Patent GB-1260501-A (GB)
Title: Traveling message display
Inventor: ANDREWS RUSSELL WILLIAM
IPC: G09G5/42
Filed: 1969-02-04
Abstract: 1260501 Matrix displays STEWART-WARNER CORP 4 Feb 1969 [5 Feb 1968] 5849/69 Index G4H 1A 3C 6A 6B 6D 6E 7B 7C 9E BD 14B A message display system for simulating motion along a path defined by a group of display devices which act faster than an incandescent lamp comprises means for providing signals in accordance with a desired display pattern, timing means operable at a shift frequency and operating means responsive to the timing means for operating the display devices along said path in sequence in accordance with the display pattern signals at the shift frequency for time less than the period of the shift frequency. The path comprises a matrix of cold cathode Ne discharge lamps 102 in which the pattern is shifted from column to column. The lamps are energized for a time of up to 50% of the shift frequency period, the time being variable to adjust the brightness of the display, the brightness may fluctuate to attract attention. Each character is represented by six pulses forming bits of a binary code and this input is fed to a receiver 204 including a series to parallel converter which allows the bits to be read out to a buffer storage 206 comprising 6 shift registers each of 16 stages. The buffer control 210 determines the number of characters in the storage 206 which indicates the input rate and causes a variable frequency clock 216 to vary the buffer output therewith. The clock has a long linear response to smooth out rapid input changes. Data in the last stage of the storage passes to a decoder 220 comprising an array of negators 802, 804 and Nand gates 806 one for each character. A lamp encoder 224 comprises an array of Nand gates 820 arranged in 10 rows corresponding to the rows of the lamp matrix. Each Nand gate 806 is connected to a pattern of gates 820 representing its character. A signal from the buffer operates the appropriate Nand gate 806 and an encoding signal is applied to selected gates 820. The outputs of each row of gates 820 are connected to a NOR gate 1000- 1, 2... and the output from these gates applied to lamp operating circuits LOR-1, 2... Each LOR circuit comprises a lamp shift register LSR and drive transistors 1002 associated with each lamp 102. A readout encoder strobe pulse from a column shift and lamp strobe control circuit 226, controlled by the clock 216, is applied to line ECSI and passes through encoded gates 820a to encode the first stage of corresponding LSR's. A lamp strobe pulse is then applied to all lamps and selected lamps in the first column associated with encoded stages of the LSR's are lit. A read out pulse is then applied to line ECS2 and passes through encoded gates 820-b to encode first stages of registers LSR, the original signals in the first stages being shifted to the second stages by lamp shift pulses. Another lamp strobe pulse is applied and the corresponding lamps in two columns are lit. Encoder pulses are sequentially applied to the remaining lines ECS. Subsequently the data in the last stage of the buffer is cancelled and data from the preceding stages all moved forward. When the data input rate falls too low the lamps are strobed twice per signal shift to prevent flicker. When data input ceases characters remain lit but stationary.