JPH0335109A - How to position transparent film - Google Patents

Abstract

PURPOSE:To easily and precisely reading the hole of a transparent film by selecting light from a light source with the aid of a wavelength selection means, transmitting only ultraviolet rays through the wavelength selection means and irradiating the transparent film with the ultraviolet rays. CONSTITUTION:When the light is emitted from the light source 13, the wavelength selection means 12 is irradiated with the light. Then, the visible rays thereof are cut by the means 12 and only the ultraviolet rays are transmitted through the means 12. With the ultraviolet rays, the lower surface of the transparent film 10 is irradiated. Then, the ultraviolet rays which irradiate the lower surface of the film 10 are absorbed by the film 10 and they are not transmitted through the film 10. However, they are not absorbed at the hole 11 of the film 10 and they are transmitted through the hole 11. Next, the ultraviolet rays transmitted through the hole 11 of the film 10 are received by an upper image pickup camera 16 and read as an image. Therefore, the hole 11 of the film 10 is easily and precisely read.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a method for positioning a transparent film. [Prior Art] In recent years, holes formed in a transparent film are sometimes optically read and the position of the transparent film is determined based on the read image. In this positioning method,
Even if the transparent film is irradiated with light from a light source, an imaging camera cannot distinguish between the transparent film and the holes.
Colored transparent film. However, since this method requires a coloring process, there is a problem in that one positioning operation becomes complicated. Conventionally, therefore, a method has been adopted in which the holes in a transparent film are read as bright and dark by utilizing reflection and refraction of the transparent film. As shown in FIG. 5, this method involves placing a light source 4 outside the line between the hole 2 of the transparent film 1 and the imaging camera 3 disposed above it, that is, diagonally above or below the hole 2; Light from this light source 4 is irradiated onto the transparent film l. Light is diffused by reflection or refraction on the transparent film 1, and this diffused light is received by the imaging camera 3 and read as an image. As shown in FIG. 6, this read image is displayed on the monitor 5 with the transparent film l being white and the holes 2 being black and dark.
Positioning is performed by moving. [Problems to be Solved by the Invention] However, with the above-described method, it is difficult to obtain a stable image because the diffusion state of the transparent film 1 changes depending on the condition of light irradiation from the light source 4. That is, in order to diffuse the light well, the angle of the light source 4 must be adjusted delicately, and the ml is extremely troublesome. Furthermore, when using a transparent film l with different positions of the holes 2, 111L is required each time, which causes a problem of time-consuming adjustment. An object of the present invention is to provide a transparent film positioning method that does not require delicate angle vR adjustment of a light source and can easily and accurately read holes in a transparent film and accurately position the transparent film. [Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention makes use of the fact that a transparent film absorbs ultraviolet rays, selects the light from a light source with a wavelength selection means, and transmits only the ultraviolet rays. The ultraviolet rays are irradiated onto a transparent film, absorbed, and transmitted through holes formed in the transparent film. The transmitted ultraviolet rays are read as an image by an imaging means, and the transparent film is positioned based on the read image. There is a particular thing. [Function] According to the present invention, when the light from the light source is selected by the wavelength selection means and only the ultraviolet rays are transmitted, and when the ultraviolet rays are irradiated onto the transparent film, the ultraviolet rays are absorbed by the transparent film, so that the ultraviolet rays are not transmitted through the transparent film. However, it does pass through the holes formed in the transparent film. Since the transmitted ultraviolet rays are read as an image by the imaging means, there is no need to delicately adjust the angle of the light source as in the conventional method, and the holes in the transparent film can be read accurately. This results in
The transparent film can be positioned accurately based on the read image. [Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 shows a configuration for reading holes in a transparent film. In this figure, 10 is a transparent film made of polyester. A hole 11 is formed at a predetermined location of the transparent film 10 so as to penetrate one hole below. A light source 13 is provided below the transparent film 1G via a wavelength selection means 12.
is installed. In this case, the wavelength selection means 12 has a structure in which two polarizing plates 14 and 15 are stacked one above the other with their polarization axes orthogonal to each other, and they cut visible light from the light emitted by the light source 13 and cut out the ultraviolet rays. Transparent only. Further, above the transparent film 10, an imaging camera 16, which will be described later, is arranged on the optical axis of the light source 13 and the wavelength selection means 12. Therefore, when the light source 13 emits light in this state, the light is irradiated onto the wavelength selection means 12.
Visible light is cut out and only ultraviolet light is transmitted. The transmitted ultraviolet rays are irradiated onto the lower surface of the transparent film IO. In this case, since the transparent film IO is made of polyester, it has light absorption characteristics as shown in FIG. Namely. The transparent film 10 transmits visible light with a wavelength of around 310 nm or more without absorbing it, so the absorption rate of visible light is low, but it increases rapidly around 310 nm.
The absorption rate of ultraviolet rays with wavelengths shorter than that is extremely high.Therefore, the ultraviolet rays irradiated on the bottom surface of the transparent film IO are absorbed by the transparent film IO and do not pass through.
However, the light passes through the holes 11 of the transparent film IO without being absorbed. The ultraviolet rays that have passed through the holes 11 of the transparent film 10 are received by the upper imaging camera 16 and read as an image. That is, this imaging camera 16 has a CCD inside.
It is equipped with a 11 image element and converts the distribution of ultraviolet light received by this COD image sensor into an electrical signal that can be displayed as an image. In this case, a CCD image sensor having spectral sensitivity characteristics as shown in FIG. 3 is used. That is, this CCD image sensor is generally sensitive to ultraviolet light, and for example, the relative sensitivity peaks at a wavelength of around 500 nm (near cyan color), and it is also sensitive to ultraviolet light around 310 nm. Therefore, the ultraviolet rays transmitted through the holes 11 of the transparent film 10 are preliminarily selected by the wavelength selection means 12 to
Since the wavelength is selected near 0 nm, the above-mentioned CC
The D image sensor can sufficiently capture an image. Therefore,
The imaging camera 16 can accurately read the transparent film 10 and its holes 11 as images. In this way, the image read by the imaging camera 16 is displayed on a transparent film on the monitor 17, as shown in FIG.
O is displayed as black, and hole 11 is displayed as white and dark. In this case, the monitor 17 can display the image in a larger size than the actual image. Therefore, positioning can be performed while viewing this image or by moving the transparent film 10 using an automatic positioning device linked to the imaging camera 16. In this case, it is also possible to determine the shape of the hole 11 in the transparent film 10 by looking at the image on the monitor 17, or to mount a component on the transparent film 10 using the hole 11 as a reference position. Therefore, according to such a method of positioning the transparent film 10, there is no need to make delicate angle adjustments of the light source 13, so that the m adjustment is efficient, and the structure of the device is simple, resulting in miniaturization and low cost. This makes it possible to achieve the following goals. In addition, in the embodiment described above, as the wavelength selection means 12, two
A stack of polarizing plates 14 and 15 was used,
Of course, the present invention is not limited to this, and a guichroic mirror or filter that reflects or transmits only ultraviolet rays may be used. Further, when positioning the transparent film 10, the automatic device may be moved by the correction amount without moving the transparent film 10. [Effects of the Invention] As explained in detail above, according to the present invention, by utilizing the fact that a transparent film absorbs ultraviolet rays, the light from the light source is selected by the wavelength selection means, and only the ultraviolet rays are transmitted. By irradiating the transparent film with ultraviolet rays, only the holes in the transparent film are transmitted through, the ultraviolet rays are read as an image by the imaging means, and the position of the transparent film is determined based on the read image, making it possible to use a conventional light source. This eliminates the need for delicate angle adjustments, allowing the holes in the transparent film to be read easily and accurately, allowing for highly accurate positioning of the transparent film.

[Brief explanation of drawings]

Figures 1-4v! J shows one embodiment of this invention. Figure 1 is a block diagram of the state in which holes in a transparent film are read, Figure 2 is a diagram showing the light absorption characteristics of the transparent film, and Figure 3 is a diagram of the C
A diagram showing the spectral sensitivity characteristics of a CD image sensor, Figure 4 shows a read image displayed on a monitor, Figure 5 shows a conventional reading method, and Figure 6 shows the image displayed on a monitor. FIG. lO...transparent film, 11...hole,
12...Wavelength selection means, 13...Light source, 16...Imaging power camera. Patent applicant Casio Computer Co., Ltd.

Claims (1)

[Claims] The light from the light source is selected by a wavelength selection means to transmit only ultraviolet rays, and the ultraviolet rays are irradiated onto a transparent film and absorbed, and are transmitted through holes formed in the transparent film,
This transmitted ultraviolet light is read as an image by an imaging means,
A transparent film positioning method characterized by positioning the transparent film based on the read image.