KR100490196B1 - Electronic device, driving method of electronic device, electric optical device and electronic equipment - Google Patents

Abstract

An electronic circuit, an electronic device, a method of driving the electronic circuit, an electro-optical device, and an electronic device capable of detecting an operating characteristic of the electronic circuit with high precision are provided.

The switching current Q13 connected to the pixel circuit 20 between the driving transistor Q11 and the organic EL element 21 and the driving current output from the driving transistor Q11 are used to detect the current. A detection transistor Q14 to be supplied is provided. In the state where the switching transistor Q13 is turned off, the switching transistor Q12 is turned on to supply the test data current Vdata to the sustain capacitor C1. Next, the detection transistor Q14 is turned on while the switching transistor Q13 is turned off, and the driving current from the driving transistor is supplied to the current detection circuit 19a through the detection transistor Q14. The current detection circuit 19a can detect the drive current for the data current Vdata for testing.

Description

ELECTRONIC DEVICE, DRIVING METHOD OF ELECTRONIC DEVICE, ELECTRIC OPTICAL DEVICE AND ELECTRONIC EQUIPMENT}

The present invention relates to an electronic circuit, an electronic device, a driving method of the electronic circuit, an electro-optical device, and an electronic device.

In recent years, the electro-optical device using an organic electroluminescent element attracts attention as a display device as an electro-optical device. As an electro-optical device using this kind of organic EL element, there is an active matrix driving method as one of the driving methods.

In an electro-optical device of an active matrix drive system, pixel circuits are provided for each organic EL element in order to control the luminance of the organic EL element. Control of the luminance gradation of the organic EL element in each pixel circuit is performed by supplying a data signal (voltage value or current value) corresponding to the luminance gradation to the sustain capacitor of the pixel circuit. That is, the holding capacitor is charged with electric charges according to the set luminance luminance gray scale.

Further, the conduction state of the driving TFT (Thin Film Transistor) is set in accordance with the amount of charge held in the holding capacitor, and a current corresponding to the conduction state is supplied to the organic EL element (see Patent Document 1, for example).

[Patent Document 1] International Publication No. WO98 / 36406 Pamphlet

By the way, although the pixel circuit consists of active elements, such as at least one transistor, it is difficult to exactly uniformize the characteristic of all the active elements. In particular, thin film transistors (TFTs) constituting pixel circuits such as displays have a large variation in characteristics. For this reason, when a predetermined data signal is input, desired luminance is hard to be obtained.

Moreover, there exists a problem that a characteristic changes with time-lapse deterioration of the active element and electro-optical element which comprise a pixel circuit.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide an electronic circuit, an electronic device, a method of driving the electronic circuit, an electro-optical device, and an electronic device capable of detecting the operating characteristics of the electronic circuit with high accuracy. have.

A first electronic device according to the present invention is an electronic device having a plurality of unit circuits, each of which holds a first transistor and an electric signal supplied through the first transistor as an electric quantity. An element, a second transistor whose conduction state is controlled based on the amount of electricity held by the holding element, a driven element to which an amount of current relative to the conduction state is supplied, and a third transistor connected in series with the second transistor And an inspection unit for detecting an amount of current through the third transistor.

According to this, by turning on the third transistor, the amount of current relative to the amount of charge from the second transistor to be supplied to the driven element can be obtained through the third transistor. Therefore, the operating characteristic of the electronic circuit can be detected. The third transistor may be provided in each unit circuit, or may be provided in common for some of the plurality of unit circuits.

A second electronic device of the present invention is an electronic device having a plurality of unit circuits, each of the plurality of unit circuits comprising a first transistor, a holding element for holding an electrical signal supplied through the first transistor as an electric quantity; And a second transistor whose conduction state is controlled based on the amount of electricity held by the holding element, and a driven element to which an amount of current relative to the conduction state is supplied, wherein the second transistor is in series with the first transistor. It is connected, and it is connectable to the test | inspection part for detecting an amount of electric current through said 1st transistor, It is characterized by the above-mentioned.

As a corresponding embodiment of this 2nd electronic device, the electronic device which has a circuit structure to which a current signal is supplied as an electrical signal like 4th embodiment mentioned later is mentioned, for example.

In the above electronic device, a fourth transistor is connected between the driven element and the second transistor.

According to this, the third transistor or the first transistor is turned on while the fourth transistor is turned off and the current supply to the driven device is stopped, thereby to be supplied to the driven device. The amount of current passing through the second transistor can be detected through the third transistor or the first transistor. That is, it is preferable that the fourth transistor is at least in an off state in the period in which the inspection unit detects.

In the electronic device, the driven element may be, for example, a current driving element such as an organic EL element. In the organic EL device, the light emitting layer is composed of an organic material.

In the electronic device, the third transistor is preferably provided in each of the plurality of unit circuits. This makes it possible to detect the current characteristics of each of the plurality of unit circuits.

In the electronic device, the holding element may be, for example, a capacitor which holds the electric signal supplied to each of the plurality of unit circuits as the amount of charge.

In the electronic device, the holding element may be a memory element such as an SRAM.

The electronic device was provided with a memory circuit which stores a correction value for an electrical signal supplied through the first transistor obtained by the inspection unit.

According to this, the operation | movement element of a driven element can be adjusted by correcting the operation characteristic of an electronic device using the correction value memorize | stored in the memory circuit.

In a method of driving an electronic device according to the present invention, a conduction state is set based on a first transistor, a holding element for holding an electric signal supplied through the first transistor as an electric quantity, and an amount of electricity held by the holding element. A method of driving an electronic device having a second transistor, a driven element supplied with an amount of current relative to the conduction state, and a third transistor connected in series with the second transistor, the method comprising: turning on the first transistor and A first step of holding an electric quantity based on an electric signal on the holding element, and electrically connecting a test portion for detecting the amount of current with the second transistor by turning the third transistor on, through the third transistor, Of current passing through a current path comprising the second transistor and the third transistor. In that it includes a second step of detecting a ryuryang characterized.

According to this, the inspection section can detect the amount of current to be supplied to the driven element in the inspection section.

In the method of driving the electronic device, it is preferable that the current path does not include the driven element.

In the method for driving the electronic device, the driven element may be a current driving element such as an organic EL element.

A first electro-optical device according to the present invention is an electro-optical device having a plurality of pixel circuits arranged corresponding to intersections of a plurality of scan lines and a plurality of data lines, wherein each of the plurality of pixel circuits includes a plurality of pixel lines. A first transistor whose conduction is controlled by a scan signal supplied through a corresponding scan line, a retention element for holding corresponding data lines of the plurality of data lines and a data signal supplied through the first transistor as an electric quantity; A second transistor whose conduction state is controlled based on the amount of electricity held by the holding element, an electro-optical element to which an amount of current relative to the conduction state is supplied, and a third transistor connected in series with the second transistor, Each of the plurality of pixel circuits is in contact with an inspection unit that detects an amount of current through the third transistor. Characterized in that possible.

In the electro-optical device, the third transistor may be provided in each of the plurality of pixel circuits, or may be provided in common in some pixel circuits of the plurality of pixel circuits.

In the electro-optical device, the third transistor may be connectable to the inspection unit via corresponding data lines of the plurality of transistors. According to this, it is possible to use a data line as inspection wiring, without providing the inspection wiring.

A second electro-optical device of the present invention is an electro-optical device having a plurality of pixel circuits arranged corresponding to intersections of a plurality of scan lines and a plurality of data lines, each of the plurality of pixel circuits corresponding to the plurality of scan lines. A first transistor whose conduction is controlled by a scan signal supplied through a scan line, a holding element for holding a corresponding data line of the plurality of data lines and a data signal supplied through the first transistor as an electric quantity, and the holding The plurality of pixel circuits, the conducting state being controlled based on the amount of electricity held in the element, the second transistor connected in series with the first transistor, and an electro-optical element to which an amount of current relative to the conducting state is supplied; Each can be connected to an inspection unit for detecting the amount of current through the first transistor. The.

In the electro-optical device, the inspection unit includes a current detection circuit that detects the amount of current, a correction value calculation circuit that obtains a correction value for the electric signal based on the amount of current detected by the current detection circuit, and the pixel circuit. And a memory circuit for storing the correction value, and when setting the electric signal, correcting the electric signal with the correction value.

According to this, a correction value for adjusting the deviation of the operating characteristics of the pixel circuit is calculated by the correction value calculating circuit, and the memory circuit stores the correction value for the pixel circuit. Therefore, the operation characteristic of the driven element can be adjusted by correcting the operation characteristic of the pixel circuit using the correction value of the electronic circuit stored in the memory circuit.

The said electro-optical device is mounted in the electronic device in this invention.

Embodiment of the Invention

(1st embodiment)

EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment which actualized this invention is described according to FIGS.

FIG. 1 shows a block circuit diagram showing a circuit configuration of an organic EL display 10 as an electro-optical device. 2 is a block circuit diagram showing an internal circuit configuration of a display panel portion and a data line driver circuit. 3 shows a circuit diagram showing an internal circuit configuration of a pixel circuit.

In Fig. 1, the organic EL display 10 includes a display panel section 11, a data line driver circuit 12, a scan line driver circuit 13, a memory 14, an oscillator circuit 15, a select circuit 16, and the like. The control circuit 17 is provided.

Each element 11-17 of the organic electroluminescent display 10 may be comprised by the independent electronic component, respectively. For example, each element 12-17 may be comprised by the semiconductor integrated circuit apparatus of a chip. Moreover, you may be comprised by the electronic component in which all or one part of each element 11-17 was integrated. For example, the data line driver circuit 12 and the scan line driver circuit 13 may be integrally formed in the display panel unit 11. All or part of each component 12-16 may be comprised by a programmable IC chip, and the function may be implemented by software by the program written in an IC chip.

As shown in FIG. 2, the display panel unit 11 includes a plurality of pixel circuits 20 arranged in a matrix. That is, each pixel circuit 20 includes a plurality of data lines X1 to Xm (m is an integer) extending along the column direction and a plurality of scanning lines Y1 to Yn (n is an integer) extending along the row direction. By connecting to each other, each pixel circuit 20 is arranged in matrix form. Each pixel circuit 20 includes an organic EL element 21 whose light emitting layer is made of an organic material as a driven element. In addition, although the transistor mentioned later formed in the pixel circuit 20 may be a silicon-based transistor, in this embodiment, it is comprised from the thin film transistor (TFT).

The data line driver circuit 12 is provided with a data voltage generator 12a for each of the data lines X1 to Xm. Each data voltage generation circuit 12a supplies an electric signal, that is, a data signal (data voltage V data) in the present embodiment, to the pixel circuit 20 through corresponding data lines X1 to Xm, respectively. When the internal state of the pixel circuit 20 is set in accordance with the data voltage Vdata, the pixel circuit 20 controls the current value flowing through the organic EL element 21 accordingly, thereby controlling the value of the organic EL element 21. The brightness is controlled.

The scan line driver circuit 13 selects and drives one of the plurality of scan lines Yn to select a pixel circuit group for one row. The scanning lines Y1 to Yn each consist of a first sub scan line Va and a second sub scan line Vb. The scan line driver circuit 13 outputs the first selection signal SL1 to the first sub-scanning line Va, and outputs the second selection signal SL2 to the second sub-scanning line Vb. The memory 14 stores display data supplied from the computer 18. In addition, the memory 14 is configured to store test display data supplied from the inspection device 19 that constitutes the correction value calculation circuit. The oscillation circuit 15 supplies a reference operation signal to other components of the organic EL display 10.

The select circuit 16 is provided between the display panel unit 11 and the data line driver circuit 12. Each select circuit 16 includes a switching circuit 16a for each data line X1 to Xm. Each switching circuit 16a is composed of a first gate transistor Q1 and a second gate transistor Q2, respectively, as shown in FIG. Further, the first gate transistor Q1 of each select circuit 16 connects the corresponding data lines X1 to Xm and the corresponding data voltage generation circuit 30, respectively. The second gate transistor Q2 of each select circuit 16 has a current detection circuit provided for each of the corresponding data lines X1 to Xm and the corresponding data lines X1 to Xm provided in the inspection apparatus 19 as the inspection unit. Each of 19a is connected. The first and second gate transistors Q1 and Q2 are controlled to be turned on and off based on the first and second gate signals G1 and G2 from the control circuit 17, respectively.

The control circuit 17 collectively controls the above elements 11 to 16. The control circuit 17 stores the display data (image data) from the computer 18 stored in the memory 14 indicating the display state of the display panel unit 11 to determine the luminance of light emission of each organic EL element 21. Convert to the matrix data indicated. The matrix data includes a scan line drive signal for sequentially selecting a pixel circuit group for one row and a data line drive signal for determining the level of the data voltage Vdata for setting the luminance of the organic EL element 21 of the selected pixel circuit group. . In addition, the scan line drive signal is supplied to the scan line drive circuit 13. In addition, the data line driving signal is supplied to the data line driving circuit 12.

In addition, the control circuit 17 enters a test mode when the organic EL display 10 inspects each pixel circuit 20 of the display panel unit 11 using the inspection apparatus 19. When the test mode is entered, the control circuit 17 converts the test display data (image data) from the inspection device 19 stored in the memory 14 into matrix data indicating the luminance of light emission of each organic EL element 21. Convert to (test matrix data).

The test matrix data includes a test scan line drive signal for sequentially selecting one pixel circuit group for one row and a level of the test data voltage Vdata for setting the test luminance of the organic EL element 21 of the selected pixel circuit group. And a data line drive signal for testing to determine. The scanning line driving signal for a test is supplied to the scanning line driving circuit 13. The data line driving signal for a test is supplied to the data line driving circuit 12. In addition, in the test mode, the control circuit 17 receives the first and second gate signals G1 and G2 for performing inspection on each pixel circuit 20 of the display panel unit 11. 16). In the normal mode other than the test mode, the control circuit 17 outputs only the first gate signal G1, turns on the first gate transistor Q1, and turns off the second gate transistor Q2. I keep it.

Next, the internal circuit configuration of the pixel circuit 20 will be described with reference to FIG. 3. For convenience of explanation, the pixel circuit 20 disposed at the intersection of the m-th data line Xm and the n-th scan line Yn and connected between both data lines Xm and the scan line Yn will be described. do.

In the present embodiment, the pixel circuit 20 is a voltage-driven pixel circuit and includes an organic EL element 21 as a driven element. The driving transistor Q11 as the second transistor, the switching transistor Q12 as the first transistor, the light emission control transistor Q13 as the fourth transistor, the detection transistor Q14 as the third transistor, and the holding capacitor as the holding element ( C1).

The switching transistor Q12 and the light emission control transistor Q13 are composed of N-channel TFTs. The driving transistor Q11 and the detecting transistor Q14 are composed of P-channel TFTs.

In the driving transistor Q11, the drain is connected to the anode of the organic EL element 21 via the switching transistor Q13, and the source is connected to the power supply line L1. The holding capacitor C1 is connected between the gate of the driving transistor Q11 and the power supply line L1. The gate of the driving transistor Q11 is connected to the data line Xm through the switching transistor Q12. The drain of the driving transistor Q11 is connected to the data line Xm through the detection transistor Q14.

The first sub scanning line Va is connected to the gate of the switching transistor Q12. The source of the detection transistor Q14 is connected to the first sub scan line Va. In addition, the gates of the light emission control transistor Q13 and the detection transistor Q14 are both connected to the second sub scan line Vb.

Next, the operation of the organic EL display 10 configured as described above will be described according to the operation of the pixel circuit 20.

(Normal mode)

First, the normal mode will be described according to the timing chart of each of the signals SL1, SL2, G1, G2 shown in FIG.

Now, when the n-th scanning line Yn is selected and each pixel circuit 20 connected to the scanning line Yn enters a light emission operation, the first sub-scanning line Va of the scanning line Yn from the scanning line driver circuit 13 is entered. ), The first selection signal SL1 for turning on the switching transistor Q12 is output, and the switching transistor Q12 is turned on. At the same time, the first gate signal G1 for turning on the first gate transistor Q1 is output from the control circuit 17 to the respective switching circuits 16a of the select circuit 16, and the first gate transistor ( Q1) is turned on. At this time, based on the switching transistor Q12 and the first gate transistor Q1, the data voltage Vdata is applied from the data voltage generation circuit 12a to the holding capacitor C1 of each pixel circuit 20 corresponding thereto. Each is supplied. After the time t1 has elapsed, the first select signal SL1 and the first gate signal G1 for turning off the switching transistor Q12 and the first gate transistor Q1 are supplied, and the data writing period ends. .

In the period in which the data voltage Vdata is supplied to the pixel circuit 20 through the switching transistor Q12 in the on state, the detection transistor Q14 and the light emission control transistor Q13 are turned on respectively.

During the time t1 or after the time t1 has elapsed, the supply of the current to the organic EL element according to the conduction state of the driving transistor Q11 is started.

Subsequently, the light emission control transistor Q13 is turned off, the supply of the current to the organic EL element is stopped, and the start of the next data writing period is awaited.

In the period in which the data voltage Vdata is supplied to the pixel circuit 20 through the switching transistor Q12, the detection transistor Q14 may be any of an on state and an off state.

However, since a slight current flowing between the pixel circuit 20 and the data line Xm through the detection transistor Q14 in the on state may cause the data voltage Vdata to perturb. As in the embodiment, the detection transistor Q14 is preferably turned off in the period in which the data voltage Vdata is supplied to the pixel circuit 20 through the switching transistor Q12.

Further, of course, the detection transistor Q14 may be turned off in the entire period of the normal mode.

In the present embodiment, the light emission control transistor Q13 and the detection transistor Q14 have a circuit configuration in which complementary operations are performed, but of course, they may be independently controlled.

By repeating this operation, the organic EL elements 21 of the pixel circuits 20 on the respective scanning lines Y1 to Yn are controlled to emit light with luminance corresponding to the data voltage Vdata, respectively, and the organic EL display 10 An image based on the display data from the computer 18 is displayed.

(Test mode)

Next, a test mode which is one embodiment of the driving method will be described. The organic EL display 10 enters the test mode by connecting to the inspection apparatus 19. When test display data is output from the inspection apparatus 19 to the organic EL display 10, the control circuit 17 enters the test mode, and the test display data is used to adjust the luminance gradation of the light emission of each organic EL element 21. It converts into the matrix data (test matrix data) shown. In addition, the control circuit 17 outputs the scan line drive signal for a test and the data line drive signal for a test to the scan line drive circuit 13 and the data line drive circuit 12.

5 is a timing chart of each signal SL1, SL2, G1, G2 in the test mode. Now, for example, the first selection signal SL1 for turning on the switching transistor Q12 is output from the scanning line driver circuit 13 to the first sub scanning line Va of the scanning line Yn, and thus the scanning line ( The switching transistor Q12 of each pixel circuit 20 on Yn is turned on. At the same time, the first gate signal G1 for turning on the first gate transistor Q1 from the control circuit 17 to the respective switching circuits 16a of the select circuit 16 is outputted to each switching circuit 16a. First gate transistor Q1 is turned on.

As a result, the test data voltage Vdata is supplied from the data voltage generation circuit 12a to the holding capacitor C1 through the switching transistor Q12 and the first gate transistor Q1 in the on state. On the other hand, in the period in which the test data voltage Vdata is being supplied, the second selection signal SL2 which turns off the detection transistor Q14 is supplied to leave the detection transistor Q14 in the off state.

After the time t1 has elapsed, the first select signal SL1 and the first gate signal G1 for turning off the switching transistor Q12 and the first gate transistor Q1 are supplied to the pixel circuit 20. The data writing period ends. At this time, the second selection signal SL2 for turning on the detection transistor Q14 and the light emission control transistor Q13 is turned on and off, respectively.

Subsequently, the second gate signal G2 for turning on the second gate transistor Q2 is supplied from the control circuit 17 to each switching circuit 16a of the select circuit 16, and the second gate transistor Q2. ) Is turned on. In the pixel circuit 20, a driving current having a current value relative to the test data voltage Vdata based on the operation of the driving transistor Q11 flows based on the second gate transistor Q2. At this time, the driving current from the driving transistor Q11 is applied to each pixel circuit 20 on the scanning line Yn of the inspection apparatus 19 through the detection transistor Q14 and the second gate transistor Q2. Are output to the respective current detection circuits 19a provided.

In addition, this operation is sequentially performed for each pixel circuit 20 of each scan line Y1 to Yn, and is provided in each current detection circuit 19a provided for each pixel circuit 20 of each scan line Y1 to Yn. Is output.

In the inspection apparatus 19, the current detection circuit 19a provided for each pixel circuit 20 of each of the scanning lines Y1 to Yn digitally converts the input output current to obtain the output current value as the detection current value, respectively. . In addition, the inspection apparatus 19 compares the detected current value of the pixel circuit 20 obtained by each current detection circuit 19a with the set current value for the data voltage Vdata for testing, respectively. In addition, the inspection apparatus 19 temporarily stores the comparison result. The set current value is a current value that must be output in standard from the pixel circuit 20 in the data voltage Vdata for the test, and is a value obtained from a test or a theory in advance.

After temporarily storing this comparison result, the same test is performed on the organic EL display 10 using a data voltage Vdata for a test having a different value. In addition, the inspection apparatus 19 compares the detected current value of the pixel circuit 20 obtained by each current detection circuit 19a with the set current value for the data voltage Vdata for testing, respectively, and compares the result. Remember.

The inspection apparatus 19 inspects the output current characteristics of the driving transistor Q11 with respect to the data voltage Vdata of each pixel circuit 20 on the basis of the comparison result with the data voltage Vdata for two different tests. In addition, the inspection apparatus 19 obtains a correction value for each pixel circuit 20 so that the characteristic of each pixel circuit 20 becomes the characteristic of a target (standard). That is, the correction value? Vd for the data voltage Vdata for the set luminance is obtained for each pixel circuit 20.

The inspection apparatus 19 outputs the correction value ΔVd obtained for each of the pixel circuits 20 to the organic EL display 10. The correction value? Vd obtained for each pixel circuit 20 is stored in a memory 17a made of a nonvolatile memory or the like built in the control circuit 17, and the test mode ends. In the present embodiment, although stored in the memory 17a, a fuse for setting the correction value may be formed, and the corresponding fuse may be cut based on the inspection result of the inspection apparatus 19.

In addition, the control circuit 17 uses the correction value ΔVd when converting the display data (image data) from the computer 18 into matrix data indicating the gradation of light emission of each organic EL element 21. . In detail, the control circuit 17 corrects the data voltage Vdata for setting the luminance of the organic EL element 21 of each pixel circuit 20 obtained based on the display data to the corresponding correction value ΔVd, respectively. Let one value be the new data voltage Vdata. The control circuit 17 outputs the new data voltage Vdata of each pixel circuit 20 to the data line driving circuit 12 as a data line driving signal.

Therefore, it is possible to detect the deviation of the operating characteristics of each pixel circuit (each transistor; in particular, the driving transistor Q11) due to the manufacturing horseshoe. The luminance of the organic EL element 21 of each pixel circuit 20 can be made constant by correcting variations in the operating characteristics of the pixel circuits 20.

In addition, when the detection current value is not within the reference range, the inspection apparatus 19 can be used as a determination material of whether or not it can be shipped as a product if the pixel circuit 20 is judged to be inoperable.

Next, the characteristic of the organic electroluminescent display 10 comprised as mentioned above is described below.

(1) In this embodiment, the switching transistor Q13 and the detection transistor Q14 are provided in the pixel circuit 20. In the test mode, the drive current of the current value with respect to the test data current Vdata from the drive transistor Q11 can be supplied to the current detection circuit 19a of the detection device 19 through the detection transistor Q14. I made it.

Therefore, the operation characteristic of each pixel circuit 20 by manufacturing variation can be detected easily. As a result, the defective product of the organic EL display 10 can be inspected before shipping.

(2) In this embodiment, the correction value which correct | amends the error of the operating characteristic based on manufacture deviation which the inspection apparatus 19 calculated | required for each pixel circuit 20 in the memory 17a built into the control circuit 17. That is, the correction value (ΔVd) for the data voltage Vdata for the set luminance was stored. Moreover, the control circuit 17 correct | amended the data voltage Vdata which sets the brightness | luminance of the organic electroluminescent element 21 of each pixel circuit 20 calculated | required based on display data with the corresponding correction value (triangle | delta) Vd, respectively.

Therefore, each pixel circuit 20 can supply the organic EL element 21 with a driving current having a uniform current value with respect to the data voltage Vdata based on the display data, and can emit the organic EL element with uniform luminance. have. In addition, since each pixel circuit 20 can correct the operation characteristics due to the manufacturing variation by the correction value ΔVd, the organic EL display, which is conventionally discarded as a defective product, can be improved as a product, thereby producing the organic display. Yield can be improved.

(3) In this embodiment, the drive current for detection is supplied to the current detection circuit 19a using the existing data lines X1 to Xm. Therefore, it is possible to suppress the increase in the circuit scale for the current detection.

In the present embodiment, the driving transistor (second transistor) Q11 and the detection transistor (third transistor) Q14 are connected in series, but the driving transistor Q11 and the detection transistor Q14 are connected in series. Other elements may be inserted in between. Also in this case, the detection transistor Q14 is connected in series with the driving transistor Q11.

(2nd embodiment)

Next, 2nd Embodiment is described. In the first embodiment, the inspection apparatus 19 was an external device, but in the present embodiment, the inspection apparatus 19 is the same as the elements 11 to 17 of the organic EL display 10 of the first embodiment. It is configured. Therefore, the inspection apparatus 19 is incorporated in a portable electronic device such as a mobile telephone, a PDA, a notebook personal computer, etc. which mount the organic EL display 10 together with the organic EL display 10.

In addition, since there is only a characteristic in the point which is incorporated in a portable electronic device, the part which is common to 1st Embodiment is abbreviate | omitted for convenience of description, and the characteristic part is demonstrated.

6 shows an electric circuit of the inspection device 19 of the present embodiment.

In Fig. 6, the current detection circuit section 31 is composed of a number of current detection circuits 31a corresponding to the data lines X1 to Xm. Each current detection circuit 31a analogly detects a drive current for the test data voltage Vdata from the drive transistor Q11 supplied from the data lines X1 to Xm via the switching circuit 16a, respectively. The test display data is stored in advance in the memory 17a of the control circuit 17.

Each current detection circuit 31a is connected to the corresponding AD converter 32a of the AD conversion circuit section 32. Each AD converter 32a converts the current value of the drive current supplied from the data lines X1 to Xm into a digital value and outputs it to the control circuit 17.

The control circuit 17 compares the current value of the drive current supplied from the data lines X1 to Xm from each AD converter 32a with the set current value for the data voltage Vdata for testing, respectively. In addition, the control circuit 17 temporarily stores the comparison result. That is, in this embodiment, the control circuit 17 performs the same inspection process as the inspection apparatus 19 of the said 1st Embodiment. In the present embodiment, the inspection is performed for each pixel circuit 20 connected on one scan line, and then the inspection of each pixel circuit on the next scan line is performed.

After temporarily storing this comparison result, the same test is performed on the organic EL display 10 using a data voltage Vdata for a test having a different value. As described above, the control circuit 17 compares the current value of the drive current supplied from the data lines X1 to Xm from each AD converter 32a with the set current value for the data voltage Vdata for testing, respectively. The result of the comparison.

The control circuit 17 examines the output current characteristics of the driving transistor Q11 with respect to the data voltage Vdata of each pixel circuit 20 on the basis of the comparison result of the data voltage Vdata for two different tests. In addition, the control circuit 17 calculates a correction value for each pixel circuit 20 so that the characteristic of each pixel circuit 20 becomes the characteristic of a target (standard). That is, the correction value? Vd for the data voltage Vdata for the set luminance is obtained for each pixel circuit 20. The control circuit 17 stores the obtained correction value? Vd in the memory 17a as the storage circuit, and the test mode ends. In addition, the control circuit 17 performs the test mode regularly or immediately after the power is turned on. The control circuit 17 drives the respective pixel circuits 20 based on the display data in the same manner as in the first embodiment using this correction value? Vd.

Next, the characteristic of the organic electroluminescent display 10 comprised as mentioned above is described below.

(1) In this embodiment, the switching transistor Q13 and the detection transistor Q14 are provided in the pixel circuit 20. In the test mode, the current value of the drive current with respect to the test data current Vdata from the drive transistor Q11 was supplied to the control circuit 17 through the detection transistor Q14.

In addition, the control circuit 17 detects operating characteristics of each pixel circuit 20. Therefore, the operation characteristic of each pixel circuit 20 by manufacturing variation can be detected easily, without using a large-scale inspection apparatus. In addition, when the control circuit 17 executes the test mode periodically or immediately after the power is turned on, the operating characteristics of the pixel circuits 20 due to aging change and environmental temperature change can be detected. .

(2) In this embodiment, the operation | movement based on the manufacturing deviation, secular variation, and change of environmental temperature which the said control circuit 17 calculated | required for each pixel circuit 20 in the memory 17a built into the control circuit 17 was carried out. The correction value for correcting the error of the characteristic, that is, the correction value ΔVd for the data voltage Vdata for the set luminance was stored. Moreover, the control circuit 17 correct | amended the data voltage Vdata which sets the brightness | luminance of the organic electroluminescent element 21 of each pixel circuit 20 calculated | required based on display data with the corresponding correction value (triangle | delta) Vd, respectively.

Therefore, each pixel circuit 20 can supply the organic EL element 21 with a driving current having a uniform current value with respect to the data voltage Vdata based on the display data even if the secular variation and the environmental temperature change. Can emit light with uniform brightness.

(3) In this embodiment, the drive current for detection is supplied to the current detection circuit 19a using the existing data lines X1 to Xm. Therefore, it is possible to suppress the increase in the circuit scale for the current detection.

(Third embodiment)

Next, application of the electronic device of the organic EL display 10 as the electro-optical device described in the first and second embodiments will be described with reference to FIGS. 7 and 8. The organic EL display 10 can be applied to various electronic devices such as mobile personal computers, mobile phones, and digital cameras.

7 is a perspective view showing the configuration of a mobile personal computer. In FIG. 7, the personal computer 50 is provided with the main-body part 52 provided with the keyboard 51, and the display unit 53 which used the said organic electroluminescent display 10. As shown in FIG. Also in this case, the display unit 53 using the organic EL display 10 exhibits the same effects as in the above embodiment. As a result, the personal computer 50 can realize image display with few defects.

8 is a perspective view showing the configuration of a mobile telephone. In FIG. 8, the cellular phone 60 is provided with a plurality of operation buttons 61, a telephone receiver 62, a telephone receiver 63, and a display unit 64 using the organic EL display 10. Also in this case, the display unit 64 using the organic EL display 10 exhibits the same effects as in the above embodiment. As a result, the cellular phone 60 can realize image display with few defects.

(4th Embodiment)

In this embodiment, the pixel circuit shown in FIG. 9 will be described with respect to the embodiment in which both the switching transistor and the detection transistor are used.

In FIG. 9, each pixel circuit 20 includes a driving transistor Q20 as a second transistor, a first switching transistor Q21 and a second switching transistor Q22, a light emission control transistor Q23, and a sustain element. The holding capacitor C1 is provided. The driving transistor Q20 is composed of a P-channel TFT. The first and second switching transistors Q21 and Q22 and the light emission control transistor Q23 are composed of N-channel TFTs.

In the driving transistor Q20, the drain is connected to the anode of the organic EL element 21 via the light emission control transistor Q23, and the source is connected to the power supply line L1. The driving voltage Vdd for driving the organic EL element 21 is supplied to the power supply line VL. The holding capacitor C1 is connected between the gate of the driving transistor Q20 and the power supply line VL.

The gate of the driving transistor Q20 is connected to the drain of the first switching transistor Q21. The source of the first switching transistor Q21 is connected to the drain of the second switching transistor Q22. The drain of the second switching transistor Q22 is connected to the drain of the driving transistor Q20.

The source of the second switching transistor Q22 is connected to the single line driver circuit 30 of the data line driver circuit 12 via the data line Xm. This single line drive circuit 30 is provided with a data current generation circuit 40a. The data current generation circuit 40a outputs a data signal I to the pixel circuit 20. The data line Xm is connected to the data current generating circuit 40a through the first switch Q11 and to the current detecting circuit 30b through the second switch Q12.

The first sub scan line Va and the second sub scan line Vb are connected to the gates of the first and second switching transistors Q21 and Q22, respectively. The first and second switching transistors Q21 and Q22 are turned on by the first scan signal SL1 and the second scan signal SL2 from the first sub scan line Va and the second sub scan line Vb. have. In addition, the gate of the light emission control transistor Q23 is controlled by the light emission control signal Gp.

In the period in which the first switch Q11, the first switching transistor Q21 and the second switching transistor Q22 are turned on, the data current generating circuit 40a supplies the data signal I to the data line Xm. When outputted through the pixel circuit 20, the data signal I is supplied to the pixel circuit 20, the charge amount corresponding to the data signal I is accumulated in the holding capacitor C1, and the conduction state of the driving transistor is set. This is a write operation.

Subsequently, when the light emission control transistor Q23 is turned on in response to the light emission control signal Gp for turning on the light emission control transistor Q23, the amount of current according to the conduction state of the driving transistor Q20 is organic EL element. 21 is supplied.

In contrast, in the test mode, the above write operation is basically the same, but instead of the normal data signal, the charge capacitor corresponding to the test signal is held in the holding capacitor. Next, the second switching transistor Q22 and the second switch Q12 are turned on while the first switching transistor Q21, the first switch Q11, and the light emission control transistor Q23 are turned off. In this way, the amount of current passing through the driving transistor Q20 is detected by the current detection circuit 30b.

In the fourth embodiment, unlike the first embodiment, one of the two switching transistors (the second switching transistor Q22) is also used as the detection transistor instead of newly installing the detection transistor.

In addition, embodiment of this invention is not limited to the said embodiment, It can also implement as follows.

In the said 1st Embodiment, the display was inspected using the inspection apparatus 19 which inspects the organic electroluminescent display before shipment. When the battery of the portable electronic device is charged with a charger for a portable electronic device such as a mobile phone, a PDA, a notebook personal computer, or the like, the organic EL display mounted on the portable electronic device during the charging is used as the inspection device 19. You can also check. In this case, it is necessary to embed a test device in the charger. In addition, when charging is started, the test mode is entered, and each pixel circuit 20 is subjected to current detection for inspection. By doing in this way, the organic EL display mounted in the portable electronic device can be corrected each time the operation characteristic due to the aging change of each pixel circuit 20 is charged.

In the above embodiment, the inspection apparatus 19 has provided the current detection circuits 19a for all the pixel circuits 20 of the display panel section 11, but as in the second embodiment, the data lines X1 to Xm. It may also be carried out in the same number as. In this case, inspection is performed for each pixel circuit 20 connected on one scan line as in the second embodiment, and then inspection of each pixel circuit on the next scan line is performed.

In the first embodiment, the correction value Vd obtained by the inspection apparatus 19 is stored in the memory 17a built in the control circuit 17, and the correction value Vd stored in the memory 17a is stored. Created a new data voltage Vdata.

In the above embodiment, the electronic circuit is embodied in the pixel circuit 20 to obtain a suitable effect. However, other than the organic EL element 21, for example, a driven element such as a light emitting element such as an LED or an FED is driven. It can also be embodied as an electronic circuit. In addition, there is a magnetic RAM as a driven element. Therefore, the present invention can also be applied to a memory device using the magnetic RAM.

In the said embodiment, when obtaining the correction value (DELTA) Vd, it tested and calculated | required using the data voltage Vdata for two different tests. The test may be performed using one test data voltage Vdata, or may be obtained by performing a test using three or more test data voltages Vdata.

In the above embodiment, the current is supplied to the current detection circuit through the data lines X1 to Xm, but the detection dedicated wiring is provided in the detection transistor Q13 and supplied to the current detection circuit 1 through these wirings. It may also be carried out.

In the said embodiment, although the organic EL element 21 was embodied as a driven element of a pixel circuit, it can also be embodied as an inorganic EL element. That is, it can also be applied to an inorganic EL display made of an inorganic EL element.

In the above embodiment, the pixel circuit 20 is embodied as a voltage-driven pixel circuit, but may be applied to an organic EL display of a current-driven pixel circuit. The present invention can also be applied to an organic EL display of a digitally driven pixel circuit such as time division and area gray scale.

According to the present invention, it is possible to provide an electronic circuit, an electronic device, a method of driving the electronic circuit, an electro-optical device, and an electronic device capable of detecting the operating characteristics of the electronic circuit with high accuracy.

1 is a block circuit diagram showing a circuit configuration of an organic EL display of this embodiment.

2 is a block circuit diagram showing an internal circuit configuration of a display panel portion and a data line driving circuit.

3 is a circuit diagram showing an internal circuit configuration of a pixel circuit.

4 is a timing chart of each signal in a normal mode.

5 is a timing chart of each signal in a test mode.

6 is an essential part electric block circuit diagram for describing the second embodiment;

Fig. 7 is a perspective view showing the structure of a mobile personal computer for explaining the third embodiment.

Fig. 8 is a perspective view showing the structure of a cellular phone for explaining the third embodiment.

9 is a circuit diagram showing an internal circuit configuration of a pixel circuit according to a fourth embodiment.

<Description of the symbols for the main parts of the drawings>

C1: holding capacitor as a capacitor

Q11: driving transistor as second transistor

Q12: switching transistor as first transistor

Q13: light emission control transistor as fourth transistor

Q14: Detection transistor as a third transistor

Y1 to Yn: scanning line

Va: first subscan

Vb: second sub-scanning line

X1 to Xm: data line

10: organic EL display as an electro-optical device

11 display panel

17: control circuit constituting the correction value calculation circuit

17a: memory as memory circuit

19: Inspection apparatus which comprises a correction value calculation circuit

19a: current detection circuit

20: pixel circuit as electronic circuit

21: organic EL device as driven device

31a: current detection circuit

Claims (15)

An electronic device having a plurality of unit circuits, Each of the plurality of unit circuits, The first transistor, A holding element for holding an electric signal supplied through said first transistor as an electric quantity; A second transistor whose conduction state is controlled based on the amount of electricity held by the holding element; A driven element to which an amount of current relative to the conduction state is supplied; A third transistor connected in series with said second transistor, And an inspection unit for detecting an amount of current through the third transistor. An electronic device having a plurality of unit circuits, Each of the plurality of unit circuits, The first transistor, A holding element for holding an electric signal supplied through said first transistor as an electric quantity; A second transistor whose conduction state is controlled based on the amount of electricity held by the holding element; A driven element to which a current amount relative to the conduction state is supplied; The second transistor is connected in series with the first transistor, And an inspection unit for detecting an amount of current through the first transistor. The method according to claim 1 or 2, And a fourth transistor is connected between the driven element and the second transistor. The method according to claim 1 or 2, The driven device is an electronic device, characterized in that the current drive device. The method of claim 3, wherein And the fourth transistor is at least in an off state in a period during which the inspection unit is detecting. The method of claim 1, And the third transistor is provided in each of the plurality of unit circuits. The method according to any one of claims 1, 2 and 6, And a memory circuit for storing a correction value for the electrical signal supplied through the first transistor obtained by the inspection unit. The method according to any one of claims 1, 2 and 6, The inspection unit detects a current passing through a current path including the second transistor, And the current path does not include the driven element. A first transistor, a holding element for holding an electric signal supplied through the first transistor as an electric quantity, a second transistor whose conduction state is set based on the amount of electricity held by the holding element, A driving method of an electronic device having a driven element supplied with a current amount and a third transistor connected in series with the second transistor, A first step of turning on the first transistor and holding the amount of electricity based on the electrical signal in the holding element; The third transistor is turned on, electrically connected to the second transistor and an inspection unit for detecting an amount of current through the third transistor, and passes through a current path including the second transistor and the third transistor. And a second step of detecting the amount of current in the current. The method of claim 9, And the current path does not include a driven element. An electro-optical device comprising a plurality of pixel circuits disposed corresponding to intersections of a plurality of scan lines and a plurality of data lines, Each of the plurality of pixel circuits, A first transistor whose conduction is controlled by a scan signal supplied through corresponding scan lines of the plurality of scan lines; A holding element for holding a corresponding data line of said plurality of data lines and a data signal supplied through said first transistor as an electric quantity; A second transistor whose conduction state is controlled based on the amount of electricity held by the holding element; An electro-optical element to which a current amount relative to the conduction state is supplied; A third transistor connected in series with said second transistor, And each of the plurality of pixel circuits is connectable to an inspection unit for detecting an amount of current through the third transistor. An electro-optical device comprising a plurality of pixel circuits disposed corresponding to intersections of a plurality of scan lines and a plurality of data lines, Each of the plurality of pixel circuits, A first transistor whose conduction is controlled by a scan signal supplied through corresponding scan lines of the plurality of scan lines; A holding element for holding a corresponding data line of said plurality of data lines and a data signal supplied through said first transistor as an electric quantity; A second transistor connected to the first transistor in series with the conduction state controlled based on the amount of electricity held by the holding element; An electro-optical element to which an amount of current relative to the conduction state is supplied; And each of the plurality of pixel circuits is connectable to an inspection unit for detecting an amount of current through the first transistor. The method of claim 11, And the third transistor is connectable to the inspection unit via corresponding data lines of the plurality of data lines. The method according to any one of claims 11 to 13, The inspection unit and the current detection circuit for detecting the amount of current; A correction value calculation circuit for obtaining a correction value for the electric signal based on the amount of current detected by the current detection circuit; A memory circuit for storing the correction value for the pixel circuit, And correct the electric signal with the correction value. The electronic device in which the electro-optical device in any one of Claims 11-13 is mounted.