CN1038536C - Light scanor with enlarged focal length - Google Patents

Abstract

The present invention relates to a bar code scanning optical scanner for enlarging focal depth by a multi-focus optical system and a method for enlarging focal depth. The scanner for enlarging focal depth is provided with an optical beam device, a multi-focus focusing optical system and an optical detector, wherein the optical beam device is used for generating radiation, the multi-focus focusing optical system is used for collecting radiation reflected from a target and at least contains a first short focus and a second long focus, and the optical detector is used for detecting radiation reflected from a viewing field and led by the multi-focus focusing optical system and generating an electric output signal for representing the radiation. Electric output signals generated by detecting bar codes filter the direct current background of electric signals through a high pass filter by combining the electric output signals of the high pass filter and the optical detector in order to improve the modulation depth of signals.

Description

Enlarge the photoscanner of depth of focus

In general, the present invention relates to enlarge the photoscanner and the method for the scan mode of depth of focus, specifically, the present invention relates to be used to utilize many focal lengths optical system with the photoscanner of the scanning that bar code enlarged depth of focus and the method that enlarges depth of focus.Though the present invention is particularly useful to the photoscanner who uses non-Laser emission light sources such as light emitting diode (LED) or LED linear array, but it also may be suitable for the photoscanner who does the LASER Light Source of using laser diode and so on.The present invention is for extremely useful based on the apparatus for reading of bar code of CCD (charge-coupled image sensor).

To be presented on the label or the lip-deep bar-code marks of goods in order reading, always to have developed various optical pickup devices and photo-scanning system.Bar-code marks also is the bar shaped figure that formed, that make the mark symbolism of various kinds by draw with the interval of various different in width separated and the width of self, bar shaped with have different reflective characteristics at interval.Reading device and scanning system are transformed into electric signal to graphic sign with photoelectric method, and this electric signal is decoded into the letter/number literal that records goods or its characteristic information.Say that typically this literal table is shown as digital form, they are used as the input of data handling system in application such as point of sale (POS) processing, shelf control.

Especially, first embodiment of this scanning system is that the shape of this scanner head makes the user can aim at (specifically being target and the mark that utilizes light beam acquiring to read) with scanner head about the handhold portable type laser scanning head of being handed by the user.

The exemplary light sources of laser scanner is gas laser or semiconductor laser, because the semiconductor devices as the laser diode has the advantage of small-sized, inexpensive and little power consumption, and special light source of wishing the use semiconductor devices as scanning system.Laser beam is done by lens typically that optics adjusts, and forms certain big or small beam and focus at the target range place.Beam and focus preferably approximates the width of reflectance varies greatly in the size at target range place, also be in the mark bar shaped and at interval in minimum widith.

Bar-code marks also is a key element typically by the rectangular strip with various different in width, is formed.This key element has determined the literal that will represent according to having done particular arrangement by the rule and the definition of compiling method or " charactery " defined.Bar shaped is the same with actual size at interval with the bar shaped of seeing with relative size at interval, by the type decided of employed symbolism.The density that in one inch, is called mark by the number of words of bar-code marks representative.In order to make the desired sequence symbolization of literal, the element arrangements combination, form bar-code marks completely, each literal that contains information is just by corresponding with it key element group's representative.In some characteries, for the bar font code from where, to where finish, used special " beginning " and " end " literal.Have multiple bar-code marks method comprising UPC/EAN, code39, code128, code bar and interweave 2/5 etc.

In the scanning system that the crowd knows, light beam directs into direction along light path by the optical element of lens and so on, and containing the target of bar-code marks on the directive surface, scanning is by making light beam become the form of a line or one group of line to come flyback retrace to realize with transverse cuts.Method for scanning can be that the beam and focus of transverse cuts mark transversely scans by the sweep trace of mark, or the visual field of scanning scanner, or both carry out simultaneously

Scanning system also contains the sensor that is used for detecting from the light of mark reflection, also is photodetector.So certainly be photodetector in scanner or position in light path with visual field bigger slightly than the scope of transverse cuts mark.Be detected from the catoptrical part of mark reflection, and be transformed into electric signal.Electronic loop or software are decoded into the numeral that representative is scanned the data of mark to this electric signal.For example, the electric signal that simulates from photodetector output is being converted into pulse width and bar shaped and the corresponding widened pulse digital signal of physical width at interval in typical case.This signal is according to binary representations specific charactery, mark internal symbol data, and is decoded into the letter/number literal with binary representation.

The normally following work of the decode procedure of the scanning system that the crowd knows.Demoder receives the widened pulse digital signal from scanner, and tries to use the algorithm of being realized by software that scanning is decoded.If successfully obtained scanning beginning literal and end of scan literal and the literal between them and they are by complete decoding, then process finishes, and (with green light and buzzer represent simultaneously or with wherein any is represented) provide the successful sign of detection to the user.If situation is not like this, demoder receives scanning (signal) next time, and exploratory decoding is carried out in this scanning (signal) again.This process continues to reach complete decoding always, when perhaps finding to utilize above-mentioned scanning (signal) till.

This signalman is according to binary representations specific charactery, mark internal symbol data, and is decoded into the letter/number literal with binary representation.

The kind that can read the optical devices of bar-code marks is not to have only laser scanner.The apparatus for reading of bar code of being equipped with that also has other kind based on the detecting device of charge-coupled device (CCD) technology.The size of the detecting device in this reading device is bigger than the mark that will read, and is perhaps substantially the same.All mark is thrown light on (floodlight) by the light from reading device, just can determine strips existence at interval when successively each pixel of CCD being read.This reading device in light weight, processing ease in order to read signal rightly, is necessary to make reading device directly to contact with signal in fact, perhaps is necessary reading device is placed on the mark.This reading device is desirable mode of operation with the situation that mark contacts as physics in some applications, and personal preference's problem of user is also arranged in addition.

Compare with the scanner based on laser instrument, it is extremely limited using the depth of focus of the bar code scanner of light emitting diode (LED).Its reason is, have led light source, will be based on the f number of the scanner of CCD far below the f number of laser scanner.Because square being directly proportional of depth of focus and f number, be very short based on the depth of focus of the scanner of LED/CCD.

Thereby fundamental purpose of the present invention provides optical scanner and the scan method that enlarges depth of focus.

Another object of the present invention provides by using many defocus distances optical system to obtain to enlarge the optical scanner and the scan method of depth of focus.

Another object of the present invention is, the particular electrical treatment loop of the low-frequency component that is used for filtering out reflected light signal is provided.

The invention provides the scanner that is used for reading with photoelectric method the expansion depth of focus of the mark with different reflectivity zone, it has:

A, produce and to be used for the device of radiation beam of illumination field of view,

B, be used for collecting from visual field internal object institute radiation reflected, the many focal lengths light-gathering optics that has the first short focal length and second long-focus at least,

C, be used for detecting, and produce the photodetector of the electrical output signal of representing this radiation from the radiation of visual field reflection by the guiding of many focal lengths light-gathering optics.

The present invention also provides and has been used for reading scan method mark, that enlarge depth of focus with different reflectivity zone with photoelectric method, and it comprises:

A, produce and to be used for the step of radiation beam of illumination field of view,

B, use have many focal lengths light-gathering optics of the first short focal length and second long-focus at least, collect the step from visual field internal object radiation reflected,

C, detection are from the step visual field reflection and also produced the electrical output signal that can represent this radiation by the radiation that many focal lengths light optical system is collected.

Will illustrate as following, the invention provides the optical scanner and the scan method that are used for reading the expansion depth of focus of mark with different reflectivity zone as the bar code figure with photoelectric method.The radiation laser beam of illumination field of view is produced by any light source in laser instrument or the non-laser light source.Although in the embodiment of following special instruction, used non-laser light source more inexpensive and LED that depth of focus is more limited and so on, principle of work of the present invention equally also can be applicable to the LASER Light Source of semiconductor laser diode or laser tube and so on.For example in CCD embodiment, by many focal lengths light-gathering optics of the rarest short focal length and long-focus to being collected by the radiation of the target reflection in the visual field, and it is directed on the photodetector detecting, and produces the electrical output signal that to represent this radiation.Have the mark in different reflectivity zone and the detecting device electrical output signal that produces is filtered the direct current background by the filtering of Hi-pass filter by detection, so just improved the depth of modulation (DOM) of signal.

In first embodiment, many focal lengths optical system contains many focal length lenses system of being made by the different many concentric lenses of a plurality of focal lengths.Photodetector contains the charge-coupled image sensor with a plurality of electric charge coupling detection pixels, and the scanning of visual field is that (not being to use the oscillatory type scanning mirror to scan) realizes by the electricity output do scanning that a plurality of electric charges couplings is detected pixels.In order to get rid of catoptrical low frequency signal composition, can use the electricity Hi-pass filter.Radiation laser beam can be produced by the LASER Light Source of light emitting diode or light emitting diode linear array or laser diode and so on.

Many focal lengths optical system among second embodiment contains and has first of short focal length and detect many many focal lengths of mirror mirror systems that second of mirror and long-focus detects mirror.In order to compensate the 1/f from the collected signal of each mirror ²Decay (f is a focal length), the area of second mirror can be compared to the area of first mirror most and do more greatly.In this embodiment, radiation laser beam can be produced by the LASER Light Source of LED or led array or laser diode and so on.Preferred photodetector is a photodiode, resulting electrical output signal when its output is the mark that has the different reflectivity part by detection, and it becomes the electric signal that excludes the direct current background after by Hi-pass filter.

In the 3rd embodiment, can use single lasing light emitter, perhaps can use to be combined into a plurality of laser beams to be focused on the different distance, come down to many focal lengths optical system of a coaxial light beam.

By below with reference to accompanying drawing to the detailed description that several embodiment did, can easily understand above-mentioned purpose and advantage about the optical scanner of expansion depth of focus of the present invention.In each accompanying drawing, same component is represented with same code name.

The accompanying drawing tube will illustrate:

Fig. 1 is the optical system sketch plan of past typical LED/CCD bar code scanner.

Fig. 2 is the typical waveform of Fig. 1 scanner detecting device, wherein, and the waveform when (A) being illustrated in scanner front end focus place, the waveform when (B) being illustrated in the far-end boundary of scanner depth of focus.

Fig. 3 is the synoptic diagram according to first embodiment of the scanner of expansion depth of focus of the present invention, and light-gathering optics wherein contains second lens that first lens that short focal length optically focused uses and long-focus optically focused are used.

Fig. 4 is the typical detectors waveform of Fig. 3 scanner, wherein, (A) expression bar code figure position when the scanner front end first lens focus place by the detected waveform of first lens, (B) be illustrated under the similarity condition by the detected waveform of second lens, (C) expression two detects the synthetic waveform of waveform.

Among Fig. 5, (A) family curve of expression Hi-pass filter, (B) height=bandpass filter signal is before passed through in expression, (C) is that the block form of high pass filter characteristic is represented, and (D) expression is by the signal after the Hi-pass filter.

Fig. 6 is the typical detectors waveform of Fig. 3 scanner, wherein (A) expression bar code figure position between first lens focus and second lens focus, the waveform that detects by first lens during boundary position of focal depth range separately of two lens, (B) waveform that detects by second lens under the expression similarity condition.

Fig. 7 is the synthetic waveform of two waveforms among Fig. 6, and wherein, (A) Hi-pass filter signal is before passed through in expression, (B) is that the block form of Hi-pass filter is represented, (C) expression is by the signal after the Hi-pass filter.

Fig. 8 is the typical detectors waveform of Fig. 3 scanner, wherein, (A) represents the waveform that the bar code figure position is detected by first lens when the second lens focal depth range border, (B) waveform that is detected by second lens under the expression similarity condition.

Fig. 9 is the synthetic waveform of two waveforms among Fig. 8, and wherein (A) expression is that the block form of Hi-pass filter represents that (C) expression is by Hi-pass filter signal afterwards by the signal (B) before the Hi-pass filter.

Figure 10 comprises according to the end face sketch plan (A) of second embodiment of the scanner of expansion depth of focus of the present invention and side sketch plan (B), and wherein the optically focused photosystem contains the 3rd lens that first lens that short focal length optically focused uses, second lens that mid-focal length optically focused is used and utmost point long-focus optically focused are used.

Figure 11 is the optical system sketch plan of non-laser LED bar code scanner in the past.

Figure 12 be with Figure 11 similarly, according to the 3rd embodiment synoptic diagram of the scanner of expansion depth of focus of the present invention.Wherein light-gathering optics contain that short focal length optically focused uses first detect that mirror and long-focus optically focused uses second detect mirror.

Among Figure 13, (A) with the typical detectors waveform of (B) representing Figure 12 scanner, (C) synthetic waveform of expression two waveforms is that the block form with differential loop of Hi-pass filter function is represented (D), and (E) represents by the waveform behind the differential loop.

Figure 14 is the synoptic diagram of embodiment of one type extreme simplification of apparatus for reading of bar code that possible be used in combination the optical scanner of expansion depth of focus of the present invention.

Code name explanation: 10 single focal length lenses systems 12,20=CCD detecting device 14 CCD are as 16,24 first lens 18,26 second lens 22, Hi-pass filter 28 the 3rd lens 30 light sources 32,50 first mirrors, 33 visual field faces, 35 hot spots, 37 optical sensors 38,52 second mirrors 39 have screen 40 slit openings 43 marks 54 differential loops 100 apparatus for reading of bar-code marks, 140 CPU146 LASER Light Source, 147 semitransparent mirrors, 148 keyboards, 149 displays, 153 handles, 154 triggers, 155 shell 156 light inlet windows, 157 optical systems (lens), 158 photodetectors, 159 vibrating mirrors, 160 scannings of perforate and print loop substrates 162 batteries 170 bar-code marks with motor 161

Fig. 1 is the sketch plan of the optical system of typical LED/CCD bar code scanner in the past, the lens combination 10 of single focal length the position at the view field imaging at its focal length place on CCD detecting device 12, conversely, formed the picture of CCD at focal length 14 places.The optical scanner of Fig. 1 has given measured object depth of focus (DOF).The bar-code marks of the given density that can read (bar of its qualification bar-code marks is wide) has determined the largest beam diameter.Also have, as shown in Figure 1, CCD is that front window (with reference to figure 3) focuses on to the front end of scanner usually, and its result will make depth of focus lose half.

Fig. 2 shows the typical detectors output waveform of the CCD scanner of Fig. 1.Fig. 2 A is when the detected waveform of bar code figure position when the scanner front end is the front window position, and Fig. 2 B is the waveform during on scanner depth of focus far-end border when the position.

Fig. 3 illustrates first embodiment according to the scanner of expansion depth of focus of the present invention, and optically focused contains first lens 16 that are useful on short focal length optically focused and second lens 18 that are used for long-focus optically focused with optical system.Preferably the use that combines with many focal lengths optical system of Hi-pass filter signal processing technology, the depth of focus of bar code scanner or working range can increase like this in the present invention.Two lens make the picture of target (bar code) be formed on the CCD detecting device simultaneously.The signal waveforms of different some A, B, C and D such as Fig. 4 are to shown in Figure 9 on the optical axis.To utilize each accompanying drawing to explain below respectively about these waveforms.

Fig. 4 represents, when the bar code figure position at the first lens focus place is the A point position at scanner front end or front window place, detects resulting typical detectors waveform with the scanner of Fig. 3.Figure (A) is the waveform that is formed by first lens, and figure (B) is the waveform that is formed by second lens.

Usually, when the depth of modulation of resulting composite signal shown in Fig. 4 (C) Fig. 4 (A) and during two signal plus (B) diminishes, caused the problem of internal so just for Aristogrid (ADC, analog-to-digital converter).In order to improve depth of modulation, eliminate the direct current ambient level by Hi-pass filter with logical frequency characteristic shown in Fig. 5 (A).Fig. 5 (B) and (D) show respectively in by Hi-pass filter 22[Fig. 5 (C) family curve has been shown] forward and backward detecting device output synthetic waveform.

Fig. 6 (A) and (B) expression when the position of bar code figure is determined in Fig. 3 between first lens focus and second lens focus, resulting typical scanner detecting device waveform during the frontier point B of separately focal depth range, (A) waveform that formed by first lens of expression (B) is represented the waveform that formed by second lens.Fig. 7 is illustrated in by Hi-pass filter 22[Fig. 7 (B)] [Fig. 7 (A)] and at the synthetic waveform of the detecting device output by [Fig. 7 (C)] after the Hi-pass filter 22 before.

The situation of position when some C and the position situation utmost point when some A is more similar.

Fig. 8 (A) and (B) expression resulting exemplary scanning device detecting device waveform when the position D on far-end border that first lens are not focused fully in Fig. 3, the second lens focal depth range, bar code figure position, the waveform that figure (A) expression is formed by first lens, the waveform that figure (B) expression is formed by second lens.Fig. 9 represents by Hi-pass filter 22[Fig. 9 (B)] [Fig. 9 (A)] and the detecting device output synthetic waveform by [Fig. 9 (C)] after the Hi-pass filter 22 before.

Utilization makes the composite signal of two signals by Hi-pass filter, has obtained having the signal of strong operability (than the modulation of the degree of depth).The function of Hi-pass filter is just as getting rid of the Discr. of dc level signal from signal.

Replacing with among the embodiment, owing to used three or more optical systems simultaneously, depth of focus is further enlarged.Figure 10 (A) and (B) expression enlarge second embodiment of scanner of depth of focus in accordance with the principles of the present invention, light-gathering optics contains first lens 24 of short focal length, second lens 26 of mid-focal length, and the 3rd lens 28 of utmost point long-focus.

Although it is rectangle that the opening of the middle lens front of Figure 10 (A) is drawn as, but select other suitable shapes such as ellipse, circle also not have what difference.Yet for target imaging far away lens on CCD, the area of opening will be done greatlyyer.Can make the f number of each optical system keep identical like this.If do not do like this, then be necessary to increase from collecting under the situation of signal at a distance, will reduce the f number of the lens of target imaging on CCD far away.Can think that collected signal roughly is proportional to 1/f2.

Though the lens shape of being advised is also remarkable, it still within the scope that up-to-date plastic optics technology may be made at present, also might use dioptric system.

The method of same expansion depth of focus also can be applicable to LED type bar code scanner shown in Figure 11.System shown in Figure 11 includes the non-laser light source 30 that LED also is light emitting diode and so on.Light source 30 produces noncoherent non-parallel wide-angle light beam 31, and light beam 31 is focused on the face 33 by curved mirror 32.The hot spot 35 that is formed by optically focused light beam 31 is big more than the bar of the bar-code marks of position in visual field face 33 and the minimum dimension at interval.The optical sensor 37 that also contains photodiode and so among Figure 11, light beam 31 is gathered on the detection surface of sensor 37 by less curved mirror 38 after the bar-code marks reflection.Except the light by screen 39 with holes and slit opening 40, other reflected light can not arrive sensor 37 because of being blocked.It is that the limit sensor visual field is the ellipse of window that this slit opening is preferably made, the window that its size is about 6 * 16 (mil) sensor 37 by mirror 38 and mirror 32 optically focused in the face 42 of the focal plane 33 of axially leaving light beam 31.Because the position of the mark 43 that will read is in face 42, so the edge of slit 40 forms a window on mark.Because in the embodiment that this exemplifies, two catoptrons 32 are identical with 38 focal length, so the interval of face 33 and face 42 equals from two catoptrons to light source 30 and the distance of sensor 37 poor

For hot spot 35 and window are moved in face 42 and the transverse cuts mark according to the shape of sweep trace, mirror 32 and 38 is by motor-driven.Between the central shaft for the central shaft that makes little mirror 38 and big mirror 32 a relative angle α is arranged, little mirror 38 is mounted on the big mirror 32.30 of light sources are having on the axis of β angle with sensor 37 positions and mirror 32 formed axis.Angle α is half of angle β

Because the window 40 of scanning light spot 35 ratio sensors 37 that produced by light beam 31 is much bigger, so only detected a minimum part of being thrown light on by light beam 31.Certainly, have only the sub-fraction reflected light to reach photodetector.Moreover the beam intensity that general LED produced is littler than LASER Light Source.So, importantly, do mirror 32 more greatly, so that more LED light is gathered on the scanning plane, reasonably improve the light intensity in the hot spot 35.

Please note the structure of typical laser scanner and inverted configuration shown in Figure 11.Also promptly, in laser scanner, laser beam bright, the height boundling has produced the hot spot that approximates the minimum dimension of bar code figure greatly, and employed photodetector then has the visual field much larger than laser beam spot.With it in pairs than be that in Figure 11, the hot spot 35 that is produced by light beam is big, and window 40 is little.

Figure 12 is the 3rd embodiment according to the scanner of expansion depth of focus of the present invention, and wherein light-gathering optics contains and is useful on the second detection mirror 52 (similar to the notion of system shown in Figure 11) that first of short focal length optically focused detects mirror 50 and is used for long-focus optically focused.If select the embodiment of Figure 12 for use, then to allow several little detection mirrors 50,52 make little opening 40 be imaged on two (or more a plurality of) different distance places in photodiode 37 the place aheads.The combination of the Hi-pass filter in such layout and the simulation process loop has enlarged depth of focus.

Figure 13 (A) and (B) the typical detectors output waveform of scanner of expression Figure 12, synthetic output signal (figure C) become the waveform shown in (figure E) after by the differential loop 54 (figure D) with Hi-pass filter function.With present commercially available a kind of Aristogrid the most efficiently, utilize the first order derivative of detector signal to form peak signal detector.At last, about Hi-pass filter, can realize with the differential loop that self just has high pass filter characteristic.

The embodiment that Figure 14 represents to use the height of apparatus for reading of bar code of a kind of possible deformation type of the optical scanner of expansion depth of focus of the present invention to simplify.Reading device 100 is hand-scanners as shown in the figure, and also can make is workstation or fixed scanner on the table.Being configured in the shell 155 of preferred embodiment realizes that shoot laser light beam 151 is placed on the mark 170 of housing exterior by exit window 156 back directives, and mark is carried out transverse cuts scanning.

As shown in figure 14, outgoing beam 151 is produced in reading device 100 by laser diode etc. usually, and is directed to the position at the bar-code marks on the target of reading device 100 front end approximate number inches.In order to make outgoing beam 151 can connect scanning patter scanning, the mode that the user is read signal according to this scanning patter transverse cuts is determined the position of hand-held device.From the light of the light of mark reflection and scattering or wherein any light 152 detect and produce electric signal series by the photosensitive devices in the reading device 100 158, these signals through processing and decoding after just reproduce the data of bar code representative.Below, " reflected light " will mean reflected light and scattered light two parts, perhaps arbitrary part wherein.

In a preferred embodiment, readout device 100 is devices of gun type, and it has the handle 153 of grips for handguns shape.The mark that user's aiming will be read, the position of determination device 100 is pulled movable trigger 154 and just can be activated light beam 151 and detecting device loop.Comprised LASER Light Source 146 in the plastic casing 155 of light weight, detecting device 158, optical system 157,147,159, CPU (CPU (central processing unit)) 140 and power supply are battery 162, have comprised signal conditioning circuit in addition.The light inlet window of shell 155 front ends both can allow outgoing beam 151 penetrate by it, also can allow the reflected light 152 that arrives inject.Reading device 100 is to design according to such use-pattern: the user makes the reading device position aim at bar-code marks (also promptly both do not contact with mark, and also do not want relative mark and do transverse cuts motion) on the position of mark leaving.Say that typically such hand-held apparatus for reading of bar code is specified in the interior operation of scope of big approximate number inch.

In order to make reading device 100 that the function of movable computer terminal be arranged, also contain keyboard 148 and display 149.

Figure 14 also illustrates, and for scanning light beam being accumulated on the bar-code marks of suitable reference surface, can use suitable lens 157 (or poly-lens system).The position of the light source 146 of semiconductor laser diode and so on is determining next on the optical axis of beam direction lens 157.Light beam is installed and is being reflected by the vibrating mirror 159 on the scan module 160 that cocking 154 activated after passing through semitransparent mirror 147 and other lens or the formation of light beam in case of necessity device.If the only invisible light that light source 146 is produced can comprise aiming light in optical system.Use the aiming light time when essential, aiming light will produce fixing, perhaps produce the visible light spot that scans as laser beam, and the user can utilize this visible light to make the reading device point of aim, and cocking 154 then.

More than be the explanation of reading, but the present invention is not only limited in these embodiment, also might be applicable to the scanning of more complicated mark about bar code original or distortion of the present invention.The present invention can also be the information that derives from literal or other mark, and perhaps the information that derives from the character of surface of scanned object is used in various machine vision or optical character identification uses.

Because the element of scanner can be combined into the integral body of minimal type in above-mentioned whole embodiment, become single printed circuit board (PCB) or incorporate module so scanning might be made.Such module can be exchanged use, obtains the laser scanning element of system as various data of different types.For example module can be contained in the portable scanner, can be installed in that scanner uses on flexible arm or machine surface stretch out on the bearing as machine, perhaps can be placed in the downside of machine upper plate, perhaps accessory or the accessory part as accurate data-acquisition system uses.

The scanning element and the optical detector components that preferably contain the laser/light system supplymentary assembly that is installed on the bearing in the module, realize by rotating mirror or vibrating mirror.For make module might and the electrical connector of other parts of data-acquisition system be electrically connected, can be connected to the Data Control line of these parts on the electrical connector that is installed in module ends or outside surface.

In each module, preferably also have specific scanning or decoding characteristics (for example, the operability at certain operating distance place or the operability on special symbols method or the printing density) correspondingly.These characteristics can by one of manual setting with touch the gauge tap that piece links to each other and select.The user only utilizes electrical connector, just can remove to scan different types of article with data-acquisition system by the module that swap data obtains in the system, perhaps can make system be adapted to different application.

Above-mentioned scan module can obtain in the system at the independent data of the one or more parts in containing keyboard, display, printer, data memory, application software and database or the like parts and realize.Such data-acquisition system, by modulator-demodular unit or isdn interface, other parts that can contain the communication network of the low power wireless communication device interior from mobile terminal to fixed signal receiver perhaps contain telephone network and the communication interface that can communicate by letter.

Although top has illustrated several embodiment and the distortion thereof about the optical scanner of expansion depth of focus of the present invention, colleagues can also do the design of multiple other distortion according to the explanation of the invention described above.

Claims (2)

1, be used for reading with photoelectric method the scanner of the expansion depth of focus of the mark with different reflectivity zone, it has a, produce and to be used for the device of radiation beam of illumination field of view, it is characterized in that it has:

B, be used for collecting from visual field internal object institute radiation reflected, the many focal lengths light-gathering optics that has the first short focal length and second long-focus at least,

C, be used for detecting, and produce the photodetector of the electrical output signal of representing this radiation from the radiation of visual field reflection by the guiding of many focal lengths light-gathering optics.

2, be used for reading scan method mark with different reflectivity zone, that enlarge depth of focus with photoelectric method, it has a, produce and be used for the step of radiation beam of illumination field of view, it is characterized in that it comprises:

B, use have many focal lengths light-gathering optics of the first short focal length and second long-focus at least, collect the step from visual field internal object radiation reflected,

C, detection are from the step visual field reflection and also produced the electrical output signal that can represent this radiation by the radiation that many focal lengths light optical system is collected.

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