JPS5991467A - Electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To obtain securely an unfixing copy without damaging an unfixing toner image by spacing a pair of rolls when a selecting means is selecting an unfixing transfer paper discharging device. CONSTITUTION:When a lever 52 is turned clockwise to a position for turning on a microswitch 58, a supporting member 54 is rotated counterclockwise, and a discharge roll 48 is separated from a discharge roll 49. The upper surface of a transportation belt 51a attains almost the same horizontal surface as the upper surface of a transportation belt 44, and a fixing device 45 does not execute a fixing. The transfer paper 34 separated from a photosensitive drum 30 moves on the transportation belt 44 to operate the microswitch 47 and the belt 51a is operated from the time point when the tip of the paper 34 reaches a discharge part 51 to transport the unfixing transfer paper 34b to the discharge part 51. At the time point when a microswitch 57 operates and the rear end reaches the discharge part 51, the belt 51a is stopped to discharge the paper 34b so as a toner image does not contact with any part but is placed horizontally.

Description

[Detailed description of the invention]

The present invention relates to an electrophotographic copying machine having a transfer paper fixing mode and an unfixing mode. When copying a document using an electrophotographic copying machine (hereinafter simply referred to as a copying machine), if the transferred toner image '5C on the transfer paper could be ejected to the output tray of the copying machine without being fixed,
JL Heme is convenient for the following reasons. In other words, an unfixed copy in which the transferred toner image has not been fixed can be easily erased using a paste or the like. After fixing with the fixing device V, the desired copy can be easily obtained by making necessary additions, and similar drawings can be obtained by using the partially erased unfixed copy as the original. etc. can be created efficiently. For this reason, copying machines that can produce unfixed copies have been proposed. Figures 1 and 2 are schematic diagrams illustrating this conventional copying machine CM. In the figure, 1 is a photosensitive drum, 2 and 3 are paper feed rollers, 4 is a paper feed guide section, 5 is a band r1j charger, 6 is a static elimination charger, 7 is a general feed belt, 8 is a fd suction fan, and 9 is a Guide plate, 10 and 11 are heating fixing rollers, 12
1 is a discharge tray for fixed transfer paper, and 13 is a discharge tray for unfixed transfer paper. When making a fixed copy, use the guide plate 9 as shown in Figure 1.
Make the upper surface 9a horizontal. Therefore, the transfer paper 14 on which the toner image has been transferred is transported by the conveyor belt 7 at 1. When being conveyed, the transfer paper 14 is guided along the upper part 11119aK of the guide plate 9. As a result, the transfer paper 1i and the heat fixing roller 1
0 and 11, the toner image is fixed by pressing and heating, 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 guide plate 90 comes into contact with the surface 9b 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 commercial, 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, and as a result, the image becomes streaked or partially erased. This may cause some inconvenience. SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic copying machine that can eliminate such inconveniences and reliably produce unfixed copies 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 copy 71M CM according to the present invention. In the figure, 21 and 22 are j punching rollers that transport the original 20, 23 is a contact glass, 24 is a pack-up plate, 25 and 26 are discharge rollers that eject the original 2o, and 27 and 28 are the originals 2o. a lamp for illuminating, 29 a convergent light transmitting array for forming a reflected light image from the original 20 on the photoreceptor drum 3o;
31 is a charger that uniformly charges the surface of the photoreceptor drum, 32
is a developing device that develops an electrostatic latent image formed on the surface of the body drum with toner. 33 is a transfer paper tray, 34 is a transfer paper, 35 is a transfer paper 34
A kick-up roller 36 and 37 separate and feed the transfer sheets one by one from the tray 33, and separation rollers 38 and 39 register 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 removes electricity from the transfer paper 34 and separates it from the photoreceptor drum 30; 42 is a separator that charges the transfer paper 34 and transfers the toner image on the surface of the photoreceptor drum 30; They are a cleaner that removes residual toner and a static eliminator that removes residual charges on the surface of the photoreceptor drum 30. 44 is a conveyor belt that conveys the separated transfer paper 34;
a and 44b are rollers that are connected to a drive source (for example, a motor) not shown to drive the conveyor belt 44; 45 is a flash lamp type fixing device that heats and fixes the toner image on the transfer paper; 46 is a roller that 34 to 1 general feed belt 4
4 is a suction fan in close contact with the 47V microswitch, 48 and 49 are drive sources such as motors (not shown), one of which is driven by a discharge roller; 50 is a discharge tray for accumulating the fixed transfer paper; and 51 are unfixed transfer paper discharge units (hereinafter simply referred to as discharge units) that discharge one unfixed transfer paper. The details of this discharge section 51 are shown in FIG. In the same case 1, conveyor belt) 51a'lf: driven rollers 51h and 51elri, each shaft 51b' on the side plate 51d.
and 51C', and the shaft 51b
' is rotatably supported by the housing of a copying machine CM (not shown). Therefore, the side plate 51d provided with the first general conveyance belt 51a and the rollers 51b + 51e is connected to the shaft 51.
It can rotate integrally around b'. The lever 52 has an i'llll 5 fixedly attached to one end thereof.
I611 is supported on the above-mentioned housing via 2a, and the rotary p1
A connecting member 52b is fixed to the connecting member 52b, and a pin 53 that fits into the elongated hole 51e formed in the side plate 51d is fixed to the connecting member 52b. At the other end of the support member 54 that supports +Ill, there is a pin 541L that fits into the elongated hole 51eK.
The supporting member 541:1 is fixedly mounted on the support member 541:1, and the body is supported by a shaft V through the Mil+54b fixedly mounted substantially at the center of the support member 541:1. Also, inside the cover 55, there is a transfer paper 34 on a conveyor bell) 51a.
A suction fan 56 (see Fig. 3) that brings the
A microswitch 57 for detecting the transfer paper 34 is provided in each of the t# 51 d, and a microswitch 58 that is actuated by the lever 52 and detects 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 dimensional block diagram of a control device for the fixing device 45. In the figure, 101 is a shift renostar for delaying the activation signal S1 of the microswitch 47;
, 111, 112. 114 and 119 are OR circuits, 1
03.1.09. I-'' and 115 flip-flops, 104, 107° 108, 110, 118 and 12
1'13 and 117 are inverters, and 116 is a differential circuit consisting of a diode, a capacitor, and a resistor. With the above configuration, the operation when fixing a toner image on the transfer paper 34 will be explained. At this 14th turn, the lever 52 is rotated in the counter-time cutting direction as shown in FIG. Rotate. Accordingly, the bin 54a slides to the right in the elongated hole 51e, the support member 54 is rotated in the cutting direction, and the discharge roller 48 is pressed against the discharge roller 49. Therefore, as shown in FIG. 3, the discharge section 51 is placed in such a manner that the upper surfaces of the conveyor belt 44 and the discharge roller 49 and the upper surface of the conveyor belt 51a thereof are not located on the same plane. The original document 20 placed on the top surface of the copying machine CM is conveyed in the direction of the arrow by the first general feed rollers 21 and 22, and the contact is guided between the lath 23 and the pack-up zero plate 24, and the discharge roller 25. l, - and 26 to the right. During this conveyance, the image of the original 20 is illuminated by the lamps 27 and 28 on the contact lath 23, and the reflected image is uniformly charged by the charger 31 via the convergent light transmitter array 29. At the same time, an image is formed on the photoreceptor drum 30 moving in the direction of the arrow, thereby forming an electrostatic latent image of the image on the original document 20 on the surface of the photoreceptor drum 30. This stillness

[The K latent image is developed with toner by the developing device 32. On the other hand, the transfer paper tray 33 is
The transfer paper 34 sent out from f′l:l+!
The photoreceptor drum 30 is moved by the registration rollers 38 and 39 so that the leading edge of the image on the photoreceptor drum 30 coincides with and contacts
The transfer device 40 transfers the toner image on the surface of the photoreceptor drum. Then, the transfer paper 3i separated by the separator 41 or 4. The transfer paper 34 is transferred to the fixing device 45 by the transport belt 44. During this conveyance, the transfer paper 34 turns on the microswitch 47. Therefore, the microswitch 47 causes the transfer paper 34 to Intercropping rI411 L while passing
, a signal St as shown in FIG. 6(,) is applied to the shift register 101. The shift register nostar 101 outputs signals obtained by delaying this signal S1 by time tI +t* and t3, respectively, to the respective output terminals Q411. Output from Qn and Qi ((b) in the same figure)
, (c) and (d)). This delay time ttij: the time required for the shift register 101 to perform m shift operations, 1, that is, the transfer paper 34
There is a delay time t2 in the time it takes for the microswitch to move from position 470 to the transfer paper inlet of the fixing device 45.
is the time required for the shift register 10 to shift n times, 1, that is, the transfer paper 34
The time required to move from the 7's digit 1i4 to the transfer paper exit of the fixing device 45, the delay time t3t, t, and the time required for the shift register 101 to shift i times, that is, the transfer paper 34 is transferred to the microswitch 47. The time required to move from the position to the discharge tray 50 (currently the discharge section 51) is set respectively. In addition, m(
n(j. Therefore, the output signal of the OR circuit 102 is as shown in FIG.
As shown in , the leading edge of the transfer paper 3 and 4 is in the fixing groove flu45.
The logic level becomes rHJ from the time when the rear end enters to the point where it freezes until it 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 of the flip-flop 103 falls to the logic level rLjl/r, so the AND circuit 120 becomes inactive and the state of the flip-flop 103 is maintained. Further, since the counter 105 is enabled while the output terminal Q of the flip-flop 103 is at the logic level rHJ, the counter 105 counts up the clock signal PC during that period, and the counter 106 is incremented at each carry (overflow). Increments the numerical value. Then, when the count value of this counter 106 reaches a value that lasts a predetermined time T1, an AND circuit 107 as shown in FIG.
The output becomes the logic level rHJ. Therefore, the output of the AND circuit 110 is synchronized with the clock signal PC (i
) as shown in the logic level rHJ and gully, which causes flip-flop 103 and counter 105 +
106 is reset. The clock signal PC generated immediately after this changes the shape of Norizzo Fro 7" 103 again, and its output terminal Q
The logic level of rises to rHJ. Therefore, the output AI of the free-ruff 0 flop 103! The logic level of Q is set at time T, while the output of the OR circuit 102 is at the logic level rHJ, and one clock period rLJ after reaching rHJ.
The situation will repeat itself. The output signal of this flip-flop 103;
It is output to the fixing device 45 as No. 1d SC, and the flash lamp of the fixing device 45 is thereby charged. Therefore, the above-mentioned time 'r1 is set as a time in which it takes a predetermined amount of charge to accumulate in this capacitor. Also, and11j1ro1]
, 0 output is sent to the fixing device 45 via the OR circuit 111.
, and the flash lamp trigger acts as a signal S'r. In this way, the flash lamp emits light every time the transfer paper 34 travels a predetermined distance after being attached to the fixing device 45.
The toner image on the transfer paper is heated and fixed. Note that this action ends when the output of the OR circuit 102 reaches the logic level "L-1", that is, when the trailing edge of the transfer paper 34 is ejected from the fixing device 45. 34a is the discharge roller 4
8 and 49, the paper 11' is delivered to 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.
be jilled At this time, the bottle 53 slides to the right through the elongated hole 51e, and rotates the side plate 51d in the direction of the force. Along with this, the bottle 54a slides to the left inside the elongated hole 51e, and the support member 54 moves opposite lFiF? The discharge roller 48 is separated from the discharge roller 49 by turning 1 in the lJi direction. In the illustrated state, the discharge portion 51 is still in contact with the locking member (not shown), and this state is maintained. As shown in FIG. 48 is separated from the discharge roller 49. As mentioned above, since the microswitch 58 is turned on by the lever 52, in this case, the activation signal Sm& of the microswitch 58 is logically expressed as shown in FIG. It has become. This signal S2 is applied to the fixing device 45 as a fixing operation prohibition signal 8D via the OR circuit 114'e, and thereby, when the logic level of this signal SD is rHJ, the above-mentioned signals SC and ST are applied to the fixing device 45. Even if it is fixed, fixing device I eraser 45 r, j: No fixing operation is performed. still,
The signal S2 acts as a control signal for the suction fan 56, thus causing the suction fan 56 to move the 'i lever 52 to the position 11. shown in FIG. , 1, the operation starts. The transfer paper 34 separated from the photosensitive drum 30 is 1iP7
When it moves on the feed belt 44, the microswitch 47 is activated in the same way as described above, and an activation signal Sl as shown at the 91st edge (a) is output. When the output terminal Qi of the shift register 101 rises to the logic level "11" after a delay of υ time t3 from this signal S1 as shown in FIG. becomes the logic level "■(" (see (f) in the same figure), and at the same time, the output of the differentiating circuit 116 becomes the logic level rHJ.
(See figure (C)). The signal SM is output from the discharge section 510 and the roller 51b. 51e and the power source for this roller? It is generated as an operation control signal for the first-strong clutch (not shown). Therefore, from the time this signal SM reaches the logic level rn, that is, from the time when the leading edge of the transfer paper 34 reaches the ejection sound US51, the conveyance pel 51B is activated. is activated, and as a result, the unfixed transfer paper 34b is transferred to the discharge section 5 by the conveyor belt 51a.
1. 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 as shown in FIG. Become. Then, when the logic level of the output MMQi of the shift register 101 falls to rLJ when QkA reaches the discharge section 51 after the transfer paper 34b, this fall is differentiated by the differentiating circuit 116, and the output of this differentiating circuit 116 is is converted into an iE ) response signal PS by the inverter 117 (see FIG. 9(d)). This Noyals signal PS resets the flip-flop 0115 via the AND circuit 118 and the OR circuit 119, whereby the logic rail of the signal SM falls to rLJ, and the conveyor belt 51a stops. In this way, the conveyor bell) 51 a&yo, transfer paper 3
From the time when the leading edge of the transfer paper 34b reaches the discharge section 51, the transfer paper 34b
The transfer sheet 34b is intercropped 11i1H with the blade whose rear end rests on the discharge section 51, whereby the transfer paper 34b is suction-held while being conveyed onto the discharge section 51. In addition, in FIG. 5, the signal R8 and JM I+:1
, a reset signal and a paper jam occurrence signal output from a copy control section (not shown), respectively. When this signal R8 is applied, the shift register 101, flip-flop 103, counters 105 and 106,
Flip-flop 109 and flip-flop 115
is reset. This signal R8 is output 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 fixing device via the OR circuit 114 as a fixing operation prohibition signal SD, thus resetting the upper capacitor 311. At the same time, the fixing operation of the fixing device is prohibited. As explained above, according to this embodiment, a transfer paper to which a toner image is fixed and a transfer paper to which a toner image is not fixed can be obtained separately. 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. If the above-mentioned signal S3 is applied to the copy control section as a copy prohibition signal, the next copying operation will not be performed unless the unfixed copies ejected to the ejection section 51 are removed. It is possible to prevent problems such as damage to the toner image caused by another transfer paper being placed on top of the toner image. This k[
This is especially effective when the present invention is implemented in a copying machine having a repeat 11 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, appropriate transfer paper conveying means should be provided before and after the heat-fixing roller (or either one of them), and the heat-fixing roller should be fully conveyed by the actuation signal S2 of the microswitch 58 or in conjunction with the discharge section 51. 1'
It is necessary to insert a heat shield material between the separated roller and the one-way feeding path of the transfer paper. Note that the lever 52 that operates the discharge section 51 can be moved manually or by a switch that selects the non-fixing mode.
It is also possible to use an electric motor or the like. FIG. 10 shows another embodiment of the electrophotographic copying apparatus according to the present invention. In this embodiment, as shown in the figure, a discharge tray 50 and a discharge section 51' are arranged in series along the transfer paper conveyance path. Furthermore, in this embodiment, whether or not the transfer paper is to be fixed, the discharge section 51' is not moved and the transfer paper is not fixed.1) The alignment roller 4B is moved upward. There is. 1. Same as the micro switch 58 mentioned above. A microswitch 58'e which performs the action P is disposed at a position where it is turned on when the roller 48 moves upward, thereby achieving the same action as in the embodiment described above. However, in this embodiment, when the transfer paper is fixed, the fan 56 is activated regardless of whether the transfer paper is fixed, and when the transfer paper is fixed, the signal SM is always set to the logic level "H".
It is necessary to control the conveyor belt 51a to operate at all times. The other parts of the figure are the same as the above-mentioned embodiment, so
The explanation will be omitted. Alternatively, the roller 48 may be provided somewhere above the discharge section 51. However, in that case, when fixing the transfer paper, the roller 48 is brought into pressure contact with the conveyor belt 51a, and when not fixing the transfer paper, the roller 48 is moved away from the conveyor bell) 51a.
4'1 must be configured to turn on the microswitch 58'. In addition, the roller 49
, and the distance P! between the discharge section 51 and the fixing device 45 is removed. Bring l# close to it and write a trigram. As explained above, according to the present invention, since the conveyance roller etc. do not come into contact with the toner image on the unfixed transfer paper, it is possible to reliably obtain the unfixed toner image without damaging the image. This has the effect of making it easier to create 4JI-like drawings, etc.

[Brief explanation of drawings]

Figures 1 and 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 transfer paper, and the operation mode of the unfixed transfer paper discharge section when obtaining a fixed transfer paper. v4.5 is a block diagram showing a control device in an embodiment of the present invention, and FIGS. 6 (IL) to (1)
Fig. 5 shows the operating state of the device when obtaining fixed transfer paper, and Fig. 7 shows the operation of the unfixed transfer paper discharge section when obtaining unfixed transfer paper. FIG. 8 is a schematic diagram showing the mode of operation, and FIG. 9 is a schematic diagram showing the operation mode of an embodiment of the present invention when obtaining unfixed transfer paper.
g) is a waveform diagram showing the operating state of the apparatus shown in FIG. 5 when obtaining unfixed transfer paper, and FIG. 10 is a partial diagram showing another embodiment of the present invention. 50...Ejection tray, 51, 51'...Ejection BIS for unfixed transfer paper, 58.58'...Micro switch.

Claims (1)

[Claims] In an electrophotographic copying machine that has a mode in which the transferred toner image formed on the transfer paper is fixed and then ejected, and a mode in which it is ejected without being fixed, there is a transfer paper ejection device that ejects the fixed transfer paper, and an unfixed transfer paper. An unfixed transfer paper discharging device for discharging unfixed transfer paper and a pair of transport rollers for transporting the transfer paper are provided downstream of the fixing device, and a selection means for selecting either the transfer paper discharging device or the unfixed transfer paper discharging device is provided for unfixed transfer paper discharging device. When selecting the transfer paper ejection device, move at least one general feed roller of the pair of conveyance rollers from the conveyance roller that comes into contact with it:
An electrophotographic copying system characterized by an i+ interval.