JPS5991471A - Electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To obtain securely an unfixing copy without damaging an unfixing toner image by connecting a transfer paper path after transfer either to a fixing transfer paper discharging device or an unfixing transfer paper discharging device to switch each control mode. CONSTITUTION:When a toner image is fixed on transfer paper 34, a discharge part 51 is placed in a state that the upper surface of a transportation belt 44 and a discharge roll 49, and the upper surface of the transportation belt 51a are not positioned on the same plane, and a control circuit attain a fixing mode. When the transfer paper 34 is discharged in an unfixed state, the upper surface of the transportation belt 51a is positioned so as to be positioned on almost the same horizontal surface as the upper surface of the transportation belt 44, also a discharge roll 48 is spaced from the discharge roll 49, the control circuit attains a non-fixing mode, a fixing operation inhibiting signal is applied to a fixing device 45, and the transportation belt 51a operates from the time point when the tip of the transfer paper 34 reaches the discharge part 51 to stop the transportation feet at the time point when the rear end of unfixed transfer paper 34b reaches the discharge part 51.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic machine having a transfer paper fixing mode and an unfixing mode.

When copying a document with an electrophotographic copying machine (hereinafter simply referred to as a copying machine), it would be extremely convenient if the transferred toner image on the transfer paper could be ejected to the output tray of the copying machine without being fixed for the following reasons.

In other words, since an unfixed copy in which the transferred toner image has not been fixed can be easily erased using a rubber band, etc., an unfixed copy with the image partially erased in this way can be removed using an appropriate fixing device. After fixation, the desired copy can be easily obtained by performing the necessary editing, and by using the partially erased unfixed copy as a manuscript, it is possible to create similar drawings, etc. can be done efficiently.

For this reason, copying machines that can produce unfixed copies have been proposed. Figures 1 and 2 are
FIG. 2 is a schematic diagram illustrating an example of this conventional copying machine CM'i.

In the figure, 1 is a photosensitive drum, 2 and 3 are paper feed rollers, 4 is a paper feed guide section, 5 is an electrostatic charger, 6 is an antistatic charger, 7 is a conveyor belt, 8 is a suction fan, 9 is a guide plate, 10 and 11 are heating fixing rollers, 12 is a discharge tray for fixed transfer paper, and 13 is a discharge tray for unfixed transfer paper.

When obtaining a fixed copy, use the guide plate 9 as shown in Figure 1.
Make the top surface 9a'r horizontal. Therefore, when the transfer paper 14 on which the toner image has been transferred is conveyed by the conveyor belt 7, the transfer paper 14 is guided along the upper surface 9a of the guide plate 9. As a result, the transfer paper 14 is heated between the heating and fixing rollers 10 and 11 to fix the toner image thereon, and is discharged onto the discharge tray 12.

When obtaining an unfixed copy, the guide plate 9 is rotated counterclockwise by a predetermined angle as shown in FIG.

Therefore, the transfer paper 14 conveyed by the conveyor belt 7 is
The transfer paper 14 comes into contact with the surface 9b of the guide plate 9 and is guided by this surface 9b, whereby the transfer paper 14 is ejected onto the ejection tray 13 without being fixed.

However, in such a copying machine CM, when obtaining an unfixed copy, the surface 9b of the guide plate 9 comes into contact with the toner image on the transfer paper 14, resulting in the inconvenience that the image is streaked or partially erased. occurs. In addition, in order to eliminate this inconvenience, the heating fixing roller 10 is separated from the roller 11 without rotating the surface 9b of the guide plate 9.
Transfer paper 14 through the entire gap created between 0 and roller 11.
If the toner is discharged, it takes several tens of minutes for the heat fixing roller to cool down, resulting in the inconvenience that all unfixed copies cannot be obtained immediately.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a copying machine which can eliminate such inconveniences and actually produce unfixed copies ff:411i without damaging unfixed toner images.

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

FIG. 3 is a schematic diagram showing an embodiment of a copying machine CM according to the present invention. In the figure, 21 and 22 are the original 20
23 is a contact glass, 24 is a conveyance roller that conveys a
25 and 26 are discharge rollers that discharge the original 20, 27 and 28 are lamps that illuminate the original 20, and 29 is a convergent light transmission member that forms a reflected light image from the original 20 on the photoreceptor drum 30. 31 is a charger that uniformly charges the surface of the photoreceptor drum; and 32 is a developer that develops a latent image formed on the surface of the photoreceptor drum with toner.

33 is a transfer paper tray, 34 is a transfer paper, 35 is a transfer paper 34
36 and 37 are separation rollers that separate and convey the transfer paper 34 one by one, and 38 and 39 are registration rollers.

40 is a transfer device that charges the transfer paper 34 and transfers the toner image on the surface of the photoreceptor drum; 41 is a separator that neutralizes the transfer paper 34 and separates it from the photoreceptor drum 30; 42 is the surface of the photoreceptor drum 30; and a static eliminator that removes residual charges on the surface of the photoreceptor drum 300.

44 is a conveyor belt that conveys the separated transfer paper 34; 45
46 is a suction fan that brings the transfer paper 34 into close contact with the conveyor belt 44; 47 is a microswitch; 48 and 49 are discharge rollers; 50 is a fixed transfer device. A discharge tray for accumulating paper 34, and 51 an unfixed transfer paper 34.
This is an unfixed transfer paper discharge section (hereinafter simply referred to as a discharge section) that discharges the unfixed transfer paper.

The details of this discharge section 51 are shown in FIG. In the same figure,
rollers 51b and 51c that drive the transport bell) 51a;
is supported on the side plate 51d via respective shafts 516 and 51c', and the shaft 51b' is rotatably supported on the casing of the copying machine CM (not shown). Therefore, the transport bell) 51a and the rollers 51b, 51c
The side plate 51d provided with this can rotate integrally around the shaft 51b'.

The lever 52 is pivotally supported by the housing via a shaft 52a fixed to one end thereof, and a connecting member 52b is attached to the same end.
Further, a pin 53 that fits into an elongated hole 51q formed in the side plate 51d is fixed to the connecting member 52b.

A pin 54a that fits into an elongated hole 51e is fixed at the other end of a support member 54 that pivotally supports the discharge roller 48 at one end thereof, and this support member 54 is fixed at approximately the center thereof. It is pivotally supported by the above-mentioned casing via a shaft 54b.

The transfer paper 34 is still on the conveyor bell) 51a inside the cover 55.
A suction fan 56 (see FIG. 3) that brings the side plate 5 into close contact with the
1d is provided with a microswitch 57 for detecting the transfer paper 34, and a microswitch 58 operated by the lever 52 to detect the position of the unfixed transfer paper discharge section 51 is provided as described above. It is installed in the casing.

FIG. 5 is a schematic diagram showing a control device for the fixing device 45. As shown in FIG. In the figure, 101 is a shift register for delaying the activation signal S1 of the microswitch 47;
, 111.112.114 and 119 are OR circuits, 1
03,109.1-J- and 115 are flip-flops, 104,107°108.110,118 and 12
0 is an AND circuit, 113 and 117 are inverters, and 116 is a differential circuit consisting of a diode, a capacitor, and a resistor.

With the above (sound generation), first transfer the transfer machine 34 (-toner f'1
``Explanation of the effect in the case of fixing is explained below. At this 1% ratio, the lever 52 is turned as shown in Figure 4.
='F It is rotated in the Ql direction, so the bottle 53 slides to the left inside the elongated hole 51p, and the side plate 51 (+ '(
('Anti +1' [rotate in the iji direction. Along with this,
The pin 54a7' slides in the elongated hole 5Ie to the right, and the support part 54 is moved in the direction of the white direction, and the discharge port 48 is pressed to 49 by J5.

Therefore, the discharge part 51 is 2%, as shown in Figure 3/i=
, r: Sea urchin conveyor belt 44 and υ]N-1X roller 49 -i, gate and its conveyor belt) 51a are the same as -
Place it in such a way that it is not located on the f-plane 1.

The original 20 placed on the top of the copying machine CM [1-1] is
”(l'j The feed rollers 21 and 22 move in the direction of the arrow K.
II11;) The contact is guided between the lath 23 and the pack 1/-t 24, and the ejection roller 25
and 26 to the right.

During this conveyance, the image of the original 20 is illuminated on the contact glass 2:3 by the lamps 27 and 28, and the reflected image is uniformly charged by the charger 31 via the focusing bulb C7 transmitter play 29. At the same time, the image is formed on the photoreceptor drum 30 which is rotating in the direction of the arrow, thereby forming an electrostatic latent image of the image on the document 20 on the surface of the photoreceptor drum 30.

This electrostatic latent image is developed with toner by a developing device 32.

On the other hand, the υ transfer paper tray 33 is
The transfer paper 34 fed from the transfer paper 34 is conveyed in synchronization with the photoconductor drum 30 by registration rollers 38 and 39 so that its leading edge coincides with and contacts the leading edge of the image on the photoconductor drum 30, and is conveyed by the transfer device 40. The toner image on the surface of the photoreceptor drum is transferred. The transfer paper 34 separated by the separator 41 is conveyed to a fixing device 45 by a conveyor belt 44.

During this conveyance, the transfer paper 34 turns on the microswitch 47. Therefore, the microswitch 47 is opened when the transfer paper 34 is passing over it, and as shown in FIG.
A signal S1 as shown in a) is applied to the shift register 101.

The shift register 101 outputs signals obtained by delaying this signal sl by times τ1, τ2, and τ3 from the output terminals Qm, Qn, and Qi, respectively ((b) in the same figure).
(c) and cd)).

The delay time T1 is the time required for the shift register 1o1 to perform m shift operations, that is, the time required for the transfer paper 34 to move from the position of the microswitch 47 to the transfer paper entrance of the fixing device 45. τ2 is
The time required for the shift register 1o1 to shift n times, that is, the time required for the transfer paper 34 to move from the position of the microswitch 47 to the transfer paper exit of the fixing device 45, and the delay time 3 are the shift The time required for the register 101 to perform one shift operation, that is, the time required for the transfer paper 34 to move from the position of the microswitch 47 to the output tray 50 (or the output unit 51) is set. Note that m (n (i).

Therefore, the output signal of the OR circuit 102 is as shown in FIG.
As shown in FIG. 3, the logic level is rHJ from the time when the leading edge of the transfer paper 34 enters the fixing device 45 until the time when the trailing edge is ejected.

Then, the clock signal PC immediately after the output signal of the OR circuit 102 rises causes the flip-flop 10 to
3 changes and its output terminal Q becomes the logic level rHJ (see (f) in the figure). At the same time, the output terminal Q of the flip-flop f103 falls to the logic level rLJ, so the AND circuit 120 is rendered inactive, thereby maintaining the state of the flip-flop 103.

Also, since the counter 105 is enabled while the output terminal Q of the flip 11y7' flop 103 is at the logic level rHJ, the counter 105 between the clock signal P
C is counted up, and the count value of the counter 106 is incremented every time there is a carry (overflow). and,
When the count value of the counter 106 reaches a value after a predetermined time TI, the output of the AND circuit 107 becomes the logic level rHJ, as shown in FIG. Therefore, the output of the AND circuit 110 becomes the logic level rHJ in synchronization with the clock signal PC as shown in FIG.
5.106 is reset.

The state of the flip-flop 103 changes again due to the clock signal PC generated immediately after this, and the logic level of its output terminal Q rises to rHJ. Therefore, the logic level of the output terminal Q of the flip-flop 103 is the same as that of the OR circuit 1.
While the output of 02 is at the logic level rl (J), the state in which the time TI reaches "lI" and then becomes one clock cycle rLJ is repeated.

The signal at the output terminal Q of the flip-flop 1 (73) is output to the fixing device 45 as a charging control signal sc via the AND circuit 104, thereby charging the flash lamp flash capacitor of the fixing device 45. , the above-mentioned time TI is set as the time required to accumulate a predetermined charge in this capacitor.The output of the AND circuit 110 is sent to the fixing device 4 via an OR circuit 111.
5 and the flood-ramp trie acts as signal ST.

In this way, the flash lamp emits light every time the transfer paper 34 advances a predetermined distance after entering the fixing device 45, and the toner image on the transfer paper is heated and fixed.
The process ends when the output of the OR circuit 102 reaches the logic level rLJ, that is, when the trailing edge of the transfer paper 34 is ejected from the fixing device 45.

Then, this fixed transfer paper 34a is transferred to the discharge roller 4.
8 and 49, the paper is discharged onto the discharge tray 50.

Next, the operation of this embodiment when the transfer paper is discharged in an unfixed state will be explained.

In this case, as shown in FIG. 7, the lever 52 is rotated clockwise to a position where the microswitch 58 is turned on. At this time, the pin 53 is inserted into the elongated hole 51e'! i = sliding to the right and side plate 51d'! r Rotate clockwise.

Along with this, the pin 54a slides completely to the left within the elongated hole 51e, and the support member 54 rotates counterclockwise, so that the discharge row 24
8 is separated from the discharge roller 49. Note that in the illustrated state, the discharge portion 51 contacts a locking member (not shown), and this state is maintained.

Therefore, as shown in FIG. 8, the upper surface of the conveyor belt 51a of the discharge section 51 is positioned on the same horizontal plane as the upper surface of the conveyor belt 44, and the discharge roller 48 is moved from the discharge roller 249. be separated.

As mentioned above, since the microswitch 58 is turned on by the lever 52, in this case, the activation signal Sz/'i of the microswitch 5B becomes the logic level rHJ as shown in FIG. ing. This signal S2
is applied to the fixing device 45 as the fixing operation prohibition signal SD via the OR circuit 114, and this signal SD
Even if the above-mentioned signals SC and ST are applied to the fixing device 45 when the logic level of the fixing device 45 is rHJ, the fixing device 45
does not perform fixing operation. Further, the signal s2 acts as a control signal for the suction fan 56, and therefore the suction fan 56 starts its operation when the lever 52 is rotated to the position shown in FIG.

When the transfer paper 34 separated from the photosensitive drum 30 moves on the conveyor belt 44, the microswitch 47 is activated in the same manner as described above, and an activation signal Sl as shown in FIG. 9(a) is output. . Then, as shown in the same figure (bl), this signal S1 and the shift register 101 are
When the output terminal Q, rises to the logic level rHJ, the state of the flip-flop 115 changes and its output signal SM
becomes the logic level rHJ (see figure (c)), and at the same time, the output of the differentiating circuit 116 becomes the logic level rHJ (see figure (c)).
c).

The signal SM is output from the roller 51b of the discharge section 51.

51c and the drive source of this roller, and therefore, when this signal SM reaches the logic level rHJ, that is, when the leading edge of the transfer paper 34 reaches the discharge section 51. At the point when the conveyor belt 51a is activated, the unfixed transfer paper 3
4b is conveyed to the discharge section 51 by the conveyor belt 51a.

The microswitch 57 is actuated by the transfer paper 34b conveyed by the discharge section 51, and the actuation signal s3 rises to the logic level rHJ, making the AND circuit 118 operable as shown in the ninth story.

Then, when the rear end of the transfer paper 34b reaches the discharge section 51, the logic level of the output terminal Q of the shift register 101 becomes r.
When it falls to LJ, this falling is the differential circuit 116.
The output of this differentiation circuit 116 is differentiated by the inverter 1.
17 into a pulse signal Ps (Fig. 9(d)
)reference). This pulse signal PS resets the flip-flop 115 via an AND circuit 118 and an OR circuit 119, thereby changing the logic level of the signal SM to "L".
Then, the conveyor bell 51a stops.

In this way, the conveyor belt 51a is opened from the time when the leading edge of the transfer paper 34b reaches the discharge section 51 until the rear end of the transfer paper 34b gets on the discharge section 51. While being conveyed onto the section 51, it is held under suction.

In FIG. 5, signals R8 and JM are a reset signal and a paper jam! output from a copy control section (not shown), respectively. This is an ll (jam) occurrence signal. This signal R
When 8 is added, shift register 101, flip-flop 103, counters 105 and 106, flip-flop 109 and frizz-flop f115 are reset.

Further, this signal R8 is outputted to the flash lamp as a trigger signal ST via the OR circuit 111, thereby resetting the capacitor that drives the flash lamp.

The signal JM is output to the flash lamp as a trigger signal ST via the OR circuit 111, and is also output to the flash lamp via the OR circuit 1.
14 to the fixing device as a fixing operation prohibition signal SD, and therefore, the upper F capacitor is reset and the fixing operation of the fixing device is prohibited.

As described above, according to this embodiment, it is possible to separately obtain a transfer paper on which a toner image is fixed and a transfer paper on which a toner image is not fixed. Further, since the unfixed transfer paper is discharged without the toner image formed thereon touching anywhere and in a substantially horizontal state, the toner image is not damaged.

Note that if the signal s3 described above is applied to the copy control section as a copy prohibition signal, the ninth copying operation will not be performed unless the unfixed copies ejected to the ejection section 51 are removed. It is possible to prevent the inconvenience that the toner image is damaged due to another transfer paper being overlapped with the soil of the transfer paper. This is particularly effective when the present invention is implemented in a copying machine having a repeat function.

In the embodiments described above, a flash lamp type fixing device is used as the fixing device, but the fixing device is not limited to this.

For example, the same method can be implemented even when a heating roller type fixing device is used. However, in that case, an appropriate transfer paper conveying means should be provided after the heating and fixing roller (or either one of them), and the heating and fixing roller should be separated by the actuation signal s2 of the microswitch 58 or in conjunction with the discharge section 51. At the same time, it is necessary to insert a heat shielding material between the separated roller and the conveyance path of the transfer paper.

The lever 52 for operating the discharge section 51 may be moved manually or by a motor operated by a switch for selecting the non-fixing mode.

As explained above, according to the present invention, unfixed copies can be reliably obtained without damage, and therefore,
This has the effect of making it easier to create similar drawings, etc.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are schematic diagrams showing a conventional copying machine;
FIG. 3 is a schematic diagram showing the operation mode of an embodiment of the present invention when obtaining a fixed copy paper, and FIG. 4 is a schematic diagram showing the operation mode of an unfixed transfer paper discharge section when obtaining a fixed transfer paper. FIG. 5 is a block diagram showing a control device in an embodiment of the present invention, and FIGS. FIG. 7 is a schematic diagram showing the operating state of the unfixed transfer paper discharge section when obtaining unfixed transfer paper, and FIG. 8 is a waveform diagram showing the operating state of the unfixed transfer paper Schematic diagram showing the operation mode of an embodiment of the present invention when obtaining paper, FIGS. 9(a) to (g) Fi, and operation of the apparatus shown in FIG. 5 when obtaining unfixed transfer paper. FIG. 3 is a waveform diagram showing the state. 50... Ejection tray, 51... Ejection section, 52...
Lever, 58...micro switch.

Claims (1)

[Claims] A mode in which the transferred toner image formed on the transfer paper is fixed and discharged, and a mode in which the transferred toner image is not fixed! ! In an electrophotographic copying machine, there is a transfer paper ejection device that ejects fixed transfer paper, an unfixed transfer paper ejection device that ejects unfixed transfer paper, and a transfer paper path after transfer. An electronic device comprising: a switching device connected to either the transfer paper ejecting device or the unfixed transfer paper ejecting device; and a mode changeover switch that operates multiple times depending on the operation of the switching device to switch the mode. Photocopy machine.