CN100456340C

CN100456340C - Low-voltage differential signal direct transmission method and device

Info

Publication number: CN100456340C
Application number: CNB2005100907113A
Authority: CN
Inventors: 王玉山
Original assignee: Yetian Science And Technology Co ltd
Current assignee: Yetian Science And Technology Co ltd
Priority date: 2005-08-11
Filing date: 2005-08-11
Publication date: 2009-01-28
Anticipated expiration: 2025-08-11
Also published as: CN1912963A

Abstract

The invention is a low-voltage differential signal direct transmission method and device, it is a transmission device between the source of drawing/image signal and the display, allowing the low-voltage differential signal (LVDS) to be directly output from the source to the display to display without digital/analog, analog/digital multiple conversion, the device mainly includes a signal filter, a panel power control unit and a panel high-voltage control unit, the device cooperates with a parameter setting unit arranged in the display to correctly determine the time sequence of the panel power signal, LVDS signal and backlight high-voltage power signal input to the display end, so as to filter unnecessary starting initial noise and effectively prolong the service life of the display panel and improve the display image quality.

Description

Low voltage differential signal direct transmission method and device

Technical field

The invention relates to the method and the device of a kind of drawing/image data transmission, refer to that especially a kind of Low Voltage Differential Signal that can directly drawing/image data source be exported directly is sent to the display module end, must not carry out the technology of numeral, analog-converted.

Background technology

Interior arrangement at LCD (LCD), except can seeing the LCD panel module, another printed circuit board promptly is the control panel of LCD, and primary clustering more common in this control panel includes: digital/analog converter (A/D converter), scale controller (Scaler), micro-control unit (MCU), screen display adjustment (OSD), Low Voltage Differential Signal are handled interface IC such as (LVDS).

Between existing LCD (LCD) or plasma display (PDP) and the drawing/image data source, be data could be shown on the display module through data formats conversion for several times.Drawing/image data source at first can change into the image data data analog format and be transferred to display element from digital format, and this end of display (LCD, PDP) is reduced into Low Voltage Differential Signal (Low Voltage Differential Signal, digital format LVDS) with the analog format conversion again.

This conversion of twice does not only have in all senses but also can cause the data distortion, therefore when the user when watching, just be not initial drawing/image data data, the picture that is presented may include noise, picture skew, ripple even problem such as blur.

Extending display identification code (Extended Display IdentificationData because of the traditional panel end, EDID) offer the information of drawing/image source end and inadequate, therefore the represented data content of Low Voltage Differential Signal (LVDS) only comprises red, green, blue (R, G, B) three primary colors, horizontal frequency, vertical scanning frequency and dot frequency etc., and can't provide the extra power supply timing control signal or the control signal of filtering noise again at this end of display module, therefore, if activated with unsuitable power supply sequential at this end of display module, then can cause having on the picture noise and produce, also can therefore shorten the serviceable life of display pannel simultaneously.

Add in order to carry out the proper proportion convergent-divergent to image data in response to different display module panel size, image can correctly be play on panel, so use the IC of scale controller (Scaler), this scale controller is promptly adjusted at screen resolution of being imported or shape size, rewrites into the original pixels matrix of display panel.If when facing comparatively special panel (as 16: 9), general scale controller still can't be adjusted image data, therefore still need additionally provide a complex set of control circuit.

Summary of the invention

Fundamental purpose of the present invention provides a kind of transmitting device between drawing/signal of video signal source and display module, allow Low Voltage Differential Signal (LVDS) directly to export the display module end to by image source end, and the multiple conversions that must not pass through digital-to-analog, analog/digital makes the unlikely distortion of picture and can possess best displaying image quality.

For reaching aforementioned purpose, the direct transmitting device of this Low Voltage Differential Signal of the present invention is to include:

One traffic filter, when the end electric power starting of drawing/image source, but the initial noise signal of filtering;

One panel power control unit, the power supply of control display module end is in correct sequential On/Off;

One backlight high-voltage power supply control module is to be used to control the backlight electric power of display module end in correct sequential On/Off and backlight illumination control (PWM);

One panel parameter storage unit, be to be arranged at this display module inside, be used to store the specification information of this display module, wherein this panel parameter storage unit Low Voltage Differential Signal (LVDS) that is the definition standard and the transmission time sequence of panel power supply signal, LVDS signal and backlight high-voltage power supply signal;

One data bus is to be connected between aforementioned drawing/source, display module and the panel parameter storage unit.

Wherein, during power-on, this panel power supply signal, LVDS signal and backlight high-voltage power supply signal are to export in regular turn; When powered-down, backlight high-voltage power supply signal, LVDS signal and panel power supply signal are to close in regular turn.

Description of drawings

Fig. 1: system block diagrams of the present invention.

Fig. 2: the sequential chart of power supply control of the present invention.

Fig. 3: the present invention controls the pwm signal oscillogram of backlight illumination.

Fig. 4: the part controlled variable in the panel parameter storage unit of the present invention.

Fig. 5: method flow diagram of the present invention.

Symbol description:

(100) drawing/image source

(200) display module

(10) traffic filter

(20) panel power control unit

(30) high voltage control backlight unit

(40) panel parameter storage unit

(50) data bus

Embodiment

See also shown in Figure 1ly, the present invention is a kind of between drawing/image source (100) and display module (200) data transmission method and device between the two.Drawing/image source (100) can be a drawing/image chip (ASIC), a display card (Display card) or other source, and display module (200) then can be the display device of a LCD (LCD), a plasma display (PDP) or other kind.

And the present invention promptly provides a kind of device, permission is from Low Voltage Differential Signal (the Low voltage differential signal in drawing/image source (100), LVDS) directly transfer to display module (200) and must not carry out digital-to-analog repeatedly, the conversion process of analog/digital, wherein, this Low Voltage Differential Signal (LVDS) is to include 18/24/36/48 rgb signal, the level that determines one or two bus and vertical scanning frequency, dot frequency etc., and concrete kenel of the present invention can be configured as a device card, and this device comprises at least:

One traffic filter (Signal Filter) (10), when the power supply one of drawing/image source (100) end is opened, can produce unnecessary initial noise, the effect of this traffic filter (10) promptly is to be used for these noise signals of filtering, to avoid directly being passed to display module (200) end;

One panel power control unit (20) is used to control the power supply of display module (200) end in correct sequential On/Off;

One backlight high-voltage power supply control module (30) is to be used to control the backlight electric power of display module (200) end in correct sequential On/Off and backlight illumination control (PWM);

One panel parameter storage unit (40), it is the specification information that is used to store this display module (200) panel, this panel parameter setup unit (40) can utilize the electronics formula ROM (read-only memory) (EEPROM) of can erasing to constitute and be installed in display module (200) inside, display panel in response to different moneys, the inside information of internal memory also can correspondingly be revised, wherein the interior stored data of this panel parameter storage unit (40) are except that original Low Voltage Differential Signal (LVDS) standard, more increased the sequential control of how controlling power supply time sequence control signal and removing noise, this EEPROM can use can reaching of 128byte capacity;

One data bus (50) is to be connected between aforementioned drawing/source (100), display module (200) and the panel parameter storage unit (40), can utilize a universal serial bus communications protocol (I ²C Bus) implemented.

Below be controlled to be example with the panel of LCD, please cooperate consult shown in Figure 2, sequential control figure for control display module power supply, be to indicate three groups of unlike signals are arranged among the figure, from top to bottom be respectively panel power supply signal, LVDS signal, (backlight) backlight hardboard power supply, three and asynchronous generation.Be the power supply signal of output slab at first, activating display module (200), give display module (200), the multiple power supply of sending hardboard backlight through second time delay behind the Δ 2 again through exporting the LVDS signal again behind the Δ 1 first time delay.And the order direction of closing display module (200) is just opposite with the aforementioned practice, and the meeting of closing at first is the power supply of hardboard backlight, through stopping the signal of LVDS the 3rd time delay behind the Δ 3, at last through the 4th time delay Δ 4 again with the panel power-off.

Via aforesaid sequential control mode, can guarantee that display module (200) holds when machine open/close, all non-stationary noises that produced in initialization procedure can be fully by filtering, and these noise signals will cause display module (200) end to produce unsuitable display action, after avoiding these noise signals, be able to effective prolongation the serviceable life of display module (200) panel.

Fig. 3 is the pwm signal oscillogram that is used for adjusting backlight illumination, pulse width via Δ in the control signal 5, can on display module (200), present different showing luminances, and the present invention must not use an extra pwm signal control circuit to adjust the pulse width of signal, and the output of this pwm signal also is directly to adjust output by this device according to the signal of video signal of input, the characteristic of display module (200).

In panel parameter storage unit (40), except the standard criterion of original LVDS, the present invention has further added the controlled variable of corresponding panel, and those additional parameter are represented as Fig. 4, comprise:

1. the sequential of the power supply of display panel control, LVDS data and hardboard power control signal backlight.

2.LVDS the quantity of rgb signal form (18/24/36/48) and LVDS channel.

3. the ON/OFF of frequency spectrum extension function and proportional control.

4.LVDS the driving energy, signal amplitude control and direct current quasi-position.

5.LVDS the gain of PLL voltage-controlled oscillating.

6.LVDS the PLL work period is controlled.

7.LVDS PLL charge-pump gain control.

8. extending display identification code EDID data.

9. rising or the falling edge via horizontal synchronization, vertical synchronization, unlatching control signal activates LCD/PDP to increase the compatibility of LCD/PDP.

Please refer to shown in Figure 5, be method flow diagram of the present invention, after the initialization operation is finished in drawing/image source (100), be to check the existence that has or not this panel parameter storage unit (40), if have, then read inner storage parameter and judge whether those parameters are correct, if the correct person of parameter, then begin calculating and conversion parameter so that the LVDS device is carried out initial job, determine panel power supply signals, LVDS signal and backlight high-voltage power supply signal three's suitable sequential at last according to those parameters.

Except aforementioned feature, the present invention supports plug to show (Plug ﹠amp simultaneously; Display) function, because the information and the characteristic of all display modules (200) end can automatically be detected and obtain in drawing/image source (100) from this panel parameter setup unit, so image source end is optimal data information can be offered display end immediately.

In sum, the present invention utilizes the practice of default panel parameter, for image source end and display module have been set up a kind of device that can directly transmit the LVDS signal between the two, must be through several D/A, A/D conversion, so the best image quality that can possess former display data, simultaneously, via correct panel power supply signal, LVDS signal and the backlight high-voltage power supply signal stipulated, be to guarantee to show that image quality is not influenced by the noise of electric power starting/when closing.

Claims

1. A low-voltage differential signal direct transmission device is connected between a drawing/image source and a display component, and the transmission device includes:

A signal filter, which can filter out the initial noise signal when the power of the drawing/image source end is turned on;

A panel power control unit, which controls the power supply of the display component to be turned on/off at the correct timing;

A backlight high-voltage power supply control unit, which is used to control the backlight source of the display component side to turn on/off and backlight brightness control at the correct timing;

A panel parameter storage unit is set inside the display component to store the specification information of the display component, wherein the panel parameter storage unit defines standard low-voltage differential signal and panel power signal, LVDS signal and backlight high-voltage power supply Signal transmission timing, when the power is turned on, the panel power signal, LVDS signal and backlight high-voltage power signal are sequentially output, and when the power is turned off, the backlight high-voltage power signal, LVDS signal and panel power signal are sequentially turned off;

A data bus is connected among the aforementioned drawing/image source, display component and panel parameter storage unit.

2. The low-voltage differential signal direct transmission device according to claim 1, wherein the panel parameter storage unit is an electronically erasable read-only memory.

3. The low-voltage differential signal direct transmission device according to claim 1 or 2, wherein the data bus is a serial bus communication protocol.

4. The low-voltage differential signal direct transmission device according to claim 3, the panel parameter storage unit is defined as follows: LVDS RGB signal format and the number of LVDS channels; LVDS driving energy, signal amplitude control and DC voltage level; Extended display identification code EDID information.

5. The low-voltage differential signal direct transmission device according to claim 4, the panel parameter storage unit is defined as: on/off and proportional control of spectrum extension function; LVDS PLL voltage control oscillation gain; LVDS PLL duty cycle Control; LVDS PLL charge-pump gain control.

6 . The low-voltage differential signal direct transmission device according to claim 5 , when the high-voltage power supply of the backlight is turned on, the PWM signal is used to adjust the brightness of the backlight.

7. A low-voltage differential signal direct transmission method is to transmit the low-voltage differential signal to a display component from a drawing/image source, the method comprising:

Execute the initialization of the drawing/image source;

Detecting whether the display unit has a panel parameter storage unit;

If so, read out the stored parameters inside the panel parameter storage unit and judge whether these parameters are correct;

If the parameters are correct, calculate and convert the parameters for initial operation of the LVDS device;

According to these parameters, the transmission timing of the panel power signal, LVDS signal and backlight high-voltage power signal is determined. When the power is turned on, the panel power signal, LVDS signal and backlight high-voltage power signal are output in sequence; when the power is turned off, the backlight The high-voltage power signal, LVDS signal and panel power signal are turned off sequentially.

8. The direct transmission method of low-voltage differential signals according to claim 7, when the high-voltage power supply of the backlight is turned on, the PWM signal is used to adjust the brightness of the backlight.