Image analysis – Applications
Reexamination Certificate
2000-09-27
2002-09-10
Mehta, Bhavesh (Department: 2621)
Image analysis
Applications
C382S181000, C076S110000, C409S093000, C409S096000
Reexamination Certificate
active
06449381
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of computer data entry devices and more particularly to automatic key identification devices.
2. Description of the Prior Art
It is common knowledge that key manufacturers code and identify their keys by series of grooves and indentations on lateral surfaces of the key. This system of key coding allows for a great number of different key combinations, thus increasing security and reducing chances for identical key combinations. Currently over 10,000 key styles are in use. At this time, locksmiths rely on the manual method of key blank identification in order to duplicate the key. This process relies on knowledge, skill and experience of the individual locksmith in order for it to be precise and cost effective. However, the greatest number of errors in key duplication occurs with the incorrect selection of the key blank since the differences in the aforementioned grooves and indentations are often too minute for correct manual identification. A mistake in selection usually results in repeated duplication using yet another key blank, additional costs acquired due to the locksmith's time, and possible loss of business. At this time there are systems of automatic key identification which identify keys through analysis of the front tip of the key. One example of such a system is U.S. Pat. No. 4,899,391 of William J. Cimino and Robert E. Powers. Also known is the key holding system as part of the automatic key identification system disclosed in U.S. Pat. No. 5,127,532 of William J. Cimino and Robert E. Powers. Also known to the inventors is the shadow image acquisition device which is part of an automatic key identification system of pending application Ser. No. 08/758,481 filed Aug. 18, 1997, now U.S. Pat. No. 6,175,638, by one of the inventors herein, Vladislav Yanovsky. In this system the key to be duplicated is inserted into the shadow image acquisition device which provides rear to front illumination by projecting light rays along the grooves and indentations located on the sides of the key. The scanner converts the shadow image into a digital signal. The digital signal is passed to the computer where the image is stored and compared to saved images of key blanks. When a match is made between the key image and the stored blank, the user is notified of the proper key blank to be used for duplication. This system is more precise than the system described in U.S. Pat. No. 5,127,532. However, both of these systems have several inherent disadvantages which are similar in nature:
1. The actual height of the shank of the inserted key differs greatly from the heights of the shanks of the stored images. The variance in size can be 35% of a single side to 50% of double-sided keys. This is clearly shown in
FIGS. 1A
,
1
B,
2
A and
2
B.
FIG. 1A
shows a side view of an uncut key blank.
FIG. 1B
shows the front cross-section of said key blank.
FIG. 2A
represents the same key which was notched (cut) along top
7
.
FIG. 2B
shows the front cross-section of the key displayed in FIG.
2
A. When comparing
FIG. 1B
to
FIG. 2B
a difference in size can be clearly seen. This is of particular interest when compared to stored cross-sectional images of different key blanks shown in
FIGS. 3A and 3B
. These images may be selected by the automated system as correct blanks;
2. The key blanks are further differentiated by measuring grooves and indentations
5
along shank
4
(FIGS.
1
B and
2
B). As plainly seen in
FIGS. 1B and 2B
grooves and indentations
5
are rather small and complex geometric shapes which are difficult to visualize and compare due to a small surface area. Analysis of grooves and indentations
10
of
FIGS. 1A and 2A
based on the lateral scan of the key blank presents a larger surface area for examination and comparison;
3. Due to wear and tear on the key, the geometric shape of its front cross-section changes, causing errors in identification;
4. Correct projection of the front cross-section of a key depends greatly on the holding device which will hold the key in a desired position relative to the light source. Any deviation from the desired position will cause optical distortion and errors in identification;
5. Evaluation of the front cross-section of a key does not allow for measurement of the key's length;
6. Evaluation of the front cross-section of a key does not allow for detection of notches of top
7
which is necessary for actual duplication of the key; and
7. Evaluation of the front cross-section does not allow for the evaluation of the head of the key which often times serves as a differentiating factor during identification.
SUMMARY OF THE INVENTION
It is the object of this invention to improve the accuracy of automatic key identification by providing images of grooves and indentations (
5
of
FIGS. 1A and 2A
) as well as direct images of flat portions (
11
and
9
of
FIGS. 1A and 2A
) of the shank of the key. These objectives can be accomplished when the light source and the lens of the camera are positioned perpendicularly to the shank of the key (
1
of
FIG. 6
) and when the light rays strike the flat surfaces of the shank and are reflected directly into the camera, forming a direct image of the flat surfaces of shank
4
of key
1
. However, when the light rays strike the surfaces of the grooves and indentations
5
on shank
4
of key
1
(FIG.
6
), they are reflected in all directions other than directly back into the lens of the camera (FIG.
6
), thereby yielding an image of the grooves and indentations on said shank of key
1
surrounded by the direct image of the flat surfaces
11
of key
1
of
FIGS. 1A and 2A
.
When comparing the scanable surfaces of grooves and indentations
5
of
FIGS. 1A and 1B
, it is clearly seen that
FIG. 1A
has a larger surface area as well as a better defined geometrical shape than FIG.
1
B. Therefore:
1. The larger surface area of the image of
FIG. 1A
allows a higher resolution and thereby better identification of the image of
FIG. 1B
;
2. A lower resolution scanner or camera can be utilized for simplicity of design as well as for cost effectiveness; and
3. The image of the grooves and indentations
10
of head
3
of key
1
can be seen in
FIG. 1A
but cannot be seen in FIG.
1
B. The image of grooves and indentations
10
on head
3
of key
1
precisely reflects the geometrical shape of grooves and indentations
5
on shank
4
of key
1
and therefore are themselves an evaluating factor for identification. When examining the side elevational view of the shank
4
of the key
1
of
FIG. 1A
, other identifying structures which are not available when viewing the front cross-section of
FIG. 1B
may be evaluated. For instance, the length of the shank of the key may be evaluated as well as individualized notches
6
on FIG.
2
A. These evaluations will allow for a more precise key blank identification since the length of the shank of the key is also used as an evaluating factor by locksmiths. Furthermore, scanning of the individualized notches
6
in
FIG. 2A
will allow for a full range of evaluation parameters to be scanned in for further identification and storage.
Thus it is the object of this invention to provide at least the following features:
1. The apparatus and method according to this invention forms images of the grooves and indentations
5
on shank
4
of key
1
of
FIG. 2A
such that the image of the grooves and indentations
5
and
10
of a notched key and unnotched key is identical and unchanged in their geometrical structure even when key
1
is uniquely notched, as seen in notches
6
of FIG.
2
A. This process dramatically increases the probability of a precise match.
2. Since indentations
5
on the shank
4
of key
1
do not actively participate in the operation of the lock and are spared the wear and tear which distort the grooves and indentations at tip
2
of shank
4
on key
1
, the images of the lateral surfaces according to this invention dramatically increases the probabilit
Sirota Anatoliy
Yanovsky Vladislav
Mehta Bhavesh
Nitkin William
LandOfFree
Key imaging system and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Key imaging system and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Key imaging system and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2864071