JPS61222783A - Heating type printer for printing dot matrix symbol in non-tapping type - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an electrically conductive printing ribbon having pigment particles which are solid at room temperature but which melt and adhere onto a record carrier upon heating to a threshold temperature; a pressure head movable along the record carrier surface and comprising a plurality of electrodes connected to a power source for heating selected portions of the print ribbon dye particles to a threshold temperature; The present invention relates to an electrothermal printing device for printing dot matrix symbols on a recording medium in a non-stamping manner, which has a cleaning member for cleaning.

(Prior Art) Non-stamping electrical heating in which a row or rows of printing electrodes and a counter electrode are brought into contact with a conductive printing ribbon placed facing a record carrier, e.g. paper. Printing methods and devices are already known.

The current flowing through such a printing ribbon causes Joule heat to be generated in the part of the printing ribbon that is in direct contact with the printing electrode, causing the corresponding shaped part to soften and be displaced onto the record carrier in contact therewith.

Such electrothermal printing devices produce no noise and yet produce good, sharp symbol records. However, this printing quality cannot always be achieved when the free end surfaces of the printing electrode and counter electrode that are brought into contact with the printing ribbon are dirty and worn. These drawbacks have already been solved in known electrothermal printing devices by replacing the printing ribbon cassette with a cleaning ribbon cassette. However, this cassette replacement is performed subjectively by looking at the badly printed characters. The user of this device must always pay close attention to the markings when deciding when to clean.

The technical problem in this field is therefore to create a dot matrix by means of an electrically conductive printing ribbon, which allows the pressure head with printing electrodes to be easily and automatically cleaned and to ensure that the record carrier is always printed with sharply contoured dots. An object of the present invention is to provide an electrothermal printing device that prints symbols in a non-stamping manner.

(Since the print ribbon according to the invention must have at least one zone coated with cleaning material, automatic cleaning of the print electrodes must always occur after a certain number of print operations. This ensures consistently high quality prints. Formation is guaranteed.Claim (2)
According to an advantageous embodiment of the invention described in , the printing electrodes are always cleaned before using a new ribbon cassette.

Advantageously, a print ribbon cassette is used in which the print ribbon supply and take-up reels are provided within the cassette.

According to the present invention, it is no longer necessary to replace the cleaning material ribbon with a cassette as in the prior art.
According to the preferred embodiment of the present invention described in ), even if the printing ribbon cassette is not completely used, it is possible to clean the press head that has been disused for a long time and becomes dirty.

Further preferred embodiments of the invention are apparent from the individual embodiments of the claims.

(Example) Figure 1 of the accompanying drawings contains pigment particles which are solid at room temperature but melt and adhere onto a record carrier 1, for example paper, by heating to a critical temperature. An electrothermal printing device is shown for printing dot matrix symbols on a record carrier 1 without striking by means of an electrically conductive printing ribbon 2 . The top of the record carrier 1 is movable by a platen rotated by a step motor (not shown). Facing the record carrier 1, a carriage 4 is provided which can slide on a guide bar 5.6;
This carriage 4 is fitted with a pressure head 7 having a printing electrode 8 and a counter electrode 12, both of which are connected to a power supply in order to heat only selected portions of the printing ribbon pigment particles to a critical temperature. ing. For example, as shown in FIG. 5, the printing ribbon 2 is composed of a flexible support layer 9 made of a highly conductive base material, a dye layer 1o that is displaceable by heating, and a layer 11 made of an electrically resistive material. ing. When a voltage is applied between the printing electrode 8 and the counter electrode 120, the fifth
A current 13 flows as shown in the figure. The Joule effect of this current provides maximum heating in the portion of the electrically resistive layer that is in contact with the print electrode 8. This heat is conducted to the dye layer 1 (13), causing a corresponding melting and dislocation onto the record carrier. A pressure head 7 presses the print ribbon 2 against the record carrier 1, which assists in displacing the molten pigment onto the record carrier. The carriage 4, fitted with the pressure head 7, is advanced step by step to form the dot matrix symbol. As shown in FIG. 1, the ribbon 2 is unwound from a conventional supply reel 14 in a typewriter and taken up again onto a take-up reel 15, during which the printing ribbon 2 is placed facing the record carrier 1. Direction change bin 16
．． 17 in a tensioned state. The supply reel 14 and the take-up reel 15 are rotatably mounted outside the printing area within the machine frame. In order to move the ribbon 2 over its entire length, for example, the take-up reel Q/15 is moved by the drive motor 1.
8 makes it rotatable.

The printing electrode and counter electrode attached to the pressing pad 7 become dirty due to friction with the recording carrier or due to dust.
As shown in FIG. 1, the printing ribbon must be connected to the core 2 (13) of the take-up reel 15 via a leading tape 19. A cleaning agent is applied to the side of this leading tape 19 facing the electrodes 8.12.

As a result, the pressure head 7 is automatically cleaned even before the printing ribbon 2 is paid out by loading a new printing ribbon spool 14,15.

1-4, a ribbon 21 is shown having a zone 22 perpendicular to the length of the ribbon 21 on the surface facing the print electrode 8, to which a cleaning material is applied. This zone 22 can also be provided, for example, in the central part of the entire length of the ribbon 21 or as a trailing tape connected to the core 23 of the supply reel 14. Particular care must be taken at the transition point from the type ribbon 21 to the cleaning material cover 22 so that no pressure shocks are introduced by the scanning device during the formation of the dot matrix symbol. It can also be provided that such cleaning of the pressure head 7 with the printing ribbon can be carried out automatically at regular automatic intervals. Also shown in FIG.
A zone 25 and 26 divided into two in the length direction is provided as shown in FIG. is also possible.

FIG. 2 shows a guide bar 27, 28 facing the record carrier 1.
An electrothermal printing device is shown having an upper sliding carriage 29 on which a pressure head 7 with a printing electrode 8 and a counterelectrode 12 is pivotably mounted. This pressure head 7 comes into contact with the record carrier 1 during a printing operation, but in the non-printing state it is raised in a known manner to avoid unnecessary wear and tear on the pressure head.

The ends of the carriage 29 carry the belt 3 (1
3). Drive row 232 is rotatably coupled to step motor 34 . A record carrier 1, for example paper, can be rotated by a rotatable platen via a belt drive 36, 37, 38 by means of a stepper motor 39. Supply reel 39 and take-up reel 4
0 is rotatably mounted in a print ribbon cassette 42 which can be mounted on a mounting device 41 of the carriage 29.

The print ribbon 43 in this cassette 42 has a leading tape 59 coated with cleaning material, which is bonded to the core of the take-up reel 40, for example. For carrying out the cleaning operation, the printing ribbon cassette 42 is provided with control means, which can abut with a control link in the printing device.

For this purpose, the mounting device 41 includes a printing ribbon 4
3 can be provided, which is the ribbon 43
By checking the upper cleaning material application zone, a program for automatic cleaning of the pressure head 7 can be carried out. This scanning device can be configured as an optical detection device having a light emitting element 44 and a light receiving element 45, as shown in FIG.

Note that this scanning device is composed of a pressing head 7 and a counter electrode 12, and is electrically coupled to a pressing control device and/or a function display device or a fault display device to perform a contactor action to scan the printing ribbon surface. Seiroko also belongs to the scope of the present invention.

The control means may also be configured as an electrical switch in contact with the bottom 46 of the printing ribbon cassette 42, for example a microswitch 47 shown in FIG. When the ribbon cassette 42 is mounted on the mounting device 41, when the microswitch swings from the position indicated by the broken line in the drawing, a special key 49 (1) arranged on the keyboard 48 is activated.
The circuit to 'Figure 6) is closed. By operating this special key 49, an actuation command impulse is given to the control means 5 (13), such as a microprocessor, for example. This control means 50 provides a drive impulse via an amplifier 51 to an electromagnet 52 which, by pivoting the pressure head 7, is brought into pressure contact with the record carrier 1 and the platen 3, so that the electrodes 8 and 12 are placed on the cleaning material application zone. Drive impulses are then applied from the control means 50 to the carriage 29 and the take-up reel 4 (13) via amplifiers 53,54.

The print ribbon released from the supply reel 39 is wound onto the take-up reel 4 (13) by the step morph 55.

At this time, the pressing head 7 slides on the surface coated with the cleaning material, and the free end surface of the electrode 8 is cleaned and made smooth. This process is terminated just before the dye layer portion of the print ribbon reaches the print position.

The press head 7 is then swung into the raised position and the printing ribbon is moved further until its pigment layer portion is in the area of the press gutter 7. This completes the cleaning operation.
The printing operation using the purified press head 7 is started.

In this way, sharp dot matrix symbols are always produced on the record carrier 1.

In the case of the device shown in FIG. 1-2, activation of the cleaning operation is only possible when a new print ribbon cassette 42 is installed. This is because it must always be ensured that the pressure head 7 is able to come into contact with the cleaning material. For this purpose, a membrane is provided on the bottom surface 46 of the ribbon cassette 42, which initially closes a switch 47, but when loading the ribbon cassette 42 onto the loading device 41, the membrane is ruptured and the switch is opened. It will be done. This ensures that switch 47 is not further actuated when loading a ribbon cassette 42 that has already been used.

If a typewriter with an electrothermal printing device has not been used for a long time and the electrodes 8.12 are dirty, do not install a new ribbon cassette and replace the pressure head 7 with the printing electrode 8.
can be configured so that it can be moved beyond the printing start position to a cleaning operation position where a member that comes into contact with and cleans the surface of the electrode 8 is disposed. This cleaning member is
In FIG. 2 , it can be configured as a cleaning pad 56 arranged on the outside of the platen 3 supporting the record carrier 1 . Furthermore, an embodiment in which a circumferential groove 58 is provided in a portion outside the printing area of the platen 3 that supports the recording carrier 1, and a cleaning material strip 57 is embedded in the circumferential groove 58 (see off-line drawing) also belongs to the scope of the present invention.

In this case, the platen 3 is provided with a strip 57
is rotated while in contact with the electrode 8 of the pressing head 7. As a result, the surface of the pressure head 7 is rubbed and the printing electrode 8 is again cleaned and its contour sharpened.

During this cleaning operation, the ribbon cassette 42 must be manually operated, but the operation control of the cleaning operation can be performed automatically by removing and removing the ribbon cassette 42.

The cleaning operation of the pressing head 7 is performed by cleaning the pressing head and the counter electrode 12.
It is also possible to switch automatically when the cleaning material strip leaves the cleaning material strip and comes into conductive contact with the print ribbon. The contact elements 7 and 12 also allow the ends of the printing ribbon to be directed.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an electrothermal printing device according to the present invention comprising a print ribbon supply reel and a take-up reel rotatably mounted in a machine frame; FIG. FIG. 3 is a similar view of the apparatus of the present invention with a supply reel and a take-up reel of print ribbon; FIG. 3 is a plan view of a printing ribbon having two zones divided in the longitudinal direction, FIGS. 2-4 are plan views showing a cleaning material zone provided perpendicular to the longitudinal direction of the printing ribbon, and FIG. A side view of the printing ribbon shown together with the scanning device, FIG. 6 is a block diagram showing the procedure for automatically cleaning the printing ribbon by attaching and removing the printing ribbon cassette, and an off-line diagram shows the cleaning element provided outside the printing area. FIG. The correspondence between the main parts and the codes is as follows. 1...Record carrier such as paper, 2...
・Print ribbon, 3...Platen, 4...
・Carriage, 7...Press head, 8...
・Print electrode, 12...Counter electrode, 14...
... Supply reel, 15 ... Take-up reel, 21.
25...Printing ribbon, 22.26...
Cleaning material zone, 29... Carriage, 30...
... Belt, 31 ... Turning roller, 32 ...
... Drive roller, 34° 35 ... Step morph, 39 ... Supply reel, 40 ...
・Take-up reel, 41... Carriage mounting device,
42... Printing ribbon cassette, 43...
・Printing ribbon, 44... Light emitting element, 45...
... Light receiving element, 47 ... Micro switch,
48...keyboard, 49...special key, 50...control means, 51...amplifier, 52...electromagnet, 53.54. ...Amplifier, 55...Step motor. Representative Patent Attorney 1) Osamu Sumi F/G, 6

Claims (1)

[Scope of Claims] (1) A conductive printing ribbon having dye particles that are solid at room temperature but melt and adhere to a recording carrier when heated to a critical temperature; a pressure head movable along the surface of the record carrier, comprising a plurality of electrodes connected to a power supply for heating selected parts to a threshold temperature; and a cleaning member for cleaning the pressure head. an electrothermal printing device for non-stamping printing of dot matrix symbols on a record carrier, comprising meltable pigment particles, the record carrier (1
A printing ribbon (2) having a layer facing the electrode (
8, 12) A printing device characterized in that it comprises at least one zone coated with a cleaning material on the side facing 8, 12). (2) A device according to claim (1), in which the print ribbon (2) unwound from the supply reel and wound onto the take-up reel faces the electrodes (8, 12); A printing device according to claim 1, comprising at least one zone perpendicular to the longitudinal direction of the ribbon coated with a cleaning material. (3) In the apparatus according to claim (2), the printing ribbon (2) is connected to the core (20) of the take-up reel (15) via a leading tape (19) configured as a cleaning tape. A printing device characterized in that it is coupled to. (4) A device according to claim (2), in which the printing ribbon (21) is coupled to the core (23) of the supply reel (14) via a trailing tape configured as a cleaning tape. A printing device characterized by: (5) The apparatus according to claim (3) or (4), wherein the printing ribbon (24) is divided into two bands (25, 26) in the longitudinal direction, and one band (25, 26) is divided into two bands (25, 26).
) is a dye layer facing the recording carrier (1), and the other zone (26) is a cleaning material layer facing the electrode (8). (6) A device according to any of the above claims, comprising a supply reel (39) and a take-up reel (40).
) is movable along the record carrier (1).
9) A printing device characterized in that it is provided in a ribbon cassette (42) adapted to be mounted on the mounting means (41) of item 9). (7) In the device according to claim (6), the ribbon cassette (42) is provided with a control means,
This activates a control link within the printing device to activate the pressure head (
7) A printing device characterized in that the printing electrode (8) can be cleaned. (8) The device according to claim (7) is provided with a device for scanning the printing ribbon (2),
Printing device, characterized in that it is thereby adapted to identify the strip of cleaning material on the printing ribbon (2) and to carry out a program for an automatic cleaning operation. (9) A printing device according to claim (8), characterized in that the scanning device comprises an optical detection device (44, 45). (10) The device according to claim (8), in which the scanning device has a contact element that scans the surface of the printing ribbon (43), and this is used as a pressure control device and/or a function display device. A printing device characterized in that it is electrically coupled to a fault indicating device. (11) The apparatus according to any one of the above claims, wherein the pressing head (7) having the printing electrode is movable beyond the printing start position to the cleaning operation position, and the pressing head (7) having the printing electrode (8) A printing device characterized in that a cleaning material for contacting and cleaning the surface is provided at the cleaning operation position. (12) A printing device according to claim (11), characterized in that the cleaning material is provided outside a platen (3) that supports the recording carrier (1). A device according to claim (11), in which the platen (3) supporting the record carrier (1) is provided with a circumferential groove (58) outside the printing area, in which a strip of cleaning material (57) is provided. )
A printing device characterized in that a is embedded therein. (14) A device according to claim (13), in which the platen (3) rotates with its cleaning material strip (57) in contact with the electrode (8) of the pressure head (7). 1. A printing device characterized in that the printing device is configured to be capable of printing. (15) Claims (11), (12), (13)
Alternatively, the printing device described in (14) is characterized in that the cleaning operation can be performed automatically by removing the ribbon cassette (42) from the mounting means (41) of the carriage (29). . (16) The device according to claim (15), wherein the mounting means (41) is provided with a switch (47), and when the ribbon cassette (42) is removed from the mounting means (41). In addition, a circuit to a special key (47) arranged on the keyboard (48) is closed by the switch, and the operation of this special key (49) causes cleaning for the press head (7). A printing device characterized in that the printing device is adapted to be operated.