JPH03140975A - Image forming device - Google Patents

Abstract

PURPOSE:To easily perform the removing operation of a recording sheet by providing a means for separating a pressing member in each conveying means from a corresponding driving roller while keeping the contact state of a pinch roller with a supporting roller at the time of interrupting image formation because of the occurrence of abnormality. CONSTITUTION:An image is formed on the recording sheet which is turned and moved in contact with the supporting roller 2 by the pinch rollers 3 and 4. A paper feeding driving part unit 250 for conveying the recording sheet in the supporting roller 2 is provided with a paper feeding roller 251 and a forward roller 252, and the central rubber part of a reverse roller 253 is energized by the rubber part of the forward roller 252. On a paper ejection side, the pinch roller 52 press-contacts with the central rubber part of a paper ejecting roller 11. In the case of detecting jamming while a printing action is performed, a head 159 is restored to a home position and nipping in a part other than a platen roller 2 and the pinch rollers 3 and 4 is all released. Thus, the removing operation of the recording sheet at the time of interrupting the image formation is easily performed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to image forming apparatuses such as printers, facsimiles, and copying machines, and in particular, to an image forming apparatus that facilitates the removal of a recording sheet when image formation is interrupted due to an abnormality. The present invention relates to an image forming apparatus.

(Prior Art) Conventionally, in image forming apparatuses such as printers, facsimile machines, and copying machines, a recording sheet is placed along a support roller using a pinch roller, and an image is formed on the recording sheet on the surface of the support roller by an image forming means. A device having such a configuration is known.

In such an image forming apparatus, since image formation is performed in synchronization with the rotation of the support roller, it is possible to accurately form an image on a recording sheet without positional deviation.

[Problem to be solved by the invention]

Incidentally, in an image forming apparatus using such a combination configuration of a support roller and a pinch roller, there is an upstream conveyance means for carrying the recording sheet to the support roller, and an upstream conveyance means for receiving the recording sheet on which an image has been formed from the support roller. A downstream transport means is required for carrying out the product. Therefore, when image formation is interrupted due to an abnormality in the apparatus such as a jam (paper jam) or the occurrence of an abnormal signal, the upstream and downstream conveying means must be used to take out the recording sheet remaining around the support roller. This created an obstacle and made removal work extremely difficult.

The present invention has been made in order to solve the above-mentioned problems in conventional image forming apparatuses, and an object of the present invention is to provide an image forming apparatus in which a recording sheet can be easily removed when image formation is interrupted due to the occurrence of an abnormality. With the goal.

[Means and operations for solving the problem] In order to solve the above problems, the present invention forms an image by an image forming means on a recording sheet that is in close contact with a support roller by a pinch roller and is rotating together with the support roller. The image forming device that
an upstream conveyance means comprising a first drive roller for carrying the recording sheet to the support roller and a first pressing member for pressing the recording sheet against the drive roller; a downstream conveyance means consisting of a second drive roller for conveying the recording sheet and a second pressing member for pressing the recording sheet against the drive roller; and a pinch roller for the support roller when image formation is interrupted due to an abnormality in the apparatus. and a means for separating each pressing member in the upstream conveying means and the downstream conveying means from the corresponding drive roller while maintaining the contact state.

In this way, when image formation is interrupted due to an abnormality in the device,
By providing a means for separating the pressing member in each conveying means from the corresponding drive roller while maintaining the pinch roller Φ contact state with the support roller, when image formation is interrupted due to an abnormality in the device, the support roller can be moved manually or electrically. By rotating the support roller, the recording sheet remaining on the circumferential surface of the support roller is pushed outward through the space formed by the separation of the pressing member from the drive roller without being obstructed by the conveyance means, and is easily pushed out. can be excluded.

〔Example〕

Examples will be described below. FIG. 1 is an external view of an embodiment of an image forming apparatus according to the present invention, in which la is an operation panel, 1b is a front door, 200 is a paper feed cassette unit, and 300 is a paper output tray. ■Open the front door 1b and open the paper cassette unit 20.
0 and the paper discharge tray 300 are removed. Figure 2 is a top view showing the frame of the device main body 1.
Figure 2 (B).

0 indicates a front frame and a rear frame, respectively. The main body frame is composed of a front frame 48 and a catcher frame 49, and the front frame 48 and catcher frame 49 are connected by stays 44 to 47 so as to face each other, and are formed into a box shape. The front frame 48 is provided with holes 48a to 48k, and the rear frame 49 is provided with holes 49a to 49q.

The stay 44 has a pair of cassette rails 2 facing each other between both frames 48 and 49 in a direction perpendicular to both frames.
07 is fixed. Furthermore, as shown in the front view of FIG.
Guide 5. Second guide 6, third guide 7, fourth guide 8
is fixed, and a head rotation center shaft 152 that rotatably supports the head unit 150 is connected to the hole 48g,
It is fixed at 49g.

A head drive shaft 180 that transmits the driving force for raising and lowering the head unit 150 is rotatably supported through bearings 20 in holes 48f and 49f, as shown in FIG. 4, and is a platen whose surface is made of rubber. The roller 2 has holes 48e and 49e.
As shown in FIG. 5, it is rotatably supported via a bearing 12. In addition, the pinch rollers 3 and 4 have holes 48i,
48, 49j, and 49k via bearings 13 so that the moving directions thereof are directed toward the center of the platen roller 2.

Then, so as to go around the bearings 13 and 12,
A pinch spring 14 is applied on the outside of both frames 48, 49, and this spring 14 causes the pinch roller 3.
4 is pressed against the platen roller 2 with a constant force (approximately 1 kgf). A plastic knob 15 is press-fitted onto the shaft of the platen roller 2 on the outside of the front frame 48, while a platen gear 193 is fixed on the outside of the rear frame 49.

As shown in FIG. 4, a lever 19 is fixed to the head drive shaft 180 on the outside of the front frame 48, and a lever 19 is fixed on the outside of the rear frame 49.
81 is fixed, and drive arms 179 are fixed at two locations with pins inside both frames.

On the other hand, the head unit 150 has a head rotation center axis 1
52, which are swingable around the head arm 154 and a pressure arm 155. They are mated. A head 159 is fixed to the tip of the head arm 154.
A pressure arm 155 corresponding to the back side of the stand is provided with studs 156 on both sides, and this stand 156
A spring 157 is disposed so as to be supported by. This spring 1
57 is compressed, one end is in contact with the helad arm 154 and the other end is in contact with the pressure arm 155, and the two arms 154, 155 are biased by this spring force, and normally the pressure arm 155 is in contact with the one end 154 of the helad arm 154
a and 154 b to contain the spring force.

The pressure arm 155 also includes the drive arm 17.
A link 178 is rotatably provided at a position corresponding to 9, and a pin 1 provided at the other end of the link 178
78a and 178b are connected by fitting into holes formed at the tip of the drive arm 179. head 1
59 rotates around a head rotation center axis 152 and is positioned such that its printing portion faces toward the center of the platen roller 2.

In FIG. 3, 301 is a tank used for pushing up the middle plate of the cassette, which will be described later, and is made of lubricating plastic and is fitted around a tongue shaft 302 so as to be rotatable. As shown in FIG. 6, two pins 303 are press-fitted into the tongue shaft 302, and these pins 303 and wall portions 301a and 301b provided on both end surfaces of the boss portion 301C of the tongue 301, respectively. .

The rotation angle of the tongue 301 with respect to the tongue shaft 302 is restricted by contact with the tongues 301a' and 301b'.

Then, the spring 304 is attached to the boss portion 301c of the tongue 301.
One end is locked to the tongue 301 and the other end is locked to the pin 303, and one wall 301a of the tank 301
is urged in a direction to press against the pin 303. Further, a lever 305 is fixed to one end of the tongue shaft 302 by caulking, and a boss portion 305a is attached to the lever 305.
It is attached so as to protrude from the lever 305 in a direction perpendicular to it. The tongue shaft 302 has holes 48h and 49 in both frames.
The lever 305 is located outside the rear frame 49, and the tongue 301 is located approximately at the center between the two frames.

Next, the paper feed drive unit 250 shown in FIG. 3 will be explained. The paper feed drive unit 250 is equipped with a paper feed roller 251 and a forward roller 252, each of which is provided with rubber in the center. As shown, holes 285a, 285a' and 2 formed in both side plates of the housing 285
85b and 285b' via bearings 279 so as to be rotatable. As shown in FIG. 7, the housing 285 is provided with holes 285 d and 285 e from which the central rubber portions of both rollers 251 and 252 project.

A paper feed gear 266 and a forward gear 265 are respectively fixed to each roller 251, 252 on the outside of the housing 285, as shown in FIG.

On the other hand, the retard arm 255 has studs 2 at both ends.
54 is caulked, and hole 2 of the housing 285
85h and 285i (Fig. 7 (8), (C1)) and are supported in a swingable manner. A lever 256 is press-fitted into one of the studs 254, and a spring receiver 257 is fixed to the other. Retard springs 258 and 259 are loosely fitted to the outer periphery of the stud 254 inside the lever 256 and the spring receiver 257, and one end of the retard springs 25B and 259 is attached to the housing 285, and the other end is attached to the housing 285. It is in contact with a bearing 279 of a reverse roller 253 which is rotatably supported by a retard arm 255.The central part of the reverse roller 253 is made of a rubber material, and the central rubber part is supported by the retard springs 258 and 259. 8th
As shown in Figure ■), it is biased by the rubber portion of the forward roller 252.

A gear 261 is rotatably fitted to the end of the reverse roller shaft on the outside of the retard arm 255, and a pad pan 263 is fixed to the reverse roller shaft on the outside. A pad 262 made of synthetic fiber is attached to the pad pan 263. A clutch spring 260 is compressed and inserted inside the gear 261, and urges the gear 261 toward the pad 262 between it and the retard arm 255.

A multi-purpose stud is provided on the outer surface of one side plate 285g of the housing 285.
As shown in Figure C), gears 267 to 271 are arranged to be rotatably fitted. The rotation of gear 269 is the rotation of gear 27
0 to gear 271 and forward gear 265 . It is configured to be transmitted to paper feed gear 266 via gear 267. Further, the signal is transmitted from gear 268 to gear 261 via idler gear 264.

The shutter 272 shown in FIG.
and the housing 285, one end 272a thereof.
is the hole 285c of the housing 285 (FIG. 7 CA),
(D)), and the other end 272b protrudes from the hole 285e of the housing 285. shutter 27
The tip of the other end 272b of No. 2 is bifurcated and is positioned on both sides of the rubber portion of the forward roller 252.

1 2 Furthermore, the intermediate portion 272C of the shutter 272 is connected to the paper feed roller 2.
The movement of the shutter 2 is restricted by the shaft of the shutter 51.
72 can be slightly moved up and down around one end 272a, and the other end 272b is arranged in a positional relationship such that the other end 272b goes in and out of the hole 285e. Note that 273 is stud 276, 2
This is the shutter holder attached to 77.

The paper feed drive unit 250 is inserted through the hole 49c of the rear frame 49, and the bearing 279 is inserted into the front frame 49.
8 holes 48c and 48d for positioning, and is fixed to the rear frame 49 with screws.

8) and 2 are diagrams showing a guide 275 and a paper feed sensor 278 provided in the paper feed drive unit 250.

The paper ejection roller 11 shown in FIG. 3 has both frame holes 48i,
49i via a bearing 279, as shown in FIG. A gear 280 is fixed to the shaft end of the paper discharge roller 11 on the outside of the rear frame 49. Paper ejection pinch section unit 5 shown in FIG.
0 is configured such that a pinch roller 52 is rotatably and loosely supported via a bearing on an arm 54 having a rotation center shaft 51, and the bearing portion is pressed by a spring to cause the pinch roller 52 to move toward the ejector. It comes into pressure contact with the central rubber portion of the paper roller 11.

Further, the arm 54 is provided with a stud 53 that extends to the outside of the rear frame 49.

As shown in Figure 1θ, the rack unit 350 includes a rack plate 354 made of sheet metal and a first rack 351 made of plastic. Second rack 352. It is constructed by assembling a cam 353 and a detection plate 355 made of sheet metal. The first rack 351 has a rack on the top surface, and an eleventh rack on the side surface.
As shown in Figure ^, an elongated groove 351a is formed.

Furthermore, Figure 11^ shows a view from above of the prisoner in Figure 10. The second rack 352 is similarly provided with a rack on its upper surface, and elongated grooves 352a and 352b are formed on its side surfaces. The cam 353 has cam grooves 353a, 353b, 353c in a closed loop, as shown in FIG.
, 353d are formed, and a leaf spring 356 is attached to close the groove 353d. Further, the cam 353 is provided with a long hole groove 353e and a cam groove 353f above the long hole groove 353e. A lever 305 provided at one end of the tongue shaft 302 shown in FIG.
The boss portion 305a of the cam 353 is connected to the grooves 353a to 353 of the cam 353.
It is designed to be inserted into d.

Note that FIG. 10 (Bl is a view seen from below in FIG. 10, and the sensors 357 and 358 for detecting the detection plate 355 are
The figure shows the arrangement of the .

As shown in FIG. 12, studs 42 and 43 are provided upright on the rear frame 49, and these studs 42,
43 and the long hole groove 353e of the rack unit 350,
353a are fitted, and the rack unit 350 is slidably attached to the rear frame 49. The rear frame 49 further includes studs 40 and 41.
is erected, and a drive frame 39 is fixed to the end thereof. Three types of motors and a plurality of gears that mesh with their worm gears are rotatably held in the drive frame 39 by studs erected on the drive frame 39.

That is, first, as shown in FIG. 4, a head lifting motor 185 and gears 184 and 182 that mesh with its worm are provided. Also, as shown in FIG. 13, the gear 18 that engages with the worm of the ink sheet take-up motor
7 is provided, and the gear 187 transmits power to a torque limiter ) 34 rotatably provided on the stud 32. Furthermore, in the drive frame 39,
As shown in FIG. 14, transmission gears 189, 190 are attached which mesh with the main motor 188.

Also, from the drive frame 39 to the rear frame 49 side, the first
As shown in FIG. 4^, the holder 31 is spot welded, and the gear slider 3o is held swingably around the hole 31a of the holder 31, as shown in FIG. The gear slider 30 has a distal end located between the first and second gears of the transmission gear 190, and an elastic member 29 fixed with a screw, so that the distal end 29a of the elastic member 29 and the distal end of the gear slider 30 are connected to each other. The protrusion 30a is
The first gear of the transmission gear 190. The second gear is in contact with elastic force. Also, the rear end 30 of the gear slider 30
b, slopes 354d, e, f of the rack plate 354 shown in FIG. 10^, (B) due to the urging force of the spring 28
It is designed to come into pressure contact with the

5 6 Further, as shown in FIG. 13, the drive frame 39 includes:
A stud 33 is provided upright, and another torque limiter ^35 is rotatably held around the stud 33. Furthermore, a ratchet lock 37 is rotatably fitted to the tip of a stud 38 erected on the drive frame 39, and as shown in FIG. A spring 36 is tensioned, and the tip 37b of the ratchet lock 37 is used as a torque limiter.
35 is engaged with a ratchet portion 35a on the outer periphery.

The other boss portion 37a of the ratchet lock 37 is engaged with elongated grooves 352a and 352b of the second rack 352 of the rack unit 350, as shown in FIG.

As shown in FIG. 12, a cassette lock 20B is swingably fitted into a stud 42 provided upright on the rear frame 49, and a pin 20B is fitted into the cassette lock 208.
08a is tightened, and its tip engages with the long hole groove 353e of the cam 353 of the rack unit 350 and the cam groove 3531, as shown in FIG. 11 (81). Also, the cassette lock 208 is biased upwardly by a spring, so that the pin 208a
are in contact with the upper walls of the grooves 353e and 353f, and rotation of the cassette lock 208 is restricted. One end 208b of the normal set lock 208 is inserted into the inside of the rear frame 49 through the hole 49d of the rear frame 49.

When the rear frame 49, rack unit 350, and drive frame 39 are combined, as shown in FIG.
4.182.181 to rotate the head drive shaft 180 in the forward and reverse directions. Furthermore, the first rack 35 is connected via the gear 183.
1 to reciprocate the rack unit 350.

On the other hand, the rotation of the ink sheet take-up motor 186 is
As shown in figure (8), gear 1B? and drives the torque limiter 34. As shown in FIG. 14, the driving force of the main motor 188 is applied to
The signal is transmitted to the platen gear 193 via the platen gear 193 to drive the platen gear 193. At the same time, as shown in the diagram showing the outside of the carrier frame 49 in FIG. Reverse roller 253 is driven. At the same time, the rotation of the gear 269 is caused by the rotation of the gears 270, 271.2.
It is transmitted to the paper discharge roller 11 via 80.

Further, as shown in FIGS. 9 and 15, the second rack 352 of the rack unit 350 includes an idler gear 282.
are in mesh with each other, and the reciprocating motion of the rack unit 350 is transmitted to the cam gear 281. A cam is formed on the outer periphery of the cam gear 281, and at a part of its rotation angle, the tip 25 of the lever 256 (FIG. 8) attached to one end of the retard arm 255 of the paper feed drive unit 250
6a and the cam are arranged in a positional relationship in which they are in contact with each other. Further, as shown in FIGS. 9 and 15, a stud 28 provided in the paper feed drive unit 250
6 and the boss portion 256b of the lever 256 form the link 28.
3 is held and rotatably fitted into the boss portion 256b, and the stud 286 and the elongated portion 283b engage to restrict rotation. Depending on the rotational position of the cam gear 281, the lever 25
6 is lifted and is configured to lift, via a link 283, a stud 53 provided on the arm 54 holding the pinch roller 52.

The two torque limiters 34 and 35 are attached to the rear frame 49.
It is arranged so as to protrude inside the rear frame 49 from the hole 49b. The torque limiter 34 is shown in Fig. 13^
As shown in FIG.
It is configured to transmit driving force with a constant torque of 00 g-CI. On the other hand, the torque limiter 35 includes a ratchet 35a, and if the tip 37b of the ratchet lock 37 is apart from the ratchet 35a, a torque of, for example, 50 g-cm is required to rotate the output end 35b. do. Tip part 3 of ratchet lock 37
7b is in contact with the ratchet 35a, the output end 35b is locked and does not rotate.

On the other hand, the ink sheet cartridge 100, which is driven and controlled by the torque limiters 34 and 35, is initially wound around the core 101 and the core 101, as shown in FIG. The ink sheet cartridge 100 is composed of an ink sheet 103 and a core 031102 for winding up the ink sheet 103.
From the hole 48a of the front frame 48 to the rear frame 49
A hole 100a is inserted in the direction and provided in the protrusion.

A pin provided upright on the front frame 48 (not shown) is fitted to determine the position of the front frame, and the position of the rear frame is determined by the torque limiter 34.3.
5 output end 35b and winding core ^101. The output end 34b and the winding core (81102 are loosely engaged and positioned. Therefore, the winding core ■) 102 is the side that winds up the ink sheet 103 via the torque limiter 34 by driving the ink sheet winding motor 186. Then, the winding core ^101
is the side that sends out the ink sheet 103. The torque limiter 35 has the function of applying a constant load torque to the winding core ^101, and the function of applying a load (more than the winding torque of the torque limiter 34) to the winding core ^101.
Ratchet 35a and end portion 37 of ratchet lock 37
It has a function of applying a load (due to the engagement of b) to stop the winding.

Further, as shown in FIG. 17^, (B), the torque limiter 34 is provided with a radial black and white pattern 34d on the front part 34c which rotates together with the output end part 34b. Reflective sensor 27 near
(Fig. 13^) is provided to detect the rotational speed of the output end 34b of the torque limiter 34.

In addition, the ink sheet cartridge 10G has a
As shown in Figure 16, a plurality of holes 100d are formed, and as shown in Figure 16, hole 4 of the rear frame 49 is formed.
Actuators 104a of a plurality of sensors 104 are provided that protrude into the frame from 9q.

The ink sheet cartridge 100 is
There are multiple types depending on the pattern type, physical property values, etc. of the hole 103, and the combination of the holes 100d changes depending on the type. Ink sheet cartridge 100
is set in printer body 1, hole 100 d
The part where is formed is the actuator 104 a
By pressing , it is possible to detect which type of ink sheet cartridge is inserted.

The paper feed cassette section unit 200 is shown in FIG. 18~(c)
As shown in FIG. 1st side guide 203° 2nd
It is composed of a side guide 205 and a rear end guide 206. The middle plate 202 includes protrusions 202a on both sides of the rear end,
202b is inserted into the hole 201f of the cassette frame 201, and the distal end portion 202c side is configured to be able to rotate up and down about the protrusions 202a and 202b.

The sheets 400 shown in FIG. 19 are stacked and stored on the intermediate plate 202 with the printed side facing down and the marked side 400a facing up. At that time, the paper 400 is
Actual images 203a, 203b of 03, Actual images 205b, 205c of the second side guide 205, Rear end guide 2
06 and the actual image 201g of the cassette frame 201. Furthermore, a presser spring 204 is provided on the first side guide 203, and this presser spring 204 has an urging force in the direction of the second side guide 205. This presser spring 204 pushes one side edge of the paper toward the second side guide 205, and the other side edge of the paper is pressed against the actual images 205b, 205c and positioned.

When using larger size paper, move the second side guide 205 and trailing edge guide 206 to the cassette frame 2.
This can be done by removing it from 01 and changing the position of the first side guide 203. The mark 400b on the back side 400a of the paper is in the form of a barcode, and indicates, for example, the size and type of paper (standard, etc.).

Different barcodes are attached for different combinations such as OHP use, tack seal use, etc.).

The M paper cassette section unit 200 has a cassette rail 20
The protruding parts 2 on both sides are attached to the guide part 207a (Fig. 2) of 7.
01a and 201b are guided and inserted from the hole 48b of the front frame 48 toward the rear frame 49. As shown in FIGS. 20 to 20C, a latch component 209 is disposed in the hole 49n of the rear frame 49 so as to correspond to the hook portion 201C of the cassette frame 201, and the latch component 209 is arranged to correspond to the hook portion 201C of the cassette frame 201. By inserting it into the main body frame, the hook portion 201C is locked by the latch component 209. Figure 20^ shows a state in which the hook part 201C is locked, and in order to release the locked state, as shown in Figure 20 (B), the hook part 201C is further moved by the amount of the stroke S.
A known latch component 209 is used which is configured to be released by pushing the latch component 209 into the inner part of the latch component 209 against a spring. FIG. 20 (C1) shows a state in which the hook portion 201C is unlocked by the latch component 209 by pushing in this way.

One end 208b (FIG. 12) of the cassette lock 208 described above is arranged to enter and exit the gap between the rear frame 49 and the cassette frame 201, and the one end 208b is inserted into the gap. In the state,
Since the stroke S for locking the hook part 201C to the latch part 209 is no longer maintained, the paper feed cassette unit 200 cannot be locked to the latch part 209, and it is impossible to release it from the locked state. It is no longer possible to do so.

As shown in FIG. 21(B), the paper discharge tray 300 has a cylindrical shape, and has openings 300a and 300b formed therein, and positioning protrusions 300c and 300d.
is provided. And paper feed cassette section unit 20
0 from the hole 48b of the front frame 48 to the rear frame 49 side, and the hole 49 of the rear frame 49.
The protrusions 300c and 300d are fitted into the 1.49m length and positioned. Also, protrusions 300c, 3
A magnet 300e is fixed to the side surface where 00d is provided, so that it is held in close contact with the rear frame 49. The paper discharge tray 300 can be easily removed by hand against the adhesion of the magnet 300e.

The protrusion 300c of the paper ejection tray 300 and the protrusion 201d (FIG. 18^) of the paper feed cassette section unit 200 described above are in a state where the paper ejection tray 300 and the paper feed cassette section unit 200 are set in the main body l of the apparatus. , protrudes outward from the rear frame 49 and is configured to be located at a portion that blocks a photo-ink rubber sensor (not shown). Then, this sensor detects the paper feed cassette unit 2.
00 and the presence or absence of the paper discharge tray 300 is detected.

Next, the operation of the image forming apparatus configured as described above will be explained. First, by driving the head lift motor 185,
The following parts work together.

(2) First, the head drive shaft 180 shown in FIG. 4 rotates, and the drive arm 179 moves the link 178, so that the pressure arm 155 rotates about the head rotation center axis 152. This rotation of pressure arm 155 leads to rotation of spring 157 and head arm 154. The head 159 itself rotates together with the helad arm 154.

(2) Due to the engagement between the gear 183 and the first rack 351, the rack unit 350 reciprocates. and the 1st theta
As shown in Fig. 3, the hole 355a made in the detection plate 355 provided in the rack unit 350 and the end of the detection plate 355 itself are connected to the home position sensor 3.
57 and position sensor 358, the position of the head can be detected in association with the home positions (H, P) and positions A to E shown in FIGS.

■ Cam slopes 354d, 354e, 35 of the rack plate 354 in conjunction with the reciprocating movement of the rack unit 350.
4f moves the gear slider 30, as shown at +81 in FIG. 15, and the gear 190 slides in conjunction with this. When the head 159 reaches the home position (H, P) and the A, B position, the gear 190
does not mesh with the platen gear 193, and the platen roller 2
is not driven. On the other hand, when the head 159 is at the C, D, or E position, the gear 190 meshes with the platen gear 193, and the platen roller 2 is driven.

■ Also, in conjunction with the reciprocating movement of the rack unit 350, a long hole groove 352a provided on the side surface of the second rack 352 is provided.
, 352b pushes the boss portion 37a of the ratchet lock 37, and the ratchet lock 37 approaches and separates from the ratchet portion 35a of the torque limiter ^35 (see Fig. 13).
C), (B)) When in contact, it works to prevent rotation of the torque limiter ^35, and when separated, it is released. Therefore, the torque limiter 35 is locked until the head 159 reaches the home position and the A-C position, and can freely rotate only at the D and E positions.

- In conjunction with the reciprocating movement of the rack unit 350, the idler gear 282 is rotated by the second rack 352, and the cam gear 281 is also rotated (see Figs. 9 and 15).
(see figure). As a result, when the cam surface of the cam gear 281 comes into contact with the lever 256 provided on the paper feed drive unit 250 side and is pushed up, the reverse roller 253 separates from the forward roller 252, and at the same time, the gear 261 also separates from the eye try gear 264. The driving force is not transmitted to gear 261. Further, the link 283 is pushed up and the stud 53 protruding from the paper ejection pinch section unit 50 is lifted up, so that the paper ejection roller 11 and the pinch roller 52 are removed.
The nip is released.

On the contrary, when the cam surface of the cam gear 281 does not contact the lever 256 at all, the reverse roller 253 is in contact with the forward roller 252 due to the force of the retard springs 258 and 259. The gear 261 then engages with the eye try gear 264, and can be driven in the opposite direction to the forward roller 252 and paper feed roller 251. Further, the link 283 moves downward, and its upper edge 283a separates from the stud 53, and the paper roller 11 and the pinch roller 5
2 is in a nip state.

As a result of the above operations, only when the head position is in positions B and C, the paper ejection roller and reverse roller section are in the nip state, respectively, and in other positions,
2. The pump is released.

Furthermore, in conjunction with the reciprocating movement of the rack unit 350, the boss portion 305a of the lever 305 provided at the end of the tongue shaft 302 fitted into the cam grooves 353a to 353d of the cam 353 is moved so that the head position is at the home position (H). ．．
As it moves from P) to E positilon, Fig. 11 CB+
In, P. A,P. B.P. C,P.

D.P. As shown by E, it is lifted upward from groove 353a, passes through groove 353b, and enters groove 353C. When the head position moves from the E position to the home position, it passes from the groove 353c to the groove 353d,
Push the leaf spring 356 downward and return to the groove 353a. Only when the head position is in the B position, the tongue shaft 302 rotates, and the tongue 301 enters into the cassette frame through the hole 201e of the cassette frame 201 by the force of the spring 304, pushes up the middle plate 202, and presses it above it. The back side of the stacked sheets is pressed against the paper feed roller 251. In other positions, the tongue 301 is lowered,
It is retracted to the outside of the cassette frame 201.

■ Furthermore, the pin 208a of the cassette lock 208 is interlocked with the reciprocation of the rack unit 350 and inserted into the cam grooves 353e and 353f of the cam 353.
In FIG. 11 [B], the same <P, A, P, B,
P.

As shown by C, P, D, P, and E, the cam groove 353 e
.

It goes up and down along the upper wall of 353f. Only when the head 159 is at the home position (H, P), the pin 208a is pushed down by the cam groove 3530, and as a result, the one end 208b of the cassette lock 20B is locked in the position of the paper feed cassette section unit 200 and the capture frame 49. The paper feed cassette unit 200 is retracted from the gap between the paper feed cassette unit 200 and becomes removable. In other positions,
One end 208b of the cassette lock 208 enters the gap between the paper feed cassette unit 200 and the rear frame 49, making it impossible to attach or detach the paper feed cassette unit 200.

■ Also, as the head drive shaft 180 rotates, the lever 1 is moved outside the front frame 48 as shown in FIG.
9 rotates. When the head 159 is in a position other than the home position, the lever 19 is separated from the pin 16a of the link 16, and as shown in FIG. being drawn. At that time, the boss portion 17a is attached to the front door 1b.
It is located at a position corresponding to the boss portion (not shown in Fig. 1 (c)), and when the front door 1b is pushed, the boss portion comes into contact with the boss portion 17a and cannot be pushed, so the front door 1b is opened. It is configured in such a way that it cannot be done.

Then, only when the head 159 reaches the home position 1 2 , the lever 19 pushes the pin 16a of the link 16, so the slide member 17 moves against the urging force of the spring 1, and the boss part of the front door 1b moves. Boss part 1 from the tip
7a comes off and it becomes possible to push the front door 15. By pushing the front door 1b over a predetermined stroke in this state, the boss portion is released from the latch member and the front door 1b can be opened as shown in FIG. 1 fBl.

Table 1 shows the correspondence between the above operations (1) to (2) and the position of the head 159.

The printing order will be explained based on Table 1, then Table 1, and FIG. 22 to FF) and FIG. 24, which shows the relationship between the printing order and the head position.

(1) When not printing, the head 159 is at the home position (H', P) (FIG. 22 (C)), and the paper feed cassette unit 200 is attached and detached, the front door 1b is opened and closed, and the ink sheet cartridge 100 is installed. It is possible to attach and detach. A sensor (not shown) detects the front door 1.
b is closed, and the paper feed cassette unit) 200. Printing is possible only after the paper discharge tray 300 and ink sheet cartridge 100 are installed.

(II) Upon receiving the print signal, the head 159 moves to the D position (El in FIG. 22) as shown in FIG. At this time, the ink sheet sensor 10 (Fig. 3)
Since the head unit 150 moves near the ink sheet sensor 10 , the surface of the head unit 150 facing the ink sheet sensor 10 functions as a reflector and reflects the light from the sensor 10 that passes through the ink sheet 103 . Ink sheet 103 is C
(cyan), 1M (magenta), and Y (yellow), the light from the reflective sensor 10 is transmitted, but when the black band provided in front of Y (yellow) is located,
Sensor light does not pass through. Ink sheet winding motor 18
6, the ink sheet 103 is wound onto the core (81102) via the torque limiter 34. When the ink sheet sensor 10 detects the tip of the black band, the drive of the ink sheet winding motor 186 is stopped. .

(I) Next, the head 159 moves to -1 A position (22nd position).
Figure CB)) and again to the B position (Figure 22 (0)
). During this time, the feeding side of the ink sheet 103 is locked, so the ink sheet take-up motor 186 is driven again to remove the slack in the ink sheet 103. When the main motor 188 is rotated forward, the paper 400 is moved by the paper feed roller 251. be sent. The forward roller 252 and reverse roller 253 are in pressure contact, but before the paper 400 is nipped, the forward roller 25
2, the reverse roller 253 is driven in the same direction as the forward roller, contrary to its driving direction. - Once the paper is nipped, the reverse roller 253 is driven in the paper advancing direction.

When a plurality of sheets of paper 400 are fed to the nip portion during paper feeding, only the topmost sheet is fed by the forward roller 252, and the remaining sheets are fed by the reverse roller 253 toward the paper feed cassette unit 200. sent back to. Therefore, the paper 400 is separated into only one sheet and fed toward the platen roller 2. Also, the force of the retard springs 258, 259 and the clutch springs 260 of the paper feed drive unit 250, the bad 262. Paper feed roller 251
.

The coefficient of friction of the forward roller 252 and the reverse roller 253 and the force of the spring 304 of the tongue portion are set to optimal values for separating the fed sheets into one sheet.

5 The leading edge of the paper fed as in 3 is directed upward along the fourth guide 8, then directed downward by the third guide 7, and is bent to the platen roller 2 and pinch roller 3. It comes into contact with the nip part of the At this time, platen roller 2
has stopped. The paper is further fed and the feeding is stopped after a slight loop amount has been formed. The loop amount is set by counting the time since the registration sensor 9 (FIG. 3) detects the paper.

(mV) Next, the head moves to the C position (Fig. 22 ■)). At this time, the tongue 301 is lowered and the gear 190
meshes with the platen gear 193. The paper remains looped and its leading edge is pressed against the nip between the platen roller 2 and the pinch roller 3.

The main motor 188 is driven again, and the leading edge of the paper is nipped to the platen roller 2 by the stiffness of the paper created by the loop.
Feeding stops temporarily when about two holes are nipped.

Through this operation, the skew of the paper in the feeding direction of the platen roller 2 is corrected, and the leading edge of the paper is positioned (registered) with respect to the platen roller 2.

(V) Next, the head moves to the E position (FIG. 22(G)). With this operation, the reverse roller 253 is also retracted downward, and the paper discharge pinch roller 52 is also retracted upward. Then, a pinch roller 151 (FIG. 3) provided in the head 159 and the head unit 150 presses the ink sheet 103 against the platen roller 2. In this state, the platen roller 2 is rotated forward by the main motor 188, and the leading edge of the paper is guided by the ink sheet 103 pressed around the platen roller 2 and nipped by the next pinch roller 4.

After being nipped by these two pinch rollers 3.4, printing of the first color is performed according to the heat generated by the head 159.

The printing range of the first color is limited to a range in which the trailing edge of the paper does not come off the pinch roller 3. During printing, be sure to apply paper 4 only to the three pinch rollers 3゜4.151 and the head 159.
00 is designed to be nipped. Therefore, during printing, the paper 400 is not affected by the conveyance forces of the other rollers. During printing of this first color,
The ink sheet winding motor 186 is also driven, but since the ink sheet 103 is strongly nipped by the head 159 to the platen roller 2, it is wound up at the circumferential speed of the platen roller 2. At this time, by detecting the number of black and white patterns 34d provided on the rear end surface 34C of the torque limiter 34 with the reflective sensor 27, the winding core (8
The diameter of the ink sheet wound around 1102 can be estimated.

(Vl) When printing of the first color is completed, the head descends to the D position (FIG. 22 [F]). Then, the ink sheet winding motor 186 is driven, and the ink sheet 103 is
Wind up to the next color position and stop.

The winding amount at this time is determined by the estimated value of the diameter of the ink sheet in the above-mentioned winding core 102, and the appropriate amount is sent out by counting the black and white patterns 34d with the reflective sensor 27 again. At the same time, the main motor 188
is reversed and feeds the paper 400 into the paper cassette unit 200.
However, during the printing of the first color, the trailing edge of the paper came off the tip 275a (Fig. 3) of the guide 275 of the paper feed drive unit 250, and the paper's stiffness caused it to touch the bottom surface of the third guide 7. Therefore, the paper does not return to the reverse roller 253, but passes between the guide 275 and the third guide 7, and is further conveyed to the paper path formed by the lower surface of the paper discharge tray 300 and the guide 275. Therefore, during this printing process, the trailing edge of the paper is stacked in the paper feed cassette and the reverse roller 253. It does not hit the paper feed roller 251 or forward roller 252.

The reverse rotation is performed within a range in which the leading edge of the paper does not come out of the nip of the pinch roller 4, and is returned to a position before the previous position where printing of the first color was started, and then stopped.

Next, the head moves again to the E position (FIG. 22(F)), and the platen roller 2 starts normal rotation.

Printing of the second color is started at the timing when the leading edge of the paper comes to the position where printing of the first color was started. The amount of forward rotation and reverse rotation of the platen roller 2 is controlled by the number of pulses 9 0 when a pulse motor is used as the main motor 188. The steps (V) and (Vl) are repeated depending on the required number of times of duplicate printing.

(■) When the last printing is completed, the head moves to the C position (see Fig. 22), and the leading edge of the paper is moved to the paper ejection roller 11.
The paper is nipped by the pinch roller 52 and discharged as the platen roller 2 rotates. Printed paper is placed in output tray 3.
The paper enters through the hole 300a marked 00 and is discharged into the paper discharge tray 300. The operator can take out the printed paper to the outside of the apparatus main body 1 through another hole 300b opened on the front side of the apparatus main body 1.

At the same time, since the feeding side of the ink sheet 103 is locked, the ink sheet take-up motor 186 is driven to remove the deflection of the ink sheet 103.

(■) Next, move the head to the home position (Fig. 22^)
to end the print operation. At this time, the next ink sheet black band is positioned before reaching the ink sheet sensor IO.

Next, the operation when a jam (paper jam) is detected will be explained. If a jam is detected by some means during the print operation, the print operation is stopped and the head 15
9 to the A position (Fig. 22 all)). Then, when the ink sheet feeding side is locked, the ink sheet winding motor 186 is driven to remove the ink sheet 103.
Remove slack. Thereafter, when the head 159 is returned to the home position, an alarm display is displayed on a display section (not shown).

Next, a method for handling a jam will be explained. Since the head has returned to the home position, the paper in the apparatus is no longer nipped at any portion other than the platen roller 2 and pinch roller 3.4.

Also, platen gear 1 transmits driving force to platen roller 2.
93 and gear 190 are disengaged. Therefore, the platen roller 2 is free from the drive system. Further, the front door can be opened and closed, and the paper feed cassette section unit 200 can be attached and detached.

In this state, first open the front door 1b,
By removing the ink sheet cartridge 100, it is possible to check whether or not there is paper in that area. Next, the paper feed cassette section unit 200 and the paper output tray 300
to the front side of the device main body 1. When the paper feed cassette section unit 200 and the paper ejection tray 300 are removed, a large space is formed where the paper feed cassette section unit 200 and the paper ejection tray 300 can be easily accessed, as shown in FIG. Three paths, a paper feed path, a paper discharge path, and a third paper path formed by the guide 275 of the paper feed drive unit 250 and the lower surface of the third guide 7, communicate with this space.

Furthermore, when the front door 1b is opened, the knob 15 is exposed at the shaft end of the platen roller 2.
5 in the counterclockwise direction, the leading edge of the paper passes between the paper ejection roller 11 and the pinch roller 52, which are separated from the paper ejection path, and is sent into the space without any obstruction. On the other hand, if the knob 15 is turned clockwise, the forward roller 252 and reverse roller 25, which are separated from the paper feed path,
3 or from the third paper path to the space without any obstruction. These three routes are
Since it is set shorter than the length of the paper, the above knob 1
The rotation of 5 always causes one end of the paper to protrude into the space. When one end of the paper protrudes into the space in this manner, it becomes possible to insert a hand into the space and pull out the jammed paper for disposal.

After clearing the jam, the paper output tray 300. Insert the paper feed cassette section unit 200 and the ink sheet cartridge 100 into the apparatus main body 1 from the front side, and then open the front door 1b.
By closing the , the operation at the time of jam detection is completed.

Note that a sensor (not shown) detects the protrusion 300c of the paper ejection tray 300 and the protrusion 2 of the paper feed cassette section unit 200.
When the printer 01d is not attached to the main body 1 of the apparatus, it is controlled not to enter the printing operation.

In this embodiment, a configuration in which the pinch roller is in constant pressure contact with the platen roller is shown.3 4 However, the present invention also applies to a configuration in which the pinch roller can be brought into contact with and separated from the platen roller. Can be applied.

Furthermore, in this embodiment, the platen roller is manually rotated using a knob when discharging jammed paper, but the platen roller may be configured to be rotated by a motor instead of manually. good.

〔Effect of the invention〕

As described above in detail based on the embodiments, according to the present invention, when image formation is interrupted due to abnormality in the apparatus, the pressing member in each conveying means is pressed while maintaining the contact state of the pinch roller with the support roller. Since a means for separating the recording sheet from the corresponding drive roller is provided, the recording sheet remaining on the circumferential surface of the support roller when image formation is interrupted is moved through the space formed by the separation of the pressing member from the drive roller, and is unobstructed by the conveying means. can be easily eliminated without being affected.

[Brief explanation of the drawing]

FIG. 1^ is an external view of an embodiment of the image forming apparatus according to the present invention, FIG.
FIG. 2 ^ is a top view showing the main body frame of the embodiment of the image forming apparatus according to the present invention, FIG.
4 is a plan view showing the configuration of the head unit, FIG. 5 is a plan view showing the platen roller portion, and FIG. A),
(Ell is a plan view and side view showing the tongue part, 7th
(0) is a plan view, a side view, and a sectional view showing the housing of the paper feed drive unit; D). ■ is a plan view and top view showing the guide portion of the paper feed drive unit, FIG. 9 is a plan view showing the paper ejection roller portion, and FIG. FIG. 11 is a plan view and a side view, and FIG. 11 is a side view showing the rack plate of the rack unit and an enlarged side view showing the cam portion thereof. FIG. Figure 13^, a3) is a plan view showing the torque limiter part and a perspective view showing the ratchet lock part thereof, Figure 14, ■) is a plan view showing the platen gear part and a perspective view showing the gear slider, FIG. 15 is a front view showing how each member is attached to the outside of the rear frame.
7) is a plan view and partially omitted side view showing a part of the torque limiter (FIG. 18).
Plan view and side view showing the paper feed cassette section unit, 1st
Fig. 9 is a plan view showing the paper, Fig. 20~(C) is a view showing the locking mode of the hook part of the paper feed cassette unit, and Fig. 21^, 03) is a plan view showing the paper ejection tray. Figures and side views, Figures 22 to 22 show Home Posisilane and A-
A diagram showing the arrangement of each member in the E position, 2nd
3^, 2) are a plan view and a top view showing the slide member portion, and FIG. 24 is a diagram showing the relationship between printing order and head position. In the figure, 1 is the apparatus main body, 2 is a platen roller, 3.
4 is a pinch roller, 11 is a paper ejection roller, 50 is a paper ejection pinch unit, 52 is a pinch roller, 100 is an ink sheet cartridge, 103 is an ink sheet, 150 is a head unit, 151 is a pinch roller, and 152 is a head rotation unit. Dynamic center axis, 159 is a head, 180 is a head drive shaft, 200 is a paper feed cassette unit, 250 is a paper feed drive unit, 251 is a paper feed roller, 252 is a forward roller, 253 is a reverse roller, 300 is a paper ejection unit The tray 350 indicates a rack unit.

Claims (1)

[Claims] 1. In an image forming apparatus in which an image forming means forms an image on a recording sheet that is in close contact with a support roller by a pinch roller and is rotating together with the support roller, the recording sheet is carried into the support roller. an upstream conveying means consisting of a first driving roller for pressing the recording sheet and a first pressing member for pressing the recording sheet against the driving roller; and a second driving roller for receiving and conveying the recording sheet from the support roller. and a second pressing member that presses the recording sheet against the drive roller; and when the image formation is interrupted due to an abnormality in the apparatus, the pinch roller maintains the contact state with the support roller, and the An image forming apparatus comprising means for separating each pressing member in the upstream conveying means and the downstream conveying means from the corresponding drive roller. 2. The image forming means has a driving means for moving the image forming means toward and away from the support roller, and is configured such that the separating operation of the means for separating the pressing members of each of the conveying means and the separating operation of the driving means are linked. 2. The image forming apparatus according to claim 1, wherein: 3. The image forming apparatus according to claim 2, wherein the driving means of the image forming means and the means for separating the pressing members of each of the conveying means are configured to be operated by the same driving source. .