JP4360943B2 - Display device - Google Patents

Description

  The present invention relates to a display device, and particularly relates to a display device mounted on a vehicle.

  FIG. 3 is a perspective view showing a center cluster of the vehicle. The center cluster 30 is provided at the center of the instrument panel of the automobile, that is, at a position between the driver's seat and the passenger seat. As shown in FIG. 3, the center cluster 30 includes an operation panel 31 attached to the front surface and an electronic device 32 disposed on the lower side of the operation panel 31.

  The electronic device 32 is assumed to be a CD playback device, a cassette tape playback device, an MD playback device, or the like having an information recording medium setting unit such as a CD (compact disc), a cassette tape, and an MD (mini disc). .

  As shown in FIG. 3, the operation panel 31 includes various operation switches 33 and 34 and a display device 35. The operation switches 33 and 34 provided on the operation panel 31 function as an operation input receiving unit for receiving operation commands for the electronic device 32 and the air conditioner. Of these, the operation switch 33 is a push switch, and the operation switch 34 is a joystick type switch.

  The electronic device 32 and the air conditioner can be operated by appropriately combining these operation switches 33 and 34. For example, it is possible to perform operations such as playback / stop of an information recording medium such as a CD or a cassette tape, and setting of the temperature / air volume of the air conditioner control unit.

  The display device 35 uses a liquid crystal display element, a fluorescent display tube, or the like as a display, and displays a clock, an outside air temperature, an operation status of the electronic device 32 and an air conditioner, and the like. For example, the display device 35 displays various information such as the volume that is the operating status of the CD or cassette tape, the set temperature that is the operating status of the air conditioner, and the wind direction. In FIG. 3, it is displayed that the set temperature is 21 ° C. and the wind direction is in two directions, the front direction and the down direction.

  FIG. 4 shows a block diagram of a display device 35 which is a conventional technique. In the display device 35 shown in FIG. 4, a liquid crystal display element (hereinafter also referred to as LCD) 40 is used as a display. Connected to the LCD 40 are an LCD drive power supply 41 for supplying a drive voltage and an LCD driver 42 for supplying a drive signal. Further, a microcomputer 43 is connected to the LCD driver 42. The microcomputer 43 controls the LCD driver 42 to supply a drive signal to the LCD 40 in order to display a desired display pattern on the LCD 40.

  Here, in the display device 35 shown in FIG. 4, a drive voltage is supplied from the LCD drive power supply 41 to the LCD 40, and this drive voltage is set to a voltage that allows the LCD 40 to be optimally driven. However, the set value of the drive voltage is a fixed value. Although FIG. 4 illustrates the case where the LCD 40 is used as a display device, a fluorescent display tube (hereinafter also referred to as VFD) may be used as the display device.

  The display device 35 mounted on the vehicle is affected by the ambient temperature used. For example, in the case of the LCD 40 shown in FIG. 4, when the ambient temperature changes, the contrast and brightness change greatly. In the case of a fluorescent display tube, the luminance changes greatly when the ambient temperature changes. When the contrast and the brightness greatly change depending on the ambient temperature, there is a problem that it becomes difficult for the driver to visually recognize the display device.

  As shown in FIG. 4, the drive voltage is set to a voltage that can be optimally driven by the LCD 40. The set drive voltage value (set value) is a fixed value assuming a general ambient temperature. Is set. For this reason, when the ambient temperature changes, the set value deviates from the optimum drive voltage at the ambient temperature at which the setting value has changed, causing the contrast and brightness of the LCD 40 to change greatly.

  Similarly, even in the case of a fluorescent display tube, the filament voltage, which is a drive voltage, is set to a voltage that can be optimally driven assuming a general ambient temperature. Since this set value is also set as a fixed value, if the ambient temperature changes, the set value will deviate from the optimum filament voltage at the changed ambient temperature, causing the luminance of the fluorescent display tube to change greatly. .

  Therefore, an object of the present invention is to provide a display device that can supply an optimal driving voltage to a display device even when the ambient temperature changes, and can maintain a constant display quality.

According to a first aspect of the present invention, there is provided a display provided in a vehicle interior, a power source for supplying a drive voltage to the display, a driver for supplying a drive signal to the display, and a desired display pattern. And a microcomputer that controls the power supply and driver to display the adjustment signal. The power supply is controlled so that the driving voltage is adjusted based on the adjustment signal and supplied to the display .

  The solution according to claim 2 of the present invention is the display device according to claim 1, wherein the display is a liquid crystal display element.

  According to a third aspect of the present invention, there is provided a display device according to the first aspect, wherein the display device is a fluorescent display tube, and the driving voltage supplied from the power source to the fluorescent display tube is a filament voltage. .

A display device according to claim 1 of the present invention displays a display provided in a vehicle interior, a power supply for supplying a drive voltage to the display, a driver for supplying a drive signal to the display, and a desired display pattern. And a microcomputer that controls the power supply and driver to display on the display, and the microcomputer reduces the influence on the display quality due to the change in the ambient temperature of the display based on the set temperature in the vehicle interior set by the air conditioner ECU Since the power supply is controlled so that the drive voltage is adjusted based on the adjustment signal and supplied to the display unit, there is no need to change the device such as providing a separate temperature sensor. There is an effect that the optimum contrast and brightness can be obtained without receiving the light. In addition, there is an effect that the ambient temperature can be predicted without performing complicated processing.

  In the display device according to claim 2 of the present invention, since the display device is a liquid crystal display element, it is not necessary to change the device such as separately providing a temperature sensor, and the liquid crystal display element is affected by changes in ambient temperature. Without being able to obtain optimal contrast and brightness.

  In the display device according to claim 3 of the present invention, the display is a fluorescent display tube, and the drive voltage supplied to the fluorescent display tube by the power source is a filament voltage. Therefore, there is an effect that the fluorescent display tube can obtain the optimum luminance without being affected by the change in the ambient temperature.

  The display device described in the present embodiment is a display device mounted on a center cluster of a vehicle. FIG. 1 is a block diagram of a display device according to this embodiment. In the display device shown in FIG. 1, the display 35 is the LCD 1. The LCD 1 is a display device that displays a desired display pattern by changing a polarization characteristic by controlling a liquid crystal layer sandwiched between two glass substrates by an electric field. Therefore, when the ambient temperature of the LCD 1 changes, the control of the liquid crystal layer by the electric field may be affected. When the LCD 1 is a transmissive type, a backlight unit incorporating a cold cathode tube or the like is provided. For this reason, when the ambient temperature of the LCD 1 changes, the luminance of the cold cathode fluorescent lamp or the like may be affected. Therefore, when the ambient temperature of the LCD 1 changes, the contrast and luminance of the LCD 1 change greatly.

  Therefore, in this embodiment, the drive voltage supplied to the LCD 1 is controlled in order to mitigate the influence of changes in the ambient temperature of the LCD 1. Examples of the drive voltage supplied to the LCD 1 include an applied voltage to the liquid crystal layer and an applied voltage to the backlight unit by an existing method. As an existing configuration, for example, the LCD 1 shown in FIG. 1 is connected to an LCD driving power source 2 that supplies a driving voltage and an LCD driver 3 that supplies a driving signal. Further, the LCD driving power source 2 and the LCD driver 3 are connected to a microcomputer 4. The microcomputer 4 controls the LCD driver 3 to supply a drive signal to the LCD 1 in order to display a desired display pattern on the LCD 1.

  In the display device according to the present embodiment, the microcomputer 4 supplies an adjustment signal to the LCD drive power source 2 based on air conditioner information from an air conditioner ECU (Electronic Control Unit) 5. The LCD drive power source 2 changes the drive voltage supplied to the LCD 1 based on the adjustment signal. That is, the microcomputer 4 predicts the ambient temperature of the LCD 1 from the air conditioner information, and controls the LCD drive power source 2 so as to supply the LCD 1 with a drive voltage optimum for the predicted ambient temperature.

  Considering the example shown in FIG. 3, the driver operates the operation switches 33 and 34 to set the set temperature of the air conditioner to 21 ° C. At this time, the air conditioner ECU 5 sends information of the set temperature of 21 ° C. to the microcomputer 4 as air conditioner information. The microcomputer 4 predicts the ambient temperature of the LCD 1 based on the information of the set temperature 21 ° C. As the prediction of the ambient temperature, for example, it is conceivable to predict a temperature obtained by adding 1 ° C. to the set temperature as the ambient temperature. Then, the microcomputer 4 sends an adjustment signal to the LCD drive power supply 2 so that the LCD drive power supply 2 supplies the LCD 1 with a drive voltage that provides an optimal contrast and brightness at the predicted ambient temperature. The microcomputer 4 obtains an adjustment signal by calculation from the predicted ambient temperature or obtains an adjustment signal corresponding to the predicted ambient temperature from the data table. The LCD drive power source 2 adjusts the optimum drive voltage value of the ambient temperature predicted based on the adjustment signal and supplies it to the LCD 1.

  As described above, in the display device according to the present embodiment, since the microcomputer 4 adjusts the driving voltage based on the air conditioner information (the set temperature in the vehicle interior) from the air conditioner ECU 5, the device changes such as providing a temperature sensor separately. Therefore, the LCD 1 that is the display 35 can obtain the optimum contrast and brightness without being affected by the change in the ambient temperature.

  In the display device shown in FIG. 1, an example in which the LCD 1 is used as the display 35 is shown. Next, an example in which a fluorescent display tube is used as the display 35 is shown below. FIG. 2 shows a block diagram of a display device in which the display device 35 is the VFD 20. In the VFD 20, a box-shaped vacuum container is formed by a front substrate and a rear substrate. In order to visually recognize the display pattern of the fluorescent display tube, a transparent glass substrate is used as the front substrate. In the VFD 20, a filament is accommodated in the vacuum vessel, and an anode is formed on the back substrate. A phosphor layer is formed on the anode, and a grid is disposed between the filament and the phosphor layer.

  In the operation of the VFD 20, the thermoelectrons emitted from the filament are accelerated by the grid and guided to the anode to which a predetermined voltage is applied. Then, the thermoelectrons collide with the phosphor layer formed on the upper surface of the anode to cause the phosphor layer to emit light. Light from the phosphor layer is visually recognized as a display pattern through the front substrate. Therefore, the brightness of the VFD 20 changes depending on the amount of thermoelectrons emitted from the filament.

  Here, the amount of thermoelectrons emitted from the filament is affected by the ambient temperature of the VFD 20. That is, when the ambient temperature of the VFD 20 is high, the temperature of the filament also increases, so that the amount of thermoelectrons emitted from the filament increases. On the contrary, when the ambient temperature of the VFD 20 is low, the temperature of the filament is also low, so that the amount of thermoelectrons emitted from the filament is reduced. Therefore, the filament voltage is controlled in the display device shown in FIG. 2 in order to mitigate the influence of the change in the ambient temperature of the VFD 20.

  As shown in FIG. 2, a filament power source 21 that supplies a filament voltage and a VFD driver 22 that supplies a drive signal are connected to the VFD 20. Further, the microcomputer 4 is connected to the filament power supply 21 and the VFD driver 22. The microcomputer 4 controls the VFD driver 22 to supply a drive signal to the VFD 20 in order to display a desired display pattern on the VFD 20.

  In the display device shown in FIG. 2, the microcomputer 4 supplies an adjustment signal to the filament power supply 21 based on air conditioner information from an air conditioner ECU (Electronic Control Unit) 5 as in the case of the LCD 1 in FIG. The microcomputer 4 obtains an adjustment signal by calculation from the predicted ambient temperature or obtains an adjustment signal corresponding to the predicted ambient temperature from the data table. The filament power supply 21 changes the filament voltage supplied to the VFD 20 based on the adjustment signal. That is, the microcomputer 4 predicts the ambient temperature of the VFD 20 from the air conditioner information, and controls the filament power source 21 so as to supply the filament voltage optimum for the predicted ambient temperature to the VFD 20.

  As described above, in the display device shown in FIG. 2, the microcomputer 4 adjusts the filament voltage based on the air conditioner information (the set temperature in the passenger compartment) from the air conditioner ECU 5, so that it is necessary to change the device such as providing a temperature sensor separately. Instead, the VFD 20 that is the display 35 can obtain the optimum luminance without being affected by the change in the ambient temperature.

  In the present embodiment, the air conditioner information is described as the set temperature in the passenger compartment. However, the present invention is not limited to this, and other information such as the air volume may be included in the air conditioner information. That is, it is conceivable to predict the ambient temperature more accurately by predicting the ambient temperature of the display 35 from a plurality of parameters such as the set temperature and the air volume.

1 is a block diagram of a display device according to an embodiment of the present invention. It is a block diagram of the other display apparatus which concerns on embodiment of this invention. It is a perspective view which shows the center cluster of a vehicle. It is a block diagram of the display apparatus which concerns on a prior art.

Explanation of symbols

1,40 LCD
2,41 LCD drive power supply 3,42 LCD driver 4,43 Microcomputer 5 Air conditioner ECU
20 VFD
21 Filament power supply 22 VFD driver 30 Center cluster 31 Operation panel 32 Electronic device 33, 34 Operation switch 35 Display 35

Claims (3)

An indicator provided in the passenger compartment;
A power supply for supplying a driving voltage to the display;
A driver for supplying a driving signal to the display;
A microcomputer for controlling the power supply and the driver so as to display a desired display pattern on the display;
The microcomputer obtains an adjustment signal for mitigating the influence on the display quality due to a change in ambient temperature of the display based on the vehicle interior set temperature set by the air conditioner ECU, and adjusts the drive voltage based on the adjustment signal The power supply is controlled so as to be supplied to the display. The display device according to claim 1,
The display is a liquid crystal display element,
The display device, wherein the power source generates a driving voltage for driving the liquid crystal display element. The display device according to claim 1,
The indicator is a fluorescent display tube,
The display device according to claim 1, wherein the driving voltage supplied from the power source to the fluorescent display tube is a filament voltage.

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