Video test method and apparatus with incremental scan rate capability

Claim 2

Video test apparatus controlled by a synchronous generator and having incremental scan capability characterized by: a) means (47,49) to provide an oscillating reference signal; b) a scan line generator (41) connected to the oscillating reference signal means (47.49) for generating a scan line frequency in response to the oscillating reference signal; c) first time base adjustment means (51,53) connected to the scan line generator for adjusting the scan line frequency in increments of one line for varying the scan characteristics of the system; (42) (41) d) a pixel clock/connected to the scan line generator/for receiving the scan line frequency; e) second time base adjustment means (55,57) for adjusting the pixel clock (42) in increments of one pixel for varying the scan characteristics of the system; f) means (61) connected to one of the pixel clock and the scan line generator for obtaining a signal at the scan line frequency; g) a reference frequency generator (43) connected to the signal obtaining means (61) to provide a dependent reference frequency dependent upon the scan line frequency, said dependent reference frequency being an integer multiple of the scan line frequency, the dependent reference frequency being provided in successive groups of said multiple, the groups being at a substantially constant phase relationship with the scan line frequency; and h) the dependent reference frequency being applied to the synchronous generator.

Claim 3

Apparatus as claimed in Claim 1 characterized by the (42) frequency of the pixel clock/is established as an integer multiple of the line scan frequency.

Claim 4

In a system for providing a scanned video image, apparatus which is capable of independentiy varying the scan characteristics characterized by: a) mean (47,49) provide an oscillating reference signal; b) a scan line generator connected to the oscllating reference signal mean (47,49) for generating a scan line frequency in response to the oscillating reference signal; c) first time base adjustment means (51,53) connected to the scan line generato (41) for adjusting the scan line generator (41) in increments of one line for varying the scan characteristics of the system; d) a pixel clock (42) nnected to the scan line generator for receiving the scan line frequency and providing a pixel signal at a frequency which is an Integer multiple of the line scan frequency; e) second time base adjustment mean adjust the pixel clock (42) in increments of one pixel, thereby varying a scan characteristic of the system; f) means/connected to one of the pixel clock (42) and the scan line generato (41) for obtaining a signal at the scan line frequency; g) a reference frequency generator (43) connected to the signal obtaining mean (61) to provide a reference frequency dependent upon the scan line frequency, said dependent reference frequency being an integer multiple of the scan line frequency, the dependent reference frequency being provided in successive groups of said multiple, the groups being in substantially constant phase relationship with the scan line frequency; and h) the dependent reference frequency providing a timing reference from which signals for horizontal and vertical synchronization and horizontal and vertical blanking are derived.

Claim 5

In a system for providing a scanned video image, apparatus which is capable of independentiy varying the scan characteristics characterized by: a) mean (47,49) provide an oscillating reference signal; b) a scan line generator connected to the oscllating reference signal mean (47,49) for generating a scan line frequency in response to the oscillating reference signal; c) first time base adjustment means (51,53) connected to the scan line generato (41) for adjusting the scan line generator (41) in increments of one line for varying the scan characteristics of the system; d) a pixel clock (42) nnected to the scan line generator for receiving the scan line frequency and providing a pixel signal at a frequency which is an Integer multiple of the line scan frequency; e) second time base adjustment mean adjust the pixel clock (42) in increments of one pixel, thereby varying a scan characteristic of the system; f) means/connected to one of the pixel clock (42) and the scan line generato (41) for obtaining a signal at the scan line frequency; g) a reference frequency generator (43) connected to the signal obtaining mean (61) to provide a reference frequency dependent upon the scan line frequency, said dependent reference frequency being an integer multiple of the scan line frequency, the dependent reference frequency being provided in successive groups of said multiple, the groups being in substantially constant phase relationship with the scan line frequency; and h) the dependent reference frequency providing a timing reference from which signals for horizontal and vertical synchronization and horizontal and vertical blanking are derived.

Claim 6

Apparatus as claimed in Claim 3 further characterized by a means ( 11 ) for generating a program of a test pattern which is capable of adapting to different vertical and horizontal resolutions obtained by adjusting the scan line frequency and pixel clock.

Claim 7

Apparatus of Claim 4 further characterized in that the means (11) for generating a program of a test pattern generates a program consisting of a plurality of characters.

Claim 8

Apparatus as claimed In Claim 1 or 3 further characterized by the reference frequency generator (43) including a phase locked loop which multiplies the scan ilne frequency and is adjusted in its output so as to provide the dependent reference frequency substantially at the nominal value.

Claim 11

Apparatus of Claim 1 further characterized in that the pixel clock(42) provides a reference signal to a means (11) to generate a program of test provldes a reference signal to a means/to generate a program of test patterns.

Claim 12

Apparatus of Claim 8 characterized in that the reference signal (42) from the pixel clock/is used to provide a timing signal to provide an output of a pattern which consists of a plurality of characters.

Claim 13

Apparatus as claimed in Claim 1 further characterized in that the reference frequency generator/provides a reference frequency signal to a ( means (11) to generate a program.

Claim 14

Apparatus as claimed in Claim 1 or 3 further characterized by a stroke generator/connected to the oscillation mean (47,49) for generating stroke signals which may be selectively used In lieu of scan ilnes and pixels.

Claim 15

Apparatus as claimed in Claim 3 or 4 further characterized in that the reference frequency generator (43) is used for provlding horizontal drive signals.

Claim 16

Apparatus as claimed in Claim 1 or 3 further characterized by a plurality of test points (TP,TP') and a muitiplexer (103) wherein the plurality of test points (TP,TP') provide signals to the muitipiexer (103) and the muitiplexer (103) is controlled In order to provide an output of the signals present at the test paints (TP,TP' in order to provide data to self-test the apparatus.

Claim 17

Apparatus as claimed In Claim 1 or 4 further characterized by means (49,50) to select a scan rate by selecting a frequency of the oscillator signal.

Claim 18

Apparatus as claimed In Claim 14 characterized by a divider and multiplexer network (49,50) which is used to select the frequency of the oscillator signal.

Claim 19

Apparatus as claimed in Claim 14 further characterized by means receiving the scan line frequency, providing an adjustable count of scan lines and having an adjustable divider enabling selection of an interlace ratio.

Claim 20

in a system for providing a television video image, apparatus which is capable of independently varying the scan characteristics characterized by: a) means (47,49) to provide an oscillating reference signal; b) a scan line generator (41) connected to the oscillating reference signal means (47,49)for generating a scan line frequency in response to the oscillating refer- , ence signal; c) first,time base adjustment means/connected to the scan line generator for adjusting the line scan frequency in increments of one line for varying the scan characteristics of the system; d) a pixel clock/connected to the scan line generator or receiving the scan line frequency and providing a pixel clock signal at a frequency which is a multiple of the line scan frequency; e) a reference frequency generator (43) deriving a signal at the scan line frequency from one of the scan line generator (41) and the pixel clock (42) to provide a reference frequency dependent upon the scan line frequency, said frequency being an integer muitiple of the line scan frequency, the dependent reference frequency being provided In successive groups of said multiple, the groups being In substantially constant phase relationship with the line scan frequency, and the dependent reference frequency providing a timing reference from which signals for horizontal and vertical synchronization and horizontal and vertical blanking are derived.

Claim 21

in a system for providing a television video image, apparatus which is capable of independently varying the scan characteristics characterized by: a) means (47,49) to provide an oscillating reference signal; b) a scan line generator (41) connected to the oscillating reference signal means (47,49)for generating a scan line frequency in response to the oscillating refer- , ence signal; c) first,time base adjustment means/connected to the scan line generator for adjusting the line scan frequency in increments of one line for varying the scan characteristics of the system; d) a pixel clock/connected to the scan line generator or receiving the scan line frequency and providing a pixel clock signal at a frequency which is a multiple of the line scan frequency; e) a reference frequency generator (43) deriving a signal at the scan line frequency from one of the scan line generator (41) and the pixel clock (42) to provide a reference frequency dependent upon the scan line frequency, said frequency being an integer muitiple of the line scan frequency, the dependent reference frequency being provided In successive groups of said multiple, the groups being In substantially constant phase relationship with the line scan frequency, and the dependent reference frequency providing a timing reference from which signals for horizontal and vertical synchronization and horizontal and vertical blanking are derived.

Claim 22

In a system for providing color television video signals, a method for generating a scan, characterized by: a) providing a display which may be varied in its scan rate and in vertical and horizontal resolution; b) providing a reference oscillation; c) generating a scan line signal at a line scan frequency derived from the reference oscillation by providing the reference oscillation to a first phase locked loop (41) and adjusting the first phase locked loop in accordance with the number of scan lines desired; d) generating a pixel signal at a pixel frequency derived from the line scan frequency by providing the line scan frequency to a second phase (42) locked loop and adjusting the second phase locked loop in accordance with a number of pixels per line to be selected, provided that the pixel frequency occurs In groups of pulses at an integer multiple of the line scan frequency; and e) generating a dependent reference frequency by providing a signal representative of the line scan frequency to a third phase locked loop (43) and adjusting the third phase locked loop (43) in order to obtain a frequency which is substantially at a nominal value and is adjusted to be an integer multiple of the line scan frequency.

Claim 23

In a system for providing color television video signals, a method for generating a scan, characterized by: a) providing a display which may be varied in its scan rate and in vertical and horizontal resolution; b) providing a reference oscillation; c) generating a scan line signal at a line scan frequency derived from the reference oscillation by providing the reference oscillation to a first phase locked loop (41) and adjusting the first phase locked loop in accordance with the number of scan lines desired; d) generating a pixel signal at a pixel frequency derived from the line scan frequency by providing the line scan frequency to a second phase (42) locked loop and adjusting the second phase locked loop in accordance with a number of pixels per line to be selected, provided that the pixel frequency occurs In groups of pulses at an integer multiple of the line scan frequency; and e) generating a dependent reference frequency by providing a signal representative of the line scan frequency to a third phase locked loop (43) and adjusting the third phase locked loop (43) in order to obtain a frequency which is substantially at a nominal value and is adjusted to be an integer multiple of the line scan frequency.