JPH02220020A - Information reader - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an information reading device used in a barcode reader or the like.

2. Description of the Related Art Conventionally, as an information reading device used in a bar code reader or the like, there is one using a focusing hologram disk, for example, as disclosed in Japanese Patent Application Laid-Open No. 117333/1983. This involves transmitting light emitted from a laser light source through a focusing hologram disk, irradiating the transmitted and focused light onto the barcode surface as the irradiated surface, scanning that surface, and then scanning the barcode surface. The light reflected by the code surface is transmitted through the focusing hologram disk again, and the focused light is detected by a photodetector, thereby reading the information recorded on the bar code surface.

In addition to an information reading device using a retroreflective optical system using such a focusing hologram disk, there is also an information reading device configured with a feedback optical system in which the hologram for optical scanning and the hologram for focusing are the same. be.

Problems to be Solved by the Invention All of these information reading devices use a hologram disk, and by using the hologram disk in this way, the focusing function of the irradiation beam irradiated on the barcode surface and its A deflection function that changes the optical path along the way using a reflective mirror, etc., a function to receive a reflected beam for return from the barcode surface, and a rask scanning function are combined, thereby reducing the number of parts and improving reading reliability. It is possible to achieve improvements in sexual performance, etc. However, in a device having such a configuration, there is a limit to how compact the device itself can be made, and in particular, there has been no improvement in terms of making it thinner.

Therefore, in order to cope with such a thin and compact design, a semiconductor laser is used as a laser light source for beam scanning of an information reading device, and an optical system including this semiconductor laser and a hologram disk is integrated. You can also deal with such problems. However, in the case of an information reading device using this semiconductor laser, normally 780n
Since a semiconductor laser in an infrared region of 10 m or more is used, it is not possible to know the scanning state or position of the scanning beam (such as the above-mentioned irradiation beam). Therefore, since such a scanning beam cannot be confirmed with the human eye, there is no guideline for adjusting the position of the scanning beam during reading scanning, which is inconvenient.

In addition, infrared L is used to confirm such scanning positions.
Some systems are equipped with a separate light source that emits a visible light beam such as an ED, and the scanning position can be confirmed by irradiating the visible light beam onto the surface of the harcode using a galvanometer mirror, etc.; however, In this case, the provision of the separate light source increases the number of parts of the scanning optical system associated therewith, resulting in a problem that the configuration of the entire apparatus becomes complicated and costs increase.

Means for Solving the Problem Therefore, in order to solve such problems, claim 1
The described invention provides a first condensing lens that converts the light emitted by the semiconductor first noser into a condensed irradiation beam,
A beam shaping member for shaping the irradiation beam that has passed through the first condensing lens is provided, a hologram disk for deflecting the irradiation beam is provided, and the irradiation beam from the semiconductor laser and the irradiated object are arranged in a central portion and a peripheral portion thereof. An optical path separating member is provided in which a region is formed to separate the reflected beam from the surface, and a second condensing lens is provided to condense the reflected beam separated by the optical path separating member. A light receiving element for detecting the focused reflected beam was provided, and a visible light source section was provided for emitting a visible light beam different from the irradiation beam obtained from the semiconductor laser.

Further, the invention according to claim 2 provides a first condenser lens that converts the light emitted by the semiconductor laser into a condensed irradiation beam, and shapes the irradiation beam that has passed through the first condenser lens. A beam shaping member is provided, a hologram disk for deflecting the irradiation beam is provided, an irradiation optical system is provided for changing the optical path of the irradiation beam before and after it enters the hologram disk, and a beam shaping member is provided, and an irradiation optical system is provided for changing the optical path of the irradiation beam before and after it is incident on the hologram disk, and a beam from the semiconductor laser is provided in the central portion and the peripheral portion thereof. An optical path separating member is provided in which a region is formed to separate the irradiation beam and the reflected beam from the irradiated surface, and a second condensing lens is provided for condensing the reflected beam separated by the optical path separating member. A light receiving element for detecting the reflected beam focused by the second condensing lens was provided, and a visible light source section for emitting a visible light beam different from the irradiation beam obtained from the semiconductor laser was provided.

According to the invention described in claim 1, by simply providing a visible light source section that emits a visible light beam in a scanning optical system configured by combining a semiconductor laser that emits an irradiation beam and a hologram disk, a visible light source section that simply emits a visible light beam is provided. Since the visible light beam can be guided onto the irradiated surface using the optical path,
The scanning position can be easily determined using the visible light beam, and there is no need to provide a separate scanning optical system exclusively for the visible light source as in the past.

Further, according to the invention as claimed in claim 2, the optical path of the irradiation beam for reading scanning emitted from the semiconductor laser and the visible
By interposing the irradiation optical system on the optical path of the visible light beam emitted from the light source, the optical path can be changed arbitrarily, and thereby the scanning position on the irradiated surface can be freely set.

Embodiment An embodiment of the invention set forth in claim 1 will be described based on FIGS. 1 to 6. First, the overall configuration of the information reading device will be explained based on FIG. 1. The light emitted from the semiconductor laser 1 is focused by a first condensing lens 2 and converted into an irradiation beam a. This irradiation beam a is beam-shaped by a mask 3 as a beam shaping member, and partially reflected by an optical path separating member. It is reflected by mirror 4. Here, as shown in FIG. 3, the partially reflecting mirror 4 has a reflecting part 5 having an area approximately the same diameter as the irradiation beam a formed in its center, and extends over the entire circumference of this reflecting part 5. A transparent portion 6 is formed therein. Therefore, in this case, the irradiation beam a is reflected by the reflecting portion 5 of the partially reflecting mirror 4, has its optical path changed, and is guided to the hologram disk 7.

As shown in FIG.
It consists of three sectors 8, and is rotated at high speed by a motor 9 attached below. Since the hologram disk 7 has a different diffraction angle for each sector 8 (for example, Sa, Sb, Sc), the irradiation beam a transmitted therethrough becomes a separate optical path for each sector 8. The irradiation beam a transmitted through the hologram disk 7 and separated into a plurality of beams is irradiated onto the surface of the barcode 10 as the irradiated surface. in this case,
In FIG. 1, the scanning direction of these irradiation beams a is perpendicular to the plane of the paper, and scanning in this manner is called "self-rusk scanning."

By performing such self-rusk scanning, the information recorded on the barcode 10 can be read more reliably.

And the reflected beam b from the barcode 1o plane is
The light enters the hologram disk 7 again due to the retroreflection function of the hologram disk 7.

The reflected beam b, which has become reverse diffracted light due to this incidence, passes through the transmitting part 6 of the partial reflection mirror 4, and then is condensed by the second condensing lens 11, and the amount of received light is detected by the light receiving element 12, Thereby, the information recorded on the barcode 10 surface can be read. The surface shape of the second condensing lens 11 is a horizontally elongated shape as shown in FIG. 4 when viewed from the side on which the reflected beam b enters.

Further, the visible light source section 13 according to the present invention includes an LED 14 that emits light in the infrared region and a condensing lens 15 that detects the light emitted from the LED 14. It is located on the opposite side.

In the information reading device configured as described above, the basic operation of the visible light source section 13 according to the present invention will be explained based on FIGS. 5 and 6. FIG. 5 shows the respective optical paths of the visible light beam C emitted by the LED 14 of the visible light source section 13 and the irradiation beam a emitted by the semiconductor laser 1.
This figure shows a state in which three optical paths are separated by three sectors 8 (Sa, Sb, Sc).

In this case, assuming that the irradiation beam a for reading is using the sector 8 at position A, the visible light beam C for scanning guide is scanned using another vacant sector 8,
This is intended to confirm the scanning position.

Now, when these scanning states are viewed from the barcode 10 side, the scanning states are as shown in FIG. At this time, the spot diameter of the irradiation beam a for reading is usually a minute spot of 0.2 mm or less, and when a self-rusk scan type hologram disk 7 is used, three thin lines such as Sl, S2, and S are used. obtain a scanning pattern. On the other hand, the visible light beam C needs to have a somewhat thick beam diameter for visualization. 1, S, 2, S. Obtain a scanning pattern like 3. Therefore, in such a scanning method, the irradiation beam a and the visible light beam C are scanned at different positions,
This allows the scanning position to be easily determined.

Next, an embodiment of the invention according to claim 2 is shown in FIGS. 7 to 9.
This will be explained based on the figure. This embodiment describes a case where a mirror 16 as an irradiation optical system is interposed on the optical path of the irradiation beam a.

That is, in FIG. 7, by changing the optical path of the irradiation beam a that has passed through the hologram disk 7 using two mirrors 16, the irradiation beam a can be converted into a visible light beam C emitted from the LED 14 of the visible light source section 13. It is synthesized with. FIG. 8 shows the basic configuration when the mirror 16 is interposed, so that the scanning state of the two beams on the barcode 10 surface is the same as shown in FIG. 9. The barcodes will be scanned together on 10 sides. By interposing the mirror 16 in this manner, the scanning direction can be changed arbitrarily, so that the degree of freedom in designing the scanning optical system can be further increased.

Here, the parts common to the invention according to claim 1 and the invention according to claim 2 will be explained. First, a partial reflection mirror 4 as an optical path separating member and a conventional perforated mirror 17
The difference between the two will be explained based on FIGS. 11 and 12. The communication state of the irradiation beam a reflected by the reflection part 5 of the partial reflection mirror 4 and the reflection beam b transmitted through the surrounding transmission part 6 is as shown in FIG. As a result, the irradiation beam a is reflected by the reflection section 5 having an area of approximately the same diameter as the irradiation beam a, while the reflected beam b is transmitted through the transmission section 6 formed on the entire surface around it and is received by the light receiving element 12. Therefore, it can be seen that the vignetting area Q of the received light beam of the reflected beam b is much smaller than the conventional vignetting area P (see FIG. 12).

Therefore, in the present invention, the total amount of light beams received by the light receiving element 12 can be larger than that of the conventional method, so that it is also possible to further increase the light utilization efficiency.

In addition, He-
Since the semiconductor laser 1 is used instead of the Ne laser, and the light emitted from it is beam-shaped using the mask 3, the reading depth can be sufficiently obtained even in a short focus irradiation beam optical system like this embodiment. It is possible to make it larger.

Next, a device actually integrated and assembled based on the information reading device described in the two embodiments described above was constructed.
This will be explained based on FIGS. (a), (b), and (c). Figure 10 (
In b), the LD unit 18 constituting the semiconductor laser 1 is located on the upper side in the drawing, and the heat sink (not shown) of the LD unit 18 is located outside the holding member 19. In addition, in FIG. 10(C), the visible light beam C emitted from the LED 14 of the visible light source section 13 passes through the condensing lens 15 and the mirror 20 in order, and then passes through the hologram disk 7 and passes through the barcode 10 surface. is irradiated. On the other hand, the irradiation beam a emitted from the semiconductor laser 1 of the LD unit 18 passes through a first condensing lens and a mask (not shown), then passes through the mirror M1, the reflecting section 5 of the partial reflection mirror 4, the mirror M2, and the hologram disk 7. , Miller M
3. M4. The light is emitted from the window 21 to the outside through the M5 in order, and is irradiated onto the barcode 10 surface. Therefore, in this case, the irradiation beam a and the visible light beam C are combined and irradiated onto the same barcode 10 surface, thereby making it easy to confirm the scanning position.

Effects of the Invention In the invention described in claim 1, a scanning optical system configured by combining a semiconductor laser and a hologram disk that emit an irradiation beam is provided with a visible light source section that simply emits a visible light beam. Since the visible light beam can be guided onto the irradiated surface using the same optical path, it becomes possible to easily determine the scanning position using the visible light beam. There is no need to separately provide a scanning optical system dedicated to the light source.

Further, in the invention according to claim 2, by interposing the irradiation optical system on the optical path of the reading scanning irradiation beam emitted from the semiconductor laser and the optical path of the visible light beam emitted from the visible light source section, The optical path can be changed arbitrarily, and thereby the scanning position on the irradiated surface can be freely set, thereby further increasing the degree of freedom in designing the scanning optical system. Furthermore, it is possible to improve the visible light irradiation beam, the light intensity reaching the irradiated surface, and even the beam focusing performance.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the invention as claimed in claim 1,
Figure 2 is a plan view of the hologram disk, Figure 3 is a front view of the optical path separating member, Figure 4 is a front view of the second condensing lens, and Figure 5 is the optical path of the irradiated beam and reflected beam in Figure 1. FIG. 6 is an optical path diagram showing the scanning state as seen from the barcode side, FIG. 7 is a configuration diagram showing an embodiment of the invention as claimed in claim 2, and FIG. 8 is the irradiation beam and reflection. An optical path diagram showing the poor optical path condition of the beam, FIG. 9 is an optical path diagram showing the scanning state as seen from the bar code side, and FIG. b
) is its plan view, Fig. 10 (C) is its front view, Fig. 11
The figure is an optical path diagram showing an optical path separating means using the optical path separating member of the present invention, and FIG. 12 is an optical path diagram showing a conventional optical path separating means. DESCRIPTION OF SYMBOLS 1... Semiconductor laser, 2... First condensing lens, 3...
... Beam shaping member, 4... Optical path separation member, 11...
- Second condensing lens, 12... Light receiving element, 13... Visible light source section, 16... Irradiation optical system, a... Irradiation beam, b... Reflected beam, C... Visible Light Beam Diagram - Atsushi' 0 Diagram ○ Diagram March Diagram

Claims (1)

[Claims] 1. A semiconductor laser, a first condensing lens that converts the light emitted by the semiconductor laser into a condensed irradiation beam, and the irradiation beam that has passed through the first condensing lens. a beam shaping member for shaping, a hologram disk for deflecting the irradiation beam, and an optical path in which a region is formed in the center and its periphery to separate the irradiation beam from the semiconductor laser and the reflected beam from the irradiated surface. a separation member, a second condenser lens that condenses the reflected beam separated by the optical path separation member, a light receiving element that detects the reflected beam condensed by the second condenser lens, and the semiconductor laser. An information reading device comprising: a visible light source section that emits a visible light beam different from the irradiation beam obtained from the information reading device. 2. A semiconductor laser, a first condenser lens that converts the light emitted by the semiconductor laser into a condensed irradiation beam, and a beam shaping member that shapes the irradiation beam that has passed through the first condenser lens. , a hologram disk that deflects the irradiation beam, an irradiation optical system that changes the optical path before and after entering the hologram disk, and a center portion and a peripheral portion thereof having the irradiation beam from the semiconductor laser and the reflected beam from the irradiated surface. a second condensing lens that condenses the reflected beam separated by the optical path separating member; and a second condensing lens that condenses the reflected beam separated by the second condensing lens, and the reflected beam condensed by the second condensing lens. What is claimed is: 1. An information reading device comprising: a light-receiving element that detects a light beam; and a visible light source section that emits a visible light beam different from the irradiation beam obtained from the semiconductor laser.