JP2022161219A - Display device - Google Patents

Abstract

To provide a display device with which a display part and a least necessary control part can be arranged inside of a double-glazing glass part contributing to excellent esthetic appearance, and the housing of the display part can be dispensed with, helping reduce the weight.SOLUTION: A display device 10 comprises: a thin-profile display part 12 for displaying a video based on display command signals related to the destination of a vehicle that includes a double-glazing glass part 8 having a hollow layer 8a; a first control part 16 including an LCD drive part that receives display command signals and outputs video signals for displaying a video on the display part 12; and a second control unit 14 including a PWM signal generation part that outputs PWM signals for adjusting the brightness of the video displayed on the display part 12, on the basis of video signals transmitted from the first control part 16. The display part 12 and the second control part 14 are arranged inside of the hollow layer 8a of the double-grazing glass part 8, and the first control part 16 is provided at a place away from the double-grazing glass part 8 in the vehicle interior and is electrically connected to the second control part 16 by a cable part.SELECTED DRAWING: Figure 1

Description

The present invention relates to display devices.

Conventionally, in trains, buses, etc., destination displays for displaying destinations, guide displays for displaying stop stations, advertising displays for displaying advertisements, fare displays for displaying fares, etc. is set up. In recent years, with the spread of thin display devices such as liquid crystal panels, digitization is progressing in these displays.

As a technique related to the present invention, for example, Patent Document 1 includes a liquid crystal panel, a backlight, and a control device that controls the liquid crystal panel and the backlight, and the control device is the liquid crystal The backlight is lit in a lighting pattern having N stages of light emission intensity levels from a first level to an Nth level (N is an integer equal to or greater than 2) during a time period in which the light transmittance of the panel is being changed. is disclosed.

Further, in Patent Document 2, a glass plate, a transmissive display panel provided on one side of the glass plate, and a transmissive display panel are arranged to face the glass plate with a hollow layer interposed therebetween so as to face the transmissive display. and a light source provided on the outer peripheral edge of the light guide plate made of the glass.

JP 2019-101368 A JP 2016-210638 A

In the invention of Patent Document 1, there is a problem that the display control unit and the display unit cannot be installed in separate locations and must be integrated. Another problem is that Patent Document 2 does not describe a specific configuration or method for externally installing the display control device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display device with excellent design. Another object of the present invention is to provide a display that contributes to weight reduction.

A display device installed in a vehicle such as a train or bus according to the present invention is provided in a vehicle including a multi-layered glass portion having a hollow layer, a thin display portion for displaying an image based on a display command signal, a first control section including an LCD driving section for receiving a display command signal and outputting a video signal for displaying the video on the display section; a first repeater section for amplifying a voltage level of the video signal; A second repeater unit that receives the video signal transmitted from the first control unit and stabilizes the voltage level, and a PWM signal generator that outputs a signal for dimming at a frequency that does not interfere with the frequency of the video signal. and a second control unit, wherein the display unit and the second control unit are arranged in the hollow layer of the double-glazed glass unit, and the first control unit controls the multi-layer display in the vehicle. It is characterized in that it is provided at a location away from the layered glass section and is electrically connected to the second control section by a cable section.

Moreover, the display device according to the present invention preferably includes a power supply section that supplies electric power to the first control section and the second control section and is provided at a location away from the multi-layered glass section.

Further, in the display device according to the present invention, the display unit includes a liquid crystal panel unit and a backlight unit, and the PWM signal output by the PWM signal generation unit has a duty ratio for driving the backlight unit. It is a set signal, and the frequency of the PWM signal is preferably controlled to a frequency that does not interfere with the frequency of the video signal.

Moreover, in the display device according to the present invention, it is preferable that the cable section includes a shield line connected to a ground of a substrate on which the first control section and the second control section are arranged.

According to the present invention, since the display section and the minimum required control section can be arranged in the multi-layered glass section, the display device can be excellent in design. In addition, when mounted on a mobile object such as a train or bus, it is possible to eliminate the housing that has conventionally accommodated the display, thereby contributing to weight reduction.

It is a figure which shows a mode that the display apparatus of embodiment which concerns on this invention is installed in the vehicle. 1 is a configuration diagram of a display device according to an embodiment of the invention; FIG. FIG. 4 is a diagram showing how the first control section and the second control section are connected by a cable section in the display device according to the embodiment of the present invention; 4 is a flow chart showing the procedure for displaying an image on the display unit in the display device of the embodiment according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. In the following, the same reference numerals are given to the same elements in all the drawings, and redundant explanations are omitted. Also, in the explanation in the text, the reference numerals mentioned before are used as necessary.

FIG. 1 is a diagram showing how a display device 10 according to an embodiment of the present invention is installed in a vehicle. The multi-layered glass portion 8 is, for example, a display installed in the window of the vehicle or inside the vehicle, and displays images and still images such as destinations, stops, advertisements, fares, and the like. FIG. 2 is a configuration diagram of the display device 10. As shown in FIG.

FIG. 3 is a diagram showing how the first control unit 16 and the second control unit 14 are connected by the cable unit 40 in the display device 10. As shown in FIG.

The display device 10 includes a display section 12 , a second control section 14 , a first control section 16 and a power supply section 18 . The display unit 12 is a thin display device that is installed inside the multi-layered glass unit 8 having the hollow layer 8a and displays an image based on a display command signal including information indicating the vehicle position and information regarding the luminance level of the display. be.

The multi-layer glass portion 8 is composed of a glass plate having a first main surface and a second main surface facing each other, and dry air is provided between the first main surface and the second main surface. An enclosed hollow layer 8a is formed. By enclosing dry air and increasing the heat insulation effect, it suppresses condensation and also has a soundproof effect. Although the thickness of the hollow layer 8a is set to 16 mm here, it can of course be changed as appropriate.

Examples of the glass plate forming the first main surface and the second main surface include ordinary glass plate, tempered glass plate, partially tempered glass plate, and the like used for vehicle window glass. These glass plates may be colored to the extent that transparency is not impaired. The glass plate is preferably, for example, a glass plate manufactured by a known float method, but may of course be formed by other methods.

The display section 12 includes a liquid crystal panel section 20 and a backlight section 22 . The liquid crystal panel section 20 has a plurality of pixels (display elements) arranged in a matrix in the vertical direction and the horizontal direction. The liquid crystal panel section 20 includes a liquid crystal layer (not shown). Also, the liquid crystal panel section 20 may include a color filter (not shown).

The backlight unit 22 has a function of irradiating the liquid crystal panel unit 20 with light such as white light. The backlight section 22 is arranged on the back side of the liquid crystal panel section 20 so as to overlap the liquid crystal panel section 20 .

The backlight unit 22 has a plurality of LEDs as light sources. The backlight section 22 may be provided with a diffusion sheet that diffuses the light emitted from the LEDs. By controlling the light emission intensity of the LEDs, the light emission intensity of the light emitting surface of the backlight section 22, that is, the light emission state of the backlight section 22 can be controlled.

The first control section 16 includes a first repeater section 32 , an external I/F 34 , an LCD drive section 36 , a video signal control section 37 , a backlight control section 38 and a CFCARD 39 . The frequency of the video signal (the frequency of the horizontal synchronizing signal and the frequency of the vertical synchronizing signal) output by the LCD driving section 36 and the frequency of the PWM signal output by the PWM signal generating section 28 are controlled so as not to interfere with each other.

The first repeater section 32 has a function of amplifying the voltage level of the video signal. The first repeater section 32 receives the input video signal and outputs a waveform conforming to the LVDS standard. Here, the first repeater section 32 amplifies the voltage level by ±250 mV or higher so that the received voltage of the second repeater section 24 is ±100 mV or higher conforming to the LVDS standard, and outputs the amplified voltage level.

The external I/F 34 is an interface circuit that acquires a display command signal transmitted from the host system. The display command signal transmitted from the host system includes information on the luminance level (“bright”, “dark”, and “OFF”) as well as vehicle position information.

The LCD driving section 36 outputs a video signal for displaying a video regarding the destination of the vehicle on the display section 12 . The frequency of the video signal output by the LCD driving section 36 is approximately 60 Hz for the vertical synchronization signal and several tens of kHz for the horizontal synchronization signal. On the other hand, the frequency of the PWM signal output by the PWM signal generator 28 is controlled to several hundred Hz so as not to interfere with them.

A display command signal including information about image data to be displayed by the display unit 12 and information about a luminance level is input to the LCD driving unit 36 via the external I/F 34 .

Based on the display command signal, the LCD driving section 36 reads display data to be displayed from the CFCARD 39 and generates a video signal. The video signal is a vertical synchronizing signal and a horizontal synchronizing signal for controlling the display timing of the liquid crystal panel section 20 .

The video signal control unit 37 turns on the power of the first repeater unit 32 upon receiving the Enable signal output from the video signal control unit 25 on the second control unit 14 side. After the power of the first repeater section 32 is switched from ON to OFF, a video signal to be displayed on the display section 12 is output to the second control section 14 .

The backlight control unit 38 has a function of setting the luminance level (“bright”, “dark”, and “OFF”) of the backlight unit 22 based on the display command signal transmitted from the host system. It receives a display command signal from the host system via the external I/F 15 , generates information about the luminance level, and transmits it to the second control unit 14 .

The CFCARD 39 stores display data such as video and still images to be displayed on the display unit 20 .

The second control section 14 includes a second repeater section 24 , a video signal control section 25 , a backlight control section 26 , a PWM signal generation section 28 and a backlight power supply section 30 .

The second repeater section 24 receives the video signal attenuated to nearly ±100 mV conforming to the LVDS standard output from the first control section 16 , stabilizes it to ±100 mV, and outputs it to the liquid crystal panel section 20 .

The video signal control unit 25 starts initialization when the power of the second control unit 14 is turned on, and when the initialization ends normally, transmits an Enable signal to the first control unit 16, and the second repeater unit. 24 has a function of turning on the power supply.

The backlight control unit 26 has a function of receiving information on the brightness level set by the backlight control unit 38 of the first control unit 16 and setting the duty ratio of the PWM signal generation unit 28 . The backlight unit 22 is dimmed by the duty ratio of the PWM signal.

The PWM signal generator 28 outputs a PWM signal, which is a dimming control signal for adjusting the brightness of the image displayed on the display 12 based on the image signal transmitted from the first controller 16 . The brightness of the image displayed on the display unit 12 is adjusted by the PWM signal generated by the PWM signal generation unit 28 .

The frequency of the PWM signal output by the PWM signal generator 28 is controlled to a frequency that does not interfere with the frequency of the video signal (the frequency of the horizontal synchronizing signal and the frequency of the vertical synchronizing signal) output by the LCD driving unit 36 . The PWM signal is a PWM signal in which a duty ratio for driving the backlight section 22 is set.

The PWM signal generator 28 generates a PWM signal based on the information indicating the luminance level received from the backlight controller 26 . The PWM signal is a signal for the backlight power supply unit 30 to drive the LEDs of the backlight unit 22 .

The backlight power supply unit 30 is connected to the plurality of LEDs of the backlight unit 22 and has a function of controlling the output of each LED based on the PWM signal transmitted from the PWM signal generation unit 28 .

The power supply unit 18 supplies power to the first control unit 16 and the second control unit 14 and is provided at a location away from the multi-layered glass unit 8 . The power supply unit 18 includes a DC/DC converter that steps up or steps down a DC power supply to a desired voltage. The DC power stabilized by the power supply unit 18 is supplied to the first control unit 16 and the second control unit 14 .

The display unit 12 and the second control unit 14 are arranged in the hollow layer 8 a of the double-glazed glass portion 8 . The display unit 12 is attached directly to the first main surface located outside the car window so that the image of the destination of the vehicle can be visually recognized from the outside of the vehicle, for example. The second control unit 14 is attached to the multi-layer glass unit 8 in the vicinity of the display unit 12 .

The first control unit 16 is provided at a location away from the multi-layer glass unit 8 inside the vehicle, and is electrically connected to the second control unit 14 by a cable unit 40 . Under the installation environment of railway vehicles used as public transportation, the cable section 40 generally requires a cable length of 10 m or more in many cases.

The cable section 40 includes a shielded wire connected to the ground of the board on which the first control section 16 and the second control section 14 are arranged. Here, the communication interface for transmitting signals via the cable section 40 is the LVDS standard (EIA/TIA-644), and the data format is the digital interface standard for flat panels such as liquid crystal displays (JEIDA-59- 1999), but other standards are of course applicable.

As shown in FIG. 3, the cable section 40 is configured with STP (Shielded Twisted Pair), and the shielded wire is connected to the SG (Signal Ground) of the substrates of both the first control section 16 and the second control section 14. and strengthen SG between devices. Each SG is connected to an SG (ground) plane in the inner layer of the substrate.

Next, the operation of the display device 10 configured as described above will be described. FIG. 4 is a flow chart showing a procedure for displaying an image on the display unit 12. As shown in FIG.

First, in the second control unit 14, when the video signal control unit 25 is powered on (S2), initialization is started (S4), and the state of DIN is confirmed (S6). Here, DIN is an abbreviation of Digital Input input from the first control unit 16, and is setting information of luminance levels (three levels of bright, dark, and OFF).

After the step of S6, it is determined whether the luminance level is in either "bright" or "dark" state (S8). In the step of S8, if the brightness level cannot be confirmed, that is, if the state is "OFF", the process returns to the step of S6 after a predetermined period of time has elapsed.

In the process of S8, when it is determined that the luminance level is either "bright" or "dark", the PWM signal generator 28 outputs a PWM signal (S10). At this time, the output is performed with a duty ratio corresponding to the setting of the luminance level (“bright” or “dark”).

After the step of S10, an Enable signal is output to the first control section 16 (S12). Then, the power of the first repeater section 32 functioning as a video repeater is turned on (S14). As a result, the video signal amplified by the first repeater section 32 of the first control section 16 is output to the second repeater section 24 of the second control section 14 .

After that, the second repeater section 24 is powered on (S 16 ), and the second repeater section 24 stabilizes the video signal amplified and transmitted from the first repeater section 32 and outputs it to the display section 12 .

After the step of S16, an Enable signal is output to the backlight power supply unit 30 (SS18), and based on the PWM signal transmitted from the PWM signal generation unit 28, each LED is controlled and the liquid crystal panel unit 20 , the image is displayed (S20).

As described above, according to the display device 10, the control section for controlling the display section 12 is divided into the first control section 16 and the second control section 14, and the second control section 14, which is susceptible to noise, 12 to minimize the influence of noise, and the first control unit 16, which is less susceptible to noise, is installed at a position away from the display unit 12.例文帳に追加Moreover, the power supply unit 18 can also be installed at a location away from the display unit 12 and the second control unit 14 .

In this way, the display unit 12 and the second control unit 14 are installed in the hollow layer 8a of the multi-layered glass unit 8 by minimizing the control functions arranged near the display unit 12 and downsizing them. Therefore, there is a remarkable effect of contributing to an improvement in visibility as well as an improvement in design. In addition, by installing the display device 10 in a moving body such as a train or a bus, it is possible to eliminate the housing that has conventionally housed the display, thereby contributing to weight reduction.

In addition, since the first control unit 16 and the second control unit 14 are separated, by providing both control units for the video signal/backlight, either the first control unit 16 or the second control unit 14 can be controlled. We constantly check to see if there are any anomalies.

In addition, since the display unit 12 and the second control unit 14 are enclosed in the multi-layered glass unit 8, there is no short circuit due to iron powder, dust, etc., and there is no need to apply a coating material, etc., resulting in a cost advantage. There is an advantage that there is

As described above, the first control section 16 and the second control section 14 are separated and connected by the cable section 40 having a cable length of 10 m or longer. In general, the voltage drops by the length of the cable. It is devised so that the data can be received on the control unit 14 side.

Further, instead of inputting the video signal amplified by the first repeater section 32 to the liquid crystal panel 20 as it is, the voltage level is stabilized in the second repeater section 24 in the second control section 14, and then the video signal is output to the display section 12. entered inside. As a result, a clean waveform can be input, and a clear image can be displayed.

In addition, since the cable length is 10 m or more, there is concern about the influence of noise, but the cable unit 40 adopts an STP cable, and the shield wire is connected to the substrates in the first control unit 16 and the second control unit 14. By doing so, SG (Signal Group) is strengthened, so that the influence of noise can be suppressed to the maximum.

As described above, the display device 10 is, for example, a destination display device that displays an image related to the destination display of the vehicle, but may display other contents, such as train or bus stop stations. It may be a guidance indicator for displaying, a fare indicator for displaying the fare, or an advertisement indicator for displaying an advertisement using a moving image.

8 multi-layer glass portion 8a hollow layer 10 display device 12 display portion 14 second control portion 16 first control portion 18 power supply portion 20 liquid crystal panel portion 22 backlight portion 24 second repeater portion 25 video signal control unit, 26 backlight control unit, 28 PWM signal generation unit, 30 backlight power supply unit, 32 first repeater unit, 36 LCD driving unit, 37 video signal control unit, 38 backlight control unit, 39 CFCARD, 40 Cable section.

Claims (4)

A thin display unit provided in a vehicle including a multi-layer glass unit having a hollow layer and displaying an image based on a display command signal;
a first control section including an LCD driving section that receives the display command signal and outputs a video signal for displaying the video on the display section; and a first repeater section that amplifies the voltage level of the video signal;
a second repeater unit that receives the video signal transmitted from the first control unit and stabilizes the voltage level; and a PWM signal generator that outputs a signal for dimming at a frequency that does not interfere with the frequency of the video signal. a second control unit including a unit;
with
The display unit and the second control unit are arranged in the hollow layer of the multi-layer glass unit,
A display device, wherein the first control section is provided at a location away from the multi-layered glass section in the vehicle, and is electrically connected to the second control section by a cable section. The display device according to claim 1,
A display device, comprising: a power supply unit that supplies electric power to the first control unit and the second control unit, and is provided at a location away from the multi-layered glass unit. In the display device according to claim 1 or claim 2,
The display section includes a liquid crystal panel section and a backlight section,
The PWM signal output by the PWM signal generation unit is a signal in which a duty ratio for driving the backlight unit is set,
A display device, wherein the frequency of the PWM signal is controlled so as not to interfere with the frequency of the video signal. In the display device according to any one of claims 1 to 3,
The display device, wherein the cable section includes a shield line connected to a ground of a board on which the first control section and the second control section are arranged.

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