DE3208793A1 - WRITING DEVICE, ESPECIALLY BEAUTIFUL WRITING DEVICE - Google Patents

Description

HOEGER, LAW & PA-RTNERi

P A T - E .N T ΙΑ N Vv A "1__ J" E "-UHLANDSTRASSE 14 c D 70OO STUTTGART 1

A 45 092 b Applicant: Centronics Data Computer

k - 176 ■ Corporation

March 4, 1982. One Wall Street

Hudson ,. New Hampshire 03051

UNITED STATES · '

Writing utensils, in particular fine writing implements

The invention relates to a writing instrument, in particular Calligraphic pen, for successive writing of characters along a line on a recording medium supported by a writing pad, with a pen, which is carried by a carriage that can be moved in the direction of the lines, and two on the carriage mounted servo motors to control the movements of the pen relative to the carriage along two transversely, in particular, axes running perpendicular to one another depending on 2 two, one of these directions each assigned control voltages which are assigned to the characters to be written in a defined manner are.

Calligraphy devices or systems are known in which a pen or stylus together with the servo devices driving them are carried by a carriage which is moved from one character position to the next, the servomotors being controlled by means of corresponding control voltages in each character position to start writing the ^:

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desired character. Such devices are described, for example, in U.S. Patents 3,182,126; 3,342,936; '3,349,176 and 4,150,902. A similar form of graphic plotter is also in U.S. Patent 3 449 754.

In devices of this type, the vectors or line segments, which form a character, typically in digital form, stored in digital storage devices. So-called read memories (RQMs) are preferably used as memories, which are in a Form are provided that allows easy replacement of these Lesespelcher, so that, for example, the Font can be changed. In the case of the known writing implements or printers, the carriage is gradually increased moved from one drawing position to the next and stopped each time in order to Allow writing of each character. In this way it is possible to change the vectors that are used for the individual characters are typical, to be defined in terms of a fixed frame of reference. In the US PS 4,150,902 it is indicated that it is possible to write while the carriage is moving; In the cited patent, however, there are no indications of how this is done in detail could.

It is clear that writing while the car is running has a significant performance advantage of the writing instrument offers, as with step-by-step

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the time required for accelerating and decelerating the moving car from the time required for the actual writing available time is deducted. However, this loss of time sets an upper limit for the Average write speed of the device, which limits its write performance, independently what improvements can be made to the speed of the servomechanisms, which drive the pen or the stylus.

In principle, it should be clear to a person skilled in the art that the coding of vectors in digital .Form is carried out in this way It could be that the direction of the vectors themselves a movement .the frame of reference is taken into account finds. With such a coding, the characters shown would be with the car running despite the moving frames of reference have the desired shape. On the other hand, however, it is also clear to the person skilled in the art that such a compensation in the original coding the individual. Characters would have to be specified and that the character encoding would then only be for a single one Car speed, would be valid. '

The invention is based on the prior art The object of the invention is to provide a writing implement, in particular a calligraphic pen, which has a high Can write speed while the car is running and at the same time with regard to the running speed of the car offers a high degree of flexibility. ■.

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This task 'is carried out at. a writing implement according to the invention solved that drive devices are provided, with the help of which the car can be selected? speed can be moved in the line direction that! Compensation voltage generating devices are provided / with the help of which a compensation voltage can be generated, which is dependent on the carriage position changes, and that linking devices are provided, with the help of which the compensation voltage with at least one of the 'control voltages

to obtain a modified control voltage can be linked in such a way that the running speed of the carriage, independent of the relative movements corresponding to the two unmodified control voltages the pen with regard to the recording medium or the writing pad can be brought about.

The decisive advantage of the writing instrument according to the invention is that the individual characters are written while the carriage moves at variable speed, in particular, the device nevertheless works extremely reliably and is relatively simple and inexpensive to build.

According to a preferred embodiment of the invention a writing instrument is provided according to the invention at where each character of a given number of characters is represented by a number of digital data words each of which defines a vector. The writing instrument works with a mechanism

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when written on a recording medium supported by a writing pad is / from a car, - which with respect to the writing pad is moved. This wagon carries two linear converters resp. Servomotors that one Pen or a pen in two to each other in drive essentially perpendicular directions, whereby · relative to the carriage a movement of the pen within a predetermined area or frame is made possible. Furthermore, there are drive devices to drive the carriage with respect to the writing pad ■ at a selectable speed and to generate one Voltage provided, which varies depending on the position. or. Deflection of the carriage · starting from a selectable point changes which corresponds to the edge of a drawing area with respect to the writing pad. In detail, two voltages, which speed components, are generated from each of the stored data words along the two transverse directions. Furthermore are two integrators are provided to speed out these voltages generate corresponding position voltages assigned to the relative position. The voltage corresponding to the position of the carriage also becomes at least one of the relative position voltages added in order to generate corresponding control voltages Z.U that correspond to the position of the pen with regard to the car. The. Servomotors are now driven in such a way that they move bring about the pen, which with regard to the

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Carriage is proportional to the control voltages and which with respect to the plate is proportional to the relative Position stresses and thus at least im essentially independent of the running speed of the car.

Although in general a movement of the pen or the trolley with regard to the recording medium or the writing pad takes place, which in particular how a typewriter roller can be designed, according to the invention, like this, consists of the above Explanation becomes clear, in principle, the possibility of corresponding movements of the writing pad or to bring about the recording medium relative to a fixed spring.

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Further details and advantages of the invention will be explained in more detail below with reference to drawings explained and / or are the subject of subclaims. Show it: ..

Fig. 1 is a schematic representation of a preferred embodiment of a pen according to the invention;

Fig. 2 is a schematic, partially as

Block diagram executed circuit diagram of a control circuit for a Calligraphic pen according to FIGS. 1 and

3 shows a block diagram of a schematic microprocessor system for Delivery of data and control signals to the control circuit according to FIG Fig. 2.

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In detail, FIG. 1 shows a carriage arrangement 11 which is mounted on two rails 13 and 15 so as to be slidable and can be moved in the longitudinal direction of a writing pad 17. The writing pad 17 can thereby be designed, for example, in the manner of a typewriter cylinder; but it could also be a feast mounted, plate-shaped writing pad that is independent of the paper feed can be used.

The carriage arrangement - hereinafter referred to as "carriage 11" for short denotes - carries two linear converters or servo motors 21 and 23, die.dem drive and positioning a stylus or a spring 25 are used. The servomotors 21, 23 are aligned so that that they can move the spring 25 essentially longitudinally transverse to each other end.er axes. Included the servomotor 21 drives the spring 25 along an axis which is parallel to the direction of travel of the carriage 11 runs τ this axis is called the X-axis, -, while the servo motor 2 3 the spring 25 along a perpendicular to it. Axis - the Y-axis - drives. Each of the servomotors 21 or 23 responds to a control signal for driving the spring 25 along the relevant axis and also contains signal generating devices to generate a return or Position signal. In the presently preferred embodiment, optical converters are used for Generation of the position signal used, as is similar in the aforementioned US Pat. No. 4,150,902 are described. The carriage 11 typically also has a third drive device

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(not shown), with the help of which the nib is moved into and out of the writing position can be, and with the help of which the pressure exerted by the pen can be varied.

Before giving a detailed explanation, it should be said that the letter is made by means of the Carriage 1T moves along the writing pad 17 from one character position to the next and thereby 'in each character position by controlling the linear servomotors 21 and 2 3 so that ' these move the spring 25 according to a set of vectors defining the character in question. The definition of these vectors is preferably in digital form in a suitable digital memory, for example, stored in a so-called read-only memory (ROM), which is preferably is conveniently interchangeable to change from one font to another. The nib 25 can be a pen that can be used to write directly, or a Feather that writes on an ink ribbon in order in this way to that which is supported by the writing pad 17 Indirectly inscribing on paper or the like, this indirect inscription being preferred.

The movement of the carriage 11 in the longitudinal direction of the writing pad 17 takes place with the aid of a direct current servomotor 27, which drives a toothed belt 29 that runs over two rollers 31 and 33. on in this way the drive takes place along the

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row or along a line, i.e. in the horizontal direction. The movement of the paper is transverse to this direction / i.e. perpendicular, the drive being carried out with the aid of a stepping motor 35, the in the exemplary embodiment, the roller-shaped writing pad 17 drives to a step-by-step rotary movement.

To obtain a feedback signal via the posi- ' functions of the carriage 11, a so-called shaft encoder 37 is connected to the shaft of the servomotor 27. This encoder 37 is of a type according to which two rectangular pulse trains with a 90 ° phase shift, i.e. with a so-called phase quadrature, so that both the speed of the Motor as well as the direction of rotation can be determined. The square pulse trains A and B are in Fig. 1 indicated. The aforementioned position information signals are supplied as control signals to a processor for overall control and also the individual servo control circuits, as is clear from FIGS. '.

As indicated above, the definitions or data of the vectors that form the individual characters are preferred stored in digital form in a read-only memory and are controlled by a microprocessor evaluated in order to generate the actual control data which the servomechanism for Drive the spring and the drive for the carriage 11 steer. The general organization of this micro-

*) RDtation pulse generator

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Processor system is shown in Fig. 3 shown. That shown System is bus-oriented, which means that the storage devices, the input / output connections (I / O connections) and the processor all are connected to a common data and control bus. This bus is denoted by the reference numeral 41, while the processor itself is designated by the reference numeral 43. In a preferred embodiment of the invention, the processor was 43 a microprocessor of the type 8085 from Intel, while the memory and the I / O connections were formed by integrated circuits from the same family of semiconductor circuits. It can be seen that the advantage of using a microprocessor controller is that the ' Operating mode can be changed in a flexible manner by programming, without extensive redesign the circuit itself would be required. Works for the exercise of his tax functions the processor with a random access memory (RAM) for storing the operating parameters. This memory is denoted by the reference numeral 45 .. Fixed data, i.e. the data which the vectors defining the individual characters of a font are stored in read-only memories. In Fig. 3 four such read memories 46 to 49 are shown.

The digital data for determining the operation of the control circuit according to FIG. 2 is provided by the microprocessor system via storing output units

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51 and 52 supplied. The output unit 51 supplies the data for the spring servo motors while the output unit 52 supplies the information or the control signals for the carriage speed, As is customary with such systems, become Various control signals are required by the processor to check the state of the mechanics or the drive devices to determine, while on the other hand various control signals are transmitted to the individual drive devices. One in two directions working input / output unit is denoted by reference numeral 53. A third 1/0 port 54 is used for vertical control, i.e. the control for the stepping motor 35. This However, the mechanism does not form part of the invention and is therefore not described in more detail here.

The data determining the vectors are preferably stored as data relating to the direction and length of the vectors. The functions of the microprocessor system according to FIG. 3 include processing this data and generate the corresponding X and Y components. These components are made with an accuracy each represented by four bit positions and applied to the digital / analog converters 61 and 62 in FIG. The values transmitted to the control circuit represent speed components. To obtain shift values, the voltages from the output of the D / A converters 61 and 6 3 are

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tion circuits 71 and 73 integrated. Any of these Integrating circuits including an inverting amplifier and an integrating capacitor C 1 or C 3. The capacitors C-. 1 and C 3 can be discharged, i.e. there is the possibility of 'the integrators reset / using the appropriate analog switch. The analog double switch, which is provided for this purpose is denoted by reference numeral 75 together with its control circuit. This reset circuit 75th is controlled by a control signal "reset" which. is one of the control signals sent by the output unit 53 of the microprocessor system according to FIG. "'" ._- ■

The output signals of the integration circuits or Integrators 71 and 73 are applied to spring amplifiers 75 and 77: via corresponding current limiting resistors R 1 and R 3, respectively. The spring amplifiers 75 and 77 speak to the difference between the integrator output signals and the corresponding ones Position signals received from the servomotors 21 and 23 for the X and Y drives, respectively. The. Spring amplifiers 75 and 77 in turn control power amplifiers or drivers 76 and in the usual way 78 for the X or Y drive. ·

The phase-shifted rectangular pulse trains A and B of the shaft encoder 37 are applied to an input of two comparators 81 and 83, respectively. To the other Input of each of these comparators becomes an appropriate one

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Intermediate reference signal V. placed. The output signal of comparator 81 is sent directly as an input to an exclusive-or gate '. 85 created and also via a delay circuit to the second input of this gate 85, the delay circuit is formed by a filter with a resistor R '6 and a capacitor C. 6 and wherein the rectangular shape of the pulses is restored by a buffer gate 87. The purpose of the OR gate with the delay circuit associated with its one input consists in am Output of the gate 85 for each positive or negative transition of the input signal A one to get a short output pulse. A completely the same Circuit C7, R7, 88 generated depending on the Input signal B is a corresponding pulse train at the output of an exclusive-or gate 89. The pulse trains from the outputs of the gates 85 and 89 are in a further exclusive-OR gate 91 summarized. At the output of this gate a pulse appears at each transition of the two input signals A and B. In the end, this way obtain a pulse repetition rate four times higher than the pulse repetition rate of either of the two Input signals. If de> - carriage by a stepper motor would be driven instead of the DC servomotor 27, then the pulse signal could be used for Continuation of this stepper motor can be used instead of the pulse train that is used in the exemplary embodiment is generated by the shaft encoder 37;

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The pulse train from the output of the gate 91 is applied to a counter 101 so that its count changes depending on the route over which the carriage 1i is moved. The counter 101 is reset at the same time as the integrators 71 and 73 start displaying each character. Thus, the counter reading of the payer 101 corresponds in a certain sense to the movement of the carriage with respect to (of the starting point) · the respective drawing position. The in The counter reading of the counter 101 in digital form is converted by a digital / analog converter 103 converted into an analog signal voltage, the data transmission from the counter to the converter via a Buffer memory 105 takes place, which is loaded synchronously with the counting process, to the so-called ripple to avoid ripple-through effect. In a sense, the output voltage forms the D / A converter 103 as the carriage 11 moves with respect to the writing pad 17, a sawtooth voltage. However, this sawtooth voltage is not a time-dependent function in the usual sense, but rather rather, it is proportional to the actual displacement of the car and thus with regard to its temporal movement Depending on the running speed of the car changeable.

The sawtooth voltage from the output of the D / A converter ^: is mixed with or added to the X-axis position signal of the integrator 73, the sawtooth signal being applied via a resistor R 9 to a summing point S at the input of the error amplifier 77. The addition of the shift

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of the car's corresponding component to the voltage defining the respective vector allows this Writing characters while the car is running without changing the basic vector coding scheme would be required, and in a way in which the traveling speed of the car may change. Due to this speed compensation, the car can be moved relatively quickly, when simple characters are written and correspondingly slower when more complex characters are written are to be written. In this way, the output of the writing device compared to such devices can be considerable be increased at which the running speed of the carriage must be kept constant, as is the case when the compensation for the running movement of the car is integrated into the scheme of the vector coding. In addition, the speed would have to be be relatively low for this case of a single fixed, predetermined running speed of the wagon, i.e. chosen so that even the most complex characters to be written are still written cleanly could.

The choice of the carriage speed is carried out by the microprocessor system according to FIG. 3 by the Output unit. 52 a data word or bit is output which represents the desired carriage speed. This bit, which has an accuracy of has at least 5 bit positions, it is applied to a D / A converter .111. The output signal of the wall

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lers 111- which is an analog 'voltage which the Desired speed is compared with a voltage that represents the actual speed is equivalent to. This voltage is obtained from the output of a frequency / voltage converter 113, the the pulse train from the output of gate 91 is supplied. As described above, the pulses become this Pulse train generated with a pulse repetition frequency proportional to the speed of the car and · which is derived from the shaft encoder, the is connected to the drive motor 27 of the car. The output voltages of the frequency / economy converter 113 and the D / A converter 111 are, via corresponding Mixing resistors R 11 and R 13 at a summing point T is applied to obtain an error signal. This error signal is generated with the help of an amplifier 11.7 reinforced. The amplified output signal is mixed with an alternating voltage component, the obtained from a so-called dither oscillator 119 and at one input of an amplifier is applied, at the second input of which the output voltage of the amplifier 117 is applied. The exit of amplifier 121 is a power amplifier 121 connected, which in turn controls the servomotor 27.

In the embodiment under consideration, there are precautions taken to convert from the same font data, i.e. from the digital data sent directly to the D / A converters 61 and 63 are applied, characters different Size. To this end

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are the converters so-called multiplying converters, where the output voltage is not only applied to. Digital value / but also to an analog reference voltage is proportional. A four-bit data word, which is again from the microprocessor system according to FIG. 3 is obtained / is applied to a decoder 72, the two separate 1 of 4 selection signals generated. Each of these signals is applied to a corresponding four-way switch 74 or 76, to select one of four predefined voltages to be used as a reference voltage to the relevant D / A converter .61 or '63 is created. The specified voltages are obtained from a voltage divider with resistors R -21 to R24. The resistors R 21 • up to R 24 are selected in such a way that they generate voltages that correspond to the desired character sizes, so that not only a normal D / A conversion is performed. The decoder 72 works as follows that there is always only one switch for each of the four-way switches is closed, so that the reference voltage applied to each of the two D / A converters 61 and 6 3, respectively can be chosen independently. - ■

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As the horizontal and vertical scale factors consequently can be chosen separately, the Possibility of using the same data characters with different scaling - distortion or just generate enlarged or reduced characters.

In the embodiment under consideration, the axis of one of the servomotors for driving the Spring parallel to the direction of travel of the carriage, while the other axis is essentially perpendicular to it. As a result, the signal compensating for the movement of the carriage need only be with one of the two Control signals for the servomotors are mixed to obtain the desired "moving frame of reference". On the other hand, it goes without saying that an arrangement could also be used in which the The axes of rotation of both servomotors make an angle, for example an angle of 45 ° with the direction of rotation of the Enclose the car and stand perpendicular to each other. In such a case, compensation signals would be provided for each of the servo control signals, taking into account the correct sign of a suitable size to compensate for the running movement of the carriage. It is also closed note that it is the relative movement between the writing surface and the nib that matters and that each of these components could be moved to obtain this relative movement. A movement however, the spring retainer, i.e., the carriage, is preferred.

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In summary, it can be stated that according to the invention the digital coding of vectors to define characters with respect to what appears to be fixed Frame or reference point is facilitated. A very fast writing of characters with the help of a movable The frame of reference - of the carriage - then becomes through it achieved / that at least to. E. one of the control voltages for a spring servo motor is a compensation voltage is added, which corresponds to the running movement of the frame or the carriage with respect to a character position. In this way, compensation for the movement of the reference frame becomes essentially independent of the Car speed reached.

Finally, it should be pointed out that the person skilled in the art, based on the exemplary embodiment under consideration, Numerous possibilities for changes and / or additions are available without him doing it had to leave the basic idea of the invention.

L e r s e i t e

Claims (9)

P A T E-M T-A N W- -A JL- T- E "" <". Γ. . UHLANDSTRASSE 14 c · D 7OOO STUTTGART 1 A 45 092 b 'Applicant; Ce.ntroni.es Data Computer k-176 Corporation. March 1982 One Wall Street Hudson; New Hampshire 03051. · USA claims 1. Writing implement, in particular pen, for successive writing of characters lengthways
a line on a recording medium supported by a writing pad, with a pen, which is carried by a carriage that can be moved in the line direction, and with two servomotors mounted on the carriage to control the movements of the pen relative to the carriage along two transverse, in particular perpendicular, to each other running axes depending on two control voltages assigned to one of these directions /
which are assigned to the characters to be written in a defined way, thereby
marked, '. that drive devices (27-33) are provided, with their
With the aid of the carriages (11) it is possible to move at a selectable speed in the line direction, so that compensation voltage generating devices (37, 81, 91, 101-105) are provided with the aid of which
a compensation voltage can be generated which changes as a function of the carriage position, and -2- . : \ : '-; I '": ■':"':' - ^: 320S793 A 45 092 b. k-176 -2- j NAC HQEREICHTJ . March 1982 '' that linking devices (S) are provided, with the help of which the compensation voltage with at least one of the control voltages can be linked in this way to obtain a modified control voltage is that of the running speed of the carriage • (11) independent, the two not modified Control voltages corresponding relative movements of the pen (25) with respect to the recording medium or the writing pad (17) can be brought about are. 2. Writing implement according to claim T, characterized in that that the linking devices for linking the compensation voltage with at least one of the control voltages have an adder network (S) .. 3. Writing implement according to claim 1 or 2, characterized in that that the compensation voltage generation devices (37, 81 - 91, 101 - 105) are designed such that the compensation voltage at the start of the write process for each Character can be reset to zero. 4. Writing implement according to one of claims 1 to 3, characterized characterized in that each of the servomotors (21, 23). Signal generation devices for generation a feedback voltage are assigned and that the logic devices at least one the control of one of the servomotors (21) - 3 - 092-b. '·. ■■■■ -' ■ ■■ - ■ - ■ "^ = - =: - 320879 k - 176. - 3 -! -. j 1 ^ AOHGiEREICHTI . March 1982 · '.-. "* - —J serving error amplifiers (77), with the help of which the relevant unmodified control voltage, the relevant feedback voltage and
the compensation voltage can be linked to obtain the modified control voltage. 5. Writing implement according to one of claims 1-4, characterized characterized in that control voltage generating devices are used to generate the two unmodified control voltages (.4t, 43, 51, 61, 72 - 76) are provided, with the help of which two Velocity voltages can be generated which represent velocity components in the direction of the two axes running transversely to one another,
that two integration circuits (71, 73) are provided, with the help of which from the speed voltages corresponding, the · position of the
Spring (25) with respect to the carriage (11) associated position stresses can be generated, and that the
Linking devices (S) are designed in such a way that, by adding the compensation voltage to at least ■ one of the position voltages, control voltages can be generated which correspond to the spring position with respect to the recording medium or the writing pad (17) »· 6. Writing implement according to claim 5, characterized in that that the movement of the spring (25) which can be brought about by one of the servomotors (21) is at least in the -4- * - ■ ^: - ^: - ^: " ^: .Λ. · :. 3203793 A 45 092 b k - 176 - 4 - 4th March 1982 essentially parallel to the direction of travel of the carriage (11) · runs and that the compensation tension by means of the linking devices (S) to the output voltage of this servomotor (21) associated, integration circuit (73) can be added. . · ' 7. Writing implement according to claim 6, characterized in that the integration circuits (71, 73) are equal to reset ±> ar in good time when the compensation voltage is reset to zero, 8. Writing implement according to claim 5 with storage devices, in which each character is a predetermined number of characters in the form of a number of corresponding digital data words is stored, ■ characterized in that the • speed voltages can be generated from the data words. 9. Writing implement according to claim 8, characterized in that that the compensation voltage generating devices (37, 81-91, 101-105) are designed in such a way are that with their help a compensation voltage can be generated, which is dependent from which starting from a character start position ■ achieved for the character to be written ' Car position 'relative to the recording medium' respectively. the writing pad (17) changes. -5-