JP5626341B2 - Light-emitting device inspection apparatus and light-emitting device inspection method - Google Patents

Description

  The present invention relates to an apparatus and method for inspecting a light emitting device.

  In recent years, light-emitting devices using organic EL (also referred to as organic EL devices) have attracted attention as devices that emit surface light with low power consumption (also referred to as surface light-emitting devices). Application is underway.

  The organic EL device has a structure in which two electrodes (an anode electrode and a cathode electrode) sandwich a light emitting layer. For this reason, in the organic EL device, if there is a defect due to the inclusion of a foreign substance in the light emitting layer, a leakage current is generated in a region near the foreign substance. Leakage current does not contribute to light emission, and causes a decrease in light emission efficiency (an index indicating the degree of brightening by light emission according to a certain energy). Therefore, an organic EL device having a large leakage current needs to be detected as a defective product.

  By the way, conventionally, the following first and second inspection techniques are known as techniques for inspecting a leakage current in an organic EL device.

  In the first inspection technique, a voltage is applied between two electrodes in the direction opposite to the direction of the voltage applied during light emission (also referred to as the forward direction), and leakage current is detected by detecting a weak current flowing at that time. Existence is inspected (for example, Patent Document 1).

  In the second inspection technique, a minute current flows between two electrodes in the forward direction or the reverse direction, and the presence or absence of leakage current is inspected by detecting weak leakage light emission of the light emitting layer at that time ( For example, Patent Documents 2 and 3).

JP 2008-112649 A JP 2009-26687 A JP 2009-277528 A

  However, the first inspection technique requires a high-performance measuring device (for example, a source meter) that measures a weak current. Further, in the second inspection technique, since a weak light emission phenomenon caused by applying a voltage lower than that during normal light emission is captured, a light emission level and a light emission region become minute, and a measurement apparatus (for example, a high resolution and sensitivity) An emission microscope). Therefore, both the first and second inspection techniques cause problems such as complication of the inspection apparatus and an increase in manufacturing cost.

  Further, if it is attempted to reduce the tact time by inspecting a plurality of organic EL devices in parallel with each other at the same time, the inspection apparatus is further complicated and the manufacturing cost is increased.

  In addition, the said problem does not arise only in an organic EL device, but is common in a light emitting device generally.

  The present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of inspecting a leakage current of a light emitting device with a simple configuration.

In order to solve the above-described problem, a light emitting device inspection apparatus according to a first aspect includes a power supply unit as a constant current source that supplies a constant inspection current flowing in a forward direction to a plurality of light emitting devices, and the light emission. A plurality of measurement units that are provided for each device and that respectively acquire information related to the luminance of each of the light emitting devices that emits light according to the inspection current, and for each of the light emitting devices, the evaluation value related to the luminance is One condition is a first condition that is less than or equal to a first threshold value, and a second condition that a lower limit value of a current required for light emission of each of the light emitting devices estimated based on the luminance is greater than or equal to a second threshold value. A determination unit that determines that a leakage current exceeding an allowable value can be generated when the value is satisfied, and information relating to luminance of one light-emitting device included in the plurality of light-emitting devices among the plurality of measurement units. Comprising a single measuring unit for acquiring, it is disposed between said one other light emitting devices other than the light-emitting device of the plurality of light emitting devices, and a shielding portion that shields visible light, a.

  A light-emitting device inspection apparatus according to a second aspect is the light-emitting device inspection apparatus according to the first aspect, wherein the inspection current has a luminance that can be detected by the measurement unit in the light-emitting device in which leakage current does not occur. The current is equal to or higher than the first current for realizing the lower limit value, and is smaller than the second current obtained by adding the allowable value to the first current.

A light-emitting device inspection apparatus according to a third aspect is the light-emitting device inspection apparatus according to the first or second aspect, wherein the plurality of light-emitting devices are electrically connected in series to the power feeding unit. In addition , the plurality of measurement units acquire information on luminance of the plurality of light emitting devices that emit light according to the inspection current at the same time.

The fourth light emitting device inspection apparatus according to the aspect, the first a light-emitting device inspecting apparatus according to a third one of the embodiment, each of the measurement unit, that not emit light in response to the test current by acquiring the test image captured light-emitting area before Symbol emitting device includes an imaging unit that acquires information relating to luminance before Symbol emitting device.

  The light-emitting device inspection apparatus according to the fifth aspect is the light-emitting device inspection apparatus according to the fourth aspect, wherein the evaluation value relating to the luminance includes an average value of luminance relating to the light-emitting area.

  The light-emitting device inspection apparatus according to the sixth aspect is the light-emitting device inspection apparatus according to the fourth aspect, wherein the evaluation value related to the luminance is occupied by a region having a luminance equal to or higher than a third threshold in the light-emitting area. Includes percentage.

  A light emitting device inspection apparatus according to a seventh aspect is the light emitting device inspection apparatus according to any one of the fourth to sixth aspects, wherein the inspection is performed based on an adjustment image acquired by the imaging unit. Each of the light emission units further includes a specifying unit that specifies a position occupied by an image area in which the light-emitted area is captured in the image, and the adjustment image emits light according to an adjustment current larger than the inspection current. It is an image that captures the device.

Emitting device inspection apparatus according to the eighth aspect, the first a light-emitting device inspecting apparatus according to a third one of the embodiment, each of the measurement unit, that not emit light in response to the test current including a photodiode for acquiring information relating to luminance before Symbol emitting device.

A light emitting device inspection apparatus according to a ninth aspect is the light emitting device inspection apparatus according to the first aspect, wherein the inspection current includes a first inspection current, a second inspection current, and a third inspection current. hints, each said measurement unit, the information relating to the first luminance before Symbol emitting devices that are to emit light in accordance with the first test current, the second emitted in response to the test current have that before Symbol emission information relating to the second brightness of the device, and sequentially acquires the information of the third luminance before Symbol emitting devices that are to emit light in accordance with the third test current, the lower limit is, for each said light emitting device , A curve using a set of the first inspection current and the first luminance, a set of the second inspection current and the second luminance, and a set of the third inspection current and the third luminance. Estimated by approximate calculation.

In the light emitting device inspection method according to the tenth aspect, a measuring unit is arranged for each light emitting device included in the plurality of light emitting devices, and one light emitting device included in the plurality of light emitting devices among the plurality of measuring units. Disposing a shielding unit that shields visible light between one measurement unit that acquires information relating to luminance of the light emitting device and a light emitting device other than the one light emitting device among the plurality of light emitting devices; , Supplying a constant inspection current flowing in the forward direction to the plurality of light emitting devices by a power supply unit as a constant current source , and information relating to the luminance of each of the light emitting devices emitting light according to the inspection current For each of the light emitting devices, a first condition for the evaluation value relating to the luminance to be a first threshold value or less, and the brightness The leakage current exceeding the allowable value by the determination unit when one of the second conditions in which the lower limit value of the current necessary for light emission of the light emitting device estimated based on the second threshold is equal to or greater than the second threshold is satisfied Determining that can occur.

  The light emitting device inspection apparatus according to any one of the first to ninth aspects can also inspect the leakage current of the light emitting device with a simple configuration.

  According to the light-emitting device inspection apparatus according to the second aspect, since the light-emitting device does not emit light when the leakage current exceeding the allowable value is generated, the inspection accuracy can be increased.

  According to the light emitting device inspection apparatus according to the third aspect, the inspection can be speeded up.

  Also with the light emitting device inspection apparatus according to any of the fourth to seventh aspects, for example, a quick inspection can be performed with a simple configuration using a general-purpose imaging unit or the like. In addition, for example, if information related to the luminance of a plurality of light emitting devices is acquired by a single imaging unit, the inspection can be speeded up.

  Even with the light emitting device inspection apparatus according to any of the fifth and sixth aspects, stable inspection is possible even if the lower limit value of the current required for light emission varies within one light emitting device.

  According to the light-emitting device inspection apparatus according to the seventh aspect, by specifying the position of the image area where the light-emitting area of the light-emitting device is captured, it is possible to inspect based on the luminance of the wider light-emitting area. It becomes.

  With the light emitting device inspection apparatus according to the eighth aspect, the configuration can be further simplified.

  According to the light emitting device inspection apparatus according to the ninth aspect, the configuration of the measurement unit can be simplified by using the inspection current that generates the luminance that can be stably detected using the measurement unit.

  According to the light emitting device inspection method according to the tenth aspect, it is possible to inspect the leakage current of the light emitting device with a simple configuration.

FIG. 1 is a diagram illustrating the relationship between drive current and light emission luminance in an organic EL device. FIG. 2 is a diagram illustrating variation in characteristics between devices. FIG. 3 is a diagram in which information related to the lower limit value of the light emission luminance that can be detected is added to FIG. FIG. 4 is a diagram illustrating a schematic configuration of a light emitting device inspection apparatus according to an embodiment. FIG. 5 is a diagram illustrating the configuration of the measurement unit. FIG. 6 is a diagram illustrating a configuration of the information processing unit. FIG. 7 is a block diagram showing a functional configuration of the light emitting device inspection apparatus. FIG. 8 is a diagram illustrating a data example of the area specifying information. FIG. 9 is a diagram illustrating a data example of the light emission evaluation information. FIG. 10 is a diagram illustrating an example of data of determination result information. FIG. 11 is a flowchart illustrating an operation flow of the light-emitting device inspection apparatus. FIG. 12 is a diagram for explaining a method of calculating a light emission evaluation value according to a modification. FIG. 13 is a diagram illustrating a functional configuration of a light emitting device inspection apparatus according to a modification. FIG. 14 is a diagram for explaining a method of estimating the light emission start current according to a modification. FIG. 15 is a diagram illustrating a schematic configuration of a measurement unit according to a modification. FIG. 16 is a diagram illustrating a functional configuration of a light emitting device inspection apparatus according to a modification.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, parts having the same configuration and function are denoted by the same reference numerals, and redundant description is omitted in the following description. Further, the drawings are schematically shown, and the sizes, positional relationships, and the like of various structures in the drawings are not accurately illustrated.

<(1) Inspection principle concerning the presence or absence of leakage current exceeding the allowable value>
A light-emitting device using organic EL (also referred to as an organic EL device) has a structure in which two electrodes (an anode electrode and a cathode electrode) sandwich a light-emitting layer. About this organic EL device, it manufactures so that a foreign material etc. may not mix in a light emitting layer as much as possible. However, if foreign matter or the like is mixed into the light emitting layer, the electrical resistance in the vicinity of the interface between the foreign matter and its peripheral portion is reduced, and current (also referred to as leakage current) is likely to flow relatively near the foreign matter, In order to generate light emission, a current may be relatively difficult to flow in a path that should originally flow in the light emitting layer.

  For this reason, in comparison with an organic EL device in which leakage current does not occur (also referred to as a leakage current non-generating device), an organic EL device in which leakage current occurs (also referred to as a leakage current generating device) has a gap between both electrodes via the light emitting layer. If the current (also referred to as drive current) flowing through the capacitor is not set high enough to compensate for the leakage current, desired light emission cannot occur.

FIG. 1 is a diagram illustrating a relationship between a driving current in an organic EL device and luminance (also referred to as light emission luminance) of a region (also referred to as a light emitting region) that can emit light according to the driving current. In Figure 1, the relationship between the drive current in the leakage current non-generating device and the light-emitting luminance is shown by the curve CV _S one-dot chain line, curve of dashed line relationship two points between the driving current and the luminance of the leakage current generating device CV _L It is shown in

As shown in FIG. 1, the leakage current non-generating device starts to emit light when the driving current exceeds the current I ₀ . This current I ₀ is also called an ideal light emission start current. On the other hand, the leakage current generating device starts to emit light when the drive current exceeds a current (I ₀ + I _L ) obtained by adding a current (also referred to as a compensation current) I _L to compensate the leakage current to the ideal light emission start current I ₀ . This current (I ₀ + I _L ) is also referred to as a leakage compensation light emission start current.

Here, the leakage current non-generating device emits light when a current I _C between the ideal light emission start current I ₀ and the leakage compensation light emission start current (I ₀ + I _L ) is given as a drive current. At this time, the light emission luminance of the leakage current non-generating device is the luminance L _C0 . On the other hand, the leakage current generating device does not emit light even when the current I _C is applied as the drive current.

Therefore, in the present embodiment, a certain compensation current I _L is set as an allowable value of leakage current, and the current I _C is set as an inspection current (also referred to as an inspection current). Then, the test current I _C is based on the emission luminance of the organic EL device is detected when it is the drive current, whether the leakage current exceeding the allowable value I _L is an organic EL device that can occur determination Is done. The allowable value I _L can be determined based on, for example, the standard of luminous efficiency required for the organic EL device.

By the way, in a device that does not generate a leakage current that is actually manufactured, a slight deviation occurs in the ideal light emission start current I ₀ due to variations in characteristics between devices.

FIG. 2 is a diagram illustrating variations in characteristics between devices that occur in a device that does not generate a leakage current. In Figure 2, of the leakage current non-generation devices, and a minimum value I _0min and the maximum value I _0max in the range of variation of the ideal light emission starting current I ₀ that is assumed it is shown. The relationship between the drive current ideal emission starting current I ₀ is related to the leakage current non-generation device as the minimum value I _0min and emission luminance is shown by dashed curve CV _Smin, ideal light emission starting current I ₀ is the maximum value I The relationship between the drive current and the light emission luminance related to the non-leakage current generating device that becomes _0max is shown by a dashed line curve CV _Smax .

For example, it is assumed that the inspection current I _C is set to a value exceeding the maximum value I _0max of the ideal light emission start current I ₀ . At this time, the leakage current non-generating device in which the ideal light emission start current I ₀ becomes the minimum value I _0min realizes the light emission luminance L _C0 by light emission according to the inspection current I _C, and the light emission start current I ₀ has the maximum value I. _The non-leakage current generating device having _{0 max} realizes the light emission luminance L _C1 by light emission corresponding to the inspection current I _C. That is, a difference L _V between the light emission luminance L _C1 and the light emission luminance L _C0 occurs.

It is also assumed that the inspection current I _C is set to a value equal to or less than the maximum value I _{0max of the} ideal light emission start current I ₀ . At this time, leakage current nonoccurrence devices ideal emission starting current I ₀ is the minimum value I _0min is emits light in response to the test current I _C, the leakage current ideal emission starting current I ₀ is the maximum value I _0max The non-generating device does not emit light according to the inspection current I _C.

Therefore, in the present embodiment, the inspection current I _C is set in consideration of variations in characteristics between devices as shown in FIG. Specifically, as the leakage current non-generation device can reliably emit light when the test current I _C is the drive current, maximum value I _0max Ideally emission starting current as representative of the ideal light emission starting current I ₀ is a I _0, in the range between the compensation light emission starting current leakage between the ideal light emission starting current _{I 0 (I 0 + I L} ), the test current I _C is set.

Further, there is a lower limit value L _{LL of the} light emission luminance that can be detected depending on the sensitivity of the sensor that detects the light emission luminance of the organic EL device. FIG. 3 is a diagram in which information relating to the lower limit value _LLL is added to FIG.

As shown in FIG. 3, in order to realize the light emission luminance L _{LL in the} device without leakage current, a current (also referred to as an offset current) I _{0 OFFSET} corresponding to the light emission luminance L _LL becomes the ideal light emission start current I ₀ . The added value (I ₀ + I _{0 OFFSET} ) may be set as the drive current. In order to realize the light emission luminance L _LL in the leakage current generating device, a value (I ₀ + I _L + I _0OFFSET ) _obtained by adding the offset current I 0 _OFFSET to the leakage compensation light emission start current (I ₀ + I _L ) What is necessary is just to set as a drive current.

In other words, the current (I ₀ + I _{0 OFFSET} ) as the first current is a drive current in which the lower limit value of the light emission luminance that can be detected by the sensor is realized in the device that does not generate a leakage current. The current (I ₀ + I _L + I _0OFFSET ) as the second current is a drive current in which the lower limit of the light emission luminance that can be detected by the sensor is realized in the leakage current generating device. Therefore, the inspection current I _C is, is the current (I ₀ + I _0OFFSET) above, are preferably and current _{(I 0 + I L + I} 0OFFSET) set to be less than the current.

  Note that, for example, in the light emitting layer manufacturing process, the thickness and the like of the light emitting layer may vary depending on conditions when a solution containing an organic material or the like for forming the light emitting layer is applied. For this reason, unevenness of light emission luminance occurs in the light emitting area in one organic EL device, and the whole light emitting area may not emit light uniformly. Specifically, a region that emits light (also referred to as a light-emitting region) and a region that does not emit light (also referred to as a non-light-emitting region) can occur in the light-emitting region. Even when such a phenomenon occurs, according to the inspection apparatus and the inspection method according to the present embodiment, it is possible to determine whether or not there is a leakage current exceeding the allowable value, and the leakage current of the organic EL device with a simple configuration. It becomes possible to inspect.

  Hereinafter, the inspection apparatus and the inspection method according to the present embodiment will be specifically described.

<(2) Schematic configuration of light-emitting device inspection apparatus>
FIG. 4 is a diagram illustrating a schematic configuration of the light-emitting device inspection apparatus 1 according to an embodiment. As shown in FIG. 4, the light emitting device inspection apparatus 1 includes a measurement unit 2 and an information processing unit 3. Here, the measurement unit 2 and the information processing unit 3 will be described sequentially.

<(2-1) Configuration of measurement unit>
FIG. 5 is a diagram illustrating the configuration of the measurement unit 2 according to an embodiment. As shown in FIG. 5, the measurement unit 2 includes a transport system 21, a shielding box unit 22, an imaging unit 23, and a tray 24.

  The transport system 21 is a portion on which the tray 24 is placed, and is a portion that moves the tray 24 in a predetermined direction (here, the horizontal direction).

The shielding box portion 22 has a box shape having an opening below, and is a portion that shields visible light. In the shielding box portion 22, the first wiring FW _P and the second wiring FW _M that supply power are respectively connected to portions located near the lowermost portion of the outer wall surface at one end and the other end. Yes.

Here, the first wiring FW _P is provided so as to penetrate the shielding box 22 up to the inner wall from the outer wall surface of the shielding box 22, provided on the inner wall surface side of the shielding box 22 It is electrically connected to the first connection terminal CN _P. On the other hand, the second wiring FW _M is provided so as to penetrate the shielding box portion 22 from the outer wall surface to the inner wall surface of the shielding box portion 22, and is provided on the inner wall surface side of the shielding box portion 22. It is electrically connected to the second connection terminal CN _M.

The shielding box portion 22 can be moved up and down by a box driving portion 22 _MT (see FIG. 7). FIG. 5 shows a state where the shielding box portion 22 has moved to the lowest position. In this state, the shielding box 22 and the tray 24 and the like are brought into close contact with each other so that the inner space of the shielding box 22 is sealed, and the inner space of the shielding box 22 from the outside of the shielding box 22 is sealed. Visible light penetration into the screen is blocked. On the other hand, when the shielding box portion 22 is moved upward, the tray 24 can be transported by the transport system 21, and a certain tray 24 is moved from an area immediately below the shielding box portion 22 to shield other trays 24. It is possible to move to a region directly below the box portion 22.

  The imaging unit 23 is provided on the upper part of the shielding box part 22 and can photograph the internal space of the shielding box part 22. The imaging unit 23 includes, for example, an imaging sensor composed of a CCD or the like in which pixels are arranged in a matrix, and image data indicating a two-dimensional distribution of pixel values corresponding to the luminance of a subject (here, a monochrome image) Any data can be obtained. Hereinafter, the image data and the image indicated by the image data are simply referred to as an image.

  In FIG. 5, the outer edge of the range that can be imaged by the imaging unit 23 is indicated by a one-dot chain line. When the shielding box portion 22 moves to the lowermost position and is in close contact with the tray 24 or the like, the four organic EL devices ED1 to ED4 arranged on the tray 24 by the imaging portion 23 emit light. The situation can be imaged.

  The tray 24 has four recesses, and the four organic EL devices ED1 in a state where the four organic EL devices ED1 to ED4 whose light-emitting areas are directed upward are fitted in the four recesses, respectively. ED4 can be conveyed. The tray 24 has conductive portions CL1 to CL5 that electrically connect the four organic EL devices ED1 to ED4 in series in a state where the four organic EL devices ED1 to ED4 are disposed on the tray 24. Yes.

Here, the organic EL device ED1 has a negative terminal 1T _M to be connected to the positive terminal 1T _P and cathode electrode connected to the anode electrode, an organic EL device ED2 is, the positive terminal 2T _P a cathode connected to the anode electrode and a negative electrode terminal 2T _M to be connected to the electrode. The organic EL device ED3 has a negative terminal 3T _M to be connected to the positive terminal 3T _P and cathode electrode connected to the anode electrode, an organic EL device ED4 is, the positive terminal 4T _P and cathode electrode connected to the anode electrode and a negative terminal 4T _M to be connected to.

Then, the conductive portion CL1 is electrically connected to the positive terminal 1T _P, conductive portion CL2 is electrically connected to the negative terminal 1T _M and the positive terminal 2T _P, conductive portion CL3 is the negative terminal 2T _M and the positive terminal 3T electrically connecting the _P, conductive portion CL4 is electrically connected to the negative terminal 3T _M and the positive terminal 4T _P, the positive electrode terminal 4T _P is electrically connected to the conductive portion CL5.

Further, when the shielding box portion 22 in close contact with and moved to the lowermost tray 24 or the like is electrically connected to the first connection terminal CN _P and the conductive portion CL1 is in contact, the second connection a state where the terminal CN _M and the conductive portion CL5 electrically connected in contact. Accordingly, a desired current can be passed between the first wiring FW _P and the second wiring FW _M by the power feeding unit 25 (see FIG. 7).

  In addition, about each organic EL device ED1-ED4 arrange | positioned on the tray 24, the state which laminated | stacked the anode electrode, the light emitting layer, and the cathode electrode on the board | substrate, and was provided with the sealing film may be sufficient, for example. In addition, a laminated state using a resin or the like so as to enhance the sealing effect may be used. Note that an inert gas may be introduced into the internal space of the shielding box 22 for the purpose of preventing the deterioration of each of the organic EL devices ED1 to ED4.

<(2-2) Configuration of information processing unit>
FIG. 6 is a diagram illustrating the configuration of the information processing unit 3 according to an embodiment. As shown in FIG. 6, the information processing unit 3 is configured by a personal computer (PC), for example, and includes an operation unit 31, a display unit 32, an interface (I / F) unit 33, a storage unit 34, an input / output unit 35, And a control unit 36.

  The operation unit 31 includes a mouse, a keyboard, and the like. The display unit 32 includes a liquid crystal display and the like. The I / F unit 33 transmits and receives various signals to and from the measurement unit 2 via a communication line.

  The storage unit 34 is composed of, for example, a hard disk and stores information related to the measurement result obtained by the measurement unit 2. In addition, the storage unit 34 stores a program PG and the like for executing processing for inspecting an organic EL device (also referred to as device inspection processing).

  The input / output unit 35 includes, for example, a disk drive, receives the storage medium 9 such as an optical disk, and exchanges various data with the control unit 36.

  The control unit 36 includes a CPU 36 a that functions as a processor and a memory 36 b that temporarily stores information, and comprehensively controls each unit of the information processing unit 3. The control unit 36 reads and executes the program PG in the storage unit 34, thereby realizing various functions related to device inspection processing, various information processing, and the like. The program and data stored in the storage medium 9 can be stored in the memory 36b or the like via the input / output unit 35.

<(3) Functional configuration of light-emitting device inspection device>
FIG. 7 is a block diagram illustrating a functional configuration of the light-emitting device inspection apparatus 1 according to an embodiment. Here, the functional configuration of the control unit 36 is described as being realized by execution of the program PG, but may be realized by dedicated hardware.

As shown in FIG. 7, the measurement unit 2 includes a transport system 21, a box drive unit 22 _MT , an imaging unit 23, an identification information acquisition unit 24 _OB , and a power feeding unit 25. In addition, the information processing unit 3 includes a transport control unit 361, a current control unit 362, an imaging control unit 363, an area specifying unit 364, an image correction unit 365, an evaluation value calculation unit 366, a determination unit 367, and a result output unit 368. ing.

  As described above, the transport system 21 is a portion on which the tray 24 is placed, and the tray 24 can be moved in the horizontal direction. The movement of the tray 24 by the transport system 21 can be realized by a configuration using, for example, a belt conveyor or a robot arm.

The box drive unit 22 _MT moves the shielding box unit 22 up and down. The box drive unit _22MT can be realized by using, for example, a cylinder that moves a shaft connected to the shielding box unit 22 up and down.

The imaging unit 23 images the state in which the four organic EL devices ED1 to ED4 emit light according to a desired current supplied from the power supply unit 25. Here, the desired current includes an inspection current I _C and an adjustment current (also referred to as an adjustment current) I _AD (see FIGS. 1 and 3) that can sufficiently emit light from the leakage current generating device. . Note that the adjustment current I _AD corresponds to, for example, a drive current in which the light emission possible region of the device that does not generate a leakage current can generate light emission luminance as normal illumination, and is considerably larger than the inspection current I _C.

The imaging unit 23 acquires an image captured with the light emitting area of the organic EL device ED1~ED4 the adjustment current I _AD is applied (also referred to as adjustment image). The imaging unit 23 acquires an image captured with the light emitting area of the organic EL device ED1~ED4 the test current I _C is applied (also referred to as test image). Both the adjustment image and the inspection image are information related to the light emission luminance of each of the organic EL devices ED1 to ED4. Here, the adjustment image and the inspection image are monochrome images indicating a two-dimensional distribution of pixel values corresponding to the light emission luminance. Here, it is assumed that the in-focus state and the aperture state of the imaging unit 23 are in a state suitable for imaging of the four organic EL devices ED1 to ED4 mounted on the tray 24.

  By the way, for example, when a simple digital camera is applied to the imaging unit 23, the pixel value of each pixel constituting the image acquired by the imaging unit 23 does not indicate the absolute value of the luminance of the subject itself, but the luminance of the subject. The signal level corresponding to is shown.

  In this case, for example, first, a digital camera (also referred to as a luminance measurement camera) that can directly acquire an image composed of a large number of pixel values corresponding to the luminance of the subject, and a digital camera applied to the imaging unit 23, The same chart (for example, Macbeth color chart) is imaged. Next, by comparing the two obtained images, the relationship between the output (each pixel value) of the digital camera applied to the imaging unit 23 and the luminance is obtained. Information indicating this relationship is stored in advance in the storage unit 34, and in the imaging control unit 363 or the like, the two-dimensional distribution of luminance related to the subject is appropriately determined from the two-dimensional distribution of pixel values obtained by the imaging unit 23. If it asks for.

The identification information acquisition unit 24 _OB acquires the identification information of the tray 24 existing immediately below the shielding box unit 22. Examples of the identification information acquisition unit 24 _OB include an IC tag reader that reads identification information (for example, a tray ID) from an IC tag attached to the tray 24. It may be provided on either side. A bar code may be used instead of the IC tag, and a bar code reader may be used instead of the IC tag reader.

The power supply unit 25 is a constant current source that can stably supply a constant current to the four organic EL devices ED1 to ED4 via the first wiring FW _P and the second wiring FW _M. The constant current includes an inspection current I _C and an adjustment current I _AD . Note that these currents I _C and I _AD are currents that flow in directions (also referred to as forward directions) in which the organic EL devices ED1 to ED4 can emit light.

The transport controller 361 moves the tray 24 by controlling the transport system 21. Further, the conveyance control unit 361 controls the box driving unit 22 _MT in synchronization with the movement of the tray 24 to move the shielding box unit 22 up and down.

The current control unit 362 controls the power supply unit 25 to supply the inspection current I _C or the adjustment current I _AD to the four organic EL devices ED1 to ED4 arranged on the tray 24.

The imaging control unit 363 controls the imaging unit 23 in synchronization with the control of the power supply unit 25 by the current control unit 362 so that the four organic EL devices ED1 to ED4 arranged on the tray 24 emit light. The captured adjustment image and inspection image are sequentially acquired. In addition, the imaging control unit 363 acquires the identification information (here, the tray ID) of the tray 24 that exists immediately below the shielding box unit 22 by controlling the identification information acquisition unit _24OB .

Based on the adjustment image acquired by the imaging unit 23, the region specifying unit 364 specifies the position where the image region in which the light-emissible region is captured occupies the inspection image. Specifically, in the adjustment image, a region composed of a plurality of pixels each representing a pixel value corresponding to a light emission luminance equal to or higher than the lower limit value L _LL of the light emission luminance detectable by the imaging unit 23 is one organic EL. The light emitting area of the device is specified as an image area that can be captured.

  The area specifying unit 364 specifies the position of the image area where the light-emission possible area corresponding to each of the organic EL devices ED1 to ED4 is captured. The four image regions specified by the region specifying unit 364 are image regions (also referred to as evaluation areas) that are used to calculate an evaluation value (also referred to as a light emission evaluation value) related to light emission luminance in the evaluation value calculation unit 366. .

Specifically, for example, an image obtained by the imaging unit 23 extends along the horizontal direction (X direction) and faces two sides, and extends along the vertical direction (Y direction) and faces each other 2. It is assumed that the image is a rectangular image whose outer edge is constituted by the sides. Then, a rectangular outer edge consisting of two sides extending in two sides in the Y direction and extending in a direction X, the inner in the region consisting of multiple pixels a mass of a pixel value corresponding to the light emission luminance L _LL or more light emitting luminance An area that is in contact (also referred to as a rectangular area) is an evaluation area. Note that the rectangular area has a similar relationship with the light-emitting area obtained by design.

  Further, for example, the order in which the four evaluation areas are arranged specifies whether the four evaluation areas correspond to the evaluation areas related to any of the four organic EL devices ED1 to ED4. It ’s fine.

  Note that pixels P1 to P4 that are predicted to capture four light-emitting areas in the adjustment image are set in advance, and based on the pixels P1 to P4, the four evaluation areas are the four organic EL devices ED1 to ED4. Which of the organic EL devices corresponds to each of the evaluation areas may be specified. In this case, for example, an evaluation area including the pixel P1 is an evaluation area related to the organic EL device ED1, and an evaluation area including the pixel P2 is an evaluation area related to the organic EL device ED2. An evaluation area including the pixel P3 is an evaluation area related to the organic EL device ED3, and an evaluation area including the pixel P4 is an evaluation area related to the organic EL device ED4.

  Information indicating the four evaluation areas specified in this way (also referred to as area specifying information) is output in the form shown in FIG. As shown in FIG. 8, in the area specifying information, the XY coordinates of the upper left pixel and the XY coordinates of the lower right pixel in the evaluation area are associated with the tray ID for each arrangement order of the organic EL devices. It is a thing. Note that the upper left coordinate of each image is the origin.

  The image correction unit 365 performs so-called shading correction on the inspection image acquired by the imaging unit 23.

  The evaluation value calculation unit 366 calculates an evaluation value (light emission evaluation value) related to the light emission luminance for each evaluation area based on the inspection image after shading correction. Each light emission evaluation value may be, for example, an average value of light emission luminance in the evaluation area. The average value may be, for example, a so-called arithmetic average value, and is any average value among various averages such as a geometric average, a square average, and an arithmetic average after excluding a significantly deviated value. There may be. Furthermore, the light emission evaluation value may be any one of various representative values such as the maximum value, the mode value, and the median value of the light emission luminance in the evaluation area.

  Further, the evaluation value calculation unit 366 generates information (also referred to as light emission evaluation information) in which the calculated light emission evaluation value relating to each organic EL device is added to the region specifying information input from the region specifying unit 364. . A data example of the light emission evaluation information is as shown in FIG. FIG. 9 shows an example in which the light emission evaluation values of the organic EL devices ED1 to ED4 are 1.5, 1.2, 1.6, and 0.01, respectively.

The determination unit 367 determines, for each organic EL device, that leakage current exceeding the allowable value can occur when the condition that the light emission evaluation value is equal to or less than the threshold value T ₁ is satisfied. For example, the threshold value T ₁ is clearly smaller than a light emission evaluation value (also referred to as a reference light emission evaluation value) calculated from light emission luminance that can be realized in a device that does not generate a leakage current in design (for example, a reference light emission evaluation value). It is sufficient that the value is an order of magnitude less than one-tenth of the value). The inspection current I _C is, if the current (I ₀ + I _0OFFSET) more than is and current _{(I 0 + I L + I} 0OFFSET) less than the current, for example, thresholds T ₁ is set to a value close to 0 May be.

For example, when the threshold T ₁ is set to 0.1, if the light emission evaluation information is as shown in FIG. 9, the fourth organic EL device ED4 has a light emission evaluation value equal to or less than the threshold T _1. Therefore, it is determined that the device is an unqualified device that may cause a leakage current exceeding the allowable value. On the other hand, 1-3-th organic EL device ED1~ED3 is leakage current exceeding the allowable values for emission evaluation value exceeds the thresholds T ₁ is determined to be eligible device not occur.

  Further, in the determination unit 367, information (determination result) in which information indicating qualification (OK) and disqualification (NG) as a determination result is added to the light emission evaluation information input from the evaluation value calculation unit 366. Also referred to as information). An example of data of the determination result information is as shown in FIG. In FIG. 10, the determination result of qualification (OK) is described for the first to third organic EL devices ED1 to ED3, respectively, and the determination result of ineligibility (NG) is described for the fourth organic EL device ED4. An example is shown.

  The determination unit 367 causes the display unit 32 to visually output the determination result information and also causes the storage unit 34 to store the determination result information. Note that the form of the determination result information that is visually output on the display unit 32 may be the form of the table shown in FIG.

  The result output unit 368 transmits the determination result information transferred from the determination unit 367 via the communication line to the aggregation server 500 installed outside the light emitting device inspection apparatus 1.

<(4) Operation flow of light-emitting device inspection device>
FIG. 11 is a flowchart showing an operation flow of the light emitting device inspection apparatus 1. This operation flow is realized by the control unit 36 reading and executing the program PG. The operation flow is started in response to an instruction from the operation unit 31, for example, and proceeds to step S1 in FIG.

In step S1, under the control of the conveyance control unit 361, together with the tray 24 is transported to immediately below the shielding box portion 22 by the transport system 21, and lowered shielding box portion 22 by the box drive unit 22 _MT, shielding The internal space of the box portion 22 is sealed.

In step S2, under the control of the current control unit 362, supply of the adjustment current I _AD to the four organic EL devices ED1 to ED4 from the power supply unit 25 is started. At this time, starts to emit light, each organic EL device ED1~ED4 is in accordance with the adjustment current I _AD.

  In step S <b> 3, an adjustment image is acquired by the imaging unit 23 under the control of the imaging control unit 363.

In step S <b> 4, the supply of the adjustment current I _AD to the four organic EL devices ED <b> 1 to ED <b> 4 from the power supply unit 25 is finished under the control of the current control unit 362. In this case, it terminates the light emission by each organic EL device ED1~ED4 is in accordance with the adjustment current I _AD.

  In step S5, the area specifying unit 364 specifies the position of the evaluation area corresponding to the light emitting area of each organic EL device ED1 to ED4 based on the adjustment image acquired in step S3, and the position of each evaluation area. The area specifying information indicating each is generated.

In step S <b> 6, supply of the inspection current I _C to the four organic EL devices ED <b> 1 to ED <b> 4 from the power supply unit 25 is started under the control of the current control unit 362. At this time, starts to emit light, each organic EL device ED1~ED4 is in accordance with the test current I _C.

  In step S <b> 7, an image for inspection is acquired by the imaging unit 23 under the control of the imaging control unit 363.

In step S <b> 8, the supply of the inspection current I _C to the four organic EL devices ED <b> 1 to ED <b> 4 from the power supply unit 25 is ended under the control of the current control unit 362. In this case, it terminates the light emission by each organic EL device ED1~ED4 is in accordance with the test current I _C.

  In step S9, the evaluation value calculation unit 366 calculates emission evaluation values for the evaluation areas related to the organic EL devices ED1 to ED4 based on the inspection image acquired in step S7.

  In step S10, whether or not each organic EL device ED1 to ED4 is qualified or ineligible is determined by the determination unit 367 based on the light emission evaluation value related to each organic EL device ED1 to ED4 calculated in step S9. Determined.

  In step S11, the determination unit 367 causes the display unit 32 to visually output determination result information indicating the determination result obtained in step S10, and stores the determination result information in the storage unit 34. Further, the result output unit 368 transmits the determination result information to the aggregation server 500 or the like via a communication line.

In step S <b> 12, under the control of the conveyance control unit 361, the shielding box unit 22 is raised by the box driving unit 22 _MT , and the tray 24 is carried out from directly below the shielding box unit 22 by the conveyance system 21.

  In step S <b> 13, the control unit 36 determines whether there is a next tray 24. If there is a next tray 24, the process returns to step S1, and if there is no next tray 24, the operation flow ends.

<(5) Summary of one embodiment>
As described above, in the light emitting device inspection apparatus 1 according to the embodiment, information on the light emission luminance of the organic EL device that emits light according to the inspection current I _C is acquired, and the evaluation value calculated from the light emission luminance is obtained. Based on this, it is determined whether or not a leakage current exceeding the allowable value can occur. For this reason, it is possible to inspect the leakage current of the organic EL device with a simple configuration.

Further, the imaging unit 23 captures an image of light emission according to the inspection current I _C in a state where the plurality of organic EL devices are electrically connected in series. At this time, the leakage current in a certain organic EL device among the plurality of organic EL devices does not affect the light emission luminance in other organic EL devices. As a result, since a plurality of organic EL devices can be inspected at the same time, the inspection can be speeded up.

Further, the imaging unit 23 acquires information related to the light emission luminance of the organic EL device that emits light according to the inspection current I _C. For this reason, for example, quick inspection can be performed with a simple configuration such as a general-purpose digital camera. Further, for example, since the light emission luminance of the plurality of organic EL devices is measured by the single imaging unit 23, it can be quickly inspected with a simple configuration.

Further, if the light emission evaluation value obtained from the light emission luminance of the organic EL device that emits light according to the inspection current I _C is an average value of the light emission luminance related to the region to be evaluated, light emission is performed in one organic EL device. Even if the lower limit value of the current required for the measurement varies, stable inspection can be performed.

In addition, an image for adjustment that captures an organic EL device that emits light in accordance with the adjustment current I _AD is acquired by imaging, and an image area in which the light-emitting area of each organic EL device is captured based on the image for adjustment The position where the image occupies the inspection image is specified. For this reason, the inspection based on the light emission luminance related to a wider area of the organic EL device that can emit light becomes possible.

<(6) Modification>
It should be noted that the present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the gist of the present invention.

For example, in the above-described embodiment, the light emission evaluation value is an average value of the light emission luminance related to the evaluation area, but is not limited thereto. For example, the light emission evaluation value may be a ratio of an image area including one or more pixels indicating a pixel value corresponding to the light emission luminance equal to or higher than the threshold T ₂ in the evaluation area corresponding to the light emission possible area.

For example, as shown in Figure 12, the evaluation area is an image area AR1 of the threshold T ₂ or more light-emitting luminance, a case composed of an image area AR2 according to the light emission luminance less than the threshold T _2. At this time, the light emission evaluation value is derived by dividing the area of the image area AR1 by the sum of the area of the image area AR1 and the area of the image area AR2.

  According to such a configuration, even when the lower limit value of the current required for light emission varies in one organic EL device, stable inspection can be performed.

  In the above embodiment, the four organic EL devices ED1 to ED4 are electrically connected in series. However, the present invention is not limited to this. For example, a current may be individually applied to each of the organic EL devices ED1 to ED4, and an arbitrary number of two or more organic EL devices may be electrically connected in series. The number of organic EL devices that can be captured by one imaging may be an arbitrary number of 1 or more.

However, from the viewpoint of speeding up the inspection, it is preferable that one or more organic EL devices to be inspected are a plurality of organic EL devices electrically connected in series to the power supply unit 25. In such an aspect, information related to the light emission luminances of a plurality of organic EL devices that emit light in response to the supply of the inspection current I _C can be acquired in parallel.

In the embodiment described above, the organic EL device is determined to be qualified or unqualified based on the light emission evaluation value related to the light emission luminance, but is not limited thereto. For example, it for the organic EL devices, current emission when gradually increasing the drive current is started (also referred to as light emission start current) is estimated, the condition under which the light emission starting current is equal to or higher than the threshold value I _T is satisfied For example, it may be determined that it is ineligible.

  The emission start current can be estimated by sequentially performing the following steps (A) and (B).

  (A) A plurality of different inspection currents (inspection currents) are sequentially supplied, and information related to the light emission luminance of the organic EL device emitting light according to each inspection current is acquired by the imaging unit 23. . At this time, for example, for each organic EL device, if the average value of the light emission luminance is obtained from the information indicating the two-dimensional distribution related to the light emission luminance obtained by the imaging unit 23, the light emission luminance of the organic EL device is obtained. good.

  (B) An operation in which a curve indicating the relationship between the drive current and the light emission luminance is approximately calculated by using a plurality of different values for the inspection current and the light emission luminance values corresponding to the respective inspection currents. By performing (also referred to as curve approximation calculation), the emission start current of the organic EL device is estimated. From another viewpoint, the light emission start current corresponds to the lower limit value of the drive current necessary for light emission of the organic EL device estimated based on the light emission luminance as the measurement result.

  Here, the estimation of the light emission start current will be described with a specific example.

  FIG. 13 is a diagram illustrating a functional configuration of the light-emitting device inspection apparatus 1 according to a modification. The functional configuration shown in FIG. 13 is based on the functional configuration of the light emitting device inspection apparatus 1 according to the embodiment shown in FIG. 7, and the evaluation value calculation unit 366 is replaced with the estimation unit 369. It is a thing.

FIG. 14 is a diagram for explaining a method of estimating the light emission start current according to a modification. In FIG. 14, similarly to FIG. 1, the relationship between the drive current in the leakage current non-generating device and the light-emitting luminance is shown by the curve CV _S one-dot chain line, the relationship between the drive current in the leakage current generating device and the light emitting luminance There has been shown by the curve CV _L of the two-dot chain line.

For example, under the control of the current controller 362, with respect to the feeding section 25 four organic EL devices ED1～ED4, three different first to third test current I ₁ ~I ₃ are sequentially applied. At this time, the imaging unit 23 acquires an image (also referred to as a first inspection image) in which a state in which the first inspection current I ₁ is applied to the four organic EL devices ED1 to ED4 is captured. In addition, the imaging unit 23 acquires an image (also referred to as a second inspection image) in which a state in which the second inspection current I ₂ is applied to the four organic EL devices ED1 to ED4. Furthermore, the imaging unit 23 acquires an image (also referred to as a third inspection image) in which a state where the third inspection current I ₃ is applied to the four organic EL devices ED1 to ED4.

Thereby, information related to the light emission luminance (also referred to as first light emission luminance) L ₁ of each of the organic EL devices ED1 to ED4 that emits light according to the first inspection current I ₁ is acquired. Further, information related to the light emission luminance (also referred to as second light emission luminance) L ₂ of each of the organic EL devices ED1 to ED4 that emits light according to the second inspection current I ₂ is acquired. Information related to the emission luminance (also referred to as third emission luminance) L ₃ of each of the organic EL devices ED1 to ED4 that emits light according to the third inspection current I ₃ is acquired.

Then, the estimation unit 369, for each organic EL device ED1～ED4, the first inspection current I ₁ and the first emission luminance L ₁ set, and the second inspection current I ₂ of the second light emission luminance L ₂ The light emission start current is estimated by a curve approximation calculation using the set, and the set of the third inspection current I ₃ and the third light emission luminance L ₃ .

More specifically, for example, the relationship between the drive current I and the light emission luminance L is expressed by a relational expression of L = a × I ² + b × I + c, which is a polynomial using constants a, b, and c. To do. Here, with respect to this relational expression, a _first expression obtained by substituting I ₁ for I and L _{1 for} L, and obtained by substituting I ₂ for I and L ₂ for L. The constants a, b, and c are obtained from the second equation obtained and the third equation obtained by substituting I ₃ for I and L ₃ for L. Then, by substituting the obtained constants a, b, and c into the above relational expression, a curve indicating the relationship between the drive current and the light emission luminance is approximately calculated, and the current I when L = 0 is obtained. Estimated as the emission start current.

  Note that, here, three light emission luminances corresponding to three different drive currents are obtained by imaging, but the present invention is not limited to this, and a curve model (also referred to as a curve model) obtained by design is set in advance. If the light emission luminance for one drive current is obtained by imaging, a mode in which a curve indicating the relationship between the drive current and the light emission luminance is approximately calculated by parallel movement of the curve model is also conceivable. However, in this aspect, if the slope of the curve indicating the relationship between the drive current and the light emission luminance is different between the organic EL devices as inspection targets, the inspection accuracy can be reduced.

  For this reason, from the viewpoint that inspection accuracy can be maintained, two emission luminances corresponding to two different drive currents are obtained by imaging, for example, a process (curve fitting) in which parallel movement and deformation of a curve model are performed. ) Is executed to obtain a curve indicating the relationship between the drive current and the light emission luminance. Further, it is more preferable that three light emission luminances corresponding to the three different drive currents described above are obtained by imaging, and a curve indicating the relationship between the drive current and the light emission luminance is obtained using the above polynomial.

  According to the aspect according to this modification, an inspection current that generates light emission luminance that can be stably detected by the imaging unit 23 can be used. For this reason, it is not necessary to increase the sensitivity of the imaging unit 23, and the configuration of the imaging unit 23 can be simplified.

◎ Further, in the above embodiment, the inspection current I _C is, has been set in the range of less than the current (I ₀ + I _0OFFSET) more than is and current _{(I 0 + I L + I} 0OFFSET), limited to Absent. For example, if the threshold value T _{1 serving as a} determination reference in the determination unit 367 is appropriately adjusted, the inspection current I _C may be set to a value equal to or greater than the current (I ₀ + I _L + I _0OFFSET ).

However, if the test current I _C is, if it is set in the range of less than the current (I ₀ + I _0OFFSET) more than is and current _{(I 0 + I L + I} 0OFFSET), leakage current exceeding the allowable value has occurred Does not detect the light emission of the organic EL device. That is, the emission luminance of the unsuitable organic EL device is detected as 0. For this reason, the qualified organic EL device and the unqualified organic EL device are clearly distinguished, and the inspection accuracy is improved. Therefore, from the viewpoint of the accuracy of the inspection is increased, as described above one embodiment, the inspection current I _C is, is the current (I ₀ + I _0OFFSET) or more and a current _{(I 0 + I L + I} 0OFFSET) of less than It is preferable to set within the range.

In the above-described embodiment, the information related to the light emission luminance of each of the organic EL devices ED1 to ED4 is obtained by the imaging unit 23, but is not limited thereto. For example, information relating to light emission luminance of each organic EL device ED1~ED4 that emits light in response to the test current I _C, may be obtained respectively by detection by a photodiode or the like. According to such a configuration, it is possible to inspect the leakage current of the organic EL device with a very simple configuration.

  FIG. 15 is a diagram illustrating a schematic configuration of a measurement unit 2A configuring the light emitting device inspection apparatus 1A according to the present modification.

  When a photodiode is employed, a configuration is required in which the light emission luminance of one organic EL device can be obtained while being separated from the influence of the light emission luminance of another organic EL device. For this reason, as shown in FIG. 15, the measurement unit 2A according to this modification is based on the measurement unit 2 according to the above-described embodiment, and the shielding box portion 22 is added with the shielding plates W1 to W3. The imaging unit 23 is replaced with four sensor units 231 to 234 each having a photodiode.

  In the measurement unit 2A, when the shielding box unit 22A is lowered and is in close contact with the tray 24, the sensor unit 231 is positioned directly above the organic EL device ED1, and the sensor unit 232 is positioned directly above the organic EL device ED2. The sensor part 233 is located immediately above the organic EL device ED3, and the sensor part 234 is located immediately above the organic EL device ED4. According to this configuration, the process for specifying the evaluation area related to each of the organic EL devices ED1 to ED4 becomes unnecessary, which contributes to the simplification of the configuration and the process.

  FIG. 16 is a block diagram showing a functional configuration of a light emitting device inspection apparatus 1A according to the present modification. The light-emitting device inspection apparatus 1A according to this modification is based on the light-emitting device inspection apparatus 1 according to the above-described embodiment, and the imaging unit 23 is replaced with four sensor units 231 to 234, and the current control unit 362. The imaging control unit 363 and the determination unit 367 are replaced with a current control unit 362A, a detection control unit 363A, and a determination unit 367A, respectively, and an area specifying unit 364, an image correction unit 365, and an evaluation value calculation unit 366. It has been removed.

The current control unit 362A supplies the inspection current I _C to each of the organic EL devices ED1 to ED4 by the power supply unit 25. The detection control unit 363A acquires information related to the detection by the four sensor units 231 to 234 and the light emission luminance as a result of the detection. The determination unit 367A uses a light emission luminance acquired by using each of the sensor units 231 to 234 as a light emission evaluation value, and when a condition that the light emission evaluation value is equal to or less than the threshold T ₁ is satisfied, Judge that it is likely to occur.

  A mode in which the four sensor units 231 to 234 are imaging units is also conceivable. In this aspect, the influence of the dark current in the imaging unit is suppressed, and the inspection accuracy can be improved.

  In the above-described embodiment, the two-dimensional distribution of light emission luminance acquired using the imaging unit 23 is used, but the present invention is not limited to this. For example, the light emission luminance related to one pixel included in each evaluation area may be used as the light emission evaluation value.

  In the above-described embodiment, the inspection target is an organic EL device, but is not limited thereto. For example, the inspection target may be another surface emitting device such as an EL device (also referred to as an inorganic EL device) configured using an inorganic material.

  It goes without saying that all or a part of each of the above-described embodiment and various modifications can be appropriately combined within a consistent range.

DESCRIPTION OF SYMBOLS 1,1A Light-emitting device inspection apparatus 2,2A Measuring part 22,22A Shielding box part 34 Memory | storage part 36 Control part 231-234 Sensor part 362,362A Current control part 363 Imaging control part 363A Detection control part 364 Area | region specific part 365 Image Correction unit 366 Evaluation value calculation unit 367, 367A Determination unit 368 Result output unit 369 Estimation unit ED1-ED4 Organic EL device

Claims (10)

A feeding section of a constant current source for supplying a constant test current flowing in a forward direction with respect to a plurality of light emitting devices,
A plurality of measurement units that are provided for each of the light emitting devices, respectively, and acquire information related to the luminance of each of the light emitting devices that emit light according to the inspection current;
For each of the light emitting devices, a lower limit value of a current required for light emission of each of the light emitting devices estimated based on the first condition that the evaluation value related to the luminance is equal to or lower than a first threshold and the luminance is equal to or higher than a second threshold A determination unit that determines that a leakage current exceeding an allowable value can occur when one of the second conditions is satisfied,
Other than the one light emitting device other than the one light emitting device of the plurality of light emitting devices, and one measuring unit that acquires information relating to the luminance of one light emitting device included in the plurality of light emitting devices of the plurality of measuring units A shielding part that shields visible light, disposed between the light emitting device and
A light emitting device inspection apparatus comprising: The light-emitting device inspection apparatus according to claim 1,
The inspection current is
From a second current that is equal to or higher than a first current for realizing a lower limit value of luminance that can be detected by the measurement unit in the light emitting device in which a leakage current does not occur, and the allowable current is added to the first current A light-emitting device inspection apparatus characterized by a small current. The light-emitting device inspection apparatus according to claim 1 or 2,
The plurality of light emitting devices are
It is electrically connected in series with the power supply unit,
The plurality of measuring units are
A light-emitting device inspection apparatus that acquires information related to luminance of the plurality of light-emitting devices emitting light according to the inspection current at the same time. The light-emitting device inspection apparatus according to any one of claims 1 to 3,
Each said measurement part is
Characterized in that it comprises a light-emitting region by acquiring the test image captured with an imaging unit that acquires information relating to luminance before Symbol emitting devices before Symbol emitting devices that are to emit light in accordance with the inspection current Light-emitting device inspection device. The light-emitting device inspection apparatus according to claim 4,
The evaluation value related to the luminance is
A light-emitting device inspection apparatus, comprising an average value of luminance related to the light-emitting area. The light-emitting device inspection apparatus according to claim 4,
The evaluation value related to the luminance is
The light-emitting device inspection apparatus includes a ratio of an area having a luminance equal to or higher than a third threshold in the light-emitting area. The light-emitting device inspection apparatus according to any one of claims 4 to 6,
A specifying unit that specifies a position occupied by an image area in which the light-emissible area is captured in the inspection image, based on an adjustment image acquired by the imaging unit;
Further comprising
The adjustment image is
A light-emitting device inspection apparatus, wherein the light-emitting device is an image obtained by capturing each light-emitting device that emits light in accordance with an adjustment current larger than the inspection current. The light-emitting device inspection apparatus according to any one of claims 1 to 3,
Each said measurement part is
Emitting device inspection apparatus characterized by comprising a photodiode for acquiring information relating to luminance before Symbol emitting devices that are to emit light in accordance with the inspection current. The light-emitting device inspection apparatus according to claim 1,
The inspection current is
Including a first inspection current, a second inspection current, and a third inspection current;
Each said measurement part is
The information according to the first luminance before Symbol emitting devices that are to emit light in accordance with a first test current, information relating to the second luminance before Symbol emitting devices that are to emit light in accordance with the second inspection current, and sequentially acquires information relating to the third luminance before Symbol emitting devices that are to emit light in accordance with the third test current,
The lower limit is
For each of the light emitting devices, a set of the first inspection current and the first luminance, a set of the second inspection current and the second luminance, and a third inspection current and the third luminance A light-emitting device inspection apparatus, which is estimated by a curve approximation calculation using a set. One measurement unit that arranges a measurement unit for each light-emitting device included in the plurality of light-emitting devices and acquires information on luminance of one light-emitting device included in the plurality of light-emitting devices among the plurality of measurement units And disposing a shielding part that shields visible light between the light emitting devices other than the one light emitting device of the plurality of light emitting devices,
To supply a constant test current flowing in a forward direction with respect to the plurality of light emitting devices by the power supply unit as a constant current source, the information relating to the luminance of each light emitting device that emits light in response to the test current Obtaining each by the plurality of measuring units;
For each of the light emitting devices, the lower limit value of the current required for light emission of the light emitting device estimated based on the first condition that the evaluation value related to the luminance is less than or equal to a first threshold and the luminance is greater than or equal to the second threshold A step of determining that a leakage current exceeding an allowable value can be generated by the determination unit when one of the second conditions is satisfied;
A light-emitting device inspection method comprising:

Images