JP3199863B2 - Color filter inspection method, inspection device, and inspection light source - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method, an inspection apparatus, and an inspection light source for a color filter used for a display panel such as a color liquid crystal display device.

[0002]

2. Description of the Related Art Generally, a liquid crystal display device has a thickness of 1 to 10 μm between two transparent substrates such as a glass substrate on which a transparent electrode is formed.
A gap of m is provided, a liquid crystal composition is sealed between the gaps, and a voltage is applied between the electrodes to drive the liquid crystal to perform display. Then, in order to perform color display,
It is common to use a color filter having a red (R), green (G), and blue (B) colored layer on one glass substrate between the gaps.

This color filter comprises a light-shielding layer (black matrix), R, G, B on a transparent substrate such as glass.
, An overcoat layer, and a transparent electrode are sequentially laminated. And in forming the colored layer,
Although a dyeing method, a pigment dispersion method, an electrodeposition method, a printing method, and the like have been put to practical use, it is extremely difficult to completely eliminate defects and unevenness in a pixel portion. Therefore, screening by appearance inspection is indispensable. Usually, as shown in FIG.
The color filter 1 on which the three primary color layers of R, G, and B are formed is transmitted through the inspection light source 2 having a good transmission balance of three colors from a distance of about 30 cm, and visually inspected from the position 3.

[0004]

Most of the conventional light sources for inspection 2 use a white three-wavelength fluorescent tube, and their spectral peak values are three peaks (R, G) of a color filter. , B). For this reason, the luminance of the pixel normal part of the color filter is relatively high,
It is considered to be at the same level as the white raster display of the liquid crystal display device.

However, in the liquid crystal display device, since the applied voltage can be turned on / off or changed for each pixel pixel, the brightness of the pixel normal portion of the color filter becomes lower than that of the white raster display, resulting in a defect. The contrast with the part may be high. For this reason, it was not possible to detect defects / unevenness that could be visually recognized by the liquid crystal display device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color filter inspection method, an inspection apparatus, and an inspection light source capable of improving the contrast ratio between a normal portion and a defective portion and performing an inspection with high accuracy.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method of inspecting a color filter having a red, green, and blue colored layer formed on a transparent substrate for the presence or absence of a defect in the colored layer by transmitted light from an inspection light source. As a light source for inspection, its spectral peak value is 590 (± 20) nm (nanometer) or 510 (nm).
Using the phosphor in one even without least of (± 20) nm
A color filter inspection method, an inspection apparatus and an inspection light source using a low-pressure mercury vapor discharge lamp .

[0008]

According to the present invention, the spectral peak value of the inspection light source is located at the valley of the spectral peak of the color filter, so that the luminance of the pixel normal portion of the color filter can be reduced similarly to the liquid crystal display device. As a result, the defect / non-uniformity that could not be detected by the conventional inspection light source can be detected.

[0009]

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

In general, most of the transmission spectrum of a color filter is provided with three peaks (R, G, B) near the peak value of a three-wavelength fluorescent tube to increase color purity. It is common practice to design a sharp peak with a small half width as much as possible. 510 nm
And a valley of the spectrum near 590 nm in many cases. Therefore, if the spectral peak value of the light source for inspection is in the vicinity of 590 nm or 510 nm, the transmittance of the portion where the pixel of the color filter is normally formed becomes low, and a defective portion or unevenness of the colored layer is thin. The transmittance of the abnormal portion causing the above becomes higher. For this reason, it is possible to increase the contrast of the defective portion or the uneven portion, and it is possible to detect the defective portion or the uneven portion that can be visually recognized by the liquid crystal display device. Hereinafter, three specific embodiments will be described. (First embodiment)

Also in the present invention, when inspecting the colored layer of the color filter for defects in the manufacturing process, the conventional visual inspection shown in FIG. 4 is performed. In the first embodiment, the inspection is performed. A low-pressure mercury vapor discharge lamp having the spectrum shown in FIG. That is,
The main peak value of this inspection light source is at 590 nm,
The mercury emission line subpeak values are 545 nm and 435 nm, and the light source is a pink light source as a whole.

In order to evaluate the inspection ability of the inspection light source, a defect having an arbitrary size was formed on the colored layer of the color filter using a laser, and the size of the defect was examined. The results are shown in Table 1 below, where TYPE1 was the case where the inspection light source of the first embodiment was used.
For each of the G and B colors, the visibility limit was smaller than that of the conventional three-wavelength fluorescent tube.

[0013]

[Table 1]The numerical values in Table 1 indicate the size of defects at the limit of visibility.
Area (unit is μm^Two ). (Second embodiment)

In the second embodiment, a light source having the spectrum shown in FIG. 2 is used as an inspection light source. That is, the main peak value of this inspection light source is at 575 nm, and the sub-peak values are at 545 nm, 480 nm, 435 nm, etc., and the light source is a white light source as a whole. The same evaluation as in the first example was performed, except that TYPE2 shown in Table 1 above was used.
This is the case where the inspection light source of the second embodiment is used, and the visibility limit for each of R, G, and B colors can be made smaller than that of the conventional three-wavelength fluorescent tube. (Third embodiment)

The inspection light source used in the third embodiment is:
The inspection light source of the second embodiment is overlapped with a yellow filter, and its spectrum is shown in FIG. The filter had an absorption edge near 500 nm, and could almost cut the subpeak value of 500 nm or less. However, a decrease in light source luminance due to this filter was hardly recognized.
Sufficient brightness could be secured. When the visibility limit of the inspection light source used in the third embodiment was examined, the visibility limit was smaller in B (blue) than in the second embodiment as shown in Table 1 above. (Fourth Embodiment) In the fourth embodiment, a lamp having a spectral peak value near 510 nm is used as a light source for inspection.

In each of the above embodiments, the presence or absence of a defect in the colored layer is visually inspected. However, it goes without saying that the inspection light source according to the present invention can be applied not only to visual inspection but also to inspection by a camera or a sensor. No. The spectral peak value of the inspection light source is 590 nm or 510 nm.
Within ± 20 nm, more preferably ± 15 n
It suffices if it is within the range of m.

[0017]

According to the present invention, as the inspection light source,
Its spectral peak value 590 (± 20) nm, or 510 (± 20) small without even phosphors on one of nm to
Since the used low-pressure mercury vapor discharge lamp is used, the contrast ratio between the normal part and the defective part of the color filter is improved, and high-precision inspection becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a spectrum of an inspection light source used in a color filter manufacturing method (inspection method) according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a spectrum of an inspection light source used in a color filter manufacturing method (inspection method) according to a second embodiment of the present invention.

FIG. 3 is a view showing a spectrum of an inspection light source used in a color filter manufacturing method (inspection method) according to a third embodiment of the present invention.

FIG. 4 is a perspective view showing a method for visually inspecting a colored layer of a color filter for the presence or absence of a defect.

[Explanation of symbols]

 1 ... color filter, 2 ... light source for inspection, 3 ... inspection position.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-99787 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21/84-21/958 G01M 11 / 00-11/08 G02B 5/20-5/28 H01J 9/24-9/50

Claims (3)

(57) [Claims] 1. A method for inspecting a color filter, in which a red, green, and blue colored layer is formed on a transparent substrate, by using transmitted light from an inspection light source to inspect the colored layer for defects. As a light source for inspection, the peak value of the spectrum is 5
90 (± 20) nm, or 510 (± 20) nm of less Do <br/> low-pressure mercury vapor discharge La that uses the phosphor in one to Kutomo
A method for inspecting a color filter, characterized by using a pump . 2. A method for forming a red, green and blue colored layer on a transparent substrate.
Color filter is raised by the transmitted light from the inspection light source.
Inspection of color filters to inspect the coloring layer for defects
In the apparatus, the peak value of the emission spectrum is 590 (± 20) nm, or 51 0 (± 20) nm inspecting apparatus of the color filter, characterized in that using a low-pressure mercury vapor discharge lamp using a phosphor in. 3. A red, green and blue colored layer is formed on a transparent substrate.
Color filter is raised by the transmitted light from the inspection light source.
Inspection of color filters to inspect the coloring layer for defects
In use a light source, the peak value of the emission spectrum is 590 (+20) nm, or 51 0 (+20) inspection light source of a color filter, comprising the low-pressure mercury vapor discharge lamp that uses the phosphor in nm.