JPH0561835A - Portable electronic device - Google Patents

Abstract

PURPOSE:To compulsorily switch off the back light of LCD under bright environment so as to prevent the consumption of power. CONSTITUTION:A device is constituted in such a way that a switch 3 is turned off by the output of an AND circuit 2 and the back light 25 of LCD 12 is switched off when incident light quantity for a light-receiving element 17a is much.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable electronic device, such as a handy terminal, having functions of collecting, searching, transmitting and receiving data.

[0002]

2. Description of the Related Art In a portable electronic device such as a handy terminal, when an LCD (liquid crystal display device) is used as an information output means, a backlight device is provided to supplement the brightness of its display screen. The light device is turned on and off by a dedicated on / off key, or is always lit and used.

[0003]

Conventionally, even when the environment of use is sufficiently bright, the backlight remains on, and forgetting to turn it off consumes unnecessary power, thereby reducing the use time per charge. I was letting it.

Therefore, the present invention provides a portable electronic device having a structure in which the backlight of a display device such as an LCD is controlled to be turned on and off according to the brightness of a use environment and can be easily realized with a simple structure. The purpose is to do.

[0005]

In order to solve the above problems, the present invention provides an information inputting means, a processing means for processing the information inputted from the information inputting means, and a processing means for processing by the processing means. Display means for displaying information, backlight means provided on the back surface of the display means for irradiating the display means with light, detecting means for detecting the brightness of the use environment, and output according to the output of the detecting means. A portable electronic device, comprising: a control unit that controls the operation of the backlight unit.

Further, according to the present invention, there is provided a portable electronic device having a light receiving element of a non-contact communication interface and using the light receiving element as the detecting means. Further, according to the present invention, there is provided a portable electronic device having a solar cell for supplying electric power and using the solar cell as the detecting means.

[0007]

When used in a bright place, the backlight can be forcibly turned off, power consumption can be prevented, and the operating time per charge of the battery can be increased. Furthermore, this can be easily and easily realized without increasing the number of parts.

[0008]

Embodiments of the present invention will be described in detail below with reference to the drawings. The following description is an embodiment in which the present invention is applied to a handy terminal.

First, the external appearance of the handy terminal of this embodiment will be described with reference to FIGS. In the main body 11 of the handy terminal of this embodiment, an LCD (liquid crystal display device) 12 for display, a keyboard 13 for input, a main battery 14, a sub battery 15 for memory backup, and CM
OS interface cover 16, optical communication interface 17, and RS-232C interface 18
And a solar cell 19 are provided. The keyboard 13 includes ten keys, function keys, mode switching keys,
An operator can input various data, including a power on / off key, LCD backlight on / off key, and the like.

On the back side of the keyboard 13, nickel (N
i) -A cadmium (Cd) rechargeable battery is installed as the main battery 14, and the power required for the operation of the entire handy terminal is supplied. The sub battery 15 is a coin-type lithium (L
i) When a battery is used and the power capacity of the main battery 14 is lowered, or when the main battery 14 is removed for charging, information stored in a volatile memory such as a RAM of a control unit described later is displayed. Used to hold. Although not shown, a small-sized and large-capacity capacitor of about 0.01 F to 0.1 F is mounted on the control unit, and the main battery 14 and the sub battery 15 are mounted.
When the sub battery 15 is replaced when both the voltages of 1 and 2 are decreased or the voltage of the main battery 14 is decreased, the information in the volatile memory can be retained for a short time. The solar battery 19 is used as an auxiliary power source for the main battery 14 and the sub battery 15.

There are three types of communication means between the handy terminal and external equipment. The first is C-MOS level serial communication. This is done via a connector provided under the cover 16 attached to the side surface of the main body 11, and if a level converter for C-MOS / RS-232-C conversion is used, external equipment such as a personal computer can be used. In addition to being able to communicate with, it is possible to connect optional equipment such as a pen-type barcode reader and a touch-type barcode reader.

Secondly, as shown in FIG. 5, non-contact by infrared light by an optical communication interface 17 using an optical element that is a combination of a light emitting element and a light receiving element attached to the side surface of the main body 11. Optical communication. This allows communication with an external device such as a personal computer without placing troubles such as attachment and detachment of a connector simply by mounting the main body 11 on a photoelectric conversion device called an optical coupling adapter (not shown).

The third is RS-232-C communication. This is also done through the DSUB connector 18 attached to the side surface of the main body 11 as shown in FIG. 6, and communication can be easily performed with an external device such as a personal computer using a general RS-232-C cable. it can.

The control unit has the configuration shown in FIG.
A ROM 21 for storing an operating system (OS), a self-diagnosis program and the like via a bus 22 to a CPU 21 for controlling the whole, an LCD 12 connected via an LCD I / F 24, and a backlight EL 25.
And the font RO that stores the font data of the characters
M (CG) 26, applications applicable to various industrial fields such as distribution, transportation, finance, insurance, RAM 27 for storing numerical data and character data used by these application software, and calendar clock data. Real-time clock for counting and storing (RT
C) 29 is connected to the battery voltage monitoring unit 28 that monitors the battery pressures of the main battery and the sub batteries 4 and 5.

In the CPU 21, a keyboard 13, a C-MOS level I / F 16, an optical communication I / F 17, and an RS-232C I / F 18 shown in FIGS. 2 to 6 are respectively a keyboard I / F 30 and a communication I / F 31. , 32, 33. To use the handy terminal with such a hardware configuration for various purposes, develop application software using a personal computer,
This terminal may be loaded by communication means.

The handy terminal is characterized by its small size, light weight and portability. Therefore, in addition to the high-density mounting of the substrate, power saving and low voltage driving are required in order to reduce the size and weight of the main battery 14. On the other hand,
If the voltage of the nickel (Ni) -cadmium (Cd) rechargeable battery 14 is lowered below the rating, the battery will be in an “over-discharge” state, and the life of the rechargeable battery 14 itself will be shortened. In order to prevent this, the monitoring unit 28 monitors the decrease in the power supply voltage, and
It is necessary to properly control the display of a warning message on the CD 12, the prohibition of operation, the driving of the buzzer 34, and the like.

FIG. 8 shows a control block diagram of the power supplies 14, 15 and 19 and an example of the maximum amount of current flowing through each block of the handy terminal of this embodiment. As shown in this example, the backlight EL 25 of the LCD 12 consumes a maximum current of about 60 mA, which is approximately the same value as the main body logic unit (CPU) 21 and the like. The purpose of this backlight 25 is LC even when working in a dark warehouse or at night.
Since the display of D12 can be continued,
It doesn't have to be on all the time, and using a backlight in a particularly bright place only wastes power.

In FIG. 1, the brightness of the usage environment is detected by using the light receiving element 17a for optical communication which is already provided in this handy terminal as a basic function, and the backlight 25 is turned on by using the detection result. , A circuit for off control is shown. The optical elements 17a and 17b are normally used for receiving and transmitting data. Further, the light receiving element 1
When a certain amount of light or more is incident on 7a, "1" is supplied from the output end to one of the AND circuits 2, and the control circuit 1 outputs an AND signal.
When "1" is supplied to the other input terminal of the circuit 2 as a brightness check signal, an output "1" is obtained, which turns off the switch 3 to turn off the backlight 25. When the brightness check signal or the RTS signal is supplied to the Vcc terminal via the OR circuit 4, the optical element 17a is energized to check the brightness of the environment.

When the brightness of the use environment is insufficient, the output of the optical element 17a becomes "0", the output of the AND circuit 2 also becomes "0", the switch 3 is turned on, and the backlight 25 is turned on. To be done.

Further, the circuit of FIG. 8 also has a configuration in which the brightness of the use environment is detected by using the solar cell 19. Originally
The solar cell 19 is used for the purpose of supplying electric power for holding the memory in which the handy terminal operates, but here, the solar cell voltage monitoring unit 28 is provided at the output of the solar cell 19.
b is provided, and when the voltage is a certain value or more, that is, the brightness is a certain value or more, the backlight 25 of the LCD 12 is provided.
The use of is prohibited.

FIG. 9 shows a block diagram of a power supply control unit according to another embodiment of the present invention. The same parts as those in FIG. 8 are designated by the same reference numerals. In FIG. 9, the first voltage detection circuit 28C is
This is for detecting that the voltage of the main battery 14 has dropped to a value A at which it is necessary to forcibly turn off the backlight 25 and turn off the switch 3. This voltage value A
Corresponds to detection level 1 in FIG. This detection circuit 28
The output of C is sent to the CPU 21 of FIG. 7, and a message notifying the operator of the voltage drop of the main battery 14 is displayed on the LCD 1.
2 to inform the user that the main battery 14 needs to be replaced and charged, and prevent erroneous operation due to over-discharge of the main battery 14 or a sudden voltage drop of the main battery 14.

On the other hand, the voltage of the main battery 14 further decreases,
When the voltage detection circuit 28d detects that the voltage has decreased to the detection level 2 in FIG. 10, this detection output is sent to the CPU 21 to perform processing for ending the work, for example, saving data in the buffer and performing reset processing. To do.

[0023]

As described above, according to the present invention,
With a relatively simple configuration, it is possible to prevent the backlight of an LCD or the like from being turned on in a bright environment, prevent wasteful power consumption, and realize a small and lightweight portable electronic device.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of an embodiment of the present invention.

FIG. 2 is a plan view of the handy terminal of this embodiment.

FIG. 3 is a side view of the handy terminal according to the embodiment.

[Fourth] Back view of the handy terminal of the same embodiment

FIG. 5 is a top side view of the handy terminal of the same embodiment.

FIG. 6 is a bottom side view of the handy terminal according to the embodiment.

FIG. 7 is an overall block diagram of the same embodiment.

FIG. 8 is a block diagram of a power supply control unit of the embodiment.

FIG. 9 is a block diagram of a power control unit according to another embodiment.

10 is a discharge time curve diagram for explaining the operation of the circuit shown in FIG.

[Explanation of symbols]

1 ... control unit, 2 ... AND circuit, 3 ... switch, 4
... OR circuit, 12 ... LCD display, 14 ... power supply,
17a: light receiving element, 25: back light.

Claims (3)

[Claims] 1. An information input means, a processing means for processing the information input from the information input means, a display means for displaying the information processed by the processing means, and a rear surface of the display means, It has a backlight means for irradiating the display means with light, a detection means for detecting the brightness of the usage environment, and a control means for controlling the operation of the backlight means according to the output of the detection means. Portable electronic device. 2. A portable electronic device according to claim 1, further comprising a light receiving element of a non-contact communication interface, wherein the light receiving element is used as the detecting means. 3. The portable electronic device according to claim 1, further comprising a solar cell for power supply, wherein the solar cell is used as the detecting means.