JPH0416889A - Image forming device - Google Patents

Abstract

PURPOSE:To enable normal transfer and fixation on even the thick paper of an envelope, etc., by detecting whether a thick paper feeder is used or not and holding the fixation temperature of a fixation part higher when the feeder is used than when paper is fed from a plain paper feeder. CONSTITUTION:The plain paper feeder which feeds forms of normal thickness is incorporated in a printer main body 10 and the envelope feeder 11 which feeds envelopes into the main body can be connected outside detachably. Then when the envelope feeder 11 is connected to the printer main body 10, the output of connection detecting circuit 14 varies from HIGH to LOW and a CPU 15 detects the connection. The CPU 15 monitors the temperature of the heater 16 of the fixation part and turns on and off the heater 16 so as to maintain set temperature. This temperature is set to temperature T2 at the time of the paper feeding by the plain paper feeder and switched to temperature T1 higher than the temperature T2 when the envelope feeder 11 is connected, and the heater 16 is turned on and off so as to maintain the temperature T1. Consequent ly, a normal image can be obtained on even the thick paper of the envelope, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to image forming apparatuses such as laser printers, laser facsimiles, and copying machines.

For example, in conventional laser printers, when thick paper such as envelopes was fed, transfer and fixation were performed under the same conditions as when paper of normal thickness was fed, so there was no transfer or fixation. In some cases, fixation was insufficient and normal images could not be obtained.

Problems to be Solved by the Invention The present invention aims to make it possible to obtain normal images even on cardboard such as envelopes.

Means for Solving the Problems The present invention provides an image forming apparatus that has a transfer section and a fixing section, and is equipped with a thick paper feeding device in addition to a regular paper feeding device.
a thick paper feeding detection means for detecting whether the thick paper feeding device is used or not, and a fixing temperature control means for increasing the fixing temperature of the fixing section when the paper feeder is used than when feeding paper from the regular paper feeding device; Alternatively, the apparatus includes a transfer current control means for increasing the transfer current of the transfer section.

When a thick paper feeder is used, the fixing temperature or transfer current is higher than normal.

Lost member Next, one embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 6, the printer main body 10 has a regular paper feed bag for feeding paper of normal thickness! ! (not shown) is built in, and an envelope feeder 11 for feeding envelopes into the printer body 10 can be detachably connected to the outside.

FIG. 1 shows a first example of the present invention, in which an envelope feeder 11
When connected to the printer main body 10, the printer main body 10
The output of the connection detection circuit 14 made up of the diode 12 and the resistor 13 changes from HIGH to LOW, and the CPU 15 detects that the envelope feeder 11 is connected. The CPU 15 monitors the temperature of the heater 16 of the fixing section and turns on and off the heater 16 to maintain the set temperature. This temperature is set to a low temperature T2 when paper is fed by a normal paper feeder, but when the envelope feeder 11 is connected, the temperature is set to a low temperature T2.
U15 changes the temperature to a constant temperature T1 higher than T2, and turns on and off the heater 16 to maintain the high temperature T1.

FIG. 2 shows the flow of setting the fixing temperature by the CPU 15.

FIG. 3 shows a second example of the present invention, in which the envelope feeder 11
is connected to the printer body 1o, a part 11a
When the switch 17 is turned on, the CPU 15 detects this and sets the temperature of the heater 16 to a high temperature in the same way as above.

FIG. 4 shows a third example of the present invention, and FIG. 5 shows a fourth example. In these examples, a transfer charger 1 is installed in the printer main body 10.
A transfer current variable device 19 that can vary the transfer current of 8 is provided. In the case of the third example, the connection of the envelope feeder 11 to the printer main body 10 is detected in the same manner as in the first example, and in the case of the fourth example, it is detected in the same manner as in the second example, and the CPU 15 Set the transfer current variable device 19 to m! 1, and the transfer current of the transfer charger 18 is made larger than that when feeding normal paper.

In addition, although the above-mentioned embodiment showed an example using the envelope feeder 11, a postcard feeder or the like may be used as the cardboard feeder.

According to the present invention, the fixing temperature or transfer current can be made higher than normal when using the cardboard feeder, so that normal images can be obtained even on cardboard such as envelopes.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the first example of the present invention, FIG. 2 is a flowchart showing the flow of setting the fixing temperature therein, and FIG.
4 and 5 are block diagrams of second, third, and fourth examples of the present invention, respectively, and FIG. 6 is a schematic block diagram of a printer to which an envelope feeder is connected. 10...Printer body 11...Envelope feeder 14...
......Connection detection circuit 5...CPU 6...Heater 7...Switch 8...・Transfer charger 9・・・・・・Transfer current variable device patent applicant Rico Co., Ltd.

Claims (1)

[Scope of Claims] 1. In an image forming apparatus having a transfer section and a fixing section and equipped with a thick paper feeding device in addition to a regular paper feeding device, detecting whether the thick paper feeding device is used or not. and a fixing temperature control means for increasing the fixing temperature of the fixing section to be higher than that when paper is fed from the regular paper feeder when the image forming apparatus is in use. . 2. In an image forming apparatus that has a transfer section and a fixing section and is equipped with a thick paper feeding device in addition to a regular paper feeding device, a thick paper feeding detection means for detecting whether the thick paper feeding device is used or not. and a transfer current control means for making the transfer current of the transfer section larger than when paper is fed from the normal paper feeder when the image forming apparatus is in use.