JP2006259239A - Device and method for driving active matrix type light emission display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for driving a light emission display panel by which successful color balance is maintained by simple structure. <P>SOLUTION: On the display panel 1, a display area (a) in which pixels of R (red), G (green), B (blue) for display are arrayed and an arrangement area b of elements for monitoring which monitor forward voltage of each of R, G, B are formed. Each element for monitoring corresponding to R, G, B is constituted of the different number of parallel connection objects, respectively, the same fixed current is supplied to each element for monitoring from fixed current sources IR, IG, IB and drive voltages VHR, VHG, VHB to be applied to respective pixels in R, G, B for display are controlled on the basis of forward voltages VfR, VfG, VfB generated at this time. The number of elements of the respective element for monitoring is set to the number of elements to obtain the drive voltage suitable for most successfully adjusting the color balance by pixels for display for each color, respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a driving apparatus and a driving method for an active matrix light-emitting display panel that displays images by selectively driving a large number of light-emitting elements to emit light using, for example, TFTs (Thin Film Transistors).

  With the widespread use of mobile phones and personal digital assistants (PDAs), there is an increasing demand for display panels that have high-definition image display functions and that can be thin and have low power consumption. Display panels have been adopted in many products as display panels that meet these requirements. On the other hand, recently, a display panel using an organic EL (electroluminescence) element utilizing the characteristic of being a self-luminous display element has been put into practical use, and this is drawing attention as a next-generation display panel that replaces a conventional liquid crystal display panel. ing. This is also due to the fact that the use of an organic compound that can be expected to have good light-emitting characteristics for the light-emitting functional layer of the device has led to higher efficiency and longer life that can withstand practical use.

  The organic EL element described above is basically configured by sequentially laminating a transparent electrode made of, for example, ITO, a light emitting functional layer made of an organic material, and a metal electrode on a transparent substrate such as glass. The light emitting functional layer is a single layer of an organic light emitting layer, or a two-layer structure comprising an organic hole transport layer and an organic light emitting layer, or a three layer comprising an organic hole transport layer, an organic light emitting layer and an organic electron transport layer. The structure may be a multilayer structure in which an electron or hole injection layer is inserted between these appropriate layers.

  The organic EL element described above can be electrically represented by an equivalent circuit as shown in FIG. That is, the organic EL element can be replaced with a configuration of a diode component E as a light emitting element and a parasitic capacitance component Cp coupled in parallel to the diode component E. The organic EL element is a capacitive light emitting element. It is considered.

  In the organic EL element, when a light emission driving voltage is applied, first, a charge corresponding to the electric capacity of the element flows into the electrode as a displacement current and is accumulated. Subsequently, when a certain voltage specific to the element (light emission threshold voltage = Vth) is exceeded, a current starts to flow from one electrode (the anode side of the diode component E) to the organic layer constituting the light emitting layer, and is proportional to this current. It can be considered that light is emitted with intensity.

  FIG. 2 shows the static light emission characteristics of such an organic EL element. According to this, as shown in FIG. 2A, the organic EL element emits light with a luminance L substantially proportional to the drive current I, and the drive voltage V becomes the light emission threshold voltage as shown by the solid line in FIG. When Vth is equal to or higher than Vth, the current I suddenly flows to emit light.

  In other words, when the drive voltage is equal to or lower than the light emission threshold voltage Vth, almost no current flows through the EL element and no light is emitted. Therefore, as shown by a solid line in FIG. 2 (c), the EL element has a luminance characteristic in which the emission luminance L increases as the value of the voltage V applied thereto increases in the light emission possible region that is higher than the threshold voltage Vth. It has the characteristic which becomes.

  On the other hand, it is known that the organic EL element described above changes the physical properties of the element due to long-term use, and the forward voltage Vf increases. For this reason, as shown in FIG. 2B, the organic EL element changes the VI (L) characteristic in the direction indicated by the arrow (characteristic indicated by the broken line) according to the actual usage time, and thus the luminance characteristic. Will also decline.

  Further, it is also known that the luminance characteristics of the organic EL element change depending on the temperature as shown by a broken line in FIG. That is, the EL element has a characteristic that in the light emission possible region larger than the above-described light emission threshold voltage, the light emission luminance L increases as the value of the voltage V applied thereto increases, but the light emission threshold voltage increases as the temperature increases. Get smaller. Therefore, the EL element is in a state in which light can be emitted with a smaller applied voltage as the temperature becomes higher, and has a luminance temperature dependency such that it is brighter at high temperatures and darker at low temperatures even when the same applied voltage capable of emitting light is applied.

  Furthermore, the above-described EL element has a problem that the light emission efficiency with respect to the driving voltage varies depending on the light emission color, and R (red), G (green), and B (blue), which can be put into practical use at present, respectively. As for the luminous efficiency of the EL element that emits light, in the initial stage, as shown in FIG. 2D, the luminous efficiency of G is high and the luminous efficiency of B is the lowest. Each of the EL elements that emit light of R, G, and B has a change with time and temperature dependency as shown in FIGS. 2B and 2C.

  Therefore, when EL elements that emit R, G, and B colors are arranged to perform full color display, the color balance (white balance) is lost due to environmental temperature and changes over time, and the display quality is kept constant. The problem that it becomes difficult to hold occurs. In particular, in an active matrix display panel driving apparatus in which each EL element is driven at a constant voltage by a TFT switching operation, the forward direction of each element as shown by the VI (L) characteristic shown in FIG. As the voltage Vf fluctuates, the light emission luminance fluctuates greatly, causing a problem that display quality is remarkably deteriorated.

Therefore, in order to solve the above-described problem, a monitoring element for monitoring the forward voltage Vf of each EL element that emits each color of R, G, and B is prepared, and the order obtained from each of the monitoring elements is obtained. Patent Document 1 discloses a driving device for a light emitting display panel in which driving voltages applied to EL elements that emit light of the respective colors are individually controlled based on a directional voltage Vf.
JP 2003-162255 A

  As described above, in the case of obtaining the forward voltage Vf of the EL elements that emit light of R, G, and B colors, together with the display EL elements arranged on the display panel, It is desirable to form the EL element by the same film formation process. Accordingly, each EL element for display and each EL element for monitoring can be formed to the same specification for each color.

  In this case, for example, in a pixel configuration in a QVGA format display panel, 320 pixels are arranged in the vertical direction of the screen. Therefore, if the monitoring elements are also formed by the same film forming process, 320 EL elements are used in parallel with each other as R, G, and B monitoring elements.

  FIG. 3 explains the situation. Reference numeral 1 denotes an active drive type light emitting display panel, and the display area a in this display panel includes a set of subpixels indicated by R, G, and B. Color display pixels surrounded by chain lines are arranged in a matrix. If the display panel 1 is in the QVGA format as described above, color display pixels of 240 pixels in the horizontal direction and 320 pixels in the vertical direction are arranged in the display area a. Shows only a part of the arrangement.

  On the other hand, a monitor element array region b is formed in a part of the display panel 1, and the monitor element array region b is formed simultaneously with the film forming process of the display region a. EL elements as elements are arranged. In this case, 320 EL elements (indicated by diode symbol marks) emitting light of R, G, and B in order from the left in the figure are connected in parallel for each line. Note that only a part of the arrangement of the monitoring elements is shown due to space limitations.

  The array line of the R, G, and B monitoring elements in the region b has a constant current source IR that supplies a constant current to each EL element as a monitoring element corresponding to R, and a monitor corresponding to G. There are provided a constant current source IG for supplying a constant current to each EL element as a monitoring element, and a constant current source IB for supplying a constant current to each EL element as a monitoring element corresponding to B. In addition, the forward voltage VfR generated when a constant current is supplied from the constant current source IR to the monitoring element is applied to the DC-DC converter 2R that supplies the drive voltage VHR to the sub-pixels that emit R. So as to be supplied as a control voltage.

  Similarly, the forward voltage VfG generated when a constant current is supplied from the constant current source IG to the monitoring element is controlled with respect to the DC-DC converter 2G that supplies the drive voltage VHG to the sub-pixel emitting G. Similarly, the forward voltage VfB generated when a constant current is supplied from the constant current source IB to the monitoring element supplies the drive voltage VHB to the sub-pixels that emit B. The control voltage is supplied to the DC-DC converter 2B.

  Each of the DC-DC converters 2R, 2G, and 2B functioning as the drive voltage control means constitutes a step-up converter using, for example, a battery as a primary power source, and monitors corresponding to the R, G, and B described above. The driving voltage values VHR, VHG, and VHB supplied to the sub-pixels are controlled in accordance with the forward voltages VfR, VfG, and VfB of the device. As a result, for each of R, G, and B, it is possible to supply the optimum drive voltage corresponding to the operating temperature and the change with time to each subpixel.

  By the way, as in the configuration shown in FIG. 3, when the drive voltages supplied to the R, G, and B display pixels are controlled based on the forward voltages VfR, VfG, and VfB of the monitoring elements, It is desirable to set the forward voltage value necessary for realizing the luminance for each color that maintains the best white balance by G and B. As described above, the forward voltage value necessary for realizing the brightness of each color that maintains the best white balance can be obtained in advance by a trial experiment or the like.

  Therefore, in the configuration shown in FIG. 3, the current values from the constant current sources applied to the monitoring elements corresponding to the respective R, G, and B are respectively adjusted to be obtained by the above-described prototype experiment. A method for setting each forward voltage value may be employed. For this, the circuit configuration of each constant current source is set to a different specification, or the circuit configuration is such that the current amount by each constant current source can be adjusted individually, and each current amount is adjusted individually. Problems such as the need for adjustment work to occur.

  The present invention has been made paying attention to the technical problems described above, and involves setting the circuit specifications for each constant current source as described above, or adjusting the amount of current from each constant current source. Provided a driving device and a driving method for an active drive type light emitting display panel that can secure a certain display quality by solving the problem and supplying a driving voltage that maintains a good white balance to the display panel. It is an object to do.

  The first preferred embodiment of the light emitting display panel drive device according to the present invention, which has been made to solve the above-mentioned problems, is a matrix according to claim 1, wherein light emitting elements exhibiting different light emission colors are used as display pixels. A drive device for an active matrix light-emitting display panel, in which each light-emitting element includes a light-emission driving transistor that selectively drives each light-emitting element to emit light, and emits light from the display pixel for each color. Based on at least two types of monitor elements corresponding to the colors for measuring the forward voltage of the elements, respectively, and the forward voltages obtained by the monitor elements, the display pixels for the respective colors Drive voltage control means for controlling the drive voltage value to be supplied, and each of the monitoring elements is a different element. Characterized in that constituted by the parallel connection of.

  According to a second preferred embodiment of the drive device for a light emitting display panel according to the present invention, as described in claim 3, light emitting elements exhibiting different light emission colors are arranged in a matrix as display pixels, and each of the light emitting elements is arranged. A drive device for an active matrix light-emitting display panel having a light-emitting drive transistor for selectively emitting light for each display pixel, and measuring a forward voltage of the light-emitting element in each display pixel for each color Based on at least two types of monitoring elements corresponding to the respective colors and the respective forward voltages obtained by the respective monitoring elements, the drive voltage value supplied to the display pixels for the respective colors is controlled. And a driving voltage control means, wherein each of the monitoring elements has a different film formation area. A.

  On the other hand, a preferable first aspect of the driving method of the light emitting display panel according to the present invention, which has been made to solve the above-mentioned problems, is that, as described in claim 11, light emitting elements exhibiting different light emission colors are used as display pixels. A driving method of an active matrix light-emitting display panel, wherein each display pixel includes a light-emitting drive transistor that is arranged in a matrix and selectively drives each light-emitting element to emit light, the display pixel for each color A forward voltage acquisition step for obtaining a voltage value corresponding to the forward voltage of the light emitting element in at least two types of monitoring elements corresponding to each color, and for each color based on the voltage value obtained by the step Drive voltage control step for controlling the drive voltage value supplied to the display pixels of the display, and the order of acquisition in the forward voltage acquisition step Direction voltage is characterized in that obtained from a parallel connection of a monitoring device having a number of different.

  According to a second preferred aspect of the driving method of the light emitting display panel according to the present invention, as described in claim 12, the light emitting elements exhibiting different light emission colors are arranged in a matrix form as display pixels, and each of the light emitting elements is arranged. A driving method of an active matrix light-emitting display panel provided with a light-emission driving transistor for selectively driving an element for each display pixel, corresponding to a forward voltage of the light-emitting element in the display pixel for each color A forward voltage acquisition step for obtaining a voltage value by at least two types of monitoring elements corresponding to each color, and a drive voltage value to be supplied to the display pixels for each color based on the voltage value obtained by the step The forward voltage acquired in the forward voltage acquisition step has different film formation areas. Characterized in that obtained from monitoring element having.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS A light emitting display panel driving apparatus according to the present invention will be described below based on the embodiments shown in the drawings. FIG. 4 is a circuit configuration diagram showing the first embodiment. In FIG. 4, compared to the example shown in FIG. 3 already described, a display area a in which color display pixels are arranged, and The scale display in the vertical direction in the array region b of the monitoring elements is expressed in a slightly narrowed form. In FIG. 4, parts that perform the same functions as those shown in FIG. 3 already described are denoted by the same reference numerals. Therefore, the description is omitted as appropriate.

  In the embodiment shown in FIG. 4 as well, the EL elements constituting the display pixels arranged in the display area a and the monitoring elements arranged in the area b are the same as in the example shown in FIG. Each light emitting color is composed of EL elements having the same specifications. That is, in the process of forming the display EL elements arranged on the display panel 1, the monitor EL elements are also formed using the same mask, whereby pixels having substantially the same dimensions (same area) are formed. Can be formed respectively. As a result, the electrical characteristics corresponding to the temperature dependency and the change with time of each EL element for display and each EL element for monitoring for each emission color can be substantially matched.

  FIG. 5 shows the configuration of each color display pixel arranged in the display area a in FIG. In FIG. 5, only the circuit configuration of two sets of color pixels including R, G, and B sub-pixels is shown for the sake of space. As shown in FIG. 5, data lines mR1, mG1, mB1,... To which data signals from the data driver are supplied are arranged in the vertical direction in the display area of the display panel, and scanning selection signals from the scanning driver are displayed. Are arranged in the horizontal direction.

  Further, the display panel is arranged with power supply lines pR1, pG1, pB1,... Corresponding to the data lines in the vertical direction, and these power supply lines serve as drive voltage control means described later. Drive voltages VHR, VHG, and VHB provided from a DC-DC converter or the like are respectively supplied.

  Each of the subpixels indicated by R, G, and B has a pixel configuration based on a conductance control system as an example. That is, as shown in FIG. 5 by assigning symbols to the elements constituting the upper left sub-pixel, the gate of the control transistor Q1 composed of an n-channel TFT is connected to the scanning selection line n1, and its source Is connected to the data line mR1. The drain of the control transistor Q1 is connected to the gate of the light emission drive transistor Q2 formed of a p-channel TFT and to one terminal of the charge holding capacitor C1.

  The source of the light emission drive transistor Q2 is connected to the other terminal of the capacitor C1 and to the power supply line pR1. Further, the anode of the EL element E1 as a light emitting element is connected to the drain of the light emission driving transistor, and the cathode of the EL element E1 is connected to the cathode side power supply line Vg. Thus, the sub-pixels having the above-described configuration constitute a color pixel by combining R, G, and B, and a large number of these color pixels are arranged in a matrix in the vertical and horizontal directions on the display panel.

  In the pixel configuration described above, when the on-voltage is supplied to the gate of the control transistor Q1 from the scan driver via the scan selection line n1, the control transistor Q1 is set to the data voltage from the data line mR1 supplied to the source. A corresponding current is passed from the source to the drain. Therefore, the capacitor C1 is charged while the gate of the control transistor Q1 is on-voltage, and the voltage is supplied to the gate of the light emission driving transistor Q2.

  Therefore, the light emission drive transistor Q2 is turned on based on the voltage between its gate and source, and applies the drive voltage VHR provided from the DC-DC converter as the drive voltage control means to the EL element E1 to emit light from the EL element. Drive. That is, in this embodiment, the light emission drive transistor Q2 formed of a TFT is configured to perform two types of switching operations (operating in a linear region) that are turned on or off by a data voltage supplied from the data driver. .

  On the other hand, when the gate of the control transistor Q1 becomes an off voltage, the transistor becomes a so-called cut-off, and the drain of the control transistor Q1 is opened, but the light emission drive transistor Q2 has a gate voltage due to the charge accumulated in the capacitor C1. Is maintained, and the state in which the drive voltage VHR is applied to the EL element E1 is continued until the next scanning, whereby the light emission of the EL element E1 is also maintained.

  Here, in the embodiment shown in FIG. 4, the constant current sources IR, IG, and IB that supply constant currents to the monitoring elements for the respective colors are configured to supply substantially the same value of current. Has been. This eliminates the problem of making the circuit configurations of the constant current sources different from each other as described with reference to FIG. 3, and the problem of having to adjust the constant current amount of each constant current source individually. be able to. The above-mentioned current having the same value means that the current is set to have the same value in design, and does not mean the same including the range of circuit variation.

  In the above-described configuration, the drive voltages VHR, VHG, and VHB supplied to the display pixels R, G, and B are for each color that maintains the best color balance (white balance) by the display pixels. It is desired that the driving voltage value necessary for realizing the luminance is set.

  For this reason, in the embodiment shown in FIG. 4, the number of elements of the parallel connection body constituting each of the monitor elements is such that the color balance by the R, G, and B display pixels is most optimally adjusted. The number of elements for obtaining the optimum driving voltage is set. As described above, the forward voltage values VfR, VfG, and VfB necessary for realizing the brightness for each color that maintains the best white balance as described above can be obtained in advance by a trial experiment or the like. .

  In the embodiment shown in FIG. 4, B (blue) emission color monitoring elements constitute eight parallel connection bodies as an example, and R (red) emission color monitoring elements as an example. Six parallel connections are configured. The G (green) emission color monitor element constitutes four parallel connection bodies as an example. Thus, with the above-described configuration, it is possible to use constant current sources IR, IG, and IB having the same specifications for each color, and the circuit can be simplified and unadjusted.

  In addition, according to the configuration shown in FIG. 4, each monitor element for each emission color can be configured by a parallel connection body with a relatively small number of EL elements. The amount of current from the current source can be reduced, and power can be saved.

  In the configuration shown in FIG. 4 described above, the drive voltage is directly applied to the display EL element by controlling the on / off of the light emission driving transistor (switching control) as in the pixel configuration described with reference to FIG. By adopting the constant voltage drive pixel configuration to which the drive voltage from the control means is applied, it is possible to realize a more preferable temperature compensation and compensation operation corresponding to a change with time.

  Next, FIG. 6 is a circuit configuration diagram showing a second embodiment of the driving apparatus according to the present invention. In FIG. 6, parts that perform the same functions as those shown in FIG. The same reference numerals are used. Therefore, the description is omitted. The embodiment shown in FIG. 6 shows an example in which a drive voltage to be supplied to a sub-pixel is generated using a voltage regulator as drive voltage control means as required.

  That is, the drive voltage VHB supplied to the B (blue) emission color sub-pixels that require a relatively high voltage is obtained by using the DC-DC converter 2B in the same manner as shown in FIG. Has been. On the other hand, the drive voltage VHR supplied to the R (red) emission color sub-pixel that requires the next highest voltage after the B emission color sub-pixel uses the drive voltage VHB from the DC-DC converter 2B. The voltage regulator 3R is used for generation. The voltage regulator 3R functions as drive voltage control means for generating a drive voltage VHR using VfR obtained from the monitoring element.

  The drive voltage VHG to be supplied to the G (green) emission color sub-pixel that requires the lowest drive voltage is generated using the voltage regulator 3G using the drive voltage VHR obtained by the voltage regulator 3R. It is configured. The voltage regulator 3G also functions as drive voltage control means for generating the drive voltage VHG using VfG obtained from the monitoring element.

  According to the series regulator configuration shown in FIG. 6 described above, it is not necessary to provide DC-DC converters corresponding to the respective emission colors, and the circuit can be simplified as compared with the configuration shown in FIG. The same effect as the structure shown in (1) can be obtained.

  FIG. 7 is a circuit configuration diagram showing a third embodiment of the driving apparatus according to the present invention. In FIG. 7 as well, parts that perform the same functions as those shown in FIG. This is indicated by the reference numeral. Therefore, the description is omitted. In the embodiment shown in FIG. 7, the drive voltages supplied to the sub-pixels of R, G, and B emission colors are generated stepwise using voltage regulators.

  That is, in the embodiment shown in FIG. 7, one step-up DC-DC converter 2C is prepared, and the drive voltage VHB supplied to the sub-pixels of B emission color is obtained using the output of this converter 2C. I am doing so. The drive voltages VHR and VHG supplied to the R and G emission color sub-pixels are configured to be obtained step by step using the voltage regulators 3R and 3G, as in the example shown in FIG.

  In the series regulator configuration shown in FIG. 7 as well, it is not necessary to provide a DC-DC converter corresponding to each emission color, and the circuit can be simplified compared to the configuration shown in FIG. The same effect as the structure shown can be obtained.

  FIG. 8 is a circuit configuration diagram showing a fourth embodiment of the driving apparatus according to the present invention. In FIG. 8 as well, parts that perform the same functions as those shown in FIG. This is indicated by the reference numeral. Therefore, the description is omitted.

  In the embodiment shown in FIG. 8, the monitoring elements corresponding to the R, G, and B emission colors are different from the monitoring elements shown in FIGS. It is comprised by the film-forming area. This is because the monitoring elements shown in FIG. 4, FIG. 6, and FIG. 7 are parallel connections of different numbers of elements having a predetermined area, whereas this is the sum of the parallel connections. These are none other than films formed in different areas.

  Therefore, the film formation areas constituting the R, G, and B monitor elements in the configuration shown in FIG. 8 are also optimum drive voltages VHR for the best color balance by the display pixels for each color. , VHG, VHB are set to film forming areas where forward voltages VfR, VfG, VfB necessary for obtaining VHG, VHB can be generated.

  Therefore, even in the configuration shown in FIG. 8, the same operation and effect as the configuration shown in FIG. 4 can be obtained. Further, the embodiment of the series regulation system shown in FIG. 6 and FIG. 7 may be used even when the monitor elements corresponding to the respective emission colors are formed with different film formation areas as shown in FIG. It can employ | adopt suitably.

  In the embodiment described above, an example is shown in which monitor elements corresponding to the respective emission colors of R, G, and B are provided. For example, depending on the characteristics of the R, G, and B emission elements. It is also possible to compensate the color balance of the display pixels for two colors using the forward voltage by one monitor element. Therefore, in the above-described case, it is possible to realize a light emitting display panel driving device that can compensate for color balance (white balance) by using at least two types of monitoring elements.

  Further, according to the embodiment described above, each monitoring element is accompanied by a light emitting operation because a predetermined current is supplied from the constant current source to each monitoring element. Therefore, it is desirable that the monitor element arrangement region b in the display panel 1 is covered with a light shielding mask (not shown) that blocks light emitted from each monitor element.

  Furthermore, in the above-described embodiment, an example in which an organic EL element is used as each of the display and monitor elements arranged on the display panel is shown. However, the change with time and temperature as shown in FIG. Even when other light-emitting elements having dependency are used, similar effects can be obtained.

It is an equivalent circuit diagram of an organic EL element. It is the static characteristic figure which showed the various characteristics of the organic EL element. It is the circuit block diagram which showed an example of the drive device with the solution subject of this invention. 1 is a circuit configuration diagram showing a first embodiment of a driving apparatus according to the present invention; FIG. 5 is a circuit configuration diagram showing an example of each color display pixel arranged in the display area shown in FIG. 4. It is the circuit block diagram which showed 2nd Embodiment of the drive device concerning this invention. It is the circuit block diagram which similarly showed 3rd Embodiment. It is the circuit block diagram which similarly showed 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emission display panel 2C-2R DC-DC converter (drive voltage control means)
3B-3R voltage regulator (drive voltage control means)
C1 Charge retention capacitor E1 Light emitting element (organic EL element)
IB to IR constant current source Q1 control transistor Q2 light emission drive transistor mB1 to mR1 data line n1, n2 scan selection line pB1 to pR1 power supply line

Claims (15)

Driving an active matrix light emitting display panel in which light emitting elements exhibiting different light emission colors are arranged in a matrix as display pixels, and each light emitting driving transistor for selectively driving each light emitting element to emit light is provided for each display pixel. A device,
Based on at least two types of monitoring elements corresponding to the colors for measuring the forward voltage of the light emitting elements in the display pixels for each color, respectively, and the forward voltages obtained by the monitoring elements. Drive voltage control means for controlling the drive voltage value supplied to the display pixels for each color, and
The driving device for an active matrix light-emitting display panel, wherein each of the monitoring elements is formed of a parallel connection body having a different number of elements.   2. The drive device for an active matrix light-emitting display panel according to claim 1, wherein the light-emitting elements constituting the display pixels and the monitor elements are composed of elements having the same specifications. Driving an active matrix light-emitting display panel in which light-emitting elements exhibiting different emission colors are arranged in a matrix as display pixels, and each light-emitting drive transistor that selectively drives each light-emitting element to emit light is provided for each display pixel. A device,
Based on at least two types of monitoring elements corresponding to the colors for measuring the forward voltage of the light emitting elements in the display pixels for each color, respectively, and the forward voltages obtained by the monitoring elements. Drive voltage control means for controlling the drive voltage value supplied to the display pixels for each color, and
The drive device for an active matrix light-emitting display panel, wherein each of the monitor elements has a different film formation area.   A constant current source for supplying a constant current to each of the monitoring elements is provided, and constant current values supplied from the constant current source to the monitoring elements are set to the same value. 4. The drive device for an active matrix light-emitting display panel according to claim 1, wherein the driving device is a light-emitting display panel.   The number of elements of the parallel connection body constituting each monitor element is set to the number of elements for obtaining the optimum driving voltage so that the color balance by the display pixels for each color is best adjusted. The drive device for an active matrix light-emitting display panel according to claim 4.   The film-forming area constituting each monitor element is set to a film-forming area that obtains the optimum driving voltage so that the color balance by the display pixels for each color is best adjusted. The drive device for an active matrix light-emitting display panel according to claim 4.   The light-emitting element that constitutes the display pixel and the monitor element are respectively formed on the same light-emitting display panel. Drive device for active matrix light-emitting display panel.   8. The display pixel according to claim 1, wherein each of the display pixels includes a light emitting element that emits R (red), G (green), and B (blue). The active matrix light-emitting display panel driver described.   The light emission drive transistor that constitutes the display pixel performs two kinds of switching operations of on and off based on the video signal, and the drive voltage from the drive voltage control means is displayed via the light emission drive transistor. 9. The drive of an active matrix light-emitting display panel according to claim 1, wherein the light-emitting element is selectively supplied to the light-emitting elements constituting the pixels. apparatus.   The light-emitting element and the monitor element in the display pixel are organic EL elements each including at least one light-emitting functional layer made of an organic material. Active matrix light emitting display panel drive device. Driving an active matrix light emitting display panel in which light emitting elements exhibiting different light emission colors are arranged in a matrix as display pixels, and each light emitting driving transistor for selectively driving each light emitting element to emit light is provided for each display pixel. A method,
A forward voltage acquisition step of obtaining a voltage value corresponding to a forward voltage of a light emitting element in the display pixel for each color by using at least two kinds of monitoring elements corresponding to each color, and the voltage obtained by the step A drive voltage control step of controlling a drive voltage value supplied to the display pixels for each color based on the values,
A driving method of an active matrix light-emitting display panel, wherein the forward voltage acquired in the forward voltage acquisition step is obtained from a parallel connection body of monitoring elements each having a different number. Driving an active matrix light emitting display panel in which light emitting elements exhibiting different light emission colors are arranged in a matrix as display pixels, and each light emitting driving transistor for selectively driving each light emitting element to emit light is provided for each display pixel. A method,
A forward voltage acquisition step of obtaining a voltage value corresponding to a forward voltage of a light emitting element in the display pixel for each color by using at least two kinds of monitoring elements corresponding to each color, and the voltage obtained by the step A drive voltage control step of controlling a drive voltage value supplied to the display pixels for each color based on the values,
A driving method of an active matrix light-emitting display panel, wherein the forward voltage acquired in the forward voltage acquisition step is obtained from monitor elements having different film formation areas.   In the forward voltage acquisition step, a constant current having the same value is supplied from each constant current source to each of the monitoring elements, and the forward voltage generated at each of the monitoring elements is acquired at this time. 13. A method for driving an active matrix light-emitting display panel according to claim 11 or claim 12.   The number of elements of the parallel connection body constituting each monitor element is set to the number of elements for obtaining the optimum driving voltage so that the color balance by the display pixels for each color is best adjusted. The method for driving an active matrix light-emitting display panel according to claim 13.   The film-forming area constituting each monitor element is set to a film-forming area that obtains the optimum driving voltage so that the color balance by the display pixels for each color is best adjusted. A method for driving an active matrix light-emitting display panel according to claim 13.

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