JP3912810B2 - Multi-directional scanner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates generally to a scanner scanning device that operates to repeatedly scan an indicator having different light reflectance portions, such as bar code symbols. In particular, the present invention relates to a multi-directional scanner having a scanning device that provides a large scanning pattern.
[0002]
[Prior art]
Various optical readers and optical scanners have been developed that can read barcode symbols or other indicators marked on an object in order to identify the object by optically reading the symbol on the object. . Typically, a barcode symbol is used as a coded pattern consisting of a series of bars of various widths, also separated from each other by spaces of various widths. Have different light reflection characteristics.
[0003]
A special variant of this type of scanner is the multi-directional scanner, which is so named because this type of scanner can read bar code symbols displayed in any direction. It is what. Typically, a multi-directional scanner can generate a “cross-hatch” type scan pattern, which features several sets of parallel lines, each set being angularly separated from each other. Therefore, the entire 360 ° is covered. Such a cross-hatch pattern is created by directing the light beam to a rotating plane or polygonal mirror that scans the light beam across a group of stationary mirrors and generating several scan lines. The stationary mirrors are angled with respect to one another, thus ensuring that the corresponding scan lines have a similar angle.
[0004]
A special variant of a multi-directional scanner known as a “display” or “projection” scanner is currently offered by many manufacturers. Typically, these scanners are intended for use in a POS environment where an article with a barcode is passed through or presented to the scanner. Examples of these include Metrologic MS-700, Fujitsu Slim Scan 1000, Spectra Physical Space, Matsushita Electric ZE-87, and the like.
[0005]
[Problems to be solved by the invention]
Usually in a POS environment, the space allowed for the scanner is very limited, so it is highly desirable to make the scanner as small as possible. However, when the scanner is made smaller, the scanning pattern becomes smaller. This results in the scanner becoming difficult to use because the operator must more carefully position the barcode symbol to be scanned in the scan pattern. Such positioning is often performed in a blind state. This is because the scanning pattern is usually not visible with normal room lighting, and the scanner is often positioned with the symbols invisible to the operator when scanned.
[0006]
Thus, it is apparent that it would be desirable to provide a scanner that accommodates small packages but generates the maximum possible scan pattern. However, providing such a scanner is not an easy task.
As mentioned above, known scanner scan patterns are typically generated by scanning a polygon mirror that scans a light beam across a fixed group of mirrors, thereby creating several scan lines.
[0007]
The fixed mirror is oriented so that the scan line reflected therefrom converges to the desired scan pattern just outside the exit window of the scanner. It will be appreciated that the size of the scan pattern increases with increasing distance from the pattern mirror, so it is better to place the fixed mirror behind the exit window. However, the further away the fixed mirror is behind the exit window, the deeper the housing becomes to accommodate the fixed mirror.
[0008]
There are other design considerations that also increase the thickness or depth of the scanner housing. As described above, the scanning pattern is formed by tilting the fixed mirror so that the scanning line converges to a desired scanning pattern close to the exit window. The closer the fixed mirror is to the exit window, the more the fixed mirror must tilt at a steep angle in order to converge the scan line to the correct position. If the scanner is thin, and therefore the fixed mirror tilts sharply, the scan line necessarily diverges rapidly from the desired scan pattern as the distance from the exit window increases. Therefore, the scan pattern collapses rapidly as it moves away from the scanner, and the operator is forced to approach the exit window before recognizing the bar code symbol.
[0009]
Therefore, since the fixed mirror is placed as far as possible from the exit window, even if the distance between the exit window and the barcode symbol is increased, the scan pattern becomes larger near the exit window, and the scan pattern remains converged, Clearly, it would be desirable to have a thick scanner housing to be useful as a scanning pattern.
[0010]
Numerous prior arts have been tried to resolve the conflict between trying to make a thick scanner to improve functionality and trying to make a thin scanner to save space in the checkout area. It was. A typical prior art is shown in FIGS.
FIG. 1 shows a first prior art in which the scanner housing (or body) 10 is deliberately thinned, and the distance between the front surface 12 and the rear surface 14 of the body is only about 1.75 inches (4.4 centimeters). Indicates a scanner. The light beam generated by the laser light source 16 is irradiated onto the rotating polygon mirror 18 rotated by the motor 20. The light reflected by the polygon mirror 18 is incident on a fixed pattern mirror 22 that directs the light out of the housing 10 through the exit window 24.
[0011]
For this scanner, the pattern mirror 22 is located immediately behind the exit window 24. This results in a thin package as a whole, but has the disadvantage that the scan pattern does not improve until the scan pattern is projected a few inches from the scanner (ie, the scan lines do not cross each other). This reduces the flexibility and functionality of the scanner because the operator often holds the bar code symbol close to the exit window 24. In the scanner shown in FIG. 1, it is sufficient not to block the scan line pointing in the correct direction in order to pass the barcode symbol closer to the exit window 24 and pass the scanner and read the appearing symbol. Is possible.
[0012]
Another prior art scanner is shown in FIG. In this scanner, the housing 26 is generally smaller than the housing shown in FIG. 1, but is slightly thicker and the distance between the front surface 42 and the back surface 44 is about 4 inches (10 centimeters). The laser light source 28 generates a light beam incident in the order of a first folding mirror 30, a second folding mirror 32, a rotating mirror 34 operated by a motor 36, and a fixed series of pattern mirrors 38. Thereafter, the light beam is reflected from the pattern mirror 38 through the exit window 40 and out of the housing 26.
[0013]
This scanner is also often used for symbols held closer than this, although it cannot produce well-formed patterns up to about 2.5 inches (6.4 cm) from the exit window. There is. The small size of the housing 26 as a whole means that the scan pattern is also small, and when the bar code symbol comes to a position that the operator believes is the correct position, the scan pattern is lost. This is relatively easy to happen.
[0014]
FIG. 3 shows an improvement of these prior arts. The scanner is housed in a housing 45 having a thickness between the front surface 46 and the back surface 48 of about 3 inches (7.6 cm). The laser light source 50 generates a light beam incident on a turn mirror 52, a rotating polygon mirror 54 operated by a motor 56, and a fixed series of pattern mirrors 57. The light beam is reflected from the pattern mirror 57 through the exit window 58 and out of the housing 45.
[0015]
The scanner further generates a scan pattern that is not sufficiently formed at the exit window 58. In addition, the scanning pattern needs to be relatively small compared to the overall size of the front face 46 of the housing 45. In one example that can be obtained commercially, the exit window 58 only covers about half of the area of the surface 46.
For use in situations where the scanning window is vertical or nearly vertical, as is becoming commonplace in wholesalers and supermarkets, none of the scanners described above have a particularly well-suited shape. Is one of the drawbacks. In such a situation, it is important to project the scan pattern close to the counter top, preferably a few inches from the counter top, so that the symbol is placed on the counter top on the side of the package near the scanner. The scan pattern does not lose sight of the symbol even when is very close.
[0016]
Of course, the scanner as described above is expensive, but is usually partially embedded in the counter top. One variation is to position the scanner on the counter top, but to ensure that the symbols cross the scan pattern, the operator must lift the article, which Of course, this is undesirable because it causes fatigue.
[0017]
In order to solve the above-described problems, the present invention further aims to develop a technique for a scanner for reading indices having different reflectivities, and a laser scanner for reading a bar code symbol, although not limited thereto.
Another object is to provide a compact scanner in which the scanning pattern is sufficiently formed at or near the exit window.
[0018]
Furthermore, as another object, a compact scanner having a large scanning pattern compared to the front surface of the scanner is provided.
Yet another object is to provide a scanner that is suitable for use with a vertical exit window, so that the article to be scanned slides through the scanner.
Yet another object is to provide a scanner that does not need to be partially embedded in the counter top for optimum efficiency.
[0019]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, a multidirectional scanner having the following configuration is provided.
(A) a housing;
(B) the exit window of the housing;
(C) a light emitter for generating a light beam;
(D) a beam scanner that scans the light beam;
(E) a plurality of pattern generation mirrors arranged to reflect the scanning light beam as a whole away from the exit window, thereby generating a scan pattern, and (f) reflect the scan pattern through the exit window Other mirrors arranged to face the outside of the housing,
A multi-directional scanner.
[0020]
Moreover, according to the 2nd aspect of this invention, the multi-directional scanner which consists of the following structures is provided.
(A) a housing having a front surface and a rear surface;
(B) an exit window in front of the housing;
(C) a laser that generates a light beam;
(D) a beam scanner that scans the light beam;
(E) a plurality of pattern generating mirrors arranged to reflect the scanning light beam towards the back surface of the housing and thereby generate a scanning pattern; and (f) a scanning pattern located adjacent to the back surface of the housing. Other plane mirrors that reflect and direct out of the housing through the exit window
A multi-directional scanner.
[0021]
Such multidirectional scanners provide a long optical path in the scanner by reversing the mirror normal to the exit window. In the preferred embodiment of the present invention, the scan line is directed from the mirror to the back of the housing where it is reflected from another large flat mirror towards the exit window. This makes the optical path in the housing approximately twice that of the scanner shown in FIG. 3 and four times that of the scanner shown in FIG.
[0022]
In the illustrated embodiment, the generated scan pattern is believed to be the largest among any known multi-directional scanner compared to the housing size. The scan pattern fills most of the front surface of the scanner housing. Preferably, the exit window also fills most of the front surface of the scanner housing and the scan pattern fills almost the entire area of the exit window. In a particularly preferred embodiment, the exit window can take over 60% (90%, 80%, 70%) of the scanner housing.
[0023]
This form is very advantageous when using the scanner in a POS where an article with a symbol is slid through the scanner and the exit window of the scanner is vertical or nearly vertical. In this situation, even if the scan pattern is close to the counter top, close to the counter top up to several inches, and the symbol is very close to the counter top on the side of the package close to the scanner, Do not lose sight of the symbol. This makes it unnecessary for the operator to lift each article or to embed the scanner partially in the counter top to ensure that the scanning pattern is blocked.
[0024]
In a preferred embodiment, it is a multi-directional scanner, for example a scanner whose scan pattern consists of a number of scan lines equally spaced over 360 °.
The light emitting source is preferably a laser, and is desirably a laser diode or a VLD (visible light laser diode).
The beam scanner means preferably consists of one or more rotating or oscillating mirrors, for example polygonal mirrors. However, the beam scanner means can also consist of other types of rotating or oscillating optical means, for example lenses. As another possibility, the beam scanner means can, for example, vibrate the light emitting means and directly scan the light beam emitted by the light emitting means.
[0025]
The scanner of the present invention can take many forms, including a manual scanner, a stationary (fixed) scanner, an occasional manual scanner, and a scanner that can also be used in a portable mode.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 4 shows a first embodiment of the scanner of the present invention.
The scanner includes a compact housing 100 having front and back surfaces 102, 104 and side surfaces 106, 108. An end face (not shown) is also provided. The depth between the faces 102, 104 is 3 inches (7.6 cm), the width between the faces 106, 108 is 6 inches (15.2 cm) and the length is 5.5 inches (14.0 cm). It is. A laser (emitter) 110, preferably a visible light laser diode (VLD), emits a light beam that travels substantially parallel to the bottom surface 104 of the housing. The light beam is then reflected from a small fixed folding mirror 112 to a rotating polygon mirror (beam scanner) 114 that is actuated by an electric motor 116. The light beam reflected by the rotating polygon mirror 114 traverses the housing 100 and returns to the pattern mirror (scanning pattern generation mirror) 118 composed of a plurality of fixed mirrors. The final scan pattern is reflected downward and returned to the scanner floor to the bottom mirror (mirror) 120 as shown. The scan pattern reflected by the bottom mirror 120 passes through the large exit window 122 and passes out of the scanner.
[0027]
Note that the pattern mirror 118 generally faces down in the housing 100 and is off the exit window 122. This property provides a long optical path within the scanner along the placement of the bottom mirror 120, thereby allowing a large scanning pattern to be provided even adjacent to the exit window 122. It can be seen that due to the large scanning pattern, the exit window 122 is also large and therefore occupies most of the area of the front surface 102.
[0028]
Due to the large exit window 122, the scanner is ideal for placing the exit window 122 vertically on the counter top. Since the scanning pattern extends very close to the edge of the scanner housing, the scanner can be placed on the counter top where the bottom of the package that slides past the scanner on the counter top. Nearby barcode symbols can be scanned.
[0029]
FIG. 5 shows a preferred arrangement of the rotating polygon mirror 114 and the pattern mirror 118 in the scanner of the present embodiment.
As can be appreciated, the rotating polygon mirror is preferably square (in plan view) with four mirror surfaces 114a-114d. The pattern mirror 118 has a semi-crown shape and is formed by five inclined mirror surfaces 118a to 118e. In use, the light beam exits the rotating polygon mirror 114 and is directed to the pattern mirror 118. After being reflected from the bottom mirror 120 (FIG. 4) again, a scanning pattern as shown in FIGS. 6 (a) to 6 (c) is generated. The scanning pattern consists of a total of 20 lines that form a cross hatch arrangement with each other. As can be seen from the figure, in each pattern, five groups each consisting of four lines are located at an angle of about 36 °.
[0030]
This special scan pattern provides a tight line that covers both the surface of the scanner and when 8 inches (20 centimeters) away, so that the bar code symbol is displayed at what angle to the scanner Also reduces the amount of barcode orientation required to cross the scan line.
6 shows a scanning pattern, FIG. 6 (a) shows the scanning pattern at the exit window 122, FIG. 6 (b) shows the scanning pattern at about 3 inches (8 cm) from the exit window, and FIG. c) shows a scanning pattern at 4.25 inches (10.8 cm) from the exit window.
[0031]
The preferred dimensions of each scanning pattern are as follows.
a = 2.214 inches (5.624 cm)
b = 1.962 inches (4.983 cm)
c = 3.6 inches (9.1 cm)
d = 3.1 inches (7.9 cm)
e = 3.2 inches (8.1 cm)
f = 3.9 inches (9.9 cm)
g = 3.6 inches (9.1 cm)
h = 4.6 inches (11.7 cm)
As another embodiment (not shown) of the present invention, the number of surfaces of the rotating polygon mirror 114 is changed, or the number of surfaces of the semi-crown pattern mirror 118 is changed. Is mentioned.
[0032]
It will be appreciated that each of the above elements, or two or more together, can find other types of useful applications that differ in configuration from those described above.
The overall inventive concept is not limited to the description given in the specific embodiments, because various modifications and structural changes can be made without departing in any way from the construction and scope of the invention. It should be understood that changes can be made.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a first prior art scanner.
FIG. 2 is a schematic diagram of a second prior art scanner.
FIG. 3 is a schematic diagram of a third prior art scanner.
FIG. 4 is a schematic diagram of the scanner according to the first embodiment of the present invention.
5 is a view of a polygon mirror and a stationary pattern mirror of the scanner of FIG. 4 as viewed from below.
6 (a) shows a preferred scanning pattern at the exit window, FIG. 6 (b) shows a preferred scan pattern 3 inches from the exit window, and FIG. 6 (c) shows from the exit window. It is a figure which shows the suitable scanning pattern in 4.25 inches.
[Explanation of symbols]
10, 26, 45, 100 Scanner housing 12, 42, 46, 102 Front surface 14, 44, 48, 104 Rear surface (back surface)
16, 28, 50, 110 Lasers 18, 54, 114 Rotating polygon mirrors 20, 36, 56, 116 Motors 22, 38, 57, 118 Stationary pattern mirrors 24, 40, 58, 122 Exit windows 30, 32, 52, 112 Folding mirror 34 Rotating mirror 120 Bottom mirror

Claims (4)

A scanner for reading symbols on commodities purchased in a POS environment having a counter top plate,
a) a housing (100) having a front surface (102), a back surface (104) and side surfaces (106, 108);
b) An exit window (122) that is on the front surface (102) and occupies most of the area of the front surface (102) and is positioned substantially vertically when the housing (100) is placed on the counter top in use. )When,
c) A folding mirror (112) disposed in the housing (100) at a position close to one of the side surfaces (106) and disposed in the housing (100) in proximity to the other side surface (108). A laser (110) that emits a laser beam toward;
d) An axis having a plurality of mirror surfaces (114a, b, c, d) and being substantially perpendicular to the exit window (122) in the housing (100) in the vicinity of the one side surface (106). A rotating polygon mirror (114) that is rotatably arranged around the plurality of mirror surfaces, the mirror surfaces rotating sequentially around the axis and reflecting the laser beam reflected by the folding mirror (112);
e) Arranged along an arc around an axis substantially perpendicular to the exit window (122) in the housing (100) at a position close to the other side surface (108), and the rotating polygon mirror (114) ) A plurality of semi-crown mirrors (118a, b, c, d, e) that reflect the laser beam reflected in the oblique direction toward the back surface;
f) a bottom mirror (120) located along the back surface (104) and reflecting the laser beam reflected by the half-crown mirror (118a, b, c, d, e);
And a laser beam configured to be emitted through the emission window (122) as a scanning pattern of a plurality of scanning lines.   The scanner according to claim 1, wherein each of the mirrors is a plane mirror.   3. The scanner according to claim 1, wherein the rotating polygon mirror has four mirror surfaces, and the half-crown mirror has five mirror surfaces.   The scanner according to any one of claims 1 to 3, wherein a distance between the two side surfaces is 15.2 cm, and a distance between the front surface and the back surface is 7.6 cm. The scanner characterized by being.

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