JPH0267580A - Printing device - Google Patents

Abstract

PURPOSE:To surely fix a developed picture with toner, etc., onto a thick recording sheet by changing the recording paper carrying speed according to the set type of a recording sheet. CONSTITUTION:The printing device is provided with a means 10 setting the type of the recording sheet 1 and a means controlling the speed of a main driving motor. When a thick recording sheet is set according to the type of the recording sheet 1, the main driving motor speed control means slows down the rotational frequency of the main driving motor to decelerate the recording sheet carrying speed. A period when the recording sheet 1 is brought into contact with a fixing roller at the time of passing through fixing roller parts 6 and 13 is prolonged, whereby sufficient heat is imparted to the recording sheet 1 from the fixing roller 6. Thus, a picture developed with toner, etc., can be surely fixed onto a thick recording sheet.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a printing device such as a printer that uses an electrophotographic method or the like and has a thermal tube device, and particularly relates to a fixing function. .

[Conventional technology]

Conventionally, in this type of printing apparatus, a type of recording paper called copying machine paper has been widely used, and the fixing temperature and recording paper conveyance speed during the printing operation are set constant.

[Problem to be solved by the invention]

In recent years, this type of printing apparatus has become multi-functional, and recording paper other than copying machine paper has come to be used. Recording paper, which is generally referred to as copying machine paper, is widely used with a basis weight of 50 to 70 g/rd, and even heavy paper is usually used with a basis weight of 90 g/d or less. . In contrast to the above-mentioned copier paper, the recording paper that has come to be used due to the multifunctionality of printing devices in recent years is paper with a basis weight of 90/rd” or higher, and even original paper for envelopes, postcards, etc. It is a recording paper.

However, in this type of printing apparatus, the printing operation is performed by setting the fixing temperature and the recording paper conveyance speed to be the same during the printing operation from the conventional copying machine paper to the above-mentioned original recording paper. For this reason, when fixing a visual image such as toner on the original recording paper, the recording paper is thick and has a large heat capacity, so a large amount of heat from the heated fixing roller is absorbed by the recording paper, and the toner etc. on the recording paper is This method had a major problem in that it was not possible to sufficiently heat-fuse the microscopic image, resulting in poor fixing. In order to solve the above problem, it is sufficient to set the fixing temperature during the conventional printing operation to a high value according to the original recording paper. In normal usage conditions, the temperature is raised more than necessary, which raises the temperature inside the device, which is undesirable in terms of durability of the members constituting the device. Furthermore, a method has been proposed in which the diameter of the fixing roller is increased so that the recording paper is in contact with the fixing roller for a longer period of time than before, thereby applying sufficient heat to the recording paper, but this increases the size and cost of the printing device. There is a problem with this.

SUMMARY OF THE INVENTION The present invention aims to solve these problems, and its purpose is to provide a highly reliable printing device with an extremely simple configuration at a low cost and free of fixing defects for various types of recording paper. It is something.

[Means to solve the problem]

The printing apparatus of the present invention is characterized by comprising means for setting the type of recording paper and means for controlling the speed of the main drive motor, and changing the recording paper conveyance speed in accordance with the setting of the type of recording paper.

[For production]

According to the above configuration of the present invention, when the original recording paper is set according to the recording paper type setting, the main drive motor speed control means slows down the rotational speed of the main drive motor to transport the recording paper. By slowing down the speed and increasing the time that the recording paper is in contact with the fixing roller when it passes through the fixing roller section, sufficient heat is applied to the recording paper from the fixing roller, and toner etc. are transferred to the original recording paper. The fixing operation of the microscope image is reliably performed.

〔Example〕

The present invention will be explained based on the drawings. Fig. 1 is a main cross-sectional view of the printing device of the invention, and Fig. 2 is a detailed view of the fixing device, which uses an electrophotographic method. 2, the paper is supplied to the registration rollers 4 by the paper feed roller 3. Further, the sheet is sequentially conveyed from the registration roller 4 to the photosensitive drum 5, the fixing roller 6, and the discharge roller 7. In this embodiment, a main drive motor 20 (not shown) is used as a drive source common to each of the above-mentioned processes. At this time, information such as characters is optically written as an electrostatic latent image on the photoreceptor drum 5 by a laser head 8 which is a writing head incorporating a polygon motor 11 for scanning the laser beam. Next, the electrostatic latent image is made visible by adhering retoner from the developing device 9 to the writing area on the photosensitive drum 5, and the toner is further transferred onto the recording paper 1 as a visible image. Further, the recording paper 1 is conveyed to a fixing roller 6, and the toner on the recording paper 1 is fixed. The fixing roller 6 is heated in advance by a heating lamp and kept at a constant temperature, and the recording paper 1 is pressed and heated by the pressure roller 13 while moving and conveying the recording paper 1 together in the direction of the arrow. Further, temperature control of the fixing roller is performed by a temperature sensor 14 and a temperature controller 15, which are disposed in pressure contact with the surface of the fixing roller 6.

Note that in FIG. 1, a paper path is formed in the weight direction of the paper, such as the paper path indicated by 100. At this time, after the paper is ensured to enter between the drum 5 and the corona discharge transfer device 102 by the roller 101, the leading edge of the paper may hit the paper guide 103 and be bent so that the drum side becomes concave. In this way, the toner adhesion surface on the drum side is not soiled and the paper can be easily transported. Further, 201 is a blade, 202 is a waste toner box, and 203 is a charger.

Note that the heat conduction from the fixing roller 6 to the recording paper 1 occurs between the recording paper 1 and the fixing roller 6 during the nip length 8 formed by the fixing roller 6 and the pressure roller 13 shown in FIG.
This is done by bringing the two into contact with each other. Furthermore, the fixing roller 6
If the recording paper 1 is controlled to have a constant temperature and rotate at a constant speed, the recording paper 1 will be in contact with the fixing roller 6 at a constant temperature for a certain period of time, and the amount of heat conducted will always be constant. becomes. In this embodiment, in order to change the amount of heat conducted according to the type of recording paper 1,
The rotational speed of the fixing roller 6 is changed to change the recording paper conveyance speed, thereby changing the contact time between the recording paper 1 and the fixing roller 6 during the nip length 8. Reference numeral 10 denotes a setting panel which is disposed on the front side of the printing apparatus and is a means for setting the type of recording paper 1, and allows settings including the feeding form of the recording paper 1. FIG. 3 shows a control circuit used in this embodiment, in which a panel signal f emitted from an oscillation circuit 16 containing a built-in crystal oscillator is sent directly or via a frequency dividing circuit 17 to a pulse signal f.
2 and sent to the selection circuit 18. Selection circuit 18
, the pulse signal f or F2 is selected according to the signal from the setting panel 10, and the pulse signal is sent to the motor constant speed control circuit 19, which causes the drive motor 20 to operate at a speed corresponding to the pulse signal f or F2. It performs constant speed control. Next, a pulse signal generated by another oscillation circuit 21 is sent to a synchronization signal generation circuit 22, and a synchronization signal F is generated. The synchronization signal F is directly or by the holding circuit 23 and AND
It is converted into a synchronizing signal F2 via the circuit 24 and sent to the selection circuit 25. The selection circuit 25 selects either the synchronization signal F1 or F2 according to the signal from the setting panel 10 and sends it to the write signal generation means 26. Write signal generating means 26
The configuration is such that a signal corresponding to the print information is sent to the laser head 8 according to the synchronization signal F1 or F2.
The pulse signal f1 corresponds to the synchronization signal F1, and the pulse signal f2 corresponds to the synchronization signal F2.

In this embodiment, the paper feeding format is roughly divided into manual paper feeding, in which paper is fed manually, and continuous paper feeding, in which paper is automatically fed from paper feed tray 2. Continuous paper feeding is used for copier paper, etc., envelopes, and postcards. Separately, if copying machine paper, etc., which is used frequently and requires a relatively small amount of heat for fixing, is used as the recording paper 1 and the setting panel 10 is set to feed the paper continuously, the recording paper conveyance speed is V.
, and if printing speed is not required and manual paper feeding, which mainly handles original recording paper, and continuous paper feeding for envelopes and postcards are set on the setting panel 10, the recording paper is selected as the original recording paper. Two types of recording paper conveyance speeds are prepared in advance so that F2 can be selected as the conveyance speed. Furthermore, the recording paper conveyance speed v
2 has the relationship V, /V2=1/2 compared to the recording paper conveyance speed V, but if it is an integer multiple, printing can be performed without any problem, and it is equivalent to the frequency dividing circuit 17. A holding circuit 23AN that prepares a plurality of means with functions and supports them.
Needless to say, if a plurality of D circuits 24 are provided, two or more recording paper conveyance speeds can be set in advance. Furthermore, FIG. 4 is a diagram explaining the relationship between the recording paper transport timing and the scanning light emitted from the laser head 8 when the recording paper transport speed is set to V, and FIG. This is a diagram similar to FIG. 4, and 27 is a sheet of paper showing the horizontal period, and the interval therebetween is about 0.0847 mm. 28 is a line showing the scanning light by the laser head 8. The rotational speed of the polygon motor 11 is set in advance so that the laser head 8 can scan once per horizontal period 27 when the recording paper conveyance speed is vl, and when the recording paper conveyance speed is v2. Since the laser head 8 scans twice during the horizontal period interval, the write signal generating means 26 sends a write signal to the laser head 8 so as to scan every other time. ing.

FIG. 6 is a flowchart for setting the recording paper type when selecting the recording paper conveyance speed.

〔Effect of the invention〕

As explained above, according to the above configuration of the present invention, by changing the recording paper conveyance speed, reliable printing without defective fixing can be achieved on original recording paper other than copy machine paper, such as envelopes, postcards, etc. There is a great advantage in that the device can be provided at low cost with an extremely simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a main sectional view showing an embodiment of the printing apparatus of the present invention. FIG. 2 is a detailed diagram of the fixing device. FIG. 3 is an explanatory diagram of the control circuit. FIG. 4 and FIG. 5 are diagrams showing the relationship between the horizontal period and the scanning of the laser head. FIG. 6 is a flowchart for selecting the recording paper conveyance speed. 1 ・ ・ 2 ・ ・ 3 ・ ・ 5 ・ ・ 7 ・ 8 ・ ・ 9 ・ ・ 10 ・ ・ 11 ・ ・ 12 ・ ・ 13 ・ ・ 14 Φ ・ 15 ・ ・ 16 ・ ・ 18 ・ ・ 19 ・ ・ 20− Fist, recording paper, paper feed tray, paper feed roller registration roller, photoconductor drum, fixing roller, paper ejection roller, laser head, developing device, setting panel, polygon motor, heating lamp, compression roller, temperature detector, Temperature controller, oscillation circuit, frequency division circuit, selection circuit, motor constant speed control circuit, main drive motor 21, 22, 23, 24, 25, 26@, oscillation circuit, synchronization signal generation circuit, holding circuit, AND circuit, Selection circuit/writing signal generation means Applicant Seiko Epson Co., Ltd. Agent Patent attorney Kizobe Suzuki (and 1 other person) 7: Note #c
#c 6゛Bakugo Roller δ, ゛Rezuichi Hetsu V 10:tk Ra! -, Dimension cut 71, "r ribbon motor 7, 1st r group. Figure 2 2δ Bamboo shoot, Figure 5

Claims (1)

[Claims] A printing apparatus having a thermal fixing device, comprising means for setting a recording paper type and a speed control means for a main drive motor, and changing the recording paper conveyance speed according to the setting of the recording paper type. printing device.