JP2000069289A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically operate an image reader with capability corresponding to a mounted contact image sensor, while reducing cost. SOLUTION: A CPU 11 places a white reference board or a white roller to a read position of a mounted contact image sensor 2 and allows a CIS drive section 14 to conduct drive operation, in response to plural kinds of contact image sensors sequentially. Then the CPU 11 monitors the peak level of an output signal sequentially outputted from the contact image sensor 2 to discriminate the kind of the mounted contact image sensor 2. When read of an actual image is conducted, the CPU 11 allows the CIS drive section 14 and an image processing section 15 to conduct the drive operation and the image processing, in response to the kind identified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image reading apparatus for reading an image using a contact image sensor.

[0002]

2. Description of the Related Art A contact image sensor accumulates charges generated by a photoelectric conversion element during one cycle of a shift pulse. Then, the contact image sensor sequentially outputs the charges accumulated during one cycle of the shift pulse in synchronization with the transfer clock.

An image reading apparatus that reads an image using such a contact image sensor supplies the shift pulse or the transfer clock to the contact image sensor to drive the contact image sensor, The sensor performs image processing such as binarization for obtaining image data in a predetermined form from an analog signal formed by serially outputting electric charges.

There are a plurality of contact type image sensors having different reading speeds. The interface of these contact image sensors is common regardless of the reading speed and the maker if it is a standard product.

[0005] However, these contact image sensors require different shift pulse and transfer clock frequencies. In addition, the speed of image processing, the threshold value for binarization, and the like also change depending on the difference in reading speed.

[0006] Therefore, by creating firmware so that the operation corresponding to each of a plurality of types of contact image sensors can be performed by switching, the reading speed differs by selecting the contact image sensor to be mounted. Realization of a plurality of models has been performed.

[0007]

In this type of image reading apparatus, the operation corresponding to which contact image sensor is performed is manually set manually.

For this reason, it is necessary to surely recognize the attached contact image sensor and to perform an appropriate setting, which is troublesome. If a setting error occurs, a correct reading operation cannot be performed. There was a problem of getting it.

There is also a method of providing a port capable of identifying the type in the contact image sensor and automatically determining the type of the mounted contact image sensor. However, the standard type of contact image sensor cannot be used. There was a problem that the cost was increased.

[0010] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a contact image sensor which is mounted without applying means for identifying the type to the contact image sensor. An image reading device that can automatically identify the type, thereby reducing costs by using a standard product as a contact image sensor and automatically operating as a device with the ability according to the attached contact image sensor To provide.

[0011]

In order to achieve the above object, the present invention provides a driving means such as a CIS driving unit which can drive a plurality of types of contact image sensors each having a different standard accumulation time; An image processing unit such as an image processing unit capable of selectively performing predetermined image processing according to each of the plurality of types of contact image sensors on an output signal of the mounted contact image sensor, After a predetermined reference surface such as a white reference plate or a white roller is positioned at the reading position of the mounted contact image sensor, a driving operation corresponding to each of the plurality of types of contact image sensors is performed by the driving unit. Test drive control means for sequentially performing the test drive control means and the drive means under the control of the test drive control means The peak level of the output signal at each accumulation time sequentially output by the mounted contact image sensor due to the movement is within a predetermined allowable range according to the accumulation time, from the accumulation time of the mounted contact image sensor. Type determining means for determining the type, and when the actual image reading is performed, the driving means performs a driving operation according to the type determined by the type determining means, and the type determined by the type determining means Reading control means for causing the image processing means to perform corresponding image processing.

By taking such measures, the mounted contact image sensors are sequentially driven by driving operations corresponding to the plurality of types of contact image sensors, and the contact image sensors sequentially output at that time. The type of the mounted contact image sensor is determined from the accumulation time during which the peak level of the output signal during the accumulation time falls within a predetermined allowable range according to the accumulation time. Then, when the actual image reading is performed, the driving operation and the image processing according to the determined type are performed. Therefore, the type of the contact image sensor is automatically determined based on the output signal of the contact image sensor, and the reading operation according to the type of the contact image sensor is automatically performed.

Further, according to the present invention, when the peak level of the output signal does not fall within a predetermined allowable range according to the accumulation time during any of the accumulation times, the type of the contact image is determined. When the type of the contact image sensor is determined to be abnormal by the type determining means, the abnormality determining means is provided to notify that fact. .

By taking such a measure, when a contact image sensor which cannot be driven by the driving means is mounted, it is determined that the mounted contact image sensor is abnormal, and the fact is notified. You.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a main configuration of an image reading apparatus according to this embodiment.

In FIG. 1, reference numeral 1 denotes an image reading apparatus main body. A contact image sensor (CIS) 2 is detachably attached to the image reading apparatus main body 1 by connectors 3 and 4.

The image reading apparatus main body 1 includes a CPU 11, an RO
M12, RAM 13, CIS drive unit 14, image processing unit 1
5, an image memory 16, an operation panel 17, and a transistor 18; a CPU 11, a ROM 12, a RAM 13,
The CIS drive unit 14, the image processing unit 15, the image memory 16 and the operation panel 17 are connected to each other via a bus 19.

The CPU 11 implements an operation as an image reading apparatus by performing control processing for comprehensively controlling each unit of the image reading apparatus main body 1 based on a control program stored in the ROM 12.

The ROM 12 stores a control program for the CPU 11 and the like.

The RAM 13 stores various kinds of information necessary for the CPU 11 to perform various kinds of processing.

The CIS drive section 14 supplies the shift pulse SH and the transfer clock CLK to the contact image sensor 2 mounted on the connector 3 and turns on / off the transistor 18 so as to be built in the contact image sensor 2. The contact image sensor 2 by controlling the turning on / off of the light emitting diode 21
Drive. The CIS drive unit 14 includes the CPU 1
Under the control of 1, there is a function of changing the frequency of the shift pulse SH and the transfer clock CLK.

The image processing section 15 outputs an image signal DAT output from the contact image sensor 2 mounted on the connector 3.
Receiving A, predetermined image processing such as binarization processing and pseudo halftone processing is performed to generate image data of a predetermined form. The image processing unit 15 is controlled by the CPU 11
It has a function of changing various parameters such as thresholds in image processing.

The CIS driver 14 and the image processor 1
5 may be realized as an image processing IC integrated on one chip.

The image memory 16 stores the image data generated by the image processing unit 15.

The operation panel 17 is used by the user to operate the CPU 1.
1 has a key input unit for accepting various instruction inputs and a display unit for displaying various information to be notified to the user.

The transistor 18 is turned on / off by the CIS drive unit 14 and turns on / off the application of the drive voltage VLED to the light emitting diode 21.

The control means realized by the CPU 11 operating based on the control program stored in the ROM 12 includes a test drive control means, a type determination means, , Reading control means and abnormality notification means.

Here, the test drive control means causes the CIS drive unit 14 to perform test drive for determining the type of the mounted contact image sensor 2. In the test drive, the image reading apparatus 1 sequentially performs a drive operation corresponding to each type of the corresponding contact image sensor 2.

The type determining means monitors the image signal DATA output from the contact image sensor 2 during the test drive, and determines the type of the mounted contact image sensor 2. The type determination means also has a function of determining, when the mounted contact image sensor 2 is not compatible with the image reading device 1, the fact is determined.

The reading control means performs a driving operation and image processing according to the type determined by the type determining means at the time of actual image reading, by the CIS driving unit 14 and the image processing unit 1.
5

The abnormality notifying means determines whether or not the attached contact image sensor 2 is not compatible with the present image reading apparatus 1 by the type determining means. A process for notifying that the image sensor 2 is abnormal is performed.

Next, the operation of the image reading apparatus configured as described above will be described.

In the present image reading apparatus, the image reading apparatus main body 1
The principle of judging the type of the contact image sensor 2 attached to is as follows.

The type of the contact image sensor 2, such as a 1 ms product or a 2 ms product, is indicated by the time required to read one line. That is, while reading 1 line requires 1 ms for a 1 ms product,
For ms products, twice as long as 2 ms is required.

That is, for example, in the case of a 1 ms product, an appropriate charge amount can be stored with a storage time of 1 ms, and a signal of an expected level can be output. Therefore, for 1ms products,
The cycle of the appropriate shift pulse SH is 1 ms. Also,
If the number of dots in one line is 2048,
The cycle of the transfer clock CLK is 1 ms / 2048 = 488
ns.

When a standard white surface is read by the 1 ms contact image sensor 2, if the above-described normal shift pulse SH and transfer clock CLK are supplied, the peak of the output image signal DATA is obtained. The level is within a certain allowable range (V ₁ to V ₁ ) as shown in FIG.
V ₀ ).

However, if a shift pulse SH (2 ms cycle) for a 2 ms product is given to a 1 ms product, the accumulation time becomes excessive, and the peak level of the output image signal DATA is as shown in FIG. As shown in the figure, the allowable range is exceeded.

When a shift pulse SH (500 μs cycle) for a 500 μs product is given to a 1 ms product, the accumulation time is insufficient, and the peak level of the output image signal DATA is as shown in FIG. As shown in FIG.

For this reason, when the driving operation corresponding to the various contact image sensors 2 is performed on the mounted contact image sensor 2 and the peak level of the output image signal DATA is within the allowable range. Is an operation state suitable for the mounted contact image sensor 2.

Therefore, the CPU 11 performs a process as shown in FIG. 3 in order to automatically perform an appropriate operation according to the type of the mounted contact image sensor 2. Here, a case where the image reading apparatus main body 1 supports two types of contact image sensors 2 of a 1 ms product and a 2 ms product will be exemplified.

When the initial operation is started, the CPU 11 causes the CIS driving unit 1 to turn on the light emitting diode 21 in a state where the white reference plate or the white roller can be read.
4 (step ST1).

In response, the CIS driver 14 turns on the transistor 18 and starts applying the driving voltage VLED to the light emitting diode 21, thereby turning on the light emitting diode 2.
1 is turned on to illuminate the white reference plate or white roller.

Subsequently, the CPU 11 sends 2 ms as the cycle of the shift pulse SH to the CIS drive unit 14,
A value suitable for the output signal of the specification of the 2 ms product is set in the image processing unit 15 as the reference value (step ST2).

In response to this, the CIS driving unit 14 operates for 2 ms.
A periodic shift pulse SH and, for example, 976 corresponding thereto
The transfer clock CLK having an ns period is supplied to the contact image sensor 2. Accordingly, the contact image sensor 2 is driven, and reading of the white reference plate or the white roller is started.

Thereafter, the CPU 11 instructs the image processing section 15 to start white correction (step ST3).

Then, one line (2048 for B4)
The image processing unit 15 generates white correction data (for dots).

Then, the CPU 11 waits for the generation of the white correction data for one line to end (step ST4). The CPU11, if the generation of the white correcting data is completed, check the white correction data that has been generated (step ST5), tolerance (V ₁ ~V ₀₎ of the peak level in accordance with the specifications of 2ms products It is determined whether it is within (step ST6).

If the peak level is within the allowable range according to the specification of the 2 ms product, the CPU 11 determines that the attached contact image sensor 2 is a 2 ms product (step ST 7) and reads the 2 ms product. The setting task is started (step ST8).

On the other hand, if the peak level is out of the allowable range according to the specification of the 2 ms product, the CPU 11 sets 1 ms as the cycle of the shift pulse SH to the CIS driving unit 14.
Further, a value suitable for the output signal of the specification of the 1 ms product is set in the image processing unit 15 as an A / D reference value (step ST9).

In response to this, the CIS driving section 14 operates for 1 ms.
A periodic shift pulse SH and, for example, 488 corresponding thereto
The transfer clock CLK having an ns period is supplied to the contact image sensor 2. Accordingly, the contact image sensor 2 is driven, and reading of the white reference plate or the white roller is started.

Thereafter, the CPU 11 instructs the image processing unit 15 to start white correction (step ST10).

Then, one line (2048 for B4)
The image processing unit 15 generates white correction data (for dots).

Then, the CPU 11 waits for the generation of the white correction data for one line to end (step ST11). Then, when the generation of the white correction data is completed, the CPU 11 checks the generated white correction data (step ST12), and its peak level has an allowable range (V _{1 to} V ₀ ) according to the specification of the 1 ms product. It is determined whether it is within (step ST13).

If the peak level is within the allowable range according to the specification of the 1 ms product, the CPU 11 determines that the attached contact image sensor 2 is a 1 ms product (step ST 14), and reads the 1 ms product. The setting task is started (step ST15).

If the peak level is out of the allowable range according to the specification of the 1 ms product, the CPU 1 determines that the mounted contact image sensor 2 is of a type that the image reading apparatus main body 1 does not support. It is determined that there is a mounting abnormality such as presence or failure (step ST16), and a notification to that effect is made (step ST1).
7). The notification of the mounting abnormality is performed, for example, by displaying on the display unit of the operation panel 17.

As described above, according to the present embodiment, the type is determined from the image signal output from the mounted contact image sensor 2, so that means for determining the type is not applied to the contact image sensor 2. In addition, the type of the attached contact image sensor 2 can be automatically determined.

Accordingly, it is possible to automatically perform an image reading operation according to the type of the mounted contact image sensor 2, and it is also possible to use a standard product as the contact image sensor 2.

As a result, the trouble of setting the type of the contact image sensor 2 can be saved, and a normal reading operation cannot be prevented from being performed due to a setting error. By using an inexpensive standard product as the contact image sensor 2, there is no increase in cost.

Further, according to the present embodiment, when it is determined that the mounted contact image sensor 2 is not any of the corresponding types, a notification to that effect is issued. The prompt replacement of the contact image sensor 2 can be encouraged, and it is possible to prevent the notification from being made in a state where the image reading cannot be performed.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, a device corresponding to two types of contact image sensors 2 of 1 ms product and 2 ms product is illustrated. However, the type of the corresponding contact image sensor 2 may be arbitrary, or three or more types Corresponding to the contact image sensor 2 described above.

In addition, various modifications can be made without departing from the gist of the present invention.

[0063]

According to the present invention, a driving means capable of respectively driving a plurality of types of contact image sensors each having a different standard accumulation time, Image processing means capable of selectively performing predetermined image processing according to each of the types of contact image sensors, and a predetermined reference plane positioned at a reading position of the mounted contact image sensor, Test drive control means for causing the drive means to sequentially perform drive operations corresponding to each of the plurality of types of contact image sensors, and the contact mounted by the drive means under the control of the test drive control means The peak level of the output signal at each accumulation time sequentially output by the image sensor depends on the accumulation time. From the accumulation time falls within a predetermined permissible range, and determines the type determining unit a type of the loaded contact image sensor, when the actual image reading execution,
Reading control means for causing the driving means to perform a driving operation in accordance with the type determined by the type determining means and performing image processing in accordance with the type determined by the type determining means. With this feature, it is possible to automatically identify the type of the mounted contact image sensor without applying means for identifying the type to the contact image sensor, thereby reducing costs by using a standard product as the contact image sensor. Also, the image reading device can automatically operate as a device having a capability according to the attached contact image sensor.

Further, according to the present invention, the type judging means is mounted when the peak level of the output signal does not fall within a predetermined allowable range corresponding to the accumulation time in any accumulation time. Abnormality notification means for determining that the contact image sensor is abnormal, and when the type determination means determines that the mounted contact image sensor is abnormal, Therefore, the image reading device can also notify of improper mounting of the contact image sensor.

[Brief description of the drawings]

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

FIG. 2 is a view for explaining the principle of determining the type of a mounted contact image sensor 2.

FIG. 3 is a flowchart showing a processing procedure of a CPU 11 in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image reading apparatus main body 2 ... Contact image sensor (CIS) 3, 4 ... Connector 11 ... CPU 12 ... ROM 13 ... RAM 14 ... CIS drive part 15 ... Image processing part 16 ... Image memory 17 ... Operation panel 18 ... Transistor 19 …bus

Claims (2)

[Claims] 1. An image reading apparatus for reading an image using a mounted contact image sensor, comprising: a driving unit capable of driving a plurality of types of contact image sensors each having a different standard accumulation time; Image processing means for selectively performing predetermined image processing corresponding to each of the plurality of types of contact image sensors on the output signal of the contact image sensor, and reading the mounted contact image sensor A test drive control unit for causing the drive unit to sequentially perform a drive operation according to each of the plurality of types of contact image sensors after a predetermined reference plane is positioned at a position, and under the control of the test drive control unit The mounted contact image sensor is sequentially driven by the driving means in Type determining means for determining the type of the mounted contact image sensor from an accumulation time in which a peak level of an output signal at each accumulation time to be output is within a predetermined allowable range according to the accumulation time; When the image reading is performed, the driving operation is performed by the driving unit in accordance with the type determined by the type determining unit, and the image processing is performed by the image processing unit in accordance with the type determined by the type determining unit. An image reading apparatus comprising: 2. The method according to claim 1, wherein when the peak level of the output signal does not fall within a predetermined allowable range corresponding to the accumulation time during any accumulation time, the attached contact image sensor is abnormal. And when the type determination unit determines that the attached contact image sensor is abnormal, the abnormality determination unit notifies the contact image sensor of the abnormality. The image reading device according to claim 1.