KR20120123169A - Angle measuring apparatus of powder deposition layer - Google Patents

Abstract

PURPOSE: A device for measuring an angle of a powder stacked layer is provided to prevent lights except for lights emitted by a back light panel being incident to a camera, thereby obtaining silhouette images of an accurate shape. CONSTITUTION: A device for measuring an angle of a powder stacked layer comprises a camera, a back light panel(30), a powder stacked layer supporting device, and an image analyzer. The back light panel is arranged in a position facing the camera. The powder stacked layer supporting device is arranged in between the camera and back light panel. The image analyzer analyzes silhouette images of a powder stacked layer photographed by the camera, thereby obtaining an angle of the power stacked layer. An optical filter is assembled in the camera. The optical filter has high transmission ratio with respect to a peak of a light emitting spectrum of the back light panel.

Description

ANGLE MEASURING APPARATUS OF POWDER DEPOSITION LAYER}

The present invention relates to an angle measuring device for a powder deposited layer.

The physical properties of the powder are measured with various parameters such as angle of repose, collapse angle, spatula angle, loose or hard bulk density, compression, cohesion, dispersion and difference angle. Patent Documents 1 and 2 show examples of the device for measuring the angle of the powder deposition layer, such as an angle of repose and a spatula angle.

The apparatus described in Patent Document 1 includes measuring means for measuring at least one of physical properties of powders such as an angle of repose, collapse angle, loose or hard bulk density, compressibility, spatula angle, cohesion degree, dispersion degree and difference angle, And control means for performing control and arithmetic processing necessary for measurement in the measuring means. The measuring means includes an angle measuring jig for rotationally driving the angle measuring arm by a pulse motor so as to be parallel to the inclined surface of the deposited sample powder. The control means drives the pulse motor to drive pulses and calculates the angle of the angle measuring arm by the count value of the number of drive pulses.

The apparatus described in patent document 2 is equipped with a camera on a base. When measuring the angle of repose, the table of repose angle is placed in the form of the back panel in front of the camera. When the spatula angle is measured, the spatula is disposed in the form of the back panel in front of the camera. When shooting with a camera, the silhouette image of the powder deposition layer on the repose angle measurement table or the silhouette image of the powder deposition layer on the spatula can be obtained. This image is analyzed by a computer and the inclination angle of the powder deposited layer is obtained.

JP 2798827 B JP 4155942 B

As in the device described in Patent Document 2, when the angle of the powder deposition layer is obtained by an image analysis technique, a situation in which the light coming from outside the device becomes a disturbance factor often disturbs the analysis of the image or lowers the analysis accuracy. However, in general, the environment in which this type of device is used is brightly lit, and it is difficult to block external light.

This invention is made | formed in view of said point, and an object of this invention is to provide the angle measuring apparatus of the powder deposition layer which can perform accurate angle measurement, without being influenced by external light.

The angle measuring device of the powder deposition layer of the present invention includes a camera, a backlight panel disposed at a position facing the camera, a powder deposition layer support apparatus disposed between the camera and the backlight panel, and the powder photographed by the camera. An image analysis device for analyzing a silhouette image of a deposition layer to obtain an angle of the powder deposition layer, wherein the backlight panel is a light source having a peak of an emission spectrum between 450 nm and 550 nm, and the camera has an emission spectrum of the backlight panel; Optical filters having a high transmittance with respect to the peak of are combined.

In the angle measuring device of the powder deposition layer of the present invention, it is preferable that the backlight panel is a light source having a peak in the emission spectrum at 460 nm to 480 nm.

In the angle measuring device of the powder deposition layer of the present invention, the backlight panel includes a combination of a light transmitting panel having a light guiding function and a light diffusing function, and an LED for irradiating light to an end face of the light transmitting panel. It is desirable to.

In the angle measuring device of the powder deposition layer of the present invention, the light transmitting panel is preferably configured by combining a light guide plate and a diffusion plate.

In the angle measuring device of the powder deposition layer of the present invention, it is preferable that the optical filter is a bandpass filter having a maximum transmittance of 30% or more with respect to the peak wavelength of the backlight panel.

In the angle measuring device of the powder deposition layer of the present invention, it is preferable that an openable cover covering the camera and the powder deposition layer support device is provided, and the backlight panel is attached to the cover.

According to the present invention, the backlight panel emits light in a predetermined wavelength region, and since the camera is combined with an optical filter having a high transmittance with respect to the emission wavelength region of the backlight panel, light other than the light emitted by the backlight panel Basically, it does not become incident light to the camera. For this reason, the silhouette image of powder deposition layer is formed only by the light from a backlight panel, and the silhouette image of an accurate shape is obtained. Analysis of the silhouette image by the image analyzer is also accurate, and the angle measurement accuracy is improved.

1 is a schematic front view of an angle measuring device of a powder deposited layer;
2 is a schematic side view of an angle measuring device of a powder deposited layer;
3 is a schematic cross-sectional view of the backlight panel, viewed from the side direction;
4 is a schematic cross-sectional view of the backlight panel, viewed from the front direction;
5 is a plan view of an LED array used in a backlight panel;
6 is an explanatory diagram of a concept of image processing;
7 is a block diagram of an angle measuring device of a powder deposited layer;
8 is a schematic cross-sectional view illustrating the angle of repose measurement.
9 is a schematic cross-sectional view illustrating the spatula angle measurement.

The two main elements constituting the external appearance of the angle measuring device 1 of the powder deposition layer are the main body 2 and the cover 3 covering the front part thereof. The main body 2 surrounds the outer side of the mount structure not shown in the housing 4 made of sheet metal, and is supported on the support surface by a plurality of height-adjustable support legs 5. The cover 3 has a main part formed of a transparent synthetic resin, and is attached to both left and right sides of the main body 2 by a pair of left and right arms 6. The tip end of the arm 6 is a point portion 7 connected to the main body 2, and the cover 3 rotates in a vertical plane around the point portion 7.

When the cover 3 is lowered, it is in a solid line state of FIG. 2. At this time, the space surrounded by the cover 3 becomes the measurement chamber 10 shown in FIG. 8 or 9. As mentioned above, since the main part is transparent, the cover 3 can look into the inside of the measurement chamber 10 even when the cover 3 is lowered. The operator can perform the measurement work without being affected by dust while visually confirming the state of the sample and the like.

The front part of the cover 3 is provided with the handle part 3a, and a hand can be raised to it, and the cover 3 can be raised to the position of the virtual line of FIG. When pulled up to the position of the virtual line of FIG. 2, the cover 3 stays in that position even if it removes a hand. After the measurement chamber 10 is opened in this manner, the operator performs the arrangement of the measured sample and the tool provided for the measurement, setting a new measurement work, and maintenance inspection work. When it is no longer necessary to keep the measurement chamber 10 open, the cover 3 is lowered. A damper is incorporated into the shaft holding the cover 3 at the point portion 7, and when the hand is released during the lowering, the cover 3 slowly descends and closes silently without giving an impact.

In the measurement chamber 10, the camera 20 and the backlight panel 30 (see FIG. 3) are disposed to face each other. Although the powder deposition layer support apparatus is arrange | positioned between the camera 20 and the backlight panel 30, this is demonstrated later.

The camera 20 is fixedly installed in the measurement chamber 10 at a constant height on the left side as viewed from the front. As the camera 20, for example, UCAM-DLU130H series (1.3 million pixels) sold by Elecom Co., Ltd. as a WEB camera, BSW13D06H series (1.3 million pixels) sold by Buffalo Co., Ltd., sold by Microvision, Inc. Global shutter CMOS board camera (monochrome) MCM-4304 (300,000 pixels), monochromatic progressive scan camera CM-030GE (300,000 pixels) sold by JAI Corporation, progressive CMOS camera (BW) sold by Atray Co., Ltd. ) ARTCAM-036MI (360,000 pixels) can be used.

The backlight panel 30 is disposed at the right end of the measurement chamber 10. The backlight panel 30 is attached to the backlight panel support portion 6a (see FIG. 2) formed on the side of the right side, specifically, the arm 6 on the right side when viewed from the front of the cover 3. The cover 3 is formed with a rectangular opening corresponding to the rectangular light emitting surface of the backlight panel 30, and the light emitting surface of the backlight panel 30 is exposed to the inside of the measurement chamber 10 through the opening. .

The backlight panel 30 also rotates with the rotation of the cover 3. When the cover 3 is closed, the backlight panel 30 faces the camera 20. Thus, by using the cover 3 as the attachment member of the backlight panel 30, it is not necessary to separately install the attachment member of the backlight panel 30, and can simplify a structure.

The backlight panel 30 has the configuration shown in FIGS. 3 to 5. (31) is a rectangular parallelepiped-shaped case which became flat in the left-right direction seen from the front. The case 31 is formed of sheet metal made of a metal having good heat dissipation, for example, aluminum. The case 31 has an opening on the left side as viewed from the front, from which the reflection sheet 32 and the light transmission panel 33 having the light guiding function and the light diffusing function are inserted. In the embodiment, the light transmission panel 33 is configured by combining two plates, that is, a light guide plate 33a and a diffusion plate 33b. As viewed from the front of the diffusion plate 33b, the vertical surface on the left side becomes the light emitting surface 30a of the backlight panel 30.

The light emitting surface 30a generates uniform surface light in the same structure as that employed in the backlight of the cellular phone. It is the high brightness type light emitting diode (hereinafter referred to as "LED") 34 that makes the light emitting surface 30a shine. A substrate 35 having a plurality of LEDs 34 attached at predetermined intervals is disposed below the light transmission panel 33. LED 34 irradiates light to the cross section of the light transmission panel 33, specifically, the cross section below the light guide plate 33a. Light changes direction inside the light guide plate 33a and enters the diffusion plate 33b. Light diffuses inside the diffusion plate 33b, and the light emitting surface 30a shines uniformly without being uniform.

The LED 34 is a monochromatic light emission type that exhibits high light emission efficiency in a specific wavelength region, and the light emission wavelength region of the light emitting surface 30a also becomes a predetermined wavelength region close to the specific wavelength region. The camera 20 is combined with an optical filter 21 having a high transmittance with respect to the emission wavelength region of the backlight panel 30. Generally as the optical filter 21, what is known as a long pass filter, a short pass filter, and a band pass filter can be used.

The light source and the optical filter 21 of the backlight panel 30 are determined according to the measurement environment. For example, when the external light is mainly sunlight, the emission spectrum of sunlight has a peak mainly at a wavelength around 500 nm. Therefore, the optical filter 21 may be used to block light in at least the wavelength region, and the light source having the peak wavelength in the wavelength region not blocked by the optical filter 21 is used as the light source of the backlight panel 30. In this case, the influence of external light during the measurement can be reduced. In addition, when the external light is mainly light of a fluorescent lamp, the emission spectrum of the fluorescent lamp has a peak mainly at wavelengths around 440 nm, 550 nm, and 620 nm. For this reason, the optical filter 21 can use the thing which can block the wavelength of 550 nm vicinity which is the highest emission intensity among those wavelength ranges, and the wavelength which is not blocked by the optical filter 21 for the light source of the backlight panel 30 is used. By using a light source having a peak wavelength in the region, it is possible to reduce the influence of external light during the measurement.

In addition, when the light emission spectrum of the light source of the backlight panel 30 has several peaks, the optical filter 21 which does not block the peak wavelength of the highest light emission intensity among those peaks is selected.

It is preferable that the light source of the backlight panel 30 has a peak wavelength in the range of 400 nm to 700 nm. More preferably, it has a peak wavelength in the range of 450 nm-550 nm, More preferably, it has a peak wavelength in the range of 460 nm-480 nm. If it is such a peak wavelength region, a blue LED, a white LED, etc. which are comparatively cheap and easy to obtain can be used as a light source, for example.

It is preferable that the maximum transmittance of the optical filter 21 is 30% or more with respect to the peak wavelength of the light source of the backlight panel 30. More preferably, it is 50% or more. Although the angle measurement is possible even if the maximum transmittance is less than 30%, the photographed image becomes dark, and there is a fear that the accuracy of the angle measurement is lowered. When using a bandpass filter for the optical filter 21, it is preferable that the half value width is 5 nm-120 nm. More preferably, they are 5 nm-40 nm. Although the full width at half maximum is more than 120 nm, it can be used, but in that case, since the wavelength region to be blocked is widened, the number of selection of the light source of the backlight panel 30 is limited. If the half width is 40 nm or less, the number of selection branches of the light source of the backlight panel 30 becomes wider.

The imaging signal of the camera 20 is input to the control device 40 shown in FIG. The control device 40 is positioned as a kind of computer, and outputs a control signal to the camera 20 and the backlight panel 30. The control apparatus 40 is provided with the image analysis apparatus 22, and the image analysis apparatus 22 analyzes a picked-up image.

The image picked up by the camera 20 is as shown in FIG. 6. An image consists of a set of multiple pixels. FIG. 6 illustrates a situation in which a powder deposit layer of conical or ridge forms on the angle of repose table or the spatula angle measuring blade.

From the image of FIG. 6, the inclination angle of the powder deposition layer can be calculated | required using the calculation formula as disclosed by Unexamined-Japanese-Patent No.4155942.

Since the backlight panel 30 emits light in a predetermined wavelength region and the camera 20 is combined with an optical filter 21 having a high transmittance with respect to the emission wavelength region of the backlight panel 30, the backlight panel 30 is used. Light other than the emitted light basically does not become incident light to the camera 20. For this reason, the silhouette image of a powder deposition layer is formed only by the light from the backlight panel 30, and the silhouette image of an accurate shape is obtained. Analysis of the silhouette image by the image analysis device 22 is also accurate, and the angle measurement accuracy is improved.

In the angle measuring device 1 of the powder deposition layer, an impact imparting device 50 (see FIG. 8) used for measuring the collapse angle is provided. Here, the collapse angle is the inclination angle of the powder deposited layer after the powder deposited layer which forms the angle of repose changes its shape according to the impact.

The impact device 50 has a bracket 51 arranged horizontally inside the housing 4, and a guide pole 52 standing vertically from the bracket 51. The bracket 51 is connected to an angle measuring table or a spatula angle measuring blade to be described later. The impact weight 53 is supported by the guide pole 52 to be movable up and down. By lifting up the impact weight 53 and dropping it on the bracket 51, vibration occurs in the bracket 51, and the vibration is transmitted to the repose angle measuring table or the spatula angle measuring blade.

In the angle measuring device 1 of the powder deposition layer, a vibrating device for filtering the sample powder to the vibrating body is provided. The main body portion of the vibrator is present in the housing 4, and only the body attachment frame 60 supported by the main body portion protrudes from the measurement chamber 10 as shown in FIG. 8. Vibration in the vertical direction is applied to the sieve attachment frame 60 by the electromagnet 61 shown in FIG. 7.

As shown in FIG. 7, the control device 40 includes a display device 70 in addition to the components already shown, such as the camera 20, the image analysis device 22, the backlight panel 30, and the electromagnet 61. Connected. The display device 70 is configured by an external monitor device or the like to display measurement data, calculation results, and the like.

Then, based on FIG. 8 and FIG. 9, how the angle measuring device 1 of a powder deposition layer is used is demonstrated.

Shown in FIG. 8 is the setting for the angle of repose measurement. A sieve 80 is attached to the upper surface of the sieve attachment frame 60. The sieve pressing part 81 is superimposed on the sieve 80, and the funnel 82 for repose angle measurement is attached to the lower surface of the sieve attachment frame 60, and these are attached to the sieve attachment frame 60 by the fastening tool 93. FIG. It is fixed. The bracket 51 of the impact imparting device 50 is connected to the bracket 84 which holds the repose angle measuring table 83 which is a powder deposition layer support apparatus. Under the repose angle measurement table 83, the container 85 which receives the sample which overflowed there is arrange | positioned. The container 85 is supported by the vertical support shaft 86 which protrudes from the inside of the housing 4 to the measurement chamber 10. The support shaft 86 can be lifted by the support shaft lift motor 87 shown in FIG. The support shaft lifting motor 87 is driven by the motor driver 88.

When the sample powder is put into the sieve 80 and the sieve attachment frame 60 is vibrated, the sample powder passing through the sieve 80 falls from the funnel 82 for repose angle measurement, and is placed on the repose angle measurement table 83. It is deposited in a conical shape. The silhouette image of the powder deposition layer is imaged with the camera 20, and the angle of repose is obtained by image analysis. After the angle of repose measurement, the powder deposited layer is collapsed by the impact by the impact imparting device 50, and the collapse angle is measured. The difference angle is then calculated. Here, the difference angle is an angle obtained by subtracting the collapse angle from the angle of repose, and it is possible to infer the fractionation property (flushing property) of the powder from the size.

9 is a setting for the spatula angle measurement. In the setting for repose angle measurement in FIG. 8, the funnel 82 for repose angle is replaced with a spatula angle measuring chute 89, and the combination of the repose angle measuring table 83 and the bracket 84 holding the table is This is also substituted by the combination of the spatula angle measuring blade 90 which is a powder deposition layer support apparatus, and the bracket 91 holding this blade. At this time, the peripheral frame 92 surrounding the spatula angle measuring blade 90 is installed on the container 85.

The sample powder is put into the sieve 80, raising the container 85 to the height which adjoins to the bracket 91 substantially. When the sieve attachment frame 60 is vibrated, the sample powder having passed through the sieve 80 falls from the spatula angle measuring chute 89 and accumulates on the spatula angle measuring blade 90. When the spatula angle measuring blade 90 is completely buried in the sample powder, the container 85 and the peripheral frame 92 are lowered, and a continuous acid-shaped powder deposit layer remains on the spatula angle measuring blade 90. The silhouette image of the powder deposition layer is imaged by the camera 20, and the inclination angle is obtained by image analysis. Thereafter, the powder deposition layer is collapsed by the impact caused by the impact device 50, and the inclination angle after the collapse is measured. Then, the average value of the inclination angles before and after collapse is calculated. This value is the spatula angle.

As mentioned above, although embodiment of this invention was described, the scope of the present invention is not limited to this, A various change can be added and implemented in the range which does not deviate from the main point of invention.

Example

The angle measurement was performed using the measuring apparatus (powder characteristic measuring apparatus "powder tester": Hosokawa Micron Co., Ltd. product) for evaluating the physical property characteristic of powder. External light was mainly light of fluorescent lamps, and the measurement was performed in an environment of illuminance of 610 lux and 6300 lux. As the LED 34, a blue LED having a peak wavelength in the range of 460 nm to 480 nm was used. As the optical filter 21, a bandpass filter having a center wavelength of 460.0 ± 2 nm, half width 6.0 ± 2 nm, and a maximum transmittance of 30.0% or more was used. In the comparative example, it measured on the conditions similar to an Example except having not attached the optical filter to the camera. In addition, the higher the illuminance of the measurement environment, the higher the intensity of external light, which adversely affects the measurement.

Table 1 shows the experimental results of the angle measurement. In Comparative Example 1, angle calculation was possible at 610 lux. Under 750 lux of Comparative Example 2, spots and slits appeared on the silhouette by the binarization process, and ridges and vertices on the silhouette could not be detected, and the angle calculation could not be performed. In Examples 1-4, the measurement was performed under 750 lux, 2200 lux, 4200 lux, and 6300 lux, respectively, and the predetermined angle measurement was able to be performed. Thus, the angle calculation was possible even in an environment of 6300 lux which greatly exceeded 3000 lux called roughness under the normal measurement environment.

The present invention is widely applicable to the angle measuring device of the powder deposition layer.

1: Angle measuring device of powder deposition layer 2: Main body
3: cover 10: measuring room
20: camera 21: optical filter
22: image analysis device 30: backlight panel
33: light transmitting panel 33a: light guide plate
33b: diffuser 34: LED
40: control device 50: impact device
60: vibration plate 80: sieve
83: angle of repose measurement table 90: spatula angle measuring blade
93: fastening tool

Claims (6)

camera;
A backlight panel disposed at a position facing the camera;
A powder deposition layer support device disposed between the camera and the backlight panel; And
An image analysis device for analyzing the silhouette image of the powder deposition layer photographed by the camera to obtain an angle of the powder deposition layer,
The backlight panel is a light source having a peak of an emission spectrum between 450 nm and 550 nm,
And an optical filter having a high transmittance with respect to the peak of the emission spectrum of the backlight panel. The apparatus of claim 1, wherein the backlight panel is a light source having a peak of an emission spectrum between 460 nm and 480 nm. The powder deposition layer according to claim 1, wherein the backlight panel comprises a combination of a light transmitting panel having a light guiding function and a light diffusing function, and an LED for irradiating light to an end surface of the light transmitting panel. Angle measuring device. The angle measuring device of the powder deposition layer according to claim 3, wherein the light transmitting panel is configured by combining a light guide plate and a diffusion plate. The angle measuring device of the powder deposition layer according to claim 1, wherein the optical filter is a bandpass filter having a maximum transmittance of 30% or more with respect to a peak wavelength of the backlight panel. The apparatus of claim 1, wherein an openable cover covering the camera and the powder deposition layer support apparatus is installed, and the backlight panel is attached to the cover.

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