Novel rail transit PIS screen

Abstract

The utility model discloses a novel rail transit PIS screen, which comprises a backlight module, the backlight module comprises a plurality of groups of LED light bar modules, and each group of LED light bar modules comprises a plurality of LED light bars; the main control board is used for realizing on / off signal control on the LED driver through an ON / OFF signal, and the main control board is used for realizing backlight brightness adjustment control on the LED driver through a PDIM dimming signal; and the switching power supply is used for inputting a 36V power supply to the LED driver. According to the utility model, the plurality of groups of LED lamp strip modules are arranged to replace the existing CCFL lamp tube, and one switching power supply and one LED driver are arranged to realize the work of the plurality of groups of LED lamp strip modules, so that the LED lamp strip module has the advantages of long service life, low power under the same brightness, small heat productivity and high luminous efficiency.

Description

Technical Field

[0001] The utility model belongs to the technical field of liquid crystal screens, and in particular relates to a novel rail transit PIS screen. Background Art

[0002] The PIS system, also known as the passenger information system, is a multimedia comprehensive information system that relies on multimedia network technology and takes the computer system as the core. It allows passengers to timely and accurately understand train operation information and public media information through media equipment installed in station halls, platforms, and train passenger compartments. The PIS system is widely used for platform train entry countdown display, train station information in carriages, video media advertising and emergency status information release, including train broadcasts, internal displays, V-screens, carriage monitoring, emergency call equipment, etc.

[0003] The LCD screen displays images by driving electrodes with thin film transistors, but it cannot emit light by itself. It is necessary to place certain light-emitting components to allow light to pass through the LCD screen. This light-emitting component is the backlight module, which is composed of a light source and optical auxiliary devices. Its main function is to convert a point light source into a uniformly emitting surface light source. The backlight module can be divided into two types: direct-lit and side-lit according to the way the light source device is placed. The direct-lit backlight module places the backlight source directly under the LCD screen. The light emitted by the light source reaches the diffuser after a certain distance in space. The diffuser diffuses the light and evenly distributes it through the diffuser film. After being brightened by the light-enhancing film, it evenly distributes it again through the diffuser film to become a surface light source and reach the LCD screen. Since the light source of this structure is directly upward, after diffusion and mixing by optical auxiliary devices, the surface light source reaching the LCD screen has good uniformity. The manufacturing process is relatively simple, but the structure is relatively thick. The edge-lit backlight module places the light source on the side of the casing frame. The emitted light is coupled to the light guide plate and converted into a surface light source. After being evenly distributed through the lower diffusion film, brightened by the light-enhancing film, and evenly distributed through the upper diffusion film, it becomes a surface light source and reaches the LCD screen. This structure emits light from the side, and indicators such as the uniformity of the surface light source and the brightness of the LCD screen will decrease. The structural process is complex, and the cost of the light guide plate is high, but the structure is thin.

[0004] In the prior art, CCFL lamps are commonly used in backlight modules. CCFL is a cold cathode fluorescent lamp, which has a small tube, simple structure, low surface temperature, high brightness, good color rendering, uniform light emission, etc., and has a high operating voltage. Figure 2, AC220V input is the total power input; there is a high-voltage generating circuit on the power board to power the CCFL high-voltage lamp, and also generates multiple DC power supplies to power the main control board; the main control board and the power board use the ON / OFF signal to control the switch signal of the lamp drive circuit, and the PDIM dimming signal to control the backlight brightness adjustment of the lamp drive circuit; the remote control and keypad are used as inputs for human-computer interaction, and the operation of the PIS screen is completed through the main control board; the speaker plays the sound; after the main control board and the logic board are connected, the video signal of the main control board is converted into a digital signal that can drive the LCD panel; the LCD panel is electrically connected to the logic board through the cable to display the image, but the working voltage of the CCFL lamp is high, and the high-voltage drive circuit generates a lot of heat; the lamp life is short; under the same luminous intensity, the power is large and the heat is more; after the light bar is damaged, the screen presents a strip-shaped black area, affecting the viewing experience. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a new type of rail transit PIS screen, which has solved the problems raised in the background technology.

[0006] The utility model provides the following technical solutions:

[0007] A new type of rail transit PIS screen, including

[0008] A backlight module, wherein the backlight module comprises a plurality of groups of LED light bar modules, and each group of the LED light bar modules comprises a plurality of LED light bars;

[0009] A main control board and an LED driver, wherein the main control board controls the on / off signal of the LED driver through an ON / OFF signal, and the main control board controls the backlight brightness adjustment of the LED driver through a PDIM dimming signal;

[0010] A switching power supply, wherein the switching power supply is used to input a 36V power supply to the LED driver;

[0011] A logic board, the logic board is electrically connected to the main control board, and the logic board is used to convert the video signal of the main control board into a digital signal for driving the liquid crystal panel;

[0012] A liquid crystal panel, the liquid crystal panel is electrically connected to the logic board via a flat cable for displaying images;

[0013] Keypad, which is used as input for human-computer interaction and completes the operation of the PIS screen through the main control board;

[0014] A speaker is used to play the sound in the PIS screen.

[0015] Preferably, it also includes a shell, wherein a reflective film, a backlight module, a diffusion plate, a first diffusion film, a second diffusion film, and a liquid crystal panel are arranged in sequence inside the shell from the bottom layer to the top layer, and the length direction of the LED light strip is arranged along the width direction of the shell, and several LED light strips located in the same LED light strip module are evenly arranged at equal intervals along the left and right length directions of the shell, and the several LED light strips are connected in series through wires.

[0016] Preferably, a plurality of the LED light strip modules are evenly arranged at equal intervals along the left and right length directions of the housing.

[0017] Preferably, a remote control module is also included, which serves as an input for human-computer interaction and completes the operation of the PIS screen through the main control board.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] The utility model discloses a new type of rail transit PIS screen, which replaces the existing CCFL lamp tubes by arranging multiple groups of LED light bar modules, and arranges a switching power supply and an LED driver to realize the operation of the multiple groups of LED light bar modules, and has the advantages of long service life, low power at the same brightness, low heat generation and high luminous efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the implementation mode of the utility model, the drawings required for use in the implementation mode are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is the overall circuit block diagram of the utility model.

[0022] Figure 2 This is a circuit block diagram of the PIS screen in the prior art of the utility model.

[0023] Figure 3 This is the power supply circuit of the LED driver of the utility model.

[0024] Figure 4 This is the LED driver power supply and control interface circuit diagram of the utility model.

[0025] Figure 5 This is a circuit diagram of the main control chip of the LED driver of the present utility model.

[0026] Figure 6 This is a boost constant current power circuit diagram of the LED driver of the utility model.

[0027] Figure 7 It is a structural schematic diagram of the utility model.

[0028] Figure 8 This is a schematic diagram of the reflective film structure of the utility model.

[0029] Fig. 9 This is a schematic diagram of the structure of the LED light bar of the present utility model. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the implementation of the utility model clearer, the technical solution in the implementation of the utility model will be clearly and completely described below in conjunction with the drawings in the implementation of the utility model. Obviously, the described implementation is only a part of the implementation of the utility model, not all of the implementations. Based on the implementation of the utility model, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1-9 As shown, a new type of rail transit PIS screen includes

[0033] A backlight module, wherein the backlight module comprises a plurality of groups of LED light bar modules, and each group of the LED light bar modules comprises a plurality of LED light bars;

[0034] A main control board and an LED driver, wherein the main control board controls the on / off signal of the LED driver through an ON / OFF signal, and the main control board controls the backlight brightness adjustment of the LED driver through a PDIM dimming signal;

[0035] A logic board, the logic board is electrically connected to the main control board, and the logic board is used to convert the video signal of the main control board into a digital signal for driving the liquid crystal panel;

[0036] A liquid crystal panel, the liquid crystal panel is electrically connected to the logic board via a flat cable for displaying images;

[0037] Keypad, which is used as input for human-computer interaction and completes the operation of the PIS screen through the main control board;

[0038] A speaker, which is used to play the sound on the PIS screen;

[0039] A switching power supply, wherein the switching power supply is used to input a 36V power supply to the LED driver;

[0040] The remote control module, as the input of human-computer interaction, completes the operation of the PIS screen through the main control board.

[0041] like Figure 1 As shown, AC220V input is the total power input; after the transformation, the PIS screen adds a switching power supply and an LED driver, and multiple sets of LED light strip modules are backlight modules. Figure 2 )The high-voltage generating circuit on the original power board was removed, and multiple DC power supplies were retained to supply power to the main control board; between the main control board and the LED driver, the on / off signal of the LED driver is controlled by the ON / OFF signal, and the backlight brightness adjustment control of the LED driver is realized by the PDIM dimming signal; the remote control and keypad are used as inputs for human-computer interaction, and the operation of the PIS screen is completed through the main control board; the speaker plays the sound; after the main control board and the logic board are connected, the video signal of the main control board is converted into a digital signal that can drive the LCD panel; the LCD panel is electrically connected to the logic board through the flat cable to realize the display of the image. It has the following advantages: the same dimming mode and adjustment accuracy of the original equipment are achieved, and the external operation mode of the equipment is unchanged; the operation of the PIS screen and all functions remain unchanged; it does not affect the appearance of the original PIS equipment; the cost of consumables and accessories required is controllable, and the economic efficiency and the use effect after the transformation meet the design goals; after the transformation, the advantages of using LED light strips: long LED life, low power and low heat generation at the same brightness; high luminous efficiency, using a reflective film with diffusion particles, and high light reflection efficiency.

[0042] By setting up multiple sets of LED light strip modules to replace the existing CCFL lamp tubes, and setting up a switching power supply and an LED driver to realize the operation of multiple sets of LED light strip modules, it has the advantages of long service life, low power at the same brightness, low heat generation, and high luminous efficiency.

[0043] like Figure 3 The figure shows the power supply circuit of the LED driver. After the 36V switching power supply is input, the linear voltage regulator and step-down circuit is formed by the voltage regulator diode D1 and the transistor Q1, and the DC power output of about 15V is output. After filtering by the filter capacitor C4, the R8 dummy load stabilizes the power output, and D5 is a 24V unidirectional TVS tube to prevent overvoltage. Finally, an auxiliary power supply of about 15V is output from VIN to provide auxiliary power to the LED driver. R10 and D4 form a 36V power supply indication circuit, and R1 and D3 form a 15V power supply indication circuit, which are used to indicate the working status of the power supply.

[0044] like Figure 4 The figure shows the circuit diagram of the LED driver power supply and control interface. P3 is the 36V power input interface, P4 is the interface between the main control board and the LED driver, ON is the power on / off control signal, and PDIM is the backlight adjustment control signal.

[0045] like Figure 5 The figure shows the main control chip circuit diagram of the LED driver. The BD9483 dedicated LED driver chip is used to control and monitor the 2-way LED boost constant current drive. It is equipped with input power supply undervoltage protection function, output overvoltage protection function, overcurrent protection function, etc.

[0046] like Figure 6 The figure shows the LED driver boost constant current power circuit diagram. After the input 36V DC power supply is boosted by the above circuit, the LED light bar module is lit. The LED dedicated driver chip detects the current of ISEN1 to realize the constant current function of the LED light bar module, thereby maintaining the consistency of the brightness of the LED light bar.

[0047] It also includes a shell, wherein a reflective film 1, a backlight module 2, a diffusion plate 3, a first diffusion film 4, a second diffusion film 5, and a liquid crystal panel 6 are arranged in sequence from the bottom layer to the top layer.

[0048] Reflective film: PET material, whiteness 89%, reflectivity 92%.

[0049] There are 12 LED light strips, and the 12 LED light strips are evenly divided into 4 groups, namely group 1, group 2, group 3, and group 4, and 3 LED light strips form a group.

[0050] Diffuser plate: PMMA material, light transmittance 75%.

[0051] First diffusion film: PET material, transmittance 73.0%, haze 95.5%.

[0052] Second diffusion film: PET material, transmittance 86.2%, haze 90.6%.

[0053] The length direction of the LED light bar is arranged along the width direction of the shell, and several LED light bars in the same LED light bar module are evenly arranged along the left and right length directions of the shell, and the several LED light bars are connected in series through wires.

[0054] A plurality of the LED light strip modules are evenly arranged at equal intervals along the left and right length directions of the housing.

[0055] Each of the LED light strips is evenly in contact with the housing, and the housing is used for heat dissipation through the high-temperature thermal conductive tape adhered to the back of the LED light strip, thereby effectively reducing the temperature of the light-emitting component and extending the service life.

[0056] The above is only a preferred implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes within the technical scope disclosed by the present invention according to the technical solution and inventive concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A new type of rail transit PIS screen, characterized by: include A backlight module, wherein the backlight module comprises a plurality of groups of LED light bar modules, and each group of the LED light bar modules comprises a plurality of LED light bars; A main control board and an LED driver, wherein the main control board controls the on / off signal of the LED driver through an ON / OFF signal, and the main control board controls the backlight brightness adjustment of the LED driver through a PDIM dimming signal; A switching power supply is used to input a 36V power supply to the LED driver.

2. According to claim 1, a new type of rail transit PIS screen is characterized in that: The invention also comprises a shell, wherein a reflective film (1), a backlight module (2), a diffusion plate (3), a first diffusion film (4), a second diffusion film (5), and a liquid crystal panel (6) are arranged in sequence from the bottom layer to the top layer inside the shell, the length direction of the LED light bar is arranged along the width direction of the shell, and a plurality of the LED light bars in the same LED light bar module are evenly arranged at equal intervals along the left and right length directions of the shell, and the plurality of the LED light bars are connected in series via wires.

3. According to claim 2, a new type of rail transit PIS screen is characterized in that: A plurality of the LED light strip modules are evenly arranged at equal intervals along the left and right length directions of the housing.

4. According to claim 1, the new rail transit PIS screen is characterized in that: It also includes a logic board, which is electrically connected to the main control board and is used to convert the video signal of the main control board into a digital signal for driving the liquid crystal panel.

5. According to claim 4, a new type of rail transit PIS screen is characterized in that: It also includes a liquid crystal panel, which is electrically connected to the logic board through a flat cable for displaying images.

6. According to the new rail transit PIS screen of claim 1, it is characterized in that: It also includes a keypad, which serves as an input for human-computer interaction and completes the operation of the PIS screen through the main control board.

7. According to claim 1, the new rail transit PIS screen is characterized in that: It also includes a speaker, which is used to play the sound in the PIS screen.

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