JPH03260619A - Liquid crystal display device with backlight - Google Patents

Abstract

PURPOSE:To attain the recognition of the sort of display data only by observing a display color by arranging light emitting elements having two different colors on the back of a display part and changing the color of a backlight in accordance with the sort of display data. CONSTITUTION:Plural groups of red LEDs 53 and green LEDs 54 are arranged on the backlight parts 52 of the display part 5 so that light of three colors, i.e. red, green and yellow, can be emitted. When a backlight switch 7 is turned on and input data are inputted from a keyboard 4, various operations are executed by an LSI 2 and their results are displayed on the display part 5. In the case of a normal calculation mode, green light is emitted by the LEDs 54 through a control circuit 6, and when the calculated result is negative, red light is emitted by the LEDs 53. In the case of memory calculation mode, both LEDs 53, 54 are simultaneously turned on to emit yellow light.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a backlit liquid crystal display device used in a display section of a calculator or the like.

[Prior Art] Conventionally, small electronic calculators such as calculators have used a backlit liquid crystal display device (hereinafter abbreviated as backlit LCD) as a display section for displaying calculation results, etc. be.

This type of backlight (Nj' L CD) is a transmissive LCD with a backlight light source placed on the back.By irradiating light from the light source from the back of the LCD,
Display data on the LCD is visualized by light passing through the LCD.

[Problems to be Solved by the Invention] However, when such a backlit LCD is used in a calculator or the like to display calculation results, it has problems with the types of data displayed, such as normal calculation results and memory calculation results. Since LCD display is performed in a single color regardless of
If you only pay attention to the display, you may misunderstand the type of data being displayed, making it difficult to use as a calculator display. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a liquid crystal display device with a backlight that allows the user to confirm the type of displayed data without making a mistake.

[Means for Solving the Problems] The liquid crystal display device with a backlight of the present invention includes a light source section having at least two types of light emitting elements emitting light of different colors on the back surface of the liquid crystal display section. The color of the backlight display is changed by selecting the lighting of the light emitting elements.

[Function] The backlit liquid crystal display device of the present invention can change the color of the backlight display by lighting the light emitting elements selected according to the type of data to be displayed. You will be able to tell from the color of the light.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the circuit configuration of the same embodiment. In the figure, 1 is a solar cell that is the main power source, and this solar cell 1
is connected to LSI2. In addition, this LSI2 has
Built-in battery 3 is connected.

This built-in battery 3 replaces the solar cell 1 as an LS when the surroundings become dark and the output of the solar cell 1 drops below a predetermined level.
It supplies power to I2.

LSI 2 has a computer function and has a keyboard 4.
Various calculations are executed according to the input key manual data, and the resulting data is displayed on the display section 5.

The display section 5 includes a transmissive LCD 51 and a transmissive LCD 5.
It consists of a backlight part 52 that irradiates light from behind 1. As shown in FIG. 2, the backlight unit 52 is made up of two types of light emitting elements (hereinafter abbreviated as LEDs) that emit light of different colors, here an LED 5B that emits red light and an LED 54 that emits green light. By arranging a plurality of LEDs and combining the light emission of these LEDs 53 and 54, it is possible to emit light in three colors: red, green, and yellow. In this case, by passing the light given to the LCD 51 from the backlight section 52 through a semi-transparent reflector (not shown), it is possible to irradiate the LCD 51 with uniform light.

The backlight section 52 has its light emitting operation controlled by the control circuit 6. The control circuit 6 is connected to the solar cell 1 and built-in battery 3 as driving power sources via a backlight switch 7, and also receives predetermined commands according to the type of data displayed on the display unit 5 from the LSI 2. is now given. In this case, the control circuit 6 connects the LE between the power lines 61 and 62 as shown in FIG.
A series circuit of D5B and a current control circuit 63 such as an electronic volume, and a current control circuit 64 similar to the above-mentioned LED 54
The series circuits are connected to each other.

The command given to the control circuit 6 from the LSI 2 is
As shown in FIG. 4, for example, when entering the normal calculation mode, "1" is given to the input signal B of the current control circuit 64 to cause the LED 54 to emit green light, and the answer based on the calculation result becomes negative. In such a case, give "1" to the input signal A of the current control circuit 63 to cause the LED 5B to emit red light, and when entering the memory calculation mode, input signals A and H of the current control circuits 63 and 64 respectively. is set to "1" and LEDs 53 and 54 are lit simultaneously to emit yellow light.

Note that 8 in the drawing is a jack for connecting an external battery (not shown) in place of the built-in battery 3.

Next, the operation of the embodiment configured as above will be explained.

If backlight switch 7 is turned on now,
Even when either the solar cell 1 or the built-in battery 3 is used, driving power is supplied to the backlight section 52 of the display section 5. On the other hand, LSI2 also has solar battery 1 or built-in battery 3.
A predetermined amount of power is supplied.

From this state, when key data is entered manually from the keyboard 4, various calculations are performed on the LSI 2 depending on this input data.
The calculation result is displayed on the display section 5. In this case, if the data displayed on the display section 5 is in the normal calculation mode, "1" is given to the input signal B of the current control circuit 64 of the control circuit 6 from the LSI 2. Then, the current control circuit 64 is turned on, the LED 54 is turned on, and green light is emitted, so that data with a green background is displayed on the LCD 51.

On the other hand, if the answer of the calculation result is negative, "1" is sent from the LSI 2 to the input signal A of the current control circuit 63 of the control circuit 6.
1, the current control circuit 63 turns on, the LED 5B lights up, red light is emitted, and the LCD
51, data with a red background will be displayed. Furthermore, if the memory calculation mode is applied, the LS
Since "1" is given to the input signals A and B of the current control circuits 63.64 of the control circuit 6 from I2, both the current control circuits 63.64 are turned on and the LED 53.5 is turned on.
4 is lit, red and green lights are emitted, and LCD 5
] Data will now be displayed on a yellow background, which is a mixture of these colors.

In addition, in such a display unit 5, when the backlight switch 7 is left open as shown in the figure, the above-mentioned backlight display is not performed, and data is displayed on the LCD 51 by reflected light from outside light. Become so.

By doing this, when the data displayed on the display section 5 is subjected to the normal calculation mode, a pig with a green background will be displayed as a backlight display, and the answer of the calculation result will be negative. In this case, data will be displayed with a red background as a backlight display, and if memory calculation mode is entered, data will be displayed with a yellow background as a backlight display.
The type of data displayed on the display unit 5 can be easily determined from these display colors, and conventionally, data displayed on an LCD is displayed in a single color regardless of the type. By simply paying attention to the color, the type of data displayed on the display section 5 can be easily determined without making a mistake, and an extremely useful effect can be expected as a display section of a calculator.

Next, FIG. 5 shows another example of the control circuit 6 used in the present invention, and the same parts as in FIG. 3 are given the same reference numerals. In this case, a series circuit of the LED 53 and the LED driver 91 and a series circuit of the LED 54 and the same LED driver 92 as described above are connected between the power lines 61 and 62, and a pulse generator 93 is connected between the power lines 61 and 62. The output of this pulse generator 93 is applied to one input terminal of a NAND circuit 94 and also to one input terminal of a NAND circuit 96 via an inverter 95.
Furthermore, the above-mentioned input signal A is applied to the other input terminal of the NAND circuit 94, and the above-mentioned input signal B is applied to the other input terminal of the NAND circuit 96. This pulse generator 9
3 outputs pulses of the rHJrLJ signal alternately at the required period.

Therefore, when "1" is given to the input signal B, the output of the pulse generator 93 is input from the NAND circuit 96 to the LED driver 92 via the inverter 95, so the backlight section 52 outputs a pulse. A green backlight display is performed by the LED 54 in synchronization with the rLJ of
Since it is input to the ED driver 91, the backlight unit 5
In 2, L is set according to the timing of rHJ of the output pulse.
Red backlight display is performed by ED53. When "1" is given to the input signals A and B, the LED driver 92 is activated at the timing of the output of the pulse generator 93 or rLJ, the LED 54 emits green light, and the pulse generator 93 The output of r
The LED driver 91 is energized at the timing of HJ and the LED
Since red light is emitted by D5B, the backlight section 5 is
2, a yellow backlight display will be performed.

Therefore, even if such a control circuit 6 is used, effects similar to those described in FIG. 3 can be expected.

Note that the present invention is not limited to the above-mentioned embodiments, but can be implemented with appropriate modifications within the scope without changing the gist.

For example, in the embodiment described above, when the normal calculation mode is applied, the LED 54 emits green light, and when the calculation result is negative, the LED 53
When entering the memory calculation mode, the LEDs 53 and 54 emit yellow light. It can also be displayed by color.

[Effects of the Invention] The backlit liquid crystal display device of the present invention includes a light source section having at least two types of light emitting elements emitting light of different colors on the back surface of the liquid crystal display section, and lights up the light emitting elements depending on the type of data to be displayed. The color of the backlight display can be changed by selecting , so the color of the backlight display can be changed by lighting up the light-emitting elements selected according to the type of data being displayed. , the type of displayed data can be easily determined without making a mistake just by looking at the displayed color.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the circuit configuration of an embodiment of the present invention, FIG. 2 is a configuration diagram showing the backlight section of a display section used in the embodiment, and FIG. FIG. 4 is a circuit diagram showing the control circuit used, and FIG. 5 is a diagram for explaining display commands output from the LSI of the same embodiment.
FIG. 7 is a circuit diagram showing another example of the control circuit used in the same embodiment. 116. Solar cell, 2... LSI, 3... Built-in battery, 41. Keyboard, 5...Display section, 51...LCD
, 52...Backlight section, 53.54...LED. 6... Control circuit, 63.64... Current control circuit, 7
...Backlight switch.

Claims (1)

[Claims] A light source section having at least two types of light emitting elements emitting light of different colors, a liquid crystal display section having the light source section on the back surface, and a light emitting element of the light source section being selectively selected depending on the type of data displayed on the liquid crystal display section. 1. A liquid crystal display device with a backlight, comprising: control means for turning on the backlight and changing the color of the backlight display.