the image data transferred from the first storage means, The transfer of image data from the first storage unit to the second storage unit is controlled, and the image data stored in the second storage unit is processed while the reading unit is reading the original document. An image reading apparatus comprising: a processing unit. 2. A predetermined one line of an original document is read in an image of any color of R, G or B, the read image signal is A / D converted, and the A / D converted image data is read. The image signal of any one of R, G, and B colors is temporarily stored in the first memory, A / D converted, and stored in the first memory. When an operation of reading an image of another color among them is started, and image data of all colors of R, G and B for one line is stored in the first memory, R, G for one line is stored. And the image data of all colors B are transferred to the second memory, and when the transfer of the image data to the second memory is completed, the reading line of the original is changed, and the reading line of the original is changed. When the second
Image data stored in the second memory is processed, and reading of the image of the changed line of the document is started during the period in which the image data stored in the second memory is processed. Image reading method. 3. After processing the image data stored in the second memory, transferring the processed image data to an external device during a period in which a changed line of the document is being read. The image reading method according to claim 2.