DE2544516A1 - Document feed error detection device - uses permanent magnet and semiconductor field plate to detect multiple document delivery - Google Patents

Abstract

A device for detecting the presence of two or more documents, e.g. cards (1, 2), in a document feed device, e.g. a card feed in an automatic accounting machine, is used to produce a signal enabling protective measures to be automatically taken to avoid card processing errors. The signal source contains a switching transistor driven by a magnetically controlled semiconducting resistance and permanent magnet. The semiconductor resistance (3) acts as a field plate between two pole shoes (4, 4'), and is placed opposite a permanent magnet (5) so that a defined resistance is exhibited in the normal position. If the air gap (6) between the field plate and the permanent magnet increases because of the presence of more than one document, the change in resistance can be used to operate the transistor.

Description

Device for recognizing documents in feeding devices from Away-

Automatic computers or the like. The invention relates to a device for recognizing more than one document, e.g., cards or the like, in document feeders such as card slots from billing machines or the like.

In the case of feed devices of this type, it proves to be particularly disadvantageous if there is more than one document in this at the same time, then for example there is a risk that one and the same card will have two different inscriptions, Entries, etc., received. To completely eliminate this deficiency in a simple way, has not yet succeeded.

The invention is based on the object, characterized in that by means of a Encoder sends a signal to signal the simultaneous presence of two or more documents is obtained in the feeder to achieve that due or by means of such a signal, all necessary precautions have been taken can be restored to the proper condition in the document feeder to manufacture.

This task is performed by a device capable of detecting more than a document such as cards or the like in document feeders such as card slots of billing machines or the like according to the invention by a transmitter for signaling the simultaneous presence of two or more documents (cards or the like.) In solved the feed device, wherein the encoder has a switching transistor, the by means of a magnetically controllable semiconductor resistor and Permanent magnet is controlled in such a way that one in the air gap between the pole pieces of a first magnetic circuit acting as a magnetically controllable semiconductor resistor field plate is pre-magnetized in such a way that it is run at the corresponding operating point, and that to form a second, external magnetic circuit, a permanent magnet, preferably a horseshoe or "U" magnet, is positioned opposite the field plate such that a predetermined semiconductor resistance is set in its basic position, the by inserting documents (such as cards or the like) into the air gap between the permanent magnet and the first magnetic circuit is changed by varying the size of the air gap learns the necessary to generate an assigned signal to control the switching transistor, is exploited.

It is particularly advantageous to use the effective components as a transmitter a contactless electronic one known per se, with field plates and permanent magnet working button with the permanent magnet parallel to the pole pieces the field plate assembly (first magnetic circuit) is held vertically to this or to the field plate but for the purpose of the variable widening of the Air gap arranged resiliently by the interposition of one or more documents is.

The inventive design of a device for recognition of documents in a document feeder is easily achieved that in particular the aforementioned troublesome disadvantage is eliminated and with in the trade tangible components is worked on, with a mechanical scanning omitted, the the dimensions and tolerances in question here and accuracy requirements cannot generally be used advantageously, or can only be realized with considerable effort.

The invention is described in more detail below with reference to the patent drawing. The figures show: FIG. 1 schematically the effective components of the encoder according to the invention, together with two documents lying one above the other, and FIG. 2 schematically a transistor control for deriving the corresponding signals.

In Figure 1, 1 and 2 place two on top of each other in the feeder documents lying, furthermore 3 as a magnetically controllable semiconductor resistor acting field plate, which is arranged between pole pieces 4,4 '. This arrangement 3,4,4 'represents a first magnetic circuit which interacts with a second external magnetic circuit, which with the help of the permanent magnet 5 in cooperation is formed with the first magnetic circuit 3, 4, 4 '. Here is the arrangement taken so that the permanent magnet 5 is parallel to the pole pieces 4,4 'of the field plate arrangement is held immovably, but while it is perpendicular to this field plate arrangement 3,4,4 'for the purpose of the variable widening of the air game 6 by interposing of one or more documents 1,2 is resiliently arranged.

The schematic circuit shown in FIG. 2 for control of a transistor, with the aid of the transmitter arrangement according to FIG. 1, is well known and does not require any further explanations, although in the present case with assistance of a downstream potentiometer R post is the operating point and thus the switching point can be set individually.

- patent claims -

Claims (2)

Claims () i. Means to recognize more than one Document, e.g., cards or the like, in document feeding devices such as card slots from accounting machines or the like, g e k e n n n z e i n e t d u r c h a giver to signal the simultaneous presence of two or more documents (1,2) (cards or the like) in the feeding device, the encoder being a switching transistor has, which by means of magnetically controllable semiconductor resistor and permanent magnet is controlled in such a way that one in the air gap between the pole pieces (4,4 ') as magnetically controllable semiconductor resistor acting field plate (3) is used and a permanent magnet (5), preferably a horseshoe or "U" magnet, opposite the Field plate (3) is arranged such that in its basic position a predetermined Semiconductor resistance is set, which is caused by inserting documents (such as cards or the like.) in the air gap (6) between permanent magnet (5) and field plate (3) by varying the size of the air gap to generate an associated signal to control the Schaktrqnsistor is exploited, the operating point of the field plate (3) by means of a variably adjustable resistor (Rpot) can be set. 2. Device according to claim 1, d a d u r c h gek e n n z ei c h -n e t that the effective components of a known contactless transmitter electron, with field plates and permanent magnet working button Find use, the permanent magnet parallel to the pole pieces (4, 4 ') of the field plate arrangement is held, perpendicular to this or to the field plate but for the purpose of variable Widening of the air gap (6) by inserting one or more documents (V2? Is arranged resiliently.