JP2011169992A - Light emitting device, electronic device, device and method for inspecting light emitting panel, and method for canceling voltage drop of the light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cancel luminance variations caused by contact resistance variations by preventing reduction in luminance due to the contact resistance. <P>SOLUTION: The anode voltage VaL of a panel 1 is fed back to a PCB part 20, and the buffer circuit 21 of the PCB part 20 controls the current amount of current Iac so as to make the anode voltage VaL approach the anode voltage Va of a power supply circuit 14. Thus, the contact resistance Rpf_af and the contact resistance Rfg_af of wiring Naf are canceled. The cathode voltage VcL of the panel 1 is fed back to the PCB part 20, and a buffer circuit 22 controls the current amount of current Iac that the cathode voltage Vc of the power supply circuit 14 is equal to the cathode voltage VcL. Thus, the contact resistances Rpf_cf and the contact resistance Rfg_cf of wiring Ncf are canceled. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting device, an electronic apparatus, a light emitting panel inspection device, a voltage drop canceling method for the light emitting device, and a light emitting panel inspection method.

  An organic electroluminescence element (organic EL element) is formed of a fluorescent organic compound that emits light when an electric field is applied, and an organic light emitting diode (hereinafter referred to as organic EL) using the organic light emitting diode. ) A light-emitting device including a display panel having an element in each pixel is attracting attention as a next-generation display device (for example, see Patent Document 1).

  An organic EL element is a current-controlled light-emitting element (display element) that emits light using a phenomenon in which light is emitted by excitons generated by recombination of electrons and holes injected into an organic compound. The organic EL element has an anode and a cathode, and a current supplied to the anode flows to the cathode and emits light with a luminance corresponding to the current value of the supplied current.

  As shown in FIG. 9, the light emitting device includes an organic EL panel 11, a gate driver 12, a data driver 13, and a power supply circuit 14.

  The organic EL panel 11 has a plurality of organic EL elements, and each organic EL element is arranged in a matrix so as to correspond to each pixel of a display image based on display data. It is driven by the gate driver 12, the data driver 13, and the power supply circuit 14 to emit light.

  The gate driver 12 is a gate line selection driver arranged for each row of the organic EL panel 11. The data driver 13 is a driver for supplying a data current corresponding to a gradation value of display data via a data line arranged for each column.

  The power supply circuit 14 is a driver for supplying an anode potential to each organic EL element through a plurality of anode lines arranged for each row and supplying a current. Note that the cathodes of all the organic EL elements are connected to a plurality of cathode lines, and the cathodes of the respective pixels are common electrodes.

  Since a medium-size or larger light emitting device has a relatively large current flowing from the power supply circuit 14 to each organic EL element, as shown in FIG. 9, a panel portion 1, a PCB (Printed Circuit Board) portion 2, and an FPC (Flexible Printed Circuits) portion. It is divided into three.

  The organic EL panel is mounted on the glass panel portion 1, and the gate driver 12 and the data driver 13 are also mounted on the panel portion 1. Only the power supply circuit 14 is mounted on the PCB unit 2.

  Each gate line, each data line, each anode line, and each cathode line are metal-wired on the glass substrate of the panel unit 1, and each terminal of the PCB unit 2 and the metal wiring of the panel unit 1 are connected via the FPC unit 3. Connected.

  A wiring Na shown in FIG. 9 indicates a wiring between the power supply circuit 14 and each anode line, and a wiring Nc indicates a wiring between the power supply circuit 14 and each cathode line.

JP 2006-276713 A

  In the light emitting device configured as described above, the bonding surface J [pf] between the PCB portion 2 and the FPC portion 3 and the bonding surface J [fg] between the FPC portion 3 and the panel portion 1 shown in FIG. Are contact resistances Rpf_a, Rfg_a, Rpf_c, and Rfg_c as shown in FIG.

  The contact resistance Rpf_a indicates the contact resistance at the joint surface J [pf] of the wiring Na, and the contact resistance Rfg_a indicates the contact resistance at the joint surface J [fg] of the wiring Na. Further, the contact resistance Rpf_c indicates the contact resistance at the joint surface J [pf] of the wiring Nc, and the contact resistance Rfg_c indicates the contact resistance at the joint surface J [fg] of the wiring Nc.

  In a high-definition light-emitting device using an organic EL element, a current flowing between a plurality of anode lines and a plurality of cathode lines may be a relatively large current of several hundred mA to several A.

  In this case, even if the resistance values of the contact resistances Rpf_a, Rfg_a, Rpf_c, and Rfg_c are low resistance values of about several ohms, a large voltage drop occurs in the wirings Na and Nc. Due to the occurrence of this large voltage drop, the luminance of the organic EL panel 11 decreases. Further, if the contact resistances Rpf_a, Rfg_a, Rpf_c, and Rfg_c vary, the luminance also varies from panel unit 1 to panel unit 1.

  Conventionally, in order to reduce the voltage drop due to the contact resistances Rpf_a, Rfg_a, Rpf_c, and Rfg_c, as shown in FIG. To lower the However, even if the number of wirings Na and Nc is increased, there is a space limitation.

  This contact resistance also becomes a problem in the inspection process before shipment of the light emitting device. In this inspection process, before connecting the panel portion 1 and the PCB portion 2 with the FPC portion 3, as shown in FIG. 12, the inspection circuit 43 is connected to the panel portion 1 via the inspection contact probe 41 and the flat cable 42. Connected and a lighting test of the organic EL element is performed.

  As shown in FIG. 13, the inspection contact probe 41 is provided with a probe contact portion 41a, and an inspection needle (not shown) that contacts the metal wiring of the panel portion 1 is provided at the tip of the probe contact portion 41a. Is provided.

  The inspection needle of the probe contact portion 41a is pressed against the metal wiring by a spring, and the panel portion 1 and the inspection circuit 43 are electrically connected. The inspection circuit 43 includes a power supply circuit 14, and a current is supplied from the power supply circuit 14 to each anode line to perform a lighting inspection of the organic EL element.

  Similarly, in this inspection process, if a voltage drop occurs due to the contact resistance generated between the inspection contact probe 41 and the metal wiring, the screen brightness of the organic EL panel 11 becomes unstable and the contact resistance varies. If there is, the screen brightness varies from panel unit 1 to panel unit 1.

  The present invention has been made in view of such a conventional problem, a light-emitting device, an electronic apparatus, and the like, which can prevent a decrease in luminance due to contact resistance and suppress variation in luminance due to variation in contact resistance, It is an object of the present invention to provide a light-emitting panel inspection device, a light-emitting device voltage drop canceling method, and a light-emitting panel inspection method.

In order to achieve this object, a light emitting device according to the first aspect of the present invention provides:
A light-emitting panel in which a plurality of light-emitting elements are arranged;
A power supply board on which a power supply circuit for supplying a drive voltage and a reference voltage is mounted;
With
The light emitting panel includes a first current inflow terminal, a current supply line connected to the first current inflow terminal, and supplying a driving current to each light emitting element through the first current inflow terminal, A first voltage output terminal connected to a current supply line and outputting a voltage value of the current supply line as a first detection voltage;
The power supply board is connected to the first current inflow terminal of the light emitting panel through a connection member, and a first current outflow terminal for flowing out the drive current to the light emitting panel, and through the connection member A first voltage detection terminal connected to the first voltage output terminal for feeding back the first detection voltage is compared with the first detection voltage and the drive voltage, and the first detection is performed. A first buffer circuit that applies a first output voltage adjusted so as to approach the driving voltage to the first current outflow terminal, and causes the drive current to outflow from the first current outflow terminal; , Provided.

The light emitting panel includes: a current output line for outputting the driving current from each light emitting element; a second current outflow terminal connected to the current output line for flowing out the driving current of the current output line; A second voltage output terminal connected to a current output line and outputting a voltage value of the current output line as a second detection voltage;
The power supply board is connected to the second current outflow terminal of the light emitting panel via the connection member, and the second current inflow terminal into which the driving current flows from the light emitting panel, and the connection member A second voltage detection terminal connected to the second voltage output terminal via which the second detection voltage is fed back, and the second detection voltage and the reference voltage are compared. A second buffer for applying the second output voltage adjusted so that the detected voltage of the second current is close to the reference voltage to the second current inflow terminal, and causing the drive current to flow in from the second current inflow terminal And a circuit.

The first buffer circuit applies the first output voltage to the first current outflow terminal to make the first detection voltage equal to the drive voltage,
The second buffer circuit may apply the second output voltage to the second current inflow terminal to make the second detection voltage equal to the reference voltage.

The power supply board includes a first current measurement unit that measures a first current value of the drive current flowing out from the first current outflow terminal, the first current outflow terminal, and the first voltage detection terminal. A first voltage measurement unit that measures a first voltage between the terminals,
A first resistance value related to the connection member based on the first current value and the first voltage value is acquired, and based on the first resistance value, the connection member, the light emitting panel, and You may make it provide the control circuit which determines the quality of the connection state with the said power supply board | substrate.

The power supply board includes a second voltage measurement circuit that measures a second voltage value between the second current inflow terminal and the second voltage detection terminal,
The control circuit acquires a second resistance value related to the connection member based on the first current value and the second voltage value, and based on the value of the second resistance value, the connection member And whether the connection state between the light-emitting panel and the power supply board is good or bad may be determined.

  An electronic apparatus according to a second aspect of the present invention includes the above light-emitting device.

An inspection device for a light-emitting panel according to a third aspect of the present invention provides:
A plurality of light emitting elements are arranged and connected to a first current inflow terminal and a current supply line for supplying a driving current to each of the light emitting elements via the first current inflow terminal, and a voltage value of the current supply line Is connected to a first voltage output terminal that outputs the drive current from each light emitting element, and a second current that causes the drive current of the current output line to flow out. A light emitting panel comprising: a current outflow terminal; and a second voltage output terminal that is connected to the current output line and outputs a voltage value of the current output line as a second detection voltage. An inspection device,
An inspection circuit;
An inspection terminal connected to the inspection circuit and in contact with at least the first current inflow terminal and the first voltage output terminal;
With
The inspection circuit includes:
A power supply circuit for supplying a drive voltage and a reference voltage;
A first current outflow terminal that contacts the first current inflow terminal of the light emitting panel via the inspection terminal portion and outflows the drive current to the light emitting panel;
A first voltage detection terminal for contacting the first voltage output terminal of the light-emitting panel via the inspection terminal unit and feeding back the first detection voltage;
Comparing the first detection voltage and the drive voltage, applying a first output voltage adjusted to bring the first detection voltage close to the drive voltage to the first current outflow terminal; And a first buffer circuit that causes the drive current to flow out of the first current outflow terminal.

Each inspection needle of the inspection terminal portion contacts the second current outflow terminal and the second voltage output terminal,
The inspection circuit includes:
A second current inflow terminal that contacts the second current outflow terminal of the light emitting panel via the inspection terminal portion and into which the drive current flows from the light emitting panel;
A second voltage detection terminal that contacts the second voltage output terminal via the inspection terminal unit and feeds back the second detection voltage;
Comparing the second detection voltage with the reference voltage and applying a second output voltage adjusted to bring the second detection voltage close to the reference voltage to the second current inflow terminal; And a second buffer circuit that allows the drive current to flow from the second current inflow terminal.

The first buffer circuit applies the first output voltage to the first current outflow terminal to make the first detection voltage equal to the drive voltage,
The second buffer circuit may apply the second output voltage to the second current inflow terminal to make the second detection voltage equal to the reference voltage.

The inspection circuit includes a first current measuring unit that measures a first current value of the drive current flowing out from the first current outflow terminal, the first current outflow terminal, and the first voltage detection terminal. A first voltage measurement unit that measures a first voltage between the terminals,
Obtaining a first contact resistance value between the inspection terminal unit and the light emitting panel based on the first current value and the first voltage value, and based on the value of the first contact resistance value, You may make it provide the control circuit which determines the presence or absence of the contact failure of a test | inspection terminal part and the said light emission panel.

The inspection circuit includes a second voltage measurement circuit that measures a second voltage value between the second current inflow terminal and the second voltage detection terminal,
The control circuit obtains a second contact resistance value between the inspection terminal unit and the light emitting panel based on the first current value and the second voltage value, and a value of the second contact resistance value Based on the above, it may be determined whether there is a contact failure between the inspection terminal portion and the light emitting panel.

The voltage drop canceling method of the light emitting device according to the fourth aspect of the present invention is:
A plurality of light emitting elements are arranged and connected to a first current inflow terminal and a current supply line for supplying a driving current to each of the light emitting elements via the first current inflow terminal, and a voltage value of the current supply line Is connected to a first voltage output terminal that outputs the drive current from each light emitting element, and a second current that causes the drive current of the current output line to flow out. A driving voltage and a reference voltage are applied to a light emitting panel including a current outflow terminal and a second voltage output terminal connected to the current output line and outputting a voltage value of the current output line as a second detection voltage. Canceling the voltage drop of the light emitting device for canceling the voltage drop due to the connection member of the light emitting device to which the power supply board on which the power supply circuit for supplying the supply voltage and the reference voltage are mounted is connected via the connection member Method There,
An inflow step of supplying a first output voltage from the power supply substrate to the first current inflow terminal of the light-emitting panel through the connection member and causing the drive current to flow into the light-emitting panel;
A first feedback step of returning the first detection voltage from the first voltage output terminal of the light-emitting panel to the power supply substrate via the connection member;
When the first detection voltage fed back in the first feedback step is compared with the drive voltage, and the first detection voltage is lower than the drive voltage, the first output voltage A first comparison step of increasing the potential of
When the first detection voltage fed back in the first feedback step is compared with the drive voltage, and the first detection voltage is higher than the drive voltage, the first output voltage A second comparison step for reducing the potential of
The first comparison step and the second comparison step are repeatedly executed until the potentials of the first detection voltage and the drive voltage become equal, and the first detection voltage and the drive voltage are A first cancel step of canceling the voltage drop due to the connection member by applying the first output voltage when the voltage becomes equal to the first current outflow terminal;
It is characterized by including.

A second feedback step of feeding back the second detection voltage from the second voltage output terminal of the light-emitting panel to the power supply board via the connection member;
When the second detection voltage fed back by the second feedback step is compared with the reference voltage, and the second detection voltage is lower than the reference voltage, the second output voltage A third comparison step for increasing the potential of
When the first detection voltage fed back in the second feedback step is compared with the drive voltage, and the potential of the first detection voltage is higher than the potential of the drive voltage, the first output A fourth comparison step for reducing the potential of the voltage;
The third comparison step and the fourth comparison step are repeatedly executed until the potentials of the second detection voltage and the reference voltage become equal, and the second detection voltage and the reference voltage are A second canceling step of canceling the voltage drop due to the connecting member by applying the second output voltage at the same potential to the second current inflow terminal;
May be included.

An inspection method for a light-emitting panel according to a fifth aspect of the present invention includes:
A plurality of light emitting elements are arranged and connected to a first current inflow terminal and a current supply line for supplying a driving current to each of the light emitting elements via the first current inflow terminal, and a voltage value of the current supply line Is connected to a first voltage output terminal that outputs the drive current from each light emitting element, and a second current that causes the drive current of the current output line to flow out. A light emitting panel comprising: a current outflow terminal; and a second voltage output terminal that is connected to the current output line and outputs a voltage value of the current output line as a second detection voltage. An inspection method,
A contact step of bringing an inspection needle of an inspection terminal portion into contact with the first current inflow terminal and the first voltage output terminal of the light emitting panel;
A first output voltage is supplied to the first current inflow terminal of the light-emitting panel from an inspection circuit having a power supply circuit that supplies a drive voltage and a reference voltage via the inspection terminal unit, and the light-emitting panel is supplied with the first output voltage. An inflow step for causing the drive current to flow; and
A first feedback step of feeding back the first detection voltage from the first voltage output terminal of the light-emitting panel to the inspection circuit via the inspection terminal unit;
The first detection voltage fed back is compared with the drive voltage, and the first output voltage is increased when the first detection voltage is lower than the drive voltage. The comparison steps of
When the first detection voltage fed back in the first feedback step is compared with the drive voltage, and the first detection voltage is higher than the drive voltage, the first output voltage A second comparison step for reducing the potential of
The first comparison step and the second comparison step are repeatedly executed until the potentials of the first detection voltage and the drive voltage become equal, and the first detection voltage and the drive voltage are Applying a first output voltage to the first current outflow terminal when the potentials are equal to each other; and
It is characterized by including.

A second feedback step of feeding back the second detection voltage from the second voltage output terminal of the light-emitting panel to the inspection circuit via the inspection terminal unit;
When the second detection voltage fed back by the second feedback step is compared with the reference voltage, and the second detection voltage is lower than the reference voltage, the second output voltage A third comparison step for increasing the potential of
When the first detection voltage fed back in the second feedback step is compared with the drive voltage, and the potential of the first detection voltage is higher than the potential of the drive voltage, the first output A fourth comparison step for reducing the potential of the voltage;
The third comparison step and the fourth comparison step are repeatedly executed until the potentials of the second detection voltage and the reference voltage become equal, and the second detection voltage and the reference voltage are A second application step of applying the second output voltage when the potentials are equal to the second current inflow terminal;
May be included.

Measuring a first current value of the drive current flowing into the first current inflow terminal of the light emitting panel;
A first current outflow terminal connected to the first current inflow terminal of the light emitting panel through the inspection terminal portion of the inspection circuit, and the first current outflow terminal of the light emitting panel through the inspection terminal portion. Measuring a first voltage between the first voltage detection terminal connected to a voltage output terminal;
Based on the first current value and the first voltage value, a first contact resistance value between the inspection terminal unit and the light emitting panel is obtained, and based on the first contact resistance value Determining the presence or absence of poor contact between the inspection terminal portion and the light emitting panel;
May be included.

A second current inflow terminal connected to the second current outflow terminal of the light emitting panel through the inspection terminal portion of the inspection circuit; and the second current inflow terminal of the light emitting panel through the inspection terminal portion. Measuring a second voltage value between the second voltage detection terminal connected to the voltage output terminal;
Obtaining a second contact resistance value between the inspection terminal unit and the light emitting panel based on the first current value and the second voltage value, and based on the value of the second contact resistance value, Determining the presence or absence of poor contact between the inspection terminal portion and the light emitting panel;
May be included.

  According to the present invention, it is possible to prevent a decrease in luminance due to contact resistance and to suppress variations in luminance due to variations in contact resistance.

It is a figure which shows the electronic device (digital camera) in which the light-emitting device which concerns on Embodiment 1 of this invention is integrated. It is a figure which shows the electronic device (computer) in which the light-emitting device in which the light-emitting device which concerns on Embodiment 1 is integrated is integrated. It is a figure which shows the electronic device (cellular phone) in which the light-emitting device in which the light-emitting device which concerns on Embodiment 1 is integrated is integrated. It is a figure which shows the structure of the light-emitting device which concerns on Embodiment 1 of this invention. It is a figure which shows an example of a structure of a pixel circuit. FIG. 5 is a diagram illustrating a configuration of a buffer circuit illustrated in FIG. 4 and a connection relationship among a PCB unit, an FPC unit, and a panel unit. It is a figure which shows the structure of the PCB part which concerns on Embodiment 2 of this invention, and the connection relationship between a PCB part, a FPC part, and a panel part. It is a figure which shows the structure of the inspection apparatus which concerns on Embodiment 3 of this invention, and the connection relation of an inspection apparatus, the contact probe for an inspection, and a panel part. It is a figure which shows the light-emitting device with which the PCB part, the FPC part, and the panel part were connected. It is the schematic which shows the connection relation of the light-emitting device shown in FIG. It is a figure which shows the conventional example which connected the PCB part and panel part which are shown in FIG. 10 by several wiring. It is a figure which shows the example which connects an inspection apparatus to a panel part via the contact probe for an inspection. It is a side view which shows the connection state of the panel part shown in FIG. 12, an inspection apparatus, and the contact probe for an inspection.

Hereinafter, a light-emitting device, an electronic apparatus, and a light-emitting device inspection device according to embodiments of the present invention will be described with reference to the drawings. The first embodiment relates to the light emitting device 10 and the electronic device, and the third embodiment relates to a light emitting device inspection device.
(Embodiment 1)

  The light emitting device 10 is incorporated in a digital camera 200 as shown in FIG. 1, a computer 210 as shown in FIG. 2, and an electronic device 220 such as a mobile phone as shown in FIG.

  As shown in FIGS. 1A and 1B, the digital camera 200 includes a lens unit 201, an operation unit 202, a display unit 203, and a viewfinder 204. The light emitting device 10 is used for the display unit 203.

  A computer 210 illustrated in FIG. 2 includes a display unit 211 and an operation unit 212, and the light emitting device 10 is used for the display unit 211.

  A mobile phone 220 illustrated in FIG. 3 includes a display unit 221, an operation unit 222, a receiving unit 223, and a transmitting unit 224, and the light emitting device 10 is used for the display unit 221.

  As shown in FIG. 4, the light emitting device 10 includes an organic EL panel 11, a gate driver 12, a data driver 13, a power supply circuit 14, and buffer circuits 21 and 22.

  The organic EL panel 11 includes a plurality of gate lines Lg, a plurality of anode lines La and a plurality of cathode lines Lc formed in the row direction, a plurality of data lines Ld formed in the column direction, each gate line Lg, and an anode. And a plurality of pixel circuits 110 formed in the vicinity of each intersection of the line La and cathode line Lc and each data line Ld. Each pixel circuit 110 is a display pixel corresponding to one pixel of the display image. Each pixel circuit 110 includes an organic EL element 111 and an EL pixel driving circuit 112. An example of the configuration of the pixel circuit 110 is shown in FIG.

  The EL pixel drive circuit 112 is a circuit that drives the organic EL element 111, and includes a drive transistor T1 that supplies a drive current to the organic EL element 111, a switch transistor T2, and a capacitor Cp. The drive transistor T1 and the switch transistor T2 are TFTs (Thin Film Transistors) configured by, for example, n-channel FETs (Field Effect Transistors). In the EL pixel driving circuit 112 shown in FIG. 5, the gate of the switch transistor T2 is connected to the gate line Lg, the drain of the switch transistor T2 is connected to the data line Ld, and the source of the switch transistor T2 is one electrode of the capacitor Cp and It is connected to the gate of the driving transistor T1. The switch transistor T2 is turned on when the voltage of the gate line Lg becomes high level by the gate driver 12. The capacitor Cp is connected between the source of the switch transistor T2 and the source of the drive transistor T1, and holds charge corresponding to the voltage applied to the data line Ld when the switch transistor T2 is turned on. The drain of the driving transistor T1 is connected to the anode line La, the source of the driving transistor T1 is connected to the other electrode of the capacitor Cp and the anode of the organic EL element 111, and the cathode of the organic EL element 111 is connected to the cathode line Lc. Yes. The drive transistor T1 supplies a drive current from the anode line La to the organic EL element 111 according to the electric charge held in the capacitor Cp.

  The gate driver 12 is a driver that sequentially selects the pixel circuits 110 in each row of the organic EL panel 11, and is configured by, for example, a shift register. The gate driver 12 is connected to the pixel circuits 110 in each row via each gate line Lg.

  The data driver 13 is a driver that applies a voltage signal having a voltage corresponding to the gradation value of the display data to each EL pixel driving circuit 112. The data driver 13 is connected to the EL pixel driving circuit 112 in each column via each data line Ld.

  The power supply circuit 14 applies an anode voltage as a drive voltage to each EL pixel drive circuit 112 via a plurality of anode lines La, and an anode-cathode current (hereinafter referred to as “current Iac”) is applied to the plurality of anode lines La. ). The current Iac is a total of drive currents supplied to the organic EL elements 111 of the plurality of pixel circuits 110.

  The power supply circuit 14 is connected to each EL pixel driving circuit 112 via a plurality of anode lines La, and is connected to the cathode of the organic EL element 111 of each pixel circuit 110 via a plurality of cathode lines Lc. The plurality of cathode lines Lc are commonly connected to the cathodes of the organic EL elements 111.

  The organic EL panel 11, the gate driver 12, and the data driver 13 are mounted on the panel unit 1 made of, for example, a glass substrate. The power supply circuit 14 and the buffer circuits 21 and 22 are mounted on a PCB section (power supply board) 20, and the panel section 1 and the PCB section 20 are connected via the FPC section 3.

  As shown in FIG. 6, the panel unit 1 has terminals Pgaf, Pgas, Pgcf, and Pgcs. The terminal Pgaf is a current inflow terminal through which the supplied current Iac flows and is connected to the plurality of anode lines La and distributes the flowing current Iac to each anode line La. The terminal Pgas is a voltage output terminal that is connected to each anode line La and outputs the anode voltage VaL detected in each anode line La.

  The terminal Pgcf is connected to a plurality of cathode lines Lc, and is a current outflow terminal for flowing out a current Iac consisting of the total current output from each organic EL element 111 to each cathode line Lc. The terminal Pgcs is each cathode A voltage output terminal connected to the line Lc for outputting the cathode voltage VcL detected on each cathode line Lc.

  The PCB section 20 has terminals Ppaf, Ppas, Ppcf, and Ppcs as shown in FIG. The terminal Ppaf is a current outflow terminal that is electrically connected through the terminal Pgaf of the panel unit via the wiring Naf and outflows the current Iac when the PCB unit 20 and the panel unit 1 are connected.

  When the PCB part 20 and the panel part 1 are connected, the terminal Ppas is electrically connected to the terminal Pgas of the panel part 1 via the wiring Nas, and feeds back the anode voltage VaL detected in each anode line La. This is a voltage detection terminal.

  The terminal Ppcf is electrically connected via the terminal Pgcf of the panel unit 1 and the wiring Ncf when the PCB unit 20 and the panel unit 1 are connected, and a current inflow terminal for flowing in the current Iac flowing out from the terminal Pgcf. It is.

  When the PCB part 20 and the panel part 1 are connected, the terminal Ppcs is electrically connected to the terminal Pgcs of the panel part 1 via the wiring Ncs, and feeds back the cathode voltage VcL detected in each cathode line Lc. This is a voltage detection terminal.

  The buffer circuit 21 is a circuit that adjusts the output voltage Va_out to cancel (suppress) a voltage drop due to the contact resistance of the wiring Naf between the terminal Ppaf of the PCB unit 20 and the terminal Pgaf of the panel unit 1. As shown in FIG. 6, the buffer circuit 21 includes an operational amplifier 21a and a transistor Q1.

  6 indicates the contact resistance of the joint surface J [pf] between the PCB portion 20 and the FPC portion 3 in the wiring Naf, and the contact resistance Rfg_af indicates the FPC portion 3 and the panel portion 1 in the wiring Naf. The contact resistance of the joint surface J [fg] is shown.

  Further, the contact resistance Rpf_as indicates the contact resistance of the joint surface J [pf] in the wiring Nas, and the contact resistance Rfg_as indicates the contact resistance of the joint surface J [fg] in the wiring Nas.

  The operational amplifier 21a compares the anode voltage Va and the anode voltage VaL, and outputs an output voltage Vout21 adjusted so that both voltages are equal. Here, the anode voltage Va is a drive voltage applied by the power supply circuit 14, and the anode voltage VaL is an actual drive voltage fed back from each anode line La of the panel unit 1. The operational amplifier 21a operates by applying a positive voltage VccA (+) and a negative VccA (−) from the power supply as operating voltages.

  The + (non-inverting) input terminal of the operational amplifier 21a is connected to the anode voltage output terminal of the power supply circuit 14, and the-(inverting) input terminal is connected to the terminal Ppas. The anode voltage VaL is fed back via the terminal Pgas of the panel unit 1 and the terminal Ppas of the PCB unit 20 and supplied to the negative input terminal.

  The transistor Q1 is a transistor that outputs an output voltage Va_out based on the output signal Vout21 output from the operational amplifier 21a and supplies a current Iac, and is configured by, for example, an npn Darlington type power transistor.

  The base of the transistor Q1 is connected to the output terminal of the operational amplifier 21a, and the emitter is connected to the terminal Ppaf. A positive voltage VccA (+) is applied to the collector of the transistor Q1.

  The buffer circuit 22 adjusts the output voltage Vc_out to cancel the voltage drop due to the contact resistances Rpf_cf and Rfg_cf of the wiring Ncf between the terminal Ppcf of the PCB unit 20 and the terminal Pgcf of the panel unit 1. The buffer circuit 22 includes an operational amplifier 22a and a transistor Q2.

  Note that the contact resistance Rpf_cf illustrated in FIG. 6 indicates the contact resistance of the joint surface J [pf] in the wiring Ncf, and the contact resistance Rfg_cf indicates the contact resistance of the joint surface J [fg] in the wiring Ncf.

  Further, the contact resistance Rpf_cs indicates the contact resistance of the joint surface J [pf] in the wiring Ncs, and the contact resistance Rfg_cs indicates the contact resistance of the joint surface J [fg] in the wiring Ncs.

  The operational amplifier 22a compares the cathode voltage Vc and the cathode voltage VcL and outputs an output voltage Vout22 adjusted so that both voltages are equal. The cathode voltage Vc is a reference voltage applied by the power supply circuit 14, and the cathode voltage VcL is an actual reference voltage fed back from each cathode line Lc of the panel unit 1. The operational amplifier 22a operates by applying a positive voltage VccC (+) and a negative voltage VccC (−) from the power supply as operating voltages.

  The + input terminal of the operational amplifier 22 a is connected to the cathode voltage output terminal of the power supply circuit 14, and the − (inverted) input terminal is connected to the terminal Ppcs of the PCB section 20. The cathode voltage VcL is fed back via the terminal Pgcs of the panel unit 1 and the terminal Ppcs of the PCB unit 20 and supplied to the negative input terminal of the operational amplifier 22a.

  The transistor Q2 is a transistor that outputs the output voltage Vc_out based on the output signal Vout22 output from the operational amplifier 22a and draws the current Iac. The transistor Q2 is constituted by a pnp Darlington type power transistor, for example.

  The base of the transistor Q2 is connected to the output terminal of the operational amplifier 22a, the emitter is connected to the terminal Ppcf of the PCB section 20, and a negative voltage VccC (−) is applied to the collector.

Next, the operation of the light emitting device 10 according to Embodiment 1 will be described.
The anode voltage Va is applied from the power supply circuit 14 to the + input terminal of the operational amplifier 21 a of the buffer circuit 21. The cathode voltage Vc is applied from the power supply circuit 14 to the + input terminal of the operational amplifier 22 a of the buffer circuit 22.

  The anode voltage Va applied from the power supply circuit 14 to the + input terminal of the operational amplifier 21a is the initial voltage 0V. The anode voltage Va is a voltage desired to be applied to each anode line La from 0V when the application of the anode voltage Va is started. stand up. Since the voltage applied to the negative input terminal of the operational amplifier 21a is 0V in the initial stage, when the anode voltage Va increases from 0V, the output voltage Vout21 of the operational amplifier 21a increases. At this time, the transistor Q1 is on.

  When the output voltage Vout21 rises, the output voltage Va_out of the buffer circuit 21 also rises, and the current Iac flows into the panel part 1 via the terminal Ppaf of the PCB part 20, the FPC part 3, and the terminal Pgaf of the panel part 1.

  The current Iac flowing from the emitter of the transistor Q1 to each anode line La of the panel unit 1 is relatively large, and a voltage drop of (Rpf_af + Rfg_af) × Iac is present between the terminal Pgaf of the panel unit 1 and the terminal Ppaf of the PCB unit 20. appear. For this reason, the anode voltage VaL is lower than the anode voltage Va.

  The anode voltage VaL of each anode line La of the panel section 1 is fed back to the negative input terminal of the operational amplifier 21a via the terminal Pgas of the panel section 1, the FPC section 3, and the terminal Ppas of the PCB section 20.

  Since the input impedance of the operational amplifier 21 a is high, almost no current flows between the terminal Pgas of the panel unit 1 and Ppas of the PCB unit 20.

  For this reason, the voltage drop due to the contact resistances Rpf_as and Rfg_as between the terminals Pgas and Ppas hardly occurs, and the voltage applied to the negative input terminal of the operational amplifier 21a becomes almost equal to the anode voltage VaL. The operational amplifier 21a detects the anode voltage VaL in this way.

  While the potential of the anode voltage VaL is lower than the potential of the anode voltage Va, the potential of the output voltage Vout21 of the operational amplifier 21a increases and the base voltage of the transistor Q1 increases. For this reason, the amount of current Iac increases. As the potential of the output voltage Vout21 increases, the potential of the output voltage Va_out of the buffer circuit 21 also increases, and the potential of the anode voltage VaL of the panel unit 1 also increases.

  Next, when the potential of the anode voltage VaL increases to a potential exceeding the potential of the anode voltage Va, the potential of the output voltage Vout21 of the operational amplifier 21a decreases and the base voltage of the transistor Q1 also decreases. For this reason, the current Iac decreases. Further, as the potential of the output voltage Vout21 decreases, the potential of the output voltage Va_out of the buffer circuit 21 also decreases, and the potential of the anode voltage VaL of the panel unit 1 also decreases. The potential of the anode voltage VaL is again slightly lower than the potential of the anode voltage Va.

  By repeating such an operation, the anode voltage VaL fed back to the −input terminal finally becomes a potential substantially equal to or equal to the anode voltage Va applied to the + input terminal of the operational amplifier 21a. As a result, the voltage drop of (Rpf_af + Rfg_af) × Iac generated between the terminal Pgaf of the panel unit 1 and the terminal Ppaf of the PCB unit 20 is cancelled.

On the other hand, on the cathode side, the cathode voltage Vc applied from the power supply circuit 14 to the + input terminal of the operational amplifier 22a of the buffer circuit 22 is, for example, 0 V (ground potential). The transistor Q2 is turned on, and is fed back to the negative input terminal of the operational amplifier 22a through the terminal Pgcs of the panel unit 1, the FPC unit 3, and the terminal Ppcs of the PCB unit 20 when the application of the anode voltage Va and the cathode voltage Vc is started. The potential of the cathode voltage VcL of each cathode drain Lc of the panel unit 1 is raised from 0 V by flowing so that the current Iac is drawn through the transistor Q2. Since the potential of the voltage applied to the negative input terminal of the operational amplifier 22a rises from 0V, the potential of the output voltage Vout22 of the operational amplifier 22a falls.
Here, since the input impedance of the operational amplifier 22a is high, almost no current flows between the terminal Pgas of the panel unit 1 and the Ppcs of the PCB unit 20, so that the voltage drops due to the contact resistances Rpf_cs and Rfg_cs between the terminals Pgcs and Ppcs. Hardly occurs, and the voltage applied to the negative input terminal of the operational amplifier 22a becomes the cathode voltage VcL. The operational amplifier 22a detects the cathode voltage VcL in this way.

  The current Iac flowing into the panel section 1 flows out from each cathode line Lc, and the flowing out current Iac flows to the emitter-collector of the transistor Q2 via the terminal Pgcf of the panel section 1, the FPC section 3, and the terminal Ppcf of the PCB section 20. And flow into.

  The current Iac flowing from each cathode line Lc of the panel unit 1 to the transistor Q2 is relatively large, and a voltage drop of (Rpf_cf + Rfg_cf) × Iac occurs between the terminal Pgcf of the panel unit 1 and the terminal Ppcf of the PCB unit 20. . For this reason, the potential of the cathode voltage VcL becomes higher than the potential of the cathode voltage Vc.

  While the potential of the cathode voltage VcL exceeds the potential of the cathode voltage Vc, the potential of the output voltage Vout22 of the operational amplifier 21a decreases, and the base voltage of the transistor Q2 decreases. For this reason, the amount of current Iac increases. Further, as the potential of the output voltage Vout22 decreases, the potential of the output voltage Vc_out of the buffer circuit 22 also decreases, and the potential of the cathode voltage VcL of the panel unit 1 also decreases.

  Next, when the potential of the cathode voltage VcL decreases to a potential lower than the potential of the cathode voltage Vc, the potential of the output voltage Vout22 of the operational amplifier 22a increases, and the base voltage of the transistor Q2 increases. For this reason, the current Iac decreases. Further, as the potential of the output voltage Vout22 increases, the potential of the output voltage Vc_out of the buffer circuit 22 also increases, and the cathode voltage VcL becomes again slightly higher than the cathode voltage Vc.

  By repeating such an operation, the cathode voltage VcL fed back to the −input terminal finally becomes a potential substantially equal to or equal to the cathode voltage Vc applied to the + input terminal of the operational amplifier 22a. As a result, the voltage drop of (Rpf_cf + Rfg_cf) × Iac generated between the terminal Pgcf of the panel unit 1 and the terminal Ppcf of the PCB unit 20 is cancelled.

  As described above, according to the first embodiment, the anode voltage VaL of the panel unit 1 is fed back to the PCB unit 1 side, the anode voltage Va and the anode voltage VaL are compared, and the anode voltage VaL is the anode voltage Va. The output voltage Va_out is adjusted so as to be equal to the potential, and the current Iac is supplied to the panel unit 1.

  Accordingly, it is possible to cancel the voltage drop generated by the contact resistances Rpf_af and Rfg_af between the terminal Ppaf of the PCB unit 20 and the terminal Pgaf of the panel unit 1.

  Also, the cathode voltage VcL of the panel unit 1 is fed back to the PCB unit 1 side, the cathode voltage Vc and the cathode voltage VcL are compared, and the output voltage Vc_out is adjusted so that the cathode voltage VcL is equal to the cathode voltage Vc. Then, the current Iac is drawn from the panel unit 1.

  Accordingly, it is possible to cancel the voltage drop caused by the contact resistances Rpf_cf and Rfg_cf between the terminal Ppcf of the PCB unit 20 and the terminal Pgcf of the panel unit 1.

For this reason, it is possible to prevent the screen luminance of the organic EL panel 11 from being lowered due to the contact resistances Rpf_af, Rfg_af, Rpf_cf, Rfg_cf, and to suppress variations in the screen luminance due to variations in the contact resistances Rpf_af, Rfg_af, Rpf_cf, Rfg_cf.
(Embodiment 2)

The light emitting device according to Embodiment 2 measures the contact resistance of the wiring.
Based on the resistance value of the contact resistance, it is possible to determine a connection failure between the PCB unit 20 and the panel unit 1.

  In the light emitting device 10 according to the second embodiment, the PCB unit 20 includes an ammeter 23 and voltmeters 24 and 25 as shown in FIG.

  The ammeter 23 is for measuring the current value of the current Iac, and is connected between the emitter of the transistor Q1 and the terminal Ppaf.

  The voltmeter 24 is connected between the terminal Ppaf and the terminal Ppas, and measures the voltage between the terminal Ppaf and the terminal Ppas.

  The voltmeter 25 is connected between the terminal Ppcf and the terminal Ppcs, and measures the voltage between the terminal Ppcf and the terminal Ppcs.

  When the anode voltage Va and the cathode voltage Vc applied by the power supply circuit 14 become voltages for lighting the organic EL element 111, the ammeter 23 measures the current Iac at this time.

  The voltage between the terminal Ppaf and the terminal Ppas measured by the voltmeter 24 is (Va_out−VaL). This voltage is a voltage drop between the terminal Ppaf of the PCB unit 20 and the terminal Pgaf of the panel unit 1. Become.

Therefore, the resistance value (Rpf_af + Rfg_af) of the contact resistance between the terminal Ppaf and the terminal Pgaf of the wiring Naf is expressed by the following equation (1).
Rpf_af + Rfg_af = (Va_out−VaL) / Iac (1)

  By comparing the resistance value (Rpf_af + Rfg_af) of the contact resistance of the wiring Naf calculated according to the equation (1) with a preset threshold value, the quality of the connection between the anode side terminal Ppaf and the terminal Pgaf is determined. be able to.

  If the resistance value (Rpf_af + Rfg_af) of the contact resistance is equal to or less than the threshold value, the connection between the terminal Ppaf and the terminal Pgaf is determined to be good. On the other hand, if the resistance value (Rpf_af + Rfg_af) of the contact resistance exceeds the threshold value, the connection between the terminal Ppaf and the terminal Pgaf is determined to be defective.

  The voltage between the terminal Ppcf and the terminal Ppcs measured by the voltmeter 25 is (Vc_out−VcL), and this voltage is a voltage drop between the terminal Ppcf of the PCB unit 20 and the terminal Pgcf of the panel unit 1. Become.

For this reason, the resistance value (Rpf_cf + Rfg_cf) of the contact resistance of the wiring Ncf is expressed by the following equation (2).
Rpf_cf + Rfg_cf = (Vc_out−VcL) / Iac (2)

  By comparing the resistance value (Rpf_cf + Rfg_cf) of the contact resistance of the wiring Ncf calculated according to the equation (2) with a preset threshold value, the quality of the connection between the cathode side terminal Ppcf and the terminal Pgcf is determined. be able to.

  If the resistance value (Rpf_cf + Rfg_cf) of the contact resistance is equal to or less than the threshold value, the connection between the terminal Ppcf and the terminal Pgcf is determined to be good. On the other hand, if the resistance value (Rpf_cf + Rfg_cf) of the contact resistance exceeds the threshold value, it is determined that the connection between the terminal Ppcf and the terminal Pgcf is defective.

  As described above, according to the second embodiment, the PCB unit 20 includes the ammeter 23 and the voltmeters 24 and 25, and the voltage drop between the current Iac, the PCB unit 20, and the panel unit 1 is measured. I made it.

Therefore, the resistance value of the contact resistance between the PCB unit 20 and the panel unit 1 can be calculated. For this reason, the pass / fail judgment of the connection between the panel unit 1 and the PCB unit 20 can be performed by comparing the calculated resistance value of the contact resistance with a preset threshold value.
(Embodiment 3)

  The light-emitting device inspection device according to the third embodiment includes a buffer circuit similar to that of the first embodiment in order to cancel a voltage drop due to contact resistance.

  The inspection device 40 is used for lighting inspection of each organic EL element 111 of the panel unit 1 in the inspection process before shipment of the light emitting device. As shown in FIG. 8, the inspection contact probe 401 and the inspection circuit 403 are used. It consists of. The inspection contact probe 401 and the inspection circuit 403 are connected to each other via, for example, a flat cable 42 similar to the conventional one.

The panel unit 1 has terminals Pgaf, Pgas, Pgcf, and Pgcs as in the first and second embodiments. The inspection contact probe 401 has a probe contact portion, and an inspection needle that contacts the terminals Pgaf, Pgas, Pgcf, and Pgcs is provided at the tip of the probe contact portion.
The contact resistance Rph_af shown in FIG. 8 indicates the contact resistance between the inspection circuit 403 and the inspection contact probe 401 in the wiring Naf, and the contact resistance Rfp_af is between the inspection contact probe 401 in the wiring Naf and the terminal Pgaf of the panel unit 1. Indicates contact resistance. The contact resistance Rph_as indicates the contact resistance between the inspection circuit 403 and the inspection contact probe 401 in the wiring Nas, and the contact resistance Rfp_as indicates the contact resistance between the inspection contact probe 401 and the terminal Pgas of the panel unit 1 in the wiring Nas. . The contact resistance Rph_cf indicates the contact resistance between the inspection circuit 403 and the inspection contact probe 401 in the wiring Ncf, and the contact resistance Rfp_cf indicates the contact resistance between the inspection contact probe 401 and the terminal Pgcf of the panel unit 1 in the wiring Ncf. . The contact resistance Rph_cs indicates the contact resistance between the inspection circuit 403 and the inspection contact probe 401 in the wiring Ncs, and the contact resistance Rfp_cs indicates the contact resistance between the inspection contact probe 401 and the terminal Pgcs of the panel unit 1 in the wiring Ncs. Indicates.

  As shown in FIG. 8, the inspection circuit 403 has terminals Ppaf, Ppas, Ppcf, and Ppcs similar to those in the first embodiment, and includes a power supply circuit 14 and buffer circuits 21 and 22.

  When the lighting inspection of each organic EL element 111 of the panel unit 1 is performed, each inspection needle of the inspection contact probe 401 is brought into contact with the terminals Pgaf, Pgas, Pgcf, and Pgcs of the panel unit 1.

  Then, the anode voltage Va is applied from the power supply circuit 14 of the inspection circuit 403 to the + input terminal of the operational amplifier 21a of the buffer circuit 21, and the cathode voltage Vc is applied to the + input terminal of the operational amplifier 22a of the buffer circuit 22. A lighting test is performed.

  As described above, according to the third embodiment, the inspection circuit 403 that performs the lighting inspection of the organic EL element 111 includes the buffer circuits 21 and 22 similar to those of the first embodiment.

  Therefore, even when the organic EL element 111 is inspected for lighting, the voltage drop caused by the contact resistance can be canceled, the luminance decrease due to the contact resistance can be prevented, and the luminance variation due to the contact resistance variation can be suppressed. Can do.

  For this reason, when the screen brightness of the organic EL panel 11 decreases or when the screen brightness varies, it can be determined that these causes are not due to the contact resistance of each part, and the lighting test of the organic EL element 111 is performed. Can be done accurately.

In carrying out the present invention, various forms are conceivable and the present invention is not limited to the above embodiment.
For example, in the third embodiment, as in the second embodiment, the inspection circuit 403 includes the ammeter 23 and the voltmeters 24 and 25, and the contact resistances (Rph_af + Rfp_af) and (R, respectively) according to the equations (1) and (2). By calculating (Rph_cf + Rfp_cf), it is possible to determine whether or not the contact between the panel unit 1 and the inspection circuit 403 is acceptable.

  If the contact resistance between the panel unit 1 and the inspection circuit 403 exceeds the threshold value, it can be determined whether or not to re-inspect as a contact failure of the inspection contact probe 41.

  Further, based on the current and voltage measured by the ammeter 23 and the voltmeters 24 and 25, the resistance value of the contact resistance is calculated according to the formulas (1) and (2), and whether or not the contact probe 401 for inspection is defective in contact. It is also possible to provide a control unit that determines whether or not.

  In the first to third embodiments, the buffer circuits 21 and 22 are described as being provided outside the power supply circuit 14 of the PCB unit 20. However, the buffer circuits 21 and 22 can also be provided in the power supply circuit 14.

  Further, the ammeter 23 and the voltmeters 24 and 25 in the second embodiment can also be provided in the power supply circuit 14.

  Further, the ammeter 23 in the second embodiment may be provided on the buffer circuit 22 side.

  In the first to third embodiments, the PCB unit 20 includes the buffer circuits 21 and 22. However, the PCB unit 20 may include one of the buffer circuits 21 and 22.

  In the first and second embodiments, the panel unit 1 and the PCB unit 20 are described as being electrically connected via the FPC unit 3. However, the first and second embodiments can be applied even when the panel unit 1 and the PCB unit 20 are connected without the FPC unit 3 interposed therebetween.

  In the first to third embodiments, the light emitting device has been described as an example. However, not only the light emitting device, but the PCB section 20 on the current supply side and the circuit board that operates by supplying the current are electrically connected via the FPC section 3, and the contact resistance between the boards becomes a problem. The first to third embodiments can also be applied to electronic devices such as a display device, a lighting device, a printer, and a copying apparatus.

  That is, the contact resistance can be canceled by providing the current source substrate of such an electronic device with the buffer circuits 21 and 22 as shown in the first to third embodiments.

  DESCRIPTION OF SYMBOLS 1 ... Panel part, 3 ... FPC part, 10 ... Light-emitting device, 11 ... Organic EL panel, 12 ... Gate driver, 13 ... Data driver, 14 ... Power supply circuit, DESCRIPTION OF SYMBOLS 20 ... PCB part, 21, 22 ... Buffer circuit, 21a, 22a ... Operational amplifier, 40 ... Inspection apparatus, 401 ... Inspection contact probe, 403 ... Inspection circuit

Claims (17)

A light-emitting panel in which a plurality of light-emitting elements are arranged;
A power supply board on which a power supply circuit for supplying a drive voltage and a reference voltage is mounted;
With
The light emitting panel includes a first current inflow terminal, a current supply line connected to the first current inflow terminal, and supplying a driving current to each light emitting element through the first current inflow terminal, A first voltage output terminal connected to a current supply line and outputting a voltage value of the current supply line as a first detection voltage;
The power supply board is connected to the first current inflow terminal of the light emitting panel through a connection member, and a first current outflow terminal for flowing out the drive current to the light emitting panel, and through the connection member A first voltage detection terminal connected to the first voltage output terminal for feeding back the first detection voltage is compared with the first detection voltage and the drive voltage, and the first detection is performed. A first buffer circuit that applies a first output voltage adjusted so as to approach the driving voltage to the first current outflow terminal, and causes the drive current to outflow from the first current outflow terminal; And a light emitting device. The light emitting panel includes: a current output line for outputting the driving current from each light emitting element; a second current outflow terminal connected to the current output line for flowing out the driving current of the current output line; A second voltage output terminal connected to a current output line and outputting a voltage value of the current output line as a second detection voltage;
The power supply board is connected to the second current outflow terminal of the light emitting panel via the connection member, and the second current inflow terminal into which the driving current flows from the light emitting panel, and the connection member A second voltage detection terminal connected to the second voltage output terminal via which the second detection voltage is fed back, and the second detection voltage and the reference voltage are compared. A second buffer for applying the second output voltage adjusted so that the detected voltage of the second current is close to the reference voltage to the second current inflow terminal, and causing the drive current to flow in from the second current inflow terminal The light-emitting device according to claim 1, further comprising a circuit. The first buffer circuit applies the first output voltage to the first current outflow terminal to make the first detection voltage equal to the drive voltage,
The second buffer circuit applies the second output voltage to the second current inflow terminal to make the second detection voltage equal to the reference voltage. Light-emitting device. The power supply board includes a first current measurement unit that measures a first current value of the drive current flowing out from the first current outflow terminal, the first current outflow terminal, and the first voltage detection terminal. A first voltage measurement unit that measures a first voltage between the terminals,
A first resistance value related to the connection member based on the first current value and the first voltage value is acquired, and based on the first resistance value, the connection member, the light emitting panel, and A control circuit for determining whether the connection state with the power supply board is good or bad;
The light-emitting device according to claim 2 or 3. The power supply board includes a second voltage measurement circuit that measures a second voltage value between the second current inflow terminal and the second voltage detection terminal,
The control circuit acquires a second resistance value related to the connection member based on the first current value and the second voltage value, and based on the value of the second resistance value, the connection member 5. The light emitting device according to claim 4, wherein the quality of the connection state between the light emitting panel and the power supply substrate is determined.   An electronic apparatus comprising the light-emitting device according to claim 1. A plurality of light emitting elements are arranged and connected to a first current inflow terminal and a current supply line for supplying a driving current to each of the light emitting elements via the first current inflow terminal, and a voltage value of the current supply line Is connected to a first voltage output terminal that outputs the drive current from each light emitting element, and a second current that causes the drive current of the current output line to flow out. A light emitting panel comprising: a current outflow terminal; and a second voltage output terminal that is connected to the current output line and outputs a voltage value of the current output line as a second detection voltage. An inspection device,
An inspection circuit;
An inspection terminal connected to the inspection circuit and in contact with at least the first current inflow terminal and the first voltage output terminal;
With
The inspection circuit includes:
A power supply circuit for supplying a drive voltage and a reference voltage;
A first current outflow terminal that contacts the first current inflow terminal of the light emitting panel via the inspection terminal portion and outflows the drive current to the light emitting panel;
A first voltage detection terminal for contacting the first voltage output terminal of the light-emitting panel via the inspection terminal unit and feeding back the first detection voltage;
Comparing the first detection voltage and the drive voltage, applying a first output voltage adjusted to bring the first detection voltage close to the drive voltage to the first current outflow terminal; An inspection device for a light-emitting panel, comprising: a first buffer circuit that causes the drive current to flow out from the first current outflow terminal. Each inspection needle of the inspection terminal portion contacts the second current outflow terminal and the second voltage output terminal,
The inspection circuit includes:
A second current inflow terminal that contacts the second current outflow terminal of the light emitting panel via the inspection terminal portion and into which the drive current flows from the light emitting panel;
A second voltage detection terminal that contacts the second voltage output terminal via the inspection terminal unit and feeds back the second detection voltage;
Comparing the second detection voltage with the reference voltage and applying a second output voltage adjusted to bring the second detection voltage close to the reference voltage to the second current inflow terminal; The light-emitting panel inspection apparatus according to claim 7, further comprising: a second buffer circuit that allows the drive current to flow from the second current inflow terminal. The first buffer circuit applies the first output voltage to the first current outflow terminal to make the first detection voltage equal to the drive voltage,
The second buffer circuit applies the second output voltage to the second current inflow terminal to make the second detection voltage equal to the reference voltage. Light emitting panel inspection device. The inspection circuit includes a first current measuring unit that measures a first current value of the drive current flowing out from the first current outflow terminal, the first current outflow terminal, and the first voltage detection terminal. A first voltage measurement unit that measures a first voltage between the terminals,
Obtaining a first contact resistance value between the inspection terminal unit and the light emitting panel based on the first current value and the first voltage value, and based on the value of the first contact resistance value, Provided with a control circuit for determining the presence or absence of poor contact between the inspection terminal portion and the light emitting panel,
The light-emitting panel inspection apparatus according to claim 8 or 9, The inspection circuit includes a second voltage measurement circuit that measures a second voltage value between the second current inflow terminal and the second voltage detection terminal,
The control circuit obtains a second contact resistance value between the inspection terminal unit and the light emitting panel based on the first current value and the second voltage value, and a value of the second contact resistance value The light emitting panel inspection apparatus according to claim 10, wherein the presence or absence of contact failure between the inspection terminal portion and the light emitting panel is determined based on the above. A plurality of light emitting elements are arranged and connected to a first current inflow terminal and a current supply line for supplying a driving current to each of the light emitting elements via the first current inflow terminal, and a voltage value of the current supply line Is connected to a first voltage output terminal that outputs the drive current from each light emitting element, and a second current that causes the drive current of the current output line to flow out. A driving voltage and a reference voltage are applied to a light emitting panel including a current outflow terminal and a second voltage output terminal connected to the current output line and outputting a voltage value of the current output line as a second detection voltage. Canceling the voltage drop of the light emitting device for canceling the voltage drop due to the connection member of the light emitting device to which the power supply board on which the power supply circuit for supplying the supply voltage and the reference voltage are mounted is connected via the connection member Method There,
An inflow step of supplying a first output voltage from the power supply substrate to the first current inflow terminal of the light-emitting panel through the connection member and causing the drive current to flow into the light-emitting panel;
A first feedback step of returning the first detection voltage from the first voltage output terminal of the light-emitting panel to the power supply substrate via the connection member;
When the first detection voltage fed back in the first feedback step is compared with the drive voltage, and the first detection voltage is lower than the drive voltage, the first output voltage A first comparison step of increasing the potential of
When the first detection voltage fed back in the first feedback step is compared with the drive voltage, and the first detection voltage is higher than the drive voltage, the first output voltage A second comparison step for reducing the potential of
The first comparison step and the second comparison step are repeatedly executed until the potentials of the first detection voltage and the drive voltage become equal, and the first detection voltage and the drive voltage are A first cancel step of canceling the voltage drop due to the connection member by applying the first output voltage when the voltage becomes equal to the first current outflow terminal;
A method for canceling a voltage drop in a light-emitting device. A second feedback step of feeding back the second detection voltage from the second voltage output terminal of the light-emitting panel to the power supply board via the connection member;
When the second detection voltage fed back by the second feedback step is compared with the reference voltage, and the second detection voltage is lower than the reference voltage, the second output voltage A third comparison step for increasing the potential of
When the first detection voltage fed back in the second feedback step is compared with the drive voltage, and the potential of the first detection voltage is higher than the potential of the drive voltage, the first output A fourth comparison step for reducing the potential of the voltage;
The third comparison step and the fourth comparison step are repeatedly executed until the potentials of the second detection voltage and the reference voltage become equal, and the second detection voltage and the reference voltage are A second canceling step of canceling the voltage drop due to the connecting member by applying the second output voltage at the same potential to the second current inflow terminal;
The method for canceling a voltage drop of a light emitting device according to claim 12, comprising: A plurality of light emitting elements are arranged and connected to a first current inflow terminal and a current supply line for supplying a driving current to each of the light emitting elements via the first current inflow terminal, and a voltage value of the current supply line Is connected to a first voltage output terminal that outputs the drive current from each light emitting element, and a second current that causes the drive current of the current output line to flow out. A light emitting panel comprising: a current outflow terminal; and a second voltage output terminal that is connected to the current output line and outputs a voltage value of the current output line as a second detection voltage. An inspection method,
A contact step of bringing an inspection needle of an inspection terminal portion into contact with the first current inflow terminal and the first voltage output terminal of the light emitting panel;
A first output voltage is supplied to the first current inflow terminal of the light-emitting panel from an inspection circuit having a power supply circuit that supplies a drive voltage and a reference voltage via the inspection terminal unit, and the light-emitting panel is supplied with the first output voltage. An inflow step for causing the drive current to flow; and
A first feedback step of feeding back the first detection voltage from the first voltage output terminal of the light-emitting panel to the inspection circuit via the inspection terminal unit;
The first detection voltage fed back is compared with the drive voltage, and the first output voltage is increased when the first detection voltage is lower than the drive voltage. The comparison steps of
When the first detection voltage fed back in the first feedback step is compared with the drive voltage, and the first detection voltage is higher than the drive voltage, the first output voltage A second comparison step for reducing the potential of
The first comparison step and the second comparison step are repeatedly executed until the potentials of the first detection voltage and the drive voltage become equal, and the first detection voltage and the drive voltage are Applying a first output voltage to the first current outflow terminal when the potentials are equal to each other; and
A method for inspecting a light-emitting panel, comprising: A second feedback step of feeding back the second detection voltage from the second voltage output terminal of the light-emitting panel to the inspection circuit via the inspection terminal unit;
When the second detection voltage fed back by the second feedback step is compared with the reference voltage, and the second detection voltage is lower than the reference voltage, the second output voltage A third comparison step for increasing the potential of
When the first detection voltage fed back in the second feedback step is compared with the drive voltage, and the potential of the first detection voltage is higher than the potential of the drive voltage, the first output A fourth comparison step for reducing the potential of the voltage;
The third comparison step and the fourth comparison step are repeatedly executed until the potentials of the second detection voltage and the reference voltage become equal, and the second detection voltage and the reference voltage are A second application step of applying the second output voltage when the potentials are equal to the second current inflow terminal;
The method for inspecting a light-emitting panel according to claim 14, comprising: Measuring a first current value of the drive current flowing into the first current inflow terminal of the light emitting panel;
A first current outflow terminal connected to the first current inflow terminal of the light emitting panel through the inspection terminal portion of the inspection circuit, and the first current outflow terminal of the light emitting panel through the inspection terminal portion. Measuring a first voltage between the first voltage detection terminal connected to a voltage output terminal;
Based on the first current value and the first voltage value, a first contact resistance value between the inspection terminal unit and the light emitting panel is obtained, and based on the first contact resistance value Determining the presence or absence of poor contact between the inspection terminal portion and the light emitting panel;
The method for inspecting a light-emitting panel according to claim 15, comprising: A second current inflow terminal connected to the second current outflow terminal of the light emitting panel through the inspection terminal portion of the inspection circuit; and the second current inflow terminal of the light emitting panel through the inspection terminal portion. Measuring a second voltage value between the second voltage detection terminal connected to the voltage output terminal;
Obtaining a second contact resistance value between the inspection terminal unit and the light emitting panel based on the first current value and the second voltage value, and based on the value of the second contact resistance value, Determining the presence or absence of poor contact between the inspection terminal portion and the light emitting panel;
The method for inspecting a light-emitting panel according to claim 16.

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