Optoelectronic displays
AssigneeCambridge Display Technology Limited
InventorsEuan Christopher Smith, Alec Gordon Gunner, Jonathan J. M. Halls
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Abstract
Apparatus and methods for providing displays based upon the principle of photoluminescent quenching are described. The invention includes a method of displaying information using photoluminescence quenching, the method comprising providing an optoelectronic display comprising a photoluminescent material between a pair of electrodes, providing illumination for the photoluminescent material to cause the photoluminescent material to photoluminescence, and biasing the electrodes to at least partially quench the photoluminescence.
Claims78
A method of displaying information using photoluminescence quenching, the method comprising:
- providing an optoelectronic display comprising a photoluminescent material between a pair of electrodes;
- providing illumination for the photoluminescent material to cause the photoluminescent material to photoluminesce;
- and
- biassing the electrodes to at least partially quench said photoluminescence, the photoluminescent material having a normally-on, photoluminescence emissive state under zero bias across the electrodes.
Method of displaying information on an optoelectronic display, the method comprising providing an optoelectronic display comprising a photoluminescent material between a pair of electrodes the method, comprising illuminating the photoluminescent material to stimulate photoluminescence and;
- applying a voltage to the electrodes to quench the photoluminescence to display information, the photoluminescent material having a normally-on, photoluminescence emissive state under zero bias across the electrodes.
Method of controlling a display driver of a light emitting display to display information, comprising:
- providing a light emitting display comprising a photoluminescent material between a pair of electrodes, applying a voltage of a first polarity from a display driver to the electrodes to reduce photoluminescence from the material to switch the light emission off and applying a reduced voltage at the first polarity, or substantially zero voltage, from the display driver to the electrodes to switch the light emission on, the photoluminescent material of the display having a normally-on, photoluminescence emissive state under zero bias across the electrodes.
A method of operating a photoluminescent device, the device comprising a semiconductor layer in the form of a film of organic photoluminescent material, a first electrode layer proximate a first surface of the semiconductor layer, a second electrode layer proximate a second surface of the semiconductor layer, the method comprising illuminating the device and applying an electric field between the first and second electrode layers across the semiconductor layer so as to render the second electrode layer negative relative to the first electrode layer to split optically excited excitons generated by the illumination into their constituent holes and electrons and to conduct said holes and electrons out of said photoluminescent film to inhibit photoluminescence from said film, the photoluminescent material of the display having a normally-on, photoluminescence emissive state under zero bias across the electrode layers.
An optoelectronic display device comprising:
- a semiconductor layer in the form of a film of organic photoluminescent material, a first electrode layer proximate a first surface of the semiconductor layer, a second electrode layer proximate a second surface of the semiconductor layer;
- and
- a light source to illuminate said photoluminescent material to stimulate photoluminescence from the material, the organic photoluminescent material of the display having a normally-on, photoluminescence emissive state under zero bias across the electrode layers.
An optoelectronic display comprising:
- a photoluminescent display device having a display on-state in which the display emits photoluminescence under optical illumination with no voltage applied to the device and a display off-state in which said photoluminescence is at least partially quenched;
- and
- device driver circuitry having an input for receiving a display signal and an output for driving said display device, said display signal having an on-state indicating that the display is to be on and an off-state indicating that the display is to be off;
- said photoluminescent display device comprising:
- a semiconductor layer in the form of a film of organic photoluminescent material, a first electrode layer proximate a first surface of the semiconductor layer, and a second electrode layer proximate a second surface of the semiconductor layer;
- and wherein
- said device driver circuitry is configured to apply an electric field between the first and second electrode layers across the semiconductor layer so as to render the second electrode layer negative relative to the first electrode layer to split optically excited excitons generated by the illumination into their constituent holes and electrons and to conduct said holes and electrons out of said photoluminescent film to inhibit photoluminescence from said film in response to said display signal having said off-state;
- said display device and device driver combination primarily operating to display information by photoluminescence quenching, the organic photoluminescent material of the display having a normally-on, photoluminescence emissive state under zero bias across the electrode layers.
An optoelectronic display comprising:
- a semiconductor layer in the form of a film of organic photoluminescent material, a first electrode layer proximate a first surface of the semiconductor layer, and a second electrode layer proximate a second surface of the semiconductor layer;
- and
- a region to channel illumination from a light source using internal reflection, to illuminate said photoluminescent material, the organic photoluminescent material of the display having a normally-on, photoluminescence emissive state under zero bias across the electrode layers.
An optoelectronic display comprising:
- a semiconductor layer in the form of a film of organic photoluminescent material, a first electrode layer proximate a first surface of the semiconductor layer, and a second electrode layer proximate a second surface of the semiconductor layer;
- a substrate carrying said semiconductor layer and said first and second electrode layers;
- and
- an optical structure on said substrate to collect and deliver light from said photoluminescent material to a viewer of the display, the organic photoluminescent material of the display having a normally-on, photoluminescence emissive state under zero bias across the electrode layers.
A pixellated optoelectronic display comprising a plurality of photoluminescent display devices each associated with a pixel of the display and having a pair of electrodes for addressing the device, and device driver circuitry for driving the electrodes to control the display, the pixels of the display having a normally-on, photoluminescence emissive state under zero bias across the electrodes, the display driver circuitry being configured to apply bias voltage to inhibit said photoluminescent emission from selected pixels of the display, to thereby display information.
An optoelectronic display operating on the principle of quenched photoluminescence, the display comprising:
- a first electrode;
- a second electrode;
- and
- a visible display element located between the first and second electrodes, the display element comprising photoluminescent material,
- the display being configured to at least partially quench photoluminescence from said photoluminescent material upon application of a voltage between said first and second electrodes and thereby visibly change from a photoluminescent emissive state to a reduced emissivity state to provide a visual display, the organic photoluminescent material of the display having a normally-on, photoluminescence emissive state under zero bias across the electrode layers.
A combination of an optoelectronic display device and instructions, the display device comprising:
- a semiconductor layer in the form of a film of organic photoluminescent material, a first electrode layer proximate a first surface of the semiconductor layer, and a second electrode layer proximate a second surface of the semiconductor layer;
- the instructions comprising instructions to apply an electric field between the first and second contact layers across the semiconductor layer so as to render the second contact layer negative relative to the first contact layer to inhibit photoluminescence from said photoluminescent film, the organic photoluminescent material of the display having a normally-on, photoluminescence emissive state under zero bias across the electrode layers.
Dependencies are inferred from the claim text.