JP2872492B2 - Printer or similar output device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention comprises means for detecting a document provided in combination with a pay-per-transport path, said means comprising one or more light sources and several light detectors. The container is located along the paper transport path, and the document thus supplied produces characters on the document supplied into the paper transport path, causing a change in the amount of light received by at least one photodetector. Printer or similar output device.

[0002]

2. Description of the Related Art For example, printers used in banking use a photoelectric component to detect the presence of a document. Such components can be used in several ways, typically in three different ways. First, a light source, eg, an LED that emits infrared light
Can be provided at the bottom of the paper transport path, and a phototransistor can be provided at a corresponding point on the upper surface of the paper transport path, wherein the phototransistor is free of obstruction, i.e., no document is located between the LED and the phototransistor. At this time, the light emitted by the LED is detected. The second basic principle is that both the light source and the photodetector are located at the bottom of the paper transport path, thus allowing light to propagate between them when a document with a reflecting lower surface is positioned over them. It is. A third basic principle is that both the photoemitter and the photodetector are located as above, ie, at the bottom of the paper transport path, but they are located at the top of the paper transport path, Are continuously connected to each other through means for reflecting light, for example, a prism. In this case,
The connection between the photoemitter and the photodetector is broken when the document is fed into the paper transport path. The aforementioned spot-like detector is typically provided at the edge of the paper transport path near the edge guide. When using this type of printer, the document must be positioned against the edge guide,
It is therefore sufficient to position the document detector near the edge guide. In such a case,
The presence of a document in the paper transport path can be detected by a single spot-like detector.

[0003] To detect whether a document is straight in the paper transport path, that is, whether its back edge is perpendicular to the longitudinal direction of the paper transport path, the aforementioned basic detection is used. Based on the container, a more advanced structure is used, in which two detectors of the aforementioned type are collinear, this line being perpendicular to the longitudinal direction of the paper transport path. When only one of these detectors indicates the presence of a document in the pay-per-transport path, it knows that the document is not straight.
Conversely, when both detectors detect the presence of a document, they know that the document is straight. this is,
Of course, it requires that the line on which the detector is located be perpendicular to the back edge guide for the document. The purpose of the back edge guide is to ensure that the document is straight before being fed into the pay-per transport path.

[0004] In a printer where the supply of documents is virtually possible at any lateral position of the pay-per transport path, ie the documents need not be positioned against the side edge guides, the documents, of course, also Can be detected using detectors of the type described above, provided that a sufficient number of detectors are located on a line extending across the pay-per transport path. However, when they are used, the problem arises that the signals of several photoemitters, in particular several photodetectors, must be observed simultaneously. While it is easy to observe several photodetectors simultaneously, conventional solutions increase the need for wiring and complicate the detector itself. These factors are
It is also important in view of the competitiveness of products in printers intended for mass production and which should also be as small as possible.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to allow a document to be fed into a pay-per-transit path at any point in time, while at the same time irrespective of the use of several photodetectors. It is to provide a printer or similar output device, in which detection is performed very simply. A printer or similar output device that can accomplish this purpose is to chain photodetectors in series, so that a change in the amount of light received by one detector will change the current flowing through the entire chain. Cause the change to be detectable by a signal detector connected to the chain.

[0006] A printer or similar output device according to the present invention can be used to monitor whether a document is at right angles to a pay-per-transport path, and thus in the event that light detectors must be positioned in pairs. Into two chains, one of each pair of photodetectors being included in one chain, and the other being included in the other chain, thus Causing a change in the amount of light received by one of the detectors to cause a change in the current flowing through the entire chain, such change being detectable by a signal detector connected to the chain; and an output of the signal detector of the chain. Connecting the signal to logic means, said logic means indicating that the document is at right angles when both of its input signals change. Characterized in providing a signal.

Preferably, a voltage is connected across the chain formed by the photodetectors, and a change in current flowing through the chain is detected based on a voltage acting across a resistor connected as part of the chain. In this way, document detection is realized.

In the simplest and most reliable embodiment, the signal detector comprises a comparator, which compares a voltage acting across a resistor connected to the photodetector chain with a reference voltage. .

[0009] In one embodiment, the photodetector is a phototransistor and the preceding phototransistor in the chain is connected to the collector electrode of the next phototransistor in the chain.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS A printer or similar output device according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a paper transport path 1 of a printer or similar device, wherein a document 2 is located at any point within the paper transport path 1. Light source U1, U
2, U3. . . UN, for example, an LED that emits infrared light
Is provided on the lower surface of the pay-per transport passage. The signal sent by the light source should be as narrow as possible,
An optical mask 3 is located on the lower surface of the paper transport path 1. The photodetectors Q1, Q2,. . . A QN, for example, a phototransistor, is located on the upper surface of the paper transport path 1 opposite the light source. An optical mask 3 is also arranged on the upper surface of the paper transport path 1 in front of the photodetector, so that the photodetector receives only the thin light rays sent by the photoemitter, so that the light is optically transmitted. The light propagates through the opening of the mask 3. Typically, the light from the photoemitter is not continuous, but is appropriately modulated,
Eliminate as much as possible the disruptive effects of light pouring onto the photodetector from the environment. The arrangement of the type shown in FIG. 1 consists of several spot-like photoemitter / photodetector pairs and can be realized according to one of the well-known principles mentioned above.

In the present invention, the photodetectors Q1, Q2, Q
3. . . QN is connected in series to chain C as shown in FIG. In this chain, the emitter electrode of the preceding phototransistor is connected to the collector electrode of the next phototransistor in the chain.
A resistor R is connected to the end of the chain, and a voltage VCC is connected across the chain C. When a document has not yet been fed into the paper transport path, all photodetectors receive light, but since the photoemitters are already active, current flows through chain C, which causes the impedance of the photodetectors to decrease. This causes a relatively high voltage loss in resistor R because it is relatively low. The voltage across the resistor R is determined by the signal detector as shown in FIG.
In an embodiment of the invention, the comparator COMP
Monitored, the comparator COMP compares the voltage acting across the resistor R with a reference voltage UREF. When the voltage across the resistor R exceeds the reference voltage,
There are no documents in the paper transport path. Then, when the document is fed through the paper transport path, its impedance substantially increases because at least one of the photodetectors is covered. Thus, the current flowing through the chain C is significantly reduced, so that the voltage acting across the resistor R is also reduced. When this voltage drops below the reference voltage UREF, the output of comparator COMP changes state, indicating that there is a document present in the paper transport path.

The arrangement shown in FIG. 2 makes it possible to detect the supply of a document very simply and reliably at any point in the pay-per transport path, provided that the distance between the photodetectors is sufficiently small. Conditions. The distance between the photodetectors is mainly determined by the smallest acceptable document width. Despite the use of several light detectors, the coupling arrangement for performing the detection is very simple when the light detectors are connected to a chain according to the invention.

FIG. 3 illustrates a coupling arrangement that utilizes the detection method according to the present invention when monitoring whether a document is at right angles to a pay-per-transport path.
In this case, as described above, the detectors are located in pairs, and a document is straight when both detectors in the pair indicate the presence of the document. When utilizing the technique according to the invention, the photodetector is connected to two chains C1.
And C2, so that each one of the chains has one photodetector Q1, Q3, Q1 of each pair of photodetectors.
5,. . . Q (N-1), and the other chain comprises each pair of other photodetectors Q2, Q4, Q6,. . . QN. Chains C1 and C2 are similarly utilized in combination with the embodiment of FIG. 2 to determine whether documents are fed into the paper transport path by comparators COMP1 and COMP2 so that the documents cover one of the photodetectors. Detect if. However, in the arrangement shown in FIG. 3, both of the pairs of photodetectors would not be shown to be positioned at right angles in the paper transport path unless both photodetectors of the pair detect the document. Comparator COMP1 and CO
After MP2 provides a signal indicating the presence of the document, it is required that the document be shown to be located at right angles to the pay-per-transit path. For this purpose, the outputs of the comparators COMP1 and COMP2 are connected to logic means, for example AND means, which, when both detector chains C1 and C2 detect the presence of the document, the output of the document at that output. A signal indicating the position of the straight line is generated.

The principles of the present invention for detecting a document in a paper transport path of a printer or similar device include:
Only described with respect to the illustrated embodiment where the photodetector is a phototransistor. However, the aforementioned coupling principles also imply that when only the basic operating principles of the other photosensitive components are considered in the formation of the coupling arrangement,
It can be applied to such a photosensitive component. The essence of the invention is that the photodetectors are connected in series in a chain, so that a change in the amount of light received by one photodetector causes a change in the current flowing through the chain, and thus the presence of a document. The reason is that it can be reliably detected based on this change.

The main features and aspects of the present invention are as follows.

1. Means for detecting a document (2) provided in combination with a pay-per-transport path (1), said means comprising one or more light sources (U1, U)
2,. . . UN) and several photodetectors (Q1, Q
2,. . . QN), wherein the photodetectors are located along the paper transport path (1), and the document (2) thus supplied comprises at least one photodetector (Q1, Q1).
2,. . . The photodetectors (Q1, Q2) in a printer or similar output device that produces characters on a document (2) fed into a paper-transport path (1), causing a change in the amount of light received by the QN). , ... Q
N) are connected sequentially to form a chain (C), and thus 1
The change in the amount of light received by the two detectors is a chain (C)
To cause a change in the current flowing through the whole,
The change is detected by a signal detector (CO) connected to the chain.
MP or a similar output device.

2. means for detecting whether the document (2) is at right angles to the pay-per-transport path (1), provided in combination with the pay-per-transport path (1), said means being one or more. Light sources (U1, U
2,. . . UN) and several photodetectors (Q1, Q
3,. . . Q (N-1); Q2, Q4,. . . QN), wherein the photodetectors are arranged in a collinear pair perpendicular to the paper transport path (1), and the photodetectors are arranged along the paper transport path (1). ,
Thus, the document (2) is transferred to the pay-per-transportation path (1).
, It is at least one pair of photodetectors (Q1, Q3,... Q (N-1);
4,. . . QN) causes a change in the amount of light received, connects the photodetector at a printer or similar output device that produces characters on a document (2) fed into a paper transport path (1). Into two chains (C1, C2), one of each pair of photodetectors (Q1, Q3,... Q (N-1) being included in one of the chains (C1). And the other photodetector (Q2, Q4,... QN) is connected to the other chain (C
2), such that a change in the amount of light received by one of the detectors causes a change in the current flowing through the entire chain, and the change is applied to the chain (C1, C2).
2) The signal detector (COMP1, COMP) connected to
2) and the output signals of the signal detectors (COMP1, COMP2) of the chain are connected to logic means (AND), and when both of the input signals change, the logic means outputs the document. A printer or similar output device for providing an output signal indicating right angle.

3. Voltage (VCC) is chained (C; C
1, C2) and detecting a change in current flowing through the chain based on a voltage acting across a resistor (R) connected as part of the chain. 3. A printer or similar output device according to claim 1 or 2.

4. The signal detector is a comparator (COM)
P; COMP1, COMP2), wherein the comparator is a resistor (R) connected to a photodetector chain.
4. A printer or similar output device according to claim 3, wherein the voltage acting across is compared with a reference voltage (UREF).

5. The photodetector is a phototransistor (Q
1, Q2,. . . QN), wherein the preceding phototransistor in the chain is connected to the collector electrode of the next phototransistor in the chain. Similar output device.

[Brief description of the drawings]

FIG. 1 illustrates an example of one method of detecting a document in a printer's pay-per-transit path.

FIG. 2 shows a method according to the invention for interconnecting photodetectors.

FIG. 3 illustrates a method according to the invention for interconnecting light detectors when the light detectors are arranged to operate in pairs to monitor whether the document is at right angles.

[Explanation of symbols]

 1 paper transport passage 2 document 3 optical mask

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B65H 7/14 B41J 13/00 B41J 29/48

Claims (2)

(57) [Claims] 1. A device for detecting a document provided in combination with a pay-per transport path, said means comprising one or more light sources and a number of light detectors, said light detector comprising: A printer or similar that is located along the transport path and that produces text on the document that is supplied in the pay-per transport path, wherein the document so supplied causes a change in the amount of light received by the at least one photodetector. Output device,
The photodetectors are sequentially connected into a chain, such that a change in the amount of light received by one detector causes a change in the current flowing through the entire chain, and the change is applied to a signal detector connected to the chain. A printer or similar output device characterized in that it can be detected by a printer. 2. A means for detecting whether a document is at right angles to the pay-per transport path, provided in combination with the pay-per transport path, said means comprising one or more light sources and some light detection. A photodetector, the photodetectors being arranged in a collinear pair perpendicular to the paper transport path, the photodetectors being disposed along the paper transport path, and thus the document When at right angles to the transport path, it causes a change in the amount of light received by at least one pair of photodetectors, a printer or similar that produces characters on the document fed into the pay-per transport path. In the output device, the photodetectors are connected into two chains, each one photodetector of each pair of photodetectors being included in one chain. Rare, and the other photodetector is included in the other chain, such that a change in the amount of light received by one detector causes a change in the current flowing through the entire chain, and connects the change to the chain. Connected to the logic means, and said logic means that when both of its input signals change, the document is at right angles. A printer or similar output device, characterized by providing an output signal as indicated.