JP3059999B2 - Barcode scanner and barcode reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar code scanner for reading a bar code, and more particularly to a bar code scanner and a bar code reader suitable for portable use, and more particularly to a technique for reducing power consumption and extending the life of a display backlight. Related to technology.

[0002]

2. Description of the Related Art A bar code scanner has a bar code contact end in contact with a bar code, irradiates a bar code with light from a bar code irradiating light source, and receives the reflected light.
A CCD type bar code scanner that electronically scans the light receiving unit, and simultaneously moves the bar code contacting end while contacting the bar code, irradiates the bar code with light from a bar code irradiation light source, and reflects the light. There is a pen-type bar code scanner that scans a bar code by receiving light. In any of the barcode scanners, in order to reduce the power consumption of the barcode irradiation light source, conventionally, when the barcode scanner is not used, the power is manually turned off.

[0003] Further, data read by a bar code scanner is decoded, and the result is displayed on a display. A liquid crystal display with a backlight may be used as the display. Since the liquid crystal display panel does not emit light, a light source (this is called a backlight) is provided on the back side of the liquid crystal display panel, and the display image of the liquid crystal display panel is viewed as a shadow image of the transmitted light from the backlight. Often done.

As a backlight of a liquid crystal display with a backlight, an ordinary cold cathode tube (CFL: Cold cathod) is used.
e Fluorescent Lamp), a fluorescent light, and in some cases EL (Electro Lumi)
essence) is used. These backlights have a relatively short light-emitting life, that is, a cumulative time until the brightness is reduced to half, and in the case of a cold cathode fluorescent lamp (CFL), 10,000 to
It takes 20,000 hours and 3,000 to 5,000 hours for EL. This is considerably shorter than the life of the liquid crystal display panel of about 50,000 hours. Therefore, when the barcode scanner is not used, it is common practice to turn off the backlight of the liquid crystal display with backlight as the display. The operation of turning on and off the backlight has conventionally been performed manually.

[0005]

As described above, in the related art, in order to reduce the power consumption of a light source for irradiating a barcode used in a barcode scanner, and to display a reading result of the barcode scanner. In order to extend the operational life of the backlight of the liquid crystal display with light, the bar code irradiation light source and the backlight were manually turned off when unnecessary. However, this manual operation is particularly troublesome if it is performed frequently, and has the disadvantage that it is easy to forget when it is performed occasionally. Particularly, in a portable barcode reader, a battery is used as a power source, and a liquid crystal display with a backlight is used for weight reduction.
It is desirable not to waste even a small amount of power, and therefore, it is required to turn off the light source for barcode irradiation and the backlight when it is unnecessary, and to turn off the backlight when it is not needed to make the backlight last longer. Is required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bar code scanner capable of easily automatically turning off a bar code irradiation light source and a backlight when unnecessary. Another object of the present invention is to provide a bar code scanner which automatically turns off a light source for bar code irradiation when unnecessary.

A third object of the present invention is to provide a bar code reader for automatically turning off the backlight of a liquid crystal display when unnecessary.

[0008]

According to the first aspect of the present invention, an accelerometer is attached to a main body of a bar code scanner, an acceleration detection signal from the accelerometer is supplied to a switch control signal generation circuit, and a switch control signal is generated. A switch-on signal is generated from the control signal generation circuit while at least the input acceleration detection signal is present.

According to the second aspect of the present invention, the bar code irradiation light source is turned on by the switch-on signal from the switch control signal generating circuit according to the first aspect of the present invention. According to the third aspect of the present invention, in a reading device in which data read by a bar code scanner is displayed on a liquid crystal display with a backlight, an accelerometer is attached to the bar code scanner, and an acceleration detection signal from the accelerometer is provided. Is supplied to the switch control signal generation circuit, whereby a switch-on signal is generated at least during the acceleration detection signal, and the backlight of the liquid crystal display is turned on by the switch-on signal.

[0010]

According to the first aspect of the present invention, when a bar code scanner is picked up to read a bar code, this is detected by an accelerometer, and a switch control signal generating circuit generates a switch-on signal. According to the invention of claim 2,
The bar code irradiation light source is turned on by the switch-on signal generated in the first aspect of the present invention, that is, the light source is always turned off, and the light source can be turned on automatically for reading to perform reading.

According to the third aspect of the present invention, when the bar code scanner is picked up to read a bar code, this is detected by the accelerometer, and a switch-on signal is generated from a switch control signal generating circuit. The backlight, which is always off, automatically turns on, the data read by the bar code scanner is displayed on the liquid crystal display, and this display can be easily read.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings. Since each of the first and second aspects of the present invention is common to a part of the third aspect of the present invention, an embodiment of the third aspect of the present invention will be described, and then the first and second aspects of the present invention will be briefly described. explain.

In FIG. 1A, data read by a CCD type bar code scanner 1 is decoded, converted into characters, and displayed on a liquid crystal display 2 with a backlight. Although not shown in the figure, it is assumed that the processing device for the decoding and the character conversion is incorporated in the liquid crystal display with backlight 2. Of course, this processing device may be arranged outside, and may be used also as another device.

FIG. 1B shows a CCD type bar code scanner 1.
As shown in C, the mounting board 1b is housed in the main body 1a, and the barcode irradiation light source 1c is housed near the barcode contact end 1d. As the light source 1c, a light emitting diode or a laser diode is usually used. Light source 1
The light from c is radiated to the outside from the bar code contact end 1d, is reflected by the bar code to be read (not shown), and the reflected light returns to the inside of the main body 1a from the bar code contact end 1d, The image is formed on the CCD light receiving surface 1g through the reflecting mirror 1e and the projection lens 1f. The CCD light receiving surface 1g is electronically scanned, and the scanning output, that is, the bar code read data is amplified and shaped as necessary and supplied to the liquid crystal display 2.

In the present invention, a bar code scanner 1 is used.
The accelerometer 3 is attached to. In the example of FIGS. 1B and 1C, the accelerometer 3 is attached to the mounting board 1b in the main body 1a. As the accelerometer 3, for example, a remarkably small one in which a mass part, a supporting piece thereof, and the like are formed from single crystal silicon by a photo-etching method can be used. The acceleration detection signal from the accelerometer 3 is amplified by an amplifier 5 as necessary and supplied to a switch control signal generation circuit 6, as shown in FIG. 2A. The switch control signal generation circuit 6 generates a switch-on signal while at least the input acceleration detection signal is present. For example, the output of the amplifier 5 is supplied to the zero-cross detection circuit 7, and the zero-cross pulse from the zero-cross detection circuit 7 is supplied to the holding circuit 9 for a certain time. The fixed time holding circuit 9 is, for example, a retriggerable monostable multivibrator, and outputs a pulse having a fixed time width from the pulse every time a pulse is input. As will be described later, the width of the output pulse is larger than the longest time in the acceleration detection signal from the accelerometer 3 which is output only by holding the barcode scanner 1 by hand.

The switch-on signal from the switch control signal generating circuit 6, ie, the output of the holding circuit 9 for a fixed time,
The bar code irradiation light source 1c is turned on, and the backlight 17 of the liquid crystal display 2 is turned on. For example, a switch 13 inserted in series between the bar code irradiation light source 1c and the power supply 12 corresponding thereto is turned on by a switch-on signal, and is inserted in series between the backlight 17 and the power supply 15 corresponding thereto. The switch 16 is turned on by the switch-on signal.

Just by holding the barcode scanner 1 with the accelerometer 3 attached to the hand, an acceleration detection signal is obtained from the accelerometer 3 based on naturally occurring hand shaking, for example, as shown in FIG. 2B. As shown in FIG. 2C, a zero-cross pulse is generated from the zero-cross detection circuit 7 at each zero-cross point of the acceleration detection signal. At the first generation time t0 of the zero-cross pulse, the switch-on signal rises from the holding circuit 9 for a certain period of time. The switch-on signal falls after the holding time T from the time point t1 at which the zero-cross pulse is generated.

With this configuration, when the barcode scanner 1 is picked up by hand to read a barcode by the barcode scanner 1, a relatively large acceleration detection signal is output from the accelerometer 3 and immediately. A switch-on signal is always generated, the bar code irradiation light source 1c is turned on, and the backlight 17 is turned on. Therefore, when a barcode reading operation is performed by the barcode scanner 1, the reading result is displayed on the liquid crystal display 2. When the barcode scanner 1 is returned to the original position, the acceleration detection signal disappears from the accelerometer 3 and the switch-on signal disappears, and both the barcode irradiation light source 1c and the backlight 17 are turned off. The holding time T is set to a time sufficient to visually read the reading result that appears on the liquid crystal display 2. However, since it is common to return the barcode scanner 1 to its original position after reading the reading result that appears on the liquid crystal display 2, the holding time T is set slightly longer than the longest time in the acceleration detection signal of FIG. 2B. That is enough.

Even when the accelerometer 3 detects only the one-dimensional direction, when the barcode scanner 1 is read by hand while the barcode scanner 1 is being operated, the movement of the barcode scanner 1 includes the one-dimensional direction. Since the above-mentioned component always occurs, the desired operation can be performed. However, in order to make the operation more reliable, an accelerometer 3 that detects a two-dimensional direction or a three-dimensional direction may be used. The switch control signal generating circuit 6 may be provided in either the bar code scanner 1 or the liquid crystal display 2. In the above description, the lighting control for the barcode irradiation light source 1c based on the switch-on signal may be stopped, and the barcode irradiation light source 1c may be constantly turned on.

According to an embodiment of the present invention, the bar code scanner 1 has a switch control signal generating circuit 6 built therein, and the bar code irradiation light source 1c is controlled to be turned on and off by a switch-on signal. The code scanner 1. The embodiment of the first aspect of the present invention is the above-described bar code scanner 1 having the switch control signal generation circuit 6 built therein. According to such a bar code scanner 1, a switch-on signal obtained from the bar code scanner 1 is backlighted. It can be used for lighting control of one or both of the light source 17 and the bar code irradiation light source 1c. In any of the above cases, a pen-type barcode scanner may be used.

[0021]

According to the first aspect of the present invention, the accelerometer is attached to the bar code scanner, and the switch-on signal generating circuit for generating the switch-on signal while the acceleration detection signal is obtained is attached. The switch-on signal can be used for controlling lighting of a bar code irradiation light source and a backlight.

According to the second aspect of the present invention, since the lighting of the bar code irradiation light source is further controlled by the switch-on signal in the first aspect of the invention, the bar code irradiation light source is turned on only during use. Is reduced. According to the third aspect of the present invention, the accelerometer is attached to the bar code scanner, and while the acceleration detection signal is obtained, the switch-on signal is generated by the switch control signal generation circuit, and the switch-on signal is used for the liquid crystal display. Since the backlight is controlled to be turned on, the lifetime of the backlight is actually increased and the power consumption is reduced.

In particular, for portable use, it is effective to use a liquid crystal display, to reduce power consumption, and to extend the life of the backlight in practice.

[Brief description of the drawings]

1A is a diagram showing connection between a CCD barcode scanner and a liquid crystal display with a backlight, FIG. 1B is a plan view showing a state where an accelerometer is attached to the CCD barcode scanner,
C is a side view, and D is a view showing a state in which an accelerometer is attached to a pen-type barcode scanner.

FIG. 2A is a block diagram showing a configuration example for signal processing of an acceleration detection signal from an accelerometer to control lighting of a barcode irradiation light source and a backlight, and B shows an example of an acceleration detection signal from an accelerometer C is a diagram showing a pulse obtained by detecting the zero-cross point of the analog waveform of B, and D is a switch-on signal obtained by inputting a pulse output of C to a holding circuit for a certain period of time and outputting the same. It is a figure showing the example of.

Claims (3)

(57) [Claims] An accelerometer attached to a bar code scanner main body, a switch control signal generation circuit supplied with an acceleration detection signal from the accelerometer, and generating a switch-on signal at least while the signal is present; A bar code scanner, comprising: 2. The bar code scanner according to claim 1, further comprising means for controlling the switch-on signal from the switch control signal generation circuit, and for turning on a bar code irradiation light source during this signal. . 3. A bar code reader for displaying data read by a bar code scanner on a liquid crystal display with a backlight, wherein an accelerometer attached to the bar code scanner and an acceleration detection signal from the accelerometer are supplied. A switch control signal generating circuit for generating a switch-on signal while at least the signal is present, and means for controlling the switch-on signal to turn on the backlight of the backlit liquid crystal display during the signal. And a bar code reader.