CN1685276A - Pulse width modulated display with hybrid coding - Google Patents
Pulse width modulated display with hybrid coding Download PDFInfo
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- CN1685276A CN1685276A CNA038191946A CN03819194A CN1685276A CN 1685276 A CN1685276 A CN 1685276A CN A038191946 A CNA038191946 A CN A038191946A CN 03819194 A CN03819194 A CN 03819194A CN 1685276 A CN1685276 A CN 1685276A
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3433—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices
- G09G3/346—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices based on modulation of the reflection angle, e.g. micromirrors
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/07—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on electro-optical liquids exhibiting Kerr effect
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3102—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators
- H04N9/312—Driving therefor
- H04N9/3123—Driving therefor using pulse width modulation
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2310/00—Command of the display device
- G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
- G09G2310/0235—Field-sequential colour display
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2320/00—Control of display operating conditions
- G09G2320/02—Improving the quality of display appearance
- G09G2320/0242—Compensation of deficiencies in the appearance of colours
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/2007—Display of intermediate tones
- G09G3/2018—Display of intermediate tones by time modulation using two or more time intervals
Abstract
A field sequential pulse width modulated display system (10) comprises a digital micromirror device (DMD) (24) having a plurality of micromirrors that each selectively reflect light to illuminate a corresponding pixel. A driver circuit (30) controls the DMD (24) responsive to sequences of pulse width segments formed by a processor (31). The processor (31) increases the pixel brightness by actuating selected pulses such that within a first range of brightness levels between first and second pixel brightness boundaries, a first large-duration pulse (or combination of pulses) becomes actuated to reach the second pixel brightness boundary, and within a second range of pixel brightness levels between second and third pixel brightness boundaries, the first large duration pulse (or combination of pulses) remains actuated. Upon reaching the third pixel brightness boundary, a second large duration pulse (or combination of pulses) now becomes actuated with the first large duration pulse (or combination of pulses) remaining actuated. Forming the pulse width segments in this manner serves to reduce motion contouring.
Description
According to 35 U.S.C.119 (e), the application requires the U.S. Provisional Patent Application sequence number No.60/404 of submission on August 13rd, 2002,156 right of priority.
Technical field
The present invention relates to a kind of pulse-length modulation light projection system, more specifically, relate to and be used to operate a kind of pulse-length modulation light projection system so that the minimum technology of motion outline (contouring).
Background technology
In recent years, there is one type semiconductor equipment, is known as digital micromirror device (DMD), comprise the removable micro-reflector of a plurality of independences that is arranged in the rectangular array.Latch therein under the control of respective drivers unit of a bit, each micro-reflector is that the limited radian of the 10-12 ° of order of magnitude rotates along the typical case.During the bit that latched before applying " 1 ", driver makes its micro-reflector unit rotational that is associated to primary importance.On the contrary, be applied to actuator unit before the bit " 0 " that latchs make actuator unit that the micro-reflector that it is associated is turned to the second place.By between light source and projecting lens, suitably locating DMD, when by its respective drivers unit rotational during to primary importance, the independent micro-reflector of each of DMD will reflex on the display screen from the rays pass through lens of light source, thereby illuminates the independent pictures element (pixel) in the display.When turning to its second place, each micro-reflector reflects light away from display screen, makes corresponding pixel present dark.An example of this DMD equipment is from Texas Instrument, the DMD of the DLPTM optical projection system of Dallas Texas.
At present, adopted the optical projection system of the DMD of the above-mentioned type to keep " unlatching " (promptly therebetween by the independent micro-reflector of control, turn to its primary importance) and micro-reflector maintenance " closing " therebetween is (promptly, turn to its second place) the duty factor compared of the time interval, control the brightness (illumination) of each pixel.。For this reason, the optical projection system of this present DMD type changes the dutycycle of each micro-reflector by the state according to pulse in the sequence of pulse width segment, uses pulse-length modulation control pixel brightness.Each pulse width segment comprises the train of impulses of various durations.The state of each pulse in the pulse width segment (that is, each pulse is to open or close) has determined that micro-reflector is held open or closes in the duration of this pulse.In other words, the width summation of the pulse in the pulse width segment of opening (being activated) is big more, and the duty cycle of each micro-reflector is just long more.
In the TV projection system of using DMD, frame time shows that promptly the time between the consecutive image is depended on selected television system at interval.The frame time interval that the current TSC-system formula of using in the U.S. needs 1/60 second, and the eurovision standard has been used 1/50 second frame time interval.At present, typically, DMD type TV projection system is by realizing colored the demonstration at each frame time simultaneously or in a sequence projection red, green and blue of interim image.Typical sequence DMD type optical projection system has been used the direct motor drive color wheel in the light path that is inserted in DMD.Color wheel has the primary color windows of a plurality of separation, and the typical case is a red, green and blue, thereby during the continuous time interval, red, green and blue light can drop on the DMD respectively.In order to realize colour picture, in the time interval, red, green and blue light must drop on the DMD last time at least at each successive frame.If only produce red, green and blue images and each expend frame time at interval 1/3, then between generation has the discernable colored color of interrupting of motion, can postpone by time of occurrence.At present, the DMD system has reduced the delay between the color thus by each color being divided into several time intervals and solving this problem according to the time-interleaved described time interval.
Be subjected to the infringement of transient motion profile by a small margin thereby have the pulse-length modulation optical projection system that a plurality of images that produce each primary colours in each frame time interim produce the above-mentioned type of colour pictures through regular meeting, for example with scene in motion or those profiles of being associated of beholder's eyes.Such puppet resembles the variation that is derived from the light pulse distribution of passing different display cycle parts.
United States Patent (USP) 5,986,640 disclose a kind of by cutting apart the scheme that the highest significant bit in the pulse width segment sequence between two or more time adjacent segment (time interval) reduces motion outline.Although this scheme is used to reduce profile, it can not eliminate the profile in all transition.In addition, come partition bit can increase the number of times that must carry out addressing, increased the bandwidth that realizes that this addressing is required thus each pixel according to the mode that is enough to reduce profile.
Therefore, need a kind of operating impulse width modulated technique for displaying that is used for,, overcome the problems referred to above of prior art simultaneously to reduce motion outline.
Summary of the invention
According to present principles, a kind of method that is used for operating impulse width modulated display system has been proposed, for example adopted the pulse width modulated display system of digital micromirror device (DMD), optionally will reflex on the display screen from the light of light source by projecting lens.In this display system, the illumination at each pixel of given color is controlled in the pulse in the sequence of response pulse duration section.The state of each pulse in each section has determined during the time interval of pulsion phase association therewith, whether described pixel is illuminated.In order to reduce the incidence of motion outline, increase the brightness of pixel by activating (actuate) selected pulse, thereby in first scope of the intensity level between first and second pixel brightness boundary, (large-duration) pulse of first duration (or combination of pulse) becomes activation, to reach second pixel brightness boundary.In second scope of the pixel brightness level between the second and the 3rd pixel brightness boundary, first duration pulse (or combination of pulse) keeps activating, and when reaching the 3rd pixel brightness boundary, second largest duration pulse (or combination of pulse) also becomes activation, and wherein first duration pulse keeps activating.
Increase along with pixel brightness, when the more high pixel brightness boundaries that reaches in succession, another still unactivated big duration pulse (or combination of pulse) becomes activation, and wherein each big duration pulse (or combination of pulse) that has been activated keeps activating.Each big duration pulse (or combination of pulse) that will become activation at each pixel brightness boundary place is called " thermometer code (thermometer code) " pulse, this is because in case be activated, this pulse (or combination of pulse) keeps activating, simultaneously also according to mercury thermometer on the similar mode of temperature level, on this brightness boundaries, increase pixel brightness.Depend on the width (that is, the duration) of each pulse in each section, given section can comprise this thermometer code pulses more than.Yet when increasing pixel brightness when reaching given pixel brightness boundary, the single thermometer code pulses of deactivation has changed state (that is, becoming activation) before having only.On the contrary, when pixel brightness is reduced to given pixel brightness boundary, have only the single thermometer code pulses that has activated to become deactivation now, wherein still will be kept thus activating by other thermometer code pulses of deactivation.
Description of drawings
Fig. 1 shows the block diagram of present pulse width modulated display system;
Fig. 2 shows the front view of the color wheel of the part display system that comprises Fig. 1; And
Fig. 3-7 has demonstrated in the concentrated area pulse diagram of present principles, and described pulse diagram shows each in a plurality of sequences of pulse width segment, is used for the display system at Fig. 1, and for given color, the brightness of the corresponding color of one of control pixel is to reduce motion outline.
Embodiment
Fig. 1 shows application report " the veneer DLP that publishes June calendar year 2001 in Texas Instrument
TMThe optical projection system optical device " in the present pulse width modulated display system 10 of open type, at this it is merged reference.System 10 comprises the lamp 12 of the focus that is positioned at paraboloidal reflector 13, and paraboloidal reflector 13 reflexes to integrator rod (integrator rod) 15 from lamp by color wheel 14 with light.Motor 16 rotary color wheel discs 14 are so that be provided with an independently red, green and blue primary color windows between lamp 12 and integrator rod 15.In exemplary embodiments shown in Figure 2, color wheel 14 has red, green and blue color windows 171 and 174,172 and 175 and 173 and 176 relative respectively on diameter.Therefore, when motor 16 during according to the color wheel 14 of counter clockwise direction rotation diagram 2, red, green and blue light can arrive the integrator rod 15 of Fig. 1 according to the order of RGBRGB.In practice, motor 16 is with sufficiently high speed rotary color wheel disc 14, so that 1/60 second frame time interim, each in the red, green and blue light arrived integrator rod five times, has produced 15 width of cloth coloured images in the frame time interval.Exist and to be used for providing continuously three primary colours each other mechanism.For example, colored (scrolling) mechanism (not shown) that rolls also can be carried out this task.
With reference to figure 1, when its during by one in the continuous red, green and blue color window of color wheel 14, integrator rod 15 will focus on from the light of lamp 12 on one group of relay optics 18.Relay optics 18 is separated into a plurality of parallel beams that arrive folding mirror 20 with light, and folding mirror 20 arrives beam reflection on total internal reflectance (TIR) prism 23 by one group of lens 22.TIR prism 23 reflexes to digital micro-mirror (DMD) 24 with parallel beam, and for example the DMD equipment of being made by Texas Instrument is used for optionally reflexing to projecting lens 26 and screen 28.
DMD24 adopts has the form of the semiconductor equipment that is arranged on a plurality of individual mirrors (not shown) in the array.As an example, the DMD that is made and sold by Texas Instrument has the reflection mirror array that 1280 row are taken advantage of 720 row, has produced 921,600 pixels of the dependent picture that projects on the screen 28.Other DMD can have different catoptron settings.As previously mentioned, be latched in the state of the binary bits in the actuator unit before the response, under the control of respective drivers unit (not shown), each micro-reflector among the DMD rotates relevant limited radian.Each micro-reflector rotates respectively and depends on that the latched bit that is applied to actuator unit is first and second positions of " 1 " or " 0 ".When being diverted its primary importance, each micro-reflector light is reflexed in the lens 26 and screen 28 on, to illuminate corresponding pixel.When each micro-reflector kept turning to its second place, corresponding pixel presented dark.Each micro-reflector reflexes to time interval (micro-reflector duty cycle) on the screen 28 by projecting lens 26 with light and has determined the brightness of pixel therebetween.
Standalone Drives unit among the DMD24 receives the drive signal from the drive circuit 30 of type known in this field, described driving circuit is with paper " High Definition DisplaySystem Based on Micromirror Device ", and the circuit described in the R.J.Grove et al.InternationalWorkshop on HDTV (in October, 1994) (being merged reference at this) is an example.Drive circuit 30 produces the drive signal that is used for the DMD24 actuator unit according to the pulse width segment sequence that is applied to drive circuit by processor 31.Each pulse width segment comprises the train of impulses of various durations, and the state of each pulse has determined that micro-reflector is held open or closes in the duration of this pulse.Typically, in a pulse width segment (sometimes being known as least significant bit (LSB) or LSB) but in the shortest energy impulse that can occur (promptly, the 1-pulse) have duration of 15 microseconds, and each the big pulse in the section has the duration of the integral multiple in the LSB time interval.In fact, each pulse in the pulse width segment and its state have determined that respective pulses is that a bit in unlatching or the digital bit stream of closing is corresponding.The be activated pulse of (unlatchings) of a bit " 1 " expression, and a bit " 0 " is represented by the pulse of deactivation (closing).
By wherein showing the following example of Fig. 1 midfield sequence system of each primary colours, can understand the motion outline Method for minimization of present principles well according to five pulse width segment.Each pulse width segment has the overall width of 51 LSB, therefore each sequence of five pulse width segment has the total pulse widths of 255 LSB, thus, have the given color of 15 milliseconds of duration for each LSB (1-pulse) typical case, can make each pixel have one of 256 intensity levels.Therefore, the pulse width segment of each 51LSB has 765 milliseconds duration.
Table 1 shows in each of five sections that comprise pulse width sequence, the setting of LSB.
Table 1
| Section | Pulse width (LSB) |
| | ?7??4??13??2??13??6??6 |
| | ?7??7??13??1??13??4??6 |
| Section 3 | ?7??4??13??2??13??6??6 |
| | ?7??7??13??1??13??4??6 |
| Section 5 | ?7??4??13??2??13??6??6 |
According to present principles, the adjacent minimum effective bit (that is, the 1-pulse) at brightness changes when one or more other pulses become activation, makes the motion outline minimum by number and the width minimum that makes the pulse that becomes deactivation.In fact, in order to increase pixel brightness, selected pulse in activating one or more sections, thereby at each pixel brightness boundary place in succession, another still unactivated big duration pulse (promptly, in the embodiment of demonstration is the 13-pulse, or the combination of pulse, for example 7-pulse and 6-pulse) become activation.In addition, when reaching previous pixel brightness boundary, the big duration pulse of each that is activated before (or combination of pulse) keeps activating.To become activation and be called " thermometer code " pulse with each the big duration pulse (or combination of pulse) that reaches given pixel brightness boundary, this is because in case be activated, this thermometer code pulses keeps activating, simultaneously also according to mercury thermometer in the similar mode of mercury, on this pixel brightness boundary, increase pixel brightness.(when reaching particular temperature level, the increase of response temperature, mercury continues to be elevated on this level).According to the width (that is, the duration) of each pulse in each section, given pulse width segment can have a plurality of thermometer code pulses.
Fig. 3-6 shows the pulse diagram of pulse width segment sequence in the mode of combination, and described pulse width segment sequence has been represented to be among the intensity level #0-#255 the corresponding pixel at given color of each.In an illustrated embodiment, select section 3 to be activated as its thermometer code pulses first section, wherein along with pixel brightness is increased on this boundary, being activated keeps activating with each thermometer code pulses that reaches pixel brightness boundary.As shown in Figure 3, reach intensity level # 1 and need activate the 1-pulse.Because section 3 does not have the 1-pulse in this example, activate the 1-pulse in the section 2.In order to reach pixel brightness level # 2, at this intensity level place, the 2-pulse in the section 3 becomes activation, the 1-pulse deactivation in the section 2.In order to reach pixel brightness level #3, the 2-pulse in 1-pulse in the section 2 and the section 3 becomes activation.
In order to reach intensity level # 4, at this intensity level place, the 4-pulse in the section 3 becomes activation, the pulse deactivation of Ji Huoing before.In order to reach pixel brightness level #5 each in the #12, select one of 4-pulse, 2-pulse and 6-pulse (first) in the section 3, and the 1-pulse in the section 2 becomes activation.Reach intensity level 13# (having constituted first pixel brightness boundary), all other pulses at this pixel brightness level place of deactivation by the 13-pulse (first) that activates in the section 3.
In order to reach intensity level # 14, activate the 1-pulse in the section 3, the 13-pulse (first) in the section 3 keeps activating.Therefore, on first pixel brightness boundary (intensity level #13), the 13-pulse (first) in the section 3 keeps activating.Therefore, the 13-pulse (first) in the section 3 has constituted first thermometer code pulses in becoming the section of activation.1-pulse in by keeping the 13-pulse activation in the section 3 and activate that 4-pulse, 2-pulse and 6-pulse (first) from section 3 select one and the section 2 has realized each among the intensity level #14-#25.At intensity level # 26 place (having constituted second pixel brightness boundary), the 13-pulse (second) in the section 3 becomes activation, and the 13-pulse (first) in the same section keeps activating.At pixel brightness level #27, two the 13-pulses (first and second) in the section 3 all keep activating, now the 1-pulse activation in the section 2 at this intensity level place.Therefore, the 13-pulse (second) in the section 3 has constituted second thermometer code pulses in becoming the section of activation.
By keeping two the 13-pulses (first and second) in the section 3 to activate, and activate one that selects in of selecting in 7-pulse, 4-pulse, 2-pulse and the 6-pulse from section 3 and the 7-pulse from section 2,1-pulse and the 4-pulse, realized each among the intensity level #28-#61.At intensity level #37 place, activate 7-pulse and 6-pulse (second) in the section 3, along with the increase of pixel brightness level, these pulses all keep activating.Therefore, 7-pulse and 6-pulse (second) have constituted combination temp meter code pulse together in the section 3.Notice that at pixel brightness level #51 place, all pulses in the section 3 become activation.Along with the pixel brightness level increases more than intensity level #51, except the 2-pulse in the section 3, all pulses of other in this section all keep activating.
With reference to figure 4, to locate at pixel brightness level #62 (having constituted adjacent more high pixel brightness boundaries), other all pulses in 13-pulse (first) in the section 2 and the section 3 except the 2-pulse all become activation.In order to reach pixel brightness level #63, activate the 1-pulse in the section 2, all other pulses in 13-pulse (first) in the section 2 and the section 3 except the 2-pulse all keep activating.Therefore, the 13-pulse (first) in the section 2 becomes first thermometer code pulses in this section that is activated.
By the pulse of selection in the activation section 2 and the 2-pulse in the section 3, the further increase that has realized pixel brightness is to reach one of intensity level #63-#74 of Fig. 4, the thermometer code pulses (being 13-pulse (first)) that activated before in its stage casing 2 keeps activating, and all pulses of other in the section 3 keep activating.In order to reach intensity level #75, all pulses in thermometer code pulses that is activated before in the 13-pulse (second) in the section 2, this section and the section 3 except the 2-pulse become activation.Therefore, when reaching relevant pixel brightness boundary, the 13-pulse (second) in the section 2 has constituted second thermometer code pulses in this section that is activated, and increases more than the pixel brightness boundary at this at pixel brightness, keeps activating.
As now understood, in case be activated to reach relevant pixel brightness boundary, for adjacent more high pixel intensity level, big pulse of each in each section (for example 13-pulse) or concentrated combination (for example 7-pulse and the 6-pulse (second) in the section 3) the maintenance activation that comprises the pulse of big duration pulse.Therefore, according to present principles, each this pulse (or combination of pulse) has constituted thermometer code pulses.In the reality, each thermometer pulse has enough big characteristic (that is, having the sufficiently long duration), therefore in case be activated to reach pixel brightness boundary, pulse keeps activating at this intensity level place more than pixel brightness boundary, has limited the pulse sum in the section simultaneously.In other words, at given pixel brightness boundary place, along with pixel brightness is increased on this boundary, single thermometer code pulses (or this pulse combined that comprises thermometer code pulses) becomes and is activated and keeps activating.On the contrary, be reduced to given pixel brightness boundary, have only single thermometer code pulses to become deactivation, also do not have the thermometer code pulses of deactivation to keep activating, up to having reached adjacent lower pixel brightness boundary for pixel brightness.Yet, each thermometer code pulses in each section should be not excessive, so that when being activated or during deactivation, the increment of pixel brightness changes (promptly, it is more senior that pixel brightness is increased to the next one, or pixel brightness is reduced to next even lower level) tangible transition can appear.
In addition, the selection of thermometer code pulses should be used for " exchange " with pulse and is limited in fact individual pulse width section (that is the selection of the pulse that, is activated) to reach specific luminance state.Yet " exchange " that will pulse is limited in fact individual pulse width section (that is the binary pulse setting of modification) to obtain advantage of the present invention.As long as the single thermometer code pulses (or combination of pulse) in single section becomes and activates or become deactivation between adjacent pixel brightness boundaries, the pulse exchange that then is used to reach particular luminance level can appear between a plurality of sections.
The front has illustrated and has been used for showing the technology that makes the motion outline minimum in pulse-length modulation.
Claims (20)
1. the method for an operating impulse width modulated display system, described display system has a plurality of pixels, for given color, pulse in the response pulse duration section sequence in each section, control the illumination of each pixel, wherein the state of each pulse in each section has determined whether described pixel is illuminated during the time interval related with this pulsion phase, and described method comprises step:
Activate selected pulse to increase the brightness of pixel, thereby in first scope of the pixel brightness level between first and second pixel brightness boundary, first duration pulse element becomes activation, to reach second pixel brightness boundary, and in second scope of the pixel brightness level between the second and the 3rd pixel brightness boundary, first duration pulse element keeps activating, and when reaching the 3rd pixel brightness boundary, second largest duration pulse element becomes activation, and simultaneously first duration pulse element keeps activating.
2. method according to claim 1, it is characterized in that the first and second big duration pulse elements one of them comprises individual pulse at least.
3. method according to claim 1, it is characterized in that the first and second big duration pulse elements one of them comprises the combination of pulse at least.
4. method according to claim 1, it is characterized in that selecting the duration of each big duration pulse element, so that increase pixel brightness and reach the relevant moment minimum of pixel brightness boundary with increasing progressively, and make the pulse number in each section minimum.
5. method according to claim 1 is characterized in that at least one pair of big duration pulse element is arranged in same section.
6. method according to claim 1 is characterized in that at least one pair of big duration pulse element is arranged in different sections.
7. method according to claim 1 is characterized in that the pulse that will be activated to increase pixel brightness is limited in the same section in fact.
8. the method for an operating impulse width modulated display system, described display system has a plurality of pixels, for given color, pulse in the response pulse duration section sequence in each section, control the illumination of each pixel, wherein the state of each pulse in each section has determined whether described pixel is illuminated during the time interval related with this pulsion phase, and described method comprises step:
Reduce the brightness of pixel by the selected pulse of deactivation, thereby in given pixel brightness boundary, the first duration pulse element that has been activated becomes deactivation now, and in adjacent lower pixel brightness boundary, first duration pulse element keeps deactivation, second largest duration pulse element becomes deactivation, and each big duration pulse element that is activated before of deactivation not yet keeps activating.
9. method according to claim 8, it is characterized in that the first and second big duration pulse elements one of them comprises individual pulse at least.
10. method according to claim 8, it is characterized in that the first and second big duration pulse elements one of them comprises the combination of pulse at least.
11. method according to claim 8, it is characterized in that selecting the duration of each big duration pulse element, so that reach the relevant moment minimum of pixel brightness boundary, and make the pulse number in each section minimum with the little pixel brightness of monotone decreasing.
12. method according to claim 8 is characterized in that described big duration pulse element is arranged in same section.
13. method according to claim 8 is characterized in that described big duration pulse element is arranged in different sections.
14. method according to claim 8 is characterized in that and will be limited in the same section in fact by the pulse of deactivation.
15. a pulse width modulated display system comprises:
Light source;
Projecting lens is used for incident light is focused on screen;
Digital micromirror device, has a plurality of independent micro-reflector that is arranged in the array, each micro-reflector response is applied to the reception of the drive signal of the actuator unit that is associated with micro-reflector, rotate relevant radian, so as will to reflex to from the light of light source in the projecting lens and screen on, thereby illuminate one of them picture element (pixel);
Be used for continuously each device that gives digital micromirror device and be reflected to projecting lens with three primary colours;
Processor, be used to form the sequence of pulse width segment, to increase the brightness of pixel by activating selected pulse, thereby in first scope of the intensity level between first and second pixel brightness boundary, first duration pulse element becomes activation, to reach second pixel brightness boundary, and in second scope of the pixel brightness level between the second and the 3rd pixel brightness boundary, first duration pulse element keeps activating, and when reaching the 3rd pixel brightness boundary, second largest duration pulse element becomes activation, and simultaneously first duration pulse element keeps activating; And
Drive circuit, the sequence of the pulse width segment that response is formed by processor is used to drive digital micromirror device, to illuminate the pixel of correspondence.
16. system according to claim 15, it is characterized in that the first and second big duration pulse elements one of them comprises individual pulse at least.
17. system according to claim 15, it is characterized in that the first and second big duration pulse elements one of them comprises the combination of pulse at least.
18. a pulse width modulated display system comprises:
Light source;
Projecting lens is used for incident light is focused on screen;
Digital micromirror device, has a plurality of independent micro-reflector that is arranged in the array, each micro-reflector response is applied to the reception of the drive signal of the actuator unit that is associated with micro-reflector, rotate relevant radian, so as will to reflex to from the light of light source in the projecting lens and screen on, thereby illuminate one of them picture element (pixel);
Be used for continuously each device that gives digital micromirror device and be reflected to projecting lens with three primary colours;
Processor, be used to form the sequence of pulse width segment, to reduce the brightness of pixel by the selected pulse of deactivation, thereby at the first pixel brightness boundary place, the first duration pulse element that has been activated becomes deactivation now, and in the adjacent second lower pixel brightness boundary, first duration pulse element keeps deactivation, second largest duration pulse element becomes deactivation, and other the big duration pulse element that is activated before that is activated not yet keeps activating; And
Drive circuit, the sequence of the pulse width segment that response is formed by processor is used to drive digital micromirror device, to illuminate the pixel of correspondence.
19. system according to claim 18, it is characterized in that the first and second big duration pulse elements one of them comprises individual pulse at least.
20. system according to claim 18, it is characterized in that the first and second big duration pulse elements one of them comprises the combination of pulse at least.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US40319002P | 2002-08-13 | 2002-08-13 | |
| US60/403,190 | 2002-08-13 | ||
| US10/354,528 | 2003-01-30 | ||
| US10/354,528 US6781737B2 (en) | 2002-08-13 | 2003-01-30 | Pulse width modulated display with hybrid coding |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1685276A true CN1685276A (en) | 2005-10-19 |
| CN100396105C CN100396105C (en) | 2008-06-18 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB038191946A Expired - Fee Related CN100396105C (en) | 2002-08-13 | 2003-08-11 | Pulse width modulated display with hybrid coding |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP1546794A4 (en) |
| JP (1) | JP2006508378A (en) |
| KR (1) | KR101015029B1 (en) |
| CN (1) | CN100396105C (en) |
| AU (1) | AU2003265408A1 (en) |
| MX (1) | MXPA05001668A (en) |
| WO (1) | WO2004015981A2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101495948B (en) | 2006-06-02 | 2012-02-01 | 化合物光子学有限公司 | Pulse width driving method using multiple pulse |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5185602A (en) * | 1989-04-10 | 1993-02-09 | Cirrus Logic, Inc. | Method and apparatus for producing perception of high quality grayscale shading on digitally commanded displays |
| EP0698874B1 (en) * | 1994-07-25 | 2001-12-12 | Texas Instruments Incorporated | Method for reducing temporal artifacts in digital video systems |
| US6204834B1 (en) * | 1994-08-17 | 2001-03-20 | Si Diamond Technology, Inc. | System and method for achieving uniform screen brightness within a matrix display |
| JP3790277B2 (en) * | 1994-11-24 | 2006-06-28 | テキサス インスツルメンツ インコーポレイテツド | Pulse width modulation digital display pixel intensity adjustment method and display system to which this method is applied |
| US5818419A (en) * | 1995-10-31 | 1998-10-06 | Fujitsu Limited | Display device and method for driving the same |
| EP0865210B1 (en) * | 1997-03-12 | 2006-07-26 | Texas Instruments Incorporated | Colour-sequential video display system |
| JP2994631B2 (en) * | 1997-12-10 | 1999-12-27 | 松下電器産業株式会社 | Drive pulse control device for PDP display |
| US6618031B1 (en) * | 1999-02-26 | 2003-09-09 | Three-Five Systems, Inc. | Method and apparatus for independent control of brightness and color balance in display and illumination systems |
| JP2000259126A (en) * | 1999-03-04 | 2000-09-22 | Matsushita Electric Ind Co Ltd | Gradational display method |
| JP4008178B2 (en) | 1999-03-04 | 2007-11-14 | 松下電器産業株式会社 | Gradation display method |
| AU1320502A (en) * | 2000-10-12 | 2002-04-22 | Reveo Inc | Digital light processing based 3d projection system and method |
-
2003
- 2003-08-11 KR KR1020057002532A patent/KR101015029B1/en active IP Right Grant
- 2003-08-11 JP JP2004528034A patent/JP2006508378A/en active Pending
- 2003-08-11 WO PCT/US2003/025119 patent/WO2004015981A2/en active Search and Examination
- 2003-08-11 CN CNB038191946A patent/CN100396105C/en not_active Expired - Fee Related
- 2003-08-11 EP EP03785185A patent/EP1546794A4/en not_active Withdrawn
- 2003-08-11 MX MXPA05001668A patent/MXPA05001668A/en active IP Right Grant
- 2003-08-11 AU AU2003265408A patent/AU2003265408A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP1546794A2 (en) | 2005-06-29 |
| CN100396105C (en) | 2008-06-18 |
| WO2004015981A3 (en) | 2005-04-14 |
| AU2003265408A8 (en) | 2004-02-25 |
| WO2004015981A2 (en) | 2004-02-19 |
| AU2003265408A1 (en) | 2004-02-25 |
| EP1546794A4 (en) | 2007-03-07 |
| JP2006508378A (en) | 2006-03-09 |
| KR101015029B1 (en) | 2011-02-16 |
| KR20050050644A (en) | 2005-05-31 |
| MXPA05001668A (en) | 2005-04-19 |
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