JP2001036929A - Picture measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily calculate the actual dimension of the evaluation picture of the display screen of a display device. SOLUTION: This picture measuring device is provided with laser beam irradiating means 11 and 12 for irradiating a display screen 3 of the evaluation picture of a display device 1 with two parallel laser beams 11a, 11b, 12a and 12b being a reference for measurement, an image pickup means 10 for image picking-up the evaluation picture and the two laser beams 11a, 11b, 12a, and 12b, and a picture processing means 13 for picture-processing an image pickup signal from the image pickup means 10 and for calculating the actual dimension of the evaluation picture by using the laser beams 11a, 11b, 12a, and 12b as the reference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image measuring device used for adjusting a jig in a production line of a display device such as a projector using a cathode ray tube, evaluating the quality of the display device, evaluating a design, and the like. About.

[0002]

2. Description of the Related Art Generally, the adjustment of a jig in a production line of a color cathode ray tube, the evaluation of the quality of the color cathode ray tube, the evaluation of a design, and the like require the use of the color cathode ray tube. An evaluation image, for example, a spot or the like is displayed on the display surface, and the actual dimensions of the spot shape or the like are calculated.

Conventionally, in order to calculate the actual size such as the spot shape on the display surface of the color cathode ray tube, the actual size such as the spot shape is calculated based on the pitch of the phosphor on the display surface of the color cathode ray tube. I was

However, a good measurement cannot be made because the pitch of the phosphor of the color cathode-ray tube varies depending on each of the color cathode-ray tubes and that the pitch varies depending on the location of the display surface. There was an inconvenience.

Further, in a display device such as a projector using a cathode ray tube, there is no reference device for calculating the actual size such as the spot shape, and the actual size such as the spot shape on the display surface cannot be calculated. Was.

The present invention has been made in view of the above points, and has been made to enable to calculate the actual size of an evaluation image such as a spot on a display surface of a display device such as a projector using a cathode ray tube.

[0007]

According to the present invention, there is provided an image measuring apparatus which irradiates a laser light irradiating means for irradiating a display surface of an evaluation image of a display device with two parallel laser beams serving as a reference for measurement; An image pickup means for picking up two laser lights, and an image processing means for performing image processing on an image pickup signal from the image pickup means and calculating the actual size of the evaluation image based on the laser light.

According to the present invention, two parallel laser beams are irradiated on the display surface for displaying the evaluation image.
The distance between the laser beams of the two coherent lights is always constant even if the distance between the display surface and the imaging means changes, and it is possible to calculate the actual size of the evaluation image based on the distance between the two laser lights. it can.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an image measuring apparatus according to the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a rear projector using a color cathode ray tube 2 whose quality is to be evaluated, and a dot image 4 to be described later is displayed as an evaluation image on a screen 3 as a display surface of the rear projector 1. I will do it. Generally, the diameter of the dot image 4 is, for example, about 10 mm on the screen 3 in the case of the rear projector 1 of 61 inches. In this rear projector 1, 5a and 5b are reflectors, respectively.

In this embodiment, a solid-state imaging device 10 using a CCD is provided, and two laser light irradiation devices, for example, laser markers 11 and 12 are provided in connection with the optical system 10a of the solid-state imaging device 10.

The two laser light irradiation devices 11 and 12
Are used to generate cross-shaped laser beam patterns 11a, 11b and 12a, 12b, respectively. Laser beams 11a, 11a from these two laser beam irradiation devices 11 and 12 are used.
The laser beam irradiation devices 11 and 12 are arranged so as to sandwich the optical system 10a of the solid-state imaging device 10 in an oblique direction as shown in FIG. In this case, the optical axis of the optical system 10a of the solid-state imaging device 10 and the laser beams 11a, 11b and 12a, 12b of the laser beam irradiation devices 11, 12 are parallel to each other.

The laser light irradiation devices 11 and 12 of the present embodiment
Crossed laser beams 11a, 11b and 12a, 12
b is applied to the screen 3 on the display surface of the rear projector 1 as shown in FIG.
a, 11b and 12a, 12b form a square grid. In this example, one side of this square grid is 5 cm.
So that it is constant at 10 cm to 10 cm.

In this case, the cross laser beam 11a, 1
The size (one side) of the rectangular grid formed by 1b and 12a, 12b is the size of the screen 3 which is the display surface of the rear projector 1 and the laser light irradiation devices 11 and 12, ie, the solid-state imaging device 1
It is always constant even if the interval with 0 changes.

In this embodiment, the solid-state imaging device 10 uses the dot image 4 as an evaluation image of the display surface 3 of the rear projector 1 and the laser light irradiation devices 11 and 12.
Crossed laser beams 11a, 11b, 12a, 12b
Are simultaneously imaged.

In this embodiment, an image signal picked up by the solid-state image pickup device 10 is supplied to an image memory 15 via an A / D conversion circuit 14 for converting an analog signal constituting the image processing device 13 into a digital signal. Make memorize.

The image processing device 13 has a central control unit (CPU) 16 composed of a microcomputer.
5 cross laser light 11a, 11 of the imaging signal stored in
Since the size of the rectangular grid composed of b and 12a, 12b is predetermined to be, for example, 5 cm to 10 cm on one side, the actual size of the evaluation image, for example, the dot image 4 is calculated based on this.

The result of the calculation is supplied to the monitor 17 for display.

According to this embodiment, two parallel cross laser beams 11a and 11b and 12a and 12b are irradiated on the display surface 3 on which an evaluation image such as a dot image 4 is displayed.
These two cross-shaped coherent light laser beams 11a and 11a
The distance between the two laser beams 11a, 11b and 12a, 12b is constant even when the distance between the display surface 3 and the solid-state imaging device 10 changes. The actual size of the dot image 4 that is the evaluation image can be calculated based on.

In the above example, the laser light irradiation devices 11 and 1
Although the example of the pattern of the laser light of No. 2 is a cross, the pattern of the laser light may be a circle, a dot, a register mark, or the like.

In the above example, a dot image was described as an evaluation image. However, it is a matter of course that the evaluation image may be a spot, a test pattern, or the like.

Further, this example is used for evaluating the quality of a color video projector using three cathode ray tubes of red, green and blue, and the displacement of the spots of the red, green and blue light beams can be measured. it can.

Further, the present invention can measure not only the above-mentioned examples but also evaluation images of other display devices such as a display device using a color cathode ray tube in actual dimensions.

Further, the present invention is not limited to the above-described example, and may adopt various other configurations without departing from the gist of the present invention.

[0025]

According to the present invention, two parallel laser beams are radiated on the display surface for displaying the evaluation image, and the distance between the two coherent laser beams is determined by the distance between the display surface and the imaging means. Is always constant even if the distance changes, and the actual size of the evaluation image can be calculated based on the interval between the two laser beams.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an example of an embodiment of an image measurement device of the present invention.

FIG. 2 is a diagram for explaining FIG. 1;

FIG. 3 is a diagram for explanation of the present invention.

[Explanation of symbols]

1 rear projector, 10 solid state imaging device, 1
1,12 laser light irradiation device, 13 image processing device, 14 A / D conversion circuit, 15 image memory, 16 central control device

Claims (5)

[Claims] A laser beam irradiating unit that irradiates a display surface of an evaluation image of a display device with two parallel laser beams serving as a reference for measurement; an imaging unit that captures the evaluation image and the two laser beams; And an image processing unit that performs image processing of an image signal from the imaging unit and calculates an actual size of the evaluation image based on the laser beam. 2. The image measuring device according to claim 1, wherein the image processing means includes an analog-to-digital conversion circuit that converts the imaging signal into a digital signal, and the analog-to-digital conversion circuit.
An image measuring apparatus, comprising: an image memory for storing an output signal of a digital conversion circuit; and a microcomputer for calculating an actual size of the evaluation image based on a laser beam of an imaging signal stored in the image memory. . 3. The image measurement apparatus according to claim 1, wherein the laser beam has a cross shape, and an optical axis of an optical system of the imaging unit and a laser beam of the laser beam irradiation unit are parallel to each other. Image measuring device. 4. The image measurement apparatus according to claim 1, wherein said imaging means is a solid-state imaging device using a CCD. 5. The image measurement device according to claim 1, wherein the display device is a projector using a cathode ray tube.