JP2003137455A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of decreasing the time with trouble for print operation by detecting that a supply roller is close to its life end point and warning the user about it. SOLUTION: An image sensor is incorporated in a recording material feeding path, and a means to conduct image processing of output from the image sensor and detect the moving amount of a recording material, and a means to determine if the moving amount is not normal are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to consumable product life detection of an image forming apparatus capable of forming an image.

[0002]

2. Description of the Related Art An image forming apparatus for visualizing an image stored in a memory by fixing a developer, that is, a toner on a recording material such as a printing paper is typified by a laser beam printer or a copying machine. Widely used due to its sex.

The printing operation in such an image forming apparatus is performed by a known electrophotographic technique, that is, exposure, development,
After the transfer process, an image visualized with toner is carried on a recording material such as print paper, and finally, the toner image is fixed on the recording material, and the process ends. The configuration is as shown in FIG.

FIG. 9 shows a main section of a conventional printer.
Is a paper cassette for the paper P, 12 is a paper presence detection lever for detecting the presence of the paper P, and 11 is a paper presence detection sensor. The paper presence / absence detection sensor 11 is a transmissive photo interrupter, and when the paper P is not present in the paper cassette 1, the paper presence / absence detection lever 12 shields the detection unit of the paper presence / absence detection sensor 11.

A feed roller 51 that conveys the paper P and a retard roller 52 that rotates in the direction of returning the paper P to the paper cassette 1 when a plurality of papers P are overlapped and supplied are provided downstream of the paper supply roller 2. A paper feed sensor 17 for detecting the completion of paper feeding, a registration roller pair 3 for synchronous conveyance are provided, and a registration sensor 27 for detecting that the paper P reaches the registration roller pair 3.

Here, if the paper P is not conveyed to the position of the paper feed sensor 17 even if the paper feed roller 2 is rotated by a certain amount, a feed error is detected and the user is notified.

A process cartridge 21 that forms a toner image on the photosensitive drum 4 based on the laser beam from the laser scanner section 18 is provided downstream of the registration roller pair 3. The toner image on the photosensitive drum 4 is transferred to the transfer roller 5
Is transferred to the sheet P by. Further, a fixing device 6 for thermally and pressure-fixing the toner image formed on the paper P is provided downstream of the process cartridge 21, and a fixing paper discharge detecting the passage of the paper P is provided downstream of the fixing device 6. A sensor 15 is provided. The paper P for which recording has been completed is stacked on a stack tray (not shown) at the top of the machine.

Further, 14 is a carrying roller for nipping and carrying the paper P.

The laser scanner section 18 includes a laser unit 26 for emitting a laser beam, a polygon motor 25 for scanning the photosensitive drum 4 with the laser beam from the laser unit 26, an imaging lens group 19, and a folding back. It is composed of a mirror 20 and the like.

The fixing device 6 includes a fixing roller 7 and a fixing roller 7.
It is composed of a heater 8 that heats the sheet, a pressure roller 9 that is in pressure contact with the fixing roller 7, a temperature sensitive element 10 such as a thermistor, and the like.

Then, the process cartridge 21
Is a photosensitive drum 4, which requires a known electrophotographic process,
It comprises a pre-exposure lamp 22, a primary charger 23, a developing device 16, a cleaner blade 24 and the like.

Next, the operation for automatically printing on the paper P will be described with reference to FIG. First, the paper P is fed from the paper cassette 1 by the paper supply roller 2, conveyed by the registration roller 3 to the photosensitive drum 4, and the image is transferred onto the paper P by the transfer roller 5. Then, it is sent to the fixing device 6.

A heater 8 is provided inside the fixing roller 7 to heat the inner peripheral surface of the fixing roller 7. Then, this heat is transmitted to the front surface side by heat conduction of the fixing roller 7 itself. A temperature sensitive element 10 such as a thermistor is in contact with the surface of the fixing roller 7. Temperature sensor 10
In accordance with the surface temperature of the fixing roller 7 detected by, the power supply to the heater 8 is controlled by a temperature control circuit (not shown), and the surface temperature of the fixing roller 7 is automatically adjusted to a predetermined fixing temperature. . The sent paper P is heated and pressed by the fixing roller 7 and the pressure roller 9, and the image is fixed on the paper P.

The paper P for which recording is completed in this way is stacked on the stack tray at the top of the main body of the image forming apparatus.

[0015]

However, according to the above-mentioned conventional example, the frictional force between the paper supply roller and the paper is reduced due to the wear of the paper supply roller or the adhesion of the fibers of the paper. Since the supply roller and the paper may slip out and many supply errors occur, it is necessary to arrange parts after understanding that the supply roller needs to be replaced, and until the replacement, the printing operation was hindered. .

According to a first aspect of the present invention, which solves the above-mentioned problems, the life of a supply roller can be quickly detected, and the user is notified in advance to shorten the period during which a print operation is disturbed. The purpose is to provide the device. Another object of the present invention is to provide an image forming apparatus capable of promptly detecting the replacement time of the supply roller even in an apparatus having a fast printing operation.

Further, a third invention of the present application aims at providing an image forming apparatus capable of reducing the cost by reducing the recording material presence sensor and the recording material presence detecting lever and further achieving the above object.

[0018]

According to a first aspect of the present invention, the object is to provide an image sensor in a recording material conveying path, perform image processing on the output of the image sensor, and determine the movement amount of the recording material. This is achieved by providing a means for detecting and a means for determining that the movement amount is abnormal.

According to the second invention of the present application, the object is to provide an image sensor for detecting the recording material in the vicinity of the recording material cassette, and to process the output of the image sensor to detect the moving amount of the recording material. And a control means for determining that the movement amount is abnormal.

According to the third invention of the present application, the above object is achieved by having both an image sensor for detecting the recording material near the recording material cassette and a function for detecting the absence of the recording material.

[0021]

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

First, a first embodiment to which the present invention can be applied will be described with reference to FIGS. In addition, the same parts as those of the conventional example will be described with the same symbols and omitted.

FIG. 1 is an enlarged view of the sheet feeding section of the printer according to the first embodiment. The difference from the conventional example of FIG. 9 is that instead of the sheet feeding sensor 17, the LED array 102 and the CMO are used.
This is a point added by the S image sensor 101. The LED array 102 is used for illumination of the detection area of the CMOS image sensor 101 and sensitivity adjustment described later. CMOS image sensor 101 is TCM5020ALU (made by Toshiba)
and so on. The peripheral circuit block will be described later.

FIG. 2 is a sectional view of the printer, and the difference from the conventional example FIG. 9 is the LED array 102 and the CMOS image sensor 101 as in FIG.

FIG. 3 is a diagram for explaining the concept of detecting the characteristics of the surface of the recording material (paper is used in this embodiment).
The surface of the recording paper has unevenness as shown in this figure when it is magnified, and when exposed to light, the bright and dark parts look like patterns. By grasping these characteristics and detecting the movement of the position, the actual movement amount of the recording paper can be known.

FIG. 4 is a block diagram of a peripheral circuit of the CMOS sensor. This embodiment will be described below with reference to FIG.

In FIG. 4, reference numeral 81 is a one-chip microcomputer (hereinafter referred to as CPU) that controls the printer body, and also controls the CMOS sensor. 83 is LE
This is a D array driver. The CPU 81 can output an analog level from the D / A port, amplify it by the driver 83, and continuously change the light amount of the LED array 102. The CPU 81 sends the control signal and the timing pulse to the information of the area in the horizontal and vertical directions to the CMOS.
It can be obtained from the sensor 101.

Next, the paper slip detection control of this embodiment will be described with reference to the flowcharts of FIGS. 5 and 6.

First, a sensitivity adjustment process, which will be described later in detail with reference to FIG. 6, is performed (S21). When the sensitivity adjustment is normally completed, a control signal and a timing pulse are sent to the CMOS image sensor to capture an image signal (S22). An area of 80% in the center in the main scanning direction and an area of 20% at the trailing edge of the paper are selected (S23). Find the highest level (the bright part). At this time, when there are a plurality of same levels, a place near the center in the main scanning direction and a place far from the rear end of the paper are preferentially selected (S24). Main scanning around that part,
Relative data of ± 10 pixels in the sub-scanning direction is stored (S2
5). Since the paper is being conveyed, the control signal and the timing pulse are sent again to the CMOS image sensor to capture the image signal (S26). The 20 × 20 area previously stored is searched (S27). The amount of movement of the pixel selected in S24 is calculated (S28), and collated with the control pulse of the paper transport motor (stepping motor) (S29). It is converted into a movement amount and it is determined whether it is within ± 5% (S30). If it is more than that, the slip counter is incremented by 1 (S31). If the slip counter reaches 10 or more (S32), it is determined that the roller has reached the end of its life, and the user is notified (S3).
3). The details of this process are not related to the present invention, and therefore will be omitted. If the slip counter is 10 or less in S32,
Proceed with processing. The comparison value converted to the movement amount in S30 is 5%
In the following cases, it is judged that the paper is not slipping, and then it is judged whether it is the trailing edge of the paper. Specifically, it is determined that the trailing edge of the paper is reached when all three lines in the main scanning direction on the trailing edge side of the paper in the sub-scanning direction have reached a level of 100 or less (S34). If the trailing edge of the paper,
Processing Exit. At this time, the slip counter is reset to 0 (S35). If it is not the trailing edge of the paper in S34, the process returns to S22.

FIG. 6 is a flowchart of the sensitivity adjustment processing in this embodiment.

First, the light quantity of the LED array is maximized (S1). A pulse for feeding the paper and stopping it near the CMOS sensor is sent to the carry motor to temporarily stop it (S
2). When the paper feeding operation has been performed three times (S3), it is determined that a paper feeding error has occurred, jam processing is performed and the user is notified (S3).
8). If it is less than three times, a control signal and a timing pulse are sent to capture an image signal (S4). CPU CMOS
When the sensor average value is 250 or more, it is determined that there is paper, and the following processing is performed (S5). If it is determined that there is not, it returns to S2. The next process that judges that there is paper is LE
The D light quantity is lowered by 5 levels, and the control signal and the timing pulse are sent again to capture the image signal (S7). At this time, LE
When the D light amount level is 0 (S8), the abnormality processing is performed (S9). Next, it is determined whether the input average value is 128 or less (S10). If this value is 129 or more, the process returns to S7. Next, the LED light amount level is increased by 5 and a control signal and a timing pulse are sent to capture an image signal (S12). It is determined whether the input average value is 128 or more (S12). 1
When it is less than 28, the process returns to S12. If 128 or more,
The paper feeding operation is restarted (S13) and the process is returned (S14).

As for the image sensor, the CMOS area sensor is used in this embodiment, but it goes without saying that another image sensor can be used instead.

(Second Embodiment) Next, a second embodiment of the present invention will be described. FIG. 7 is a sectional view of an image forming apparatus to which the present invention can be applied. The difference from the first embodiment is that
This is that the CMOS sensor 101 can detect the paper P stored in the paper cassette 1.

The sensitivity adjustment process is shown in FIG.

The same processes as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. Only the differences will be described here. First, in the present embodiment, the sensitivity can be adjusted while the paper is stored in the paper cassette 1, so S2, S3, S6, S13
Is unnecessary. If no paper is detected in S5, a process of notifying the user that there is no paper is performed (S31). The detailed operation is not related to the present invention and thus will not be described.

The paper slip detection process is performed according to the flow chart (FIG. 6) described in the first embodiment, and the only different process is S34. This process is "size detection of paper cassette 1 (not shown)". Did you send the paper feed amount of the size detected by "?"

With such a construction that the paper in the paper cassette is detected in the stored state, the image sensor, the paper out sensor and the lever can be used together, and the cost can be suppressed.

[0038]

As described above, the first aspect of the present application
According to the invention, the life of the supply roller can be detected quickly,
By notifying the user in advance, it is possible to shorten the period during which the print operation is disturbed.

According to the second invention of the present application,
Even with a device having a fast printing operation, it is possible to quickly detect the replacement time of the supply roller without stopping the paper once.

Further, according to the third invention of the present application, the cost can be suppressed by eliminating the paper presence sensor and the paper presence detection lever.

[Brief description of drawings]

FIG. 1 is an enlarged view of a paper feed unit of a printer according to a first embodiment.

FIG. 2 is a sectional view of the printer showing the configuration of the first embodiment.

FIG. 3 is an explanatory diagram showing the basic principle of the present invention.

FIG. 4 is a block diagram of the periphery of the image sensor according to the first and second embodiments.

FIG. 5 is a first sequence flowchart of the first embodiment.

FIG. 6 is a second sequence flowchart of the first embodiment.

FIG. 7 is a sectional view of the printer showing the configuration of the second embodiment.

FIG. 8 is a first sequence flowchart of the second embodiment.

FIG. 9 is a cross-sectional view of a printer showing a configuration of a conventional example.

[Explanation of symbols]

1 paper cassette 2 Paper supply roller 6 fixing unit 11 Paper presence sensor 12 Paper out detection lever 18 Scanner unit 21 Process cartridge 81 1-chip microcomputer (CPU) 101 CMOS area image sensor 102 LED array

Claims (3)

[Claims] 1. An image forming apparatus in which a plurality of recording materials are stored in a recording material cassette, and each of the recording materials is taken out during a printing operation to perform an image forming process. An image forming apparatus comprising: a unit configured to image-process the output of the recording medium to detect a movement amount of a recording material; and a unit to determine that the movement amount is abnormal. 2. An image sensor for detecting a recording material in the vicinity of the recording material cassette in an image forming apparatus for storing a plurality of recording materials in a recording material cassette and taking out one of the recording materials during a printing operation to perform an image forming process. An image forming apparatus comprising: a means for performing image processing on an output of the image sensor to detect a movement amount of a recording material; and a control means for determining that the movement amount is abnormal. 3. The image forming apparatus according to claim 2, wherein the image sensor for detecting the recording material near the recording material cassette also has a function of detecting the absence of the recording material.