KR20070068832A - Ink-jet apparatus - Google Patents

Abstract

An ink-jet apparatus is provided to promptly and easily manufacture a display substrate by repairing a bad pixel and easily check a dropping state of ink. An ink-jet apparatus includes a stage(10), a nozzle head(31), and a head body(30). A substrate(100) is installed on the stage. The nozzle head is installed on a top of the stage to have a plurality of nozzles for dropping ink(120). A pair of drive units(21,23) move the stage and the nozzle head in a first direction at a level with the stage and in a second direction at right angles to the first direction. The head body has a plurality of nozzle heads for dropping the ink and a pixel checking unit(40) coupled with the nozzle heads. The pixel checking unit has a light source(41) to illuminate the light on pixels dropped thereon the ink and an imaging device(42) to take a photograph of a dropping state of the ink.

Description

Inkjet Device {INK-JET APPARATUS}

1 is a schematic diagram of an inkjet apparatus according to an embodiment of the present invention,

2 is a control block diagram of an inkjet apparatus according to an embodiment of the present invention,

3 is a control flowchart illustrating an inkjet method according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: Stage 21: Support body

23: 1st drive part 25: 2nd drive part

30: Head body 31: Nozzle head

32: ink supply part 40: pixel inspection part

41: light source 42: imaging unit

50: control unit 100: substrate

The present invention relates to an inkjet device, and more particularly, to an inkjet device for dropping a polymer material.

Recently, flat panel displays such as liquid crystal displays and organic light emitting diodes (OLEDs) have been used in place of existing CRTs.

The liquid crystal display device includes a first substrate on which a thin film transistor is formed, a second substrate disposed opposite to the first substrate, and a liquid crystal display panel on which a liquid crystal layer is positioned. Since the liquid crystal display panel is a non-light emitting device, a backlight unit for irradiating light may be disposed on the rear surface of the thin film transistor substrate. Light transmitted from the backlight unit is controlled according to the arrangement of the liquid crystal layer.

Organic electroluminescent devices are in the spotlight due to the advantages of low voltage driving, light weight, wide viewing angle and high speed response. The organic light emitting display device is divided into a passive matrix and an active matrix according to a driving method. The passive type has a simple manufacturing process, but the power consumption increases rapidly as the display area and resolution increase. Therefore, the passive type is mainly applied to small displays. Active type, on the other hand, has a complex manufacturing process but has the advantage of realizing a large screen and high resolution.

Various organic layers such as a color filter layer, an organic semiconductor layer, a light emitting layer, and an alignment layer are present in these display devices. Recently, many of these organic layers are formed by an ink jet method. The inkjet method can pattern an organic layer without a process such as exposure, development, and etching, and has an advantage of reducing the amount of organic material used.

In the case of the organic material layer deposited by the inkjet method, it is generally made of a polymer. After the dropping of the ink, a process of checking the dropping state of the ink as to whether the ink has been properly filled at a predetermined position should be accompanied, but in the case of an ink containing a polymer material, the dropping state is clearly defined by a CCD camera, which is a conventional imaging means. There is an unknown problem. Therefore, there is a hassle of having to perform a separate process for detecting defective pixels by inspecting the dripping state of the ink after the dropping of the ink.

Accordingly, it is an object of the present invention to provide an inkjet device which can easily inspect the dripping state of ink.

The object is a stage in which a substrate on which a pixel is formed is seated according to the present invention; At least one nozzle head having a plurality of nozzles for dropping ink onto the pixels; It is achieved by an inkjet apparatus including a pixel inspection unit having a light source for irradiating light to the pixel in which ink is dripped, and an imaging unit for imaging the dripping state of ink.

In the case of an OLED panel, an organic layer made of a material such as PEDOT (Poly Elyene Dioxty Thiospnene) can capture the filling state of the ink without irradiating light such as ultraviolet light, but in the case of a light emitting layer made of a polymer material, it is necessary to irradiate ultraviolet light. Since the state can be clearly observed, the light preferably contains ultraviolet rays.

In this case, in order to image the photo luminescence sensor by ultraviolet rays, the imaging unit preferably includes a micro microscope.

In order to observe the dripping state of the organic layer which is not a polymer, it is preferable that the said imaging part contains a CCD.

The pixel inspection unit is coupled to the nozzle head and may move together with the nozzle head.

A drive unit for relatively moving the stage and the nozzle head in a first direction horizontal to the stage and in a second direction perpendicular to the first direction; It is preferable to further include a ink supply unit for dropping ink through the nozzle head to be free to move relative.

And a control unit for controlling the driving unit and the ink supply unit to drop an additional ink onto the pixel on which the defect is detected, when a defect of the dropped ink is detected based on the light emission state of the imaged ink. It is desirable to remove.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

In various embodiments, the same reference numerals are given to the same elements, and the same elements may be representatively described in one embodiment and may be omitted in other embodiments.

1 is a schematic view of an inkjet apparatus according to an embodiment of the present invention, showing an inkjet apparatus viewed from the front.

As shown in the drawing, the inkjet apparatus according to the present exemplary embodiment includes a stage 10 on which the substrate 100 is seated, a nozzle head 31 and a nozzle head positioned on the stage 10 and having a plurality of nozzles for dropping ink. And a head body 30 having a pixel inspection portion 40 coupled to the numeral 31.

The head body 30 and the stage 10 may be relatively moved in a first direction and a second direction perpendicular to the first direction. The inkjet apparatus is connected to the head main body 30 and includes a first driver 23 for relative movement in a first direction, and a relative movement in a second direction between the stage 10 and the head main body 30. It includes a two driving unit 25. Although not shown, the inkjet apparatus includes a third driving part for moving the stage 10 in a third direction perpendicular to the first and second directions, respectively. In the inkjet apparatus according to the present exemplary embodiment, the stage 10 may move in the third direction, and the head body 30 may move in the first direction and the second direction with respect to the stage 10.

The stage 10 is provided with each pillar having a bottom surface having a substantially rectangular shape, and forms a seating area on which the substrate 100, on which the organic layer is to be formed, is mounted by ink jetting. The stage 10 may include fixing means such as a vacuum chuck and an electrostatic chuck for fixing the seated substrate. Although not shown, the inkjet apparatus 1 may further include a rail for facilitating the movement of the stage 10.

The substrate 100 mounted on the stage 10 includes a partition wall 110 for partitioning pixels and a predetermined organic layer formed by dropping ink 120 between the partition walls 110. The ink according to the present embodiment includes a polymer, and in particular, the light emitting layer formed on the OLED among the display devices may be described as an example.

The upper part of the stage 10 is substantially '' 'shaped and is provided with a support body 21 for supporting the head body 30. The support body 21 is provided with a rotating screw 22. One end of the rotating screw 22 is rotatably connected to one side of the support body 21, and the other end is connected to the first driving part 23 fixed to the other side of the support body 21. The rotating screw 22 is screwed to the rotating shaft connecting portion 24 is formed with a female thread. The rotary shaft connecting portion 24 reciprocates along the first direction according to the rotation direction of the rotary screw 22.

As the rotary shaft connecting portion 24 moves, the head body 30 connected to the rotary shaft connecting portion 24 also reciprocates. Since the rotating screw 22 extends perpendicular to the second direction, the movement of the nozzle head 31 is perpendicular to the movement of the stage 10.

The head body 30 includes a plurality of nozzle heads 31 for dropping ink and a pixel inspection unit 40 provided adjacent to the nozzle heads 31. The head body 30 is connected to the rotation shaft connecting portion 24 through the second driving portion 25. The second driving unit 25 is capable of contraction and extension so that the head body 30 can reciprocate in a second direction perpendicular to the plate surface of the stage 10. Accordingly, the head body 30 may be approached or spaced apart from the stage 10.

The configuration for the relative movement of the stage 10 and the head body 30 described above is only one embodiment, and any configuration that can relatively move the stage 10 and the head body 31 is applicable.

The nozzle head 31 is provided in plural numbers including a plurality of nozzles, and the ink is dropped into the pixels on the substrate 100. The inkjet apparatus further includes an ink supply unit (not shown), and ink supplied from the ink supply unit is discharged to the outside through the nozzle head. The ink contains a solute dissolved in a solvent. The nozzle head according to the present embodiment drops ink on the substrate 100 while moving in the first direction.

The pixel inspection unit 40 includes a light source 41 for irradiating light to the pixel on which the ink 120 is dropped, and an imaging unit 42 for imaging the drop state of the ink, and detects defective pixels. The pixel inspection unit 40 is included in the head body 30 and depends on the movement of the head body 30. That is, the pixel inspection unit 40 is preferably coupled adjacent to the nozzle head 31 so that the pixel inspection can be performed immediately after the dropping of ink by the nozzle head 31.

The light irradiated to the pixel from the light source 41 is preferably ultraviolet light having high energy. In the case of electroluminescence, which induces light emission by applying an electrical signal to the light emitting layer formed on the substrate 100, photo-luminescence is to induce light emission by irradiating light such as ultraviolet rays to the light emitting layer. It is called). In this embodiment, the light emitting layer made of a polymer is irradiated with ultraviolet light to induce light emission, and the image pickup unit 42 picks up the light to detect pixels in which the light emitting layer is not properly formed.

It is preferable that the imaging part 42 is a micro microscope which can image an ultraviolet-ray. In general, if an optical microscope capable of imaging white light is used, the state of pixels may not be accurately determined. The user can observe the dripping state of the ink through the imaging unit 42. The dripping state of the ink relates to whether the ink is sufficiently formed in the predetermined pixel, and primarily includes a filling state as to whether the ink is filled in the entire area of the pixel. In addition, in order to inspect the defects of the pixels in various ways, it is preferable that a three-dimensional shape such as a step, a thickness, etc. formed in the light emitting layer is imaged.

Although not shown, the pixel inspection unit 40 may include a charge-coupled device (CCD) rather than a micro microscope. The CCD is used to inspect the state of formation of an organic layer made of an organic material such as PEDOT. It is preferable to easily detect the defect of the pixel formed in a board | substrate by simultaneously equipped with the micro microscope which can image an ultraviolet-ray for the inspection of a light emitting layer, and the CCD which can test the other organic layer.

2 is a control block diagram of an inkjet apparatus according to an embodiment of the present invention, and FIG. 3 is a control flowchart for explaining the inkjet method according to the present embodiment. A method of detecting and repairing a bad pixel will be described with reference to FIGS. 2 and 3.

The inkjet apparatus further includes a controller 50 for controlling the driving units 23 and 25 and the ink supply unit 32 to repair the defective pixels detected by the pixel inspecting unit 40.

First, the nozzle head 31 drops ink onto the pixels on the substrate 100 by the movement of the driving units 23 and 25 (S10). The nozzle head 31 adds ink to the pixels while moving relative to the stage 10 in the first, second and third directions. As described above, the ink according to the present embodiment includes a polymer material.

When ink is dripped by the nozzle head 31, ultraviolet-ray is irradiated from the light source 41 provided adjacent to the nozzle head 31 in the moving direction of the nozzle head 31, or the direction in which ink is dripped (S20). Ultraviolet rays provided to the ink stimulate the light emitting area of the ink material to induce optical light emission, and this light serves as a basis for determining whether the ink is dropped in a desired amount at a desired position.

The imaging unit 42 captures the light emitting state of the ink by ultraviolet rays (S30), and information about the pixel in which the defect is detected by the imaging unit 42 is provided to the control unit 50. The pixels formed on the substrate may be set to be recognizable by coordinates (x, y) on a two-dimensional plane. When the ink is not dipped at all or is not sufficiently dipped by the imaging unit 42, the controller ( 50 detects the bad pixel by recognizing the coordinates for the pixel (S40).

Then, the controller 50 moves the drivers 23 and 25 to add ink to the defective pixels. When the nozzle head 31 is positioned on the defective pixel by the driving units 23 and 25, the ink is dropped by the ink supply unit 32.

As such, by providing the light source 41 for irradiating ultraviolet rays and the imaging unit 42 capable of capturing the drop state of the ink through the nozzle head 31 adjacent to the nozzle head 31, the pixel immediately after dropping of the ink is added without additional process. You can check for defects. In addition, since the repair of the defective pixels can be performed in the same process, the display substrate can be manufactured more quickly and easily.

Although some embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that modifications may be made to the embodiment without departing from the spirit or spirit of the invention. . It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

As described above, according to the present invention, there is provided an inkjet device capable of easily inspecting the dripping state of ink.

Claims (7)

A stage on which a substrate on which pixels are formed is mounted; At least one nozzle head having a plurality of nozzles for dropping ink onto the pixels; And a pixel inspection unit having a light source for irradiating light to the pixel in which ink is dripped and an imaging unit for imaging the dripping state of ink. The method of claim 1, And the light comprises ultraviolet light. The method of claim 2, And the imaging unit comprises a micro microscope. The method of claim 1, And the imaging unit comprises a CCD. The method of claim 1, And the pixel inspection unit is coupled to the nozzle head. The method of claim 1, A drive unit for relatively moving the stage and the nozzle head in a first direction horizontal to the stage and in a second direction perpendicular to the first direction; And an ink supply unit for dropping ink through the nozzle head. The method of claim 6, And a control unit for controlling the driving unit and the ink supply unit to drop an additional ink onto the pixel on which the defect is detected, when a defect of the dropped ink is detected based on the light emission state of the imaged ink. Inkjet device.

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