JPS6149858A - Image former - Google Patents

Abstract

PURPOSE:To miniaturize an image former by providing a coil spring between the first presser to be coupled with the axial periphery of a thermal head drive shaft and the second presser fixed to the drive shaft. CONSTITUTION:When a thermal head is separated from a platen, an aperture (delta1) is present only on one side between the projection 128 of the first presser 123 and the groove 127 of a drive shaft 126. The length of the coil spring 132 becomes l1-natural length. When a motor 83 is driven and the drive shaft 126 is turned to the direction of arrow X, the first presser 123 is turned through the second presser 129 and the spring 132 and the thermal head is driven toward the direction of platen through a rod 75. The second presser 129 is further turned and the spring 132 is extended to a length (l2)<(l1). An aperture (delta2) is formed in the opposite direction of the aperture (delta1), and the thermal head is pressingly contacted with the platen. The coil spring can thus be made smaller to permit the miniaturization of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus that uses, for example, a thermal transfer gun as a transfer material.

[Technical background of [invention] and its problems]

In this type of image forming apparatus, transfer is performed with a thermal head pressing a thermal transfer ribbon against a sheet of paper, which is a transfer material, wrapped around a platen.

By the way, the thermal head is pressed against the platen by the urging force of a tension spring, but in the case of the conventional configuration, it is necessary to use a large bone to obtain the required pressing force, and the image forming apparatus There was a problem with miniaturization.

Further, after the thermal head is returned to its original position by the driving force of the motor, the spring is held in a stretched state for a length equal to the natural length of the spring.

Therefore, since a considerable force is constantly acting on the spring, the spring deteriorates quickly and has the disadvantage of shortening its lifespan. 7. The motor that returns the thermal head to its original position requires a large amount of energy because it must drive the thermal head against the urging force of a large spring.

[Purpose of the invention]

This invention has been made based on the above circumstances, and its purpose is to make it possible to reduce the size of the device, and to extend the life of the elastic member.
Furthermore, the present invention aims to provide an image forming apparatus that can be driven with less energy.

[Summary of the invention]

In this invention, a coil spring is interposed between a first holding member that can be engaged with the axial rotation of the drive shaft and a second holding member that is fixed to the drive shaft, and the coil spring is rotated together with the drive shaft. A biasing force is applied to the first presser member by the second presser member and the coil spring, and an appropriate pressure is applied to the thermal head via the first presser member.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 shows the external appearance of the image forming apparatus. An image information reading device 2 is detachably provided on the upper surface of the main body 1 of the apparatus. This image information reading device 2 has a document cover 3.
f): The cover 3 is provided so as to be openable and closable, and a document table (not shown) made of transparent glass on which a document is placed is provided below the cover 3 . This image information reading device 2 optically scans a document set on a document table by reciprocating a scanner section (details will be described later) consisting of an N-element optical system along the lower surface of the document table. This optical information is photoelectrically converted, and an operation channel 4 is provided on the top surface. The signal converted by this image information reading device 2 is supplied to an image forming section 5 which is detachably provided on the right side of the device main body 1, and in this image forming section 5, a transfer material is transferred according to the converted signal. An image is formed on the paper. At the front of the upper part of this image forming section 5 are four operation channels 6.
is provided.

This operation/mother panel 6 includes an online scanner key 7 for selecting the image information reading device 2 connected to the device main body 1.
, an eject key 9 that is operated when taking out the thermal transfer resin as a transfer agent (from a door 8 provided on the side), and a display 1
o is provided. Furthermore, a guide section 11 for manually feeding paper is provided on the front surface of the image forming section 5, and a paper discharge tray 12 is provided on the top surface to discharge the paper after the transfer. Furthermore, a paper feed cassette 13 for storing paper is provided in the main body 1 of the apparatus located below the image forming section 5 so as to be freely accessible and removable.

On the other hand, FIG. 6 shows the configuration of the image information reading device. Two light sources 23 are arranged in parallel on a carriage 22 constituting the scanner section 21, and two lenses 24 are arranged between the light sources 23 in an inverted V shape. A photoelectric converter 25 consisting of a color CCD is provided at the lower end of this lens 24. the carriage 22
One end is slidably inserted into the guide shaft 26, and is attached to a so-called timing belt (toothed belt) 27 stretched along the guide shaft 26. The timing belt 27 is driven by the pulse motor 28, and is stretched between the motor pulley P1 provided on the rotating shaft of the pulse motor 28 and the idle pulley 28. In response to the movement of the belt 27, the scanner section 21 moves in the direction shown by the arrow A,
It is moved in direction B.

Note that 29 is a converter that converts the output signal of the photoelectric converter 25 into a digital signal, and 30 is a converter that supplies the power output from the inverter 31 to the light source 23 and converts the output signal of the 0 converter 29 into the digital signal. This is a flat cable that supplies the image forming section 5.

FIG. 7 shows the operation panel 4 of the image information reading device 2. As shown in FIG. This operation panel 4 includes a print key 41 for instructing to start printing, and a numeric keypad 42 for specifying the number of prints.
, a clear/stop key 43 for canceling the number of prints or instructing to stop printing, a number display 44 for displaying the number of print sheets, etc., a halftone mode key 45 for specifying the halftone mode corresponding to full color and its density, single color or It consists of a binary mode key 46 for specifying a binary mode corresponding to seven colors and its density, a mode display 47 for displaying the set mode key, and a display 48 for making various displays. This indicator 48 includes a jam display section 480 that lights up when a paper jam occurs in the main body 1 of the apparatus, and various states such as a ribbon cassette installed in the main body 1 of the apparatus, such as no glue or a cassette itself installed. by operating the ribbon display section 482 that displays the loading status of the paper feed cassette 8 or the presence or absence of paper, the scanner display section 48m+48B that displays the operating status of the scanner section 11, and the mode keys 45 and 46. It consists of a density display section 486 that displays the set density.

Further, the image forming section 5 has a configuration as shown in FIG. That is, the platen 5o is located approximately at the center of the image forming section 5, and the platen 5o
A thermal head 51 serving as a recording head is arranged in front of the recording head 0 (leftward in the state of FIG. 8) so as to be movable toward and away from the platen 50.

Furthermore, to the above thermal yF'51 connection case) R
8, and a thermal transfer ribbon (ink ribbon) 52 is interposed between the thermal head 51 and the platen 50.

Then, the paper P with this thermal transfer resin 52 interposed
is pressed against the platen 50, and in this state, a T-shaped heating element (not shown) of the thermal head 51 generates heat according to the image information, thereby heating the ink on the den 52 for thermal transfer. It is designed to be melted and transferred onto paper P.

Further, a paper feed roller 53 is provided in the main body 1 of the apparatus diagonally below the platen 50, and is configured to sequentially take out the paper P as a transfer material stored in the paper feed cassette 13 one by one. The taken out paper P passes through a paper guide path 54 and is guided to a registration roller 55 disposed diagonally above the paper feed roller 53.

The tip alignment is performed by the -ra 55.

Thereafter, the pressing roller 56 is transferred toward the platen 5o.
．． 57, it is wound around the platen 5o and is accurately fed.

On the other hand, is the thermal head 51 thermal transfer? The paper P is pressed against the platen 50 via the ribbon 52, and as shown in FIG. 9, the ink 60 on the thermal transfer ribbon 52 is heated and melted and transferred onto the paper P.

Further, the thermal transfer ribbon 52 is yellow (A) and has a size approximately equal to that of the paper P, as shown by range A in FIG. 10, for example.
, magenta (c), cyan (6) ink portions 60h,
60b and 60o are provided side by side, or yellow (A) as shown by the range opening.

Magenta (B), cyan (O1 black (B)) ink portions 6
0*.

60b, 60c, and 60d are arranged side by side.1
After transferring the colors one by one, the paper P is returned to its original position and overlapped one after another accurately.

Further, each ink portion 6θa to 60tl is identified at the side edge portion corresponding to each ink portion 60° to 60d of the thermal transfer ribbon 52, and the leading edge of each ink portion 60a to 60d is controlled to match the leading edge of the paper. A necessary barcode BC is provided. This barcode BC is read by a barcode scanner (indicated by 78 in FIG. 12) which will be described later.

Incidentally, if the thermal transfer II &amp; Even if the ink does not have the black ink portion 60d, intertwining points can be created by overlapping the three colors.

In this way, the paper P is reciprocated by the number of colors by the rotation of the slaten 50, but the path of the paper P at this time is the first one, which is sequentially arranged along the lower surface of the paper output tray 12. It will be guided onto the second guide 61.62.

That is, the explanation will be made with reference to FIGS.

First, the paper P supplied from the paper feed cassette 13 passes through the registration roller 55 and the first sorting dart 63 arrangement portion, and is wound around the platen 50 . (11th
(See (A)) Next, the platen 50 is rotated using an unillustrated motor as a drive source to transport the paper P at a predetermined speed and to form a line tod shape along the axial direction of the platen 50. A heating element (not shown) of the thermal head 951 generates heat according to the image information, and the ink 60 of the thermal transfer ribbon 52 is transferred onto the paper P.

Furthermore, the leading edge of the paper P that has passed through the platen 50 is
The paper is sent onto a first guide 61 provided along the lower surface of the paper discharge tray 12 by a vibrator 64 . (11th
(See figure ←))・In this way, one color of ink 60
The paper P on which the image has been transferred is transported backwards by reversing the platen 50, and is moved by the rotational displacement operation of the first vibrating member 63 to a second guide 61 provided along the lower surface of the first guide 61. is sent on the id 62. (See FIG. 11(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 60 have been transferred is
The second vibrator 64 guides the paper to the paper discharge a-ra pair 65 and discharges it onto the paper discharge tray 12. (See FIG. 11)) In FIG. 8, roller pairs 66.61 are for conveying manually fed paper, and these roller pairs 66.6
The paper conveyed by the rollers 7 is guided to the registration rollers 55 via a guide path 68.

Next, the configuration of the image forming section 5 will be further explained. In FIGS. 12 to 14, the printer block 71 has a shape that is almost the same as the outer shape of the reden case (Rc), and this block 71 supports the thermal head 51 from the back side and also functions as a heat sink. A head holder 72 forming a fc-
)7 par 73, one end of which is attached to the head holder 72, and the other end of which is connected to a first pressing member 123, which will be described later. Pressing shaft 126. 1st. Coil spring 13 interposed between second holding members 123 and 129
2. A barcode detector 78 consisting of a light emitting element and a light receiving element is provided to detect a barcode printed on the thermal transfer (ink) ribbon 52.

The platen 50 is attached to a frame 79 attached to both sides of the printer block 71, and this frame 79 is provided with support shafts 80 and 81 for pressure rollers 56 and 57 that push the paper against the platen 50. It is being

The pressure rollers 56, 57 are driven by a solenoid (not shown). Also, a paper guide 82 is provided between the pressure roller 56 and the lever and balance 50.
is provided. Further, the frame 79 includes a motor 83 for driving the thermal head 51 as shown in FIG.
and a motor frame 84. A cam is provided on the rotating shaft (not shown) of the motor 83), and the lever 8 provided on the rotating shaft 76 is moved by this cam.
5 is rotated, and the thermal head 5 is driven against the biasing force of the coil spring 77. Also,
The motor frame 84 includes a platen drive motor 86,
Ribbon drive motors 89 and 90 are provided to drive cores ay and ss (shown in FIG. 12) of a thermal transfer (ink) ribbon 52 housed in a ribbon cassette ()Re. These motors 86, 89, and 90 drive the platen 50 and the winding cores 87 and 88 through gears (not shown).
As shown in FIG. 14, engaging protrusions 911 and 912 are provided at the rotation center of the gear that drives the winding core 87.8B. By controlling these motors 89 and 90, the thermal transfer roller 752 can run in both forward and reverse directions.

In addition, in the reden case, )Rc is the principal block 71.
It is said that it can be attached and detached from the That is, as shown in FIG. i5, the IJ & link cassette Rc has a holder 72,
In order to form a space 92 for accommodating the member 73 and the thermal head 51, the cross section is formed into a substantially U-shape. In addition, the core storage section 931 is included in the R8 cassette.

93, and the fitting portion 711 of the printer block 71 between
(shown in Figures 13 and 14) is fitted into the slit 9
33 is formed along the length direction. This +),
, 93B, and the fitting portion 711 are approximately equal in length, and this length t is set to be more than half the width of the thermal transfer IJ yyn 52. Therefore, by moving the resin cassette Rc with respect to the printer block 71 in its length direction, the resin cassette Rc can be attached to or removed from the printer block 71. Further, the side surfaces of the core storage portions 93 i and 932 are provided with engagement recesses 941*9'2 that are attached to the cores 87 and 88 stored inside.
The engaging recesses 941+942 and the engaging protrusions 91 in a state where the printer block 71 is attached to the engaging recesses 941+942.

912 are engaged with each other. When the thermal head 51 is driven in the direction of the platen 50 with the ribbon cassette Rc attached to the printer block 71,
The thermal transfer resin 52 is attached to the member 73 as shown in FIG.
It is brought into contact with the platen 56 by. This platen 5o
A sheet (not shown) is interposed between the thermal transfer ribbon 52 and the thermal transfer ribbon 52, and as the thermal head 51 generates heat according to image information, the ink on the thermal transfer ribbon 52 is heated and melted and transferred to the sheet.

FIG. 16 schematically shows the overall control system.

That is, the main control section 100 is mainly composed of, for example, a CPU (seven central processing unit) and its peripheral circuits, to which a pass line 101 is connected. This pass line 101 includes an operation panel 4 of the image information reading device 2, an operation/control circuit 6 of the image forming section 5, and a display control circuit 10 that controls these operation panels 4 and 6, respectively.
2, 10,? , storage unit 104, scanner control unit 105
, photoelectric conversion section 106, color conversion section 101.2 color separation section 10
&, conveyance control section 109, thermal head drive section 110,
A thermal head temperature control section 111 is connected to each of them.

The display control circuits 102 and 103 each operate in response to a signal sent from the main control section 100 via the pass line 101, and display the display 48 provided on the operation panel 4.
．． It controls 10. Further, signals from keys operated on the operation channels 4 and 6 are supplied to the main control section 10θ via the pass line 101, and control is performed in response to these signals. Furthermore, the storage unit 104 is connected to the main control unit 100.
It operates in response to signals sent from the path line 10 through the path line 101, and stores information sent through the path line 101, or reads stored information.

On the other hand, the scanner control section 105 operates in response to signals sent from the main control section 100 via the pass line 101, and controls the light source 23 and pulse motor 28 of the scanner section 21, and the photoelectric conversion section 106, respectively. . The photoelectric conversion unit 106 detects an image on a document according to a signal sent from the main control unit 100 via the pass line 101, and outputs a digitalized light color signal. The color conversion unit 107 is the photoelectric conversion unit 1
The color signal of the light output from 06 is yellow, magenta,
It is converted into color signals of cyan and black inks, and these color signals are output to the pass line. In addition, ゛color conversion section 1
07 also performs color conversion on the signal sent from the pass line 101, and cannot output a new signal to the pass line 101. 'The conveyance control section 109 operates in response to a signal sent from the main control section 100 via the pass line 101, and operates the motor g6 that drives the platen 50.
, motors 89 and 90 that drive the winding core IJ1.8g of the ribbon cassette R0, a paper feed roller 53, and a registration roller 5.
5, a motor that drives the paper ejection roller 65, etc., and a motor that drives the first. Second allocation c −F s s.

64 (none of which are shown). The thermal head drive section 110 is the main control section 100
It operates in response to signals sent from the thermal head via the pass line 101 and signals from the thermal head temperature control section 11 to drive and control the thermal elements of the thermal head 51. The thermal head temperature control section 111 is connected to the main control section 100
A temperature control signal is output to the thermal head drive section 110 in response to a signal sent from the thermal head drive section 110 via the pass line 101.

Next, the pressing mechanism of the thermal head, which is the main part of the present invention, will be further explained.

As shown in FIG. 1, a head holder (heat sink) 72
The opening and one end of the door 5, 75 are fixed to the opening. That is, as shown in FIG. 2, the back side of the head holder 72 has a mouth and a four part 72 into which one end of the door 5 is fitted! is provided, and with one end of the rod 975 fitted into this recess 721, the presser plate 12 fitted into the rod 75 is inserted into the screw 12.
2 to the head holder 72, and the opening and door 5 are attached. One end of a first holding member 123 is rotatably attached to the other end of the door 5 with a pin 124 . In the middle part of this presser member 123, as shown in FIG.
As shown in a), a through hole 125 is provided, and a drive shaft 126 is fitted into the through hole 125. This drive shaft 126 is provided with a groove 127 in the axial direction, and a protrusion 128 protruding from the inner surface of the through hole 125 is loosely fitted into this groove 127. A gap tl is formed around the axis between the groove 128 and the groove 127.

Further, a second press member 129 is provided adjacent to the first press member 123. This pressing member 129 is the fourth
As shown in the figure (&), a through hole 130 is provided at one end,
A protrusion 131 having the same shape as the groove 127 is formed on the inner surface of the through hole 130 . Therefore, in a state in which the drive shaft 126 is fitted into the through hole 13σ, the holding member 129 is fixed to the shaft turn.

Furthermore, the first. The other ends of the second holding members 123 and 129 are spaced apart from each other by a predetermined distance, and an elastic member such as a tension coil spring 132 is connected between these other ends.
is provided.

Further, a drive link 133 is provided at one end of the drive shaft 126.
The tip of a crankshaft 135 rotated by the motor 83 is fitted into the elongated hole 134 of the drive link 133 .

The operation in the above configuration will be explained. If the thermal head 51 is located further away from the platen 50, the first. Second
Pressing member 123. ．． 129 is shown in Figure 3 (a) and Figure 4 (
a) With the reed at the position shown by K, the coil spring 132 has a length of 2 ri. At this time, the coil spring 132 is tl −
Assume that it is stretched by its natural length. Therefore, a gap tl is created on only one side between the protrusion 128 of the first holding member 123 and the groove 121 of the drive shaft 126.

Next, when the motor 83 is driven and the drive shaft 126 is rotated in the direction of the arrow X shown in FIG.
, the Ml holding member 123 is rotated via the coil spring 132, and the thermal head 51 is accordingly driven in the direction of the platen 50 via the rod P75. Figure 3)
As shown in FIG. 4(b), after the thermal head 51 comes into contact with the platen 50, the second pressing member 129 is further rotated to extend the coil spring 132, and the biasing force of the coil spring 132 causes the thermal head 51 to contact the platen 50. The thermal head 51 is pressed against the platen 50. At this time, the length of the coil spring 132 is t (<tt), and there is a distance between the protrusion 128 of the first holding member 123 and the groove 127 of the drive shaft 126 in the direction opposite to δ1. A gap of <δ1) is generated.

When the thermal head 51 is moved away from the platen 50, the motor 83 is rotated in the opposite direction, and the drive shaft 126 is rotated in the direction of the arrow Y shown in FIG. Along with this, the thermal head 5 is driven via the first and second pressing members 123, 129, the coil spring 132, and the rod 75, as shown in FIG.
a), the state shown in FIG. 4(a) is restored.

According to the above embodiment, the coil spring 132 is interposed between the presser member 123 that can be engaged with the axial rotation of the drive shaft 126 and the presser member 129 that is fixed to the drive shaft 126. Thermal head 5
It puts pressure on 1. Therefore, the thermal spring 132 is smaller than that of the conventional one.

Since the card 51 can be driven, the image forming apparatus can be downsized.

Further, the coil spring 132 is activated when the thermal head 51 is pressed against the platen 50 or when the thermal head 51 is in pressure contact with the platen 50.
In the restored state, the length is only slightly longer than its natural length, so it has the advantage of less deterioration and a longer lifespan.

In general, the driving motor 83 requires a large force against the biasing force of the coil spring 132 only when the thermal head 51 is pressed against the platen 50, and at other times, it requires a large force to drive the thermal head 51 etc. It doesn't require that much force.

Therefore, there is an advantage that driving the motor 83 requires less energy than the conventional method.

〔Effect of the invention〕

As detailed above, according to the present invention, it is possible to reduce the size of the device, extend the life of the elastic member, and form an image that can be driven with less energy. equipment can be provided.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the image forming apparatus according to the present invention, and is a perspective view of the main parts showing the suppression mechanism of the thermal head, and FIG. 2 is an exploded view showing a part of FIG. 1. A perspective view, FIG. 3, and FIG. 4 are shown to explain the operation of FIG. 1, and FIG. 5 is a side view showing only the main parts, and FIG. 5 is a perspective view showing an overview of the image forming apparatus. , FIG. 6 is a perspective view showing the schematic configuration of the image information reading device, FIG. 7 is a plan view showing the configuration of the operation/gunnel, FIG. 8 is a side sectional view showing the configuration of the image forming section, and FIG. 9 10 is a perspective view shown to explain the transfer operation state, FIG. 10 is a plan view showing the ink application state of the thermal transfer gun, and FIGS. 12 to 14 show the main parts of the image forming section, and FIG. 12 is a side sectional view, FIG. 13 is a perspective view, and FIG.
Fig. 14 is a side sectional view showing the state in which the ribbon cassette is removed in Fig. 12, and Fig. 15 is a cross-sectional view showing the state in which the ribbon cassette is removed. FIG. 16 is a perspective view showing the structure of links 7 and 7, and FIG. 16 is a block diagram showing the structure of the control system. DESCRIPTION OF SYMBOLS 1... Apparatus body, 5... Image forming part, 51... Thermal head, 52... Thermal transfer IJ bomb, 72...
Holder, 75... Rod, 123, 129... First
．． Second holding member, 126... Drive shaft, 132...
coil spring. Applicant's agent Patent attorney Takehiko Suzue Figure 9 Figure 10 A Figure 11 Figure 11 Figure 12 Figure 356-1

Claims (3)

[Claims] (1) In an image forming apparatus that heats and melts the colorant of a transfer material using a thermal head and transfers it to a transfer material, a drive shaft that is rotatably driven and a drive shaft that is fitted around the drive shaft so that it can be engaged with the drive shaft. and a first link that interlocks the thermal head.
a presser member, a second presser member fixed to the drive shaft, and a second presser member interposed between the first and second presser members.
an elastic member that applies a biasing force to the first presser member as the presser member moves. (2) The drive shaft has a groove formed along its axis, and the first holding member has a protrusion that is loosely fitted into the groove. The image forming apparatus according to item 1. (3) The image forming apparatus according to claim 1, wherein the elastic member is a coil spring.