JPH065433B2 - Fixing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for recording an image using toner such as a printer and a facsimile machine, and more particularly, to efficiently obtain a fixed toner image by using a cut paper. To a fixing device suitable for.

[Conventional technology]

As a fixing device used in printers, facsimiles, etc., a method is known in which toner powder is used for an image, a recording method by electrostatic force is used for development, and a toner image is heated and fixed by a flash of a xenon flash lamp for fixing. Has been.

In this type of fixing device, it is desired to efficiently supply the fixing energy.

In the conventional fixing device of this type, even when the recording paper suddenly disappears in the fixing portion during printing, flash energy irradiation equivalent to the energy required for fixing is performed. in this case,
There are inconveniences such as waste of electric power and heating of the recording paper conveying device. In order to eliminate such inconvenience, there is also known a fixing device which is provided with a recording paper detection means and detects that the recording paper is not in the fixing portion and stops the flash light irradiation. However, even with such an apparatus, there is no guarantee that the flashing light equivalent to the fixing energy will not be applied to the portion without the recording paper at all depending on the detection timing. Therefore, the above-mentioned inconveniences are reduced, but they are not eliminated, and similar inconveniences exist to some extent. This is because the conventional apparatus targets only continuous paper and therefore detects the absence of recording paper as an abnormal occurrence. In the case of such an abnormality occurrence, not only the irradiation is stopped but also the abnormality occurrence display means is activated, the driving of the conveying device is stopped, and in some cases, the driving of the developing drum and the developing device is stopped. Therefore, it becomes impossible to print and it is necessary to add some artificial operation to recover.

When the cut paper is used in the above-described conventional flash fixing device, the above-described inconvenience occurs for each recording paper because there is always a portion where there is no recording paper between the recording paper and the next recording paper. Therefore, there are problems that power is wasted, the transport device is heated to deform the recording paper, and there is a risk of ignition at times. In the case of the fixing device equipped with the recording paper detection means, in addition to the above-mentioned drawbacks, the abnormality occurrence display means is activated and the drive of the conveyance device is stopped, even though there is no situation that should be recognized as an abnormality by the user. There is also an inconvenience that the means for coping with the occurrence of an abnormality such as a printing operation is activated to make printing impossible.

Further, there is also known a recording apparatus in which a drive signal of a pulse motor for running the recording paper at a variable speed is synchronized with a flash irradiation timing to prevent waste of electric power. An example of this type of fixing device is JP-B-60-19309. However, in the case of cutting paper printing, since the above pulse motor conveys the cutting paper continuously, the drive signal does not include a marker indicating the gap between the recording papers. Even when paper is printed, the above-mentioned inconvenience occurs similarly.

[Problems to be solved by the invention]

The above-mentioned prior art does not consider flush fixing of the cut paper printing, wastes electric power, deforms the recording paper to heat the conveying device, and causes a risk of ignition. However, there is a problem that the means for coping with is activated and printing is disabled.

An object of the present invention is to eliminate waste of electric power, to heat the conveying device, and to fix a plurality of sheets of cut paper continuously without deforming the recording paper.

[Means for solving problems]

The purpose of the above is to print multiple sheets of continuous cut paper,
This is achieved by flash irradiation by synchronizing the transportation cycle of the recording paper periodically transported to the fixing device and the light emission cycle of the flash lamp.

[Action]

The recording paper feeding clock and recording paper detection means provided in the conveying device output a signal in synchronization with the recording paper conveyance cycle. In synchronization with this, the flash lamp is caused to emit light and is generated a predetermined number of times according to the length of the recording paper in the conveying direction, so that no flash light is emitted between the recording paper and the next chemical recording paper.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional side view of the recording apparatus of the present invention, in which 1 is a flash lamp, 2 is a light emitting circuit, 3 is a delay circuit, 4 is a paper feed timer circuit, 5 is a paper feed drive signal circuit, and 6 is paper feed. A roller, 7 is a recording sheet which is a cut sheet cut into a predetermined length, 8 is a sheet feeding stacker which is a recording sheet holding means, 9 is a recording sheet conveying roller, 10 is a recording sheet conveying tractor, 11 is a transfer device, 12 is a photoconductor drum, 13 is a paper output stacker, and 14
Is the transport path. The paper feed timer circuit 4, the paper feed drive signal circuit 5, and the paper feed roller 6 constitute recording paper selection means.
The recording paper conveying roller 9 conveying path 14 constitutes recording paper conveying means. FIG. 2 is a circuit diagram of the light emitting circuit 3, wherein 15 is a lamp, 16 is a light emission trigger signal switch, 17 is a light emission control circuit, and 18 is an input terminal. FIG. 3 is a sectional side view of the flash lamp 1, and 19 is a reflector. FIG. 4 shows the output signal of each circuit, where K is the paper feed timer circuit 4 and L
Is the paper feed drive signal circuit 5, M is the delay circuit 3, and N is the output signal of the light emission control circuit 17. Further, a indicates a stop time of the paper feed roller 6, b indicates a rotation time, and c indicates a delay time of the delay circuit. In FIG. 1, after the recording paper 7 is placed on the conveyance path 14 closest to the paper feed stacker 8 by the paper feed roller 6,
Conveying roller 9, other conveying path 14, conveying tractor 10
Is transported at a constant speed. In the meantime, the recording paper 7 is developed with toner as an unfixed image on the recording paper 7 by the transfer device 11 and then reaches the flash lamp 1 where it is irradiated with a predetermined number of flash light, for example, once.
The toner is fused and fixed on the upper portion, and is stored in the sheet discharge stacker 13. The recording paper 7 of this embodiment is A4 size,
It is 8.5 inches long in the transport direction. Further, it has a continuous printing mode, and during continuous printing, the gap between the recording papers is kept at a fixed length longer than the fixing length at which one lamp fixes.
Therefore, the paper feed roller 6 is rotated until one recording sheet is placed on the transport path 14 and then stopped for a certain period of time, and is rotated until the next recording sheet is placed on the transport path. During this time, the transport roller 9 and the transport tractor 10 continue to rotate at a constant speed. The sheet feeding roller 6 is repeatedly rotated by a pulse motor (not shown), and its rotation is controlled by a driving signal output from the sheet feeding driving signal circuit 5. A signal which is a basis of the signal of the paper feed drive signal circuit 5 is a square wave having a constant period output from the paper feed timer circuit 4. Here, since the recording paper 7 is conveyed at a predetermined speed, for example, a constant speed, when attention is paid to one recording paper, the recording paper 7 is conveyed after the paper feed roller 6 starts rotating to put the recording paper on the conveyance path. The time to reach the lamp 1 is constant. Therefore, the output of the paper feed timer circuit 4 is input as the first timing signal to the delay circuit 3 which delays by that time, and the output of the delay circuit is shown as the second timing signal in the light emitting circuit 3 shown in FIG. Light emission control circuit 17
When the input is made through the input terminal 18, the lamp 15 emits light only when the recording paper 7 reaches just below the flash lamp as shown in FIG. Here, the light emission signal trigger switch 16 is closed only when a + 5V signal is input from the light emission control circuit 17, and then three lamps 15 simultaneously emit light. The signals described above are as shown in FIG.

Further, as shown in FIG. 3, the fixing range of the fixing device 1 is set to, for example, 8.5 inches by adjusting the reflection plate 19, which corresponds to the length of the A4 recording sheet in the conveying direction. Therefore, according to the light emitting procedure of the present embodiment described above, the flash light does not illuminate the gap between the recording papers, and even if the light is irradiated, the light is weak enough to not reach the energy required for fixing. Therefore, the transport tractor is not heated, and there is an effect that power is not wasted. Although the three lamps 15 are used in the embodiment of FIG. 1, one lamp may be used to emit light three times in synchronization with the conveyance, as long as it is flashed on the entire recording paper. However, it is not particularly limited.

FIG. 5 is a sectional side view of the recording apparatus of the reference example using the detecting means, and 20 is a recording paper detector serving as the recording paper detecting means. The recording paper detector 20 is the fixing device 1 in the conveyance path 14.
Is attached to the lower surface of the conveyance path 14 at a position closest to the fixing device 1 between the sheet feeding roller 6 and the sheet feeding roller 6, and a signal of + 5V is output when the recording sheet is on the recording sheet detector 20 by an optical sensor, and a signal of 0V is output when there is no recording sheet. Output. As a result, the output of the recording paper detector 20 becomes the same as the output of the paper feed timer circuit 4 with the time delay. In this reference example, the output of the paper feed timer circuit 4 is not input to the delay circuit 3, but instead the output of the recording paper detector 20 is input as the first timing signal. Other configurations are similar to those of the embodiment shown in FIG. At this time, the delay time of the delay circuit 3 is
It is set in accordance with the time from when the recording paper passes through the recording paper detector 20 to immediately below the fixing device 1. Therefore, similar to the first embodiment, there is an effect that only the recording paper is irradiated with the flash light. Further, when the output of the paper feed timer circuit 4 is used for the input of the delay circuit 3, the lamp 15 emits light even when a trouble that the recording paper does not reach the fixing device 1 due to a jam or the like during the transportation of the recording paper. However, if the method of inputting the output of the recording paper detector 20 of the present embodiment to the delay circuit 3 is used, the flash lamp does not emit light until the recording paper reaches the recording paper detector 20, so when the above trouble occurs. This has the effect of automatically stopping the flash irradiation. However, when the detector 20 is arranged as shown in the figure, light from the flash lamp leaks and heat is generated in the detector, and the detector malfunctions due to the influence of this heat, or if it is an optical detector. There is a problem that it is directly affected by the light of the flash lamp and malfunctions.

The case of printing only A4 size recording paper has been described above. Next, another embodiment capable of printing both A4 and A3 size recording paper will be described. The present embodiment is provided with a switching switch which allows the operator to select either A3 or A4 size. The other configuration is the same as that of FIG. 1, and the gap between the recording papers is constant in the case of A3 size recording paper printing and A4 size recording paper printing. It is similar to the one.
For A3 size recording paper, the length in the recording paper conveyance direction is
It is 17 inches, which is twice the size of A4 size recording paper. Therefore, in the case of A3 size recording paper printing, the time of the convex portion of the square wave which is the basis of the rotation time of the paper feeding roller 6 in the output of the paper feeding timer 4 is twice as long as the A4 size recording paper printing.
Further, the output signal of the light emission control circuit 17 indicates that the flash lamp 15 first outputs A4 while one recording sheet passes through the fixing device 1.
As in the case of printing a recording paper of a size, the light is emitted once, and then is emitted once after being conveyed for 8.5 inches, so that the light is emitted twice in total. FIG. 6 is a diagram showing the output signal of each circuit when printing A3 size recording paper, and the symbols are the same as in FIG.

In this embodiment, when the operator designates the A4 size recording paper print mode, the output waveform shown in FIG.
The paper feed timer 4 and the light emission control circuit 17 are provided with two output formats so that the output waveform shown in FIG. 6 is obtained when the size recording paper printing mode is designated. According to this embodiment, the same effects as those of the embodiment of FIG. 1 are obtained, and further, both A4 size recording paper and A3 size recording paper can be printed.

FIG. 7 is a sectional side view of a flash fixing device according to another embodiment of the present invention. FIG. 7A shows the case of printing A3 size recording paper, and FIG. 7B shows the case of printing A4 size recording paper.
The shape of 9 changes according to each case, and the fixing range is 17 inches in FIG. 7 (a) and 8.5 inches in FIG. 7 (b). If a member whose shape changes according to the applied voltage is used for the reflection plate 19 as described above, A3
Both size recording paper and A4 size recording paper can be fixed with one light emission, and the output mode of the light emission control circuit can be set in only one mode.

〔The invention's effect〕

As described above, according to the present invention, in the continuous cut paper printing of a plurality of sheets, since the flash irradiation between the recording paper and the next recording paper is scarcely performed, there is no waste of electric power and the heating of the transport device is performed. It has the effect of preventing deformation of the recording paper.

[Brief description of drawings]

1 is a sectional side view of a recording apparatus according to an embodiment of the present invention, FIG. 2 is a light emitting circuit diagram of the present invention, FIG. 3 is a sectional side view of a flash fixing device of the present invention, and FIG. 4 is the present invention. FIG. 5 is an output waveform diagram of each circuit in the case of printing A4 size recording paper, FIG. 5 is a sectional side view of a recording apparatus of a reference example using a detector, and FIG. 6 is an A3 size recording paper printing of the present invention. FIG. 7 is an output waveform diagram, and FIG. 7 is a sectional side view of a flash fixing device according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Flash fixing device, 2 ... Light emitting circuit, 3 ... Delay circuit, 4 ... Paper feeding timer circuit, 5 ... Paper feeding drive signal circuit, 6
... paper feed roller, 7 ... recording paper, 9 ... recording paper transport roller, 1
0 ... Recording paper transport tractor, 14 ... Transport path, 15 ... Flash lamp, 17 ... Emission control circuit, 20 ... Recording paper detector.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaru Higaki 4026 Kuji Town, Hitachi City, Hitachi, Ibaraki Prefecture, Hitachi Research Institute, Ltd. (72) Inventor Shigetaka Fujihara 4026 Kuji Town, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory (56) Reference JP-A-56-59271 (JP, A) JP-A-57-201272 (JP, A) JP-A-54-134649 (JP, A) JP-A-58-28764 (JP, A) JP-A-61-32869 (JP, A) JP-A-61-28961 (JP, A)

Claims (12)

[Claims] 1. A recording paper holding means for holding a plurality of recording papers cut into a predetermined length, and a recording paper selecting means for selecting one of the plurality of recording papers based on a predetermined timing signal. A recording sheet conveying unit that conveys the selected recording sheet at a predetermined speed, and a control unit that determines the number of times the flash lamp emits light based on the length of the recording sheet in the conveying direction, the conveying speed, and the predetermined timing signal. And a flash lamp that emits light a predetermined number of times based on a signal from the control unit to fuse the toner to the selected recording paper. 2. The fixing device according to claim 1, wherein the predetermined speed of the conveying means is substantially constant. 3. A recording paper holding means for holding a plurality of recording papers cut into a predetermined length, a timing signal generating circuit for generating a timing signal, and a first timing signal generated by the timing signal generating circuit. A recording paper selecting means for selecting one of the recording papers, a recording paper carrying means for carrying the selected recording paper at a predetermined speed, and a second timing signal generated by the timing signal generating circuit. A flash lamp that emits light a predetermined number of times based on the above, and a flash lamp that fuses a toner image onto the selected recording paper, and the timing signal generation circuit sends a first timing signal to the selected recording paper by the recording paper conveying means. Delay circuit for generating the second timing signal by delaying the recording paper holding means from the recording paper holding means to the flash lamp. Fixing apparatus characterized in that it comprises. 4. The fixing device according to claim 3, wherein the predetermined speed of the conveying means is substantially constant. 5. The fixing device according to claim 3, wherein the predetermined number of times the flash lamp emits light is determined according to the length of the recording paper in the conveying direction. 6. A recording paper holding means for holding a plurality of recording papers having different lengths, each cut into a predetermined length, arranged by length, and designating the length of the recording paper to be used. Input means, timing signal generating circuit for generating a predetermined timing signal, and recording paper selection means for selecting one of the recording papers of the plurality of lengths based on the signal from the input means and a predetermined timing signal. A recording paper conveying means for conveying the selected recording paper at a predetermined speed, and the timing signal generating circuit based on a predetermined timing signal, a signal from the input means and a recording paper conveyance speed. It is composed of a control circuit that generates a light emission timing signal, and a flash lamp that emits light that fuses toner to the selected recording paper based on the light emission timing signal generated by the control circuit. Fixing apparatus wherein a. 7. The fixing device according to claim 6, wherein the predetermined speed of the conveying means is substantially constant. 8. The fixing device according to claim 6, wherein the predetermined number of times the flash lamp emits light is determined according to the length of the recording paper in the conveying direction. 9. The fixing device according to claim 8, wherein the predetermined number of times the flash lamp emits light is determined by using the data received from the input means, the predetermined number of times emits light, and the selection is made. A fixing device, which is a flash lamp for fusing toner to a recording sheet that has been formed. 10. A recording paper holding means for holding a plurality of recording papers having different lengths, each cut into a predetermined length, arranged by length, and designating the length of the recording paper to be used. Inputting means, a timing signal generating circuit for generating a predetermined timing signal, and one of the recording papers having a plurality of lengths are used as a signal from the inputting means and a first timing signal from the timing signal generating circuit. A recording paper selection means for selecting the recording paper based on the selected recording paper, a recording paper conveyance means for conveying the selected recording paper at a predetermined speed, a signal from the input means, and a second timing signal from the timing signal generation circuit. A flash lamp that emits light a predetermined number of times based on the recording paper holding means and fuses the toner to the selected recording paper, and the timing signal generating circuit outputs the first timing signal to the recording paper holding means. Fixing device characterized by having a delay circuit for outputting a second timing signal is delayed in response to being conveyed to the flash lamp. 11. The fixing device according to claim 10, wherein the predetermined speed of the conveying means is substantially constant. 12. The fixing device according to claim 10, wherein the predetermined number of times that the flash lamp emits light is determined according to the length of the recording paper in the conveying direction.