Radiation imagery chemistry: process – composition – or product th – Radiation modifying product or process of making – Screen other than for cathode-ray tube
Reexamination Certificate
1999-12-23
2001-04-24
McPherson, John A. (Department: 1756)
Radiation imagery chemistry: process, composition, or product th
Radiation modifying product or process of making
Screen other than for cathode-ray tube
C356S239200, C356S433000, C349S106000, C347S107000
Reexamination Certificate
active
06221544
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an inspecting method of a color filter for inspecting the coloring density of a coloring portion of the color filter at high speed with high accuracy, and a manufacturing method of the color filter utilizing this inspecting method.
2. Related Background Art
A color filter constituting a liquid crystal display unit is generally constructed by arranging coloring portions colored in red (R), green (G) and blue (B) as three primary colors of light on a transparent substrate. A dyeing method, a pigment dispersing method, an electrodepositing method, etc. are conventionally used as a manufacturing method of the color filter. However, an ink jet system simple in process and economically advantageous has recently been used.
When a coloring portion is formed by using the ink jet system, ink is individually given to predetermined areas. Therefore, unlike the other systems, a problem of uneven coloring is caused by the density distribution in the coloring portions. A defect of the uneven coloring is more than visually recognizable even when this density distribution is only several %, depending on a color of the coloring portion. Accordingly, in a manufacturing process of the color filter using the ink jet system, it is required that these color irregularities are discriminated with high accuracy and an ink amount to be given is further controlled on the basis of the results of this discrimination.
In an inspection of the color irregularities of the color filter, generally, an absolute value of the coloring density is a problem as well as the color irregularities. Therefore, a reference light amount is adjusted. In the reference light amount adjustment, a transmitting light amount is adjusted in a transparent (no light shielding layer such as a black matrix, etc. exists) uncoloring portion within a non-display area. An amount of incident light entering to a CCD camera at an adjusting time of this reference light amount reaches two to five times an amount of incident light entering to the CCD camera when the transmitting light amount of the coloring portion is measured. Therefore, when a light amount of the light source is set such that this light amount is equal to or smaller than a light amount providing a full output of the CCD camara at the time of the reference light amount adjusting, only a light amount of ⅕ to ½ times this set light amount is entered to the CCD camera at a measuring time of the coloring portion. Therefore, a reduction in S/N is caused by a dark electric current of the CCD, etc. In particular, in the inspection of the uneven coloring in the color filter, it is necessary to discriminate the amount of incident light entered from a transmitting light amount equal to or smaller than 1% in the coloring portion of the same color. Therefore, it is necessary to avoid this reduction in S/N. To avoid this reduction, it is considered that the light amount of the light source at the measurement time of the coloring portion is increased.
However, when the light amount of the light source is adjusted, the light amount is unstable for some time after the adjustment. As described above, it is necessary to discriminate the coloring density distribution at a level of several %. Accordingly, such an unstable light amount just after the adjustment of the light amount causes an error in measurement. Therefore, when the light amount is adjusted, it is necessary to take time until the light amount is stabilized, which is an obstacle in improving efficiency by shortening an inspecting time.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an inspecting method capable of inspecting uneven coloring of a color filter at high speed with high accuracy, a manufacturing method of the color filter with the use of an ink jet system in which the uneven coloring are reduced by utilizing this inspecting method, and an inspecting method of the color filter in the ink jet system.
The present invention resides in an inspecting method of a color filter comprising: irradiating with light from a light source a coloring portion; measuring a transmitting light amount transmitted through the coloring portion by a light receiving element; and calculating a coloring density of the coloring portion; in which the light amount of the light source is set substantially constant, the amount of incident light received by the light receiving element is adjusted by an optical element arranged within an optical path, the transmitting light amount of an uncoloring portion is measured and the coloring density of the coloring portion is inspected by comparing the transmitting light amount of the coloring portion to the transmitting light amount of the uncoloring portion.
In the present invention, the light amount is adjusted by using the optical element, and the light amount of the light source is made constant. Therefore, an error in measurement due to an unstable light amount caused by the adjustment of the light amount of the light source is prevented. Accordingly, no time for stabilization after the adjustment of the light amount is required. In the present invention, the amount of incident light received by the light receiving element can be easily adjusted to a light amount suitable for the light reception of this light receiving element by using the optical element. Therefore, the measurement can be precisely made by the same light receiving element. Particularly, when an ink amount to be given is controlled on the basis of the results of an inspection of uneven coloring, it is necessary to correlate an absolute value in one measurement with an absolute value in another measurement. Therefore, it is necessary to adjust the light amount by measuring a reference before each measurement. Namely, it is necessary to measure the light amount value of a transparent uncoloring portion within a non-display area and adjust this light amount value to a constant value so as to remove elements except for coloring. In this case, the transmitting light amounts of the coloring and uncoloring portions are greatly different from each other. However, in the present invention, the amount of incident light or the transmitting light amount is adjusted by the optical element, so that the transmitting light amounts of the coloring and uncoloring portions can be precisely measured by the same light receiving element.
REFERENCES:
patent: 5400135 (1995-03-01), Maeda
patent: 5773173 (1998-06-01), Nakano et al.
patent: 9-043097 (1997-02-01), None
patent: 10-142101 (1998-05-01), None
patent: 10-315510 (1998-11-01), None
patent: 11-006786 (1999-01-01), None
Fujiike Hiroshi
Hayashi Satoshi
Marumoto Yoshitomo
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
McPherson John A.
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