Modulation circuit, image display using the same, and modulation method

A modulation circuit for outputting pulse signals modulated according to a value of a binary code, comprising:

• a selecting means for dividing the binary code from the most significant bit to least significant bit into a plurality of parts, and selecting and outputting the therefore obtained divided binary codes in a preset order;
• and
• a pulse outputting means for receiving the divided binary codes from the selecting means, and outputting a plurality of said pulse signals of a predetermined period each having a pulse width and a level corresponding to one of the divided binary codes;
• wherein for each of the divided binary codes, the selecting means divides the predetermined period into a plurality of sub-frame periods of lengths corresponding to the bit lengths of the divided binary codes and selects and outputs the divided binary code corresponding to a sub-frame period in that sub-frame period;
• and
• wherein when the bit length of the i-th (i is a natural number) divided binary code from the least significant bit of the binary code is B(i) (B(i) is a natural number), the pulse outputting means sets the level of a pulse signal corresponding to the (i+1)-th divided binary code from the least significant bit of the binary code to a magnitude of 2 to the B(i) power (2B(i)) times the level of the pulse signal corresponding to the i-th divided binary code;
• further comprising a clock counting means for receiving clock pulses, counting the clock pulses from an initial value at the beginning of each sub-frame period, and outputting the clock count, wherein
• the pulse outputting means detects the time when the magnitudes of the clock count and the value of the divided binary code invert and inverts the level of the pulse signal near this time.

An image display including light emitting diodes, each LED receiving pulse signals modulated according to a value of a binary code and emit light of luminances corresponding to the levels of the pulse signals, comprising:

• a selecting means for dividing a binary code into a plurality of binary codes from the most significant bit to the least significant bit and selecting and outputting the divided binary codes produced by the division in a preset order and
• a pulse outputting means for receiving the divided binary codes from the selecting means and outputting a plurality of the pulse signals having pulse widths and levels corresponding to the divided binary codes at a predetermined period;
• wherein the selecting means and the pulse outputting means are part of a modulation circuit that separates at least lower bit group and higher bit group to generate the modulated pulse signals;
• and
• wherein each LED is serially connected and each LED is electrically connected to its own modulation circuit.

An image display including light emitting elements which receive pulse signals modulated according to a value of a binary code and emit light of luminances corresponding to the levels of the pulse signals, comprising:

• a selecting means for dividing a binary code into a plurality of binary codes from the most significant bit to the least significant bit and selecting and outputting the divided binary codes produced by the division in a preset order and
• a pulse outputting means for receiving the divided binary codes from the selecting means and outputting a plurality of the pulse signals having pulse widths and levels corresponding to the divided binary codes at a predetermined period
• wherein for each of the divided binary codes, the selecting means divides the predetermined period into a plurality of sub-frame periods of lengths corresponding to the bit lengths of the divided binary codes and selects and outputs the divided binary code corresponding to a sub-frame period in that sub-frame period;
• further comprising a clock counting means for receiving clock pulses, counting the clock pulses from an initial value at the beginning of each sub-frame period, and outputting the clock count, wherein
• the pulse outputting means detects the time when the magnitudes of the clock count and the value of the divided binary code invert and inverts the level of the pulse signal near this time.

An image display including light emitting elements which receive pulse signals modulated according to a value of a binary code and emit light of luminances corresponding to the levels of the pulse signals, comprising:

• a selecting means for dividing a binary code into a plurality of binary codes from the most significant bit to the least significant bit and selecting and outputting the divided binary codes produced by the division in a preset order, and
• a pulse outputting means for receiving the divided binary codes from the selecting means and outputting a plurality of the pulse signals having pulse widths and levels corresponding to the divided binary codes at a predetermined period;
• wherein for each of the divided binary codes, the selecting means divides the predetermined period into a plurality of sub-frame periods of lengths corresponding to the bit lengths of the divided binary codes and selects and outputs the divided binary code corresponding to a sub-frame period in that sub-frame period;
• and
• wherein when the bit length of the i-th (i is a natural number) divided binary code from the least significant bit of the binary code is B(i) (B(i) is a natural number), the pulse outputting means sets the level of a pulse signal corresponding to the (i+1)-th divided binary code from the least significant bit of the binary code to a magnitude of 2 to the B(i) power (2B(i)) times the level of the pulse signal corresponding to the i-th divided binary code;
• further comprising a clock counting means for receiving clock pulses, counting the clock pulses from an initial value at the beginning of each sub-frame period, and outputting the clock count, wherein
• the pulse outputting means detects the time when the magnitudes of the clock count and the value of the divided binary code invert and inverts the level of the pulse signal near this time.