JPH05307632A - Optical card recording / reading method - Google Patents

Abstract

(57) [Abstract] [Purpose] To increase the recording density of information in an optical card processing device. [Structure] Marks are configured so that five or more marks of the same polarity, black or white, do not continue, and the number of marks is determined from the length of the mark at the time of reading to allow for a pitch error between recording and reading. Increased capacity. In addition, at the time of reading, based on the density data of the AD-converted mark,
Calculate the number of marks by obtaining the exact change point of the mark from the midpoint of the maximum and minimum values before and after the change point of the mark density, or the maximum and minimum points of the difference data between two adjacent points of the density data. did. [Effect] It becomes possible to perform stable reading against a deviation in pitch between recording and reading and a change in the density of marks or cards, and it is possible to increase the recording density.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a card processing device for recording and reading information with optical detection marks.

[0002]

2. Description of the Related Art Conventionally, a bar code is well known for recording and reading the most widely used optical mark. However, since the reading of the barcode is considered on the assumption that the mark is manually scanned, there are the following problems. That is, the basic principle of the bar code is to convert information of 0 or 1 into information by making it correspond to two types of marks, wide and narrow, and recording these marks alternately in black and white. In order to record, it is necessary to combine a narrow mark, which is the minimum recording / reading width, and a wide mark, which has a recording width larger than that. Therefore, the recording area is required to be 1 to 2 times that of the method of recording 0 as white and 1 as black at the same pitch.

On the other hand, as compared with the method of mechanically scanning a mark, the scanning pitch for writing and reading is stable, and the recording area does not increase or decrease depending on the information content.
A method of recording 0 and 1 at the same pitch by making them correspond to white and black is used. In such a card processing apparatus, a method of detecting a mark at a fixed position and reading a mark row, or a method of detecting a mark at a fixed pitch from the edge of a start mark and sequentially reading a mark row as shown in FIG. In addition, whether the mark is black or white is determined by the output voltage of the mark reading sensor being higher or lower than a preset voltage.

[0004]

However, since the mark pitch at the time of recording and the mark pitch at the time of reading differ due to the error between the devices or the expansion and contraction of the card which changes due to temperature, humidity, etc., FIG. As shown in, the reading pitch with respect to the mark is deviated, and a reading error may occur. Also, since black and white are judged by comparison with a fixed voltage, when the recorded mark density or the reflectance of the card changes, the size of the read mark differs from the size of the actually recorded mark. Problem occurs.

Therefore, each mark width must be increased so that a reading error does not occur even if the positions of these marks are deviated, and there is a problem that the recording density cannot be improved accordingly. It was For example, conventionally, in a card processing device having a mark recording area of 164 dots, there is a possibility that there will be a shift of about 3 dots at the time of recording and reading, so one mark is composed of 7 dots.

An object of the present invention is to provide an optical card processing device capable of recording information at a higher density by using a new recording / reading method without changing the device or the card. ..

[0007]

In order to solve the above-mentioned problems, the present invention, when converting information into marks, has a numerical value such that white or black marks of the same polarity do not exceed a specified number, for example, 5 or more. I converted it to record it. Further, at the time of reading, the mark density is AD-converted and stored in synchronization with the timing signal, and the midpoint between the maximum value and the minimum value immediately before and after the stored change point of the mark density is used as the black / white determination density of the mark. The change point is calculated to calculate the length of consecutive marks, or the difference between two adjacent points in the stored mark density data is calculated, and the positive and negative peaks of the difference value are used as the change points of the marks. The length is calculated and the number of marks included is determined by dividing the calculated length by the mark width.

[0008]

In the optical card constructed as described above, if the length of continuous marks at the time of reading is 3.5 or more and less than 4.5, it can be judged as four.
Assuming that the maximum number of consecutive marks of the same polarity is N, the gap between the recording and reading of marks is -1 / the width of the mark.
If it is (2 × N) or more and less than 1 / (2 × N), correct reading is possible. Further, even if the density of the mark and the reflectance of the card are changed, it is possible to obtain the accurate length of the mark, so that the mark can be read with higher accuracy.

For example, since it is guaranteed that up to four white or black marks of the same polarity are continuous, at the time of recording and reading, -12.5% or more, +1.
Even if a deviation of less than 2.5% occurs, it can be recognized correctly.
With a card processing device that has a mark recording area for 4 dots,
Even if one mark is composed of 4 dots, sufficient reading accuracy can be obtained.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an optical mark processing device according to the present invention. The CPU 2 uses the input / output device 1 to input and output data and device operation commands with respect to external devices. The CPU 2 is configured so that the Y motor 10 can reciprocate the card in the Y direction and the X motor 8 can reciprocate the head unit 5 on the card in the X direction. The X motor 8 is a DC motor,
It is connected to the tacho generator 9, and the CPU 2 can obtain a signal synchronized with the rotation of the X motor 8 from the tacho generator 9. Hereafter, this synchronization signal is referred to as TG
Describe as a signal.

The head unit 5 comprises a head 7 and a sensor 6. The sensor 6 is a reflection type optical sensor and outputs a voltage according to the density of a mark on a card. The output voltage of the sensor is converted into a numerical value by the AD converter 3, while the CPU 2 drives the X motor 8 to read the data from the AD converter 3 in synchronization with the TG signal and sequentially read the mark row for one row on the card. It can be read as mark density data.

The head 7 is a 7-dot thermal head,
The card uses a thermal method. The CPU 2 drives the X motor 8 and drives the thermal head by applying an appropriate energizing pulse to the head driver 4 in synchronization with the TG signal, thereby recording a mark row for one line on the card. In this way, the CPU 2 scans an arbitrary line on the card with the head unit 5 by applying a drive signal to each of the X and Y motor drivers, and thereby records or reads a mark column in the arbitrary line. Is configured to be possible. In this embodiment, the thermal type head and the card are used, but the same can be realized by printing by a thermal transfer type, an impact type, printing or the like.

Further, the CPU 2 has a built-in RAM so that the mark density data read from the AD converter in synchronization with the TG signal can be stored for one line. FIG. 2 shows a table having 256 elements for converting 8-bit information into 9-bit mark information. It is displayed in binary for easy understanding, and the element number is shown in parentheses. Is also shown. This table is configured so that only 4 bits of 0 or 1 are continuous, and that the highest and lowest bits are also configured so that only 2 bits of 0 or 1 are continuous. There is. Therefore, even if any data in the table is concatenated, 0
Alternatively, 5 or more 1 bits do not continue.

When the CPU 2 records the information input via the input / output device 1 as a mark, it adds 24-bit information B by adding error detection information and the like to the recorded information A. This information B is divided into 3 bytes of 8 bits each, and each byte is set as an element number from the table 9
Get the data converted to bits. When the obtained three 9-bit data are concatenated, 27-bit information C is obtained.
The CPU 2 records the 1 bit of this information C as a black mark and the 0 bit as a white mark on the card. In this way, a mark string in which five or more blacks or whites are not continuous is realized.

However, this mark string is 1 for every 8 bits.
Since redundant bits are added, a recording area that is 12.5% wider than the originally required recording area is required. The ratio of this redundant bit is a unit larger than 8 bits,
For example, it can be reduced by converting 12 bits to 13 bits, and the recording density can be improved. FIG. 3 shows an actual recording format. The index mark 31 is composed of 5 dots vertically and 12 dots horizontally,
This is a mark for determining the base point for detecting the row position and reading. A blank 32 of 4 dots is always provided between the index mark 31 and the first mark 33, and the change of the mark from the index mark 31 to the blank 32 is used as a base point during reading. The first mark 33 to the 27th mark 34 are areas that are composed of vertical 7 dots and horizontal 4 dots, and record 1 bit of the information C with black mark and 0 bit with white mark. The character area 35 is an area for displaying the information A as characters. Characters can be printed with 7 dots vertically and 6 dots horizontally, including the ¥ symbol.

The bit configuration and recording format of the mark described here is an example of converting and recording so that the marks of the same polarity do not continue more than a specific number, and it is easy to record with another bit configuration and format. is there. Next, the processing at the time of reading will be described. The CPU 2 drives the Y motor 10 in accordance with the operation command input from the input / output device 1 and conveys the card until the designated row comes directly under the head unit 5. Thereafter, the X motor 8 is driven to read the mark for one line, and the density data for this one line is stored in the memory.

FIG. 4 is a graph of the mark density data when the mark train is read, and FIG.
It is a mark recorded by converting the hexadecimal number 563412H into information C in a table. FIG. 4B is a plot of the density data obtained by reading the marks in FIG. 4A with the density data, that is, the AD conversion value as the vertical axis and the TG signal count as the horizontal axis. In this way, the mark is stored in the memory of the CPU 2 as density data. 4C is a graph in which difference data obtained by subtracting the T + 1th density data from the T + 1th density data of the TG signal having the waveform of FIG. 4B is plotted. If the information C indicating the presence / absence of an actual mark can be restored from the density data shown in FIG. 4B, the information C is changed to the information B, and the information B is checked for validity by the information for error detection or the like and recorded. The information A that has been stored can be restored.

Two examples will be described below as a method of reading the information C from the density data. The first is a method of calculating the mark change points as the density for determining the black and white of the midpoint between the maximum value and the minimum value before and after the change point of the mark density data and calculating the length of consecutive marks. Is. Figure 5 (A)
Is the waveform of the density data near the black mark, a to j are the 0th to 9th density data of the TG signal, and the vicinity of d to f is the portion with the black mark. Here, a method of calculating the length of the black mark will be described.

First, in order to obtain the change point from white to black, the maximum value and the minimum value of a to f are searched for, and b and e are obtained.
To get The exact change point is the midpoint M between the maximum and minimum values.
This is the position of the TG signal that crosses 1. M1 = (b + e) / 2 The point that crosses M1 is between c and d, so a straight line connecting c and d is used to determine the TG position that crosses M1 as follows. In the following equation, 2 is the TG position of c.

N1 = 2 + (c-M1) ÷ (cd) Next, in order to find the change point from black to white, the maximum and minimum values of e to j are searched, and e and i are obtained to obtain black. From this, calculate the white midpoint M2. M2 = (e + i) / 2 M2 is between f and g, so connect f and g with a straight line
The TG position across 2 is determined as follows. In the following formula, 5 is f
Is the TG position of.

N2 = 5 + (M2-f) / (g-f) Since the TG position of the change point from white to black and from black to white is known in this way, the length L of this black mark is L = N2-N1. Since one mark is recorded with a width of four TG signals, the number N of black marks can be calculated by rounding off as N = (L + 2) ÷ 4. .. By repeatedly applying the same processing, it is possible to restore the information C by sequentially calculating the number of black and white marks.

The second method is to calculate the difference between two adjacent points of the mark density data and calculate the length of consecutive marks using the positive and negative peaks of the difference value as the mark change points. .. In the graph of the difference data shown in FIG. 4C, the maximum value is the change point from black to white, and the minimum value is the change point from white to black. Therefore, the length from the maximum value to the minimum value is the length of the white mark, and the length from the minimum value to the maximum value is the length of the black mark.

FIG. 5B is a plot of the difference of the density data of FIG. 5A as k = b-a and l = c-b. Here, the TG position of the minimum value is obtained from the data before and after the minimum value m as follows. In the following equation, 2 is the TG position of m. N1 = 2 + (1−m) ÷ (1 + n−2 × m) This calculation adds the amount of change from 1 to m and the amount of change from m to n to obtain the change amount from 1 to m. Ratio to T
It is added to the G position.

Similarly, the TG position of the maximum value can be obtained from the data before and after the maximum value p as follows. In the following equation, 5 is the TG position of p. N2 = 5 + (p−o) ÷ (2 × p−o−q) N1 and N2 obtained in this way are correct T of maximum and minimum values.
Although it has a certain offset instead of the G position, when the length of the mark is obtained, the offsets included in both N1 and N2 are offset by subtraction, so the length of the mark can be obtained correctly. is there. The length L of this black mark
Can be obtained by L = N2-N1. Since one mark is recorded with a width of four TG signals, the number N of black marks is rounded off as N = (L + 2) ÷ 4. Can be calculated by By repeatedly applying the same processing in this way, it is possible to sequentially calculate the number of black and white marks and restore the information C, and convert the information C to the information B based on the table TBL. It is possible to restore the recorded information A by confirming the validity of the information from the information B using the information for error detection or the like.

When recording and reading by the method described above, it is guaranteed that only a maximum of four black or white marks are continuous, so -12.5% or more, +12.
Even if there is a deviation or error of less than 5%, it can be read correctly. In the present embodiment, when the mark information is created, the marks are configured so that the marks are 4 dots wide and 5 or more marks of the same polarity are not continuous. It is possible to increase the information recording density by reducing the number of continuous marks having the same polarity and the conversion unit from the information B to the information C to reduce the number of redundant bits. Is.

[0026]

As described above, according to the present invention, it is possible to stably read information regardless of the recording error or deviation of the device or the card, and the card processing capable of high-density information recording. A device can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram of a card processing device of the present invention.

FIG. 2 is an explanatory diagram showing contents of a table for converting 8-bit information into 9-bit mark information.

FIG. 3 is an explanatory diagram showing an example of a recording format.

FIG. 4 is a graph illustrating a mark row, mark density data, and difference data.

FIG. 5 is an explanatory diagram of a density data waveform near a black mark and a difference data waveform thereof.

FIG. 6 is an explanatory diagram showing a conventional mark reading method.

[Explanation of reference numerals] 1 input / output device 2 CPU 3 AD converter 4 head driver 5 head unit 6 sensor 7 head 8 X motor 9 tacho generator 10 Y motor

Claims (2)

[Claims] 1. The information converted into a black / white or effective / ineffective bipolar mark array arranged in a row is recorded on a card, and the recorded mark row is read and converted to original information. In the optical card processing device to do, while recording so that the marks of the same polarity do not continue in a specified number or more in the mark row, determine the number of the marks from the length of the continuous marks within the specified number, Assuming that the maximum number of consecutive marks of the same polarity is N, the deviation of the recording and reading pitches of marks is -1 / the recording mark width.
A method of recording / reading an optical card, which is acceptable from (2 × N) to less than 1 / (2 × N). 2. The output voltage of the mark reading sensor is set to A
In an optical card processing device provided with an AD converter for D conversion, mark density data obtained by AD converting the output voltage of the sensor at the time of reading the mark is used as a timing signal in order to read the continuous length of the mark. Sequentially storing in the memory in sequence and storing one row of mark density data, then calculating the mark change point and calculating the length of consecutive marks, or between two adjacent points of the stored mark density data. A method for reading an optical card, characterized in that the length of consecutive marks is calculated with the positive and negative peaks of the difference value as the change points of the marks.