JPH0442715B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is provided in, for example, a passbook printing device that automatically prints transaction details of a bankbook in an automatic teller machine, and detects printed lines of a passbook. The present invention relates to a reading circuit used in such applications.

[Conventional technology]

Conventionally, the technology in the above-mentioned field was
-There is something described in Publication No. 715. In such a conventional example, a line signal corresponding to each line is first generated on the printed surface of a bankbook, and the printed surface is optically scanned by a photoelectric conversion means for each row signal.
Thereby, the presence or absence of a printed line on the printing surface is determined, and printing, etc. is performed according to the determination result.

This conventional example will be explained below based on FIGS. 2, 3, and 4.

FIG. 2 is a block diagram of a reading circuit for detecting printed lines in a conventional passbook printing device.

In FIG. 2, the output of the photoelectric converter 1 as the photoelectric conversion means described above is subjected to analog processing in an analog processing section 2, and then supplied to a level comparison section 3. This level comparison section 3 is connected to the analog processing section 2.
The output signal is sliced at a predetermined level for each scanning line and quantized into a black level and a white level.

On the other hand, the printing presence/absence condition setting section 4 outputs conditions such as the range of the passbook surface to the printing presence/absence detection section 5 in order to detect printed lines.

This printing presence/absence detecting section 5 includes the level comparing section 3.
The output of the printing condition setting section 4 is combined with the output of the printing presence/absence condition setting section 4 to determine whether printing is present.

That is, the print presence/absence detector 5 counts the bits that are quantized and determined to be black level by the level comparator 3 for each scanning line until the next row signal is output, and the total number is set. If it is greater than the value, it is determined that there is printing, and otherwise it is determined that there is no printing.

Note that the structural example of a passbook printing device incorporating this circuit and the printing example of a passbook are not directly related to the present invention and are described in Japanese Patent Publication No. 1983-715.
Omitted.

FIG. 3 is a circuit diagram showing an example of the level comparator 3 shown in FIG. 2.

In FIG. 3, transistors Tr 1 , Tr ₁ ,
Either Tr ₂ or Tr ₃ is turned on. _{The voltage -V _ _ _ _}
is divided, and the slice level S of the voltage comparator 3a
Enter as .

The time chart at this time is shown in Figure 4. Here, FIG. 4 shows the scanning output signal S ₁ subjected to analog processing from the analog processing section 2, the slice level S,
A time chart of the output _S2 to the print presence/absence detection section 5 is shown.

[Problem that the invention seeks to solve]

However, in such conventional examples, the slice level is set in advance depending on the dropout color of the passbook used, the ribbon used, etc.

Therefore, if the print density of the drop-out color on the printing surface of the passbook appears in a striped pattern on the same page, or if the passbook itself is bent or wrinkled, the read output for printed line detection may vary depending on the reading location. There is a problem in that the photoelectric output changes due to deterioration of the photoelectric converter and the like, making it impossible to perform accurate level comparison in the level comparing section.

The present invention was made to solve the above problem, and its purpose is to make it possible to determine the correct printed line even if the scanning output changes depending on the conditions of the passbook base or the conditions of the photoelectric converter itself. It's about doing.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a reading circuit that optically scans a passbook or the like to determine the presence or absence of a printed line on the printed surface of the passbook. The present invention includes a plurality of circuits that hold a read voltage, a plurality of circuits that sequentially discharge the held read voltage, and a circuit that generates a slice level of a read signal from the held white side read voltage. Features.

[Effect]

In the present invention having the above-mentioned characteristics, first, the reading voltage on the white side when a passbook is optically scanned is held respectively. Each held read voltage is logically ORed to produce a read slice level.

With this slice level, the read voltage on the white side when optically scanned is sliced and quantized into a black level and a white level and output. Based on this output, the presence or absence of printing is determined.

By the way, the held read voltage is discharged at regular intervals. Therefore,
Due to this discharge, the reading voltage on the white side of the new bankbook printing surface is always maintained, and the slice level is always calibrated.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 5.
This will be explained based on FIG.

FIG. 1 is a circuit diagram showing an example of a level comparison section of a reading circuit according to the present invention, FIG. 5 is a block diagram of a reading circuit according to the present invention, and FIG. 6 is a scanning output signal S ₀
FIG.

First, in FIG. 5, the read voltage, that is, the scanning output signal _S0 from the photoelectric converter 5, which is composed of a CCD sensor, etc., is subjected to analog processing in the analog processing section 6, and then sent to the level comparison section with a waveform as shown in FIG. 7.

This level comparison section 7 slices the output signal of the analog processing section 6 at a predetermined level, which will be described later, for each scanning line, and quantizes it into a black level and a white level.

On the other hand, the printing presence/absence condition setting section 8 outputs conditions such as the range of the passbook surface to the printing presence/absence detection section 9 in order to detect printed lines.

This printing presence/absence detecting section 9 includes the level comparing section 7.
The output of the printing condition setting section 8 is combined with the output of the printing presence/absence condition setting section 8 to determine whether printing is present.

Next, the operation of the level comparing section 7 described above will be explained in detail based on FIGS. 1 and 7. here,
FIG. 7 is a time chart showing the reset of the peak holding voltage in FIG.

In FIG. 1, the scanning output signal _S0 , which has been analog-processed as described above, is inputted as input a with a waveform as shown in FIG.

This input signal is input to one input terminal of the comparator θ ₁ and is also input to the slice level generation circuit section 11
input to the amplifiers θ ₂ and θ ₃ . These amplifiers θ ₂ ,
θ ₃ is the amplification gain of 1 due to resistors R ₄ , R ₅ , R ₆ , and R ₇
It is set as.

Furthermore, when the above-mentioned scanning output signal S ₀ is input to the input a, the peak voltage holding capacitors C ₁ and C ₂
is charged and held at the maximum voltage of the white level shown in FIG. 6 (lowest side in the figure). The respective voltages held therein are ORed via diodes D ₁ and D ₂ .

This ORed voltage is divided by resistors R ₈ and R ₉ and inputted to one terminal of the comparator θ ₁ as a slice level of the scanning output signal S ₀ . Moreover, as mentioned above, the scanning output signal S ₀ is connected to this other terminal.
is entered directly.

Incidentally, a pulse signal having a waveform shown in FIG. 7 is input to resets 1 and 2. As a result, the voltages held in the capacitors C ₁ and C ₂ are discharged as shown at points a and b in FIG. 7 by turning on the transistors Tr ₄ and Tr ₅ at regular intervals.

Incidentally, the repetition time of this discharge is determined by the photoelectric converter 5.
Although it depends on the scanning density of the bankbook surface, in this embodiment, the discharge is performed when scanning the bankbook surface equivalent to 1 mm to 2 mm.

Therefore, this discharge causes capacitor C ₁ ,
C ₂ always holds the peak voltage of the white level of the new passbook printing surface. Therefore, the slice level is always calibrated.

〔Effect of the invention〕

As described above, according to the reading circuit according to the present invention, the slice level of the read signal is generated from the held white side reading, and the slice level is generated by discharging and holding the read voltage sequentially.
This has the effect that there are no inconveniences caused by the conditions of the bankbook itself or the conditions of the photoelectric converter itself.

For example, even if the passbook side is preprinted every other line in drop-out color, the slice level will follow the reading voltage on the white side, so the voltage will always be appropriate and the presence or absence of printed lines will be correctly determined. It has the effect of

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an example of a level comparison section used in an embodiment of the present invention, FIG. 2 is a block diagram of a conventional example, and FIG. 3 is a circuit diagram of an example of the level comparison section of FIG. , FIG. 4 is a time chart in the level comparison section, FIG. 5 is a block diagram showing an embodiment of the present invention, FIG. 6 is a waveform chart showing an example of the scanning output signal _S0 , and FIG. 3 is a time chart showing the reset of the peak holding voltage in the figure. 5...Photoelectric converter, 6...Analog processing section, 7
...Level comparison section, 8...Printing presence/absence condition setting section,
9...Print presence/absence detection section, 11...Slice level generation circuit section, _θ1 ...Comparator, _θ2 , _θ3 ...Amplifier,
C ₁ , C ₂ ... Capacitor, D, D ₁ , D ₂ ... Diode.

Claims (1)

[Scope of Claims] 1. In a reading circuit that optically scans a passbook or the like to determine the presence or absence of a printed line on the printed surface thereof, a plurality of circuits that hold the read voltage on the white side when optically scanned. A read circuit comprising: a plurality of circuits that sequentially discharge the held read voltage; and a circuit that generates a slice level of a read signal from each of the held read voltages on the white side. .