DE2337494A1 - Pick-up of signals from tape tracks - involves using sensor arranged to inhibit pick-up from adjacent tracks during cross-running - Google Patents

Abstract

The tape tracks scanner has sensors which are arranged in a row across the tape in such a way that there is a sensor on either side of the track which does not pick up any signal. An OR logic circuit for each track is connected through a selection circuit with each of the sensors which blocks ro releases the output of the track sensor, depending on the position of the track, so as to prevent signal errors arising from the cross-running of the tape. Each selection circuit is in two stages linked together by a linking circuit, the first stage incorporating a monostable switch whose function is to determine the position of the tracks.

Description

LICENTIA
Patent-Verwaltungs-GmbH 6000 Frankfurt (Main) 70, {Pheodor-Stern-Eai 1

(Donau), July 20, 1973 PT-UL / Bs / rß UL 73/95

"Arrangement for scanning signals along at least one track"

The invention relates to an arrangement for scanning signals along at least one lane with a row of sensors located transversely to the lane direction in such an arrangement, that the track signals are steadily moving when the track is shifted transversely at least one of the sensors can be recorded, the tracks being recorded next to one another at such a large distance are that on both sides of the tracks to be scanned at least

a
at least ^ eJ sensor is not subjected to track signals, with an OR element for each track to be read out, since ^{5 is} connected to each of the sensors via a selection circuit for

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Pricing or blocking of the one leading to the OR element Output of the assigned sensor depending on the position of the track to be read.

The task is purely to scan signals along a track or simultaneously along several parallel tracks the achievement of an undisturbed signal sampling despite occurring Transverse displacements of the track fen) or the scanning device, which are almost always unavoidable, especially as a deflection of the current.

The well-known and often common use is not track-guided Scanning devices (such as magnetic heads or optical Scanning systems) requires measures for the most precise guidance or storage of the track carrier and / or the scanning device to keep mutual lateral deflections within an acceptable tolerance range. Especially when using If traces are closely spaced, it is difficult or impossible to guarantee an adapted tolerance range.

It is known (German AusIegungsschrift 1 160 676), one row of sensors in such a direction transverse to the direction of travel

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Arrangement that the track signals "with transverse shifts of the track can always be picked up by at least one of the sensors, an OR element for picking up the sensor signals and a selection circuit to be assigned that enables or disables the output of individual sensors depending on the track position "causes, namely, that characters change in a track Run through the position under the row of sensors, are detected by a selected activated sensor. The selection happens after a preselection you move the Sensor row, by setting bistable multivibrators by means of an additional sensor row that pre-scans the scrolling characters. Hi he caused a delay the selection that limits the permissible rate of change of the template.

From the German Auslegeschrift 1 262 644, which deals with the selection of "certain sensors of a series of sensors that have a Scan the character to be recognized, in accordance with the signals from all sensors in the row, which reflect the height of the character busy it is. known that this can be dispensed with special prescanning sensors.

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There is also an arrangement "known (German interpretation 2 108 837)," in which a selection circuit that has been activated once supplies a signal that the respective "neighboring Selection circuit, which is not acted upon by sensor signals ", prepared for the price circuit and again in the Lock state passes as soon as the sensor signals fail. This offers the possibility if the position of the sensors does not change to be able to either scan or ignore one or more tracks. This arrangement, however, has major advantages. On the one hand, the circuit fails if it happens that between the read-out recording s track and an adjacent one Track disturbances occur, for example dirt particles in an optical recording system, which are generated by the sensors are passed on as signals. This leads to the fact that the sensors located between the two tracks are activated and then also enable the sensor to which the adjacent lane is activated the misinformation stemming from isolated dirt particles, corrected by redundant coding of the recording track the connection of a second track represents an irreversible falsification of all of them on the trail is the following information. As a second disadvantage

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The above-mentioned arrangement should be noted that it is associated with unnecessarily high effort, if "beat" is seen, several read different tracks at the same time. To the line of receivers a complete set of selection circuits must then be connected for each track to be read out.

The invention is based on the object "in an arrangement for the scanning of signals along at least one track an extensive protection against the undesired perception to reach another lane.

The invention is also based on the object of reducing the cost of components for such a circuit arrangement to reduce, which leads to great savings in particular when the arrangement is for simultaneous readout several tracks should be laid out.

According to the invention, this is in an arrangement for scanning signals along at least one track with a transverse to Row of sensors lying in the direction of the track in such an arrangement that the track signals are always transmitted when the track is shifted transversely

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can be recorded by at least one of the sensors, the tracks being recorded next to each other at such a large distance that at least one sensor is not acted upon by track signals on either side of the tracks to be scanned, with an OR element for each track to be read, because ^s with Each of the sensors is connected via a selection circuit for activating or blocking the output of the assigned sensor leading to the OR gate, depending on the position of the track to be read > achieved in that the selection circuit is divided into two stages, the first stage of the selection circuit an identification sign. delivers ^ as soon as the assigned sensor is acted upon by track signals, and the second stage of the selection circuit

de s
an activation or blocking / leading to ¹ "the OR element

Output takes over.

In one embodiment of the inventive arrangement is the first stage of each selection circuit with the serious stages of other selection circuits via a link member connected ^ which prevents a detection signal is generated by such first stages, whose associated sensor is not with real track signals but with as false

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detected faults in the recording medium is applied. The first stage is advantageous with at least one selection circuit via a logic element in this way connected to the first stages of the selection circuits belonging to the same OR gate and to adjacent sensors, da3 then no detection signal is generated if the neighboring first stages both generate a detection signal.

In one embodiment of the arrangement according to the invention the first stage of each selection circuit is formed by an inonostable multivibrator, which is connected to its Input signal present from the associated sensor is set, and at a specified point in time after the last received sensor signal drops.

In an advantageous embodiment of the invention, this can be prevented be that a flip-flop is set by a sensor signal at its first input by another signal is applied to a second input of this flip-flop. This is to prevent the multivibrator from being set,

as if the sensor is not with real track signals but / wrong

detected interference signals is applied.

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ORIGINAL INSPECTED

The monostable multivibrator can have a second input, which is connected to the outputs of the first via an AND element Stages of the two adjacent selection circuits is connected, with the presence of a signal at this input This first stage prevents generation of a detection signal will.

In one embodiment of the invention, the second stage of each selection circuit is via a logic element with the first stage of this selection circuit and also with the second stages of the same OR gate and adjacent sensors associated selection circuits so linked that it is unlocked when from the associated first stage of the selection circuit a detection signal comes and at the same time one the adjacent second stage is unlocked.

This link consists advantageously of one OR gate, the inputs of which are connected to the second stages of the two adjacent selection circuits and one AND element whose first input is connected to the output of the OR element and whose second input is connected to the output of the assigned first Stage and the output of which is connected to an input of the second stage.

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ORIGINAL INSPECTED

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Compared with known circuit arrangements for scanning signals along at least one track, the inventive Arrangement above all the advantage that an extensive protection against the conception of a second track with nevertheless relatively can be achieved by simple means.

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In addition, only some of the selection circuits are available several times for the simultaneous reading out of several tracks, so that In particular with a large number of tracks to be read out, a large saving of components can result. The invention is to be explained in more detail below using an exemplary embodiment. In the accompanying drawing show:

Figure 1: a circuit section of the arrangement according to the invention,

Figure 2: the circuit of a complete embodiment of the arrangement according to the invention »

ftussohnitt iner from e erfindungsgemäffan 3: eineiyschaltungsanordnung for simultaneously reading

multiple tracks.

The arrangement according to the invention looks in a manner known per se for each track to be read out an OR gate, which is connected to each of the sensors via a selection circuit for Activation - or blocking of the one leading to the OR element Output of an assigned sensor depending on the position of the track to be read. In contrast to known arrangements however, the selection circuit of the fiction according to the arrangement is divided into two stages, the first stage a detection signal is provided as soon as the assigned sensor is applied with track signals and the second stage the

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ORIGINAL INSPECTED

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Al

Activation or blocking of the one leading to the OR element Sensor output takes over. This is between the first stage and the second stage of the selection circuit a logic element arranged «In contrast to previously known solutions offers the inventive implementation of the selection circuit Possibility to suppress sensor signals in a simple way ^ if these lead to the activation of several tracks. In addition, there is always only one first level for each sensor Selection circuit necessary, even if there are several · OR gates connected for simultaneous reading of several tracks will.

In Figure 1, labeled A, one of the OR gates is shown, of which one for each to be read out at the same time Trace must be present in the overall circuit arrangement. For this purpose, one of the selection circuits is also recorded, each of which connects this OR element A with each sensor S. The first stage of the selection circuit is labeled B, the second stage with C. The components belonging to B and C, respectively are surrounded by a dashed line. The selection circuit shown in FIG. 1 is connected to the η-th sensor S of any number of sensors connected. Accordingly

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all markings of components and connections are index in

provided with the selection circuit shown in / FIG. 1 belong. Lines that "load to the left or right

Adjacent selection circuits are marked with, or ■ . A logic element arranged between the first stage and the second stage, which is designated by D in FIG. 1, is also important for the function of the selection circuit. A signal generator E _{n is} disclosed as a further circuit element, but this does not have to be present in every selection circuit. To protect against simultaneous free switching of more than one track for each OR element A, a logic element F can also be included in the circuit arrangement. However, if the occurrence of interfering signals is excluded, the circuit arrangement can also be used without this logic element F.

In the embodiment shown in Fig. 1, S _n denotes a sensor which can scan traces of a recording material, not shown here, and which provides the information stored in the traces of the recording material at its output in the form of pulses. These output signals from the sensor S _n first reach the first stage B of the selection circuit. This first stage B

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_n stent from a monostable multivibrator K represented by a at one of its inputs b _n lying output signal of the sensor Si _n for an unlimited period of time passing can be set. At the single output q _{n of} the monostable _{multivibrator H n} , a detection signal occurs which indicates that the sensor S _n assigned to this selection circuit is emitting output signals. The ao-stable multivibrator is designed so that its hold time can be extended, that is, it remains set as long as the time interval between the individual _{output signals coming from the sensor S n} does not exceed the predetermined hold time of the monostable multivibrator M _n . This holding time must be optimally designed. On the one hand, it should be avoided that the monostable multivibrator M _r already drops out in pauses between the output signals of the sensor S _n. On the other hand, a migration of a _{track to be scanned by the sensor S n} should as soon as possible due to the absence of a detection signal ε at the output q. _{n of} the monostable multivibrator M _n can be detected. In one embodiment of the invention it can be prevented that the KippschiLtung M _{n is set} by an output signal of the sensor S _n at its input b by at its second. Input a _n a blocking signal is applied. Such a blocking

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signal is fed to the input a ^ via a logic element P. An AND element is suitable as the logic element F, the output of which connects to the input Z _{n of} the flip-flop M _n , and whose inputs connect to the outputs I _{n +} ^ - and Q _{n-1 of} the flip-flop circuits M _n ^ "and M _n-1 "Adjacent selection circuits, not shown in Pig. I, are connected.

This prevents the flip-flop M from being set if the sensor S is not connected to the track signals of a recording track / but with disturbances in the recording medium "beauff-eh is beat. For example, it is certain that the output signals of the sensor S originate from such disturbances

η
must, if at the same time "both" neighboring sensors S or S - also deliver ^ output signals, because the distance between the recording tracks is so great that the middle sensor S in this Pail cannot scan any of the recording tracks. A simultaneous activation of several recording tracks on the OR element A can be prevented in this way. The first stage of each selection circuit is therefore limited to the setting of the position of the existing recording tracks. The task of optionally activating a desired recording track and suppressing other recording modes is taken over exclusively by the second stages of the selection circuits, which for this purpose are connected to each other and to the first stage of the selection circuit.

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In the one in Pig. 1, the second stage of the selection circuit is designed so that the output of the sensor S continues to be via an AND gate Z _n with;

is
connected to the OR element A ⁷ , in such a way that output signals from the sensor S can only reach the OR element if the OR element T _{n is also} activated. This OR element 2_ can be controlled by an unlock signal from a signal generator E on the one hand. Such a signal generator must be present in at least one of the selection circuits of the circuit arrangement, which on the other hand only supplies the OR gate CD with an output signal if it was already controlled itself or if it was controlled by a corresponding OR element of an adjacent selection circuit. This becomes clearer when considering the logic circuit D lying between the first stage B and the second stage C of the selection circuit. An AND element U, the first input of which is connected to the output c of the OR element T _n , and its second. Input is connected to the output q of the monostable multivibrator M. the first stage of the selection circuit, leads with its output to a first input of said OR gate T _n . This ensures that the OR element T ^ if it has been activated once, for example by the signal generator E η or by a corresponding OR element

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an adjacent selection circuit, as long as an output signal appears at the output q ^ of the Kippschaltuig It _n , that is, as long as the track signal enabled for the OR element A is at the sensor S. In the circuit arrangement according to Pig. 1 a further ΤΠίΠΪ-element V _{n is} provided, the output of which is connected to a further input of the OR element T, the first input of which is also connected to the output q of the flip-flop M _n , and the second input of which is connected to the output of a further OR -Glange V ■ is connected. The two inputs of this OR gate V lead to the second stages of the adjacent selection circuits, which are not shown in the drawing, and are there connected to the output C _n · of an OR gate T, or the output C _{1 of} a OR gate T ₁ . By means of these logic elements it is achieved that when a recording track migrates to another sensor, the sensor to which the track signals are newly applied is enabled. It is assumed, for example, that the sensor S _{n is} blocked, that one of the sensors S _n-1 or S, is activated _f and the scanned recording trace is now moving in the direction of the sensor S. The inputs of the OR element V are connected to the outputs C _n-1 and C- ^ _{1 of the OEER elements T n-1} and T _{n + 1} belonging to adjacent selection circuits. The OR element

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T is thus controlled by the AND element V _n when a sensor adjacent to the sensor S is enabled and the trigger stage M is set at the same time. The recording track to be read out is already being scanned by an adjacent sensor when it disappears from one sensor. During the short time of the sensor change3, the circuit arrangement shown allows the OR element T to be controlled for a sufficient time until it can be controlled independently of the OR elements 3? -ι or T ^ of the adjacent selection circuits even over in the mt. These neighboring OR elements are no longer activated (the biting of the associated sensor is blocked) as soon as the read track has completely disappeared from the sensor in question, which had previously scanned it ^e

The arrangement according to the invention for scanning signals along at least one track can be implemented by a further exemplary embodiment, which is shown in FIG. It Such a circuit arrangement is particularly advantageous to be built from commercially available HÄED links, NOR links, which can be linked in such a way that their logical function is that of that used in the exemplary embodiment according to FIG UKD elements or OR elements.

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In this exemplary embodiment, there are η sun sensors S to Sq in total, with a selection circuit being assigned to each sensor. The output of each sensor again leads to the first stage of the associated selection circuit and is connected to the input B Dorr a monostable multivibrator to M. & Λ Q. Further, the output of each sensor is also connected to an input of each transmitter

it
sor assigned NAIiD-GIied / Z. to Zg, The mode of operation of the selection circuits has already been explained in detail in connection with the exemplary embodiment according to FIG. 1, so that a repeated detailed description of the selection circuits in the exemplary embodiment according to FIG. 2 is unnecessary. Deviating from the exemplary embodiment according to FIG. 1, the exemplary embodiment according to FIG. This deviation from all other selection circuits is necessary because these external selection circuits each have only one adjacent selection circuit.

In contrast to previously known arrangements for scanning signals along at least one track, the inventive device offers Arrangement in particular then a possibility

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to reduce the circuit complexity if "with such an arrangement several different tracks are to be read out simultaneously. An embodiment of the circuit arrangement according to the invention, which explains such savings possibilities in more detail, is described in FIG. 3. It is assumed that two different tracks are to be read out simultaneously. these tracks are a and b referred According to wear all parts of the circuitry for reading the track or track a b are required domestic in Figure 3 behind their _name. brackets the reference to the track a or the track b. For each track to be read out at the same time, an OR gate is to be provided which is connected to the sensors via selection circuits , which are labeled A (a) and A (b), respectively this OR element A (a) or A (b) is connected to the second stages of the associated selection circuits, of which, however, in the exemplary embodiment according to FIG. or C (b). Furthermore, logic elements D (a) and D (b) are shown in this embodiment, each of the second stage of a selection circuit with a first stage of a selection circuit

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need to connect. The task of the illustrated second stages the selection circuits as well as the logic elements was described in detail in connection with the exemplary embodiment Fig. 1 explains so that a repetition is unnecessary. The identification of the connections of the circuit parts shown through mdizes also corresponds completely to those selected in FIG Designations. The inventive subdivision of a selection circuit into two stages now enables savings a number of first stages of the selection circuits. In the exemplary embodiment according to FIG. 3, there is only one such first stage 3 of a selection circuit provided via the logic elements: D (a) and D (b) with two second stages a selection circuit C (a) or C (b) is connected.

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Claims (12)

TJL 73/95 Claims ly arrangement for scanning signals along at least one track with a set of sensors lying transversely to the track direction in such an arrangement that the track signals can always be picked up by at least one of the sensors when the track is shifted transversely, with the tracks being recorded next to each other at such a large distance are that on both sides of the tracks to be scanned, at least one sensor is not subjected to track signals, with an OR element for each track to be read, which is connected to each of the sensors via a selection circuit for enabling or disabling the one leading to the OR element Output of the assigned sensor as a function of the position of the track to be read, characterized in that the selection circuit! Is divided into two stages, the first stage of the selection circuit delivering a detection signal as soon as the assigned sensor is acted upon by track signals, and the second stage of the Selective activation a release The aging or blocking of the output leading to the OR element is carried out with the aid of a logic combination circuit connected upstream of this second step. - 21 - 509807/0458 -aar- UL 73/95 2. Arrangement according to claim 1, characterized in that the first stage of each selection circuit with the first stages some or all other selection circuits is connected via a logic element which prevents a detection signal from being generated by such first stages, their associated sensor
not with real track signals but with incorrectly recognized faults in the recording medium: is. 3. Arrangement according to claim 2, characterized in that the first stage of at least one selection circuit is connected via a logic element in such a way to the first stages of the selection circuits belonging to the same OR element and to adjacent sensors that no detection signal is generated,
when the adjacent first stages both generate an Erfcemur-gssignal. 4. Arrangement according to one of claims 1 to 3 »characterized in that the first stage of each selection circuit consists of a monostable multivibrator M, which is set by a signal of the associated sensor S _{n lying at the input b n of} the multivibrator M ^ and which is to after a specified point in time
the last received sensor signal drops. - 22 - 509807/0458 73/95 5. Arrangement according to claim 4, characterized in that the first stage of the selection circuit designed as a monostable multivibrator has another input a, which has a Link with the outputs of the first stages of the "two" "is connected to neighboring selection circuits, where when there is an output signal from both neighboring Stages at this input a ^ the generation of a detection signal of the monostable multivibrator H --- is prevented. 6. Arrangement according to one of claims 3 to 5 »characterized in that at least one signal generator E is provided, which is connected to the second stage of at least one selection circuit _/ and through whose output signal this selection circuit can be locked ent. 7. Arrangement according to claim 1, characterized in that the second stage of each AuEwahlkreisjiiber a logic element with the first stage of the same selection circuit and with the to the second stages of the same OR gate and to "neighboring sensors belonging selection circuits is linked in such a way that it is unlocked when from the first stage of the same selection circuit a detection signal arrives and at the same time unlocks a second penalty of the neighboring selection circuits is. - 23 509807/0458 UL 73/95 8. The arrangement according to claim 1, characterized in that the logic element between the first and second stages consists of an OR element, the inputs of which are connected to the second stages of the two adjacent selection circuits, and an AND element, the first input of which is connected the output of the OR gate whose second input is connected to the output of the associated first stage and whose output is connected to an input of the second stage of the selection circuit. 9. Arrangement according to claim 7> characterized in that da3 the second stage of each selection circuit, provided it has been unlocked once, remains unlocked as long as the detection signal of the associated first stage is present. 10. Arrangement according to claim 9 *, characterized in that the unlocking is maintained by means of an AND gate, one input of which is connected to the output of the second stage, whose other input is connected to the output of the first stage and its output to an input of the second stage is. 11. Arrangement according to one of the preceding claims, characterized in that the second stage of each selection circuit.g is formed by an OR gate, the output of which is connected to a 509807/0458 - _ ₂ 4- BAD ORSGiNAL UL 73/95 χζ The input of an AND element goes, the second input of the AND element being connected to the associated sensor. 12. Arrangement according to claim 1, characterized in that approx £ in an arrangement for simultaneously reading out a plurality of different recording tracks, the selection circuits which , to the same sensors but to different OR gates A (a) or A (b), with a common first stage one Selection circuit are connected. 509 807/0458 BATH ORIGINAL , 2 * Blank page