EP1072033A1 - Dispositif de commande d'affichage comprenant des modes d'economie de la consommation d'energie - Google Patents

Dispositif de commande d'affichage comprenant des modes d'economie de la consommation d'energie

Info

Publication number
EP1072033A1
EP1072033A1 EP99915946A EP99915946A EP1072033A1 EP 1072033 A1 EP1072033 A1 EP 1072033A1 EP 99915946 A EP99915946 A EP 99915946A EP 99915946 A EP99915946 A EP 99915946A EP 1072033 A1 EP1072033 A1 EP 1072033A1
Authority
EP
European Patent Office
Prior art keywords
display
pixels
control device
display control
power
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP99915946A
Other languages
German (de)
English (en)
Inventor
Jeremy Henley Burroughes
Richard Henry Friend
Karl Pichler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cambridge Display Technology Ltd
Original Assignee
Cambridge Display Technology Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB9808016.1A external-priority patent/GB9808016D0/en
Application filed by Cambridge Display Technology Ltd filed Critical Cambridge Display Technology Ltd
Publication of EP1072033A1 publication Critical patent/EP1072033A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • G09G3/22—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 using controlled light sources
    • G09G3/30—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 using controlled light sources using electroluminescent panels
    • G09G3/32—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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • G09G3/3225—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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix
    • G09G3/3233—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 using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix with pixel circuitry controlling the current through the light-emitting element
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
    • G06F1/26—Power supply means, e.g. regulation thereof
    • G06F1/32—Means for saving power
    • G06F1/3203—Power management, i.e. event-based initiation of a power-saving mode
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F1/00—Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00
    • G06F1/26—Power supply means, e.g. regulation thereof
    • G06F1/32—Means for saving power
    • G06F1/3203—Power management, i.e. event-based initiation of a power-saving mode
    • G06F1/3206—Monitoring of events, devices or parameters that trigger a change in power modality
    • G06F1/3215—Monitoring of peripheral devices
    • G06F1/3218—Monitoring of peripheral devices of display devices
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators
    • G09G5/10—Intensity circuits
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
    • G09G2300/0809—Several active elements per pixel in active matrix panels
    • G09G2300/0842—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor
    • 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
    • G09G2320/04—Maintaining the quality of display appearance
    • G09G2320/043—Preventing or counteracting the effects of ageing
    • G09G2320/046—Dealing with screen burn-in prevention or compensation of the effects thereof
    • 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
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0626—Adjustment of display parameters for control of overall brightness
    • 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
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0686—Adjustment of display parameters with two or more screen areas displaying information with different brightness or colours
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G09G2330/021—Power management, e.g. power saving
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G09G2330/021—Power management, e.g. power saving
    • G09G2330/022—Power management, e.g. power saving in absence of operation, e.g. no data being entered during a predetermined time
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2360/00—Aspects of the architecture of display systems
    • G09G2360/14—Detecting light within display terminals, e.g. using a single or a plurality of photosensors
    • G09G2360/144—Detecting light within display terminals, e.g. using a single or a plurality of photosensors the light being ambient light
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2370/00—Aspects of data communication
    • G09G2370/04—Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller
    • 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
    • G09G3/2011—Display of intermediate tones by amplitude modulation
    • 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
    • G09G3/2092—Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto
    • 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
    • G09G3/22—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 using controlled light sources

Definitions

  • This invention relates to display controllers and methods for controlling light- emissive displays, particularly with the aim of reducing power consumption.
  • Display devices for general applications typically have a matrix of pixels arranged orthogonally in rows and columns.
  • the pixels are individually controllable by a display controller device which is connected to the display so as to be able to address and control the state of each pixel individually.
  • a display controller device which is connected to the display so as to be able to address and control the state of each pixel individually.
  • the display is battery-powered and is formed with light-emissive pixels provided by devices such as LEDs, field emission devices or organic or inorganic electroluminescent devices.
  • One aim of this invention is to allow the efficiency of display devices to be enhanced by improvements to the methods and/or means of controlling the devices.
  • a display control device for a light-emissive display, comprising: input means for receiving display data defining a visual display pattern; processing means for processing the display data to generate control data for controlling the pixels of the display and having a first, normal mode of operation in which it controls the pixels to display the pattern as defined by the display data, and a second, power-saving mode of operation in which it controls a set of pixels of the display to operate with reduced power consumption whilst maintaining display of the pattern; and output means for connection to the pixels to transmit the control data to the pixels.
  • a display control device for a light-emissive display, comprising: input means for receiving display data defining a visual display pattern; processing means for processing the display data to generate control data for controlling the pixels of the display and having a first, normal mode of operation in which it controls the pixels to display the pattern as defined by the display data, and a second, power-saving mode of operation in which it controls a set of pixels of a part of the area of the display to operate with reduced power consumption; and output means for connection to the pixels to transmit the control data to the pixels.
  • the set of pixels may comprise all or only some of the pixels of the display. When the set of pixels comprises only some of the pixels of the display they are preferably adjacent pixels.
  • the set of pixels preferably represents a user interface area of the display (e.g. a menu or icon) or an area of the display that is occupied by text.
  • the pixels of the set are suitably controlled so as to invert their brightnesses in comparison to the normal mode of operation (suitably whilst maintaining the relative contrast of the pixels of the set) or to reduce their brightnesses of the pixels in comparison to the normal mode of operation (suitably whilst reducing the relative contrast of the pixels of the set).
  • the display control device may itself determine when to enter or leave the power- saving mode, or it may receive instructions to do so from another device.
  • the display control device may comprise monitoring means for monitoring (directly or indirectly) the operation of user input means (e.g. a mouse or keyboard) of an associated device (suitably the device that generates the display data).
  • the display control device may also include timing means for timing the duration since the last operation of the user input means and causing the processing means to enter the power saving mode of operation when longer than a predetermined duration has elapsed.
  • the monitoring means may be capable of causing the processing means to enter the normal mode of operation in response to operation of the user input means. Where the set of pixels represent a localised region of the display (e.g. a user interface region) the monitoring means may cause the processing means to enter the normal mode of operation in response to movement by the user interface means of a pointer (e.g. a mouse pointer or a cursor) to or near to that localised region.
  • a pointer e.g.
  • the pixels other than those of the said set are preferably controlled as in the normal mode of operation.
  • two or more sets of pixels of the display may be controlled in similar or different power-saving schemes.
  • the pattern is preferably a pattern of differentiated pixel brightness.
  • relative differences in brightness are preferably maintained.
  • a display control device as described above and a display.
  • the display preferably comprises a plurality of pixels.
  • the pixels may be disposed in an orthogonal grid layout, or in other regular layouts, or irregularly disposed.
  • the display is preferably a light-emissive display, preferably an organic light- emissive display.
  • the pixels preferably comprise light-emissive regions which suitably comprise an organic light-emissive material for light emission and/or thin- film transistor control circuitry.
  • One preferred structure for a pixel is that it comprises a layer of organic light-emissive material between two charge-carrier injecting layers - suitably anode and cathode electrodes.
  • One of the charge carrier injecting layers preferably has a work function of greater than 4.3 eV.
  • That layer may comprise a metallic oxide such as indium-tin oxide ("ITO") or tin oxide ("TO").
  • the other charge carrier injecting layer (the electron injecting layer) preferably has a work function less than 3.5 eV.
  • That layer may suitably be made of a metal with a low work function (Ca, Ba, Yb, Sm, Li etc.) or an alloy comprising one or more of such metals together optionally with other metals (e.g. Al).
  • At least one of the electrode layers is suitably light transmissive, and preferably transparent, suitably at the frequency of light emission from the pixel.
  • the transport layer may suitably comprise one or more polymers such as polystyrene sulphonic acid doped polyethylene dioxythiophene ("PEDOT-PSS”) and/or poly(2,7-(9,9-di-n- octylfluorene)-(1 ,4-phenylene-(4-imino(benzoic acid))-1 ,4-phenylene-(4- imino(benzoic acid))-1 ,4-phenylene)) (“BFA”) and/or polyaniline and/or PPV.
  • PEDOT-PSS polystyrene sulphonic acid doped polyethylene dioxythiophene
  • BFA polyaniline and/or PPV
  • the light-emissive layer may comprise one or more organic materials, suitably polymers, preferably conjugated or partially conjugated polymers. Suitable materials include poly(p-phenylenevinylene) (“PPV”), poly(2-methoxy-5(2'- ethyl)hexyloxyphenylene-vinylene) (“MEH-PPV”), a PPV-derivative (e.g.
  • a di- alkoxy or di-alkyl derivative a polyfluorene and/or a co-polymer incorporating polyfluorene segments, PPVs and/or related co-polymers
  • poly (2,7-(9,9-di-n- octylfluorene)-(1 ,4-phenylene-((4-secbutylphenyl)imino)-1 ,4-phenylene)) ("TFB")
  • PFM poly(2,7 - (9,9 - di-n-octylfluorene) - (1 ,4-phenylene-((4-me
  • the processing means is suitably responsive to a photo-detector to enter the power- saving mode, or to reduce the brightness of all or part of the display, when the photo-detector detects a brightness lower than a predetermined threshold.
  • the processing means may perform other processing in dependence on the output of the photo-detector.
  • the threshold may represent one step in a more complex power saving routine performed in dependence on the output of the photo-detector: for example, the power of the display could be reduced gradually as the detected light decreases.
  • the photo-detector is preferably arranged to detect a representation of the light incident on the display. One step in achieving this is preferably for the detector to be optically isolated from the light emitted from the display.
  • the processing means may be responsive to one or more such photo-detectors.
  • the or each photo-detector is located in the display, for instance as a pixel of the display, but other solutions are possible, as described below. Regions of the display may be controlled independently in dependence on one or more photo- detectors.
  • the display and/or the display controller are suitably battery-powered and/or adapted for being battery-powered.
  • figure 1 shows a plan view of some of the pixels of an organic light-emissive display device
  • figure 2 shows a cross-section of the device on the line A-A' in figure 1 to illustrate the structure of one of the pixels
  • figure 3 shows a circuit diagram of the pixel of figure 2
  • figure 4 shows a schematic diagram of a multi-pixel device and its control apparatus
  • figure 5 shows a typical computer screen display.
  • Figure 1 shows some of the pixels of an organic light-emitting display device.
  • the pixels are arranged in orthogonal rows and columns. Typical sizes for the entire display range from 100x100 pixels to 1000x1000, but larger or smaller sizes, and sizes with unequal numbers of pixels on each side are possible.
  • FIG. 2 shows a cross section of pixel unit 1 in figure 1.
  • the display is formed on a light-transmissive substrate 10, such as a glass sheet.
  • a light-transmissive substrate 10 such as a glass sheet.
  • TFT thin-film transistor
  • the active matrix circuitry will be described in more detail below.
  • the active matrix circuitry terminates in an anode electrode 12.
  • the anode electrode is of a light-transmissive conductive material such as indium-tin oxide (ITO).
  • ITO indium-tin oxide
  • a bank layer 13 of an insulating material such as SiO 2 is deposited over the TFT circuitry and is patterned as shown, to leave holes through the bank layer over the anode electrodes. Then an organic light-emissive material 14 is deposited.
  • the organic material could be deposited as a layer over the whole device (e.g. by spin-coating a precursor polymer) and then patterned to form individual pixels or areas of pixels; or the pixels/areas could be deposited individually (e.g. by ink-jet printing), especially when forming a multi-colour (e.g. red/green/blue) device with pixels which each emit different colours of light.
  • the resulting layer of organic material is around 1000A thick.
  • To deposit the light- emitting material by ink-jet printing the material may be sprayed through an ink-jet printer spray head. A suitable spraying cycle is 14,400 drops per second, with a drop volume of 30pl. Finally, a cathode electrode 15, for example of a aluminium:lithium alloy, is deposited over the whole device.
  • PPV poly(p-phenylenevinylene)
  • MEH-PPV poly(2-methoxy-5(2'-ethyl) hexyloxyphenylene-vinylene)
  • Akt ⁇ tris(8-hydroxyquinoline)aluminium
  • FIG. 3 shows a circuit diagram for the TFT circuitry associated with the pixel unit 1.
  • the light-emissive region itself is illustrated as block 14, which is connected between electrodes 12 and 15.
  • the TFT circuitry receives inputs from three lines: row electrode 20, column electrode 21 and current supply electrode 22.
  • Current supply electrode 22 is connected to the TFT circuits of all the pixels of the display device and a voltage sufficient for emission from the pixels of the display is applied constantly between it and electrode 15.
  • Each pixel can be addressed individually by its row and column electrodes because any pair of row and column electrodes intersect at a single pixel.
  • the switching transistor 24 is turned on and the storage capacitor 25 is charged. Electrodes 20 and 21 can then be turned off and another pixel addressed.
  • the current transistor 26 Since the capacitor 25 is charged the current transistor 26 is switched on and the voltage applied at electrode 23 is applied to the pixel, causing it to emit.
  • the brightness of the pixel can be controlled by controlling the charging of capacitor 25 (and therefore the turn-on state of transistor 26) by means of electrodes 21 and 22.
  • FIG 4 shows an arrangement for controlling the display device 2.
  • the display device is connected to a display controller 30, which acts as an interface between the display device and a source of video data such as a computer 31. (The display controller could be integrated with the display).
  • the computer 31 supplies video data to the display controller by means of line 32.
  • the video data defines the visual pattern to be shown on the display.
  • the display controller comprises a processor 33 which receives the video data, a memory 34 which stores instructions for the processor, a memory 35 which is used by the processor as a temporary store and a multiplexer 36 which is connected at 37 to the row and column electrodes of the display 2.
  • the display controller also supplies a constant voltage between the electrodes 23 and 15.
  • Video data from the computer 31 is stored by the processor 33 (on the basis of the instructions stored in memory 34) in a video memory space in memory 35 as information defining the status of each pixel of the display according to the video data.
  • the status may be just "on” or “off, but in a more complex device brightness information may need to be stored and the processor may need to convert colour information in the video feed at 32 into information for individual single-colour (e.g. red, green or blue) pixels.
  • the processor On the basis of the instructions in memory 34 and the interpreted video data in memory 35 the processor also outputs information to the multiplexer 36 to refresh the display.
  • the computer 31 can also send instructions to the processor 30, for example to change its mode of operation.
  • the processor can store information on its mode of operation in the memory 35.
  • the display controller is integrated with the computer 31 (or with an alternative source of video information) the 8
  • processor 30 is suitably able to monitor the status of the computer (or other source), especially to check for events such as key-presses or movements of a mouse.
  • the display controller controls the pixels just as defined by the video data. Unlike typical liquid crystal displays (LCDs) the power used by each pixel of this device is not independent of the pixel's brightness. By exploiting this feature the display controller implements several functions that can be used to reduce power consumption by the display.
  • LCDs liquid crystal displays
  • the display controller is capable of inverting the brightnesses of all the pixels of the display: changing dim pixels to be bright, off pixels to be on, etc. This can be done (e.g.) under command of the computer 31 or in response to an event such as the operation of a user input device of the computer 31 or in response to a predetermined time elapsing from a certain event or in response to the status of the display itself.
  • Each pixel of the display 2 uses more power the brighter it is. Therefore, when most of the screen is bright, inverting the brightness of the display will save power.
  • the display may be inverted so as to save power (suitably to implement a relatively low background brightness) when (e.g.):
  • a predetermined (e.g. user-set) time elapses from the operation of user input devices of the computer (e.g. a keyboard 39 and/or mouse 40).
  • the display controller detects by monitoring the display status (either from the contents of memory 35 or from the power supplied at 38) that it would save power if the display brightness were inverted. A minimum time delay may be specified between one inversion and the next, so as to reduce flickering of the display. 4. Text is being displayed over a predetermined (e.g. user-set) area of the display.
  • Remaining battery power is below a predetermined (e.g. user-set level).
  • the display may be inverted so as to leave a power saving state when (e.g.):
  • One of the user input devices of the computer is operated.
  • Text is being displayed over less than a predetermined (e.g. user-set) area of the display.
  • the user may configure the system to select which of the circumstances are to cause inversion of the display.
  • the selected circumstances may correspond to a mode of the display controller 30 which can be selected via computer 31.
  • the circumstances may apply in combination - for instance to specify switching to the power saving mode when text is being displayed over a predetermined (e.g. user- set) area of the display and a predetermined time elapses from the operation of user input devices of the computer.
  • an organic electroluminescent display of the type described above may (in text-display applications) be projected to operate at a time-averaged current density as low as 0.1 mA/cm 2 at a drive voltage of less than 10 V, giving a power consumption of less than 1 mW/cm 2 .
  • Figure 5 shows a typical computer display in a MicrosoftTM windows environment.
  • the display includes areas (indicated generally at 40 in figure 5) which represent user interface features such as menus; buttons for controlling windows 41 , controlling program features 42 or activating programs; and standard graphical window features such as menu bars 43, status indicators 44, title bars 45, sliders 46 and toolbars 47.
  • user interface features are commonly displayed in a constant position on the screen, and for much of the time when a computer display is in operation they are not needed by a user.
  • a second power-saving function of the present system is to invert the brightness of, dim (e.g. uniformly reduce the brightness of) or turn off areas of the display that are 10
  • Such a power saving state can be triggered by one or more of a number of events either alone or in combination - when:
  • a predetermined (e.g. user-set) time elapses from the operation of user input devices of the computer (e.g. a keyboard and/or mouse).
  • a predetermined (e.g. user-set) time elapses from the use of the user interface feature in question.
  • the display controller detects by monitoring the display status (from memory 35) that it would save power if the power saving state were used for one or more of the user interface features.
  • a minimum time delay may be specified between one change and the next, so as to reduce flickering.
  • Remaining battery power is below a predetermined (e.g. user-set level).
  • the display of the user interface features may be reverted to its natural state when:
  • One of the user input devices of the computer is operated.
  • a pointer e.g. a mouse pointer
  • a pointer is moved on or near to the feature.
  • Remaining battery power is above a predetermined (e.g. user-set) level, or another power source is available.
  • the user may configure the system to select which of these circumstances are to cause inversion of the display.
  • the selected circumstances may correspond to a mode of the display controller 30.
  • the circumstances may apply in combination.
  • Another advantage of this second power-saving aspect is that it can address the problem that since many user interface features remain in one place on the display for a prolonged time they can accelerate deterioration of the display over heavily used parts of the display ("windows burn-in"). This may be addressed by, for at least part of the time, reducing the intensity of the features or not displaying them at all.
  • the brightness of all the user interface features on the display may be adjusted together or independently.
  • the user interface features may be detected by a pattern-matching routine executed by the processor 33 or by means of direct information sent by the computer 31 to the display controller to inform the display controller specifically of the location of the user interface features.
  • a solution to this problem is to use the level of ambient light as another parameter in determining how the display is to operate.
  • One approach is to install a photo-detector beside the display to measure the incident light; the display controller is then arranged to receive the output of the photo-detector and to be responsive to the photo-detector to increase the brightness of the display as the intensity of incident light detected by the photo-detector increases.
  • a photo-detector beside the display could be a component independent from the display (e.g. fitted to the display surround or packaging) or could be integrated with the display.
  • To integrate the detector with the display it could be deposited on the same substrate as the display and/or share one or more of the other components of the display (e.g. one or more layers of material which make up the display pixels).
  • Such a detector could be an organic, inorganic or hybrid detector, and could have the same structure as the display or a different structure. The detector should ideally be arranged so that the light it detects is directly or indirectly representative of the light incident on the display itself. 12
  • the detector should be optically isolated from the display so that it does not detect light emitted from the display itself. This could be achieved by an opaque barrier between the detector and the display, or by the detector measuring the ambient light when the display is not emitting, for instance during the display's refresh cycle.
  • a more sophisticated solution is to provide a plurality of photo-detectors around the periphery of the display; for example to provide four detectors, one located at each corner of the display. Then the display controller could control the brightness of the display in dependence on the brightnesses detected by all the detectors.
  • One possibility is for the brightness of the whole display to be adjusted in dependence on a function (e.g. an average or maximum) of the brightnesses detected by all the detectors.
  • Another possibility is for the brightness of regions of the display to be adjusted independently, e.g. in dependence on the brightness detected by the detector nearest to that region. In the latter case it would be advantageous to control the brightness at the boundaries between the regions to smooth out differences in display brightness.
  • These solutions could be especially valuable for larger displays (e.g. greater than 10cm x 10cm) where the incident light on the display may be significantly non-uniform over the display's area.
  • a still more advanced solution is to integrate one or more photo-detectors into the display itself.
  • One approach is to use a pixel of the display as a photo-detector. The pixel is stopped from emitting and reverse-biased so that it acts as a photo- detector. The resulting signal is sent to the display controller, possibly via other equipment such as an amplifier, for use as described above.
  • the measurement step is preferably brief, so that light emission by the pixel is not interrupted obtrusively. The measurement step could be performed during the display's refresh cycle, or emission from the entire display or from the pixel(s) that is/are to be used for detection could be stopped temporarily to allow measurement.
  • One or more of the display's pixels could be used in this way, for example a grid of spaced-apart pixels could be used for detection. In large displays this approach is especially 13
  • the step of detecting the ambient light may be performed relatively infrequently (e.g. once every 5 or 10 seconds or longer) because the level of ambient light will rarely change greatly over a short period. Alternatively, the ambient light may be detected more frequently.
  • Detection of ambient light above a pre-set threshold may be another event that can trigger (either by itself or in conjunction with another event) one of the power-saving modes described above.
  • the principles set out above could be combined to provide for a gradual power reduction during inactivity or partial inactivity of a user.
  • the second power saving feature could be implemented to reduce the intensity of one or more user interface features and after a second (longer) time period the first power saving feature could be implemented to invert the brightness of a text area or of all of the display.
  • the display could be turned off.
  • a passive matrix display (where each pixel is connected between its row and column lines and is driven directly by them with no storage circuitry) could be used.
  • the organic light-emissive pixels could be replaced by inorganic light-emissive pixels.
  • Alternative devices for the pixels include field emission devices, inorganic electroluminescent devices and, generally, LED devices.
  • the pixels could be used as backlights for one or more LCD pixels of an overlain LCD display plane.
  • the pixels could be of different shapes (for example of special part-character shapes) or laid out in different array configurations (non-orthogonal, for example); one specific example is alpha-numeric character displays.
  • the display could be monochrome or colour (for instance with pixels in groups of red, green and blue).
  • the unit described as computer 31 above could, for example, be a portable or desktop personal computer, a portable digital assistant ("PDA”) or a mobile phone.
  • PDA portable digital assistant
  • the operations of user input devices referred to above could be any suitable operation - for example movement of a mouse or pressing of any key on a keyboard - or a predefined (e.g. user-set) operation or sequence of operations - for example pressing a combination of keys at the same time.
  • Other user input devices such as trackballs, touchpads etc. could be used.
  • the direct instructions mentioned above could be from a user (by means of a menu command, a typed command or a mechanical switch) or from the device 31 to the display controller 30.
  • the present invention may include any feature or combination of features disclosed herein either implicitly or explicitly or any generalisation thereof irrespective of whether it relates to the presently claimed invention.

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  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Power Sources (AREA)
  • Digital Computer Display Output (AREA)

Abstract

Un dispositif (30) de commande d'affichage destiné à un affichage actif (2) comprend: un système d'entrée (32, 33) prévu pour recevoir des données d'affichage définissant une forme d'affichage visuel; un système de traitement (33, 34, 35) conçu pour traiter les données d'affichage afin de générer des données de commande des pixels de l'affichage et ayant un premier mode de fonctionnement normal dans lequel il commande les pixels pour afficher la forme telle qu'elle est définie par les données d'affichage, et un deuxième mode de fonctionnement économiseur d'énergie dans lequel il commande un ensemble de pixels de l'affichage pour fonctionner avec une consommation réduite d'énergie tout en maintenant l'affichage de la forme; et un système de sortie assurant la connexion des pixels afin qu'ils reçoivent les données de commande.
EP99915946A 1998-04-15 1999-04-14 Dispositif de commande d'affichage comprenant des modes d'economie de la consommation d'energie Withdrawn EP1072033A1 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
GB9808016 1998-04-15
GBGB9808016.1A GB9808016D0 (en) 1998-04-15 1998-04-15 Display control
GBGB9810280.9A GB9810280D0 (en) 1998-04-15 1998-05-13 Display control
GB9810280 1998-05-13
PCT/GB1999/001145 WO1999053472A1 (fr) 1998-04-15 1999-04-14 Dispositif de commande d'affichage comprenant des modes d'economie de la consommation d'energie

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Publication Number Publication Date
EP1072033A1 true EP1072033A1 (fr) 2001-01-31

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EP (1) EP1072033A1 (fr)
JP (1) JP2002511608A (fr)
WO (1) WO1999053472A1 (fr)

Families Citing this family (46)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3245856B2 (ja) * 1999-01-29 2002-01-15 日本電気株式会社 携帯情報端末及び表示電力制御方法
US6587086B1 (en) 1999-10-26 2003-07-01 Semiconductor Energy Laboratory Co., Ltd. Electro-optical device
DE19956109A1 (de) 1999-11-22 2001-05-23 Mannesmann Vdo Ag Elektronische Einrichtung mit einer Anzeigeeinheit
TW587239B (en) 1999-11-30 2004-05-11 Semiconductor Energy Lab Electric device
TWI252592B (en) 2000-01-17 2006-04-01 Semiconductor Energy Lab EL display device
WO2001069583A1 (fr) * 2000-03-14 2001-09-20 Koninklijke Philips Electronics N.V. Dispositif d'affichage
JP4731846B2 (ja) * 2000-04-18 2011-07-27 株式会社半導体エネルギー研究所 表示装置
US20010030511A1 (en) 2000-04-18 2001-10-18 Shunpei Yamazaki Display device
US6611108B2 (en) * 2000-04-26 2003-08-26 Semiconductor Energy Laboratory Co., Ltd. Electronic device and driving method thereof
US6995753B2 (en) 2000-06-06 2006-02-07 Semiconductor Energy Laboratory Co., Ltd. Display device and method of manufacturing the same
JP2002072963A (ja) 2000-06-12 2002-03-12 Semiconductor Energy Lab Co Ltd 発光モジュールおよびその駆動方法並びに光センサ
KR100335092B1 (ko) * 2000-07-04 2002-05-04 구자홍 표시 소자의 구동 제어 방법
JP2002162934A (ja) 2000-09-29 2002-06-07 Eastman Kodak Co 発光フィードバックのフラットパネルディスプレイ
JP3937789B2 (ja) 2000-10-12 2007-06-27 セイコーエプソン株式会社 有機エレクトロルミネッセンス素子を含む駆動回路及び電子機器及び電気光学装置
JP2002123208A (ja) 2000-10-13 2002-04-26 Nec Corp 画像表示装置およびその駆動方法
US6320325B1 (en) * 2000-11-06 2001-11-20 Eastman Kodak Company Emissive display with luminance feedback from a representative pixel
JP2002169509A (ja) * 2000-11-30 2002-06-14 Sanyo Electric Co Ltd 平面表示パネルの駆動方法及び有機エレクトロルミネッセンス表示パネルの駆動方法
JP2002358031A (ja) 2001-06-01 2002-12-13 Semiconductor Energy Lab Co Ltd 発光装置及びその駆動方法
DE10140991C2 (de) 2001-08-21 2003-08-21 Osram Opto Semiconductors Gmbh Organische Leuchtdiode mit Energieversorgung, Herstellungsverfahren dazu und Anwendungen
US7002593B2 (en) * 2001-11-01 2006-02-21 Eastman Kodak Company Method for reducing the power used by emissive display devices
GB2391995A (en) * 2002-08-15 2004-02-18 Seiko Epson Corp Mobile telephone comprising sensors which optimise the contrast or colour of the screen.
JP2004117921A (ja) * 2002-09-26 2004-04-15 Toshiba Matsushita Display Technology Co Ltd Ｅｌ表示装置およびｅｌ表示装置の駆動方法
WO2004047061A2 (fr) * 2002-11-15 2004-06-03 Koninklijke Philips Electronics N.V. Dispositif d'affichage, dispositif electrique comprenant un tel dispositif d'affichage, et procede de pilotage d'un dispositif d'affichage
JP4574127B2 (ja) 2003-03-26 2010-11-04 株式会社半導体エネルギー研究所 素子基板及び発光装置
DE10314166A1 (de) * 2003-03-28 2004-10-14 Siemens Ag Screensaver für organische Displays
GB0307789D0 (en) 2003-04-04 2003-05-07 Koninkl Philips Electronics Nv Electroluminescent display devices
US7026597B2 (en) * 2003-04-09 2006-04-11 Eastman Kodak Company OLED display with integrated elongated photosensor
US20040233146A1 (en) * 2003-05-21 2004-11-25 Nguyen Don J. Selective window display
US7193622B2 (en) 2003-11-21 2007-03-20 Motorola, Inc. Method and apparatus for dynamically changing pixel depth
CN1981318A (zh) 2004-04-12 2007-06-13 彩光公司 用于有源矩阵发光显示器的低功耗电路及其控制方法
US20050285822A1 (en) 2004-06-29 2005-12-29 Damoder Reddy High-performance emissive display device for computers, information appliances, and entertainment systems
US8704803B2 (en) 2004-08-27 2014-04-22 Semiconductor Energy Laboratory Co., Ltd. Display device and electronic appliance using the display device
JP2007072455A (ja) * 2005-08-12 2007-03-22 Semiconductor Energy Lab Co Ltd 表示装置
US20070109284A1 (en) 2005-08-12 2007-05-17 Semiconductor Energy Laboratory Co., Ltd. Display device
EP1772849B1 (fr) * 2005-10-06 2012-08-15 Vestel Elektronik Sanayi ve Ticaret A.S. Procédé et dispositif pour prevenir l'endommagement des pixel d'un dispositif de visualisation
KR100732813B1 (ko) * 2006-08-03 2007-06-27 삼성에스디아이 주식회사 휴대용 단말기 및 그 제어방법
JP4149494B2 (ja) * 2007-02-16 2008-09-10 松下電器産業株式会社 アクティブマトリクス型表示装置。
JP5270120B2 (ja) * 2007-07-25 2013-08-21 グローバル・オーエルイーディー・テクノロジー・リミテッド・ライアビリティ・カンパニー デュアルディスプレイ装置
US8036679B1 (en) 2007-10-03 2011-10-11 University of South Floirda Optimizing performance of location-aware applications using state machines
KR100894606B1 (ko) * 2007-10-29 2009-04-24 삼성모바일디스플레이주식회사 유기 전계 발광 표시 장치 및 그의 전원 공급 방법
DE102008016938B3 (de) * 2008-04-01 2009-12-31 Elmos Semiconductor Ag Vorrichtung zur Überwachung einer Monitorsteuerung
JP5321033B2 (ja) * 2008-12-11 2013-10-23 ソニー株式会社 表示装置及び表示装置の駆動方法
KR101040902B1 (ko) 2009-01-23 2011-06-16 삼성모바일디스플레이주식회사 유기 전계 발광 표시장치 및 그 구동방법
US20100320919A1 (en) * 2009-06-22 2010-12-23 Nokia Corporation Method and apparatus for modifying pixels based at least in part on ambient light level
KR20120136628A (ko) * 2011-06-09 2012-12-20 엘지전자 주식회사 영상표시장치 및 그 동작방법
WO2014203438A1 (fr) 2013-06-17 2014-12-24 ソニー株式会社 Dispositif de commande d'affichage d'image, système d'affichage d'image, procédé et programme de commande d'affichage d'image

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR940001691B1 (ko) * 1990-06-25 1994-03-05 가부시기가이샤 도시바 배터리 구동식 퍼스널 컴퓨터
US5598565A (en) * 1993-12-29 1997-01-28 Intel Corporation Method and apparatus for screen power saving
EP0707301A1 (fr) * 1994-09-14 1996-04-17 Texas Instruments Incorporated Gestion de l'énergie dans un dispositif d'affichage
US5748160A (en) * 1995-08-21 1998-05-05 Mororola, Inc. Active driven LED matrices

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9953472A1 *

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