US 4,360,805 A · Digital erase of raster lines

Abstract

The perception of raster lines on a television monitor is obscured by continuously and cyclically vertically shifting and presenting in successive frames the raster in successive upward positions and then in successive downward positions by incremental amounts, the total maximum vertical shift distance being less than the distance between original horizontal raster lines, thus giving the appearance of blending the information between original horizontal raster lines. Vertical raster deflection is accomplished by cyclically delaying the original, or normal, vertically sync pulses by amounts which incrementally increase to a maximum for producing a vertical frame rise less than the distance between original horizontal raster lines and decrementally decrease to no delay. A photographic camera capable of multiple frame exposure time is used to produce photographs of the video monitor without connections or operational dependence upon the television monitor system. An all-digital system provides increased reliability and repeatability as well as manufacturing and maintenance economies.

Claims12

Dependent claims

A method of obscuring the perception of a base raster of a raster scan display device by bidirectionally vertically shifting said base raster in a manner in which a sequence of other rasters are produced with a maximum shift of any one of such other rasters in either direction being less than the distance between a pair of adjacent horizontal scan lines of said base raster, said base raster being produced by scanning an electron beam in response to original vertical and horizontal sync pulses, said method comprising:

presenting a predetermined number of rasters with the horizontal lines thereof shifted vertically by a predeterminedly-changed amount in a cyclical sequence wherein
(a) in one stage of said sequence, rasters are presented each at an increasingly higher position relative to the position corresponding to said base raster in response to
(i) delayed vertical sync signals each of which is predeterminedly increasingly delayed relative to the corresponding original vertical sync pulses, and to
(ii) original horizontal sync pulses, and
(b) in an opposite stage of said sequence, rasters are presented each at a lower position relative to the immediately preceding raster in response to
(i) delayed vertical sync signals each of which is delayed by a predeterminedly decreased amount of time relative to the time of delay of the immediately preceding delayed vertical sync signal, and to
(ii) original horizontal sync pulses.

4 more elements

In apparatus for use with raster scan display device having input means for receiving vertical sync signals for initiating vertical deflection, horizontal sync signals for initiating horizontal deflection, and separate picture information signals, and a display tube controllable by successive vertical sync signals to produce successive rasters comprised of vertically-spaced horizontal lines intensity modulated by said picture information signals, the improvement which results in the presentation of:

(i) a base raster produced in response to original vertical sync signals corresponding to original vertical sync pulses and original horizontal sync signals identical to original horizontal sync pulses, and
(ii) a predetermined number of shifted rasters displayed with the horizontal lines thereof shifted vertically in sequence, and wherein in said sequence a predetermined number of said shifted rasters are shifted vertically upward, each by a predetermined amount relative to the position of said base raster, with the horizontal lines of the highest-shifted raster being below the next upwardly-adjacent horizontal lines of said base raster, to thereby reduce perception of space between the horizontal lines in the base raster, said improvement comprising:
(a) means effective in response to the occurrence of a sequence of a predetermined number of said original vertical sync pulses for producing a vertical sync signal for each of said original vertical sync pulses, with the produced vertical sync signals occurring in a multistage cycle wherein:
(i) in one stage a predetermined number of produced vertical sync signals are each delayed by a predeterminedly increased amount of time relative to the original vertical sync signal with which each corresponds but short of being delayed such that the horizontal lines of the highest-shifted raster lines would correspond with the immediately upward-adjacent horizontal lines of the base raster,
(ii) in another stage, a predetermined number of produced vertical sync signals are each delayed by a predeterminedly decreased amount of time relative to the time of delay of the immediately preceding produced vertical sync signal;
and
(b) means for controlling said display device in response to:
(i) the horizontal sync signals for said raster, and to
(ii) said produced vertical sync signals.

6 more elements

In apparatus for use with a system having a raster scan display device operative under the control of video information signals and horizontal and vertical sync signals;

the improvement constituting means for vertically shifting the raster of said display device thereby to obscure the perception of the lines of said raster, said improvement comprising:
(a) means for producing a sequence of original horizontal sync pulses and original vertical sync pulses;
(b) means for producing an End-of-Field pulse a predeterminedly-fixed amount of time after each original vertical sync pulse;
(c) means for producing a Change-Count pulse (i) identical to said End-of-Field pulse when said display device is operated in a non-interlace mode and (ii) in response to every other End-of-Field pulse when said device is operated in an interlace mode;
(d) horizontal sync signal input means connected to said display device;
(e) vertical sync signal input means connected to said display device;
(f) means for supplying said sequence of horizontal sync pulses to said horizontal sync signal input means;
(g) bidirectional counter means having a binary memory, input means for receiving said Change-Count pulses as clock pulses to said bidirectional counter means, output means representing the binary state of said binary memory, and said bidirectional counter means being effective for cyclically counting up and counting down the binary state of said memory in response to said Change-Count pulses received at said input means;
(h) means controlled by said output means of said bidirectional counter means for producing a sequence of vertical sync signals each of which is delayed relative to a respective original vertical sync pulse by an amount of time proportionally related to said binary state of said binary memory of said bidirectional counter;
and
(i) means for supplying said sequence of produced vertical sync signals to said vertical sync signal input means to said display device.

8 more elements

In apparatus for use with a raster scan display device operative under the control of video information signals, horizontal sync signals, and vertical sync signals, the improvement constituting means for vertically shifting said raster thereby to obscure the perception of the lines thereof, said improvement comprising:

(a) means for producing a sequence of original horizontal sync pulses and original vertical sync pulses;
(b) means for producing an End-of-Field pulse a predeterminedly-fixed amount of time after each original vertical sync pulse;
(c) interlace flip-flop means for producing Change-Count pulses in response to:
(i) End-of-Field pulses when said display device is operated in a non-interlace mode;
and
(ii) alternate End-of-Field pulses when said display device is operated in an interlace mode;
(d) horizontal sync signal input means connected to said device;
(e) vertical sync signal input means connected to said device;
(f) means for supplying said sequence of original horizontal sync pulses to said horizontal sync signal input means;
(g) bidirectional counter means having a binary memory storing a binary state, input means for receiving said Change-Count pulses as clock pulses to said bidirectional counter means, output means outputting the binary state of said binary memory and having output bits corresponding in number to the bits of said binary memory, and said bidirectional counter means being effective for cyclically counting up and counting down the binary state of said memory in response to said Change-Count pulses received at said input means;
(h) shift register means comprising a shift register input, and a contents having bit positions corresponding in number to at least the number of frames to be displayed as interlineations between two of the original horizontal raster lines;
(i) programmable clock generator means having a clock system output for providing output clock pulses to said input of said shift register, with a period of each of said output clock pulses being selectively predetermined and such that the time equal to the product of
(1) the number of interlineations multiplied by
(2) the period of said programmable clock generator output clock pulse is less than the time between original vertical sync pulses;
(j) data select means for selecting the bit position of said contents of said shift register means corresponding to the binary state of said binary memory of said bidirectional counter;
(k) output means for supplying to said vertical sync signal input means the signal on the bit position of said contents of said shift register means selected by said data select means as the delayed vertical sync signal and in the same sequence as generated, whereby
(i) the original vertical sync pulse is received by said shift register means,
(ii) said original vertical sync pulses are right-shifted through the bit positions of said shift register means one position for each said output clock pulse of said programmable clock generator,
(iii) a train of binary information in said bit position of said shift register means corresponding to the binary state of said binary memory of said bidirectional counter is fed by said data select means to said output means,
(iv) each bit of said train of binary information in said bit position of said shift register means reaches said output means delayed relative to its corresponding original vertical sync pulse by an amount of time equal to said binary state of said binary memory of said bidirectional counter multiplied by the period of a single output clock pulse,
(v) an End-of-Field pulse is produced,
(vi) a Change-Count pulse
(a) identical to said End-of-Field pulse when said display device is operated in a non-interlace mode, and
(b) responsive to every other End-of-Field pulse when said display device is operated in an interlace mode is received by said bidirectional counter, and
(vii) said binary state of said binary memory of said bidirectional counter is changed by one in one direction when said binary state of said binary memory of said bidirectional counter had most previously been all zero bits rather than all one bits and is changed by one in the opposite direction when said binary state of said binary memory had most previously been all one bits rather than all zero bits.

22 more elements

Dependencies are inferred from the claim text.

Digital erase of raster lines

Life of this patent

Digital erase of raster lines

Life of this patent

Abstract

Claims12