JPH0350585A - Fixing device - Google Patents

Abstract

PURPOSE:To perform stable fixation even in the case of using papers having different thickensses by detecting the thickness of the paper and controlling the temperature of a thermal roller and the rotating speed thereof in consideration of the thickness of the paper. CONSTITUTION:The device is provided with a thickness detection part 4 which detects the thickness of the paper at the time of loading the continuous paper and a control part 6 which controls a heater 9 for heating the thermal roller based on the information on the detected thickness and a driving motor 10. The control part 6 selects the optimum parameter value out of plural parameter value groups stored in a parameter part 5 based on the information, etc., from the thickness detector 4. In accordance with the selected parameter value, the heater 9 is controlled by a heater driver 7 so that the surface temperature of the thermal roller may be a specified one, and the rotating speeds of the thermal roller and a backup roller are controlled by a roller driver 8 so as to give specified tension to the paper 1. Thus, the stable fixation is performed even when the thickness of the paper used is varied.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fixing device, and more particularly to a fixing device for an electrophotographic printing device that heats and fixes toner attached to paper using a heat roller. [Prior Art] In recent years, printing devices used for outputting information from information processing devices, particularly electrophotographic printing devices using a laser beam and a photosensitive drum, are required to have higher speed and higher quality. As is well known, an electrophotographic printing device consists of four processes: exposure, development, transfer, and fixing, and if there is a performance problem in one of these processes, the print quality will deteriorate. Of these, the fixing section is particularly important, and is affected by the width, thickness, surface treatment, etc. of the paper.

Figure 3 is a structural diagram showing an example of a conventional fixing device. Continuous slip type paper 1 with toner transferred from the photoreceptor drum
passes through the loop plate 2, the Baber brake 11, the preheater 12, and between the heat roller 13 and the backup roller 14, whose surface temperature is controlled by the heater 9 to be constant, with a constant pressure. It is heat-pressed and fixed. The preheater 12 uses a heater 9a to heat the paper 1 to improve fixing performance.
The paper brake 1L sucks air in the direction of the white arrow A to prevent the paper 1 traveling at high speed from lifting off from the preheater 12. Furthermore, the loop plate 2 is rotatable in the direction of arrow B around the shaft 2a in order to apply a constant tension to the paper l, and the stop position of the shaft 2a is detected by an optical sensor, and the paper transport system detects the position of the shaft 2a. The rotational speed of the heat roller 13 and pack-up roller 14 is controlled in stages in conjunction with the paper width information provided, thereby preventing meandering and wrinkling of the paper l. [Problems to be Solved by the Invention] The conventional fixing device described above controls the rotation speed in several stages for the position of the loop plate and the width of the paper, but it does not have a means to detect the thickness of the paper. First, the surface temperature of the heat roller is controlled to be optimal for the thickness of the paper being used, so if thick paper is used, fusing may be insufficient.
When using thin paper, the paper had the disadvantage of yellowing due to overheating. An object of the present invention is to provide a fixing device that can perform stable fixing even when the thickness of paper used changes. [Means for Solving the Problems] The fixing device of the present invention is a fixing device of an electrophotographic printing device that heats and fixes toner adhered to paper using a heated thermal roller. a thickness detection means for detecting the thickness of the heat roller; and a heater for heating the heat roller and a drive motor for driving the heat roller according to predetermined conditions based on the thickness information detected by the thickness detection means. The system is equipped with a control means for controlling the [Example] Next, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention. A thickness detection unit 4 that detects the thickness of the paper when loading continuous paper, and control that controls the heater 9 that heats the heat roller and the drive motor 10 based on the thickness information detected by the thickness detection unit 4. 6. In addition to the information from the thickness detector 4, the control unit 6 receives paper width information detected by a switch or the like in a paper transport system such as a tractor, and position information of the loop plate. The optimum parameter value is selected from among the plurality of parameter value groups stored in the parameter section 5 from the combination of . In accordance with the selected parameter value, the heater driver 7 controls the heater 9 so that the surface temperature of the heat roller reaches the specified temperature,
The rotational speeds of the heat roller 13 and pack-up roller 14 are controlled fiI1 by the roller driver 8 so as to apply a specified tension to the paper 1. FIG. 2 is a configuration diagram showing an example of the thickness detection section 4 shown in FIG. 1. As shown in Fig. 2, a laser sensor 3 is provided at a position facing the paper side of a loop plate 2 for applying a constant tension to the paper, and detects the thickness of the paper when the paper l is loaded. ．． FIG. 2(a) shows the state before the paper 1 is loaded, and FIG. 2(b) shows the state after the paper is loaded. The paper thickness t can be easily detected by fixing the position of the loop plate 2 and comparing the output of the laser sensor 3 before and after the paper is attached. In the embodiment shown in FIG. 1, the control unit 6 is designed to control the heater 9 that heats the heat roller and the drive motor 10, but it is also possible to control the heater 9a of the preheater in the same way. good. or,
Although the laser sensor 3 is provided in the loop plate portion of the fixing device, it may be provided in a location other than the fixing device. [Effects of the Invention] As described above in detail, the present invention detects the thickness of paper to control the temperature vi of the heat roller, and further controls the rotational speed of the heat roller in consideration of the paper thickness. Since it can be done precisely, it can be used on paper of different thicknesses. Even if used, stable fusing is achieved without any adjustment, which has the effect of improving operability.

[Brief explanation of drawings]

Fig. 1 is a block diagram of one embodiment of the present invention, and Fig. 2 is a block diagram of an embodiment of the present invention.
The configuration diagram of an example of the thickness detection section shown in the figure is shown, and FIG. 3 is an elliptical diagram of an example of a conventional fixing device. 1...Paper, 2
......Loop plate, 2a...Shaft, 3...
... Laser sensor, 4... Thickness detection section, 5.
...Parameter section, 6...Control section, 7.
...Heater driver, 8...Roller driver, 9,9a...Heater, IO...
Drive motor, l1...Paper brake, 12
...Preheater, l3...1...Heat roller, 14
...Backup roller.

Claims (1)

[Claims] In a fixing device of an electrophotographic printing device that heats and fixes toner attached to paper using a heated thermal roller, a thickness detection means that detects the thickness of paper when loading continuous paper, and this thickness detection A fixing device comprising: a heater that heats the heat roller according to predetermined conditions based on thickness information detected by the device; and a control device that controls a drive motor that drives the heat roller.