JPH03216678A - How to print magnetically read characters - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for printing magnetically readable characters using an electrophotographic printer.

[Conventional technology]

Traditionally, magnetic ink characters have been printed for reading by offset printing or type impact transfer of magnetic ink layers. Attempts have been made to do this using an electrophotographic printer.

[Problem to be solved by the invention]

However, in electrophotographic printing, there is a problem in that due to characteristics specific to electrophotography such as edge effects, the amount of toner deposited is uneven, which may disrupt the output waveform of the magnetic signal during reading, making it impossible to read. There is.

In view of the above-mentioned points, an object of the present invention is to provide a method for printing magnetically readable characters using an electrophotographic printer without disturbance of the output waveform of a magnetic signal and with very few reading errors.

[Means to solve the problem]

In order to achieve the above object, the present invention uses a bitmap font closest to a predetermined character shape as a base, in a method for printing magnetically readable characters using an electrophotographic printer, and applies development characteristics of electrophotography to this bitmap font. Using a font with dots added or deleted according to the residual magnetization of 15em
It is characterized in that it is developed using a toner containing a magnetic material with a coercive force of 150 μg or more and a coercive force of 150 μg or more.

Further, one aspect of the present invention is characterized in that the font is a font in which every 0 to 2 dots are added along the inner edge of the character.

Another aspect of the present invention is characterized in that the font is a font in which dots are thinned out by uniformly dispersing them in specific areas of characters.

Further, another aspect of the present invention is characterized in that the position of the average line edge is adjusted using a font in which dots are added or deleted every 1 to 3 dots along the edge of the character in the vertical direction. do.

[For production]

In the present invention, the font is based on a bitmap font that is closest to the determined character shape, and dots are added or deleted according to the development characteristics of electrophotography, and the residual magnetization is 15 emu/g or more and the coercive force is 150. Since printing is performed using toner containing a magnetic substance of e (Oersted) or higher, it is possible to bring the output waveform of the magnetic signal closer to the standard, and it is possible to reduce the possibility of reading errors using an electrophotographic printer. It is possible to print small amount of magnetic ink characters.

【Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Magnetic ink character reading is stipulated by ISO (International Standards) and JIS (Japanese Industrial Standards), and E1
A font called 3B is printed with magnetic ink and is magnetized, then scanned by a magnetic head, and characters are recognized based on the position and size of the peak of the output waveform of the magnetic head.

In order to print these magnetic ink characters with an electrophotographic printer that uses a photoreceptor and toner, the toner must have magnetism so that the characters printed on the paper have a specified magnetization. This can be easily achieved by mixing about 30 to 50% by weight of a magnetic material with large residual magnetization, such as needle-like crystal magnetite, into a normal toner.

It has been found through experiments that if the mixed magnetic powder has a residual magnetization of 15 emu/g or more and a coercive force of 150 .mu.e or more, a sufficient magnetic output can be obtained with the mixed amount that enables fixing within the above range. In addition, when investigating cases where characters printed using magnetic ink character toner could not be read by commercially available magnetic ink character reading devices, it was found that the size and position of the peak of the output waveform differed from the standard as described below. I found out that it was off.

FIG. 2(a) shows an enlarged amount symbol. After uniformly magnetizing this amount symbol in the direction of the arrow in the same figure, when it is scanned in the direction of the arrow in the same figure with a magnetic head having a gap length long enough to cover the entire character in the vertical direction, it is shown in Figure 2 ( An output waveform as shown in b) is obtained. One division of the horizontal axis in FIG. 2(b) is 0.331 Ilm. As shown by the solid line in the standard output waveform, the peak value of the output from each line edge is the same size.

However, printed matter produced by electrophotographic printers often differs from this standard waveform. for example,
The output waveform from the printed matter by the Laser Jet series ■ (product name), a printer sold by Hewlett-Packard, is the output from the edges of the pattern on both sides, as shown superimposed by the broken line in Figure 2 (b). The output from the edge of the central pattern is about 1.5 times larger than that of the center pattern. It was found that the cause of this was that the pattern in the center was strongly developed and had a large amount of attached toner.

FIG. 1 shows a bitmap of that central pattern in an embodiment of the invention. The dot density is 300 DPI (dots per inch). When the dots in the shaded area in the figure were exposed, the missing dot did not appear white in the developed pattern, and the pattern was developed to look the same, and the output was The peak of the waveform decreased and approached the values from the patterns on both sides, resulting in a closer approach to the standard output waveform.

FIG. 3 shows the symbol corresponding to the number 8.

When this symbol pattern is printed using the above-mentioned Laser Jet Series ■ (product name), only the lower opening will be developed with a gap larger than the desired pattern, as shown by the broken line in the figure. Since the size of the upper opening is close to the normal size, this seems to be due to the difference in the thickness of the lines on both sides of the opening, which has a different effect on development. As a result, in the output pattern, the position of the line edge of the upper opening and the lower opening is shifted, so the peak value corresponding to this line edge becomes 0 to 20% lower, and the position of the peak shifts outward. This has the disadvantage of misalignment.

FIG. 4 shows a bitmap near the left edge of the lower opening of the pattern of FIG. 3 in an embodiment of the present invention. At the time of the above printing, the area indicated by diagonal lines in the figure was the exposed portion. On the other hand, when printing using a font (pattern) with black dots added, the third
The opening at the bottom of the figure is now approximately the same size as the opening at the top, and the exit waveform of the magnetic output pattern has also been improved.

In E13B font, the line width of characters is 0. 33
0ffiffi is the unit, 300 DPI
For a printer with a dot density of 4 dots, 0. 3
The line width is 39 mm, which is close to the above line width value. 240
For printers with DPI dot density, it is 3 dots,
In the case of a printer with a dot density of 400 DPI, 5 dots is 0.3175III1, which is closest to the above line width value.

The position of the average line edge of characters is ±0. There is a standard of 0.038 mm, and if characters are constructed in dot units as described above, the line width may deviate from the standard line width due to cumulative errors and positional deviations due to the development characteristics of the electrophotographic method. Even in such a case, by adding or deleting dots along the line edge, it is possible to keep the peak position of the output waveform within the standard according to the position of the line edge. FIG. 5 shows a case in which the line edge position is substantially at the center of the dot in an embodiment of the present invention. The squares in the figure indicate the positions of printable dots. Assume that the position of the broken line is at the center of a-a' and bb', and that the position of this broken line is the desired line edge. Whether the M edge is a-a' or bb', in the case of a printer with a dot density of 3000 PI, it is 0. The line edge shifts by about 0.42 mm, and the standard is no longer met. On the other hand, by arranging the dots as indicated by diagonal lines in the figure, it is possible to bring the position of the average line edge closer to the normal position.

In this example, dots are added every other time on the a-a' boundary, but depending on the desired position of the line edge, two dots may be added.
The dots may be added every ~3 dots, or the dots may be thinned out every 1~3 dots.

If you use a font with such dots added or deleted to faithfully reproduce the dots on an electrophotographic printer, the characters will have uneven line edges and may no longer meet the standards regarding uneven line edges. However, when using the Laser Jet Series II (product name), for example, the unevenness of the actual print is smoothed out and is almost invisible to the naked eye, so it is not a problem at all in terms of standards. There wasn't.

【Effect of the invention〕

As explained above, according to the present invention, a font with dots added or deleted according to the development characteristics of electrophotography is used based on a bitmap font closest to a determined character shape, and a residual magnetization of 15 emu is used. Since printing is performed using toner containing a magnetic material with a coercive force of 150 ■e or more and a coercive force of 150 ■e or more, it is possible to bring the output waveform of the magnetic signal closer to the standard, making it possible to use an electrophotographic printer. The effect of printing magnetic ink characters with very few reading errors can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a font for adjusting the magnetic output value in the embodiment of the present invention, FIG. 2(a) is an enlarged diagram of an amount symbol, and FIG.
b) is a waveform diagram showing the output signal waveform for that symbol; FIG. 3 is a plan view showing how the symbol "8" is developed; FIGS. 4 and 5 are the positions of line edges in the embodiment of the present invention. It is a figure which shows an example of moving.

Claims (1)

[Claims] 1) In a method for printing magnetically readable characters using an electrophotographic printer, a bitmap font closest to a predetermined character shape is used as a basis, and dots are added to this according to the development characteristics of the electrophotography. A method for printing magnetically readable characters, which is characterized by using a font to which is added or deleted, and developing using a toner containing a magnetic material with a residual magnetization of 15 emu/g or more and a coercive force of 150 ■e or more. 2) The method for printing magnetically readable characters according to claim 1, wherein a font in which dots are added every 0 to 2 along the inner edge of the character is used as the font. 3) The method for printing magnetically readable characters according to claim 1, characterized in that the font is a font in which dots are thinned out by uniformly dispersing them in a specific area of the character. 4) The magnetism according to claim 1, characterized in that the position of the average line edge is adjusted using a font in which dots are added or deleted every 1 to 3 dots along the edge in the vertical direction of the character. How to print read characters.