JPS63272159A - Thermosensitive transfer copying device - Google Patents

Abstract

PURPOSE:To obtain copies of high image quality by pressing and sliding a sensor body to and on the surface of an original platen glass by an elastic member to fix the distance between an image sensor and the surface of the original platen glass in the case of scanning of the sensor body on the lower face of the original platen glass on which an original is placed. CONSTITUTION:Rolls 37 are provided in the front of a sensor body 33 and in the end part of the depth for the purpose of keeping a distance between the surface of the original and a contact image sensor 36 and are pushed up by compression springs 38 provided between a sensor base 32 and the sensor body 33 and are slided on an original platen glass 2 while contacting with the lower face of the original platen glass 2 and rotating. Consequently, the distance between the copy surface of the original placed on the original platen glass 2 and the contact image sensor 36 is always kept constant if the thickness of the original platen glass 2 is uniform. Thus, the focus position is always fixed to obtain copies of high image quality.

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.

An electrophotographic copying machine is a device that uses plain paper without surface treatment to make copies.

Mechanisms such as charging, exposure, development, transfer, and cleaning are arranged around the photoreceptor drum such as selenium, and after charging the rotating photoreceptor drum surface, the irradiated light image of the paper is transferred to an optical system consisting of mirrors, lenses, etc. The latent image exposed to slits is developed into a visible image using toner, and this toner image is transferred to plain paper that is fed synchronously, and the copy paper on which the toner image has been transferred is heated. Copies are obtained by pressure fixing.

(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 optical systems such as mirrors and lenses are moved to perform 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. Furthermore, 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 internal temperature of 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-mentioned problems, the thermal transfer copying apparatus of the present invention includes a printing means consisting of a thermal head and a thermal ink sheet, and a printing device that scans an original to be copied to produce an image of the original. Image sensor for reading, light source for illumination.

and a sensor body integrally configured with a light converging fiber lens, and when the sensor body scans the lower surface of the document table glass on which a document is placed, the distance between the image sensor and the document table glass surface is determined. In order to maintain the sensor body constant, the sensor body is pressed and slid against the glass surface of the document table using an elastic member.

(Function) According to the above-mentioned structure, the present invention allows a document image read by an image sensor to be printed by a thermal head via a heat-sensitive ink sheet, and printed on plain paper without surface treatment. Can be copied.

Furthermore, since the distance to the hN surface image sensor can be maintained constant at all times, the focal position is always constant and copies with high image quality can be obtained.

(Example) Hereinafter, an example of the present invention will be described 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 a document to be copied is placed, and a document table is used to press the document 3 placed on top of the document table glass 2 so as to make it come into close contact with the document platen glass 2. A cover 4 is supported so as to be openable and closable using a back side 5 as a fulcrum. The document platen glass 2 is arranged to be horizontally long when viewed from the front so that an A4 size document can be placed horizontally. A print section 10 for copying images onto copy paper is provided on the rear side of the main body 1.

First, a copy paper insertion slot 11 for inserting copy paper is opened in the print section IO.
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 M1
3 is supported by a hinge at the innermost position of the main body 1,
It can be opened and closed.

The guide M13 can be closed to cover the copy paper insertion slot 11 and the like when the main body 1 is not used.

A copy paper output port 14 is located in front of the copy paper insertion port 11.
The guide plate 15 that forms the opening is provided with an opening of
As shown in FIG.
'It is tilted as if it were changed more than that. Copy paper 1
2 can use up to the maximum size of A4 size paper, and the A4 size paper is fed in the longitudinal direction, and is copied upward from the copy paper outlet 14 and comes out. Copy paper 12 coming out from copy paper outlet 14
The copy paper is printed and ejected in such a way that the printed copy image can be seen when viewed from the front side, and if the copy paper is made of paper with low rigidity, it will fall toward the copy paper insertion slot ll side. There is. 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 original 3 is placed at the left front end 20 of the original platen 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 document table glass 2. As shown in 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 document 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 is moved left and right by the fixed end 41 being pulled by the bell 1-40 while sliding on the lower surface of the document table glass 2 by the roller 37. Driven by rotation. Image sensor unit 3
0 is driven by a Norse motor 42 and reciprocates between an origin switch 43 and an end point switch 44. The power supply to the LED array 34 of the image sensor unit 30 or the output from the image sensor 36 is connected to the flat wire 3.
9 is used to communicate with the main unit.

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 features such as being maintenance-free, noiseless, and inexpensive.However, the thermal heads traditionally used are flat type. This is called a printed circuit board on one side of a flat board.

Each circuit element, lna, has a heating element section in which fine heating elements of, for example, 8 dots are 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 end face 51, 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, the heating element formed on the end face 51 is composed of heating elements divided into 8 dots per 1 m over the 210+@ width 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 heat-sensitive ink sheet supply shaft 53 and a winding shaft 54 are arranged on both sides of the end-face type thermal head. A heat-sensitive ink sheet 55 is attached to the supply shaft 53.
is rolled up with its heat-sensitive ink surface facing outward, and this heat-sensitive ink sheet 55 is guided to the heating element end face 51 of the thermal head 50 while being under tension downward with a metal weight shaft 56. ing. As shown in Figure 5,
The heating element end surface 51 is pressed from above by a transfer roller 59 made of a rubber material and held by a roller frame 58 that can be opened and closed about a fulcrum 57.

The transfer roller 59 has a length of 220 m, a diameter of 201 mm at the center, and a cylindrical shape with a smaller diameter of 0.15 mm at both ends. A diameter of 20mm is a range of 70mm at the center, and a diameter of 19.85mm at both ends from that point.
The mm part is a linear tapered finish.

By making the transfer roller 59 into a cone shape and pressing both ends with springs weighing 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. It will be done.

Further, this turret-shaped transfer roller 59 also serves to prevent wrinkles that tend to occur in the thermal ink sheets 1 to 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 FIG. 6, the edge 62 of the blade 61
is in the tangential direction of the transfer roller 59 that is in pressure contact with the end surface 51 of the heating element, and is approximately 7 mm 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 1-55 are fed in close contact for a certain period of time, and then the thermal ink sheet 1-55 suddenly changes its direction downward at the edge 62, and the copy paper 12 continues straight. Become. The angle of the edge 62 of the blade 61 is less than 90 degrees so that the downward direction change toward the thermal ink sheet 1-55 is abrupt.

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

If the angle 0 is 30' or more, it will affect the separation of the copy paper 12, but preferably 60' to 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 5o 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 12 55 undergoes a sudden direction change at the edge 62, resulting in copy paper 1
2 and the heat-sensitive ink sheet 55 can be separated well. The supply shaft 53 and take-up shaft 54 of the thermal ink sheet are shown in FIG.
As shown in FIG. 5, it is held in a casing 70. The ink sheet cartridge 71 has a casing 70.
Supply shaft 539 Winding shaft 54. Weight shaft 56. The ink sheet cartridge 71 consists of a thermal ink sheet 55, and when copying is used, the ink sheet cartridge 71 is loaded into the thermal head 50 from above. The casing 70 of the ink sheet cartridge 71 has an open lower 2 on its lower surface into which the thermal head 50 can be inserted, and an open lower 3 on its upper surface from which the upper surface of the heating element end surface 51 of the thermal head 50 can slightly protrude. It is being 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 pack when the thermal ink sheet 55 is wound onto 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 pack tension.

The upper surfaces 83 and 84 of the casing 70 of the ink sheet cartridge 71 also serve as guide surfaces for the copy paper 12, as shown in FIG. 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 formed by the edge 62 of the blade 61 after the ink is transferred.
When the thermal ink sheet 55 is separated and the copy paper 12 continues straight, a guide surface is formed to prevent the leading edge of the copy paper from falling down due to being pulled by the thermal ink sheet 55. The upper surface 84 guides the leading edge of the copy paper 12 to the copy paper outlet 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, the previous copy paper is pushed by the leading edge of the previous copy paper and falls into the step 85. It is provided for the function of being 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 on the way. Therefore, even if the thickness of the thermal ink sheet 55 wound around the winding shaft 54 changes and the diameter increases, a constant amount of the thermal ink sheet 55 fed at the peripheral speed of the transfer roller 59 is always wound up reliably. ing.

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 units I to 30, the feed amount of the copy paper 12 sent by the transfer roller 59 and the feed amount of the image sensor unit 30 are different. The reduction ratio is set so that the amount of movement 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. The original platen cover 4 is opened and the original 3 to be copied is set face down on the original platen 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 75
is turned on and the copy is enabled.

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.
The melted ink is transferred to the copy paper 12 according to the image. In this embodiment, the copy paper guide 22 is adjusted to match the width of the copy paper 12. next,
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 mm at both ends in the width direction is created. Although it is possible to change the print size continuously according to the value of the slide volume, in this embodiment, the commonly used paper size A4. B5. A5. B
The width changes step by step to 6 mag. However, it is not limited to this.

Corresponding to the sheet width set by the leading edge of the copy paper 12 and the copy paper guide 22, as shown in FIG. 7, there are portions 80 and 81 that are not printed, each having an area of approximately 5111ff1. Since printing is stopped when the trailing edge of the copy paper 12 passes the paper sensor 75, there are about five unprinted portions 82 at the trailing edge of the copy paper 12.

The non-printed 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 1-55 separate when they begin to separate at the edge 62. If the original 3 is wider than the copy paper 12, the non-printed areas 81 on both sides of the copy paper 12
Heat is applied to the thermal head 50 up to the part without 2,
To prevent unnecessary ink from being transferred to the transfer roller 59.

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, the copy paper is extremely long,
Since the copy paper 12 continues to be fed even after the image sensor unit 30 finishes scanning, there will be no paper jam.

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 1-30 returns to the same star 1 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 thermal ink sheet I-, and can be copied onto plain paper without surface treatment.

(2) Since the distance between the document surface and the image sensor can be maintained constant at all times, the focal position is always constant and copies can be obtained in terms of image quality.

[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, FIG. 2 is a sectional view of an image sensor unit 1 of the present invention, and FIG. 3 is a perspective view of an image sensor unit of the present invention.
FIG. 4 is a cross-sectional view of the main part of the printing section of the present invention, and FIG. 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 copy paper for explaining the present invention in detail. DESCRIPTION OF SYMBOLS 1...Main body, 2...Document glass, 3...Original, 10...Print section, 11...Copy paper insertion slot, 12...Copy paper, 14-...Copy paper eject Exit, 22... Copy paper guide, 30...
・Image sensor unit, 33...sensor body,
34... LED array, 35... Light converging 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. Patent applicant: Matsushita Electric Industrial Co., Ltd.
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7.Roller 32cm 38cm
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51 Zo Nessho Shomen 53 Romin Yaso 54 Benevolent Axis 55 Kitai/Cuzoto 56 3-way Axis 57-Fully Point 58 Roller Frame 59°
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5 Medicinal round t) Figure 5 14 Copy 1 fl Stable gate 15 Force 4 card paper 50 To thermal, door 51 Photothermal body basin surface 53 Feeding vehicle 54 Port handling shaft 5
5 Exothermal ink sheet 56-b axis 57° 'L voice, 5810
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0 Goo / Nku 71 Ink U Tokato Sosshi 72 Open Roa 3 1 Taro

Claims (2)

[Claims] (1) Equipped with a sensor body that integrates a printing means consisting of a thermal head and a heat-sensitive ink sheet, an image sensor that scans the original to be copied and reads the original image, a light source for illumination, and a light converging fiber lens. When this sensor body scans the lower surface of the document glass on which the document is placed, the sensor body is attached to the document glass surface using an elastic member in order to maintain a constant distance between the image sensor and the document glass surface. A thermal transfer copying device characterized by being configured to perform pressing and sliding operations. (2) The sensor body is provided with a roller that slides in contact with the glass surface of the document table to maintain a constant distance from the glass surface of the document table. Thermal transfer copying device.