JPH11284805A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image reader that warrants proper image reading regardless of a comparatively simple configuration. SOLUTION: A linear image sensor 9 is placed in the vicinity of an image forming optical system, main scanning is applied in a lengthwise direction of the linear image sensor 9 by electronic scanning and subscanning is applied in a direction orthogonal to the lengthwise direction through relative movement between the linear image sensor 9 and the image forming optical system to provide an output of image information. The image reader is provided with a moving section 1 that carries the linear image sensor 9 and is moved in a subscanning direction of a mechanism section configuring the sub scanning system, a subscanning motor 5 that drives the moving section 1, means 3, 4 that change a load with respect to the subscanning motor 5 at a moving end of the moving section 1, a means 8 that detects a load fluctuation in the subscanning motor 5, and drive control means 6, 7 that control driving of the subscanning motor 5 based on the load fluctuation of the subscanning motor 5. A moving range of the moving section 5 is set based on a detection signal of load fluctuation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image scanner using a linear image sensor.

[0002]

2. Description of the Related Art Normally, in a mechanism section constituting a sub-scanning system in an image scanner, a movable section moving in the sub-scanning direction and a sensor for recognizing a position of the movable section for defining a necessary range for reading an image of a document. Is installed, and the movable range of the movable portion is recognized based on the output of the sensor.

[0003]

However, in the above-mentioned prior art apparatus, the cost increases because a sensor for position recognition is required. Further, a place for installing such a sensor is required, and the structure of the apparatus must be increased. Further, a recognizing means for recognizing the output of the position recognizing sensor is required, which also increases the cost.

[0004] In view of such circumstances, an object of the present invention is to provide an image reading apparatus which guarantees proper image reading with a relatively simple configuration.

[0005]

An image reading apparatus according to the present invention is provided with a linear image sensor near an imaging optical system,
Image information is output by performing main scanning by electronic scanning in the longitudinal direction of the linear image sensor and performing sub-scanning by relative movement of the linear image sensor and the imaging optical system in a direction orthogonal to the longitudinal direction. In the image reading apparatus described above, a movable part that moves in the sub-scanning direction of a mechanism part that carries a linear image sensor and constitutes a sub-scanning system, a sub-scanning motor that drives the movable part, Means for changing the load on the scanning motor; means for detecting a change in load on the sub-scanning motor; and drive control means for controlling driving of the sub-scanning motor based on the change in load on the sub-scanning motor. The movable range of the movable section is set by the detection signal.

Further, in the image reading apparatus of the present invention, the load of the sub-scanning motor is physically changed at the moving end of the movable section, and this load variation is electrically detected.

In the image reading apparatus of the present invention, a sub-scanning system capable of reading a range wider than the maximum image range of a document to be read and an image recognizing means capable of recognizing only the image information portion of the document are provided. The image recognition means outputs only image information from a document as actual image information.

Further, the image reading apparatus of the present invention is characterized in that the image reading apparatus has a mode changeover switch which can arbitrarily select whether or not to operate the image recognition means.

According to the present invention, the movable end of the sub-scanning system is recognized by detecting a change in the load of the motor that drives the movable unit, and the movable range of the sub-scanning system is determined by the recognized movable end. Stipulate. Image reading is performed in the entire movable range of the movable portion, and only image data actually required from the read image data is output as actual image data by image recognition means. This eliminates the need for a position recognition sensor, thereby achieving cost reduction and simplification of the structure.

In addition, a mode changeover switch which can arbitrarily select whether or not to operate the image recognizing means is set, whereby the intention of the user can be reflected.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
A preferred embodiment of the image reading apparatus according to the present invention will be described. FIG. 1 is a block diagram for explaining an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a movable portion of a sub-scanning system, 2 denotes a guide for physically regulating the movable portion 1, and 3 and 4 denote movable portions 1 respectively. Is a sub-scanning motor for operating the movable unit 1, and the movable unit 1, the guide 2, the end 3, the end 4, and the sub-scanning motor 5 form a sub-scanning mechanism. It is configured.

Further, 6 is a microcomputer (microcomputer) for controlling the sub-scanning system, 7 is a driver circuit for driving the sub-scanning motor 5, 8 is a current detecting circuit for detecting the amount of current flowing through the sub-scanning motor 5, and 9 is This is an image sensor that actually reads an original, and is attached to the movable unit 1.
Reference numeral 10 denotes an image processing circuit which processes an output signal of the image sensor 9 and can output image data obtained by extracting only a document image portion by image recognition.

Reference numeral 12 denotes an original. Here, in FIG. 1, a is a range in which the document 12 can exist in the sub-scanning mechanism, and b is a range in which the movable unit 1 can actually move. The dimensional relationship between the ranges a and b is generally a <b
It is.

First, the movable section 1 scans the guide 2 by the sub-scanning motor 5. The movable range of the movable part 1 is limited by the end 3 and the end 4, that is, the range b
It is movable within. The document reading range is the range a, and is generally set to a <b. The sub-scanning motor 5
Driven by a driver circuit 7 controlled by the microcomputer 6. The current detection circuit 8 detects a current flowing through the sub-scanning motor 5, and the information is supplied to the microcomputer 6. The image sensor 9 is attached to the movable unit 1 and performs sub-scanning for reading the actual document 12 by scanning the movable unit 1 with the sub-scanning motor 5. The output signal of the image sensor 9 is supplied to an image processing circuit 10 and is processed as image data.

Next, the operation of this embodiment will be described. It should be noted that the flowchart shown in FIG. The movable unit 1 starts sub-scanning from the end 3 (steps S101, S102), and at the same time, the image sensor 9
Performs image reading of the document 12 (step S103), and the image processing circuit 10 performs image processing. Movable part 1
Continues the sub-scanning to the end 4, and the operation is limited by the end 4. Here, if the operation is restricted by the end portion 4, a change occurs in the motor drive current flowing through the sub-scanning motor 5. By detecting the current change by the current detection circuit 8,
It is detected that the operation of the movable portion 1 is restricted by the end portion 4 and the information is transmitted to the microcomputer 6 (step S10).
4). The microcomputer 6 having received this information instructs the driver circuit 7 and the image processing circuit 10 to end the sub-scanning and the image reading (step S105).

Now, the image reading takes in all data during the range b. The image processing circuit 10 performs image recognition by the image recognizing means (step S106), extracts only the image data in the range a which is the actual document reading range, and outputs it as final image data (steps S107 and S10).
8).

As described above, in the sub-scan in the image reading,
The movable range is recognized by recognizing a change in the motor drive current of the sub-scanning motor 5 that moves the movable portion 1,
Image reading is performed in the entire movable range. From the read image data, only image data actually required by the image recognition means is output as actual image data. This makes it unnecessary to provide a sensor for recognizing the movable range of the movable unit 1, and can achieve cost reduction and simplification of the structure.

In the description of the present embodiment, a change in the motor drive current is recognized as means for recognizing the movable range of the sub-scan. As long as the means is capable of recognizing the load fluctuation of the sub-scanning motor 5, the same effect can be obtained regardless of the means. Similarly, an example of a structure for physically stopping the sub-scanning movable range has been described. The same effect can be obtained as long as the means varies load on the motor 5 irrespective of the means.

FIG. 3 is a block diagram for explaining a second embodiment of the present invention. The difference from FIG. 1 described in the above-mentioned embodiment is that the operation / operation of the image recognition or image extraction operation is performed. That is, a mode changeover switch 11 for instructing the image processing circuit 10 of non-operation is provided. This allows the user to arbitrarily select whether to perform an image recognition operation or to perform an image extraction operation, thereby reflecting the user's intention.

The operation in the second embodiment is shown in FIG.
The description will be made based on the flowchart of FIG. First, the movable unit 1 starts sub-scanning from the end 3 (step S201,
S202). The mode of the switch 11 is detected (step S203). If the switch 11 is set to a mode in which image recognition is not performed, the process proceeds to step S211 and the image sensor 9 reads an image of the document 12 (step S211). Image processing is performed by the processing circuit 10. The image processing circuit 10 outputs the image data to be read (step S212), and the movable unit 1 performs steps S211 and S2 as long as there is no change in the drive current of the motor.
Step 212 is repeated to continue the sub-scanning to the end portion 4.

Here, when the operation is restricted by the end portion 4 and a change appears in the motor drive current flowing through the sub-scanning motor,
The current detection circuit 8 detects the change and transmits information to the microcomputer 6. The microcomputer 6 having received the information instructs the driver circuit 7 and the image processing circuit 10 to end the sub-scanning (Step S209), and instructs to end the image reading (Step S210).

If it is determined in step S203 that the switch 11 has been set to the mode for performing image recognition, the process proceeds to step S20.
Proceeding to 4, the image sensor 9 reads the image of the original, and the image processing circuit 10 performs image processing. Next, the image processing circuit 10 performs image recognition (step S20).
5) In step S306, it is determined whether the document is a document portion. If it is a document portion, it is output as read image data (step S207). If it is not the document portion, the image data is not output as the image data, and step S2
Proceed to 08.

The movable section 1 repeats steps S204 to S207 while the drive current of the motor does not change, and continues sub-scanning to the end 4. Step S208
When the operation is limited by the end portion 4 and a change appears in the motor driving current flowing through the sub-scanning motor, the current detection circuit 8 detects the change and transmits information to the microcomputer 6. The sub-operation ends in step S209.

As described above, in this embodiment, the image reading operation captures all data during the period b, but in the image recognition mode, only the image data in the range a, which is the actual document reading range, is extracted. And output as image data. In the mode in which image recognition is not performed, all of the read image data is output as final image data during the range b.

[0025]

As described above, according to the present invention, in this type of image reading apparatus, the cost can be effectively reduced and the structure can be simplified by particularly omitting the position recognition sensor effectively. Can be. In addition, by adopting a configuration in which the intention of the user is prosperous, extremely good usability can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of an embodiment of an image reading apparatus according to the present invention.

FIG. 2 is a flowchart showing an operation in the embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration example of an image reading apparatus according to a second embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation according to the second exemplary embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Movable part 2 Guide 3 End part 4 End part 5 Sub-scanning motor 6 Microcomputer 7 Driver circuit 8 Current detection circuit 9 Image sensor 10 Image processing circuit 11 Mode switch 12 Document

Claims (4)

[Claims] 1. A linear image sensor is provided in the vicinity of an imaging optical system, main scanning is performed by electronic scanning in a longitudinal direction of the linear image sensor, and the linear image sensor and the imaging optical system are arranged in a direction orthogonal to the longitudinal direction. An image reading device configured to output image information by performing sub-scanning by relative movement of a moving unit that moves in a sub-scanning direction of a mechanism unit that supports a linear image sensor and forms a sub-scanning system; A sub-scanning motor for driving the movable section; a means for changing a load on the sub-scanning motor at a moving end of the movable section; a means for detecting a change in load on the sub-scanning motor; Drive control means for controlling the drive of the scanning motor, wherein the movable range of the movable portion is set by a load variation detection signal. Image reading device. 2. The image reading apparatus according to claim 1, wherein a load of the sub-scanning motor is physically changed at a moving end of the movable portion, and the load variation is electrically detected. Reader. 3. A sub-scanning system capable of reading a range wider than a maximum image range of a document to be read, and an image recognizing unit capable of recognizing only an image information portion of the document. 3. The image reading apparatus according to claim 1, wherein only image information from a document is output as actual image information. 4. The image reading apparatus according to claim 3, further comprising a mode changeover switch capable of arbitrarily selecting whether or not to perform an operation of the image recognition means.