JP2008195103A - Controller for vehicle air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for a vehicle air conditioner capable of adjusting luminance of back illumination closely and properly not only in the daytime and at night but also in all weathers such as sunny, cloudy, and rainy weathers or the like. <P>SOLUTION: This controller for the vehicle air conditioner is provided with a headlight operation detection means 27 for detecting on/off operation of a headlight, a sunshine amount sensor 28 for detecting brightness outside a vehicle body by amount of sunshine, and a wiper operation detection means 30 for detecting on/off operation of a wiper. This controller has a controlling part 25 for determining whether it is sunny, cloudy or rainy weather or nighttime based on the output signals of the sunshine amount sensor 28 and the detection signals of the wiper operation detection means 30 when the headlight operation detection means 27 detects the on operation of the headlight and adjusting luminance of an illumination lamp 19 to the luminance set in advance by corresponding to sunny, cloudy, or rainy weathers or nighttime. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a controller for a vehicle air conditioner that can adjust the brightness of a backlight according to the brightness outside the vehicle.

  In a vehicle air conditioner, illumination with high luminance is performed to improve visibility of an indicator of a display unit that displays an operation state or the like, or back illumination such as an LCD (liquid crystal display). This backlight is usually switched by turning on / off the headlights (including small lights), and the brightness is reduced (dimmed at night) so that it does not interfere with driving at night. ing. For this reason, when the daytime headlight is turned on, the brightness is lowered in the nighttime dimming state, and the display section becomes dark and difficult to see. Thus, when it becomes difficult to see a display part, it will take time for visual recognition and will affect safe driving of vehicles. In other words, when the field of view deteriorates due to rain, fog, or the like during driving of the vehicle, lights (including small lights) may be turned on even in the daytime. In this case, when the outside of the vehicle is relatively bright and the brightness of the back illumination is reduced due to the dimming at night, the visibility from the outside of the vehicle is reduced, causing a problem in safe driving.

  Therefore, when the daylight headlights are turned on using the output signal of the solar radiation sensor installed for the air conditioner or auto light, the night light is reduced until the solar radiation falls below the set value. Cancel the light so that the brightness of the back lighting keeps the maximum brightness, and even if the headlight is turned on due to rain or fog in the daytime, it will not be dimmed at night and prevent deterioration of visibility Have been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 7-186828

However, the thing of the above-mentioned patent document 1 has the brightness of the back illumination as the maximum brightness when the headlight is turned on in the daytime. At the maximum brightness adjusted in the clear sky, the brightness outside the vehicle decreases, such as fog, cloudiness, rain, etc. On the other hand, it is too bright and difficult to see.
In terms of design conditions, the circuit constants for power regulation under the vehicle operating environment conditions (temperature: 80 ° C) are set based on the brightness during normal sunny weather, so the maximum current flowing to the backlight is suppressed. The necessary brightness may be insufficient, and it is the actual situation that expensive high-brightness illumination is selected or the number of light sources is increased.

  The present invention has been made in view of such circumstances, and the brightness of the back illumination is not limited to day and night, but also in sunny, cloudy, rainy, etc., under a wide range of vehicle environment (temperature) conditions. An object of the present invention is to provide a controller for a vehicle air conditioner capable of finely and appropriately adjusting the vehicle.

In order to solve the above-described problems, the vehicle air conditioner controller of the present invention employs the following means.
That is, the vehicle air conditioner controller according to the present invention includes an illumination lamp that illuminates the display unit with a predetermined amount of light, and the vehicle air conditioner controller switches the luminance of the illumination lamp based on on / off of the headlight. A light operation detecting means for detecting the on / off operation of the headlight, a solar radiation amount sensor for detecting the brightness outside the vehicle by the amount of solar radiation, and a wiper operation detecting means for detecting the on / off operation of the wiper, When the on-operation of the headlight is detected by the light operation detecting means, it is determined whether it is sunny, cloudy, rainy, or night based on the output signal of the solar radiation amount sensor and the detection signal of the wiper operation detecting means. A control unit is provided for adjusting the brightness of the illumination lamp to a preset brightness corresponding to sunny, cloudy, rainy, and night. It is characterized by being able to be removed.

  According to the present invention, when an on-operation of the headlight is detected, in response to the output signal of the solar radiation amount sensor and the detection signal of the wiper operation detecting means, it is determined whether it is sunny, cloudy, rainy or night, A control unit is provided to adjust the brightness of the illumination lamp to a preset brightness corresponding to sunny, cloudy, rainy, and night, respectively. Appropriate brightness that is set according to the weather by dimming at night and changing the brightness of the illumination lamp according to the brightness outside the car that changes according to weather conditions such as sunny, cloudy, rainy, etc. The brightness of the illumination lamp can be finely adjusted so that Therefore, the visibility of display characters, pictures, etc. displayed on the display unit can be improved, and thus the safety of driving the vehicle can be improved. In the present invention, the brightness of the illumination lamp is brighter when it is raining than when it is cloudy.

  Furthermore, the controller for a vehicle air conditioner according to the present invention is the controller for a vehicle air conditioner described above, wherein the control unit detects a temperature inside the vehicle including a temperature around the illumination lamp, and a temperature detected by the temperature sensor. When the temperature is equal to or higher than a set temperature, the control unit includes a restricting unit that limits a current to the illumination lamp and regulates the brightness of the illumination lamp to the set brightness.

  According to the present invention, the control unit limits the current to the illumination lamp when the temperature detected by the temperature sensor is equal to or higher than the set temperature, and the brightness of the illumination lamp is set to the set brightness. Since it has the control part which controls, it can ensure a required brightness | luminance and can maintain visibility, preventing the temperature rise of an illumination lamp. Therefore, it is not necessary to select expensive high-brightness illumination or increase the number of lights, and high-function and high-brightness display unit illumination can be realized at low cost. Note that the atmosphere temperature in the vehicle including the vicinity of the illumination lamp is not limited to the temperature in the vicinity of the illumination lamp, but may be any temperature inside the vehicle.

  Furthermore, the vehicle air conditioner controller according to the present invention is the vehicle air conditioner controller described above, wherein the control unit has two positive characteristic resistors having different resistance characteristics in which resistance characteristics are determined based on an allowable temperature of the illumination lamp. The power supply circuit is connected to the illumination lamp in series.

  According to the present invention, the control unit has a power supply circuit in which a parallel circuit of two positive characteristic resistors having different resistance characteristics whose resistance characteristics are determined from the allowable temperature of the illumination lamp is connected in series to the illumination lamp. Utilizing the fact that the resistance values of the two positive characteristic resistors change depending on the ambient temperature of the illumination lamp, the required brightness is maintained and the visibility is maintained while preventing the temperature rise of the illumination lamp be able to. Therefore, it is not necessary to select expensive high-brightness illumination or increase the number of lights, and high-function and high-brightness display unit illumination can be realized at low cost.

  Furthermore, the controller for a vehicle air conditioner according to the present invention is the controller for a vehicle air conditioner according to any one of the above-described controllers, and the control unit is irrelevant to input signals from the detection means and the sensor when the ignition switch is turned on. The illumination lamp includes an initial lighting unit that lights up at a set luminance for a predetermined time.

  According to the present invention, when the ignition switch is turned on, the control unit has the initial lighting unit that lights the illumination lamp for a predetermined time with the set brightness regardless of the input signals from the detection means and the sensor. When the person operates the ignition switch, the illumination lamp is lit for a predetermined time with the set brightness. As a result, when the driver starts driving the vehicle, the contents (operation state, operation state, etc.) displayed on the display unit can be visually recognized to determine whether or not the setting change is necessary.

  Furthermore, the controller for a vehicle air conditioner according to the present invention is the controller for a vehicle air conditioner according to any one of the above, wherein the brightness of the illumination lamp that is adjusted in accordance with the sunny, cloudy, and rainy weather is stepwise. It is characterized by being adjusted.

  According to the present invention, the brightness of the illumination lamp that is adjusted corresponding to each weather such as sunny, cloudy, and rain is adjusted in stages, so that the appropriate brightness corresponding to each weather such as sunny, cloudy, and rainy. Can be illuminated with a brightness of. Therefore, the visibility can be stabilized at a high level without being affected by the brightness outside the vehicle that changes depending on the weather.

  Furthermore, the vehicle air conditioner controller according to the present invention is the vehicle air conditioner controller according to any one of the above-described vehicle air conditioner controllers, wherein the brightness of the illumination lamp adjusted in accordance with the sunny, cloudy, and rainy weather is set for each weather. It is characterized by being continuously adjusted linearly.

  According to the present invention, the brightness of the illumination lamp that is adjusted corresponding to each weather such as sunny, cloudy, and rain is continuously adjusted linearly for each weather. Therefore, in each weather that is sunny, cloudy, and rainy. It is possible to illuminate at a brightness corresponding to the brightness outside the vehicle at that time. Therefore, the visibility can be stabilized at a higher level without being influenced by the weather and the brightness at that time.

  According to the present invention, the brightness of the back illumination can be adjusted to an appropriate brightness set in advance corresponding to clear weather, cloudy weather, rainy weather, and night, respectively. The brightness of the display unit can be finely adjusted to improve the visibility with respect to the display on the display unit, and thus the safety of driving the vehicle can be improved.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows a front view of a controller for a vehicle air conditioner according to the first embodiment of the present invention. The vehicle air conditioner controller 1 includes a composite dial switch 4 in which an inside / outside air changeover switch 2 and a blowing mode changeover switch 3 are integrated, and a composite dial switch 7 in which a blower on / off switch 5 and an air volume adjustment switch 6 are integrated. And a control panel 11 on which a composite dial switch 10 in which an air conditioner on / off switch 8 and a temperature control switch 9 are integrated is installed.

  On the surface of the control panel 11, a pictorial symbol 3A for the blowing mode changeover switch 3, a pictorial symbol 6A for the air volume adjusting switch 6, and a pictorial symbol 9A for the temperature adjusting switch 9 are displayed. In addition, a liquid crystal display panel 12 is installed on the surface of the control panel 11. On the liquid crystal display panel 12, characters and pictorial symbols 3B for the blowing mode changeover switch 3 and characters and pictures for the air volume adjustment switch 6 are displayed. Reference numeral 6B and letters and numbers 9B for the temperature control switch 9 are displayed.

The above-mentioned composite dial switches 4, 7, and 10 are switches in which the push function and the dial function are combined. The following is an example of the configuration of the composite dial switch 10 for temperature adjustment. A description will be given with reference to FIG. The other composite dial switches 4 and 7 have the same configuration.
The control panel 11 and the printed circuit board 14 are assembled to the cases 13A and 13B of the vehicle air conditioner controller 1. A cylindrical switch case 15 is fixed to the printed circuit board 14, and a push switch 16 is installed on the inside thereof. A terminal 17 of the push switch 16 is penetrated through a hole provided in the printed circuit board 14 and soldered to the printed circuit board 14.

  Further, on the inner peripheral side of the cylindrical switch case 15, a push member 18 that is in contact with the tip of the push switch 16 and can be linearly moved by the on / off stroke along the axial direction of the push switch 16 is inserted. The An illumination lamp 19 is provided inside the push member 18. The terminal 20 of the illumination lamp 19 is penetrated through a hole provided in the push member 18 and a hole provided in the printed board 14 and is soldered to the printed board 14. The illumination lamp 19 may be a light bulb type general lamp or a lamp formed of a light emitting diode (LED).

  A translucent character portion 22 is provided at the center of the push member 18 so that the character can be visually recognized by the light of the illumination lamp 19 provided inside the push member 18. A dial knob 23 is provided on the outer peripheral side of the push member 18, and is supported on the printed circuit board 14 via a rotary encoder 24 so as to be capable of rotational displacement. The rotary encoder 24 detects the amount and direction of rotation of the dial knob 23, and is slidably rotated on the inner peripheral side of the ring-shaped fixing member 24A and a ring-shaped fixing member 24A fixedly installed on the printed circuit board 14. And a ring-shaped rotating member 24B fitted to be possible. The ring-shaped rotating member 24B is integrally connected to the dial knob 23 and is rotationally displaced integrally with the dial knob 23.

A control unit 25 having a configuration as shown in FIG. 3 is incorporated in the printed circuit board 14. The control unit 25 detects an IGSW operation detection unit 26 that detects the operation of the ignition switch (IGSW), a light operation detection unit 27 that detects an on / off operation of a headlight (including a small light), and a solar radiation amount. The solar radiation amount sensor 28, an in-vehicle temperature sensor 29 for detecting the in-vehicle temperature, and a wiper operation detecting unit 30 for detecting the on / off operation of the wiper are provided, and will be described later based on input signals from the detecting unit and the sensor. According to the control flow, the brightness of the illumination lamp 19 is adjusted to a preset brightness.
The vehicle interior temperature sensor 29 may be any sensor that can detect the in-house atmosphere temperature inside the vehicle including the temperature in the vicinity of the illumination lamp 19.

  The brightness adjustment of the illumination lamp 19 is adjusted to a predetermined duty ratio as shown in FIGS. 4B and 4C from the output port 32 of the microcomputer 31, as shown in FIG. 4A. This is realized by outputting the square wave pulse thus generated and operating the transistor 33 with this output signal to flow a required current through the illumination lamp 19. 4B shows a waveform when the duty ratio is 100% and the maximum luminance, FIG. 4C shows a waveform when the duty ratio is t2 / t1%, and the luminance adjustment is as follows. It is generally adjusted between 20% and 100% with respect to the maximum luminance.

According to the control flow shown in FIG. 5, the control unit 25 determines whether it is sunny, cloudy, rainy, or night as follows, and the brightness of the illumination lamp 19 corresponds to sunny, cloudy, rainy, or night, respectively. The brightness is adjusted to a preset brightness.
The control flow is started by confirming whether an ignition switch (not shown) is turned on by a signal from the IGSW operation detecting means 26 (step S1). If the ignition switch is turned on in step S1 and it is determined “YES”, then on / off of the headlight is determined in step S2 based on the detection signal from the write operation detection means 27. If the headlight is off and it is determined as “NO”, it is determined that it is daytime, and the duty ratio for adjusting the luminance of the illumination lamp 19 is set to the sunny illumination duty (maximum luminance with a duty ratio of 100%). Set (step S7).

  If the light is on in step S2 and it is determined as “YES”, the process proceeds to step S3 to determine whether it is clear or not. This determination is made by the method shown in FIG. 6 based on the output of the solar radiation sensor 28 that detects the solar radiation. FIG. 6 shows that the output of the solar radiation sensor 28 is on the horizontal axis, and the output is larger and brighter as it goes to the right. The vertical axis is divided into night, cloudy, rainy, and sunny in order from the bottom to the top. The lower left area is night, the middle area is cloudy or rainy, and the upper right area is clear. Therefore, it is determined whether the nighttime, cloudy, rainy, or sunny depending on which region the output of the solar radiation sensor 28 enters.

  In step S3, the output of the solar radiation amount sensor 28 is in a clear area, and if it is determined “YES”, the duty ratio of brightness adjustment is set to the clear illumination duty as it is (step S7). If the amount of solar radiation is not in the clear region and it is determined as “NO” in step S3, the process proceeds to step S4 to determine whether it is cloudy. In step S4, if the output of the solar radiation amount sensor 28 is not in a cloudy or rainy region and is determined to be “NO”, it is determined that it is nighttime, the luminance of the illumination lamp 19 is switched, and nighttime illumination is performed. Nighttime dimming is executed (step S5).

  In step S4, if the output of the solar radiation amount sensor 28 is in a cloudy or rainy region and it is determined “YES”, the process proceeds to step S6 to determine whether or not it is raining. Whether or not it is raining is determined by a wiper on / off operation detection signal from the wiper operation detection means 30. In step S6, if the wiper is on and it is determined “YES”, it is determined that it is raining, and the duty ratio for adjusting the luminance of the illumination lamp 19 is set to the rainy illumination duty (step S8). When the wiper is off, it is determined as “NO”, it is determined that the wiper is cloudy, and the duty ratio for adjusting the luminance of the illumination lamp 19 is set to the cloudy illumination duty (step S9).

As shown in FIG. 7, the luminance adjustment duty ratio of the illumination lamp 19 is 100% when it is sunny, for example, 20% or less for nighttime dimming, 30 to 60% for cloudiness, and 50 to 80 for rain. %, The duty ratio is set larger in the rain than in the cloudy so that the brightness becomes brighter.
As described above, the brightness when the headlight is turned on is fine, cloudy, rainy so that the brightness of the illumination lamp 19 can be varied in accordance with the brightness of the outside of the vehicle that changes according to the weather, such as sunny, cloudy, and rainy. , One of the nights is judged, and a duty ratio corresponding to each is set.

  After the duty ratio is set as described above, it is determined whether or not the in-vehicle temperature detected by the in-vehicle temperature sensor 29 is equal to or higher than a predetermined temperature (40 to 50 ° C.) in step S10 which is a luminance regulating unit. Is done. Here, when the vehicle interior temperature is equal to or higher than the predetermined temperature (40 to 50 ° C.), the upper limit of the luminance adjustment duty ratio is reduced from 100% to, for example, 80 to 60%, and compared with the duty ratio set by the logic. Thus, the illumination lamp 19 is driven at the lower duty ratio. In this way, the current to the illumination lamp 19 is limited, and the brightness of the illumination lamp 19 is restricted to the set brightness, thereby preventing a temperature rise due to heat generation of the illumination lamp 19 and extending the life of the illumination lamp 19, while maintaining the required brightness. To ensure visibility.

Thus, according to the present embodiment, the following operational effects are obtained.
The illumination lamp 19 of the display section provided in the control panel 11 of the vehicle air conditioner controller 1 (the same applies to the back illumination of the liquid crystal display panel 12) can be switched not only in luminance by day and night, but also in daytime headlights. When is turned on, the brightness is finely adjusted depending on the weather at that time, that is, fine weather, cloudy weather, and rainy weather. In other words, the headlight is normally turned off during the daytime, and if the in-vehicle temperature detected by the in-vehicle temperature sensor 29 is equal to or lower than a predetermined temperature, the illumination lamp 19 is used to ensure visibility with respect to the brightness outside the vehicle. Illuminated at maximum brightness. On the other hand, when the headlight is turned on at night, the sun goes down and the output of the solar radiation sensor 28 becomes small. Therefore, in the sunny judgment in step S3 and the cloudy judgment in step S4 shown in FIG. Since it is determined as “NO”, it is dimmed at night according to the darkness outside the vehicle, so that it does not hinder driving.

Also, when the headlights are turned on due to rain, fog, etc. during the daytime, the brightness of the outside of the vehicle is somewhat lower than when it is sunny, so the brightness of the illumination lamp 19 is higher than when it is sunny. On the other hand, at the same brightness, it is too bright and the display is difficult to see.
Therefore, when the headlight is turned on in the daytime, it is determined whether the weather at that time is sunny, cloudy, or rainy, and the control unit 25 determines each weather so that the brightness corresponds to the brightness outside the vehicle at that time. A corresponding duty ratio for brightness adjustment is set, and the current to the illumination lamp 19 is controlled to adjust the brightness of the illumination lamp 19. Thereby, the brightness | luminance of the illumination lamp 19 can be finely adjusted according to the appropriate brightness | luminance preset according to each weather. Therefore, the visibility with respect to the display of a display part can be improved and the safety | security of a vehicle driving can be improved by extension.

  Further, when the in-vehicle temperature detected by the in-vehicle temperature sensor 29 is equal to or higher than the set temperature, the upper limit of the luminance adjustment duty ratio is reduced, the current to the illumination lamp 19 is limited, and the luminance of the illumination lamp 19 is regulated to the set luminance. Like to do. For this reason, the required brightness | luminance can be ensured and visibility can be maintained, preventing the temperature rise by the heat_generation | fever of the illumination lamp 19 and extending the lifetime of the illumination lamp 19. FIG. Therefore, it is not necessary to select expensive high-brightness illumination or increase the number of lights, and it is possible to realize high-functional and high-brightness back lighting at low cost.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
This embodiment is different from the first embodiment described above in that an initial lighting unit is attached to the control unit 25. The other points are the same as in the first embodiment, and a description thereof will be omitted. In the present embodiment, as shown in FIG. 8, in step S1 for confirming whether the ignition switch is turned on / off, and in step S2 for confirming the headlight on / off operation based on a signal from the IGSW operation detecting means 26. In the meantime, regardless of day or night or the weather, the initial lighting step S11 that constitutes the initial lighting part in order to turn on the illumination lamp 19 at a predetermined time, for example, 1 to 5 seconds, at a set brightness, for example, 80 to 100% of the maximum brightness. Is provided.

  As described above, by providing the initial lighting step S11 by the initial lighting unit, when the driver tries to start driving the vehicle by operating the ignition switch, first, the illumination lamp 19 is lit at a set luminance for a predetermined time. Can be done. As a result, when the driver starts driving the vehicle, the initial state (operating state) displayed on the display unit can be visually recognized, and it is possible to confirm whether or not the setting is necessary.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
The present embodiment is different from the first embodiment in the manner of setting the duty ratio for adjusting the luminance of the illumination lamp 19. Since other points are the same as those in the first embodiment, description thereof will be omitted. In the present embodiment, the duty ratio for adjusting the luminance of the illumination lamp 19 is continuously changed linearly for clear, cloudy, and rain so that the luminance of the illumination lamp 19 can be continuously adjusted linearly. ing.

  As described above, the brightness of the illumination lamp 19 is continuously and linearly adjusted corresponding to each weather such as sunny, cloudy, and rainy. Therefore, the brightness outside the vehicle in each weather such as sunny, cloudy, and rainy. Illumination can be performed with a brightness corresponding to the above, and visibility can be enhanced to a high level without being influenced by the weather or brightness at that time.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG.
This embodiment is different from the first embodiment described above in that the current limitation to the illumination lamp 19 is performed in hardware. Since other points are the same as those in the first embodiment, description thereof will be omitted. In the present embodiment, the power supply circuit of the illumination lamp 19 on the printed circuit board 14 includes a parallel circuit of a positive characteristic resistor 21A having a resistance R1 and a positive characteristic resistor 21B having a resistance R2, and the illumination lamp 19 and the parallel circuit. By connecting in series, a current limiting circuit to the illumination lamp 19 is configured. The characteristics with respect to the temperature of the resistors R1 and R2 in the positive characteristic resistors 21A and 21B are as shown in FIG. 10B. When the temperatures exceed T1 and T2, respectively, the resistors R1 and R2 rapidly increase and flow. The current is limited to prevent the temperature of the illumination lamp 19 from rising and to maintain its life.

  In the above configuration, the resistance R of the positive characteristic resistors 21A and 21B is as follows. When the ambient temperature is equal to or lower than T1, the resistance R is R = R1 × R2 / (R1 + R2), and the resistance is determined from the specification values of the positive characteristic resistors 21A and 21B so that the maximum luminance is obtained at this resistance R. R is determined. When the ambient temperature is between T1 and T2, the resistance R of the positive characteristic resistors 21A and 21B becomes R≈R2, the current to the illumination lamp 19 is limited, and the luminance of the illumination lamp 19 is reduced. As in the case of the first embodiment, the resistance characteristic R2 of the positive characteristic resistor 21B is determined so that the luminance is reduced to, for example, 80% to 60% of the maximum luminance. The brightness of 80 to 60% with respect to the maximum brightness is a brightness at which characters or the like can be sufficiently visually recognized. Here, since the resistance characteristic R2 of the positive characteristic resistor 21B is determined, the resistance characteristic R1 of the positive characteristic resistor 21A is determined from the necessary characteristic of the resistance R when the ambient temperature is equal to or lower than T1.

When the ambient temperature becomes higher than T2, the resistance R becomes R≈∞, and almost no current flows through the illumination lamp 19. In this state, it is impossible to visually recognize characters, etc., but this is a daytime when the ambient temperature is high, when no night lighting is required, or when it is normally abnormal and requires inspection. Can make sense.
Since the temperature of the illumination lamp 19 and the temperature of the positive characteristic resistors 21A and 21B have a certain relationship from the installed positional relationship and the surrounding heat transfer, the value of T1 is the illumination lamp 19 What is necessary is just to obtain | require the temperature of the positive characteristic resistors 21A and 21B in the case of the permissible temperature, and to set only predetermined temperature lower than it. The value of T2 may be set so as to be the temperature of the positive characteristic resistors 21A and 21B at the allowable temperature of the illumination lamp 19.

With the above configuration, it is possible to prevent a temperature increase due to heat generated by the illumination lamp 19 while sufficiently ensuring the visibility of characters and the like displayed on the display unit.
Therefore, according to this embodiment, it is not necessary to select expensive high-luminance specification illumination or increase the number of illuminations, and it is possible to realize high-function and high-luminance illumination at low cost.

The present invention is not limited to the invention according to the above-described embodiment, and can be appropriately modified without departing from the gist thereof.
For example, in the first embodiment, the in-vehicle temperature sensor 29 is provided to detect the ambient temperature inside the vehicle including the vicinity of the illumination lamp 19, and this temperature sensor is an existing one provided in the vehicle air conditioner. Of course, an in-vehicle temperature sensor can be used, and a dedicated temperature sensor may be provided in the vicinity of the illumination lamp 19 to use the detected value.

It is a front view of the controller for vehicle air conditioners concerning a 1st embodiment of the present invention. It is AA sectional drawing in FIG. It is a schematic block diagram of the control part in the controller for vehicle air conditioners shown in FIG. It is a schematic block diagram of the brightness | luminance adjustment means of the control part in the controller for vehicle air conditioners shown in FIG. It is a control flowchart figure of the control part in the controller for vehicle air conditioners shown in FIG. It is explanatory drawing of the determination method of sunny, cloudy or rain, and the night by the solar radiation amount sensor in the control part in the controller for vehicle air conditioners shown in FIG. It is explanatory drawing of the duty ratio setting method for the brightness | luminance adjustment in the control part in the controller for vehicle air conditioners shown in FIG. It is a control flowchart figure of the control part in the controller for vehicle air conditioners concerning 2nd Embodiment of this invention. It is explanatory drawing of the duty ratio setting method for the brightness | luminance adjustment in the control part in the controller for vehicle air conditioners concerning 3rd Embodiment of this invention. It is a block diagram of the electric current limiting part to the illumination lamp in the controller for vehicle air conditioners concerning 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner controller 3A, 6A, 9A Character and pictorial sign 21A, 21B Positive characteristic resistor 19 Illumination lamp 25 Control part 26 IGSW operation | movement detection means 27 Light operation detection means 28 Solar radiation amount sensor 29 Car interior temperature sensor 30 Wiper operation detection means

Claims (6)

In a vehicle air conditioner controller that includes an illumination lamp that illuminates the display unit with a predetermined amount of light, and switches the luminance of the illumination lamp in accordance with on / off of the headlight.
A light operation detecting means for detecting the on / off operation of the headlight, a solar radiation amount sensor for detecting the brightness outside the vehicle by the amount of solar radiation, and a wiper operation detecting means for detecting the on / off operation of the wiper,
When the headlight ON operation is detected by the light operation detection means, it is determined whether it is sunny, cloudy, rainy, or night based on the output signal of the solar radiation amount sensor and the detection signal of the wiper operation detection means And a controller for adjusting the brightness of the illumination lamp to a preset brightness corresponding to sunny, cloudy, rainy, and night, respectively.   The control unit detects a temperature inside the vehicle including a temperature around the illumination lamp, and limits a current to the illumination lamp when a temperature detected by the temperature sensor is equal to or higher than a set temperature. The controller for a vehicle air conditioner according to claim 1, further comprising a restricting unit that restricts the brightness to the set brightness.   The control unit includes a power supply circuit in which a parallel circuit of two positive characteristic resistors having different resistance characteristics whose resistance characteristics are determined based on an allowable temperature of the illumination lamp is connected in series to the illumination lamp. The vehicle air conditioner controller according to claim 1.   The control unit includes an initial lighting unit that lights the illumination lamp at a set luminance for a predetermined time regardless of input signals from the detection units and sensors when an ignition switch is turned on. Item 4. The vehicle air conditioner controller according to any one of Items 1 to 3.   5. The vehicle air conditioner controller according to claim 1, wherein the brightness of the illumination lamp that is adjusted in accordance with the sunny, cloudy, and rainy weather is adjusted in stages. . 5. The brightness of the illumination lamp that is adjusted in accordance with the sunny weather, cloudy weather, and rainy weather is linearly and continuously adjusted for each weather. 6. Vehicle air conditioner controller.

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