JPH02301468A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To form a good image by preventing the wrinkles or slackening of an ink ribbon by providing a drive means for moving a feed-out means in the direction reverse to the taking-up and moving direction of an ink ribbon due to a taking-up means. CONSTITUTION:A ribbon motor 251 is rotationally driven so as to take up an ink ribbon 260 at a speed faster than the relative moving speed of recording paper P to a thermal head 253. When tension of a definite value or more is applied to the ink ribbon 260 by the slide clutch mechanism of an ink ribbon taking-up drive part 264, sliding is generated in the rotation of a core 263 on a taking-up side and the moving speed of the ink ribbon 260 is kept constant. Further, in order to secure the back tension of the ink ribbon 260, the rotatory power of the ribbon motor 251 is transmitted to the gear 267 of a core 262 on a feed-out side through an ink ribbon feed out drive part 268 to rotate the core 262 on the feed-out side in the direction opposite to feed-out direction of the ink ribbon 260. Since tension is applied in the direction reverse to the taking-up direction of the ink ribbon 260, the wrinkle or slackening of the ink ribbon 260 is removed and a good image can be formed.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) This invention reads an image of a document and converts it into an electrical signal.
The present invention relates to an image forming apparatus that forms an image converted into an electrical signal on an image forming medium.

(Prior Art) Conventionally, in an image forming apparatus that reads an image of a document and forms an image on recording paper as an image forming medium, a printer that employs a thermal transfer method is used as an image forming means. In a printer that employs such a thermal transfer method, there is a core in the middle of the delivery side core as a delivery means for feeding out the ink ribbon, and the winding side core as the winding means for winding up the fed out ink ribbon. A thermal head (printing head) is provided so as to contact the ink ribbon, and a platen roller as a pressing means is provided on the opposite side of the thermal head with the ink ribbon in between, and between the ink ribbon and the platen roller, a platen roller is provided as a pressing means. The recording paper fed into the platen roller passes the recording paper through the thermal head (
In this state, the thermal head selectively generates heat according to the image data, thereby transferring the image onto the recording paper. In a printer that employs such a thermal transfer method, the driving force from the driving source is not transmitted to the sending-out side core of the ink ribbon, but the ink ribbon is wound around the winding-side core to which the driving force from the driving source is transmitted. It is pulled and rotated by the tension that occurs. A slip clutch mechanism or the like is used in such a delivery core to provide pack tension.
It is designed to prevent the ink ribbon from loosening.

However, the thermal head, ink ribbon, and
c! Since pressure is applied between the thermal head and the platen roller to bring the sheets of paper into close contact with each other, pack tension is not constantly applied to the ink ribbon between the thermal head and the delivery-side core. Therefore, there is a drawback that the ink ribbon is wrinkled or loosened, making it impossible to form a good image. Further, there is another problem in that once wrinkles occur, the wrinkles cannot be removed only by the tension provided by a slipping clutch mechanism or the like.

(Problems to be Solved by the Invention) This invention provides that, as described above, in the device that applies pack tension to the ink ribbon using a slipping clutch mechanism or the like, pressure is applied between the thermal head and the platen roller. Therefore, in order to solve the disadvantage that good image formation cannot be performed due to wrinkles or slack in the ink ribbon between the thermal head and the delivery-side core, and the problem that wrinkles once formed cannot be easily removed, this method was developed. An object of the present invention is to provide an image forming apparatus capable of forming good images by preventing wrinkles and loosening of an ink ribbon.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, an image forming apparatus of the present invention includes an ink ribbon in the middle part stretched between a winding means and a feeding means. In the image forming apparatus, the image forming apparatus is provided with a print head arranged and forms an image while pressing an image forming medium against the print head via the ink ribbon that is wound and moved by the winding means. The present invention is characterized by comprising a driving means for driving the ink ribbon in a direction opposite to the winding movement direction of the ink ribbon by the winding means.

In addition, for the same purpose, a print head disposed in the middle of the ink ribbon stretched between the winding means and the feeding means, and a pressing means disposed to face the print head. In the image forming apparatus, the image forming apparatus is configured to form an image while pressing an image forming medium against the print head by a pressing means via the ink ribbon which is wound and moved by the winding means, the feeding means is connected to the winding means. a driving means for driving the ink ribbon in a direction opposite to the winding and moving direction of the ink ribbon, and when driving the feeding means by this driving means,
It is characterized by comprising a control means for separating the rad stop and the pressing means from the printing.

(Function) This invention not only applies tension to the ink ribbon sent out from the delivery means side during image formation by pulling it using, for example, a slip clutch mechanism, but also uses a drive means to drive the ink ribbon in the opposite direction to the winding direction. It is designed to apply tension.

This makes it possible to remove wrinkles and looseness and form a good image.

For example, prior to image formation, by driving the driving means with the printing head and the pressing means separated, the ink ribbon is pulled from both the winding means and the feeding means to remove wrinkles in the ink ribbon. After the removal, the printing head is pressed by the pressing means, and then the image forming operation is performed. This completely removes wrinkles from the ink ribbon, making it possible to form good images.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an image forming apparatus 40 according to the present invention.

An operation panel 50 is provided on the top surface of the image forming apparatus 40. A paper feed/separation section 6 is provided on one side of the image forming apparatus 40.
0 is set. This paper feeding/separating section 60
Alternatively, an original document (not shown) is separated one by one before being fed. The document or recording paper P guided into the image forming apparatus 40 by the paper feeding/separating section 60 is
The paper is transported by the paper transport section 150 and discharged to the outside of the device 40 .

An image reading section 200 is located halfway below this paper conveyance section 150.
is provided, and an image recording section 250 is provided above. The image reading section 200 reads image information on the document sheet being conveyed through the paper conveying section +50 and converts it into an electrical signal. It is used to record images.

Also, inside the image reading unit 200, a control unit 1, which will be described later, is provided.
30 are provided.

FIG. 2 shows the operation panel 50. The operation panel 50 is provided with a status display 51, copy number setting keys 52, 53, a density display 54, a density setting key 55, a copy key 5B, and a clear/stop key 57.

The status display 51 is composed of a two-digit seven segment LED, and normally displays the number of copies, and displays "1" as a default.

In addition, if a paper jam occurs in the original or recording paper,
A symbol corresponding to each, for example rJJ, is displayed.

The number of copies setting keys 52 and 53 are used to
The numbers displayed in 1 are increased and decreased, respectively, and the number of copies is set.

The density setting key 55 is used to change and set the density of the image to be formed, and each time this density setting key 55 is pressed, the three LEDs 54 making up the density display 54 are pressed.
The lighting states of a to 54c change cyclically in the order of NDL→N, and the set density is displayed.

The copy key 56 gives an instruction to start a copying operation, and when the clear/stop key 57 is pressed twice, an instruction to stop the copying operation is given.

Furthermore, when the clear/stop key 57 is pressed only once, the settings on the operation panel 50 return to default, the status display 51 displays "1", and the display 54 displays the L E D 54b corresponding to N. is lit.

FIG. 3 shows the separation/sheet feeding section 60. As shown in FIG.

The separation/feeding section 60 includes a recording paper tray 61, a document tray 62, a pickup mechanism 70, a separation mechanism 90, and a document detection switch 63.

At the top of the recording paper tray 61 where the recording paper P is set, there is a
A document tray 62 is provided on which a document tray is set. A pickup mechanism 70 is provided above the document tray 62. This pickup mechanism 70 includes an arm 79 rotatably provided around a shaft 71;
A roller 81 is provided at the tip of this arm 79 and is provided between the roller 81 and the arm 79 for taking out the document or recording paper P.
It is composed of a document detection switch 63 that detects the document or recording paper P, and the like.

Further, an opening 64 indicated by a broken line is provided at the left end of the document tray 62 so as not to impede the swinging of the pickup mechanism 70 and the document detection switch 63.

The pickup mechanism 70 is capable of swinging around a shaft 71, and is normally held at a position above the document tray 62 as shown by the dashed dotted line. When separating/feeding the recording paper P, it is moved to the position indicated by the solid line.

FIG. 4(a) specifically shows the pickup mechanism 70. This pickup mechanism 70 includes a pickup motor 72, gears 73, 74, shaft 71° pulley 75, 76, timing belt 77, coil spring 78,
It is composed of an arm 79, a bearing 80, and a roller 81.

FIG. 4(b) specifically shows the relationship between the arm 79 and the shaft 71. As shown in the figure, arm 7
9 is rotatably provided on the shaft 71, and this arm 7
9 is provided with a cylindrical projection 79a concentrically with the shaft 71. Further, the pulley 75 is fixed to the shaft 71, and the pulley 75 is similarly provided with a protrusion 75a. A coil spring 78 is integrally wound around these projections 75a1 and 79a. pulley 75
Since it is fixed to the shaft 71, it is rotated together with the shaft 71, but the rotation is transmitted to the arm 79 via the coil spring 78, and the arm 79 is given the function of a torque limiter.

Therefore, when the pickup motor 72 is rotated in the direction of the arrow A, all the components attached to the shaft 71 via the gears 73 and 74 rotate in the direction of the arrow B about the shaft 71. When the roller 81 comes into contact with an unillustrated document or recording paper P and a certain amount of contact pressure is generated, the force between the pulley protrusion 75a and the coil spring 78, or between the arm protrusion 75a and the coil spring 78 increases. Slippage occurs and the arm 79 cannot rotate any further. Furthermore, as the pickup motor 72 continues to rotate, the rotation of the pulley 75 is transferred to the roller 8 via the timing belt 77 and the pulley 76.
1, causing rotation in the direction of arrow C. At this time, since a certain contact pressure is generated between the original paper or the recording paper P and the roller 81, the original paper or the recording paper P is sent out in the direction of the separation mechanism 90.

On the other hand, when the pickup motor 72 is driven in the direction opposite to the arrow A, all of the components attached to the shaft 7■
The arm 79 is rotated about the shaft 7I in the direction opposite to the arrow B, and the arm 79 can be returned to its original position.

FIG. 5(a) specifically shows the separation mechanism 90. This separation mechanism 90 includes a separation motor 91, a gear 92
．． 93.94, normal rotation roller 95, normal rotation shaft 95a1
It is composed of a reversing roller 96, a reversing shaft 97, a hub 98, and a coil spring 99.

FIG. 5(b) specifically shows the configuration of the reversing roller 9B. a hub 98 fixed to a reversing shaft 97;
A reversing roller 9 rotatably provided on a reversing shaft 97
B is provided with protrusions 98a and 98a, respectively. Coil springs 99 are attached to these protrusions Has 96a.
is wound, and the above-mentioned torque limiter function is also set here.

Therefore, when the separation motor 91 is rotated in the direction of arrow E, the forward rotation roller 95 is rotated in the direction of arrow F through gears 92, 93, and 94, and the reverse rotation shaft 97 is rotated in the direction of arrow G. Forward rotation roller 95 and reverse rotation roller 9 manufactured by
6 are urged to press against each other by a spring (not shown), and since the frictional force between both rollers is greater than the torque transmitted by the coil spring 99, slippage occurs, and the reverse roller 96 rotates in the direction of arrow H. be done.

On the other hand, when two or more originals or recording papers are sent out from the above-mentioned pickup mechanism 70 in an overlapping state and are sandwiched between the forward rotation roller 95 and the reverse rotation roller 96, the coil spring is activated due to the frictional force between the sheets. Since the transmission torque of 99 is set to be large, the reversing roller 96 is indicated by the arrow! When the paper is rotated in the direction of the arrow H and pushed back, and only one sheet of paper is held, the rotation returns to the direction of the arrow H and only one sheet is sent out.

FIG. 6 shows the paper conveying section 150. In this paper transport section 150, a transport path 151 is provided with an entrance roller pair 152, an intermediate roller pair 153, an exit roller pair 154, and a platen roller 155. These inlet roller pair 152, intermediate roller pair 153, and outlet roller pair 154
The lower roller is driven by the conveyance motor 181, and the upper roller is driven by the lower roller. A document or recording paper P (not shown) is conveyed by these three types of roller pairs.

The platen roller 155 is driven by a motor tet along with an entrance roller pair 152, an intermediate roller pair 153, and an exit roller pair 154. This platen roller 155
is provided at one end of the platen arm 15B, and the other end of this platen arm 156 is provided rotatably.

An eccentric cam 157 that moves the platen arm 15B up and down is in contact with the intermediate portion of the platen arm 156, and the eccentric cam 157 is operated by a cam motor 1511. In front of the entrance roller pair 152 and the output roller pair 154, an entrance switch 159 and an exit switch 160 for detecting the entry and ejection of the document D1 recording paper P are provided.

FIG. 7 shows the image reading section 200.

The image reading unit 200 is composed of, for example, a light source 2011 made of xeno-Nrambuka, an optical lens array 208, a CCD sensor 203, and a signal processing circuit. The light [201] is lit by an inverter circuit (not shown).
The document is illuminated, and its image is projected onto the CCD sensor 203 by the optical lens array 208. CCD sensor 2
The electrical signal of the image photoelectrically converted by 03 is converted into a digital signal by a signal processing circuit to be described later, and then sent to the control unit 130.
sent to.

FIGS. 8(a) to 8(e) show the image recording section 250. FIG. This image recording section 250 has a thermal head 253
, a pressure mechanism 255, an ink ribbon 260, and an ink ribbon motor 251.

The pressurizing mechanism 255 includes a pair of springs 25B and 25B, as shown in FIGS.
It consists of brackets 257, 257 in which 256 is accommodated, and a regulating plate 258, and the springs 25G, 25B and brackets 257, 257 act as shown in Figures (b) and (d).
Press the thermal head 253 in the direction of arrow X shown in
The heating element 259 is pressed against the recording paper P. Furthermore, the regulating plate 258 engages with a protrusion 253a provided on the opposite side of the thermal head 253 from the heating element 259, thereby limiting the movable range of the thermal head 253. The heating element section 259 of the thermal head 253 is separated from the platen roller 155 in the paper conveying section 150 when the platen roller 155 is lowered.

The ink ribbon 2 [10, as shown in FIG.
The recording paper P is wound onto the winding-side core 263 at the same speed as the relative movement speed between the recording paper P and the thermal head 253. This winding-side core 263 is rotationally driven by a ribbon motor 251 as a drive source via an ink ribbon winding drive section 264 and a gear 265 provided at the end of the winding-side core 283.

The ribbon motor 251 is rotationally driven to wind up the ink ribbon 260 at a speed faster than the relative movement speed of the recording paper P with respect to the thermal head 253. As a result, when a tension above a certain level is applied to the ink ribbon 260 by the slip clutch mechanism provided inside the ink ribbon take-up drive section 264, a slip occurs in the rotation of the take-up side core 263, and the ink ribbon 260
The movement speed of is kept constant.

In addition, a ribbon motor 251 is attached to the delivery side core 262 to ensure back tension of the ink ribbon 260.
The rotational force is transmitted to the gear 287 via the ink ribbon delivery drive unit 268 to rotate the delivery side core 262 in the opposite direction to the direction in which the ink ribbon 260 is delivered. Further, the ink ribbon delivery drive unit 28g is provided with a slip clutch mechanism 266, and when a tension above a certain level is applied to the ink ribbon 260, the slip clutch mechanism 266 causes the rotation of the delivery side core 262 to slip. , a constant back tension is always applied to the ink ribbon 260. In this state, the moving speed of the ink ribbon 260 is kept constant. Note that this ribbon motor 251 is stopped so as not to wind up the ink ribbon 260 during an image reading operation in which the original document is being read.

FIG. 9 shows the configuration of the electric circuit of this image forming apparatus. This electric circuit includes a control section 130, an image recording section 200, and an image reading section 250.

The control section 130 is configured as follows.

That is, the CPU 100 is responsible for controlling the entire device. The ROM 101 is a read-only memory that stores a control program for operating the CPU 100 and fixed data necessary for other processing. R.A.
RAM 102 stores image data read by the image reading unit 200, and the image data stored in RAM 102 is sent to the image recording unit 250, where a corresponding image is formed on the recording paper P. Ru. Also, this RAF
vl102 is also used as a buffer for the work of the CPU100.

The input/output port 105 controls data exchange with the operation panel 50 described above.

The input/output ports 106 to 109 are connected to the cam motor 15, respectively.
8. A drive signal from the CPU 100 is given to the motor drivers 120 to 123 that drive the pickup motor 72, the separation motor 91, and the transport motor 161 that drives the pair of artificial rollers 152.

The input/output boat 110 controls the sending of detection signals from the document detection switch 63, the population switch 159, and the exit switch 160 to the CPU 100.

The address counter 115 is a counter for specifying write and read addresses for image data stored in the RAM 102.

The copy counter 116 counts the number of recorded copies, and the number of copies is manually set from the operation panel 50. This set number of copies is subtracted during image recording by a control signal from the CPU 100.

The document counter 117 counts the number of documents, and is counted up during image reading by a control signal from the CPU too, and is counted down during image recording.

The timer 118 has a function of counting delay time and a function of counting paper conveyance time for paper jam detection. The former includes the time t3 for rotating the pickup motor 72 in reverse, the time t4 from the time the document passes through the entrance switch 159 during image reading until the light source 201 and CCD sensor 203 are turned off, and the time t4 for turning off the light source 201 and CCD sensor 203 during image recording. The time t5 from when the ribbon motor 251 and the thermal head 253 are stopped is counted.

The latter also includes a preset paper jam detection time tl,
For comparison with t2, the time from when the pickup motor 72 starts normal rotation until the entrance switch 159 is turned on with respect to the original document and the recording paper P, and the time from when the entrance switch 159 is turned on.
9 is turned off until the exit switch 160 is turned off.

The input/output boat l11 has a motor driver 252 that drives a ribbon motor 251 of the image recording section 250, and a CPU.
100 provides a drive signal.

The input/output boat 112 is a light source 201 of the image reading unit 200.
A lighting signal from the CPU 100 is given to an inverter circuit 202 that lights up the CPU 100.

In addition, the human output port 113 sends a secondary battery charging control signal to the charger 125 to instruct the secondary battery 125 to be charged or not.
4.

CPU too, image reading section 200 and image recording section 2
Timing control signals are transmitted and received from the image reading section 200 to the control section 130 and from the control section 130 to the image recording section 250 via the control signal bus BUS 1. is transmitted via image signal bus B.
This is done via US2.

The image reading unit 200 includes the inverter circuit 202 and the C
A CCD drive circuit 204 that drives the CCD sensor 203 according to a CCD control signal sent from the P U 100 via the control signal bus BUS 1, and a signal processing circuit 2 that processes the image signal photoelectrically exchanged by the CCD sensor 203.
Consists of 05. This signal processing circuit 205 is composed of an amplifier circuit 20B1 that amplifies the image signal with a predetermined gain, and a binarization circuit 207 that simply binarizes the signal into black pixels and white pixels with a predetermined level as the boundary. There is.

The image data output from the binarization circuit 207 is sent to the control unit IO via the image signal bus BUS2, and the control unit 1
30, the address is specified by the address counter 115, which is incremented in synchronization with the CCD read timing signal, and written into the RAM 102.

The image reading unit 250 has a motor driver 2 that drives a ribbon motor 251 based on an ink ribbon winding signal supplied from the CPU 100 through the input/output port 111.
52 and the thermal head 25 by a thermal head control signal sent from the CPU 100 via the BUS 1.
The thermal head control circuit 254 drives the thermal head.

The image data stored in the RAM 102 of the control unit 130 is addressed and read out by the address counter 115, which is subtracted or added in synchronization with the thermal head recording timing signal, and is read out via the image signal bus BUS2. It is sent to the head 253 and recorded.

Next, the operation of the image forming apparatus 40 will be explained with reference to the flowcharts shown in FIGS. 10 to 12.

First, as shown in FIG. 10, when the power is turned on, initialization is performed. That is, RAM 102, counters 115, 117, timer! 18 is set to "0", and the copy counter 11B is set to "1".

Further, the status display 51 on the operation panel 50 displays "1" representing the default number of copies, and the L E D 54b corresponding to N on the concentration display 54 is lit (STI).

Next, press the input keys 52, 53, 55 on the operation panel 50.
゜Check 58 and 57, store the operation corresponding to the pressed key in the RAM 102, and press the copy key 5.
Wait for 6 to be pressed. Then, when the copy key 56 is pressed, the process moves to a copy operation (ST3 to ST7).
).

FIG. 11 is a flowchart showing an image reading operation in a copying operation. First, check the original detection switch 63, and if it is off, the original empty "OE"
is displayed blinking on the status display 51 (STIo, 11)
. If the document tray is set in the document tray 62,
Since the document detection switch 63 is turned on, the cam motor 1
58 to separate the platen roller 155 from the thermal head 253 and begin reading operation (ST12).

In this case, the document tray is set with the reading surface facing downward.

First, the pickup motor 72 and the separation motor 9
1 (ST13.14), the pickup mechanism 70 takes out the document from the document tray 82, and the separation mechanism 9
Separate/feed the original at 0. At this time, if a paper jam is detected by the population switch 159 and the timer 118 (srts, 1B), the separation motor 91. The pickup motor 72 is stopped and "J" indicating a paper jam is displayed on the status display 51 (ST17.+8).

Furthermore, if the document reaches the entrance switch 159 during the 11th hour, the motors 91, 72, . At the same time, the motor 161 and light source 201 are turned on, and the CCD sensor 203 reads the document (ST19 to ST23).

The image signal sent from the CCD sensor 203 via the signal processing circuit 205 and the image signal bus BUS2 is stored in RAM 1.
02 (ST24). At this time, the address counter 115 is counted up in synchronization with the drive signal of the CCD sensor 203.

The document image is read, and the rear edge of the document is placed at the entrance switch 15.
9 is detected (5T25), the reading operation is terminated after a preset time t4, and the light source 20
1 is turned off and the CCD sensor 203 is turned off (5
T2B). However, the transport motor 161 continues to rotate.

At this time, if the time measurement by the timer 118 exceeds the preset t2 time without the exit switch 160 being turned off, it is determined that there is a paper jam, the conveyance motor 161 is turned off, and the status indicator 51 indicates that there is a paper jam. Display rJJ to be executed (TS27-30).

Furthermore, if the original paper is discharged within time t2, the conveyance motor 161 is stopped after the rear end of the original paper passes the exit switch 160, and the original counter 117 is counted up (5T27.3L32). .

When the above reading operation is completed, the document detection switch 63 is checked to determine whether or not there is any document remaining in the document tray 62. That is, when there is a document in the document tray 62 and the document detection switch 63 is on (ST33), the above-described reading operation is repeated from the beginning, and the document counter 117 is counted up each time (ST33-13).
). On the other hand, if the original detection switch 63 is off, it means that all the originals have been read, and the original number data of the original counter 117 is written to the RAM 102 (ST34).
), move to 5T35.

Through the above operations, image signals are stored in the RAM 102 in the order in which the originals are read.

FIG. 12 is a flowchart showing the image recording operation in the copying operation. First, it is determined whether the platen roller 155 is in pressure contact with the thermal head 253 (S
T341. ). Then, when it is determined that the platen roller 155 is in pressure contact with the thermal head 253,
The pressure contact is released by driving the cam motor 158 and rotating the cam 157 by half a rotation (ST342). In this state, the ink ribbon 280 is in contact with the multi-head 253, but is not pressed by the platen roller 155, so the ink ribbon 260 can move slightly in the main scanning direction and the sub-scanning direction. Therefore, the ribbon motor 251 is operated for a certain period of time, the take-up side core 263 is rotated in the winding direction, and the delivery side core 2B2 is rotated in the opposite direction to the delivery direction, and the ink ribbon 260 is pulled to both sides (ST343
).

This makes it possible to maintain a stable position without deviation in the main scanning direction, and in the event that wrinkles occur, these wrinkles can be removed. Next, the platen roller 155 is brought into pressure contact with the thermal head 253 by the cam motor 158, and then the recording operation begins (ST
35).

Next, the pickup motor 72 and separation motor 91 are turned on, and the pickup mechanism 70 separates/feeds the recording paper P (ST36.37). That is, since there is no document in the document tray B2, the pickup mechanism 70 comes into contact with the recording paper P through the opening 62a, and the pickup mechanism 70 contacts the recording paper P through the opening 62a.
Separate and feed paper. At this time, detection of a paper jam in which the recording paper P does not reach the entrance switch 159 is the same as in the case of the document jam described above (ST38 to ST41).

When the inlet switch 159 is turned on, the separation motor 91 and pickup motor 72 are turned off (ST42.43).
, the transport motor 161 is turned on (ST44). After the conveyance motor 161 is turned on, the ribbon motor 251 is operated to wind up the ribbon 260 while the RAM 1
The image data stored in BUS 02 is read out in page descending order, that is, sequentially from the last page, and sent to the image signal bus BUS 2.
The image is transferred to the thermal head via the CPU 100 and recorded on the recording paper P (S75 to 53).
).

When the trailing edge of the recording paper P passes the entrance switch 159,
Recording will end after 15 hours (ST4g, 49), and paper jam detection will be performed in the same way as in the case of original paper jam (S75~
53). If no paper jam occurs, transport motor 1
81 is turned off and the original counter 117 is decremented (ST54.55). And the manuscript counter 11
When the content of 7 does not reach "0", the process moves to the next recording (S75 to 5T61). When the recording for the number of original sheets is completed, the copy number counter 118 is decremented (ST57), and when the content of the copy number counter 116 does not reach "0", the original counter 117 and the address counter 115 are written to the RAM 102 at the end of reading. is reset to the value
Recording is restarted (ST58-60-5TBI).

5T81.62 is provided to prevent erroneous recording even if a document is added to the document tray 62 during the recording operation. In this way, the copy counter 11
Recording continues until the value of B becomes "0", and the copying operation ends.

Note that image data reading for each page of a multiple-page original is performed in the reverse page order from the last page to the first page, and the recorded and ejected recording paper P has the bottom layer as the last page of the original and one page as the last page of the original. The top page is the first page of the manuscript.

According to the embodiment described above, instead of applying tension to the ink ribbon 260 sent out from the delivery side core 262 during image formation using, for example, a slip clutch mechanism, the rotational force of the ribbon saver 251 is applied to the ink ribbon 260. The information is transmitted to the gear 267 via the ribbon delivery drive section 28g, and the ink ribbon 2
By rotating the delivery side core 262 in the opposite direction to the direction in which the ink ribbon 60 is delivered, tension is applied in the direction opposite to the winding direction of the ink ribbon 260, thereby eliminating wrinkles and slack in the ink ribbon 260 and producing a good image. It is possible to form.

Also, for example, prior to image recording, the thermal head 25
The ribbon motor 251 is driven with the ribbon motor 251 separated from the ink ribbon roller 155 and the ink ribbon winding drive section 264 and the gear 265 provided at the end of the winding core 263. At the same time as winding the take-up core 263, the delivery core 262 is driven in the opposite direction to send out the ink ribbon 280 via the ink ribbon delivery drive unit 268 and the gear 287 provided at the end of the delivery core 262.
By rotating the ink ribbon 260, the ink ribbon 260 is pulled from both the take-up side core 263 and the delivery side core 262 to remove wrinkles from the ink ribbon 260, and then the platen roller 155 presses the thermal head 253, and then the image is Since the recording operation was performed, the ink ribbon 28f
) can be set in the normal position, wrinkles on the ink ribbon 260 can be completely removed, and good image recording can be performed.

Further, an image reading section 200 is provided below the paper transport section 150 and an image recording section 250 is provided above the paper transport section 150 to transport the image of the document downward and form an image on the recording paper P being transported. It is done on the top. Therefore, the paper transport section 150
Since the image of the original document is facing downward and the image of the recording paper is facing upward, it is possible to easily separate the original document and the recording paper.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide an image forming apparatus that can prevent the ink ribbon from wrinkling or loosening and can form a good image.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic sectional view of an image forming apparatus, FIG. 2 is a plan view showing the operation panel, and FIG. 3 is a main part of the paper feed section. 4 shows the pickup mechanism, FIG. 4A shows a perspective view of the main part, FIG. Fig. 6(a) is a perspective view of the main part, Fig. 6(b) is a side sectional view of the main part, Fig. 6 is a side view of the main part of the paper transport section, and Fig. 7 is a diagram of the image reading section. FIG. 8 is a side view of the main parts, and FIG. 8 shows the image recording section, FIG. ) is a bottom view of the same figure (a), the same figure (d) is a side view of the same figure (e),
FIG. 9(e) is a plan view showing the ribbon cassette, FIG. 9 is a configuration diagram showing the electric circuit, and FIGS. 10 to 12 are flowcharts showing the operation. 40... Image forming device, 50... Operation panel, 60
...Paper feeding/separation section, 100...CPU (control means), 102...RAM5150...Paper transport section, 1
55... platen roller (pressing means), 200...
- Image reading section, 250... Image recording section, 253...
Thermal head (print head), 260... Ink ribbon, 262... Delivery side core (delivery means), 263
... Winding side core (winding means), 288... Ink ribbon delivery drive section (driving means), D... Document, P...
- Recording paper (image forming medium). Applicant's representative Patent attorney Takehiko Suzue Figure 2 (b) Figure 5 (C) (d) (e) Figure 8 Figure 10 Figure 12

Claims (2)

[Claims] (1) A print head is provided in the middle of an ink ribbon stretched between a winding means and a feeding means, and an image is printed through the ink ribbon that is wound and moved by the winding means. An image forming apparatus that forms an image while pressing a forming medium against the print head, further comprising a driving means for driving the feeding means in a direction opposite to a direction in which the ink ribbon is wound and moved by the winding means. image forming apparatus. (2) A print head disposed in the middle of the ink ribbon stretched between the winding means and the feeding means, and a pressing means disposed to face the print head; In an image forming apparatus that forms an image while pressing an image forming medium against the print head by a pressing means via the ink ribbon that is wound and moved by a take-up means, the sending means is moved by the ink ribbon by the take-up means. and a control means for separating the printing head and the pressing means when the driving means drives the feeding means. Image forming device.