KR-20260066971-A - Level shifting device and display device including the same

Abstract

The embodiments relate to a level shifting device and a display device including the same, comprising: a control unit that outputs a switching signal based on a plurality of output selection signals input in parallel through corresponding input pins; and a first switching unit that includes a plurality of first switching elements each connected between the input terminal and the output terminal of the level selection signal and turned on in response to the switching signal.

Inventors

• 김정재
• 이상욱

Assignees

• 엘지디스플레이 주식회사

Dates

Publication Date

20260512

Application Date

20241105

Claims (20)

1. A control unit that outputs a switching signal based on a plurality of output selection signals input in parallel through corresponding input pins; and A first switching unit comprising a plurality of first switching elements each connected between the input terminal and the output terminal of a level selection signal and turned on in response to the switching signal, wherein The above control unit is, Based on the plurality of output selection signals above, the switching signal of the turn-on level is output to one of the first switching elements, and The above first switching elements are, A level shifting device that is turned on according to the above switching signal and outputs the level selection signal as output signals to a corresponding output terminal.
2. In paragraph 1, the plurality of output selection signals are, A level shifting device that indicates each bit of a binary code containing information about the output signal to which the voltage level is to be transitioned among the above output signals.
3. In paragraph 1, A level shifting device further comprising a second switching unit including a plurality of second switching elements each connected between the first switching elements and the output terminals and turned on in response to a latch signal.
4. In paragraph 3, the second switching unit is, First capacitors respectively connected between one end of the second switching elements and the ground voltage; and A level shifting device further comprising second capacitors connected respectively between the other end of the second switching elements and the ground voltage.
5. In paragraph 4, the control unit is, A level shifting device that further receives the above latch signal and, in response to the above latch signal of the turn-on level, outputs the switching signal to a first switching element selected by the plurality of output selection signals among the first switching elements.
6. In paragraph 5, each of the above second switching elements is, A level shifting device that outputs a level selection signal input through a corresponding first switching element to a corresponding output terminal in response to the latch signal of the above turn-on level.
7. In paragraph 6, the first capacitors or the second capacitors are, A level shifting device that stores a voltage corresponding to the level selection signal when the corresponding first switching element or the corresponding second switching element is turned on.
8. In Paragraph 7, A level shifting device in which, when the second switching elements are turned off, a signal corresponding to the voltage stored in the second capacitors is output to the output terminals.
9. In paragraph 5, the control unit is, A level shifting device that receives a free latch signal further, and when the free latch signal is at a turn-on level, outputs the switching signal to a first switching element selected by the plurality of output selection signals among the first switching elements.
10. In paragraph 9, the first capacitors are, A level shifting device that stores a voltage corresponding to the level selection signal when the first switching elements are turned on in response to the free latch signal while the above latch signal is applied at a turn-off level.
11. In Paragraph 10, A level shifting device in which, when the above latch signal is applied at a turn-on level, a signal corresponding to the voltage stored in the first capacitors is output to the output terminal through the second switching elements.
12. A display panel where pixels are arranged; A timing control unit that controls the driving timing of the above-mentioned display panel; A level shifting device that generates output signals based on a gate drive control signal applied from the timing control unit and outputs them to corresponding output terminals; and A gate driving unit comprising a plurality of stage circuits each connected to the output terminals of the level shifting device and applying a gate signal to the pixels in response to the output signal, The above timing control unit is, Information regarding the output signal whose voltage level is to transition among the above output signals is encoded into binary code to generate a plurality of output selection signals, and The above level shifting device is, A display device comprising a control unit that receives the plurality of output selection signals in parallel through corresponding input pins and generates the output signals based on the plurality of output selection signals.
13. In Clause 12, the control unit above is, Outputting a switching signal based on the above plurality of output selection signals, and The above level shifting device is, A first switching unit comprising a plurality of first switching elements each connected between the input terminal and the output terminal of a level selection signal and turned on in response to the switching signal; and A display device further comprising a second switching unit including a plurality of second switching elements each connected between the first switching elements and the output terminals and turned on in response to a latch signal.
14. In Clause 13, the second switching unit is, First capacitors respectively connected between one end of the second switching elements and the ground voltage; and A display device further comprising second capacitors respectively connected between the other end of the second switching elements and the ground voltage.
15. In Clause 14, the control unit above is, A display device that further receives the above latch signal and outputs the switching signal to one of the first switching elements in response to the above latch signal of the turn-on level.
16. In paragraph 15, each of the above second switching elements is, A display device that outputs the level selection signal input through a corresponding first switching element to a corresponding output terminal in response to the latch signal of the above turn-on level.
17. In paragraph 16, the first capacitors or the second capacitors are, A display device that stores a voltage corresponding to the level selection signal when the corresponding first switching element or the corresponding second switching element is turned on.
18. In Paragraph 17, A display device in which, when the second switching elements are turned off, a signal corresponding to the voltage stored in the second capacitors is output to the output terminals.
19. In item 15, the above control unit is, A display device that receives a free latch signal further, and outputs the switching signal to a first switching element selected by the plurality of output selection signals among the first switching elements when the free latch signal is at a turn-on level.
20. In paragraph 19, the above-mentioned first capacitors are, While the above latch signal is applied at a turn-off level, when the first switching elements are turned on in response to the above free latch signal, a voltage corresponding to the level selection signal is stored, and A display device in which, when the above latch signal is applied at a turn-on level, a signal corresponding to the voltage stored in the first capacitors is output to the output terminal through the second switching elements.

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. A display device is equipped with a level shifting device to boost or lower the voltage of signals applied to a display panel so that the signals have a desired voltage level. A typical level shifting device is equipped with input pins corresponding to each signal to be applied to the display panel, and is configured to boost or lower the signals input through the input pins using independent level shifters. While such a level shifting device can boost or lower the voltage of signals at a high speed, it has the problem of a large size due to the increased number of input pins and the inclusion of multiple level shifters. To reduce the number of input pins and level shifters, a method can be used where signals are sequentially input to a single input pin and sequentially boosted or lowered through a single level shifter, but this has the disadvantage of requiring a long waiting time for signal processing. 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 drawing showing the structure of a level shifting device according to the first embodiment. Figure 6 is a diagram showing the input and output signals of the level shifting device illustrated in Figure 5. FIGS. 7 to 13 are drawings for explaining the driving method of the level shifting device illustrated in FIG. 5. FIG. 14 is a drawing showing the structure of a level shifting device according to a second embodiment. FIG. 15 is a diagram showing the input and output signals of the level shifting device illustrated in FIG. 14. FIGS. 16 to 24 are drawings for explaining the driving method of the level shifting device illustrated in FIG. 14. 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) can control the operation timing of the gate driver (20) and the data driver (30). The timing control unit (10) can receive an image signal (RGB) and a control signal (CS) from an external host system, etc. The image signal (RGB) may include multiple grayscale data. The control signal (CS) may include, for example, a horizontal sy