JPS6063178A - Image-forming device - Google Patents

Abstract

PURPOSE:To obtain clear images free of stagger of images, by a method wherein when forming an image by reciprocating a transfer recording material concurrently with rotation of a platen, a deviation in the feed quantity accompanied by forward and reverse rotation of the platen by a platen-driving means is corrected. CONSTITUTION:The platen-driving means 100 is constituted by fitting a toothed belt 47 to a motor pulley 46 fitted to a driving shaft of a pulse motor 45 and a platen pulley 48 fitted to a shaft of the platen 10. Further, the deviation in the feed quantity accompanied by the forward and reverse rotation of the platen 10 by the means 100 is corrected by a feed quantity correcting means (controlling circuit) 101. A transfer material 15 is intermediately provided between the platen 10 and a recording head 11 faced thereto, and a coloring material of the transfer material 15 is transferred onto a paper used as a transfer recording material, thereby forming an image. The transfer recording material is reciprocated concurrently with the rotation of the platen, thereby forming predetermined images.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a transfer type image forming apparatus that forms an image on the surface of the transfer material by transferring, for example, a colorant of a thermal transfer material to the transfer material. .

[Technical background of the invention and its problems]

Thermal transfer image forming devices are small, inexpensive, make little noise, and can use plain paper as the transfer material, so they have recently become popular not only for recording the output of computers and word processors, but also as copying devices. It is being put into practical use.

Normally, in this type of transfer type image forming apparatus, in order to form a multicolor image, the platen is rotated in both forward and reverse directions, and the transfer material is returned to its original position for each color, so that the transfer is performed in only one direction. .

However, in the past, a platen driving means that transmits the driving force from a driving source to the platen via a toothed belt (timing belt) is usually adopted. Due to backlash between the pulley teeth and the belt teeth, a very slight positional deviation occurs due to the l:9 forward/reverse torque direction.

Therefore, especially in the case of the above-mentioned unidirectional transfer method, the number of times the transfer material is sent is twice as many as the number of colors.
There is a serious problem that image misalignment occurs due to misalignment of the transferred material, and a clear image may not be obtained.

[Purpose of the invention]

The present invention was made based on the above circumstances, and
The purpose of this is to form a predetermined image by reciprocating the transfer material as the platen rotates, and to create a clear image without image shift due to shifting of the transfer material. An object of the present invention is to provide an image forming apparatus that can provide the following.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention has been made to reduce the amount of feed due to the forward and reverse rotation of the platen by means of a platen driving means that transmits power from a driving source to the platen via a toothed timing belt. A feed amount correction means is provided to correct the deviation.

[Embodiments of the invention]

A first embodiment of the present invention will be described below with reference to FIGS. 1 to 14.

FIG. 1 shows the external appearance of the image forming apparatus, and FIG. 2 shows its schematic configuration. In FIGS. 1 and 2, reference numeral 1 denotes a main body of an image forming apparatus, and an operation panel section 1a is formed on the upper front surface of the apparatus main body 1. As shown in FIG. Further, a document table 2 having a document holding cover 3 on the left side of the upper surface of the apparatus main body 1 is provided.
The lower side is a document scanning section (scanner section) 4 that scans the document set on the document table 2, and the right side of the apparatus main body 1 is an image forming section (printer section) 5.

On the operation panel section 1a, a copy number setting section 7 consisting of a display section 6 and a numeric keypad 7, buttons 8, etc. are arranged.

Further, as shown in FIG. 2, the document scanning section 4 optically scans the document set on the document table 2 by reciprocating the movable scanning section 9 of the exposure optical system along the lower surface of the document table 2. This optical information is photoelectrically converted and input to the image forming section 5.

The image forming section 5 still has a configuration as shown in FIGS. 2 and 3. That is, the platen 10 is located approximately at the center of the image forming section 5, and a thermal head 11 as a recording head is located in front of the platen 1o (toward the left in the state of FIG. 3). It is arranged so that it can be moved in and out.

Further, a thermal transfer ribbon (ink ribbon) 15 as a transfer material is interposed between the thermal head 11 and the platen 0.

Then, with this thermal transfer ribbon 15 interposed, the paper P
is pressed against the platen 10, and in this state, a heating element (not shown) formed in the shape of a line tod of the thermal head 11 generates heat according to the image information, thereby heating the colorant (ink) on the thermal transfer ribbon 15. It is designed to be melted and transferred onto paper P.

Further, a paper feed roller 16 is provided below the remaining portion of the platen 10, and is adapted to sequentially take out sheets of paper P as a transfer material stored in a paper feed cassette 17 one by one. The taken out paper P is aligned at its leading edge by a registration row : ) 18 disposed diagonally above the paper feed row 216 , and then transferred toward the platen 10 by pressing rollers 19 , 20 . It will be sent exactly as it is wrapped around it.

On the other hand, the thermal head 11 presses the paper P against the platen 10 via the thermal transfer ribbon 15 as a transfer material.
As shown in FIG. 4, the ink 21 as a colorant on the thermal transfer ribbon 15 is heated and melted and transferred onto the paper P.

Further, the thermal transfer ribbon 15 has approximately the same size as the paper P, as shown by range A in FIG.
J1 (!) are arranged side by side, or as shown by the range opening, yellow (7), magenta M, cyan (Q, black) ink portions 21 a e21 b e21 c, 21
d are arranged side by side, and after transferring one color at a time, the paper P is returned to its original position and overlapped one after another accurately.

A thermal transfer ribbon containing a black ink portion 21d is used when it is desired to produce black clearly, and even a ribbon without a black ink portion 21d can produce approximately black by overlapping three colors.

In this way, the paper P is reciprocated by the number of colors by the rotation of the platen 10, but the path of the paper P at this time is the first one that is sequentially arranged along the lower surface of the paper output tray 22. It will be guided onto the second guide 23.24.

That is, the explanation will be made with reference to FIG. 6 0) to 6).

First, the paper P supplied from the paper feed cassette 17 passes through the arrangement portion of the registration roller 18 and the first distribution guide 25, and is wound around the platen IO. (See FIG. 6(S)) Next, the platen 10 rotates using a pulse motor (not shown) as a driving source to transport the paper P at a predetermined speed and form a line tod shape along the axial direction of the platen 10. A heating element (not shown) of the thermal head 11 generates heat according to the image information, and the thermal transfer ribbon 15
2 of the ink is transferred onto the paper P.

Furthermore, the leading edge of the paper P that has passed through the platen 10 is located at the second
The paper is sent onto a first guide 23 provided along the lower surface of the paper discharge tray 22 by a sorting guide 26 . (See FIG. 6(b)) In this way, the paper P onto which the ink 21 of one color has been transferred is transported backwards by reversing the platen 10, and the paper P is transferred to the first distribution guide 25. The rotational displacement operation sends the material onto the second guide 24 provided along the lower surface of the first guide 23 . (See FIG. 6(c)) In this way, by reciprocating the paper P a plurality of times, a plurality of colors are transferred.

Finally, the paper P to which all the colors of ink 21 have been transferred is
The paper is guided by the second sorting guide 26 to a pair of paper discharge rollers 27 and discharged onto the paper discharge tray 22 . (See Fig. 6)) The image forming apparatus also includes an original scanning unit 4 as shown in Fig. 7.
Two-color conversion section 12. Mesori section 132 image forming section 5. and an overall control section 14.

Then, the green ■ detected by the document scanning unit 4,
The color component values of yellow (7) and cyan (0) are converted by the color conversion unit 12 into magenta (Ml, Ml,
The color is converted to yellow (to), cyan (0), and this color-converted value is stored in the memory units 1 to 3 together with the position information on the document for each color. Based on the value read from section 13, magenta (b)
, yellow (7), cyan (0, black CB) C black is magenta (Ml, yellow (to), cyan (output of M of Q)
The print medium is transferred onto paper P. In addition, the overall control section 1
4 is a document scanning section 42, a color conversion section 12. Memory sound b13. and controls the entire image forming section 5.

In addition, a pair of paper ejection rollers 27. Paper ejection tray 22° 1st. Second
The guides 23, 24 are unitized so that this unit can be removed if necessary.

As shown in detail in FIG. 8, the thermal head holder 11 is attached to a head holder 31 which doubles as a heat sink and whose back is surrounded by a member 30 attached to a frame block 29. The ribbon 15 has both ends 7
Case 3 with 5 windings and 9 winding core 32 T 3 J
The frame block 3575i is assembled into a frame block 29 and is detachably attached to the frame block 29. The frame block 29 is made of die-casting or plastic, and is formed into a substantially U-shaped cross section so as to obtain sufficient strength. The configuration is such that the positioning accuracy of the ribbon cassette 35 is improved by fitting the core storage portions.

Further, as shown in FIG. 9, the head holder 31 to which the thermal head 27 is attached is configured to be movable by a distance X in the direction toward and away from the platen 1°. The structure is such that a gap δ for the thermal transfer ribbon 15 to enter between the ribbon guide 61°61 and the platen 10 can be secured as necessary, making it easy to reciprocate the paper P and to attach and detach the ribbon cassette 35. And it can be done reliably.

That is, as shown in FIGS. 10 and 11, the guide shafts 58e39 are attached to the head holder 31 via the stays 36937, and these guide shafts 38.
Bearing part 2 formed in the middle part with 7 frame block 29
It has a structure in which it is buried in 9a and 29b or supported by a near bearing.

Still, the head holder 31 is supported so as to be able to reciprocate in this manner, and its movement toward and away from the stylus platen 10 is controlled by the head moving mechanism 40. That is, as shown in FIG. 11, a head motor 42 is attached to a motor frame 41, and a drive shaft 4 of this motor 42 is attached to a motor frame 41.
An arm 43 is attached to the arm 2a as shown in FIG.
The rotational motion of 3 is converted into a reciprocating motion and transmitted to the head holder 31.0 Further, the motor frame 41 to which the head motor 42 is attached has a structure as shown in FIG. A platen motor 45 consisting of a motor is provided, and the driving force of the motor 45 is transmitted through a power transmission mechanism consisting of a pulley 46, a belt 47, and a pulley 48, and also serves as transfer material transfer means. The platen 10 is moved in the forward direction or the reverse direction.Furthermore, ribbon motors each having a coupling 50 attached to a drive shaft are installed at positions corresponding to the cassette mounting portions 49 to which the ribbon cassettes 35 are mounted. 51951 is attached.

On the other hand, both ends of the thermal transfer ribbon 150 housed in the ribbon cassette 35 are wound around the round core 32° 330, and the driving force receiving end 3'at 33a is exposed to the outer surface through a through hole formed in the end surface of the case 34. The tip is exposed and there is a 13th
As shown in the figure, engagement recesses 52.52 are now formed.

When the ribbon cassette 35 is completely installed in a predetermined position, the coupling somso engages with the engagement recess 52052 of the winding core 32133, and the thermal transfer ribbon 15 can be wound.

- Further, as shown in FIGS. 8 and 12, the ribbon cassette 35 has two parallel winding cores 3293B around which both ends of the thermal transfer ribbon 15 are wound, and a midway portion of the thermal transfer ribbon 15. is arranged between the platen 10 and the thermal head 11 and is enclosed in a case 34 so that a portion thereof is exposed.

A slit 53 is formed between the core accommodating portions 34a and 34b of the case 34 along the axial direction of the cores 32 and 33 and is open at one end.
The driving force receiving end 32ae3 of the winding core 32.33 is located on the open end side of the winding core 32.33.
3a is provided.

Further, the case 34 of the ribbon cassette 35 is arranged to hold the thermal transfer ribbon 1 as shown in FIGS. 8, 12, and 13.
The cross section forming a space for accommodating the thermal head 11 attached to the head holder 31 and the thermal head 11 integrally formed between the back surface of the exposed part of the head holder 31 and the case 34 is U-shaped. The width dimension of the thermal transfer ribbon 15 is larger than the maximum winding diameter by the winding core 32033, and the cutting depth of the slit 53 formed in the case 34 is more than half the width dimension of the thermal transfer ribbon 150. 0 In this way, if the total length of the ribbon cassette 35f'L case 34 is L, it consists of the range tl where the top and bottom are connected, and the range t2 where the top and bottom are divided into two by the slit 53. . The width t of the slit 530 is set to be slightly wider than the thickness of the cassette fitting portion 29c of the frame block 29, and the cutting depth of the slit 53 is t! is set to be approximately the same width as the cassette insertion portion 29c.

Therefore, when installing the ribbon cassette 35, the opening end surface of the slit 53 is opposed to the end surface of the cassette fitting part 29c, and the ribbon cassette 35 is pushed in along its longitudinal direction (in the axial direction of the platen) as shown in FIG. The cassette fitting portion 29c and the slit 53 may be engaged with each other, and when removing the cassette, the cassette fitting portion 29c and the slit 53 may be pulled out in the opposite direction.

Insertion and removal of the ribbon cassettes 35 and 35 is performed by opening the door 55 of the cassette insertion and removal port 54 formed on the front surface of the main body 1 of the apparatus. (See FIG. 1) Furthermore, as shown in FIG. 14, the platen 1o has a motor pulley 46 attached to the drive shaft of a pulse motor 45 as a drive source, and a platen pulley 48 attached to the shaft of the platen 10. By passing a toothed belt (timing belt) 47 between the two, the forward or reverse driving force of the pulse motor 45 is transmitted.

The toothed belt 47 is shown in FIGS. 15(a) and 15(b).
), a tooth profile is formed with rubber 66 using a core wire 65 to maintain strength, and a canvas 67 is used to reduce the coefficient of friction between the pulley and the pulley. (Some models do not have the canvas 67.) The force from the pulley 46 is transmitted from the pulley 46 to the rubber 66, and then transmitted to the driven object, the pulley 48, via the core wire 65... It differs from transmission using a chain or the like in that a rubber 66 is interposed in the middle. This is because the rubber 66 is an elastic body and has the characteristic of absorbing vibrations from the pulley 62.

Also, the tooth profile of the toothed belt 47 is shown in FIG. 15(a).
As shown in the figure, it has a trapezoidal shape so that it meshes neatly with the pulley bacteria, and θ indicates its apex angle. In the figure, Ta indicates the height of the teeth, and Tb indicates the height of the entire belt. Also,
PFi represents the tooth to tooth pitch.

In addition, Fig. 16 shows the toothed belt 47 and pulley 46 (48).
In the figure, R represents the outer diameter of the pulley, D2 represents the pitch diameter, E represents the two-way pitch, F represents the pulley pitch circle, and G represents the belt pitch line. Note that the pitch circle is the meshing pitch circle.

On the other hand, since the toothed belt 47 and the pulley 46.4B engage in involute meshing, it goes without saying that it is desirable that the generally trapezoidal tooth profile be closer to an involute.

Next, with reference to FIGS. 17 to 23, set the platen 1.
The pulse width of 6°, which is the driving source of 0, will be explained.

17 and 18 show the structure of the motor 60. FIG. That is, 81 is a casing, and an annular rotor 82 is provided within this casing 81. A rotating shaft 83 of this rotor 82 is rotatably connected to the casing 8 via a bearing (not shown). The rotor 82 has permanent magnets 8 magnetized into eight poles in the circumferential direction.
4 is included.

A stator 85 having 12 slots is disposed inside the rotor 82, and the rotor 82 rotates around the stator 85. The winding 86 wound around the stator 85 has four poles and three phases (
U, V, W), each phase winding 86U, 8
Each end of 6V#86W is connected internally,
This is a so-called star connection as shown in FIG.

The above windings 86U, 86V, 86W are star connected, so
It is excited by a combination of two phases, and there are six slots in that combination, and the poles in each case are shifted by one slot as shown in Figure 20 (a) to (f). Become something. Now, if the excitation is performed in the order of (a) to (f) in FIG. 20, the rotor 83 will rotate clockwise by one slot due to the action of the magnetic field from the winding 86 and the magnetic field from the permanent magnet 84. , (a) to (f), it rotates by 90 degrees. Conversely, if you excite in the order of (f) to (a),
The direction of rotation is opposite to the above case.

On the other hand, three Hall elements 87 are placed adjacent to the stator 850 and the rotor 83, each with an interval of one slot.
U, 87V, and 87W are being evaluated.

Here, when the rotor 83 is rotated clockwise, the output voltage (Hall voltage) of each Hall element 87U, 87V, 87W becomes an AC voltage whose phase is shifted by IA period as shown in FIG. Therefore, when the rotor 83 rotates once, each Hall voltage changes four times. That is, one period of the Hall voltage corresponds to a rotation angle of the rotor 830 of 90K.

Therefore, according to each Hall voltage mentioned above, the winding 861L86V
The rotor 83 can be rotated by switching the excitation direction of e8#. For example, when rotating clockwise, the Hall voltage of Hall element 87U (D Hall voltage is negative (-)) and the Hall voltage of Hall element 87V is zero (0).
Assuming that the Hall voltage of the Hall element 87'W is positive (+), the rotor 83 is in the position shown in FIG. 20(f). Here, when the excitation phase is switched from U to W, the rotor 83 rotates 15 degrees clockwise, and the 20th
Try to settle down to the position shown in Figure (a). However, when the rotor 83 reaches this position, the Hall voltage of the Hall element 87U changes to zero, the Hall voltage of the Hall element 87V changes to negative, and the Hall voltage of the Hall element 87W changes to positive, and the excitation phase changes accordingly to U-. +v direction, and acts to rotate the rotor 83 further by 15 degrees to the position shown in FIG. 20(b). In this way, by sequentially switching the excitation phase according to each Hall voltage, the rotor 83
continues to rotate clockwise, and switching of its excitation phase is performed by a motor drive circuit 71, which will be described next.

FIG. 22 shows the rotation detection circuit 70 and motor drive circuit 71. That is, first, in the motor drive circuit 71, the Hall elements 87U, 87V, 87'
Each output signal of W is sent to a comparator 88U a8.
It is supplied to 8V-88W and each waveform is shaped. The outputs of the comparators 88U and 88Ve88W are supplied to a rotation direction switching circuit 89, respectively. This rotational direction switching circuit 89 is for selecting the rotational direction of the rotor 83 based on the rotational direction signal from the ADF control section, and is configured by, for example, three exclusive OR circuits, so that the rotational direction signal is ” level, comparator 8
The output of 8U*/7B'J y8IIIVI is inverted and sent to the current switching circuit 90. This current switching circuit 9o outputs an excitation phase switching signal UHeUL l*Vb sWH according to each output 89U, 89V, 89W of the rotation direction switching circuit 89.
, 'wL, respectively, and the truth table thereof is as shown below.

Therefore, the output UH/VH lightning WII of the current switching circuit 9o
are NPN transistors 91U and 91V, respectively.

Powered by a pace of 91W. This transistor 91U
#91V, 91W (Each emitter yp of D is connected to the collector of an NPN transistor 92, and the emitter of this transistor 92 is grounded.The base of the transistor 92 is connected to a rotation control signal from the ADF control section 66. is supplied.

In addition, the collectors of the transistors 91U, 91V, and 91W are each connected to a PNP type transistor 931L93.
V.

Connected to 93W pace. In addition, the current switching circuit 90
The outputs UL, IVL, and IVL are respectively supplied to the bases of NPN transistors 94U, 94V, and 9#. The collectors of the transistors 93U and 94U are connected in common, and the connection point is the winding 8 of the motor 72.
Connected to the other end of 6U. Further, the transistor 93
The collectors of V # 94V are connected in common, and the connection point is connected to the other end of the winding 86V of the motor 72. Further, the collectors of the transistors %W and 94W are connected in common, and the connection point is the winding 8 of the motor 72.
# Connected to the other end. Note that the transistor 93U
, 93V.

Each emitter of 93W is connected to the DC power supply Vc, and the above-mentioned two-tone
D x and the transmitter are each grounded.

In such a configuration, when the rotation control signal reaches 1 level, the transistor 92 is turned on, which also turns on the transistors 91U, 91V, and 91W, and the outputs UHtVH and WH- of the current switching circuit 90 are connected to the transistor 92.
Inform each of 3U and 93Ve93W.

On the other hand, when the rotation control signal reaches the 10'' level, the transistors 91Ue91Ve91We92 are cut off, and the transistor 93Ue93Vt9
3W is also a cutoff. For example, if the Hall voltages of the Hall elements 87U, 87V, and 87W are negative, zero, and positive, respectively, and the rotational direction signal is at the "0" level, the output of the rotational direction switching circuit 89 is 89Ue89V, 8(JW is 0”.

'θ'', 11''. As a result, UH and wL of the output of the current switching circuit 90 from Marie are at the ``1'' level, and the others are at the ``0'' level.

Therefore, when the rotation control signal is at the 1'' level, transistors 9.?Ut9# are turned on, and current flows from transistor 93U to winding 86U to winding 8# to transistor 9#. This corresponds to figure (a).

Next, in the rotation detection circuit 70, the AND circuit 95UK
In this case, each output of comparator 88U and 88V is connected to AND circuit 9.
Each output of the comparator 881L8gW is connected to 5V, and the comparator 88v is connected to the AND circuit 95W.

Each output of 8gVJ is supplied respectively. The output of each AND circuit wr95Ue95Vm95VI is supplied to an OR circuit 96, and a rotation detection signal (pulse) is obtained from the output of the OR circuit 96.

Incidentally, a timing chart of this rotation detection circuit 70 is shown in FIG. 23.

However, even when using the platen driving means 100 in which the pulse motor 45 is used as a driving source and the driving force is transmitted through the toothed belt 47, the elasticity and elongation of the teeth of the toothed belt 64 are , backlash between the pulley teeth and the belt teeth causes a positional deviation Δt±δ in the forward and reverse torque directions. However, since the variation δ is very small, it is possible to form an image without positional deviation by correcting Δ in forward and reverse directions.

As shown in FIG. 14, a feed amount correction means 102 is provided which sends a signal from the control circuit 101 to the motor drive circuit 71 to correct the feed amount.

Next, experimental results regarding the phase shift during forward and reverse rotation of the toothed belt (timing belt) 47 will be explained.

Figure 24 shows the experimental equipment, in which 45' is a pulse motor with a 1.8° dynamic torque of 10 b*fcm, 4
7' is the test belt, DR (46') is the pulley, DN (4
g') is a pulley, 105 is a rotary encoder, 106
is hysteresis brake (MAXI OKofllcm)
), 107 is a quaternary encoder, and 108 is a reversible counter.

The test method is 1) Attach the test belt 47', rotate the motor 45' while applying a load, stop when there is no backlash between the belt and the pulley, and set the value of the reversible counter 108 to zero.

10 Rotate the DN (48 pulley) twice in the same direction, then rotate it twice in the opposite direction, and read the value on the counter 108 after stopping.

111) Next, start from reverse rotation, rotate back and forth for 2 rotations, and read the value.

iv> DR (Measurement is carried out 10 times while changing the angle of the 46-pulley.

Then, the number of pulses read by the counter 108 in the forward direction and after the reverse rotation is converted into a displacement on the belt pitch line G (see FIG. 16), and the difference in both directions is calculated.

Perform this operation on both the brake shaft and motor shaft, and
In order to eliminate the influence of the deviation of the brake shaft 5' itself, the displacement of the motor shaft was subtracted from the displacement of the brake shaft, and this was taken as the position close to the stop position.

FIG. 25 shows the influence of drive speed on stop position accuracy. The test conditions at this time were as follows.

Belt size: B100MXL6.4 (DR
/N): P20/P60 initial tension crab 1.64f Load torque = 2Kgfcrn Rotation angle = DN pulley forward/reverse 720°, 1 s every 360°
EC stop As a result, there is almost no change (E' is not present) between 5 Orpm and 15 Orpm on the DN axis.Also, regarding the influence of acceleration/deceleration, the faster the acceleration/deceleration, the better the stopping accuracy.

FIG. 26 shows the influence of rotation angle on stop position accuracy.

The test conditions at this time were as follows.

Belt size: B100MXL6.4 pulley (DR/
DN): P20/P60 initial tension crab 1.6TCof Load torque: 2Kyfcm Number of drive pulses: 2200PPS (400P/R) Acceleration/deceleration: 30m s/100OPPS As a result, there is no additional effect.

FIG. 27 shows the influence of load torque and initial tension on stop position accuracy. The test conditions at this time were as follows: Belt size: B100MXL6.4 pulley (DR/
DN): P20/P60 drive pulse number: 2200P
PS (400P/R) Acceleration/deceleration: 30m s/100OPPS Rotation angle:
Stops every 720° and 360° in forward and reverse directions As a result, regarding the influence of load torque, first of all, the deviation is negative when there is no load, but this is due to the inertia force at the time of stopping, error in belt pulley PLI), etc. It can be considered as

Misalignment due to load can be divided into elastic elongation of the core wire and distortion of the belt teeth.

Further, regarding the initial tension, the allowable tension TaX of 0.67 to 1.6 Kff was set as the standard state for belt widths of 6.4 and above. This is a value that is generally used and is not particularly strong. In Figure 27, the initial tension is 0.8 Kq f
The results are shown when changing up to ~3.2 Ky f.

When the tension was increased to 3.2 Kyf, the misalignment was slightly improved, but the overtension was present and there seemed to be a problem with the belt life.

At 0.8 Ky f, the stopping accuracy deteriorated significantly. Although it is not necessary to increase the initial tension excessively, a certain amount of tension is required to maintain stopping accuracy.

FIG. 28 shows the influence of belt size on stop position accuracy. The test conditions at this time were as follows.

Pulley (DH/DN): P 20 / P a O cut-off crab 0. F3Kff (3.2ms width) 1.6Ky
f (6,4 yen width J 2.4 Kyf (9,5 yen width) Load torque: 2tf side drive pulse number: 2200PPS (400P;/R) Acceleration/deceleration: 30m s/100OPPS Rotation angle:
The DN pulley rotates forward and reverse, stopping once every 720° and 360°. As a result, the belt width is compared with a belt width of 3.2 ma + * 6.4 w - 9.5 m as shown in the figure. If the belt width is 3.2 mm, the load on the 2Kff11 saw will not be overloaded, and the deviation will be very large. 9.4 in 6
．． The deviation is reduced by 0.08 to 0.02 m compared to 4. Furthermore, when considering the elongation of the belt, the difference is approximately 0.
．． It becomes 01.

Regarding the belt length, the relationship between the number of belt teeth and the deviation of the stop position is shown in the figure. The difference in conditions can hardly be considered other than the span length, and is thought to be due to the elongation of the core wire.

The elongation of the core wire when the load torque is 2hf-0 is 0.325X1
0″3, the elongation of the belt for each length is as follows.

In reality, it is thought that the part meshing with the pulley will also expand and contract to some extent, so it is expected that the influence of the core wire will be a little more significant.

FIG. 29 shows the influence of pulley combinations on stopping position accuracy. The test conditions at this time were as shown below.

Belt size: B100MXL6.4 initial tension crab 1.6
Load torque: 2 pieces f-(7) Number of drive pulses: 2200PPS (400P/RJ Acceleration/deceleration: 30m s/100OPPS Rotation angle =
According to the test results, one crown is stopped every 720 degrees and 360 degrees in forward and reverse direction of the DN pulley.The larger the number of teeth on the DN pulley, the smaller the tension on the tooth belt, the smaller the deviation, but the difference is not that large. Even if the speed ratio is large, it can be said that the larger the DN pulley, the better the accuracy.

To summarize the above experimental results: (a) The angular accuracy exerted by the motor itself is small and stable at 0.02 or less.

(b) The slower the acceleration/deceleration, the more the phase will shift.

(e) If the tension is less than the standard tension, the amount of deviation will be considerably large.

(d) As long as the belt width is 6.4 or more, there is no difference. Furthermore, as the belt length increases, the amount of deviation increases.

(e) The elongation of the belt due to the load torque is the total amount of deviation (f
) It was found that the more teeth the driven pulley has, the smaller the amount of deviation.

In addition, in the present experimental results, the phase shift in forward and reverse directions is Δt
is about 0.1, but the variation δ is extremely small. Therefore, in the present invention, as described above, by electrically correcting in the forward and reverse directions, when the paper P as the transfer material is transported in the forward and reverse directions, This is to prevent positional shift in the image and obtain a clear image without image shift.

Although the paper feed cassette 17 is attached to and removed from the front side of the apparatus main body 1 and a portion thereof protrudes from the front side of the apparatus main body 1, the present invention is not limited to this. As shown in FIG. 30, the paper feed cassette 17 may be completely housed in the main body 1 of the apparatus, or as shown in FIG. It may be applied to anything that can be obtained, and it does not have to be a cassette type. In short, it goes without saying that the present invention may be applied to any image forming apparatus that forms a predetermined image by transferring the colorant of the transfer material to the transfer material.

In addition, it goes without saying that the present invention can be modified in various ways without departing from the gist of the invention.

In the description of the other embodiments (FIGS. 30 and 31), the same parts as in the embodiment described above are given the same reference numerals and detailed explanations will be omitted.

〔Effect of the invention〕

As explained above, according to the present invention, the deviation in the feed amount due to the forward and reverse rotation of the platen by the platen driving means that transmits power from the drive source to the platen through the toothed timing belt can be reduced. This is provided with a feeding amount correction means for correction.

Therefore, in a device in which a predetermined image is formed by reciprocating the transfer material as the platen rotates, it is possible to obtain a clear image without image shift due to shifting of the transfer material. This has the advantage that it is possible to provide an image forming apparatus that has the following characteristics.

[Brief explanation of the drawing]

1 to 14 show an embodiment of the present invention, in which FIG. 1 is an external perspective view of an image forming apparatus, FIG. 2 is a partially cutaway schematic perspective view, and FIG. is a schematic vertical side view, FIG. 4 is a perspective view for explaining the state of transfer MB production, FIG. 5 is a plan view showing the ink application state of the thermal transfer ribbon, and FIGS. An explanatory diagram explaining the movement of paper during transfer, Figure 7 is a block diagram showing the configuration of the main parts, Figure 8 is an enlarged sectional view of the transfer machine which is the main part, and Figure 9 shows the thermal head relative to the platen. Figure 10 is a perspective view showing the state in which the head holder with the thermal head attached is supported; Figure 1 is the arrangement of the drive systems for the platen, thermal transfer ribbon, and thermal head. FIG. 12 is a schematic side view showing the mechanism for moving the thermal head toward and away from the platen; FIG. 13 is a schematic perspective view showing the ribbon cassette installed; FIG. 15(a) and 15(b) are respectively explanatory diagrams of the configuration of the toothed belt, FIG. 16 is an explanatory diagram showing the meshing state of the toothed belt with the pulley, and FIG. 18 is a side sectional view schematically showing the structure of a DC brushless motor, and FIG. 18 is a plan view showing the structure of the rotor and stator of the motor.
Fig. 19 is a diagram showing the connection state of the windings of the above motor;
Figure 0 is a diagram showing the relationship between the rotor and stator to explain the operation of the motor, Figure 21 is a waveform diagram showing the Hall voltage of the Hall element, and Figure 22 is a diagram showing the rotation detection circuit and motor drive circuit. Fig. 23 is a timing chart to explain the operation of the rotation detection circuit, Fig. 24 is an explanatory diagram showing the experimental setup for phase shift in forward and reverse rotation of a toothed belt, and Fig. 25 is a timing chart for explaining the operation of the rotation detection circuit. An explanatory diagram showing the influence of speed on stopping position accuracy, Fig. 26 is an explanatory diagram showing the influence of rotation angle on stopping position accuracy, and Fig. 27 is an explanatory diagram showing the influence of load torque and initial tension on stopping position accuracy. Figure 28 is an explanatory diagram showing the influence of belt size on stopping position accuracy, Figure 29 is an explanatory diagram showing the influence of pulley combination on stopping position accuracy, and Figures 30 and 31 are illustrations to which the present invention is applied. OP...Transfer material (paper), 15...Transfer material (thermal transfer ribbon), 10...Platen, 11... Recording head (thermal head), 45... Drive source () (rus motor), 47... Toothed belt (timing belt), 1
00...Platen drive means, 101...Feeding amount correction means. Applicant's representative Patent attorney Takehiko Suzue Figure 1 22 Figure 2 Figure 4 Figure 5 A Figure 6 Figure 8 Figure 9 Figure 12 Figure 13 Prisoner 14 Plot Figure 15 (a) (b) Figure 16 Figure 23 Figure 1 Ding Todoroki 96 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 4 □ 5 salaries 1, 2-01 Patent Tt Commissioner Kazuo Wakasugi 1, Incident Indication of Japanese Patent Application No. 171533/1982 2. Name of the invention Image formation gtt 3. Relationship with the Ministry of the Ministry of Health and Welfare to make amendments to 411 cases. Patent applicant (3M) Tokyo Shibaura Electric Co., Ltd. 4. Agent procedure amendment document Showa 5α6.20 Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office, Patent Application No. 71533 No. 1988-1, Title of the invention, Image forming device 3, Person making the amendment, Relationship with the case Patent originator (307) Co., Ltd. Toshiba 4, Agent 5, Voluntary amendment 7, Contents of amendment +l+ From page 17, line 15 of the specification to page 24, line 1q, C, it is written as follows: ``Next, Figures 17 to 23
When ~ is shown with reference to the figure, it becomes as shown in Fig. 23. '' is corrected as shown below. Next, with reference to FIGS. 17 to 16, set platen 1.
The pulse motor 60, which is the drive source of the motor 0, will be explained. 17 and 18 show the structure of the pulse motor 45. FIG. That is, 81 is a cylindrical casing, and a plurality of stators 82 are installed along the inner wall of this casing 8.
．． ... are provided for each. This stator 82.
... are erected facing the center of the casing 8, and two stator windings 8 are provided for each stator 82.
3A and 83τ, 83B and 8300 (in the following explanation, they may be collectively displayed as stator winding 83)
are each wrapped. In the center of the casing 81, there is a shirt) 84 (
Two supported rotors 85 are provided. This rotor 85 has a magnet 8 magnetized in the axial direction as shown in the figure.
6 and the iron core 87 washed ashore on both ends of this magnet 86.
88°. The above iron core is 87.88. 8 by magnets 86, respectively. It is magnetized to the north pole. The stator 82 is placed on the surface of the iron core 87,88.
．． Grooves 90 of the same pitch are carved in the grooves 89 provided on the rotor 85 side of the iron cores 87 and 89.
0 is shifted by half a pitch. The operating principle of the stevening motor configured as described above will be explained. When a power supply is connected to the stator winding 83A (called PJ, lower single phase, and may also be written as CA phase, B phase, and π phase as shown in the symbols in FIG. 18), the upper and lower phases in FIG. The magnetic poles of the human face are both north poles, and the left and right magnetic poles of the human face are both 8 poles. Therefore, iron core 87. I
Magnetic repulsion and attraction force act on IB due to the human face and the magnet 86, causing the rotor 85 to rotate. Next, when the B phase is excited, the upper right B phase and lower left B phase in FIG. 18 become N poles, and the lower right and upper left B phases become S poles. This causes the rotor 85 to rotate further. Similarly, the rotor 85 rotates by exciting the human phase and the B phase. Note that the rotation pitch of the rotor 85 is 1/2 of the pitch of the grooves 89.9o. FIG. 19 shows a motor drive device that drives the above-mentioned Noculus motor 6Q. This motor drive device performs constant current drive using a constant current circuit using a chopper. Constant current drive is a drive method in which a voltage higher than the rated voltage of the Tanabata is applied and the current is controlled so that the current t1 does not exceed the rated current value of the motor. There is an advantage that you can get below,
The details will be explained, but to simplify the explanation, only an example in which the windings 83A and 8JA are driven will be explained. In the figure, 91 is an excitation power source, one end of which is grounded. Reference numeral 92 denotes a transistor for the arm that is controlled on and off by the arm amount control unit 93, the emitter of which is connected to the other end of the power supply 91, and the collector of which is connected to the winding 8 JA,
8. ? A is connected to a common connection point at each end of A. Reference numerals 94 and 95 indicate phase selection transistors which are controlled on and off by the phase switching control section 96, each of whose collectors are connected to the other ends of the windings 83A and 831%, and whose emitters are commonly connected. The common connection point 97 is grounded via a current detection resistor 98. Diodes 99 and 110 are connected in parallel to the winding 83 and 113k with the polarities shown, respectively. 111 is also a diode, connected to winding 83, 8
3 and ground with the polarity shown. 112 is a comparator, one input terminal of which is connected to the connection point 97.
The reference value is input to the other input terminal. In such a configuration, for example, when the human face is excited, the transistor 94 is on and the transistor 95 is off. A current flows through the winding 8 JA from a power source 91 through a transistor 92 as shown in 11. This current (1) is detected by a resistor 98 and compared with a reference value by a comparator 12, and when the winding current exceeds the reference value, the transistor 92 is turned off. At this time, since the winding 8JA has inductance, the current tends to continue to flow, and the current flows through the diode 11 like I2. Therefore, by repeatedly turning on and off the transistor 92 at a certain timing by the Chirotsuno 4 control unit 93, the winding current can be controlled to be approximately equal to the reference value. Next, when exciting the human face, transistor 94 is turned off and transistor 95 is turned on. At this time, the current continues to flow through the first winding 83A, so the current flows through the diode 99 as shown by Is. On the other hand, since the transistor 95 is turned on, a current tries to flow through the winding 83τ like I4, but since the windings 83 and 83 are inductively coupled to each other, the rise of the current , is affected by the rate of decrease in . That is, if the decrease in current I is gradual, the rise of current I4 is also gradual. Thereafter, as in the case of exciting the human phase, the current flowing through the winding 83'K is detected by the resistor 98+2, and the winding current is maintained at a constant level by turning on and off the transistor 92. The windings 83B and 83B can also be driven by a completely similar circuit. (2) “24th cause” on page 25, line 13 of the specification
Correct the statement to read "Figure 20." (3) In the first line of page 27 of the specification, "Figure 25" should be corrected to "Figure 21." (4) On the 13th line of the same page, replace “Figure 26” with “Figure 2.
Figure 4” is corrected. (7) On page 31, line 9 of the specification, "Figure 29" should be corrected to "Figure 25." (8) In the 12th line of page 33 of the specification, it says "@30 causes", it should be corrected to I[Figure 26]. (9) On the 14th line of the same page, it says ``27
"Fig." is corrected. 0I Page 34 of the specification, line 3 to line 4 C, rusao figure and l't31)''
(Figs. 26 and 27)”. αD From page 36, line 1 to line 20, 52 of the specification, Figure 17 shows the structure of the DC brushless morph.
Figures 30 and 31 indicate that the phrase ``the present invention'' has been replaced with ``the 17th factor''.
The figure is a longitudinal sectional view schematically showing the structure of a pulse motor.
Fig. 8 is a plan view showing the structure of the rotor and stator of the motor, Fig. 19 is a diagram showing the motor drive device of the motor, and Fig. 20 is a plan view showing the structure of the rotor and stator of the motor. Figure 21 is an explanatory diagram showing the influence of driving speed on stopping position accuracy, Figure 22 is an explanatory diagram showing the influence of rotation angle on stopping position accuracy, and Figure 23 is an explanatory diagram showing the experimental equipment.
The figure is an explanatory diagram showing the influence of load torque and initial tension on stopping position accuracy, Figure 24 is an explanatory diagram showing the influence of belt size on stopping position accuracy, and Figure 25 is an explanatory diagram showing the influence of pulley combination on stopping position accuracy. The explanatory diagrams illustrating the invention, FIGS. 26 and 27, are corrected to ``the present invention. Figures 17, 18, and 19 of the drawings are corrected as shown in the attached sheet. (2) Figures 20, 21, 22 and 2 of the drawings
Delete Figure 3/Q4 Correct the figure number as shown below and show it in the attached drawing without placing it. The text in Figure 24 has been corrected to read Figure 20. The text in Figure 25 has been corrected to read Figure 21. The text in Figure 26 has been corrected to read Figure 22. The text in Figure 27 has been corrected to read Figure 23. The text in Figure 28 has been corrected to read Figure 24. The text in Figure 29 has been corrected to read Figure 25. The text in Figure 30 has been corrected to read Figure 26. The text in Figure 31 has been corrected to read Figure 27. 1st Part I Figure @26i Figure ZS No.

Claims (4)

[Claims] (1) A transfer material is interposed between the platen and the recording head facing the platen, and the colorant of this transfer material is transferred to the transferred material to form an image.The transferred material is rotated by the platen. In an image forming apparatus that forms a predetermined image by reciprocating the platen, a platen driving means transmits power from a drive source to the platen;
An image forming apparatus comprising: a feed amount correction means for correcting a deviation in the feed amount due to forward and reverse rotation of the platen by the platen driving means. (2) The image forming apparatus according to claim 1, wherein the correction means is capable of adjusting the amount of correction thereof. (3) The image forming apparatus according to claim 1, wherein the drive source of the platen drive means is a pulse motor. (4) The image forming apparatus according to claim 1, wherein the platen driving means transmits power from a driving source to the platen.