TWI467564B - Gamma voltage generation device - Google Patents

Description

Gamma voltage generating device

The present disclosure is directed to a display correction technique, and more particularly to a gamma voltage generating device.

The display is an integral part of the electronic device. By means of the display, the electronic device can display the data thereon for viewing by the user. The display has many special designs in order to achieve the best effect for human eyes, and the gamma voltage setting is one of them. The brightness of the image is often a non-linear relationship with the design of the display voltage or the photographic mechanism of the human eye itself, so an appropriate mechanism is needed to correct it to achieve the best display.

In order to correct the nonlinearity of the image brightness, the gamma voltage curve between voltage and brightness can be adjusted by the gamma voltage. However, with the advancement of display technology, the reference voltage needs to be more precise in the design of the gamma voltage generating device, and the voltage adjustment mechanism must also be more flexible.

Therefore, how to design a new gamma voltage generating device to overcome the above problems is an urgent problem to be solved in the industry.

Therefore, one aspect of the disclosure is to provide a gamma voltage generating device, including: a stable bias generating module, a first resistor string, a digital control module, a first digital analog converter, a second resistor string, and At least one Two-digit analog converter. A stable bias generating module is used to generate a stable bias voltage. The first resistor string includes a plurality of first resistors of equal resistance, and 俾 is used to generate a plurality of first output voltages according to the stable bias voltage. The digital control module includes a storage unit for providing a plurality of reference voltage value control codes and a complex gamma voltage value control code. The first digital analog converter is configured to receive the first output voltage to output a corresponding gamma reference voltage according to one of the reference voltage value control codes. The second resistor string includes a plurality of second resistors of equal resistance, 俾 for generating a plurality of second output voltages according to the gamma reference voltage. The second digital analog converters are each configured to receive the second output voltage to output a corresponding one of the group gamma voltages according to one of the complex gamma voltage value control codes.

According to an embodiment of the present disclosure, the storage unit further includes an interface register and an output register. The interface register extracts the reference voltage value control code and the gamma voltage value control code from the data source, and updates the reference voltage value control code and the gamma voltage value control code to the output register to output the reference voltage value control code. One to one of the first digital analog converter and one of the output gamma voltage value control codes to the second digital analog converter.

According to another embodiment of the present disclosure, the digital control module further includes a multiplexer for connecting to the output register, and selecting one of the reference voltage value control codes according to the selection signal to output to the first digital analog converter and One of the gamma voltage value control codes is selected for output to the second digital analog converter.

According to still another embodiment of the present disclosure, the data source is a control unit and a digital interface, and the control unit is configured to receive an input instruction by the digital interface, and the interface register receives the reference voltage from the control unit according to the input instruction. Value control code and gamma voltage value control code to The test voltage value control code and the gamma voltage value control code are updated to the output register.

According to still another embodiment of the present disclosure, the data source is a non-volatile memory further included in the digital control module, and one of the reference voltage value control codes and one of the gamma voltage value control codes are stored, and the interface is temporarily When the register is initialized, the reference voltage value control code and the gamma voltage value control code are retrieved from the non-volatile memory to update the reference voltage value control code and the gamma voltage value control code to the output register. The digital control module further includes a control unit and a digital interface. The control unit is configured to receive input commands from the digital interface to read and write non-volatile memory through the interface register. The non-volatile memory is an Electronically-Erasable Programmable Read-Only Memory (EEPROM).

There is further an embodiment in accordance with the present disclosure, wherein the stable bias generating module further includes a first amplifier to amplify a stable bias voltage. The first digital analog converter further includes a second amplifier to amplify the gamma reference voltage. The second digital analog converter further includes a plurality of third amplifiers to amplify the set of gamma voltages.

According to still another embodiment of the present disclosure, the set of gamma voltages is output to a source driver of the display panel.

The advantage of applying the disclosure is that the digital control module controls the first and second digital analog converters to generate the gamma reference voltage and the gamma voltage, and the components can be integrated on a single chip, and the voltage is controlled and adjusted. It has considerable flexibility and easily achieves the above objectives.

Please refer to Figure 1. 1 is a block diagram of a gamma voltage generating device 1 in an implementation of the present disclosure. The gamma voltage generating device 1 includes a stable bias generating module 100, a first resistor string 102, a digital control module 104, a first digital analog converter 106, a second resistor string 108, and a second digital analog converter 110.

In one embodiment, the gamma voltage generating device 1 further includes a voltage regulating module 112 for converting the external voltage V1 into an internal voltage V2 used by each module in the pre-gamma voltage generating device 1 to make each mode The group can work. For example, the external voltage V1 can be 18 volts to be converted to a 5.5 volt internal voltage V2 suitable for operation of the gamma voltage generating device 1 via the voltage regulating module 112. In other embodiments, the values of the external voltage V1 and the internal voltage V2 may be adjusted as appropriate.

The stable bias generating module 100 is configured to generate a stable bias voltage Vbias. The stable bias voltage Vbias means that the value of this bias voltage is not disturbed by temperature or other environmental factors, and the output can be stabilized. In one embodiment, the stable bias generating module 100 is a bandgap voltage reference source. The first resistor string 102 includes a plurality of first resistors of equal resistance, 俾 for generating a plurality of first output voltages 101 according to the stable bias voltage Vbias.

The digital control module 104 is configured to output a reference voltage value control code 201 to the first digital analog converter 106 and a gamma voltage value control code 203 to the second digital analog converter 110. The mechanism for its operation will be described in more detail later.

The first digital analog converter 106 receives the first output voltage 101 to output a corresponding gamma reference according to one of the reference voltage value control codes 201. Voltage Vref. The second resistor string 108 includes a plurality of second resistors of equal resistance, 俾 for generating a plurality of second output voltages 103 according to the gamma reference voltage Vref. The second digital analog converters 110 are each configured to receive the second output voltage 103 to output a corresponding one of the group gamma voltages Vg according to one of the gamma voltage value control codes 203. Each of the voltages of the set of gamma voltages Vg is sent to a different channel for further transfer to a source driver (not shown) of the display panel in which the gamma voltage generating device 1 is located for gamma correction. In various embodiments, the number of second digital analog converters 110 can be adjusted depending on the actual condition of the display panel.

It should be noted that the stable bias generating module 100, the first digital analog converter 106, and the second digital analog converter 110 may respectively include the first amplifier 100a, the second amplifier 106a, and the third amplifier 110a to respectively The output stable bias voltage Vbias, the gamma reference voltage Vref, and the gamma voltage Vg are amplified. In various embodiments, the voltage amplification ratios of the first amplifier 100a, the second amplifier 106a, and the third amplifier 110a may be adjusted as the case may be, and are not limited to a specific value.

Please refer to Figure 2. FIG. 2 is a more detailed block diagram of the digital control module 104 in an embodiment of the disclosure. The digital control module 104 has a digital interface 200, a control unit 202, a memory unit including an interface register 204 and an output register 206, a multiplexer 208, and a non-volatile memory 210.

The memory unit including the interface register 204 and the output register 206 is used to provide the aforementioned reference voltage value control code 201 and gamma voltage value control code 203. In different embodiments, the interface register 204 can capture the reference voltage value control code 201 from the non-volatile memory 210 or the control unit 202. And a gamma voltage value control code 203.

The non-volatile memory 210 is, in one embodiment, an electronic erasable rewritable read-only memory that can store different arrays of control codes, such as control code 1 through control code N as shown in FIG. A set of control codes may include a reference voltage value control code 201 and a gamma voltage value control code 203, each of which corresponds to a gamma voltage curve to perform a desired gamma correction.

Please also refer to Figure 3A. FIG. 3A is a schematic diagram of a writing process of the non-volatile memory 210 in an embodiment of the disclosure. Under the input of the digital interface 200, the control unit 202 can write the non-volatile memory 210 through the interface register 204 to write the data of the control code into the non-volatile memory 210. When the interface register 204 writes data to the non-volatile memory 210, the data can be updated to the output register 206 at the same time.

Please also refer to Figure 3B. FIG. 3B is a schematic diagram of a readout process of the non-volatile memory 210 in an embodiment of the disclosure. At the input of the digital interface 200, the control unit 202 can read the data in the non-volatile memory 210 through the interface register 204. In an embodiment, when the digital interface 200 reads the non-volatile memory 210 through the control unit 202, the data read to the interface register 204 is also updated to the output register 206, and the last digit is The interface 200 then reads the data through the interface register 204.

Since the data in the non-volatile memory 210 does not disappear with the power off, the interface register 204 can retrieve its stored control code from the non-volatile memory 210 during initialization, and further control The code is updated to output register 206. Please also refer to the 3C chart. FIG. 3C is a schematic diagram of the writing process of the output register 206 in an embodiment of the disclosure. Figure. In another embodiment, the control unit 202 can be configured to receive an input command from the digital interface 200, and the interface register 204 directly receives the control code including the reference voltage value control code and the gamma voltage value control code from the control unit 202 according to the input instruction. To further update the control code to the output register 206.

Please also refer to the 3D drawing. FIG. 3D is a schematic diagram of a readout process of the output buffer 206 in an embodiment of the disclosure. Since the output register 206 basically changes with the update of the interface register 204 data, the digital interface 200 only needs to read the data of the interface register 204.

Please refer back to Figure 2. The multiplexer 208 is connected to the output register 206, and selects a reference voltage value control code 201 to output to the first digital analog converter 106 according to the selection signal 205 and selects a gamma voltage value control code 203 to output to the second digital analogy. Converter 110. In an embodiment, the selection signal 205 can be generated directly by the digital interface 200 through the control unit 202.

Therefore, the gamma voltage generating device 1 of the present disclosure can select the reference voltage value control code corresponding to the appropriate gamma voltage curve and the gamma voltage value control code by the digital control module 104, and convert by the first digital analogy. The device 106 generates a gamma reference voltage Vref according to the first output voltage 101 according to the reference voltage value control code 201, and generates a gamma voltage Vg according to the second output voltage 103 according to the gamma voltage value control code 203 by the second digital analog converter 110. . In the present disclosure, the manner of controlling the generation of the gamma voltage in a digital manner can make the output of the gamma voltage more precise, more flexible in adjustment, and make the gamma voltage generating device 1 easier to perform on the circuit design. Integration.

Although the disclosure has been disclosed above in the embodiments, it is not The scope of protection of the present disclosure is defined by the scope of the appended claims, which is to be construed as being limited by the scope of the disclosure. Subject to it.

1‧‧‧Gamma voltage generating device

100‧‧‧Stability Bias Generation Module

100a‧‧‧First amplifier

101‧‧‧First output voltage

102‧‧‧First resistor string

103‧‧‧second output voltage

104‧‧‧Digital Control Module

106‧‧‧First digital analog converter

106a‧‧‧second amplifier

108‧‧‧second resistor string

110‧‧‧second digital analog converter

110a‧‧‧3rd amplifier

112‧‧‧Voltage adjustment module

200‧‧‧ digital interface

201‧‧‧Reference voltage value control code

202‧‧‧Control unit

203‧‧‧ gamma voltage value control code

204‧‧‧Interface register

205‧‧‧Select signal

206‧‧‧Output register

208‧‧‧Multiplexer

210‧‧‧ Non-volatile memory

The above and other objects, features, advantages and embodiments of the present disclosure will be more apparent and understood. The description of the drawings is as follows: FIG. 1 is a block diagram of a gamma voltage generating device in an implementation of the disclosure. FIG. 2 is a more detailed block diagram of a digital control module in a gamma voltage generating apparatus according to an embodiment of the present disclosure; FIG. 3A is a diagram of non-volatile memory writing in an embodiment of the present disclosure; FIG. 3B is a schematic diagram of a readout process of a non-volatile memory in an embodiment of the disclosure; FIG. 3C is a schematic diagram of a write flow of an output register in an embodiment of the disclosure; FIG. 3D is a schematic diagram of a readout process of an output register in an embodiment of the disclosure.

1‧‧‧Gamma voltage generating device

100‧‧‧Stability Bias Generation Module

100a‧‧‧First amplifier

101‧‧‧First output voltage

102‧‧‧First resistor string

103‧‧‧second output voltage

104‧‧‧Digital Control Module

106‧‧‧First digital analog converter

106a‧‧‧second amplifier

108‧‧‧second resistor string

110‧‧‧second digital analog converter

110a‧‧‧3rd amplifier

112‧‧‧Voltage adjustment module

201‧‧‧Reference voltage value control code

203‧‧‧ gamma voltage value control code

Claims (11)

A gamma voltage generating device includes: a stable bias generating module for generating a stable bias voltage; a first resistor string including a plurality of first resistances of equal resistance values, The stable bias voltage generates a plurality of first output voltages; a digital control module includes a storage unit for providing a plurality of reference voltage value control codes and a complex gamma voltage value control code, wherein the storage unit comprises: an interface register Extracting the reference voltage value control code and the gamma voltage value control code from a data source; and an output register, wherein the interface register is the reference voltage value control code and the gamma The voltage value control code is updated to the output register; a first digital analog converter is configured to receive the first output voltages to output one of the reference voltage value control codes according to the output of the output register Corresponding to a gamma reference voltage; a second resistor string comprising a plurality of second resistors having equal resistance values, 俾 for generating a plurality of second output voltages according to the gamma reference voltage; and at least a second number Analog converters, each for receiving such a second output voltage, wherein the control code to one of these outputs in accordance with a gamma value of the output voltage of the output register group corresponding to one of the gamma voltages. The gamma voltage generating device of claim 1, wherein the digital control module further comprises a multiplexer for connecting to the output register, and selecting the reference voltage control code according to a selection signal. An output And outputting to the first digital analog converter and selecting one of the gamma voltage value control codes to the second digital analog converter. The gamma voltage generating device of claim 1, wherein the data source further comprises a control unit and a digital interface, wherein the control unit is configured to receive an input command from the digital interface, the interface The register receives the reference voltage value control code and the gamma voltage value control code from the control unit according to the input instruction, to update the reference voltage value control code and the gamma voltage value control code to the Output register. The gamma voltage generating device of claim 1, wherein the data source further comprises a non-volatile memory for storing the reference voltage value control code and the gamma One of the voltage control codes. The gamma voltage generating device of claim 4, wherein the interface register retrieves the reference voltage value control code and the gamma voltage value control code from the non-volatile memory when initializing The reference voltage value control codes and the gamma voltage value control codes are updated to the output register. The gamma voltage generating device of claim 5, wherein the digital control module further comprises a control unit and a digital interface, wherein the control unit is configured to receive an input command from the digital interface to temporarily store the interface through the interface The non-volatile memory is read and written. The gamma voltage generating device of claim 4, wherein the non-volatile memory is an Electrically-Erasable Programmable Read-Only Memory (EEPROM). The gamma voltage generating device of claim 1, wherein the stable bias generating module further comprises a first amplifier to amplify the stable bias voltage. The gamma voltage generating device of claim 1, wherein the first digital analog converter further comprises a second amplifier to amplify the gamma reference voltage. The gamma voltage generating device of claim 1, wherein the second digital analog converter further comprises a plurality of third amplifiers to amplify the set of gamma voltages. The gamma voltage generating device of claim 1, wherein the set of gamma voltages is output to a source driver of a display panel.