Optics: measuring and testing – Inspection of flaws or impurities
Reexamination Certificate
2000-08-22
2002-07-02
Pham, Hoa Q. (Department: 2877)
Optics: measuring and testing
Inspection of flaws or impurities
C356S237600, C356S614000
Reexamination Certificate
active
06414751
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a displacement measurement apparatus which detects displacement distribution in the direction of a height of a convex portion or a concave portion formed on the surface of a card.
There is available a detection apparatus of an optical system for displacement on the surface having the structure shown in
FIG. 23
, as an apparatus for detecting displacement distribution in the direction of a height formed on the surface of an object to be inspected.
In the drawing, the numeral
1
represents a linear light source which emits linear light.
As shown in
FIG. 24
, the linear light source
1
is composed of light source
3
and cylindrical cover
7
which contains the light source
3
and has on its end surface slit
5
representing a linear light generating means.
In
FIG. 23
again, a linear light emitted from the linear light source
1
is projected on object to be inspected
11
through rotary mirror
9
serving as a scanning means.
Reflected light from the object to be inspected
11
enters PSD (semiconductor position detection element) array
13
divided into plural pieces in the linear direction of the linear light, and thereby, displacement distribution on the surface of the object to be inspected
11
is detected.
In recent years, there has spread a card
21
having an arrangement shown in FIG.
25
.
The numeral
23
represents a magnetic stripe on which magnetic information is recorded, and
25
represents a character row formed by a convex portion or a concave portion (12345678910, Konica Tarou, in FIG.
25
).
When reading a convex portion or a concave portion (displacement in the direction of a height on the surface) on card
21
by the use of the detection apparatus of an optical system for displacement on the surface, if the card
21
has been subjected to printing and reflectance for light on the surface of the card
21
has been lowered accordingly, the convex portion or the concave portion can not be read accurately, which is a problem.
SUMMARY OF THE INVENTION
The invention has been achieved in view of the problem mentioned above, and its object is to provide a displacement measurement apparatus wherein a convex portion or a concave portion on a card can be read accurately even in the case of a card having poor reflectance.
The above object can be attained by the following structures.
Structure (1-1) A surface displacement detecting apparatus for detecting a concave, a convex or a hole on a surface of a detection object, comprises:
a light shielding device provided in a direction crossing the surface of the detection object,
a light irradiating device provided at one side of the light shielding device and to irradiate the detection object with light;
a light receiving device provided at the other side of the light shielding device and to receive at least one of regular reflection light and diffuse reflection light from the surface of the detection object; and
a conveyor to convey at least one of the detection object and the light irradiating device.
Structure (1-2) In the surface displacement detecting apparatus of (1-1), the light irradiating device comprises a light source and an optical element to irradiate the detection object with the light emitted from the light source and the light receiving device comprises a condenser lens to condense at least one of the regular reflection light and the diffuse reflection light from the surface of the detection object and a light receiving element to receive the condensed light.
Structure (1-3) In the surface displacement detecting apparatus of (1-2), the light irradiating device shapes the light in a line and irradiates the detection object with the line-shaped light.
Structure (1-4) In the surface displacement detecting apparatus of (1-2), the optical element is a cylindrical lens.
Structure (1-5) In the surface displacement detecting apparatus of (1-2), the light irradiating device forms a plurality of spot light aligned in a straight line as the light and irradiates the detection object with the plurality of spot light.
Structure (1-6) In the surface displacement detecting apparatus of (1-5), wherein the optical element is a micro lens array.
Structure (1-7) In the surface displacement detecting apparatus of (1-1), wherein the detection object comprises a flat surface and a concave and the light irradiating device, the light shielding device and the light receiving device are arranged such that light reflected from the flat surface is shielded by the light shielding device and light reflected from the concave proceeds to the light receiving element.
Structure (1-8) In the surface displacement detecting apparatus of (1-1), the detection object comprises a flat surface and a concave and the light irradiating device, the light shielding device and the light receiving device are arranged such that light diffused from the flat surface is shielded by the light shielding device and light diffused from the concave proceeds to the light receiving element.
Structure (1-9) In the surface displacement detecting apparatus of (1-1), the width of the light on the detection object is smaller than the width of the concave, the convex or the hole.
Structure (1-10) In the surface displacement detecting apparatus of (1-2), the surface displacement detecting apparatus detects the concave, the convex or the hole from a light receiving position on the light receiving element.
Structure (1-11) In the surface displacement detecting apparatus of (1-2), the light receiving device comprises a plurality of light receiving elements aligned in a straight line as the light receiving element or the light receiving element is split into a plurality of light receiving elements aligned in a straight line.
Structure (1-12) In the surface displacement detecting apparatus of (1-2), the light receiving elements are a PSD array in which n pieces of PSD are arranged in a predetermined direction or PD which is split into n pieces in a predetermined direction and into m pieces in a direction perpendicular to the predetermined direction, where n is an integer not less than 2 and m is an integer not less than 1.
Structure (1-13) In the surface displacement detecting apparatus of (1-3), the light receiving elements are a PSD array in which n pieces of PSD are arranged in a direction along the line-shaped light or PD which is split into n pieces in a direction along the line-shaped light and m pieces in a direction perpendicular to along the line-shaped light, where n is an integer not less than 2 and into m is an integer not less than 1.
Structure (1-14) In the surface displacement detecting apparatus of (1-5), the light receiving elements are a PSD array in which n pieces of PSD are arranged in a direction along the plurality of aligned spot light or PD which is split into n pieces in a direction along the plurality of aligned spot light and into m pieces in a direction perpendicular to along the plurality of aligned spot light, where n is an integer not less than 2 and m is an integer not less than 1.
Structure (1-15) In the surface displacement detecting apparatus of (1-1), the light shielding device is shiftable in a direction crossing the surface of the detection object and the light shielding device is brought in contact with the detection object.
Structure (1-16) In the surface displacement detecting apparatus of (1-1), the light shielding device has an edge surface facing the detection object and is arranged to form a space between the edge surface and the detection object.
Structure (1-17) In the surface displacement detecting apparatus of (1-10), the light receiving position on the light receiving element displaces in a direction parallel to the light receiving element.
Structure (1-18) In the surface displacement detecting apparatus of (1-1), the detection object is a card having the concave, the convex or the hole.
Structure (1-19) In the surface displacement detecting apparatus of (1-1), a range of the displacement of the concave, the convex or the hole on the detection object is not larger
Arai Norikazu
Banno Makoto
Kurogama Tatsuji
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Konica Corporation
Pham Hoa Q.
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