TWI312978B - Method and drive means for color correction in an organic electroluminescent device - Google Patents

Description

1312978 A7

The color correction method for an organic luminescence device of the present invention includes a layer of luminescent material having a pixel (6) and a layer of optical material (5), which is located at a Between the first electrode and the second electrode, at least one of the first and second light emitting elements. The invention also relates to a driving device for an organic luminescence device comprising - a cold material, between the first and second electrode patterns, wherein: the pattern defines at least one pixel, each of which comprises at least A first and a second. The drive is coupled to the electrodes and configured to supply power to the luminescent material to illuminate the material. 〃 Organic cold-lighting one-pole technology, such as polyester light-emitting diodes (PolyLED or PLED) or organic light-emitting diodes (〇LED), is a recently developed technology based on specific organic materials, such as The ester can be used in a semiconductor of a light-emitting diode. This technique is very interesting because polyester materials are light, flexible and inexpensive to produce. As a result, polyLEDs and OLEDs offer opportunities to produce thin and highly flexible displays such as electronic news or the like. Applications for such displays can be used in displays for mobile phones. The above display has several advantageous features over competing technologies such as LCD displays. First, organic cold light displays are more efficient when producing light, and are three times more efficient than LCD displays for polyLCD displays. Results 'The polyLED can operate three times longer under the same battery. In addition, the luminescence organic display has the advantage of contrast and brightness. PolyLED displays are not depending on the point of view, because light is transmitted in multiple directions at the same density. In any case, 'organic illuminator technology has progressed to a point where all make 4 - this paper scale 中国 Chinese National Standard (CNS) A4 specification (210 X 297 mm) 1312978 A7 ____B7 V. Invention description (2) ^ Use this The technical color display is considered as a choice. Several methods can be used to achieve the main color. A direct attempt is to use white light and color filters to produce colors, such as TFT-LCD displays. The biggest drawback of this approach is the increased complexity and cost of using color filters. In addition, 2/3 of the effective spectrum emitted from a white light is absorbed by the color filter, making this method also not energy efficient. In any case, for organic luminescent devices, another method of producing color is to adjust the basic emissive material such that the coordinates of the CIE color x*y match the desired red, green, and blue colored dots. This can be accomplished by low molecular weight devices, such as 〇LED devices by adjusting the turbidity in the host material. For polyol applications, such as pLEDs, spectral changes can be obtained by altering the major and side chain composition of the polyol material. It is also possible to increase the infiltration of the polyester material to obtain. Since the luminescent polyester material can be used in red, green, and blue, a color display can be obtained simply by applying the red, green, and blue material to a suitable position of a pixel within an array structure comprising a plurality of pixels. This is available from prior art printing techniques. In any case, the big problem with the above method is that it produces color. This is due to the fact that the actual X and y CIE color coordinates are based on the overall time when the pixel is driven. This effect is basically applied to all organic luminescent materials regardless of color. During the life of the display, the emission spectrum of the luminescent material and the final CIE color point move over time. As a result, while working to obtain corrections for red, green, and blue dots and specific CIE color coordinate values, their position will change as the pixel is driven for a certain period of time. In addition, because all pixels are not time-driven, the above "attenuation" program will vary with the pixels of the display. -5- This paper size applies to China National Standard (CNS) A4 specification (210X297 mm)

Binding

Line 1312978

The invention is different. In addition, 14 pairs of full color applications are particularly important because all colors are not driven at the same time' and each color exhibits a similar but non-unique spectral degradation. A solution to this problem is described in the patent document WO _9945525. The structure described takes into account that the pixel matrix contains three monochromatic luminescent diodes (R, G, B). The diodes are controlled by a circuit that transmits an electrical energy to each of the diodes, wherein the electrical energy is determined by p=k*pr, wherein the reference energy is dedicated to each color diode. , and ^^ is a coefficient selected based on the rendered color. In addition, in the time consideration, the reference energy is varied to compensate for the attenuation of the diode. In any event, the main disadvantage of this system is that the overall time of each diode of the display has been stored in a suffix device, and the compensation obtained is based on this information. As a result, this system requires a large memory space making it somewhat impractical to implement. In addition, this system requires continuous startup to follow the overall time. As a result, it is an object of the present invention to provide an improved method and object for reducing the above problems. The present invention is defined by the scope of the independent patent application. The independent patent application scope defines specific examples of advantages. All of the objects are described in the Summary of the Invention 'The method comprises the steps of inputting a data signal of information displayed by the light-emitting element, and a correction factor is generated for each light-emitting element in a correction device, the coefficients being Basic: (i) a relationship between a measured voltage change of a light-emitting element flowing through a predetermined current (Is) and a voltage change of the light-emitting element and a color point wavelength change (Δλ), or -6-ben Paper scale applies to China National Standard (CNS) Α4 specification (210X297 mm) 1312978 A7 ----------B7 V. Invention description) --- ...) illuminating element at - predetermined voltage (Vs) across In the meantime, the current change of the light-emitting element and the relationship between the wavelengths of a color point and the current of the light-emitting 7G element and the wavelength change of the color point (4), and the correction coefficient is output from the correction device. On the data signal. The advantage of this method is that the color correction can be easily obtained at any time during the driving of the device, since the entire color point can be obtained by adjusting the voltage obtained by the current flowing through the respective light-emitting elements. In addition, the voltage and current on a display can be easily measured' resulting in a simple and cost effective method. If desired, the correction factor can be based on measurements performed on more than one of the light-emitting elements within the pixel, preferably each of the light-emitting elements within the pixel. The measured voltage and electrical pick-up changes and color points can be different for different light-emitting elements. Preferably, the correction means includes a search table having information about the pre-measurement of the voltage of the light-emitting element, a current applied to the light-emitting element, and a wavelength change of the light-emitting element. By storing this information, it can be integrated and does not need to be clearly stated. This information can be easily accessed in the - search form. According to a preferred embodiment, the method comprises the steps of: transmitting in a predetermined time interval, having a predetermined electrical energy L, and measuring the voltage on the light-emitting element when the current is transmitted through the light-emitting element, calculating the measured A voltage between the voltage and a pre-voltage of a corresponding current, the input voltage is changed to the correction device, and a correction parameter change is output from the correction device. When a determined current flows through the device, a simple correction can be made by measuring the voltage across the device. Preferably, the wavelength variation (Δλ) of the illuminating element is calculated as follows: Δλ = k · Δ Υ The paper scale is applicable to the Chinese National Standard (CNS) Α 4 specification (210×297 mm) 1312978, the invention description (where Δλ is the obtained wavelength A change, which causes the correction coefficient and AV to be voltage #. ^ ^ ^ illuminates 70 pieces and each type of illuminating element pre-stores a value of 2. The correction factor can be a constant or a function of the display or current, such as. Using the organic cold precursor 枓 'which has a linear relationship between electric (four) and wavelength change, the search table is often smaller, and the bit is actually (four) (four) (four) positive coefficient two, because the table needs some The memory space can be easily obtained. In addition, the same correction factor "for the same type of light-emitting element. = the same type of light-emitting element" means a light-emitting element having the same composition and size of the light-emitting layer and having the first and the The same composition and size of the two electrodes. For example, for a full color matrix display with red, green and blue illuminating elements, all of the luminescent elements of one color (red, green or blue) are In the same pattern, only three correction coefficients k need to be stored. According to one of the specific examples, the previous voltage is an initial voltage across the light-emitting element, which is measured when the device is manufactured. All measured values are stored in advance. The comparison of values results in a stable system. According to another variation of this embodiment, the pre-voltage is a voltage of the illuminating element that is pre-measured during the driving of the device, resulting in the device not requiring an initial metering. For example, the method includes the following steps: transmitting in a predetermined time interval, one of the light-emitting elements has a predetermined voltage, and measuring a current on the light-emitting element when the voltage is applied to the light-emitting element, calculating a current between the measured current and a pre-current Changing the 'input current change to the correcting device' and outputting a modified parameter change corresponding to the wavelength change Δλ of the light-emitting element based on the current change from the correcting device. When a determined voltage is applied to the -8 - the paper scale is applicable to the Chinese country Standard (CNS) Α4 size (210X 297 mm) 1312978 V. Description of invention (6 The device', on the measuring device A simple correction can be made by the current. Preferably, the wavelength variation of the illuminating element is calculated as follows: Δλ = k · Δ Ι where Δλ 疋 is obtained; ^ wavelength variation ' & is - correction system 'number and current Changing the value of k 疋 for each illuminating element or for each type of illuminating element in advance in the correction device. The correction factor may be a constant or the number 'such as ν (ν, υ. using the organic luminescent light) The material, which has a linear relationship between voltage change and wavelength change, allows a very small search table because only the advantage of the correction factor k needs to be stored, since the table requires some memory space to be easily obtained. Further, the same modified mooring can be used for the same type of light-emitting element. "The same type of light-emitting element" indicates a light-emitting π member having the same composition and size of the light-emitting layer and the same composition and size of the first and second electrodes. For example, for a full color matrix display having red, green and blue illuminating elements, all of the illuminating elements of one color (red, green or blue) are of the same type, and only three correction coefficients k need to be stored. According to one of the specific examples, the previous voltage is the initial current of the first-class illuminating element, which is measured at the time of manufacture of the device. All measured values are compared to pre-stored values resulting in a stable system. According to another variation of this embodiment, the previous current is a current of the illuminating element that was previously measured during the driving of the device, resulting in the device not requiring an initial metering. Preferably, the luminescent material is one of a polyester luminescent material and an organic luminescent material, all of which are well tested with good properties. Further, according to a preferred embodiment, at least one pixel substantially contains three or more light-emitting elements -9. The paper scale applies to the Chinese National Standard (CNS) A4 specification (2i〇x 297 mm) 1312978 A7

1312978

. A display that has a solid color behavior independent of the display material attenuation can also be obtained. The object of the present invention will become more apparent from the following description of the specific examples. A presently preferred embodiment of the present invention will be described in more detail with reference to the accompanying drawings. Figure la is a graph illustrating a wavelength change and a voltage on a luminescent display as a function of a constant overall drive time given by the display. Figure 1b illustrates the relationship between the voltage change and the wavelength change of the luminescent display. Fig. 2 illustrates a specific example of a cold light display in which a method and a device according to the present invention can be used. Fig. 2 illustrates a specific example of a cold light display in which a method and a device according to the present invention can be used. The basic device structure of a luminescent display 1 comprises: a structured first electrode 2 or an anode; a transparent material 'such as a common light-transmissive type IT 〇; a second electrode 3 or cathode; and an emission luminescent layer 5' Sandwiched between the anode 2 and the cathode 3. In the display example shown in Figure 2, an additional conductive layer 4, such as a conductive polyester layer (e.g., PEDOT), is sandwiched between the anode 2 and the emissive layer 5. Other layer structures may also contain fewer or more organic layers. The emissive layer 5 can be a layer of a polyester luminescent material such as a PolyLED display, or an organic luminescent material layer of a led display. When operating, a current I is transmitted between the anode and the cathode (as shown). The luminescent layer 5 is emitted to drive the material within the luminescent layer 5 to emit. The display example shown in FIG. 2 includes an array of pixels 6 (only one pixel is shown) and also refers to, for example, light-emitting diodes (LEDs), which are applied by electrodes 2, 3 and the boundary between them. National Standard (CNS) A4 specification (210X 297 mm) 1312978, invention description (9 shot layer 5 defined. For full color applications, each pixel is divided into three sub-pixels, or light-emitting elements 6R, 6G, 6B, comprising a luminescent material for emitting red, green and blue light, respectively. The pixel/sub-pixel pattern can be produced on a substrate via a printing technique. Further, a driving device 7 is connected to the electrode 2' 3 To drive the display 1. For the above pixel/sub-pixel device, a driving device unit is arranged to each pixel 6 including three sub-pixels 6R, 6G, 6B. The t driving device 7 includes an input device 8 for Receiving a data signal s from an image generator (not shown). In the above example, the received data signal 3 includes a color that is driven by the sub-pixel (6R, 6G, 6B) with respect to a desired color or by pixel 6 Point information. One with R, nB multi-vinegar ( , the red, green or blue luminescent multi-element) of all the colors in the color triangle defined by the emission of the corner is obtained by linearly combining the R, G, B emission vectors to obtain a combination of red, green and blue sub-pixel light. Each _color point may be represented by a set of (four) colors also within the X and y axes. The driving device 7 may include a signal processing device n, wherein the color point information of each sub-pixel is converted into driving information to: The pixel produces a desired color for a particular pixel. In any event, the beta can also be included in the wheel profile signal (4). Thus, the drive information is applied to each of the transmit sub-pixels of the display via output connector 9. How to 'as above' in the life cycle of the display, there are still guaranteed positive parameters in the balance of the existing display ^ H due to the color two. & this change depends on the specific driving time of a particular pixel or sub-pixel 疋 0 As suggested by this month, the above drive unit additionally includes a correction device for -12-

1312978 A7 ------____B7 V. INSTRUCTIONS (10) ' ------ ΐ Γ Γ Γ Γ ’ 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如 如The k L positive device 10 is connected to the signal processing device u. - The present invention is based on the relationship between the life cycle of an organic cold junction (such as the above display) - the change in electricity (or current), and the spectral change emitted during the life of the device 'as a pixel or sub-pixel When the current is driven by a predetermined current (or electrician), as shown in Fig. 1, for a specific current passing through the luminescent material, the voltage V and characteristics of an display change from an index of the overall driving time t of the pixel. The voltage change κΔν and the spectrum change profile—a basic linear relationship can be generated, as shown in Figure lb. This linear relationship is represented by the line LF and is steep. Further, this linear relationship is independent of the overall drive time of the display. 'But it depends on the current. As a result, by measuring the voltage or current on the display while keeping the other value at a constant value, the wavelength change result can be obtained. A color point correction coefficient can be applied to a data signal and transmitted to A display to compensate for the attenuation of the display, because the attenuation changes the relationship between current and voltage. In addition, the color correction can be electrically processed and will be described below. When the display is activated, the display device can be color corrected in two different ways. According to the first specific example of the present invention, as shown in FIG. 2, a data signal 8 is input to the signal through an input device 8 and then transmitted to the signal. The processing device 11 and the respective pixels/sub-pixels 'outputted to the display via an output device 9 to display an image of the display device. When the display device is manufactured, a "metering" is completed, wherein - the sub-pixel The voltage V〇 is measured by the selected current Is flowing through the sub-pixel. And “the paper size is measured by the Chinese National Standard (CNS) A4 specification (210X297 public) -13- 1312978 A7

B7 = then the functions stored in the device are executed. In addition, the compensation curve of the field image of the strong and the mother-in-law is... each material used, "° shown in Figure 1b, is generated by the measurement of -wavelength change/voltage variation, as shown in the figure: 'Constant constant current Time function. The generation of the compensation curve and the measurement of the material need only be done once, and this compensation curve is a material property. In the case of the singular material, the voltage change Δν and the wavelength change Λλ are linear, as shown in Fig. 1 . As can be seen from Figure lb, the following relationships are available. Δλ = k · ΔΥ where Δ is the wavelength change obtained, which is a correction factor and Δν is the voltage change J. In this specific example, as shown in FIG. 1b, k is basically a material constant. In any case, the correction factor can be a voltage and alkali current function on the display, such as k = k (V, I;) » Only a small memory area is needed to store a search table, since only the curve values need to be stored. Or the correction factor k of the curve. The value is corresponding to the compensation curve shown in Figure lb for a predetermined period of time, such as one hour, or when the display is activated, a corresponding current Is is transmitted through the display, wherein the voltage v of the display is measured via a voltmeter. The measured voltage value v is thus compared to the initial voltage value v 〇 when a particular current flows through the display. The voltage displacement Δν can be obtained by the following equation: AV = |V - V 〇 | When Δν is known ' Δλ can be obtained simply by the correction factor stored in the search table. Therefore, a suitable correction factor can be applied to the data signal S before it is transmitted to the display, wherein the color correction is adjusted by passing through a sub-pixel of a pixel - 14. The paper scale is applicable to the Chinese National Standard (CNS) Α 4 specification (210 Χ 297 gong) PCT) 1312978 12, invention description (current to start 'to make the entire color point of the pixel unchanged. ^ pixel (four) color point change, it must also adjust the voltage / current flowing through the same sub-pixel to change. According to a second specific example of the present invention, the "metering" is achieved by measuring the current of the voltage value Vs. The corresponding compensation curve, as shown in Figure lb, can be generated by the relationship between the wavelength and the wavelength change. The current I. corresponds to the compensation curve during a predetermined time period 'such as one hour, or when the display starts, the current is transmitted through the display, and the corresponding value Vs is applied to the display, and the current flowing through the display (4) is passed through - The ammeter measurement. The measured current is therefore compared to the initial current value 1 产生 produced by a particular voltage on the display. The current change ΔΙ can be obtained by: ΔΙ=|Ι- 〇| When ΔΙ is known, Δλ can be obtained simply via the correction factor stored in the search table. Therefore, an appropriate correction factor can be applied to the data (4) S of the signal processing device 11 before it is transmitted to the display. Color correction can be activated. > For the two specific examples above, it can correlate the voltage/current value with a previously measured same parameter value, rather than correlating the measured voltage/electrical value with an initial value. Here, an additional memory for storing the previously measured voltage/current values is required. This can also be performed on each screen. It is also possible to use voltage/current variations and materials that have no linear relationship between wavelengths. "In any case, in this case. A larger search table is required to provide correction coefficients for multiple varying wavelengths. This paper scale applies to the China® Family Standard (CNS) Α4 specification (210X 297 public) -15 1312978 V. Invention Description (η) Via the above method , can be accompanied by the surname t ^ j to maintain - correct the color balance in the display ί:: ΓΓ adjust the emission wavelength of the sub-pixel separately, and the overall color point of the pixel due to H This can be achieved by providing a display with a driver in accordance with the present invention, which includes means for determining::! The power/current variation of a transmitter and the frequency used to determine each transmission benefit. The change, and the (4) signal of the red, green, and blue emitters used to apply a correction parameter to the red, green, and blue emitters of the = pixel to correct the spectral variation of the fourth (the fourth) is not limited to the above specific example 'but All possible variations of the patent application are contemplated. The present invention has been described in connection with a display device, and specifically refers to a full color display device. In any case, please note that the present invention can be applied to other technical devices such as a black and white display. Device, non-graphic display or - organic luminescent diode for a backlight or other. Further, even if the above device is a polyLED device, the color correction method can be applied to other organic luminescent devices such as organic LED (OLED) devices. Note that the above predetermined voltages Vo and currents 10 may be different for different sub-pixels. In addition, it can drive a display device in the voltage measurement mode portion and partially in the current measurement mode. In summary, the present invention relates to a method for color correction in an organic luminescence device having V to a pixel, comprising a layer of luminescent material, the package being lost between the first and second electrodes. The pixel constitutes at least a first and a a second illuminating element, wherein the method comprises the steps of: inputting a data signal having information not displayed by the illuminating element, and generating a correction coefficient for each illuminating element at -16 - the paper size is suitable for the material (CNS) A4 size (10) x 297 public) 1312978 A7 B7 V. Invention description (14) - In the correction device, the correction factor is based on a color point wavelength change Δλ and the voltage of any light-emitting element at a specific current (Is) And a relationship between a current flowing through one of the light-emitting elements at a specific voltage (vs), and a correction coefficient applied to the data signal from the correction device. The invention also relates to a drive device for performing the above method. It should be noted that the above-described specific examples are not intended to limit the invention, and those skilled in the art can devise many alternative embodiments without departing from the scope of the invention. In the case of such patents, all reference signals do not constitute a limitation. The words "include" do not exclude the presentation of components or steps, and not only the applicants listed in (4). """ or ·, _" does not exclude multiple components before the component. The invention may be implemented by a computer containing several unique components and via a suitable stylized computer. The devices may also be hard-assembled by one or the same item. The specific measurement of the coefficients in the patents of different individual towels does not mean that the combinations of the measurements cannot be used in combination. -17-

Claims (1)

Sixth, apply for patents圏 (6R 6G), wherein the method comprises the following steps: - loosening I, the device having at least one pixel (6), the layer being sandwiched between the third and third) 'the pixel constitutes the first and the first The second light-emitting element (1) wheel eight--a data signal (S) containing information to be displayed by the light-emitting element (6R, 6G), a correction coefficient is generated for the mother light-emitting element (6R'6G) by a correction coefficient The measurement is as follows: when a predetermined current (Is) flows through the light-emitting element, a voltage (V) changes across a light-emitting element (^) and a voltage change measured by the light-emitting element and a color point wavelength change ( a relationship between Δλ), or a current (1) change flowing through a light-emitting element (6R, 6G) during a predetermined voltage (Vs) across the light-emitting element, and a measurement of the light-emitting element (6R, 6G) Current change and one color point wavelength change ^ one relationship between humans, (111) applying the correction coefficient to the data signal; and (iv) applying the modified data signal (s) to the light-emitting element (6r, 6g). The method of claim 1, wherein the correction coefficient comprises A search table for pre-measuring information about a voltage applied to a light-emitting element (611 or 6(}), or a current applied to the light-emitting element (6R or 6G), and a wavelength-changing slave relationship of the light-emitting element. The method of claim 1, further comprising the step of transmitting one of the light-emitting elements (6R, 6G) having a predetermined current (Is) for a predetermined period of time, and measuring the voltage (V) of the light-emitting element (6R, 6G) When the predetermined current (Is) is transmitted through the light-emitting elements (6R, 6G), the paper size is applicable to the National Standard (CNS) A4 specification (210 X 297 mm). 1312978 Patent Application Range Depending on the voltage change AV between the measured voltage and the pre-voltage (V〇) of the predetermined current (Is), and the output - the light-emitting element (6r, 6g) based on the voltage change AV A correction factor for the wavelength change Δλ. 4. The method of claim 3, wherein the wavelength change Δλ of the light-emitting element (6r, (6) is calculated as: Δλ = k - AV > wherein k 疋 correction coefficient and k therein is for each illuminating element (6R, 6G) or each type of illuminating element pre-stored. 5. The method of claim 3, wherein the pre-voltage % is measured across the illuminating element (6R, 6G) when manufacturing the device (1) 6. The method of claim 3, wherein the pre-voltage v is a voltage that is measured across the light-emitting elements (6R, 6G) when the device is driven. The method of item 1, comprising the step of transmitting a light-emitting element (6R, 6G) having a predetermined voltage (Vs) during a predetermined time period, measuring a current (1) on the light-emitting element (6R '6G) at the predetermined voltage (\^) In the case of the light-emitting element (6R, 6G), a current change (Δ) between the measured current (1) and the predetermined current (Is) and a current change ΔΙ between the current and the current change Δ: [based on the light-emitting element ( A correction system for the wavelength change Δλ of 6r, 6G) 8. The method of claim 7, wherein the wavelength change Δλ of the light-emitting element (6R, 6G) is calculated as: -2- 1312978 AB c D , the patent application formula = Κ · Δ1 > 9. =- The positive coefficient of 疋t and its medium k are pre-stored in the correction device (1〇) for each of the light-emitting elements (6R, 0G) or the parent type of light-emitting elements. The method of the invention is the method of The material layer (7) comprises a mixture of 3 - 兀 I luminescent materials, _ organic luminescent materials, or - a mixture of poly vinegar and an organic luminescent material. 1. The method of claim W, wherein the coefficient is for each luminescence The light output from the element (6R, 6G) provides a substantially constant overall color point of the pixel. '11 kinds of driving devices (7) for the organic luminescent device (1), including a sandwich on the first and the a layer of luminescent material (5) between two electrode types (2, 3), wherein at least one pixel (6) defines at least one first and a second light-emitting element (6R, 0G), The driving device (7) is connected to the electrodes (2, 3) and configured to apply a current (1) to the cold light a material for obtaining illumination from the material, the driving device (7) comprising: an input connection (8) for wheeling a data signal (S) containing information to be displayed by the light-emitting element (6R '6G), a correction device (10) for applying a correction coefficient to the data signal (s). The far correction coefficient is based on a color point change and applying a voltage (v) to the light-emitting element (6R '6G) and The current (1) flows through a relationship between a measured change in one of the light-emitting elements (6R, 6G), and an output device (9) for outputting the color corrected data signal to the light-emitting elements (6R, 6G). This paper scale applies to the Chinese National Standard (CNS) A4 specification (21〇x 297 mm)