Tone display method and apparatus reducing flicker

A luminous display device comprising:

• a display panel including a plurality of luminous elements, each of said luminous elements adapted for controllable light emission;
• means for indicating time intervals of a plurality of sub-fields of a field of a television signal, each sub-field having a duration corresponding to the value of a respective one of the bits of a multiple-bit binary code;
• means for supplying said luminous elements with an energization signal including a plurality of signal portions, each signal portion having a duration corresponding tot he duration of a respective one of the sub-fields;
• and
• means for supplying each luminous element with a control signal to cause said luminous elements to selectively emit light during sub-fields indicated by the control signal, so that the brightness levels of said luminous elements correspond with the control signal.

A method of tone display for controlling the brightness of a picture to be displayed by varying luminous times of luminous elements forming a display panel, said method comprising the steps of:

• dividing time corresponding to a field of television signals into a plurality of sub-fields corresponding to bits of a multiple-bit code representing a level of brightness of each luminous element, and allotting said sub-fields to said luminous elements, said plurality of sub-fields having lengths of time proportional to weights of corresponding bits;
• consecutively supplying said luminous elements with multiple-bit codes;
• causing said luminous elements to emit light in sub-fields corresponding to said bits, having either "1" or "0", of said multiple-bit codes,
• wherein for each luminous element, a time interval from a light emission start time at a sub-field where the first light emission occurs in a time corresponding to a field of television signals till a light emission start time at a sub-field where the last light emission occurs in a time corresponding to the next field of television signals is made shorter than the critical fusion period of the perception characteristic of human eyes, and
• wherein at least one of said sub-fields is divided into at least two smaller sub-fields sandwiching at least one sub-field therebetween, thereby making it possible to cause each luminous element to emit light at least two times in a field of television signals.

A luminous display device comprising:

• a display panel having arranged thereon a plurality of luminous elements, light emission or no light emission of said luminous elements being controllable;
• means for consecutively supplying said luminous elements with multiple-bit codes representing levels of brightness thereof;
• means for dividing time corresponding to a field of television signals into a plurality of sub-fields having lengths of time proportional to weights of corresponding bits of a multiple-bit code to assign said sub-fields to said luminous elements;
• means for causing said luminous elements to emit light in sub-fields corresponding to said bits, having values of either "1" or "0", of said multiple-bit codes;
• wherein for each luminous element, a time interval from a light emission start time at a sub-field where the first light emission occurs in a time corresponding to a field of television signals till a light emission start time at a sub-field where the last light emission occurs in a time corresponding to the next field of television signals is made shorter than the critical fusion period of the perception characteristic of human eyes, and
• wherein at least one of said sub-fields is divided into at least two smaller sub-fields sandwiching at least one sub-field therebetween, thereby making it possible to cause each luminous element to emit light at least two times in a field of television signals.