Device for color picture reproduction

Claim 1

A device for color picture reproduction, said device comprising: a beam-index display tube; said tube having a gun to form a scanning electron beam; said gun having a control electrode; said tube further including a screen having a pattern of color stripe triplets, index stripes, first guard stripes between the color stripes in each triplet and second guard stripes between said color stripe triplets; the width of said second guard stripes being equal to three times the width of said first guard stripes; said index stripes being located in the middle of said second guard stripes; said color stripes and index stripes being adapted to emit light upon the impingement thereon of said scanning electron beam; said light emitted by said index stripes being in or near the ultraviolet region; said device further comprising writing signal shaping system means having four inputs and an output for producing a writing signal from three primary color signals fed to three of said inputs; said output of said system being connected to said control electrode of said gun; said device further comprising an index light detector, a differentiator, and an operational amplifier, each having an input and an output; said device further comprising a feedback circuit of said operational amplifier; said detector receiving at its input said light emitted by said index stripes and producing at its output indexing impulses; the input of said differentiator being connected to the output of said detector, the input of said operational amplifier being connected to the output of said differentiator, and the outpuT of said operational amplifier being connected to the fourth input of said writing signal shaping system means; said feedback circuit being adapted to cut-off said operational amplifier during time intervals between the appearance of said indexing pulses.

Claim 2

A device for color picture reproduction, said device comprising: a beam-index display tube; said tube having a gun to form a scanning electron beam; said gun having a control electrode; said tube further including a screen having a pattern of color stripe triplets, index stripes, first guard stripes between the color stripes in each triplet and second guard stripes between said color stripe triplets; the width of said second guard stripes being equal to three times the width of said first guard stripes; said index stripes being located in the middle of said second guard stripes; said color stripes and index stripes being adapted to emit light upon the impingement thereon of said scanning electron beam; said light emitted by said index stripes being in or near the ultraviolet region; said device further comprising writing signal shaping system means having four inputs and an output for producing a writing signal from three primary color signals fed to three of said inputs; said output of said system being connected to said control electrode of said gun; said device further comprising an index light detector, a differentiator, and an operational amplifier, each having an input and an output; said device further comprising a feedback circuit of said operational amplifier; said detector receiving at its input said light emitted by said index stripes and producing at its output indexing impulses; the input of said differentiator being connected to the output of said detector, the input of said operational amplifier being connected to the output of said differentiator, and the outpuT of said operational amplifier being connected to the fourth input of said writing signal shaping system means; said feedback circuit being adapted to cut-off said operational amplifier during time intervals between the appearance of said indexing pulses.

Claim 3

A device for color picture reproduction, said device comprising: a beam-index display tube; said tube having a gun to form a scanning electron beam; said gun having a control electrode; said tube further including a screen having a pattern of color stripe triplets, index stripes, first guard stripes between the color stripes in each triplet and second guard stripes between the color stripe triplets; the width of said second guard stripes being equal to three times the width of said first guard stripes; said index stripes being located in the middle of said second guard stripes; said color stripes and index stripes being adapted to emit light upon the impingement thereon of said scanning electron beam; the light emitted by said index stripes being in or near the ultraviolet region; said device further comprising a writing signal shaping system, said system having four inputs and an output for producing a writing signal from three primary color signals fed to three of its inputs; said outut of said system being connected to said control electrode of said gun; said device further comprising an index light detector, a differentiator, and an operational amplifier, each having an input and an output; said device further comprising a feedback circuit of said operational amplifier; said detector receiving at its input the light emitted by said index stripes and producing at its output indexing impulses; the input of said differentiator being connected to the output of said detector, the input of said operational amplifier being connected to the output of said differentiator, and the output of said operational amplifier being connected to the fourth input of said writing signal shaping system; said feedback circuit being adapted to cut-off said operational amplifier during time intervals between the appearance of said indexing pulses; said writing signal shaping system including three primary-color switches, a delay line, and a pulse-width modulator; said switches having a plurality of inputs and a common output which output serves as said output of said writing signal shaping system; a first input of each of said switches serving as one of said three inputs of said writing signal shaping system used to feed three primary color signals; a first of said switches, whose second input is connected to said fourth input of said writing signal shaping system, connected to the output of said operational amplifier; said delay line having an input thereof connected to the second input of said first of said switches; outputs of said delay line coupled to the second inputs of the other two of said switches; said pulse-width modulator being connected to and driving said feedback circuit of said operational amplifier, each input of said modulator being connected to each first input of said primary-color switches which receive color signals corresponding to color stripes adjacent to an index stripe.

Claim 4

A device for color picture reproduction, said device comprising: a beam-index display tube; said tube having a gun to form a scanning electron beam; said gun having a control electrode; said tube further including a screen having a pattern of color stripe triplets, index stripes, first guard stripes between the color stripes in each triplet and second guard stripes between the color stripe triplets; the width of said second guard stripes being equal to three times the width of said first guard stripes; said index stripes being located in the middle of said second guard stripes; said color stripes and index stripes being adapted to emit light upon the impingement thereon of said scanning electron beam; the light emitted by said index stripes being in or near the ultraviolet region; said device further comprising a writing signal shaping system, said system having four inputs and an output for producing a writing signal from three primary color signals fed to three of its inputs; said outut of said system being connected to said control electrode of said gun; said device further comprising an index light detector, a differentiator, and an operational amplifier, each having an input and an output; said device further comprising a feedback circuit of said operational amplifier; said detector receiving at its input the light emitted by said index stripes and producing at its output indexing impulses; the input of said differentiator being connected to the output of said detector, the input of said operational amplifier being connected to the output of said differentiator, and the output of said operational amplifier being connected to the fourth input of said writing signal shaping system; said feedback circuit being adapted to cut-off said operational amplifier during time intervals between the appearance of said indexing pulses; said writing signal shaping system including three primary-color switches, a delay line, and a pulse-width modulator; said switches having a plurality of inputs and a common output which output serves as said output of said writing signal shaping system; a first input of each of said switches serving as one of said three inputs of said writing signal shaping system used to feed three primary color signals; a first of said switches, whose second input is connected to said fourth input of said writing signal shaping system, connected to the output of said operational amplifier; said delay line having an input thereof connected to the second input of said first of said switches; outputs of said delay line coupled to the second inputs of the other two of said switches; said pulse-width modulator being connected to and driving said feedback circuit of said operational amplifier, each input of said modulator being connected to each first input of said primary-color switches which receive color signals corresponding to color stripes adjacent to an index stripe.