DE1574556C - Circuit arrangement for coding characters - Google Patents

Description

The invention relates to a circuit arrangement for coding characters in key-operated machines, in particular office machines with double coding for keys with double assignment. The definition "character" includes in the following description Letters, numbers and symbols.

Various coding methods have already been developed for machines equipped with keys. They differ from one another in the number of bits and also in the bit sequence. With double occupancy Buttons, d. This means that keys that have the same uppercase and lowercase letters are based on an ISO proposal a separate code word is used for each character.

The circuit arrangements for realizing the ISO proposal are, however, quite complex and complicated. In a known circuit arrangement, for example, each is assigned twice Key assigned to two lines, and at points of intersection of the key lines with channel lines there are threaded magnetic cores. A special control circuit must be used for this known circuit arrangement are provided.

The invention is based on the object of proposing a circuit arrangement for coding, which enables completely free code assignment with very little circuit complexity and thus also for Codes according to the ISO proposal is suitable.

The circuit arrangement according to the invention is characterized in that one key for two assigned characters only one key line is provided, which is used to form two separate ones Code words for each character, on the one hand, via first directional guides polarized in a certain direction with a first channel line and on the other hand via opposite polarity to the first directional conductors second directional conductor coupled to a second channel line according to the desired code assignment are; that each first channel line via an inverter stage with the corresponding, at the same time as Output code line serving, second channel line is coupled and that the key lines in one switch position with negative potential and the other switch position with positive potential can be acted upon.

The invention is based on an embodiment

example with reference to the drawing described below.

The embodiment relates to an eight-channel code. The eight channels of the matrix are each two channel lines Ik-Xg, 2k-2g.

3k-3g. . . Associated with 8k-8g . The channel lines Ik, 2k, 3k .. .8k are at the output via the resistors R 1, R 2, R 3 ... R 8 with the control electrodes of the pnp transistors T1, T2, Γ3. . . 78 connected. These transistors are connected as inverters and their emitters are connected to the positive line 13. Their collectors are coupled to the relevant channel lines Ig, 2g, 3g ... 8g. The connection of the two channel lines that belong together can of course also be made via any other inverting element.

The channel lines 1 k-1 g, 2 k-2 g, 3 k-3 g ... 8 k-8 § are crossed by the key lines Ll, L2, L3 ... Ln . The upper end of the key line is at the contacts Kl, K2, K3 ... Kn of the key switch Tk, the second side of which is coupled via line 11 to the switch U of the changeover contact of the type basket of the typewriter. In its first position, this switch switches negative potential (line 9) and in its second position positive potential (line 10) to line 11. For the generation of the corresponding code word, the channel lines Ik, 2 k, 3 k ... 8 k are over with Their cathodes on the key lines lying directional conductor 14 connected to the key lines. The directional conductors 15, which the channel lines Ig, 2g, 3g ... Connect 8g to the key lines, have opposite polarity. This results in the following code generation. With the switch position of the switch U shown in the drawing, the circuit arrangement generates codes for lowercase letters, since a negative potential is applied to the key contact Tk via the switch U and line 11. By pressing the Tk key, this potential is transferred to the key line L1 and protrudes

the directional conductors 14 in the channel lines Ik, 2k, 4k. Sk, Tk and 8k as well as the resistors Rl; i? 2, R4, R 5, R 7 and R8 at the base of the transistors Tl, T2, TA, T5, Tl and T8. The transistors are switched through and via their collectors

The code word of the lowercase letter LLQLLQLL reaches the outputs of the sewer lines. If, as shown in dotted lines, when the type basket is switched to capital letters, the switch U on the positive line 10 is

sets, a positive potential is applied to the key contacts via line 11. By pressing the Tk button of the power circuit to the key line Ll g ^e ~ is closed and the lying with their anodes at the key line isolator positive signals are the code word of the associated key uppercase directly reads in the output · The code word in this case: QLLLOLLL -

1 sheet of drawings

Claims (1)

Patent claims: Circuitry for encoding characters in key-controlled machines, in particular office machines with double coding for double occupied keys, characterized in that assigned to two of a (Tk) key mark is provided only a key line (Ll, LI.. .Ln), which for the formation of two separate code words (k), (g) for each character on the one hand via a first directional conductor (14) with a first channel line (Ik, 2 k ... 8 k) polarized in a certain direction and on the other hand via a second directional conductor polarized in the opposite direction to the first directional conductor Directional conductor (15) are coupled to a second channel line (Ig, 2g.. .8g) in accordance with the desired code assignment, so that each first channel line (1 k, 2k ... 8k) has an inverter stage (Tl, T2... T8) is coupled to the corresponding second channel line (Ig, 2 g ... 8 g) , which is also used as an output code line, and that the key lines (Ll, L2 ... Ln) in one switching position with negative potential (9) and in the other switching position with positive potential (10) can be applied.