Abstract A memory of a video display system including raster type cathode ray tube display means stores character codes, codes indicating the height of a bar graph displayed in a direction perpendicular to the raster trace of the cathode ray tube, codes indicating the start of the area of the bar graph and codes indicating the end of the bar graph in the address corresponding to the display position in the display means. The memory transfers out each code successively in the order of the display position. A character generator is connected to the memory and receives the character codes from the memory and produces character video signals corresponding to the character codes. A detector is connected to the memory and detects codes indicating the start of the area of the bar graph and codes indicating the end of the bar graph. A register connected to the memory and to a source of horizontal synchronizing signals counts the horizontal synchronizing signals for determining the number of the scanning line in the display means and for comparing the number of the scanning line determined with codes indicating the height of the bar graph. A first gate circuit is connected to the character generator and stops the output of the character generator when codes indicating the start of the area of the bar graph are detected by the detector. The first gate circuit transfers the output of the character generator to a video signal amplifier when codes indicating the end of the bar graph are detected by the detector. A second gate circuit connected to a source of clock signals transfers a clock signal for the display of the bar graph to the video signal amplifier when the number of the scanning line is greater than the number corresponding to codes indicating the height of the bar graph as determined by the register.
A video display system including raster type cathode ray tube display means, said video display system comprising: memory means for storing character codes, codes indicating the height of a bar graph displayed in a direction perpendicular to the raster trace of the cathode ray tube, codes indicating the start of the area of the bar graph, and codes indicating the end of the bar graph in the address corresponding to the display position in the display means, said memory means transferring out each code successively in the order of the display position; character generating means having an input connected to the memory means and an output for receiving the character codes from the memory means and producing character video signals corresponding to the character codes; detecting means having inputs connected to the memory means and an output for detecting codes indicating the start of the area of the bar graph and codes indicating the end of the bar graph; a source of horizontal synchronizing signals; register means having inputs connected to the memory means and to the source of horizontal synchronizing signals for counting the horizontal synchronizing signals, for deTermining the number of the scanning line in the display means and for comparing the number of the scanning line determined with codes indicating the height of the bar graph; a video signal amplifier; a first gate circuit connected to the output of the character generating means for stopping the output of the character generating means when codes indicating the start of the area of the bar graph are detected by the detecting means and for transferring the output of the character generating means to the video signal amplifier when codes indicating the end of the bar graph are detected by the detecting means; a source of clock signals; and a second gate circuit connected to the source of clock signals for transferring a clock signal for the display of the bar graph to the video signal amplifier when the number of the scanning line is greater than the number corresponding to codes indicating the height of the bar graph as determined by the register means.
Claim 2
Dependent Claim
355 words
A video display system including raster type cathode ray tube display means, said video display system comprising: memory means for storing character codes, codes indicating the height of a bar graph displayed in a direction perpendicular to the raster trace of the cathode ray tube, codes indicating the start of the area of the bar graph, and codes indicating the end of the bar graph in the address corresponding to the display position in the display means, said memory means transferring out each code successively in the order of the display position; character generating means having an input connected to the memory means and an output for receiving the character codes from the memory means and producing character video signals corresponding to the character codes; detecting means having inputs connected to the memory means and an output for detecting codes indicating the start of the area of the bar graph and codes indicating the end of the bar graph; a source of horizontal synchronizing signals; register means having inputs connected to the memory means and to the source of horizontal synchronizing signals for counting the horizontal synchronizing signals, for deTermining the number of the scanning line in the display means and for comparing the number of the scanning line determined with codes indicating the height of the bar graph; a video signal amplifier; a first gate circuit connected to the output of the character generating means for stopping the output of the character generating means when codes indicating the start of the area of the bar graph are detected by the detecting means and for transferring the output of the character generating means to the video signal amplifier when codes indicating the end of the bar graph are detected by the detecting means; a source of clock signals; and a second gate circuit connected to the source of clock signals for transferring a clock signal for the display of the bar graph to the video signal amplifier when the number of the scanning line is greater than the number corresponding to codes indicating the height of the bar graph as determined by the register means.
Claim 3
Dependent Claim
35 words
A video display system as claimed in claim 1, wherein codes indicating the height of the bar graph are represented by the number of the scanning line displaying the highest position of the bar graph.
Claim 4
Dependent Claim
54 words
A video display system as claimed in claim 1, wherein codes indicating the height of the bar graph are common to character codes, and wherein the first gate circuit is controlled by the detecting means thereby permitting a change of the use of codes indicating the height of the bar graph and character codes.