JP2020067637A - Display device for vehicle - Google Patents

Abstract

To provide a display device for vehicle that is capable of preventing blurring of an image of a screen while avoiding increases in its physical size and cost.SOLUTION: A backlight 30 included in a display device 10 illuminates an LCD panel 20. A temperature detection part 40 detects a temperature of an installation atmosphere of the LCD panel 20. A warming part 51 warms the LCD panel 20 beforehand by switching the backlight 30 from off to on, when the temperature detected by the temperature detection part 40 is a predetermined temperature or less. Thus, the use of preheating of the backlight 30 improves responsiveness of a liquid crystal of the LCD panel, and prevents blurring of an image even when in low temperatures. Furthermore, the use of the existing backlight 30 also allows the display device 10 to avoid increases in its physical size and cost.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle display device.

  At low temperatures, the liquid crystal response of the LCD panel is poor, and the image on the screen of the display device becomes unclear. Therefore, conventionally, overdrive is performed for correction in order to suppress the blur.

  However, when the display device is mounted on a vehicle, the temperature becomes extremely low, and therefore the responsiveness of the LCD panel cannot be completely corrected even when overdriving. For example, in the case of a display device such as a back monitor that does not always turn on the backlight, the above-mentioned problem becomes prominent.

  On the other hand, Patent Document 1 describes an image display system in which an LCD panel is sandwiched by two heaters and the LCD panel is heated simultaneously from above and below.

JP, 2014-182158, A

  However, mounting the heater separately leads to an increase in size and an increase in cost.

  The present invention has been made in view of the above points, and an object thereof is a vehicle capable of suppressing blurring of a screen image while avoiding an increase in physique and an increase in cost. To provide a display device for use.

  The vehicular display device of the present invention is installed in a vehicle and includes an LCD panel, a backlight, a temperature detection unit, and a heating unit. The backlight illuminates the LCD panel. The temperature detector detects the temperature of the LCD panel or the temperature of the installation atmosphere of the LCD panel. When the temperature detected by the temperature detection unit is equal to or lower than the predetermined temperature, the heating unit switches the backlight from off to on and preheats the LCD panel.

  According to the present invention, by utilizing the preheating of the backlight, the response of the liquid crystal of the LCD panel is improved, and the blurring of the image on the screen is suppressed even at low temperature. Further, by using the existing backlight, it is possible to avoid the increase in size of the vehicle display device and the increase in cost.

1 is an installation diagram of a vehicle display device according to a first embodiment. The block diagram of the display device for vehicles by 1st embodiment. 3 is a flowchart illustrating a control process of a control unit of the vehicle display device according to the first embodiment. The block diagram of the display device for vehicles by 2nd embodiment. The flowchart explaining the control process of the control part of the display device for vehicles by 2nd embodiment.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. The same reference numerals are given to the configurations that are substantially the same between the embodiments, and description thereof will be omitted.

(First embodiment)
A vehicle display device (hereinafter, display device) according to the first embodiment will be described with reference to FIGS. As shown in FIG. 1, a display device 10 used in a vehicle 1 is installed inside the vehicle 1 near a ceiling 15 at an upper part of a vehicle compartment 4 including front seats 2 and 3. The display device 10 is used, for example, as a monitor that displays an image of a back camera. In this embodiment, the display device 10 is arranged on the windshield 12 near the right front pillar 11. When the shift range of the vehicle 1 is switched to the back, the display device 10 displays an image behind the vehicle 1.

  As shown in FIG. 2, the display device 10 includes an LCD panel 20, a backlight 30, a temperature detection unit 40, and a control unit 50.

The backlight 30 is, for example, an LED backlight and illuminates the LCD panel 20 from the back side.
The temperature detection unit 40 is composed of, for example, a thermistor and is built in the display device 10. The temperature detection unit 40 detects the temperature of the installation atmosphere of the LCD panel 20.

  Two glass substrates are used in the LCD panel 20, and a pair of transparent electrodes facing each other with a liquid crystal substance sandwiched therebetween are formed inside the glass substrates. When a voltage is applied to this transparent electrode, an electric field is generated between the electrodes, and the liquid crystal molecules with polarity change their arrangement in a certain direction. This movement becomes a blind of light, which allows the light to pass or be blocked.

  The control unit 50 has a heating unit 51. When the temperature detected by the temperature detection unit 40 is equal to or lower than the predetermined temperature, the warming unit 51 switches the backlight 30 from off to on and heats the LCD panel 20 in advance by receiving a signal. That is, when the shift range of the vehicle 1 is other than back, the backlight 30 is normally turned off, but the warming unit 51 turns on the backlight 30 at a low temperature and utilizes the preheating of the backlight 30. The temperature of the LCD panel 20 is raised.

  Next, the control process executed by the control unit 50 in the display device 10 will be described based on FIG. The routine shown in FIG. 3 is repeatedly executed during startup of the display device 10.

  First, in step (hereinafter, simply referred to as “S”) 10, the heating unit 51 determines whether the temperature detection unit 40 has detected a temperature equal to or lower than a predetermined temperature. If the temperature is equal to or lower than the predetermined temperature (S10: YES), the process proceeds to S20. When the temperature is higher than the predetermined temperature (S10: NO), the process ends the routine of FIG.

  In S20, the heating unit 51 switches the backlight 30 from off to on. After S20, the process ends the routine of FIG.

(effect)
As described above, in the first embodiment, the backlight 30 illuminates the LCD panel 20. The temperature detection unit 40 detects the temperature of the installation atmosphere of the LCD panel 20. When the temperature detected by the temperature detection unit 40 is equal to or lower than the predetermined temperature, the heating unit 51 switches the backlight 30 from off to on and preheats the LCD panel 20.
As a result, by utilizing the preheating of the backlight 30, the response of the liquid crystal of the LCD panel 20 is improved, and the blurring of the image on the screen is suppressed even at low temperatures. Furthermore, by using the existing backlight 30, it is possible to avoid an increase in the size of the display device 10 and an increase in cost.

(Second embodiment)
As shown in FIG. 4, the control unit 50 of the display device 60 according to the second embodiment further includes a brightness adjustment unit 52. The brightness adjusting unit 52 reduces the light transmittance of the LCD panel 20 when the heating unit 51 turns on the backlight 30. In the present embodiment, the brightness adjusting unit 52 sets the light transmittance of the LCD panel 20 to 0 so that the light emitted by the backlight 30 for heating at low temperature does not appear on the screen of the display device 60. That is, the screen brightness is set to 0), and the amount of light passing through the LCD panel 20 is set to 0. The warming unit 51 turns on the backlight 30 after the light transmittance of the LCD panel 20 is reduced by the brightness adjusting unit 52.

  Next, the control process executed by the control unit 50 of the display device 60 will be described with reference to FIG. The routine shown in FIG. 5 is repeatedly executed during the startup of the display device 60. In S15 executed after S10, the brightness adjusting unit 52 adjusts the screen brightness to zero. After S15, the process proceeds to S20. After S20, the process ends the routine of FIG.

(effect)
As described above, in the second embodiment, as in the first embodiment, the heating unit 51 lights the backlight 30 to heat the LCD panel 20 when the temperature is low. Therefore, the same effect as in the first embodiment is obtained. Can be obtained. In the second embodiment, a brightness adjusting section 52 is further provided. The brightness adjusting unit 52 reduces the light transmittance of the LCD panel 20 when the heating unit 51 turns on the backlight 30. As a result, a change in screen display during preheating due to the backlight 30 can be suppressed, so that a user's discomfort can be suppressed.

  Further, in the second embodiment, the heating unit 51 turns on the backlight 30 after the light transmittance of the LCD panel 20 is reduced by the brightness adjusting unit 52. Particularly in the second embodiment, the backlight 30 is turned on after the light transmittance of the LCD panel 20 is set to zero. As a result, the screen display does not change at the start of preheating by the backlight 30, so that the user's discomfort can be eliminated.

(Other embodiments)
In another embodiment, when the brightness adjustment unit adjusts the light transmittance so that the light emitted from the backlight for heating does not pass through the screen of the display device, the light transmittance and the LCD panel pass. The amount of light to be emitted may not be completely zero.

  In other embodiments, the display device may be installed anywhere visible to the user. For example, the display device may be arranged on the front pillar 11, the room mirror 13, the dashboard 14, the ceiling 15, the handle 16 and the like in FIG. 1.

  In another embodiment, the temperature detection unit may detect the temperature of the LCD panel. Further, the temperature detection unit only needs to detect the temperature of the installation atmosphere of the LCD panel (that is, the temperature of the installation space or the temperature of the space equivalent to the installation space), and may not be built in the display device.

  In other embodiments, the display device is not limited to a monitor that displays an image of the back camera, but may be used as a monitor of another system. The display device may display information such as the driving state of the vehicle, the state of the vehicle occupant, or the state around the vehicle, or may display a video or image for entertainment. In short, the application does not matter as long as it is a type of monitor that is not constantly lit.

  The present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit of the invention.

10, 60 ... Display device,
20 ... LCD panel,
30 ... Backlight,
40 ... Temperature detector,
50 ... control unit,
51 ... heating section,
52 ... Brightness adjustment unit.

Claims (3)

A display device installed in a vehicle,
LCD panel,
A backlight for illuminating the LCD panel,
A temperature detector for detecting the temperature of the LCD panel or the temperature of the installation atmosphere of the LCD panel;
When the temperature detected by the temperature detection unit is equal to or lower than a predetermined temperature, a heating unit that switches the backlight from off to on to heat the LCD panel in advance,
Display device for a vehicle including   The vehicle display device according to claim 1, further comprising a brightness adjustment unit that reduces the light transmittance of the LCD panel when the heating unit turns on the backlight.   The vehicle display device according to claim 2, wherein the warming unit lights the backlight after the light transmittance of the LCD panel is reduced by the brightness adjusting unit.

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