JP2971021B2 - Glass bottle top tilt inspection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus for measuring a top inclination of a glass bottle opening.

[0002]

2. Description of the Related Art In general, as a method of obtaining the top inclination of the vial of a glass bottle, light is emitted from a projector to the vial of the vial while rotating the vial around the bottle axis, and the reflected light is reflected. Light is received by a light receiver, and the difference between the maximum value and the minimum value of the reflected light amount is determined to obtain a ceiling inclination (Japanese Patent Publication No. 60-42883). There is known a method of obtaining a top tilt from a tilt.

[0003]

However, according to the conventional method in which a board is placed on a bottle opening to obtain a top inclination, a stable inspection can only be performed at about 30 lines / min. There is a problem that it is unsuitable for a production line that produces books / min. Further, in the device described in Japanese Patent Publication No. 60-42883, (1) the reflected light cannot be received by the light receiver unless the reflected light from the top surface of the bottle opening is diffused to some extent. Accuracy depends on the surface condition of the bottle top. (2) If the glass bottle rotates eccentrically or the height of the glass bottle changes, there is a problem that reflected light cannot be detected, and the detection accuracy of the top tilt decreases.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to inspect the top inclination of a glass bottle capable of measuring the top inclination of the vial at a high speed and with high accuracy. It is to provide a device.

[0005]

According to the first aspect of the present invention, there is provided a rotation driving means for rotating a glass bottle around a bottle axis, and a photographing means for photographing the opening of the rotating glass bottle obliquely above a depression angle α. And the bottle opening outside diameter is measured from the image of the bottle opening taken by this photographing means, the maximum value and the minimum value of the bottle opening diameter are obtained, and the top inclination of the glass bottle is calculated from the difference between the maximum value and the minimum value. Computing means for performing the operation.

According to a second aspect of the present invention, in the first aspect, when the top inclination of the glass bottle is h and the actual bottle opening diameter of the glass bottle is d, the depression angle α is ta.
n ^-1 (h / d) <α <60 °.

According to a third aspect of the present invention, in the first or second aspect, the photographing means is an image processing camera, and the camera is provided with a telecentric lens. It is.

According to a fourth aspect of the present invention, there is provided a rotary driving means for holding the body portion of the glass bottle and rotating the glass bottle around the axis of the glass bottle;
Photographing means for photographing obliquely from above, means for measuring the inclination of the bottom of the rotating glass bottle, and measuring the bottle outside diameter from the image of the bottle mouth taken by the photographing means, the maximum value of the bottle outside diameter And a minimum value, and a correction means for correcting the inclination of the bottom of the bottle to the top inclination of the bottle body obtained from the difference between the maximum value and the minimum value, and calculating the top inclination of the bottom of the bottle. It is characterized by the following.

According to a fifth aspect of the present invention, when the top inclination of the glass bottle is h and the actual bottle opening diameter of the glass bottle is d, the depression angle α is ta.
n ^-1 (h / d) <α <60 °.

According to a sixth aspect of the present invention, in the fourth or fifth aspect, the photographing means is an image processing camera, and the camera is provided with a telecentric lens. It is.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes a slide plate. This slide plate 1
The bottom 3a of the glass bottle 3 is guided, and a hole 5 is formed in the guide surface 1a of the slide plate 1. A pair of rollers 7 faces the hole 5 from below. The bottom 3a is rotatably supported.
When the glass bottle 3 is guided on the guide surface 1a of the slide plate 1 (measurement station S), the glass bottle 3
Is held between the pair of free rollers 9 and the drive wheel 11, and the driving force of the drive wheel 11 rotates the glass bottle 3. According to this, the glass bottle 3
Is rotated with reference to the trunk 3b.

In the measuring station S, the light from the light source 13 is applied to the bottle opening 3c of the glass bottle 3 to be bright, and a telecentric lens 15 is provided diagonally above the brightened bottle opening 3c. A camera (photographing means) 17 is provided. The installation angle (= depression angle) of the camera 17 is depression angle α = 30 °.

The control system is controlled by control means (hereinafter referred to as "PC") 100. The personal computer 100 has an image monitor 101, an operation monitor 102, and a control unit (arithmetic means) 103. A camera controller 21 for controlling the camera 15 is provided in an image memory board 103a of the control unit 103. Is connected. The general-purpose I / O port 103b of the control unit 103 has a terminal block 10
4, a motor 23 is connected. The motor 23 drives the drive wheel 11 through a timing belt 25. The rotation angle of the drive wheel 11 is detected by the encoder 27. Further, the high-speed I
The camera controller 21, the encoder 27, and the magnetic displacement sensor 29 are connected to the / O port 103c through the terminal block 105.
9 detects the vertical position of the roller 7 supporting the bottle bottom 3a of the glass bottle 3.

Next, the operation of detecting the top tilt will be described. According to this embodiment, when the glass bottle 3 enters the measuring station S, the glass bottle 3 is driven by the drive wheel 11 and rotates around the bottle axis. In this rotation, the body 3b of the glass bottle 3 becomes a reference (= hold), so if the bottle bottom 3a of the glass bottle 3 is inclined, the roller 7 hitting the lowered portion of the bottle bottom 3a is pushed down. The roller 7 is displaced vertically downward.

While the glass bottle 3 rotates around the bottle axis, the camera 17 always takes a picture of the mouth 3c of the glass bottle 3, and the image of the bottle mouth 3c is
1. The image is displayed on the image monitor 101 through the image memory board 103a as shown in FIG. 2B. The image of the bottle opening 3c displayed on the image monitor 101 has an elliptical shape. That is, referring to FIG. 2A, assuming that the distance between the edges A and B (hereinafter, referred to as “outer diameter”) of the projected bottle opening 3c is L, the outer diameter of the image is, as shown in FIG. The image is displayed on the monitor 101 as L.

Since the camera 17 always takes a picture of the bottle opening 3c of the glass bottle 3, when the glass bottle 3 is rotated and driven, as shown in FIGS. The outside diameter L of the mouth 3c repeatedly increases and decreases.

In the example shown in FIG. 2A (or FIG. 4B), the inclined surface of the bottle opening 3c has a downward slope as viewed from the camera 17, and the image on the image monitor 101 at this time is shown in FIG.
g, and the outside diameter of the bottle opening 3c indicates the minimum value Lmin. On the other hand, in the example shown in FIG. 3D (or FIG. 4A), the inclined surface of the bottle opening 3c has an upward slope as viewed from the camera 17, and the bottle opening 3c is displayed on the image monitor 101 at this time. The outside diameter indicates the maximum value Lmax.

The maximum value Lmax and the minimum value Lmin
(= Lmax−Lmin) is a measured value proportional to the top tilt as described later.

Next, the principle of detecting the inclination of the ceiling will be described. First, the difference between the maximum value Lmax and the minimum value Lmin of the outside diameter L at the bottle opening 3c of the glass bottle 3 is determined by the ceiling inclination detection amount H.
(= Lmax−Lmin).

Referring to FIG. 4 (FIG. 4a corresponds to FIG. 3d and FIG. 4b corresponds to FIG. 3a), the substantial outer diameter of the bottle opening 3c is d, the ceiling inclination (displacement amount) is h, and the ceiling is h. the inclination angle beta, the camera angle of incidence and alpha _1, top length d ₁ of the bottle mouth 3c
Then, d ₁ = d / cos β (1) Next, the maximum value of the image outer diameter measured by the camera is obtained.
Referring to FIG. 4a, the maximum value Lmax to be obtained for the image outer diameter
Lmax = d ₁ × cos (α ₁ −β) By substituting equation (1), = (d / cos β) × cos (α ₁ −β) (2) Next, the minimum value of the image outer diameter is obtained. . Referring to FIG. 4B, the minimum value Lmin for obtaining the image outer diameter is similarly calculated by substituting Lmin = d ₁ × cos (α ₁ + β) (1) as follows: = (d / cos β) × cos (α ₁ ) + Β) (3) Since the ceiling inclination detection amount H is the difference between the maximum value and the minimum value of the outside diameter L at the bottle opening 3c of the glass bottle 3 as described above, H = Lmax−Lmin = (d / cosβ) × (cos (α ₁ −β) −cos (α ₁ + β)) When developed by the addition theorem, = (2d / cos β) × sin α ₁ × sin β Since the camera depression angle α = 90−α ₁ , α ₁ = 90-α
By substituting: = (2d / cosβ) × sin (90−α) × sinβ sinβ / cosβ = tanβ, then: = 2d × tanβ × cosα (4) On the other hand, from FIG. h = 2 × h × cos α (5) According to this, the top inclination h is obtained as in equation (6).

H = H / (2 × cos α) (6) According to this embodiment, the top inclination h is obtained by taking the difference between the maximum value and the minimum value of the outside diameter L, so that the top inclination detection Since the amount H is doubled, it can be measured accurately. This measurement is controlled by the control unit 103.

As is apparent from the equation (6), the smaller the camera depression angle α is, the more advantageous the measurement of the top inclination h is. However, if the camera depression angle α is too small,
As shown in FIG. 5, it becomes impossible to measure the upward inclination of the downwardly inclined bottle mouth 3c as viewed from the camera 17. The depression angle α that can be measured is the depression angle α> tan ⁻¹ (h, where h is the top inclination of the glass bottle 3 and d is the actual bottle opening diameter of the glass bottle 3.
/ D). Further, if the image is taken at a depression angle α = 60 °, the expression (6) becomes h = H, and the merit of taking an image from obliquely above becomes small.

Therefore, taking these factors into consideration, it is desirable to set the camera depression angle α as shown in the following equation (7).

Tan ⁻¹ (h / d) <α <60 ° (7) When the camera 17 is provided at the depression angle α, the edges A and B of the bottle opening 3 c of the glass bottle 3 are simultaneously focused with reference to FIG. Can not match. For example, if the focus is on the edge B close to the camera 17, the edge A
Is out of focus. Referring to FIG. 6B, the image magnification differs depending on the positions of edges A and B. That is, the edge B close to the camera 17 is greatly reflected, and the camera 1
The edge A far away at 7 appears small. According to this embodiment, the telecentric lens 15 is provided to solve these problems.

The telecentric lens 15 can focus on the entire range (edges A and B) even if the distance between the lens and the subject changes within a certain range, and furthermore, can focus on the entire range (edge A). , B), a constant image magnification can be maintained. According to this, the top tilt of the glass bottle 3 can be measured more accurately without being affected by the position of the bottle mouth or the height of the bottle.

According to the above embodiment, as shown in FIG. 1, the glass bottle 3 is rotated and driven with reference to the body 3b. Therefore, in the above-described method of measuring the top inclination h, only the inclination of the bottle opening 3c of the glass bottle 3 is measured.

Therefore, as another embodiment, there is proposed a method (means) for measuring a substantial ceiling inclination based on the bottle bottom 3a of the glass bottle 3. With reference to FIG. 7, according to this embodiment, the inclination ha of the bottle bottom 3a of the glass bottle 3 is considered in the above-described inclination h. Since the glass bottle 3 is rotated and driven with reference to the body 3b, the substantial top inclination h 'with respect to the bottom 3a is as follows: h' = the top surface inclination amount h + the bottom inclination amount ha ( 8) is represented by That is, the inclination amount ha of the bottle bottom is added.

The top inclination h 'based on the bottle bottom 3a is calculated and calculated by the control unit 103. Next, a method of calculating the top inclination h' will be described.

First, the inclination of the top surface is calculated. FIG.
As shown in b, when the rotation angle of the glass bottle 3 is θ, when the top surface is viewed by the camera 17 installed diagonally above the top surface (depression angle α), it looks like a monitor in the same figure. The outside diameter detected at this time is defined as β · Y (θ). β is a coefficient for converting the detection amount Y (θ) (pixel) of the line camera into millimeters.

The intersection of an extended line connecting the point A and the edge A 'of the actual top surface and a horizontal line passing through BC is defined as a virtual point A ". Only exists when you are. As shown in FIG. 8A, when the inclined surface of the top surface faces the front with respect to the camera 17, B · A ″ becomes larger than the original outside diameter B · C. When the diameter is D, the detected amount β · Y (θ) is ΔB · A · A ″
Thus, β · Y (θ) = Dsinα (9) By transforming this equation, D = (β · Y (θ)) / sinα (10) When the inclination h (θ) of the top surface at this time is represented by the virtual outer diameter D and the original outer diameter d, h (θ) = (D−d) tan α (11) Here, when the inclination angle φ (θ) of the top surface is obtained from h (θ), φ (θ) = tan ⁻¹ (h (θ) / d) (12). Substituting equation (11), the inclination angle φ (θ) of the top surface becomes φ (θ) = tan ⁻¹ [{(β · Y (θ) / sinα−d) tanα} / d] (13) .

Next, the inclination of the bottle bottom is calculated.

As shown in FIG. 9, when the glass bottle 3 having no verticality is fixed by the body 3b, the bottle bottom 3a is inclined with respect to the vertical plane. When the rotation angle of the bottle is θ,
The inclination γ (θ) of the bottle bottom 3a is obtained from the outputs L and R of the two displacement sensors 29 attached to the bottle bottom 3a as follows.

Γ (θ) = tan ⁻¹ {f · (LR) / d ′} (14) f is a coefficient for converting the output values L and R (bit) of the displacement sensor into (mm) It is.

Finally, the inclination φ obtained for each
From (θ) and γ (θ), the top inclination h ′ based on the bottle bottom at the rotation angle θ, that is, the top inclination degree ε (θ) is obtained. The top inclination ε (θ) at the instant of the rotation angle θ is obtained by adding the top surface inclination φ (θ) and the bottom inclination γ (θ).

Ε (θ) = φ (θ) + γ (θ) (15) When ε> 0, the bottle is inclined toward the front side with respect to the camera 17. When ε <0, the bottle is tilted toward the camera 17. In other words, it is inclined to the opposite side. In the case of ε = 0, there is no inclination.

Since the value of ε (θ) is the top inclination only at the rotation angle θ, θ is changed from 0 ° to 360 °
The ceiling inclination for one round of c is obtained. This ε (0 °)-ε
(360 °), the top inclination ε _{max which} is the maximum and the top inclination ε _min which is the minimum, the top inclination h (mm) of this bottle
Is calculated as follows: h = dtan (ε _max −ε _min ) / 2 (16) The rotation angle θ is obtained by the encoder 27.

[0037]

As is apparent from the above description, according to the present invention, the outer diameter of the bottle is measured from the image of the bottle taken by the photographing means, and the maximum value and the minimum value of the outer diameter of the bottle are obtained. Since the top inclination of the glass bottle is calculated from the difference between the maximum value and the minimum value, the top inclination of the bottle opening can be measured at high speed and with high accuracy.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of a ceiling tilt inspection apparatus according to the present invention.

FIGS. 2A and 2B are explanatory diagrams when photographing a bottle mouth, in which FIG. 2A is a side view, and FIG. 2B is a diagram in which an image of the bottle mouth is monitored on a screen.

3 (a) to 3 (g) are diagrams showing changes on the screen of the bottle opening when the glass bottle is rotated 360 °. FIG.

FIGS. 4A and 4B are diagrams illustrating the principle of measuring the inclination of the ceiling.

FIG. 5 is a diagram illustrating the effect of the installation depression angle of the camera.

FIGS. 6A and 6B are diagrams for explaining a shooting situation of a camera.

FIG. 7 is a view for explaining the principle of measuring the top tilt based on the bottle bottom.

FIGS. 8A and 8B are diagrams illustrating a method of calculating a top inclination of a bottle opening.

FIG. 9 is a diagram illustrating a method of calculating the top inclination of the bottle bottom.

[Explanation of symbols]

 Reference Signs List 3 glass bottle 3a bottle bottom 3b trunk 3c bottle mouth 7 roller 15 telecentric lens 17 camera (photographing means) 27 encoder 29 magnetic displacement sensor 100 control means α depression angle

Continuation of front page (56) References JP-A-4-147003 (JP, A) JP-A-63-222245 (JP, A) JP-A-50-81359 (JP, A) JP-A-8-54213 (JP, A) , A) JP-A-9-42932 (JP, A) JP-A-4-318407 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01B 11/00-11/30 102

Claims (6)

(57) [Claims] 1. A rotation driving means for rotating a glass bottle around a bottle axis, a photographing means for photographing the opening of the rotating glass bottle obliquely from a depression angle α, and an image of the bottle mouth photographed by the photographing means. The glass characterized by comprising an arithmetic means for measuring the outer diameter of the bottle opening, obtaining the maximum value and the minimum value of the outer diameter of the bottle opening, and calculating the ceiling inclination of the glass bottle from the difference between the maximum value and the minimum value. Bottle tilting inspection device. 2. When the top inclination of the glass bottle is h and the actual outside diameter of the glass bottle opening is d, the depression angle α
Is set to be tan ^-1 (h / d) <α <60 °. The apparatus for inspecting the inclination of a glass bottle according to claim 1, wherein 3. The apparatus according to claim 1, wherein said photographing means is a camera for image processing, and said camera is provided with a telecentric lens. 4. A rotation driving means for holding the body of the glass bottle and rotating the glass bottle around the axis of the glass bottle, a photographing means for photographing the opening of the rotating glass bottle from obliquely above the depression angle α, Means for measuring the inclination of the bottom of the glass bottle to be measured, and measuring the outside diameter of the bottle from the image of the bottle taken by the photographing means, obtaining the maximum and minimum values of the outside diameter of the bottle, and determining the maximum and minimum values. Calculating means for correcting the inclination of the bottom of the bottle to the inclination of the bottom of the bottle obtained from the difference from the value and calculating the inclination of the bottom of the glass bottle. apparatus. 5. The depression angle α, where h is the top inclination of the glass bottle and d is the actual bottle opening diameter of the glass bottle.
Is set to be tan ^-1 (h / d) <α <60 °. 6. The apparatus according to claim 4, wherein said photographing means is a camera for image processing, and said camera is provided with a telecentric lens.