DE102005015674B4 - Gamma setting method for a multi-channel driver of a monitor and device thereof - Google Patents

Abstract

Multi-channel driver (20) for a monitor (10), comprising:
an m-bit counter (22) for outputting an m-bit count signal;
a GAMMA setting unit (23) connected to the m-bit counter (22) and mapping the m-bit count signal on a portion of a GAMMA curve to output an n-bit signal output from the m Bit count signal is mapped; and
a plurality of PWM driver components (21), wherein each of the PWM driver components (21) comprises two input terminals and one output terminal, one of the input terminals being connected to an output terminal of the GAMMA setting unit (23) via a first n-bit register; another of the input terminals receives an n-bit input signal through a second n-bit register and, by comparing two of the n-bit input signals, outputs a PWM drive signal to a corresponding data channel (11) of the monitor (10) m> n.

Description

The This invention relates generally to a GAMMA tuning method for a Multi-channel driver of a monitor and a device for this and in particular a GAMMA setting method and a device for this, the one given layout area of a driver can effectively reduce.

A conventional Driver circuit for a digital monitor is a GAMMA setting method or circuit. Because different monitors have different channel sizes, becomes a size one Layout area of the driver circuit changed.

Out US 5,929,835 A1 a GAMMA correction unit for a monitor is described, which has several PMW driver components. The GAMMA correction unit has an m-bit counter, using comparators 62 . 64 and 66 a comparison with n-bit registers of approximate GAMMA curve values (cf. 8th ) with the counter values.

Out US Pat. No. 6,806,861 B1 a GAMMA correction unit is known which has several PMW driver components. Here, a 24-bit RGB video input signal is gradually converted into signals for an LCD driver chip using an approximate GAMMA curve to correct the data.

Out US 2004/0189679 A1 is a method for GAMMA correction for an LCD display described in which an m-bit video signal in a corrected n-bit output signal (m> n) converted using a look-up table for GAMMA correction values becomes.

Out DE 692 22 247 T2 For example, a GAMMA correction method using look-up tables is known. Here, an m-bit signal is mapped to an n-bit signal, where m is preferably greater than n.

Regarding 5 is a conventional data channel driver 60 shown. The traditional data channel driver 60 includes several digital m-bit comparators 61 , an m-bit counter 62 and a lookup table 63 , Each of the m-bit comparators 61 includes two m-bit input ports and one PWM output port. The two m-bit input terminals are separately connected to an m-bit register D [m]. The m-bit counter 62 is at an input terminal of a register D [m] of the digital comparators 61 connected. The lookup table 63 includes integrated mapping data to convert n-bits to m-bits such that an n-bit input signal is provided to look up a value from the look-up table and to be converted to an m-bit voltage signal. An output terminal of the lookup table 63 is to the other register D [m] of each digital m-bit comparator 61 connected. If an n-bit input signal of the driver 60 is input, the n-bit input signal from the look-up table 63 is converted into a corresponding m-bit signal, and then the corresponding m-bit signal is output through the register D [m] to the output terminal of each digital m-bit comparator.

The previously mentioned driver 60 , which is a major function of digital comparators 61 uses, is used to output a counter 62 and an input signal of the driver 60 compare so that a driver signal to a corresponding data channel 51 a monitor 50 is issued. Since an m-bit count signal is greater than an n-bit input signal, ie m> n, the digital comparators must 61 select an m-bit size for the digital comparator to perform a signal comparison. In this way, the n-bit input from the lookup table must be 63 be converted into the m-bit signal to the digital comparators 61 To be able to be compared with the m-bit signal, so that the driver signal is output successfully.

The number of digital comparators 61 of the driver 60 corresponds to the number of data channels of the monitor. In addition, the two input terminals of each digital comparator 61 be connected separately to two registers D [m] to receive the input signal. If the driver 60 For a monitor with multiple data channels, therefore, both the number of digital comparators increases 61 as well as a quality of the register D [m] many times over. In addition, the conventional monitor particularly requires a high resolution and a large number of pixels; Of course, the number of drivers for the monitor increases. Thus, the layout of the control circuit obviously becomes more complex and the cost becomes excessive. In order to prevent the driver circuits from becoming the barrier to future developments, a small circuit layout and low cost driver circuit design are necessary and even critical for future monitor development.

The object of the invention is to provide a GAMMA setting method for a multi-channel driver of a monitor which overcomes the aforementioned drawbacks. The object is achieved by the subject matter of claim 1 and the independent method claim 7. On the basis of a GAMMA adjustment approach, where m is greater than n, the invention converts mainly a m-bit input signal of a high-bit signal to an n-bit signal of a low-bit signal. Therefore, the low-bit digital driver components can be used to reduce an overall layout area of the monitor driver when the driver is applied to the multi-channel monitor.

Around the previously mentioned Task to fulfill exists a major technique therein is the GAMMA tuning method to a multi-channel driver of a monitor.

It also includes the driver mainly a GAMMA setter that performs a simulated GAMMA curve and provides several PWM driver components. The GAMMA adjustment unit is used to extract an m-bit of high-bit count signal output from an m-bit counter to convert an n-bit of low-level signals and then into an n-bit PWM driver component enter. Moreover, since the n-bit driver component receives the n-bit input signal generates a PWM drive signal and to a particular data channel output after the PWM driver component receives the n-bit input signal with the converted n-bit count signal compared.

According to the above mentioned Method, the two input signals to the PWM driver component are both n-bits. Therefore can the driver choose the n bit of the low bit PWM driver component to use. Compared to m bits of the high bit driver components for the conventional driver, the present Invention to reduce the layout area to a high degree exactly, in particular for the Monitor for several data channels.

According to one Another object of the present invention, the present Invention be applied to a flat or a curved digital monitor. As a driver of the present invention, low-bit driver components used, the driver can be on any monitor for multiple data channels be applied. The present invention can not only downsize the layout area, but also to a great extent accordingly reduce the costs.

In the drawings:

Shows 1 a circuit block diagram of a driver for a monitor for a plurality of data channels of an embodiment of the present invention.

Shows 2 a flowchart of a GAMMA Einstellansatzes the present invention.

Shows 3 a GAMMA curve of an m-bit signal corresponding to a particular voltage range according to the present invention.

Shows 4 a partial curve of 3 ,

Shows 5 a block diagram of a conventional driver for a monitor with multiple data channels.

The The present invention discloses a GAMMA adjustment method for a Monitor as well as a device therefor, which can be applied to any driver of the monitor, the multiple data channels has. Furthermore For example, the present invention can be accomplished by using a low bit driver also to a great extent reduce a range of each driver component. Therefore, the The present invention contemplates the use of an excessive layout area Moderate circuit and also reduce the production costs.

Regarding 1 FIG. 12 is a circuit block diagram of a driver for a multi-data channel monitor in accordance with an embodiment of the present invention. FIG. The circuit diagram includes a monitor 10 and a subcircuit of a channel driver 20 , Multiple data channels 11 of the monitor 10 each correspond to several output terminals of the channel driver 20 , The channel driver 20 includes at least one m-bit counter 22 , a GAMMA adjustment unit 23 and several PWM driver components 21 ,

The m-bit counter 22 is used to calculate an m-bit output signal (m-bit DI). The GAMMA adjustment unit 23 is to an output terminal of the m-bit counter 22 coupled to map the m-bit output signal (m-bit DI) to a particular portion of a GAMMA waveform and subsequently output an n-bit signal (n-bit DI) at a particular range to obtain the n-bit signal. Output bit signal (n-bit DI).

Each of the PWM driver components 21 includes two input terminals and one output terminal. One of the input terminals is connected to an output terminal of the GAMMA setting unit via a respective register D [n] 23 connected and the other input terminal receives via an appropriate register D [n] an n-bit input signal DI [n: 1]. By comparing the two n-bit input signals, a PWM drive signal is sent to a corresponding data channel 11 of the monitor 10 output. There is also every PWM driver component 21 a digital n-bit comparator.

A bit count signal output from the m-bit counter 22 , is greater than the n-bit input signal DI [n: 1]. That is, m is greater than n. The GAMMA adjustment unit 23 provides a GAMMA simulated curve for n-bit converted m bits. If the m-bit counter 22 outputs an m-bit count signal, first, an n-bit count signal from the GAMMA setting unit 23 and then together with the n-bit input signal DI [n: 1] into the driver component 21 entered. Each PWM driver component 21 then compares the two n-bit input signals to an output PWM drive signal on a corresponding data channel 11 of the monitor 10 issue.

Regarding 2 . 3 and 4 are shown operations of a setting method, that of the GAMMA setting unit 23 be executed. The method is described as follows. First, a localized curved portion of an input signal is determined (step 231 ). As in 3 1, an approximate GAMMA curve C1 'and a true GAMMA curve C1 are shown in solid lines and dotted lines, respectively. The approximate GAMMA curve C1 'represents a relationship of an m-bit signal versus a voltage range Vmin to Vmax represented by n-bit values. The approximate GAMMA curve C1 'includes several lines L1, L2 and L3 with different slopes and lengths, so that it can be decided on which line L1, L2 and L3 the m-bit input signal is and a minimum voltage value of the particular line is output can be. The minimum voltage value is represented by an n-bit value and subsequently used as the setting value. By way of example, an m-bit input signal to be converted will be referred to below as CNT and placed on line L2.

geteilt, so dass entsprechend der n-Bit-Spannungswert G' erhalten wird.A calculation formula for an n-bit voltage value G 'corresponding to the m-bit input signal is calculated (step 232 ). According to the calculation formula, a minimum value Xa-1 of the line L2 corresponding to the m-bit input signal CNT is subtracted from the m-bit input signal CNT and then subtracted by the slope of the line L2

divided, so that in accordance with the n-bit voltage value G 'is obtained.

Then, a step of adding a set value is executed (step 233 ). The previous step 232 is calculated to obtain a relative voltage value G 'of the corresponding line L2 of the m-bit input signal CNT. Therefore, the set value must be added to obtain a current voltage value corresponding to the m-bit signal CNT. That is, the result of the second step 232 is the voltage value of the first step 231 is added to obtain the current n-bit voltage value by adjusting accordingly.

Accordingly, the GAMMA setting unit stores 23 an approximate GAMMA curve C1 '. The number of lines (L1-L3) for forming the approximate GAMMA curve C1 'depends on a resolution of the simulated GAMMA curve C1. In addition, the corresponding voltage range (Vmin to Vmax) of the approximate GAMMA curve C1 'is represented by the n-bit value. If the m-bit counter 22 Therefore, by inputting an m-bit signal, a corresponding n-bit signal can be obtained by calculation.

Preferably, the GAMMA adjustment unit 23 implemented by a divider. An operation formula of the divisor is

In which G 'a converted one n-bit signal from the m-bit signal is, CNT is the m-bit signal, Xa a maximum value of the local limited line, Xa-1 is a minimum of the localized Line is and a + 1 is a number of total lines.

A Lookup table can be created to calculate the previously mentioned Save data to data for M bits, which are converted into n bits, where m> n. If an m-bit count signal is input, the m-bit count signal can be looked up in the look-up table and activating the m-bit input signal directly into an n-bit voltage signal be converted to look up a value from the look-up table, which is to be converted into an n-bit voltage signal.

In short, the present invention uses the GAMMA adjustment unit 23 to convert the high bit input signal to the corresponding low bit signal. The low bit signal is then input to the driver component along with the driver low bit input signal. Since the two input signals consist of low bits, the driver component can use the digital low bit comparator and the register, which is much better than the conventional driver. Each of the data channels is connected to a digital comparator. Accordingly, the present invention provides the digital low-bit comparator so that the overall components of the driver can greatly reduce the layout area of the circuit and, moreover, reduce driver costs.

Claims (9)

Multi-channel driver ( 20 ) for a monitor ( 10 ), full: an m-bit counter ( 22 ) for outputting an m-bit count signal; a GAMMA setting unit ( 23 ) to the m-bit counter ( 22 ) and mapping the m-bit count signal on a portion of a GAMMA waveform to output an n-bit signal mapped by the m-bit count signal; and several PWM driver components ( 21 ), each of the PWM driver components ( 21 ) comprises two input terminals and one output terminal, one of the input terminals being connected to an output terminal of the GAMMA setting unit via a first n-bit register ( 23 ) and the other of the input terminals receives an n-bit input signal through a second n-bit register, and by comparing two of the n-bit input signals, a PWM drive signal to a corresponding data channel ( 11 ) of the monitor ( 10 ), where m> n. A multi-channel driver according to claim 1, wherein the PWM driver component ( 21 ) is a digital n-bit comparator. A multi-channel driver according to claim 1, wherein the GAMMA setting unit ( 23 ) is a divider. A multi-channel driver according to claim 2, wherein the GAMMA setting unit ( 23 ) is a divider. A multi-channel driver according to claim 1, wherein the GAMMA setting unit ( 23 ) is a look-up table. A multi-channel driver according to claim 2, wherein the GAMMA setting unit ( 23 ) is a look-up table. GAMMA setting method for a multi-channel driver ( 20 ) of a monitor ( 10 comprising: (a) determining a localized curve region of an m-bit input signal, wherein an approximate GAMMA curve of a voltage region represented by n-bit values, a relationship between the m-bit input signal and shows the n-bit values, where the approximate GAMMA curve is formed by a plurality of lines of different slopes and lengths to decide in which line the m-bit input signal is located and to output a minimum voltage value which is from an n-bit value. Bit value is displayed as a set value, according to the localized line; (b) using a calculation formula for an m-bit input signal corresponding to the n-bit voltage value developed by subtracting a minimum value of the localized line corresponding to the m-bit input signal from the m-bit input signal and then divided by the slope of the arrayed line to obtain a relative bit voltage value corresponding to the m-bit input signal; and (c) adding the set value, wherein step (b) is to obtain the n-bit relative voltage value of the m-bit signal so that the set value of step (a) is added to the n-bit relative voltage value , thus deriving a current voltage value of the m-bit signal. A GAMMA adjustment method according to claim 7, wherein step (b) is performed by a GAMMA setting unit implemented by a divider, an operation formula of said divider

where G 'is a converted n-bit value from the m-bit input signal; CNT is the m-bit signal; Xa is a maximum value of the line; Xa-1 is a minimum value of the line; and a + 1 is a number of the plurality of lines. GAMMA adjustment method according to claim 7, wherein a Look-up table stores m-bit integrated mapping data stored in n bits, where m> n, to activate the m-bit input signal, look up a value in the lookup table to get the m-bit input signal in an n-bit voltage signal convert.