JPH01155488A - Uneven character reader - Google Patents

Abstract

PURPOSE:To accurately read uneven characters without being affected by means of characters of printing and the like by irradiating an object to be read by means of at least two light sources at different timings and operating the exclusive OR of an output from a light receiving means at that time. CONSTITUTION:Light beams from two light sources 13 and 14 are radiated on a plastic card 10 as the object to be read at different timings, and the light- receiving sensor 16 receives the reflecting light beams. Since the sensor 16 is arranged in the middle of the light sources 13 and 14, the same picture can be obtained in the case of the characters of printing even if it is radiated from either light sources. In the case of the uneven characters on the other hand, different pictures are generated when it is radiated from different directions. With operating the exclusive OR of data of the picture when two light sources are radiated, both can be identified. Consequently, the printed characters and the like are prevented from being erroneously read.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reading device for reading embossed characters formed on a flat surface of plastic, metal, or the like.

[Conventional technology]

FIG. 2 shows the configuration of a conventional reading device disclosed in, for example, Japanese Patent Laid-Open No. 144884/1984. In the figure, 1 is an object to be read such as a plastic card, and the object 1 has characters, figures, etc. engraved (embossed) in the form of concave or convex parts on the flat surface of the object 1. Lamps 3A to 3D on which letters are engraved (formed as recesses) sequentially illuminate the object 1 from four different diagonal directions. A television camera 2 photographs the object 1 illuminated by lamps 3A to 3D.

4 is a binarization circuit, which binarizes the output of the television camera 2. A switch 5 sequentially switches and outputs the output of the binarization circuit 4 when illuminated by the lamps 3A to 3D to the memories 6A to 6D. 7 is or gate,
The outputs of the memories 6A to 6D are output to the memory 8.

When the lamp 3A is illuminated, an image of the characters stamped on the object 1 is photographed by the television camera 2. The signal corresponding to the image at this time is binarized by the binarization circuit 4, input to the memory 6A via the switch 5, and stored. The image stored at this time includes lamp 3.
A shadow is created in the area where the light from A does not reach.

Similarly, the image when illuminated by lamp 3B is memory 6B, the image when illuminated by lamp 3C is memory 6C, and the image when illuminated by lamp 3D is memory 6.
D, respectively. These images are also shadowed by the corresponding lamps.

The outputs of the memories 6A to 6D are added together via the OR gate 7 and input to the memory 8. Therefore, the memory 8 stores an image in which the shadows formed by the respective lamps are combined.

[Problem that the invention seeks to solve]

Since conventional devices combine four images into one image when illuminated from four directions, there is a risk that not only characters with uneven shapes but also characters printed etc. will be read. Ta.

Therefore, the present invention aims to realize a device that can correctly read characters with uneven shapes without being affected by characters printed or the like.

[Means for solving problems]

The concavo-convex character reading device of the present invention has at least one disposed at different positions that generates light that linearly irradiates an object to be read in which a character shape, etc. consisting of concave portions or convex portions is formed on a flat surface from different directions. two light sources, a light receiving means disposed between the two light sources to receive reflected light reflected by an object to be read, a control circuit for driving the two light sources at different timings, and a control circuit for driving the two light sources at different timings. and an exclusive OR circuit that calculates an exclusive OR of the outputs of the light receiving means when

[Effect]

Light generated from at least two light sources is linearly irradiated onto an object to be read, such as a plastic card, at different timings, and the reflected light is received by the light receiving means. Characters, figures, symbols, etc. are engraved on the flat surface of the object in the form of concave or convex portions.

Since the light-receiving means is arranged between the two light sources, in the case of flat characters printed or the like, a similar image can be obtained no matter which light source illuminates the characters.

On the other hand, in the case of letters with uneven shapes, different images are generated when the letters are illuminated from different directions.

As a result, by calculating the exclusive OR of the image data obtained when the two light sources are illuminated, it is possible to distinguish between the two.

Therefore, incorrect reading of printed characters etc. is prevented.

〔Example〕

FIG. 1 shows the configuration of a reading device according to the present invention. In the figure, reference numeral 10 denotes a plastic card as an object to be read, and characters (including figures, symbols, etc.) are engraved on a flat surface 11 of the card 10 by a recess 12. 13.
14 is an LED array as a light source, which generates light to irradiate the card 10. Reference numeral 15 denotes a convergent rod lens array as a light condensing means, which is arranged so that one focal point is located near the flat section 11 and the other focal point is located near the light receiving element array 17 of the light receiving sensor 16.

The light output from the LED arrays 13 and 14 illuminates the same part of the card 10 in a straight line in a direction perpendicular to the plane of the paper, and the light receiving element array 17 is similarly arranged in a straight line to receive the reflected light. There is. Although the number of arrays corresponds to the resolution to be achieved, for example, five light receiving elements can be arrayed per square inch.

FIG. 3 is a block diagram of the reading device of the present invention.

In the figure, 31 is a control circuit that drives two LED arrays 13.14 and memories 32.33. 34 is an exclusive OR circuit that calculates an exclusive OR of the outputs of the memories 32 and 33.

Therefore, when reading, the control circuit 31 first reads the LE
The D array 13 is driven to illuminate the card 10. The reflected light from the card 10 is input to the light receiving sensor 16 via the convergent rod lens array 15. The light receiving element array 17 on the light receiving sensor 16 is scanned, and its output is stored in the memory 32.

Next, the other LED array 14 illuminates the same position on the card 10 in the same manner, and the image at that time is stored in the memory 33.

As shown in FIG. 1(, ), the illumination position is on the flat surface 11 of the card 10, and when there are characters printed there, for example, as shown in FIG. 4(a), the LED array 13 is activated. The output of the light receiving sensor 16 at this time is as shown in FIG. 4(b). That is, a low-level signal is output in a black portion where ink or the like is printed, and a high-level signal is output in a white portion where no printing is performed.

Since the memory 32 associates logic 1 with a high-level input signal and logic 0 with a low-level input signal, the data stored in the memory 32 becomes as shown in FIG. 4(d).

Light receiving sensor 16 (and focusing rod lens array 15)
is placed exactly in the middle of the two LED arrays 13 and 14. In other words, the light receiving sensor 16 is arranged so that its optical axis is perpendicular to the card 10, and the two LED arrays 13 and 14 are arranged symmetrically with respect to the optical axis of the light receiving sensor 16.

Therefore, when the LED array 14 illuminates a printed character pattern formed two-dimensionally on the flat part 11, the output of the light receiving sensor 16 is as shown in FIG. 4(c), and the LED
This is the same as when the array 13 is illuminated. As a result, the data stored in the memory 33 becomes the same as the data stored in the memory 32 as shown in FIG. 4(e), and the exclusive OR of the data stored in the memories 32 and 33 becomes as shown in FIG. 4(f). Always 0.

When the LED arrays 13 and 14 have finished reading the same portion, the card 10 is moved by a predetermined pitch in the left direction (in the direction of arrow A) in FIG. 1 by a roller or the like (not shown). The new position is then read in the same way.

When the angle of the inclined surface 21 of the concave portion 12 with respect to the flat portion 11 is α, the optical axis of the LED array 13 (14) on the flat portion 1
The angle θ with respect to 1 is set to a smaller value than the angle α. Therefore, when the reading position is the recess 12, FIG.
As shown in b), when illuminated by one LED array 13, a shadow 22 is formed in the recess 12;
As shown in Figure (c), no shadow is formed in the recess 12 when illuminated by the other LED array 14.

For example, as shown in Fig. 5(a), characters (
When the embossed characters) are present, the output of the light receiving sensor 16 when the LED array 13 emits light is at a low level in the part corresponding to the recessed part, as shown in FIG.
The level is high in areas where no recesses are formed.

As a result, as shown in FIG. 5(d), the data stored in the memory 32 becomes logic 1 in the plane part of logic O1 in the recessed part.

On the other hand, when the LED array 14 emits light, the output of the light receiving sensor 16 is always at a high level as shown in FIG. 5(c), so the data stored in the memory 33 is all logic 1 as shown in FIG. . Therefore, as shown in FIG. 5(f), the output of the exclusive OR circuit 34 becomes logic 1 in the concave portion and logic 0 in the plane portion.

In this manner, the output of the exclusive OR circuit 34 becomes logic 1 in the logic O1 recesses on the flat surface regardless of whether or not there is printing, so that the characters formed by the recesses can be read accurately.

In the above, the output of the light receiving sensor 16 is stored in two memories, but it can also be stored in one memory by using different addresses. It is also possible to store data in a memory when one LED array emits light, and input data directly into the exclusive OR circuit 34 when the other LED array emits light. In this case, the memory can be constructed from a delay circuit.

Furthermore, it is also possible to arrange a pair of LED arrays in a direction parallel to the direction of movement of the card 10 so that the characters can be read in the same way.

In addition, for ease of understanding, in the above embodiment, LE
Although the angle θ of the D array 13, 14 is set smaller than the angle α of the inclined surface 21, even if it is set larger, the angle θ of the plane portion 1
Since the amount of reflection at the recess 1 and the recess 12 are different, the present invention can be applied.

〔effect〕

As described above, according to the present invention, since the exclusive OR of the outputs of the light receiving means is calculated when at least two light sources are driven at different timings, flat characters etc. printed on a flat surface can be printed. Even if there is a concave portion or a convex portion, there is little risk of erroneously detecting it as a concave portion or a convex portion.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the configuration of the reading device of the present invention, and FIG.
The figure is a block diagram showing the configuration of a conventional reading device, FIG. 3 is a block diagram of the reading device of the present invention, FIG. 4 is a diagram explaining the reading state of the flat part of the card, and FIG. 5 is the uneven part thereof. FIG. 1... Object to be read 2... Television camera 3A to 3D... Lamp 4... Binarization circuit 5... Switches 6A to 6D... Memory 7... OR gate 8... Memory 10...Plastic card 11...Flat portion 12...Concave portion 13.14...LED array 15...Focusing rod lens array 16...Light receiving sensor 17...Light receiving element array 21... ... Inclined surface 22 ... Shadow 31 ... Control circuit 32, 33 ... Memory 34 ... Exclusive OR circuit Patent applicant Oki Electric Industry Co., Ltd.

Claims (1)

[Scope of Claims] At least two light sources disposed at different positions that generate light that linearly irradiates an object to be read in which characters, figures, etc. are formed with concave or convex portions on a flat surface from different directions. and a light receiving means disposed between the two light sources to receive the reflected light reflected by the object to be read, a control circuit for driving the two light sources at different timings, and a control circuit for driving the two light sources at different timings. An uneven character reading device comprising: an exclusive OR circuit that calculates an exclusive OR of the outputs of the light receiving means.