Claims
- 1. A display driving method which drives a display to make a gradation display on a screen of the display depending on a length of a light emission time in each of sub fields forming one field, where one field is a time in which an image is displayed, N sub fields SF1 through SFN form one field, and each sub field includes an address display-time for selecting pixels which are to emit light within the sub field and a sustain time which is equal to the light emission time and determines a luminance level, said display driving method comprising the steps of:displaying input image data on the display using N+1 gradation levels from a luminance level 0 to a luminance level N; and increasing a luminance quantity when displaying a luminance level m by adding 1 sub field which is to assume a light emission state in addition to all sub fields which assume the light emission state when displaying a luminance level m−1, where m is an integer satisfying 0<m<N.
- 2. The display driving method as claimed in claim 1, which further comprises the steps of:controlling lengths of light emission times to give a non-linear display characteristic with respect to the input image data so as to satisfy a relationship T(SF1)≦T(SF2)≦ . . . ≦T(SFm)≦T(SFm+1)≦ . . . ≦T(SFN−1)≦T(SFN) when a sub field which does not assume a light emission state for the luminance level m−1 but first assumes the light emission state for the luminance level m is denoted by SFm, a sub field which does not assume the light emission state for the luminance level m but first assumes the light emission state for the luminance level m+1 is denoted by SFm+1, the length of the light emission time of the sub field SFm is denoted by T(SFm), and the length of the light emission time of the sub field SFm+1 is denoted by R(SFm+1).
- 3. The display driving method as claimed in claim 2, which further comprises the steps of:carrying out a distortion correction process with respect to the input image data using an inverse function with respect to the non-linear display characteristic, at a state prior to giving the non-linear display characteristic with respect to the input image data.
- 4. The display driving method as claimed in claim 3, which further comprises the steps of:carrying out a multi-level gradation process with respect to the input image data at a stage after carrying out the distortion correction process.
- 5. The display driving method as claimed in claim 1, which further comprises the steps of:out of an entire luminance region to be displayed, allocating a first number of sub fields for displaying gradation steps of a low luminance portion and allocating a second number of sub fields for displaying gradation steps of a high luminance portion, where said first number is greater than the second number.
- 6. The display driving method as claimed in claim 5, which further comprises the steps of:setting a number of sustain pulses for emitting light from corresponding pixels on the screen of the display so that a number of sustain pulses in each sub field allocated for displaying the gradation steps of the low luminance portion is smaller than a number of sustain pulses in each sub field allocated for displaying the gradation steps of the high luminance portion.
- 7. A display driving apparatus which drives a display to make a gradation display on a screen of the display depending on a length of a light emission time in each of sub fields forming one field, where one field is a time in which an image is displayed, N sub fields SF1 through SFN form one field, and each sub field includes an address display-time in which a wall charge is formed with respect to all pixels which are to emit light within the sub field and a sustain time which is equal to the light emission time and determines a luminance level, said display driving apparatus comprising:means for displaying input image data on the display using N+1 gradation levels from a luminance level 0 to a luminance level N; and means for increasing a luminance quantity when displaying a luminance level m by adding one sub field which is to assume a light emission state in addition to all sub fields which assume the light emission state when displaying a luminance level m−1, where m is an integer satisfying 0<m<N.
- 8. The display driving apparatus as claimed in claim 7, which further comprises:means for controlling lengths of light emission times to give a non-linear display characteristic with respect to the input image data so as to satisfy a relationship T(SF1)≦(SF2)≦ . . . ≦T(SFm)≦T(SFm+1)≦ . . . ≦T(SFN−1)≦T(SFN) when a sub field which does not assume a light emission state for the luminance level m−1 but first assumes the light emission state for the luminance level m is denoted by SFm, a sub field which does not assume the light emission state for the luminance level m but first assumes the light emission state for the luminance level m+1 is denoted by SFm1, the length of the light emission time of the sub field SFm is denoted by T(SFm), and the length of the light emission time of the sub field SFm+1 is denoted by T(SF+1).
- 9. The display driving apparatus as claimed in claim 8, which further comprises:means for carrying out a distortion correction process with respect to the input image data using an inverse function with respect to the non-linear display characteristic, at a state prior to giving the non-linear display characteristic with respect to the input image data.
- 10. The displaying driving apparatus as claimed in claim 9, which further comprises:means for carrying out a multi-level gradation process with respect to the input image data at a stage after carrying out the distortion correction process.
- 11. The display driving apparatus as claimed in claim 7, which further comprises:means for allocating, out of an entire luminance region to be displayed, a first number of sub fields for displaying gradation steps of a low luminance portion and allocating a second number of sub fields for displaying gradation steps of a high luminance portion, where said first number is greater than the second number.
- 12. The display driving apparatus as claimed in claim 11, which further comprises:means for setting a number of sustain pulses for emitting light from corresponding pixels on the screen of the display so that a number of sustain pulses in each sub field allocated for displaying the gradation steps for the low luminance portion is smaller than a number of sustain pulses in each sub field allocated for displaying the gradation steps of the high luminance portion.
Priority Claims (3)
Number |
Date |
Country |
Kind |
7-275911 |
Oct 1995 |
JP |
|
8-122075 |
May 1996 |
JP |
|
8-263398 |
Oct 1996 |
JP |
|
Parent Case Info
This application is a division of application Ser. No. 08/735,750, filed Oct. 23, 1996, now U.S. Pat. No. 6,144,364.
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