JPH06337213A - Measuring method for area of dot printing pattern of light guide plate - Google Patents

Abstract

PURPOSE:To accurately and easily measure the area of each dot of the dot pattern of a printed light guide plate having shape deformation and the backlash of a contour within a short time. CONSTITUTION:When the area of the dot pattern printed on the rear surface of a light guide plate by ink is measured, the light guide plate 1 is placed on the transmission illumination part 4 on an X-Y stage 3 and the X-Y stage 3 is operated by the command from a position control personal computer 5 and one dot of the dot pattern to be measured on the light guide plate is moved to the position of a CCD camera 6 to be set thereto. Subsequently, a trigger is outputted to an image processor 7 from the position control personal computer 5 and the image of one dot is taken in the image processor 7 by the CCD camera 6 and the area of the image is calculated by counting the number of pixels and the calculated area value is outputted to the position control personal computer 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention measures the area of each dot in a dot pattern printed with ink for reflecting light on a light guide plate used for a backlight of a liquid crystal display which is a display device such as a personal computer. Regarding the method.

[0002]

2. Description of the Related Art In order to measure the area of each dot of a dot pattern in which ink is printed on the back side of the above light guide plate, the diameter (X direction, Y direction) of each circular dot is measured with a microscope. The area was calculated by the formula.

By the way, according to this method, each dot of the dot pattern after printing, even if it is a circular dot by design,
Accurate measurement was not possible due to deformation of the shape and rattling of the contour. However, for the purpose of reflecting light, the area is more important than the shape.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention is to provide a method capable of accurately and easily measuring the area of each dot of a dot pattern after printing having shape deformation and rattling of a contour. Is.

[0005]

A method for measuring the area of a dot printed pattern of a light guide plate of the present invention for solving the above problems measures the area of a dot pattern formed by printing ink on the back side of the light guide plate. In this case, after the light guide plate is placed on the transillumination part on the XY stage, the XY stage is operated by the movement command from the position control personal computer, and one dot of the dot pattern measured by the light guide plate is read by the CCD camera. Position to move to the position, then trigger output from the position control personal computer to the image processing device and the 1 dot image is CCD
It is characterized in that an area is obtained by counting the number of pixels by taking it into an image processing apparatus by a camera and then the area value is output to a position control personal computer.

[0006]

In the method for measuring the area of the dot printing pattern of the light guide plate according to the present invention described above, the area of one pixel is obtained by taking the image of one dot into the image processing apparatus by the CCD camera and counting the number of pixels. The area of 1 dot can be accurately obtained by calibrating the height in advance, that is, by setting the condition in which the threshold value and the light intensity (luminance) in the pixels around 1 dot are taken into consideration. Therefore, by doing this for each dot,
The area of each dot in a dot pattern after printing with shape deformation and rattling of the contour can be accurately measured in a short time.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for measuring the area of a dot print pattern on a light guide plate according to the present invention will be described with reference to the drawings. In measuring the area of the dot pattern 2 formed by printing ink on the back side of the light guide plate 1 as shown in FIG. 1, the light guide plate 1 is transmitted through the XY stage 3 as shown in FIG. Part 4
Then, the XY stage 3 is operated by a movement command from the position control personal computer 5, and one dot of the dot pattern 2 to be measured on the light guide plate 1 is moved to the position of the CCD camera 6 and positioned. . Next, the position control personal computer 5 outputs a 1-dot image to the image processing device 7 by trigger output to the image processing device 7 by the CCD camera 6, and the area is obtained by counting the number of pixels. This pixel count is performed by calibrating the size of one pixel 8 in advance by dividing a 1-dot image into many vertically and horizontally as shown in FIG. The area of one dot could be accurately determined by setting the condition in which the threshold value of the pixel 8 around the dot and the light intensity (luminance) were taken into consideration. After that, the area value of 1 dot was output to the position control personal computer 5, compared with the design value, and processed.
After that, the areas of a large number of dots were measured through the same steps, the areas of all the dots in the dot pattern 2 were calculated, output to the position control personal computer 5, compared with the design value, and data processed. Table 1 has 151 rows and 201 rows, with a diameter of 0.27 mm to 0.85.
It shows the measurement result of 165 points of the 30351 dots of the dot pattern 2 which changes to mm, and the area can be measured extremely accurately.

[0008]

[Table 1]

[0009]

As described above, according to the area measuring method of the dot print pattern of the light guide plate according to the present invention, the area of each dot of the dot pattern after the printing having the shape deformation and the rattling of the contour can be accurately measured in a short time. Easy to measure.

[Brief description of drawings]

FIG. 1 is a perspective view showing a dot printing pattern of a light guide plate.

FIG. 2 is a schematic diagram showing a method for measuring an area of a dot print pattern of a light guide plate according to the present invention.

FIG. 3 is a diagram showing a state in which a 1-dot image of a dot pattern is divided into a large number of vertical and horizontal pixels.

[Explanation of symbols]

 1 Light guide plate 2 Dot pattern 3 XY stage 4 Transmitted illumination unit 5 Position control personal computer 6 CCD camera 7 Image processing device 8 pixels

Claims (1)

[Claims] 1. When measuring the area of a dot pattern in which ink is printed on the back side of a light guide plate, the light guide plate is placed on a transillumination unit on an XY stage, and a movement command is issued from a position control personal computer. Operate the XY stage, move 1 dot of the dot pattern to be measured on the light guide plate to the position of the CCD camera and position it, then trigger output from the position control personal computer to the image processing device and CC the 1 dot image.
A method for measuring the area of a dot print pattern of a light guide plate, which is characterized in that the area is obtained by counting the number of pixels by taking it into an image processing device with a D camera, and then the area value is output to a position control personal computer.