JPH09326031A - Image input method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely input an image with high resolution and in the whole range of a width direction even by means of a small number of camera at the time of image-inputting a printing pattern and inspecting its printing state. SOLUTION: This image inputting method is applied at the time of inspecting the printing state based on an inspecting image image-inputted by a camera movable in the width direction of an original edition by setting the pattern printed on the traveling original edition to be the object to inspect. In this case, plural monitoring areas (i) extended in a vertical direction by setting the visual field width of the camera to be a horizontal width to the object to inspect so as to partially overlap with an adjacent monitoring area (j) and at least one inspecting point (c) equal to the size of a visual field, which is image-inputted by the camera, is set to each of all the set monitoring areas 1 to (n). Then, while moving the camera, the inspecting point (c) set for each monitoring area is successively image-inputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input method and apparatus, and in particular, to an inspection image obtained by inputting an image with a camera movable in the width direction of an original sheet, as an inspection target. The present invention relates to an image input method and apparatus suitable for application when inspecting a print state.

[0002]

2. Description of the Related Art A running stock is continuously printed by a rotary printing machine, a pattern printed on the stock is optically input by a camera, and a print inspection is performed based on the input image. It is being appreciated. Specifically, in the case of a visual inspection device,
The input image is displayed on the monitor as a still image, and the operator judges the occurrence of the defect by looking at the picture. In the case of the automatic inspection device, the occurrence of the defect is judged by image processing based on the input image. .

The following three methods are known as image input methods by a camera, which are applied when visual inspection or an automatic inspection device is used to inspect a pattern being printed on the printing press.

One of them is, as shown in FIG. 14, about a printed material to be inspected which runs in the direction of the arrow,
One method is to input the entire width of the inspection target with one CCD camera (line sensor), and the other is to input the entire width of the inspection target with a plurality of CCD cameras (line sensors) as shown in FIG. Still another method is a method of selecting and inputting an arbitrary inspection point from the inspection target with one CCD camera (area sensor) as shown in FIG.

[0005]

However, as shown in FIG. 14, when inputting the full width with one line sensor camera, since an image cannot be input with high resolution, a minute defect is detected. I can't inspect.

Further, as shown in FIG. 15, when inputting the full width with a plurality of line sensor cameras, the resolution of the input image can be increased proportionally by increasing the number of cameras, Compared with the case of one camera, there are various problems as described below.

(1) Installation, adjustment and maintenance of the camera are difficult. The field of view of each camera should be well overlapped so that the entire width can be input. Further, even if all the cameras have the same design, the individual cameras are electrically delicately different from each other. Therefore, adjustments such as gain control and shading correction must be performed for each. If these adjustments are neglected, the input performance varies from camera to camera, and it becomes difficult to guarantee a certain quality in the inspection. (2) The device scale becomes large, and therefore the installation space becomes large. Basic devices such as a camera control unit and an image processing unit must be independent for each camera. (3) The device price increases. Considering the effect of mass production, the price of the input device of n cameras is not simply n times the price of one input device, but it is still quite expensive.

Further, as shown in FIG. 16, when one area sensor camera is moved in the width direction and an arbitrary inspection point is selected by the camera, as shown by the arrow, the range is Since there is a range that is not input at all in the width direction of the inspection target, the reliability of the inspection becomes low. In this case, there are cases where the two inspection points on the left side overlap (shaded in the figure),
The width is not constant.

The present invention has been made to solve the above-mentioned conventional problems, and when a print pattern is input as an image and the print state is inspected, a high resolution and a wide range can be achieved even with a small number of cameras. An object is to provide an image input technique capable of surely inputting the entire range of directions.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a pattern printed on a running original is inspected, and a print state is inspected based on an inspection image input by a camera movable in the width direction of the original. In the image input method applied when performing, a step of setting, in the inspection target, a plurality of monitoring areas that extend in the vertical direction with the width of the field of view of the camera as the width, without any gap in the width direction, and all the set monitoring areas In each of the above, including the step of setting one or more inspection points for image input by the camera, and the step of sequentially inputting the image of the inspection points set for each monitoring area while moving the camera. The above-mentioned problems are solved.

The present invention is also applied to the case where a pattern printed on a running original is inspected and the print state is inspected based on an inspection image input by a camera movable in the width direction of the original. In the image input device, the inspection target has a plurality of monitoring areas extending in the vertical direction with the field of view of the camera as the width, and a means for setting a gap in the width direction without any gap, and each of the monitoring areas is set to the above. A means for setting one or more inspection points for image input with a camera,
The problem is similarly solved by a configuration including means for sequentially inputting images of the inspection points set for each monitoring area while moving the camera.

That is, in the present invention, since the image is input in units of the inspection points set for each of the monitoring areas, the image can be input while narrowing the field of view of the camera. Therefore, the inspection image can be input with high resolution. At the same time, since at least one inspection image is input for all the monitoring areas set without gaps in the width direction, it is possible to prevent an inspection omission in which there is a range that is not inspected in the width direction. The reliability of can be improved.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic perspective view showing the outer appearance of an image input device according to the present invention, and FIG. 2 is a block diagram showing the outline of the functional units constituting the image input device.

The image input device according to the present embodiment is applied to a print inspection device. After being printed by a rotary printing machine (not shown) located upstream, the image input device travels in the direction of the arrow while being fed by rollers 10. A camera 14 including a CCD area sensor for inputting an inspection image from the original 12 and an illuminating device 1 including an optical fiber for illuminating the original 12 during image input.
And a camera box 18 in which 6 and 6 are accommodated. The camera box 18 can be moved in the width direction of the material 12 by a motor of a camera moving device (linear guide) 20, and can move the accommodated camera 14 to any position in the width direction. It is possible.

The attached light source box 22 drives a light source for supplying light to the optical fiber (not shown) to the illumination device 16 in the camera box 18 and a motor of the camera moving device 20. And a motor driver for.

Further, the image input device is provided with a device body 24 in which a control unit 28, which will be described later, is built in for controlling the entire device, and the device body 24 transmits / receives data through a cable (not shown). The operation control of the camera box 18 and the light source box 22 based on the signal
Image processing of an inspection image input by the camera 14 in the camera box 18 is performed.

To explain this embodiment in further detail, the image input device is, as shown in FIG.
Image input unit 2 including lighting device 16 and camera moving device 20
6 and the control unit 2 built in the device body 24
8, an inspection unit 30 that performs basic processing as an automatic inspection device, and an operation unit 32 that operates the device body 24 and the like.
And are provided as main functional parts.

The image input section 26 includes a camera controller 34 for controlling the timing of image input by the camera 14, a camera movement controller 36 for controlling the camera moving device 20, a camera 14, an illuminating device 16, and a camera moving device 20, respectively. And a synchronizing circuit 38 for properly synchronizing the timing of the operation of the.

Further, the control unit 28 is provided with an inspection device control circuit 40 for controlling image input and the like, and also has an inspection point setting position memory 42 constituting a main part of the image input device, a monitoring area and an inspection. It includes a point designating circuit 44, an image multiplexer circuit 46 for inputting / outputting image data, and an operation circuit 48 which is an interface of the operation unit 32.

Further, the inspection section 30 has a reference image memory 50 and an input image memory 52 for storing the image data input via the image multiplexer circuit 46, and a positional deviation correction circuit for matching the reference image with the input image. 54,
A comparison circuit 56 that compares corresponding pixels of both images and a threshold memory 58 that stores a threshold value used for defect determination.
And

Further, the operation section 32 has an operation panel 60 for inputting operation data to the control section 28, an operation monitor 62 for displaying the input data and the like, and an image display for displaying inspection images and the like. And a monitor 64. Then, between the image input unit 26, the control unit 28, the inspection unit 30, and the operation unit 32, signals are transmitted and received in the directions indicated by the arrows, and various processes described below are executed. Further, for example, a pulse signal from a rotary encoder (not shown) attached to the roller 10 or an operation signal of the printing machine is input to the inspection device control circuit 40. There is.

In FIG. 2, it is assumed that the inspection unit 30 compares the reference image with the input image. However, there is no part corresponding to the inspection unit 30, and the image is displayed on the image display monitor 64. It may be an inspection device.

In the image input apparatus of this embodiment, the camera 1 is attached to the pattern printed on the original 12 to be inspected.
A plurality of monitoring areas extending in the vertical direction with the width of the field of view 4 as the width is set so as to have no gap in the width direction by, for example, partially overlapping adjacent monitoring areas, and all the set monitoring areas. A means for setting one or more inspection points for image input by the camera in each of the monitoring areas, and a means for sequentially inputting the image of the inspection points set for each monitoring area while moving the camera, The image input unit 26, the control unit 28, and the operation unit 3
It is composed of two.

Next, the operation of this embodiment will be described according to the processing procedure shown in FIG.

First, parameters are input using the operation panel 60 to set the monitoring area (step 1). The parameters include the width of the printed material, the perimeter of the plate cylinder corresponding to the inspection range in the vertical direction of the inspection target, the pattern width corresponding to the inspection range in the horizontal direction, the visual field size of the camera 14, and the like.

FIG. 4 shows how the above monitoring area is set.
The concept is shown in (A). The inspection object is a printed pattern of one revolution of the plate cylinder, and the monitoring area is formed by dividing the object into a plurality of pieces along the flow direction of the material, and has a width equal to the visual field width of the camera 14 in the vertical direction. As a strip-shaped area extending to
Moreover, the adjacent monitoring areas are set to overlap each other so that no gap is formed between the monitoring areas.

Next, similarly, inspection points are set using the operation panel 60 (step 2). This inspection point is an area (position) where the inspection image is input by the camera 14, and as shown in FIG. 4B, a state in which two inspection points are set for the i-th monitoring area is shown in FIG. At least one is set for all of the monitoring areas set as in (A). Also, this inspection point is shown enlarged in FIG. 4 (C), but this is equal to the visual field size of the camera 14, and is set to a size of 30 mm × 30 mm, for example.

There are three methods for setting the inspection points in step 2, default, preset and automatic setting. The default is a method of setting the inspection points of all the monitoring areas at the beginning of the pattern, as shown in FIG. 5 where there is one inspection point for each monitoring area. As shown in FIG. 6, the preset is applied in the case of a repeat product or the like, and the position set at the time of the previous printing is stored,
From the second time onward, it is a method of automatically setting to that position and setting to an appropriate position separately for each monitoring area.

As shown in FIG. 7, automatic setting is a method of automatically setting inspection points separately for each monitoring area.
For example, the following method can be mentioned. (1) Set at random. (2) Set a standard such as that the input image is a flat image with many specific colors such as white, and select and set the position most suitable for this standard from each monitoring area To do. The inspection points set as described above are stored in the inspection point setting position memory 22 of the control unit 28.
Is stored.

When the inspection points are set, the inspection process for the printed matter is executed (step 3). In this inspection process, first, based on the data read from the memory 42, the monitoring area and inspection point instruction circuit 44
In accordance with an instruction input from the image input unit 26 to the target inspection point, the camera 14 is moved to the surveillance area to which the target inspection point belongs (step 3A), and then the camera 14 is moved at a timing matching the target inspection point. In step S3B, the image is captured (step 3B), and the captured inspection image is image-processed (step 3C). Then, the camera 14 is moved to the surveillance area to which the next inspection point belongs. The operation is repeated until there are no more inspection points set.

It should be noted that the reason why the inspection is in progress in step 3C is that if the inspection image is captured in step 3B, the next step is performed in step 3A without waiting for the processing of the inspection image to be completed in order to improve efficiency. It means that the camera 14 is moved to the inspection point.

The camera movement in step 3A and the image capturing in step 3B in the inspection process in step 3 will be described in more detail. As shown in FIG.
Are moved (traversed) in the width direction of the material 12 and all the inspection points set for each monitoring area are sequentially input. Specifically, for example, when an image is input to inspect the printing state on the printing machine, the above-mentioned FIG.
As shown in FIG.
An image is captured from a target inspection point in synchronism with a pulse signal from a rotary encoder 10A attached to the roller 10 that sends 2, and this operation is executed for all inspection points.

At this time, the order in which the camera is moved between the monitoring areas is arbitrary, but the image input of the inspection point is performed by intermittent input as shown in FIG. 9, for example. This intermittent input is a method of sequentially inputting the inspection points set in all the monitoring areas while moving the camera 14, so that inspection can be performed without forming a gap in the width direction.

In FIG. 9A, it is possible to sequentially input images of the inspection points for all the monitoring areas from the inspection point A in the leftmost monitoring area to the inspection point F in the rightmost monitoring area. Although shown, this is not executed for the same inspection object (print pattern), but as shown in FIG.
On the other hand, with respect to the same type of pattern that is continuously printed, it means that an image is input once for every 10 sheets, for example. As a result, as shown in FIG. 9A, it is possible to input an inspection image for the same type of pattern without a gap in the width direction.

Next, a method for correcting the position of the initially set inspection point when it is necessary to change the inspection point during execution of the inspection process of step 3 will be described with reference to the flowchart of FIG. .

First, when it is necessary to correct the inspection point set in the initialization described above in step 11 or during the execution of the inspection process corresponding to step 3 in step 12 (step 13), If the monitoring area number is instructed in 14, the camera 14 is moved to the monitoring area of the instructed number (step 15), and the image of the inspection point in that area is input (step 2).
0), the image of the input inspection point is displayed on the monitor (step 21). Then, after returning to the step 14 through the step 13, when it is confirmed that the camera 14 has moved to the target monitoring area from the monitor displayed in the step 21, or when it is not necessary to move the camera 14 from the beginning. Step 16 or Step 18
Proceed to. In step 16 or 18, if there is an instruction to move upstream or downstream, step 17 respectively.
Alternatively, in step 19, the input timing of the inspection point is corrected to the upstream side or the downstream side, the image of the inspection point is displayed on the monitor in step 21 after the step 20, and it can be confirmed that the corrected position is appropriate on the monitor. At this time, that is, when the inspection point correction is unnecessary (step 13), the same inspection process as that of step 3 of FIG.

The above-described inspection point correction procedure will be specifically described with reference to FIGS. 11 to 13 by taking an example of the case where the inspection point is corrected during the inspection process.

First, as shown in FIG. 11, when an image of the inspection point B is being input in the second monitoring area 2 from the left, an instruction to correct the position of the inspection point E in the monitoring area 5 is input. Then, as shown in FIG. 12, the camera 14 moves to the surveillance area 5, and if there is an instruction to move the inspection point E of the surveillance area 5 upstream, the image input timing of the inspection point E is the upstream side. (Downward in the figure) is corrected, and the image of the new lower inspection point E shown in FIG. 13 is input.

According to the present embodiment described in detail above, since the field of view of the camera 14 can be narrowed and a high resolution input image can be obtained, one camera is used to detect the entire width of the inspection object, as shown in FIG. Since a defect having a size that cannot be detected by the conventional method as described above can be input as an image, the inspection accuracy can be improved.

Further, in this embodiment, since there is only one camera, installation, adjustment, maintenance, etc. can be performed easily. Moreover, the device scale is not so large, and can be suppressed to, for example, an intermediate device scale between one camera and a plurality of input devices. Also, 1 for all monitoring areas
Since the inspection points are set at more than one place and all the inspection points are always inputted as an image, it is possible to prevent the omission of the inspection in the width direction. Therefore, the reliability of the inspection is higher than that of the conventional method shown in FIG. It is possible to improve the property.

In this embodiment, in particular, the defect to be inspected is caused by the lack of a doctor blade for removing the excessive ink on the plate cylinder, etc. It is suitable as an image input method for detecting "a defect which cannot be detected unless it is inspected with a very fine and high resolution and which continues once it occurs", which is typified by the defect (1).

The present invention has been specifically described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

For example, in the above-described embodiment, the case where the monitoring area is set so as to partially overlap with the adjacent monitoring area is shown, but the present invention is not limited to this, and the overlapping width is zero. Good.

Although the case where only one camera is used is shown, a plurality of cameras may be used in order to shorten the input sample time.

Further, the image input technique of the present invention may be applied to the image input in the automatic inspection apparatus which processes the input image in the inspection section 30 shown in FIG. 2 as described above. It may be sequentially displayed on the monitor 64 and used for image input in the visual inspection device. Further, in the case of the automatic inspection apparatus including the inspection unit 30, in the above-described embodiment, the image processing for comparing the corresponding pixels with the reference image is shown, but the image processing method after input is Not limited to.

[0047]

As described above, according to the present invention,
When a print pattern is input as an image and the print state thereof is inspected, even with a small number of cameras, it is possible to reliably input the image with high resolution and in the entire width direction.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an external appearance of a main part of an image input device according to an embodiment of the invention.

FIG. 2 is a block diagram showing an outline of each functional unit constituting the image input device.

FIG. 3 is a flowchart showing a processing procedure in the above embodiment.

FIG. 4 is an explanatory diagram conceptually showing a monitoring area and inspection points.

FIG. 5 is an explanatory diagram showing an initialization method of inspection points.

FIG. 6 is an explanatory diagram showing another method of initializing the inspection point.

FIG. 7 is an explanatory view showing still another initialization method of inspection points.

FIG. 8 is an explanatory view conceptually showing a method of camera movement and image input.

FIG. 9 is an explanatory view conceptually showing intermittent input of images by a camera.

FIG. 10 is a flowchart showing a procedure for correcting inspection points.

FIG. 11 is an explanatory diagram showing an image input state before inspection point correction.

FIG. 12 is an explanatory diagram showing a state in which the camera is moved to the surveillance area to which the inspection point to be corrected belongs.

FIG. 13 is an explanatory diagram showing an image input state after correction of inspection points.

FIG. 14 is an explanatory diagram showing an example of a conventional image input method.

FIG. 15 is an explanatory diagram showing another example of a conventional image input method.

FIG. 16 is an explanatory diagram showing still another example of a conventional image input method.

[Explanation of symbols]

 10 ... Roller 12 ... Original fabric 14 ... Camera 16 ... Illumination device 18 ... Camera box 20 ... Camera moving device 22 ... Light source box 24 ... Device body 26 ... Image input unit 28 ... Control unit 30 ... Inspection unit 32 ... Operation unit 40 ... Inspection device control circuit 42 ... Inspection point setting position memory 44 ... Monitoring area and inspection point instruction circuit 60 ... Operation panel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenta Hayashi 1-1-1, Ichigayakacho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd.

Claims (3)

[Claims] 1. An image input method applied when inspecting a printing state based on an inspection image which is image-inputted by a camera movable in a width direction of a material, with a pattern printed on a traveling material as an inspection object. In the inspection target, a step of setting a plurality of monitoring areas extending in the vertical direction with the field of view of the camera as a width in the width direction without any gap, and an image captured by the camera in each of the set monitoring areas. A step of setting one or more inspection points to be input; a step of sequentially inputting images of the inspection points set for each monitoring area while moving the camera;
An image input method comprising: 2. The image input method according to claim 1, wherein the surveillance area is set so as to partially overlap an adjacent surveillance area. 3. An image input device applied to an inspected print state based on an inspection image which is image-inputted by a camera movable in the width direction of the original, targeting a pattern printed on a running original. In the inspection object, means for setting a plurality of monitoring areas extending in the vertical direction with the width of the field of view of the camera as the width, and a means for setting all the monitoring areas set in the width direction without gaps by the camera. An image input device comprising: a unit for setting one or more inspection points to be input; and a unit for sequentially inputting images of the inspection points set for each monitoring area while moving the camera. .