JPS638472B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables, when copying a manuscript to be corrected, to eject a transfer sheet on which the image has been processed to a semi-fixed state, correct it, and then process it again in the fixing device of the copying machine. Regarding copying machines that can be used.

Note that in this specification, the term "semi-fixed state" refers to a transfer paper on which a developed image formed on a photoreceptor drum has been transferred to its surface.
Refers to the state of transfer paper when fixing is performed with a small amount of energy such that the temperature rise at the interface between the transfer paper and toner is insufficient. When the transfer paper is in a semi-fixed state, the adhesion between the transfer paper and the toner image is still incomplete and the toner image is easy to erase, but the toner does not stick to the toner even if you touch it lightly when correcting the toner image. . Therefore, it is easier to handle than the unfixed transfer paper described below.

In addition, the unfixed state refers to the state of the transfer paper that has been transferred by the transfer charger. Therefore, when the transfer paper is in an unfixed state, the toner adheres to the transfer paper only by electrostatic attraction, and although erasability is good, the toner image is unstable and must be handled with care.

Conventionally, in order to facilitate erasure and addition in copying machines for copying drawings, a path for directly ejecting paper is provided in front of the atmosphere fixing device, and after partially erasing the paper by ejecting it from this path, copying is performed. There is a copying machine in which fusing is performed again by a dedicated user outside the machine.

However, it is corrected by the conventional copying machine as mentioned above.
When performing partial erasure, etc., the directly ejected transfer paper is in an unfixed state, and when the portion is corrected, the toner image in the uncorrected portion is often damaged.

Another drawback is that a user is required for fixing after the correction is completed.

The present invention has been made in view of the above, and it is possible to eliminate the above-mentioned drawbacks, eject the semi-fixed transfer paper when correction is desired, and re-fix it by the fixing device of the copying machine after the correction is completed. The present invention will be described below with reference to examples.

FIG. 1 is an explanatory diagram of the configuration of an example of a copying machine to which the present invention is applied. The original 1 is transported with its image surface facing down by the original transport roller 2, and is irradiated with a fluorescent lamp 3 through a slit section on the contact glass, and then passed through a convergent light transmitter 4 to a photoreceptor that rotates at the same speed as the original. The electrostatic latent image of the image of the document 1 exposed on the drum 5 is visualized by the developing brush 6, and the electrostatic latent image of the image of the document 1 is visualized on the photoreceptor drum 5, and the electrostatic latent image is transferred onto the transfer paper 8 which is conveyed in synchronization with the conveyance speed of the document 1 in advance. The visualized image is transferred by a transfer charger 7, and while being ejected by a conveyor belt 9 capable of forward and reverse rotation, it is intermittently flash-fixed on the conveyor belt 9 by flashing light from a xenon lamp 10 and onto a paper discharge tray 11. The paper is ejected.

FIG. 2 is a detailed explanatory diagram of the vicinity of the fixing device.
The paper path switching guide 12 is provided so that the position of the solid line or the broken line can be selected using, for example, an electromagnet, and a conveyor belt 9 is provided on the extension of one end 12', and a suction fan is installed in the space between the conveyor belts as necessary. 1
A suction tank 14 with 3 is provided. In addition to the conveyance path by the conveyor belt 9, a paper discharge guide 15 is provided on the extension of the other tip 12'' of the paper passage switching guide 12 when the paper passing path switching guide 12 is moved to the position indicated by the broken line. There is.

On the other hand, a reflective shade 16 is provided opposite the conveyor belt, and a xenon lamp 10 whose light emission time can be adjusted is provided within the reflective shade 16. Further, a reflectance detector 17 is provided on the paper path switching guide 12 side facing the conveyor belt 9, and a paper detector 18 is provided on the paper ejection tray 11 side, and roller drive levers 21 are provided on both ends thereof. First paper output roller 1
9 and a second paper ejection roller 20, and when the paper path switching guide 12 is selected at the position indicated by the solid line, the first paper ejection roller 19 comes into contact with the conveyor belt 9, and the paper path is switched. When the guide 12 is selected to the position indicated by the broken line, the second paper discharge roller 20 moves in conjunction with the paper path switching guide 12 so as to contact the conveyor belt 9. Note that the paper path switching guide 12 is linked to switching between forward and reverse rotation of the conveyor belt 9, and when the conveyor belt 9 rotates normally, the paper path switch guide 12 is at the position indicated by the solid line, and when the conveyor belt 9 is reversely rotated, the paper path switching guide 12 is in the position of the solid line. For the switching guide 12, the position indicated by the broken line is selected.

If complete fixing is to be performed as in the normal case, forward rotation of the conveyor belt 9 is selected, the paper path switching guide 12 is at the position indicated by the solid line, and the first paper ejection roller 19 is set to the position of the conveyor belt 9. is in contact with. The transfer paper 8 that has passed through the transfer charger 7 passes over a paper path switching guide 12 and is conveyed by a conveyor belt 9. While being conveyed by this conveyor belt 9, a xenon lamp 10 emits light at each pitch of a reflective shade 16. , energy is applied to completely fix the toner on the transfer paper, and the toner is completely fixed and is discharged to the paper discharge tray 11 through the first paper discharge roller 19 .

In this case, the suction pump 13 is driven and the suction tank 14 suctions the transfer paper 8 toward the conveyor belt 9 side. If this suction is sufficiently performed, the first paper discharge roller 19, the second paper discharge roller 20, and the roller drive lever 21 may be omitted. Further, when the transfer paper 8 has a high light transmittance, such as a second base paper, and the flash light from the xenon lamp 10 passes through it, the fixing performance deteriorates. In order to prevent this, the conveyor belt 9 preferably has a metal reflective surface or is white.

Next, a case will be described in which the transfer paper is ejected in a semi-fixed state, then corrected and then completely fixed.

First, the transfer paper from the transfer charger 7 passes through the same path as in the case of complete fixing described above to the paper output tray 1.
1 is discharged. However, in the case of semi-fixing, the emission energy of the xenon lamp 10 is controlled manually or automatically by the output of the reflectance detector 17, and the transfer paper 8 is semi-fixed while it is being conveyed by the conveyor belt 9. , output tray 1 in semi-fixed state.
1 is discharged. This semi-fixed transfer paper 8 is corrected in necessary areas.

On the other hand, the rotation direction of the conveyor belt 9 is switched to the reverse direction. As a result of this switching, the paper feeding switching guide 12 is switched to the position shown by the broken line, and the roller drive lever 2 is also switched to the position shown by the broken line.
1 is switched so that the second paper discharge roller 20 comes into contact with the surface of the conveyor belt 9.

Next, when the corrected semi-fixed transfer paper 8 is inserted from the paper output tray 11 side, this transfer paper 8 is conveyed by the conveyor belt 9 in the opposite direction to the conveyance direction of the transfer paper 8 described above, and is transferred to the conveyor belt 9. While being conveyed, the transfer paper 8 is completely fixed by the flash of the xenon lamp 10, and the leading edge of the transfer paper 8 comes into contact with the curved surface of the paper path switching guide 12, and the transfer paper 8 moves along the curved surface. Change the direction of travel and move the paper ejection guide 15
is discharged through. This ejected transfer paper 8 has been completely fixed.

Note that when re-fixing the semi-fixed transfer paper 8, the power supply system of the entire copying machine is separated into one for the fixing device and the other for the copying machine main body, and when re-fixing the semi-fixed transfer paper 8, the copying machine The driving of the copying machine main body may be stopped by, for example, cutting off the power supply for the main body, and a message to that effect may be displayed.

Next, in this embodiment, the flash lamp 10
The reason for fixing using flash light will be explained below.

In a normal atmosphere fixing device, fixing is performed by raising the entire transfer paper and toner above the fixing (melting) temperature.
It is necessary to maintain the temperature at a high temperature of ~330℃, and the temperature cannot be lowered rapidly even if the heating source is shut off. Therefore, in semi-fixing, a separate fixing device must be used, and two devices are installed in the copying machine. A fixing device is required, which increases the complexity and size of the device. Furthermore, the fixability varies depending on the quality of the transfer paper. For example, tracing paper is easier to fix than plain paper. Moreover, it is difficult to set the semi-fixed state by temperature. Therefore, it is almost impossible to discharge the transfer paper in a semi-fixed state.

Further, in a pressure and atmosphere fixing device using a fixing roller, it is not easy to convey the transfer paper in the reverse direction because a conveyance gripper device, a wrapping prevention device, etc. are required.

On the other hand, in a fixing device that uses flash light from a flash lamp, the transfer paper is irradiated with light energy for a short time, so the light on the white paper is repeatedly reflected by a reflecting mirror until it reaches the toner (black) area to perform fixation. , the fixing time is short and the temperature rise of the transfer paper and device is small. Furthermore, since there is no contact, it is easy to transport the transfer paper. Furthermore, it has advantages such as easy control of fixing energy and good responsiveness.

Therefore, in a flash fixing device, the fixing properties are determined by the physical properties of the toner, that is, the melting temperature of the toner, the ratio of the image area to the non-image area on the transfer paper, so-called image density, the light emission energy from the flash lamp, the light emission time of the flash lamp, the transfer It can be changed by changing the reflectance of the paper or the size of the reflective shade, that is, the irradiation area. In practical terms, it is easy to obtain a semi-fixed state by changing the emission energy or emission time.

Therefore, an example for obtaining transfer paper in a semi-fixed state will be described below. This example is an example of controlling light emission energy.

FIG. 3 is a block diagram of a xenon lamp emission energy control circuit applied to an embodiment of the present invention.

The switch 23 is a switch that turns on and off the supply of the output of the power supply 25 to the boost rectifier circuit 24 in response to a signal from the control circuit 24. Boost rectifier circuit 24
The output voltage is input to a capacitor 26 that stores the energy input to the xenon lamp 10, and the charging voltage of the capacitor 26 is divided and detected by resistors 27 and 28. capacitor 26 which is detected by selecting one and dividing the voltage by resistors 27 and 28.
The control circuit 23 controls the switch 22 so that the capacitor 26 is charged to a voltage corresponding to the voltage of the reference power source 30 or 31. Note that 32 is a trigger pulse generation circuit for generating the xenon lamp 10, which is triggered by the trigger signal T. Further, P is a timing signal that puts the control circuit 23 into an operating state. The trigger signal T and the timing signal P are provided from a control device (not shown) of the copying machine, as well as control signals for the copying process of the copying machine.

Now, the voltage Vref ₁ of the reference power supply 31 is set to the control circuit 23.
The charging voltage of the capacitor 26 when input to
Assuming that Vref ₂ corresponds to the voltage during semi-fixing, Vref ₁ > Vref ₂ .

When complete fixing is selected, the reference power source 31 is selected by the switch 29, the control circuit 23 is activated by the timing signal P, and the voltage V _R28 applied to the resistor 28 is compared with Vref ₁ , so that V _R28 = Vref ₁ When the switch 22 is turned off, the capacitor 26
is charged to the charging voltage required for complete fixing.
Next, the trigger signal T causes the xenon lamp 10 to emit light with the voltage of the capacitor 26, giving energy necessary for complete fixing to the transfer paper 8, thereby performing complete fixing.
Similarly, when semi-fixing is selected, the reference power supply 30 is selected by the switch 29, the voltage V _R28 and Vref ₂ are compared, and when V _R28 = Vref ₂ , the switch 23 is turned off and the capacitor 26 is required for semi-fixing. The battery will be charged to the desired charging voltage. Next, this capacitor 26
The xenon lamp 10 emits light at a voltage of
Semi-fixing is performed by giving the energy necessary for semi-fixing to.

Further, although it is not necessary to eject the transfer paper 8 in an unfixed state in the embodiment of the present invention, when ejecting the transfer paper in an unfixed state, the switch 29 is set to a low voltage that prevents the xenon lamp 10 from emitting light. The voltage may be selectable so that the transfer paper is ejected in an unfixed state, or the timing signal P may be inhibited so that the capacitor 26 is not charged.

In addition, although the selection switch 29 is used to select the fully fixing and semi-fixing states, it is also possible to adjust the fixing energy by using a variable resistor that changes the fixing energy. It's okay.

Note that although the reference power supplies 30 and 31 with predetermined voltages are used during complete fixing and semi-fixing in the above description, it is necessary to change the voltages of the reference power supplies 30 and 31 during complete fixing and semi-fixing depending on the image density of the document. In other words, when the image density is high, the reference power source 3
The voltages of reference power supplies 30 and 31 are changed to high values, and when the image density is low, the voltages of reference power supplies 30 and 31 are changed to low values. For this purpose, the image density is detected by the reflectance detector 17 when it passes through the transfer charger 7 and enters the fixing device, and the voltages of the reference power supplies 30 and 31 are divided into voltages Vref _{1 and 31} , respectively.
It is sufficient to select it as Vref ₂ using the switch 29 and input it to the control circuit.

In addition, the reflectance detector 17 detects the image ratio over the entire area of the transfer paper 8 irradiated by one light emission from the xenon lamp 10, for example, in a direction perpendicular to the direction of travel, over the entire width of the transfer paper 8. A light receiving element such as a single or a plurality of solar cells or cadmium sulfide cells is arranged across the photosensitive element, and the light receiving element receives reflected light from the transfer paper 8 from the light emitting element and averages it to detect the image ratio. To calculate the average value of the output from the light-receiving element, for example, the output of the light-receiving element is converted into a digital value by an analog-to-digital converter, the average value is calculated by a microprocessor, the average value is temporarily stored in a storage device, and then the next Similarly, the average value is calculated for the output of the light-receiving element, and the average value is temporarily stored in the storage device.
The average value is calculated over the irradiation width and used as the image ratio. The output voltages of the reference power supplies 30 and 31 are adjusted according to this image ratio.

Next, a case will be described in which the fixing device of a copying machine according to an embodiment of the present invention is used for re-fixing.

When a semi-fixed or unfixed transfer paper 8 is inserted from the paper output tray 11 side, the paper detector 18
A paper detection signal is output as shown in FIG. 4a. The trailing edge of this paper detection signal is shown in Figure 4b.
As shown in the figure, a delay circuit delays the trailing edge of the transfer paper until it passes the fixing device. This is because it is necessary to cause the xenon lamp 10 to emit light until the transfer paper 8 passes through the fixing device. In addition, the paper detection signal
The pulse generator for generating the timing signal P' and trigger signal T' of the power supply device of the flash lamp 10 shown in FIG. 3 is operated until the delay signal shown in FIG. 4b is terminated. FIG. 4c shows the output signal of the pulse generator, and FIGS. 4d and 4e show the timing of generation of the timing signal P' and the trigger signal T'. The timing signal P' and trigger signal T' generated by this pulse generator are logically summed with the timing signal P and trigger signal T shown in FIG. is applied to cause the xenon lamp 10 to emit light.

In addition, FIG. 4f shows the suction fan 13 and the conveyor belt 9.
This shows the operation timing for reverse rotation. When the re-fixing mode is selected, the reverse rotation operation of the suction fan 13 and the conveyor belt 9 may be operated at all times or may be controlled at specific timings.

The period of the output signal of the pulse generator is determined in relation to the speed of reverse rotation of the conveyor belt 9, and the output signal is adjusted so that the irradiated surfaces of the xenon lamps 10 overlap to some extent so that there are no unfixed parts. Determine the cycle. Further, if there is a delay signal (FIG. 4b) at the start of oscillation, the pulse generator is operated until the end of one cycle. By doing this, the energy in the capacitor 26 of the flash power supply will not remain stored.

In addition, in order to prevent the conveyor belt 9 from slipping when inserting the transfer paper 8 from the paper output tray 11 side, or from inserting too much transfer paper 8, the speed during reverse rotation of the conveyor belt 9 is set to be the same as the speed during forward rotation. Or better yet, slow down.

As explained above, according to the present invention, the energy level generated by the flash lamp that supplies fixing energy is adjusted so that the toner image on the transfer paper is completely fixed.
Ejecting transfer paper in a fully fixed state, semi-fixed state, or unfixed state by providing means for setting at least two fixing energy levels of the fixing energy levels necessary for fixing in a semi-fixed state or an unfixed state. You can edit the image if necessary. Furthermore, by providing a discharge means for inserting the transfer paper from the paper discharge port side of the fixing device, fixing it again by the fixing device, and discharging it from a newly provided paper discharge path, the above-mentioned corrected semi-fixed state or The transfer paper having the unfixed toner image is reinserted into the fixing device, and the fixing device performs the fixing action again, so that the transfer paper after the toner image correction can be completely fixed.

Furthermore, no other fixing device is required for the above-mentioned re-fixing.

In addition, during re-fixing, the paper ejection roller as a transfer paper conveyance device is switched, and the paper ejection roller on the entrance side of the transfer paper is not in contact with the transfer paper during re-fixing, so the transfer paper is in a semi-fixed state or unfixed. There is no damage to the toner image in the state.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram of an example of a copying machine to which the present invention is applied, FIG. 2 is a detailed explanatory diagram of the vicinity of a fixing device of a copying machine according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a block diagram of a power supply device for a flash lamp of a fixing device of a copying machine according to an embodiment of the present invention, and FIG. 4 is a control timing diagram of the flash power supply device during re-fixing of a fixing device of a copying machine according to an embodiment of the present invention. 1... Document, 2... Conveyance roller, 5... Photosensitive drum, 7... Transfer charger, 8... Transfer paper,
9...Transport belt, 10...Xenon lamp, 1
1... Paper output tray, 12... Paper path switching guide,
15... Paper ejection guide, 16... Reflective shade, 17...
Reflectance detector, 18...Paper detector, 19 and 2
0...First and second paper discharge rollers, 21...Roller drive lever, 22 and 29...Switch, 2
3... Control circuit, 24... Boost rectifier circuit, 26...
...Capacitor, 30 and 31...Reference power supply, 3
2...Trigger pulse generator.

Claims (1)

[Scope of Claims] 1. In a copying machine equipped with a fixing device that performs fixing by irradiating flash light from a flash lamp onto the image forming surface of a transfer paper after a visible image is formed, the fixing energy generated from the flash lamp is used. means for variablely setting the toner image on the transfer paper to at least two of the energy levels necessary to fix the toner image on the transfer paper in a fully fixed state, a semi-fixed state or an unfixed state; A copying machine comprising means for re-fixing a transfer paper having a toner image using the fixing device. 2. In a copying machine equipped with a fixing device that performs fixation by irradiating flash light from a flash lamp onto the image forming surface of transfer paper after a visible image has been formed, the fixing energy generated from the flash lamp is variable to fix the toner on the transfer paper. means for setting the fixing energy level to at least two of the energy levels necessary to fix the image in a fully fixed state, a semi-fixed state or an unfixed state; and a transfer paper having a toner image in a semi-fixed state or an unfixed state. A copying machine comprising: an ejection means that is inserted from the ejection port side of the fixing device, re-fixed by the fixing device, and ejected from a newly provided ejection path. 3. In a copying machine equipped with a fixing device that performs fixation by irradiating flash light from a flash lamp onto the image forming surface of transfer paper after a visible image has been formed, the fixing energy generated from the flash lamp is variable to fix the toner on the transfer paper. means for setting at least two fixing energy levels of the energy levels necessary to fix the image in a fully fixed state, a semi-fixed state or an unfixed state; and a transfer paper having a toner image in a semi-fixed state or an unfixed state. a means for enabling re-fixing using the fixing device, and a contact conveying means on the toner image side on the transfer paper of the transfer paper conveying device during the passage of the transfer paper during the re-fixing, and a contact conveying means on the toner image side on the transfer paper in a non-contact manner during the re-fixing operation. A copying machine characterized by comprising: means for switching the state.