CA2057894A1

CA2057894A1 - Scanner system with input capability

Info

Publication number: CA2057894A1
Application number: CA 2057894
Authority: CA
Inventors: Harry P. Brueggemann; Melvin E. Swanberg; & R Tech Development S
Original assignee: Individual
Current assignee: S & R Tech Dev
Priority date: 1990-04-06
Filing date: 1991-04-08
Publication date: 1991-10-07
Also published as: AU7695091A; WO1991015794A1; EP0477337A1

Abstract

2057894 9115794 PCTABScor01 A scanner system (10) includes a light source (11) for producing a light beam (12), scanning components (13) for directing the light beam to a spot (14) at a predetermined location relative to the scanning components (13) and for moving the spot (14) along a scan line (15) of specified length at the predetermined location, and a detector arrangement (30) responsive to light reflected from a surface (21) placed at the predetermined location for producing a signal related to a visually discernible pattern on the surface (21). The detector arrangement (30) is exposed to the full length of the scan line (15), preferably being configured to be responsive to light reflected toward it from substantially any point on the surface (21) along the full length of the scan line (15).
One embodiment includes an optical element (140) disposed along the scan line (115) intermediate the scan line (115) and the detector arrangement (130).

Description

20~94 Scanner System With Inut~CapabilitY

Backaround of the Inv~ention Technical Field This invention relates generally to s laser scanners, and more particularly to a iaser scanner having input capabil$ty.
Bac~groun~ ormation A scanner ha~ing input capability is sometimes called a raster input scanner or RIS. It produces a signal r~lated to a visually discernible pattern on a scanned surface and that enables various input functions such as reading a printed document. Some scanners do so by flooding the surface with light and reading reflected energy at each of many closely spaced positions along a scan l$ne in order to produce the desired ~ignal. Since surface reflectivity varies according to the visually discernible pattern, information about the pattern becomes encoded on the signal.
Another type of scanner has output capability.
Sometimes called a ra~ter output scanner or ROS, such a scanner does the opposite of an RIS, producing a visually discernible pattern on a photoreceptor to enable ~arious output functions such as printing a page. To do so, the scanner direct~ a light beam to a spot on the photoreceptor, moving the spot along a scan line by such m~ans as a multifaceted rotating polygon while controlling the exposuré at each of many closely spaced wosl/ls7s4 PCT/US91/02407 i9 ~
~ 2-spot positions along the scan line according to encoded pattern information.
Although existing RIS and ROS units operate quite effectively in many respects, certain problems arise in attempting to combine their input and output capabilities in a single multimode unit. In other words, the addition of exi~ting RIS technology to an ROS design involves certain inef~iciencies. Two light ~ources may be required, for example, one to illuminate the scanned surface for input purpo~es and one to scan the photoreceptor very precisely for output purposes. But that means extra cost, volume, and complexity, and so it i8 desirable to have some better way to m~ke use of existing ROS components for RIS purposes.
SUDa~Y of the Invention ; This in~ention solves the problem outlined above by providing a scanner that illuminates the surface to be ~canned with ROS-type scanning componentry and reads surface reflectivity with a photodetector arrangement expo~ed to`t~- whole ~can line at once. The photodet-ctor arrang~ent c~n be mall and low co~t, and ;~ it nables use of exi~ting ROS-type scanning componentry.
It eliminates the need for a second light ~ource. It - 25 comblnes RIS and RIS t-chnologie~ more efficiently. It reduce~ the ~ize of the multimode unit, and it reduces - co~t., ., .

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wosl/ls7s4 PCT~US91/02407 205~89~

To b~tter visualize ~he advantages, recall that existing RIS technology floods the surface with light.
So existing RIS detectors must not only read surface reflectivi.ty. They must provide information about spot position as well. But the present invention illuminates just a spot at a time in a pr~cisely controlled manner.
Thus, in enabling use of ROS-type scanning componentry the in~ention also eliminates the need ~or a detector that provides information about spot position because that information is available from the preoise manner in which the ROS-scanning componentry operates.
Generally, a scanner constructed according to the invention includes a light source for producing a light beam. That may be an ROS-type component. It also includes scanning componQnt~ for directing the light beam to a spot at a predetermined location relative to the scanning components and for moving the ~pot along a scan line of specified length at the predetermined location.
That may be an ROS-type component too. In addition, the systam includ~s a datector arrangement responsive to light reflectsd from a surface placed at the prsdetQrmined location for producing a signal related to a visually discernible patt~rn on the surface. The detector arrangement is exposed to the full length of the scan line and 80 it anabla~ u~ of ROS-type light and scanning components instead o~ having to flood the sur~ace with light from a~separate ~ource.

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wos1/1s7s4 PCT/US91/02407 4~

Preferably, all those components are contained in a light-tight enclosure. Then only light from the light beam that is reflected from the surface being scanned affects the detector arrangement. In addition, the detector arrangement may include at least one photodetector device that is configured to be simultaneou~ly exposed to light reflected toward it from sub$tantially any point on the sur~ace along the full length of th~ ~can line.
Furthermor~, the detector arrangement may include at least one detector array having a plurality of detector device~ dispo~ed along the scan line. They may be ~paced apart a predetermined di~tance that is proportional to a di~tance by which the det-ctor device~ are paced apart from the scan line. Preferably, the detector arrangement includes two such arrays dispo~ed along the scan line, each o~ which iR con~igured as an elongated element with a plurality of photodetQctor devices, each device being re~ponRive to light reflectQd from the surface along a portion of the acan line. The outputs of the individual photodetector devico~ are ~u~med by suitable circuitry while a timing circuit relato~ th- generatod signal to the po~ition o~ tha ~pot along the ~can line.
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~rief Descri~tion of the Drawinas FIGURE l of the drawings i8 a diagrammatic repre~entation of a scanner sy~tem constructed according to the invention;

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wos1/1s7s4 PCT/US91/02407 _5_ 2 05 789~

FIGURE 2 is an en~ ed diagrammatic repre~entation of the detector element and scanned ~urface in cross section;
FIG~RE 3 is a block diagram of the detÆctor element circuitry ~howing the detector elements, individual amplifiers, and a ~umming circuit;
FIGURE 4 is a repre~entation of a plot showing detector output as a function of spot position;
FIGURE 5 is a diagram~atic repreaentation of a second embodiment of a scanner 8y8tem con~tructed according to the invention that includes a cylindrically shaped optical element intermediate the ~an line and the detector array;
FIGURE 6 i~ an enlarged cross sectlonal view o~ the ~econd embodiment takan in th- cross-~can plane;
FIGURE 7 iB a further enlarged cross sectional view taken in tho cro~s-~can plane of a third Qmbodiment having a non-cylindxically shaped optical ~lement; and FIGURE 8 i~ a diagrammatic repr~sentation of a fourth embodiment having a Fre~nel len~ array between the scan line and the detector array.

~criptlon of the Pre~erred Embodiments F~g. 1 illustrate~ a ~canner ~y~tam lO constructed according to the invention. Gen~rally, the scanner sy3tem lO includes a light source ll for generàting a light bea~ 12 and scanning means 13 ~or directing the light beam 12 to a spot 14 at a predetermined location WO91/157s4 PCT/US91/02407 ~ ~Q ~ -6-relative to the scanning means 13 The scanning means 13 also serves to move the spot 14 along a scan line lS of specified length at the pr-d~termined location For that purpose, the scanning means 13 include~ a rotatable elem~nt or polygon 17 with a plurality of light rc~lecting facets 18 (eight fa¢Qts being illustrated) and other known ~echanical conponents that are depicted in Fig 1 by the polygon 17 rotating about a rotational axi~ 19 in the direction of an arrow 20 A~ the polygon 17 rotate~, the light beam 12 is dir-cted by th- fac-t 18 toward an i~age plane at a surface 21 to b~ scann-d, ~uch as th~ sur~ace of a docu~ nO 22, scanning acro~s th surface 21 in a known ~nn r along th ~can~line ~S fron a fir~t nd 23 of the lS can~line lS pa~st a c-nter (the~illustrat-d po~ition of th~ -pot; 14) nd on to a ~ocond nd 24 of the scan lin~-lS Thu~,~th light b-a~ 12 ~can~ in a ~can plane ; d~fined a~ a plane containing both the scan line lS and a c~ntral light b-a~ po-ition that i~ the po~ition occupied by th~light b-a~ 12 whon it i~ directed toward th-c-nt-r of th~ ~can }in lS (i e , the po~ition of the 11ght~b-a~ 12 that ia illu-trated in Fig 1) Tho~- co~pon c t- ~ay be ~i~ilar in nany respect~ to corr~ ponding~co~pon-nts of xi-ting ~cann~r sy~t-~ and tho ~¢~nn r sy-t 10 ~ay include a post-~acet lens sy t-~25 baving ~irst ,and ~econd ~l-m~nt- 26 and 27 that co~p~n~te ~or ~ield curvatura and wobble Wobble r-sults in the light bea~ 12 being dir-ct~d above or :

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below the scan line l5 in a direction perpendicular to the scan plane as de~cribed in U S Patent Application Serial No 496,459 ~iled March 20, l990, and that application is incorporat~d by reference for the details provided Of course, the post-facet len~ system 25 may be omitted without departing ~rom the inventive concepts disclosed.
The light source ll ~ay include a known type of infrared laser diode, and known conditioning optics, for exa~ple It forms a light beam 12 directed at the facets 18 such that the light b-am 12 i8 collimat~d in the scan plane and focusQd in the cross-~can plane That i~ done 80 that the light beam 12 has a proper diameter in the ~can plane and a proper Numeric Aperture (NA) in the cro~s-scan plane In the ~can plane, th~
conditioning optic can be a s1ngle aspheric lens of short focal l-ngth, for exa~ple, or a la~er diode collector which i~ ilar to a nicroocope ob~-cti~e but de~igned for infrared light and for infinite con~ugates In the cro-~-ocan plan (i - , th- plane containing both the central llght b-am po~ition and a lin perp-ndicular to th- ~can pl~n ), ths optic ha~ th- same diode collector, with th- addition of a cylinder len~ to focus the ;~ colli~ated bea~ at the facets 18 Suitable light source circultry turn~ the light source ll on and off in order to write on the doc~ment 22 MAany of thos~ things are well-known in the-art and r f-r-nc- i- ~ad- to ~ru gg-~ann U S P~t-nt .

WO gl/15794 PCr/USgl/0240?

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Nos 4,512,625, 4,247,160, 4,230~394, 4,662,709, 4,805,974, 4,682,842, 4,624,528, and 4,595,947 for the various details of scanner system construction provided For that purpo~e, reference is also made to Starkweather U S Patent Nos 4,475,787, 3,995,110, 3,867,571, 4,040,096, and 4,034,408 Any of various light sources may be Qmployed without departing from the broader inventive concept~ di~clos~d, howev~r A major way th ~canner 8yBt~m 10 differs from existing designs is in having a detector arrangement 30 as ~ubseguently described with reference to Figs 1-4 It erves as d~t-ctor means re~ponsive to light re~lected from a -urfw placed at the pr~determin-d location (e g , the ~ur~ace 21) for producing a ~ignal relat~d to a vi~ua~lly disc-rnible pattesn on the surface (such a~
t xt or graphic~), and it is exposed to the full length o~the~scan lin 15 That en~bl-~ use of ROS-type ~ canning co~po~ent~ without th- need fos a separate light ,'~ source to illu~inate th ~usface 21 The illu~trat-d detector arsangemQnt 30 s-sv-s as d-tector ~ an~ r-~pon~ive to light sQflected fsom a ur~ac- placed at th- pr-d t-r~ined location (i e , th~
~ surfa¢Q 21 of the docu~ent 22) for producing a ~ignal ,~ r-lated to a vi~ually disc-snible pattesn on the surfac- 21 It i~ xpos-d to the full length of the scan line 15 in the sense that it is responsive to light ; ''reflected'~rom ~ub~tant~aily all points on the surface 21 along the scan line 15 Thus, it providss infor~ation ", ,;, ~ .
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W O 91/15794 PC~r/US91/02407 9- 20~ 789 1 about surface reflectivity at each spot position or pixel position along the scan line 15.
As the light beam 12 ~cans the spot 14 along the scan line 15, light reflected from the surface 21 impinges upon the detector arrangement 30. That causes the detector arrangement 30 to produce the desired signal, encoded with information about surface reflectivity along ths ~can line 15. That, in turn, provide~ information about the visually discernible pattern on the surface 21. Fig. 1 doe~ not include a pattern on the surface 21, but it may typically be text or graphic~ to be read.
From the foragoing and subseguent de~cription~, it is appar~nt th~t any of variou~ dif~erent types of detector arrang~ment~ can be used. The illustrated detector arrangement 30, however, includes first and second detector arrays 31 and 32 (Fig. 1). Each of the detector arrays 31 and 32 includes a plurality of detector devices 33 (three being designated in Fig. 1 for the detector array 31). They are mounted according to known techniques on some known type of support structure, ~uch a~ a somewhat re~ilient strip 34 de~ignated in Fig. 1 for the detector array 31.
Each of the d-tector arrays 31 and 32 includes at lea~t one detector device, preferably a known type of photodet-ctor device. It could conceivably be elongated and di~po~ed along the ~can line 15. But a~ illustrated in Fig. 1, each of the detector array~ 31 and 32 includes wosl/l~794 PCT/US9t/02407 ~,9~ -lo-nineteen detector devices 33 (preferably photodetector devices) spaced apart one-half inch from center to center (dimension "';" in Fig. 2~. Thus, they extend nine inches along the nine inch scan line 15. They are parallel 5 connected as subsequently described in the sense that they can each contribute to a ~ingle output signal from detactor circuitry 35 (de~ignated OUTFUT in ~ig~. 1 and 3).
Preferably, the detector arrays 31 and 32 are located a distance from the scan line 15 that i~
proportional to that one-half inch spacing. The detector array~ 31 and 32, for example, are located one-half inch from the scan line 15 (dimension "d" in Fig. 2). Those dimensions are cho~en according to known d~sign technique~ in view of the characteristics of the detector d~vices 33, the light beam 12, the reflectivity of th~
surface 21, and the signal desired. So the dimensions may vary significantly depending on the particular~ of a given application.
The instantaneous distance of the ~pot 14 along the ~can line from the first end 23 is design~ted "x" in Fig. 2. A~ the ~pot 14 move~ ~way from the first end 23, a lesser proportion of total reflected light impinges upon tha detsctor Dl while a grsater proportion impinges upon the detector D2. The proportion upon Dl varies as the cosine to the Sourth power of the angle A in Fig. 2 while the proportion upon D2 varies as the co~ine to the fourth power of the angle B. Th~ output of the wo9l/ls7s4 PCT/US91/02~7 20~789~

detectors Dl and D2 vary accordingly, as do the outputs of D3 and the other detectors 33 The output of the detectors Dl, D2, and D3 are represented by the dashed linea at 36, 37, and 38 in Fig 4, while the solid line at 39 represents the combination of detector outputs In that regard, the d~tectors 33 are properly spaced and the detector arrays 31 and 32 are otherwise suitably configured so that th~ rippl~ Or the OUTPUT does not impair perrormance The combination of detector signals leaves a residual ripple as the spot 14 ~oves along the scan line 15 The ripple is reduced, and the output signal is increased, when the ~pacing bQtween the d-t~ctors 33 is reduced In using two detector arrays as ~illu~trated in Fig 1, the detectors are positioned so ; 15 that~the po~itions of oppo~ing detectors are ~taggered That holps minimize ripple Th~conb1nation of th~ output~ of Dl, D2, and D3 (-i e ~,~ th~outputs of the a~plifi~rs) is produced by the -~dst-ctor circuitry 35 In that regard, th- detector circuitry 3S ~ay b- fabricated according to known t-chnigu 8 as an integral part of th- d~t~ctor arr~ys 31 and 3~2 OD th trips 34, although it is ~hown in Fig '-as a s~parate co~ponent, and it may include a su~ming circuit 3Sa as ~hown in Fig '3 The signals from the ~-~25 plur~l~ity oS d tector~ Dl~ D2~ D3 Dn ar~ pref~rably ~irst ~pli~ied by amplifier~ Al, A2, A3 ~ and the ~'~outputs of'thos'e'amplif'~or~ are coupled to'the summing ~3circuitry 35a The signals from the detectors ti e ~ the :

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~9~ -12-amplifier outputs) may be combined by simple addition of the signal~ in a resistor network. Alternatively, they may be combined by using diodes providing an "OR"
selection of one of the ampli~ier outpu~s. In other S words, the OUTPUT is equal to the signal from the amplifier having the greateQt amp~itude.
Consideration of signal to noise ratio involves the source of noise commonly known as nspeckle." It results from coherent interference and it can be described as a - 10 very irregular pattern o~ the reflected energy, having many narrow lobes. For the small detectors 33, the lobe pattern may or may not illuminate a given detector. As the spot 14 ~ove~ along the ~can line 15, those lobes will fIuctuate wildly and ~danc-,H cau~ing the energy on nearb~ detector~ 33 to rluctuat-, and produce a noise slgnal. That noise can be reduced by increasing the angle Or collection of th rerlected energy such that the -~energy in many lobQs i8 detectQd. One way that is accomp1ished is by using many detectors spaced at close - 20 interval-, increasing the ~iz- of the detectors, or using one long narrow d~tector. But doing ~o is counter to the -desire to mini~iz~ the ar-a of the detector and thus ;~ minimize the capacity of the detsctor, as a fast response and wide bandwidth is reguired.
The angle of collection o~ ~nergy is incroased without increasing the size of the detector by using a - ~ cylindri¢al l~n~!as subsQquèntly de-cribed with reference to Figs. 5 and 6. They show a sQcond embodiment or ~ .

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~canner ~y~tem 100 constructed according to the invention It is generally similar in many respects to the scanner system 10 and o only differences are described in further detail For convenience, numerals S d~signating parts of the scanner ~ystem 100 are increased by one hundred over those dQsignating ~imilar parts of the scanner system 10 Like the 8cannor sy~t~ 10, the ~c~nner system loO
inclua-~ a li~ht boa~ 112 that is directed to a spot 114 on a sur~ace 121 to be ~canned (i e , the ~urface of a docum~nt 122), and the ~pot 114 moves along a scan line 115 from a ~irst end 123 of the scan line 115 to a second end 124 In addltion, th- scanner sy~tem 100 includ a d tector arrang-~ nt 130 that include~ a plurallty~o~ detector dovic-- 133 ~ut unlike the canner sy-te~ 10, th~ 8cann-r ~y8t~ 100 includes an optical ele~ont~l40 ~ounted by ~uitable known ~eans in a ~- po~ltlon int-r~ diat- the dotectos device 133 and the scan line 114 It ~orv-s to converge re~lected light towara th- det-ctor dovic-~ 133 Stat-d another way, it ~; incr-a--- the angl- o~ coll-ctlon o~ en rgy without -~ ~ incr aslng th ize o~ th d t-ctor It i~ in th~ ~orm of a cylindrical rod, th- illustrated optical element 14 boing ~abrlcat-d o~ uitable~known ~aterial, ~uch as 25 ~ glas~ or plastic, in a cylindrical shape according to known optical dQsign tQchniquos ~ i Figl 7 liiustrate~ a third ~mbodiment or ~canner - syst-m 200 con~tructed according to the invention It is :, "

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wosl/ls7s4 PCT/US91/02~-~ 14-generally similar in many respects to the scanner system 100 and 80 only differences are described in further detail For convenience, numerals designating parts of the scanner sy~tem 200 are increased by one hundred over tho~e designating similar parts of the scanner ~y~tem 100 LiXe the scanner ~ystQm 100, the scanner system 200 in_lude~ an optical elemQnt 240 that serves to converge re~lected light toward a detector device 233 mounted on a strip 234 Unlike the scann-r ~v~tem 100, however, the optical element 240 is not cylindrically shaped Instead, it includ~s a convex ~urface 241 disposed toward th~ spot 214 and a flatter surface 242 di~pos~d toward the detector de~ice 233 That con~iguration facilitates ~ounting of the detQctor array and ~t can simplify fabrication of the optical element 240 To further colI-ction ~fici n Q, the ~hape and size is opti~ized for th- spacing between the scan line and the detectors, the siz- o~ the detectors, and other such parameters In addition, th- detoctor~ are placed into optical contact with the optical el-ment 240 by fabricating the detector and optical el~ent a- a ingl- ass~bly Fig 8 illu~trat-s yet another embodiment ~ con~truct-d according to the invention, a third -~ 25 e~bodin nt or scann~r ~ystQm 300 It i8 g~nerally similar in many respects to the scanner ~ystem 100 and ~o only d~f~-renc~s ar~ d~scrib~d in`rurther detail For ; conveni~nce, numerals designating parts or the scanner :
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system 300 are increased by two hundred over those designating similar parts of the scanner system 100.
Like the scanner sy_tem 100, the scanner system 300 includes an optical element 340 that serves to converge reflected light toward a detector array 331 having a plurality of detector d-vice~ 333 mounted on a strip 334.
Unlike the sc~nner syste~ lOo, however, the optical element 340 includes a plurality of Fresnel lenses 343, one ~or each of the detector device 333. They serve to converge reflected light from a respective Qegment of the scan line 315 (a scan segment) to a respective one of the detector devices 333. Thus, reduced scan ~egments appear at the detector devices 333. In addition, the Fresnel lenses serve the u~ual function of reducing lens thickn-~s and weight~
Stated another way, the array of Fresnel lenses h~lps increase the collection angle and decrease the detector size. They do that while -eemingly demagnifying or reducing the motion of the spot 14. That permits use of smaller detectors with little decrea_e in the energy that is coilected at the detector. There is one Fresnel len~ for ach d~tector 333, much like the lens arrays that are u~ed with small IED di~plays, and it provides imaging of the spot 314 on at lea_t one detector 333 at all times, such that prior to the spot 314 moving out of the field of view of one Fre~nel len~/detector element, it will ~ave passed into th- fi-ld of view of the next Fresnel l-n~/detector elQment. In other words, there is ' .

wos1~1s794 PCT/US9t/024~-~ 9~ -16-a region of overlap. Preferably, the detector signals are combined using the "OR" summing circuitry described previnusly. That avoids the spike which occurs in the overlap region if the signal is summed. Also, using the "OR" ~umming circuitry avoids the summation of noise from the d-tectors not contributing to the ~ignal.
~ hus, the invention provides a scanner that illuminates the surface to be Qcanned with ROS-type scanning componentry and reads ~ur~ace reflectivity with a photodetector arrangement exposed to the whole scan line at once. The photodetector arrangement can be small and low cost, and it enable~ use of exi~ting ROS-typQ scanning componentry. Tt ~liminates the need ~or a ~econd l$ght ~ource. It combines RIS and RIS
tec ~ o10gie~ ~ore efficiently. It reduce~ the size of the multimode unit, and ~t reduces cost.

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Claims

CLAIMS:

1. A scanner system comprising a light source for producing a light beam; scanning means for directing the light beam to a spot at a predetermined location relative to the scanning means and for moving the spot along a scan line of specified length at the predetermined location;
characterized by detector means responsive to light reflected from a surface placed at the predetermined location for producing a signal related to a visually discernible pattern on the surface, which detector means comprises at least one detector device that is exposed to at least a segment of the scan line.

2. A scanner system as recited in Claim 1, wherein the detector means is disposed alongside the scan line.

3. A scanner system as recited in Claim 1, wherein the detector means extends along substantially the full length of the scan line.

4. A scanner system as recited in any one of Claims 1, 2 or 3 wherein the detector device is elongated.

5. A scanner system as recited in claim 4 wherein the detector device includes at least one photodetector device that is configured to be responsive to light reflected towards it from substantially any point on the surface along the segment of the scan line.

6. A scanner system as recited in Claim 1, wherein the detector means includes at least one detector array having a plurality of detector devices.

7. A scanner system as recited in Claim 6, wherein the detector devices include at least one photodetector device.

8. A scanner system as in claim 6, wherein the detector devices are spaced apart along the scan line.

9. A scanner system as recited in Claim 6, wherein the detector devices are spaced apart along the scan line a predetermined distance that is proportional to a distance by which the detector are spaced apart from the scan line.

10. A scanner system as recited in Claim 6, wherein the detector means includes at least two detector arrays disposed along the scan line.

11. A scanner system as recited in Claim 6, wherein the detector array is configured as an elongated element disposed along the scan line.

12. A scanner system as recited in Claim 6, further characterized by means defining a summing circuit for summing the outputs of the detector devices.

13. A scanner system as recited in Claim 6, further characterized by directing means defining an optical element disposed intermediate the scan line and the detector means for directing light reflected from the surface toward the detector means.

14. A scanner system as in Claim 13, wherein the directing means includes a cylindrical lens.

15. A scanner system as in Claim 13, wherein the directing means includes a Fresnel lens.

16. A scanner system as recited in Claim 13, wherein the detector means is characterized by at least one detector array having a plurality of detector devices disposed along the scan line; and the directing means is characterized by a Fresnel lens array having a plurality of Fresnel lenses disposed along the scan line, each Fresnel lens being configured to direct light reflected from the surface along a respective segment of the scan line toward a respective one of the detector devices.

17. A scanner system as recited in Claim 6, wherein the detector device is configured to be responsive to light reflected toward it from substantially any point on the surface along the scan line.

18. A scanner system as recited in Claim 6, wherein the detector device includes at least one photodetector device that is configured to be exposed to light reflected toward it from substantially any point on the surface along the segment of the scan line.

19. A scanner system having input as well as output scanning modes, comprising means defining a light source for producing a light beam, said light beam encoded with information regarding a visually discernible pattern when in the output scanning mode; single scanning means, for both the input as well as output scanning mode, for directing the light beam to a spot and moving the spot along a scan line of specified length; characterized by:

for the input scanning mode, detector means responsive to light reflected from a surface placed at a predetermined location for producing a signal related to a visually discernible pattern on the surface; and for the output scanning mode, means for outputting the visually discernible pattern as encoded in the light beam and represented by the scan line.

20. A scanner system as in claim 19 wherein the detector means comprises a detector array having a plurality of detector devices.

21. A scanner system as in claim 20 wherein the detector devices are disposed along the scan line.

22. A scanner system as in claim 20 further comprising directing means for directing light reflected from the scan line to the detector devices.

23. A scanner system as in claim 22 wherein the directing means comprises at least one lens for converging light reflected from the scan line to the detector devices.

24. A scanner system as in claim 19 wherein the detector means comprises at least one elongated detector device.

25. A scanner system as in claim 24 wherein the detector device is disposed alongside the scan line.