JPH065434B2 - Transfer paper winding detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a transfer paper wrap detection for a copying machine that detects when the transfer paper is wrapped around a high temperature roller or the like for heating and fixing the toner on the transfer paper. Regarding the device.

<Prior Art> In a conventional copying machine, there is no detection that the transfer paper is wrapped around the fixing roller, and the paper output sensor detects whether the transfer paper is output from the upper and lower fixing rollers.

<Problems to be Solved by the Invention> In the transfer paper winding detection device having the above configuration, the transfer paper that has passed through the pair of high temperature rollers is peeled by the peeling claws that are pressed against the upper and lower rollers. , If you copy the original with a lot of black solid, which is the condition that the tip of the peeling claw (the part that is in contact with the high temperature roller) is deformed or the roller surface is easily stuck, the transfer paper is not peeled by the claw. Or wrap it around the lower roller. At this time, the paper output detection switch displays a paper jam inside the machine, but if the transfer paper is completely wrapped around and the user cannot remove the transfer paper, the normal copy ready status is notified. , There are cases in which copying is subsequently performed. If such a state continues,
The heating of the heater carbonizes the transfer paper 1, leading to smoke and ignition.

The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a transfer paper wrapping detection device capable of preventing smoking or ignition of the transfer paper even when the transfer paper wraps around the high temperature roller.

<Means for Solving Problems> In order to solve the above problems, the present invention provides a pair of upper and lower high temperature rollers 2 and 3 for heating and fixing the toner on the transfer paper 1 as shown in the front view of FIG. , A first temperature sensor 4, 5 and a second temperature sensor 6, for detecting its surface temperature
7, the first temperature sensors 4 and 5 are arranged corresponding to an image forming area (a range indicated by L1 in the figure) which is a portion on the surface of the high temperature roller through which the transfer paper 1 passes. The second temperature sensors 6 and 7 are arranged corresponding to a non-image area (a range indicated by L2 in the drawing) which is a portion on the surface of the high temperature roller where the transfer paper 1 does not pass. , 6, 7 is provided with a control device 9 for controlling the energization of a heater 8 as a heating means provided in the high temperature rollers 2, 3 according to the output temperature signals from the first temperature control device. When the temperature difference between the image forming area and the non-image forming area in the same high temperature roller detected by the sensors 4 and 5 and the second temperature sensors 6 and 7 reaches a predetermined value, energization to the heater 8 is stopped and All the operations of the copier It has been allowed to have the ability to stop.

<Operation> According to the present invention, when the transfer paper 1 is wrapped around the upper high temperature roller 2, the surface temperature of the image forming area of the upper high temperature roller 2 around which the transfer paper 1 is wrapped decreases. On the other hand, the surface temperature does not change in the non-image area where the transfer paper 1 is not wrapped. Then, when the surface temperature difference T1 of the upper high temperature roller 2 calculated based on the output temperature signals of the first temperature sensor 4 and the second temperature sensor 6 reaches a predetermined value, the controller 9
Stops energizing the heater 8 and stops all operations of the copying machine.

Similarly, when the transfer paper 1 is wrapped around the lower high temperature roller 3, when the surface temperature difference T1 of the high temperature roller 3 reaches a predetermined value, the control device 9 stops energizing the heater 8 and all of the copying machines. Since the operation is stopped, it is possible to prevent smoke or ignition from the transfer paper 1.

<Embodiment> An embodiment of the transfer winding detection device of the present invention will be described below with reference to FIGS. 1 to 5. FIG. 1 is a front view of a transfer paper wrapping detection apparatus showing an embodiment of the present invention, FIG. 2 is a side view showing a state in which the transfer paper is wrapped around a high temperature roller, and FIG. The electric circuit diagram, FIG. 4 is a graph showing the relationship between the surface temperature of the high temperature roller and the time when the transfer paper is not wrapped around the high temperature roller, and FIG. 5 is the transfer paper wrapped around the high temperature roller. It is a graph which shows the surface temperature of the high temperature roller of a state, and the relationship of time.

Then, as shown in the figure, the present invention has a pair of upper and lower high temperature rollers 2 and 3 for heating and fixing the toner on the transfer paper 1, and an image forming area of both the high temperature rollers 2 and 3 (range indicated by L1 in the figure).
The first temperature sensors 4 and 5 disposed on the first temperature sensor and the second temperature disposed on the non-image areas of both the high temperature rollers 2 and 3 (portion indicated by L2 in the range indicated by L2 and L3 in the figure) The sensors 6 and 7 and the control device 9 that controls the energization of the heater 8 as the heating means provided in the high temperature rollers 2 and 3 based on the output temperature signals from the sensors 4, 5, 6 and 7. The control device 9 is provided to stop energizing the heater 8 and copy when the temperature difference detected by the first temperature sensor 4, 5 and the second temperature sensor 6, 7 reaches a predetermined value. It was given the function of stopping all of the machines and their operations.

Each of the first temperature sensor 4, 5 and the second temperature sensor 6, 7 is a thermistor having a characteristic that its resistance value decreases as the temperature rises and its resistance value increases as the temperature falls. 5, 6 and 7 are uniformly pressed against the surface of the high temperature rollers 2 and 3 with a force of about 150 ± 30 g, and the high temperature rollers 2 and 3 have peeling claws 10 that are pressed against the surface of the image area. Then, as shown in FIG. 3, one ends of the first temperature sensors 4 and 5 and the second temperature sensors 6 and 7 respectively sandwich the resistors R1 and R2, and the + input terminals 12 and − of the operational amplifier 11 (comparator). It is connected to the input terminal 13, and the other ends of the first temperature sensors 4 and 5 and the second temperature sensors 6 and 7 are connected to the power supply Vc. A temperature control circuit Tcc is connected to the intermediate point 14 between the resistor R2 and the-input terminal 13.

The output terminal 1 of the operational amplifier 11 is provided on the input side of the control device 9.
5 is connected, and the drive circuit of the heater 8 and the copy drive circuit 16 are connected to the output side. Reference numeral 17 in the figure denotes a paper output sensor.

Next, the operation will be described. The change in the surface temperature T of the rollers 2 and 3 during the normal copying operation is as shown in FIG. However, as shown in FIG. 2, the transfer paper 1 passing between the high temperature rollers 2 and 3 passes through the peeling claw 10 and is not peeled off, and when it is wrapped around the upper high temperature roller 2, the graph of FIG. As shown in FIG. 5, a temperature difference T1 of about 50 to 60 ° C. occurs between the first temperature sensor 4 and the second temperature sensor 6. This temperature difference is determined by the characteristics of each sensor.
Electrical conversion is performed by the circuit of FIG. At this time, + input terminal voltage <−input terminal voltage, the output of the operational amplifier 11 becomes L level, and this output signal causes the control device 9 to stop energizing the heater 8 and stop the operation of the copy driving circuit 16. Output.

The output conditions of the op amp 11 are as follows.

Resistance value of resistance R1 <winding resistance value of resistance R2; + input terminal voltage <-when input terminal voltage, L level signal is output from output terminal 15 Normal status; + input terminal voltage> -input terminal voltage At this time, an H level signal is output from the output terminal 15. Further, in the above example, the transfer paper 1 is shown wrapped around the upper high temperature roller 2, but when the transfer paper is wrapped around the lower high temperature roller 3, , First temperature sensor 5 and second temperature sensor 7
Since a temperature difference T1 occurs during the period, an L level signal is output from the output terminal 15, and the control device 9 outputs a stop signal to the heater and the copy drive circuit 16.

Therefore, when the transfer paper 1 is wrapped around the high temperature rollers 2 and 3, the heater 8 is de-energized and the operation of the copying machine is stopped. Therefore, smoke or ignition from the transfer paper 1 can be prevented.

The present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

For example, in the above embodiment, the heater 8 is the high temperature roller 2,
Although it is embedded in No. 3, it may be placed outside the high temperature rollers 2 and 3.

<Effect of the Invention> As is apparent from the above description, according to the present invention, the first temperature sensor for detecting the surface temperature of the region around which the transfer paper is wrapped and the region around which the transfer paper is not wrapped around the same high temperature roller. Since a second temperature sensor for detecting the surface temperature of the transfer paper is installed, the winding of the transfer paper around the high temperature roller can be detected based on the surface temperature difference in each area, and the energization of the heating means is stopped. At the same time, since all the operations of the copying machine are stopped, it is very effective to prevent smoke and ignition from the transfer paper.

In this case, since the surface temperature on the same high temperature roller is detected at two places, it is not necessary to consider the state of the high temperature roller (for example, the rising state when the power is turned on), and the configuration is very simple. Therefore, it is possible to accurately detect the wrapping of the transfer paper without being affected by the surrounding conditions.

[Brief description of drawings]

FIG. 1 is a front view of a transfer paper wrapping detection apparatus showing an embodiment of the present invention, FIG. 2 is a side view showing a state in which the transfer paper is wrapped around a high temperature roller, and FIG. The electric circuit diagram, FIG. 4 is a graph showing the relationship between the surface temperature of the high temperature roller and the time when the transfer paper is not wrapped around the high temperature roller, and FIG. 5 is the transfer paper wrapped around the high temperature roller. It is a graph which shows the surface temperature of the high temperature roller of a state, and the relationship of time. 1: transfer paper, 2, 3: high temperature roller, 4, 5: first temperature sensor, 6, 7: second temperature sensor, 8: heater,
9: control device, 10: peeling nail, 11: operational amplifier, 1
2: input terminal, 13: input terminal, 15: output terminal, 1
6: Copy drive circuit, L1: Range of image forming area, L2:
The extent of the non-image area.

Claims (1)

[Claims] 1. A first temperature sensor and a second temperature sensor for detecting the surface temperature of a pair of high-temperature rollers for heating and fixing a toner on a transfer paper, the first temperature sensor being the high temperature roller. The second temperature sensor is arranged corresponding to an image forming area which is a portion where the transfer paper on the roller surface passes, and the second temperature sensor corresponds to a non-image area which is a portion where the transfer paper on the high temperature roller surface does not pass. A control device is provided, which controls the energization of the heating means provided on the high temperature roller according to the output temperature signals from both the sensors, and the control device includes the first temperature sensor and the second temperature sensor. It has a function of stopping energization to the heating means when the temperature difference between the image forming area and the non-image forming area on the same high temperature roller detected reaches a predetermined value. And a transfer paper wrapping detection device.