JP5025588B2 - Spacer formation inspection apparatus, display panel manufacturing apparatus, and display panel manufacturing method - Google Patents

Description

  The present invention relates to a spacer formation inspection apparatus, a display panel manufacturing apparatus, and a display panel manufacturing method in which spacers are applied on a display panel substrate by an inkjet method, and in particular, a spacer is applied to a predetermined position on the display panel substrate. The present invention relates to a spacer formation inspection device, a display panel manufacturing device, and a display panel manufacturing method.

  For example, in an active matrix liquid crystal display device, a liquid crystal panel is configured by enclosing a liquid crystal between a TFT (Thin Film Transistor) substrate and a color filter substrate. In the manufacturing process, a spacer is formed on the surface of the TFT substrate or the color filter substrate to keep the distance between the two substrates, and the TFT substrate and the color filter substrate are overlapped with each other through the formed spacer. The liquid crystal may be dropped before the TFT substrate and the color filter substrate are overlaid, or may be injected after the TFT substrate and the color filter substrate are overlaid.

If the spacer is disposed in the pixel region of the color filter substrate, the image quality of the liquid crystal panel is deteriorated. Therefore, the spacer must be accurately disposed above the light shielding layer (black matrix) that partitions each pixel. In Patent Document 1, the discharge speed of the spacer from the inkjet head and the discharge direction of the spacer are measured with a strobe and a camera, the number of discharge spacers is measured with a camera, and if within the set range, the spacer is discharged onto the substrate. A technique is disclosed in which the inkjet head is cleaned if it is outside the set range.
JP 11-316380 A

  The technique described in Patent Document 1 measures the number of spacers ejected from an inkjet head with a camera. However, since the spacer is composed of transparent particles such as beads, it is extremely difficult to actually measure with a camera. In addition, the illumination light is reflected on the surface of the solvent simultaneously ejected, and it is very difficult to image and observe the number of spacers (bead particles) inside the coating liquid during and immediately after ejection. is there.

  The present invention has been made in view of the above points, and a spacer forming inspection apparatus, a display panel manufacturing apparatus, and a display capable of inspecting whether or not a spacer is applied to a predetermined position on a display panel substrate. An object of the present invention is to provide a panel manufacturing method.

The first feature of the spacer formation inspection apparatus of the present invention is that when the ink comprising spherical particles is ejected from the inkjet head onto the display panel substrate to form the spacers composed of the spherical particles on the display panel substrate. Before the ink containing the spherical particles is ejected onto the display panel substrate, the display panel substrate is irradiated with light to detect a pre-ejection signal based on the reflected light and the ink containing the spherical particles. Is ejected onto the display panel substrate, and the display panel substrate is irradiated with light in a state where the gloss of the ink exists, and a post-ejection signal based on the reflected light is detected, By comparing the pre-ejection signal and the post-ejection signal, whether or not the ink containing the spherical particles has been ejected from the inkjet head, and the ink containing the spherical particles It is to check whether injected at a predetermined position of the display panel substrate.
The ink droplets ejected from the inkjet head are volatile, and are heated at a low temperature after ejection and fixed on the display panel substrate by utilizing the curing phenomenon of the thermosetting resin contained in the ink. Yes. As a result, when the ink dries and loses its gloss, the inspection using the reflected light becomes very difficult. Therefore, in the present invention, the reflected light signal before ink ejection (pre-ejection signal) and the reflected light signal before ink drying immediately after ink ejection (post-ejection signal) are detected, and the two are compared to detect the ink. The injection state of was detected. Thereby, it is possible to easily inspect whether or not the spacer is applied to a predetermined position on the display panel substrate.

  According to a second feature of the spacer formation inspection apparatus of the present invention, in the spacer formation inspection apparatus according to the first feature, light irradiation is performed to irradiate the display panel side with light from a position separated from the display panel substrate. And reflected light detection means for receiving reflected light reflected from the display panel side out of the light irradiated by the light irradiation means at a position spaced from the display panel surface and outputting a detection signal thereof. It is in having. As shown in FIG. 1, the light irradiating means and the reflected light detecting means for irradiating light on the display panel substrate and detecting the pre-ejection signal and the post-ejection signal based on the reflected light are displayed as shown in FIG. It corresponds to what is separately provided on the space on the panel substrate. The light irradiating means and the reflected light detecting means may be provided at the same spatial position, and only the reflected light in the irradiated light may be branched and received by a half mirror or the like.

  The first feature of the display panel manufacturing apparatus of the present invention is that the inkjet head means for ejecting ink containing spherical particles onto the display panel substrate, and the inkjet head means with the display panel substrate mounted thereon. Stage means controlled to move relative to each other, frame means for controlling movement of the ink jet head means relative to the stage means, and ink jet head means by controlling movement of the frame means and the stage means. Controlling the ejection state of the inkjet head means while controlling the relative positional relationship between the spherical particles and the stage means, and ejecting the ink containing the spherical particles to the desired position of the display panel substrate. Control means for forming a spacer made of the ink and the ink containing the spherical particles Before being ejected onto the panel substrate, the display panel substrate is irradiated with light to detect a pre-ejection signal based on the reflected light, and the ink containing the spherical particles is ejected onto the display panel substrate. After that, in the state where the gloss of the ink exists, the display panel substrate is irradiated with light to detect a post-ejection signal based on the reflected light, and the pre-ejection signal and the post-ejection signal are compared. Thus, a spacer formation inspection is performed to inspect whether or not the ink including the spherical particles is ejected from the inkjet head and whether or not the ink including the spherical particles is ejected to a predetermined position on the display panel substrate. And means. This is an invention of a display panel manufacturing apparatus that employs the above-described first feature of the spacer formation inspection apparatus as a spacer formation inspection means.

  According to a second feature of the display panel manufacturing apparatus of the present invention, in the display panel manufacturing apparatus according to the first feature, the spacer formation inspection means is configured to display the display from a position separated from the display panel substrate. A light irradiating means for irradiating light to the display panel side, and reflected light reflected from the display panel side of the light irradiated by the light irradiating means at a position separated from the display panel surface; And a reflected light detecting means for outputting a detection signal. This is an invention of a display panel manufacturing apparatus in which the above-described second feature of the spacer formation inspection apparatus is adopted as the spacer formation inspection means.

  The display panel manufacturing method of the present invention is characterized in that a spacer is manufactured on a display panel using the display panel manufacturing apparatus described in the first or second feature. This relates to a display panel manufacturing method in which a gap forming spacer is arranged on a display panel substrate using the display panel manufacturing apparatus described above.

  According to the present invention, it is possible to easily inspect whether or not a spacer is applied to a predetermined position on the display panel substrate.

  FIG. 1 is a diagram showing a schematic configuration of a spacer forming apparatus according to an embodiment of the present invention. Although this embodiment shows an example of a spacer forming apparatus in which a spacer is disposed on a color filter substrate of a liquid crystal panel, the present embodiment can also be applied to a case in which a spacer is disposed on a TFT substrate. The spacer forming apparatus includes a table 10, a base 11, an X guide 12, a Y guide 13, a moving table 14, an inkjet head 40, an ink tank 50, and a control device 60.

  The table 10 holds the color filter substrate 20 by vacuum suction. The base 11 is provided with an X guide 12 on which the table 10 is mounted, and the table 10 moves along the X guide 12 in the X direction (the lateral direction in the drawing). In addition, although a ball screw, a linear motor, etc. are used as a drive means, these illustration is abbreviate | omitted.

  The base 11 is provided with a gate-type slide frame 13 straddling the table 10, and a movable table 14 is attached to the slide frame 13. The moving table 14 moves in the Y direction (the drawing depth direction) along the slide frame 13. An ink jet head 40 and an ink tank 50 are mounted on the movable table 14, and the ink tank 50 supplies ink to be described later to the ink jet head 40. The ink jet head 40 can eject the ink supplied from the ink tank 50 to an arbitrary position on the surface of the color filter substrate 20 by moving the table 10 in the X direction and moving the moving table 14 in the Y direction. It has become. The table 10 is movable in the X direction (horizontal direction in the drawing) and the Y direction (depth direction in the drawing) relative to the inkjet head unit 40 with the color filter substrate 20 mounted thereon, and is also in the XY plane. It may be configured to be rotatable in the θ direction. In this embodiment, the case where there is one inkjet head unit 40 is shown, but two, four, or more inkjet head units may be provided.

  The reflected light detection head 70 is composed of a CCD array sensor provided along the longitudinal direction of the slide frame 13. Under the reflected light detection head 70, a detection illumination 80 is provided along the longitudinal direction of the slide frame 13. The detection illumination 80 is composed of an LED light source in which a plurality of LEDs are arranged in an array. The reflected light detection head 70 receives the reflected light reflected from the color filter substrate 20 among the light emitted from the LED light source 80, and outputs a reflected light detection signal corresponding to the reflected light amount to the control device 60.

  FIG. 2 is a flowchart showing an example of processing of the spacer forming apparatus and the liquid crystal panel manufacturing apparatus according to the embodiment of the present invention. FIG. 2A is a flowchart showing an example of a spacer forming apparatus process according to an embodiment of the present invention, and FIG. 2B shows an example of a liquid crystal panel manufacturing apparatus process according to an embodiment of the present invention. It is a flowchart.

  In an example of the spacer forming apparatus shown in FIG. 2A, first, an ink containing spherical particles (spacers) and a thermosetting resin is applied to the color filter using the inkjet head 40 of the spacer forming apparatus shown in FIG. It sprays on the surface of the board | substrate 20 (step 101), and the spacer which consists of a spherical particle and a thermosetting resin is arrange | positioned on the color filter board | substrate 20. FIG. Then, by heating the color filter substrate 20 at a low temperature (step 102), the thermosetting resin is cured, and spacers made of spherical particles and a thermosetting resin are formed on the color filter substrate 20.

  FIG. 3 is a diagram illustrating an arrangement example of spacers on the color filter substrate. Usually, a lattice-shaped light shielding layer (black matrix) 22 is formed inside the color filter substrate 20, and R, G, and B color filter elements 231 to 234 are formed in the lattice of the light shielding layer 22. ing. In this embodiment, the inkjet head 40 is used to eject the plurality of spherical particles 21 to 28 and the ink 1 containing the thermosetting resin to a position above the light shielding layer 22, thereby the plurality of spherical particles 21 to 28 and the heat. Ink 1 made of a curable resin is applied to a predetermined position of the light shielding layer 22.

  Since the ink 1 containing the thermosetting resin has an appropriate viscosity, when the ink 1 is ejected onto the color filter substrate 20 using the inkjet head 40, the ink spreads little on the color filter substrate 20, and as shown in FIG. The plurality of spherical particles 21 to 28 included in the ink 1 are arranged in a narrow area.

  In an example of the process for manufacturing the liquid crystal panel shown in FIG. 2B, first, the color filter substrate 20 is made of spherical particles 21 to 28 using the example of the process for forming the spacer shown in FIG. A spacer is formed (step 201). Next, a sealing material is applied around the color filter substrate 20, and liquid crystal is dropped on the color filter substrate 20 (step 202). Then, the TFT substrate is superposed on the color filter substrate 20 via a spacer made of spherical particles 21 to 28 (step 203). A liquid crystal panel is manufactured through the above processing.

  In FIG. 3, each color filter element has a rectangular shape, and its periphery is partitioned by a light shielding layer (black matrix) 22 made of resin or chrome. Each color filter element is ejected with RGB ink and is arranged in the order of R, G, and B.

  FIG. 4 is a diagram illustrating an example of a detection signal of the reflected light detection head in each detection field. FIG. 4A shows the detection visual field of the reflected light detection head 70 in the Y direction (vertical direction in the drawing) near the center of the color filter elements 231 and 233 in FIG. Yes, the ink 1 containing the plurality of spherical particles 21 to 28 and the thermosetting resin is not ejected from the inkjet head 40, or after the ink ejection, the color filter substrate 20 is heated at a low temperature, and the thermosetting resin is An example of a reflected light detection signal received by the reflected light detection head 70 after curing is shown. This reflected light detection signal indicates that the reflection is large on the light shielding layer (black matrix) 22 made of resin or chrome, and that the reflection is small on the color filter element, which corresponds to the arrangement of the color filter elements in FIG. It is a regular signal.

  FIG. 4B shows the detection of reflected light in the Y direction (vertical direction in the drawing) near the middle of the light shielding layer (black matrix) 22 between the color filter elements 231 and 233 and the color filter elements 232 and 234 in FIG. There is a detection visual field of the head 70, and the ink 1 including the plurality of spherical particles 21 to 28 and the thermosetting resin is not ejected from the inkjet head 40, or the color filter substrate 20 is heated at a low temperature after the ink ejection. An example of the reflected light detection signal received by the reflected light detection head 70 after the thermosetting resin is cured is shown. Since this reflected light detection signal is a reflected signal on the light-shielding layer (black matrix) 22 made of resin or chrome having a large reflection, it shows a high signal as a whole, and is also regular according to the arrangement of the filter elements in FIG. It is a signal. A similar regular signal is obtained even when applied to a specific portion of the filter element.

  4C corresponds to FIG. 4A, and the ink 1 including the plurality of spherical particles 21 to 28 and the thermosetting resin from the inkjet head 40 is substantially at the center of the light shielding layer (black matrix) 22. An example of the reflected light detection signal received by the reflected light detection head 70 immediately after being ejected in the vicinity is shown. This reflected light detection signal shows that the reflection is large on the light shielding layer (black matrix) 22 and the reflection is small and attenuated on the color filter element, but the plurality of spherical particles 21 to 28 and the thermosetting resin Immediately after the ink 1 containing is jetted and applied to the vicinity of the center of the light shielding layer (black matrix) 22, the reflected light from the light shielding layer (black matrix) 22 is drastically reduced by reflection by the glossy ink 1. As shown in FIG. 4C, the peak value is attenuated by about 30 percent as compared with the waveform of FIG.

  FIG. 4D corresponds to FIG. 4B, and the ink 1 including the plurality of spherical particles 21 to 28 and the thermosetting resin from the inkjet head 40 is substantially in the middle of the light shielding layer (black matrix) 22. An example of the reflected light detection signal received by the reflected light detection head 70 immediately after being ejected in the vicinity is shown. Since this reflected light detection signal is a reflected signal on the light shielding layer (black matrix) 22, it shows a high signal as a whole, and is a regular signal corresponding to the arrangement of the filter elements in FIG. Since the ink 1 containing the particles 21 to 28 and the thermosetting resin is immediately sprayed and applied to the vicinity of the center of the light shielding layer (black matrix) 22, the reflection from the glossy ink 1 causes the light from the light shielding layer (black matrix) 22. As shown in FIG. 4 (d), the same attenuation as in FIG. 4 (c) is observed as compared to the waveform in FIG. 4 (b).

  In this embodiment, the reflected light detection head 70 and the LED light source 80 are used, and the ink 1 containing the plurality of spherical particles 21 to 28 and the thermosetting resin is not applied, as shown in FIGS. Based on the detected signal, contamination, surface state, shape defect, etc. on the surface of the spacer forming pad are detected. If the defect continues or exceeds the defect limit, it is extracted as a process problem at an early stage. In addition, the detected signals of FIGS. 4A and 4B are temporarily stored, and compared with the waveforms of FIGS. 4C and 4D after coating, the ink for forming the spacer is used. The unapplied position of 1 is specified, or the non-ejecting nozzle is specified. When an unapplied position or an uninjected nozzle is specified, repair and nozzle clogging correction limits are found and extracted as process problems.

In the above embodiment, the case where the reflected light detection head 70 and the LED light source 80 are provided along the longitudinal direction of the slide frame 13 has been described. However, like the inkjet head 40, the reflected light detection head 70 and the LED light source 80 are provided. It may be configured as a unit and interlocked with the operation of the inkjet head 40.
Note that the present invention is not limited to a liquid crystal panel, and can be applied to a display panel in which two display panel substrates are stacked with a spacer interposed therebetween.

It is a figure which shows schematic structure of the spacer formation apparatus which concerns on one embodiment of this invention. It is a flowchart which shows an example of the process of the spacer formation apparatus which concerns on one embodiment of this invention, and an example of the process of the manufacturing apparatus of a liquid crystal panel. It is a figure which shows the example of arrangement | positioning of the spacer on a color filter board | substrate. It is a figure which shows an example of the detection signal of the reflected light detection head in each detection visual field.

Explanation of symbols

21 to 28 ... spherical particles 10 ... table 11 ... base 12 ... X guide 13 ... slide frame 14 ... moving table 20 ... color filter substrate 22 ... light shielding layers 231 to 234 ... color filter element 40 ... inkjet head 50 ... ink tank 60 ... Control device 70 ... reflected light detection head 80 ... LED light source

Claims (5)

In the case of forming a spacer made of spherical particles on the display panel substrate by ejecting ink containing spherical particles from an inkjet head onto the display panel substrate,
Before the ink containing the spherical particles is ejected onto the display panel substrate, the display panel substrate is irradiated with light to detect a pre-ejection signal based on the reflected light and the ink containing the spherical particles. Is ejected onto the display panel substrate, and the display panel substrate is irradiated with light in a state where the gloss of the ink exists, and a post-ejection signal based on the reflected light is detected, By comparing the pre-ejection signal and the post-ejection signal, whether or not the ink containing the spherical particles has been ejected from the inkjet head, and the ink containing the spherical particles is ejected to a predetermined position on the display panel substrate. A spacer formation inspection apparatus characterized by inspecting whether or not it has been performed.   2. The spacer formation inspection apparatus according to claim 1, wherein: the light irradiation means for irradiating the display panel side with light from a position separated from the display panel substrate; and the display among the light irradiated by the light irradiation means. And a reflected light detecting means for receiving the reflected light reflected from the display panel side at a position spaced from the display panel surface and outputting a detection signal thereof. Inkjet head means for ejecting ink containing spherical particles on a display panel substrate;
Stage means that is controlled to move relative to the inkjet head means in a state where the display panel substrate is mounted;
Frame means for controlling movement of the inkjet head means relative to the stage means;
The display panel substrate is controlled by controlling the ejection state of the ink jet head means while controlling the relative positional relationship between the ink jet head means and the stage means by controlling the movement of the frame means and the stage means. Control means for forming a spacer made of the spherical particles by ejecting ink containing the spherical particles at a desired position of
Before the ink containing the spherical particles is ejected onto the display panel substrate, the display panel substrate is irradiated with light to detect a pre-ejection signal based on the reflected light and the ink containing the spherical particles. Is ejected onto the display panel substrate, and the display panel substrate is irradiated with light in a state where the gloss of the ink exists, and a post-ejection signal based on the reflected light is detected, By comparing the pre-ejection signal and the post-ejection signal, whether or not the ink containing the spherical particles has been ejected from the inkjet head, and the ink containing the spherical particles is ejected to a predetermined position on the display panel substrate. A display panel manufacturing apparatus, comprising: a spacer formation inspection means for inspecting whether or not it has been performed.   4. The display panel manufacturing apparatus according to claim 3, wherein the spacer formation inspection means includes a light irradiation means for irradiating the display panel side with light from a position spaced from the display panel substrate, and the light irradiation means. And reflected light detection means for receiving reflected light reflected from the display panel side at a position separated from the display panel surface and outputting a detection signal thereof. Display panel manufacturing equipment.   5. A display panel manufacturing method, wherein a gap forming spacer is arranged on a display panel substrate using the display panel manufacturing apparatus according to claim 3.

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