JPH04112270U - Fusing device - Google Patents

Abstract

(57) [Summary] [Purpose] In a fixing device that uses an endless belt mechanism to press a heating roller, it is possible to prevent poor fixing of the paper edge and damage to expensive parts such as the belt itself and the sensor for detecting the belt edge. To prevent. [Structure] Abnormality detection sensors 22a and 22b are provided on both sides of the endless belt 11 at positions outside of belt end detection sensors 16a and 16b. These abnormality detection sensors 22
Due to a and 22b, the deviation of the constant value abnormality of the endless belt 11,
That is, an abnormal state in the abnormality detection range B is detected, and the operation of the entire apparatus is stopped based on the result.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention enables toner images to be printed on paper in electronic copying machines, image recording devices, etc. It is related to the fixing device for fixing, especially the pressing by an endless belt against the heating roller. The present invention relates to a fixing device equipped with a pressure mechanism.

0002

[Conventional technology]

In general, image forming devices that use dry toner, such as electronic copying machines and image recording devices, In a machine, a toner image formed on an image carrier such as a photoreceptor drum is transferred to paper. The paper carrying the unfixed toner image is transported toward the fixing device, and this fixed In the fusing device, toner is melted and fixed by applying heat and pressure. Ru.

0003 By the way, this fixing device is generally used between a pressure roller and a heating roller. A heated roller method is used that nip the paper and fix it using heat and pressure. However, with this heating roller type fixing device, the paper is passed between both rollers. When applying heat and pressure, there are problems such as wrinkles in the paper and misalignment of images. Ta.

[Problem that the idea aims to solve]

In order to solve this problem, the present applicant and the same applicant first developed a heating roller. In response, we proposed a fixing device equipped with a pressing mechanism using an endless belt mechanism. This fuser According to the paper, it is possible to maintain a constant speed distribution in the width direction of the paper. It is possible to prevent wrinkles and image shift.

0004 In this fixing device by the present applicant, in order to operate it smoothly, Controlling the meandering of the route is an essential requirement, but in the unlikely event that a problem occurs, it is necessary to This can lead to poor fixing of the belt and damage to expensive parts such as the belt itself and the sensor for detecting the edge of the belt. It is thought of.

[0005] The present invention was devised in view of these problems, and its purpose is to prevent damage caused by meandering. Fixing system that can prevent fixing failure and damage to belts, etc. in the event of a problem. The goal is to provide equipment.

[0006]

[Means to solve the problem]

The fixing device according to the present invention applies heat and pressure to the paper that carries the toner image. There is a heating roller that melts the toner and fixes it on the paper, and a heating roller that melts the toner and fixes it on the paper. An endless belt is used as a pressure means to press the paper, and the meandering of this endless belt is detected. a first belt end detection means, and a detection result of the first belt end detection means; belt meandering correction means for correcting meandering of the endless belt; a second belt end detection means that detects when the meandering exceeds a certain value; A device that stops the operation of the entire device based on the detection result of the second belt end detection means. and stop means.

[0007] With this configuration, in the fixing device of the present invention, the meandering of the endless belt is constant. When the value exceeds this value, the entire device stops operating, which may result in poor fixing at the edges of the paper or This can prevent damage to parts such as the belt itself and the sensor for detecting the belt end.

[0008]

【Example】

Embodiments of the present invention will be described below with reference to the drawings. Figure 3 shows an example of the present invention. This figure shows the configuration of such a fixing device. Figure 1 is viewed from the direction of arrow A-A shown in Figure 3. This is a diagram. This fixing device 1 is installed in a copying machine, and has a heat generating lamp 3 inside. A heating roller 2 housed therein and a pressure base for pressing the paper against the heating roller 2 are installed. belt mechanism 4, and pressure for performing a pressing action from the back side of the pressure belt mechanism 4. It is composed of a plate 5. On the upstream side of the fixing device 1, there is a transport mechanism 6 and a gas An idle plate 7 is arranged, and a discharge roller 8 is arranged on the downstream side. Also, Canada A temperature sensor 9 is provided for the heat roller 2 to adjust the temperature of the heat roller 2. The sea urchin is turning. Also, on the ejection side, there is a A second peeling claw 10 is arranged. Endless belt 11 that constitutes the pressure belt mechanism 4 is made by coating glass floss with fluororesin and constructing it as an endless belt member. This is what I did.

[0009] The endless belt 11 includes an intrusion roller 12, a drive roller 13, a tension roller 14, and and the meandering correction roller 15, which controls the drive and tension of the belt. settings and to prevent meandering. Also, the endless belt 11 On both sides of the endless belt 11, upstream of the position where the paper is set, there are Belt end detection sensors 16a and 16b are arranged as first belt end detection means. It is placed. The belt end detection sensors 16a and 16b perform the fixing operation. Detect the meandering of the endless belt 11 within the normal meandering range shown by A in Fig. 1 while It is designed to perform corrective action based on the detection signal. In addition, ten The tension roller 14 applies a constant tension to the endless belt 11 by a spring 17. It is now granted.

0010 The meandering correction roller 15 is a long roller arranged in the width direction of the endless belt 11. Meandering correction mechanisms are placed at both ends of the roller shaft. This meander correction machine The structure is composed of a solenoid 18 and a link 19. Link 19 is fulcrum 20 The solenoid 18 is attached to the base and the solenoid 18 is attached to the other end. is connected to the shaft 21 of the meandering correction roller 15. This meandering correction mechanism The solenoid 18 is driven by the signals from the part detection sensors 16a and 16b, and the endless The meandering correction roller 15 is swung according to the deviation of the belt 11, and the endless belt 11 is corrected. This is to correct the position. Note that the trajectory R along which the meandering correction roller 15 swings is as follows: Draw an ellipse centered on the axis of the intrusion roller 12 and the axis of the tension roller 14. , the meandering correction roller 15 is swung along the elliptical arc, and the meandering correction roller 15 is It is configured to constitute a guide mechanism.

[0011] In addition, in FIG. 1, belt end detection sensors 16 are provided on both sides of the endless belt 11. An abnormality detection sensor as a second belt end detection means is installed at a position outside of a and 16b. sensors 22a and 22b are provided, and these abnormality detection sensors 22a and 22b The deviation of the endless belt 11 is more than a certain value, that is, the abnormality in the abnormality detection range B. It is designed to detect the state.

0012 FIG. 2 shows the meandering within the normal meandering range A of the endless belt 11 in this fixing device. This figure shows the line correction operation, and (a) shows the detection by the belt end detection sensor 16a. The state after the belt end detection sensor 16b shows the state after detection by the belt end detection sensor 16b. ing. Note that FIG. 2 represents a cross-sectional structure viewed from the direction of arrow B-B in FIG. . The endless belt 11 is meandering and the belt end detection sensor 16a detects this. In this state, the solenoid 18 is in the OFF state, and the endless belt is turned off while maintaining this state. 11 meanders in the direction of the arrow. If the endless belt 11 meanders in this state, the other belt The root end detection sensor 16b detects this and the solenoid 18 is turned on. The meandering correction roller 15 swings. As a result, the endless belt 11 is shown in FIG. 2(b). While meandering in the opposite direction, the belt end detection sensor 16a detects the endless belt again. 11 is detected, and this operation is repeated thereafter.

[0013] FIG. 4 shows the configuration of the meandering correction circuit using the belt end detection sensors 16a and 16b. It represents. The belt end detection sensor 16a includes a light emitting diode 30a and a belt end detection sensor 16a. It is composed of a normal photointerrupter consisting of a phototransistor 31a. Ru. Similarly, the belt end detection sensor 16b includes a light emitting diode 30b and a photodetector. It is constituted by a photointerrupter consisting of a transistor 31b. One frame The collector of the phototransistor 31a is composed of NAND gates 33 and 34. An inverter 70 is connected to one input terminal R of the RS type flip-flop circuit 32. connected via. The collector of the other phototransistor 31b is also connected to the It is connected to the input terminal S of the flip-flop circuit 32 via the inverter 71. Ru. The output terminal Q of the flip-flop circuit 32 is switched via a resistor 35a. Connected to the base of the transistor 35 and grounded via the resistor 35b. ing. The collector of this transistor 35 is connected to one end of the solenoid 18, On the other hand, the emitter is grounded. A diode 18a is connected in parallel to the solenoid 18. The other end is connected to the power supply line 42.

[0014] In this meandering correction circuit, the belt end detection sensor 16a is connected to the endless belt 11. When a meandering is detected, the phototransistor 31a is turned off, and as a result, the free The input terminal R of the flip-flop circuit 32 becomes low level "0". On the other hand, at this time The phototransistor 31b on the side of the belt end detection sensor 16b remains on. Yes, the input terminal S of the flip-flop circuit 32 is at a high level "1". did Therefore, the output terminal Q of the flip-flop circuit 32 becomes low level "0". this state, the switching transistor 35 is in the off state, so that the solenoid 18 is off. From this state, the endless belt 11 snakes in the opposite direction, and the belt If the phototransistor 31b detects this, the phototransistor 31b is turned off, and as a result, the input terminal S of the flip-flop circuit 32 becomes low level "0". becomes.

[0015] On the other hand, at this time, the phototransistor 31a on the belt end detection sensor 16a side is Therefore, the input terminal R of the flip-flop circuit 32 is in the on state. The high level is "1". As a result, the output terminal Q of the flip-flop circuit 32 becomes high. level becomes "1". As a result, the switching transistor 35 is turned on. Then, a driving current flows through the solenoid 18, and the solenoid 18 is turned on. like this By repeating these operations, the meandering of the endless belt 11 as shown in Fig. 2 is corrected. It will be done.

[0016] FIG. 5 shows the configuration of an abnormality detection circuit using abnormality detection sensors 22a and 22b. be. The abnormality detection sensor 22a is a light emitting diode 30a and a phototransistor. 31a, and an abnormality detection sensor 22b. is a photointerface consisting of a light emitting diode 30b and a phototransistor 31b. The configuration is similar to that of the belt end detection sensors 16a and 16b. be. The output signal of the abnormality detection sensor 22a is sent to the NAND gate via the inverter 70. Input terminal of RS type flip-flop circuit 36 configured by ports 33 and 34 It is designed to be input to S. On the other hand, the output signal of the abnormality detection sensor 22b is RS configured by the same NAND gates 33 and 34 via an inverter 71 The signal is input to an input terminal S of a type flip-flop circuit 36.

[0017] The output signals of these flip-flop circuits 36 and 37 are sent to an OR circuit 38, respectively. It is designed to be input to the input terminal of. The output terminal of the OR circuit 38 is a resistor 39 a to the base of the switching transistor 39, and a resistor It is grounded via 39b. The emitter side of the switching transistor 39 is In addition to being grounded, the cathode side of the light emitting display diode 40 is connected to the collector. It is continued. A relay 4 is further connected to the collector of the switching transistor 39. One end of 1 is connected. A resistor 40 is connected to the anode side of the light emitting display diode 40. It is connected to the power supply line 42 via a. The relay 41 has a diode 41a are connected in parallel, and the other end is connected to the power supply line 42. In addition, free A reset signal from the reset circuit 43 is connected to each input terminal R of the flip-flop circuits 36 and 37. signal is input.

[0018] The contact (normally open contact) 41a of the relay 41 is the power supply terminal (AC 100V) between 53 and 54, to the main motor 45 and heaters 46 and 47. are connected in parallel. A relay 44 is connected between the power terminal 53 and the contact 41a. is provided, and the contact (normally closed contact) 44a of this relay 44 is connected to the power terminal 53 and the main It is provided between the motor 45 and one end of each of the heaters 46 and 47. main motor Between the other end of 45 and the power supply terminal 54, there is an SSR (solid state resistor) as a switching element. A de-state relay) 48 is provided, which is operated based on a control signal from an operation control circuit 49. Then, the main motor 45 is controlled to be turned on and off. Hi again An SSR 50 is provided between the other ends of the motors 46 and 47 and the power supply terminal 54, and the temperature Based on the control signal from the control circuit 51, the heaters 46 and 47 are not controlled on and off. It is now possible to do so. The temperature control circuit 51 detects the temperature of the thermistor 52, A control signal is output based on this detected temperature.

[0019] In this abnormality detection circuit, when no abnormality is detected, the phototransmission Both registers 31a and 31b are on, and flip-flop circuits 36 and 37 The outputs Q of both are low level "0". In this state, the switching transistor The register 39 is off and the relay 41 is not operating.

[0020] For example, the fact that the endless belt 11 has entered the abnormality detection range B means that an abnormality is detected. When detected by the sensor 22a, the phototransistor of the abnormality detection sensor 22a Since the input terminal 31a is turned off, the input terminal S of the flip-flop circuit 36 is at a low level. becomes “0”. On the other hand, input terminal R is at high level "1". Therefore, free The output terminal Q of the flip-flop circuit 36 becomes high level "1". Therefore, or times The output signal of the circuit 38 is high level regardless of the output level of the flip-flop circuit 37. Since the signal becomes "1", the switching transistor 39 is turned on, and its Current flows through the result light-emitting display diode 40 and relay 41, and the light-emitting display diode When the ode 40 emits light, the contact 41a of the relay 41 shown in FIG. 6 closes. . Therefore, a driving current flows through the relay 44, and the contact 44a of this relay 44 is opened. Ru. As a result, the main motor 45 and heaters 46 and 47 are both turned off, The operation of this fixing device and the entire copying machine stops. By the abnormality detection sensor 22a The same applies when it is detected that the endless belt 11 has entered the abnormality detection range B. So, I will omit that explanation. In addition, if the endless belt 11 is moved outside the abnormality detection range B, After this, by turning on the reset switch 43a of the reset circuit 43, The abnormality detection circuit can be reset.

[0021] FIG. 7 shows another embodiment of the present invention, in which the paper is ejected after an abnormality is detected. The system is configured to later stop the operation of the entire copying machine and display a failure indication. Na Components that are the same as those in FIG. 6 are given the same reference numerals, and their explanation will be omitted. In this circuit , the output signal of the OR circuit 38 is sent to the control circuit 55. The control circuit 55 is shown in FIG. ROM (read only memory) 57 in which such control programs are stored; RAM (Random Access Memory) for temporarily storing various data 58 and a CPU that performs control operations based on the programs stored in these memories. (central control unit) 59. The control circuit 55 further includes a copying machine. When a paper ejection signal is input from the paper ejection detection sensor 59 provided in the paper ejection section of It is now possible to

[0022] The control circuit 55 operates based on signals from the OR circuit 38 and the paper discharge detection sensor 59. A failure indication signal is sent to the switching transistor 62 via the resistor 62a, and the resistor 6 4a to the switching transistor 64, as shown in FIG. Similarly, a device stop signal is sent to the switching transistor 39 via the resistor 39a. are output respectively. There is a failure in the switching transistor 62. The cathode side of the display diode 63 is connected, and the anode of this diode 63 A power supply line 42 is connected to the side via a resistor 63a. switching tran One end of a paper feed clutch 65 is connected to the register 64, and this paper feed clutch 65 A power line 42 is connected to the other end.

[0023] In the abnormality detection circuit of this embodiment, an abnormality signal is sent from the OR circuit 38 to the control circuit 55. When the number is input, the CPU 56 executes the program according to the program stored in the ROM 57. control operation. That is, an abnormal signal is input from the OR circuit 38 (step 1; Y), the CPU 56 sends a paper feed stop signal to the switching transistor 64. paper feed, turn off the paper feed clutch 65 (step 2), and then turn off the paper ejection detection sensor. Confirm that the last paper has been ejected by the paper ejection signal from the sensor 59 (step 3;Y). After this, the CPU 56 sends a device stop signal to the switching transistor 39. and a failure indication signal to the switching transistor 62, respectively, and the copying machine The entire operation is stopped (step 4), and the fault indication diode 63 is A failure display (step 5) is performed.

[0024] In this way, in the fixing device of this embodiment, the meandering of the endless belt 11 is detected as an abnormality. If it enters range B, the entire operation of the copier will be automatically stopped and the machine will malfunction. Fault indication will be displayed automatically. Therefore, it is possible to prevent poor fixing and damage to parts. can be done.

[0025]

[Effect of the idea]

As explained above, according to the fixing device according to the present invention, the meandering of the endless belt is constant. When the value exceeds this value, the operation of the entire device is stopped, which prevents fusing problems at the edges of the paper. This prevents damage to the belt itself and expensive parts such as belt edge detection sensors. can.

[Brief explanation of drawings]

FIG. 1 shows the configuration of main parts of a fixing device according to an embodiment of the present invention, and is a diagram seen from the direction of the arrow A-A in FIG. 3. FIG.

2 is a sectional view taken along the line BB in FIG. 3, for explaining a meandering correction operation of the endless belt in the fixing device in FIG. 1; FIG.

FIG. 3 is a side view showing the configuration of a fixing device according to an embodiment of the present invention.

FIG. 4 is a configuration diagram of a meandering correction circuit used in the fixing device of FIG. 1;

FIG. 5 is a configuration diagram of an abnormality detection circuit used in the fixing device of FIG. 1;

6 is a circuit configuration diagram of the entire copying machine for explaining the operation of the abnormality detection circuit shown in FIG. 5; FIG.

7 is a diagram illustrating another configuration example of an abnormality detection circuit used in the fixing device of FIG. 1. FIG.

FIG. 8 is a flowchart for explaining the operation of the abnormality detection circuit of FIG. 7;

[Explanation of symbols]

1...Fixing device, 2...Heating roller, 4...Pressure belt mechanism,
11... Endless belt, 16a, 16b... Belt end detection sensor, 22a, 22b... Abnormality detection sensor

Claims (1)

[Scope of utility model registration request] Claim 1: A heating roller that heats and presses a paper carrying a toner image to melt the toner and fix it on the paper, and an endless pressure means that presses the paper against the heating roller. a belt, a first belt end detection means for detecting the meandering of the endless belt, a belt meandering correction means for correcting the meandering of the endless belt based on the detection result of the first belt end detection means; a second belt end detection means that detects when the meandering of the endless belt exceeds a certain value; and a device stop means that stops the operation of the entire apparatus based on the detection result of the second belt end detection means. A fixing device characterized by comprising: