DE2451939A1 - Coded sorting label for application to goods - avoids identical symbols being adjacent and read as single symbol - Google Patents

Abstract

A coding label is for application to objects to be sorted by an automatically operated code reading system, with an increased assurance against faulty decoding; each symbol is represented by a permutation of a selection of n from m possible states; each place in the label may have one of the m states but never the same as in the adjacent place; the three states may be represented by three colours or by three shades of grey, black, and white, and the code condition that adjacent places may not be of the same shade or colour assures a sharp boundary between successive places in the code and the avoidance of two successive identical places being decoded at a single symbol.

Description

Code plate for marking objects The invention relates to a code plate for attachment to a number of different types of objects for the purpose of marking these items, especially when they are being transported the conveyor of a distribution system or the like.

Code markings are generally made up of a combination of several Characteristics such as color, brightness, duration of elapsed time, and so on. Color code, such as those used for electrical resistance elements, consist of a combination of thirteen different colors, red, yellow, gold etc., a combination of the colors representing digits from zero to nine. Similar Morse code consists of two different states, namely long and short Time intervals, the long time interval being three times as large as the short one.

Sin main problem that with conventional, from a combination of a Number of different code markings combined with one another exists there is a risk that the information will often be lost during transmission or decoding get lost.

In addition, the devices for automatic decoding are such codes never simple in structure. In particular are such Code the consist of a combination of several different types of states, for example long and short time intervals, easily subject to distortion during transmission and often ultimately lead to incorrect decoding. This with the. usual Problems related to code marks are discussed below in the description Referring to the drawings explained in more detail.

The invention is based on the general object of disadvantages such as they occur in coding according to the state of the art, to avoid or at least to avoid mitigate. In particular, an object of the invention can be seen in to create a code plate with a special code that is free from distortion during decoding. The code plate should allow a number of different Kinds of articles especially in a distribution or transport system easily and to identify them with high accuracy.

With the code as used for the code plate according to the invention a character is represented by a permutation made up of a combination a number n of m different types of preselected states or features exists according to a given rule. This permutation can be called "n-digit m-system ", in which m and n are independent variables. Each digit can assume one of the m different states, but never such a state, which is identical to one of the states of the two neighboring positions.

More precisely, the state of position i is always different from the states of the position i - 1 and the position i + 1. In the code on the inventive Code plate are for the representation of a character or a meaning n permutation factors provided, a combination of these permutations to represent a more complex one Meaning is used. For the present invention it is therefore necessary that the state of a combination never equals one of the states of the neighboring ones Combinations is.

According to the invention, the first digit of the code is selected from a group which contains a large number m of arbitrarily chosen different states, while the position n on the other states that do not belong to the group mentioned is chosen.

The invention is illustrated in the following description of preferred embodiments explained in more detail with reference to the drawings. In the drawings, Fig. 1 shows a schematic Display of Morse code expressed by electrical signals; Fig. 2 a - Schematic representation of the Morse code according to Fig. 1, expressed by degrees of brightness or states; 3 shows a schematic representation to illustrate errors, as they occur when using the Morse code for distribution systems or the like can; Figure 4 is a schematic representation of the expressed by electrical signals Codes for a code plate according to the invention; Fig. 5 shows an embodiment for a code plate according to the invention; 6 is a schematic circuit diagram for a decoder for decoding the code contained on a code plate according to the invention; Fig. 7 shows a schematic representation to explain the mode of operation of the decoder according to FIG Fig. 6; and FIG. 8 shows a further exemplary embodiment for a code plate according to the invention.

Fig. 1 shows the timing diagram of electrical signals in Morse code, which represent the letters "S" and "U". In Fig. 1, the state is ON by a black area and the OFF state expressed by a white area, the information according to FIG. 1 can be shown in accordance with the illustration according to FIG. 2 in which the black areas are cross-hatched.

A typical application of this code is a method at which the field of FIG. 2 is printed on or attached to an object is used, for example, by an optical reader to identify the object to be read.

This procedure plays a role in distribution, traffic or similar systems a very important role. Especially if the code is automatically transmitted by a reader is read, alphanumeric characters in coded form are much more useful than in IZarschrift, because coded characters are easier to handle and a simplification of the apparatus.

However, a code label attached to an article does not always have consistent shape. It can happen that the label, whose shape is in the normal state is shown in Fig. 2, when mounted on a cylindrical object approximately in the deformed shape shown in Fig. 3 enters the reader.

As a typical method for decoding the ones contained on the code plate Information with the aid of an optical reader, the following procedure is explained. The reader is moved in the horizontal direction, taking the code plate reflected light photoelectrically converted into the ON-OFF sinals shown in FIG and these signals will ultimately be decoded. This procedure works effective as long as the visible information of the code plate is among those shown in FIG Normal conditions is maintained. If, on the other hand, it is roughly in the position shown in FIG. 3 shown deformed state, the actual periodicity of the code is disturbed and prevents correct decoding.

The following describes the principle of the invention and some typical ones Embodiments are explained in more detail.

The code contained on the code plate according to the invention is as follows compiled. To facilitate understanding of the present description is made the explanation based on the code which is referred to above as the "n-digit m-system" has been. First, assume that m are different types of states a1, a2 ... am exist, where a1, a2 ... a1 (with 1 as a whole Number between 1 and a-1) of a group and the states al + 1, al + 2, ... am of the remaining Assigned to a group. The first place is through the selection of a state from the group -a1, a2. . . a1, the second digit, the state of which depends on the the first digit is different by selecting a state from the group a1, a2, ... am and the third digit, the state of which differs from that of the second digit is, also by choosing from the same group a1, a2, ... am. In the same Way like the second and third digits are the further digits up to the spot (n-1) formed by repeating the selection rule. The nth digit from the Digit (n-1) is different, is finally selected from the other group with the states al + 1, al + 2, ... am selected.

As a simple example, assume 1 = 1. In this case the first digit the state a1, while the digits 2 to (n-1) are generated by that in each case one that differs from the state of the immediately preceding passage State selected and finally the nth digit that is different from the digit (n-1) is formed by selecting from the states a2, a3, ... am.

The table below is used to make it easier to understand I explained an example in which to represent the digits "O", gn "2", ... "9" using the code plate according to the invention m = 3 (with the states a1, a2, a3) and n = 5.

TABLE 1 CODE NUMBER a1 a2 a1 a2 a3 "O" a1 a2 a1 a3 a2 "1" a1 a2 a3 a1 a2 "2" a1 a2 a3 a1 a2 "3" a1 a2 a3 a2 a3 "4" 2323 a1 a3 a1 a2 a3 "5" a1 a3 a1 a3 a2 "6" a1 a3 a2 a1 a2 "7" a1 a3 a2 a1 a3 "8" a1 a3 a2 a3 a2 "9" The example in Table I corresponds to the case where 1 = 1, so that the first position can only have the state a1 and the leftmost element of the combination consisting of a total of five elements is regarded as the first position. In other cases, the rightmost element of the combination can be considered the first digit, where 1 = 2; or a method is conceivable in which the state of the first digit is selected to be different from a1. An explanation of these further cases or methods should be superfluous here.

In the case of the code of the type described above, the state of one is correct Never match with those of the neighboring places; therefore the code is completely independent of path and time. So there is no way or risk of incorrect decoding even if the code is deformed State is read.

Fig. 4 illustrates a code in which the in the individual places contained states a1, a2 and a3 of the above-mentioned code the voltages OV, 1V or 2V are assigned. The electrical signal shown in Fig. 4 corresponds to arithmetic number 695.

Fig. 5 illustrates a code in which the states a1, a2 and a3 are assigned to the colors gray, black and white. The code plate shown in FIG contains the same information as the electrical signal according to FIG. 4, where in Fig. 5 the gray fields are hatched and the black ones are cross-hatched.

In the following, a decoding device is intended for decoding with reference to FIGS. 6 and 7 of the code contained on a code plate according to the invention are explained. Included reference is made to the code shown in FIG. In Fig. 6 are with the Reference numerals 11 and 12 denote photoelectric converters, with 21, 22, 23 and 24 comparators, their output variables for the different colors or brightness levels of the code pattern are given in Table II below, and with 31 to 34, 41, 42 and 51 to 53 links.

TABLE II ic - KM PARATOR ENTRANCE - 21, 23 22, 24 A. gray (ov) 0 1 black (1V) O 0 white (2V) 1 1 In FIG. 7, 11 and 12, as in FIG. 6, denote the photoelectric converters, while 10 denotes a part of a code plate which corresponds to the left section of the code plate according to FIG. The photoelectric converters 11 and 12 are arranged at a distance from one another which is sufficiently small compared to the length of one digit of the code.

In the representation according to -Fig. 7 become the photoelectric converters 11 and 12 moved relative to the code plate 10. In accordance with the table II appears at the logic element 32, a logic output signal L when the photoelectric converter 11 scans a gray field of the code plate 10. Similar appears at the output of the logic element 31 or of the logic element 33 a logical L if the converter 11 has a white or a black field on the code plate 10 keys. The two non-equivalence elements 41, 42 and the NOR element 34 form one Clock signal generator stage.

Keys the two photoelectric converters 11 and 12 the same State (the same color or brightness), appears at the output of the NOR element 34 a logic L, i.e. a clock signal which the three AND gates 51, 52 and 53 is fed. On the other hand, if the transducers 11 and 12 press different states, so a logical 0 appears at the output of the NOR element 34. From the UtS elements 51, 52 and 53 will only receive a logical L if the two photoelectric Transducers 11 and 12 key the same state.

If the two converters, for example, press a white field, then appears at the output of the AND gate 51 a logic L, while the outputs of the other two UTJD members have a logical 0. By combining the logical output signals the AND gates 51, 52 and 53 is determined, the contained on the Oode plate Automatically decode information very easily.

As set out above, the characterizes on a according to the invention Code plate contained code by the fact that the state of a Job never coincides with the states of the neighboring places. Even if the Length of the individual setting wheel codes is always independent of such Fluctuations ensure accurate decoding. In other words, none occurs Case in which decoding is impossible because of the condition of the encoder disk were. Correct decoding is always and also, for example, in such Possible cases in which the coding plate is mounted on a curved plane, Variations in the distance between the coding plate and the photoelectric converter of the reader or the code plate is inclined.

The code generated according to the invention can be selected by suitable selection of the various physical quantities used in a wide range of applications. For example, optical parameters such as brightness, hue, saturation, reflectivity, Transmittance, deflectivity, deflection angle, etc. individually or in combination used to generate several states and the above states a1, a2, ... am be assigned. In the embodiment of FIG. 5 is for the states Brightness has been used.

The same goals can be achieved not only with the ones mentioned above optical sizes, but also through geometric conditions or states such as concavity, protrusions, holes, depth, etc., also by electrical quantities such as voltage, current, electrical resistance, magnetic field strength, coercive force, magnetic resistance, field strength, electrostatic capacity, etc. Again, can the above sizes alone or in combination of two or more sizes or States are used.

Referring to Fig. 8, there is another embodiment of the present invention shown, wherein the structure of a location comprises two levels A and B, one 0 is expressed by the fact that A and B are white, the state 1 if A is black and B white, and state 2 if A and B are black. So this example is a combination of brightness (i.e. an optical quantity) and length (i.e.

a geometric quantity, the length being perpendicular to the main direction of the code) to generate three states.

Only two brightness values and only two length values are used here. Such an arrangement is advantageous in that the input or reading part can be simpler in its structure.

For decoding with the aid of a decoder, it is advisable to use a Place a certain start mark in front of the code plate to mark the beginning the reading on the code plate.

Claims (4)

Claims Code plate, characterized by a code, the first digit of which is a State from the group of states a1, a2, ... a1, where m different states a1, a2, ... am exist and 1 is any integer between 1 and (m-1) whose i-th position is a state from the group of states a1, a2, ... am with Has the exception of the state of the (i-1) th digit, where i runs from 2 to (n-1), and the last or nth position of which is a state from the group of states al + 1, al + 2, .B. with the exception of the state of the (n-1) th digit. 2. Code plate according to claim 1, characterized in that the m states are represented by three colors. 3. Code plate according to claim 2, characterized in that the three Colors are white, one with a gray lightness value and black. 4. Code plate according to claim 3, characterized in that the color with a gray brightness value is yellow.