JP2005274538A - Apparatus for visual inspection of object to be inspected - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for visual inspection of an object to be inspected, which is easy to set colors of light projected onto the object and is made compact easily. <P>SOLUTION: The apparatus for testing the appearance of the object is equipped with a lighting device which irradiates the object with the light; an imaging device which captures an optical image of the object being irradiated with the light and outputs image data corresponding to the optical image; and an image processing device which checks the image data based on reference data. The above lighting device includes at least one organic electroluminescent element which emits the light under the condition that direct-current voltage is applied. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for inspecting the appearance of an inspection object.

  Inspection of the appearance of various products and parts typified by electrical products such as button batteries, medical supplies such as injection needles and pharmaceutical ampoules, and daily necessities such as paper cups (eg, shape, dimensions, scratches, foreign objects, or placement For inspection, an inspection apparatus including an image processing apparatus is used. An inspection apparatus that uses such various products and parts as inspection objects is an illumination device that irradiates light to the inspection object, an optical image of the light-irradiated inspection object, and corresponds to this optical image. The image pickup apparatus outputs image data, and the image processing apparatus that collates image data output from the image pickup apparatus with reference data.

  As described above, there are various types of products and parts that require an appearance inspection, and their shapes and colors are diverse. When the appearance of the inspection object is inspected, it is preferable that the color of light of the illumination device is a color corresponding to the inspection object. For example, when inspecting foreign matter adhering to a white paper cup, the light color of the lighting device is preferably white, and when inspecting the outer shape of a metal part, the influence of reflected light on the surface thereof In order to suppress this, it is preferable that the color of the light of the lighting device is blue. Conventionally, for example, a light emitting diode has been used as a light source of an illumination device of an inspection apparatus.

Patent Document 1 discloses an image processing system using an electroluminescence sheet that emits light by applying an alternating voltage as a light source of an illumination device. This image processing system is used, for example, to perform pattern matching between a captured image and an image stored in advance, or to calculate the position and angle of a notch on a wafer. By using the electroluminescence sheet as described above for the lighting device, the lighting device can be thinned, so that the degree of freedom in designing the image processing system can be increased, and the luminance of the lighting device can be made uniform. Therefore, it is said that the cause of disturbance in image processing can be reduced.
JP 2003-132343 A

  In the image processing system described in Patent Document 1, it is difficult to adjust the emission color of the electroluminescence sheet. This is because a material that emits light by application of an alternating voltage used in the electroluminescence sheet described above has a poor variation in the emission color, and it is difficult to search for a material that emits light in a desired color. For this reason, the image processing system described above is not sufficiently satisfactory for use as an inspection apparatus corresponding to each inspection object. In addition, the above-described image processing system is likely to be large because an AC power source and an inverter for driving the electroluminescence sheet are required.

  An object of the present invention is to provide an apparatus for inspecting the appearance of an inspection object that allows easy setting of the color of light applied to the inspection object and that can be easily reduced in size.

  The present invention relates to an illumination device that irradiates light on an inspection object, an imaging device that captures an optical image of the light-irradiated inspection object and outputs image data corresponding to the optical image, and the image data and reference data The illumination device includes at least one organic electroluminescence element that emits light when a DC voltage is applied, and is an apparatus for inspecting the appearance of an inspection object. .

Preferred embodiments of the inspection apparatus of the present invention are as follows.
(1) The illumination device and the imaging device are arranged to face each other so as to sandwich the inspection object.
(2) The illumination device has an annular shape with a through hole in the center, and the imaging device is arranged to capture an optical image of the inspection object through the annular through hole of the illumination device.
(3) The illumination device includes an organic electroluminescence element and a half mirror, and the half mirror reflects light emitted from the organic electroluminescence element to irradiate the inspection object, and the light reflected by the inspection object is imaged. Arranged to tell.

(4) A device for controlling the driving voltage of the organic electroluminescence element of the lighting device is provided.
(5) In the inspection apparatus of (4), the illumination device includes at least one set of three organic electroluminescence elements each having a different emission color, and the control device outputs the image pickup device. Based on the image data, the driving voltage of each organic electroluminescence element in each group is controlled to adjust the color of light irradiated to the inspection object.
(6) In the inspection apparatus of (4) above, the control device controls the drive voltage to light the organic electroluminescence element intermittently.
(7) The control device controls the drive voltage based on the image data output from the imaging device, and stabilizes the light emission luminance of the organic electroluminescence element.

  The illumination device of the inspection apparatus according to the present invention includes an organic electroluminescence element that emits light when a DC voltage is applied. The organic electroluminescence element can easily set the emission color to a desired color by selecting the organic light emitting material. Therefore, the inspection apparatus of the present invention can easily set the color of light emitted by the illumination device to a color corresponding to the inspection object, and can accurately inspect the appearance of various inspection objects. In addition, since the inspection apparatus of the present invention does not require the use of an AC power source or an inverter for driving the organic electroluminescence element used in the lighting device, it can be easily downsized.

  The inspection apparatus of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing a configuration example of an inspection apparatus of the present invention and a mode of use thereof. 2 is a plan view showing the arrangement of the illumination device 12 and the inspection object 11 of the inspection device 10 of FIG.

  The inspection apparatus 10 in FIG. 1 has an illuminating device 12 that irradiates light to the inspection object 11, and an imaging apparatus 13 that captures an optical image of the inspection object 11 irradiated with light and outputs image data corresponding to the optical image. , And an image processing device 14 for comparing the image data with the reference data. 1 includes one organic electroluminescence element 15 that emits light when a DC voltage is applied.

  FIG. 3 is a plan view showing the configuration of the organic electroluminescence element 15 provided in the illumination device 12 of the inspection apparatus 10 of FIG. The organic electroluminescence element (light emitting element) 15 in FIG. 3 has a transparent positive electrode layer 32, a hole transport layer 33, an organic light emitting material layer 34, and a negative electrode layer 35 laminated on the surface of a transparent substrate 31 in this order. It has a configuration. The light emitted from the organic electroluminescence element 15 is extracted from the transparent substrate 31 side to the outside of the light emitting element.

  In the organic electroluminescence element 15, when a DC voltage is applied between the positive electrode layer 32 and the negative electrode layer 35, holes from the positive electrode layer 32 and electrons from the negative electrode layer 35 are formed from the organic light emitting material layer 34. Light is emitted by the emission of light when the excitons (excitons) injected into the inside and deactivated by recombination of holes and electrons are deactivated. The organic electroluminescent element 15 can easily set the emission color to a desired color by selecting an organic light emitting material for forming the organic light emitting material layer 34. The hole transport layer 33 has a function of efficiently injecting holes injected from the positive electrode layer 32 into the organic light emitting material layer 34 to increase the light emission efficiency of the organic electroluminescence element 15.

  In this way, by using an organic electroluminescence element that allows easy setting of the emission color, it is easy to set the color of irradiation light according to various inspection objects, that is, the appearance of various inspection objects is accurate. An inspection apparatus capable of inspection can be realized.

  Next, the configuration and operation of the inspection apparatus of the present invention will be described in detail with reference to FIGS. As illustrated in FIGS. 1 and 2, the illumination device 12 and the imaging device 13 of the inspection device 10 are disposed to face each other with the inspection object 11 interposed therebetween. An inspection object 11 shown in FIG. 1 is an injection needle used for a medical syringe, and is formed of a metal material. The inspection object 11 is temporarily fixed to the inspection object carrier 19. When the transport tool 19 moves in the direction indicated by the arrow 20 shown in FIG. 1, the inspection object 11 is transported along with this. The inspection apparatus 10 inspects the appearance of the inspection object 11 conveyed by the conveyance tool 19 in order.

  The illuminating device 12 includes an organic electroluminescence element 15 and a case 16 made of, for example, aluminum that houses the light emitting element 15. The organic electroluminescence element 15 is accommodated in the case 16 so that the transparent substrate side faces the inspection object 11 side.

  It is known that an organic electroluminescent element has its light emission characteristics (eg, light emission luminance) deteriorated when moisture in the air is absorbed by the organic light emitting material layer. In order to suppress the deterioration of the light emission characteristics, it is preferable that the organic electroluminescence element 15 is subjected to moisture-proofing treatment. As an example of the moisture-proof treatment method, a method of bonding a metal or glass cap on the substrate of the organic electroluminescence element 15 so as to hermetically accommodate the organic light emitting material layer, and an organic electroluminescence element, Examples thereof include a method of covering with a thin film (eg, silicon dioxide thin film) exhibiting low moisture permeability.

  When the case 16 that houses the organic electroluminescence element 15 is formed of a conductive material such as aluminum, for example, the case 16 and the light emitting element 15 are electrically insulated from each other. It is preferable to coat an insulating material (e.g., epoxy resin) on a portion in contact with the element 15.

  The illuminating device 12 irradiates the inspection object 11 with light emitted from the organic electroluminescence element 15 by application of a DC voltage. And the imaging device 13 images the optical image of the test object 11 irradiated with light, and outputs the image data corresponding to this optical image.

  In the inspection apparatus 10 shown in FIG. 1, since the illumination device 12 and the imaging device 13 are arranged to face each other with the inspection object 11 interposed therebetween, the optical image of the inspection object 11 captured by the imaging device 13 is an inspection. The object is dark and the background is bright. When white light is irradiated onto the metal injection needle that is the inspection object 11 at the time of this imaging, the metal surface has high reflectivity, and the edge of the injection needle is glaring and a good optical image cannot be obtained. There is. In order to reduce the influence of such reflection on the metal surface, the emission color of the organic electroluminescence element 15 of the inspection apparatus 10 of FIG. 1 is set to blue, for example.

  The imaging device 13 captures an optical image of the inspection object 11, and then outputs image data corresponding to the optical image. The image data is sent to the image processing device 14. The image processing device 14 collates the image data output from the imaging device with the reference data. By this collation, the appearance of the injection needle that is the inspection object 11, for example, the thickness and length of the needle, or the sharpness of the needle tip (angle of the needle tip), etc., is inspected. On the monitor 18 provided in the inspection apparatus 10 of FIG. 1, for example, an inspection result of the inspection object or an optical image of the inspection object determined to be defective is displayed.

  The collation between the image data and the reference data is performed by a method similar to the case of a known image processing system represented by the conventional image processing system or a known inspection apparatus. Examples of data collation methods include a method of pattern matching image data corresponding to an imaged inspection object and image data (reference data) corresponding to an imaged inspection object, and an imaged inspection Examples include a method of calculating numerical data related to the thickness and length of the injection needle from image data corresponding to the object, and collating this numerical data with numerical data (reference data) indicating an allowable range of a non-defective inspection object. It is done.

  In addition, as in the case of the conventional image processing apparatus system and inspection apparatus, in order to facilitate the handling of image data in the image processing apparatus 14, various pre-processing may be performed on the image data output from the imaging apparatus 13. it can. Examples of pre-processing include binarization processing, gamma correction processing, density conversion processing, and shading processing.

  In addition, there is no restriction | limiting in particular in the number of the organic electroluminescent elements with which the illuminating device 12 is provided. For example, a lighting device is configured using a large number of organic electroluminescence elements, and by applying a direct current voltage to each of the light emitting elements, a voltage drop generated in the electrode layer of the light emitting element is reduced. The light emission luminance in the surface on the inspection object side of the illumination device becomes uniform. As a result, the inspection object is uniformly irradiated with light, so that the inspection object can be inspected more accurately.

  As shown in FIG. 1, the inspection device 10 is preferably provided with a device 17 that controls the drive voltage of the organic electroluminescence element 15. By controlling the driving voltage of the organic electroluminescence element by the driving voltage control device 17, it is possible to provide a more practical inspection device by taking advantage of the light emitting element or compensating for the disadvantage as described below. .

  For example, the illumination device of the inspection device is configured to include at least one set of three organic electroluminescence elements each having a different emission color, and the drive voltage control device also stores image data output from the imaging device. In addition, it is preferable to adjust the color of light applied to the inspection object by controlling the driving voltage of each organic electroluminescence element in each group.

  The image data output from the imaging device 13 of the inspection apparatus 10 includes information indicating the color of the inspection object and the intensity of reflected light on the surface thereof. Based on this, the drive voltage of each organic electroluminescence element of each set included in the lighting device is controlled to control the operation of each light emitting element (eg, control of lighting / non-lighting or brightness control). By doing so, the color of the light of the illumination device can be adjusted according to the inspection object. Such an inspection apparatus is excellent in versatility because there is no need to replace the illumination apparatus with an illumination apparatus that emits light of a color corresponding to the inspection object even when the inspection object is changed. . In addition, the fine adjustment of the color of the light which an illuminating device irradiates to a test object becomes easy, so that the number of the groups of the organic electroluminescent element with which an illuminating device is provided is increased.

  Moreover, it is also preferable that the control device 17 controls the drive voltage to light the organic electroluminescence element 15 intermittently. It is known that an organic electroluminescent element is easily deteriorated in its organic light emitting material layer due to heat, and its light emission characteristics are deteriorated (for example, luminance is reduced). By driving the organic electroluminescence element 15 intermittently by the drive voltage control device 17, the amount of heat generated by the lighting device 12 can be reduced. Thereby, since the deterioration of the light emission characteristics of the organic electroluminescence element is reduced, even when the inspection apparatus is used for a long time, the inspection object can be inspected stably.

  Furthermore, it is also preferable that the control device 17 controls the drive voltage based on the image data output from the imaging device 13 to stabilize the light emission luminance of the organic electroluminescence element 15. Thereby, the fall of the test | inspection precision resulting from the fall of the light emission luminance of the organic electroluminescent element by the influence of the water | moisture content in air is suppressed, for example, and a test | inspection target object can be test | inspected stably.

  FIG. 4 is a diagram showing another configuration example of the inspection apparatus of the present invention and a mode of use thereof. FIG. 5 is a plan view showing the arrangement of the illumination device 42 and the inspection object 41 of the inspection device 40 of FIG. 4 has an annular shape in which the illumination device 42 has a through hole in the center, and the imaging device 13 passes through the annular through hole of the illumination device 42 and an optical image of the inspection object 41. 1 is the same as the inspection apparatus 10 in FIG.

  The inspection object 41 shown in FIGS. 4 and 5 is a metal component (generally called a lead frame) used for manufacturing a crimp terminal. The inspection object 41 is fixed to the inspection object carrier 49. When the transport tool 49 moves in the direction indicated by the arrow 20 shown in FIG. 4, the inspection object 41 is transported along with this. The inspection device 40 inspects the appearance of the inspection object 41 conveyed by the conveyance tool 49 in order.

  The organic electroluminescence element 45 provided in the illumination device 42 of the inspection device 40 in FIG. 4 has an annular shape as in the illumination device 42. The configuration of the organic electroluminescence element 45 is the same as that of the organic electroluminescence element 15 in FIG. 3 except that the shape is annular. By using such a ring-shaped organic electroluminescence element 45, a sufficient amount of light is applied to the inspection object 41, and a clear optical image of the inspection object 41 is captured by the imaging device 13. Accuracy can be improved.

  In the case of the inspection apparatus 40 shown in FIG. 4, the optical image of the inspection object 41 imaged by the imaging apparatus 13 has a bright inspection object and a dark background. When white light is irradiated onto the metal component that is the inspection object 41 during this imaging, the surface of the metal component may be glazed and a good optical image may not be obtained due to the high reflectance of the metal surface. In order to reduce the influence of such reflection on the metal surface, the emission color of the organic electroluminescence element 45 of the inspection apparatus 40 in FIG. 4 is set to, for example, blue.

  The imaging device 13 captures an optical image of the inspection object 41 irradiated with light, and then outputs image data corresponding to the optical image. The image data is sent to the image processing device 14. The image processing device 14 collates the image data output from the imaging device 13 with the reference data. By this collation, the appearance of the metal part that is the inspection object 41, for example, the shape, dimension, foreign matter, and scratches of the part is inspected.

  An example of a method for collating image data and reference data in the inspection apparatus of FIG. 4 is the same as that of the inspection apparatus of FIG. In addition, as an example of a method for inspecting a foreign object or a flaw on the surface of the inspection object 41, the area of the region showing the same color on the surface of the inspection object 41 is shown based on the image data output from the imaging device 13. There is a method of calculating data and collating it with reference data.

  FIG. 6 is a diagram showing still another configuration example of the inspection apparatus of the present invention and a mode of use thereof. FIG. 7 is a plan view showing the arrangement of the illumination device 62 and the inspection object 61 of the inspection device 60 of FIG. In the configuration of the inspection device 60 in FIG. 6, the illumination device 62 includes an organic electroluminescence element 65 and a half mirror 71, and the half mirror 71 reflects light emitted from the organic electroluminescence element 65 to irradiate the inspection object 61. However, it is the same as the inspection apparatus 10 in FIG. 1 except that the light reflected by the inspection object 61 is arranged to be transmitted to the imaging apparatus 13.

  The inspection object 61 shown in FIGS. 6 and 7 is a button battery. The button battery is accommodated and held in a container 61 a attached to the inspection object transport tool 69. When the transport tool 69 moves in the direction indicated by the arrow 20 in FIG. 6, the inspection object 61 accommodated and held in the container 61a is transported together with this. The inspection device 60 inspects the appearance of the inspection object 61 conveyed by the conveyance tool 69 in order.

  Light emitted from the organic electroluminescence element 65 included in the illumination device 62 is reflected by the half mirror 71 and is irradiated perpendicularly to the surface of the button battery as the inspection object 61. The light reflected from the surface of the battery is transmitted to the imaging device 13 through the half mirror 71. Such an illumination device that emits light is generally called a coaxial epi-illumination device. By using the coaxial epi-illumination device, for example, it is easy to inspect foreign matters, scratches, or marks on a glossy surface such as the surface of a button battery.

  In the case of the inspection apparatus 60 shown in FIG. 6, the optical image of the inspection object 61 imaged by the imaging apparatus 13 has a bright inspection object and a dark background. The emission color of the organic electroluminescence element 65 of the inspection device 60 of FIG. 6 is set to, for example, blue for the same reason as that of the inspection device 40 of FIG.

  The imaging device 13 captures an optical image of the inspection object 61 irradiated with light, and then outputs image data corresponding to the optical image. The image data is sent to the image processing device 14. The image processing device 14 collates the image data output from the imaging device 13 with the reference data. By this collation, the appearance of the button battery as the inspection object 61, for example, the diameter of the battery, foreign matter or scratches on the battery surface, or characters displayed on the battery surface (eg, battery polarity, output voltage, or model) Etc.) are checked.

  The inspection apparatus of the present invention can also be used for, for example, inspection of the shape and arrangement of wiring patterns provided on the surface of a printed wiring board. For example, the layout of the land of the wiring pattern is inspected by calculating data indicating the center position of the land by the image processing apparatus and comparing this data with data indicating the correct position of the land center (reference data). Can do.

  The inspection apparatus of the present invention can also be used for inspecting the arrangement of objects to be inspected. For example, when an electronic component is mounted on a printed wiring board by an automatic mounting apparatus, it may be necessary to inspect the arrangement (posture) of a component (for example, a diode) having polarity or the arrangement of the component after mounting. With the inspection apparatus of the present invention, for example, based on the image data output from the imaging apparatus, data related to marks indicating the arrangement of the inspection object displayed on the surface of the component (inspection object) in the image processing apparatus is calculated. Then, by collating this with the reference data, the arrangement of the parts can be inspected.

  Next, the organic electroluminescent element used for the inspection apparatus of the present invention will be described. The organic electroluminescent element used for the inspection apparatus of the present invention can be produced in the same manner as a known organic electroluminescent element. For details on organic electroluminescence devices, see “Remaining Research Issues and Strategies for Practical Use of Organic LED Devices” (Bunshin Publishing, 1999) and “Handbook of Optical and Electronic Functional Organic Materials” (Asakura Shoten, 1997). Has been described.

  The transparent positive electrode layer is formed of a metal having a high work function (4 eV or more), a conductive compound, or a mixture thereof. Typical examples of the material of the positive electrode layer include tin-doped indium oxide (ITO) and zinc-doped indium oxide (IZO).

  The thickness of the positive electrode layer is generally 1 μm or less, and preferably 200 nm or less. The resistance of the positive electrode layer is several hundred Ω / sq. The following is preferable.

  Examples of the method for forming the positive electrode layer include vacuum deposition, sputtering, spin coating, casting, LB, pyrosol, spray, and ink jet printing.

  The negative electrode layer is formed of a metal having a low work function (4 eV or less), an alloy composition, a conductive compound, or a mixture thereof. Typical examples of the material of the negative electrode layer include metals such as Al, Ti, In, Na, K, Mg, Li, Cs, Rb, Ca, and rare earth metals, Na-K alloys, Mg-Ag alloys, Mg-Cu. Alloys and alloy compositions such as Al-Li alloys are mentioned.

  The thickness of the negative electrode layer is generally 1 μm or less, and more preferably 200 nm or less. The resistance of the negative electrode layer is several hundred Ω / sq. The following is preferable. The negative electrode layer is formed by the same method as the positive electrode layer.

  In order to increase the luminous efficiency of the organic electroluminescent element, the organic light emitting material layer is provided with a hole transport layer on the surface on the positive electrode layer side or an electron transport layer on the surface on the negative electrode layer side. Can do. Below, the structural example of these layers (organic material layer) is shown.

(A) Organic light emitting material layer (b) Hole transport layer / organic light emitting material layer (c) Organic light emitting material layer / electron transport layer (d) Hole transport layer / organic light emitting material layer / electron transport layer

  Examples of the material for the hole transport layer include tetraarylbenzidine compounds, aromatic amines, pyrazoline derivatives, and triphenylene derivatives. The thickness of the hole transport layer is preferably in the range of 2 to 200 nm.

  Examples of the method for forming the hole transport layer include vacuum deposition, spin coating, casting, LB, spraying, blade coating, screen printing, gravure printing, and inkjet printing. .

  In order to improve the hole mobility, an electron accepting acceptor is preferably added to the hole transporting layer. Examples of electron-accepting acceptors include metal halides, Lewis acids, and organic acids. A hole transport layer to which an electron accepting acceptor is added is described in JP-A No. 11-283750.

  The organic light-emitting material layer is formed from an organic light-emitting material or a small amount of organic light-emitting material on an organic material (hereinafter referred to as host material) that exhibits carrier transport properties (hole transport property, electron transport property, or amphoteric transport property). It is formed from the material which added the material. By selecting the organic light emitting material used for the organic light emitting material layer, the emission color of the organic electroluminescence element can be easily set.

In the case where the organic light emitting material layer is formed from an organic light emitting material, a material having excellent film forming properties and excellent film stability is used as the organic light emitting material. Examples of such organic light-emitting materials include metal complexes typified by Alq ₃ (tris- (8-hydroxyquinolinato) aluminum), polyphenylene vinylene (PPV) derivatives, polyfluorene derivatives, and the like. When the organic light emitting material layer is formed from a material obtained by adding a small amount of an organic light emitting material to a host material, examples of the host material include Alq ₃ , TPD (triphenyldiamine), and an electron transporting oxadiazole derivative ( PBD), polycarbonate copolymer, polyvinyl carbazole, or the like is used. As the organic light-emitting material used together with the host material, since the addition amount is small, in addition to the organic light-emitting material, a fluorescent dye that is difficult to form a stable thin film by itself can be used. Examples of fluorescent dyes include coumarin, DCM derivatives, quinacridone, perylene, and rubrene. Even when the organic light emitting material layer is formed of an organic light emitting material as described above, a small amount of an organic light emitting material such as a fluorescent dye can be added in order to adjust the emission color.

  The thickness of the organic light emitting material layer is preferably 200 nm or less in order to obtain practical light emission luminance. The organic light emitting material layer is formed by the same method as the hole transport layer.

  Examples of materials for the electron transport layer include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthalene pyrylene, carbodiimide, fluorenylidenemethane derivatives, anthraquinodimethane. And electron transport materials such as anthrone derivatives, oxadiazole derivatives, quinoline derivatives, quinoxaline derivatives, perylene derivatives, pyridine derivatives, pyrimidine derivatives, and stilbene derivatives. An aluminum quinolinol complex such as tris (8-hydroxyquinoline) aluminum (Alq) can also be used. The thickness of the electron transport layer is preferably in the range of 5 to 300 nm. The electron transport layer is formed by the same method as the hole transport layer.

  Also, between the positive electrode layer and the negative electrode layer of the organic electroluminescence device, various layers other than the above-described hole transport layer and electron transport layer in order to improve the light emission characteristics of the light emitting device, For example, a hole injection layer (or electron injection layer) can be provided on the surface of the positive electrode layer (or negative electrode layer) on the organic light emitting material layer side.

  A typical example of the material for the hole injection layer is copper phthalocyanine (CuPc), and a typical example of the material for the electron injection layer is an alkali metal compound such as LiF (lithium fluoride). The hole injection layer is also referred to as an anode buffer layer and the electron injection layer is also referred to as a cathode buffer layer. For details of these layers, see “Remaining research subjects and strategies for practical use of organic LED elements” (Bunshin Publishing, 1999). It is described in detail in literatures such as year, p44-45).

It is a figure which shows the structural example of the test | inspection apparatus of this invention, and the aspect of its use. It is a top view which shows arrangement | positioning with the illuminating device of a test | inspection apparatus of FIG. 1, and a test target object. It is sectional drawing which shows the structure of the organic electroluminescent element with which the illuminating device of the inspection apparatus of FIG. 1 is provided. It is a figure which shows another structural example of the test | inspection apparatus of this invention, and the aspect of its use. It is a top view which shows arrangement | positioning with the illuminating device of a test | inspection apparatus of FIG. 4, and a test target object. It is a figure which shows another example of a structure of the test | inspection apparatus of this invention, and the mode of its use. It is a top view which shows arrangement | positioning with the illuminating device of a test | inspection apparatus of FIG. 6, and a test target object.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inspection apparatus 11 Inspection object 12 Illumination apparatus 13 Imaging apparatus 14 Image processing apparatus 15 Organic electroluminescent element 16 Case 17 Drive voltage control apparatus 18 Monitor 19 Inspection object conveyance tool 20 Transfer tool moving direction 31 Transparent substrate 32 Transparent Electrode layer 33 Hole transport layer 34 Organic light emitting material layer 35 Negative electrode layer 40 Inspection device 41 Inspection object 42 Illumination device 45 Organic electroluminescence element 46 Case 49 Inspection object carrier 60 Inspection device 61 Inspection object 61a Container 62 Illumination device 65 Organic electroluminescence element 66 Case 69 Carrying tool for inspection object 71 Half mirror

Claims (8)

  An illuminating device that irradiates light onto an inspection object, an imaging device that captures an optical image of the light-irradiated inspection object and outputs image data corresponding to the optical image, and collation between the image data and reference data An apparatus for inspecting the appearance of an inspection object, comprising: an image processing apparatus to be performed, wherein the illumination apparatus includes at least one organic electroluminescence element that emits light when a DC voltage is applied.   The inspection device according to claim 1, wherein the illumination device and the imaging device are arranged to face each other so as to sandwich the inspection object.   The illumination device has an annular shape having a through-hole in the center, and the imaging device is arranged to take an optical image of the inspection object through the annular through-hole of the illumination device. Inspection equipment.   The illumination device includes an organic electroluminescence element and a half mirror, and the half mirror reflects light emitted from the organic electroluminescence element to irradiate the inspection object, and transmits the light reflected by the inspection object to the imaging apparatus. The inspection apparatus according to claim 1, which is disposed in   The inspection apparatus according to claim 1, further comprising an apparatus that controls a drive voltage of the organic electroluminescence element of the illumination apparatus.   The lighting device includes at least one set of three organic electroluminescence elements each having a different emission color, and the control device uses each set of organic electroluminescence elements based on image data output from the imaging device. The inspection apparatus according to claim 5, wherein the color of light applied to the inspection object is adjusted by controlling a driving voltage of the electroluminescence element.   The inspection apparatus according to claim 5, wherein the control device controls the driving voltage to intermittently light the organic electroluminescence element. The inspection device according to claim 5, wherein the control device controls the drive voltage based on image data output from the imaging device to stabilize the light emission luminance of the organic electroluminescence element.

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