JPS61254921A - Light beam scanner - Google Patents

Abstract

PURPOSE:To constitute a compact bar code reader and to improve efficiency of operation by making split luminous flux incident on a hologram disk at a different angular position and providing a mirror group which reflects light mutually nearby the angular position in parallel to the disk surface. CONSTITUTION:Luminous flux III among three split pieces of luminous flux is transmitted through the plate 5a of the hologram disk 5 and deflected outwardly by its diffraction, and the light is reflected while deflected from an incidence point (a) to a point (b) on the conic surface of a mirror 33 and reflected upward slantingly while moving the incidence point a' to a point b' on the surface of a plane mirror 43 arranged opposite to draw a scanning track A-K, so that a track L-M is drawn through a mirror 43'. A plate 5b moves to the position of a mirror 33 to vary an angle of deflection slightly, so two other tracks are drawn. Similarly, pieces of luminous flux II and I draw tracks, and 12 scanning patterns in three groups which cross one another slantingly are formed. the optical path of luminous flux is set in parallel to the disk, so a heat is reduced in thickness and an article label is moved to an open space under the head when a bar code is read, thereby reducing the labor of a cashier.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a light beam scanning device used for reading bar codes and the like. The simplest barcode reading device used in a POS system is a light pen type device, which is held in the hand and scans the barcode. To eliminate the complication of manual scanning, there are handheld devices that repeatedly scan a single scanning trajectory with a light beam, and all you need to do is touch the tip of the device to the barcode. The two-handed operation of holding the barcode league in one hand is the same as with a light pen, and the workability has not been improved much. - A stationary device has been developed that scans with a light beam along a number of scanning trajectories in various directions and reads barcodes by passing the product through the scanning area.

With this device, you only need to hold the product in your hand and pass it over or in front of the device, and the barcodes can be arranged diagonally or horizontally as long as they are facing the device. There is no need to be careful, and barcodes can be automatically read while transferring products from one basket to another at the cash register, making it very easy to use.

The present invention relates to the above-mentioned stationary barcode reader light beam scanning device.

Conventional technology The above-mentioned stationary barcode league repeats the operation of sequentially scanning one bar at a time along a standard trajectory pattern as shown in Figure 4 at high speed, and passes the product over this scanning area while holding it in the hand. Since reading is performed several times during scanning, and the scanning path has various directions, regardless of the direction in which the bars of the barcode are lined up, one of the scanning directions will cross the barcode. Therefore, the staff member does not have to worry about the direction in which the barcodes are lined up. Initially, the means for performing such scanning with a light beam consisted of a rotating mirror and fixed mirrors arranged in various orientations around the rotating mirror. In recent years, barcode leagues using hologram plates have been proposed. By using light diffraction by the hologram plate, it is possible to deflect the direction of the light beam and also give it a converging effect, eliminating the need for a converging lens system, making it possible to simplify the optical system and reduce the weight of the rotating parts, and the hologram plate itself Since it can be mass-produced, it has advantages such as lower cost of equipment. Although the present invention is also a light beam scanning device using a hologram plate, there are the following devices as previously proposed devices of this type.

1981 National Conference of the Institute of Electronics and Communication Engineers, Communication Division C 1988
October) Proceedings 54-4 Hologram scanner for barcode reading. The proposed device transmits a light beam from above through a mirror 52 to a hologram plate disk 51 rotating in a horizontal plane, as shown in FIG. The beam is guided to the window 55 on the top of the box by mirrors 53 and 54 placed on the bottom and side surfaces of the box, so as to define the scanning area of the light beam on the box. Mi 5-53.54 arranged on the bottom and side surfaces ensure the optical path length from the holographic plate 51 to the light beam convergence point in order to obtain a sufficient scanning area within the limited deflection angle of the holographic plate 51. The space below the hologram disk 51 is used.

When observing the actual operation of a supermarket etc. using such a device, when a customer places a basket 10 containing a product on the right side of the barcode league, as shown in Figure 3A, the cashier checks the product. The products are taken one by one and passed over the barcode league and put into the empty basket 10' on the left side, and as the product passes over the barcode league, the barcode leader is read. In this way, when the product is placed in the basket 10' on the left, the customer pays the price, receives a receipt, and places the item in the basket 10'.
Take it to a suitable place and put it in your own basket. On the other hand, the cashier moves the empty basket 10 on the right side over the barcode league to the left side and serves the next customer. Lifting and moving empty baskets in this way every time was a very tedious task for the staff, as it was done frequently. Therefore, as shown in FIG. 3B, if a gap is provided below a portion of the barcode reader so that the empty basket can be slid and moved to the left, the workload will be considerably reduced. However, with conventional devices, the position of the reading unit is high due to the n limit due to its configuration, making it inconvenient to read barcodes on products. , it is necessary to make the structure as thin as possible.

C. Purpose of the invention The present invention was made in view of the above-mentioned disadvantages.
The purpose is to provide a fA barcode reader to improve work efficiency.

2. Means for Solving the Problems In order to achieve the above-mentioned object, the present invention includes a light source that emits a light beam, a rotatably provided hologram plate disk, and a plurality of light beams that are emitted from the light source. an optical means that splits the light beam into light beams and makes the light beams enter the hologram plate disk at different angular positions with respect to the center of the hologram plate; Each of the above luminous fluxes -
a group of mirrors that reflect the light beam parallel to the disk surface toward the opposite side of the disk; A group of mirrors is provided to reflect the light toward the hologram plate, and the hologram plate disk is constructed by alternately arranging hologram plates and light shielding parts in the circumferential direction to deflect and converge the light weight.

E. Function The present invention secures the necessary optical path length by making the optical path of the light beam follow the hologram disk plate.

Example An embodiment of the present invention is shown in FIGS. 1 and 2. FIG.

The embodiment will be explained below with reference to FIG. This embodiment is an example in which one laser beam is divided into three beams.

The light beam emitted from the laser light source 1 passes through semi-transparent mirrors 2, 2.
′ is divided into 3y6 bundles I, [[, [[, and the luminous flux 1 is directed vertically upward by the semi-transparent mirror 2, and the luminous flux U
sm are each directed vertically upward by a mirror 6,61 so that they are vertically incident on the hologram plate disk located above from below. Semi-transparent mirror 2,2
′ is 2/3 each in order to match the beam intensity.
．． One with a transmittance of 1/2 is used. disk 5
, hologram plates 5a and 5b are located at opposite positions across the center of the disk 5, and light shielding portions 5C and 5C are provided between the two hologram plates.

31, 32, 33 are the directions of each light beam I, n, m, to the disk 5 at the outer periphery of the disk 5.

Now, the effect of the optical configuration shown in the figure will be explained using the luminous flux ■ as an example. The light beam (■) that has passed through the hologram playback (hologram play) 5a is deflected toward the outside of the disk 5 due to diffraction, and as the disk 5 rotates, the light beam (■) enters a conical surface with the point of incidence P on the disk 5 as its apex. while sweeping the area and entering the mirror 33,
The light is reflected by the mirror 33 toward the opposite side of the disk 5 in parallel with the surface of the disk 5, and is made incident on a plane mirror 43, 43' arranged opposite to the mirror 33 around the disk 50. While the hologram plate 5a passes the incident point P, the light beam ■ swings on the mirror 33 from point a to point b, and along with this, the light beam
It can swing to the end on the other side of 3'.

The mirrors 43 and 43' are arranged adjacent to each other as shown in the figure, both of which are oriented slightly upward, and while the point of incidence of the light beam 4 on the mirror 43 moves from a' to b', the mirrors 43 and 43' are arranged at an angle. The upwardly reflected light beam ■ traces a scanning trajectory 4~. Subsequently, the light beam (2) is polarized and two parallel scanning lines are drawn. Thereafter, while the hologram plate 5b is passing through the light beam incident point P on the disk 5, the same process as described above is performed again. Here, the light beam deflection angle of the hologram plate 5b is slightly different from that of the hologram plate 5a, so while the hologram plate 5b passes the incident point P, the light beam Two scanning trajectories are drawn parallel to and alternating with these, and in the end, four parallel scanning trajectories are drawn during one revolution of the disk 5. This scanning trajectory corresponds to A, B, and A in Fig. 4.
A and B are based on the hologram plate 5a.

The construction is based on 5b of the same. Regarding the light beam ■, the mirror 32 and mirrors 42 and 42' placed opposite to it on the opposite side of the disk 50 allow the light beam ■ to reach the point of incidence Q on the disk 5 while the hologram plates 5a and 5b are passing through. , the same relationship as explained by the luminous flux ■ holds, and the light beam ■.

■Positions of incident points P and Q on disk 5 and mirror 3
Due to the relationship between the arrangement directions of 3.43.43' and 32.42.42', the scanning locus A~B! Parallel scanning locus O, force, etc. obliquely intersecting with the beams are drawn, and in exactly the same way, the luminous flux I is directed to the mirror 31.
and 41. Draw the scanning trajectory ke, ko, etc. by 41',
During one rotation of the hologram plate disk 5, as shown in FIG.
A scanning pattern consisting of a set of 12 scanning lines is formed.

The hologram disk 5 includes hologram plates 5a and 5b.
A light shielding part 5c, 5c is provided between them, so that one hologram plate covers the 3yfJ bundle 1. II,
While passing through any of the incident points Pt, Q, etc. of III, other hologram plates are prevented from passing through other incident points, and each scanning line in the scanning pattern is chronologically scanned one at a time. They are drawn to it.

In the above explanation, the luminous flux is divided into three parts, but this may be subdivided. Further, although two hologram plates are used, any number of hologram plates may be used, and a shield 3'6 may be provided between them so that there is no time for two or more scanning lines to be drawn at a time.

The barcodes scanned by the scanning lines drawn in this manner are read by sensors 101, 102, 103 disposed below each mirror 41, 42, 43. Incidentally, the disturbance light entering the sensor S is cut off by an electric filter.

In the above explanation of FIG. 2, the light source 1 is arranged horizontally, but as shown in FIG. The light is reflected and made incident on the semi-transparent mirror 2°2'. 8 is a motor that rotates the hologram plate disk 5.

FIGS. 3C and 3D show the use of the barcode league of the present invention; in the figures, 9 is a counter and R is the device of the present invention. 10 is a basket containing goods, and 10' is an empty basket. G is a product and is transferred to the basket 10' by passing over the head of the device R as indicated by the solid line arrow, and as it passes over the head H, the bar code is read. When all the barcodes of the products in the base 10 have been read, the basket 10 becomes empty, the basket 10' containing the products is taken away, and the basket 10 is left in its wake.
is moved under the head H as shown by the chain arrow,
Another basket containing goods is placed in the place of basket 10.

In this way, when transferring products from one basket to another, there is no need to pass them through an unnecessarily high position, and the cashier's workload is significantly reduced as the empty baskets can simply be moved sideways. It is.

G. Effect As is clear from the above explanation, according to the lecture of the present invention, a portion parallel to the hologram plate disk is provided in the optical path of the light beam transmitted through the hologram plate, and an optical path length corresponding to approximately the diameter of the disk is set. As a result, the head section H can be made thin and compact, and even if the lower part is an open space, the optical path length can be obtained to sufficiently widen the scanning area at the convergence point of the light beam. Head in a cursive shape! By creating an open space under f[5H, the cashier's workload is reduced.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional side view of a device according to an embodiment of the present invention, Fig. 2 is a perspective view of an optical system of the same embodiment, Fig. 3 is a diagram explaining the usage state of the device, and Fig. 3A is a conventional example. FIG. 3B shows an example proposed by the inventor, FIGS. 3C and D show the present invention, FIG. 4 shows a scanning pattern of a light beam, and FIG. 5 shows a conventional example. FIG. 2 is a longitudinal cross-sectional view of an example device. Agent Hiroshi Agata, Patent Attorney Figure 1 Figure 4 Figure 2 Figure 5c: Light shielding part A Figure 3

Claims (1)

[Claims] a light source that emits a light beam; a hologram plate disk that is rotatably provided; the light beam that is emitted from the light source is divided into a plurality of light beams, and these light beams are sent to the hologram plate disk at different angles with respect to the center thereof; an optical means arranged at the periphery of the hologram plate disk, which corresponds to each of the light beams transmitted through the disk and deflected, and directs the same light beams parallel to the surface of the disk to the opposite side of the disk; A group of mirrors that reflect the light beams toward the hologram plate disk, and a group of mirrors facing each mirror group that reflect the reflected light beams toward the light beam scanning area above are provided, and the hologram plate disk deflects and converges the light beams. 1. A light beam scanning device comprising a hologram plate and a light shielding portion arranged alternately in the circumferential direction.