JP2701073B2 - Method and circuit configuration for generating information about type of printer head and method for driving printer head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention generates information indicating the type of a printer head in a printer that includes at least one printing unit and whose setting member has electrical resistance. On how to make it.

SUMMARY OF THE INVENTION A method for generating information indicative of the type of printer head (18) provided in a printer and having at least one print (86, 88, 90) is described. The setting member of the printed body (86, 88, 90) has an electrical resistance detected by the evaluation circuit. This resistance is assigned to a plurality of resistance ranges corresponding to different types of printer heads. The evaluation circuit generates, as information, type signals (40a, 40b, 40c) according to the assignment of the result. The type signals (40a, 40b, 40c) are entrusted to a control device which supplies control signals suitable for the various types of printer heads (17, 18) in each case. The invention can be used in practice for all printer heads in which the printing body is actuated by an electrical or electrical setting member and thus has an electrical resistance.

[Background Art and Problems] A printer for outputting text, data, and graphic information is incorporated in an electronic data processing apparatus. The transfer of the printed symbols onto a carrier, for example paper, is performed by a printer head. Modern printers are distinguished by the fact that different types of printer heads can be contained within the printer housing. Such a printer is for example DE-OS3511386
Is described in. In this device, the print heads of the print stations are interchangeable, and a single printer can have multiple such print stations. The printer here has a simple basic housing that can be mass-produced very economically. Depending on the case used, the basic housing is loaded with a different printer head, and the customer's personal replacement wishes are only taken into account in the final mounting operation. Thus, a very large variety of printers and economical production are achieved. This type of device is used as a printer for, for example, a bankbook or a receipt.

There is a series of printing methods that differ in the principle of operation and the structure of the printer head. The printer head has a large number of printed bodies having different structures corresponding to various printing methods in order to transfer print symbols onto a carrier. Among them, the mosaic printing method has a special meaning. In this method, the symbol type (hinata, pattern) is formed in a mosaic form from individual color points generated by the printed body. The prints are actuated by the respective setting members. The electrical resistance of the setting member can be a resistance or impedance with a capacitive or inductive component as well as a resistance. In the ink mosaic printing method, such a printing body is composed of nozzles, and when the piezoelectric (piezo effect) setting member is controlled by an electric pulse, ink droplets are scattered on a carrier, and the ink droplets are scattered there. Form a color point. A print symbol is established by arranging a number of individual color points in a mesh. In another method, needle printing, individual prints are formed as needles. These are protruded by the electric setting member according to the acting force of the coil through which the current flows, and push the color tape toward the carrier, thereby also establishing a point-like symbol pattern. Finally, regarding the thermal transfer method, in the thermal transfer method, the printing material has an ohmic resistance as a setting member, and this heat is generated when a current flows. The dot-shaped printed symbols are transferred to a carrier via a heat-soluble color tape or formed directly on a heat-sensitive record carrier.

In order to perform a printing operation, the printer head must be supplied with control signals, which have a fixed range of values and correspond to control parameters. This control parameter is generated in the control unit supplied with the information to be printed. Important control parameters must be supplied, for example, to select a print for printing mosaic points or to select a combination of prints for printing certain symbols, and, for example, to perform a print operation on the print each time. The amount of energy in the form of electrical energy. Other important control parameters determine the chronological state of the printing process as well as the time. By controlling the printing process with precise time, the position of the printed symbols on the carrier is determined by the relative movement of the printer head and the carrier. Different types of printer heads have different control parameters. Assuming that various types of printer heads are provided in a single printer, the control parameters to be provided by the controller should also be adapted to the type of printer head. Since the control parameters of the various printing methods are known,
It can be configured to contain all control parameters of the printer head provided in the printer and to call out as needed. The control parameters can be stored, for example, as data in a storage device or can be generated by a control circuit. This allows the controller to supply certain printer heads with the available control parameters, however, the controller needs information about the type of printer head to be controlled.

This can be done in such a way that the operator checks the type or type of printer head and communicates this information to the control device by actuating the signaling switch. Taking such measures involves the risk of malfunction due to misidentification of the printer head or erroneous switching. Therefore, mechanical measures are required to eliminate unintended and inappropriate switching of the signaling switch. Therefore, in order to eliminate the malfunction of the printer with a high probability, it would be desirable for the information about the type of the printer head to be automatically transmitted by the printer.

"Means for Solving the Problems" It is an object of the present invention to provide a method for automatically detecting the type of a printer head incorporated in a printer and transmitting this information to a control device.

This problem is solved in that the resistance is detected and assigned to one of a plurality of resistance areas corresponding to different printer heads, and the assignment results in a type signal being generated.

As a feature that distinguishes various printer heads, the electrical resistance of a printed body is used. This resistance is characteristic of certain types of printer heads. For example, a printed body of an ink jet printer head having a piezoelectric setting member has a high resistance (Wirkwiderstan) having a capacitive resistance component.
d), whereas the printed body with the coil of the needle printer head has a low resistance with an inductive component.
The resistance value of the printed body of the thermal transfer head is generally intermediate between these values. The resistance of a type of printer head, for example a needle printer head, can also characterize a particular embodiment or type of printer head. Therefore, a coil for operating a print body of a needle printer head having a large needle height and a coil for a needle printer head having a small needle height are separately defined. That is, the resistance value of the equivalent coil can be evaluated as a distinguishing feature.

The resistance of the prints of various types of printer heads is generally well known from the start or can be determined by simple measurements.

The resistance of the print of a particular type of printer head is within an acceptable range of the defined resistance range. The invention makes use of this recognition, in which the resistance of the printed body of the printer head to be examined is detected and assigned to a predetermined resistance range. The resulting assignment is represented by a type signal. The resistance of a print may be ascertained in a simple manner by the circuitry of the print itself through which electrical energy for operating the print is supplied. In this case, a conventional printer head can be used without requiring any structural measures on the printer head, such as additional contacts or signal output. This has significant economic benefits. The invention can be applied in practice to all types of printer heads which are activated by an electrical or electrical setting element and therefore have an electrical resistance.

When detecting the resistance, the resistance value ∞ has practical meaning as detection information. This value means that a specific print body whose resistance value should be specified is not provided in the printer head. The presence or absence of a given print characterizes a particular type of printer head. For example, in such a method, a seven-needle printer head (7-Nadel-Druckkopf) is replaced with a nine-needle printer head (9).
-Nadel-Dckkopf). There, the resistance values of the eighth and ninth prints are detected. If this is infinite, it represents a 7 segment type needle printer head. It is possible to supply a control parameter according to a type signal to a specific printer head by using a control device having various control parameters of a plurality of types of printer heads provided for one printer. According to such a processing method, the total consumption during control is small. This is because a single control device can control a plurality of different printer heads. When exchanging the printer head, it is not necessary to exchange the control device which would be necessary if such a control device is not used. This makes the handling of the printer easier and therefore more reliable.

Another teaching of the present invention is that the control device can generate different control parameters depending on the type of printer head to be controlled, and the control parameters that are adapted to the respective printer head will depend on the type of printer head. It is characterized by being set by the type signal that it represents.

Here, the control device obtains information on the type of the printer head in the printer by the type signal. Because the control parameters of the various types of printer heads are known, configure the control measures so that the control device has all the control parameters for the type of printer head in the printer and can call them as needed. Is possible. The control parameters can be stored, for example, as data in a storage device or set by controllable circuits. The set of parameters assigned to a particular type of printer head is thereby generated according to the type signal. As a result, the printer head is provided with available control information. According to this processing method, the total consumption during control is small. This is because a single controller can control a plurality of different types of printer heads. When replacing the printer head, therefore, there is no need to replace the controls required in the prior art, thereby making the handling of the printer easier and therefore more reliable. In printers with multiple print stations, multiple printer heads can be controlled simultaneously. The various printer heads are then supplied from the control unit with control parameters corresponding to a type signal indicating the type of printer head to be controlled in each case, for example according to a time-division method.

A circuit configuration for executing the method of the present invention is characterized in that a measuring resistor through which a current corresponding to a resistance value of a certain printed body flows is provided for detecting the resistance. This measuring resistor is connected in series with the resistance of the setting member of the print body whose resistance value is to be determined. The two resistors, which carry current through themselves, thereby form a voltage divider. The voltage drop U at the measurement resistor is used as the magnitude of the resistance value of the printed body and reaches the connected evaluation circuit. The voltage drop U is then represented by U = V · RM / (R + RM). Here, V is the supply voltage, R is the resistance of the printed body, and RM is the measured resistance.

Furthermore, in the present invention, at least two prints are connected in parallel by a decoupling diode that works in the direction of current flow. This parallel connection is connected in series with the measuring resistor. By this measure, multiple prints of one or more printer heads are connected without reaction,
In other words, the blocking layer of the decoupling diode acts between the printing bodies connected to each other, and the blocking layer blocks the flow of current between the printing bodies. The decoupling diode is connected so that a test current required for detecting the resistance value of the printed body can flow in a direction in which the current of the decoupling diode flows. The test current of the print concerned is superimposed and flows through the measuring resistor, whereby a voltage is generated. By connecting a plurality of prints together, high responsiveness in evaluating the voltage is achieved.

As an additional feature in this connection, in the case of a print station capable of accommodating printer heads having various numbers of prints, at least one print type belonging to a printer head having a relatively small number of prints, and many At least one print body belonging to the only printer head having the print body is connected to a decoupling diode. For example, in a printing station capable of accommodating a needle printer head having seven needles as well as a needle printer head having nine needles, for example, prints 6 and 8 are connected to each other via a decoupling diode. . If the print station houses a nine-needle printer head, a test voltage will be applied to the measurement resistor. However, when a seven-needle printer head is present in the print station as a printer head, the position of the ninth print is not covered, and only the test voltage of the sixth print is evaluated. Thereby, it is possible to distinguish in a simple manner the printer heads themselves having different numbers of the same kind of prints.

Furthermore, the teaching of the present invention teaches that the signal path between the measuring resistor and the print is connected at the base between the emitter and the collector of a switch transistor controlled by a test signal. The switch transistor is switched between a "blocked" and a "passed" state by a test signal. In the "pass" state, the test current serving to detect the resistance value passes through the resistance of the print. In this state, the print body is in the stop position, that is, the print body is not supplied with a current pulse capable of starting the printing operation and altering the test current. In the "interrupted" state, the test current does not flow in the print body. The print is ready to receive the current pulses required for printing.

A further additional embodiment of the circuit arrangement according to the invention is characterized in that an evaluation circuit is provided for generating the type signal. The evaluation circuit includes at least one threshold circuit (comparison circuit), and the threshold value belongs to a specific resistance range corresponding to the type of the printer head. The threshold circuit compares a voltage corresponding to the resistance of the print body with a reference voltage. This forms a threshold value, above which the output signal of the threshold circuit is switched. The reference voltage is selected such that the two states of the output signal of the threshold circuit are clearly attributed to a certain resistance range and thereby to a particular printer head type. Therefore, up to two types of printer heads can be distinguished based on the output signal.

To identify a plurality of types of printer heads, a corresponding number of threshold circuits are used. Here, the output signals of the threshold circuit are logically combined in a preferred manner. This means that the output signal of each threshold circuit is combined with the inverted output signal of the threshold circuit with the higher threshold and combined into the type signal, and This is performed by outputting the output signal of the threshold circuit as a type signal directly or through a gate circuit which is not inverted. With this measure, the type signal is assigned to any type of printer head. The logical combination of the output signals of the threshold circuit is that only one of the type signals has a binary "1" while all other type signals have a binary "0". Realize. Signaling a particular type of printer head by digital coding is thereby achieved in a particularly simple manner.

Embodiments of the present invention will be apparent with reference to the drawings. In FIG. 1, various functional elements of a printer including a plurality of print stations denoted by 10, 12, and 14 are shown. This print station 10,
Both 12, 14 house one printer head, which is mechanically and electrically detachably connected to the print station, respectively, and can be replaced. Print stations 10, 1
2, 14 are mounted to accommodate various types of printer heads. In FIG. 1, a print station 10 is assigned to a printer head 16 formed as an ink mosaic printer. The print station 12 has a printer head 18 operating according to the needle printing method and having nine prints.
Is connected. The print station 14 contains a needle printer head 20 having seven prints.

The printer heads 16, 18, 20 transmit control parameters specific to the printer head from the control device 22 to the signal paths 24, 26,
Supplied via 28. The controller 22 obtains information to be printed from a controller (not shown) in the printer information or an external controller via a signal path 30.

The printer head identification circuit 32 is a print station
From 10, 12, 14 there are obtained electrical signals 34, 36, 38 that clearly characterize the type of printer heads 16, 18, 20 present in the printing stations 10, 12, 14.

The printer head identification circuit 32 forms a type signal 40 indicating the type of the printer head from the electric signals 34, 36, 38. The individual type signals reach the control device 22. This is such that various types of printer heads 16, 18, 20 are provided with control parameters that are adapted to the respective printer head.

In FIG. 2, the control device 22 is arranged alongside other various components.
Is represented. The symbols of the components already described in FIG. 1 are retained. The type signal 40 is given to various components via the printer head identification circuit 32. Various types of printer heads 18, 20 are controlled by a multiplexer 50. It connects one of the printer heads 18, 20 according to a selection (control) signal 52. The selection signal 52 originates from a controller also located above which coordinates the printing operation of the various print stations. Driver 54 is printer head 1
Supply the pulses of current necessary to operate the printed body of 8, 20 here. The driver 54 provides printer head-specific control parameters that are still to be described here. The selection of a print for printing a certain symbol or mosaic point is made indirectly through symbol generators 56 and 58. The symbol generator stores, in the form of a type font, instructions that act to generate a specific print symbol of a print body in the printer head. Symbol generator
56 works here to generate print symbols for a mosaic printer head with 9 prints, and symbol generator 58 works to generate print symbols for a mosaic printer head with 7 prints. . The information to be printed is obtained by the symbol generators 56, 58 by means of signals 60 from a control located above.

The data multiplexer 62 further connects the data of the symbol generators 56 and 58 to the driver 54. At this time, the connection state of the data multiplexer 62 is controlled by the type signal 40.

The energy to activate the selected print through the symbol generator is derived from a controllable power source 64. This power supply similarly supplies a current whose intensity is controlled by the type signal 40.

The start and the time of the printing operation are controlled by a controllable clock circuit 66. The clock circuit connects or cuts off the current supplied to the print body via the driver 54. The time of the current flow and the temporal state of the current pulses associated with the position transmission signal, which indicates the relative position between the printer head and the display carrier, vary for different types of printer heads. Therefore, this time parameter is generated according to the type signal 40 and provided to the driver 54.

Further, the type signal 40 is provided to the display unit 68.
This indicates the type of the printer head 18, 20 provided in the printer by the signal lamps 70, 72, 74. The type signal 40 is transmitted by the adapter 76 for further evaluation elsewhere. Therefore, the supply of the print carrier or the supply of the color tape is monitored according to the type signal 40,
It is possible to control. In addition, other controllers, for example, that control the relative movement between the printer head and the print carrier in row and column directions, can also evaluate the type signal to adapt the control process to the type of printer head in the printer. It is possible.

FIG. 3 shows a circuit arrangement which makes it possible to automatically identify various types of printer heads. The symbols in FIGS. 1 and 2 remain as long as the same constituent group is used. By means of the multiplexer 50, the printer head 17 and the needle printer head 18 which operate according to the thermal transfer method are connected to the supply voltage V. The multiplexer 50 is controlled by the selection signal 52. At the printer heads 17 and 18, three of the many prints are shown. In the printer head 17, these are printing bodies 80, 82 and 84, to which diodes 81, 83 and 85 are connected, respectively.
This diode prevents shunting of the current between the printing bodies connected in parallel. Print heads 86, 88, 90 on printer head 18
Are shown, and diodes 87, 89, and 91 are similarly connected thereto. The diode 92 connected in the cut-off direction serves to reduce the voltage pulses that can be induced by the induction when the prints 86, 88, 90 are cut off. A diode 93 connected in the blocking direction is also attached to the printer head 17. This is certainly not a requirement in a thermal transfer printer head. This is because this print shows ohmic behavior. However, at the position of the thermal transfer printer head 17, a needle printer head having a printed body having an inductive behavior may be provided, so the diode 93 is also provided here.

Connection terminals 94, 96, 98, 99 and 100, 102, 104, 105 are provided for electrically separating the printer heads 17, 18 from the printer housing. The printing bodies 86, 88, 90 of the needle printer head 18 have small electromagnets that, when driven by current pulses, project movable needles that produce halftone dots on the print carrier via the color tape.

The needles of the printing bodies 86, 88, 90 are arranged vertically to each other,
As a result, when the printer head 18 moves across the print carrier, the prints (86, 88,
Control of 90) produces a reticulated symbol. driver
54 supplies the required current pulses along with a controllable power supply 64. The time status and time of the print and the current pulse are provided by the control unit 22 as additional control parameters 106. Print heads 80, 82, 84 in printer head 17
Consists of a small electrical thermal resistance which transfers a dot-like printed symbol onto a print carrier via a color tape which is heated and melted by the supply of an electric current. Again, the printer head 17 is supplied with current pulses from a driver 54 and a controllable power supply 64.

The connected cathodes of diodes 83 and 89 and the cathodes of diodes 85 and 91 are connected to decoupling diodes 108 and 110, respectively. Their connections on the cathode side are collected at the junction 112 of the current. The junction 112 of the current is
It is connected to the collector of an npn conduction type switch transistor 114, and its base is supplied with a test signal 115. The emitter of the switch transistor 114 is grounded via the measuring resistor 116 and is directly connected to the first threshold circuit 118, the second threshold circuit 120, and the third threshold circuit.
It is connected to 122 non-inverting input terminals. Threshold circuit 1
A first reference voltage 124,
A second reference voltage 126 and a third reference voltage 128 are provided. The reference voltage 124 then has the lowest voltage value,
The reference voltage 128 has the highest voltage value. Threshold circuit 1
18, 120 and 122 are the reference voltages 124, 126 and 12 respectively attached.
When 8 is larger than the input voltage without inversion, a low-level signal is output. Voltage is reference voltage 124, 126, 12
If one of the eight levels is exceeded, the associated threshold circuit 118, 120, 122 switches its output signal to a high level. Here, the low level is assigned to a binary “0”, and the high level is assigned to a binary “1”.

The output signal of the threshold circuit 118 is supplied to the non-inverting input of the AND gate 130. It has two other, but inverting inputs, where the output signal of the threshold circuit 120 and the output signal of the threshold circuit 122 are located. The output signal of the threshold circuit 120 is the second AND gate 1
Supplied to 32 non-inverting inputs. Another inverting input is connected to the output of threshold circuit 122.
Finally, a third gate 134 is provided in the circuit configuration, which serves as a non-inverting drive circuit, the input of which is directly connected to the output of the threshold circuit 122.
Gates 130, 132 and 134 generate type signals 40a, 40b and 40c.

Next, the operation of the circuit configuration for identifying the printer head will be described. First, the multiplexer 50 outputs the selection signal 52
It is assumed that the printer head 17 is controlled to be connected to the supply voltage V. The print head 17 is thereby activated and can be in a test mode in which the type of the print head is detected. Here, the test signal 115 is connected to the base of the switch transistor 114. At the same time, the driver 54 is controlled such that the switches shown in FIG. 3 for supplying current to the printing bodies 80, 82, 84 are open. The control signals for the switch transistor 114 as well as for the driver 54 are supplied by an upper control device, not shown.

The current flows through a current path composed of the printing body 82, the diode 83, and the diode 108 to the junction 112 of the current. This current is applied to the printed body 84, diode 85 and diode 11
In addition to the current flowing through zero, it is supplied to ground via switch transistor 114 as well as measuring resistor 116. The strength of the current depends essentially on the height of the supply voltage V, the resistance of the prints 82, 84 and the size of the measuring resistor 116. This current produces a voltage at the measurement resistor 116, which is supplied to threshold circuits 118,120,122. The threshold circuits 118, 120, 122 compare this voltage value to the reference voltages 124, 126, 128 supplied thereto, and if the voltage at the measuring resistor 116 is greater than the reference voltages 124, 126, 128 respectively. At a high level.

The resistance of the prints 82, 84 is known and varies only in a very small range. Thereby, the current flowing through the measuring resistor 116 and its voltage drop also characterize the type of printer head 16 to be tested. Reference voltage 124, 126, 12
8 are therefore assigned to a specific range of the voltage of the measuring resistor characterizing a certain kind of printer head. They are each chosen to be at the lower end of such a voltage range.

Assuming that the actual voltage on the measurement resistor 116 is slightly greater than the reference voltage 126, the threshold circuit 120 adjusts its output to a high level corresponding to a binary "1". Since the reference voltage 124 is smaller than the reference voltage 126 as described above, the output signal of the threshold circuit 118 also becomes binary “1”. However, the output signal of the threshold circuit 120 is connected to the connected AND gate 130.
The result of the AND combination is logically "0", and the type signal 40a having a binary "0" is issued from the AND gate 130. Assume further that reference voltage 128 is greater than the voltage of measurement resistor 116. Then, the output signal of threshold circuit 122 is logically "0", and therefore, type signal 40c of gate 134 is also "0". The output signal of the threshold circuit 122 is inverted and supplied to the AND gate 132. As a result, the AND circuit 132 satisfies the AND condition together with the binary "1" of the threshold circuit 120. The signal 40b is output. The type signal 40b is attached here to the printer head “thermal transfer head”. A binary "1" indicates that the printer head 17 tested is a thermal transfer head. Threshold circuits 118, 12
Due to the special logical combination of the output signals of 0, 122, it is achieved that only one of the type signals 40a, 40b, 40c can have a binary "1". Depending on the type of the type signal configuration, the type of the printer head is represented by a simple and clear code. However, other forms of coding are conceivable.
For example, it is a serialization code or PCM encoding by converting the voltage of the measurement resistor 116 into a frequency. The binary information is then decoded by the controller 22 in a known manner and is finally evaluated. Threshold circuits 118, 120, 122
May be understood as binary bit positions. In this case, the gates 130, 132, 134 can be deleted. If the voltage at the measuring resistor 116 exceeds the first reference voltage 124, the binary number has the value "1"; if it exceeds the reference voltage 126, it has the value "3"; if it exceeds the reference voltage 128, the value "3". Has 7 ".

The test mode in which the switch transistor 114 is connected in the cut-off state by the test signal 115 ends. The printing bodies 80, 82, and 84 of the printer head 17 are driven by current pulses of the driver 54, and execute a printing operation. After the end of the printing operation, the printer head 17 is separated from the supply voltage V. Now the printer head 18 is a multiplexer
Connected by 50 ready for operation. Here also, in the test mode provided before the start of printing, the type of the printer head is detected by the method described above.

The head identification circuit having the components 124 to 134 is similarly expandable according to the number of printer heads to be identified. It is also possible to identify printer heads that have the same printed body resistance but different numbers of printed bodies. By way of example, a seven-needle printer head and a nine-needle printer head are mentioned here. The anode of the diode 108 is connected to a printing body having an anode for identifying the printer head.
The printed body is the one present in both types of printer heads, for example the 7th printed body. diode
The anode 110 is connected to a print body that exists only in the printer head having the larger number of needles, for example, the print body number 8. If the print station has a nine-needle printer head, a total of a seventh and an eighth printed body, connected in parallel in the measuring resistor 116, flow. However, if the print station is equipped with a seven-needle printer head, the test current evaluated for printer head identification is halved.

Further, it is possible to apply a reference voltage of 0 volt to the threshold circuit. As a result, the absence or lack of a certain printer head or print body can be identified and signaled.

FIG. 4 shows various signals and states of the circuit according to FIG. 3 with respect to time t. By supplying the supply voltage V via the multiplexer 50, the printer head 17 and the printer head 18 are switched from a stopped state to a state ready for operation, which is the fourth state.
In the figure, they are shown in the “OFF” and “ON” states. After the printer head 17 is turned on, the type of the printer head is identified. Here, the test signal 115 is set to the binary value “1” for a certain time. At this time, the driver 54 remains off, that is, the printer head 1
The print body of 7 is not supplied with a current pulse.

During the test mode, the resistance of the print bodies 82, 84 of the printer head 17 is detected, and the type signal 40b adopts a binary "1" during the test. Test work is test signal 11
The process is terminated by returning 5 to binary "0", whereby the type signal 40b also takes binary "0". Now the actual printing operation controlled by the driver 54 can take place.

Similarly, the type of the printer head 18 is detected, and the above-described steps are performed. The type of the printer head 18 is represented here by the binary "1" of the type signal 40c, which is the type signal of the needle printer head.

The method according to the invention can be used for almost any type of printer head. The only requirement for this is that the setting members of the printing body each have a measurable electrical resistance. This is always a resistance (Wirkwi
It does not have to be derstand, but can also be a reactance, such as a capacitive resistance in the case of a piezoelectric setting member in an ink jet printer head, or an impedance with a mixed capacitive and inductive component.

In the case of reactance and impedance, this can be connected as part of a current circuit in which the test signal is supplied in the form of a voltage or current having a course according to a given time in order to detect the resistance of the print setting member. preferable. The dependence of the reactance component of the resistance on the frequency causes a characteristic change in a test signal from which a mode in a circuit can be detected by an electric magnitude such as a voltage or a current.
This magnitude is evaluated by known network analysis methods and the result is used to determine the electrical resistance of the setting member.

In particular, the test signal is given a specific curved wave, for example, a rectangular wave. The distortion of the curved shape caused by the reactance component of the resistance, which can be measured in the circuit, for example as a voltage at the measuring resistance, is a measure of the resistance value. It is also detected in a simple manner whether the setting element contains an inductive resistance component or a capacitive resistance component. The piezoelectric setting member of the ink jet printer head has a capacitive resistance. This causes that when a rectangular test signal voltage is input into the circuit, a high current flows first in the circuit and then drops exponentially in the next stage. If the setting element has an inductive component, as in the case of a needle printer head, the current in the circuit only rises gradually. By evaluating the course of the current with respect to time, it is possible to detect the type of resistance of the setting member and thus also the type of printer head.

The test signal rectangle is only one of several possible bending waves. Other known shapes are, for example, sawtooth curves, impulse ramps or needle pulses. This bending wave is also characteristically distorted if the resistance of the setting member includes an ineffective part, so that the ineffective part together with the effective part can be used to detect the type of printer head. Further, as the test signal, an AC signal, for example, a sinusoidal AC voltage whose frequency changes can be used. Thereby, the value of the reactance component of the resistance of the setting element is adapted to the given evaluation range, and the sensitivity of the connected evaluation circuit is further increased by identifying printer heads with a frequency-dependent resistance component.

[Effects of the Invention] As described above, according to the present invention, the type of the printer head incorporated in the printer can be automatically detected, and this information can be transmitted to the control device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing various elements of a printer. FIG. 2 is a diagram showing a configuration group of a control device for controlling a printer head. FIG. 3 is a diagram showing a circuit configuration for identifying different types of printer heads. FIG. 4 is a diagram showing signal flows and time states of the circuit configuration in FIG. 3; 10, 12, 14 Print station 16, 18, 20 Printer head 22 Controller 32 Printer head identification circuit 80, 82, 84, 86, 88, 90 Printed body 116 Measurement resistance

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-170039 (JP, A) JP-A-63-262255 (JP, A) JP-A-60-225772 (JP, A) JP-A-58-58 167185 (JP, A) JP-A-56-126182 (JP, A) JP-A-61-160957 (JP, U) European publication 195949 (EP, A1)

Claims (14)

(57) [Claims] A plurality of prints (80, 82, 84, 86, 88, 90)
A method for generating information indicating the type of a plurality of printer heads (16, 18) provided in a printer having: a measurement resistor (116) for measuring a resistance of the plurality of prints; A decoupling diode (108, 110) acting in a conducting direction for connecting each of the plurality of printed bodies in series with the measuring resistor, and a current flowing through the measuring resistor depending on a resistance value of the printed body. Are assigned to several voltage ranges corresponding to several resistance ranges corresponding to different types of printer heads, and according to the allocation result, classification signals (40, 40) corresponding to the plurality of printer heads, respectively. 40a, 40b, 40
c) generating the information on the type of printer head characterized by generating c). 2. The method according to claim 1, wherein only a part of the printing body is connected to the measuring resistor. 3. Various types of printer heads (17, 18,
The method according to claim 1 or 2, wherein in (20), the type signal is generated based on a resistance of a print body belonging only to a specific printer head. 4. Various types of printer heads (17, 18,
20. The printing method according to claim 1, wherein different printing fonts, each of which belongs to a certain type of printer head, are provided for use in selecting the printing body. Way in one. 5. The printed body is connected as part of a circuit to which a test signal is supplied, and an electrical quantity of the circuit is evaluated to detect a resistance.
The method according to any one of the above. 6. The method according to claim 5, wherein the test signal has a given bending wave, and the distortion of the bending wave is evaluated for resistance detection. 7. The method according to claim 6, wherein the bending wave is rectangular and the ascending and / or descending surface distortion is evaluated. 8. The method according to claim 5, wherein the AC signal is a signal whose frequency is set so that the value of the reactance component of the resistor exceeds a given value. 9. A print station (10, 12, 14) capable of accommodating printer heads having different numbers of prints, wherein at least one print (88) belonging to the printer head having the smaller number of prints and 2. The method according to claim 1, wherein at least one printing body belonging only to the printer head with the larger number of printing bodies is connected to the decoupling diodes respectively. Circuit configuration for 10. A measurement resistor (116) and a printed body (82, 84, 8).
A controllable switch (114) is connected to the signal path between the control signal (8, 90) and the switch is controlled by a test signal (115) at the control input. 10. The method according to claim 9, wherein
Circuit configuration in. 11. A threshold circuit (118, 120, 122) assigned to a resistance range corresponding to a type of printer head having a threshold for generating the type signal (40, 40a, 40b, 40c). Circuit arrangement for performing the method of claim 1 or at least one of the claims 9 and 10. 12. An individual threshold circuit (118, 120, 122).
Is higher than the threshold circuit (118, 120, 122) so that only the output signal of the threshold circuit (122) having the highest threshold is supplied as the type signal (40c). 12. The circuit configuration according to claim 11, wherein the signal is combined with an inverted output signal of a threshold circuit having a high threshold value to generate a classification signal (40a, 40b, 40c). 13. At least 2 provided in a printer.
A method of alternately driving two printer heads, wherein the at least two printer heads are in a standby state, and when each of the at least two printer heads is driven, (1) before each printer head is driven Identifying the type of the driven printer head based on the type signal generated by the method of claim 1, and (2) transmitting a control signal to the driven printer head based on the identification result. A printer head driving method characterized by the above-mentioned. 14. The printer head driving method according to claim 13, wherein a parameter unique to the driven printer head is supplied to the printer head based on the control signal.