JPH03268188A - Bar code reader - Google Patents

Abstract

PURPOSE:To prevent the generation of misreading by allowing a light emitting element to emit visual light for irradiating a bar code readable range, and when the incident light of a light receiving element exceeds a prescribed value due to the approach of an article, allowing a semiconductor laser to emit laser beams. CONSTITUTION:The light emitting element L for emitting visual light is turned on and off until an article approaches, and when the article approaches the element L, continuously lighted and excites the semiconductor laser mounted on a bar code reader body R to start the reading of a bar code. Thereby, an operator can discriminates the bar code readable state of the bar code reader by the continuous lighting of the element L and the positioning of the bar code on a range irradiated with beams projected from the element L can be discriminated. It is preferable to determine the irradiating range of the element L in consideration of the shape, size, especially height of the article on which the bar code is printed out.

Description

[Detailed description of the invention]

[Already required] This article relates to barcode leagues used as input devices for POS systems, etc. It is an object of the present invention to obtain a Harcoat Tricks that can display the readable state of barcodes and identify the half-l-readable range. In a barcode reader that uses a semiconductor laser as a light source and is equipped with an article proximity sensor consisting of a light emitting element and a light receiving element that detects light reflected from the article from the light emitting element, this light emitting element illuminates the Harkot readable range. The light emitting element is configured to emit visible light such that the light emitting element emit light when the amount of light incident on the light receiving element exceeds a predetermined value due to the approach of an article, and to cause the semiconductor laser to emit light and to cause the light emitting element to continuously light up. did. [Industrial Application Field] This invention relates to barcode leagues used as human-powered devices such as POS systems. [Prior Art] Bako League is widely used as an input device for POS systems, etc., but the Baco League uses a pen-shaped glue to trace the barcode in an orthogonal direction, or a league with a built-in scanning function is used to create the bar code. There are contact methods, such as the kunochi method, which performs reading by touching the barcode, and non-contact methods, which perform non-contact reading by scanning the barcode with a laser beam. This non-contact type barcode league is normally configured as a stationary device, but it has become widely used because it is extremely easy to operate. FIG. 2 is a diagram showing an example of a conventional no-coat league to which the present invention can be applied, in which a laser beam from a semiconductor laser 1 is reflected by a polygon mirror 2, and further reflected downward by a mirror 3 to form a barcode. In this figure, the article 10 with the barcode 4 marked with "I" is shown as being placed on the table 5. The laser beam reflected by this barcode enters the photoelectric conversion element 8 through the opposite path to that described above, that is, from the mirror 3 and the polygon mirror 2, through the filter 6 and lens 7 that block disturbance light and pass the laser beam. , barcode reading 1
This photoelectric conversion element 8 outputs it as a word. Reference numeral 9 denotes an infrared light emitting element such as a light emitting unit 8, which is located on the back side of this light emitting element in the figure, and is paired with a light receiving element (not shown) to read the article 1.
This constitutes an article approach sensor for detecting whether or not 0' approaches. The light emitting element 9 of this article proximity sensor blinks when no article is approaching, and when an article 10' approaches as shown by the dotted line, the light from the light emitting element 9 is reflected by this article and the light receiving element is illuminated. When it is detected that the bar code is incident on the bar code with an intensity exceeding a predetermined value, the light emitting element 9 is turned off, the semiconductor laser 1 is turned on, and the bar code reading mechanism is activated. In this way, by shutting off the semiconductor laser 1 and placing the barcode reading mechanism in a stopped state when no article is approaching, it is possible to prevent the effects of erroneous reading due to ambient light. FIG. 3 is a block diagram of a conventional circuit to which the present invention can be applied, and the same components as shown in FIG. 2 are designated by the same reference numerals as in FIG. 2. The article approach sensor section 30 is equipped with a double light emitting element 9 and a light receiving element 31, and the light emitting element 9 repeatedly blinks in response to a light emission control signal from the control section 20. The article detection circuit 32 detects the approach of an article based on the output of the element 31, and sends the article detection signal to the control section 20.
send to As a result, the control unit 20 sends a laser emission signal to the drive circuit 41 of the coat reading unit 40, and the laser diode 1
A semiconductor laser shown as is caused to emit light, and a polygon mirror drive moke 43 is rotated via a morph control circuit 42 to cause the light from the laser quarto to be scanned by a polygon mirror (FIG. 2). The photodiode 8 receives the scanning light reflected from the bar code attached to the article, converts it into an electric signal, sends it to the demodulation circuit 44, demodulates the data, and sends it to the control section 2.
Transfer to 0. It goes without saying that this control section performs necessary processing on the demodulated data, stores it in the recording device, and then outputs it to a host computer or a predetermined device. [Problem to be solved by the invention] However, although helium-neon gas lasers have traditionally been used as lasers for barcode leagues, these days most semiconductor lasers are used because they are smaller and consume less power. Lasers are now being used. By the way, as mentioned above, the conventionally used helium
The wavelength of a neon gas laser is 633 nm, while the wavelength when a visible laser quartz is used as the semiconductor laser is 670 to 680 nm, but there is a difference of about 10 times in terms of the amount of light perceived by the human eye. It is difficult to distinguish whether this semiconductor laser is lit or not, and therefore, it is difficult to judge at which position the barcode is located for correct reading. Aapko. The object of the present invention is to obtain a Hercodriak that makes it possible to display the readable state of a barcode and identify the barcode reading range. [Means for solving the problem] A semiconductor laser is used. In the 8-dreak, which is used as a light source and is equipped with an article proximity sensor consisting of a light emitting element and a light receiving element that detects the light reflected from the light emitting element from the article, the light emitting element illuminates the Harkot readable range. The device is configured to emit light from the semiconductor laser and continuously light the light emitting device when the amount of light incident on the light receiving element reaches a predetermined value due to the approach of an object. [Function] To explain using the diagram of the conventional example shown in Fig. 2, by making the light emitted from the light emitting element 9 visible light when the object approaches sen -> no, the operator can see whether the light emitting element 9 is emitting light or not. In addition, by changing the irradiation range to irradiate the area where the barcode can be read from the approaching direction of the item as shown in Figure 2, the operator can read the barcode. If the article is positioned so that the barcode is illuminated by the light from the light emitting element 9, the barcode can be read correctly. It is desirable to determine the size, especially the height, etc., and it is clear that it does not necessarily have to match the barcode readable range on the table 5. [Example] Figure 1 is This is a conceptual diagram showing an embodiment of the present invention.
The barcode league main body R has a structure similar to that explained with reference to FIG. The mark is indicated by a thick dotted line on the front and on the reading surface. The barcode readable range is the trapezoidal range delimited by a dashed line surrounding the scanning line range of the reading table r) and indicated by a downward-left hunting line. Visible light from the light-emitting element of the article proximity sensor, shown by the hunting part downward to the right in the figure, is irradiated so as to cover as wide a readable range as possible. In addition,
S is a light receiving part of this article proximity sensor. As mentioned above, the light emitting element that generates this visible light blinks until the object approaches, and when the object approaches, it lights up continuously and energizes the semiconductor laser in the barcode league body to print the barcode. Since reading starts, the operator can identify the barcode reading state by seeing this light-emitting element light up continuously, and the operator can position the barcode within the range illuminated by this light-emitting element. I can identify good things. FIG. 4 is a block diagram showing an embodiment of the structure of the article proximity sensor section according to the present invention, and FIG. 5 is an operational waveform diagram thereof. A light-emitting wire 56 corresponding to the light-emitting element 9 in FIG. 3 repeats blinking by the output of the drive circuit 57 supplied from the OR circuit 58 and the timing signal from the light-emission timing generation circuit 59 shown in (■) in FIG. When an article approaches, the output of the light receiving element 51 amplified by the amplifier circuit 52 becomes the fifth
As shown in FIG. 5, the amplitude becomes greater than the threshold (2), and the output of the binarization circuit 53 becomes a binary waveform as shown in FIG. The AND circuit 54 takes the logical product of the output of the binarization circuit 53 and the timing signal from the light emission timing generation circuit 59, and the output shown in FIG. After counting three pulses in the figure in order to avoid the influence of disturbance along with the above-mentioned AND circuit, an article approach signal is output to a control circuit (not shown) (not shown in FIG. 5). As a result, this control circuit supplies a light emission control signal to the other input terminal of the OR circuit 58, as indicated by 0 in FIG. This OR circuit 58 outputs
from there to the drive circuit 57. Note that even if the light from this light-emitting element 56' illuminates the barcode to be read, the barcode is read by changing the intensity of reflection of the laser beam by the barcode. Does not affect data. FIG. 6 is a flowchart showing an example of the operation according to the present invention. In step [1], the approach of the article is monitored in the article approach sensor section, and when the article approaches, the bar code reading section is activated in step [2]. A semiconductor laser such as a laser diode is caused to emit light, and in the following step [3], a light emitting element of the article proximity sensor section is caused to emit light continuously. In the next step [4], the timer is activated to read the bar code, and in step [5], a check is made to see if the bar code reading and demodulation have been successful. If the reading or demodulation fails, the process moves to step [6] and the reading and demodulation are not repeated until the timer started recently in step [4] exceeds the scheduled time. If the reading and demodulation are successful in step [5] above, it means that the barcode reading power <l/% has been completed, so the timer that was recently started in step [4] is stopped in step [7], and the following steps are performed. [8] Step [
Stop the emission of the semiconductor laser of the barcode reading section that was emitted in step 2], and then

At [9], the continuous light emitting of the light emitting element of the article approach sensor unit that was caused to emit light continuously at step [3] is stopped. Note that if reading and demodulation are not successful until the scheduled time has elapsed in step [6], the process moves to step [8] and barcode reading is stopped. [Effects of the Invention] According to the present invention, by making the light emitting element of the article proximity sensor emit visible light, it is possible to identify that the bar code is readable by continuous lighting. Furthermore, since it is shown that the range of light irradiated by this light emitting element is within the range in which barcodes can be read, it is not only possible to make imitations extremely easily, but also achieve the special effect of eliminating the possibility of misreading.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a conventional example. FIG. 3 is a block diagram of a barcode league to which the present invention can be applied, FIG. 4 is a block diagram showing the configuration of the article proximity sensor section according to the present invention, FIG. 5 is an operation waveform diagram of the embodiment, and FIG. 6 is It is a flowchart which shows the example of the operation. 3

Claims (1)

[Claims] In a barcode reader that uses a semiconductor laser as a light source and includes an article proximity sensor consisting of a light emitting element and a light receiving element that detects light reflected from the article from the light emitting element, the light emitting element extends the barcode readable range. The device generates visible light that irradiates the device, and also causes the semiconductor laser to emit light when the amount of light incident on the light-receiving element exceeds a predetermined value due to the approach of an article, and causes the light-emitting device to continuously light up. A barcode reader that is characterized by: