CN1042982C - Non-laser scanner and scan method - Google Patents

Abstract

The present invention relates to mark reading, particularly to a photoelectric scanner for reading bar code marks, more specifically a non-laser source non-laser scanner. The scanner uses a luminous diode for transmitting a light beam and receiving reflecting light returned by marks. Consequently, the marks of image bar codes are read. An optical system in the scanner focuses the light beam and the visual field of a light sensor on two planes of a shell body; a device for imaging an observation window is arranged in the scanner; the observation window is smaller than a scanning point. The scanner uses the luminous diode (LED) as a light source; however, the LED can only see the scanning point part which can be seen by the observation window. Therefore, on the premise that reading performance is not damaged, a large scanning point (numbers of millimeters) of the LED can be used.

Description

Non-laser type scanister and method

The present invention relates to read mark, particularly read the photoelectric scanner of bar code mark, relate to the non-laser type scanner of non-laser light source specifically.

In the past, as the United States Patent (USP) the 4th, 251 of Lyceum bohr Tai Kenuojinsi company, No. 798, the 4th, 387, No. 297, the 4th, 409, No. 470, the 4th, 806, No. 742, the 4th, shown in 825, No. 057, use laser class scanner and non-laser class scanner have been proposed, be used to read the bar code mark, particularly the bar code mark of universal product mark (UPC) form.

Usually, by LASER Light Source, for example the laser beam launched of Gas LASER Tube or semiconductor laser diode focuses on through optical system, forms circular light spot on mark.By scanning mechanism luminous point is strafed mark, formed and mark respective scanned collection of illustrative plates.By the laser beam that reflects on the mark, by for example photodiode detection of photodetector, detecting device and LASER Light Source, optical system, scanning mechanism are installed in the housing together.For the ease of palm top, be preferably in handle is set on the shell.

The code pattern that mark itself is made up of a string striped, the width of fringe difference, interval width is also different, and striped has different reflective characters with the interval, and according to specific purposes and mark density, size is changeable.Generally, in order to discern the retail commodity, at the UPC mark of retail business circles use, each striped is about about 1/1000 (1 mil) with size at interval.And the cross section diameter of circular light spot is about the 6-10 mil.

Adopted the laser type scanner to obtain suitable success commercial, still, strong request reduces the price of scanner in the past.Because the laser aid size is little but can send extremely strong light beam, this is the special benefits that it has, still, LASER Light Source, compared with non-laser light source, example is much higher with light emitting diode prices such as (LED).Led light source is that cost is low at least, and is in light weight, do not rely on a lot of elements and forms optical system, and in addition, power consumption is few.But because the non-collimation formula light of led light source, the luminous point that focus on several mil sizes is very difficult, and this is the problem that exists during non-laser light source uses.Led light source can be focused into the spot definition of several millimeter, owing to will read secret note and interval about several mils, if use above-mentioned such large-sized luminous point, all can cause very big burden for the signal Processing-decoding scheme of scanner.In addition, also can cause skip and cause and read error.

In contrast, when using the laser type scanner, the size of luminous point and bar and size at interval are equal extent, thereby signal Processing-decoding scheme does not just have so big burden.Generally, the photodiode in such laser type scanner surrounds luminous point, can see with the common plane of luminous point in bigger space is arranged.

Fundamental purpose of the present invention provides the photo-electric scanner of improvement.Second purpose is to non-laser type scanner cheaply, improves the practicality and the reliability of scanner, eliminate errors, reduces cost.The 3rd purpose provides and forms the method that is contained in the inspection window within the analyzing spot.Focused beam forms analyzing spot, and after the visual field focusing with photodiode, forms observation window in analyzing spot.The 4th purpose provides analyzing spot and observation window is located at method in the outer Different Plane of scanner shell.

Effect of the present invention is: because the light source among the present invention is a non-laser light source, as light emitting diode, its cost is more much lower than LASER Light Source, and its weight is also light, and it is simple in structure, do not resemble LASER Light Source and need depend on the optical system that a lot of elements are formed, bring the low advantage of power consumption thus again, low, simple in structure, the dependable performance of scanner cost, zero defect that in a word should invention, practical, be convenient to the operation, when the operator stays out of, also can adapt to the variation of scanning mode automatically.

In order to reach above-mentioned projects, the invention provides the apparatus and method of using led light source to read mark.

Non-laser type scanner of the present invention is that the visual field with light beam and optical sensor focuses on the outer Different Plane of scanner shell.

This device comprises with the lower part:

Utilize light emitting diode to produce the non-laser light source part of light beam; Utilize the beam condensing unit of catoptron, make the garden shape analyzing spot that is incident upon behind the beam condenser in the scanning plane and forms given size; Analyzing spot is according on the mark to scope of work closely; Scanister, analyzing spot scans mark, utilizes this device that at least a portion is returned along the incident light direction; Photoelectric sensor detects the returning part of above-mentioned visual field reflects light, and detected various different light intensity degree electricity consumption signal indications is come out, and sensor is the photodiode formula sensor of band opening; Signal processing apparatus in order to handle above-said current signal, obtains representing the data of signal; Imaging device is used to make the observation figure imaging of above-mentioned photoelectric sensor and observation window is placed on the inspection surface that leaves scanning plane.This device has the imaging mirror of the spherical reflecting surface of tool.Above-mentioned scanister has sweep unit, on this sweep unit, above-mentioned focusing mirror and imaging mirror is installed, and they can be rotated together around rotation axis.

Described light source is for producing the light source of non-laser beam, for example led light source.Described focus set, light beam is focused on the scanning plane of device outside, and the analyzing spot of size is determined in formation, and analyzing spot placed on the mark of placing in the scanning plane short range, sweep unit, make analyzing spot carry out horizontal rectilinear scanning, for example by motor-driven mirror to mark.Light is reflected to all directions by mark.At least a portion of the light that is reflected by mark is towards advancing with the device reverse direction.This part catoptrical returning part has various light intensity to whole sweep trace.

Photodetector photodiode for example in the device detects the various light intensity of the reflected light returning part of whole visual field, and photodiode produces electric signal, in order to represent detected various different light intensity degree.Signal processing apparatus is handled electric signal, and forms the data of expression mark.

One of apparatus features of the present invention is to be equipped with the imaging device that makes the observation window imaging.Observation window is littler than the size of analyzing spot, is placed in the inspection surface that leaves scanning plane.Consequently, photodiode can only observedly only be the part of luminous point by observation window, and therefore, device can use LED to make light source, does not suffer a loss for making reading performance, can allow bigger analyzing spot (number millimeter).Because observation window is for counting the size about mil, photodiode can only be observed the very little part of the central authorities of analyzing spot.In this device, photodiode can not be observed the broad space that surrounds analyzing spot, can only see space very narrow in the analyzing spot thus.

As embodiment, focalizer has focusing mirror, and it makes light beam form the garden shape analyzing spot of given size.Focusing mirror is best to have spherical reflecting surface.

Imaging device is provided with the diaphragm of aperture near photodiode sensor, perhaps establish very small-sized photodiode.Reflected light arrives on the photodiode by the aperture of diaphragm.Aperture has determined the sensing range of photodiode.

In addition, imaging device also is provided with imaging mirror.Imaging mirror preferably has spherical reflecting surface.According to the requirement of scanister, in order to sweep away mark along longitudinal direction, focusing mirror and imaging mirror preferably are contained on the scanister, and they can be moved simultaneously.Therefore, above-mentioned two catoptrons are mounted to the state that can sway simultaneously.

Imaging mirror is installed on the focusing mirror, and above-mentioned axle is departed from an angle.As best embodiment, light beam is launched along the 1st optical axis.And, the observation window of sensor device by imaging device along the 2nd optical axis imaging.The angle of above-mentioned the 1st optical axis and the 2nd optical axis is 2 times of angle between imaging mirror and focusing mirror.

For can palm top, housing be provided with handle.Can allow the antetheca of hand held device housing be close to when the user operates and read mark, also can longitudinally leave a gap, make the scanister can be towards mark with mark.Preferred plan is that scanister is close to use.Thus, the big portion of light path is in housing, and in an embodiment, scanning plane and inspection surface at the housing antetheca or in its vicinity leave a distance mutually.

In another embodiment,, a pair of photodiode can be set, each have sensor openings in order to increase the effective range of sensor device.In this embodiment, be provided with a pair of diaphragm in the respective imaging device, be provided with aperture near each diaphragm corresponding sensor opening, perhaps constitute the aperture of sensor openings.In the imaging device, each visual field of photodiode imaging respectively, and outside housing, in the different inspection surface a pair of observation window is being set.Preferably use like this, the decoding of the highdensity mark inspection surface of " closely ", the inspection surface of " at a distance " is then used in the decoding of low-density mark.

In the above-described embodiments, feature is, detects the character of the bar-code marks in reading, and identification is high density or low-density bar code mark, correspondingly changes the frequency span of signal processing circuit.Like this, treatment circuit can use only frequency span to reading various bar codes.Because during broadband, many noises can be propagated into by treatment circuit, for high-density bar code, only use necessary frequency span, lower frequency span as far as possible.As for low-density bar code mark, then there is no need to use the broadband signal treatment circuit identical with the high density bar code.

In this device,, omit mechanical part and electronic component as far as possible in order to reduce the cost that reads bar code device.As an embodiment, as hand-scanner, when energized, need not normally used trigger-type switch and adopt other modes, the user is after finishing the preliminary work that reads bar code, as long as one picks up handheld scanner, action sensor just detects, and starts light source and scanning motor immediately.After finishing bar code decoding, can deenergization and scanning motor by suspending circuit.

This method may further comprise the steps:

Produce light beam; Form analyzing spot, above-mentioned light beam is through forming the analyzing spot of given size on scanning plane behind the focusing mirror, with above-mentioned scanning fixed fire in scanning plane closely on the mark in the scope of operation; Scan, analyzing spot sweeps away mark, and forms sweep trace under the minute surface action, and reflected light reflects from mark, and the catoptrical returning part of its at least a portion is penetrated back along the direction of above-mentioned light source incident; Light-to-current inversion, whole visual field catoptrical through curved surface mirror reflects returning part, by sensor, and the various light intensities that will detect convert electric signal to; The processing of electric signal is handled above-said current signal, obtains representing the data of mark; Imaging process, the observation window imaging of the sensor, and observation window is placed on the inspection surface that leaves scanning plane.

With reference to accompanying drawing, read following embodiment, can further understand the formation and the using method of invention.

Fig. 1: the simple front elevation of the 1st embodiment of non-laser type scanister;

Fig. 2: the analyzing spot that the bar code mark that is read by the scanister of Fig. 1 and going up overlaps and the enlarged drawing of observation window.

Fig. 3: the front elevation that is used for the scanning motor catoptron assembling body of Fig. 1 scanister.

The planimetric map of the scanning motor of Fig. 4: Fig. 3 and catoptron assembling body.

Fig. 5: according to the front elevation of Fig. 1,3,4 the portable scanister that embodiment constituted.

Fig. 6: the digitizer circuit diagram that is used for Fig. 1～Fig. 5 scanister.

Fig. 7: the time-domain signal figure of presentation graphs 6 circuit voltages.

Fig. 8: the circuit diagram of alternative embodiment of motion sensor that is used for the scanister of Fig. 1～Fig. 5.

Fig. 9: the 2nd embodiment about the non-laser type scanister of the present invention faces sketch (corresponding with Fig. 1).

Figure 10: the bar-code marks of Fig. 9 embodiment and represent the enlarged drawing (corresponding) of two watch windows and analyzing spot with Fig. 2.

Figure 11: relate to the commercially available scanner front elevation of the present invention.

Figure 12: relate to commercially available scanner side view of the present invention.

Figure 13: available digitizer circuit diagram in Fig. 1～Fig. 5 scanister.

The explanation of symbol: 10 non-laser light sources (LED), 11 incoherent non-collimation wide-angle light beam.12 focusing mirrors, 13 focussing planes 14,14b bar-code marks 15 analyzing spots 16, the lines of 16a mark 14 and minimum dimension 17 at interval, 17a, 17b optical sensor 18,18a, 18b imaging reflective mirror 18,19a, 19b diaphragm 20,20a, 20b aperture 21,21a, output 58 pilot lamp of output 57 controllers of 21b observation window 22 scanning planes 23 scanning motors 24 sweep traces 25 rifle sandwich type elements 26 small of the stock portions 27 rifle bodies, 28 windows, 29 surface of packages, 30 circuit substrates, 31 cables, 32 current-to-voltage converters, 33 differentiators, 34 amplifiers, 35 delay elements, 36 peak detection comparers, 37 pseudo-transition gate pulse comparer 38 threshold limit value circuit 39 locking comparers 40 transistors 41 output terminals 42 analogue grounds 43 auxiliary circuits 50 coils 51 FET switches (switch with field-effect transistors) 52 power supplys 53 detecting devices 54 outputs 55 controllers 56 controllers or the output shaft 62 covers 64 printed chassiss 66 light emitting diodes 68 photodiodes 70 scanning mechanisms 72 coils 74 magnet 76 motor support framves 78 a pair of leaf spring 80 small mirrors 82 large-scale catoptrons 84 of alarm 60 motors, 86 optical axises, 88 planes, 90 catoptron bracing frames, 92 turning axles, 94 lines, 96 differentiating circuit, 98 low-pass filters, 100 resistors 102, output 112 zero-crossing detectors 114 treatment circuit nets 116 output terminals 118 detecting devices of 104 capacitors, 106 FET switches, 108 lines, 110 low-pass filters

In conjunction with the accompanying drawings embodiment is described as follows:

" mark " used in the present invention this term is comprising a kind of striped or the mark that constitute with the part with different reflective characters.As the upc bar code mark that is found everywhere, perhaps code 39, Codeadar Interler Leaved 2 to 5 grades or other code literal.

Scanister shown in Figure 1 has the non-laser type light source 10 of light emitting diode (LED) etc., and the light beam that light source 10 produces is incoherent, uncollimated wide-angle light beam 11.Light beam 11 is focused on the plane 13 by curved reflector 12.Fig. 2 represents the bar code mark 14 that is read.Noticeablely be, the luminous point 15 that light beam 11 produces after focusing on, more much bigger than the lines or the minimum dimension 16 at interval of mark in the inspection surface 14.The scanister of Fig. 1 has optical sensor 17, such as photodiode.Light beam 11 shines the light that reflects on the mark, is focused on by little shape curved reflector 18, concentrates to be mapped on the detection faces of above-mentioned optical sensor 17.Diaphragm 19 retainings fall a part of reflected light, and the sub-fraction reflected light of light beam is reached on the sensor 17.Aperture 20 is preferably 6 * 16 mils, and as shown in Figure 2, this is the border of observation window 21 with regard to the visual field that has determined optical sensor.The observation window 21 of optical sensor 17 is imaged on the plane 22 by curved reflector 18.Light beam 11 is focused on by curved reflector 12 and produces focal planes 13, and the certain distance in focal plane 13 is left on plane 22 on its optical axis direction.Because the number of reading 14 is placed in the plane 22, the picture of the aperture 20 in the plane 22, the observation window 21 of formation optical sensor on mark.Two curved reflectors 12 are identical with 18 focal length in illustration, and therefore, the distance between plane 13 and the plane 22 equals poor to the distance of catoptron of light source 10 and optical sensor 17.

As shown in Figures 3 and 4, catoptron 12,18 drivings by motor 23 make analyzing spot 15 and observation window 21 sweep away mark in the plane 22 along sweep trace 24.Small reflector 18 is installed on the large reflective mirror 12, and the central shaft of catoptron 18 only departs from an angle [alpha] with respect to the central shaft of catoptron 18, and the optical axis of light source 10 only departs from an angle beta with respect to the optical axis of optical sensor 17, and angle α is 1/2 of angle β.

Because the analyzing spot 15 that light beam 11 produces is more much bigger than the observation window of optical sensor 17, the sub-fraction that the just light beam that therefore detects shines, certainly, reflected light only has only small part to shine on the optical sensor.Generally, a little less than the light beam of beam intensity that photodiode produces than the LASER Light Source generation.Thereby, in order to allow luminous point 15 that enough big light intensity is arranged, utilize the light of more light emitting diode to focus on the scanning plane, the size that adds large reflective mirror 12 then is critical problem.It should be noted that, the structure of typical laser scanner and the structure of Fig. 1, Fig. 2 are antithesis, promptly under the situation of laser scanner, on focus, assemble bright light beam, the luminous point of minimum dimension 16 equal extent of formation and bar code collection of illustrative plates, therefore, the visual field of the optical sensor of use is big more a lot of than laser spot.In contrast, under the situation of LED scanner, the luminous point 15 that is formed by light beam is big, and the observation window 21 of optical sensor is then little.

One of embodiments of the invention as shown in Figure 5, as leader's rifle, small of the stock part 26 in the portable gun-shaped shell that rifle body portion 27 is formed, is provided with Fig. 1～scanister shown in Figure 3.In this embodiment, scanister is a bar code scanner of being close to formula, and when reading, the front end of housing is close to the microscler sign indicating number mark 14 on the surface of package.The front end of the rifle body 27 of housing 25 is provided with window 28, and LED light beam 11 window thus passes through, and also passes through it by the reflected light that reflects on the mark.When reading mark, window 28 is close to the bar-code marks 14 on the surface of package 29, perhaps is placed on the very approaching position.Actual window member also can omit (promptly establish hole also can) on housing, perhaps window 28 is arranged on the front end inboard of housing 25, leaves the about 1/2 inch position of front end and also is fine.Can prevent to abrade window like this.

Optical sensor leaves on the position of window 28 certain distances near the front end of rifle body 27 in vertical direction, therefore, understands easily, and the imaging plane 22 in hole 20 and the plane of optical sensor 17 are almost in same plane.Catoptron 12,18 and CD-ROM drive motor 23 are assemblied in the rear end of rifle body 27.Be used for the circuit that the electric signal that optical sensor produces is handled and install interior other necessary control circuits, be arranged on the circuit board 30 in the small of the stock 26.In the device of Fig. 5, cable 31 is except the voltage of supplying with light source 10 and motor 23, and also as the lead of transport process bar-code marks data, cable draws receives terminal or main website.Change above-mentioned connection, also can use the RF line to pass the signal to main website.Also can in housing 25, load onto accumulator, for example in the small of the stock, load onto accumulator, can obtain small portable, portable scanister thus.

The scan method of this portable scanister may further comprise the steps:

When portable scanister was placed on the support, this device kept stationary state (said apparatus remains static, and scanning motor and light source are not powered); The user picks up this device and shifts to the mark that will read, and the motion of said apparatus is detected; Comprise detection, the electric signal that detects the voltage in the scanning motor coil and produce by reflected light to the action of the movable member of scanning motor.Corresponding above-mentioned detection, above-mentioned scanning motor and light source energising, the electric signal indication is arranged after, with light source and motor outage.

Circuit shown in Figure 6 is that the simulating signal that optical sensor produces is become the digital signal that can represent bar code, is reasonable digitizer.It is online that optical sensor 17 is connected electric signal processing circuit, and the bar code electric signal that scanning is obtained carries out data processing.The signal of each point in Fig. 7 presentation graphs 6 circuit.

Fig. 7 (a) expression optical sensor is defeated by the original analog of current-to-voltage convertor 32.The voltage input differentiator 33 that converter 32 produces.Differentiator 33 produces a derived function of the simulating signal of having changed.A derived function input amplifier 34 with signal.34 pairs of derived functions of amplifier are carried out amplification and filtering.The solid line of Fig. 7 (b) is the derived function (and being reverse) after the amplification filtering.Why reverse above-mentioned signal is, is because converter 32, differentiator 33 and amplifier 34 all carry out reverse reason to its input signal separately.

A derived function signal after the amplification filtering is imported respectively in following four elements, i.e. delay element 35, peak detection comparer 36, pseudo-transient process gate pulse comparer 37 and threshold limit value circuit 38.The dotted line of Fig. 7 (b) is represented a delayed derived function signal.A derived function signal that amplifies and a derived function signal of delay are imported the reverse input end and the positive input of peak detection comparer 36 respectively.Shown in Fig. 7 (b), these two signals have intersection, promptly have equivalent point.In these point of crossing, peak detection comparer 36 changes its output state.The output signal of Fig. 7 (c) expression peak detection comparer 36.Peak detection comparer 36 is output signal input locking comparer 39.

Also import the reverse input end of pseudo-transient process gate pulse comparer 37 through a derived function signal after the amplifier amplification.The positive input of comparer 37 is input feedback signal then.The output signal of the pseudo-transient process gate pulse comparer 37 of Fig. 7 (d) expression.Peak detection comparer 36 changes to after the final state, when pseudo-transient process gate pulse comparer 37 has changed state, and 39 transition states of locking comparer.In other words, just after the transient process of gate pulse comparer, during the beginning of peak detection comparer 36 transient process, locking comparer 39 is the change state.Like this, even because noise makes the output of peak detection comparer 36 produce pseudo-transient process, 37 of pseudo-transient process gate pulse comparers otherwise barefoot lock, the output of locking comparer 39 can not produce pseudo-transient process.

The output of locking comparer 39 is passed to output terminal 41 through transistor 40.The signal of Fig. 7 (e) expression output terminal.In addition, when each point is necessary analogue ground in the circuit, realize with auxiliary circuit 43.

The barefoot lock level of gate pulse comparer 37 is decided by the hysteresis that positive feedback produces.This level is set to hang down slightly than the minimum signal peak value of prediction, omits height a bit than noise level.In order to ensure digitized maximal accuracy, should give the hysteresis of peak detection comparer 36 minimums on the other hand.

It is certain negative value DC voltage that threshold limit value circuit 38 is set threshold limit values, threshold limit value circuit 38, and the continuous impulse row that are limited to above threshold value exist, and needn't suspend and may restart, and are similar to the effect of one shot multivibrator.If the stand-by time of pulse is longer than time out, compulsory informal voucher (at interval) state that turns back to of the output of digitizing striped.The output waveform of Fig. 7 (f) expression threshold limit value circuit 38.The critical value of this threshold limit value circuit 38, promptly the performance of getting rid of noise is improved in the zone beyond at the bar code two ends.

Circuit diagram when being the closing and connect of scanning motor 23 shown in Figure 8.When reading the bar code mark and being ready to, for the enough manual gated sweep action beginnings of energy, general product is provided with the trigger-type switch at the small of the stock position of handheld scanner, but, in this scanister, quantity and built-up time in order to reduce element reduce cost, and raising reliability, this device saves the trigger-type switch, as long as user one picks up scanister, just connects circuit and makes testing agency's pick-up unit action.When the user is placed on device on the sales counter, use the acceleration signal that detects, close scanning motor 23 and light source 10 (the same with stopping device), when picking up device, the acceleration signal of detection makes device start working automatically.

For this reason, the coil 50 of motor 23 is serially connected on the power supply 52 through FET switch 51, only adds voltage just for motor 23 when FET switch 51 is connected.The voltage that is added on the coil 50 is detected by detecting device 53.But, on motor coil, not during making alive,, on coil, induce little voltage by the rotation of coil rotor, no matter how to rotate can both perception for motor drive shaft.Because catoptron 12,18 can rotate freely with the coaxial support of motor, not during making alive, need only the device that makes a movement a little on the motor coil 50, catoptron also moves.The output 54 of detecting device 53 is received on the controller 55, and the output 56 of controller 55 is added to the control of FET switch 51 and extremely goes up, its objective is control motor connection with close.Controller 55 can perhaps use the controller that adopts among Fig. 6 with the microcontroller of Intel's 8031 forms, and this controller is the digitizing barcode signal for the output terminal 41 of evaluation map 6, and use.In order to start led light source 10, used the output signal 57 of controller 55.In addition, when finishing bar code decoding, the output 48 starting pilot lamp (perhaps alarm) with controller 55 make the user know EO.In addition, for countdown various out-of-date during, controller 55 can be used built-in timing register.For example, begin certain hour with detecting device 53 engaging means after, or after the correct identification of bar code, scanning motor and light source can be stopped automatically.When the user picked up housing 25 and reads other bar codes, even make device be in off-state by out-of-date circuit, as long as device is shifted to next bar-code marks, device was just opened once more.

Scanister not only can be a contact shown in Figure 5, also can keep the noncontact form more than mark number inch, as United States Patent (USP) the 4th, 387, No. 297, the 4th, 409, No. 470 and the 4th, 816, No. 660 records like that, be exactly contactless.Housing 25 can be arranged on the counter top or on other supporting surfaces, can use upwards scan-type, and scan-type or side scan-type can be assembled into independently worktable downwards.Perhaps, scanner head pack into fixing or or adjustable trestle in also be feasible.

Scanning mechanism comprises the catoptron 12,18 that can swing, and they are installed on the output shaft of motor 23, and scanning mechanism makes analyzing spot 15 moulds obtain sweep trace to strafing mark 14.Scanning mechanism preferably adopts United States Patent (USP) the 4th, 387, No. 297 records, high-velocity scanning motor.Among the application, point out to be fixed on the output shaft 60 of scanning motor 23 very main with catoptron 12 with focusing on.Motor 23 drives output shaft 60 and catoptron 12, around axis, swing with per second speed for several times along two garden Zhou Fangxiang, in (the garden week radian of swing generally is significantly smaller than 360 degree, is about 32 degree among the embodiment of Fig. 1 and Fig. 5) most preferred embodiment, focus on catoptron 12 and output shaft 60 and swing together, like this, in the corresponding arc length in the about 32 degree angles of scanning plane 22 interscan points 15 swings, in sweep trace 24, about per second longitudinally sweeps away mark 14 20～40 times repeatedly.

About along single scanning line 24, sweep away mark 14, be described, owing to reading the scanning spectra that can form various forms on the basis of mark, the invention is not restricted to above content, for example as U.S. Patent application the 317th, No. 533 (application on March 1st, 1989), United States Patent (USP) the 4th, 369, No. 361 and the 4th, 387, that puts down in writing for No. 297 is such, also passable by the collection of illustrative plates that one group of sweep trace that is parallel to each other is formed.

As previously mentioned, for recognition value, generally use close bar-code marks 14 at retail sector, each striped is about about several mils with size at interval.The analyzing spot 15 that dual-purpose catoptron 12 focuses on is about several millimeter.In order to detect the striped front and back end of bar-code marks, analyzing spot is excessive, worries that decoding can produce error.In the laser type scanner, the sectional dimension of analyzing spot generally has only about 6～10 mils, adopts complicated high-precision signal treatment circuit if do not rely on, and lose too much energy, in order to reach optimum that this size of minimum should get reading and decipher error.

According to the present invention, imaging device is arranged in the housing 25, and imaging device is provided with for observation window 21 imagings of photodiode 17.Observation window 21 is narrower than the scope of analyzing spot, drops on fully in the analyzing spot 15.The imaging device advantageous device has imaging mirror 18 and has the diaphragm 19 in hole 20.For imaging is rotated around the output shaft 60 of scanning motor 23 together with catoptron 18, imaging preferably is installed on the focusing mirror 12 with catoptron 18.The axis of imaging mirror 18 and focusing and catoptron depart from an angle.Hole 20 is arranged near the sensor openings of photodiode 17.Sensor openings itself can replace the effect in hole 20, changes a mode, and photodiode 17 hour is favourable very.That is, the photodetector noise of so little shape is little, and the cost of scanner is low, optical devices also are difficult for polluting, aperture 20 is preferably made rectangle or ellipse garden shape, and short-axis direction size (for example 6 mils) is consistent with the direction of scanning, and long axis direction size (for example 16 mils) is vertical with the direction of scanning.Under slot 20 and imaging mirror 18 actings in conjunction, as shown in Figure 2, form same rectangular observation window 21.For example aperture 20 is ellipse gardens, and observation window equally also is ellipse garden.

In addition, have the imaging mirror 18 of spherical reflecting surface, observation window 21 is arranged in some inspection surfaces 22 in housing 25 outsides.Inspection surface 22 longitudinally leaves certain distance with scanning plane 13.Focusing mirror 12 not necessarily must be like this with imaging mirror 18, but preferably has identical focal length.Hole 20 is imaged on the inspection surface 22 with approximate 1 times enlargement factor, forms the aperture aberration that is about 6 * 16 mils (size of observation window 21).The light beam 11 that the 1st optical axis and LED10 and focusing mirror are 12 is coaxial, second optical axis and imaging with between catoptron 18 and optical diode to return the light velocity coaxial.The 1st optical axis and and the 2nd optical axis between angle beta be 2 times of angle α between imaging mirror and focusing mirror.

According to the present invention, photodiode 17 is seen the very little part in analyzing spot 15 centers only.In fact, the picture of aperture 20 becomes the part in the analyzing spot.Thereby if use the scanner head of several millimeters sizes, though there is not inherent distinctive decoding error, the size along the direction of scanning in generation is used and the bar or the suitable observation window 22 of the size of space that read mark.

Because other shapes also are fine, and the invention is not restricted to oblong shaped orifices.Depth of focus and the ability that reads mark are decided by the shape of aperture.

Fig. 9 is an another embodiment of the present invention.This apparatus for reading of bar code is not single photodiode, and is to use a pair of photodiode 17a, 17b.Photodiode 17a, 17b and diaphragm 19a, 19b be corresponding imaging mirror 18a, 18b respectively.As shown in figure 10, imaging mirror 18a, 18b form a pair of overlapping observation window 21a, 21b.Observation window 21a is applicable to highdensity bar-code marks, and another bigger observation window 21b then is applicable to low-density bar-code marks.The width correspondence that observation window 21b has the minimum dimension of the formation element of bar-code marks 14b., observation window 21a, 21b not only leave scanning plane 13, leave each other be on the different inspection surfaces good.Therefore,, also can clearly focus on, enlarge scope of work at mark from the reading device different distance.

Figure 11 and Figure 12 be in the scanner of the present invention on market welcome embodiment.Scanning machinery is contained in the shell 62, and shell 62 is to make with light plastic, even insouciant use is also very solid.Critical piece can both be contained on the printed circuit board (PCB) 64.As critical piece,, outside the various electronic units, also comprise the miscellaneous part that above-mentioned mark is scanned except light emitting diode 66, photodiode 68, scanning mechanism 70.

Scanning mechanism 70 is made up of coil 72, magnet 74, motor bracket 76, a pair of leaf spring 78 (preferably mylar), small mirrors 80 and large-scale catoptron 82.Light by the LED66 emission advances along axis 84, and after the bar-code marks reflection, the reflected light that turns back to photodetector advances along axis 86.The same with the foregoing description, axis 84 and 86 angle β are preferably about 8 degree.By the light of LED emission, after large-scale catoptron 82 reflections, in plane 88, penetrate scanner, then return in the scanner.Axis 84 is the best with the angle γ on plane 88 with 7.5～8 degree.As shown in figure 12, in order to obtain this angle, after installing and disposing large-scale catoptron 82, allow LED66 stick up a bit slightly upward.

For mark is scanned, in coil 72, add per second electric pulse repeatedly, for example per second is about 40 times.Coil one galvanization just attracts to be fixed on the magnet 74 in the mirror support 90.Catoptron 80 and catoptron 82 are installed on mirror support 90.Magnet one is sucked in the coil 72, and with mirror support 90, catoptron 80,82 also rotates around fulcrum together.Because rotation, leaf spring produces distorting stress.Voltage one cancellation in the coil, leaf spring makes mirror support and catoptron turn back to rest position together.The restoring force respective electrical spike train drive coil 72 of leaf spring 78, scanning is smoothly carried out equably then with desired frequency, sweep amplitude.

Shown in Figure 11 and 12, bar code scanner of the present invention does not use the trigger-type switch of usefulness in the past.Replace, this scanner uses motion sensor.As shown in Figure 8, as long as user one picks up scanner 1.Motion sensor just detects This move, detects corresponding to this, has connected the electric pulse row generation source and the light source of coil 72, after this, by out-of-date circuit or corresponding to finishing bar code decoding, closes generation source in light source and the arteries and veins again.The user picks up scanner when next bar-code marks moves, and motion makes sensor to scanning than beginning again after the motion.

Below Figure 13 is illustrated.The electric signal that bar-code marks scanning produces is handled by signal processing circuit, and optical sensor 17 is received on this circuit.Digitizer can adopt U.S. Patent application the 440th, No. 510 (application on November 22nd, 1989) identical versions, the other forms of structure that perhaps adopts the cited patent documentation in front to put down in writing, for example United States Patent (USP) the 4th, the form of 360, No. 793 records also can.But, be as one of feature of most preferred embodiment, added automatic frequency span control device.The analog electrical signal warp 94 that optical sensor 17 produces is delivered to differentiating circuit 96.A derived function of differentiating circuit 96 output simulating signals.The frequency range of a simulating signal or a derived function signal is the form that frequency span is decided by the bar-code marks 14 that is scanned.High-density bar code mark 14, because the frequency height of transition between the B﹠W, simulating signal medium wave peak and trough are just many.Promptly the zero crossing of a derived function is also many.The output of differentiating circuit 96 is received on the low-pass filter 98, and low-pass filter is made up of resistance 100 and capacitor 102.The cutoff frequency of low-pass filter 98 is decided by series capacitors value on the resistance.Thereby in order to change cutoff frequency (also being in order to change the response band width of digitizer net certainly), it is in parallel with capacitor 102 that building-out condenser 104 has been installed.In addition, for capacitor is disconnected from wave filter, be provided with switch 106, if when being added in voltage on 108 lines and surpassing switch with field-effect transistors 106 threshold voltages, fet switch 106 is just connected circuit, so capacitor 104 just is connected in parallel on the capacitor 102, make cutoff frequency reduce (frequency band narrows down).But, if be added in when being no-voltage in fet switch 106 control extremely by 108 lines, because capacitor 104 disconnects, cutoff frequency raise (frequency band is widened).The output 110 of wave filter is received on the zero-crossing detector 112.Because when the density of bar code mark was high, corresponding to the zero crossing increased frequency of unit interval, the output signal of zero-crossing detector 112 was that frequency band is widened with regard to having than higher radio-frequency component.Again, the output of zero-crossing detector 112 is received on other treatment circuits 114 of common form.On the output terminal 116 of this treatment circuit 114, produce the digital electric signal.This signal is transported to terminal by cable 31, perhaps discerns the bar code data in housing 25, for decoding is for further processing.The output signal of zero-crossing detector 112 is also received on the detecting device 118 (for example, integrating circuit and transducer).Detecting device 118 closes on 106 the line 108 turning back to field effect transistor, produces high voltage as low-density bar-code marks, as generation no-voltage when be highdensity bar code.Like this, when high-density bar code was scanned, capacitor 104 disconnected from circuit, has enlarged the frequency span of wave filter, and during to low-density bar code, capacitor 104 is stayed on the circuit, and the frequency span of wave filter is reduced.Thereby when low density bar codes was scanned, because frequency band is narrow, treatment circuit had been eliminated noise, thereby can correctly discern microscler sign indicating number mark, had improved reliability.

Foregoing circuit is replaced, can allow the frequency span commutation circuit respond the output of the output identification bar code device for the treatment of apparatus 114.Check the bar code signal that output terminal 116 produces, with judgement read correctness.To come in order distinguishing printing word string and bar code on noise or the packing, can to make in all sorts of ways or integrated application effect several method carries out.For example, according to the transition number of 1 scanning, promptly the corresponding black and white ratio of 1 scanning can learn that the collection of illustrative plates in the scanning is not text strings or other figures, roughly can determine it is bar-code marks.In addition, there is correct bar code collection of illustrative plates in the reservoir, can compares with the bar code signal of 116 outputs.Based on identification, can select broadband or narrow-band to the form (high density or low-density) of the bar code of reality in the scanning.That is, if in certain once scans, during recognition failures, after the switch of frequency band width, can judge whether scanning is correct next time.

More than the composed component of Chan Shuing uses separately or after two or more combinations, constitutes other forms different with above-mentioned form etc., also can be applied.This is understandable.

The present invention specifies with the LED-type scanner, but in the scope that the present invention relates to, can carry out the structural change of various modification formulas, therefore, and the concrete detailed construction that is not limited to put down in writing above.

Even further do not study, because above explanation is fully clear and definite for main points of the present invention, the brainstrust in this field, even stand in the essential characteristic of seeing on the technology position in the past also without detriment to uniqueness of the present invention, use modern knowledge, the present invention can be easy to be applicable to various uses.But, this should belong to impartial scope, has been included in certainly in this patent claim scope.

Claims (40)

1, a kind of non-laser type scanister that reads mark, this device comprises with the lower part:

The Lights section of a, generation light beam;

B, beam condensing unit make the analyzing spot that is incident upon behind the beam condenser in the scanning plane and forms given size;

C, scanister make analyzing spot scan mark, utilize this device that at least a portion is returned along the incident light direction;

D, photoelectric sensor detect the returning part of above-mentioned visual field reflects light, and the detected different light intensity degree electricity consumption signal indication that makes preparations for sowing are come out;

E, signal processing apparatus in order to handle above-said current signal, obtain representing the data of signal; It is characterized in that:

F, imaging device are used to make the observation window imaging of above-mentioned photoelectric sensor and observation window are placed on the inspection surface that leaves scanning plane; And

Described the Lights section is a non-laser light source; And described beam condensing unit impinges upon on the mark in the scope of work closely analyzing spot.

2, the device of putting down in writing according to claim 1 is characterized in that, above-mentioned non-laser light source is a light emitting diode.

3, the device of putting down in writing according to claim 1 is characterized in that, said beam condensing unit is the optical focus catoptron, in order to form the circular scan point.

4, the device of putting down in writing according to claim 3 is characterized in that, said focusing has spherical reflecting surface with catoptron.

5, the device of putting down in writing according to claim 1 is characterized in that, said photoelectric sensor has the photodiode of sensor openings, is adorning narrow meshed diaphragm near sensor openings, and above-mentioned catoptrical returning part is by this aperture.

6, the device of putting down in writing according to claim 5 is characterized in that, said aperture is a rectangle, extends to minor face along mark to longitudinal direction, extends to long limit facing to the mark transverse direction.

7, the device of putting down in writing according to claim 5 is characterized in that, said aperture is an ellipse garden shape, extends to minor axis along mark to longitudinal direction, extends to major axis along mark to transverse direction.

8, the device of putting down in writing according to claim 5 is characterized in that, imaging device has imaging mirror.

9, the device of being put down in writing according to Claim 8 is characterized in that, imaging mirror has spherical reflecting surface.

10, the device of putting down in writing according to claim 1, it is characterized in that above-mentioned focalizer has to focus on uses catoptron, above-mentioned imaging device has imaging mirror, in order to make above-mentioned two catoptrons sweep away mark action together longitudinally, they are installed on the shell.

11, the device of putting down in writing according to claim 10 is characterized in that, above-mentioned scanister tool sweep unit on this sweep unit, is installed above-mentioned focusing with catoptron and imaging catoptron, and they can be rotated together around axle.

12, the device of putting down in writing according to claim 11 is characterized in that, above-mentioned imaging is installed in focusing with on the catoptron with catoptron, and departs from angle of above-mentioned axle.

13, the device of putting down in writing according to claim 12, it is characterized in that, above-mentioned light supply apparatus is along the primary optic axis outgoing beam, above-mentioned imaging device with the visual field of the sensor device along the second optical axis focal imaging on focus, about 2 times of the fleet angle that above-mentioned two optical axis angulations are imaging mirror and focusing mirror.

14, the device of putting down in writing according to claim 1, it is characterized in that, above-mentioned shell is in order to be convenient to palm top, have handle portion, the user is holding handle makes shell towards mark, vertically leave certain intervals by antetheca to mark, just can read mark, above-mentioned scanning plane and inspection surface leave certain distance for the antetheca of shell along longitudinal direction.

15, the device of putting down in writing according to claim 1, it is characterized in that, the sensor device is a pair of photodiode that respectively carries sensor openings, above-mentioned imaging device is for being equipped with a pair of diaphragm that has aperture separately respectively near sensor openings, to the poly-picture in the visual field of photodiode separately respectively, on the different inspection surface in the outside of shell, a pair of observation window is housed.

16, a kind of non-laser scanning method that reads mark, this method may further comprise the steps:

A, generation light beam;

B, formation analyzing spot, above-mentioned light beam focuses on the back forms given size on scanning plane analyzing spot;

C, scan, analyzing spot sweeps away the formation sweep trace to mark, and reflected light reflects from mark, and the catoptrical returning part of its at least a portion is penetrated back along the direction of above-mentioned light source incident;

D, light-to-current inversion, the catoptrical returning part of whole visual field, by sensor, and the various light intensities that will detect convert electric signal to;

The processing of e, electric signal is handled above-said current signal, obtains representing the data of mark; It is characterized in that this method also comprises:

F, imaging process, the observation window imaging of the sensor, and observation window is placed on the inspection surface that leaves scanning plane; And

The step of described generation light beam is to produce light beam with a non-laser light source, and the step of described formation analyzing spot is to make on the mark of described scanning fixed fire in short range.

17, the method for putting down in writing according to claim 16 is characterized in that, above-mentioned step b is that light beam is from the camber reflection mirror reflection.

18, the method for putting down in writing according to claim 16 is characterized in that, above-mentioned steps d is for using the above-mentioned returning part light of camber reflection mirror reflection.

19, the method for putting down in writing according to claim 17 is characterized in that, above-mentioned steps c comprises allows above-mentioned curved reflector move.

20, the method for putting down in writing according to claim 16 is characterized in that, above-mentioned observation window has the minimum dimension width much at one with expression mark feature.

21, a kind of portable scanister, the method for action is characterized in that, this method may further comprise the steps:

A, when portable scanister is placed on the support, this device keeps stationary state (said apparatus remains static, and scanning motor and light source are not powered);

B, user pick up this device and shift to the mark that will read, and the motion of said apparatus is detected;

C, corresponding above-mentioned detection, above-mentioned scanning motor and light source energising.

22, report the method for putting down in writing according to claim 21, it is characterized in that above-mentioned steps b comprises that the action to the movable member of scanning motor detects.

23, the method for putting down in writing according to claim 22 is characterized in that, the detection of motion of above-mentioned movable member is to detect the voltage that produces in the coil of scanning motor earlier.

24, the method for putting down in writing according to claim 21 is characterized in that, produces light beam by above-mentioned light source, by scanning motor, with above-mentioned light beam bar-code marks is carried out transversal scanning.

25, the method for putting down in writing according to claim 22 is characterized in that, comprises that detection is by the light of mark reflection and corresponding therewith generation electrical signal detection stage.

26, the method for putting down in writing according to claim 25 is characterized in that, to after the scanning of stripe shape mark the electric signal indication having been arranged, after official hour, with light source and motor outage.

27, the method for putting down in writing according to claim 21, it is characterized in that, above-mentioned light source is a light emitting diode, the light beam that with curved reflector light emitting diode is sent by scanning focuses on the scanning plane, the light that reflects on the mark is collected on the photodetector with curved reflector by light harvesting, drives above two curved reflectors with above-mentioned scanning motor.

28, a kind of bar code scanner is characterized in that, this scanner comprises following components:

A, hand-held unit, this assembly are placed on the support and when remaining static, scanning motor and light source are in closed condition.

B, detecting device when the user shifts to said modules bar code and reads the position, adapt above-mentioned sensors work with the action of said modules.

C, controller, in response to above-mentioned detecting device, scanning motor and light source energising.

29, the scanner of putting down in writing according to claim 28 is characterized in that, above-mentioned detecting device detects the action of the movable member of scanning motor.

30, the scanner of being put down in writing according to claim 29 is characterized in that, the action of above-mentioned movable member produces electric signal in the coil of scanning motor, by detecting the action that this voltage signal detects movable member.

31, the scanner of putting down in writing according to claim 30 is characterized in that, above-mentioned scanning motor is rotary-type motor or resonance type motor.

32, the scanner of putting down in writing according to claim 28 is characterized in that, said modules has curved reflector and light source, is driven by scanning motor, the bar code mark that light beam transversal scanning will be read.

33, annotate 32 scanners of being put down in writing according to the right village, it is characterized in that above-mentioned light source is a light emitting diode.

34, the scanner of putting down in writing according to claim 32 is characterized in that, said modules has optical sensor and is used to receive the reflected light that mark reflects, and reflected light is to be reflected by the curved reflector that above-mentioned scanning motor drives.

35, a kind of method that makes the action of bar code scanner is characterized in that this method may further comprise the steps:

A, with beam alignment bar code mark;

B, detect the corresponding generation of the light electric signal of the light that reflects by the bar code mark and detection;

C, above-said current signal is received the selectable circuit of bandwidth;

The performance density of the expression bar code feature in d, the detection above-said current signal produces control signal, and,

E, utilize above-mentioned control letter and the above-mentioned frequency span that can select of change.

36, the method for putting down in writing according to claim 35 is characterized in that, foregoing circuit is the wave filter that can select frequency span, and in order to select frequency span, wave filter has the capacitor that can select electric capacity.

37, the method for putting down in writing according to claim 35 is characterized in that, when above-mentioned performance density was low, above-mentioned frequency span narrowed down.

38, the method for putting down in writing according to claim 35 is characterized in that, when above-mentioned performance density was high, above-mentioned frequency span broadened.

39, annotate 35 methods of being put down in writing according to the right village, it is characterized in that above-mentioned light beam is produced by light emitting diode.

40, the method for putting down in writing according to claim 39 is characterized in that, above-mentioned light beam sweeps away the bar code mark with the form of luminous point, and the reflected light of above-mentioned mark impinges upon on the detecting device and produces electric signal.

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