JPH10109784A - Printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate misprint due to multiple feeding of recording paper and save recording paper and toner. SOLUTION: An image information entered from one of a scanner 1, a control part 3 and a line control part 4 is transmitted to a printer 9 through a printer interface 8 by controlling of a control part 6. If multiple feeding of recording paper carried to print in the printer 9 causes is detected in a recording paper multiple feeding detecting part 10. The control part 6 compares a voltage change level transmitted from the recording paper multiple feeding detecting part 10 with a threshold value of the voltage change level stored in a memory 5. The control part 6 determines that the recording paper is multiple fed when the voltage change level from the recording paper multiple feeding detecting part 10 exceeds the threshold value of the memory 5 and warns against a user to accurately reset the recording paper from an alarm display part 11 and instructs to stop print action of the printer 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus, and more particularly to a facsimile apparatus using a cut sheet as an image recording sheet or a printing mechanism of a copying machine.

[0002]

2. Description of the Related Art Conventionally, in a facsimile apparatus, a document in a paper format is optically read by a document reading section, and the optical information is converted into an electric signal, thereby handling the document information as digital data and transmitting the document information. And has a function of transmitting to the other party. Since the other machine has a function of restoring the original by printing the received manuscript information on recording paper (cut paper), this function makes the received manuscript information available to the user of the other machine.

In a copying machine (copier), a document in a paper format is optically read by a document reading section, and the document information as digital data obtained by converting the optical information into an electric signal is recorded. It has a function of creating a copy of an original by printing on paper (cut paper).

In the facsimile apparatus and the copier described above, when a double feed occurs in which the recording sheets are conveyed in an overlapping manner, for example, as shown in FIG. 5, the first recording sheet a1 and the second recording sheet a1 The character "A" is printed over the recording paper a2, and the printed information cannot be accurately obtained even if the first recording paper a1 or the second recording paper a2 is viewed independently.

To solve this problem, Japanese Patent Application Laid-Open No. 7-41207 discloses a method in which when double feed of cut sheets is detected, print data is accumulated and reprinting is performed.

In the facsimile apparatus adopting the above method, cut paper is used as a received image recording paper, and the length of the recording paper in the sub-scanning direction that actually crosses the pre-registration sensor from the on / off signal of the pre-registration sensor is used. Means for measuring (page length), double feed discrimination means for comparing this page length with the size of a paper feed cassette in which recording paper is being conveyed, and discriminating double feed of recording paper, And a control unit that performs an operation based on the determination result of the means.

In this facsimile apparatus, the length (page length) of the recording paper actually crossing the pre-registration sensor in the sub-scanning direction is measured from the on / off signal of the pre-registration sensor due to the conveyance of the recording paper. When the page length is longer than the size of the paper feed cassette by comparing the size of the paper feed cassette in which the inner recording paper is stored, it is determined that the recording paper is multi-fed, and re-recording of the multi-feed page is executed. As a result, it is possible to prevent missing of a received image from being recorded even if double feeding / non-feeding of recording paper occurs.

[0008]

In the above-described conventional facsimile apparatus, the length of the recording paper that has actually crossed the pre-registration sensor in the sub-scanning direction is measured as double feed discrimination means.
By comparing this with the size of the paper feed cassette in which the recording paper being conveyed is stored, double feed of recording paper is determined.
In this case, even if it is determined that the recording paper is multi-fed, the recording paper is sent to the printer unit as it is, so that printing on the recording paper is executed.

Thereafter, the page determined to be a double feed is re-recorded. In other words, when multi-feeding is performed, printing is performed on the multi-fed recording paper, so that useless printing is performed on the multi-fed recording paper (a plurality of recording papers). Recording paper and toner are wasted.

SUMMARY OF THE INVENTION An object of the present invention is to provide a printing apparatus which solves the above-mentioned problems, eliminates misprinting caused by double feeding of recording paper, and saves recording paper and toner.

[0011]

A printing apparatus according to the present invention is a printing apparatus including a printing mechanism for printing print data on paper cut to a predetermined size, wherein the printing mechanism is provided in front of the printing mechanism. A light source that irradiates the paper with irradiation light, a detection unit that detects double feeding of the paper using the irradiation light that is irradiated onto the paper from the light source, and the detection unit detects the double feeding of the paper. Suppressing means for suppressing printing of the print data on the paper by a printing mechanism.

As described above, in the printing apparatus of the present invention, when a recording sheet cut to a predetermined size in order to print a received or copied recorded image is conveyed, the recording sheet is double fed ( When the recording paper is conveyed while being slightly shifted due to static electricity or the like), the double feeding is detected by photoelectric conversion in front of the printing mechanism.

That is, in a facsimile and a copying machine using cut paper as image recording paper, when conveying the recording paper, irradiation light is applied from the front or back of the recording paper, and the transmitted light is incident on the photoelectric conversion element.

Normally, the recording paper has a uniform thickness and density in a blank state, so that the transmitted light has a uniform brightness and the output voltage of the photoelectric element has a uniform value. However, when the recording paper is multi-fed, there is a difference in the thickness and density of the recording paper between the portion where the recording paper overlaps and the portion where the recording paper does not overlap.

That is, the brightness of the transmitted light changes before and after the overlapping portion of the recording paper. Therefore, the output voltage of the photoelectric conversion element also changes in this portion. When this voltage fluctuation exceeds a predetermined fixed value, it is determined that the recording paper is multi-fed.

If it is determined in the above processing that the recording paper is being multi-fed, an alarm for a recording paper abnormality is issued immediately and printing on the recording paper is stopped. Thus, when the recording paper is fed multiple times, the conveyance of the recording paper is stopped when the double feeding detection sensor (combination of the light source and the photoelectric element) detects the double feeding. Raise an alarm for abnormalities. That is, by mounting the double feed detection sensor sufficiently in front of the printer fixing device, it is possible to prevent erroneous printing on recording paper, and it is possible to reduce costs by eliminating waste of recording paper and toner.

[0017]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a printing apparatus according to one embodiment of the present invention. In the figure, the printing apparatus includes a scanner 1, a reading control unit 2, a printer control unit 3, a line control unit 4, a memory 5, a control unit 6, a communication control unit 7, a printer interface 8,
The printer 9 includes a printer 9, a recording paper double feed detection unit 10, and an alarm display unit 11.

Image information input from one of the scanner 1, the printer controller 3, and the line controller 4 is transferred to the printer 9 via the printer interface 8 under the control of the controller 6. For the recording paper (not shown) being conveyed for printing by the printer 9, the recording paper double-feed detection unit 10 detects whether or not the recording paper is multi-fed. In this case, since the double feed of the recording paper is detected by a change in the voltage level, the output voltage level of a sensor (not shown) in the recording paper double feed detection unit 10 is sent to the control unit 6.

Here, a predetermined constant voltage change level is stored in the memory 5, and the control unit 6 stores the voltage change level sent from the recording paper double feed detecting unit 10 and the memory 5. The voltage change level is compared with the current voltage change level. The control unit 6 determines that the recording paper is multi-fed when the voltage change level sent from the recording paper multi-feed detection unit 10 exceeds the threshold of the voltage change level stored in the memory 5. Then, the alarm display section 11 warns the user to set the recording paper correctly again, and at the same time stops the printing operation of the printer 9.

FIG. 2 is a diagram showing an example of a detection method by the recording paper double feed detection unit 10 of FIG. In the figure, a light source 12
Is arranged so as to irradiate irradiation light onto the back surface of the recording paper conveyed by the conveyance rollers 16 and 17, and the sensor 13 is disposed at a position facing the light source 12 across the recording paper conveyance path. ing.

The image formed on the drum 14 is transferred by the transfer charger 15 to the recording paper that has passed between the light source 12 and the sensor 13, and discharged by rollers 18 and 19.
Is transported to a fixing unit (not shown).

In this case, the irradiation light emitted from the light source 12 is applied to the back surface of the recording paper, and the transmitted light transmitted through the recording paper enters the sensor 13 of the photoelectric conversion element. Normally, the irradiation light from the light source 12 is directly incident on the sensor 13 until the recording paper passes between the light source 12 and the sensor 13.

Since the recording paper has a constant thickness and density, the transmitted light from the recording paper has a constant illuminance. However, when the recording papers a1 and a2 are double-fed with a slight shift, there is a difference between the thickness and the density of the recording paper before and after the portion where the recording papers a1 and a2 overlap. Naturally, the recording papers a1, a
2 becomes thicker than the thickness of only the recording paper a1,
The transmitted light from the recording papers a1 and a2 attenuates, and the output voltage from the sensor 13 also decreases. When the voltage change level exceeds a certain value, it is determined that the recording papers a1 and a2 are multi-fed.

FIG. 3 is a diagram showing a change in the voltage level output from the recording paper double feed detecting section 10 in FIG. FIG. 3 (a)
Is a recording paper double feed detection unit 1 when the recording paper is normally conveyed.
FIG. 3B shows a change in the voltage level output from 0, and FIG.
Represents the change in the voltage level output from the recording paper double feed detection unit 10 when the recording paper is multi-fed, and FIG. 3C shows the characteristics of the sensor 13.

When the recording paper is not conveyed, the irradiation light from the light source 12 is directly incident on the sensor 13, so that a certain level of voltage is generated. On the other hand, recording paper a
When only 1 is conveyed normally, the light source 12 and the sensor 13
Since the recording paper a1 blocks the light from the light source 12, the amount of light emitted from the light source 12 that passes through the recording paper a1 and enters the sensor 13 is reduced. [See FIG. 3A].

On the other hand, when the recording papers a1 and a2 are multi-fed, the recording papers a1 and a2 block the space between the light source 12 and the sensor 13, so that the recording papers a1 and a2 pass through and enter the sensor 13. The amount of light emitted from the light source 12 is one sheet of recording paper a.
1, the voltage level from the sensor 13 is lower than when only the recording paper a1 is conveyed (see FIG. 3B). When the voltage change level in this case exceeds the threshold value of the voltage change level stored in the memory 5, the control unit 6 determines that the recording sheets a1 and a2 are multi-feeding.

FIG. 4 is a flowchart showing the recording paper double feed detecting process according to one embodiment of the present invention. These FIGS. 1-4
The recording paper double feed detection process according to one embodiment of the present invention will be described with reference to FIG.

When the apparatus is in the standby state by turning on the power, the threshold value X of the voltage change level of the sensor 13 is stored in the memory 5 as an initial value (step S1 in FIG. 4).
After that, the apparatus is used, and the image information is input by the scanner 1 and the reading control unit 2 during the copying operation, or the image information from the information processing device (PC) (not shown) is input by the printer control unit 3; The image information is received by the line controller 4 and the communication controller 7 (step S2 in FIG. 4).

The image information thus input is transferred from the control unit 6 to the printer 9 via the printer interface 8, and is printed on the recording paper a1 (step S in FIG. 4).
3). The control unit 6 monitors and detects whether or not the recording paper a1 conveyed for printing is multi-fed based on the voltage change level from the sensor 13 of the recording paper multi-feed detection unit 10 (FIG. 4).
Step S4).

The control unit 6 compares the voltage change level of the sensor 13 with the threshold value X of the voltage change level stored in the memory 5 (step S5 in FIG. 4). If the voltage change level of the sensor 13 is larger than the threshold value X, the control unit 6 determines that the recording papers a1 and a2 are multi-fed, stops printing by the printer 9 (step S7 in FIG. 4), and provides the user with the recording paper. a1, a2
Alarm display section 1 to set the alarm correctly
1 (step S8 in FIG. 4).

The control section 6 determines whether the user has set the recording papers a1 and a2 correctly (step S4 in FIG. 4).
9) If the recording papers a1 and a2 are correctly set, the process returns to step S3, and the printing operation of the printer 9 is restarted.

If the voltage change level from the sensor 13 is smaller than the threshold value X, the control unit 6 determines that the recording paper a1 is normally conveyed, and continues printing by the printer 9 to the end. The operation ends (step S in FIG. 4).
6). Although an embodiment of the present invention describes an apparatus having both a printer function, a copy function, and a facsimile function, the present invention can be applied to an apparatus having only one of these functions. It is.

As described above, when printing on the recording papers a1 and a2 cut to a predetermined size, the conveyed recording papers a1 and a2 are provided with a light source in front of the printer 9 (drum 14 and transfer charger 15). Irradiation light from 12
The control unit 6 monitors the voltage change level from the sensor 13 that receives the light that has passed through the recording papers a1 and a2,
When the voltage change level exceeds a preset threshold value X, printing by the printer 9 is suppressed, and an alarm is displayed on the alarm display section 11, whereby the recording paper a1,
Misprinting due to double feeding of a2 can be eliminated, and recording papers a1 and a2 and toner can be saved.

[0034]

As described above, according to the present invention, in a printing apparatus including a printing mechanism for printing print data on paper cut to a predetermined size, the paper is irradiated before the printing mechanism. Erroneous printing due to multifeeding of paper can be eliminated by detecting multifeeding of paper using the irradiated light and suppressing printing of print data on paper by the printing mechanism when double feeding of paper is detected. This has the effect of saving paper and toner.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating an example of a detection method by a recording paper double feed detection unit in FIG. 1;

FIG. 3A illustrates a case where a recording sheet is normally conveyed;
FIG. 3B is a diagram showing a change in the voltage level output from the recording paper double feed detecting unit of FIG. 1, and FIG. FIG. 3C is a diagram showing characteristics of the sensor of FIG.

FIG. 4 is a flowchart showing a recording paper double feed detection process according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of printing when recording paper is multi-fed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scanner 2 Reading control part 3 Printer control part 4 Line control part 5 Memory 6 Control part 7 Communication control part 8 Printer interface 9 Printer 10 Recording paper double feed detection part 11 Alarm display part 12 Light source 13 Sensor 14 Drum 15 Transfer charger

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 21/00 386 G03G 21/00 386

Claims (4)

[Claims] 1. A printing apparatus including a printing mechanism for printing print data on paper cut to a predetermined size, comprising: a light source for irradiating the paper with irradiation light in front of the printing mechanism; Detecting means for detecting double feeding of the paper using irradiation light emitted from the light source to the paper, and detecting the double feeding of the paper by the printing mechanism when the detecting means detects double feeding of the paper. A printing apparatus, comprising: a suppression unit that suppresses printing. 2. A conversion device, wherein the detection device is disposed at a position facing the light source with the paper conveyance path interposed therebetween, and the light emitted from the light source converts light transmitted through the paper into a voltage. 2. The printing apparatus according to claim 1, further comprising: a detecting unit configured to detect a change in the voltage converted by the converting unit to detect the passage of the sheet and the double feeding of the sheet. 3. The detecting means detects the passage of the sheet by a decrease in voltage from the converting means caused when the irradiation light passes through the sheet, and the voltage from the converting means passes through the sheet. 2. The apparatus according to claim 1, wherein the multi-feed of the paper is detected when the voltage is lower than the voltage at the time.
Or the printing device according to claim 2. 4. The printing apparatus according to claim 1, further comprising a notifying unit for notifying a conveyance failure of the sheet when the detecting unit detects the double feeding of the sheet.