JPS60165278A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To eliminate the slackening of a transfer material completely by providing a driving means for driving winding cores with a braking means for selectively applying a braking force. CONSTITUTION:When stopping the winding of a heat transfer ribbon 15, an operation stop command is provided to an electromagnet 62 and driving circuits 68 and 70 of ribbon motors 51 and 51 to release the application of a voltage to the electromagnet 62. The driving of the ribbon motors 51 and 51 is stopped to halt the winding of the heat transfer ribbon 15. With the release of voltage applied to the electromagnet 62, a link 63 is pulled forward by the energized force of a spring 67 so that pads 66 and 66 presses against the outer surface of rotors 51a and 51a of the ribbon motors 51 and 51 to apply a driving force to winding cores 32 and 33 with a friction and lock it. The heat transfer ribbon 15 will not slacken even under an external vibration and even due to reaction to the tension of the heat transfer ribbon 15.

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 come into practical use not only for recording output from computers and word processors, but also as copying devices. It is being done.

Normally, this type of device forms an image on paper by bringing the thermal head into pressure contact with the platen through the transfer material and paper, but the outer edge of the transfer material is attached to a pair of cores. It is wound up each time a negative color is printed.

However, in the past, when the core was not driven, the core was in a free state, so if it was subjected to external vibrations, the core would move, and the tension of the transfer material would be reduced when the core was not driven. The repulsion causes the core to return, causing the transfer material to loosen, causing various problems when driving the next transfer material, and also making it troublesome to replace the transfer material.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to prevent the transfer material from becoming loose even when subjected to external vibrations or a single force of repulsion from the transfer material. The present invention is intended to provide an image forming apparatus that has the following features.

[Summary of the invention]

In order to achieve the above object, the present invention includes a braking means that selectively applies a braking force to the driving means that drives the winding core.

[Embodiments of the invention]

Hereinafter, the present invention will be described with reference to an embodiment shown in the drawings.

FIG. 1 shows the external appearance of the image forming apparatus, and FIG. 2 shows its schematic configuration. In FIG. 1 and FIG. 2, reference numeral 1 indicates 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.

The operation panel section 18 is provided with a copy number setting section 1 consisting of a display section 6 and a tincture pad, buttons 8, and the like.

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 then photoelectrically converted and input to the image forming section 5.

Further, the image forming section 5 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 6, and in front of the platen 10 (towards the left in the state of FIG. 3), a thermal head 11 as a recording head is located relative to the platen 10. 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 10.

Then, with this thermal transfer ribbon 15 interposed, the paper P
is pressed against the platen 10, and in this state, a line-shaped heating element (not shown) of the thermal head 11 generates heat according to the image information, so that the colorant (ink) on the thermal transfer ribbon 16 is pressed. is heated and melted and transferred onto the paper P.

Further, a paper feed roller 16 is provided diagonally below the plateage 10, and is configured to sequentially take out sheets P as transfer materials stored in the paper feed cassette 11 one by one. The leading edge of the taken out paper P is aligned by a registration roller 18 disposed diagonally above the paper feed roller 16, and then transported toward the platen 10 and wound around the platen 10 by pressing rollers 1e and go. It will be hung and sent accurately.

On the other hand, the thermal head 114i presses the paper P against the platen 10 via the thermal transfer ribbon 16 as a transfer material, and as shown in FIG. It is designed to be transferred to P.

The thermal transfer ribbon 15 has approximately the same size as the paper P, as shown by range A in FIG.
, JJC side by side or yellow (Y) as indicated by the range opening.

Magenta (M), cyan (C), black CB) ink sections 218, 21b, 21d are arranged side by side, and each color is transferred one by one and the paper P is returned to its original position to ensure accuracy. Layer them one after another.

A thermal transfer ribbon containing a black ink portion 21d is used when it is desired to produce a clear black color, and even a ribbon without a black ink portion JZd can produce a nearly perfect appearance 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 guides 23 and 24.

That is, the explanation will be made with reference to FIGS. 6(a) to 6).

First, the paper P supplied from the paper feed cassette 11 passes through the registration roller 18 and the first distribution guide 25 arrangement portion and becomes a sheet wrapped around the platen 10 . (See FIG. 6(a)) Then, 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 it into a line tod shape along the axial direction of the platen 10. The heating element of the thermal head 11 (
(not shown) generates heat according to the image information, and the thermal transfer ribbon 1
The ink 21 of No. 5 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 Figure 6 (4)) 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 rotational displacement movement of the first distribution guide 25 The paper P is sent onto the second guide 24 provided along the lower surface of the first guide 23. (See Figure 1g6 (c)) In this way, by reciprocating the paper P multiple times, multiple 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 the pair of paper discharge rollers 21 and discharged onto the paper discharge tray 22 . (See FIG. 6(B)) Furthermore, as shown in FIG. Memory section 131 image forming section 5. and an overall control section 14.

Then, the green (G) detected by the original scanning unit 4
), yellow (Y), and cyan (C), the color conversion unit 12 converts the values of the color components of magenta (
M), yellow (Y), and cyan (C), and the color-converted values are stored in the memory unit 1.3 for each color together with position information on the document. The image forming unit 5 uses the values read from the memory unit 13 to display magenta (M), yellow (Y), cyan (C), and black (B) [black is magenta (M), yellow (Y), and cyan (C)]. A of
ND output] print medium is transferred onto paper P. The overall control section 14 includes the document scanning section 4° color conversion section 12. Memory section 13. 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 2B and 24 are formed into a unit, and this unit can be removed as necessary.

Further, the thermal head 11 is attached to a head holder 31 which also serves as a heat sink and whose back is surrounded by a member 30 attached to a frame block 29, as shown in detail in Figure IIg. The thermal transfer ribbon 15 is wound at both ends and is assembled into a case 34 together with cores qt and ss to form a cassette, and the ribbon cassette 35 is detachably attached to the frame block 29. .

The frame block 29 is integrally formed by die-casting or plastic, and has a substantially U-shaped cross section to provide sufficient strength, and the U-shaped portion accommodates one of the winding cores of the ribbon cassette 85. By fitting the parts, the positioning accuracy of the ribbon cassette 35 is increased.

Further, as shown in FIG. 9, the head holder 31 to which the thermal head 27 is attached is configured to be able to move by a distance X in the direction toward and away from the platen 10. stop,
The configuration 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 r and to attach and detach the ribbon cassette ss. And it can be done reliably.

That is, as shown in FIG. 1O and FIG.
, ss are formed in the frame block 29 in the middle.

It is configured to be pivotally supported by a linear bearing embedded in 29b.

Further, the head holder 31 supported so as to be reciprocally movable in this manner has its movement towards and away from the platen 10 controlled by the head moving mechanism 40.

Further, the motor frame 41 to which the head motor 42 is attached is provided with a platen motor 45 consisting of a pulse motor as shown in FIG. The platen 10, which also serves as transfer material transfer means, is transferred in the forward or reverse direction via a power transmission mechanism consisting of a belt 41, a belt 41, and a pulley 48. Further, ribbon motors 51 and 51 each having a coupling 50 attached to a drive shaft are attached at positions corresponding to the cassette attachment portion 49 to which the ribbon cassette 35 is attached.

On the other hand, the driving force receiving ends 32a and ssa of the winding cores 32 and 33, around which both ends of the thermal transfer ribbon 15 housed in the ribbon cassette 35 are wound, are connected through through holes formed in the end surface of the case 34. It is exposed on the outer surface, and the tip has the 13th
As shown in the figure, the engagement recess 52. '5! has been formed.

The driving force receiving end portions 32a, 3 of the winding cores 32, 33
Engagement recesses 52, 51 of 3a! The above ribbon motor 6
The opening to which the couplings 50 of 1 and 51 are detachably connected also includes the ribbon motors 51 and 51.
Braking means 61 is provided near the rotors 5111, 5111. As shown in FIG. 11, this braking means 61 is equipped with an electromagnet 62, and a link 63 having a two-pole shape is connected to this electromagnet 62. this link 6
A long hole 64 is bored in the approximate center of 3 along its longitudinal direction, and a guide pin 65 is inserted into this long hole 64.

In addition, pads 6 formed of rubber or the like having a large coefficient of friction are provided at the branched ends of the ring 63.
6.66 are attached, and these pads 66.176 are connected to the rotor 5131. of the ribbon motor 51.51. It is designed to be brought into contact with and separated from the outer circumferential surface of jJa. Further, a spring 61 is connected to the center portion of the tip of the link 63 and biased in the direction of arrow a. Further, the electromagnet 62 is connected to a control circuit 69 via an electromagnet drive circuit 68,
The ribbon motor 51#61 is connected to a control circuit 69 via a ribbon motor drive circuit 10.

Thus, the thermal transfer ribbon 15 is wound up by the rotation of the winding cores 32 and 3B each time one color is printed, but at this time, the control circuit 69 controls the electromagnet 62 and the ribbon motor 51.
Each drive circuit of 51 - An operation command is given to 68 and 70, and voltage is applied to the electromagnet 62, and the ribbon motor 5
Drive 1°61. The link 68 is pulled in the direction of the arrow by the voltage applied by the electromagnet 62 against the biasing force of the spring 51. As a result, pad 66 of link 63 .
66 is the ribbon motor 51.51 rotor 51M, 57
separated from +1. In this separated state, the ribbon motors 51 and 51 are operated to rotate the winding cores 32 and 33, and the thermal transfer ribbon 15 is wound up.

On the other hand, when the winding of the thermal transfer ribbon 16 is stopped, the control circuit 6
9, the electromagnet 62 and the ribbon motor 51.51
A command to stop operation is given to each drive circuit 68.7o, the voltage application to the electromagnet 62 is released, and the drive of the ribbon motor 51.51 is stopped, and the thermal transfer ribbon 15 is stopped.
winding is stopped. At this time, as the voltage application to the electromagnet 62 is removed, the link 63 is pulled forward by the biasing force of the spring 67 as shown in FIG.
．． , 66 is the rotor 51m of the ribbon motor 51, 51
, 5111, and its frictional force applies braking force to the winding cores 32 and 33 to lock them.

In this way, after the winding of the thermal transfer ribbon 15 is stopped, the winding core s
Since it and ss are locked, the thermal transfer ribbon 15 will not loosen even if subjected to external vibrations, and will not loosen even if a reaction force of the tension of the thermal transfer ribbon 15 is received.

In addition, since the thermal transfer ribbon 15 can be stopped with a certain amount of tension applied to it, it is convenient for separating the paper P and the thermal transfer ribbon 15 during jam removal during operation, and also for attaching and detaching the ribbon cassette 14. becomes easier.

〔Effect of the invention〕

As described above, the present invention includes a braking means that selectively applies a braking force to the driving means for driving the core of the transfer material, so that the core can be kept in a locked state when the core is not driven. . Therefore, the transfer material does not loosen even when subjected to external vibrations or the reaction force of the tension of the transfer material, and when the next transfer material is driven, it can be wound up by a predetermined amount, making it possible to perform good transfer. This has the effect of making it easier to replace materials.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is an external perspective view of an image forming apparatus, FIG. 2 is a partially cutaway schematic perspective view, and FIG. 3 is a schematic longitudinal side view. , @Figure 4 is a perspective view to explain the transfer operation state, Figure 5 is a plan view showing the ink application status of the thermal transfer ribbon, and Figure 6) explains the movement of paper during multicolor transfer. Explanatory diagram, No. 7
The figure is a block diagram showing the configuration of the main parts, Fig. 8 is an enlarged sectional view of the transfer machine, which is the main part, and Fig. 9 is a perspective view showing the state where the thermal head and ribbon guide are separated from the platen. 11 is a configuration diagram showing the braking means and its drive system. FIG. 12 is a side view showing the arrangement of the braking means. FIG. 13 is a perspective view showing the control means and the ribbon cassette, and FIG. 14 is an explanatory diagram showing the operation of the braking means. P... Transfer material (paper), 15... Transfer material (thermal transfer ribbon), 10... Platen, 11... Recording head (thermal head), sx, ss... Core, 51. 5
1... Drive means (ribbon motor), 61... Braking means. Applicant's representative Patent attorney Takehiko Suzue Figure 1 7 Figure 2 Figure 4 Figure 5 I10 Figure 6 Figure 8 Figure 9 Figure 12 Figure 51a Figure 13

Claims (2)

[Claims] (1) In an image forming apparatus that forms an image by transferring a colorant of a transfer material to a transfer target material in a transfer section, a winding core around which an end of the transfer material is wound, and a driving means for driving this winding core. and a braking device that selectively applies a braking force to the driving device. (2) The image forming apparatus according to claim 1, wherein the braking means includes an electromagnet, and a braking force is applied by applying a voltage to the electromagnet.