JPH08122272A - Inspection device of liquid crystal color filter - Google Patents

Abstract

PURPOSE: To enhance measuring accuracy and reliability by providing a laser beam source, an optical path length variable means, a displacement length display means, a focus adjusting means and a reflected light intensity maximum position detecting means. CONSTITUTION: A laser beam from a laser beam source 41 passes through a beam splitter 42, and is condensed by a condenser lens 43. The condensed laser beam is reflected to an upper mirror 44, and is reflected by reflecting mirrors 47 and 48 held by a mirror holding jig 49, and is further reflected by a lower mirror 45, and is condensed by a condenser lens 46, and is irradiated, for example, to an R color filter 13 of a liquid crystal color filter 18. The jig 49 periodically reciprocates in slow motion by an actuator 51, and changes the optical path length of the laser beam. When the focus of the laser beam coincides with the origin of a surface of the filter 13, strong diffusion is caused from the surface of the filter 13, and the reflected light reflected by the filter 13 is reflected by the beam splitter 42 through the respective mirrors 45, 48, 47 and 44 and the condenser lens 43, and is made incident on a reflected light intensity detector 53.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal color filter inspecting apparatus for inspecting the height of foreign matter such as printing protrusions, dust and pigment lumps by measuring the height of a liquid crystal color filter.

[0002]

2. Description of the Related Art FIG. 3 is a cross section of a general liquid crystal color filter, FIGS. 4 and 5 are schematic views showing a measurement state by a conventional liquid crystal color filter height inspection device, and FIG. 6 is a liquid crystal color by a conventional inspection device. The graph which shows the height measurement result of a filter is shown.

As shown in FIG. 3, the black matrix 12 is formed by depositing chromium (Cr) on the glass substrate 11.
Are formed, and the R (red) filter 1 is used as a color filter in each opening of the black matrix 12.
3, G (green) filter 14 and B (blue) filter 15 are printed alternately. Then, an overcoat layer 16 is coated on each color filter 13, 14, 15 by a method such as spin coating. Further, a transparent electrode 17 is formed on the overcoat layer 16 to form a liquid crystal color filter 18.

In the liquid crystal color filter 18 thus formed, if the foreign matter 21 adheres to the respective color filters 13, 14 and 15 or if there is a projection 22 during printing, an uneven portion 23 is formed on the transparent electrode 17. Will occur. This uneven portion 23 is a liquid crystal display (hereinafter referred to as LSD. LSD =
If the cell gap is larger than that of a liquid crystal display (LCD), it will come into contact with a counter electrode (not shown) to cause a short circuit, and the quality will be impaired as LSD such as defects, color defects, and color unevenness. Therefore, the above-mentioned color filters 13,
It is an important point in the LSD manufacturing process to inspect whether or not the heights of the foreign matter 21 and the printing protrusions 22 on the surfaces 14 and 15 are below the allowable values.

Conventionally, the color filters 13, 14, 1
As a method for measuring the height of the foreign matter 21 and the printing protrusions 22 on the surface 5, it is considered appropriate to use a laser displacement meter. That is, as shown in FIG. 4, in a measuring device using a scattering type laser displacement meter, a black matrix 12 is formed on a glass substrate 11 and respective filters 13, 14 and 15 are printed in the openings, and an overcoat layer is formed. 1
The state before 6 is coated. Then, in the liquid crystal color filter 18, for example, the laser light L is emitted from the semiconductor laser light source 31 of the laser displacement meter, condensed by the lens 32, and the condensed laser light L is emitted to the R color filter 13. Then, the R color filter 13
The reflected light L ₁ reflected by the lens 33 is condensed by the lens 33, and the condensed reflected light L ₁ is received by the semiconductor position detector (PSD) 34 to measure the displacement, and the displacement is measured by the triangulation method. The height of the color filter 13 is measured. Also, FIG.
As shown in FIG. 3, in the measuring device using the regular reflection type laser displacement meter, similarly, the laser light L is emitted from the semiconductor laser light source 31, and the laser light L condensed by the lens 32 is emitted to the R color filter 13. Then, the reflected light L ₁ reflected is condensed by the lens 33 and received by the semiconductor position detector (PSD) 34 to measure its displacement, and the height of the R color filter 13 is measured by the triangulation method. To do.

[0006]

However, there are various problems in measuring the heights of the color filters 13, 14 and 15 with a laser displacement meter in the above-mentioned conventional height inspection measurement of the liquid crystal color filter. there were. That is, as shown in FIGS. 4 and 5, the wavelength of the laser light L emitted from the semiconductor laser light source 31 is used by light on the long wavelength side of 670 [nm] or more. Although partially reflected, the light is partially transmitted and reaches the black matrix 12 on the back surface of the R color filter 13. Then, the laser light L is reflected by the black matrix 12, and the reflected light L ₂ thus reflected is reflected by the semiconductor position detector (P
The light is received at SD) 34. In general, since the black matrix 12 is formed by vapor deposition of chromium (Cr), its surface reflectance is high, and the reflected light L ₂ has a higher light power than the reflected light L ₁ of the R color filter 13. Is also big. Therefore, as shown in FIG. 6, the reflected light received by the semiconductor position detector (PSD) 34 is greatly affected by the reflected light L _{2 from} the black matrix 12, and there is a problem that accurate measurement cannot be performed.

Further, when the surface height is measured along the surface of the color filters 13, 14 and 15 in the conventional height inspection measurement of the liquid crystal color filter, the color, roughness and gloss of the measured surface, The distribution of the reflection intensity changes depending on whether it is a mirror surface or not. That is, as the measurement surface, each color filter 13,
Accurate measurement cannot be performed because the black matrixes 14 and 15 are periodically positioned. Therefore, the measurement parameters must be sequentially changed at the time of measurement, or must be corrected at the time of data processing, which makes the work troublesome.

The present invention solves such a problem, and an object of the present invention is to provide a highly accurate and highly reliable liquid crystal color filter inspection device.

[0009]

In a liquid crystal color filter inspection apparatus of the present invention for achieving the above object, a black matrix is formed on a substrate and a color filter is formed in an opening of the black matrix. In a liquid crystal color filter inspection device for measuring the height of a liquid crystal color filter, a laser light source for emitting laser light, an optical path length changing means for changing the optical path length of the laser light emitted from the laser light source, and the optical path length. Displacement amount display means for displaying the amount of displacement by the variable means, focus coupling means for condensing the laser light emitted from the laser light source to couple the focus at an arbitrary position, and the focus of the laser light is the liquid crystal color. A reflected light intensity maximum position detecting means for detecting a position where the reflected light intensity of the laser light becomes maximum when the surface of the filter is matched; It is an feature.

[0010]

The laser light is emitted from the laser light source, the laser light is condensed by the focus combining means to combine the focus at an arbitrary position, and the optical path length of the laser light emitted by the optical path length varying means is changed. The displacement amount display means displays the displacement amount by the optical path length varying means. At this time, by detecting the position where the reflected light intensity of the laser light becomes maximum when the focus of the laser light matches the surface of the liquid crystal color filter by the reflected light intensity maximum position detection means, the color filter is detected from the detection result. Height is measured accurately.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing a liquid crystal color filter inspecting apparatus according to an embodiment of the present invention, and FIG. 2 is a graph showing the result of measuring the height of the liquid crystal color filter. It should be noted that members having the same functions as those described in the related art are designated by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 1, a liquid crystal color filter 1
8, a black matrix 12 is formed on a glass substrate 11, and an R (red) filter 13, a G (green) filter 14, and a B are provided in respective openings of the black matrix 12.
The (blue) filters 15 are formed by alternately printing, and each of the color filters 13, 14, 15 is formed in a state before the overcoat layer and the transparent electrode 17 are formed on the color filters 13, 14, 15. Measure the height. The liquid crystal color filter 18 is supported by a driving device (not shown) so as to be movable in the X direction and the Y direction which are orthogonal to each other horizontally, and can be positioned at a predetermined position by the position control device 41.

On the other hand, in the liquid crystal color filter inspection apparatus of the present embodiment, the laser light source 41 for emitting the laser light L is used.
A beam splitter 42 and a condenser lens 43 are provided below the. A pair of upper and lower mirrors 44 and 45 are arranged below the condenser lens 43, and a laser beam L is arranged below the pair of mirrors 44 and 45.
A condenser lens 46 is provided as a focus coupling means for condensing light and condensing the focus at an arbitrary position. The pair of upper and lower mirrors 44 and 45 are tilted in opposite directions at an angle of approximately 45 degrees, and a pair of reflecting mirrors 47 and 48 are provided on a mirror holding jig 49 at a position facing each side of the mirrors 44 and 45. It is held and arranged. The mirror holding jig 49 is movable by an actuator 51 having a driving source 50, and the reflection mirrors 47 and 48 are connected to the upper and lower mirrors 44 and 44.
The optical path length varying means is configured by allowing the lens 45 to move closer to and away from it. That is, the optical path length of the laser light L emitted from the laser light source 41 can be changed by moving the reflecting mirrors 47 and 48 by the actuator 51. The drive source 5 of the actuator 51
A displacement amount display device 52 is connected to 0 so that the displacement amount of the optical path length can be displayed.

In addition, the beam splitter 42 has an opposite side.
A light intensity detector 53 is provided. This reflected light intensity
The detector 53 is a laser reflection from the liquid crystal color filter 18.
Light L ₁Is reflected by the beam splitter 42 and input.
The laser reflected light L₁The reflected light intensity of
The detection result is output to the displacement amount display device 52.
I'm supposed to be forced.

Therefore, when the laser light L is emitted from the laser light source 41, the laser light L passes through the beam splitter 42 and is condensed by the condenser lens 43. Then, the laser light L condensed by the condenser lens 43 is reflected by the upper mirror 44, reaches the reflection mirrors 47 and 48 held by the mirror holding jig 49, is reflected here, and is further lowered. Mirror 4
The light is reflected by the light source 5, the light is condensed by the condenser lens 46, and is irradiated onto the R color filter 13 of the liquid crystal color filter 18, for example.

At this time, the mirror holding jig 49 is actuated.
The laser makes a fine reciprocating movement periodically by the Eta 51.
The optical path length of the light L is changed. That is, the actuator
Mirror holding jig 4 for reflecting mirrors 47 and 48 by 51
By moving 9 freely, the focus position of the laser beam L is the liquid crystal.
Move the R color filter 13 of the color filter 18 up and down
Move. The focus of the laser light L is the R color filter.
When the origin of the surface of 13 is matched, this R color filter
There is strong scattering from the surface of 13 and its reflected light L ₁Is focused
It reaches the lens 46. Then, in the R color filter 13
Reflected light L₁Is a condenser lens 46 and each mirror 4
5, 48, 47, 44, beam through condenser lens 43
The reflected light intensity detector 53 is reflected by the splitter 42.
Incident. The reflected light intensity detector 53 is a laser
Reflected light L₁The displacement amount display device 52 detects the reflected light intensity of the
Output to.

The displacement amount display device 52 records the intensity of the reflected light of the reflected light L ₁ , and the reflecting mirror 4 by the actuator 51 is recorded.
A displacement signal is output corresponding to the movement amount of 7,48. In this way, the height of the R color filter 13 is accurately measured.

That is, as shown in FIG. 2, each peak value P is the boundary portion of each color filter 13, 14, 15 and includes the reflected light from the black matrix 12. Further, it can be seen that the variable value D is the foreign matter 21 on the G color filter 14.

[0020]

As described above in detail with reference to the embodiments, according to the liquid crystal color filter inspection apparatus of the present invention,
The laser light emitted from the laser light source is condensed by the focus combining means to combine the focus at an arbitrary position, and the optical path length of the laser light emitted by the optical path length varying means is changed to be displayed by the displacement amount displaying means. The displacement amount by the optical path length varying means is displayed, and at this time, the position at which the reflected light intensity of the laser light becomes maximum when the focus of the laser light matches the surface of the liquid crystal color filter by the reflected light intensity maximum position detection means. Since it is detected, the difference in color and reflectance of the color filter does not affect the measurement displacement, and the reflected light of the black matrix does not affect the measurement displacement, and the color filter surface can be detected almost completely. Since the laser light is incident vertically and only the displacement of the reflected light is detected, the color filter height can be accurately measured, and the measurement accuracy can be improved. It is possible to improve the reliability of the device is improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a liquid crystal color filter inspection device according to an embodiment of the present invention.

FIG. 2 is a graph showing the result of measuring the height of a liquid crystal color filter.

FIG. 3 is a cross-sectional view of a general liquid crystal color filter.

FIG. 4 is a schematic diagram showing a measurement state by a conventional liquid crystal color filter height inspection device.

FIG. 5 is a schematic diagram showing a measurement state by a conventional liquid crystal color filter height inspection device.

FIG. 6 is a graph showing the result of measuring the height of a liquid crystal color filter by a conventional inspection device.

[Explanation of symbols]

 11 Glass Substrate 12 Black Matrix 13 R Color Filter 14 G Color Filter 15 B Color Filter 18 Liquid Crystal Color Filter 21 Foreign Material 22 Printing Protrusion 41 Laser Light Source 42 Beam Splitter 43, 45 Condenser Lens 44, 45, 47, 48 Mirror 49 Mirror Holding Jig 51 Actuator 52 Displacement amount display device 53 Reflected light intensity detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Ikeshita 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Works

Claims (1)

[Claims] 1. A laser emitting a laser beam in a liquid crystal color filter inspection device for measuring the height of a liquid crystal color filter in which a black matrix is formed on a substrate and a color filter is formed in an opening of the black matrix. A light source, an optical path length varying means for changing the optical path length of the laser light emitted from the laser light source, a displacement amount display means for displaying a displacement amount by the optical path length varying means, and a laser light emitted from the laser light source. A focus combining means for collecting light and combining the focus at an arbitrary position, and a position where the reflected light intensity of the laser light becomes maximum when the focus of the laser light matches the surface of the liquid crystal color filter. An apparatus for inspecting a liquid crystal color filter, comprising: maximum reflected light intensity position detecting means.