JPS59164218A - Car air-conditioner with indicator - Google Patents

Abstract

PURPOSE:To ease seeing car indicators by inputting the ambient brightness based on the informations of the sunlight intensity detected for sun-light correction and lowering the indicator brightness when the detected sun-light intensity becomes lower than the predetermined value. CONSTITUTION:A control panel is provided with switches 1a and 1b for manual operation of an air-conditioner and light emitting diode (LED) 2a and 2b for indicating the manual setting state. Meanwhile, a photo-diode 6 that forms a sun- lignt source is provided, and its output is put in a microcomputer 3 via both an amplifier 7 and an A/D converter 8. Then, from the input sun-light intensity, forward current corresponding to the sunlight intensity is obtained, according to the characteristics stored in the memory, in order to calculate an LED lighting time t corresponding to an LED driving cycle. In other words, in daytime LEDs 2a and 2b are lit brightly through continuous electrification, while in night time they are electrified intermittently to lower the forward current and consequently the brightness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to nighttime dimming of an automobile air conditioner with a display device 9, and relates to a device suitable for displaying a display at a brightness that corresponds to the surrounding brightness.

[Prior art]

Conventional automobile display devices have been configured so that the display becomes darker when the light switch is turned on, in order to prevent the display from becoming too bright and interfering with driving if the display brightness at night is the same as during the day.

However, it is necessary to turn on the lights even in the daytime to notify other vehicles of the presence of the vehicle, and if the lights are dimmed even then, there is a problem that the display becomes difficult to see because of the bright surroundings. In the evening, even when the surroundings get dark, it is common not to turn on the lights, and if the display is the same brightness as during the day, the problem is that it will cause glare and interfere with driving.

[Purpose of the invention]

An object of the present invention is to display a display at a brightness that corresponds to the brightness of the surroundings to make it easier to see, and to simplify the control circuit by eliminating the need for a light switch signal.

[Summary of the invention]

The present invention detects the surrounding brightness from information on the amount of solar radiation detected for solar radiation correction, and when the amount of solar radiation decreases to a predetermined value, the display dims to adjust the brightness according to the surrounding brightness. It is designed to be displayed as follows.

[Embodiments of the invention]

An example of the present invention is shown below. The control panel has switches LA and LB for manual operation of the air conditioner, and manual settings! Light emitting diode 2 for displaying the original
a+2b is provided.

Since the brightness of the light emitting diodes 2a and 2b is proportional to the forward current, as shown in FIG. 2, by controlling the forward current according to the amount of solar radiation, it is possible to reduce the brightness when the surroundings are dark. The forward current is controlled by changing the constant current circuit T9 or by changing the energization time with respect to the drive cycle as described in this embodiment. As shown in Figure 3, during the daytime (in case A) the electricity continues to be applied to make it brighter, and the dimming region (in case B) is determined by the energizing time (11, e.g. 1 ．．
8 m (8)) to reduce the average forward current and lower the brightness. The dimming method differs depending on the display element, and in the case of a fluorescent display tube, it is carried out by changing the applied voltage using a constant voltage circuit.

A configuration diagram of this embodiment is shown in FIG. 1, and FIG. 4 shows a schematic program flow of the microcomputer 3 of FIG. 1.

The microcomputer 1 includes a central processing unit (CPU),
Read-only memory (ROM) that stores programs;
Random access memo to store data! j(R
AM), various registers such as an input/output terminal register (Ilo), and a timer that divides and counts an oscillator and its system clock and generates interrupts.

When the microcomputer 3 is reset, it starts executing main processing. While the main processing is repeated as background processing, five interrupts are executed every time set in the timer.

In step 30, the partial pressure signals of the thermistor 4 and resistor 5 of the inside air temperature sensor, and the signal of the photodiode 6 of the solar radiation sensor are transmitted via the amplifier 7 and the analog-to-digital converter 8 to the car, the indoor air temperature ( T, ) and solar radiation (Q
), and in step 31, arithmetic processing for air conditioning cycle control is performed. In step 32, the forward current (I) is determined from the characteristics shown in FIG. 2 stored in the microcomputer 3 based on the amount of solar radiation inputted in step 30, and the lighting time (1) for the LED drive period (T) is calculated as ( 1) Calculate from formula.

1 t=4'¥-(1) 1, □ However, ■1.8 is the daytime forward current under the surrounding conditions.

In step 33, a control target position of the air mix door 11 that controls the rate at which the air cooled by the evaporator 9 is reheated through the heater 10 is calculated. Step 34
Now, the blower motor applied voltage is calculated and the blower motor 13 is controlled via the fan controller 12. While the above main processing is repeated, the interrupt processing described below is performed. When an interrupt occurs due to the overflow of the timer, it is determined in step 40 whether the light emitting diode (LED) is on, and if the next period is a period of extinguishing, the extinguishing time ('f'-t) is determined in step 41. After setting the timer,
In step 42, the light emitting diodes 2a and 2b are turned off.

On the other hand, if it is the lighting cycle, a lighting time (1) is set in the timer in step 43, and then, in step 44, the light emitting diodes 2a and 2b indicating the set mode are lit. The light emitting diodes 2a and 2b are driven by the transistor 1 through current limiting resistors 14a and 14b.
5a, 15b, and resistor 16a.

16b is its base resistance. In step 45, the on/off of the manual selection switch 1a #1b is connected to the power supply side by resistors 17a and 17b, and a small amount of input is applied to the potential, the manual selection is accepted, and the corresponding flag is set in the RA.
Set to M. In step 46, a signal from the feedback potentiometer 18 linked to the air mix door 11 is inputted via the analog-to-digital converter 8, the position of the air mix store 11 is detected, and the target position determined in step 33 of the main throw is input. In comparison, the electromagnetic valve 20 is
A and 20b control the negative pressure applied to the actuator 21 to control the air mix door 11 to the target position in balance with the return spring 22.

According to one embodiment of the present invention, it is possible to detect information on the amount of solar radiation and the fact that the surroundings are dark, and to dim the light at night without receiving a signal from a light switch.

〔Effect of the invention〕

According to the present invention, the brightness of the display can be controlled according to the surrounding brightness, and the display can always be easily viewed.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a forward current characteristic diagram with respect to the amount of solar radiation shown in Fig. 1, Fig. 3 is a time chart for driving the display element in Fig. 1, and Fig. 4 is a This is the processing flow shown in FIG.

Claims (1)

[Claims] A display device including 10 light emitting elements and displaying day and night;
In a control device that controls an automobile air conditioner by inputting and processing at least a signal from a solar radiation detection element, when the solar radiation detected by the solar radiation detection element becomes less than a predetermined value, the display is displayed. An air conditioner for an automobile with a display device, characterized in that the device is configured to lower its brightness. 2. An air conditioner for an automobile with a display device according to claim 1, wherein the brightness of the display device is adjusted by changing the ratio of energization time to a display drive cycle. 3. An air conditioner for an automobile with a display device according to claim 1, wherein the brightness of the display device is adjusted by adjusting the voltage applied to the display element.