JP2749696B2 - Barcode reader - Google Patents

Description

〔Overview〕

The present invention relates to a barcode reader used as an input device of a POS system or the like. It is an object of the present invention to obtain a barcode reader that can easily determine whether a barcode can be read and identify a position where the barcode can be read. A barcode reading section comprising a semiconductor laser light source and a laser light receiving element, and a visible light emitting element provided so that the visible light irradiates a range where a barcode can be read by laser light from the semiconductor laser light source; A bar code reader comprising: a visible light receiving element configured to detect the reflected light of visible light from the visible light emitting element; and a visible light receiving element configured to detect reflected light of the article. In some cases, the semiconductor laser light source emits light and the visible light emitting element is continuously turned on, and control means is provided for controlling the visible light emitting element to be turned on intermittently during a period in which the semiconductor laser light source is not emitting light. . [Industrial application field] The present invention relates to a barcode reader used as an input device of a POS system or the like. [Prior art] Bar code readers are widely used as input devices for POS systems and the like.
Use a pen-type reader to trace the barcode in the orthogonal direction, or a contact method such as a touch method in which a reader with a built-in scanning function is brought into contact with the barcode and read it, and a laser beam scans the barcode. There is a non-contact method in which reading is performed in a non-contact manner. This non-contact type bar code reader is usually configured as a stationary type device, but has been widely used because of its excellent operability. FIG. 2 is a view showing an example of a conventional bar code reader to which the present invention can be applied. A laser beam from a semiconductor laser light source 1 is reflected by a polygon mirror 2 and further reflected downward by a mirror 3 so that an article or the like can be seen. In this figure, the article 10 with the bar code 4 is shown as being placed on the table 5. The laser light reflected by the bar code is in the reverse path, that is, a filter 6 for blocking disturbance light and the like from the mirror 3 and the polygon mirror 2 and passing the laser light.
Then, the light enters the photoelectric conversion element 8 through the lens 7 and is output from the photoelectric conversion element 8 as a bar code read signal. Reference numeral 9 denotes an infrared light-emitting element such as a light-emitting diode, which is located on the back side of the infrared light-emitting element in FIG. An article approach sensor for detecting whether or not the item approach is performed. The infrared light emitting element 9 of the article approach sensor blinks when the article is not approaching, and the article 10 ′ approaches as shown in the figure, and the infrared light from the light emitting element 9 is reflected by this article, and When it is detected that the light has entered the infrared light receiving element with a predetermined intensity or more, the infrared light emitting element 9 is turned off and the semiconductor laser light source 1 is turned on to activate the bar code reading mechanism. As described above, when the article is not approaching, the semiconductor laser light source 1 is shut off and the bar code reading mechanism is stopped, whereby erroneous reading due to disturbance light can be prevented. FIG. 3 is a block diagram of a conventional bar code reader to which the present invention can be applied. In FIG. 3, the same components as those shown in FIG. 2 are denoted by the same reference numerals. The article approach sensor unit 30 includes the infrared light emitting element 9 and the infrared light receiving element 31 described above. The infrared light emitting element 9 repeats blinking according to a light emission control signal from the control unit 20. The article detection circuit 32 detects the approach of the article based on the output of the infrared light receiving element 31, and sends an article detection signal to the control unit 20. As a result, the control section 20 sends a laser emission signal to the drive circuit 41 of the bar code reading section 40 to cause the semiconductor laser light source shown as the laser diode 1 to emit light. Is rotated, and the laser beam from the laser diode is reflected by the polygon mirror (FIG. 2) to perform scanning. The photodiode 8 that detects the laser light receives the laser light reflected from the bar code attached to the article or the like, converts the laser light into an electric signal, sends the electric signal to the demodulation circuit 44, and converts the data recorded as the bar code into data. The signal is demodulated and transferred to the control unit 20. The control unit 20 also performs required processing such as performing required processing on the demodulated data, storing the data in a storage device, and outputting the data to a host computer or a predetermined device. [Problems to be Solved by the Invention] By the way, a helium-neon gas laser has conventionally been used as a laser used in a bar code reader. Is used. However, while the wavelength of the output laser light of a conventionally used helium-neon gas laser is 633 nm, the wavelength of the output laser light when a visible light laser diode is used as a semiconductor laser is 670 to 680 nm. There are differences. Due to this difference in wavelength, the amount of light perceived by human eyes when a semiconductor laser is used becomes about 1/10 of that of a helium-neon gas laser, and it is difficult to distinguish whether the semiconductor laser light source is turned on or not. Since it is difficult to identify the scanning range of the laser beam from the semiconductor laser light source, there is a problem that it is difficult for the operator to identify where the bar code to be read is located and the reading is correctly performed. The present invention determines whether or not a barcode can be read,
It is an object of the present invention to obtain a barcode reader that can easily identify a position where a barcode can be read. [Means for Solving the Problems] A barcode reading section comprising a semiconductor laser light source and a laser light receiving element, and a visible light beam is applied to a range in which a barcode can be read by laser light from the semiconductor laser light source. A bar code reader comprising: a visible light emitting element provided in the apparatus; and a visible light receiving element configured to detect reflected light of visible light from the visible light reflected from the article. When the sensor unit detects the approach of the article, the semiconductor laser light source emits light and the visible light emitting element is continuously turned on, and the visible light emitting element is intermittently turned on during a period in which the semiconductor laser light source is not emitted. Control means for performing the control is provided. [Operation] The operation will be described with reference to the conventional example shown in FIG. 2. By setting the light emission of the light emitting element 9 of the article proximity sensor to visible light, the operator can determine whether the visible light emitting element 9 is emitting light. Can be identified. Also, by irradiating the irradiation range to the area where the bar code can be read from the approach direction of the article as shown in FIG. If the operator positions the article so as to be illuminated by the light from the bar code, the bar code is correctly read. The irradiation range of the visible light emitting element 9 is desirably determined in consideration of the shape and size, particularly height, of the article to which the bar code is attached. It will be apparent that there is no need to match the barcode readable range on D. [Embodiment] FIG. 1 is a conceptual diagram showing an embodiment of the present invention. A bar code reader body R has the same configuration as that described with reference to FIG. A scanning line by a laser beam from a semiconductor laser light source scanned by a mirror is indicated by a thick dotted line on the transparent window W of the main body R and on the reading table D. The trapezoidal range indicated by hatching that is separated by a chain line surrounding the scanning line range on the reading table D is the readable range of the barcode, and the barcode readable range of the barcode attached to the article as described above. In order to cover the readable range as widely as possible, the visible light from the visible light emitting element L of the article proximity sensor portion shown by hatching downward to the right in the figure is irradiated. S is a visible light receiving unit of the article approach sensor unit. As described above, the visible light emitting element L for generating visible light blinks until the article approaches, and when the article approaches, starts continuous lighting and energizes the semiconductor laser light source of the bar code reader body. The reading of the bar code is started, so that the operator can identify that the visible light emitting element L is in the bar code reading state by continuously lighting the visible light emitting element L. It is possible to identify that the barcode only needs to be located in the range. FIG. 4 is a block diagram showing an embodiment of the configuration of the article proximity sensor unit according to the present invention, and FIG. 5 is an operation waveform diagram thereof. The visible light emitting element 56 corresponding to the light emitting element 9 in FIG.
In the standby state, that is, when the article is not approaching, the timing signal shown in FIG. 5 from the light emission timing generation circuit 59 repeats blinking by the output of the drive circuit 57 supplied via the OR circuit 58. When the article approaches, the amplitude of the output of the visible light receiving element 51 amplified by the amplifier circuit 52 exceeds the threshold as shown in FIG. 5, and the output of the binarization circuit 53 becomes as shown in FIG. The result is a binary waveform as shown. The AND circuit 54 calculates the logical product of the output of the binarization circuit 53 (FIG. 5) and the timing signal (FIG. 5) from the light emission timing generation circuit 59, and the output shown in FIG. The number of pulses is counted by the article approach detection circuit 55. In order to avoid the influence of disturbance, in the example shown in the figure, three pulses are counted, and then the article approach signal shown in FIG. The control unit that has received the article approach signal supplies the light emission control signal shown in FIG. 5 to the input terminal above the OR circuit 58, and the timing signal ( Regardless of the value of FIG. 5), an output for continuously emitting the visible light emitting element 56 is sent from the OR circuit 58 to the drive circuit 57. Therefore, the output of the drive circuit 57 driven by the output of the OR circuit 58 is as shown in FIG. 5, and the visible light emitting element 56 is turned on while the output of the drive circuit is at the "H" level. Even if the visible light from the visible light emitting element 56 is irradiating the bar code to be read, the reading of the bar code is based on the change in the reflection intensity of the laser light from the laser light source due to the bar code. Does not affect the data read from the barcode. FIG. 6 is a flowchart showing an operation example according to the present invention. In step [1], the approach of an article is monitored by the article approach sensor unit, and when an article approaches and an article is detected, step [2] is performed. ], The semiconductor laser light source such as the laser diode of the bar code reading section is caused to emit light, and in the following step [3], the visible light emitting element of the article proximity sensor section is continuously caused to emit light. In the next step [4], the timer is reset and started to perform reading, and in step [5], it is checked whether the reading of the bar code and its demodulation are successful.
If the reading or demodulation fails, the process proceeds to step [6], and the reading and demodulation are repeated until the time counted by the timer restarted in step [4] exceeds the scheduled time. If the reading and demodulation are successful in the above step [5], it means that the reading of the bar code has been completed. Therefore, the timer which has been reset-started in the step [4] is stopped in the step [7], and the step [8] Stopping the light emission of the semiconductor laser light source of the bar code reading unit that was caused to emit light in [2], and

In [9], the continuous light emission of the visible light emitting element of the article proximity sensor unit which has been continuously emitted in step [3] is stopped. If reading and demodulation are not successful until the scheduled time is exceeded in step [6], the process proceeds to step [8] to stop the light emission of the semiconductor laser light source and stop reading the bar code. At the same time, the continuous light emission of the visible light emitting element is also stopped. [Effects of the Invention] According to the present invention, since the light emitting element of the article proximity sensor unit generates visible light, it is possible to identify that the bar code can be read by continuous lighting. Further, since the irradiation range of the visible light emitting element is indicated as a range in which a bar code can be read, not only the operation is extremely easy, but also a special effect that erroneous reading does not occur is achieved. .

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an embodiment of the present invention. FIG. 2 shows a conventional example. FIG. 3 is a block diagram of a bar code reader to which the present invention can be applied. FIG. 4 is a block diagram showing an embodiment of the configuration of the article proximity sensor unit. FIG. 5 is an operation waveform diagram of the embodiment. FIG. 6 is a flowchart showing an example of the operation.

Claims (1)

(57) [Claims] 1. A bar code reading section comprising a semiconductor laser light source and a laser light receiving element, and a visible light provided so as to irradiate a range in which a bar code can be read by laser light from the semiconductor laser light source. A bar code reader comprising: a light emitting element; and an article proximity sensor unit including a visible light receiving element that detects reflected light of visible light from the visible light emitting element reflected from the article. When the approach of the semiconductor laser light source is detected, the semiconductor laser light source is made to emit light and the visible light emitting element is turned on continuously. During a period when the semiconductor laser light source is not emitting light, the visible light emitting element is controlled to be turned on and off intermittently. A bar code reader comprising control means.