JP2000146851A - Device and method for inspecting translucent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely conduct inspection for articles different in translucency with excellent reproducibility. SOLUTION: An emitting light brightness control means is provided to regulate light emitting brightness of a white color LED in response to the translucency of an inspecting object article to make constant the intensity of transmitted light photographed by a camera 21, in an LED light emission control part 40 in an inspection device for a translucent article, in which a light source 20 comprising the white color LED in one side and the camera 21 for photographing the light trasnsmitted through the translucent article in the other side are arranged respectively to sandwich the inspection object article (parison 1) comprising a translucent body, and by which the inspected object article is inspected based on a difference in light intensity of an image photographed by the camera 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for inspecting a translucent article, and more particularly, to a method for photographing light transmitted through a translucent article with a camera, and inspecting the article to be inspected based on the difference between black and white. The present invention relates to an apparatus and a method for inspecting a light-transmitting article for inspecting a light-transmitting article.

[0002]

2. Description of the Related Art As a method for inspecting a translucent article such as a transparent or translucent plastic article or a glass article, for example, for abnormal thickness or mixing of foreign matter, light is irradiated from a light source provided on one of the translucent articles. In addition, there is known a method of performing image analysis by photographing transmitted light with a camera provided on the other side. In such an inspection using transmitted light, the transmitted light is generally recognized as a difference in brightness between black and white (gray processing). Therefore, an optimal light source and camera are combined in accordance with the translucency of the article to be inspected. Like that.

On the other hand, in a plastic bottle production line, it is common practice to produce bottles of different colors on one production line. Therefore, not only the bottle after the manufacture, but also the inspection of the parison for blow molding is performed by the respective inspection devices provided in the production line.

However, if the color tone of the parison or the like to be inspected is different, the intensity of the light transmitted through the parison or the like and photographed by the camera changes from the color tone, and the difference in brightness after gray processing becomes insufficient. There is a possibility that reliable image processing cannot be performed. Therefore, it is necessary to change the light source or adjust the aperture of the lens according to the color tone of the parison or the like.

[0005]

However, the replacement of the light source must be performed manually, which is a troublesome operation.
Reproducibility may be lost due to optical axis alignment or the like. On the other hand, in the adjustment of the aperture, the reproducibility of the manual adjustment remains unreliable, and although an automatic aperture adjustment mechanism can be provided, there is a problem that the cost of the inspection apparatus is significantly increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light-transmitting article inspection apparatus and method which can easily and reliably inspect articles having different color tones with good reproducibility.

[0007]

In order to achieve the above object, a light-transmitting article inspection apparatus according to the present invention comprises a light source comprising a white LED on one side and a light source comprising a white LED on the other side with an article to be inspected comprising a light-transmitting body interposed therebetween. In a light-transmitting article inspection apparatus that arranges cameras that respectively capture light transmitted through the light-transmitting article irradiated from the light source and that inspects the inspection target article based on a difference in brightness between images captured by the camera, It is characterized in that light emission luminance control means for adjusting the light emission luminance of the white LED according to the translucency of the article to be inspected is provided.

Further, the method for inspecting a translucent article according to the present invention comprises:
A method for inspecting a translucent article in which a camera shoots transmitted light emitted from a light source composed of a white LED and transmitted through the translucent article to be inspected, and inspects the article to be inspected based on a difference in brightness of the captured image. Wherein the emission luminance of the white LED is adjusted in accordance with the translucency of the article to be inspected so that the intensity of the transmitted light is constant.

[0009]

1 to 3 show an embodiment of an apparatus for inspecting a translucent article according to the present invention. FIG. 1 is a block diagram showing a relationship with a transport means, and FIG. 2 is an LED. FIG. 3 is a block diagram illustrating an example of a light emission control unit, and FIG. 3 is a schematic circuit diagram illustrating an example of a control principle of an LED lighting amplifier.

First, as shown in FIG. 1, the inspection apparatus for a light-transmitting article, for example, a parison 1 for blow molding, which is an article to be inspected, is transferred to a parison holding section 11 of an appropriate conveyance apparatus 10 as conveyance means. While being conveyed in a predetermined direction at a predetermined speed, a white L
A light source 20 composed of an ED is arranged on the other side, and a camera 21 for photographing light emitted from the light source 20 and transmitted through the parison 1 is arranged, and the parison 1 is inspected based on the difference in brightness between images photographed by the camera 21. Is formed.

In such an inspection apparatus, a white LED
The light emission of the light source 20 and the photographing by the camera 21 are controlled by a signal from an inspection signal generator 13 such as a VARICAM provided in a device driving unit 12 for driving the transport device 11. The inspection signal generator 13 detects from the movement of the apparatus driving unit 12 that the position of the parison 1 conveyed by the operation of the apparatus driving unit 12, that is, the position of the parison holding unit 11 of the conveying apparatus 10 has reached the inspection position. , Inspection start signal 3
It is output to the camera 21 and the LED light emission control unit 40 as 0. Upon receiving the inspection start signal 30, the camera 21 outputs to the LED light emission control unit 40 a light emission permission signal 31 indicating that the camera is in a photographable state, that is, the LED may be caused to emit light. Then, the LED light emission control unit 40
When both signals 30 and 31 are received, a light emission signal (light emission current) 32 of the light source 20 is output, and the LED is caused to emit light corresponding to the time required for the inspection.

As shown in FIG. 2, the LED light emission control unit 40 receives a test start signal 30 and a light emission permission signal 31 and outputs a light emission command signal 33 to a controller 41.
And an illumination amplifier 4 that outputs the light emission signal 32 to the light source 20 in response to a light emission command signal 33 from the controller 41.
2, an operation panel 43 for setting the type of the parison 1 to be inspected, and a dimming instruction (brightness setting) signal 35 output to the illumination amplifier 42 based on the type signal 34 output from the operation panel 43. And a sequencer 44 for performing the operations.

Further, as shown in FIG.
Includes a power supply 51, a switch unit 52 that is turned on when a light emission command signal 33 is input, and a current setting unit 53 that changes the current flowing to the light source 20 by the dimming command signal 35 to change the light emission brightness of the LED. The light emission command signal 3
When the switch section 52 is turned on by the switch 3, the current set by the current setting section 53 is output to the white LED as the power supply 20 as the light emission signal 32 by the dimming command signal 35.

The current control in the current setting section 53, that is, the control of the light emission luminance of the LED can be performed by an arbitrary method. For example, the control can be performed by the following digital processing. First, the DC current from the power
The pulse is converted into a pulse of Hz to several tens of MHz, and a plurality of pulses, for example, 32 pulses are made into one set, and the effective current value is reduced by arbitrarily reducing the number of pulses in each set. That is, if the current value when all 32 pulses of each set are used is “100” (32/32), the current value is “50” (16/32) if the number of pulses is 16 and the LED is LED. Can be reduced by half. Therefore, by performing a test in advance for each parison having a different color tone to obtain the optimum luminance, the LED can always emit light with the optimum luminance in accordance with the color tone of the parison to be inspected.

The thus formed LED light emission control unit 4
0 indicates that when an input to inspect the colorless and transparent (clear) parison 1 is performed on the operation panel 43, a dimming command signal 35 corresponding to the type signal 34 is output from the sequencer 44 to the illumination amplifier 42, and In the amplifier 42, the current setting unit 53 sets the number of pulses to, for example, 16/32 based on the dimming command signal 35. And the controller 41
When the light emission command signal 33 is input and the switch unit 52 is turned on, a time corresponding to the inspection time, for example, 1
For / 1000 seconds, the light emission signal 32 is output, and the LED of the light source 20 emits light with a luminance of about 50% of the light emission ability.

A blue parison 1 is displayed on the operation panel 43.
Is input, the sequencer 4
4 outputs a dimming command signal 35 corresponding to the blue type signal 34 to the illumination amplifier 42, and the current setting unit 53 sets the number of pulses to, for example, 25/32. As a result, the LED of the light source 20 emits light at a luminance of about 80% of the light emitting ability.

As described above, when inspecting a blue parison having a lower translucency (transparency) than a clear parison,
By increasing the brightness of the LED from 50% to about 80%, the intensity of the transmitted light reaching the camera 21 can be made constant, and the analysis by the gray processing can be reliably performed in a stable state. Of course, the light emission time of the light source 20 can be changed by the setting of the controller 41.

Further, even when a parison having a different color tone is inspected, the LED of the light source 20 is replaced or the camera 2 is not replaced.
There is no need for complicated work such as adjusting the aperture of 1,
Since the inspection can be performed only by inputting the type to the operation panel 43, the reproducibility is excellent, and the inspection of parisons having different color tones can be continuously performed. Also, by changing the number of pulses by digital processing,
The brightness can be adjusted precisely and reliably. Further, by using a white LED as a light source, it is possible to easily cope with the inspection of parisons (translucent articles) of various colors.

The transport means and the like in the inspection apparatus can be of an optimal type as appropriate according to the shape of the translucent article to be transported. In addition, analysis of an image captured by a camera can be performed by a known method according to the size and shape of the translucent article.

[0020]

As described above, according to the present invention,
Since inspection of articles having different translucencies can be performed under constant conditions only by electrical processing, not only troublesome operations such as replacement and adjustment are unnecessary, but also reproducibility and reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a light-transmissive article inspection apparatus according to the present invention and showing a relationship with a transporting means.

FIG. 2 is a block diagram of an LED emission control unit.

FIG. 3 is a schematic circuit diagram for explaining an example of a control principle of the LED lighting amplifier.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Parison, 10 ... Conveying device, 11 ... Parison holding part, 12 ... Device drive part, 13 ... Test signal generator, 20 ...
Light source, 21 camera, 30 inspection start signal, 31 light emission permission signal, 32 light emission signal, 33 light emission command signal, 34
... Type signal, 35 ... Dimming command signal, 40 ... LED light emission control unit, 41 ... Controller, 42 ... Lighting amplifier, 43
... operation panel, 44 ... sequencer, 51 ... power supply, 52 ...
Switch part, 53 ... current setting part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tenyu Nagata 2480 Mado, Hiratsuka-shi, Kanagawa Prefecture F-term in the Hiratsuka Plant of Mitsubishi Plastics Co., Ltd. (Reference) 2G051 AA41 AA42 BA04 CA03 CA04 CB02 EA11 EA16 EB01

Claims (2)

[Claims] 1. A light source comprising a white LED is disposed on one side of an object to be inspected made of a translucent body, and a camera is arranged on the other side for photographing light emitted from the light source and transmitted through the translucent article. A light-transmitting article inspection apparatus for inspecting an object to be inspected based on a difference in brightness of an image photographed in the step (a), wherein the white LED
A light-transmissive article inspection apparatus, further comprising a light-emission luminance control means for adjusting the light-emission luminance of the light-transmitting article. 2. A light-transmitting device that captures, using a camera, transmitted light that is emitted from a light source made of a white LED and transmits through a light-transmissive inspection object, and inspects the inspection object based on a difference in brightness of the captured image. In the method for inspecting a transparent article, the luminance of the white LED is adjusted in accordance with the translucency of the article to be inspected so that the intensity of the transmitted light is constant. Method.