Video signal hard copying apparatus

Claim 2

A video signal hard copying apparatus for printing on a copying sheet of paper an input color video signal including R, G, B signals, and horizontal and vertical synchronizing signals, comprising: (a) first and second input signal selection means connected correspondingly to input terminals for the R, G, B signals and to an input terminal for the horizontal synchronizing signal, for selecting at need any of the R, G, B signals and of the horizontal signal or those signals in combination; (b) first, second and third digital-to-analog converter means for generating first, second and third reference voltages each changing stepwise; (c) first comparator means connected at one input to the input signal selection means for the R, G, B signals and connected at the other input to the first digital-to-­analog converter means for comparing the R, G, B signals selected by the first input signal selection means with the first reference voltage and outputting a digital signal pattern composed of logical "0s" and/or logical "1s" indicative of the states of the R, G, B signals; (d) second comparator means connected at one input to the input signal selection means for the horizontal synchronizing signal and connected at the other end to the second digital-to-analog converter means for comparing the B signal selected by the first input signal selection means and the horizontal synchronizing signal with the second reference voltage and outputting a digital signal pattern composed of "0s" and/or "1s" indicative of the states of the B signal and the horizontal synchronizing signal; (e) third comparator means connected at one input to an input terminal for the vertical synchronizing signal and connected at the other end to the third digital-to-­analog converter means for comparing the vertical synchronizing signal with the third reference voltage and outputting a digital signal pattern composed of "0s" and/or "1s" indicative of the states of the vertical synchronizing signal; and (f) first, second and third multiplexer means connected respectively and correspondingly to the first, second and third comparator means for selecting and outputting one of the digital signal patterns output respectively from the first, second and third comparator means.

Claim 3

A video signal hard copying apparatus according to claim 1, wherein it further includes first and second memory means connected respectively to the first and second multiplexer means for temporarily storing the digital signals output from the first and second multiplexer means; and address generator means connected to the third multiplexer means and to the first and second memory means for generating addresses indicative of locations in the first and second memory means to temporarily store the digital signal patterns output from the first and second multiplexer means on the basis of a trigger signal output from the third multiplexer means.

Claim 4

A video signal hard copying apparatus according to claim 1, wherein the first and second input signal selection means are relays.

Claim 5

An automatic setting apparatus for generating a video signal sampling clock for use in a video signal hard copying apparatus for printing on a copying sheet of paper an input color video signal including color signals R, G, B, and horizontal and vertical synchronizing signals, the automatic setting apparatus comprising: (a) display means for displaying thereon predetermined marks involved in the video signal being input; (b) memory means connected to the display means for previously storing the predetermined distance and for permitting first and second address thereof at which the first and second marks are stored to be specified corresponding to the predetermined distance previously stored therein; (c) frequency multiplier means composed of a phase-­locked loop and a frequency divider for receiving the horizontal signal involved in the color video signal transmitted from an external video terminal and a frequency dividing ratio setting signal, and automatically adjusting and generating a correct sampling clock for the color video signal on the basis of the frequency dividing ratio setting signal; (d) write address setting means connected to the memory means for setting the first address to the memory so as to coincide with an address at which one end of the predetermined distance corresponding to the first mark is stored upon starting of the operation from the outside therethrough, and thereafter generating the second address incrementing stepwise and setting the same to the memory means; and (e) storage state judging and adjusting means connected to the display means, memory means, frequency multiplier means, and write address setting means for judging whether or not the second address for the second mask coincides with the other end of the predetermined distance, on the basis of the image information concerning the first and second marks transmitted from the display means and of the predetermined mark distance information transmitted from the memory means, and when no coincidence is judged in the judging step, adjusting, generating transmitting an expectation address to the write address setting means and further transmitting the frequency dividing ratio setting signal corresponding to the expectation address to the frequency multiplier means, the write address setting means generating the second address on the basis of the expectation address to set it to the memory, until the second address coincide with the other end of the predetermined distance and hence until the frequency dividing ratio setting signal is correctly specified for generation of the correct sampling clock in the frequency multiplier means.

Claim 6

An automatic setting apparatus for generating a video signal sampling clock for use in a video signal hard copying apparatus for printing on a copying sheet of paper an input color video signal including color signals R, G, B, and horizontal and vertical synchronizing signals, the automatic setting apparatus comprising: (a) display means for displaying thereon predetermined marks involved in the video signal being input; (b) memory means connected to the display means for previously storing the predetermined distance and for permitting first and second address thereof at which the first and second marks are stored to be specified corresponding to the predetermined distance previously stored therein; (c) frequency multiplier means composed of a phase-­locked loop and a frequency divider for receiving the horizontal signal involved in the color video signal transmitted from an external video terminal and a frequency dividing ratio setting signal, and automatically adjusting and generating a correct sampling clock for the color video signal on the basis of the frequency dividing ratio setting signal; (d) write address setting means connected to the memory means for setting the first address to the memory so as to coincide with an address at which one end of the predetermined distance corresponding to the first mark is stored upon starting of the operation from the outside therethrough, and thereafter generating the second address incrementing stepwise and setting the same to the memory means; and (e) storage state judging and adjusting means connected to the display means, memory means, frequency multiplier means, and write address setting means for judging whether or not the second address for the second mask coincides with the other end of the predetermined distance, on the basis of the image information concerning the first and second marks transmitted from the display means and of the predetermined mark distance information transmitted from the memory means, and when no coincidence is judged in the judging step, adjusting, generating transmitting an expectation address to the write address setting means and further transmitting the frequency dividing ratio setting signal corresponding to the expectation address to the frequency multiplier means, the write address setting means generating the second address on the basis of the expectation address to set it to the memory, until the second address coincide with the other end of the predetermined distance and hence until the frequency dividing ratio setting signal is correctly specified for generation of the correct sampling clock in the frequency multiplier means.

Claim 7

An automatic setting apparatus for generating a video signal sampling clock for use in a vide signal hard copying apparatus according to claim 4, wherein display means displays thereon predetermined first and second marks involved in the video signal being input at left and right ends thereof separated by a predetermined distance.