JPH0633407Y2 - Dust visual inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a device for visually observing dust floating in the air or in a liquid, and more particularly to a method of doubling the amount of light in such a dust visual device. is there.

(B) Conventional technology The control of dust floating in the air or liquid is extremely important industrially, and as a device for controlling such floating, a dust measuring instrument that conventionally measures the number of dusts using light scattering, or sedimentation There was a dust meter that calculates the dust concentration by measuring the weight of dust.

In addition, there is a dust visualizing device that the present inventors previously proposed as a device for directly observing the dust by visual inspection and checking the contamination state (actual application No. 58-171535). Then, it is observed as a bright spot in the dark field of the magnifying glass.

Further, a device for detecting the dust concentration by comparing the dust observed with such a dust visual device with a bright dot-like reference piece has also been proposed by the present inventors (Japanese Patent Application No. 60-185674).
No.), Japanese Patent Application No. 62-088386).

(C) Problems to be solved by the device Among the conventional devices described above, the dust meter by the scattered light method and the weight method is not suitable for portable use because it is expensive, heavy, and cumbersome to handle. .

In addition, in the dust visualizing apparatus proposed by the present inventors, the light beam for irradiating the dust must be fairly strong in order to see the minute floating dust, and therefore, when it is portable, the battery of the lamp is used. It was necessary to increase the capacity.

Further, in the conventional powder visual inspection apparatus, the inside of the housing is closed to form a dark field and the light beam is formed in the closed space. When the light beam is strong, the light absorbing member at the tip of the beam sufficiently absorbs the light. However, there is a drawback in that the light is scattered and the darkness of the visual field is deteriorated to prevent the visual recognition of dust.

SUMMARY OF THE INVENTION The present invention eliminates the above drawbacks of the conventional device and provides a portable floating dust detection device that strengthens the light beam without increasing the battery capacity and does not reduce the darkness of the visual field.

(D) Means for Solving the Problems The present invention will be described with reference to the drawing. In FIG. 1, a magnifying glass is used to remove dust floating at the focus of the light beam 5 collected by the first condenser lens 3 in FIG. In the dust visual observation apparatus for observing by 7 the second condensing lens 6 is provided facing the light beam 5, and the mirror 12 is provided in the vicinity of the rear of the second condensing lens 6 to condense the light beam 5. The distance l from the point to the second condenser lens 6 is equal to the focal length f of the second condenser lens.

(E) Function In this device, the light beam 5 condensed by the first condensing lens 3 is diffused after passing the condensing point 18 and is incident on the opposing second condensing lens 6 and comes close to the back. Although it is reflected by the mirror 12 provided in the above and passes through the second condensing lens 6 again, the distance l between the condensing point 18 and the second condensing lens 6
Is equal to the focal length f of the condensing lens 6, the reflected light reflected by the mirror 12 is condensed again at the condensing point 18, and further travels to the first condensing lens 3 through the same path as the irradiation light.

Thus, in the visual field of the magnifying glass 7, the stray dust that is doubly irradiated by the projected light and the reflected light is observed as a bright spot of high brightness without generating stray light due to scattered light.

(F) Embodiment FIG. 1 is a view showing a cross section of a dust visual inspection apparatus according to an embodiment of the present invention.

In the figure, a lamp 2 is provided inside a housing 1 formed by inserting and engaging a cylindrical front housing 16 and a rear housing 17 rotatably with each other.
Slit plate 13 having first condenser lens 3 and slit 4
Are arranged in common in this order, and a second condenser lens 6 is provided so as to face the light beam 5 formed by condensing the light of the lamp 2 by the condenser lens 3. A mirror 12 is provided in the vicinity of the condenser lens 6 close to the condenser lens 6.

Distance l between the condensing point 18 of the light beam 5 and the second condensing lens 6
Is equal to the focal length f of the condensing lens 6, and a magnifying glass 7 is provided on the upper side surface of the front housing 16 at a position where the condensing point 18 of the light beam 5 is included in the visual field.

The sample inlets 14 and 14 provided on both sides of the front casing 16 so as to face each other are orthogonal to the sample inlets 15 and 15 provided at the rear casing 17 so as to rotate the front and rear casings. It is designed to open and close by doing.

Now, in the dust visualizing apparatus of the present embodiment having such a structure, the front casing 16 is rotated so that the sample inlets 14 and 14 are aligned with the sample inlets 15 and 15 to take in dust-containing air into the casing 1. After that, the sample inlet is further rotated to turn on the lamp 2 by a switch (not shown), and the light of the lamp 2 is condensed by the first condenser lens 3 and passes through the slit 4 to form a light beam 5. .

Although the light beam 5 passes through the condensing point 18 and then enters the opposing second condensing lens 6, it passes through the condensing lens 6 because the condensing point 18 is located at the focal point of the condensing lens 6. The reflected light becomes parallel light, is reflected by the rear mirror 12, passes through the condenser lens 6 again, and is then condensed at the condensing point 6. Therefore, the floating dust at the condensing point is doubly irradiated with the projected light and the reflected light, and the light beam 5 only reciprocates between the first condensing lens 3 and the second condensing lens 6. Therefore, the field of view of the magnifying glass 7 was much higher than that of the conventional device because it was not diffusely reflected on the wall surface, and the dust was observed as a bright spot with extremely high brightness.

(G) Effect of the device As described above, the dust visual inspection device of the present invention has a simple structure, is light and inexpensive, and is easy to handle compared to the conventional dust meter by the light scattering method or the weight method. Suitable for dust detection equipment.

Further, in the dust visualizing apparatus of the present invention, the light beam is formed by superimposing the reflected light on the projected light, so that a sufficiently bright light beam can be obtained without increasing the battery capacity, and the light beam is the first condenser lens. There is no scattering on the wall surface or the like only by reciprocating between the third condenser lens and the second condenser lens, so that the darkness of the field of view of the magnifying glass 7 does not deteriorate.

Thus, the present invention provides a portable dust detection device for observing suspended dust as a bright spot that shines in a higher dark field than a conventional device of this type without increasing the battery capacity.

[Brief description of drawings]

1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. 1 ... Housing, 2 ... Lamp (lens bulb) 3 ... First condensing lens 4 ... Slit 5 ... Light beam 6 ... Second condensing lens 7 ... Magnifying glass, 8 ... Mirror lens 9 …… Observation port, 10 …… Eyepiece lens 11 …… Objective lens, 12 …… Mirror 13 …… Slit plate, 14 …… Sample inlet 15 …… Sample inlet, 16 …… Front housing 17 ...... Rear housing, 18 ...... Focus point

Claims (1)

[Scope of utility model registration request] 1. A dust visualizing apparatus for observing, by a magnifying glass, dust that floats at a condensing point of a light beam 5 condensed by a first condenser lens 3, facing a focal length of the light beam 5. The second condensing lens 6 of f is provided, the mirror 12 is provided in the vicinity of the rear of the second condensing lens 6, and the light beam 5
The dust visual inspection device is characterized in that l = f, where l is the distance from the condensing point to the second condensing lens 6.