114results about How to "Constant brightness" patented technology

This invention provides a display device in which it is possible to have a light emitting element emitted light with constant luminance without coming under the influence of deterioration over time, and it is possible to realize accurate gray scale express, and yet, it is possible to speed up writing of a signal current to each pixel, and influence of noise of a leak current etc. is suppressed, and a driving method thereof. A plurality of pairs of switch parts and current source circuits are disposed in each pixel. Switching of each of a plurality of the switch parts is controlled by a digital video signal. When the switch part is turned ON, by a current supplied from the current source circuit making a pair with the switch part, the light emitting element emits light. A current which is supplied from one current source circuit to the light emitting element is constant. A value of a current flowing through the light emitting element is comparable to a value of added currents which are supplied to the light emitting element from respective all current source circuits making pairs with the switch parts which are in the conductive states.

A liquid crystal display device includes: a driver circuit portion; a pixel portion; a signal generation circuit for generating a control signal for driving the driver circuit portion and an image signal which is supplied to the pixel portion; a memory circuit; a comparison circuit for detecting a difference of image signals for a series of frame periods among image signals stored for respective frame periods in the memory circuit; a selection circuit which selects and outputs the image signals for the series of frame periods when the difference is detected in the comparison circuit; and a display control circuit which supplies the control signal and the image signals output from the selection circuit, to the driver circuit portion when the difference is detected in the comparison circuit, and stops supplying the control signal to the driver circuit portion when the difference is not detected in the comparison circuit.

The present invention provides a luminaire comprising an housing having thermally separate compartments for an electronics portion and a lighting portion. These thermally separate compartments can provide a means for providing thermal isolation between the respective components, namely the electronics portion and the lighting portion. In this manner thermal interaction between these portions can be reduced, thereby improving performance of the luminaire. The lighting portion comprises a plurality of light-emitting elements and further includes optics for the manipulation of illumination created by the light-emitting elements. A power supply for supply of energy to the light-emitting elements and a controller for controlling application of energy from a power source to the light-emitting elements is provided in the electronics portion and can be thermally separated within the electronics portion. Moreover, an optical device comprising two linear diffuser elements can be used to further improve the light emission characteristics of the light-emitting elements thereby providing a directly viewable luminaire wherein the illumination produced by point light sources appears uniform along the length of the luminaire.

The present invention provides a TFT that has a channel length particularly longer than that of an existing one, specifically, several tens to several hundreds times longer than that of the existing one, and thereby allowing turning to an on-state at a gate voltage particularly higher than the existing one and driving, and allowing having a low channel conductance gd. According to the present invention, not only the simple dispersion of on-current but also the normalized dispersion thereof can be reduced, and other than the reduction of the dispersion between the individual TFTs, the dispersion of the OLEDs themselves and the dispersion due to the deterioration of the OLED can be reduced.

Various embodiments involving structures and methods for illumination can be employed, for example, in projectors, head-mounted displays, helmet-mounted displays, back projection TVs, flat panel displays as well as other optical systems. Certain embodiments may include prism elements for illuminating, for example, a spatial light modulator. Light may be coupled to the prism in some cases using fiber optics or lightpipes. The optical system may also include a diffuser having scatter features arranged to scatter light appropriately to produce a desired luminance profile. Other embodiments are possible as well.

A liquid crystal display apparatus and backlight adjustment method are provided. Backlight luminance sensors 111A to 111D are disposed in the vicinity of four outer corners of an effective screen of an LCD panel 121. Each of the backlight luminance sensors 111A to 111D detects the luminance of each of three primary colors. A backlight unit is composed of a three-primary LED array and a light diffusion unit. Transistors of the backlight luminance sensors and transistors of a pixel portion are formed on the same substrate in the same process. When a transistor is irradiated with backlight in its sufficient off region, an off current occurs due to light excitation. Since the value of the off current corresponds to the luminance of the rays of backlight that irradiates the transistor, the luminance of the backlight is detected with an output voltage into which the off current is converted. As a result, the luminance of the backlight is kept constant.

This invention provides a display apparatus in which it is possible to have a light emitting element emitted light with constant luminance without coming under the influence of deterioration over time, and it is possible to realize accurate gray scale express, and yet, it is possible to speed up writing of a signal current to each pixel, and influence of noise of a leak current etc. is suppressed, and a driving method thereof. A plurality of pairs of switch parts and current source circuits are disposed in each pixel. Switching of each of a plurality of the switch parts is controlled by a digital video signal. When the switch part is turned on, by a current supplied from the current source circuit making a pair with the switch part, the light emitting element emits light. A current which is supplied from one current source circuit to the light emitting element is constant. A value of a current flowing through the light emitting element is comparable to a value of added currents which are supplied to the light emitting element from respective all current source circuits making pairs with the switch parts which are in the conductive states.

An electronic-circuit assembling process to be carried out in an electronic-circuit assembling system, for assembling an electronic circuit, by mounting electronic circuit components supplied from a component supplier, onto a circuit board, wherein the electronic circuit components includes at least one of different-property components having respective different electrical properties. The process includes: (a) a different-property-component-related information obtaining step of obtaining a different-property-component-related information including (a-i) a property-related information that enables recognition of the electrical property of the different-property component supplied from the component supplier and (a-ii) a different-property-component supply position that is a position of the component supplier supplying the different-property component, such that the different-property-component-related information is obtained by detecting the property-related information and / or the different-property-component supply position; (b) a mounting step of mounting, based on information related to the different-property-component supply position, the electronic circuit components including the different-property component, onto the circuit board; and (c) a property-related information providing step of providing the circuit board with the property-related information of the different-property component mounted on the circuit board.

A picture / character simultaneously displaying device includes: a picture display device for displaying a picture based on picture data; and a character display device for displaying characters synchronous with the picture based on character data. The character data contains therein text data about characters synchronous with a picture to be displayed, and metadata about characters to be displayed.

The present invention is to provide a light emitting device capable of obtaining a certain luminance without influence by the temperature change, and a driving method thereof. A current mirror circuit formed by using a transistor is provided for each pixel. The first transistor and the second transistor of the current mirror circuit are connected such that the drain currents thereof are maintained at proportional values regardless of the load resistance value. Thereby, a light emitting device capable of controlling the OLED driving current and the luminance of the OLED by controlling the drain current of the first transistor at a value corresponding to a video signal in a driving circuit, and supplying the drain current of the second transistor to the OLED, is provided.

An LED lighting device comprises: a rectification circuit unit for receiving input power from a power source unit and outputting a rectified power; an LED unit having a plurality of LED channels connected in series and a resistor unit connected to the last end of the LED channels; a current sensing resistor; and a switch circuit unit comprising a plurality of switches, wherein an nth switch is connected to the rear end of an nth LED channel so as to control an operation of the nth LED channel and is controlled by a sum of a current of the nth switch and a current of an (n+1)th switch, which flows through the current sensing resistor.

By controlling the luminance of light emitting element not by means of a voltage to be impressed to the TFT but by means of controlling a current that flows to the TFT in a signal line drive circuit, the current that flows to the light emitting element is held to a desired value without depending on the characteristics of the TFT. Further, a voltage of inverted bias is impressed to the light emitting element every predetermined period. Since a multiplier effect is given by the two configurations described above, it is possible to prevent the luminance from deteriorating due to a deterioration of the organic luminescent layer, and further, it is possible to maintain the current that flows to the light emitting element to a desired value without depending on the characteristics of the TFT.

In a display device having a light emitting element, an accurate setting operation needs much time, unless a current value of the signal current (video signal) is set to high value. On the contrary, the driving current value for causing a light emitting element to emit light is very small. Therefore, it is difficult to perform an accurate setting operation. However, according to the present invention, the current source circuit includes plural transistors. The plural transistors are connected in parallel when the setting operation is performed on the current source circuit, whereas the plural transistors are connected in series when the light emitting element is caused to emit light. Further, the speed of the setting operation is increased because a light emitting element is capable of emitting light with a constant luminance and a current value to set up a current source circuit is higher than a driving current value when a light emitting element emits light.

A drive device for a light emitting diode element comprises a light emitting diode element circuit part configured to be formed by connecting at least one light emitting diode element based on a predetermined connection form, a power supply unit configured to generate a direct-current (DC) supply voltage for driving the light emitting diode element of the light emitting diode element circuit part for light emission of the light emitting diode element, and apply the DC supply voltage to the light emitting diode element circuit part, a power-supply application on / off unit configured to be provided to turn on / off application of the DC supply voltage to the light emitting diode element circuit part, and a current control circuit part configured to be caused to switch its operation so as to carry out constant current operation if application of the DC supply voltage is in an on-state and carry out voltage keeping operation if application of the DC supply voltage is in an off-state.

The purpose of the invention is providing a current-input display device which can emit light at a constant luminance and provide a high definition display. According to the invention, a current which is almost the same as a current source can be inputted by adding a transistor in a pixel circuit, the circuit has a large output resistance enough not to be influenced by a change in I-V characteristic due to a deterioration of a light emitting element, a change in temperature and the like, and a high definition display can be obtained by conducting a correction if there are any influential changes in characteristics.

A LED lighting chain is disclosed to include a front plug, a rear plug, an AC-DC converter formed of four rectifying diodes, and a LED serial set, wherein the LED serial set has a voltage dropping device formed of a resistance and two capacitors so arranged that changing the resistance and capacitors relatively changes the voltage of the LED serial set, and therefore increasing the number of LEDs does not change the brightness of the LED serial set. Further, a resistance is connected in parallel to each capacitor of the voltage dropping device so that when power is off, residual electric energy is discharged out of the capacitors to ensure safety of the LED lighting chain and to prevent damage to the LEDs during start.

A light emitting device capable of preventing a luminance of individual light emitting elements from being fluctuated by applying electrical characteristics of TFTs for properly controlling current being fed to individual light emitting elements, and also capable of generating the constant luminance without adversely being affected by possible degradation of organic light emitting layers and variable temperature by way of preventing the luminance of light emitting elements from being lowered through degradation of organic light emitting layers. Instead of controlling the luminance of light emitting elements by means of a voltage applied to TFTs, by way of properly controlling current flowing into TFTs via a signal-line driving circuit, it is possible to hold on the current flowing into light emitting elements at a desired value without adversely being affected by electrical characteristics of TFTs. Further, a voltage biasing in an inverse direction is fed to light emitting elements per predetermined period of time. The above-described double means multiply such practical effects to more securely prevent the luminance from being lowered by possible degradation of organic light emitting layers, and make it possible to hold on such current flowing into light emitting elements at a desired value without being affected by electrical characteristics of TFTs.

An EL display device free of a dispersion in the brightness caused by deterioration in the EL elements. The display device uses pixels of the current-controlled type to suppress a change in the current flowing through the EL elements caused by the deterioration in the EL elements. The display device further uses elements capable of short-circuiting or opening three nodes simultaneously. No bank is used for dividing the EL layers into separate colors. EL elements of the mixed junction type are used. A reverse bias voltage is applied to the EL elements at regular intervals. The display device suppresses dispersion in the brightness caused by the deterioration in the EL elements.

In a display device having a light emitting element, an accurate setting operation needs much time, unless a current value of the signal current (video signal) is set to high value. On the contrary, the driving current value for causing a light emitting element to emit light is very small. Therefore, it is difficult to perform an accurate setting operation. However, according to the present invention, the current source circuit includes plural transistors. The plural transistors are connected in parallel when the setting operation is performed on the current source circuit, whereas the plural transistors are connected in series when the light emitting element is caused to emit light. Further, the speed of the setting operation is increased because a light emitting element is capable of emitting light with a constant luminance and a current value to set up a current source circuit is higher than a driving current value when a light emitting element emits light.

In order to keep the luminance of a light emitting element constant, the correction is performed by an external device such as a computer, in which case a display device is inevitably complicated and increased in size. Even when degradation characteristics of the light emitting element are previously stored in a computer, the degradation characteristics vary at random depending on hysteresis of the light emitting element; therefore, changes in luminance cannot be corrected. According to the invention, a display device includes a displaying light emitting element provided in a display portion and a plurality of monitoring light emitting elements having the similar characteristics as the displaying light emitting element. At least one of the monitoring light emitting elements is operated under a condition different from the displaying light emitting element, and the ratio of the total amount of charge flowing through the displaying light emitting element to that flowing through the monitoring light emitting element is controlled to satisfy a certain relation in view of luminance degradation. When the one monitoring light emitting element reaches a predetermined voltage or time, the connection is switched from the one monitoring light emitting element to another monitoring light emitting element that has been operated under the same condition as the displaying light emitting element.

To provide a light-source driving method for supplying power to a light source of a projector and a projector employing the light-source driving method there are provided a lamp-drive-power control section (3) as a light-source driving section for outputting a first drive waveform and a second drive waveform, and a high-current on-off switch section 5 as a current-control instructing section for making a controllable instruction to switch the first drive waveform and second drive waveform outputted from the lamp-drive-power control section (3).

Systems and methods are provided for use in correcting flicker of a display (e.g., an LCD display). For example, correction may employ the insertion of at least one transition data frame between display data frames for use in displaying a transition image by pixel elements of the display such that a user perceives display of a constant average luminance by the pixel elements.

A reflection sheet includes a reflection layer that reflects light irradiated from an external device and a dissipating layer that is formed on the reflection layer and dissipates the heat generated from a lamp unit in a horizontal direction toward an outside of the lamp unit. The dissipation layer has a thermal conductivity in a horizontal direction higher than that in a vertical direction and thus the heat may rapidly be transmitted to a first container. As a result, this may suppress the increment of temperatures in a backlight assembly, increase the luminance of the lamp unit, and improve a display quality of a liquid crystal display device.

The present invention is to provide a light emitting device capable of obtaining a certain luminance without influence by the temperature change, and a driving method thereof. A current mirror circuit formed by using a transistor is provided for each pixel. The first transistor and the second transistor of the current mirror circuit are connected such that the drain currents thereof are maintained at proportional values regardless of the load resistance value. Thereby, a light emitting device capable of controlling the OLED driving current and the luminance of the OLED by controlling the drain current of the first transistor at a value corresponding to a video signal in a driving circuit, and supplying the drain current of the second transistor to the OLED, is provided.

A lighting system includes: a plurality of lighting devices; a controller; and a sensor which detects brightness of a region illuminated by at least two lighting devices among the plurality of lighting devices, wherein the controller includes a lighting controller operable in a plurality of operation modes, the plurality of operation modes include a sensor mode, and when the lighting controller obtains an instruction to operate in the sensor mode, the lighting controller performs (a) transition control for controlling the at least two lighting devices, by transmitting a transition instruction, to cause the at least two lighting devices to provide illumination at a predetermined dimming level, without using a result of detection by the sensor, and (b) dimming control for controlling the at least two lighting devices to cause the brightness indicated by the result of detection by the sensor to approach the target value, after transmitting the transition instruction.

An organic optoelectronic component and a method for operating the organic optoelectronic component are disclosed. In an embodiment an organic optoelectronic component includes at least one organic light emitting element, at least one first organic light detecting element including at least one first organic light detecting layer, and at least one second organic light detecting element including at least one second organic light detecting layer, wherein the at least one organic light emitting element, the at least one first organic light detecting element and the at least one second light detecting element are arranged laterally on a common substrate, wherein the at least one first organic light detecting element is configured to detect ambient light, and wherein the at least one second organic light detecting layer of the at least one second organic light detecting element is arranged between two non-transparent layers.

The invention relates to the technical field of display brightness control of an OLED miniaturized display and specifically relates to an OLED miniaturized display constant-brightness modulation method. According to the invention, a compensation coefficient is determined through actual measurement of a difference between a current brightness value and a calibrated brightness value, driving current compensation or driving voltage compensation is carried out through the compensation coefficient, and thus the purpose of maintaining constant brightens of the OLED miniaturized display is realized. According to the invention, modulation stepping is automatically adjusted according to the difference between current brightness and fixed brightness in a modulation process so that the phenomenon of excessive modulation caused by too frequent modulation or mismatch between the modulations stepping and the brightness difference in a conventional modulation mode is avoided.

There is disclosed a method of controlling an electron gun without causing decreases in brightness of the electron beam if a current-limiting aperture cannot be used. The electron gun (10) has a cathode (11), a Wehnelt electrode (12), a control electrode (13), an anode (14), and a controller (22). The Wehnelt electrode (12) has a first opening (12c) in which the tip of the cathode is inserted, and focuses thermal electrons emitted from the tip of the cathode (11). The thermal electrons emitted from the tip of the cathode (11) are caused to pass into a second opening (13c) by the control electrode (13). The anode (14) accelerates the thermal electrons emitted from the cathode (11) such that the thermal electrons passed through the second opening (13c) pass through a third opening (14b) and impinge as an electron beam (B1) on a powdered sample (8). The controller (22) sets the bias voltage and the control voltage based on combination conditions of the bias voltage and control voltage to maintain the brightness of the beam constant.