JP2001356666A - Electrophotographic printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic printer which does not require a long time for start of fixing, does not cause time shortage when raising a fixing temperature to the necessary temperature when printing a cardboard, has a large gradient of fixing temperature rise when a fixing heater is turned on and a large temperature gradient in detection of fixing abnormality, and consequently reaches the temperature at which fixing is enabled in a short time, also detects the fixing abnormality in a short time, and provides a print product with satisfactory quality. SOLUTION: The electrophotographic printer has a fixing roller, a pressure roller, a controller and an engine. The controller is connected with a host, and data and print indication, etc., are exchanged between both. The data sent from the host are developed by the controller, then delivered to the engine and printed out. Delivery of the data from the controller to the engine is started after reaching the first reload temperature lower than the temperature at which fixing is enabled, and printing operation is started after reaching the second reload temperature higher than the first reload temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic printer having a fixing unit.

[0002]

2. Description of the Related Art The configuration of a conventional electrophotographic printer P of this type will be described with reference to an embodiment of the present invention shown in FIG. 1. Reference numeral 1 denotes a laser optical system, 2 denotes a charger, and 3 denotes a developing unit. Reference numeral 4 denotes a photoconductor, 5 denotes a paper feed unit, 6 denotes a transfer charger, 7 denotes a fixing unit, 9 denotes a paper discharge unit, 10 denotes a registration roller, 11 denotes a cleaning unit, 12 denotes an engine board, and 13 denotes a controller board. The fixing means 7 has a fixing roller 14, a core material 15, a fixing heater 16, a pressure roller 17, and a pressure lever 18, as shown in FIG.

FIG. 3 is a functional block diagram of the above-mentioned electrophotographic printer P.
22 is connected to a host 21 such as a personal computer, and exchanges data to be printed and print instructions between the two. Data from the host 21 is transferred to the engine 23 after being developed by the controller 22 of the electrophotographic printer P. Then, the engine 23 that has received them enters a print operation and prints out.

In this case, the data developed by the controller 22 is sent to the engine 23 only after the fixing temperature reaches the temperature at which the fixing can be performed. Therefore, when trying to print from the energy saving mode, it is necessary to wait for fixing to start, so that there is a problem that a long time is required for the work. So, to avoid this, keep the fixing temperature low,
When the data is received from the controller 22 with the engine 23 in the ready state, if the amount of data is small, the reception is completed immediately, and the printing operation such as paper feeding and registration rotation is started. There is a problem in that the printing operation is started before the ascent is raised, and defective fixing products are provided.

In the case of thick paper printing or manual paper feeding, the fixing temperature is switched to a higher setting temperature for thick paper than the setting temperature for plain paper. However, if the reload temperature is the same and the data amount is small, the fixing temperature is immediately changed. When the data reception is completed and the printing operation starts, there is no time to raise the fixing temperature to the required temperature during this time, so the first sheet has the same fixing temperature as that for plain paper regardless of the set temperature. As a result, there is a problem that a fixing failure occurs.

Further, in this electrophotographic printer P, the rising gradient of the fixing temperature when the fixing heater 16 is turned on is 6 degrees.
Since the temperature is about 7 degrees / second, it takes a very long time for the temperature to reach the temperature at which the fixing can be performed, and the detection of the fixing abnormality has a problem that it takes a very long time because the temperature gradient is small.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional electrophotographic printer. When printing from the energy saving mode, it does not take much time until the fixing is started, and the thick paper is used. When trying to print, there is no shortage of time to raise the fixing temperature to the required temperature, there is no occurrence of defective fixing, and the gradient of the fixing temperature rise when the fixing heater is turned on and the detection of fixing abnormality are detected. An object of the present invention is to provide an electrophotographic printer capable of providing a high quality print product with a large temperature gradient, a short time until the temperature reaches a temperature at which fixing can be performed, and a short detection of fixing abnormality.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a fixing roller which is driven to rotate, a pressure roller which is brought into contact with the fixing roller at a predetermined pressure, a controller, , An engine, and the controller is connected to a host such as a personal computer, and both exchange data, print instructions, etc., and the data from the host is transferred to the engine after being developed by the controller, and the engine transmits the passed data. In the electrophotographic printer for printing out, according to the first aspect of the present invention, the transfer of the data from the controller to the engine is started after the first reload temperature lower than the fixable temperature is reached, and the printing operation is started. The start time is set after reaching a second reload temperature higher than the first reload temperature.

According to a second aspect of the present invention, when a thick paper feed or manual feed is instructed by the host, immediately before the data developed by the controller is passed to the engine, the thick paper feed or the manual feed is performed. The instruction is input to the engine, and the engine switches from the first set temperature to the second set temperature higher than the first set temperature, and sets the third set temperature which is the thick paper fixing temperature.
After reaching the reload temperature, the printing operation is started.

According to a third aspect of the present invention, the rising gradient of the fixing temperature when the fixing heater is turned on is 14 to 20 deg / sec.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. In this description, the same parts as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted. Different parts will be mainly described. The operation of this embodiment will be described with reference to FIG. In this operation, after reaching the first reload temperature T1 (120 ° C.) lower than the feasible fixing temperature, data is sent from the controller 22 to the engine 23 to reduce the print waiting time.

This embodiment has a linear velocity of 110 mm / s to 140 mm / s
, And has an energy saving mode, in which case the fixing heater 16 is off. In such an inactive electrophotographic printer P, the host
The print instruction from 21 is transmitted to the engine 23 side at the time point A via the controller 22, and the fixing heater 16 is turned on. This is for shortening the printing time. Specifically, in the energy saving mode, the fixing set temperature (hereinafter abbreviated as the set temperature) is set to 25 ° C. or less, preferably a low temperature of about −5 ° C. When the print instruction is received from the host 21 while the printer 16 is turned off, the instruction of the controller 22 is received almost at the same time, the set temperature is changed to the first set temperature, and the fixing is performed so as to reach the first set temperature. The heater 16 is turned on.

In this embodiment, as shown in FIG. 3, after reaching a first reload temperature T1 (120 ° C.) lower than the feasible temperature, data is sent from the controller 22 to the engine 23 so that the print waiting time is reduced. Shorten. If the data amount is small, the second reload temperature T2 of the fixable temperature
Since the printing operation is not started up to (150 ° C.), occurrence of fixing failure can be prevented.
Here, the printing operation means the start of paper feeding or the start of rotation of the registration roller 10. Although illustration is omitted,
If the data volume is large, the second
Since the reload temperature T2 has been reached, the printing operation starts immediately. In this way, it is possible to obtain a print of good image quality with a short waiting time and no defective fixing.
The reason why the first set temperature t1 is set to 160 ° C., which is higher than the first reload temperature T1 of the feasible fixing temperature, is that there is a possibility that the fusing temperature during paper passing will inevitably fluctuate, and that a fusing defect may occur. , To prevent it.

Next, the case of thick paper or manual paper feed will be described with reference to FIG. In this case, in response to an instruction for thick paper or manual paper feed, the setting temperature is switched to the set temperature for thick paper, and the third reload temperature T3 (165
° C), and even if the data amount is small, the printing operation is not started until the third reload temperature T3. For this reason, even with thick paper, fixing failure does not occur, and a print of good image quality can be obtained.

Next, in the example shown in FIGS. 6 to 8, the fixing roller 14 of the fixing means 7 of this embodiment has a carbon steel tube STKM11 as a core material, a total length of 375 mm, and an outer diameter Φ of the paper passing portion 24 of 29.8. m
m, inner diameter Φ is 29.2mm, wall thickness is 0.3mm, outer diameter Φ of bearing part 25 is 30mm, wall thickness is 0.3mm, 0.1 ~ 0.
The thickness is 0.4 to 0.8 mm, which is 5 mm thick, and is 0.4 mm in the embodiment shown in FIG. As described above, by reducing the thickness of the sheet passing portion, the rise of the fixing can be made much faster than in the conventional example.

The reason why the thickness of the fixing roller 14 is set as described above is that the thickness of the fixing roller 14 is reduced in order to increase the gradient of the fixing temperature rise of the fixing means 7 as much as possible. If the pressure roller 17 is pressed too much, there is a problem that when the pressure roller 17 is pressed, the fixing roller 14 cannot be nip-formed due to deformation due to crushing or bending, resulting in poor fixing, or wrinkling of the transfer paper. The purpose is to solve such a problem.

That is, the strength is improved by increasing the thickness of the bearing portion 25 so that the fixing roller
Can be reduced, and the occurrence of defective fixing and wrinkles can be prevented. In particular, when the thickness is 1.2 mm or less, there is almost no effect on the magnitude of the temperature gradient. The material is also made of carbon steel pipe STKM11, and has a higher strength than that of the conventional example using Al. On the surface of the core material 15 of such a fixing roller 14, a coating 19 mainly composed of perfluoroalkoxy resin is used.
And its length is 355mm.

As the fixing roller 14, a halogen heater is used, and a single rated 100 V, 1200 W, or 800
W and 400W are used. Thus, the gradient of the rise in the fixing temperature was increased to 14 to 20 degrees / second. By doing so, it is possible to complete the detection of the fixing abnormality in a short time by judging whether or not there is an abnormality by checking the time until the temperature rises to a certain temperature. Naturally, the time required to reach the fixing temperature can be greatly shortened, and by sending data from the controller 22 to the engine 23 at a temperature lower than the fixing temperature, the printing time can be further reduced and the data amount can be reduced. In order to prevent the fixing failure, the printing operation is started until the second reload temperature T2.
Even if the data reception time is 0 second, the temperature rises to a feasible temperature in a very short time of less than 2 seconds from the data reception to the start of printing, so that a printer with a short print waiting time without any discomfort can be obtained. .

[0019]

According to the present invention, there is provided a fixing roller as described above, which includes a fixing roller driven to rotate, a pressing roller abutted on the fixing roller with a predetermined pressure, a controller, and an engine. Is connected to a host such as a personal computer, and both exchange data, print instructions, etc., and the data from the host is developed by the controller and passed to the engine, and the engine prints out the passed data in an electrophotographic printer. According to the first aspect of the present invention, the transfer of the data from the controller to the engine is started after the first reload temperature lower than the feasible temperature is reached, and the start time of the printing operation is the first time.
After the second reload temperature, which is higher than the reload temperature, is reached, it takes no time to start fixing, and when printing on thick paper, there is no shortage of time to raise the fixing temperature to the required temperature. When the heater is turned on, the gradient of the rise in the fixing temperature and the temperature gradient of the fixing abnormality detection are large, and the time required to reach the fixing temperature and the fixing abnormality detection are short, so that a good quality print product can be obtained. is there.

According to a second aspect of the present invention, when a thick paper feed or a manual feed is instructed by the host, immediately before the data developed by the controller is passed to the engine, the thick paper feed or the manual feed is performed. The instruction is input to the engine, and the engine switches from the first set temperature to the second set temperature higher than the first set temperature, and sets the third set temperature which is the thick paper fixing temperature.
After reaching the reload temperature, the printing operation starts, so
There is an effect that prints of good image quality can be obtained without the risk of fixing failure occurring even on thick paper.

According to the third aspect of the present invention, since the rising gradient of the fixing temperature when the fixing heater is turned on is 14 to 20 deg / sec, the fixing abnormality detection time and the arrival time to the fixing temperature can be reduced. In addition, since data can be sent from the controller to the engine in a time lower than the feasible temperature, the printing time can be further reduced, and the amount of data is small to prevent poor fixing. Even if the printing time is waited until the second reload temperature, the temperature rises to the feasible temperature in a very short time, so that it is possible to obtain a print without any discomfort in a short time.

[Brief description of the drawings]

FIG. 1 is a schematic front view of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a main part of an identification attaching section.

FIG. 3 is a functional block diagram of the embodiment of the present invention.

FIG. 4 is a time chart of a first operation example of the above.

FIG. 5 is a time chart of a second operation example of the above.

FIG. 6 is a longitudinal sectional view of a first example of a fixing roller.

FIG. 7 is a longitudinal sectional view of the second example.

FIG. 8 is a longitudinal sectional view of the third example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Laser optical system 2 Charger 3 Developing part 4 Photoreceptor 5 Paper supply part 6 Transfer charger 7 Fixing means 9 Paper discharge part 10 Registration roller 11 Cleaning part 12 Engine board 13 Controller board 14 Fixing roller 15 Core material 16 Fixing heater 17 Addition Pressure roller 18 Pressure lever 19 Coating 21 Host 22 Controller 23 Engine 24 Paper passing section 25 Bearing section

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H027 DA12 DC02 EA12 EC02 EC20 ED25 ED30 EE07 EF04 EF06 EJ15 FA15 FA25 FA30 FA35 ZA07 ZA08 2H033 AA47 BA25 BA30 BB17 BB28 CA07 CA16 CA30 CA32 CA48 3K058 AA02 AACB CB28 CB25 CC06 CC09 CE17 DA02 GA06 5C074 BB02 BB26 CC26 DD11 EE03 EE08 EE14 GG12

Claims (3)

[Claims] An image forming apparatus includes: a fixing roller that is driven to rotate; a pressure roller that is brought into contact with the fixing roller with a predetermined pressure; a controller; and an engine. The controller is connected to a host such as a personal computer. It exchanges data, print instructions, etc., the data coming from the host is developed by the controller and passed to the engine, and the engine prints out the passed data in an electrophotographic printer,
The transfer of the data from the controller to the engine is started after the first reload temperature lower than the feasible temperature is reached, and the printing operation is started after the second reload temperature is higher than the first reload temperature. And an electrophotographic printer. 2. When a thick paper feed or manual paper feed is instructed by the host, immediately before passing the data developed by the controller to the engine, an instruction of the thick paper feed or manual paper feed is input to the engine. The engine switches from the first set temperature to a second set temperature higher than the first set temperature,
2. The electrophotographic printer according to claim 1, wherein a printing operation is started after reaching a third reload temperature which is a thick paper fixing temperature. 3. The electrophotographic printer according to claim 1, wherein a rising gradient of a fixing temperature when the fixing heater is turned on is 14 to 20 deg / sec.