DK155386B - ROTATING ELECTRICAL PRINTER FOR PRINTING ALPHANUM NUMBERS - Google Patents

Description

in

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The invention relates to a rotary electric typewriter of the kind specified in the preamble of claim 1.

As the processing speed of modern data processing equipment increases, the need for an inexpensive high-speed printing apparatus has also increased. Very fast devices of this kind have already been developed, which are, however, very complicated and expensive. There are also cheaper typewriters, but these are usually slow and yet quite complicated. As a result, the price per pressure rate unit (character per second) been undesirably high.

The known appliances are large, and the maintenance costs are also high, and they have caused unwanted shutdowns, resulting in a reduction in the effective operating time. Furthermore, known printing devices of the said kind are very noisy.

Thus, from US Patent No. 2,910,339, a printing apparatus is known which is a rotor printer which is very slow. In this known printing apparatus, the dots produced with successive pins, to form marks, must be spaced apart and exactly aligned to prevent wavy or uneven lines in the direction of movement of the paper. The provision of such time control means increases the complexity of this known apparatus and hence the price. In addition, it is a further component which may fail, thereby causing further possible malfunction of the apparatus.

US Patent Nos. 3,363,261 and 3,686,679 disclose printing apparatus, which, however, is not rotatable. They are, on the other hand, apparatus in which pins are fastened to complicated structures, e.g. flexible tapes and pulleys to guide the pins past a piece of paper during printing. The flexible bands 2

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can produce considerable inaccuracies in the locations of the characters, and the design required for the movement of the tapes is massive, complicated, and costly. DSA Patent No. 2 127 331 discloses a printing apparatus which appears superficially to be a rotatable printing apparatus, but this is not actually the case.

The rotor does not rotate continuously, but stops and moves to bring the rows of dots away from each other, and this rotor thus acts on an intermittent basis.

The object of the invention is to provide a reproduction or printing apparatus which operates at relatively high speed and which is inexpensive, so that the speed unit is very moderate. It is furthermore intended to indicate a device which is small, simple and reliable. Finally, the purpose is to indicate an apparatus that operates smoothly and quietly and thus does not give rise to annoying noise.

This object is achieved according to the invention in that the rotary electric typewriter initially stated is characterized by the characteristic part of claim 1.

The printing apparatus according to the invention can operate at speeds that are many times faster than the speeds at which known apparatus can operate. Furthermore, the apparatus according to the invention greatly simplifies the problems of adjusting the dots produced by the pins, the pins being mechanically fixed together in a group so that they are permanently aligned. Then it is only necessary to determine precisely the circumferential position of the dots in order to obtain the correct alignment of the dots. Furthermore, mounting the pins on the rotor is far simpler than with known devices, since groups of pins

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tiers are mounted together in a single block, which is itself fixed to the rotor so that one does not need the many individual mounting screws and the other complicated construction necessary for mounting each pin separately, such as for example. is the case with that of U.S. Pat.

2 910 339 known apparatus. Thus, the apparatus of the invention may be smaller and simpler in construction as well as faster and more reliable. Contrary to those of U.S. Pat.

3 363 261 and 3 686 679 known printing apparatus rotate the rotor of the apparatus according to the invention continuously under printing, and its location is easily maintained accurately in relation to the recording material for obtaining high quality printing.

The invention will now be described in more detail with reference to the drawing, in which: FIG. 1 is a perspective view of an embodiment of the apparatus according to the invention; FIG. 2 shows the embodiment of FIG. 1, seen from the opposite side with the paper guide lifted and with a portion of the paper removed; FIG. 3 shows a piece of the writing paper of the embodiment of FIG. 1, provided with a font produced by the apparatus according to the invention; FIG. 4 shows the one in FIG. 1 in separate mode; FIG. 5 is a cross-section through line 5-5 of FIG. 1, FIG. 6 shows the rotor from the apparatus of FIG. 1 taken along line 6-6 of FIG. 5, FIG. 7 shows a time slice for the FIG. 1 to 5, partially schematic, FIG. 8 shows a set of signal sequences demonstrating the operation of the time disk and the associated electronics,

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FIG. 11 and 12 are partly schematic views of a portion of the apparatus shown in two different operating positions in the two figures; 15 shows another embodiment of the apparatus according to the invention; FIG. 14 is a partial sectional view of another embodiment of the apparatus according to the invention; FIG. 15 is a partial sectional view taken along line 15-15 of FIG. 14? FIG. 16 is the one shown in FIG. 14 and 15, FIG. 17 is a side view of one of the printheads of FIG. 14-16, FIG. 18 shows the one in FIG. 17 from the end, while FIG. 19 shows parts seen in cross section 19-19 of FIG. 14th

Pig. 1 and 2 show an embodiment 20 of the printing apparatus according to the invention. This includes a base plate 22, a cylindrical housing 24, a cylindrical collar 26 serving as a roller, and a drive motor 30 for operating a rotor 28. On a shaft 48, a timing disc 54 (Fig. 2) is arranged for timing. printing.

In a magazine 32 is a roll 34 of paper 36 which is sensitive to electrical discharge. The paper 3.6 runs upward from the roller 34 over a straight guide bar 35 against a curved paper guide 38. The paper guide 38 is hinged to the outside of the housing 24 at 40 so that it can be lifted as shown in FIG. 2. As shown in FIG. 1, the paper guide 38 is held by a lock 42 when the apparatus is in operation.

In FIG. 2, a drive roll 56 can be seen to pull paper forward from the roll 34 and through the curved paper guide 38 so that the paper forms an arc, after which the paper is passed through the collar 26 close to its upper part of the inner surface. Once printed on the underside of the paper 36, the paper emerges from the collar 26's

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left edge as shown in Fig. 1. At the left edge of collar 26 is a tear-off edge 46? which has a jagged edge 47 over which the paper can be easily torn off.

The inside of the paper 36 (i.e., the concave surface) is covered first with a dark material and then with a light colored material such as aluminum or zinc oxide which can be eroded or evaporated by an electric discharge or spark. The rotor 28 has three printheads 62, 64 and 66, each having five mutually spaced axial distances spaced apart 68 (see Figures 5 and 6).

As will be explained later, the motor 30 drives both the paper feed roller 56 and the rotor 28. The print tips are selectively activated to form an image on the underside of the paper on the basis of a 5 x 7 dot matrix.

In FIG. 3 is an example of a printout of the apparatus 20.

Each printhead has five wires sufficient to produce all the dots of a character seen in the horizontal writing direction. Therefore, each time one of the printheads passes over the paper, at least one printed character will be produced.

It is preferred that the words be printed on the paper as shown in FIG. 3 in the direction of arrow 31. When multiple lines of text are to be written, corresponding data is stored in a store in the apparatus and read out so that each print head prints an entire vertical column of characters, ie. one character from each line. For example, the first column A of FIG. 3 is printed by the passage of a single printhead, the column B is printed by the passage of another printhead, while the column C is printed by the passage of a third printhead. Since there are three printheads, three columns of characters can be printed for each rotation of the rotor. The number of characters printed per Thus, rotation will be equal to three times the number of printed lines.

Of course, it is also possible to print the words in a vertical direction instead of the one in FIG. 3. In this case, the writing speed will be comparable to that otherwise \

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cases described.

The apparatus 20 will now be further described.

The drive system of the apparatus can be seen in FIG. 4 and 5, the shaft 48 and the drive motor 30 are shown. The motor 30 is mounted on an end plate 70 of the housing 24 by means of screws 80. The output shaft 76 of the motor 30 * is provided with a toothed drive wheel 78 which, via a toothed rim 50, drives a large, toothed wheel 52 which is secured to the shaft 48 The wheels 78 and 52 are sized to achieve a speed reduction of one to four. The timing disc 54 is attached to the wheel 52 and thus to the shaft 48.

The shaft 48 is mounted in ball bearings 72 in the end plate 70 and to the right end of the shaft is attached a stop disk 74 (Fig. 5). At the opposite end of the housing 24 is another end plate 88. In this end plate, the shaft rotates in ball bearings 92 and is held by means of a stop disk 108.

The rotor 28 is mounted on a spacer 110 (see Figs. 4 and 5) by means of screws, which spacer is also connected to a grinding disc 104 which is adjacent to the stop disc 108.

The spacer, towing ring and rotor 128 are secured to the stop washer 108 by a threaded nut 114 »which is screwed onto a thread 49 (Fig. 4) on the left end of shaft 48. Therefore, the rotor 28, spacer 110, grinding disc 104, wheel 52 and timing disc 54 rotate firmly relative to each other.

The paper feed wheel 56 is driven by a gear coupling of the shaft 48. As shown in FIG. 4 and 5, the roller 56 is pivotally mounted on a shaft 96 attached to an upper extension 89 (Fig. 4) of the plate 88. The upper surface of the roller 56 extends through a slot 91.

A lower projection 90 of the end plate 88 constitutes the bearing of a shaft 84 'to which is attached a sprocket 86 which fits with a auger 82 on the shaft 48. Thereby, a tapered sprocket 92 which cooperates with another tapered sprocket 94 shaft 96 which drives the paper feed roller 56 with a substantially smaller

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speed than the rotor 28's speed.

The feed roller 56 cooperates with an idle roller 98 disposed on a shaft 100 in the curved paper guide 58. Above the idler roller 100 is a cover 102 for protecting the roller.

As can be seen in FIG. 5 », the writing paper 56 is tight between the two. rubber rollers 56 and 98 so that rotation of the roll 56 will pull the paper through the apparatus without appreciable slip.

equal. 10 schematically shows the electrical circuit established when a spark between a writing pin 68 and the paper 56 is jumped. The conductive underside 59 of the paper must be connected to a return terminal of the voltage supply 69 which is connected to the writing pin 68 to produce an electric discharge. The underside of the paper is connected to the ground source of the voltage source by means of an earth connection shown in Figures 2, 4 and 5. The earth connection comprises a conductive coil spring 58 wound around a curved metal rod 60 attached to the end plate 70 of the frame. FIG. 4 and connected to the frame. The ends of the spring 58 are secured by means of rings 61.

As shown in FIG. 5, the rod 60 is bent forward while being arcuate so that it fits under the right edge of the cover 58. The top of the spring windings resiliently presses against the underside of the paper 56 and pushes it up against the paper guide 58. The many turns of the spring result in many close-fitting frame connections to the underside of the paper.

This combination of frame connection and paper tightening means also has a third function, namely, that it helps to shape the paper in a bow so that it can easily pass through the paper guide 38.

As shown in Figures 1, 2, 4 and 5, the paper roll 54 is disposed on a spindle 120, the ends of which fit into slots 118 in two end plates 122 of the magazine 52. The plates 122 are attached to the bottom plate 22. The friction of the individual parts to prevent overflow of the paper roll after the paper feed is stopped.

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As best seen in FIG. 5, the rod or roller 35 serves to guide the paper from the roller 34 towards the printing apparatus by substantially changing the direction of the paper. However, one important function is to ensure that the paper is always delivered from approximately the same height to the printing apparatus, whether the roll is new or nearly used up. Therefore, the advantage of the magazine shown can be realized when it is contemplated that changes in the paper feed direction may cause wrinkles or other uneven paper feed.

Eig. 6 shows the construction of the rotor 28 and the location of the three printheads 62, 64 and 66. Eig. 6 shows schematically what can be seen for the rotor along line 6-6 in fig. 5, where the spacer 110 and other parts are omitted.

The contact points between the writing stands 68 and the circle 125, which represent the inner surface of the collar 26, are indicated by reference numerals 119, 121 and 123. The writing pins are arranged in a plastic blank which is attached to the rotor via a bracket 128. The bracket 128 has a curved slot 130 with a screw 132 so that the writing pin can be moved outward or inward to increase or decrease the writing pin pressure on the roll or paper on the roll.

As can be seen in FIG. 6, the angle between the writing pins and a radius through their contact points, 119, 121 and 123, is about 70 °, respectively. Therefore, the tinkle between the writing pin 68 and the tangent line 127 at the point 119 is 20 °. Thus, the writing pin will not move in a perpendicular position relative to the paper. Bette leads to a smoother operation of the appliance and reduces the possibility of the writing pin tearing up the paper as it passes.

Referring to FIG. 5, it can be seen that the diameter of the roller or collar ___ 26 is larger than the diameter of the housing 24. Bites are necessary for the paper 36 to extend over the collar or inner surface of the roller. Ask the lower two-thirds 116 of the rear edge of the collar 26 * to be smaller in diameter so that it fits with a flange 93 on the plate 88 to which the collar is secured by screws not shown.

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The paper tear ring 46 is attached to a cut 95 in the inner surface of the leading edge of the collar 26.

It can also be seen from FIG. 5, each printhead 62, 64 and 66 is connected to terminals on the back of the grinding disc 104 by wires 112 (see also Fig. 9). The clamps are blinded through the disc 104 to the lug rings on the opposite side of the disc.

It should also be noted that the printheads 62 and 64 of FIG. 5 is shown turned from their actual position so that they appear more clearly.

Determining when the dots are to be formed using the pen is important for accurate printing. The time control function is provided by a transparent disc 54 (Figs. 2, 4, 5 and 7) which has a series of thin, opaque black bars 166 (Fig. 7) and has a single wide black line 168. Ideally, the three sensing means A, B and C are spaced 120 ° apart at an angular distance, as is the case for the three printheads 62, 64 and 66. However, due to the construction of the housing 24 and the paper conductor 38, this is not possible. As a result, the sensing means A and C are spaced apart by an angle of 180 ° and the angular distance between the sensing means A and B is 60 °. The pool means B is fixedly positioned, while the sensing means A and C are movable along the periphery of the disc 54, so that the beginning and ending of a writing function of the printheads can be mutually adjusted. This makes it relatively easy to make the first print head alignment and also makes it easy to adjust for other printing inaccuracies without having to remove the print heads. In the arrangement shown, a simple adjustment option is obtained without the rotor being out of balance.

The fixed sensor B (Figs. 4, 7, 11, 12) has a detector structure 146 attached to a mounting plate 148. The detector structure 146 comprises a U-shaped housing, one leg of which comprises a small light emitting diode (LED) 155 (Fig. 11), which is arranged to transmit light to the second leg of the housing, which contains a small phototransistor 155 for detecting the light. The eototransi store is covered by a mask (not shown) consisting of an opaque thin film with a narrow translucent slit such that *

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germinate the light falling through the slit will be detected.

The detector 146 of the pool member B is inserted through a hole 138 in the housing 24 and is secured after the disc 54 is mounted in the housing. The two legs of detector 146 .. fit around the edge of the disc so that the light from the LED shines through the area of the disc where the marks 166 and 168 are located and detected by the phototransistor.

Each of the other sensing means A and 0 contains a detector similar to the detector 146. The detector 146 in each of the sensing means A and C is mounted on an I-shaped bracket 154 which is pivotally connected at 152 to a mounting bracket 150. The bracket 154 has a long arm with a longitudinal groove 156.

Referring to FIG. 4, 11 and 12, it will be seen that two cam members 158 and 160 exist for adjustment. Each of these has a body that pivotally fits into a hole in the end plate 70 of the housing 24 and has a notched head so that the member can be rotated with a screwdriver. Each adjusting member 158 and 160 also has an eccentrically disposed pin 162 or 164. As shown in Figures 11 and 12, the pin 162 or 164 fits into the groove 156. As the head of the cam member 158 or 16Q is rotated, the arm of the console 154 will be raised upward. or lowered around the suspension point 152, thereby moving to the position of the location where the detector detects lines 166 and 168. The suspension points 152 are shown schematically in FIG. 7th

The detailed operation of the disc 54 and sensing means A, B and C will be explained later in connection with Figures 8 - 10. In general, however, it can be said that the closely spaced lines 166 control the location of a point (or a series of up to five points) and that the broad mark 168 serves as a reference mark. By means of the cam means 158 and 160, very precise adjustment of the location of the dots can be achieved, the cam means being adapted to move the sensing means A and C with respect to the sensing means B, so as to adjust at the relative start and end times for the printing heads of marks. .

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FIG. 9 shows the electrical control circuit for the apparatus 20, the drive motor 30 is shown in the far left corner, and the writing pin 68 is shown in the upper right, there is also shown the blades dial 104, the brushes 106 which are associated with the blades and the leads 112 leading from the blades. to the writing pins. It can be seen from FIG. 9, that each of the lug rings is unbroken, so that each of the brushes 106 is in continuous contact with three writing pins, one from each of the three writing heads.

Each of the writing pins is the same for the three printheads. That is, the outer brush is connected to the first writing pin in each head, the next brush is connected to the second writing pin in each head, etc. This means that the writing pins in all three heads (referred to as groups A, B and C in Fig. 9) is activated simultaneously. The paper 36 must therefore not extend more than one third of the circumference of the roller 26. Otherwise, unwanted dots would be produced on the paper. For example, if wider paper were to be used, this would probably be possible by activating the writing pins selectively using segmented slip rings.

From a DC voltage source, such as a 117 volt converter at 60 Hz, power is supplied to the control circuit, which could also be generated by a battery.

Center front, top of fig. 9, there is shown a memory 200 consisting of six 480 bit switch registers, the output of memory 200 being connected to a ROM (read memory) code converter 202 which will be referred to as "character generator" which is adapted to convert character identification signals from memory 200 to corresponding dot matrix. signals on five output lines 203. The dot matrix signals are adapted to activate some of the five writing pins which contact the paper so as to form a series of dots of the particular character being printed.

Eode converter 202 is addressed by means of three input lines 264, 266 and 268 to successively produce on output lines 203 information to form seven consecutive rows of dots of a given character so that pressure can be applied.

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is a 5 x 7 dot matrix shape character, this will be "described" later.

the store 200 carries a sufficient capacity to store characters for twelve lines of text, each containing forty characters. By adding more switch registers, the storage capacity of 200 can be increased. If the width of the paper is 10 cm and the characters are approximately 4.7 mm high, up to 24 lines across the paper can be printed with a minimum line spacing. The lines can be made as long as desired if the necessary extra storage capacity is added.

If the characters are printed in a single line and if instead of memory 200 a "PIPO" memory is used, the lines may be of unlimited length.

In the store 200's input lines 204 are fed data. For reading in and from the storage 200, a storage control circuit 206 is provided.

Via input line 226, a high frequency clock signal (1 MHz) is transmitted to one input terminal of a NAND sluice 228. At a somewhat lower frequency, strobe pulses are applied via another input line 216 which strobe pulses are transmitted to an input terminal of a sluice 218. data, a D-type multivibrator 236 (bottom left corner of Fig. 9) is in the deleted position in which a signal is present on the output terminal Q and no output signal is present on the output terminal Q. The "low" signal on the Q output activates a lock 218, which outputs strobe pulses via a second lock 220 and an AND lock 222 over read / write line 224 to memory 200. The strobe pulses cause data to be input on the common data input line 225 to the shift registers in the memory.

When the multivibrator 236 is deleted, the multivibrator 23 signal 236 is routed through line 244 to deactivate a lock 219 so that no data can be read through that lock.

At the same time as input of data to memory 200, the output of the gate 222 over line 230 is transmitted to the clock input terminal of another shift register 232, which also has a storage capacity of 480 bits, which is identical to the shift registers in memory 200.

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The switch register 252 is used to detect when the storage 200 is filled up and to indicate when the printing operation should start.

When the switch register 232 is filled up, on line 234 it outputs an output signal to the clock pulse terminal of the multivibrator 236. This sets the multivibrator and generates a signal on the Q output line which is transmitted via line 238 to a drive circuit 208 for the motor. is a semiconductor relay for controlling the motor.

The change of the multivibrator 236 to the set position activates the lock 219 and thus makes it possible to read data out of the memory during the printing operation, as will be described below. Furthermore, the lock 218 is deactivated by the signal on the Q terminal, so that data can no longer be read into the memory from the input lines 204.

The function of the multivibrator 236 also causes a state change on its Q terminal which activates a margin counting circuit. A counter 246 counts two "column sink" signals representing two turns of the time disk 54 (not shown in Fig. 9) before that counter allows the printing operation to start, thereby obtaining a certain, unprinted margin on the paper between the characters must be printed and the paper's torn edge.

In the lower right of FIG. 9, three sensing means A, B and. C from FIG. 4 and 7 arranged to detect the narrow time marks 166 and the wide time mark 168 on the time disk 54. As shown in FIG. 9, the sensing means A, B and C may comprise amplifiers and Schmitt triggers for amplifying and signal forming the pulses from the detectors.

The column sink signals shown in FIG. 8, is counted using the margin counter. These signals are generated as follows: There is a column sync counter 212 comprising two JE multivibrators 300 and 302, with multivibrator 302 receiving signal from the C sensor on its clock input terminal, while both multivibrators 300 and 302 receiving B the sensing signal on their respective erasure. In FIG. 7, as an example, the washer 64 rotates counterclockwise. The sensors A, B and C produce signals when a translucent portion of the disc 54 is located between the LED and the phototransistor. Whenever a translucent region of the disc 54 is located next to the B sensor, the erase input terminal of the multivibrators 302 and 300 will be driven to low level, thereby erasing the column synchronization counter 212. As the wide mark 168 (which is two and a half times wider than any of the marks 166) passes the sensing means B, this will temporarily interrupt the erase signal from the multivibrators 300 and 302 and enable them to count pulses received from the sensing means. C, which now feels the narrow marks 166. Although it may appear that the thin marks 166 end at the time at which the wide mark 168 is first detected by the sensing means B, this is not the case because it wide markings are located 64.1 ° from the front end of the train of marks 166, while the sensing means B is nominally only 60 ° from the sensing means A. The sensing means C is therefore 220 ° clockwise away from the sensing means B, and the end of the thin marks 166 is 224.1 ° away and there will still be several marks 166 left for passage through the sensing means C. Therefore, the counter counts up to 2 before the broad pulse 168 ends and the counter is again deleted. This produces an output pulse on the multivibrator 300's S terminal. This pulse is the "column sink" signal shown in FIG. 8, which appears on line 248 of FIG. 9th

After the wide pulse has passed the sensing means B, but before the thin lines reach the sensing means B, the counter will remain erased and no column sink signal will be generated. After the thin lines 166 have reached the sensing means B, and also after both the sensing means B and C have detected the thin lines, the counter 212 will be deleted once for each transparent area between the thin lines and therefore cannot count to two nor do not produce a column sink signal. As a result, the column sink signal is generated only once for each rotation of the disc 54 until the time that the wide mark 168 passes the sensing means B.

.. ... It has also been stated above that the column sink signals are transmitted via wire. 248 to the margin counter 246, which counts two of these sig-

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signals. The counter 246 then outputs an output of line 250 to start the printing operation.

Referring to the lower middle portion of FIG. 9, the signal on line 250 from the margin counter 246 is transmitted to the clock input schematic of another D-type multivibrator 251, which changes state and produces a signal on its Q output terminal. This signal is transmitted via line 254 to the margin counter to deactivate it and is also transmitted via line 252 as a "start" signal to a pressure actuation multivibrator 254.

The multivibrator 254 is a D-type multivibrator which is locked by signals applied to its locking terminal 253 from an AND lock 290 in the middle of FIG. 9. The AND gate 290 receives an activation signal on its lower wire and is activated by pulses from the sensing means A received via line 298. Thereby the pulses from A are sensed through to the clock input terminal of the multivibrator 254. The first of the pulses produced in A the sensing means due to the thin lines 166, in conjunction with the "start" signal on line 252, causes a state change for the multivibrator 254. The subsequent clock pulses from the A sensing means also effect a timing of the later operation of the multivibrator 254. The function of multivibrator 254 changes the state of Q output line 254 and Q output line 274. At the same time, the "high" signal on line 256 is transmitted to one input terminal of another NAND lock 260, whose second input terminal is supplied at a high level, which is connected to the δ output terminal. from a D-type multivibrator 258, which is deleted at this time.

The output of lock 260 activates row counter 262, whose function is to count the number of rows printed as well as the space between the character lines, whereby the ROM encoder 202 is addressed via address lines 264, 266 and 268 and causes it to output its information via the AND locks 272 and the amplifiers 314 to the brushes 106 and thence to the writing pins 68. Of course, neither of the AND locks 272 will produce a correct output unless both input terminals have the same condition.

One of the input terminals of each of the locks 272 is connected to the output terminal of a NAND sluice 272 which has three input terminals.

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The output of the lock 270 activates each of the AND locks .272 when the signal on each of the input lines (274 and 276) is in the correct state. The signal on line 274 is in the correct state whenever the multivibrator 254 is set to enable printing. Conductor '276 is connected to one input terminal 284 of a multiplexer circuit 282 (bottom right of Fig. 9) which, as will be explained later, always receives the pulses produced in the sensing means A, B and C as a result of the thin lines 166. Thus, the loop 270 is repetitively activated as a result of the timing control pulses produced by the thin lines 166, but only during the short duration of these pulses.

The time control pulses are also transmitted from line 284 to the row counter 262 via line 263. The row counter counts the number of time pulses and thus passes its addressing routine and counts the number of rows being printed. Since there are seven dots over each character, the row counter for every seven pulses will change the combination of output signals on wires 264, 266 and 268 for sequential addressing of the ROM encoder 202.

At the eighth pulse on line 271, the condition of the counter will be "high". This will deactivate. lock 270. and sends an activation signal via line 277 to the activation multivibrator 258. The multivibrator 258 does not change its state at this time because it is a D-type multivibrator which requires a clock pulse on the clock pulse scheme to change state. The signal on line 271 is also sent to the line counter 278, which is thereby counted one forward.

The clock pulse line 257 from the multivibrator 258 can be connected to either line 264 or 268 to select the distance between the character lines. Line 264 is activated when counter 262 counts by two, and line 268 is activated when counter 262 counts up to five.

Assuming a line spacing of two is selected by connecting line 257 to line 264, when row counter 262 has reached its ninth step, line 264 will have a high level setting the multivibrator 258. If if a line spacing of five is selected, the same operations will be done on the twelfth instead of the ninth count level.

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17 When the multivibrator 258 is set, it Q receives high level output schema and delivers a signal for activating a monostable multivibrator 261 in the storage control circuit 206 in the upper left of FIG. 9. The monostable multivibrator generates an impulse transmitted via locks 219, 220 and 222 to read / write line 224 for readout of information for the second character from memory 200. It should be noted that the information for the first character already appeared on the output lines of the store 200 because this was the first information stored in the store 200.

By setting the multivibrator 258, its Q output terminal will be low level which causes the output signal of the lock 260 to get high level and deletes all the output signals from the row counter 262 to zero. The resulting low signal on line 271 and 277 deletes the multivibrator 258 and activates the lock 270 again so that the next character can be pressed.

The counter 262 now starts a new counting sequence of timing control pulses received over line 263 and the printing of the next character in the column begins. The next character is printed in the same way as described in connection with the first character, and the process is repeated until one character has been printed in each of the twelve or twenty-four lines in which characters are printed. A character column is thereby completed.

The signal on line 271 from row counter 262 is also transmitted to a line counter 278 which counts the number of lines printed. For the line counter 278, there are two different connections, one of which activates the internal circuit to count up to twelve lines, and the other of which activates the circuit to count up to twenty-four lines according to the user's choice.

Assuming twelve lines are to be printed, the line counter 278, after the twelfth character has been printed by a particular print head, will output an output of line 280 to an AND lock 282 which also receives an input of the multivibrator 236 via line 240 so that the multivibrator 254 is now deleted. This disables the printing machine until the time when the next vertical bar of characters is pressed,

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18 when the next print head is in the starting position.

In addition to the multiplexer 282 and the column sync counter 212, the timing circuit 210 for the generation of dots comprises a data selection counter 214 and a counter 288 for division by 117.

The multiplexer 282 is adapted to connect different input signals to output lines 284 and 286, depending on the signal state of lines 291 and 292. The following table shows the function of the multiplexer:

Truth table for multiplexer 282 291 292 284 286 Allowed function

(1) 0 0 A B pressure column A

(2) 1 0 B C pressure column B

(3) 0 1 C - pressure column C

lake ^ read sync signal to state

The data selection counter 214 comprises two J-K type multivibrators 304 and 306. When the first pulse from counter 288 changes the state of multi-vibrator 304, data on output lines 284 and 286 will change according to the above table. When the next pulse is received from circuit 288, the state of the second multivibrator 306 will be changed and data on wires 284 and 286 will be changed again in accordance with the table. In this way, the A signals are first transmitted, then the B signals, and then the C signals to the printing control circuit.

Referring to FIG. 8, the "column sink" signal occurs at time tg, and the sensor timing signals start shortly thereafter at time t-. Referring specifically to the waveform in Fig. 8 for the sensing means B, it can be seen that the B sensing means begins to produce timing control pulses at the time t The pulses from the sensing means B are transmitted via the output line 286 from the multiplexer to the counter 288. Printing by the "A" printhead ends at time t ^ (Fig. 8) when the line counter erases the multivibrator 254. When the counter 288 has counted 117 pulses ( one-third of the 351 pulses generated by the thin lines

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19 166 on the disk), counter 288 generates an output signal which is transmitted to one input terminal of an AND lock 294, the other input terminal of which is connected to the Q output terminal of the multi-vibrator 300. The AND lock 294 is thereby activated and emits a signal via line 296 for deleting the line counter 278. This eliminates the output of the line counter on line 280 and deactivates AND lock 282 and causes the multivibrator 254 to change state and to start the "B" print head to print a new column of characters. This occurs on time t ^, shortly after t,.

3 "B" print head prints characters from time t ^ to tg.

At time tg, the line counter will stop printing again. Meanwhile, time control pulses have been delivered from the sensing means C to the counter 288, which has occurred since time t ^. When the counter 288 again produces an output signal after counting 117 pulses from the sensing means C, the third printhead will be activated to start writing at time ty until the line counter stops printing at time tg. Then, the column sync pulse reappears at time tQ and the printing process is repeated with a new rotation of the rotor 28. This is repeated until all the information in the bearing 200 has been read and printed.

During the reading of information from the storage 200, the shift register 230 changes the same number of times as each of the shift registers in the storage. When register 232 is filled up, a circuit not shown will produce a pulse on line 234, whereby the multivibrator 236 returns to its initial state, the motor drive circuit 208 will be deactivated and the motor will be stopped. The same circuit will also delete any of the shift registers or multivibrators that are not already deleted, so that the circuit is prepared for printing a new job.

If it is desired to duplicate the written text, i.e. To repeat the same printing operation, this can easily be done as follows. Prior to loading into the memory, the "R strobe" terminal on the shift register 232 is connected to the "R" input terminal for the shift registers in the memory 200 and a low-level signal source is applied. The switching registers are of a type that, when this is done, causes the data

DK 155386 B

20 is recycled and re-stored in the warehouse 200's shift registers instead of being destroyed upon unloading. The same applies to the shift register 232. In this working mode, the device will automatically be able to type the same text over and over again as many times as desired.

According to the invention there is a control circuit 215 for automatic control of the blackening. This circuit comprises a tachometer 308 (monostable multivibrator) whose output signal is transmitted to an integration circuit 310 whose output signal is amplified by a linear amplifier 312. The output of amplifier 312 is transmitted to the input terminals of amplifiers 314 to increase or decrease is transferred to the writing pins as a function of engine speed.

The pulses transmitted via line 284 have a frequency which is directly proportional to the speed of the rotor, corresponding to the fine lines 166 detected by the sensing means A, B and C. The pulses at the output of the tachometer 308 have a constant width. which is determined by the parameters of the multivibrator. However, since the time spacing between the pulses varies with the speed of the rotor, the output of the integration circuit 310 will be proportional to the speed of the rotor. Thereby, the amplifier 312's output signal is increased or decreased and thus the output of the amplifiers 314 ·. For example, for the preferred embodiment of the invention, which has been tested, the voltage of the printheads was 50 Volts at a writing speed of (from) 500 characters per second. At 3,000 characters per second and with maintained line count and line spacing, the write voltage was 70 volts.

By means of the automatic grinding control circuit, the grinding and readability of the printed characters will be substantially constant regardless of large variations in rotor speed. For example, it can be mentioned that very satisfactory printing has been obtained when the rotor has only been rotated by hand at low speed and when the speed has been 3,000 characters per minute. second..

21 DK 155386 B

It should be understood that the speed is 3 »000 characters per second. second should not be considered as an upper limit on the performance of the device. The speed will vary with the number of lines and characters to be printed, etc. However, it should be noted that the invention works satisfactorily at this rate of 3 · 000 marks per second. second, in view of the fact that the apparatus according to the invention is a simple, inexpensive and compact machine.

The invention is considered to have many applications in the printing of alphanumeric characters. Eg. For example, the invention can be used to make copies from a cathode ray tube or television screen for a computer terminal or other. The page number of the image produced at any time on the cathode ray tube can be read out easily. The printing mechanism itself for the apparatus of the invention is so small (e.g., 10 x 10 x 20 cm or less) that it can be built into the same module size used for cathode ray tubes or display screens.

The apparatus according to the invention can advantageously be used in many cases where there is not much space available. Eg. The appliance is useful in airplanes, spacecraft and police, fire and other similar vehicles.

The apparatus is expected to be manufactured at a very low price and with a high degree of reliability, especially in the working mode where only a single line is printed.

As an alternative embodiment of the invention, it may be conceivable to use the logic circuit of a computer terminal instead of some of the ones in FIG. 9 control circuit. Alternatively, the pressure control signals may be generated by special programming of a general computer.

Although it is preferred to use electrical discharge in connection with the invention, the three printing heads on the rotor could also be constructed differently. Eg. a group of push rods could be used instead of writing pins. In such an embodiment, each shock bar is actuated by means of an electromagnet to strike a ribbon or the like and thus produce marks.

22 DK 155386 B

in dot matrix form on a conventional piece of paper. Apparatus which produces dots by ink can similarly be used for printing on ordinary paper.

i The number of printheads on the rotor can also be varied as well as the number of writing pins in each head can be varied. However, the use of three printheads has proved appropriate and has therefore been used as an example. In FIG. 3, there is a slight variation from left to right at the beginning of the top and bottom line.

This is because the rotor rotates while the paper is continuously advancing, so that there is a slight longitudinal offset between the lines. This slight bias has not been found to compensate. However, if this bias is undesirable in a particular embodiment of the apparatus, it can be avoided in the embodiment shown in FIG. 13.

FIG. 13 schematically shows an apparatus similar to the one shown in the previous figures, except that the paper is fed at an angle Θ of 2 ° and 4 minutes with respect to the longitudinal axis of the apparatus, which angle is sufficient to compensate for said bias. If changes in the number of printheads and / or writing pins are made, the compensation angle Θ can be changed accordingly.

It has been described above how a mechanical adjustment of the three printheads can be made by means of the cam members 158 and 160, but it will be appreciated that the same adjustment can be obtained by purely electronic means. Such a modification can be obtained by adjusting the counters which control the start time of each of the printing heads of the printing head and in this way delay or accelerate the start time of each printing a specific time. However, with current technology, a mechanical adjustment of the kind described above is expected to produce sufficiently accurate results, and this will be significantly cheaper than electronic adjustment.

FIG. 14 shows a rotary printing apparatus 20 which is substantially similar to the embodiment shown in the previous figures, but there is a difference in the rotor structure at the left side of the apparatus and in the frame connection to the paper.

23 DK 155386 B

Referring to FIG. 14 and 15, the three printheads 420 are pivotally mounted on the inner surface of the rotor 28. In FIG.

15 only two printheads 420 are shown, and in FIG. 14 only one of these is shown for the sake of clarity in the drawing.

Referring to FIG. 17 and 18 and FIG. 14 and 15, each writing head 5 comprises spaced-apart wires 68 parallel to each other, which are molded into a pin holder 424. Via a pressure circuit 426, electrical energy is supplied to the writing pins where the printed circuit is attached to the holder 424. This structure is secured to an L-shaped slider 428 which slides into a groove in a mounting block 422. A threaded screw 432 cooperates with the downwardly extending lower portion 430 of the slider 428 and is pivotally connected to the block 422. Thus, turning the screw 432 will cause a movement of the slide 428 and thus the position of the pin 68.

Each of the three printheads is rotatably mounted on the rotor 28 by means of a holder shown in FIG. 14 and 19, and will be described in more detail below. Each printing head 420 has an arm 434 which is attached to the block 422 and extends in the direction perpendicular to the writing pin 68. At the end of the arm 434 is an enlarged hollow portion 436 filled with lead or containing other heavy metal insert 438 The insert 438 causes a relatively large mass to utilize the centrifugal force to bring the writing pin into contact with the paper 36.

In FIG. 15, it can be seen that a tension spring 454 is connected to each arm 434, the other end of which is connected to a pin 456 extending parallel to the drive shaft 48. The connecting point between the spring 457 and the arm 434 is located between the block 422 and the arm 434. end 436.

The construction described works such that the writing pin 68 is automatically pulled away from the paper 36 when the rotational speed of the rotor 28 falls below a predetermined minimum speed such as 500 rpm or the like. The tension springs are rotated together with the print heads 420 about their pivot axes as shown at 452 clockwise. Thereby, the writing pin is pulled away from the paper 36.

24

DK 155386B

As the rotor 28 starts its rotation, the centrifugal force will act on the heavy inserts 438 at the ends of the arms 434, thereby exerting tension on the springs and turning the arms 434 counterclockwise. When the desired speed of rotation is reached, the writing pin 68 "will touch the surface of the paper 36.

Further, there is a stop device such that an increase in the speed of rotation does not cause the writing pins 68 to be pressed too hard against the paper 36. This stopping device comprises a cam 458 (Fig. 2) and a screw 460. The trailing edge of the block 422 for each printhead interacts with the cam. so that the rotation of the printhead clockwise is stopped and stabilized in a position where the pressure of the writing pin 68 against the paper is appropriate. This position can be changed by adjusting the screw 460.

The radial extent of the writing pin 68 can be adjusted, as previously mentioned, simply by turning the screw 432, thereby extending the writing pin radially outward or inward, thereby compensating for wear or displacement from the original positions of the writing pins.

Each printhead 420 can also be adjusted in the axial direction (in the direction parallel to the drive shaft 48) by means of a device, as shown in more detail in FIG. 19 and also in FIG. 14. An adjusting screw 412 is provided, the head of which is mounted on the outer surface of the disc 28. The screw has a smooth shaft 446 which fits in and slides into a sleeve 448 which serves as a bearing for the shaft 446 as well as the inner surface of the block 422. As shown in FIG. 17, the block 422 is provided with a large hole 442 into which the sleeve 448 fits and is provided with a small threaded hole 444 in a plate 440 (see Fig. 18) which is attached to one side of the printhead.

Referring to FIG. 19, the screw is retained by a locking ring 450 which fits into a groove at the end of the shaft 446. The shank 446 has a threaded end 452 for cooperating with the threaded hole 444.

The alignment of the printhead is done simply by inserting a screwdriver into the notch of the head 412 and turning the screw. This means that 25

DK 1553 i i 6 B

the distance between the block 422 and the disc 28 is changed, whereby each printing head can be aligned axially. This means that characters printed with the help of a print head keep the correct spacing relative to characters printed using the other print heads.

The rotor 28 is mounted on the shaft 48 by means of the one shown in FIG. 14. The rotor 28 is secured to a hub 400 by means of four screws 402 (see Fig. 16). The grinding disc 104 is secured to the other side of the hub 400 and provides electrical contact to the electrical circuit of the apparatus, as has been described. On the shaft is a stop device 108. The hub 400 has a central cut-out in which the pins 456 are mounted, to which the springs 454 are attached.

Referring to FIG. 14, the hub 400 has at the rear a cutout 457 in which a compression spring 459 is mounted.

In FIG. 16, it can be seen that the rotor 28 is secured to the end of the drive shaft 48 by means of a locking mechanism. The locking mechanism comprises a locking plate 404 with two then perpendicular end tabs 406 which can be actuated to push the plate 404. The plate 404 is secured to the outer surface of the rotor 28 by a pair of rivets 410 which abut the plate 404 through a pair of elongates. slots. Bending discs are arranged between the plate 404 and the rivet heads to ensure a constant frictional connection between the plate and the surface of the rotor so that the plate remains in the position to which it has been guided.

The plate 404 has a slot with an enlarged hole 408, the diameter of which is slightly larger than the end of the drive shaft 48. The drive shaft 48 has a groove 418 along the periphery (see Fig. 14) for interaction with the edges of the slit in the plate, thereby engaging the shaft 48.

By actuating plate 404 downwardly as shown in FIG. 16, its grip around the end of the shaft will cease so that the disc 28 can extend 26

DK 155386B

taken. The spring 459 pushes the rotor outward and helps to remove it.

When the rotor is to be placed on the shaft again, the end of shaft 48 is inserted through hole 408, after which plate 404 is actuated upwardly so that the edges of the slit of the plate interact with the groove in the shaft.

The design of the rotor and writing pins described above is very advantageous. Whenever the rotor is desired to be removed from the apparatus or when it is desired to start on a new strip of paper, the writing pin 68 will not be in the way, because it is retracted and free from contact with the writing paper. Furthermore, the apparatus will achieve the correct writing speed faster because there is no frictional force when the writing pins do not touch the paper until the desired speed is achieved.

The apparatus has means for axially adjusting the writing pins without removing the rotor from the apparatus. This adjustment can easily be made by turning the screw 412 available at the left open end of the apparatus.

There are also simple mechanical means for adjusting the effective length of the writing pin, simply by turning the screw 432.

This makes it easy to align the writing pins so that the print is correct and easy to read. Due to the mechanical adjustment capability by means of the screws 432, two of the three photocells and the associated electronics described in connection with FIG. 1-13 is avoided.

The rotor is very easy to remove with the aid of those shown in FIG. 16, the spring 459 being particularly noted.

The movement of the writing pins away from and against the paper may also be provided by other means than by the centrifugal force. Eg. this can be achieved by using magnets which are activated a certain time after the printheads are started. The same magnets can be used to keep the writing pins out of contact with the paper when the rotor decelerates or after the rotor has come into contact

27 DK 155386 B

a stop. The magnets can be activated manually if desired.

FIG. 14 shows another embodiment of frame connection to the paper 36. Instead of the previously described curved spring 58, the paper feed wheel 56 is made of metal (e.g. steel) and is connected to a frame by a brush 461. Brush 461 has contact with the end of shaft 96 on which wheel 56 is disposed. This construction provides an advantageous rolling frame connection to the paper. Thus, abrasion and friction due to the previously described sliding joint are avoided and damage to the paper is avoided. Furthermore, by making the wheel 56 of metal instead of rubber, it prevents the wheel 56 from being deformed as a result of constant pressure against the wheel 98 when the machine is stationary.

In the following, some specifications will be given for some of the materials and components used for a proven embodiment of the invention. .

Appropriate writing paper is readily available. A suitable paper is covered with a black opaque material and then with either aluminum or zinc oxide. A preferred paper thickness is 0.05 mm. The aluminum-coated paper is advantageous because it often requires lower writing pin voltages to evaporate the aluminum coating, so that the black material sub-bottom becomes visible.

The writing pins used preferably had a diameter of 0.125 mm and were spaced 0.4 mm apart from center to center. The desired distance between the dots on the paper is approximately 0.4 mm in both vertical and horizontal directions. However, it should be noted that there is sometimes some vertical pull-out of the dots due to the rotation of the rotor. When printing marks, this is sometimes an advantage, as the dots thereby tend to merge in the vertical direction.

The writing pins are made of thorium-coated tungsten, and the preferred angle between the writing pin and the roller is 60-704 (see Fig. 6).

28 DK 155386 B

It is preferred that as much of the device frame as possible is molded in plastic to make this easy and cheap. The housing 24 and many other parts of the apparatus can be molded in reinforced plastic, such as fiberglass reinforced polystyrene, which has good strength and abrasion properties where the main drive shaft 48 is made of metal.

The roll 26 is preferably molded from glass-reinforced styrene-acrylonitrile polymer or polycarbonate resin or nylon. A roller of the former material is found to have excellent properties in that it is not electrically conductive and does not tend to be worn by the writing pins despite being made of a very hard material.

A DC motor has been found suitable for operation of the device and can have a 12 volt operating voltage and consume 1.3 amps at 4,400 rpm.

The optical sensing means 146 for detecting the timing marks on the disc 54 are of a kind referred to as "optical switches". The commercially available aggregates have been modified by applying a mask as previously described. ;

Said encoding of the characters is preferably the ASCII II code, with code converters readily available in this code.

The electrical components of the embodiment shown in FIG. 9 circuits will be partially listed below and are available in various phases. brikater.

Component Identification

Rome Code Converter 202 2512 "Character Generator"

Signetics operates in ASCII II code shift registers in storage 200 and integrated shift registers shift register 232 type 2529 with data recirculation facility multivibrators 236, 251, 254, 74LS integrated D-type 258 bistable multivibrators

29 DK 155386 B

Component (continued) Identification of multivibrators 300, 302, 304 and 74Ls73 j-type integrated bistable multivibrators multiplexer 282. ,, _. . Integrated multiplexer type 74153 row counter 262 .., integrated four bit counter connected to 16-margin counter 246 74LS90 integrated counter connected to 2-line counter 278 74LS190 integrated counter with 74LS74 multivibrator connected to 2-slot 270 input circuit # 7427 plus NOR lock integrator 310 operational amplifier A741 with capacitive feedback tachometer 308 74LS121 integrated mono stable multivibrator AND locks 272 integrated NAND locks no.

7403 locks 222, 282, 294, 290 integrated AND locks no.

74LS08 counts 288 two pieces 74LS193 integrated counters connected to division-with 117 OR locks 218, 219 and 220 NOR locks # 74LS02

Claims (3)

A rotary electrical writing apparatus for printing alphanumeric characters and comprising a rotor (28), means (40, 30) for rotating the rotor, at least one group (62, 64, 66) of pins on the rotor, feeding means (56) for moving a registration sheet (36) past the rotor substantially continuously in a direction transverse to the rotational movement of the rotor so that said pins touch the sheet, and electric control means adapted to selectively activate said pins so that each pin forms a dot on the sheet (36) having a predetermined position and thus providing images from transverse rows and perpendicular columns of such dots, characterized in that said group (62, 64, 66) comprises a plurality of pins (68) having axial spacing, and the pins (68) of said group are located close to each other so as to provide a column for each passage of the pins across the registration sheet (36), In group (61, 63, 66) there are a plurality of pins (68) corresponding to the number required to provide all the dots in the horizontal and vertical positions for each of said characters, so that a passage of a group (62, 64, 66) of pins (68) across the registration sheet (36) will result in printing of at least one character on the sheet. Apparatus according to claim 1, wherein the alphanumeric characters are printed to form words, wherein the sheet (36) is an electrically sensitive paper in the form of an elongated strip, wherein said feeding means (56) DK 155386 B is arranged to moving the strip in its longitudinal direction past said rotor (28) and wherein the distance between the pins (68) in each group (62, 64, 66) corresponds to the desired distance between the dots in the printed character, characterized in that the number of characters in each word during each rotation of the rotor (28) is equal to the number of pin groups (62, 64, 66) of the rotor (28). Apparatus according to claim 1 or 2, characterized in that position indicating means (54) are provided which comprise a disc (54) with marks (166, 168) consisting of alternately translucent and translucent linear regions of the disc and that the arc distance between adjacent opaque regions is proportional to the desired distance between the dots, and that there is a detector (146) comprising a lamp and a photocell so arranged that the photocell receives light from the lamp, modified by the linear regions on the dial.