Display apparatus having functions of displaying video signals as enlarged/thinned pictures

A display apparatus comprising a driving circuit having:

• a pulse generating circuit to generate, in addition to original clock pulse signals, second clock pulse signals for a copy purpose with a desired timing in a horizontal period in an operation to display a video signal having a vertical-pixel count smaller than a predetermined vertical-pixel count of a display unit as a vertically enlarged picture on a screen of said display unit by using two kinds of adjacent fields, the video signal of each of original lines in a horizontal direction being copied into a copied line for displaying the enlarged picture, a number of copied lines being equal to a difference between said predetermined vertical-pixel count of said display unit and a vertical-pixel count of the video signal, the copied lines being adjacent to the original lines on said display unit, the original clock pulse signals being required in an operation of displaying a video signal having a vertical-pixel count equal to said predetermined vertical-pixel count of said display unit, the second clock pulse signals being pulses which do not overlap with the original clock pulse signals, and to repeat generation of said original clock pulse signals and said second clock pulse signals for each horizontal period;
• a gate-clock generating circuit to receive said original clock pulse signals and said second clock pulse signals from said pulse generating circuit and to generate gate-clock signals obtained as a result of superposing all of said original clock pulse signals on some of said second clock pulse signals wherein the number of said superposed second clock pulse signals is equal to a difference obtained as a result of subtraction of said vertical-pixel count of said video signal from said predetermined vertical-pixel count of said display unit, the second clock pulse signals being in a desired horizontal period, said gate-clock signals containing said original clock pulse signals and said superposed second clock pulse signals and being for said two kinds of adjacent fields;
• and
• a gate driving circuit to receive said gate clock signals from said gate-clock generating circuit and to generate gate driving signals used for driving a predetermined number of gate lines as pulses of said gate clock signals for each horizontal period,
• wherein said gate clock signals generated from said gate-clock generating circuit cause said gate driving circuit to generate different gate driving signals for two adjacent gate lines in the same field,
• the gate lines corresponding to the copied lines of said display unit are driven by the second clock pulse signals, which do not overlap with the original clock pulses, in the same horizontal period as the horizontal period in which the gate lines corresponding to the original lines are driven, and
• wherein the desired second clock pulse signals to be superposed are determined by a combination of a second clock pulse signal and an output enable signal that has been generated from a latch circuit and inverted.

A display apparatus comprising a driving circuit having:

• a pulse generating circuit to generate, in addition to original clock pulse signals, second clock pulse signals for a copy purpose with a desired timing in a horizontal period in an operation to display a video signal having a vertical-pixel count smaller than a predetermined vertical-pixel count of a display unit as a vertically enlarged picture on a screen of said display unit by using two kinds of adjacent fields, the video signal of each of original lines in a horizontal direction being copied into a copied line for displaying the enlarged picture, a number of copied lines being equal to a difference between said predetermined vertical-pixel count of said display unit and a vertical-pixel count of the video signal, the copied lines being adjacent to the original lines on said display unit, the original clock pulse signals being required in an operation of displaying a video signal having a vertical-pixel count equal to said predetermined vertical-pixel count of said display unit, the second clock pulse signals being pulses which do not overlap with the original clock pulse signals, and to repeat generation of said original clock pulse signals and said second clock pulse signals for each horizontal period;
• a gate-clock generating circuit to receive said original clock pulse signals and said second clock pulse signals from said pulse generating circuit and to generate gate-clock signals obtained as a result of superposing all of said original clock pulse signals on some of said second clock pulse signals wherein the number of said superposed second clock pulse signals is equal to a difference obtained as a result of subtraction of said vertical-pixel count of said video signal from said predetermined vertical-pixel count of said display unit, the second clock pulse signals being in a desired horizontal period, said gate-clock signals containing said original clock pulse signals and said superposed second clock pulse signals and being for said two kinds of adjacent fields;
• and
• a gate driving circuit to receive said gate clock signals from said gate-clock generating circuit and to generate gate driving signals used for driving a predetermined number of gate lines as pulses of said gate clock signals for each horizontal period,
• wherein said gate clock signals generated from said gate-clock generating circuit cause said gate driving circuit to generate different gate driving signals for two adjacent gate lines in the same field,
• the gate lines corresponding to the copied lines of said display unit are driven by the second clock pulse signals, which do not overlap with the original clock pulses, in the same horizontal period as the horizontal period in which the gate lines corresponding to the original lines are driven , and
• wherein the second clock pulse signals are superposed such that the second clock pulse signals are generated in the two kinds of adjacent fields shifted from each other by at least one horizontal period.

A display apparatus comprising a driving circuit having:

• a pulse generating circuit to generate, in addition to original clock pulse signals, second clock pulse signals for a copy purpose with a desired timing in a horizontal period in an operation to display a video signal having a vertical-pixel count smaller than a predetermined vertical-pixel count of a display unit as a vertically enlarged picture on a screen of said display unit by using two kinds of adjacent fields, the video signal of each of original lines in a horizontal direction being copied into a copied line for displaying the enlarged picture, a number of copied lines being equal to a difference between said predetermined vertical-pixel count of said display unit and a vertical-pixel count of the video signal, the copied lines being adjacent to the original lines on said display unit, the original clock pulse signals being required in an operation of displaying a video signal having a vertical-pixel count equal to said predetermined vertical-pixel count of said display unit, the second clock pulse signals being pulses which do not overlap with the original clock pulse signals, and to repeat generation of said original clock pulse signals and said second clock pulse signals for each horizontal period;
• a gate-clock generating circuit to receive said original clock pulse signals and said second clock pulse signals from said pulse generating circuit and to generate gate-clock signals obtained as a result of superposing all of said original clock pulse signals on some of said second clock pulse signals wherein the number of said superposed second clock pulse signals is equal to a difference obtained as a result of subtraction of said vertical-pixel count of said video signal from said predetermined vertical-pixel count of said display unit, the second clock pulse signals being in a desired horizontal period, said gate-clock signals containing said original clock pulse signals and said superposed second clock pulse signals and being for said two kinds of adjacent fields;
• and
• a gate driving circuit to receive said gate clock signals from said gate-clock generating circuit and to generate gate driving signals used for driving a predetermined number of gate lines as pulses of said gate clock signals for each horizontal period,
• wherein said gate clock signals generated from said gate-clock generating circuit cause said gate driving circuit to generate different gate driving signals for two adjacent gate lines in the same field,
• the gate lines corresponding to the copied lines of said display unit are driven by the second clock pulse signals, which do not overlap with the original clock pulses, in the same horizontal period as the horizontal period in which the gate lines corresponding to the original lines are driven , and
• wherein the original clock pulse signals are generated during the first ⅔ of each horizontal period and the second clock pulse signals are generated during the last ⅓ of each horizontal period.

A display apparatus comprising a driving circuit having:

• a pulse generating circuit to generate, in addition to two original clock pulse signals, second clock pulse signals for a thinning purpose with a desired timing in a desired horizontal period in an operation to display a video signal having a vertical-pixel count greater than a predetermined vertical-pixel count of a display unit as a vertically reduced picture on a screen on said display unit by using two kinds of adjacent fields by writing a video signal in a horizontal period into two adjacent gate lines of said display unit, the number of gate lines to be driven being greater than the number of gate lines of said display unit, the video signal of each of the lines in the horizontal direction being thinned out for displaying the reduced picture, the lines being positioned away from each other in the vertical direction of the video signal, the number of lines being equal to a difference between the predetermined vertical-pixel count of said display unit and a vertical-pixel count of the video signal, the two original clock pulse signals being generated in a horizontal period as required in an operation of displaying a video signal having a vertical-pixel count equal to said predetermined vertical-pixel count of said display unit, said second clock pulse signals having pulses corresponding to positions of said original clock pulse signals to be thinned, and to repeat generation of said original clock pulse signals for each horizontal period and generation of said second clock pulse signals for a desired horizontal period;
• a gate-clock generating circuit to receive said original clock pulse signals and said second clock pulse signals from said pulse generating circuit and to generate gate-clock signals obtained as a result of superposing all of said original clock pulse signals on some of said second clock pulse signals wherein the number of said superposed second clock pulse signals is equal to a difference obtained as a result of subtraction of said vertical-pixel count of said display unit from said predetermined vertical-pixel count of said video signal, said second clock pulse signals being in a desired horizontal period, said gate-clock signals containing the original clock pulse signal thinned by the desired superposed second clock pulse signals and being for said two kinds of adjacent fields;
• and
• a gate driving circuit to receive said gate clock signals from said gate-clock generating circuit and to generate gate driving signals used for driving a predetermined number of gate lines as pulses of said gate clock signals for each horizontal period,
• wherein said gate clock signals generated from said gate-clock generating circuit cause said gate driving circuit to generate different gate driving signals for two adjacent gate lines in the same field and the second clock pulse signals are superposed such that the superposed second clock pulse signals generated in the two kinds of adjacent fields are shifted from each other by at least one horizontal period.

A display apparatus comprising a driving circuit having:

• a pulse generating circuit to generate, in addition to two original clock pulse signals, second clock pulse signals for a thinning purpose with a desired timing in a desired horizontal period in an operation to display a video signal having a vertical-pixel count greater than a predetermined vertical-pixel count of a display unit as a vertically reduced picture on a screen on said display unit by using two kinds of adjacent fields by writing a video signal in a horizontal period into two adjacent gate lines of said display unit, the number of gate lines to be driven being greater than the number of gate lines of said display unit, the video signal of each of the lines in the horizontal direction being thinned out for displaying the reduced picture, the lines being positioned away from each other in the vertical direction of the video signal, the number of lines being equal to a difference between the predetermined vertical-pixel count of said display unit and a vertical-pixel count of the video signal, the two original clock pulse signals being generated in a horizontal period as required in an operation of displaying a video signal having a vertical-pixel count equal to said predetermined vertical-pixel count of said display unit, said second clock pulse signals having pulses corresponding to positions of said original clock pulse signals to be thinned, and to repeat generation of said original clock pulse signals for each horizontal period and generation of said second clock pulse signals for a desired horizontal period;
• a gate-clock generating circuit to receive said original clock pulse signals and said second clock pulse signals from said pulse generating circuit and to generate gate-clock signals obtained as a result of superposing all of said original clock pulse signals on some of said second clock pulse signals wherein the number of said superposed second clock pulse signals is equal to a difference obtained as a result of subtraction of said vertical-pixel count of said display unit from said predetermined vertical-pixel count of said video signal, said second clock pulse signals being in a desired horizontal period, said gate-clock signals containing the original clock pulse signal thinned by the desired superposed second clock pulse signals and being for said two kinds of adjacent fields;
• and
• a gate driving circuit to receive said gate clock signals from said gate-clock generating circuit and to generate gate driving signals used for driving a predetermined number of gate lines as pulses of said gate clock signals for each horizontal period,
• wherein said gate clock signals generated from said gate-clock generating circuit cause said gate driving circuit to generate different gate driving signals for two adjacent gate lines in the same field and one second clock pulse signal is generated every other horizontal period and successive second clock pulse signals are generated in leading portions and intermediate portions of the horizontal periods.

A display apparatus comprising a driving circuit having:

• a pulse generating circuit to generate, in addition to two original clock pulse signals, second clock pulse signals for a thinning purpose with a desired timing in a desired horizontal period in an operation to display a video signal having a vertical-pixel count greater than a predetermined vertical-pixel count of a display unit as a vertically reduced picture on a screen on said display unit by using two kinds of adjacent fields by writing a video signal in a horizontal period into two adjacent gate lines of said display unit, the number of gate lines to be driven being greater than the number of gate lines of said display unit, the video signal of each of the lines in the horizontal direction being thinned out for displaying the reduced picture, the lines being positioned away from each other in the vertical direction of the video signal, the number of lines being equal to a difference between the predetermined vertical-pixel count of said display unit and a vertical-pixel count of the video signal, the two original clock pulse signals being generated in a horizontal period as required in an operation of displaying a video signal having a vertical-pixel count equal to said predetermined vertical-pixel count of said display unit, said second clock pulse signals having pulses corresponding to positions of said original clock pulse signals to be thinned, and to repeat generation of said original clock pulse signals for each horizontal period and generation of said second clock pulse signals for a desired horizontal period;
• a gate-clock generating circuit to receive said original clock pulse signals and said second clock pulse signals from said pulse generating circuit and to generate gate-clock signals obtained as a result of superposing all of said original clock pulse signals on some of said second clock pulse signals wherein the number of said superposed second clock pulse signals is equal to a difference obtained as a result of subtraction of said vertical-pixel count of said display unit from said predetermined vertical-pixel count of said video signal, said second clock pulse signals being in a desired horizontal period, said gate-clock signals containing the original clock pulse signal thinned by the desired superposed second clock pulse signals and being for said two kinds of adjacent fields;
• and
• a gate driving circuit to receive said gate clock signals from said gate-clock generating circuit and to generate gate driving signals used for driving a predetermined number of gate lines as pulses of said gate clock signals for each horizontal period,
• wherein said gate clock signals generated from said gate-clock generating circuit cause said gate driving circuit to generate different gate driving signals for two adjacent gate lines in the same field and the desired second clock pulse signals to be superposed are determined by a combination of a second clock pulse signal and an output enable signal that has been generated from a latch circuit and inverted.

A display apparatus comprising a driving circuit having:

• a first pulse generating circuit to generate a first set of second clock pulse signals for a copy purpose with a desired timing in a horizontal period in an operation to display a first video signal having a vertical-pixel count smaller than a predetermined vertical-pixel count of a display unit as an enlarged picture on a screen of the display unit by using two kinds of adjacent fields in addition to as many original clock pulse signals as required in an operation of displaying a video signal having a vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being pulses which do not overlap with the original clock pulse signals, and to repeat generation of the original clock pulse signals and the first set of second clock pulse signals for each horizontal period;
• a first gate-clock generating circuit to receive the original clock pulse signals and the first set of second clock pulse signals from the first pulse generating circuit and to generate first gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the first set of second clock pulse signals wherein the number of the superposed first set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the vertical-pixel count of the first video signal from the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being in a desired horizontal period, the first gate-clock signals containing the original clock pulse signals and the superposed first set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a first gate driving circuit to receive the first gate clock signals from the first gate-clock generating circuit and to generate first gate driving signals used for driving a predetermined number of gate lines as pulses of the first gate clock signals for each horizontal period,
• wherein the first gate clock signals generated from the first gate-clock generating circuit cause the first gate driving circuit to generate the different first gate driving signals for two adjacent gate lines in the same field,
• a second pulse generating circuit to display the screen on the display unit by using the two kinds of adjacent fields by writing a video signal in a horizontal period into two adjacent gate lines of the display unit wherein, in an operation to display a second video signal having a second vertical-pixel count greater than the predetermined vertical-pixel count of the display unit, the second video signal is thinned by generating a second set of second clock pulse signals for a thinning purpose with a desired timing in a desired horizontal period in addition to two original clock pulse signals generated in a horizontal period as required in an operation of displaying the video signal having the vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the second set of second clock pulse signals having pulses corresponding to positions of the original clock pulse signals to be thinned, and by repeating generation of the original clock pulse signals for each horizontal period and generation of the second set of second clock pulse signals for a desired horizontal period;
• a second gate-clock generating circuit to receive the original clock pulse signals and the second set of second clock pulse signals from the second pulse generating circuit and to generate second gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the second set of second clock pulse signals wherein the number of the superposed second set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the second vertical-pixel count of the display unit from the predetermined vertical-pixel count of the video signal, the second set of second clock pulse signals being in a desired horizontal period, the second gate-clock signals containing the original clock pulse signal thinned by the desired superposed second set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a second gate driving circuit to receive the second gate clock signals from the second gate-clock generating circuit and to generate second gate driving signals used for driving a predetermined number of gate lines as pulses of the second gate clock signals for each horizontal period,
• wherein the second gate clock signals generated from the second gate-clock generating circuit cause the second gate driving circuit to generate the different second gate driving signals for two adjacent gate lines in the same field, and
• wherein the desired first and second set of second clock pulse signals to be superposed are determined by a combination of a second clock pulse signal of the first and second set of second clock pulse signals and a first and second set of output enable signals that have been generated from a latch circuit and inverted, respectively.

A display apparatus comprising a driving circuit having:

• a first pulse generating circuit to generate a first set of second clock pulse signals for a copy purpose with a desired timing in a horizontal period in an operation to display a first video signal having a vertical-pixel count smaller than a predetermined vertical-pixel count of a display unit as an enlarged picture on a screen of the display unit by using two kinds of adjacent fields in addition to as many original clock pulse signals as required in an operation of displaying a video signal having a vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being pulses which do not overlap with the original clock pulse signals, and to repeat generation of the original clock pulse signals and the first set of second clock pulse signals for each horizontal period;
• a first gate-clock generating circuit to receive the original clock pulse signals and the first set of second clock pulse signals from the first pulse generating circuit and to generate first gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the first set of second clock pulse signals wherein the number of the superposed first set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the vertical-pixel count of the first video signal from the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being in a desired horizontal period, the first gate-clock signals containing the original clock pulse signals and the superposed first set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a first gate driving circuit to receive the first gate clock signals from the first gate-clock generating circuit and to generate first gate driving signals used for driving a predetermined number of gate lines as pulses of the first gate clock signals for each horizontal period,
• wherein the first gate clock signals generated from the first gate-clock generating circuit cause the first gate driving circuit to generate the different first gate driving signals for two adjacent gate lines in the same field,
• a second pulse generating circuit to display the screen on the display unit by using the two kinds of adjacent fields by writing a video signal in a horizontal period into two adjacent gate lines of the display unit wherein, in an operation to display a second video signal having a second vertical-pixel count greater than the predetermined vertical-pixel count of the display unit, the second video signal is thinned by generating a second set of second clock pulse signals for a thinning purpose with a desired timing in a desired horizontal period in addition to two original clock pulse signals generated in a horizontal period as required in an operation of displaying the video signal having the vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the second set of second clock pulse signals having pulses corresponding to positions of the original clock pulse signals to be thinned, and by repeating generation of the original clock pulse signals for each horizontal period and generation of the second set of second clock pulse signals for a desired horizontal period;
• a second gate-clock generating circuit to receive the original clock pulse signals and the second set of second clock pulse signals from the second pulse generating circuit and to generate second gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the second set of second clock pulse signals wherein the number of the superposed second set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the second vertical-pixel count of the display unit from the predetermined vertical-pixel count of the video signal, the second set of second clock pulse signals being in a desired horizontal period, the second gate-clock signals containing the original clock pulse signal thinned by the desired superposed second set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a second gate driving circuit to receive the second gate clock signals from the second gate-clock generating circuit and to generate second gate driving signals used for driving a predetermined number of gate lines as pulses of the second gate clock signals for each horizontal period,
• wherein the second gate clock signals generated from the second gate-clock generating circuit cause the second gate driving circuit to generate the different second gate driving signals for two adjacent gate lines in the same field, and
• wherein the first set of second clock pulse signals are superposed such that the superposed first set of second clock pulse signals are generated in the two kinds of adjacent fields shifted from each other by at least one horizontal period.

A display apparatus comprising a driving circuit having:

• a first pulse generating circuit to generate a first set of second clock pulse signals for a copy purpose with a desired timing in a horizontal period in an operation to display a first video signal having a vertical-pixel count smaller than a predetermined vertical-pixel count of a display unit as an enlarged picture on a screen of the display unit by using two kinds of adjacent fields in addition to as many original clock pulse signals as required in an operation of displaying a video signal having a vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being pulses which do not overlap with the original clock pulse signals, and to repeat generation of the original clock pulse signals and the first set of second clock pulse signals for each horizontal period;
• a first gate-clock generating circuit to receive the original clock pulse signals and the first set of second clock pulse signals from the first pulse generating circuit and to generate first gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the first set of second clock pulse signals wherein the number of the superposed first set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the vertical-pixel count of the first video signal from the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being in a desired horizontal period, the first gate-clock signals containing the original clock pulse signals and the superposed first set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a first gate driving circuit to receive the first gate clock signals from the first gate-clock generating circuit and to generate first gate driving signals used for driving a predetermined number of gate lines as pulses of the first gate clock signals for each horizontal period,
• wherein the first gate clock signals generated from the first gate-clock generating circuit cause the first gate driving circuit to generate the different first gate driving signals for two adjacent gate lines in the same field,
• a second pulse generating circuit to display the screen on the display unit by using the two kinds of adjacent fields by writing a video signal in a horizontal period into two adjacent gate lines of the display unit wherein, in an operation to display a second video signal having a second vertical-pixel count greater than the predetermined vertical-pixel count of the display unit, the second video signal is thinned by generating a second set of second clock pulse signals for a thinning purpose with a desired timing in a desired horizontal period in addition to two original clock pulse signals generated in a horizontal period as required in an operation of displaying the video signal having the vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the second set of second clock pulse signals having pulses corresponding to positions of the original clock pulse signals to be thinned, and by repeating generation of the original clock pulse signals for each horizontal period and generation of the second set of second clock pulse signals for a desired horizontal period;
• a second gate-clock generating circuit to receive the original clock pulse signals and the second set of second clock pulse signals from the second pulse generating circuit and to generate second gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the second set of second clock pulse signals wherein the number of the superposed second set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the second vertical-pixel count of the display unit from the predetermined vertical-pixel count of the video signal, the second set of second clock pulse signals being in a desired horizontal period, the second gate-clock signals containing the original clock pulse signal thinned by the desired superposed second set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a second gate driving circuit to receive the second gate clock signals from the second gate-clock generating circuit and to generate second gate driving signals used for driving a predetermined number of gate lines as pulses of the second gate clock signals for each horizontal period,
• wherein the second gate clock signals generated from the second gate-clock generating circuit cause the second gate driving circuit to generate the different second gate driving signals for two adjacent gate lines in the same field, and
• wherein the original clock pulse signals are generated during the first ⅔ of each horizontal period and the first set of second clock pulse signals are generated during the last ⅓ of each horizontal period.

A display apparatus comprising a driving circuit having:

• a first pulse generating circuit to generate a first set of second clock pulse signals for a copy purpose with a desired timing in a horizontal period in an operation to display a first video signal having a vertical-pixel count smaller than a predetermined vertical-pixel count of a display unit as an enlarged picture on a screen of the display unit by using two kinds of adjacent fields in addition to as many original clock pulse signals as required in an operation of displaying a video signal having a vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being pulses which do not overlap with the original clock pulse signals, and to repeat generation of the original clock pulse signals and the first set of second clock pulse signals for each horizontal period;
• a first gate-clock generating circuit to receive the original clock pulse signals and the first set of second clock pulse signals from the first pulse generating circuit and to generate first gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the first set of second clock pulse signals wherein the number of the superposed first set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the vertical-pixel count of the first video signal from the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being in a desired horizontal period, the first gate-clock signals containing the original clock pulse signals and the superposed first set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a first gate driving circuit to receive the first gate clock signals from the first gate-clock generating circuit and to generate first gate driving signals used for driving a predetermined number of gate lines as pulses of the first gate clock signals for each horizontal period,
• wherein the first gate clock signals generated from the first gate-clock generating circuit cause the first gate driving circuit to generate the different first gate driving signals for two adjacent gate lines in the same field,
• a second pulse generating circuit to display the screen on the display unit by using the two kinds of adjacent fields by writing a video signal in a horizontal period into two adjacent gate lines of the display unit wherein, in an operation to display a second video signal having a second vertical-pixel count greater than the predetermined vertical-pixel count of the display unit, the second video signal is thinned by generating a second set of second clock pulse signals for a thinning purpose with a desired timing in a desired horizontal period in addition to two original clock pulse signals generated in a horizontal period as required in an operation of displaying the video signal having the vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the second set of second clock pulse signals having pulses corresponding to positions of the original clock pulse signals to be thinned, and by repeating generation of the original clock pulse signals for each horizontal period and generation of the second set of second clock pulse signals for a desired horizontal period;
• a second gate-clock generating circuit to receive the original clock pulse signals and the second set of second clock pulse signals from the second pulse generating circuit and to generate second gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the second set of second clock pulse signals wherein the number of the superposed second set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the second vertical-pixel count of the display unit from the predetermined vertical-pixel count of the video signal, the second set of second clock pulse signals being in a desired horizontal period, the second gate-clock signals containing the original clock pulse signal thinned by the desired superposed second set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a second gate driving circuit to receive the second gate clock signals from the second gate-clock generating circuit and to generate second gate driving signals used for driving a predetermined number of gate lines as pulses of the second gate clock signals for each horizontal period,
• wherein the second gate clock signals generated from the second gate-clock generating circuit cause the second gate driving circuit to generate the different second gate driving signals for two adjacent gate lines in the same field, and
• wherein the second set of second clock pulse signals are superposed such that the superposed second set of second clock pulse signals generated in the two kinds of adjacent fields are shifted from each other by at least one horizontal period.

A display apparatus comprising a driving circuit having:

• a first pulse generating circuit to generate a first set of second clock pulse signals for a copy purpose with a desired timing in a horizontal period in an operation to display a first video signal having a vertical-pixel count smaller than a predetermined vertical-pixel count of a display unit as an enlarged picture on a screen of the display unit by using two kinds of adjacent fields in addition to as many original clock pulse signals as required in an operation of displaying a video signal having a vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being pulses which do not overlap with the original clock pulse signals, and to repeat generation of the original clock pulse signals and the first set of second clock pulse signals for each horizontal period;
• a first gate-clock generating circuit to receive the original clock pulse signals and the first set of second clock pulse signals from the first pulse generating circuit and to generate first gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the first set of second clock pulse signals wherein the number of the superposed first set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the vertical-pixel count of the first video signal from the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being in a desired horizontal period, the first gate-clock signals containing the original clock pulse signals and the superposed first set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a first gate driving circuit to receive the first gate clock signals from the first gate-clock generating circuit and to generate first gate driving signals used for driving a predetermined number of gate lines as pulses of the first gate clock signals for each horizontal period,
• wherein the first gate clock signals generated from the first gate-clock generating circuit cause the first gate driving circuit to generate the different first gate driving signals for two adjacent gate lines in the same field,
• a second pulse generating circuit to display the screen on the display unit by using the two kinds of adjacent fields by writing a video signal in a horizontal period into two adjacent gate lines of the display unit wherein, in an operation to display a second video signal having a second vertical-pixel count greater than the predetermined vertical-pixel count of the display unit, the second video signal is thinned by generating a second set of second clock pulse signals for a thinning purpose with a desired timing in a desired horizontal period in addition to two original clock pulse signals generated in a horizontal period as required in an operation of displaying the video signal having the vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the second set of second clock pulse signals having pulses corresponding to positions of the original clock pulse signals to be thinned, and by repeating generation of the original clock pulse signals for each horizontal period and generation of the second set of second clock pulse signals for a desired horizontal period;
• a second gate-clock generating circuit to receive the original clock pulse signals and the second set of second clock pulse signals from the second pulse generating circuit and to generate second gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the second set of second clock pulse signals wherein the number of the superposed second set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the second vertical-pixel count of the display unit from the predetermined vertical-pixel count of the video signal, the second set of second clock pulse signals being in a desired horizontal period, the second gate-clock signals containing the original clock pulse signal thinned by the desired superposed second set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a second gate driving circuit to receive the second gate clock signals from the second gate-clock generating circuit and to generate second gate driving signals used for driving a predetermined number of gate lines as pulses of the second gate clock signals for each horizontal period,
• wherein the second gate clock signals generated from the second gate-clock generating circuit cause the second gate driving circuit to generate the different second gate driving signals for two adjacent gate lines in the same field, and
• wherein one of the second set of second clock pulse signals is generated every other horizontal period and successive second clock pulse signals of the second set of second clock pulse signals are generated in leading portions and intermediate portions of the horizontal periods.

A display apparatus comprising a driving circuit having:

• a first pulse generating circuit to generate a first set of second clock pulse signals for a copy purpose with a desired timing in a horizontal period in an operation to display a first video signal having a vertical-pixel count smaller than a predetermined vertical-pixel count of a display unit as an enlarged picture on a screen of the display unit by using two kinds of adjacent fields in addition to as many original clock pulse signals as required in an operation of displaying a video signal having a vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being pulses which do not overlap with the original clock pulse signals, and to repeat generation of the original clock pulse signals and the first set of second clock pulse signals for each horizontal period;
• a first gate-clock generating circuit to receive the original clock pulse signals and the first set of second clock pulse signals from the first pulse generating circuit and to generate first gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the first set of second clock pulse signals wherein the number of the superposed first set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the vertical-pixel count of the first video signal from the predetermined vertical-pixel count of the display unit, the first set of second clock pulse signals being in a desired horizontal period, the first gate-clock signals containing the original clock pulse signals and the superposed first set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a first gate driving circuit to receive the first gate clock signals from the first gate-clock generating circuit and to generate first gate driving signals used for driving a predetermined number of gate lines as pulses of the first gate clock signals for each horizontal period,
• wherein the first gate clock signals generated from the first gate-clock generating circuit cause the first gate driving circuit to generate the different first gate driving signals for two adjacent gate lines in the same field,
• a second pulse generating circuit to display the screen on the display unit by using the two kinds of adjacent fields by writing a video signal in a horizontal period into two adjacent gate lines of the display unit wherein, in an operation to display a second video signal having a second vertical-pixel count greater than the predetermined vertical-pixel count of the display unit, the second video signal is thinned by generating a second set of second clock pulse signals for a thinning purpose with a desired timing in a desired horizontal period in addition to two original clock pulse signals generated in a horizontal period as required in an operation of displaying the video signal having the vertical-pixel count equal to the predetermined vertical-pixel count of the display unit, the second set of second clock pulse signals having pulses corresponding to positions of the original clock pulse signals to be thinned, and by repeating generation of the original clock pulse signals for each horizontal period and generation of the second set of second clock pulse signals for a desired horizontal period;
• a second gate-clock generating circuit to receive the original clock pulse signals and the second set of second clock pulse signals from the second pulse generating circuit and to generate second gate-clock signals obtained as a result of superposing all of the original clock pulse signals on some of the second set of second clock pulse signals wherein the number of the superposed second set of second clock pulse signals is equal to a difference obtained as a result of subtraction of the second vertical-pixel count of the display unit from the predetermined vertical-pixel count of the video signal, the second set of second clock pulse signals being in a desired horizontal period, the second gate-clock signals containing the original clock pulse signal thinned by the desired superposed second set of second clock pulse signals and being for the two kinds of adjacent fields;
• and
• a second gate driving circuit to receive the second gate clock signals from the second gate-clock generating circuit and to generate second gate driving signals used for driving a predetermined number of gate lines as pulses of the second gate clock signals for each horizontal period,
• wherein the second gate clock signals generated from the second gate-clock generating circuit cause the second gate driving circuit to generate the different second gate driving signals for two adjacent gate lines in the same field, and
• further comprising a discriminating circuit to determine which of the first pulse generating circuit and the second pulse generating circuit is to be used.