JPS6259310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixing method used in copying machines, laser printers, and the like.

Conventionally, this type of fixing method includes a fixing method using a flash lamp, a roll fixing method, and a radiation heat fixing method. In the fixing method using flash lamps, two flash lamps are used as shown in Figure 1.
This flash lamp is made by emitting light from L ₁ and L ₂ at the same time.
Flashing light of L ₁ and L ₂ is applied to the recording paper P for fixing. In this case, as shown in FIGS. 2 and 3, the output of the AC power source S ₁ is boosted by a transformer T ₁ and applied to capacitors C ₁ and C ₂ through diodes D ₁ and D ₂ , respectively. Then, the charging voltages of the capacitors C ₁ and C ₂ are applied to the flashing lamps L ₁ and L ₂ respectively, and the flashing lamps L ₁ and L ₂ are simultaneously triggered in synchronization with the recording paper P by a trigger circuit (not shown). I am issuing it. Further, when the recording paper P is conveyed over a distance corresponding to the length l in 2 seconds, for example, the flashing lamps L ₁ and L ₂ are configured to emit flash light for 2 seconds.

However, with this fixing method, flash lamps cannot be used.
Since L ₁ and L ₂ are emitted at the same time, the capacitor
C ₁ and C ₂ are charged at the same time, resulting in a large rush current, increasing noise to other devices, and increasing the load on the DC power source before the diodes D ₁ and D ₂ , shortening its lifespan.

Therefore, in order to reduce the lash current, the fourth
Although it is conceivable to alternately charge the capacitors C ₁ and C ₂ as shown in the figure, this is not preferable because it would result in a large difference in the amount of charge between the capacitors C ₁ and C ₂ .

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks and provide a fixing method that can charge a capacitor to a required amount with a small lash current.

Embodiments of the present invention will be described below with reference to the drawings.

In the fixing section of a copying machine (or printer, etc.), two flashing lamps L ₃ and L ₄ are installed above the path of the recording paper P along the traveling direction of the recording paper P, as shown in FIGS. 5 and 6. juxtaposed each flashlamp L ₃ ,
L ₄ has reflectors M ₁ and M ₂ arranged on the sides and rear, and provides flash light to an area roughly dividing the recording paper P into two in the front and back of the path of the recording paper P. ing.

Now, when the recording paper P knocks down the micro switch MS ₁ , the switch S ₁ is turned on and the capacitor C ₃ is charged. Then, when the recording paper advances by l, switch MS ₃ is activated. Switches MS ₃ and MS ₂ operate almost simultaneously, and capacitor C ₄ starts charging by switches MS ₂ and S ₂ . Capacitor _C4 is then charged until switch _MS4 is activated. After that, the same operation is repeated even if the recording paper is continuously fed. However, here it is necessary to leave some space between the recording sheets for the flashing time. Further MS ₃ and MS ₄
Since it is only necessary to activate the trigger circuit, it is preferable that the circuit be turned off after sending the pulse signal. If the length of the recording paper P in the traveling direction is l, when the front part of the recording paper P with a length of 1/2 liter enters the flashlight irradiation range of the flashing lamp L ₃ , the micro switch MS ₃ switches the recording paper P. When the leading edge of the recording paper P is detected, the trigger circuit triggers the flashing lamp _L3 , and the flashing lamp _L3 applies flashing light to the front side of the recording paper P, thereby fixing the toner image. Next, when the 1/2 liter rear portion of the recording paper P enters the flashlight irradiation range of the flashlight lamp _L4 , a micro switch is activated.
The MS ₄ detects the leading edge of the recording paper P, and the trigger circuit triggers the flashing lamp L _4. The flashing lamp L ₄ applies flashing light to the rear part of the recording paper P, fixing the toner image. It will be done. Here, the flash is within 1 second, and its peak width is generally 1/10 to 1/1
It is about 100000sec. Further, as shown in FIGS. 6 and 7, the output of the AC power source S ₂ is boosted by a transformer T ₂ , rectified by diodes D ₃ and D ₄ , and applied to capacitors C ₃ and C _4, respectively. Then, the charging voltages of the capacitors C ₃ and C ₄ are applied to the flashing lamps L ₃ and L ₄ , respectively, and the switches S ₃ and S ₄ are turned on in conjunction with the micro switches MS ₃ and MS ₄ , respectively. The light lamps L ₃ and L ₄ are triggered by trigger circuits TR ₁ and TR ₂ , respectively, to emit light.
The switches S ₃ and S ₄ may be alternately turned on for a certain period of time by a timer in synchronization with the recording paper P, and the micro switches MS ₁ , MS ₂ , MS ₃ , and MS ₄ may be replaced by photocells, Cds cells, A detection means based on a change in capacitance or the like may be used.

If the flashing lamps L ₃ and L ₄ are made to emit light alternately in this way, the capacitors C ₃ and C ₄ can be charged alternately, and the combined charging current can be reduced. Therefore, the lash current can be reduced and made uniform, reducing noise to other devices and reducing the load on the DC power supply. Furthermore, since the flashing lamps L ₃ and L ₄ are made to emit light alternately, the amounts of charge in the capacitors C ₃ and C ₄ can be made equal, and good fixing characteristics can be obtained.

Figure 8 shows the flashing lamp in the above embodiment.
This shows the capacitor charging current when the light emitting time of L ₃ and L ₄ is shortened to 1/2 and the conveyance speed of the recording paper P is doubled.However, the conveyance speed of the recording paper P can be further increased to increase the fixing speed. is possible, and also a capacitor
The peaks of the charging currents of C ₃ and C ₄ never overlap.

In the above embodiment, two flash lamps L ₃ and L ₄ were used, but as shown in FIG. 9, three reflectors M ₃ were used.
Flashing lamps L ₅ to _{L 7} with ~M ₅ are used to emit light in sequence, and the recording paper P is divided into three in the direction of travel, and each of the flashing lamps L ₅ to _{L 7} is applied to each part P ₁ to P ₃ . Fixation can also be performed by applying light to each. In this case, as shown in FIG _. 10, three capacitors C ₅ to C ₇ are charged with a DC power source, and the respective charging voltages are applied to the flash lamps L ₅ to _{L 8} respectively. ₇ can be triggered sequentially in synchronization with the recording paper P using a trigger circuit. In this way, it is possible to further increase the speed. Furthermore, as shown _{in FIG .}
L ₁₁ is used to sequentially emit light, and the recording paper P is divided into four parts in the direction of travel, and each part P ₁ to _{P 4} is illuminated with a flashing lamp.
Fixing can be performed by applying each of the flashlights _L8 to _L11 , respectively, or similarly, fixing can be performed using five or more flashlight lamps.

In addition, in each of the above-mentioned fixing methods, one flash lamp L _i has three or more electrodes as shown in FIG.
ER ₁ to _{ER 3} may be provided to divide the light source into two or more flashing light sources, and the charging voltage of the capacitors Ci ₁ and Ci ₂ may be applied to these, respectively. Each capacitor Ci ₁ and Ci ₂ is charged by one AC power source S ₂ and two DC power sources E ₁ and E ₂ made of a transformer T ₂ and two diodes. 13 and 14 show an example in which the flashing lamps L ₃ and L ₄ are each divided into two in the fixing method shown in FIG. 5, and their charging currents. And Figure 15 is the first
This is to prevent the charging start-up of the capacitors from overlapping when charging as shown in Figure 4, and as shown in Figures 16 and 17.
The figure illustrates the charging method. In the microswitches MS ₅ , MS ₆ , and MS _{7 ,} the dotted line portions indicate the state in which they are tilted down by the recording paper P. First, the micro switch MS ₅ falls down and the capacitor C ₃₁ is charged,
Next, when microswitch MS ₆ falls down, charging of capacitor C ₃₁ is cut off and charging of capacitor C ₃₂ starts, and then microswitch MS ₇ falls down and charging of capacitor C ₃₂ is stopped. Similarly, although not shown, the capacitors C ₄₁ and C ₄₂ are charged. Although a microswitch is used in this example, it is also possible to replace it with an electronic circuit such as a flip-flop.

FIG. 18 shows an example suitable for cases where the width of the recording paper is wide or when it is desired to downsize the flash lamp and lower its discharge voltage. In this example, the capacitor is the 14th
It is charged as shown in Figure 17, and the flashing lamp lights up.
Light is emitted in the order of L ₃₁ , L ₃₂ , L ₄₁ , and L ₄₂ . Furthermore, the 19th
As shown in the figure, it is also possible to align the longitudinal direction of the flashing lamps L ₃ and L ₄ approximately with the traveling direction of the recording paper P.

Further, FIG. 20 is an example of a divided flash, in which one recording paper P is irradiated 1/4 at a time. FIG. 21 shows the relationship between charging and flashing of the capacitor in this example. Further, each flashing lamp is provided with a capacitor, but as shown in FIG. 22, one flashing lamp Lx may be provided with a plurality of capacitors Cx ₁ and Cx ₂ and used selectively by the switch SW.

In the embodiment shown in Fig. 5 above, the flash lamp
Capacitors using xenon lamps as L ₃ and L ₄
When the terminal voltage of C ₃ and C ₄ was set to about 700V and flashlight was applied to a sheet of recording paper for 2 seconds each, once for 2 seconds from flash lamps L ₃ and L ₄ , for a total of 4 seconds, 15 copies were made per minute. I was able to obtain things continuously. When fixing was carried out in the same manner by doubling the fixing speed and using a toner with a melting point 30° C. lower, 30 good copies were obtained per minute.

As described above, in the fixing method according to the present invention, since the charging start times of n sets (n is a positive integer) of capacitors are staggered, the rush current can be reduced, noise to other devices can be reduced, and the power supply can reduce the burden on Further, n sets of flashing light sources are connected to n sets of different parts in the traveling direction on one side of the recording paper, and the flashing light source which is the most upstream in the recording paper traveling direction corresponds to the most downstream part in the recording paper traveling direction. The flash light source next to the most upstream flash light source corresponds to the next part of the most downstream part, and each flash irradiation range of n sets of flash light sources is printed on one sheet of recording paper. The corresponding flashlight irradiation range is divided into n groups in the recording paper traveling direction, and each set is set so that there are n sets of flashlight irradiation ranges, and each of the n-divided parts of the recording paper is divided into n groups of flashlight sources corresponding to these. At predetermined times that are sequentially shifted before entering each flashlight irradiation range, n sets of capacitors are charged by the DC output, which is boosted by the transformer and rectified by the rectifier. Starting, the charging voltage of these n sets of capacitors was applied to each of the n sets of flash light sources, and each of the n divided portions of the recording paper came within the flash irradiation range of the corresponding n sets of flash light sources. At the same time, each of n sets of flashing light sources is made to emit light, so the charging start time of each capacitor is sequentially shifted, and the light emission time of each flashing light source is sequentially shifted, so that the charging time of each capacitor is approximately equal, and the charging time of each capacitor is approximately equal. Since there is no large difference in the amount of charge, each capacitor can be charged to the required amount, and each flashing light source can apply the required amount of flashlight to each part of the recording paper for good fixing. .

[Brief explanation of the drawing]

Fig. 1 is a front view showing the device used in the conventional fixing method, Fig. 2 is a circuit diagram showing the electric circuit in the same device, Fig. 3 is a timing chart of the electric circuit, and Fig. 4 is a front view showing the device used in the conventional fixing method. 5 is a front view showing a fixing device according to an embodiment of the present invention, FIG. 6 is a circuit diagram showing an electric circuit in the fixing device, and FIGS. 7 and 8 are the same. Timing charts of the electric circuit, FIGS. 9 to 22, are diagrams for explaining other embodiments of the present invention. L ₃ to L ₁₁ , L _i , L _x ... Flash lamp, M ₁ to _{M 9}
... Reflector, P ... Recording paper, MS ₁ , MS ₂ ... Micro switch, S _{2 ... AC power supply, T 2 ...} Transformer, D ₃ , D ₄ ... Diode, S ₁ , S ₂ ... Switch, TR ₁ , TR ₂ ...Trigger circuit, _C3 , _C4 ...Capacitor.

Claims (1)

[Scope of Claims] 1. N sets (n is a positive integer) of flashing light sources arranged offset in the traveling direction of the recording paper flash light into each part of one surface of the recording paper divided into n parts in the traveling direction. A method of fixing by sequentially applying n sets of flashing light sources to different parts in the traveling direction on one side of the recording paper, and the flashing light source that is the most upstream in the traveling direction of the recording paper. Corresponding to the most downstream part in the traveling direction, the flashing light source next to the most upstream flashing light source corresponds to the next part to the most downstream part, and the n sets of flashing light sources are Each flashlight irradiation range is set to be n sets of flashlight irradiation ranges obtained by dividing the flashlight irradiation range corresponding to one sheet of recording paper into n in the recording paper traveling direction, and each part of the recording paper is divided into n parts. The output of the same AC power source is boosted by the transformer and rectified by the rectifier at each predetermined time sequentially shifted before each time when the corresponding n sets of flash light sources enter the flash irradiation range. The DC output starts charging each of the n sets of capacitors, and the charging voltage of the n sets of capacitors is applied to each of the n sets of flashing light sources. A fixing method characterized by causing each of n sets of flashing light sources to emit light when entering the flashlight irradiation range of the flashing light source.