KR-20260066972-A - Level shifting device and display device including the same

KR20260066972AKR 20260066972 AKR20260066972 AKR 20260066972AKR-20260066972-A

Abstract

The embodiments relate to a level shifting device and a display device including the same, comprising: a control circuit that receives a latch signal and a command signal from the outside and outputs an address signal and a shift signal; and a level shifting circuit that receives the address signal and the shift signal and outputs a plurality of output signals.

Inventors

이상욱
김정재

Assignees

엘지디스플레이 주식회사

Dates

Publication Date: 20260512
Application Date: 20241105

Claims (18)

A control circuit that receives a latch signal and a command signal from the outside and outputs an address signal and a shift signal; and A level shifting circuit that receives the above address signal and shift signal and outputs a plurality of output signals, wherein The above level shifting circuit is, Generating the plurality of output signals from the input data corresponding to the address signal among the plurality of preset input data, and The above plurality of output signals are, A level shifting device in which pulses are sequentially shifted in response to the above command signal.
In paragraph 1, the control circuit is, A first control circuit that controls the output value of the address signal in response to the above latch signal; and A level shifting device comprising a second control circuit that outputs a shift signal corresponding to a command signal in response to the above latch signal.
In paragraph 2, the first control circuit is, A level shifting device comprising an adder that adds an address value within an address signal by a predetermined offset in response to the latch signal of the turn-on level.
In paragraph 3, the above adder is, An enable input terminal receiving the above latch signal; An output terminal that outputs the above address signal; A first input terminal for receiving a logic signal corresponding to the above offset; and It includes a second input terminal connected to the output terminal above, and A level shifting device that maintains the address signal output to the output terminal when the latch signal of the turn-off level is input, and logically adds the signals input to the first input terminal and the second input terminal and outputs the address signal when the latch signal of the turn-on level is input.
In paragraph 2, the second control circuit is, A decoder that outputs a shift value corresponding to the command signal among a plurality of shift values; and A level shifting device comprising an adder that adds the shift value output from the decoder to the shift value in the shift signal in response to the latch signal of the turn-off level.
In paragraph 5, the second control circuit is, It further includes a counter circuit for counting the number of pulses of the above command signal, and The above decoder is, A level shifting device that receives a plurality of preset shift values and a number of pulses, and outputs a shift value among the plurality of preset shift values that corresponds to the number of pulses.
In paragraph 6, the above adder is, An enable input terminal that receives the inverted signal of the above latch signal; An output terminal that outputs the above shift signal; A first input terminal connected to the output terminal of the above decoder; and It includes a second input terminal connected to the output terminal above, and A level shifting device that maintains the shift signal output to the output terminal when the inverted signal of the turn-off level is input, and logically adds the signals input to the first input terminal and the second input terminal to output the shift signal when the inverted signal of the turn-on level is input.
In paragraph 6, the above counter circuit is, It includes an enable terminal that receives the inverted signal of the above latch signal, and A level shifting device that counts the number of pulses of the command signal while the inverted signal of the turn-on level is input.
In paragraph 1, the level shifting circuit is, A level shifting device comprising a memory that stores a plurality of pre-set input data as a lookup table.
In Paragraph 9, A level shifting device in which a plurality of pre-set input data are each placed in the columns of the lookup table, and bits constituting one input data are each placed in the rows of the lookup table.
In Clause 10, the level shifting circuit is, A level shifting device that, within the lookup table, selects input data placed in a column corresponding to the address signal, shifts the bits of the selected input data in correspondence with the shift signal, and generates the plurality of output signals corresponding to each of the shifted bits.
In paragraph 9, the level shifting circuit is, A decoder that outputs input data corresponding to the address signal among the plurality of preset input data within the above lookup table; A bit shifter that shifts the bits of the input data output from the decoder by a shift value within the shift signal and separates and outputs the shifted bits one bit at a time; and A level shifting device comprising output buffers that buffer and output each bit output from the bit shifter.
A display panel where pixels are arranged; A timing control unit that outputs control signals for driving the above pixels; A level shifting device that generates a plurality of output signals based on control signals output from the above timing control unit; and A gate driving unit that generates gate signals based on the plurality of output signals and applies the gate signals to the pixels, The above level shifting device is, A control circuit that receives a latch signal and a command signal from the above timing control unit and outputs an address signal and a shift signal; and A level shifting circuit that receives the above address signal and shift signal and outputs the above plurality of output signals, wherein The above level shifting circuit is, Generating the plurality of output signals from the input data corresponding to the address signal among the plurality of preset input data, and The above plurality of output signals are, A display device in which pulses are sequentially shifted in response to the above command signal.
In Clause 13, the above control circuit is, A first control circuit that controls the output value of the address signal in response to the above latch signal; and A display device comprising a second control circuit that outputs a shift signal corresponding to a command signal in response to the above latch signal.
In paragraph 14, the first control circuit is, A display device comprising an adder that adds an address value within an address signal by a predetermined offset in response to the latch signal of the turn-on level.
In paragraph 14, the second control circuit is, A counter circuit for counting the number of pulses of the above command signal; A decoder that outputs a shift value corresponding to the number of pulses among a plurality of shift values; and A display device comprising an adder that adds the shift value output from the decoder to the shift value in the shift signal in response to the latch signal of the turn-off level.
In Clause 13, the level shifting circuit is, A display device comprising a memory that stores the above-mentioned preset input data as a lookup table.
In Clause 17, the level shifting circuit is, A decoder that outputs input data corresponding to the address signal among the plurality of preset input data within the above lookup table; A bit shifter that shifts the bits of the input data output from the decoder by a shift value within the shift signal and separates and outputs the shifted bits one bit at a time; and A display device comprising output buffers that buffer and output each bit output from the bit shifter.

Description

Level shifting device and display device including the same The present invention relates to a level shifting device and a display device including the same. A pixel of a display device includes a light-emitting element and a driving circuit for driving the light-emitting element. While the light-emitting element can be selected in various ways depending on the type of display device, Organic Light Emitting Diodes (OLEDs) are currently being actively used due to their fast response speed and excellent luminous efficiency, brightness, viewing angle, contrast ratio, and color reproduction rate. The display device is equipped with a level shifting device to boost or lower signals so that signals applied to the display panel, such as scan signals, have a desired voltage level. A typical level shifting device has output channels corresponding to each of the signals to be applied to the display panel, and includes an analog or digital circuit for boosting or lowering output signals to be output to the output channels. As the number of signals applied to the display panel increases, the number of circuit elements within the level shifting device increases, causing the size of the level shifting device to grow. This makes it difficult to thin the display device and increases manufacturing costs. This problem becomes even more severe, particularly in organic light-emitting displays using internal compensation, where more scan signals are required to compensate for the threshold voltage of the driving transistor. FIG. 1 is a block diagram showing the configuration of a display device according to one embodiment. FIG. 2 is a circuit diagram of a pixel according to one embodiment. FIG. 3 is a diagram showing the configuration of a gate driving unit according to one embodiment. Figure 4 is a simplified diagram of the stage circuit illustrated in Figure 3. FIG. 5 is a diagram showing the structure of a level shifting device according to one embodiment. FIG. 6 is a diagram showing the structure of a lookup table according to one embodiment. Figure 7 is a diagram showing the structure of a level shifting device in more detail. FIG. 8 is a drawing showing a lookup table according to the first embodiment. FIG. 9 is a diagram showing the input and output signals of a level shifting device according to a first embodiment. FIG. 10 is a diagram showing the input and output signals of a level shifting device according to a second embodiment. FIG. 11 is a drawing showing a lookup table according to a second embodiment. FIG. 12 is a diagram showing the input and output signals of a level shifting device according to a third embodiment. FIG. 13 is a drawing showing a lookup table according to a third embodiment. FIG. 14 is a diagram showing the input and output signals of a level shifting device according to a fourth embodiment. Hereinafter, embodiments are described with reference to the drawings. In this specification, where a component (or region, layer, part, etc.) is described as being "on," "connected," or "joined" to another component, it means that it may be directly connected/joined to the other component or that a third component may be placed between them. Identical reference numerals denote identical components. Additionally, in the drawings, the thicknesses, proportions, and dimensions of the components are exaggerated for the effective illustration of the technical content. "And/or" includes all of one or more combinations that the associated components may define. Terms such as "first," "second," etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present embodiments, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes a plural expression unless the context clearly indicates otherwise. Terms such as "below," "lower side," "above," and "upper side" are used to describe the relationships between the components depicted in the drawings. These terms are relative concepts and are described based on the directions indicated in the drawings. Terms such as "include" or "have" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. FIG. 1 is a block diagram showing the configuration of a display device according to one embodiment. Referring to FIG. 1, the display device (1) includes a timing control unit (10), a level shifting device (100), a gate driving unit (20), a data driving unit (30), a power supply unit (40), and a display panel (50). The timing control unit (10) c