US3576442A

US3576442A - Ampul inspector using multiple line scan cathode-ray tube

Info

Publication number: US3576442A
Application number: US637461A
Authority: US
Inventors: Hoshitaka Nakamura
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-11-26
Filing date: 1967-05-10
Publication date: 1971-04-27
Anticipated expiration: 1988-04-27
Also published as: DE1648634A1; CH470664A; DE1648634B2

Abstract

A device for electronically scanning, with a multiple line scan, a rotating ampul to detect foreign particles therein, a signal being produced in which pulses represent the particles. The pulses are counted in the binary system and a decimal count derived therefrom which is compared with a selected standard. A Braun tube is used to display the particles.

Description

United States Patent Inventor Hoshitaka Nakamura N0. 33, 2-chome Ichigaya Kaga-cho Shinjuku-ku, Tokyo, Japan Appl. No. 637,461 Filed May 10, 1967 Patented Apr. 27, 1971 Priority Nov. 26, 1966 Japan 41/7733] and 41/77332 AMPUL INSPECTOR USING MULTIPLE LINE SCAN CATHODE-RAY TUBE 10 Claims, 7 Drawing Figs.

U.S. Cl 250/223, 3 56/ 1 96 Int. Cl G06m 7/00 Field of Search 250/222 (M), 223 (B); 36/196- l98; 178/7.7

TUBE l2 Calhoun Primary Examiner-James W. Lawrence Assistant Examiner-Martin Abramson Attorney-Waters, Roditi, Schwartz & Nissen "KB, I

', AMPam:

ascrmrme (444524 [9 0 b References Cited UNITED STATES PATENTS Sachtleben ABSTRACT: A device for electronically scanning, with a multiple line scan, a rotating ampul to detect foreign particles therein, a signal being produced in which pulses represent the particles. The pulses are counted in the binary system and a decimal count derived therefrom which is compared with a selected standard. A Braun tube is used to display the parti- Patented April 27, 1911 3 Sheets-Sheet I GEAZ FIG.2

AMPOUL E I 1 MOM/70R 5/840 I4 7055 S MOW/7'0"? 676. 66M

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FIG.3

AMPUlL INSPECTOR USING MULTIPLE LINE SCAN CATHODE-RAY TUBE BRIEF SUMMARY OF THE INVENTION The invention is directed to object examining apparatus comprising support means for supporting and rotating said object, electronic means for effecting at least one multiple line scanning of said object to detect particles of fine matter therein, signal means to represent the thusly detected particles in an electron signal and counting means to count the thusly represented particles, said particles being represented as pulses inv said electronic signal and wherein a different number of particles can be counted for each scanning.

The counting meansincludes means to remember the largest count for said object and means to generate a signal when a predetermined count is reached.

Specifically, the counting means includes binary counting means for counting the pulses and representing the same in the binary system, means to convert the binary representation into a decimal representation and to remember the largest count for said object and means to establish a standard tolerable count for the object and to generate a signal when the standard tolerable count is matched.

In further accordance with the invention, means is coupled to the camera means to generate horizontal and vertical synchronizing signals for controlling the rate of scanning and means is provided to modify the horizontal and vertical synchronizing signals for controlling the number of lines in each scan and the distance between said lines.

The invention further contemplates the provision of object detection means to examine the presence of the object in the support means and to generate a start signal to actuate said camera means.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows the image of particles of foreign matter contained in an ampul as shown with scan lines on a Braun tube;

FIG. 2 shows the image of foreign matter signals alone appearing on the Braun tube which indicates the size and/or the number of particles of foreign matter;

FIG. 3 is a block diagram showing the system provided in accordance with the present invention;

FIG. 4-A is a diagram showing the signals occurring in respective portions of the device of this invention based on a horizontal synchronizing signal;

FIG. 4'B is a diagram showing the signals at the respective portions of the device of this invention based on a vertical synchronizing signal (with regard to the signals, they are classifted as inputs and outputs of the respective means and various alphabetic notations are accordingly given to them to identify the means with which they are associated);

H6. 5 is a diagramvshowing foreign matter" signals and resetting signals; and

FIG. 6 is a block diagram showing a counting and maximum-value storing circuit used in accordance with the invention.

DETAILED DESCRIPTION The present invention relates to apparatus for automatically inspecting, in accordance with a predetennined standard, the surface or the inside of various objects or materials.

The present invention can be used for automatically and continuously inspecting ampuls or baeyers having chemicals sealed therein. The apparatus of the present invention can also be used for the examination of the condition of the surface of a solid substance such as the uniformity of the surface or for the detection of scars on the surface of the solid substance, or it can be used to inspect for microbes floating in a fluid scaled within a transparent container.

Bad ampuls can be characterized, for example, by a lack or excess of chemicals contained therein, contamination of or scars on the external walls thereof, or particles of foreign matter contained in such chemicals (such as glass, fiber, dust, crystals or the like). In the following text the inspection of ampuls containing particles of foreign matter is in particular explained.

Hitherto, the inspection of ampuls such as mentioned above has most frequently been carried out by the naked eye and, therefore, has not been effective. The irregularity of the inspections, attributable to the difference of individual inspectors, has been remarkable and accuracy has not been very high. There have been a great number of problems in this field, and there is a great need for an automatic ampul inspector which has sufficient inspecting accuracy for reliably removing bad ampuls and which has sufficient speed for maintaining an acceptable inspecting efficiency. At the same time, the above-mentioned need for an automatic ampul inspector has become greater in view of the fact that production efficiency can be improved by means of combining processes for production and for inspection. There have hitherto been made attempts to replace inspection by means of the naked eye by inspection carried out by various mechanisms. Some of these attempts have actually been used to a limited extent.

There have been proposed, for example, devices to illuminate ampuls so that particles of foreign matter can be easily detected, or means to float foreign matter by turning the ampuls upside down on conveyors employed therefor.

As a substitute for inspection by means of the naked eye, a secondary emission electron amplifying tube or photoelectric tube has been used.

In the above-mentioned conventional means, ampuls are rotated to float whatever particles of foreign matter are located therein, and then said ampuls are placed in position for inspection. The ampuls are then illuminated and the light rays from a part of the surface ,of the side of the liquid-containing ampul are condensed on the light-receiving surface of the above-mentioned photoelectric tube. In the event particles of foreign matter are mixed up in the chemical solution in an ampul, the foreign matter floats across a part of the surface of the ampul and accordingly illumination of the light-receiving surface is changed. The change of the illumination is represented by a change of electric current. When a change of electric current is observed, it is determined that particles of foreign matter are present in the chemical within the ampul.

However, with regard to contamination or scars on the external wall of the ampul, these cannot be detected, while "the ampul is not moving because they do not result in a change of electric current even with the passage of time. Further, when an ampul is rotated at a given position for inspection, the ampul itself works as an irregular convex lens to change the direction of illumination, and therefore the illumination on the light-receiving surface is changed even by an ampul containing no foreign matter. This type of change is erroneously mistaken as indicating an ampul containing particles of foreign matter.

Moreover, when the known ampul-transmitting means as a whole is subjected to the slightest shaking such as originates from a motor, the illumination on the light-receiving surface is changedfAlso, the illumination of the light source itself is changed even by the slightest variations of voltage. Errors under these circumstances cannot be avoided.

In addition to the above, the fact that the inspection requires several seconds is a drawback in view of the need for efficiency in inspection.

In accordance with the present invention, an electronic camera is employed to take pictures or images of the objects to be inspected. By changing the number of the scanning lines of the camera tube of said electronic camera, the interval of the scanning lines is used as a variable inspection unit, and particles of foreign matter or scars or contamination of the wall of the ampuls are inspect-measured.

In case a particle of foreign matter is comparatively large (see particle A in FIG. 1) and covers several scanning lines, the size of the particle of foreign matter is represented by several foreign matter signals. If a particle of foreign matter is comparatively small (see particles B and C in FIG. 1), such particle of foreign matter is represented by a single foreign matter signal. The foreign matter signals appear in the fonn shown in FIG. 2 on a monitor Braun tube.

In accordance with the present invention, the size of detectable foreign matter may be as low as 5 microns. It is, however, possible to select a larger particle size as the minimum standard on which the inspection tube is to be based.

Another problem with which the invention is concerned is due to the fact that particles of foreign matter are floating during the time during which the inspection is being carried out. Due to this, there is the possibility that a few particles are counted as only one particle by reason of their being aligned with each other in front of the camera. In order to avoid this possibility, in accordance with the present invention, a plurality of electronic pictures can be taken for each ampul, and the picture which shows the maximum number of particles of foreign matter is the one from which the quality of an ampul is detennined with reference to such maximum value.

It is an object of this invention to provide an automatic inspector particularly for use in detecting the amount of miscellaneous minute foreign substances contained in a solution within an ampul in a most accurate manner. Other objects and advantages of this invention will further become apparent hereinafter.

With particular reference to FIGS. 3 and 4, an ampul 17 is, in accordance with the invention, first rotated in one direction while standing erect by means of an automatic transmitting means 19 (the rotational velocity thereof being less than about 6,000 rpm), and then said ampul is rotated in the opposite direction. By means of said rotation in the opposite direction, centripetal force is brought about and the particles of foreign matter are floated. Parallel light rays are projected through the bottom of the ampul 17 by means of a light source 18 in order to illuminate the particles of foreign matter within the liquid contained in the ampul. The image of the entire chemical solution within the ampul is formed, through a telescopic lens system of large focal length, on the camera tube of an electronic camera 1 arranged at one side of the ampul 17.

The resolution of the camera tube can be varied by changing the oscillation frequency of the horizontal synchronizing signals of the variable horizontal and vertical synchronizing signal generator 3. For example, it is possible to change the distance between the scanning lines within the range of from several tens of microns to several hundred microns by changing the horizontal synchronizing signals within the range of from 200 to 400 lines (see signal he in FIG. 4-A; also signal p.h in FIG. 4-8) with reference to the vertical synchronizing signal each one-fiftieth of a second (see signal a.c in FIG. 4-A).

By having the vertical synchronizing signal variable, the time required for taking a picture is changed from one-fiftieth to one-thirtieth of a second. Thereby the time required for exposure is changed. The contrast of the image can be changed accordingly.

It is recommended that, in order to obtain vertical synchronizing signals of a comparatively lower frequency, the outputs of two crystal oscillating members having different, comparatively higher, oscillation frequencies should be added to make a signal having a frequency of less difference. Such signal should be utilized as the vertical synchronizing signal.

The image from the camera tube (see wave d of FIG. 4-A) is enlarged on the monitor Braun tube 16 when the contact is switched over to contact d and can be observed with the naked eye.

On the other hand, the wave d of the image can be shaped by means of a video-signal-shaping circuit 2, whereby the wave e is formed. For this, each small projection x on the wave d, which projection shows the existence of a particle of foreign matter, is formed into a pulse y.

Wave form e is stripped of the horizontal and vertical synchronizing signal components by means of a horizontal and vertical synchronizing signal erasing circuit 6, whereby there is formed a video wave 3 of the image alone. This signal is transmitted to a gate circuit 7 for controlling the number of photographs.

In FIG. 4-A, signal f is the signal for erasing the horizontal synchronizing signal, and signal 1' is the signal for erasing the vertical synchronizing signal. Both of these signals are generated by the erasing signal-generating circuit 4.

An inspection starting signal I which detects the fact that an ampul has been placed at the predetermined inspecting position is generated in a photoelectric means 12 and transmitted to a circuit 5 for generating a signal to set up the number of inspection photographs to be taken. The circuit 5 receives the signal I and the vertical synchronizing signal p at its input and delivers, through a contact piece 5a which is set on an appropriate contact, the rectangular wave i of FIG. 4-B having a duration corresponding to the desired number of inspection images. Rectangular wave i has a leading edge in coincidence with the vertical synchronizing signal immediately following the signal t, and a trailing edge following the vertical synchronizing signal corresponding to the desired number of images. The gate signal for the case of 4 images is shown. The gate signal i is transmitted from the above-mentioned circuit 5 to a set-signal-generating circuit 8 and a gate circuit 7. The gate circuit 7, which is used for controlling the number of photographs, is an AND-circuit. The AND-circuit 7 receives the video-shaping signal g and the rectangular wave i and generates the foreign matter signal j.

The foreign matter signal j and the reset signal r, produced by shaping the vertical synchronizing signal within the time corresponding to the number of the desired inspection images, enter a digital counter circuit 9, and the foreign matter signal j is divided for each image by the reset signal r and is counted.

The counter circuit 9 counts out how many particles of foreign matter are present by the minimum unit of the measurement of foreign matter, i.e., the distance between the scanning lines as the length of inspection unit.

The counter circuit 9 of FIG. 6 is composed of four flip-flop circuits and can therefore count up to four figures on a binary number basis, i.e., up to 16 in accordance with the decimal system.

The counted value signal It enters the counted value distribution circuit 10 composed of an AND-combination of diodes. The total number of particles of foreign matter within one image can be obtained thereby. The pulses whose number corresponds to said total are generated in turn at the output terminal thereof. As the counted value distribution circuit, a tree circuit or ring-counter mechanism can be employed.

As many flip-flops as are required for the maximum count possible in the counter circuit 9 are provided in a maximum memory circuit 11 at the output of the counted value distribution circuit 10. Said flip-flops are so modified, for instance, by using diodes that in case a pulse signal once enters the input, it

is not reversed even if succeeding pulse signals enter the input,

unless reset signal enters.

When the counting pulses of one image from the counter circuit 9 enter the input terminal of the counted value distribution circuit 10, as many pulses as are equal to the number of the counted value of the particles of foreign matter belonging to one image, appear at the outputs of the circuit 10 and, among the flip-flops (flmf as many flip-flops as correspond to the counted value are reversed. In case the counted value of the particles of foreign matter of the image which enters the circuit 10 is smaller than the counted value of the particles of foreign matter of the preceding image, the memory state of the flip-flop is not changed. In case it is larger than the counted value of the particles of foreign matter on the preceding image, as many flip-flops as correspond to the difference from the counted value of the particles of foreign matter of the preceding image are newly reversed and the larger number is memorized.

Thus, any number of particles of foreign matter of an image which is greater than the number of particles of foreign matter already memorized is newly memorized. The maximum memory circuit 11 therefore only memorizes the number of particles of foreign matter of the image having the maximum number of such particles. This maximum value is retained on the indicator tube of the maximum memory signal indicating circuit 13 and the indication thereof is maintained until the result of the inspection of the next ampul arrives.

The movable contact 15a of a selection circuit 15 for generating a signal for excluding bad ampuls is, in advance, connected to one of the output terminals of the flip-flops of the maximum memory circuit 11 in accordance with a standard value selected for passing or rejecting ampuls. When the particular flip-flop involved delivers an output signal through the movable contact 15a a judgement signal n is released by circuit 15.

The circuits of FIG. 6 include the counter 9, the counted value distribution circuit or matrix (composed, for example, of a diode matrix), and the memory circuit 11 (in accordance with the illustrated embodiment), said memory portion is composed of 16 flip-flops. This number corresponds to the decimal number corresponding to the binary number which can be represented by four flip-flops of the counter portion. The judging or selection circuit for determining the maximum allowable number of particles of foreign matter is also included. FIG. 5 shows the reset signal r and the foreign matter signal j to be counted.

The foreign matter signal j arriving at the digital counter circuit consists of a train of pulses whose pulse width w and distance d are not regular, but whose amplitude is regular (see FIG. 5).

The reset signal (see FIG. 5), for showing clearly the limits of each group of incoming-valve representing groups, is supplied to the counter portion and the number of pulses is determined for each group.

The pulses of the respective groups are supplied to one input terminal of the counter 9. When the signal r indicating the beginning or end of each group enters via the other input terminal of the counter portion 9 the digital count is reduced to 0 and the counter is ready for the arrival of the incoming pulse group.

The value counted by the counter for each group enters the matrix 10 in the form of a counted value signal. Circuit 10 is a counted value output distribution matrix composed of an AND-combination of diodes. The binary system counted value signal is, in turn, converted into a decimal system counted value signal. In other words, as many pulses as corresponds to the decimal number are generated on the output side and, then, they enter flip-flop f flip-flop f flip-flop f and set up the flip-flops corresponding to a decimal number.

With regard to the flip-flops on the output side, they are conventionally designed so that 0 is switched to 1 when an input pulse is present but, even if another input pulse should be received, the state of l is retained without being switched to 0. The flip-flops can be turned to 0 only by a reset signal.

By way of explanation of the operation of the embodiment shown in FIG. 6, it is presumed, for example, that groups of four, three and eight pulses arrive at the circuits, in this order, and that the specific value 8 of the particles of foreign matter 'should be detected. Firstly, the four pulses are counted by the flip-flops (f through f to be 1, 0 and 0, and enter the matrix 10. Through the output terminal thereof, the flip-flops (f, through f,) are switched from the original state'of 0, 0, O and 0 to the state of l, l, l and 1. Thus the number 4 is stored. Next, the pulse r showing the end of the group enters the counter 9 and then the group composed of three pulses enters the counter 9. The flip-flops of the counter 9 count to the state of O, l and l but flip-flops), through f have already memorized the values of the preceding four pulses and have assumed the state of l, l and 1. These states are not changed by the incomi'ng three-pulse group. Next, the pulse r indicating the end of the group enters, and the subsequent group composed of eight pulses enters the counter 9. Eight pulses in all are added one by one to the flip-flops f, to f, on the output side of the matrix It).

The flip-flops f, through 1} have already memorized and retained the value of four by assuming the states of l, l, l and 1. Therefore, the flip-flops, which are newly converted to I, l, l and 1, are the flip-flops f through 12,.

The movable contact 15a of the judging signal-generating circuit 15 is, in advance, connected to the output side of the flip-flop 1;, for detecting the specific value 8. Therefore, at the moment when the eight pulses arrive and the flip-flops f, through f are converted to Is so that the flip-flop j}, is converted into I, the judging signal for the confirmation of the presence of the eight pulses is transmitted to the judging signal-generating circuit 15.

When one judging inspection is terminated, the reset signal for converting the flip-flopsf through f is transmitted and the circuits are readied for the next inspection.

Bad ampuls are detected by means of the generation of the judging signal. Good ampuls are transmitted to a subsequent process. The judging signal n is delayed relative to the starting signal 1. Bad ampuls are removed from a position through which several ampuls pass between the time at which a bad ampul is detected and its removal.

In the diagram of FIG. 3, circuit 14 is a signal-generating circuit for a video-shaping signal monitor signal s, and is used for projecting the image of FIG. 2 on the monitor 16.

In the diagram of FIG. 3, circuit 4 is a signal-generating circuit for erasing the horizontal and vertical synchronizing signals, and generates the signal f for erasing the horizontal synchronizing signal and the signal 1' for erasing the vertical synchronizing signal. These signals are transmitted to the horizontal and vertical signal-erasing circuit 6.

As already mentioned, several tens of pictures of the state of the wall of each ampul and the particles of foreign matter are taken. The image which shows the worst state of an ampul is taken as the one which represents the state of that ampul. Thereby, a strict examination of the ampuls can be carried out.

When ampuls are continuously inspected by using the device of the present invention, from one to 10 pictures are taken per ampul. The inspection can be finished within from one-fiftieth to one-fifth of a second.

When ampuls are inspected by the naked eye or by photoelectric means, the accuracy of the inspection is from 30 to 50 percent. When the device of the present invention is employed, the accuracy of inspection is very high and ranges from 96 to 99.4 percent. In addition, the image of an ampul is enlarged as much as 1,000 times on the monitor. Therefore, it is very easy to detect the main cause of the foreign matter contained in the ampul.

In accordance with the explanation already given, scars on the wall of an ampul or dust adhering to the external wall of an ampul are detected as foreign matter. In case it is desired that only particles of foreign matter contained in an ampul should be detected, the rotation of the ampul is increased, and the image of the dust is obscured and becomes undetectable. It is thus possible to detect only particles of foreign matter within the ampul.

lclaim:

1. Object examining apparatus comprising support means for supporting and rotating said object, electronic camera means for effecting at least one multiple line scanning of said object to detect particles of foreign matter therein, signal means to represent the thusly detected particles in an electron signal, and counting means to count the thusly represented particles, said particles being represented as pulses in said electronic signal and wherein a different number of particles can be counted for each scanning, said counting means including binary counting means for counting said pulses and representing the same in the binary system, means to convert the binary representation into a decimal representation and to remember the largest count for said object, and means to establish a standard tolerable count for the object and to generate a signal when the standard tolerable count is matched.

2. Apparatus as claimed in claim 1, wherein the binary counting means includes a plurality of flip-flop circuits the collective states of which constitute a binary representation.

3. Apparatus as claimed in claim 2, wherein the means to convert the binary representation includes a matrix coupled to said flip-flop circuits and a further plurality of flip-flop circuits coupled to said matrix.

4. Object examining apparatus comprising support means for supporting and rotating said object, electronic camera means for effecting at least one multiple line scanning of said object to detect particles of foreign matter therein, signal means to represent the thusly detected particles in an electron signal, counting means to count the thusly represented particles, signal generator means coupled to said camera means to generate horizontal and vertical signals, means coupled to said signal generator means to change" the frequency of the horizontal synchronizing signals for controlling the distance between scanning lines with respect to the minimum particle size of foreign matter to be detected, and to change the frequency of the vertical synchronizing signals for controlling the time for taking a photograph with respect to the speed of moving particles, and means coupled to said signal generator means to provide a number of photographs for each object by allowing a number of vertical signals corresponding to the number of photographs to pass to said counting means.

5. Apparatus as claimed in claim 4 comprising object detection means to examine'for the presence of the object in said support means and to generate a start signal to actuate said means which provides a number of photographs for each object.

6. Apparatus as claimed in claim 4, wherein the synchronizing signals appear in said electronic signal, the apparatus further comprising means to erase the synchronizing signals therefrom.

7. Apparatus as claimed in claim 5, wherein the object is an ampul, including a light source for transmitting light through the arnpul in said support means.

8. Apparatus as claimed in claim 4, wherein said camera means produces a succession of images of said object in a plurality of scans, said counting means counting the particles in each scan and wherein a different number of particles can be counted for each scan, means to remember the largest count for said object and means to generate a signal when a predetermined count is reached.

9. Apparatus as claimed in claim 5, wherein said camera means produces a succession of images of said object in a plurality of scans, said counting means counting the particles in each scan and wherein a different number of particles can be counted for each scan, means to remember the largest count for said object and means to generate a signal when a predetermined count is reached.

10. Apparatus as claimed in claim 1 comprising means to display visually the remembered largest count.

Claims

4. Object examining apparatus comprising support means for supporting and rotating said object, electronic camera means for effecting at least one multiple line scanning of said object to detect particles of foreign matter therein, signal means to represent the thusly detected particles in an electron signal, counting means to count the thusly represented particles, signal generator means coupled to said camera means to generate horizontal and vertical signals, means coupled to said signal generator means to change the frequency of the horizontal synchronizing signals for controlling the distance between scanning lines with respect to the minimum particle size of foreign matter to be detected, and to change the frequency of the vertical synchronizing signals for controlling the time for taking a photograph with respect to the speed of moving particles, and means coupled to said signal generator means to provide a number of photographs for each object by allowing a number of vertical signals correspOnding to the number of photographs to pass to said counting means.

5. Apparatus as claimed in claim 4 comprising object detection means to examine for the presence of the object in said support means and to generate a start signal to actuate said means which provides a number of photographs for each object.

7. Apparatus as claimed in claim 5, wherein the object is an ampul, including a light source for transmitting light through the ampul in said support means.