Display control apparatus and display control method

• US 6,972,773 B2
• Filed: 07/20/2001
• Issued: 12/06/2005
• Est. Priority Date: 07/27/2000
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Matsui, Takeshi, Nishi, Tomohiro
• Primary Examiner(s): Brier, Jeffery
• Assistant Examiner(s): AMINI, JAVID A
• Application Number:
  US09/909,714
• Publication Number:
  US 20020021303A1
• Time in Patent Office: 1,600 Days
• Field of Search: 345/611, 345/82, 345/207, 345690-694, 345/148, 345/97, 382/148
• US Class Current: 345/611
• CPC Class Codes: G09G 2320/0266 Reduction of sub-frame artefacts
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2025 the sub-frames having all the same time duration
• CPC Class Codes: G09G 3/2033 with splitting one or more sub-frames corresponding to the most significant bits into two or more sub-frames
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/28 using luminous gas-discharge panels, e.g. plasma panels
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: H04N 5/7408 Direct viewing projectors, e.g. an image displayed on a video CRT or LCD display being projected on a screen
• CPC Class Codes: H04N 5/7416 involving the use of a spatial light modulator, e.g. a light valve, controlled by a video signal
• CPC Class Codes: H04N 9/31 Projection devices for colour picture display , e.g. using electronic spatial light modulators [ESLM]
• CPC Class Codes: H04N 9/3123 using pulse width modulation
• CPC Class Codes: H04N 9/69 for modifying the colour signals by gamma correction controlling camera response for colour signals H04N23/83

Abstract

The invention provides a display control apparatus and a display control method wherein, where digital gradation display is performed, occurrences of a moving picture pseudo contour can be reduced simply. A signal production circuit produces a signal for driving a display section so that light of divisional light amounts obtained by dividing light amounts corresponding to bits which compose digital values which are pixel values may be emitted in a such manner as to be distributed within a time corresponding to one screen. In this instance, where both of a first light amount corresponding to a predetermined bit and a second light amount corresponding to a bit in a lower order by one bit to the bit are divided, the first and second light amounts are divided so that the division number of the first light amount may be smaller than twice the division number of the second light amount.

Claims

1. A display control apparatus for controlling a display apparatus which displays an image in digital gradation, the image being from a frame of a plurality of frames, the display control apparatus comprising:

inputting means for inputting digital values corresponding to pixel values which compose the image; and

signal production means for producing a signal for driving said display apparatus so that the display apparatus emits a light including divisional light amounts in such a manner as to be distributed within a time corresponding to display of the frame, the light amounts being obtained by dividing light amounts corresponding to bits which compose the digital values, light amounts corresponding to higher order bits providing one of more and less light than light amounts corresponding to lower order bits,

wherein when both of a first light amount of the light amounts corresponding to a predetermined bit of the bits that compose the digital values and a second light amount of the light amounts corresponding to a bit in a lower order by one bit to the predetermined bit are divided, the first and second light amounts are divided so that a difference between division numbers of the first and second light amounts of adjacent bits whose light amounts are divided is one of 0 and 1, including a case wherein at least one of the division numbers is greater than 2, thereby effecting a reduction of a moving picture pseudo contour in display of the image in digital gradation,

wherein the display apparatus includes light emission means for emitting light of variable intensity, the light emission means including at least one light source for emitting the light with variable intensity and a light valve corresponding to each pixel that switches on or off to effect emission of the light from said light source, the light valve being driven by the signal from the signal production means.

2. A display control apparatus according to claim 1, wherein the light amounts corresponding to the bits are divided in a direction of time in which the light is emitted or in a direction of intensity of the light.

3. A display control apparatus according to claim 1, wherein said signal production means produces the signal for driving said display apparatus so that the light of the divisional light amounts obtained by dividing the light amounts corresponding to the bits may be emitted at timings at which the light may be symmetrical within the time corresponding to one screen.

4. A display control apparatus according to claim 1, wherein said signal production means produces the signal for driving said display apparatus so that the light of the divisional light amounts obtained by dividing the light amount corresponding to a predetermined bit and the light of the divisional light amounts obtained by dividing the light amount corresponding to a bit adjacent to the bit may be emitted at timings close to each other within the time corresponding to display of the frame.

5. A display control apparatus according to claim 1, wherein said signal production means produces the signal for driving said display apparatus so that the light of the divisional light amounts obtained by dividing the light amount corresponding to the most significant bit is emitted at least at the top and last timings within the time corresponding to display of the frame.

6. A display control apparatus according to claim 1, wherein said signal production means produces the signal for causing said light emission means to emit pulse width modulated light.

7. A display control apparatus according to claim 1, wherein said signal production means produces the signal for causing said light emission means to emit at least one of pulse width modulated light and intensity modulated light.

8. A display control apparatus according to claim 1, wherein said light emission means emits light of a plurality of color components.

9. A display control apparatus according to claim 1, wherein said signal production means produces the signal for causing digital gradation display by a plane sequential rewriting method to be performed.

10. A display control apparatus according to claim 1, wherein said signal production means produces the signal for causing said light emission means to emit intensity modulated light.

11. A display control method for controlling a display apparatus which displays an image in digital gradation, the image being from a frame of a plurality of frames, the method comprising:

an inputting step of receiving digital values corresponding to pixel values which compose the image; and

a signal production step of producing a signal for driving said display apparatus so that the display apparatus emits a light including divisional light amounts in such a manner as to be distributed within a time corresponding to display of the frame, the light amounts being obtained by dividing light amounts corresponding to bits which compose the digital values, light amounts corresponding to higher order bits providing one of more and less light than light amounts corresponding to lower order bits;

wherein when both of a first light amount of the light amounts corresponding to a predetermined bit of the bits that compose the digital values and a second light amount of the light amounts corresponding to a bit in a lower order by one bit to the predetermined bit are divided, the first and second light amounts are divided so that a difference between division numbers of the first and second light amounts of adjacent bits whose light amounts are divided is one of 0 and 1, including a case wherein at least one of the division numbers is greater than 2, thereby effecting a reduction of a moving picture pseudo contour in display of the image in digital gradation,

wherein the display apparatus includes light emission means for emitting light of variable intensity, the light emission means including at least one light source for emitting the light with variable intensity and a light valve corresponding to each pixel that switches on or off to effect emission of the light from said light source, the light valve being driven by the produced signal.