CA1081009A - Optical scanning system using a polygonal rotating mirror - Google Patents
Optical scanning system using a polygonal rotating mirrorInfo
- Publication number
- CA1081009A CA1081009A CA262,799A CA262799A CA1081009A CA 1081009 A CA1081009 A CA 1081009A CA 262799 A CA262799 A CA 262799A CA 1081009 A CA1081009 A CA 1081009A
- Authority
- CA
- Canada
- Prior art keywords
- rotating mirror
- code
- scanning
- polygonal rotating
- scanning lines
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/08—Mirrors
- G02B5/09—Multifaceted or polygonal mirrors, e.g. polygonal scanning mirrors; Fresnel mirrors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Mechanical Optical Scanning Systems (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An optical scanning system for scanning a code pattern comprising several parallel lines provided on an article is disclosed. The system in-cludes a light source, such as a laser, which directs a beam of light at a polygonal rotating mirror which has several reflecting surfaces. Several stationary mirrors are located in the path of beam reflection from the rotat-ing mirror to derive several light-beam scanning lines which intersect each other on the surface of conveyor belt carrying articles bearing the code to be scanned. All of the code bars of each article is completely scanned by at least one of the scanning lines. The lengths of the scanning lines may be increased by tilting the reflecting surfaces of the rotating mirror with respect to each other. The invention ensures that the code on each article will be scanned completely in one stroke irrespective of the orientation of the code with respect to the conveyor.
An optical scanning system for scanning a code pattern comprising several parallel lines provided on an article is disclosed. The system in-cludes a light source, such as a laser, which directs a beam of light at a polygonal rotating mirror which has several reflecting surfaces. Several stationary mirrors are located in the path of beam reflection from the rotat-ing mirror to derive several light-beam scanning lines which intersect each other on the surface of conveyor belt carrying articles bearing the code to be scanned. All of the code bars of each article is completely scanned by at least one of the scanning lines. The lengths of the scanning lines may be increased by tilting the reflecting surfaces of the rotating mirror with respect to each other. The invention ensures that the code on each article will be scanned completely in one stroke irrespective of the orientation of the code with respect to the conveyor.
Description
The present invention relates to an optical scanning system of the type serving the optical scanning purpose by deflecting a beam of light rays by means of a polygonal rotating mirror.
In scanning codes (e.g. bar codes) by a beam of light rays particu-larly in cases where the code on the surface being scanned is inclined at an angle of a certain magnitude or over, it is impossible for a single scanning line to traverse all of the bars forming the code in one sca~ling stroke.
To say more specifically, in scanning bar code having a bar-height H, and a code-width W, if tne scanning line is inclined at a certain ange d = tan 1 H
or more with respect to the bar code, it is impossible to scan all of the code bars.
It is, therefore, an object of the present invention to provide an optical scanning system capable of scanning all of code bars forming a bar code in one scanning stroke.
According to the present invention, there is provided an optical scanning system for scanning a code pattern formed of a plurality of substan-tially parallel lines of a predetermined length printed on an article by a beam of light rays, said system comprising: means for producing said light beam; a polygonal rotating mirror having an even number of reflecting sur-faces, said reflec~ing surfaces being alternately inclined at predeterminedangles with respect to an axis of said polygonal rotating mirror, said light beam being directed from said light beam producing means to at least one of said reflecting surfaces of said polygonal rotating mirror so as to be deflected as said mirror is rotated; and a plurality of stationary mirrors for reflecting in turn said deflected light beam to form a plurality of light-beam scanning lines intersecting each other on the surface of said article so that said code pattern may be scanned by at least one of said scanning lines.
The features and advantages of the present invention will be better understood from the following detailed description of preferred embodi-ments of the present invention taken in conjunction with the accompanying -~
drawings, wherein:
..
Figure 1 is a schematic perspective view of a first embodiment of the present invention;
-la- :
,~.
:~ 0~1 0~ ' Figure 2 is a diagrammatic plan of the firs~ embodiment, illustrat-ing the principles thereof;
~ Figure 3 lllustrates the arrangement of scanning lines obtainable with the first embodiment;
Figure 4 is bar code to be scanned by the light ray;
Figur& S is a block diagram of the decoder in the first e~bodiment;
lOB1009 F$g~ 6 illustrates the relationship be~ween the bar code and .
scanning lines obtainable with a polygonal rotating mirror reduced in number of reflecting surfaces to obtain an increased angle of deflection and scanning lines of extended length;
Figure 7 is a schematlc perspective view of the second embodi-ment of the present invention;
Flgures 8 and 9 respectively represent a front elevation and a plan, illustrating the principles of the second embodiment; and Figure 10 illustrates the arrangement of scanning lines obtainable with the second embodiment.
Referring to Figure 1, a first embodiment of the present invention comprises a light source llj such as a laser device, a polygonal rotating mirror 12, three reflecting mirrors 13, 14 and 15, a llght sensitive element 16. and a eonveyor belt 17 for transferring articles 18 on each of which a bar code 19 to be scanned is marked.
The polygonal deflecting mirror 12 is shaped as a regular octagonal prism of limited axial length and having eight reflecting surfaces and - driven to rotate about its axis by appropriate drive means (not shown).
The light source il emits a beam of light rays ?O wh~ch impinges upon the successive reflecting surfaces of the polygonal rotating mirror 12 and is reflected therefrom while being deflected as the mirror rotates.
In this instance, the angle through which the beam 20 is deflected is 90, assuming that the spot diameter of the light beam is negligible.
The light beam deflected in this manner is gain reflected by the reflect-ing mirrors 13, 14, and 15 and, impinging upon the conveyor belt 17, - which is moving in the direction of the arrow 21, forms three scanning lines 22, 23, and 24 on the surface of the conveyor, to scan the bar -.. . . .
code l9 marked on successive articles 18 being carried thereon. I
, One example of arrangement of reflecting mirrors 13, 14 and 15 is diagrammatically illustrated in the plan of Fig. 2. As illustrated, the .
- 3 - ;
, - , - . : - . , : .. . :
angle of deflection through which the light ra~ 20 is deflected at point ~1 is divided into three equal portions, each assigned to one of the three reflecting mirrors 13, 14 and 15. In other words, the three reflecting mirrors are arranged in a manner so that, in Figure
In scanning codes (e.g. bar codes) by a beam of light rays particu-larly in cases where the code on the surface being scanned is inclined at an angle of a certain magnitude or over, it is impossible for a single scanning line to traverse all of the bars forming the code in one sca~ling stroke.
To say more specifically, in scanning bar code having a bar-height H, and a code-width W, if tne scanning line is inclined at a certain ange d = tan 1 H
or more with respect to the bar code, it is impossible to scan all of the code bars.
It is, therefore, an object of the present invention to provide an optical scanning system capable of scanning all of code bars forming a bar code in one scanning stroke.
According to the present invention, there is provided an optical scanning system for scanning a code pattern formed of a plurality of substan-tially parallel lines of a predetermined length printed on an article by a beam of light rays, said system comprising: means for producing said light beam; a polygonal rotating mirror having an even number of reflecting sur-faces, said reflec~ing surfaces being alternately inclined at predeterminedangles with respect to an axis of said polygonal rotating mirror, said light beam being directed from said light beam producing means to at least one of said reflecting surfaces of said polygonal rotating mirror so as to be deflected as said mirror is rotated; and a plurality of stationary mirrors for reflecting in turn said deflected light beam to form a plurality of light-beam scanning lines intersecting each other on the surface of said article so that said code pattern may be scanned by at least one of said scanning lines.
The features and advantages of the present invention will be better understood from the following detailed description of preferred embodi-ments of the present invention taken in conjunction with the accompanying -~
drawings, wherein:
..
Figure 1 is a schematic perspective view of a first embodiment of the present invention;
-la- :
,~.
:~ 0~1 0~ ' Figure 2 is a diagrammatic plan of the firs~ embodiment, illustrat-ing the principles thereof;
~ Figure 3 lllustrates the arrangement of scanning lines obtainable with the first embodiment;
Figure 4 is bar code to be scanned by the light ray;
Figur& S is a block diagram of the decoder in the first e~bodiment;
lOB1009 F$g~ 6 illustrates the relationship be~ween the bar code and .
scanning lines obtainable with a polygonal rotating mirror reduced in number of reflecting surfaces to obtain an increased angle of deflection and scanning lines of extended length;
Figure 7 is a schematlc perspective view of the second embodi-ment of the present invention;
Flgures 8 and 9 respectively represent a front elevation and a plan, illustrating the principles of the second embodiment; and Figure 10 illustrates the arrangement of scanning lines obtainable with the second embodiment.
Referring to Figure 1, a first embodiment of the present invention comprises a light source llj such as a laser device, a polygonal rotating mirror 12, three reflecting mirrors 13, 14 and 15, a llght sensitive element 16. and a eonveyor belt 17 for transferring articles 18 on each of which a bar code 19 to be scanned is marked.
The polygonal deflecting mirror 12 is shaped as a regular octagonal prism of limited axial length and having eight reflecting surfaces and - driven to rotate about its axis by appropriate drive means (not shown).
The light source il emits a beam of light rays ?O wh~ch impinges upon the successive reflecting surfaces of the polygonal rotating mirror 12 and is reflected therefrom while being deflected as the mirror rotates.
In this instance, the angle through which the beam 20 is deflected is 90, assuming that the spot diameter of the light beam is negligible.
The light beam deflected in this manner is gain reflected by the reflect-ing mirrors 13, 14, and 15 and, impinging upon the conveyor belt 17, - which is moving in the direction of the arrow 21, forms three scanning lines 22, 23, and 24 on the surface of the conveyor, to scan the bar -.. . . .
code l9 marked on successive articles 18 being carried thereon. I
, One example of arrangement of reflecting mirrors 13, 14 and 15 is diagrammatically illustrated in the plan of Fig. 2. As illustrated, the .
- 3 - ;
, - , - . : - . , : .. . :
angle of deflection through which the light ra~ 20 is deflected at point ~1 is divided into three equal portions, each assigned to one of the three reflecting mirrors 13, 14 and 15. In other words, the three reflecting mirrors are arranged in a manner so that, in Figure
2, lines OlAl, OlBl and OlCl form perpendicular bisectors of the respective reflecting mirrors 13, 14 and 15, satisfying the condition that ~ AlOlB~ BlOlCl = 30. Further, two of the reflecting mirrors, 13 and 15 are arranged so that their extensions intersect at point Bl.
The reflecting mirrors 13, 14, 15 are each directed so that the light beam reflected therefrom proceeds in a direction normal to the plane of Figure 2 and, impinging upon the scan surface, which is parallel to the plane of Figure 2 and spaced from the reflecting mir~ors by at least a certain distance, forms on the scan surface three scanning lines 22, 23 and 24, one for each of the reflecting mirrors~ as shown in Figure 3. These scanning lines meet at a point B'l on the scan surface. Points Al, Bl and Cl in Figure 3 represent respective points ~-at which the light beam reflected by the reflecting mirrors 13, 14 and 15 at respective points Al, Bl and Cl reaches the scan surface. As indicated, the scanning lines 22 and 24 intersect the remaining scan-ning line 23 at an angle of 30.
Referring again to Figure 1, the light rays of the scanning ;
lines 22, 23 and 24 are picked up in turn by the light sensitive ele-ment 16 to produce an electric signal. The bar code 19 comprises, as shown in Figure 4, a start code l9a, a stop code l9b and a data code l9c. Therefore, the signal from the light sensitive element 16 ~;
is of a pulse train. The pulse signal is applied to a decoder 25 shown in Figure 5. The pulse signal is supplied through an amplifier -251 and a pulse shaper 252 to a checker 253. The checker 253 checks -~~hether all of the code bars are completely scanned. In other words, Nhen the pulse train contains the pulse signal representing both the start code lga and the stop code l9c, the checker 253 transmits the ~ 4 r ~ :.
. . . . . . .. . . . .
pulse train to a decoder 254 as a correct ~ignal.
W~th the arrangement described a~ove, the length of the scanning lines is determined by the angle of deflection, which in ;
turn is determined E~ the number of reflecting surfaces of the polygonal rotatlng mirror, and the optical distance from the point of reflection on the rotating mirror to the scan surface. With the optical distance limitedl therefore, the s nning lines formed may not have a length required to serve the intended purpose. One known method of increasing the length of scanning lines is to reduce the number of reflecting surfaces of the rotating mirror thereby to in-crease the angle of deflection. For example, if the rotating mirror ~e shaped as a regular tetragonal prism having four reflecting side surfaces, an angle of deflection is o~tainable which is 180 or twice as large as that obtained with an octagonal rotating mirror and with three reflecting mirrors arranged one for each one-third portion of such angle of deflection in the same manner as described with reference to Figures 1 and 2, scanning lines will be obtained which have each a length nearly~twice as large. The angle of intersection ~etween the scanning lines in this instance is in-creased to 45, giving a scanning range extended for codes inclined to a larger extent. In cases, however, where the codes used are of a width W and height H, having a diagonal at an angle, tan l W' which is 22.5 or less, any of the scanning lines cannot effectively scan such codes if the codes are inclined at 22.5 or thereabout on the scan surface, as will be readily observed in Figure 6. This incon-venience is increased as the number of reflecting surfaces of the alternately inclined at an angle of ~90 + O) degree and that of ~90 - O) degrees to the reference plane, wh~ch is at right angles to the axis of rotation of the rotating mirror Z6. For convenience, 3Q such angle of inclination of the reflecting surfaces to the reference ~lane ~ e referred to herein as an "angle of tilt". Now, the . 5 ;
8i~
light heam, proceeding along a line ~ntersecting the axis of the rotating mirror 26 a* right angles thereto, is reflected by one of the reflecting surfaces of the rotating mirror 26 and thus deflected a~out point ~2 (Figure 9) through an angle of 90 as the mirror 26 rotates. Actually, the light beam 20 has a definite spot diameter and hence the angle of deflections is a lit~le less than 90. In addition, the actual point of re1ection, the point 2' moves along the line of light incidence with rotation of the polygonal rotating mirror 26. For convenience, however, it is assumed in the following description that the angle of deflection is 90 and that the point 2 is fixed.
Now, the light beam 20 impinging upon a reflecting surface having an angle of tilt of (90 - 0~ degrees is reflected along the arrowed broken line in Figure 8 and deflected through 90 as the polygonal rotating mirror 26 rotates. As seen in Figure 9, reflect-ing mirrors 27 and 28 are arranged symmetrically with respect to the axis of incident light beam 20 and lines 02A2 and 02B2, each extending at an angle of 22.5 to the beam axis, form perpendicular bisectors of t~e respective reflecting, mirrors 27 and 28. The light beam 20 as reflected by either the reflecting mirror 27 or 28 proceeds in a plane normal to that of Figure 9.
On the other hand, the light beam 20 as impinging upon one of the reflecting surfaces of rotating mirror 26 which have an angle of tilt of ~90 ~ ~) degrees is reflected along the arrowed solid line in Figure 8 and deflected through an angle of 90 with rotation of the rotating mirror 26. The light beam is again reflected by the re~
flecting mirror 29~ which is arranged at right angles to the lines 02C2 in Figure 9 and forms on the scan surface 17 a scanning line which passes approximately through the point of intersection between 3a the two scanning lines formed by means of the respective reflecting -mirrors 27 and 28.
``
108~309 .
- . ~ .
In Figure 10, which illustrates the three scanning lines formed on the scan surface in the manner described above, references A2', B2' and C2' indicate respective points at which the light beam 20 as reflected at points A2, B2 and C2 on the respective reflecting mirrors 27, 28 and 29 impinges on the scan surface. ~s indicated in this figure, the angle of intersection between the scanning lines i~ 22.5 as long as ~he scan surface remains parallel to the reference plane of the polygonal rotating mirror 26~ In this manner, scanning lines of e~tended length and mutually intersecting at an angle not increased .
to any extent can be obtained with the device of the invention.
- To summarize, in the second embodiment of the present inven~ion, a polygonal rotating mirror having reflecting surfaces titled at .
different angles is employed and the light beam impinging upon the ~ successive reflecting surfaces differing in angle of tilt is deflected ~
in a dir~ction determined by the angle of tilt of the respective - ~ `
leflecting surfaces. This makes it possible to obtain an unusually wide angle of deflection for formation of scanning lines of extended length through the intermediary of reflecting mirror means. Further, the arrangement of reflecting mirrors in the manner described is effective to ~0 keep the angle cf intersection between the scanning lines obtained from being unnecessarily increased and thus makes it possible tc reduce the height of codes to be scanned.
' ' ' ' . . ' ' ' . . : . , :
.
.: . .~
~, . . .
'' ' ' ' ' " ':' ' ' ' `
.
~ .. . ' .
. ~ - :
The reflecting mirrors 13, 14, 15 are each directed so that the light beam reflected therefrom proceeds in a direction normal to the plane of Figure 2 and, impinging upon the scan surface, which is parallel to the plane of Figure 2 and spaced from the reflecting mir~ors by at least a certain distance, forms on the scan surface three scanning lines 22, 23 and 24, one for each of the reflecting mirrors~ as shown in Figure 3. These scanning lines meet at a point B'l on the scan surface. Points Al, Bl and Cl in Figure 3 represent respective points ~-at which the light beam reflected by the reflecting mirrors 13, 14 and 15 at respective points Al, Bl and Cl reaches the scan surface. As indicated, the scanning lines 22 and 24 intersect the remaining scan-ning line 23 at an angle of 30.
Referring again to Figure 1, the light rays of the scanning ;
lines 22, 23 and 24 are picked up in turn by the light sensitive ele-ment 16 to produce an electric signal. The bar code 19 comprises, as shown in Figure 4, a start code l9a, a stop code l9b and a data code l9c. Therefore, the signal from the light sensitive element 16 ~;
is of a pulse train. The pulse signal is applied to a decoder 25 shown in Figure 5. The pulse signal is supplied through an amplifier -251 and a pulse shaper 252 to a checker 253. The checker 253 checks -~~hether all of the code bars are completely scanned. In other words, Nhen the pulse train contains the pulse signal representing both the start code lga and the stop code l9c, the checker 253 transmits the ~ 4 r ~ :.
. . . . . . .. . . . .
pulse train to a decoder 254 as a correct ~ignal.
W~th the arrangement described a~ove, the length of the scanning lines is determined by the angle of deflection, which in ;
turn is determined E~ the number of reflecting surfaces of the polygonal rotatlng mirror, and the optical distance from the point of reflection on the rotating mirror to the scan surface. With the optical distance limitedl therefore, the s nning lines formed may not have a length required to serve the intended purpose. One known method of increasing the length of scanning lines is to reduce the number of reflecting surfaces of the rotating mirror thereby to in-crease the angle of deflection. For example, if the rotating mirror ~e shaped as a regular tetragonal prism having four reflecting side surfaces, an angle of deflection is o~tainable which is 180 or twice as large as that obtained with an octagonal rotating mirror and with three reflecting mirrors arranged one for each one-third portion of such angle of deflection in the same manner as described with reference to Figures 1 and 2, scanning lines will be obtained which have each a length nearly~twice as large. The angle of intersection ~etween the scanning lines in this instance is in-creased to 45, giving a scanning range extended for codes inclined to a larger extent. In cases, however, where the codes used are of a width W and height H, having a diagonal at an angle, tan l W' which is 22.5 or less, any of the scanning lines cannot effectively scan such codes if the codes are inclined at 22.5 or thereabout on the scan surface, as will be readily observed in Figure 6. This incon-venience is increased as the number of reflecting surfaces of the alternately inclined at an angle of ~90 + O) degree and that of ~90 - O) degrees to the reference plane, wh~ch is at right angles to the axis of rotation of the rotating mirror Z6. For convenience, 3Q such angle of inclination of the reflecting surfaces to the reference ~lane ~ e referred to herein as an "angle of tilt". Now, the . 5 ;
8i~
light heam, proceeding along a line ~ntersecting the axis of the rotating mirror 26 a* right angles thereto, is reflected by one of the reflecting surfaces of the rotating mirror 26 and thus deflected a~out point ~2 (Figure 9) through an angle of 90 as the mirror 26 rotates. Actually, the light beam 20 has a definite spot diameter and hence the angle of deflections is a lit~le less than 90. In addition, the actual point of re1ection, the point 2' moves along the line of light incidence with rotation of the polygonal rotating mirror 26. For convenience, however, it is assumed in the following description that the angle of deflection is 90 and that the point 2 is fixed.
Now, the light beam 20 impinging upon a reflecting surface having an angle of tilt of (90 - 0~ degrees is reflected along the arrowed broken line in Figure 8 and deflected through 90 as the polygonal rotating mirror 26 rotates. As seen in Figure 9, reflect-ing mirrors 27 and 28 are arranged symmetrically with respect to the axis of incident light beam 20 and lines 02A2 and 02B2, each extending at an angle of 22.5 to the beam axis, form perpendicular bisectors of t~e respective reflecting, mirrors 27 and 28. The light beam 20 as reflected by either the reflecting mirror 27 or 28 proceeds in a plane normal to that of Figure 9.
On the other hand, the light beam 20 as impinging upon one of the reflecting surfaces of rotating mirror 26 which have an angle of tilt of ~90 ~ ~) degrees is reflected along the arrowed solid line in Figure 8 and deflected through an angle of 90 with rotation of the rotating mirror 26. The light beam is again reflected by the re~
flecting mirror 29~ which is arranged at right angles to the lines 02C2 in Figure 9 and forms on the scan surface 17 a scanning line which passes approximately through the point of intersection between 3a the two scanning lines formed by means of the respective reflecting -mirrors 27 and 28.
``
108~309 .
- . ~ .
In Figure 10, which illustrates the three scanning lines formed on the scan surface in the manner described above, references A2', B2' and C2' indicate respective points at which the light beam 20 as reflected at points A2, B2 and C2 on the respective reflecting mirrors 27, 28 and 29 impinges on the scan surface. ~s indicated in this figure, the angle of intersection between the scanning lines i~ 22.5 as long as ~he scan surface remains parallel to the reference plane of the polygonal rotating mirror 26~ In this manner, scanning lines of e~tended length and mutually intersecting at an angle not increased .
to any extent can be obtained with the device of the invention.
- To summarize, in the second embodiment of the present inven~ion, a polygonal rotating mirror having reflecting surfaces titled at .
different angles is employed and the light beam impinging upon the ~ successive reflecting surfaces differing in angle of tilt is deflected ~
in a dir~ction determined by the angle of tilt of the respective - ~ `
leflecting surfaces. This makes it possible to obtain an unusually wide angle of deflection for formation of scanning lines of extended length through the intermediary of reflecting mirror means. Further, the arrangement of reflecting mirrors in the manner described is effective to ~0 keep the angle cf intersection between the scanning lines obtained from being unnecessarily increased and thus makes it possible tc reduce the height of codes to be scanned.
' ' ' ' . . ' ' ' . . : . , :
.
.: . .~
~, . . .
'' ' ' ' ' " ':' ' ' ' `
.
~ .. . ' .
. ~ - :
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An optical scanning system for scanning a code pattern formed of a plurality of substantially parallel lines of a predetermined length printed on an article by a beam of light rays, said system comprising: means for producing said light beam; a polygonal rotating mirror having an even number of reflecting surfaces, said reflecting surfaces being alternately inclined at predetermined angles with respect to an axis of said polygonal rotating mirror, said light beam being directed from said light beam producing means to at least one of said reflecting surfaces of said polygonal rotating mirror so as to be deflected as said mirror is rotated; and a plurality of station-ary mirrors for reflecting in turn said deflected light beam to form a plurality of light-beam scanning lines intersecting each other on the sur-face of said article so that said code pattern may be scanned by at least one of said scanning lines.
2. An optical scanning system as claimed in claim 1 wherein said reflecting surfaces are alternately inclined at an angle (90 + .THETA.) degrees and an angle (90 - .THETA.) degrees to a reference plane which is at right angles to the axis of rotation of said polygonal rotating mirror.
3. An optical scanning system as claimed in claim 2 wherein the number of said plurality of stationary mirrors is three and said stationary mirrors are arranged so that two of said scanning lines interest the third scanning line at equal angles.
4. An optical scanning system as claimed in claim 3 wherein said polygonal rotating mirror is octagonal.
5. An optical scanning system as claimed in claim 4 wherein said equal angles are 22.5 degrees.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50120965A JPS5244650A (en) | 1975-10-06 | 1975-10-06 | Optical scanner |
| JP51011993A JPS5820410B2 (en) | 1976-02-05 | 1976-02-05 | optical scanning device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1081009A true CA1081009A (en) | 1980-07-08 |
Family
ID=26347529
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA262,799A Expired CA1081009A (en) | 1975-10-06 | 1976-10-06 | Optical scanning system using a polygonal rotating mirror |
Country Status (2)
| Country | Link |
|---|---|
| AU (1) | AU509724B2 (en) |
| CA (1) | CA1081009A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5223700A (en) * | 1989-07-07 | 1993-06-29 | Sumitomo Electric Industries, Inc. | Bar code reader having a polygon mirror providing different scan line lengths |
| US6621609B1 (en) | 1994-02-02 | 2003-09-16 | Advanced Laser Technologies, Inc. | Light beam display |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56164312A (en) * | 1980-05-22 | 1981-12-17 | Konishiroku Photo Ind Co Ltd | Optical deflecting device |
-
1976
- 1976-10-06 AU AU18426/76A patent/AU509724B2/en not_active Expired
- 1976-10-06 CA CA262,799A patent/CA1081009A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5223700A (en) * | 1989-07-07 | 1993-06-29 | Sumitomo Electric Industries, Inc. | Bar code reader having a polygon mirror providing different scan line lengths |
| US6621609B1 (en) | 1994-02-02 | 2003-09-16 | Advanced Laser Technologies, Inc. | Light beam display |
Also Published As
| Publication number | Publication date |
|---|---|
| AU509724B2 (en) | 1980-05-22 |
| AU1842676A (en) | 1978-04-13 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |