JPS63270170A - Thermal transfer copying machine - Google Patents

Abstract

PURPOSE:To enable a copying to be conducted on a surface-untreated plain paper and to prevent the occurrence of wrinkles, by a method wherein a transfer roller is shaped in a barrel form by making the end parts smaller in diameter than the center part. CONSTITUTION:A thermosensible ink sheet 55 is guided to a heating element end face 51 of a thermal head 50 with a tension applied downwards by a weight shaft 56. The heating element end face 51 is pressed from upwards by a transfer roller 59 which is made of a rubber material and held by a roller frame 58 capable of rotatably opening/closing about a fulcrum 57. The transfer roller 59 has a barrel shape. By making the transfer roller 59 in a barrel form and pressing the ends thereof with a spring, the close contact between the transfer roller 59 and the heating element end face 51 is enhanced, and a uniform density can be obtained over the full width. Additionally, the barrel transfer roller 59 prevents wrinkles from easily occurring on the thermosensible ink sheet 55 and a copying paper 12.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention includes a thermal transfer type printing unit using an edge-type thermal head and a thermal ink sheet, and an image sensor unit that reads original images. The present invention relates to a thermal transfer copying device that copies images onto plain paper.

(Conventional Example) In recent years, various types of copying devices have been realized and become popular. In general, direct printing type copying machines that use surface-treated paper such as thermosensitive coloring paper, and electrostatic type electrophotographic copying machines that use plain paper are well known.

There are electrophotographic copying machines that make copies using plain paper without surface treatment, and mechanisms such as charging, exposure, development, transfer, and cleaning are arranged around a photoreceptor drum made of selenium, etc. After charging the surface of the rotating photoreceptor drum, the irradiated light image of the original is sequentially exposed to slits using optical means such as mirrors and lenses, and the latent image is developed with toner to form a visible image, and this toner image is The toner image is transferred onto plain paper that is fed synchronously, and the copy paper on which the toner image has been transferred is fixed under heat and pressure to obtain a copy.

(Problems to be Solved by the Invention) However, although the above-described direct printing type copying apparatus has a simple configuration and can be downsized, it cannot use plain paper.

Further, in an electrophotographic copying apparatus that can use plain paper, a certain amount of volume is required because the optical system such as mirrors and lenses is moved to perform slit exposure. For this reason, there is a limit to the reduction in size of the configuration, making it difficult to make the device more compact. moreover.

In order to heat and fix the toner image, it is necessary to provide a fixing device having a heat source of about IKW, which causes an increase in power consumption and an increase in the temperature inside the machine.

Therefore, it was necessary to provide a preheat control means to reduce power consumption and an exhaust fan to discharge the heated air to the outside of the machine.

Furthermore, since fine powder toner is used for development, the toner powder is scattered inside the machine, contaminating the interior of the machine, and having an adverse effect on copied images. Therefore, in order to obtain stable copies of high quality, various problems have occurred, such as the need for maintenance work to periodically clean the scattered toner powder.

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a thermal transfer copying apparatus that is compact, lightweight, and does not require maintenance as in conventional apparatuses.

(Means for Solving the Problems) In order to solve the above problems, the thermal transfer copying apparatus of the present invention includes a thermal head, a supply shaft and a take-up shaft disposed on both sides of the thermal head. The printing device is equipped with a printing means consisting of a thermal ink sheet supplied by the thermal ink sheet and a transfer roller in pressure contact with the thermal head, and the transfer roller is a cylindrical roller having a diameter smaller at both ends than a diameter at the center. It is prepared.

(Function) According to the present invention, with the above-described configuration, a document image read by an image sensor is printed by a thermal head via a heat-sensitive ink sheet, and is copied onto plain paper without surface treatment. can.

In addition, because the transfer roller is in a cylindrical shape, when the heat-sensitive ink sheet is pressed against the thermal head,
It acts to stretch outward from the center to both ends, thereby preventing wrinkles from forming.

(Example) An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a thermal transfer copying apparatus according to an embodiment of the present invention. In FIG. 1, there is a document platen glass 2 on the front side of the main body 1 on which an original to be copied is placed, and an M document 3 placed on top of this is pressed down so that it comes into close contact with the document platen glass 2. A base cover 4 is supported so as to be openable and closable using a back side 5 as a fulcrum. The document table glass 2 is arranged so that it is horizontally long when viewed from the front so that an A4 size document can be placed horizontally.1 On the rear side of the main body 1 is a print section for copying images onto copy paper. 10 are provided.

The print section 10 is first provided with a copy paper insertion slot 11 for inserting copy paper.
Insert one end of 2. The inserted copy paper 12 is held leaning against the guide lid 13 so that it does not fall down and come out from the insertion slot 11. Guide lid 1
3 is supported by a hinge at the innermost position of the main body 1,
It can be opened and closed.

The guide lid 13 can be closed when the main body 1 is not used to cover the copy paper insertion slot 11 and the like.

In front of the copy paper insertion [] 11 is the copy paper output port 1.
As shown in FIG.
The copy paper 12 can be used up to the maximum size of A4,
The paper of the same size is fed in the longitudinal direction, and comes out from the copy paper outlet 14 after being copied in the "Y" direction. The copy paper 12 that comes out of the copy paper outlet 14 is printed and discharged in such a direction that the printed copy image can be seen when viewed from the front side, and if the copy paper is paper with low rigidity, It is designed to fall down toward the copy paper insertion slot 11 side. Therefore, the person making the copy can perform the copying operation while always checking the printed surface from the front side.

In this embodiment, the left front end 20 of the 1MMB2 original table glass 2
The copy paper 12 is set so as to match the right edge 21 of the copy paper insertion slot 11.

When copying onto paper having a width narrower than A4 size, a copy paper guide 22 slidably provided in the copy paper insertion slot 11 is slid to match the width of the copy paper.

A start button 23 is provided on the top surface of the main body 1, and a power switch 24 is provided on the left side of the main body.

FIG. 2 is a cross-sectional view of an image sensor unit provided under the 1 m plate glass 2. FIG.

In the image sensor unit 30, a sensor main body 33 is placed on a sensor base 32 which is slidably guided by a guide shaft 31 fixed to the main body 1.

The sensor body 33 includes an illumination LE for illuminating the original.
A D array 34, a light converging fiber lens 35 for forming and projecting an optical image of the original at the same magnification, and a contact type image sensor 36 provided on the imaging plane of the original image are attached.

If the positional relationship between the document 3 placed on the document platen glass 2 and the contact image sensor 36 is not set correctly, the optical image projected onto the contact image sensor 36 will be out of focus, resulting in a contact image. An appropriate output signal will not be obtained from the sensor 36.

In this embodiment, in order to accurately determine the distance between the document surface and the contact image sensor 36, rollers 37 are provided at the front and back ends of the sensor body 33, and the rollers 37 are connected to the sensor base 33. The sensor body 33 is pushed upward by a compression spring 38 provided between the sensor body 33 and the sensor body 33 so as to come into contact with the lower surface of the document table glass 2 and slide while rotating. Therefore, if the thickness of the original platen glass 2 is kept constant, the copy surface of the original placed on the original platen glass 2 and the contact image sensor 36 can always be kept constant.

FIG. 3 is a perspective view showing a method of driving the image sensor unit. A guide shaft 31 is fixed along the longitudinal direction of the 6m platen glass 2, and the image sensor unit 30 is guided by the guide shaft 31. The belt 40 is stretched between the left and right ends of the main body 1, and rotates by the rotation of the pulse motor 42. Driven. The image sensor unit 30 is driven by a pulse motor 42 and reciprocates between an IjK point switch 43 and an end point switch 44. Power supply to the LED array 34 of the image sensor unit 30 or the image sensor 36
The output from is connected to the main body side by a flat line 39.

As shown in FIG. 4, the end face type thermal head 50 is mounted substantially upward from the bottom of the substrate of the main body 1.

Thermal heads have traditionally been used in thermal recording type facsimile machines, electronic typewriters, word processors, computer printers, etc. due to their characteristics of being maintenance-free, noiseless, and inexpensive. This is called a flat type, with a printed circuit board on one side of a flat board.

The circuit element is an array of fine heating elements, for example 8 dots per meter, arranged in a row, and although it has the advantage of being easy to manufacture due to its flat layout, the area occupied by the thermal head is large. This was not desirable in terms of making the device more compact.

On the other hand, the thermal head 50 used in this embodiment is of the so-called end-face type, and as shown in FIG.
A glass glaze layer is formed on the glass glaze layer 2, and a heating resistor film is formed on the glass glaze layer on the end face 51, and the heating resistor film is connected to the circuit element 60 on the side surface through an electrode film. .

In this embodiment, only one heating element is formed on the end face 51.

It is composed of heating elements divided into 8 dots per 1 mm over 210 nwm IRX of A4 size. However, it is not necessarily necessary to have the same length as the width of the paper surface, but it is sufficient that the length dimension is the same as the image forming dimension of the paper surface.The surface of the heating element is protected by a wear-resistant protective film. The edge-type thermal head has a convex heating element surface and has the following characteristics: good thermal transfer characteristics, good linearity of the heating element forming surface, uniform print density, and compact head. have. As shown in FIG. 4, a supply shaft 53 and a winding shaft 54 for the thermal ink sheet are arranged on both sides of the end-face type thermal head. A thermal ink sheet 55 is wound around the supply shaft 53 with the thermal ink surface facing outward, and the thermal ink sheet 55 is placed under tension with a metal weight shaft 56 when it is placed in the thermal head. 50 is guided to the end face 51 of the heating element. As shown in FIG.
It is pressed by a transfer roller 59 made of a rubber material and held by a roller frame 58 that can be opened and closed with the center of rotation at . The transfer roller 59 has a length of 220 cm.
, the diameter of its central part is 20m5, and each end is 0.15m smaller in diameter. Diameter 2
0m is the range of 70m at the center, and from that position to the 19.85mm diameter portions at both ends is a linear tapered finish. In this way, the transfer roller 59 is shaped like a cone,
By pressing both ends with a spring of about 1.2 kg on each side, the adhesion between the transfer roller 59 and the end surface 51 of the heating element is improved, and uniform density can be obtained over the entire width.

Further, the cylindrical transfer roller 59 also serves to prevent wrinkles that tend to occur on the thermal ink sheet 55 and the copy paper 12.

Note that the shape of the cylindrical transfer roller is such that its tapered portions are connected by straight lines, but in this example, connecting them with straight lines was more effective against wrinkles than connecting them with curves.

Immediately to the left of the contact surface of the transfer roller 59 on the end face 51 of the heating element, a blade 61 made of a plastic material is fixed, the details of which are shown in FIG.

The heat-sensitive ink sheet 55 that has passed through the heating element end face 51 is wound up on the winding shaft 54 so that the heat-sensitive ink surface is on the inside. As shown in No. 64, the edge 62 of the blade 61 is in the tangential direction of the transfer roller 59 which is in pressure contact with the end face 51 of the first heating element, and is about 7 m away from the contact position on the downstream side in the copy paper feeding direction. Therefore, the copy paper 12 is fed into the gap between the transfer roller 59 and the thermal ink sheet 55, is pressed and heated by the transfer roller 59 and the thermal head 50, and the ink is transferred to the copy paper 12 until it reaches the edge 62. During this period, the copy paper 12 and the thermal ink sheet 55 are fed in close contact for a certain period of time, and then the thermal ink sheet 55 suddenly changes its direction downward at the edge 62, and the copy paper 12 continues straight.

The angle of the edge 62 of the blade 61 is smaller than 90''' so that the downward direction change toward the thermal ink sheet 55 is rapid.

The thermal ink sheet 55 is then wound around the winding shaft 54 at an angle θ with respect to the feeding direction.

If the angle θ is 30° or more, it will work on separating the copy paper 12, but it is preferably between 60° and 90°.

It should be noted that if the angle is 90° or more, a better separation effect will be produced, but the manner in which the thermal head 50 is arranged will change.

The thermal head 50 transfers the ink to the copy paper 12.
The ink transferred to the copy paper 12 is heated by the heat-sensitive ink sheet 12 and separated after a certain period of time has passed, and the ink transferred to the copy paper 12 cools down and is sufficiently adsorbed to the copy paper surface before being peeled off. Never take sides,
This results in good transfer.

Furthermore, the position of the edge 62 where the thermal ink sheet 55 and the copy paper 12 separate is in the tangential direction of the transfer roller 59, and while the copy paper 12 tends to move straight due to its rigidity, the thermal ink sheet 55 haetsuji 6
As a result of the sudden direction change in part 2, the copy paper 12
and the heat-sensitive ink sheet 55 are well separated. The heat-sensitive ink sheet supply shaft 53 and take-up shaft 54 are held in a casing 70, as shown in FIGS. 4 and 5.

The ink sheet cartridge 71 has a casing 70. Supply shaft 532, winding shaft 54, weight shaft 56. The ink sheet cartridge 71 consists of a heat-sensitive ink sheet 55, and is loaded into the thermal head 50 from above when copying is used.The casing 70 of the ink sheet cartridge 71 has a casing 70 that allows the thermal head 50 to be inserted into the bottom surface of the casing 70 of the ink sheet cartridge 71. The open lower 2 and the thermal head 5 on the top.
The opening lower 3 is provided so that the upper surface of the end surface 51 of the heating element 0 can protrude slightly. Felt is used as a bearing for the supply shaft 53, and this felt is fixed to the casing 70, and the frictional resistance generated when the supply shaft 53 rotates causes a backlash when the thermal ink sheet 55 is wound around the winding shaft 54. It works to give tension. Similarly, the weight shaft 56 also serves to absorb torque fluctuations when the thermal ink sheet 55 is wound up, and also serves to provide back tension.

The upper surface 83, 84 of the casing 70 of the ink sheet cartridge 71 is attached to the copy paper 12 as shown in No. 61A.
It also serves as a guide surface. The upper surface 83 on the entrance side is set at such a height that when the copy paper 12 is inserted, its leading edge is just guided into the nip formed by the transfer roller 59 and the heating element end surface 51 of the thermal head 50. The upper surface 84 on the exit side is attached to the edge 6 of the blade 61 after the ink has been transferred.
When the thermal ink sheet 55 is separated at 2 and the copy paper 12 advances straight, a guide surface is formed to prevent the leading edge of the copy paper from falling down due to being pulled by the heat sensitive ink sheet 55. The top surface 84 guides the leading edge of the copy paper 12 and guides it to the copy paper ejection port 14.The reason why the step 85 is provided in the middle of the top surface 84 is that when the previous copy operation is completed and the next copy is made as is, It is provided to function so that the previous copy paper is pushed by the leading edge of the previous copy paper, falls into this step 85, and is held. The winding shaft 54 of the thermal ink sheet and the transfer roller 59 are driven by the same pulse motor (not shown). The driving force of the pulse motor is transmitted to the transfer roller 59 via a gear train for deceleration, whereas the driving force to the winding shaft 54 is transmitted by a slip mechanism made of felt and a spring provided in the middle. A thermal ink sheet 55 is wound around a winding shaft 54.
Even if the thickness of the heat-sensitive ink sheet 55 changes and the diameter increases, a constant amount of the thermal ink sheet 55 sent at the peripheral speed of the transfer roller 59 is always wound up reliably.

When the same number of pulses are applied to the pulse motor for driving the transfer roller 59 and the pulse motor 42 for driving the image sensor unit 30, the transfer amount of the copy paper 12 sent by the transfer roller 59 and the image sensor unit 3
The reduction ratio is set so that the amount of movement of 0 is equal.

Black is usually used for general copying,
In this embodiment as well, the heat-sensitive ink sheet 55 is coated with black ink, but the color is not limited to black.
A variety of thermal ink sheets can be used, such as red, blue, green, yellow, cyan, magenta, brown, gold, silver, etc. To replace the heat-sensitive ink sheet 55, the roller frame 58 is opened upward and the ink sheet cartridge 71 is installed and removed (FIG. 5).

Next, a procedure for actually performing copying according to this embodiment will be explained. First, after confirming that the ink sheet cartridge 71 is correctly set, the power switch 24 is turned on. yXX Open the cover 4 and set the original 3 to be copied face down on the original glass 2.

Insert the copy paper 12 from the copy paper insertion slot 11.

Adjust the copy paper guide 22 according to the width of the copy paper 12. When the copy paper 12 is inserted into the copy paper insertion slot 11 and the leading edge of the copy paper 12 reaches the nip between the transfer roller 59 and the thermal ink sheet 55 covering the heating element end surface 51 of the thermal head 50, the paper sensor 7
5 is turned ON, and the state becomes ready for copying.

When the copy start button 23 is pressed in this state, the pulse motor 42 and the pulse motor for driving the transfer roller 59 start rotating, the image sensor unit 30 starts scanning the document 3, the transfer roller 59 starts rotating, and the copy paper 12 When the ink sheet 55 is sent, the heating element of the thermal head 50 is heated according to the image of the document 3, and the thermal ink sheet 55 is heated.
In this embodiment, the copy paper guide 22 is adjusted to match the width of the copy paper 12.
This adjustment mechanism will be explained.

As the copy paper guide 22 slides, the movement of the copy paper guide 22 is transmitted to the slide volume via a speed reduction mechanism including a rack and gears.

The resistance value of this slide volume is electrically detected and
Depending on the value and the dimensions of the copy paper guide 22, a non-printing portion 81 of about 5 m on both ends in the width direction is created. Although it is possible to continuously change the print width according to the value of the slide volume, in this embodiment, it is possible to change the printing width to the generally used paper size A4. B5. A5. B6
The width changes step by step. However, it is not limited to this.

The leading edge of the copy paper 12 and the copy paper guide 22 correspond to the set paper width, as shown in FIG.

A non-printed portion 80.81 of about 5 mm is formed in each case. Since printing is stopped when the trailing edge of the copy paper 12 passes the paper sensor 75, there is also a portion 82 at the trailing edge of the copy paper 12 where no printing is done.

The non-printing portion 80 at the leading edge of the copy paper 12 has a great effect in ensuring that the copy paper 12 and the thermal ink sheet 55 are separated when they begin to separate at the edge 62. The non-printed areas 81 on both sides of the copy paper 12 are
is wider than the copy paper 12, the copy paper 12
This prevents unnecessary ink from being transferred to the transfer roller 59 due to heat being applied to the thermal head 50 up to the portion where there is no .

When the image sensor unit 30 reaches the end point switch 44, it begins to return. However, the transfer roller 59 continues to rotate as long as the paper sensor 75 detects the presence of paper. Therefore, even if an extremely long copy paper arrives and the scan of the image sensor unit 30 is finished, the copy paper 12 continues to be fed, so that no paper jam occurs.

Also, when copy paper that is short in length arrives, the paper sensor 75 detects the end of the paper, and after a while the transfer roller 5
Since the rotation of 9 is stopped, there is no need to use too much extra heat-sensitive ink sheet.

The image sensor unit 30 returns to the same starting position as before the start of scanning and stops.

In this embodiment, when the copy paper is set in the copy paper insertion slot 11 again during the return operation until the image sensor unit 30 returns to the start position, the image sensor unit 30 automatically returns to the start position and the next copy is automatically inserted. This is useful when making multiple copies in succession.

(Effect of the invention) The present invention has the following excellent effects.

(1) The original image read by the image sensor is printed by a thermal head via a heat-sensitive ink sheet, and can be copied onto plain paper without surface treatment.

(2) Since the transfer roller is in a cylindrical shape, when the heat-sensitive ink sheet is pressed against the thermal head,
The material is stretched outward from the center to both ends, thereby preventing wrinkles from forming.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a thermal transfer copying apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view of an image sensor unit of the present invention.
FIG. 3 is a perspective view of the image sensor unit of the present invention, FIG. 4 is a cross-sectional view of the main part of the print section of the present invention, and FIG. A sectional view of the main parts showing where the
FIG. 6 is a cross-sectional view showing details of the thermal head of the printing section of the present invention, and FIG. 7 is a plan view of a copy sheet for explaining the present invention in detail. 1...Main body, 2...Original table glass, 3...Original, lO...Print section, 11...Copy paper insertion slot, 12...Copy paper, 14...Copy paper output Exit°, 22... Copy paper guide, 30.
...Image sensor unit, 33...Sensor body, 34...LED array, 35...Light convergence fiber lens, 36...Image sensor, 37...
... Roller, 38 ... Spring, 50 ... Thermal head, 53 ... Supply shaft, 54 ... Winding shaft,
55...Thermal ink sheet, 56...Weight shaft,
59...Transfer roller, 61...Blade, 7
1... Ink sheet cartridge, 72, 73...
Opening, 83.84...Top surface. Fig. 1 1°° Book 2... Manuscript stand p.
Input 3... Hara Yang 4... Hara S@Kade- 5... Raw yarn 1 right cover 4 English and Italian 3 1 Kano pudding 1,4 = p11... Copy Tsukigoe J-Entrance
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Hanawadai Rikiku 2ri L ke Zetsubo 21...Kor-Gumi resistance entrance 11 verses 1...copy)! 1 power 4 de
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3... ,l,% 35...Yp
Anti-Ulk firer (-Rence 030...4 mage 7 unit 36...4 mage 7 nina 31...
Force-id shaft 37...Roller 32...One stroke to the sensor
X・t。 33... Zemp tree 4+ Figure 4 1... 444 u... Coffee paper input port 12... Copy"-1'F1 paper
14°°゛ Copy 1 punishment place name υ 15° Baka゛ 4 card board
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・Tank supply Nu... Inf sheet with width axis 55-II 56... 8 Morphing shaft 57... Support, 1 58°°° Roller frame ・ Trochanter roller τ... Casing 75
・Paper paper, tump Figure 5 ll111 14...Copy-7Fl ground fog opening 15...Force °4 armpit 50...Thermal head 51.
・Heat selling rod 53... Portable axis Nu゛° port delivery 5 axis 55... Anxious 4-ink sheet 5
6°° 8 key 57...good book
Leap °・υ-ra frame 59...study 50-ra
70...Kaenging. 71...
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Claims (2)

[Claims] (1) A printing means comprising a thermal head, a thermal ink sheet supplied by a supply shaft and a take-up shaft disposed on both sides of the thermal head, and a transfer roller in pressure contact with the thermal head; A thermal transfer copying device characterized in that the transfer roller is a cylindrical roller having a diameter smaller at both ends than a diameter at the center. (2) A thermal transfer copying apparatus according to claim (1), characterized in that a back tension due to frictional force is added to the supply shaft that supplies the thermal ink sheet.