JPH0895125A - Method and device for photographing consecutively moving subject - Google Patents

Abstract

PURPOSE: To photograph a consecutively moving subject as a still picture by specifying the arranging directions of an fθ lens and a rotary mirror and photographing the subject while rotating in accordance with the movement of the subject. CONSTITUTION: The fθ lens 4 is arranged in parallel with a moving direction 8 and the rotary mirror 3 is arranged in a direction parallel with the moving direction 8 so as to perform photographing while rotating in accordance with the movement of the subject 5. A pattern 6 and a mark 7 are printed and formed on the subject 5. Since the subject 5 is ejected from a printing machine at constant velocity, the rotary mirror 3 rotates synchronizing with the velocity of the subject 5. Since the angular velocity of the rotary mirror 3 is fixed though the mark 7 moves on a plane at the constant velocity, the fθ lens 4 is provided in order to correct the velocity within the range of visual field. Though the mark 7 moves at the constant velocity, it is observed as if it is still at a constant position from a photographing device within a range scanned by the rotary mirror 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for photographing a pattern, a mark or the like for inspecting a subject such as a continuously moving printed matter or detecting a signal for controlling a printing press. In particular, the present invention relates to a method and apparatus for photographing a continuously moving subject as a still image.

[0002]

2. Description of the Related Art Conventionally, a CCD camera or the like is usually used to detect a pattern or mark on a continuously-moved printed matter, and photographing is performed in synchronization with the rotation of a printing machine. There is. Since the CCD camera has its own clock and scans the screen by this, if the timing of scanning and the synchronizing signal from the printing machine do not match, the timing of shooting may be delayed or shooting may not be possible. This is a serious problem for shooting for the purpose of mark position detection. Moreover, the speed of the printed matter discharged from the printing machine is as high as 2 to 8 m / sec. Therefore, in order to take a picture without blurring, a large-scale certification device or a strobe synchronized with the rotation of the printing machine is used. Equipment is required.

[0003]

SUMMARY OF THE INVENTION The present invention is a method and apparatus for photographing a continuously moving subject that does not have such drawbacks. It is a still image of a continuously moving subject that is free from blurring and does not require a strobe or the like. The present invention relates to a photographing method and apparatus.

[0004]

In order to achieve the above object in the present invention, first, in the first invention, the moving direction (direction) of the rotating mirror (3), the fθ lens (4) and the camera (1) is 8) A method of photographing a continuously moving subject, wherein the fθ lens (4) is arranged parallel to the moving direction (8), and the rotating mirror (3) is parallel to the moving direction (8). This is a method for photographing a continuously moving subject, which is arranged and rotates in response to the movement of the subject (5) for photographing.

The second aspect of the present invention is an apparatus for photographing a subject continuously moving in a moving direction (8) composed of a rotating mirror (3), an fθ lens (4) and a camera (1). The fθ lens (4) is arranged in parallel with the moving direction (8), and the rotating mirror (3) is arranged in parallel with the moving direction (8) to provide a continuously moving object photographing device. .

Furthermore, in the third aspect of the invention, there is provided a device comprising a reflecting mirror, a camera (1) and the like, the mounting angle of which is controlled so as to follow the mark (7) of the subject (5). This is an imaging device for a continuously moving subject in which the mounting angle of the mirror is arranged parallel to the moving direction.

[0007]

According to the continuously moving object photographing method and apparatus of the present invention as described above, the fθ lens (4) is arranged in parallel with the moving direction (8), and the rotating mirror (3) is arranged with the moving direction (8). Since the images are arranged in parallel and rotated in response to the movement of the subject (5) to take a picture, the time during which the picture can be taken still is extended, and the picture can be taken regardless of the scanning timing of the camera (1). In addition, the shooting system does not require a special lighting device such as a strobe.

[0008]

The present invention will be described in detail with reference to the following examples.
As shown in FIG. 1, a camera (1) such as a CCD camera,
A lens group (2) for correcting the field of view and magnification, a rotating mirror (3), an fθ lens (4) and the like are provided. A subject (5) such as a printed matter is continuously moving. Then, the pattern (6) is printed and the mark (7) is printed on the subject (5). In this embodiment, this mark (7) is photographed.

Since the subject (5) is discharged from the printing machine at a constant speed, the rotating mirror (3) rotates in synchronization with the speed of the subject (5). That is, the moving distance of the mark (7) must be equal to the length of the rotating mirror (3) projected on the subject (5) by rotating for a certain period of time. In this way, the pattern (6) is scanned in one surface of the rotating mirror (3) or in a direction of moving the number of surfaces of an integral multiple (8), in which case vignetting occurs when the surfaces change.

In the fθ lens (4), the mark (7) moves on a plane at a constant speed, while the rotating mirror (3).
Since the angular velocity is constant, is provided for velocity correction within the field of view. The rotating mirror (3) is not limited to the polygonal mirror as in the embodiment, but may be a plane mirror that can scan the subject (5) by changing the angle.

According to the above-mentioned embodiment, the mark (7) moves at a constant speed, whereas the image is taken from the photographing device as if it is stationary at a fixed position within the scanning range of the rotating mirror (3). To be done.

[0012]

Since the present invention has the above-mentioned constitution, it has the following effects. That is, since the mark or the like on the moving printed matter can be photographed still, the photographable time becomes long. Therefore, shooting can be performed regardless of the scanning movement direction (8) of a camera such as CCD (usually 1/60 sec), and error detection is eliminated in mark position detection. Further, since the shutter speed can be set low, a large illumination device is not required, and it is possible to shoot in a narrow space such as inside the device.

[Brief description of drawings]

FIG. 1 is a perspective explanatory view showing an embodiment of the method of the present invention.

[Explanation of symbols]

 1 ... Camera 2 ... Lens group 3 ... Rotating mirror 4 ... fθ lens 5 ... Subject 6 ... Pattern 7 ... Mark 8 ... Moving direction

Claims (3)

[Claims] 1. A method for photographing an object continuously moving in a moving direction (8) by a rotating mirror (3), an fθ lens (4), a camera (1), etc., wherein the fθ lens (4) is The rotating mirror (3) is arranged in parallel with the moving direction (8), the rotating mirror (3) is arranged in parallel with the moving direction (8), and the rotating mirror (3) is rotated corresponding to the movement of the subject (5) for photographing. How to shoot continuously moving subjects. 2. An apparatus for photographing a subject continuously moving in a moving direction (8) comprising a rotating mirror (3), an fθ lens (4), a camera (1), etc., said fθ
The lens (4) is arranged parallel to the moving direction (8), and the rotating mirror (3) is arranged parallel to the moving direction (8). 3. A device comprising a reflecting mirror, a mounting angle of which is controlled so as to follow the mark (7) of a subject (5), a camera (1), etc., wherein the mounting angle of the reflecting mirror is the moving direction. An image capturing device for continuously moving subjects arranged in parallel with.