DATA CODE ON A CODE SHEET AND APPARATUS OF RECOGNIZING THE CODE

Abstract: A sheet (1) for data code wherein deci­ mal numerals or n-ary numerals that represent data codes such as 1, 2, 4, or 8 are displayed in advance in a figure, e.g., in four squares having four segments (2₀ to 2₃). The numerals are ar­ ranged in a predetermined order starting from the minimum digits that correspond to binary digit positional numerals, and any one or some of the four segments (2₀ to 2₃) are blackened. When a black segment is denoted by 1 and a white segment by 0, numerals representing the data codes can be easily converted into binary numerals which can, then, be directly recog­ nized visually. The method of recognizing the data code comprises projecting the light from a light source onto the sheet 1 for data code, and receiving the reflected light or the transmission light by light-receiving elements (5₀ to 5₃) that correspond to the four segments (2₀ to 2₃). The light-receiving element corresponding to a black data code produces an output signal 1 and the light-receiving element corresponding to a white data code produces an output signal 0. Therefore, numerals representing the data code are directly produced as digital signals based on binary signals, whereby the method is established for recognizing the data code. There can further be used a method of recognizing the data codes by projecting light from a light source onto the data code sheet 1, receiving the reflected light or transmitted light by an im­ age sensor, transferring the signal of the image sensor as an image signal, and subjecting the data code to the image pro­ cessing.

Description: The present invention relates to a data code on a code sheet and apparatus for reading said data code. Hitherto, conventional bar codes have been used for printing a code onto various products and for use in all aspects of manufacturing and at point of sale retail stores. The bar code system comprises a plurality of parallel, aligned bars, each bar having a given width to represent a particular number, or character. The bar code is read by illuminating the code with a beam of light and the reflected light is read by an optical sensor. The sensor may be, for example, of a fixed beam type in which the object having the code printed thereon is moved in front of it. Alternatively, the sensor may be of the moving type whereby the object having the code printed thereon is fixed and the sensor is moved across the code. The reflected light forms analogue signals which is converted by the sensor to digital signals and then these signals are image processed by a microprocessor to extract the relevant information. This results in the optical sensor being relatively complex and expensive. Since the bar widths are used to represent numbers or characters, the bar code must be printed with great accuracy to ensure that the code accurately represents the information required. Furthermore, a user merely looking at the code is unable to decipher the information written thereon since the naked eye is unable to accurately determine the widths of the bars. A code has been proposed, which is described in pending PCT application no. PCT/JP87/0007 (= EP-A-0 299 066, cited under Art. 54(3)). The code comprises at least one unit being divided into at least two regions having substantially similar dimensions, whereby each characteristic of the code has a particular arrangement of shaded and/or blank regions. One known disadvantage with this code is that only decimal notation such as numerals 0-9 may be represented. Another known disadvantage with this code is that the orientation of each unit can not be determined and hence inaccurate data may be extracted. In addition, one well known code is binary notation, which is especially used in computing or microprocessing fields. However, most users are not used to working in binary, but are highly proficient in using decimal notation. Conversion from decimal to binary and vice versa is not easily computed manually and is usually done by a machine. Hitherto, there are no known codes which easily allow a user to convert between decimal and binary notation. We acknowledge the disclosure in FR-A-1272313 which forms the basis of the preamble of claims 1 and 5. It describes the machine-controlled sorting of packages marked with a square shaded code. Signals representing the binary state (shaded or not shaded) of each region of the code are decoded and used directly to perform the required function. Further, Patent Abstracts of Japan, vol. 2, no. 108, Sept. 8, 1978, p. 5731 E 78 & JP-A- 53-73026 discloses a binary code for use on facsimile reproduced sheets, which has a square unit comprising four square regions each of which is shaded to represent respective binary numbers 1, 2, 4 and 8. An object of the present invention is to provide a data code and apparatus for reading such a data code which alleviates the aforementioned disadvantages. According to the present invention there is provided a data code as defined in Claim 1, and apparatus as defined in Claim 5 for reading that code. Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic representation of an embodiment the data code, in which each unit of the data code corresponds to the respective decimal, hexidecimal or binary notation; Figure 2 illustrates each region of the data code representing binary or decimal notation as shown in Figure 1; Figure 3 illustrates examples of the data code according to Figure 1; Figure 4 illustrates a positional arrangement of the data code shown in Figure 1; Figure 5 schematically represents variations of a unit; Figure 6 schematically illustrates the data code representing each letter of the Roman Alphabet; Figure 7 illustrates units of a data code according to an embodiment of the present invention; Figure 8 illustrates each unit being coupled to means for distinguishing the orientation of the units of the embodiment shown in figure 6; Figure 9 illustrates examples of the preferred embodiment shown in Figure 6 having known symbols printed thereon; Figure 10 illustrates a data code and apparatus for reading thereof according to a second preferred embodiment of the present invention: Figure 11 is a schematic block diagram of the apparatus shown in figure 10; Figure 12 is a schematic diagram of the apparatus according to a third preferred embodiment; Figure 13 is a schematic block diagram of the circuit of the apparatus shown in figure 12. An embodiment of the data code is shown in figure 1 and comprises a number of units 2 each being divided into four equal regions 4. Each of the regions 4 of any unit 2 may be shaded, or printed manually or by a printing machine, to create a unique arrangement of shaded and blank regions to define a particular unit and hence a particular characteristic of the data code. Each of the decimal numbers 0 to 9 are represented by a particular combination of blank and shaded regions. Each of the units shown in figure 1 comprises four regions, however two or more regions may be used for each unit. Furthermore. each region may form a rectangular, circular or triangular shape, but each of the regions must have substantially similar dimensions for a particular data code. Each of the units 2 of the data code is used to represent decimal, hexidecimal or binary notation as shown in figure 1. Here each region represents a column of binary notation starting with the lowest order column, 1, and successive columns 2, 4, 8. Hence numerals in decimal or other binary notation can be represented. If, respective regions for each unit always represent the same column then the value of a unit can be determined at a glance. Figure 2 further illustrates the data code being used to represent decimal, hexidecimal or binary notation. The decimal numbers 1, 2, 4 and 8 may be printed onto the data code sheet before any one of the regions are shaded. These numbers are directly related to binary or hexidecimal notation since each region 4 is used to represent a column of notation, for example the 1, 10, 100, 1000 in binary notation. For example, 4a represents column 2⁰, equivalent to the decimal or hexidecimal number 0 or the binary number 1; b represents column 2¹, equivalent to the decimal or hexidecimal number 2 or the binary number 10; region 4c represents column 2² = 4 = 100; and similarly region d represents 2³ = 8 = 1000. A number of units may be used to represent larger numbers. Accordingly each unit 2 may be used to represent decimal, hexidecimal, or binary notation. As shown in figure 3 the unit 2 may also have decimal notation printed on each of the regions 4. Thus in figure 3a regions 4b, 4c, and 4d are shaded thus indicating that the unit represents the decimal number 14 ( since 2 + 4 + 8 = 14) and the binary number 1110. Similarly the unit illustrated in figure 3b represents the decimal number 13 and the binary number 1101 and the unit in figure 3c represents the decimal number 250 and the binary number 11111010. Thus the data code easily enables a user to identify a binary or a decimal notation merely viewing the data code. Computers are generally based on hexidecimal notation and the data code is applicable to such notation and therefore directly compatable with computers. Figure 4 illustrates possible positional arrangements of the data code in decimal notation or hexidecimal notation when printed on a sheet 1. Figure 5 illustrates a number of different types of units which may be used in the data code but the present invention is not limited just to these types of units. Any one of these units may be used to form a data code applicable to the notation which the code is representing. For example, a notation requiring 6 regions for each unit may be denoted by units 5a and 5b. Accordingly. the following types of notation can be represented by a minimum number of regions or bits: For example, figure 6 illustrates the Roman Alphabet of capitals in terms of binary notation and the data code. For example, the letter N may be represented by the binary notation 00100011 or by the 2 units. The data code therefore facilitates reading, understanding and remembering codes of the Roman alphabet in capitals. Figure 7 illustrates a data code according to an embodiment. The regions 4 of each of the units 2 include means for distinguishing the orientation of the unit, such as a bar 6. The bar 6 facilitates reading of the code and enables the code to be correctly positioned. If the sensor reads the first column whilst viewing position a, then the sensor will recognise that the centre of the unit is not aligned with the origin of its two dimensional axis and thus will adjust the reading of the columns until it is aligned. As shown in figure 8, the bar 6 should be aligned along the X axis having the centre of each unit aligned with the origin of the two dimensional axis in the sensor. However, this embodiment enables the data code to be read easily even if the data code is placed at an angle ϑ to a reader. For example, in figure 8c alignment of the data code using the bar 6 enables the sensor to compensate for the code being at an angle ϑ. Each unit of the data code may also have known characters or punctuation marks printed in some or all of the regions as shown in figure 9. This further enables the data code to be easily read and interpreted. The data code facilitates reading and understanding of decimal. hexidecimal and binary notation in both education and industry. The data code may be written by hand and may be used to operate electronic devices thereby making such devices more accessable. Furthermore, the data code may be used as an interface language between characters of different languages. Figures 10 to 13 illustrate a data code printed on a sheet 1 and apparatus for reading said data code. Referring to figure 10 and 11, the apparatus 8 illuminates each unit of the data code using a light source 9, such as an LED lamp or a laser beam. The reflected light is received by respective photoreceptors 10, such as a Mos-type sensor or CDD. The photoreceptors 10 are coupled to a decoder 12 having input terminals 1, 2, 4, 8 corresponding to each photoreceptor 10 for the appropriate region 4. The input signals are extracted in binary column order and sent to a CPU 14 for displaying or converting the digital signals into the apropriate numbers, characters or symbols for a suitable display 16. The photoreceptors 10 are responsive to the variations in the regions since less light is reflected back from a shaded region. The photoreceptors will record the binary number 1 in response to the light received from a shaded region and the binary number 0 in response to the light being received from a blank region. In conjunction with each region representing a column of binary notion, the apparatus 8 can read directly from the data code, the binary numbers, thereby obviating any analogue to digital conversion. Each unit 2 is illuminated by the light source 9 controlled by a switch 18 which illuminates each unit 2 in turn. This enables the photoreceptors 10 to submit signals in succession. Alternatively, as shown in figure 12 and 13, the signals from the illuminated data code, may be received by an image sensor 20 via an optical system 22, the sensor 20 comprises two or more photoreceptors 10 in a two dimensional array. The sensor produces a signal which is outputted in a time series and stored in a memory 32. The stored data is displayed sequentially to reveal the data code. Circuit 24 shown in figure 13 enables the signals to be co-ordinated and comprises a clock 26, a vertical syncronising circuit 28 and a horizontal syncronising circuit 30. Each signal received at the terminals 1, 2, 4 and 8 of the decoder 12 is sent to the CPU 34 via the buffer memory and control unit 32. These reading methods enable the system to avoid analogue to digital conversion as required by the prior art systems. The foregoing description has been given by way of example only, and it will be appreciated by persons skilled in the art that modifications may be made without departing from the scope of the present invention as defined by the claims.

Claims: A data code on a code sheet comprising at least one unit (2), the or each unit being divided into regions (4, 4a, 4b, ...) having similar dimensions, the areas of the regions combining to constitute the area of the unit or units, and one such unit having at least four such regions, characterized in that each region corresponds to a different column of binary notation commencing with the lowest order column and thereafter the successive columns, the same region of the code always being representative of the same binary column in one-to-one correspondence, and each unit having a particular arrangement of shaded regions so that the code represents directly a particular binary number; said data code further comprising orientation means (6) for distinguishing the orientation of said data code comprising a shaded bar dissecting the or each unit into two parts having two regions each. A data code as claimed in Claim 1, in which the or each unit with at least four regions comprises a square having four regions, each of which regions comprising a square. A data code as claimed in Claim 1, in which each region comprises any one of a rectangle, circle or triangle. A data code as claimed in any one of the preceding claims in which the numeric value of each region is printed thereon. Apparatus for reading a data code according to any preceding claim, comprising means (9) for illuminating the data code, an image sensor (20) comprising an optical system coupled to an array of photoreceptors for receiving the illumination from the data code and for producing a signal dependent upon the illumination received; characterized by means (32) for storing said signal and display means (14, 16) for sequentially displaying said signal. Apparatus as claimed in Claim 5, further comprising a switch (18) coupled to the illuminating means (9) for enabling the regions to be read sequentially. Apparatus as claimed in Claim 5 or 6, in which the array of photoreceptors is a two-dimensional array. An apparatus as claimed in Claim 5, further comprising means (24) for co-ordinating the signals produced by said image sensor.

Inventors: TOMIOKA MAKOTO, TOMIOKA, MAKOTO
Applicants: TOMIOKA MAKOTO, TOMIOKA, MAKOTO
Application year: 1988
Main classification: G06K7
IPC codes: G06K19, G06K7