JPH0425829A - Image reader - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image reading device having a document conveying function.

[Prior Art] Conventionally, an image reading device having a document conveyance function is provided with a mechanical switch or an optical switch in the middle of the conveyance path in order to detect when the document has been conveyed to a fixed position on the reading table. After detecting that the document has passed through the position of the switch, the document is conveyed by a certain amount to a fixed position on the reading table.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, since the original was detected by a mechanical switch or an optical switch, there were the following problems (1) to (4).

■ When detecting the presence or absence of a document using a mechanical switch, the document gets caught in the mechanical switch and is damaged.

■ When detecting the presence or absence of a document optically, an area in a color document whose color is similar to the area without a document is mistakenly recognized as the document position.

■ If the document skews or slips off the conveyor belt after passing through the document detection switch in the middle of the conveyance path, a mismatch occurs between the document reading position and the position where the document is set.

An object of the present invention is to provide an image reading device that solves the above problems.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a document mounting table in which electrodes are provided on the same plane as the document reading position, and a method for transporting the document on the document placing table. The present invention is characterized in that it includes a conductive conveyor belt, and a determining means for determining whether or not conduction between the electrodes and the conveyor belt is interrupted by the document conveyed by the conveyor belt.

[Function] In the present invention, a conductive conveyor belt conveys a document on a document table on which electrodes are disposed on the same plane at the document reading position, and the document conveyed by the conveyor belt connects with the electrodes. A determining means determines whether or not conduction of the conveyor belt is interrupted.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the invention. This is an example of a copying machine, and its appearance is shown in FIG.

The copying apparatus shown in FIG.
It is composed of. When the copy start key 506 is pressed, the A4 paper cassette 501.84 paper cassette 502. Among the papers stored in the A3 paper cassette 503, the paper in the cassette displayed in the message display section 505 is fed to the printer 202, printed, and then discharged to the paper discharge tray 504.

FIG. 3 shows the configuration of the second illustrated document conveying device 103. As shown in FIG.

The document conveyance device 103 transports the document 107 fed by the document feed device 106 to the document conveyance belt drive motor 1.
The document is conveyed to a predetermined position on the document platen glass 102 by a conductive document conveyance belt 104 driven by the document scanner 05. The document conveyance belt 104 is grounded.

FIG. 4 shows an example of the arrangement of transparent electrodes on the document platen glass 102 shown in the third figure. An A3-sized electrode 301 is provided on the document table glass 02, and in the figure, the area indicated by the broken line has the size of B4 size, and the area indicated by the dotted chain line has the size of A4 size. be. Electrodes 306 and 309 are arranged at the upper left corner and lower left corner of the original table glass 102.
08.305 are arranged at the lower left corner and the lower left corner of the region indicated by the broken line, and the electrode 307 is arranged at the lower left corner of the region indicated by the dashed line.

As shown in FIG. 1, the electrode 301 is grounded, and the electrodes 305 to 309 are connected to the control section 201 and connected to a power source with a voltage of 5.5 cm via a pull-up resistor.

The control unit 201 controls the document transport device 103. Original feeding device 10
6. Scanner 101. In addition to controlling the printer 202 (see FIG. 5), the electrodes 305 to 305 serve as determination means.
309 and the document conveyance belt 104 is interrupted. Table 1 shows the relationship between electrode level and determination.

Table 1 H: High level (+5V) L2 low level (Ov) X: Arbitrary (+5orOV) Next, the operation of this copying apparatus will be explained with reference to the flowchart shown in the sixth figure.

When copying, the operator places the original directly on the original platen 102 and presses the copy start key if there is only one original, or presses the copy start key on the automatic original feeder 106 when there are multiple originals.
Place the original on the machine and press the copy start key to instruct the copying machine to perform copying.

When the copy start key is pressed (S601), it is detected whether or not there is a document in the document feed section (S602), and if there is no document, a single page document copy is performed (S603).
If there is a document, perform automatic document feed copying (36041).

FIG. 7 is a flowchart showing the control procedure by the control unit 201 when copying a single sheet original.

When copying a single sheet original starts, the control unit 201 detects the potential of each transparent electrode 305 to 309 on the original platen glass 102, determines the original size according to Table 1 in step 5701, and as a result of the determination, the size of the original is A4. B4. If the size is A3, copy operations for each size are performed in steps 3702 to 5704. On the other hand, if there is no original or there is a shortage of originals, a message is displayed in steps 5705 and 3706.

The relationship between the potential of the transparent electrode and the document size is as follows.

(a) When there is no document, the electrodes 305 to 309 are in contact with the conductive document conveyance belt 104, and the document conveyance belt 104 is in contact with the electrode 301, but the electrodes 301 and the document conveyance belt 104 are connected to GND. Therefore, the levels of the electrodes 305 to 309 are all L (=OV).

(b) Next, when an A4 size document is set in the area indicated by the dashed line in FIG. It becomes H (=5V) due to the resistance. On the other hand, since the electrodes 308 and 309 are always in contact with the document conveying belt 104, their level becomes L as in the case when there is no document.

Therefore, the levels of the electrodes 305 to 309 are grouped and H in this order.
, H, L, L], it is determined that an A4 size original is set.

(c) When an 84-size original is set in the area indicated by the broken line in FIG.
Since contact with 04 is cut off by the original, its level becomes H due to the pull-up resistor. In addition, the electrode 309
is in contact with the document conveyance belt 104, so its level is L.

Therefore, the levels of electrodes 305 to 309 are set in this order [
H, H, H, H, L], so it is determined that a B4 size original is set.

(d) When an A3 size original is set so as to cover the electrode 301, all electrodes 305 to 309 are cut off from contact with the original transport belt 104 by the original, so their level is set to H by the pull-up resistor. Become. therefore,
The levels of electrodes 305 to 309 are group, H, H, H in this order.
, H], it is determined that an A3 size original is set.

(e) Electrode level is no original, A4. B4. A3
If none of the sizes apply, it is determined that the original is not set correctly (improper original).

According to the document size determined as described above, the scanner 101 and printer 202 are controlled to make a copy of an appropriate size. Since the control of the scanner and printer is well known, the explanation thereof will be omitted here.

In addition, if the document size judgment result is that there is no document, a message indicating that the document is not available is displayed on the display unit 505, for example, "Please set the document. A message, for example, "Please set the original correctly" is displayed on the display unit 505.

FIG. 8 is a flowchart showing the control procedure by the control unit 201 during automatic change paper feeding copying.

When automatic document feeding copying starts, step 580
1, the drive motor of the document conveyance device 103 is controlled, and only one document set in the paper feed section is conveyed by the document conveyance belt 104, and sent to the document table glass 102.

Then, as a result of checking the potentials of the transparent electrodes 305 and 306, when the level of one or both of the electrodes becomes H, it is determined that the conveyance is completed and the original is set on the original platen glass 102. . The control unit drives the drive motor until the level of the electrodes 305 and 306 reaches H, and stops the drive motor when the level reaches H.

Then, in step 5802, when the level of the electrodes 305 and 306 is H to detect a document, the transparent electrode 305
The original size is determined from the levels 309 to 309, and steps 3803 to 580 are performed in the same manner as in the case of single-sheet original copying.
A4 at 5. B4. The scanner and printer are controlled according to the size of the A3 original to make copies of the appropriate size.

Further, when the level of either one of the transparent electrodes 305 and 306 is H, it is determined in step 3806 that the document has been skewed during conveyance, and if Table 1 is not applicable, the document is conveyed normally. It is determined that the document was not corrected (for example, the document was folded), and in this case, a message indicating that the document is incorrect, such as "Please try again", is displayed on the display section.

Once the above-mentioned copy of the correct size has been made, step 58
At step 07, the drive motor is driven and the document conveying belt 104 is
The original on the original platen glass is sent to the original ejecting section 108, and the original is ejected. Then, in step 5808, it is determined whether or not there is a document in the document feeding section, and if the result of the determination is that there is, the above operations of document conveyance, document size detection, and document ejection are repeated. On the other hand, if there is no document in the document feed section, the copying operation is ended.

Note that the transparent electrodes on the document table glass may be arranged in a matrix. In this case, if the absolute position of the document can be determined, and the scanner is controlled based on that information, and the image reading position is controlled, a copying machine that correctly reads and copies the document no matter where the document is placed on the platen glass can be realized. can do.

[Effects of the Invention] As described above, according to the present invention, electrodes are provided on the document table so as to be on the same plane, the conveyor belt is made conductive, and whether or not there is electrical continuity between the electrodes and the conveyor belt is determined. Since the position of the document is determined based on the following, there is no damage caused by the document being caught during transport, ■ there is no misrecognition of color documents, and ■ the detected size matches the scanned size. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the external appearance of a copying apparatus according to the embodiment, and FIG. 3 is a sectional view showing the configuration of the second illustrated document conveying device 103. 4 is a diagram showing an example of the arrangement of electrodes on the original platen glass 102 shown in the third figure; FIG. 5 is a block diagram showing a copying device control system according to an embodiment; FIG. 6 is a diagram showing a copying device control system according to an embodiment. FIG. 7 is a flowchart showing the control procedure by the control unit 201 during single-sheet original copying, and FIG. 8 is a flowchart showing the control procedure by the control unit 201 during automatic document feeding copying. 104... Original conveyance belt, 201... Control unit, 301° 305-309... Electrode. +04 Figure ■ Figure

Claims (1)

[Scope of Claims] 1) A document mounting table having electrodes disposed on the same plane as the document reading position, a conductive conveyance belt for conveying the document on the document loading table, and a document conveyed by the conveyance belt. 1. An image reading apparatus comprising: a determination unit for determining whether or not conduction between the electrode and the conveyance belt is interrupted by the original document.