JPH04283887A - Reader - Google Patents

Abstract

PURPOSE:To provide the compact reader that corresponds to the operability of an operator with the degree of freedom in the arrangement of optical parts by forming the scanning beam in the prescribed direction while providing plural transmission holograms with different diffracted angles on the optical axis of the scanning beam between a beam scanning part and a reading window. CONSTITUTION:The beam scanned from a beam scanning part 24 is irradiated from a reading window 26 composed of the hologram to an object 5 being in the outer space, and the characteristics of the object 5 is read by receiving the reflected light. On the light path of the scanning beam between the beam scanning part 24 and the reading window 26, plural transmission holograms 6 with different diffracted angles are arranged in the horizontal and vertical directions.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is directed to point-of-sale information management (P
Regarding reading devices such as barcode scanners used in point of sales (hereinafter referred to as POS) systems, in particular, multiple transmission holograms with different diffraction indexes are placed on the optical axis of the scanning beam between the beam scanning section and the reading window. The present invention relates to a reading device that can be provided to form a scanning beam in a predetermined direction.

[0002] In recent years, POS systems have become widespread in department stores, supermarkets, and the like, and the efficiency of sales management and registration input of sales products is progressing. Barcode scanners are widely used for inputting data such as product prices in POS systems. When reading a barcode with a scanner, an operator passes a product on which the barcode is written through a predetermined spatial area above the reading window of the scanner.

[0003] In recent years, such scanners have been significantly miniaturized by adopting a "holowind system" in which a hologram is provided in the reading window. However, due to the arrangement of the multiple scanning pattern forming mirrors inside the scanner, the front and back width of the device becomes large, and the scanning beam is irradiated obliquely from the reading window, so the barcode reading area is closer to the operation direction than the space above the scanner. On the other hand, it is placed closer to the front, which does not suit the operator's sense of operation, so a method that can improve this is desired.

0004

2. Description of the Related Art FIG. 8 is a perspective view showing the inside of a scanner. As shown in the figure, a thin scanner 1 has a
The optical unit 2 is composed of an optical unit 2, a data processing section 3, and a reading control section 4. The optical unit 2 is configured such that the light emitted from the output section 22, which consists of a light source 20 composed of, for example, a laser diode and a beam shaping lens 21, is flat. The scanning beam is reflected by the small-area plane mirror 27b provided at the center of the mirror 27a and the concave mirror 23, and then radiated by the rotating polygon mirror 24a to form a scanning pattern on the mirror (
(hereinafter referred to as R, Z, L scanning beam mirrors) 25a-2
A beam scanning function that scans the barcode 50 of the product 5a in the upper space from a reading window (hereinafter referred to as "holowind") 26a formed by a transmission hologram with a scanning beam reflected at 5c and in different angular directions, and a bar code of the product 5a. code 5
The reflected light that scanned 0 is sent to the hollow window 26a, the scanning pattern forming mirrors 25a to 25c, the polygon mirror 24a,
It has a light receiving and converting function of reading the light through the concave mirror 23 and the plane mirror 27c with the light receiving sensor 28 and converting it into an electrical signal.

[0005] As shown in FIG. 9, the barcode 50 is composed of a combination of thick lines, thin lines, and their spacing.
Letters, numbers, symbols, etc. are displayed according to the permutation of a predetermined number of these, and are printed directly on the packaging or container of the product 5a, or printed on a label or the like and affixed to the product 5a.

The polygon mirror 24a has, for example, five reflective surfaces, is rotated by a motor M1 and scans five times in one rotation, and each surface is provided at a different angle with respect to the vertical direction. A scanning beam is emitted by reflecting the light in the direction. The motor M1 and the light source 20 are connected to the reading control section 4, and the light receiving sensor 28 is connected to the reading control section 4 via the data processing section 3. The reading control unit 4 is connected to an electronic register (not shown). Further, the optical unit 2, data processing section 3, and reading control section 4 are housed in a housing 10.

R, Z, L scanning beam mirrors 25a-2
5c is a three-sided mirror that divides the scanning beam formed by being reflected by the rotating polygon mirror 24a and reflects it in three directions (R, Z, L) to enter the hollow window 26a.

On the surface of the hollow window 26a, five scanning patterns are formed in three directions by the transmission hologram, and on the vertical virtual screen, there are scanning patterns in five directions. The data processing unit 3 includes each light receiving sensor 28 of the scanner 1.
The electrical signal received and converted by the sensor is recognized as a barcode signal through a sensor amplifier, an analog/digital (A/D) conversion circuit, and a binarization circuit (not shown).

Accordingly, in the scanner 1, scanning beams diffracted in respective predetermined directions by the transmission holograms of the hollow window 26a are emitted under the control of each part by the reading control section 4, and the operator can scan a spatial region above the hollow window 26a in a predetermined direction. Barcode 50 of product 5a moved in the direction
The barcode 50 is read by the reflected light and the data is recognized.

0010

According to the above conventional method, the scanning beam formed by reflection by the polygon mirror 24a is divided by the R, Z, and L scanning beam mirrors 25a to 25c to generate scanning beams in different directions. However, as shown in FIG. 10(a), the thin optical unit 2
In order to obtain a desired scanning pattern on the surface of the hollow window 26a, mirrors 25a to 25 for R, Z, and L scanning beams are used.
c must be placed so as to protrude beyond the width of the hollow window 26a. For this reason, the external shape of the scanner 1 becomes larger in the direction perpendicular to the operating direction (the depth direction when installed horizontally, and the height direction when installed vertically), as shown in FIG. 10(b). . Scanner 1 like this
In this case, as shown in Figure 10(c), the barcode 50
The reading area is at the front of the device, which does not suit the operator's sense of operation. Furthermore, when installed vertically, the top of the device becomes high, which poses a problem in that the system configuration of the scanner and related devices is restricted.

SUMMARY OF THE INVENTION An object of the present invention is to provide a compact reading device that allows flexibility in the arrangement of optical components and meets the operability of an operator.

0012

[Means for Solving the Problems] FIG. 1 is a diagram showing the basic configuration of the present invention. In the figure, 5 is an object, 24 is a beam scanning section, 26 is a reading window composed of a hologram through which the beam scanned from the beam scanning section 24 is irradiated onto the object 5 existing in the external space, and 6 is the beam scanning section 24 and reading window 2
A plurality of transmission holograms having different diffraction angles are arranged horizontally or vertically on the optical path of the scanning beam between 6 and 6.

Therefore, the configuration is such that the beam scanned by the beam scanning section 24 passes through a plurality of transmission holograms 6 and is irradiated from the reading window 26 onto the object 5 existing in the external space.

[0014]

[Operation] The beam scanned from the beam scanning unit 24 is diffracted in different directions by a plurality of transmission holograms 6 arranged side by side or vertically and having different diffraction angles, and an object existing in the external space is detected from the reading window 26. Irradiate 5,
The characteristics of the object 5 can be read by the reflected light.

Therefore, it is not necessary to arrange a plurality of scanning pattern forming mirrors, and by setting the diffraction angles of the plurality of transmission holograms 6 corresponding to the reading window 26, there is a degree of freedom in the position where the transmission holograms 6 are arranged. The device can be made smaller.

[0016]

[Embodiment] An embodiment of the present invention will be explained with reference to FIGS. 2 and 3. The same reference numerals indicate the same objects throughout the figures. Figure 2
1 is a configuration diagram in which the present invention is applied to the scanner described in the conventional example. The product 5a, the R, Z, and L scanning holograms 6a to 6c, the polygon mirror 24a, and the hollow window 26b in FIG. 2 correspond to the object 5, the transmission hologram 6, the beam scanning unit 24, and the reading window 26 in FIG. 1, respectively. ing.

As shown in the perspective view and side view of FIGS. 2(a) and 2(b), a polygon mirror is used in place of the R, Z, L scanning beam mirrors 25a to 25c and concave mirror 23 explained in FIG. 24a, a transmission hologram (hereinafter R, Z
, L-scanning holograms) 6a to 6c are arranged in horizontal alignment (actually, they are formed integrally on one hologram plate). Therefore, no components are placed below the hollow window 26b.

The R, Z, and L scanning holograms 6a to 6c have different diffraction angles, and split the scanning beam formed by the polygon mirror 24a, diffract it in a predetermined direction, and enter the hollow window 26b. do.

The hollow window 26b is formed to diffract the scanning beams incident from the R, Z, and L scanning holograms 6a to 6c, respectively, and radiate a scanning pattern in a predetermined direction to the outside. In addition, the plane mirror 27 explained in FIG.
a to 27c are omitted.

Next, the R, Z, L scanning hologram 6a
An example of how to create 6c will be explained with reference to FIG. first,
For example, dry plates A to C are prepared with gelatin-based silver salt or dichromate gelatin coated on the glass or plastic substrate surface, and the Z scanning hologram 6b passes through the center of the dry plate B, as shown in FIG. 3(a). It is created using a line light source 7 and a point light source 8, each having an optical axis on the y-axis. Here, a cylindrical lens 70 is used to obtain the linear light source 7. The generatrix of the cylindrical lens 70 is parallel to the x-axis.

Further, the R scanning hologram 6a is shown in FIG. 3(b).
), the optical axes of the linear light source 7 and the point light source 8 are shifted in the x direction with respect to the y axis passing through the center of the dry plate A. Furthermore, the cylindrical lens 70 is rotated about the intersection of the generatrix and the optical axis so that the generatrix and the x-axis have a torsional relationship. At this time, with respect to the y-axis passing through the center of dry plate C,
If the direction in which the optical axis is shifted and the direction in which the cylindrical lens 70 is rotated is set in the opposite direction to that of the R-scanning hologram 6a, an L-scanning hologram 6c can be created.

With such a configuration, the emission section 22
The emitted light is emitted as a scanning beam by the rotating polygon mirror 24a, and is divided and diffracted by the R, Z, and L scanning holograms 6a to 6c, respectively, and the scanning beams enter the hollow window 26a at different deflection angles. The light is diffracted and a predetermined scanning pattern is synthesized outside the hollow window 26a.

[0023] Product 5a scanned by the scanning pattern
The reflected light of the barcode 50 returns to the polygon mirror 24a in the opposite direction along the same path as when it was emitted, is focused by the concave mirror 23, and is received by the light receiving sensor 28 and read.

In this way, instead of the R, Z, L scanning beam mirrors 25a to 25c and the concave mirror 23, which have a small degree of freedom in arrangement, in the conventional example, the R, Z,
With the L-scan holograms 6a to 6c, the optical components can be consolidated, and as shown in FIG. ) can be reduced in size, improving operability for the operator, eliminating restrictions on scanner installation, and allowing the reading area to be adjusted to the operator's operating sense.

Next, a different embodiment (1) is shown in FIG. 5, and the difference between FIG. 5 and the embodiment explained in FIG.
In contrast to the case where the R, Z, and L scanning holograms were arranged side by side in the horizontal direction, they were arranged side by side in the vertical direction.

That is, as shown in the perspective view and side view of FIGS. 5(a) and 5(b), the R, Z
, L scanning holograms 6A to 6C are vertically aligned (actually formed integrally on one hologram plate).

The polygon mirror 24b has six mirror surfaces on its outer periphery, each mirror surface has three different tilt angles, and each surface is incident on each of the R, Z, and L scanning holograms 6A to 6C. It is formed like this.

The R, Z, and L scanning holograms 6A to 6C have different diffraction angles, and split the scanning beam formed by the polygon mirror 24b, diffract it in a predetermined direction, and enter the hollow window 26c. do. R, Z, L
The method for creating the scanning holograms 6A to 6C is the same as the method described in FIG. 3.

The hollow window 26c is formed to diffract the scanning beams incident from the R, Z, and L scanning holograms 6A to 6C, respectively, and radiate a scanning pattern in a predetermined direction to the outside. In addition, the plane mirror 27 explained in FIG.
a to 27c are omitted.

With such a configuration, the emission section 22
The emitted light is emitted as a scanning beam by the rotating polygon mirror 24b, and is divided and diffracted by the R, Z, and L scanning holograms 6A to 6C, respectively, and the scanning beams enter the hollow window 26c at different deflection angles. The light is diffracted and a predetermined scanning pattern is synthesized outside the hollow window 26c.

Product 5a scanned by the scanning pattern
The reflected light of the barcode 50 returns to the polygon mirror 24b in the opposite direction along the same path as when it was emitted, is focused by the concave mirror 23, and is received by the light receiving sensor 28 and read.

In this way, R, Z explained in the conventional example
, L scanning beam mirrors 25a to 25c, a hologram 6A for R, Z, and L scanning, which has a degree of freedom in arrangement.
By providing .about.6B, optical components can be integrated, and the same effects as in the above embodiments can be obtained.

A different embodiment (2) is shown in FIG. 6, and the difference between FIG. 6 and the embodiment explained in FIG.
Instead of the concave mirror, a condensing hologram was provided. That is, as shown in the perspective view and side view of FIGS. 6(a) and 6(b), the R, Z, and L scanning holograms 6a to 6
A reflective condensing hologram 9 is disposed (actually formed integrally on one hologram plate) in contact with the lower side of the hologram 6c along its entire length.

A small-area plane mirror 7c is provided at the center of the condensing hologram 9 for separating and deflecting the laser beam from the emission section 22 toward the polygon mirror 24a. Next, an example of a method for creating the condensing hologram 9 will be explained with reference to FIG. First, when a spherical wave 10 and a plane wave 11 are irradiated from the front and back sides of a dry plate D similar to the dry plates A to C described in the above embodiment, a reflection hologram, that is, a condensing hologram 9 shown in FIG. 2 is created. becomes. By creating the R, Z, L scanning holograms 6a to 6c and the condensing hologram 9 on the same dry plate, the number of parts can be reduced.

With such a configuration, the emission section 22
The emitted light is reflected by the plane mirrors 7a and 7c, and a scanning beam is emitted by the rotating polygon mirror 24a, which is divided and diffracted by the R, Z, and L scanning holograms 6a to 6c, respectively, and the scanning beams are different. The light enters the hollow window 26b at a deflection angle, is diffracted, and a predetermined scanning pattern is synthesized outside the hollow window 26b.

Product 5a scanned by the scanning pattern
The reflected light from the barcode 50 returns to the polygon mirror 24a in the opposite direction along the same path as when it was emitted, and is reflected by the condensing hologram 9.
The light is collected by the light receiving sensor 28 and read by the light receiving sensor 28.

In this way, R, Z explained in the conventional example
, L scanning beam mirrors 25a to 25c and concave mirror 23, R, Z, and L scanning holograms 6a to 6c with degrees of freedom and a condensing hologram 9 are used to consolidate the optical components. Effects similar to those of the embodiment can be obtained.

Furthermore, in the above embodiment and the different embodiments (1) and (2), a transparent scanner can be realized by making the surface facing the hollow window, ie, the bottom surface, transparent. Transparent scanners have no parts between the Holowind and the transparent bottom, and when installed horizontally, the HoloWind can be turned downward, allowing the operator to operate while viewing the barcode of the product, and eliminating dirt on the HoloWind surface. Moreover, when installed vertically, the partition between the customer and the operator can be made transparent, which eliminates the sense of discomfort.

[0039]

As explained above, according to the present invention, a plurality of transmission holograms having different diffraction angles are arranged horizontally or vertically on the optical path of the scanning beam between the beam scanning section and the reading window. As a result, optical parts can be consolidated, making the device even more compact, eliminating restrictions on device installation, and improving operability for the operator, allowing the reading area to be controlled by the operator. This has the advantage that it can be adjusted to the senses, and by making the surface facing the hollow window transparent, a transparent scanner can be realized.

[Brief explanation of the drawing]

[Figure 1] Principle configuration diagram of the present invention

[Figure 2] Block diagram showing an embodiment of the present invention

[Figure 3]
Explanatory diagram of how to create a hologram for R, Z, L scanning

[Figure 4] Perspective view explaining the example

[Figure 5] Configuration diagram showing different embodiment (1)

[Figure 6
] Configuration diagram showing different embodiment (2)

[Figure 7]
Explanatory diagram of different embodiment (2)

[Fig. 8] A perspective perspective view of a scanner to which the present invention is applied.

[Figure 9] Illustration of barcode

[Figure 10] Explanatory diagram of conventional example

[Explanation of symbols]

Claims (4)

[Claims] Claim 1: A beam scanned by a beam scanning unit (24) is irradiated onto an object (5) existing in an external space through a reading window (26) composed of a hologram, and the reflected light is received to detect the object. (5) A reading device for reading the characteristics of the beam scanning section (24) and the reading window (26).
) A reading device characterized in that a plurality of transmission holograms (6) having different diffraction angles are arranged side by side or vertically on the optical path of the scanning beam between the two. 2. The plurality of transmission holograms (6)
2. The reading device according to claim 1, wherein the scanning beam is divided by the following. 3. A condensing hologram having a condensing function is formed on the same substrate as the plurality of transmissive holograms (6) arranged in the horizontal direction.
reader. 4. The reading device according to claim 3, wherein the condensing hologram is a reflection hologram.