Method and apparatus for driving a display device to produce a gray scale effect

Claim 2

A process according to claim 1, wherein said plurality of sub-field parts are disposed in the centre portion of said field period.

Claim 3

A process according to claim 1, wherein said step of dividing comprises: dividing said sub-field having the highest luminance value among said plural sub-fields into first sub-field parts, dividing said sub-field having the second highest luminance value among said plural sub-fields into second sub-field parts, and disposing said sub-fields parts and said second sub-field parts in the centre portion of said field period so that each part of said first sub-field parts and each part of said second sub-field parts are alternately disposed.

Claim 4

A process according to claim 1, wherein said step of dividing comprises: dividing said sub-field having the highest luminance value among said plural sub-fields into first sub-field parts, dividing said sub-field having the second highest luminance value among said plural sub-fields into second sub-field parts, dividing said sub-field having the third highest luminance value among said plural sub-fields into third sub-field parts, and disposing said first sub-field parts, said second sub-field parts, and said third sub-field parts in the centre portion of said field period so that each part of said first sub-field parts, each part of said second sub-field parts, and each part of said third sub-field parts are continuously disposed.

Claim 5

A process according to claim 1, wherein said step of dividing comprises: dividing said sub-field having the highest luminance value among said plural sub-fields into first sub-field parts, dividing said sub-field having the second highest luminance value among said plural sub-fields into second sub-fields parts, dividing said sub-field having the third highest luminance value among said plural sub-fields into third sub-field parts, and dividing said sub-field having the fourth highest luminance value among said plural sub-fields into fourth sub-field parts, and disposing said first sub-field parts, said second sub-field parts, said third sub-field parts, and said fourth sub-field parts in the centre portion of said field period so that each part of said first sub-field parts, each part of said second sub-field parts, each part of said third sub-field parts, each part of said fourth sub-field parts are continuously disposed.

Claim 6

A process according to claim 1 or 2, wherein said plurality of sub-field parts are disposed discontinuously with each other in said field period.

Claim 7

A process according to claim 1, wherein said plurality of sub-field parts are disposed in both end portions of said field period, and sub-fields, which are not divided into said plurality of sub-field parts, are disposed in the centre portion of said field period.

Claim 8

A driving circuit for producing a gray scale output in a display device having a matrix-shaped electrode structure, comprising: data writing means for generating writing discharge at required matrix positions, a sub-field control circuit for issuing sub-field signals for specifying one of plural sub-fields, sustaining discharge means for generating sustaining discharge at said required matrix positions in accordance with said sub-field signals, and erasing discharge means for generating erasing charge at said required matrix positions in accordance with said sub-field signals, wherein said sub-field control circuit is operable to output one or more sub-field signals corresponding to the highest luminance value or highest luminance values, as a plurality of discontinuous sub-field part signals at different times during the field period, and wherein said sustaining means is operable to output a respective sustaining pulse for each sub field or sub-field part.

Claim 9

Apparatus for generating a signal for producing a variable luminance display effect in a display device, the apparatus being operable to generate the signal as a sequence of fields each corresponding to a desired output luminance value in quantised form, each field comprising a sequence of sub-fields representing quanta of luminance, at least the maximum quantum being represented by a plurality of non-adjacent sub-fields.

Claim 10

A signal for driving a display device to produce a variable luminance display effect, the signal format comprising a sequence of fields each corresponding to a desired output luminance value in quantised form, each field comprising a sequence of sub-fields representing quanta of luminance, at least the maximum quantum being represented by a plurality of non-adjacent sub-fields.