KR20000014784A - Auto dimming device of a car a/v system and method thereof - Google Patents

Abstract

PURPOSE: An auto dimming device of a car A/V system is provided to realize an illumination corresponding to an intensity of illumination subdividing and adjusting the display data amount according to an external illumination amount. CONSTITUTION: The auto dimming device of a car A/V system comprises a detection part(10), an analog-to-digital(A/D) converting part(20), a micom(30), a potential meter(40) and a thin film transistor liquid crystal display(TFT LCD) (50). The detection part(10) detects an external intensity of illumination, and the A/D converting part(20) converts the detected value into a digital value dividing to predetermined steps according to the intensity of illumination. The micom(30) controls the digital value from the A/D converting part(20) according to the predetermined steps. The potential meter(40) receives the output from the micom(30) to output an analog voltage value according to the predetermined steps, and the TFT LCD(50) performs a display of the predetermined step according to the output from the potential meter(40).

Description

Auto dimming device and method for automobile A / V system

The present invention relates to a dimmer of an A / V system of an automobile, and more particularly, to an auto dimming apparatus and a method for automatically dimming an A / V system dimmer of an automobile according to illuminance in an automobile.

The conventional dimmer of the automatic A / V system has been illuminated the same regardless of the brightness of the surroundings, and always illuminates the same day or night. In general, the brighter the ambient light, such as daytime, the brighter the light, the darker the night, such as dark dimming can be identified well and does not cause eye fatigue. As described above, there is a problem in that the display state is non-uniform due to the non-correspondence of ambient light reflection and dimming amount.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and an auto dimming device for an automotive A / V system which performs automatic dimmer operation by subdividing and adjusting a change stage using a software of a microcomputer according to an external dimming amount. And to provide a method.

1 is a block diagram of an autodimming device of an automotive A / V system of the present invention;

2 is a graph showing the illumination intensity change level of the photoconductive cell of the device of the present invention;

3 is a diagram showing the conversion output of the A / D conversion unit of the apparatus of the present invention;

4 is a diagram showing data values corresponding to potential meter ratings of the microcomputer output of the apparatus of the present invention.

5 is a flow chart of the auto dimming method of the present invention.

<Explanation of symbols for main parts of the drawings>

10: detector 20: A / D converter

30: microcomputer 40: potential meter

50: TFT LCD

In order to achieve the above object, the present invention provides a detection unit for detecting an external illuminance, an A / D conversion unit for converting the detected value into digital values by dividing the detected value into predetermined steps according to the illuminance, and converting the value of the digital output to the A microcomputer for controlling according to a predetermined step, a potential meter for outputting an analog voltage value in a predetermined step that receives the output of the microcomputer, and a TFT LCD for displaying a predetermined step according to the output of the potentiometer meter; Provided is an auto dimming device for an automotive A / V system.

At this time, the detection unit includes a photoconductive cell CdS for detecting the brightness of the surroundings, a switch SW1 for switching the illumination power source, load resistors R1 and R2 connected to the switch, and a transistor Q1 connected to the load resistor.

When the switch SW1 is on, the collector potential of the transistor Q1 is at a low level, so that the photoconductive cell CdS is grounded and the autodimming function may be released.

The predetermined step may be composed of 17 steps.

The apparatus of the present invention will be described below with reference to the drawings.

1 is a block diagram of an auto dimming apparatus of an automotive A / V system according to the present invention. As shown in FIG. 1, a detector 10 for detecting ambient brightness and a voltage value of the detected analog are divided into predetermined steps. A / D conversion unit 20 for converting to a predetermined value, the microcomputer 30 for outputting the output from the A / D conversion unit 20 to a potential meter rating value of a predetermined step, and the output from the microcomputer 30 is predetermined. The potential meter 40 outputs the analog voltage value of the step, and the TFT LCD 50 performs the display of the level changed by the voltage value from the potential meter 40. As shown in FIG.

The detector comprises a photoconductive cell CdS for detecting the brightness of the surroundings, a switch SW1 for switching the illumination power source, load resistors R1 and R2 connected to the switch, and a transistor Q1 connected to the load resistor. The photoconductive cell outputs a voltage difference according to a change in a resistance value due to a change in ambient light.

The operation of the apparatus of the present invention configured as described above will now be described.

When power is applied to this ILL terminal as the tail lamp power on / off switch of the vehicle of the ILL power source shown in the drawing, the apparatus of the present invention is deactivated.

That is, when power is applied from the ILL terminal, SW1 is turned on, voltage is applied to the transistor Q1 through the resistors R1 and R2 so that the collector potential of the transistor is at the low level. The auto dimming function is released to a rigid body so that only the same constant illumination as in the prior art can be performed. In the off state of the switch SW1, since the voltage value from the photoconductive cell is transmitted, the auto dimming function is set.

The change level of the voltage value of the photoconductive cell CdS varies from 0V to 5V. As shown in FIG. 2, the voltage level is output differently according to sunlight, fluorescent lamps and incandescent lamps. Therefore, the output voltage changed according to the change of the external brightness can be obtained.

When CdS detects the external brightness, the detected analog voltage is input to the A / D converter 20, and this analog value is changed to a digital value for the input of the microcomputer 30. The A / D converter 20 outputs the change level of the detector 20 in 17 steps as shown in FIG. 3. That is, in the present invention, the brightness of the LCD 50 is divided into 17 stages and is illuminated. Since the brightness level can be changed according to the purpose of use, the brightness level is not limited to the above level.

Then, as shown in FIG. 4, the microcomputer 30 outputs data in accordance with the resistance value class of the potential meter to the potential meter of the rear stage according to the 17 class voltage of the A / D converter 20. Output data corresponding to the rating value of the potential meter output from the microcomputer 30 is input to the potential meter 40 and output as a DC analog voltage value corresponding to the data value, the output of the potential meter 40 It is output to the TFT LCD 50 to realize auto dimming of the automotive A / V system corresponding to the brightness of the surroundings.

In addition, the potential meter currently uses only 64 steps, although 64 steps are currently available.

5 is a flowchart of an auto dimming method of an automotive A / V system of the present invention, in which the auto dimming method detects ambient brightness (S10) and divides the detected data value into predetermined steps to convert the A / D. In step S20, invoking a potential meter grade corresponding to the A / D converted value in step S30, converting a digital value of the potential meter grade into an analog data value in step S40, and an accessory power supply of the vehicle Checking whether it is off (S50) and if the accessory power is off in step S50 is terminated, if not off to return to step S10.

According to the present invention as described above, in the vehicle A / V system, the display data amount is subdivided and adjusted according to the external dimming amount using the software of the microcomputer, so that dimming corresponding to the ambient illuminance can be realized. It can be effective.

Although the present invention has been described with reference to an embodiment of the present invention, the present invention is not limited thereto and various modifications and changes can be made without departing from the spirit and scope of the appended claims.

Claims (5)

A detector for detecting an external illuminance, an A / D converter for dividing the detected value into digital values in predetermined steps according to the illuminance, a microcomputer for controlling the value of the digital output according to the predetermined step, and A potential meter for outputting an analog voltage value at a predetermined step changed by receiving the output of the microcomputer and a TFT LCD for displaying a predetermined step according to the output of the potentiometer meter of the automotive A / V system. Auto dimming device. 2. The detector of claim 1, wherein the detection unit includes a photoconductive cell (CdS) for detecting the brightness of an ambient light, a switch SW1 for switching an illumination power source, load resistors R1 and R2 connected to the switch, and a transistor Q1 connected to the load resistor. Auto dimming apparatus for an automotive A / V system, characterized in that the configuration. 2. The auto dimming apparatus of claim 1, wherein the predetermined step is 17 steps. 3. The auto dimming device for an automotive A / V system according to claim 2, wherein the collector potential of the transistor Q1 is at a low level when the switch SW1 is turned on so that the photoconductive cell CdS is grounded and the autodimming function is released. Detecting ambient brightness (S10), dividing the detected data value into predetermined steps (S20), and loading a potential meter level corresponding to the A / D converted value (S30). And converting the digital value of the potential meter grade into an analog data value (S40) and checking whether the accessory power of the vehicle is off (S50). Otherwise, the process returns to step S10.