JPH11341234A - Device and method for picture reading and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture reader which is equipped with a detection means for a start switch by the minimum necessary expenses not by using an electrical switch. SOLUTION: This picture reader is equipped with a shielding material 7 which is made variable so as to prevent a reflected light from a standard white plate 6 from reaching a CIS 1 and a start switch 8 for having the shielding material 7 move so as to shield the reflected light from the standard white plate 6. Then, it becomes possible to detect that the start switch 8 is pressed by an output level of a part where the reflected light from the standard white plate 6 is shielded by the shielding material 7 being low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor which converts an image read by transporting an original into an electric image signal, and converts the image signal into a digital signal by an A / D converter. The present invention relates to an image reading device, an image reading method, and a storage medium that can be transferred to an external device.

[0002]

2. Description of the Related Art Conventionally, in an image reading apparatus provided with an operation means (hereinafter referred to as a start switch) as a switch for starting a reading operation, a means for detecting that the start switch is pressed is provided as follows. This is done by detecting the electrical level of the signal line by using an electrical switch.

[0003]

However, when the above-mentioned electric switch is used, the switch, a board for mounting the switch, and a cable for connecting to the control board are required. Therefore, a considerably large-scale device configuration is required, and the cost is increased accordingly.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide an image reading apparatus equipped with a start switch detecting means and an image reading apparatus at a minimum necessary cost by not using the electric switch. It is to provide a method and a storage medium.

[0005]

According to the present invention, there is provided an image reading apparatus comprising: an image sensor for scanning a document and converting the read image into an electrical image signal; and an A / D for converting the image signal into a digital signal. A converter, a standard white plate for performing shading correction, a transfer unit for transferring the digitally converted image signal to an external device, and an optical path between the image sensor and the standard white plate can be shielded. ,
A shielding member movable to the portion of the optical path, and operating means for operating and moving the shielding member from the outside, monitor an output signal of the image sensor, and actuate the An operation of the operating means is detected by detecting that a change in an input signal from the standard white plate has occurred due to the shielding member blocking the optical path.

In one aspect of the image reading apparatus of the present invention, the output signal from the image sensor is monitored at a predetermined cycle, and when the operation of the operating means is detected,
Start the read operation.

An image reading apparatus according to the present invention is an image reading apparatus for illuminating a subject with light while scanning the subject, receiving light from the subject, converting the light into an electric signal, and reading an image of the subject. A shading correction function, and a function of blocking an optical path at the time of shading correction, monitoring the electric signal, detecting that the electric signal has changed due to the shielding at the time of shading correction, and The operation of is detected.

In one aspect of the image reading apparatus of the present invention, the monitoring of the electric signal is performed at a predetermined cycle, and when the operation of the shielding is detected, the reading operation is started.

An image reading method according to the present invention is an image reading method for illuminating a subject with light while scanning the subject, receiving light from the subject, converting the light into an electric signal, and reading an image of the subject. When shading correction is performed, the optical path at the time of the shading correction is shielded, the electric signal is monitored, and when the shading correction detects a change in the electric signal due to the shielding, the shading correction is performed. Detects operation.

In one embodiment of the image reading method of the present invention, the monitoring of the electric signal is performed at a predetermined cycle, and when the operation of the shielding is detected, the reading operation is started.

[0011] The storage medium of the present invention stores a program for causing a computer to function as each unit of the image reading apparatus.

The storage medium of the present invention stores a program for causing a computer to execute the procedure of the image reading method.

[0013]

According to the present invention, it is possible to detect that the start switch has been pressed by a change in the output signal of the image sensor without using a large-scale means such as an electric switch. The reading operation can be started easily and reliably.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic side view showing the internal configuration of an image reading apparatus according to an embodiment of the present invention.

The main components of this image reading apparatus are a contact type image sensor 1 (hereinafter referred to as CIS 1), a photodiode 2, a selfoc lens 3, an LED array 4,
A contact glass 5, a platen glass 10 for placing a document 9, and a standard white plate 6 for shading correction processing
And a variable shielding member 7 for preventing the reflected light from the standard white plate 6 from reaching the CIS 1, and moving the shielding member 7 so as to block the optical path of the reflected light from the standard white plate 6. And a start switch 8.

FIG. 2 is a block diagram showing the configuration of the control circuit according to this embodiment. The circuit operation of the present case will be described below with reference to FIG.

In FIG. 2, reference numeral 201 denotes a CIS, and an LED 202 serving as a light source is also integrated.
While transporting the original 9 on the contact glass 5 of the
LED of each color for each line by LED control circuit 203
By switching on and turning on, it is possible to read a color image in the order of R, G, B lines.

The amplifier 204 is an amplifier for amplifying the signal output from the CIS 201, and 205 is an A / D converter for performing A / D conversion of the amplified output to obtain an 8-bit digital output, for example. Shading RA
M206 stores shading correction data by reading a calibration sheet in advance, and a shading correction circuit 207 performs shading correction of the read image signal based on the data of the shading RAM 206. The peak detection circuit 208 is a circuit that detects a peak value in the read image data for each line, and is used to detect the leading edge of a document.

A gamma conversion circuit 209 performs gamma conversion of image data read according to a gamma curve preset by a host computer.

The buffer RAM 210 is a RAM for temporarily storing image data in an actual reading operation and communication with the host computer, and the packing / buffer RAM control circuit 211 is used to adjust timing in the host computer. After performing a packing process in accordance with a preset image output mode (binary, 4-bit multi-level, 8-bit multi-level, 24-bit multi-level), write the data to the buffer RAM 210, and buffer the interface circuit 213 with the data. RAM 21
The image data is read from 0 and output.

The interface circuit 213 receives a control signal and outputs an image signal with an external device serving as a host device of the image reading apparatus according to the present embodiment such as a personal computer.

Reference numeral 215 denotes a microcomputer-type CPU, for example, which has a ROM 215A in which processing procedures are stored and a working RAM 215B, and controls each unit in accordance with the procedures stored in the ROM 215A.

216 is a crystal oscillator, for example, 214 is a CP
This is a timing signal generation circuit that divides the output of the oscillator 216 according to the setting of U215 and generates various timing signals serving as operation references.

FIG. 3 shows the waveform of the output signal from the CIS 1, wherein the X-axis indicates the image position in the main scanning direction, and the Y-axis indicates the output level of the sensor. FIG. 3A shows an output waveform when the start switch is not pressed, and a uniform white level is output.
FIG. 3B shows an output waveform when the start switch is pressed. The output level of the portion where the light reflected from the standard white plate 6 is shielded by the shielding member 7 is low, and the start switch 8 is turned off. Can be detected.

Next, a method of controlling a reading operation according to the present invention will be described with reference to the flowchart of FIG.
This program is a timer interrupt processing program, and this processing is performed at a predetermined cycle.

In step S1, the LED 202 is turned on. In step S2, the black peak value (minimum output level) of the output signal from the CIS 1 is detected by the peak detection circuit 2.
08 is read. In step S3, if the peak value is larger than a predetermined value, for example, 10H, it is determined that the start switch has not been pressed, and the process proceeds to step S5. If not, it is determined that the start switch has been pressed. The process proceeds to step S4 to set the start flag, and then proceeds to step S5. Step 5
, The LED 202 is turned off to end the timer interrupt processing. In the main program, the reading operation is started by detecting that the start flag is set.

As described above, in this embodiment, it is detected that the start switch 8 has been pressed by a change in the output signal of the CIS 1 which is an image sensor, without using a large-scale means such as an electric switch. The reading operation can be easily and reliably started with such a simple configuration.

-Modification- In the present embodiment, a contact image sensor is used as the image reading sensor. However, the use of a conventionally used CCD image sensor is also an effective means.

Note that the program code itself for operating various devices and means for supplying the program code to a computer so as to realize the functions of the image reading apparatus described in the present embodiment and its modifications are provided. For example, a storage medium storing such a program code belongs to the category of the present invention.

In this case, the program code stored in the storage medium is read out by a predetermined storage / reproduction device, and the EEPROM operates. As a storage medium for storing such a program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, and the like can be used.

When the computer executes the supplied program code, not only the functions of the respective embodiments are realized, but also the OS (operating system) or other application running on the computer in the program code. Such a program code is also included in the present invention when the functions of each embodiment are realized in cooperation with software or the like.

Further, after the supplied program code is stored in a memory provided on a function expansion board of a computer or a function expansion unit connected to the computer, the function expansion board or the function expansion unit is specified based on the instruction of the program code. The present invention also includes a system in which a CPU or the like included in the system performs part or all of actual processing, and the processing realizes the functions of the present embodiment.

[0033]

According to the present invention, between the standard white plate used for shading processing and the optical path of the image sensor, a shielding member for shielding the optical path which can be moved by a start switch which can be operated from the outside. By monitoring the output from the image sensor by having
Since it is possible to detect that the start switch has been pressed, it is possible to provide the start switch at a minimum necessary cost.

[Brief description of the drawings]

FIG. 1 is an internal configuration diagram showing an embodiment of an image reading apparatus to which the present invention is applied.

FIG. 2 is a block diagram illustrating an example of an electrical configuration of the image reading apparatus according to the embodiment.

FIG. 3 is an output waveform diagram for explaining processing contents of the embodiment.

FIG. 4 is a flowchart specifically showing a processing operation of the present embodiment.

[Explanation of symbols]

 1,201 Image sensor (CIS) 2 Photodiode 3 Selfoc lens 4 LED array 5 Contact glass 6 Standard white plate 7 Shielding member 8 Start switch 9 Original 202 LED 203 LED control circuit 204 Amplifier 205 A / D converter 206 Shading RAM 207 Shading correction circuit 208 Peak detection circuit 209 Gamma conversion circuit 210 Buffer RAM 211 Packing / buffer RAM control circuit 213 Interface circuit 214 Timing signal generation circuit 215 CPU 216 Crystal oscillator

Claims (8)

[Claims] 1. An image sensor for converting an image read by scanning a document into an electric image signal, an A / D converter for converting the image signal into a digital signal, and a standard white color for performing shading correction A plate, transfer means for transferring the digitally converted image signal to an external device, and a shield movable to a portion of the optical path so as to shield an optical path between the image sensor and the standard white plate. A member, and operating means for operating and moving the shielding member from the outside, monitoring an output signal of the image sensor, and actuating the operating means, whereby the shielding member shields the optical path, and An image reading apparatus, wherein an operation of the operating means is detected by detecting a change in an input signal from a standard white plate. 2. The image according to claim 1, wherein an output signal from the image sensor is monitored at a predetermined cycle, and when an operation of the operation unit is detected, a reading operation is started. Reader. 3. An image reading apparatus for illuminating a subject with light while scanning the subject, receiving light from the subject, converting the received light into an electric signal, and reading an image of the subject, wherein the shading correction function is provided. Along with providing a function of shielding the optical path at the time of shading correction, monitoring the electric signal, detecting that the electric signal has changed due to the shielding at the time of shading correction,
An image reading apparatus for detecting an operation of the shielding. 4. The image reading apparatus according to claim 3, wherein the monitoring of the electric signal is performed at a predetermined cycle, and a reading operation is started when the operation of the shielding is detected. 5. An image reading method for illuminating a subject while scanning the subject, receiving light from the subject, converting the received light into an electric signal, and reading an image of the subject, wherein shading correction is performed. At this time, while blocking the optical path at the time of the shading correction, monitoring the electric signal, detecting that the electric signal has changed due to the shielding at the time of shading correction,
An image reading method, wherein an operation of the shielding is detected. 6. The image reading method according to claim 5, wherein the monitoring of the electric signal is performed at a predetermined cycle, and a reading operation is started when an operation of the shielding is detected. 7. A storage medium storing a program for causing a computer to function as each unit of the image reading apparatus according to claim 1. Description: 8. A storage medium storing a program for causing a computer to execute the procedure of the image reading method according to claim 5 or 6.