JP2000299784A - Image reading device, its control method and its recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly generate the white and black color references and to early read the images by generating and storing the collating data on both references which are generated before an original is read and comparing the collating data on the preceding white and black color references with the collating data which are generated for the reading of this time. SOLUTION: An image reader 1 transfers the read data 11 which are outputted after a reading means 2 reads at first a white or black reference area to a data generation means 5 to generate the collating data 12. The data 12 are transferred to a data collation means 6 and compared with the collating data which are generated in a preceding image read mode and stored in a data storing means 7. When a difference is recognized between the data 12 which undergone the said collation via the means 6 and the collating data generated in the preceding image read mode, a reference generation means 3 generates the reference data 13.

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 for providing image data to a host apparatus, which quickly generates a white reference and a black reference which are generated prior to an image reading operation without lowering the accuracy. More particularly, the present invention relates to a computer-readable recording medium that stores a program for controlling the image reading apparatus.

[0002]

2. Description of the Related Art Here, the definitions of the following terms according to the present invention and the technical background thereof will be described to clarify the concepts included therein.

The white reference is a white reference value read by an image reading apparatus. That is, the value of the white reference defines the maximum output value output from each read pixel provided in the reading unit of the image reading apparatus.

By defining the above-mentioned white reference for each read pixel, the non-uniformity of the output characteristic of each read pixel is leveled, and the unevenness of the irradiation light emitted from the light source lamp is leveled. The uniformity of the image data provided by the image reading device can be guaranteed.

[0005] In principle, the above-mentioned white reference reads a white reference area having uniform brightness and defines the read output value as the white reference of the image reading apparatus. In practice, a predetermined area of the white reference area is read by a plurality of scanning lines, and the average value of the output values of each read pixel is calculated to form a white reference, thereby forming a local area in the white reference area. This is a means for eliminating the influence of the non-uniformity of the typical brightness.

At the same time, a dark read output value which locally protrudes from the output values of the individual read pixels read by the plurality of scanning lines is determined as dust adhering to the white reference area, and the white read value is determined. A dust removal operation for removing an abnormal value from the reference is performed.

As described above, the white reference reads out a white reference region having a uniform brightness in principle and determines the maximum output value. Therefore, the light source lamp for illuminating the white reference region is used. When the illuminance changes, the white reference also changes. Therefore, when there is a difference between the illuminance of the light source lamp illuminating the white reference area when generating the white reference and the illuminance of the light source lamp at the time of actually irradiating the original to be read, The output value obtained by reading the original document that has been read does not sufficiently exhibit the original reading ability of the image reading apparatus, and provides image data with reduced reproducibility to the host apparatus. There is a danger of getting lost.

Accordingly, the difference between the illuminance of the light source lamp illuminating the white reference area when the white reference area is generated and the illuminance of the light source lamp when the original to be read is actually illuminated is eliminated. In general, a procedure of waiting until the illuminance of the light source lamp is sufficiently stabilized and performing generation of a white reference only when the illuminance of the light source lamp is sufficiently stabilized is performed, or alternatively, reading is performed. The procedure of executing the white reference generation every time immediately before reading the original to be processed is adopted.

In practice, it is necessary to leave the light source lamp of the image reading apparatus turned on for a long time until the illuminance of the light source lamp is sufficiently stabilized. In many cases, a method of generating a white reference every time immediately before reading an original to be read is used.

However, in the case where the method of generating the white reference every time immediately before reading the original to be read is adopted, the white reference area is read each time an image reading instruction is received, and then the individual white reference is read. , An average value of the read output values is calculated for each of the read pixels, and a dust removal operation is further performed. Therefore, the image reading apparatus has an inoperative time that is apparently unrelated to the image reading instruction from the host device from when the image reading instruction is received from the host device to when the image reading is actually started.

The black reference is a black reference value read by the image reading device. That is, the above-mentioned black reference value defines the minimum output value output from each read pixel provided in the reading unit of the image reading apparatus.

By defining the above-mentioned black reference and the above-mentioned white reference for each read pixel, the non-uniformity of the output characteristic of each read pixel is leveled, and the image reading apparatus is provided. It is possible to guarantee the uniformity of the image data.

In the above-mentioned black reference, in principle, incident light arriving at each read pixel is zero, and the read output value constitutes a black reference with a level of zero.
Actually, even if the incident light arriving at each read pixel is zero, the read output value does not become zero due to the presence of the dark current. Therefore, in an image reading apparatus which needs to read strict gradation of image information, for example, a light source lamp is turned off to create a state in which incident light does not arrive at each of the read pixels, and a state in which the incident light does not arrive. , The read output value output by each read pixel is defined as the black reference of the image reading apparatus.

The output value of each pixel when the incoming light is zero is irrelevant to the change in the amount of light of the light source lamp. The dark voltage fluctuates with the elapse of time as the ambient temperature rises due to electronic components and the like placed in the area.

Further, in reality, the output value output from each pixel in the state where the incident light is zero is a very small output value mainly constituted by a dark current, so that it is easily affected by noise. In particular, the thermal noise noise caused by the heat generation of the element is random noise, and is difficult to remove by a circuit method.

As a method for finding a substantial true value from data containing random noise as described above, a statistical method of calculating an average value from individual data is applied. That is, the reading unit performs a predetermined number of readings in a state where the incoming light is zero, calculates an average value for each pixel, and configures a black reference using the average value.

As a matter of course, the average value can be made closer to the true value by increasing the number of samples. Therefore, by determining in advance the accuracy of the image data required for the image reading apparatus and knowing the deviation value of the data, it is possible to define the actual number of times of reading the black reference area in the black reference generation.

Referring to FIGS. 17 to 23, a description will be given of a principle configuration of an image reading apparatus to which a conventional technique is applied for generating a white reference and a black reference, and a control method thereof.

FIG. 17 is an explanatory diagram showing a principle configuration in which an image reading apparatus to which the conventional technique is applied generates a white reference and a black reference. That is, the image reading device 5
In step 1, the reading means 52 transfers the read data 61, which reads and outputs the white reference area or the black reference area, to the reference generation means 53, and the reference generation means 53 converts the reference data 63 based on the read data 61. Prepare for reading a document to be generated and read.

Referring to FIGS. 18 and 19, an overall schematic flow in which an image reading apparatus to which the conventional technique is applied generates a white reference and a black reference will be described.

The main configuration will be described based on the block diagram of FIG. That is, the arithmetic control unit B52 incorporated in the image reading device B51 includes a reference generation unit B57, and generates a white reference or a black reference based on a read output value obtained by reading the white reference region or the black reference region by the reading unit B53. I do.

The overall operation flow will be described with reference to the flowchart of FIG. The reference numerals quoted in the description of each step are based on FIG.

In step S501, the image reading device B5
1 receives a document reading instruction from the host device B60, proceeds to step S502, the reading unit B53 reads the reference area, and outputs the read output value to the reference generation unit B5.
7, the process proceeds to step S503, and the reference generation unit B57 generates reference data.

If the reading unit B53 has read the white reference area in step S502, the process proceeds to step S5.
03, the white reference data is generated. When the reading unit B53 reads the black reference area in step S502, the black reference data is generated in step S503. The flow of the generation of the white reference data and the generation of the black reference data are individually executed in a predetermined order.

In step S504, a document to be read is read by applying the white reference data and the black reference data.

Referring to FIGS. 20 and 21, a flow of generating a white reference by an image reading apparatus to which the conventional technique is applied will be described.

The main configuration will be described based on the block diagram of FIG. That is, the arithmetic control unit B52a incorporated in the image reading device B51a includes a white reference generation unit B57a, and generates white reference data B61 based on a read output value obtained by reading the white reference region by the reading unit B53.

The white reference generation unit B57a is connected to the dust removal unit B57b, and calculates a component obtained by reading dust adhering to the white reference area from a read output value obtained by reading the white reference area by the reading unit B53. Remove.

Here, the image reading device B51a and the arithmetic control unit B52a shown in FIG.
The image reading device B51 and the arithmetic control unit B52 shown in 2 are expressed from different viewpoints, and the characteristic parts necessary to explain the process of generating the white reference data are emphasized.

An operation flow for generating white reference data will be described with reference to the flowchart of FIG. The reference numerals quoted in the description of each step are based on FIG.

In step S511, the image reading device B5
1a receives a document reading instruction from the host device B60, proceeds to step S512, and the reading unit B53 reads the entire area designated in the white reference area, and transfers the read output value to the white reference generation unit B57a.

In step S513, the dust removing unit B57b
Is reading the dust attached to the white reference area from the read output value in the white reference generation unit B57a, the component data is removed.

In step S514, the white reference generation unit B5
7a calculates the average value of the output values for each pixel in the read output value.

In step S515, the white reference data B61 is formed using the average value of the output values, and the flow of the white reference data generation ends.

In step S516, black reference data is generated. The detailed flow in step S516 will be described later.

In step S517, the original document to be read is read by applying the white reference data and the black reference data.

Referring to FIGS. 22 and 23, a flow of generating a black reference by an image reading apparatus to which the conventional technique is applied will be described.

The main configuration will be described based on the block diagram of FIG. That is, the arithmetic control unit B52b incorporated in the image reading device B51b includes a black reference generation unit B57c, and generates the black reference data B65 based on the read output value obtained by reading the black reference region by the reading unit B53.

The image reading device B51b and the arithmetic control unit B52b shown in FIG.
The image reading device B51 and the arithmetic control unit B52 shown in 2 are expressed from different viewpoints, and the characteristic parts necessary to explain the process of generating the black reference data are emphasized.

An operation flow for generating black reference data will be described with reference to the flowchart of FIG. The reference numerals quoted in the description of each step are based on FIG.

In step S521, the image reading device B5
1b receives a document reading instruction from the host device B60, and proceeds to step S522 to generate white reference data. The flow for executing the generation of the white reference data in step S522 has already been described with reference to FIGS.
Therefore, the detailed description of the flow is omitted here.

In step S523, the reading unit B53 executes reading a predetermined number of times in the light-shielded state, and transfers the data of the read output value to the black reference generation unit B57c.

The number of samples to be read in the light-shielded state, which is executed in step S523, is set to a number necessary to suppress the influence of random noise due to thermal noise as described above.

In step S524, the black reference generation unit B5
In step 7c, an average value of the read output values of the individual read pixels is calculated based on the read output value data transferred from the reading unit B53.

In step S525, the average value of the output values is used to form the black reference data B65, and the flow of the black reference data generation ends.

In step S526, the original document to be read is read by applying the above-described white reference data and black reference data.

[0047]

As described above, in the conventional image reading apparatus and the control method thereof,
There are the following problems.

When the image reading device provides image data according to an instruction from the host device, a white reference and a black reference are generated prior to reading of a document. Therefore,
The time period in which the white reference and the black reference are generated is a non-operation time period before the document is read, and is one of the factors that hinders a rapid reading process.

Accordingly, it is an object of the present invention to provide an image reading apparatus and a control method thereof that can quickly generate a white reference and a black reference and execute image reading early. .

[0050]

In order to solve the above problems, the present invention employs the following means.

1) In the image reading apparatus, means for generating collation data based on white reference and black reference generated prior to reading of a document, storage means for storing the collation data until the next reading, Prior to the generation of the white reference and the black reference, there is provided means for comparing and collating the collation data according to the previous white reference and the black reference with the collation data generated at the time of the current reading.

By adopting this means, the image reading apparatus uses the white reference and the black reference applied to the previous image reading before the generation of the white reference and the black reference to be applied to the current image reading, as collation data. The function of providing a mechanism for detecting the fluctuation via the function is obtained.

2) In the control method of the image reading apparatus, collation data in which respective characteristics of the white reference and the black reference generated prior to reading of the original are clarified are generated, and the reference data of the white reference and the black reference are generated. Prior to the generation, the data is compared and collated with the collation data of the white standard and the black standard applied to the previous image reading.

By adopting this means, the image reading apparatus uses the white reference and the black reference applied to the previous image reading prior to the generation of the white reference and the black reference to be applied to the current image reading, as collation data. To obtain the effect of detecting the fluctuation.

3) In the control method of the image reading apparatus, the method of generating the white reference and the black reference is simplified according to the fluctuation of the white reference and the black reference detected by comparing and comparing the reference data.

By taking this means, an effect is obtained that a method of generating a white reference and a black reference is selected in accordance with the level of stability of the image reading apparatus.

4) A procedure for generating the above-mentioned reference data for the white reference and the black reference, and a procedure for comparing and collating with the above-mentioned reference data prior to the next reading operation to detect a change in the white reference and the black reference. And a procedure for selecting a generation method according to the degree of change of the white reference and the black reference are stored in a computer-readable recording medium as a part of a control program of the image reading apparatus.

By taking this means, the image reading apparatus has an effect that a procedure for selecting an optimal method as a method for generating the white reference and the black reference is provided as a part of the control program.

[0059]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention takes the following forms.

1) In an image reading apparatus for providing image data in accordance with an instruction from a host device, a means for generating white-based and black-based reference data generated by the image reading apparatus prior to image reading; Storage means for storing the data for comparison and comparison between the white reference and the black reference until the next reading execution, and the white reference and the black reference applied to the previous reading before the generation of the white reference and the black reference. A collation unit is provided for comparing and collating the collation data with the collation data generated prior to the current reading.

By adopting this mode, the image reading apparatus uses the white reference and the black reference applied to the previous image reading before generating the white reference and the black reference to be applied to the current image reading, as the comparison data. The function of providing a mechanism for detecting the fluctuation via the function is obtained.

2) In a control method of an image reading apparatus for providing image data according to an instruction of a host device,
The image reading device generates the reference data before generating the white reference and the black reference to be applied to the current image reading, and the comparison data according to the white reference and the black reference applied to the previous image reading. Then, a method of generating a white reference and / or a black reference to be applied to the current image reading is determined.

By adopting this mode, the image reading apparatus can change the white reference and the black reference applied to the previous image reading in advance before generating the white reference and the black reference applied to the current image reading. The effect of detecting is obtained.

3) In the control method of the image reading apparatus, the image reading apparatus reads a white reference area prior to generation of a white reference to be applied to the current image reading. The method of generating the white reference to be applied to the current image reading is determined by generating the data and comparing and collating the data with the matching data relating to the white reference applied to the previous image reading.

By adopting this mode, the image reading apparatus changes the method of generating the white reference and the black reference applied to the current image reading in accordance with the variation with respect to the white reference and the black reference applied to the previous image reading. The effect of determining is obtained.

4) The collation data generated prior to the generation of the white reference applied to the current image reading by the image reading apparatus is obtained by reading the entire area designated by the image reading apparatus in the white reference area. It consists of the average of the output values.

5) Alternatively, in the control method of the image reading apparatus, the collation data generated by the image reading apparatus prior to generation of the white reference applied to the current image reading may be the image reading apparatus. Is composed of the average value of the read output values of one scanning line specified in the white reference area.

6) Further, the collation data generated prior to the generation of the white reference applied to the current image reading by the image reading device includes one scan designated by the image reading device in the white reference region. The line is constituted by an average value of only read output values read by predetermined pixels.

By taking this form, the image reading apparatus has an effect of generating collation data from a read output value obtained by reading the white reference area.

7) Prior to the generation of the white reference applied to the current image reading by the image reading apparatus, the comparison data is generated from the average value of the read output values obtained by reading the white reference area, and the previous image is generated. Compared and collated with the collation data according to the white reference applied to the reading, the difference between the collation data generated this time and the collation data according to the white reference applied to the previous image reading exceeding a predetermined range. A white reference to be applied to the current image reading is newly generated only when is detected.

By adopting this form, the image reading apparatus applies the white reference applied to the previous image reading without generating a new white reference when the white reference is stable and has little variation. The effect is obtained.

8) Prior to the generation of the white reference applied to the current image reading by the image reading device, the comparison data is generated from the average value of the read output values obtained by reading the white reference area, and the previous image is generated. Based on the difference between the matching data generated this time and the matching data according to the white reference applied to the previous image reading, the comparison is performed with the matching data according to the white reference applied to the reading. The white reference applied to the image reading is corrected to be a white reference applied to the current image reading.

By adopting this form, the image reading apparatus performs the necessary correction on the white reference applied to the previous reading without applying a new white reference at the time of reading the current image. Get.

9) Prior to the generation of the white reference applied to the current image reading by the image reading apparatus, the comparison data is generated from the average value of the read output values obtained by reading the white reference area, and the previous image is generated. Compare and collate with the collation data according to the white reference applied to the reading, and read the current image according to the difference between the collation data generated this time and the collation data according to the white reference applied to the previous image reading. The exposure amount in the operation is corrected, and the white reference applied to the previous image reading is set as the white reference applied to the current image reading.

With this configuration, the image reading apparatus sets an exposure amount that matches the white reference applied to the previous reading without generating a new white reference when reading the current image, and reads the image. Is performed.

10) Prior to the generation of the white reference applied to the current image reading by the image reading apparatus, collation data is generated from the average value of the read output values obtained by reading the white reference area, and the previous image is generated. Compare and collate with the collation data according to the white reference applied to the reading, and read the current image according to the difference between the collation data generated this time and the collation data according to the white reference applied to the previous image reading. The gain of the read output value in the operation is corrected, and the white reference applied to the previous image reading is set as the white reference applied to the current image reading.

By taking this form, the image reading apparatus sets the level of the output value that matches the white standard applied to the previous reading without generating a new white standard when reading the current image. Get action.

11) Prior to the generation of the white reference applied to the current image reading by the image reading apparatus, collation data is generated from the average value of the read output values obtained by reading the white reference area, and the previous image is generated. Compare and collate with the collation data according to the white reference applied to the reading, the difference between the collation data according to the white reference applied to the previous image reading and the comparison data generated this time exceeds a predetermined range. If not detected, the white reference applied to the previous reading is applied to the subsequent image reading.

By taking this form, if the image reading apparatus confirms that the amount of light irradiated on the document is stable, it does not generate a new white reference but continues the white reference applied to the previous image reading. The effect of applying is obtained.

12) In the control method of the image reading apparatus, prior to generation of the black reference applied to the current image reading by the image reading apparatus, the black reference area is read from a read output value obtained by reading one scanning line. Matching data composed of the calculated deviation value is generated, and the number of scanning lines to be applied to the generation of the black reference applied to the current image reading by the image reading apparatus is determined based on the matching data.

13) The number of scanning lines applied to the generation of the black reference applied to the current image reading by the image reading apparatus based on the collation data is determined by the deviation value and the reading operation determined in advance based on an evaluation test. Determined based on a correspondence table with the number of lines.

By adopting these forms, the image reading apparatus uses the reference data calculated from the read output value read by one scanning line prior to the generation of the black reference, and the black reference to be applied to the current image reading. An effect of determining the number of read scanning lines in the black reference region for generation is obtained.

14) Prior to the generation of the black reference applied to the current image reading by the image reading apparatus, collation data is generated from the deviation value of the read output value obtained by reading the black reference area, and the previous image is generated. Compare and collate with the collation data according to the white standard applied to the reading, the difference between the collation data generated this time and the collation data according to the black standard applied to the previous image reading exceeds a predetermined range. If not detected, the black reference applied to the previous reading is applied to the subsequent image reading.

By adopting this form, the image reading apparatus does not generate a new black reference and checks the black reference applied to the previous image reading without confirming the stability of the read output of the reading section for reading the image. An effect of continuously applying is obtained.

15) As a part of a program for realizing control of an image reading device that provides image data in accordance with an instruction from a host device, the image reading device uses a white reference and a black reference that are applied to reading of an image this time. Prior to the generation, the procedure for generating the data for comparison, the procedure for comparing and collating with the data for comparison relating to the white reference and the black reference applied to the previous image reading, the procedure for generating the white reference and / or Alternatively, the procedure for determining the method of generating the black reference is stored in a computer-readable recording medium.

By adopting this mode, the image reading apparatus has an effect of providing a procedure for generating and operating collation data.

[0087]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1 to FIG. 17, a description will be given of a basic configuration in which an image reading apparatus according to a representative embodiment of the present invention generates a white reference and a black reference, and a control method thereof.

FIG. 1 is an explanatory diagram showing a principle configuration in which an image reading apparatus to which a representative embodiment of the present invention is applied generates a white reference and a black reference. That is, in the image reading apparatus 1, the reading unit 2 first reads the white reference area or the black reference area and outputs the read data 1.
1 is transferred to the data generating means 5, and the data generating means 5 outputs the verification data 1 based on the read data 11.
Generate 2.

The collation data 12 is transferred to the data collation means 6 and compared with collation data generated in the previous image reading stored in the data storage means 7.

The difference between the collation data generated in the previous image reading and the collation data 12 compared and collated by the data collating means 6 is different from the collation data generated in the previous image reading. Is found, the reference generating means 3 generates reference data 13 based on the read data 11 newly read by the reading means 2.

If the collation data to be compared and collated is not stored in the data storage means 7,
The collation data 12 generated by the data generation means 5 is stored in the data storage means as it is to prepare for the next comparison and collation, and the reference generation means 3 generates the reference data 13 based on the read data 11 read by the reading means 2 again. To prepare for reading an image of a document to be read.

With reference to FIGS. 2 and 3, an overall schematic flow in which an image reading apparatus to which the representative embodiment of the present invention is applied generates a white reference and a black reference will be described.

The main configuration will be described based on the block diagram of FIG. That is, the arithmetic control unit B02 included in the image reading device B01 includes a reference generation unit B07, and generates a white reference or a black reference based on a read output value obtained by reading the white reference region or the black reference region by the reading unit B03, respectively. I do.

The data generation section B04 provided in the arithmetic control section B02 is provided with a reading section B03 before the reference generation section B07 generates a white reference or a black reference.
In response to the transfer of the read output value, the matching data is generated, and the matching data is transferred to a data matching unit or a data storage unit.

Further, the control program B08 for controlling the image reading device B01 executes generation of a control system of the image reading device using a computer-readable recording medium.

An overall operation flow for generating reference data including white reference data and black reference data will be described with reference to the flowchart of FIG. The reference numerals quoted in the description of each step are based on FIG.

In step S001, the image reading device B0
1 receives an image reading instruction from the host device B10,
Proceeding to step S002, the reading unit B03 reads the reference area and transfers the read data obtained by reading the reference area to the data generation unit B04.

In step S003, the data generator B04 generates collation data based on the read data obtained by reading the reference area.

In step S004, the data storage unit B06
Search for collation data related to the reference data applied to the previous reading to be stored in.

If the data storage unit B06 finds collation data related to the reference data applied to the previous reading in step S005, the process proceeds to step S006, and the collation data generated by the data generation unit for the current reading is obtained. The data is compared and compared with the collation data relating to the reference data applied to the previous reading found in the data storage unit B06.

As a result of the comparison and collation of the collation data in step S007, if a difference exceeding a predetermined reference value is found in both of them, it is determined that there is a change in the collation data, and the flow advances to step S008. The reading unit B03 executes the reading related to the reference data generation again, and transfers the read data acquired by the reading to the reference generating unit B07.
Generates predetermined reference data and reads the current image.

In step S009, the data generation unit B
The collation data generated by the data generation unit 04 is transferred to the data storage unit B06, replaced with the collation data already saved, and saved to prepare for the next image reading.

In step S010, image reading of a document to be read is started based on the reference data.

If the collation data relating to the reference data applied to the previous reading is not found in the data storage unit B06 in the above step S005, it is determined that the current image reading is the first image reading. ,
Proceed to step S008.

Further, in the step S007, when the comparison and collation of the collation data do not find any difference exceeding a predetermined level, it is determined that there is no change in the collation data. , Step S
The process proceeds to 012, where the reference data applied to the previous image reading is designated as the reference data applied to the current image reading, and the process proceeds to step S010.

Referring to FIGS. 4 to 12, a description will be given of a flow in which the image reading apparatus to which the representative embodiment of the present invention is applied generates a white reference. That is, FIG. 4 is a block diagram showing a main configuration, and FIG. 5 is a flowchart showing an operation flow. 6 to 12 are flow charts for explaining details of specific steps in the flow chart shown in FIG.

The main configuration will be described based on the block diagram of FIG. That is, the arithmetic control unit B02a incorporated in the image reading device B01a includes a white reference generation unit B07a and is connected to the dust removal unit B07b. The white reference generation unit B07a generates white reference data B11 based on a read output value obtained by reading the white reference area by the reading unit B03.
Generate

The image reading device B01a and the arithmetic control unit B02a shown in FIG. 4 are the same as the image reading device B01 and the arithmetic control unit B shown in FIG.
02 is expressed from different viewpoints and emphasizes the characteristic parts necessary for explaining the process of generating the white reference data.

The data generating unit B04 is provided with the reading unit B.
03 generates collation data based on the read output value obtained by reading the white reference area, and transfers the collation data to the data collation unit B05 or the data storage unit B06.

The exposure time setting section B12 adjusts a shutter gate and the like when reading a document to be read, and sets an exposure time when the reading section B03 reads the document.

The gain control section B13 is provided with a reading section B03.
Controls the amplification factor when amplifying the read output value obtained by reading the original to be read, and outputs the white reference generation unit B
07a, the level of the read value to be transferred is set.

An operation flow for generating white reference data will be described with reference to the flowchart of FIG. The reference numerals quoted in the description of each step are based on FIG.

In step S101, the image reading device B0
1a receives an image reading instruction from the host device B10, and proceeds to step S102 to generate collation data.

Details of the generation of the collation data in step S102 are shown in FIG. 6, FIG. 7, or FIG.

Based on FIG. 6, the above-mentioned step S102 is performed.
A detailed flow of applying a representative embodiment of the present invention in the flow of generating the data for verification shown in FIG.

In step S121, the reading unit B03 reads the entire white reference region, and transfers the read output value to the data generation unit B04.

In step S122, the data generator B04 calculates an average value of the individual data of the read output values transferred from the reader B03.

In step S123, the above average value is designated as collation data relating to the white reference data applied to the current image reading, and the flow of the collation data generation ends.

Based on FIG. 7, the aforementioned step S102
A detailed flow of applying another representative embodiment of the present invention in the flow of collation data generation shown in FIG.

In step S131, the reading section B03 reads a specific reading line designated in advance in the white reference area, and outputs the read output value to the data generating section B04.
Transfer to

In step S132, the data generator B04 calculates an average value of the individual data of the read output values transferred from the reader B03.

In step S133, the above average value is designated as collation data relating to the white reference data to be applied to the current image reading, and the flow of the collation data generation ends.

Based on FIG. 8, the aforementioned step S102
A detailed flow of applying another representative embodiment of the present invention in the flow of collation data generation shown in FIG.

In step S141, the reading section B03 reads a specific reading line specified in advance in the white reference area, and outputs the read output value to the data generating section B04.
Transfer to

In step S142, the data generator B04 extracts only the read output value of a specific pixel designated in advance from the individual data of the read output value transferred from the reader B03.

In step S143, the data generator B04 calculates the average of the read output values of the specific pixels.

In step S144, the above average value is designated as collation data relating to the white reference data applied to the current image reading, and the flow of the collation data generation ends.

Returning to FIG. 5, the description of the flow will be continued.

At step S103, the data storage unit B06
Are searched for collation data according to the white color standard applied to the previous image reading.

If the collation data relating to the white reference applied to the previous image reading is found in step S104, the process proceeds to step S105, where the data collation unit B05 generates the collation data generated based on the current image reading instruction. Then, the data is compared and collated with the collation data based on the white reference applied to the previous image reading extracted from the data storage unit B06.

In step S106, the collation data generated based on the current image reading instruction and the collation data based on the white reference applied to the previous image reading extracted from the data storage unit B06 are previously stored. If a difference exceeding the predetermined reference value is found, it is determined that there is a change in the collation data, and the flow advances to step S107 to generate white reference data.

The details of the generation of the white reference data in step S107 are described in FIGS. 9, 10, 11 or 1.
According to 2.

Referring to FIG. 9, a detailed flow of one typical embodiment of the present invention applied to the flow of white reference data generation shown in step S107 in FIG. 5 will be described.

In step S151, the reading section B03 reads the entire area specified by the white reference area, and transfers the read output value to the white reference generation section B07a.

In step S152, the white reference generation unit B07a verifies the read data transferred from the reading unit B03 and detects dust in the optical path. If the dust removal unit B07b detects the dust, the component data obtained by reading the dust is read. Is removed.

In step S153, the white reference generation unit B0
7a calculates the average value of the read values for each pixel based on the read data after the dust removal.

In step S154, the average value is used to form white reference data to be applied to the current image reading, and the flow of the white reference data generation ends.

Referring to FIG. 10, a detailed flow in which another representative embodiment of the present invention is applied to the flow of generating white reference data shown in step S107 in FIG. 5 will be described.

In step S161, the presence or absence of the white reference data applied to the previous reading is checked. If the white reference data applied to the previous reading is found, the process proceeds to step S16.
Proceeding to 2, the difference value between the collation data generated this time and the collation data according to the white reference applied to the previous reading is calculated.

In step S163, a correction value to be applied to the white reference data applied to the previous reading is calculated based on the difference value, and the flow advances to step S164 to apply the correction value to the previous reading. The correction is executed by adding to the obtained white reference data.

This is based on the fact that even if the light amount fluctuates and the output value of the reading unit B03 fluctuates, the relationship between the output values of the read pixels constituting the reading unit B03 does not fluctuate. This realizes a method of obtaining white reference data to be applied to the current reading by sliding white reference data applied to the previous reading with a correction value calculated from a variation value of the collation data.

In step S165, the above-described correction is performed on the white reference data applied to the previous reading to form white reference data to be applied to the current image reading.

If the white reference data applied to the previous reading is not found in step S161, the flow proceeds to step S167, where the reading unit B03 reads the entire area by designating the white reference area, and outputs the read output value. The data is transferred to the white reference generation unit B07a.

In step S168, the white reference generation unit B07a verifies the read data transferred from the reading unit B03 and detects dust in the optical path, and the dust removal unit B07b reads the component data obtained by reading the dust. Is removed.

In step S169, the white reference generation unit B0
7a calculates an average value of the read values for each pixel based on the read data after removing the dust, and proceeds to step S165 to use the average value to apply the white reference to the present reading. The data is configured, and the flow of the white reference data generation ends.

Referring to FIG. 11, a detailed flow in which another representative embodiment of the present invention is applied to the flow of white reference data generation shown in step S107 in FIG. 5 will be described.

In step S171, the presence or absence of the white reference data applied to the previous reading is checked. If the white reference data applied to the previous reading is found, step S172 is performed.
To calculate the difference value between the collation data generated this time and the collation data related to the white reference data applied to the previous reading.

In step S173, a correction rate value to be applied to the exposure time applied to the previous reading is calculated based on the difference value, and the flow advances to step S174 to apply the correction rate value to the previous reading. The correction is executed by multiplying the applied exposure time, and the correction is completed, and the exposure time value is stored in the exposure time setting section B12.

This is based on the fact that even if the light amount fluctuates and the output value of the reading unit B03 fluctuates, the relationship between the output values of the read pixels constituting the reading unit B03 does not fluctuate. By increasing or decreasing the exposure time applied to the previous reading with the correction value calculated from the variation value of the data for collation, the white reference data applied to the current reading is diverted as it is to the white reference data applied to the current reading. The method is realized.

In step S175, the white reference data applied to the previous reading is used as it is as white reference data to be applied to the current image reading.

If the white reference data applied to the previous reading is not found in step S171, the process proceeds to step S176, where the reading unit B03 reads the entire area specified by the white reference area, and reads the read output value. The data is transferred to the white reference generation unit B07a.

In step S177, the white reference generating unit B07a verifies the read data transferred from the reading unit B03 and detects dust in the optical path. If the dust is detected in the optical path, the dust removing unit B07b reads the component data. Is removed.

In step S178, the white reference generation unit B0
7a calculates an average value of the read values for each pixel based on the read data after removing the dust, and proceeds to step S179 to convert the white reference data to be applied to the current read with the average value. Then, the flow of the white reference data generation ends.

Referring to FIG. 12, a detailed flow in which another representative embodiment of the present invention is applied to the flow of generating white reference data shown in step S107 in FIG. 5 will be described.

In step S181, the presence or absence of the white reference data applied to the previous reading is checked. If the white reference data applied to the previous reading is found, step S182 is performed.
To calculate the difference value between the collation data generated this time and the collation data related to the white reference data applied to the previous reading.

In step S183, a correction rate value to be applied to the gain ratio applied to the previous reading is calculated based on the difference value, and the flow advances to step S184 to apply the correction rate value to the previous reading. The correction is performed by multiplying the gain ratio by the applied gain ratio and stored in the gain control unit B13.

This is based on the fact that even if the light amount fluctuates and the output value of the reading unit B03 fluctuates, the relationship between the output values of the read pixels constituting the reading unit B03 does not fluctuate. By sliding the read value with the correction value calculated from the variation value of the collation data, the white reference data applied to the current reading is realized by using the white reference data applied to the previous reading as it is. is there.

In step S185, the white reference data applied to the previous reading is used as it is as white reference data to be applied to the current image reading.

If the white reference data applied to the previous reading is not found in step S181, the flow proceeds to step S186, where the reading unit B03 reads the entire area by designating the white reference area and outputs the read output value. The data is transferred to the white reference generation unit B07a.

In step S187, the white reference generation unit B07a verifies the read data transferred from the reading unit B03 and detects dust in the optical path. If the dust removal unit B07b detects the dust, the component data obtained by reading the dust is read. Is removed.

In step S188, the white reference generation unit B0
7a calculates an average value of the read values for each pixel based on the read data after the dust removal, and proceeds to step S189 to convert the white reference data to be applied to the current read with the average value. Then, the flow of the white reference data generation ends.

Returning to FIG. 5, the description of the operation flow will be continued.

In step S108, the collation data generated by the current reading instruction is stored in the data storage unit B06.

In step S106, as a result of comparison and collation between the collation data generated by the current reading instruction and the collation data related to the white reference data generated by the previous reading, the two have exceeded the predetermined level. If no difference is found, it is determined that there is no change in the collation data, and the flow advances to step S112 to designate the reference data applied to the previous image reading as the reference data applied to the current image reading. I do.

The flow further advances to step S109 to determine black reference data. The details of the black reference data determination flow will be described later.

In step S110, reading of the document to be read is started.

Referring to FIGS. 13 to 16, a description will be given of a flow in which the image reading apparatus to which the representative embodiment of the present invention is applied generates a black reference. That is, FIG. 13 is a block diagram showing a main configuration, and FIG. 14 is a flowchart showing an operation flow. FIG. 15 and FIG.
15 is a flowchart illustrating details of specific steps in the flowchart shown in FIG.

The main configuration will be described based on the block diagram of FIG. That is, the arithmetic control unit B02b incorporated in the image reading device B01b includes a black reference generation unit B07c, and generates the black reference data B15 based on the read output value obtained by reading the black reference region by the reading unit B03.

Here, the image reading device B01b and the arithmetic control unit B02b shown in FIG. 13 represent the image reading device B01 and the arithmetic control unit B02 shown in FIG. Characteristic parts necessary for explaining the process of generating the are emphasized.

The data generating unit B04 is provided with the reading unit B.
03 generates collation data based on the read output value obtained by reading the black reference area, and transfers the collation data to the data collation unit B05 or the data storage unit B06.

The sample number table B16 shows the correspondence between the deviation value indicating the degree of variation of the output value obtained by reading the black reference area and the number of samples read from the black reference area determined by an evaluation test performed in advance. Stores tables.

That is, if the deviation value of the output value obtained by reading the black reference area is small, the number of samples for reading the black reference area is set in the correspondence table in accordance with the deviation value.

The operation flow for generating the black reference data will be described with reference to the flowchart of FIG. The reference numerals quoted in the description of each step are based on FIG.

In step S201, the image reading device B0
1b receives an image reading instruction from the host device B10, and proceeds to step S202 to determine white reference data. Since the details of the flow for determining the white reference data have already been described with reference to FIGS. 4 to 12, the detailed description is omitted here.

In step S203, collation data is generated. The details of the flow for generating the above-mentioned collation data are shown in FIG.

Based on FIG. 15, the aforementioned step S20
The details of the collation data generation flow executed in step 3 will be described.

In step S203a, the reading unit B03
Performs one reading while the black reference area is shielded, and transfers the read output value to the data generation unit B04.

At step S203b, the data generation unit B0
Reference numeral 4 calculates an average value of the read output values of the individual pixels read from the read output values.

In step S203c, data generation unit B0
Reference numeral 4 calculates a standard deviation value from the difference between the read output value of each pixel and the average value.

In step S203c, data generation unit B0
Reference numeral 4 designates the standard deviation value as collation data relating to the black reference data in the present reading instruction, and terminates the flow of the collation data generation.

Returning to FIG. 14, the description of the flow will be continued.

In step S204, the data storage unit B06 is examined to search for collation data relating to the black reference data applied to the previous image reading.

If data for collation relating to the black reference data applied to the previous image reading is found in the data storage unit B06 in step S205, the process proceeds to step S206, where the data collation unit B05 compares the collation data generated this time with the collation data generated this time. The comparison and collation with the collation data concerning the black reference data applied to the previous image reading are performed.

In step S207, if a difference between the collation data generated this time and the collation data relating to the black reference data applied to the previous image reading exceeding a predetermined value is found, the black reference is used. It is determined that a change has occurred, and the process proceeds to step S208 to generate black reference data. Details of the flow of generating the black reference data in step S208 are shown in FIG.

Referring to FIG. 16, step S20 is performed.
8 will be described in detail.

In step S208a, the standard deviation value generated this time as the data for collation is specified, and in step S208
Proceeding to b, the number of samples corresponding to the standard deviation value is selected from the sample number table.

In step S208c, the reading unit B03
Reads the black reference area in the light-shielded state according to the number of samples selected above, and outputs the read output value to the black reference
07c.

In step S208d, the black reference generation unit B07c calculates an average value for each pixel based on the read output value.

In step S208e, the black reference data is constructed using the average value of the read output calculated for each pixel, and the flow of the black reference data generation ends.

Returning to FIG. 14, the description of the flow will be continued.

In step S209, the collation data generated this time is stored in the data storage unit B06.

In step S205, if no collation data relating to the black reference data applied to the previous image reading is found in the data storage unit B06,
Proceeding to step S208, black reference data is generated.

In step S207, a difference exceeding a prescribed value determined in advance is found from the result of comparison and collation between the collation data generated this time and the collation data relating to the black reference data applied to the previous image reading. If not, it is determined that there is no change between them, and the process proceeds to step S212, where the previous black reference data is designated as it is as black reference data to be applied to the current image reading.

In step S210, the reading of the original to be read is started by applying the determined white reference data and black reference data.

[0195]

According to the present invention, the following effects can be expected.

1) In an image reading apparatus for providing image data in accordance with an instruction from a host apparatus, a means for generating white-based and black-based collation data generated by the image reading apparatus prior to image reading; Storage means for storing the data for comparison and comparison between the white reference and the black reference until the next reading execution, and the white reference and the black reference applied to the previous reading before the generation of the white reference and the black reference. A collation unit is provided for comparing and collating the collation data with the collation data generated prior to the current reading.

By adopting this means, the image reading apparatus can compare the white reference and the black reference applied to the previous image reading with the collation data before generating the white reference and the black reference to be applied to the current image reading. The effect of providing a mechanism for detecting the fluctuation via the control unit is obtained.

2) In a control method of an image reading apparatus for providing image data according to an instruction of a host device,
The image reading device generates the reference data before generating the white reference and the black reference to be applied to the current image reading, and the comparison data according to the white reference and the black reference applied to the previous image reading. Then, a method of generating a white reference and / or a black reference to be applied to the current image reading is determined.

By adopting this means, the image reading apparatus can preliminarily generate the white reference and the black reference to be applied to the current image reading, and change the white reference and the black reference applied to the previous image reading in advance. The effect of detecting is obtained.

3) In the control method of the image reading apparatus, the image reading apparatus reads a white reference area prior to generation of a white reference applied to the current image reading, and uses the average value of the read output values to perform comparison. The method of generating the white reference to be applied to the current image reading is determined by generating the data and comparing and collating the data with the matching data relating to the white reference applied to the previous image reading.

By taking this means, the image reading apparatus adjusts the generation method of the white reference and the black reference applied to the current image reading in accordance with the variation with respect to the white reference and the black reference applied to the previous image reading. Since the determination is made, an effect is obtained that the most efficient generation method of the white reference and the black reference is selected according to the state of the image reading apparatus.

4) The collation data generated prior to the generation of the white reference applied to the current image reading by the image reading apparatus is obtained by reading the entire area designated by the image reading apparatus in the white reference area. It consists of the average of the output values.

5) Alternatively, in the control method of the image reading device, the collation data generated by the image reading device prior to generation of the white reference applied to the current image reading may be the image reading device. Is composed of the average value of the read output values of one scanning line specified in the white reference area.

6) Further, the collation data generated prior to the generation of the white reference applied to the current image reading by the image reading apparatus is one scan designated by the image reading apparatus in the white reference area. The line is constituted by an average value of only read output values read by predetermined pixels.

By adopting this means, the image reading apparatus generates collation data from the read output value obtained by reading the white reference area, and has the effect of quickly determining the fluctuation of the white reference.

7) Prior to the generation of the white reference applied to the current image reading by the image reading apparatus, collation data is generated from the average value of read output values obtained by reading the white reference area, and the previous image is generated. Compared and collated with the collation data according to the white reference applied to the reading, the difference between the collation data generated this time and the collation data according to the white reference applied to the previous image reading exceeding a predetermined range. A white reference to be applied to the current image reading is newly generated only when is detected.

By adopting this means, the image reading apparatus applies the white reference applied to the previous image reading without generating a new white reference when the white reference is stable and has little variation. Therefore, an effect of efficiently operating the optimal white reference is obtained.

8) Prior to the generation of the white reference applied to the current image reading by the image reading apparatus, the comparison data is generated from the average value of the read output values obtained by reading the white reference area, and the previous image is generated. Based on the difference between the matching data generated this time and the matching data according to the white reference applied to the previous image reading, the comparison is performed with the matching data according to the white reference applied to the reading. The white reference applied to the image reading is corrected to be a white reference applied to the current image reading.

By taking this means, the image reading apparatus can apply the necessary correction to the white reference applied to the previous reading without generating a new white reference when reading the current image. So you can
This has the effect of minimizing the operation time required to generate the white reference executed prior to image reading.

9) Prior to the generation of the white reference applied to the current image reading by the image reading apparatus, the comparison data is generated from the average value of the read output values obtained by reading the white reference area, and the previous image is generated. Compare and collate with the collation data according to the white reference applied to the reading, and read the current image according to the difference between the collation data generated this time and the collation data according to the white reference applied to the previous image reading. The exposure amount in the operation is corrected, and the white reference applied to the previous image reading is set as the white reference applied to the current image reading.

By taking this means, the image reading apparatus sets an exposure amount which matches the white reference applied to the previous reading without generating a new white reference when reading the current image, and reads the image. Is performed, the effect of minimizing the operation time required to generate the white reference executed prior to the image reading is obtained.

10) Prior to the generation of the white reference applied to the current image reading by the image reading apparatus, collation data is generated from the average value of read output values obtained by reading the white reference area, and the previous image is generated. Compare and collate with the collation data according to the white reference applied to the reading, and read the current image according to the difference between the collation data generated this time and the collation data according to the white reference applied to the previous image reading. The gain of the read output value in the operation is corrected, and the white reference applied to the previous image reading is set as the white reference applied to the current image reading.

By taking this measure, the image reading apparatus sets the level of the output value that matches the white standard applied to the previous reading without generating a new white standard when reading the current image. In addition, the operation time required for generating the white reference executed prior to the image reading can be minimized.

11) Prior to the generation of the white reference applied to the current image reading by the image reading apparatus, collation data is generated from the average value of read output values obtained by reading the white reference area, and the previous image is generated. Compare and collate with the collation data according to the white reference applied to the reading, the difference between the collation data according to the white reference applied to the previous image reading and the comparison data generated this time exceeds a predetermined range. If not detected, the white reference applied to the previous reading is applied to the subsequent image reading.

By taking this measure, if the image reading apparatus confirms that the amount of light irradiating the document is stable, it does not generate a new white reference but continues the white reference applied to the previous image reading. Since the present invention is applied, the effect of minimizing the operation time required for generating the white reference executed prior to the image reading is obtained.

12) In the control method of the image reading apparatus, prior to generation of the black reference applied to the current image reading by the image reading apparatus, a black reference area is read from a read output value by one scanning line. Matching data composed of the calculated deviation value is generated, and the number of scanning lines to be applied to the generation of the black reference applied to the current image reading by the image reading apparatus is determined based on the matching data.

13) The number of scanning lines to be applied to the generation of the black reference applied to the current image reading by the image reading apparatus according to the collation data is determined by the deviation value and the reading operation determined in advance based on an evaluation test. Determined based on a correspondence table with the number of lines.

By taking these means, the image reading apparatus can use the collation data calculated from the read output value read by one scanning line prior to the generation of the black reference to generate the black reference to be applied to the current image reading. Since the number of scanning lines to be read in the black reference area to be generated is determined, the effect of minimizing the operation time required to generate the black reference executed prior to image reading is obtained.

14) Prior to the generation of the black reference applied to the current image reading by the image reading apparatus, collation data is generated from the deviation value of the read output value obtained by reading the black reference area, and the previous image is generated. Compare and collate with the collation data according to the white standard applied to the reading, the difference between the collation data generated this time and the collation data according to the black standard applied to the previous image reading exceeds a predetermined range. If not detected, the black reference applied to the previous reading is applied to the subsequent image reading.

By adopting this means, the image reading apparatus does not generate a new black reference if the read output of the reading section for reading an image is stable, but uses the black reference applied to the previous image reading. Since the application is continuously performed, the operation time required for generating the black reference to be executed prior to the image reading can be minimized.

15) As a part of a program for controlling an image reading apparatus that provides image data in accordance with an instruction from a host device, the image reading apparatus uses a white reference and a black reference applied to reading of an image this time. Prior to the generation, the procedure for generating the data for comparison, the procedure for comparing and collating with the data for comparison relating to the white reference and the black reference applied to the previous image reading, the procedure for generating the white reference and / or Alternatively, the procedure for determining the method of generating the black reference is stored in a computer-readable recording medium.

[0222] By taking this means, the image reading apparatus has an effect that the image reading apparatus is provided with a procedure for generating and operating collation data and efficiently generating a white reference and a black reference generated prior to image reading. obtain.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration according to a representative embodiment of the present invention.

FIG. 2 is a block diagram according to a representative embodiment of the present invention.

FIG. 3 is a flowchart according to a representative embodiment of the present invention.

FIG. 4 is a block diagram of white reference generation according to a representative embodiment of the present invention.

FIG. 5 is a flowchart for white reference generation according to a representative embodiment of the present invention.

FIG. 6 is a flowchart for white reference generation according to a representative embodiment of the present invention.

FIG. 7 is a flowchart for white reference generation according to a representative embodiment of the present invention.

FIG. 8 is a flowchart for white reference generation according to a representative embodiment of the present invention.

FIG. 9 is a flowchart for white reference generation according to a representative embodiment of the present invention.

FIG. 10 is a flowchart for white reference generation according to a representative embodiment of the present invention.

FIG. 11 is a flowchart for white reference generation according to a representative embodiment of the present invention.

FIG. 12 is a flowchart for white reference generation according to a representative embodiment of the present invention.

FIG. 13 is a block diagram of black reference generation according to a representative embodiment of the present invention.

FIG. 14 is a flowchart for black reference generation according to a representative embodiment of the present invention.

FIG. 15 is a flowchart for black reference generation according to a representative embodiment of the present invention.

FIG. 16 is a flowchart for black reference generation according to a representative embodiment of the present invention.

FIG. 17 is an explanatory diagram of a configuration according to an embodiment to which a conventional technique is applied.

FIG. 18 is a block diagram according to an embodiment to which a conventional technique is applied.

FIG. 19 is a flowchart according to an embodiment to which a conventional technique is applied.

FIG. 20 is a block diagram showing white reference generation according to an embodiment to which the related art is applied.

FIG. 21 is a flowchart for white reference generation according to an embodiment to which the related art is applied.

FIG. 22 is a block diagram of a black reference generation according to an embodiment to which the related art is applied.

And FIG. 23 is a flowchart for generating a black reference according to an embodiment to which the related art is applied.

[Explanation of symbols]

 1: Image reading device 2: Reading means 3: Reference generation means 5: Data generation means 6: Data collation means 7: Data storage means 11: Read data 12: Verification data 13: Reference data B01, B01a, B01b: Image reading Apparatus B02, B02a, B02b: Operation control unit B03: Reading unit B04: Data generation unit B05: Data collation unit B06: Data storage unit B07: Reference generation unit B07a: White reference generation unit B07b: Dust removal unit B07c: Black reference generation Section B08: control program B11: white reference data B12: exposure time setting section B13: gain control section B15: black reference data B16: sample number table

Claims (15)

[Claims] 1. An image reading apparatus for providing image data in accordance with an instruction from a host device, comprising: means for generating white-based and black-based collation data generated by the image reading apparatus prior to image reading; Storage means for storing the data for comparison and comparison of the white reference and the black reference until the next reading execution; and, prior to generation of the white reference and the black reference, the white reference and the black reference applied to the previous reading are stored. An image reading apparatus comprising: a collation unit configured to compare and collate collation data with collation data generated prior to the current reading. 2. A method for controlling an image reading apparatus for providing image data in accordance with an instruction from a host apparatus, wherein the image reading apparatus performs the collation prior to generation of a white reference and a black reference applied to reading of a current image. Of the white and / or black standards to be applied to the current image reading by generating the data for use and comparing and collating with the matching data for the white and black standards applied to the previous image reading A method for controlling an image reading device. 3. A method for controlling an image reading apparatus according to claim 1, wherein said image reading apparatus reads a white reference area prior to generation of a white reference applied to the current image reading, based on an average value of read output values. A method of generating a white reference to be applied to the current image reading by generating data and comparing and collating the data with the matching data relating to the white reference applied to the previous image reading. 3. The control method of the image reading device according to 2. 4. The method for controlling an image reading device according to claim 1, wherein the collation data generated by the image reading device prior to generation of a white reference applied to current image reading is:
4. The method according to claim 3, wherein the image reading device is configured to have an average value of read output values obtained by reading all regions specified in the white reference region. 5. The method for controlling an image reading device according to claim 1, wherein the collation data generated by the image reading device before generating a white reference applied to the current image reading is:
4. The control method according to claim 3, wherein the image reading apparatus has an average value of read output values of one scanning line specified in a white reference area. 6. The control method for an image reading apparatus according to claim 1, wherein the collation data generated by the image reading apparatus prior to generation of a white reference applied to current image reading is:
6. The image reading apparatus according to claim 5, wherein the image reading apparatus has an average value of only read output values of pixels determined in advance in one scanning line designated in a white reference area. Control method. 7. A control method for an image reading apparatus according to claim 1, wherein prior to generation of a white reference applied to the current image reading by said image reading apparatus, comparison is performed based on an average value of read output values obtained by reading a white reference area. The comparison data generated for the previous image reading is compared with the comparison data according to the white reference applied to the previous image reading, and the comparison data generated this time is the comparison data according to the white reference applied to the previous image reading. 4. The method according to claim 3, wherein a white reference to be applied to the current image reading is newly generated only when a difference exceeding a predetermined range is detected. 8. The method for controlling an image reading device according to claim 1, wherein prior to generation of a white reference applied to the current image reading by the image reading device, comparison is performed based on an average value of read output values obtained by reading a white reference region. The comparison data is generated and compared with the comparison data according to the white reference applied to the previous image reading, and the comparison data generated this time and the comparison data according to the white reference applied to the previous image reading are compared. 4. The image reading apparatus according to claim 3, wherein a correction is made to the white reference applied to the previous image reading in accordance with the difference between the white reference and the white reference applied to the current image reading. Control method. 9. The method for controlling an image reading apparatus according to claim 1, wherein prior to generation of a white reference applied to the current image reading by the image reading apparatus, comparison is performed based on an average value of read output values obtained by reading a white reference area. The comparison data is generated and compared with the comparison data according to the white reference applied to the previous image reading, and the comparison data generated this time and the comparison data according to the white reference applied to the previous image reading are compared. The exposure amount in the current image reading operation is corrected in accordance with the difference between the first and second image reading operations, and the white reference applied to the previous image reading is used as the white reference applied to the current image reading. 3. The method for controlling an image reading device according to claim 1. 10. The method for controlling an image reading device according to claim 1, wherein prior to generation of a white reference applied to the current image reading by the image reading device, comparison is performed based on an average value of read output values obtained by reading a white reference region. The comparison data is generated and compared with the comparison data according to the white reference applied to the previous image reading, and the comparison data generated this time and the comparison data according to the white reference applied to the previous image reading are compared. And correcting the gain of the read output value in the current image reading operation in accordance with the difference between the current image reading operation and the white standard applied to the previous image reading as the white standard applied to the current image reading. A control method for an image reading device according to claim 3. 11. The method for controlling an image reading device according to claim 1, wherein prior to generation of a white reference applied to the current image reading by the image reading device, comparison is performed based on an average value of read output values obtained by reading a white reference region. The comparison data generated for the previous image reading is compared with the comparison data according to the white reference applied to the previous image reading, and the comparison data generated this time is the comparison data according to the white reference applied to the previous image reading. 4. The image reading apparatus according to claim 3, wherein when a difference exceeding a predetermined range is not detected, the white reference applied to the previous reading is applied to the subsequent image reading. Control method. 12. The method according to claim 1, wherein the image reading device reads a black reference area by one scanning line prior to generating a black reference applied to the current image reading. Generating collation data composed of deviation values calculated from the values, and determining, by the collation data, the number of scanning lines to be applied to the generation of the black reference applied to the current image reading by the image reading apparatus. The method for controlling an image reading device according to claim 2, wherein: 13. The method for controlling an image reading apparatus according to claim 1, wherein the number of scanning lines applied to the generation of a black reference applied to the current image reading by the image reading apparatus is determined in advance by an evaluation test based on the collation data. 13. The control method of the image reading apparatus according to claim 12, wherein the determination is performed based on a correspondence table between the deviation value and the number of read operation lines determined based on the reference value. 14. The method for controlling an image reading device according to claim 1, wherein prior to generation of a black reference applied to the current image reading by the image reading device, a collation is performed based on a deviation value of a read output value obtained by reading a black reference region. The comparison data is generated and compared with the comparison data according to the white reference applied to the previous image reading, and the comparison data generated this time is the comparison data according to the black reference applied to the previous image reading. 13. The image reading apparatus according to claim 12, wherein if a difference exceeding a predetermined range is not detected, the black reference applied to the previous reading is applied to the subsequent image reading. Control method. 15. A recording medium for storing a program for controlling an image reading apparatus that provides image data in accordance with an instruction from a host apparatus, wherein the image reading apparatus applies a white reference and a black color for reading a current image. A procedure for generating the reference data prior to the generation of the reference, a procedure for comparing and collating with the reference data for the white reference and the black reference applied to the previous image reading, and a white reference for the current image reading And / or a procedure for determining a method of generating a black reference.