JPS63198177A - Optical reader - Google Patents

Abstract

PURPOSE:To constantly stably read a bar code without receiving the influence of a user by disposing a polarizing part before a light receiving part, electrically scanning and reading the bar code. CONSTITUTION:An LCD driver 26 controls an LCD 27 in such a manner that the LCD 27 passes a light only at one place and the place is moved from a left to a right, the light emitting from a light emitted part 22 abuts against a paper only from the window of the LCD 27, is reflected and returned to the light receiving part 23 through the LCD 27 again. The light entering the light receiving part 23 is transformed to an electric signal, amplifier by an amplifier 24 and transformed to a digital signal by a level decision part 25. When the LCD is approached to the paper on which the bar code is printed, the bar code can be read sequentially from the left side to the right side of the LCD 27. Thereby, the reading of the bar code is constantly executed under a constant state without receiving the influence of the skillfulness of the user.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical reading device used in a barcode reader that reads barcodes.

(Structure of conventional example and its problems) FIGS. 4(a) and 4(b) are an external view and a front sectional view of a conventional optical reading device, respectively.

In FIG. 4(a), 1 is a barcode reader, 2 is paper, and 3 is a barcode printed on the paper 2. In FIG.

In FIG. 4(b), 4 is a light emitting section, 5 is a lens, and 6 is a light receiving section, which are fixed to the tip of the barcode reader 1.

Next, the operation of the above conventional example will be explained.

In FIG. 4(a), when the barcode reader 1 moves over the barcode 3 from left to right as indicated by the arrow, the reflectance of light differs between the white part and the black part of the paper 2. Therefore, white/black information can be read from the light receiving section 6 as an electrical signal. In this way, barcodes can be read even with the conventional example.

However, in the above-mentioned conventional example, since the barcode reader is moved manually, there is a drawback that unless a skilled person uses the barcode reader, the barcode reader may not be able to read the barcode properly due to the following reasons.

■ The moving speed of the barcode reader is not constant.

■ The distance between the barcode reader and the paper is not constant.

■　The angle between the barcode reader and the paper is not constant.

(Objective of the Invention) The present invention eliminates the drawbacks of the above-mentioned conventional examples, and aims to enable anyone to read barcodes correctly.

(Structure of the Invention) In order to achieve the above object, the present invention provides a polarizing section in front of the light receiving section, and electrically scans and reads barcodes without being influenced by the user. This provides the effect of always being able to read barcodes stably.

(Example) The configuration of an embodiment of the present invention will be described below.

FIG. 1(a) is an external view of an optical reading device used in a barcode reader according to an embodiment of the present invention, where 10 is a light emitting section and 11 is a light receiving section.

FIG. 1(b) is a front view of the reading section, and FIG. 1(c) is a side sectional view.

12 is a polarizing section, and in this embodiment, it is an LCD (liquid crystal);
is a terminal section for connecting the LCD and an external control circuit. 14 is paper with a barcode printed on it.

15 and 16 are light guide parts such as acrylic plates for guiding light.

FIG. 2 is a schematic block diagram showing the configuration of an embodiment of the present invention.

21 is a power supply section, 22 is a light emitting section, and the power supply section 21 is connected to the light emitting section 22.

23 is a light receiving section, the output of which is connected to an amplifier 24.

Reference numeral 25 denotes a level judgment section, which judges the analog signal sent from the amplifier 24 as H (high) if it is above a certain value, and L (if it is less than that).
This is a circuit that determines that the output voltage is low (low).

26 is an LCD driver, which is connected to the LCD 27.

Next, the above embodiment will be explained.

In FIG. 2, the LCD driver 26 is connected to the LCD 27.
Light passes through only a few places, and the LCD 27 is controlled so that the light moves from left to right (Figure 3).

FIG. 3 is a diagram showing the state of polarization of LCD.

Therefore, the light emitted from the light emitting section 22 hits the paper only through the window (portion through which the light passes) of the LCD 27, is reflected, and returns to the LCD 27.
27 and returns to the light receiving section 23.

The light entering the light receiving section 23 is converted into an electrical signal and sent to the amplifier 2.
4 and converted into a digital signal by the level determination section 25.

As shown in FIG. 3, since the window of the LCD 27 moves from left to right, signals are sequentially read from the left side to the right side of the LCD 27. Due to this function, when the LCD 27 is brought close to the paper on which the barcode is printed, the barcode can be read.

In this embodiment, since the barcode is read by automatic scanning, it is always carried out in a constant state without being affected by the user's skill level, so there is an advantage that reading errors are less likely to occur.

In this embodiment, both the light emitting section and the light receiving section pass through the window of the LCD, but only one of them may pass through the window of the LCD.

Also, a light bulb is used as a light emitting element, but this is an LE
D. Needless to say, anything that emits light, such as a neon bulb, is fine.

Similarly, if the light receiving part is something that converts light into electrical signals, it is CdS.
It may also be a solar battery or the like.

(Effects of the Invention) The present invention has the above-described configuration, and provides the following effects.

(a) Since the reading unit does not move, there are fewer reading errors.

(b) The reading speed is fast (because the reading device always reads at the maximum speed it can read).

(C) If a reading error occurs, the reading process can be performed again.

(d) It is cheaper than a scanning type using a CCD or the like.

It has the following advantages.

[Brief explanation of the drawing]

Fig. 1 is an external view of an optical reading device used in a barcode reader according to an embodiment of the present invention, Fig. 2 is a schematic block diagram showing the configuration of an embodiment of the present invention, and Fig. 3 is a polarized light of an LCD. FIG. FIG. 4 is a diagram showing an external view and a front sectional view of a conventional optical reading device. 1...Barcode reader, 2...Paper, 3...
・Barcode, 4... Light emitting part, 5... Lens, 6... Light receiving part, 10... Light emitting part, 11... Light receiving part, 12... Polarizing part, 13... Terminal Part, 14...
・Paper, 15. 16... Light guide section, 21... Power supply section, 2
2... Light emitting section, 23... Light receiving section, 24... Amplifier, 25... Level judgment section, 26... LCD driver, 27... LCD. Patent applicant: Matsushita Electric Industrial Co., Ltd. Figure 1 (a) (b) (C) 10... Light receiving section 11 Female section 12 C5 Light section Fig. 2 21--Electric scale 22-Light guide section 23 Receiving section 27-LCD Fig. 3 Fig. 4 (a) (b)

Claims (1)

[Claims] It consists of a light emitting part, a polarizing part, a light receiving part, and a barcode reader that reads barcodes, and is characterized by having a polarizing part in front of the light receiving part, and electrically scanning and reading barcodes. optical reading device.