Driver IC

Abstract

The driver IC may comprise a light emitting circuit connected between a first node and a second node, a first mode switching switch configured to selectively connect a first pad to the first node or the second node according to a switching mode, and a second mode switching switch configured to selectively connect a second pad to the first node or the second node according to the switching mode. The first pad may be electrically connected to one of an anode and a cathode of the light emitting element according to a switching mode, and the second pad may be connected to one of a first power line and a second power line according to the switching mode. The first power line may have a first power voltage greater than a second power voltage of the second power line.

Description

Drive IC

[0001] The embodiment relates to a driving IC.

[0002] The display market is growing, and its range of applications is continuously expanding. Along with this expansion, product resolutions and features are diversifying.

[0003] As product specifications become more diverse, the driving methods for displays are also becoming more complex.

[0004] Driver ICs used to drive display devices are designed specifically for their specific applications. Therefore, the design's application potential is limited, requiring a custom driver IC for each product.

[0005] Existing display devices employ various methods to ensure uniformity. For example, internal compensation is performed by configuring a light-emitting circuit in each pixel (or subpixel), or external compensation is performed using a specific method.

[0006] Meanwhile, most of the circuit configurations for the operation of the light-emitting circuit included in the driving IC have their own capacitors built into the light-emitting circuit, thereby securing constant current characteristics.

[0007] Figure 1 is a circuit diagram illustrating a conventional light-emitting circuit.

[0008] As illustrated in Fig. 1, a conventional light-emitting circuit includes a driving transistor (M1), a scan transistor (M2), a sensing transistor (M3), and a capacitor (CSTG).

[0009] When the scan transistor (M2) is turned on in response to the scan signal (SCAN), the data signal (VDATA) is supplied to the driving transistor (M1) via the scan transistor (M2). The driving transistor (M1) supplies a light-emitting current corresponding to the data signal (VDATA) to the light-emitting element (ED), so that the light-emitting element (ED) emits light.

[0010] The capacitor (CSTG) supplies the light emitting current as a constant current to the light emitting element (ED).

[0011] When the sensing transistor (M3) is turned on in response to the sensing control signal (SEN), the luminescence current flowing in the driving transistor (M1) is detected as a sensing signal (VSEN). The characteristics of the corresponding luminescence circuit are calibrated or compensated using the sensing signal (VSEN).

[0012] Meanwhile, the light-emitting circuit of an active matrix display device controls brightness using either the pulse amplitude modulation (PWM) method itself or a PWM method utilizing the pulse amplitude modulation (PAM) method. In these cases, a capacitor is necessarily included within each pixel (or subpixel).

[0013] If the light-emitting circuit is designed to have a capacitor inside every pixel, limitations such as area may arise, or additional problems may arise due to the capacitor inside each pixel.

[0014] Meanwhile, in the pixel structure of existing display devices, the cathodes of the light-emitting elements are commonly connected or the anodes of the light-emitting elements are commonly connected. A structure in which the cathodes of the light-emitting elements are commonly connected is called a common cathode structure, and a structure in which the anodes of the light-emitting elements are commonly connected is called a common anode structure.

[0015] A driver IC designed for a common anode structure cannot be used in a common cathode structure. Similarly, a driver IC designed for a common cathode structure cannot be used in a common anode structure.

[0016] Therefore, there is an urgent need to develop a driving IC that can be used universally regardless of the common anode structure and common cathode structure.

[0017] The present invention aims to solve the above-mentioned and other problems.

[0018] Another object of the invention is to provide a driver IC that can be universally used in common anode structures and common cathode structures.

[0019] The technical problems of the embodiment are not limited to those described in this article, but include those that can be understood through the description of the invention.

[0020] According to one aspect of the embodiment to achieve the above or other objects, a driving IC includes: a light-emitting circuit connected between a first node and a second node; a first mode switching switch selectively connecting a first pad to the first node or the second node according to a switching mode; and a second mode switching switch selectively connecting a second pad to the first node or the second node according to the switching mode; wherein the first pad is electrically connected to one of an anode and a cathode of a light-emitting element according to the switching mode, the second pad is connected to one of a first power line and a second power line according to the switching mode, and the first power line can have a first power voltage that is higher than a second power voltage of the second power line.

[0021] The above switching mode may include a first switching mode for a common anode structure and a second switching mode for a common cathode structure. In the first switching mode, the first pad may be connected to the first node by the first mode switching switch, and the second pad may be connected to the second node by the second mode switching switch, and the first pad may be connected to the cathode of the light-emitting element and the second pad may be connected to the second power line.

[0022] In the second switching mode, the first pad may be connected to the second node by the first mode switching switch, the second pad may be connected to the first node by the second mode switching switch, the first pad may be connected to the anode of the light-emitting element, and the second pad may be connected to the first power line.

[0023] The light-emitting circuit may include a constant current source between the first node and the second node; a first light-emitting control switch between the first node and the constant current source; and a second light-emitting control switch between the constant current source and the second node.

[0024] The light-emitting circuit may include: a first constant current source between the first node and the second node; a first constant current switch connected in series with the first constant current source; a first light-emitting control switch between the first node and the first constant current switch; a second constant current source connected in parallel with the first constant current source between the first node and the second node; a second constant current switch connected in series with the second constant current source; and a second light-emitting control switch between the second constant current switch and the second node.

[0025] The first constant current switch and the second constant current switch include transistors of the same type and can be individually turned on in response to a first control signal and a second control signal.

[0026] The first constant current switch and the second constant current switch include transistors of different types and can be complementarily turned on in response to the same control signal.

[0027] The light-emitting circuit may include: a first constant current source between the first node and the second node; a first light-emitting control switch connected in series with the first constant current source; a second constant current source connected in parallel with the first constant current source between the first node and the second node; and a second light-emitting control switch connected in series with the second constant current source.

[0028] The first light-emitting control switch may include a PMOS transistor, and the second light-emitting control switch may include an NMOS transistor. The driving IC may further include an OR gate connected to a gate of the PMOS transistor; and an AND gate connected to a gate of the NMOS transistor.

[0029] The above driving IC may further include a measurement line connected to the light emitting circuit.

[0030] The first mode switching switch and the second mode switching switch may include transmission gates or pass transistors.

[0031] According to at least one of the embodiments, even if a plurality of light-emitting elements arranged on a substrate are connected with a common anode structure or a common cathode structure, there is an advantage in that the driving IC can be universally applied to a common anode structure and a common cathode structure by switching the connection of the light-emitting circuits to match the structure.

[0032] Further scope of applicability of the embodiments will become apparent from the detailed description below. However, since various changes and modifications within the spirit and scope of the embodiments will be readily apparent to those skilled in the art, it should be understood that the detailed description and specific embodiments, such as preferred embodiments, are given by way of example only.

[0033] Figure 1 is a circuit diagram illustrating a conventional light-emitting circuit.

[0034] Fig. 2 is a circuit diagram illustrating a driving IC according to the first embodiment.

[0035] Figure 3 illustrates the operation of the driving IC according to the first embodiment in the first switching mode.

[0036] Figure 4 illustrates the operation of the second switching mode in the driving IC according to the first embodiment.

[0037] Fig. 5 is a circuit diagram illustrating a driving IC according to the second embodiment.

[0038] Fig. 6 illustrates the operation of the driving IC in the first switching mode according to the second embodiment.

[0039] Fig. 7 illustrates the operation of the second switching mode in the driving IC according to the second embodiment.

[0040] Fig. 8 is a circuit diagram illustrating a driving IC according to the third embodiment.

[0041] Fig. 9 illustrates the operation of the driving IC in the first switching mode according to the third embodiment.

[0042] Fig. 10 illustrates the operation of the second switching mode in the driving IC according to the third embodiment.

[0043] Fig. 11 is a circuit diagram illustrating a driving IC according to the fourth embodiment.

[0044] Fig. 12 illustrates the operation of the driving IC in the first switching mode according to the fourth embodiment.

[0045] Fig. 13 illustrates the operation of the second switching mode in the driving IC according to the fourth embodiment.

[0046] Fig. 14 is a circuit diagram illustrating a driving IC according to the fifth embodiment.

[0047] Fig. 15 illustrates the operation of the driving IC in the first switching mode according to the fifth embodiment.

[0048] Fig. 16 illustrates the operation of the second switching mode in the driving IC according to the fifth embodiment.

[0049] Fig. 17 is a circuit diagram illustrating a driving IC according to the sixth embodiment.

[0050] Fig. 18 illustrates the operation of the driving IC in the first switching mode according to the sixth embodiment.

[0051] Fig. 19 illustrates the operation of the second switching mode in the driving IC according to the sixth embodiment.

[0052] Fig. 20 is a circuit diagram illustrating a driving IC according to the seventh embodiment.

[0053] Fig. 21 illustrates the operation of the driving IC in the first switching mode according to the seventh embodiment.

[0054] Fig. 22 illustrates the operation of the second switching mode in the driving IC according to the seventh embodiment.

[0055] Fig. 23 is a circuit diagram illustrating a driving IC according to the eighth embodiment.

[0056] The sizes, shapes, and dimensions of components depicted in the drawings may differ from the actual components. Furthermore, even if the same components are depicted with different sizes, shapes, and dimensions across drawings, this is merely an example within the drawings, and the same components may have the same sizes, shapes, and dimensions across drawings.

[0057] Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers and redundant descriptions thereof will be omitted. The suffixes 'module' and 'part' used for components in the following description are given or used interchangeably in consideration of the ease of writing the specification, and do not have distinct meanings or roles in themselves. In addition, the attached drawings are intended to make it easier to understand the embodiments disclosed in the present specification, and the technical ideas disclosed in the present specification are not limited by the attached drawings. In addition, when an element such as a layer, region, or substrate is referred to as existing 'on' another element, this includes that it may be directly on the other element or that other intermediate elements may exist therebetween.

[0058] In an embodiment, a display device may include a substrate comprising a plurality of pixels. An image may be displayed using the plurality of pixels. Each pixel may include a plurality of subpixels.

[0059] In an embodiment, a plurality of driving ICs and a plurality of light-emitting elements may be arranged on a substrate. The plurality of light-emitting elements may be arranged in a plurality of subpixels on the substrate. At least one light-emitting element may be arranged in one subpixel.

[0060] For example, a plurality of driver ICs may be arranged in a plurality of subpixels on the substrate. As another example, a plurality of driver ICs may be arranged in areas other than the plurality of subpixels. For example, a single driver IC may be connected to at least two pixels, i.e., six or more subpixels, and may control the light emission of light-emitting elements arranged in the six or more pixels.

[0061] In an embodiment, the light-emitting element may be a semiconductor light-emitting element, but is not limited thereto. For example, a first light-emitting element, a second light-emitting element, and a third light-emitting element may be arranged in a first subpixel, a second subpixel, and a third subpixel constituting a pixel, respectively. The first light-emitting element may emit red light, the second light-emitting element may emit green light, and the third light-emitting element may emit blue light.

[0062] In an embodiment, a plurality of power lines and a plurality of signal lines may be arranged on a substrate. The plurality of signal lines may be electrically connected to a plurality of driving ICs. The plurality of power lines may be electrically connected to a plurality of light-emitting elements.

[0063] As will be explained later, the plurality of power lines may include a first power line supplying a first power voltage, a second power line supplying a second power voltage, a third power line supplying a third power voltage, etc. The first power voltage or the third power voltage may be greater than the second power voltage. A constant light-emitting current, i.e., a constant current, is generated using the first power voltage and the second power voltage, and the plurality of light-emitting elements may emit light using the constant current.

[0064] The plurality of signal lines may include control signal lines for transmitting control signals and data signal lines for transmitting digital data, program signals, etc. Here, the digital data, program signals, etc. may refer to an image of each frame. Accordingly, for each frame, the digital data, program signals, etc. are transmitted to the driving ICs, and the plurality of light-emitting elements emit light through the control of the driving ICs, thereby displaying an image.

[0065] By controlling the on-period (or light-emitting period) of light-emitting elements using digital data and program signals, grayscale expression in multiple subpixels can be possible.

[0066] For example, the digital data may include a signal regarding the on / off of each light-emitting element. For example, the digital data may include a 1 indicating that each light-emitting element is on, and the data may include a 0 indicating that each light-emitting element is off, but is not limited thereto. If the digital data is 1, the corresponding light-emitting element may light up, and if the digital data is 0, the corresponding light-emitting element may stop emitting.

[0067] For example, the program signal is a control signal for writing input data and may include grayscale information, etc.

[0068] For each frame, light-emitting elements are turned on using digital data, program signals, etc., and the on-period of each light-emitting element is controlled, so that an image with a desired grayscale can be displayed. For example, an image with a higher grayscale can be displayed as the on-period increases. For the same subpixel, the corresponding light-emitting element is turned on with different on-periods on a frame-by-frame basis, so that an image with different grayscale can be displayed on a frame-by-frame basis.

[0069] Meanwhile, the first light-emitting element, the second light-emitting element, and the third light-emitting element may be packaged to form a single light-emitting chip. In this case, multiple light-emitting chips may be arranged in multiple pixels on the substrate.

[0070] Meanwhile, in an embodiment, the display device may have a common anode structure or a common cathode structure. When the display device has a common anode structure, the anodes of a plurality of light-emitting elements arranged on the substrate may be commonly connected to a first power line. When the display device has a common cathode structure, the cathodes of a plurality of light-emitting elements arranged on the substrate may be commonly connected to a second power line (172).

[0071] Meanwhile, in the embodiment, the driving IC can be universally applied to a display device having a common anode structure or a display device having a common cathode structure.

[0072] In an embodiment, the driving IC may be operable to correspond to a common anode structure and a common cathode structure depending on the switching mode. Here, the operation may mean an operation of connecting the light-emitting circuit to correspond to the common anode structure and the common cathode structure.

[0073] Hereinafter, various embodiments will be described in detail with reference to FIGS. 2 to 23. For convenience, the drawings illustrate one light-emitting element connected to one light-emitting element, but a plurality may be included. That is, a plurality of light-emitting circuits, a plurality of first mode switching switches, and a plurality of second mode switching switches may be provided. By the operations of the plurality of first mode switching switches and the plurality of second mode switching switches, the plurality of light-emitting circuits may be electrically connected to the plurality of light-emitting elements so as to have a common anode structure and a common cathode structure. In order to have a common anode structure, the plurality of light-emitting circuits may be electrically connected to the cathodes of the plurality of light-emitting elements, respectively. In order to have a common cathode structure, the plurality of light-emitting circuits may be electrically connected to the anodes of the plurality of light-emitting elements, respectively.

[0074] Fig. 2 is a circuit diagram illustrating a driving IC according to the first embodiment.

[0075] Referring to FIG. 2, the driving IC (101) according to the first embodiment may include a light-emitting circuit (110), a first mode switching switch (120), a second mode switching switch (130), etc.

[0076] The light-emitting circuit (110) can be electrically connected to a light-emitting element placed on a substrate separately from the driving IC (101). The light-emitting circuit (110) can control the light emission of the light-emitting element. Through the control of the light-emitting circuit (110), not only the light emission of the light-emitting element but also the on period of the light-emitting element can be controlled.

[0077] The light-emitting circuit (110) may be connected between the first node (N1) and the second node (N2). The light-emitting circuit (110) may include a constant current source (210) that generates a constant current. The constant current may be referred to as a light-emitting current. The light-emitting current of the constant current source (210) is supplied to the light-emitting element, so that the light-emitting element may emit light. At this time, the light-emitting circuit (110) supplies the light-emitting current to the light-emitting element during the on-period of each frame, so that the light-emitting element may emit light during the on-period of each frame. The light-emitting element may stop emitting light during the remaining period, i.e., the off-period, excluding the on-period in each frame.

[0078] In an embodiment, the first mode switching switch (120) and the second mode switching switch (130) may each include transmission gates, pass transistors, etc.

[0079] In an embodiment, the switching mode may include a first switching mode for a common anode structure and a second switching mode for a common cathode structure. The switching mode may be implemented using a first control signal (S1) and a second control signal (S2) input to the driving IC (101).

[0080] The first mode switching switch (120) can selectively connect the first pad (140) to the first node (N1) or the second node (N2) depending on the first switching mode or the second switching mode. The second mode switching switch (130) can selectively connect the second pad (150) to the first node (N1) or the second node (N2) depending on the first switching mode or the second switching mode. Here, the pad may be called a terminal, a lead, a pin, a solder ball, etc.

[0081] The first pad (140) can be electrically connected to one of the anode and the cathode of the light emitting element depending on the first switching mode or the second switching mode. The second pad (150) can be connected to one of the first power line (171) and the second power line (172) depending on the first switching mode or the second switching mode. The first power line (171) can have a first power voltage (EVDD) that is greater than a second power voltage (EVSS) of the second power line (172).

[0082] The first mode switching switch (120) can selectively connect the first pad (140) to the first node (N1) or the second node (N2) in response to a first control signal (S1). The second mode switching switch (130) can selectively connect the second pad (150) to the first node (N1) or the second node (N2) in response to a second control signal (S2).

[0083] As illustrated in FIG. 3, in the first switching mode, the first pad (140) may be connected to the first node (N1) by the first mode switching switch (120), and the second pad (150) may be connected to the second node (N2) by the second mode switching switch (130). At this time, the first power line (171) on the substrate may be connected to the anode (161) of the light-emitting element (160), and the first pad (140) may be connected to the cathode (162) of the light-emitting element (160). Accordingly, a display device having a common anode structure in which the light-emitting circuit (110) is connected to the cathode (162) of the light-emitting element (160) through the first pad (140) and to the second power line (172) through the second pad (150) may be configured.

[0084] Although not shown, when a plurality of light-emitting circuits and a plurality of light-emitting elements are provided, the plurality of light-emitting circuits may be connected to the cathodes of the plurality of light-emitting elements through the first pads, and the plurality of light-emitting elements may be commonly connected to a second power line (172) through the second pads.

[0085] As illustrated in FIG. 4, in the second switching mode, the first pad (140) may be connected to the second node (N2) by the first mode switching switch (120), and the second pad (150) may be connected to the first node (N1) by the second mode switching switch (130). At this time, the first pad (140) may be connected to the anode (161) of the light-emitting element (160) on the substrate, and the second power line (172) may be connected to the cathode (162) of the light-emitting element (160). Accordingly, a display device having a common cathode structure in which the light-emitting circuit (110) is connected to the anode (161) of the light-emitting element (160) through the first pad (140) and to the first power line (171) through the second pad (150) may be configured.

[0086] Although not shown, when a plurality of light-emitting circuits and a plurality of light-emitting elements are provided, the plurality of light-emitting circuits may be commonly connected to the first power line (171) and the plurality of light-emitting circuits may be connected to the anodes of the plurality of light-emitting elements through the first pads, respectively.

[0087] Therefore, according to the first embodiment, even if a plurality of light-emitting elements arranged on a substrate are connected with a common anode structure or a common cathode structure, the driving IC (101) can be universally applied to the common anode structure and the common cathode structure by switching the connection of the light-emitting circuits to match the structure.

[0088] Fig. 5 is a circuit diagram illustrating a driving IC according to the second embodiment.

[0089] The second embodiment is identical to the first embodiment except for the first light-emitting control switch (221) and the second light-emitting control switch (222). In the second embodiment, the same components as in the first embodiment are given the same drawing reference numerals, and detailed descriptions are omitted.

[0090] Referring to FIG. 5, the driving IC (102) according to the second embodiment may include a light-emitting circuit (110), a first mode switching switch (120), a second mode switching switch (130), etc.

[0091] The light emitting circuit (110) may include a constant current source (210), a first light emitting control switch (221), a second light emitting control switch (222), etc.

[0092] A constant current source (210) may be connected between a first node (N1) and a second node (N2). A first light-emitting control switch (221) may be connected between the first node (N1) and the constant current source (210), and a second light-emitting control switch (222) may be connected between the constant current source (210) and a second node (N2).

[0093] One of the first light-emitting control switch (221) and the second light-emitting control switch (222) may be omitted.

[0094] The first light-emitting control switch (221) and the second light-emitting control switch (222) can each control the supply time (or duration) of the constant current, i.e., the light-emitting current, supplied to the light-emitting element connected to the first pad (140) for each frame.

[0095] The first light-emitting control switch (221) and the second light-emitting control switch (222) can be turned on / off in response to the first control signal (S31) and the second control signal (S32), respectively.

[0096] During the on-period of each frame, the first light-emitting control switch (221) and the second light-emitting control switch (222) can be turned on in response to the first control signal (S31) and the second control signal (S32). Accordingly, during the on-period of each frame, light-emitting current is supplied to the light-emitting element connected to the first pad (140), so that the light-emitting element can emit light during the on-period. Since the on-periods of each frame are different, the gradation of the image can be expressed.

[0097] During the off period of each frame, the first light-emitting control switch (221) and the second light-emitting control switch (222) can be turned off in response to the first control signal and the second control signal. Accordingly, during the off period of each frame, a constant current, i.e., a light-emitting current, is not supplied to the light-emitting element connected to the first pad (140), so that the light-emitting element can stop emitting light during the off period.

[0098] Since a frame is fixed, if the on-period increases, the off-period may decrease. As the on-period increases, the grayscale of the image may increase.

[0099] As illustrated in FIG. 6, in the first switching mode, the first pad (140) can be connected to the first node (N1) by the first mode switching switch (120), and the second pad (150) can be connected to the second node (N2) by the second mode switching switch (130). Accordingly, a display device having a common anode structure in which the light-emitting circuit (110) is connected to the cathode (162) of the light-emitting element (160) through the first pad (140) and to the second power line (172) through the second pad (150) can be configured.

[0100] As illustrated in FIG. 7, in the second switching mode, the first pad (140) can be connected to the second node (N2) by the first mode switching switch (120), and the second pad (150) can be connected to the first node (N1) by the second mode switching switch (130). Accordingly, a display device having a common cathode structure in which the light-emitting circuit (110) is connected to the anode (161) of the light-emitting element (160) through the first pad (140) and to the first power line (171) through the second pad (150) can be configured.

[0101] Therefore, according to the second embodiment, even if a plurality of light-emitting elements arranged on a substrate are connected with a common anode structure or a common cathode structure, the driving IC (102) can be universally applied to the common anode structure and the common cathode structure by switching the connection of the light-emitting circuits to match the structure.

[0102] Fig. 8 is a circuit diagram illustrating a driving IC according to the third embodiment.

[0103] Referring to FIG. 8, the driving IC (103) according to the third embodiment may include a first constant current source (211), a second constant current source (212), a first selection switch (213), a second selection switch (214), a first light-emitting control switch (221), a second light-emitting control switch (222), etc.

[0104] Since the first light-emitting control switch (221) and the second light-emitting control switch (222) have been described in the second embodiment (Fig. 5), detailed descriptions are omitted.

[0105] The first light emitting control switch (221) and the second light emitting control switch (222) can be connected in series between the first node (N1) and the second node (N2). The first light emitting control switch (221) can be connected between the first node (N1) and the first selection switch (213) and between the first node (N1) and the second constant current source (212). The second light emitting control switch (222) can be connected between the first constant current source (211) and the second node (N2) and between the second selection switch (214) and the second node (N2).

[0106] The first constant current source (211) can be connected between the first node (N1) and the second node (N2). The first constant current source (211) can be connected between the first light-emitting control switch (221) and the second light-emitting control switch (222).

[0107] A second constant current source (212) can be connected between the first node (N1) and the second node (N2). The second constant current source (212) can be connected between the first light-emitting control switch (221) and the second light-emitting control switch (222).

[0108] The first constant current source (211) and the second constant current source (212) may be connected in parallel with each other. The first constant current source (211) may supply a constant current to the light-emitting element connected to the first pad (140) in the first switching mode for the common anode structure. The second constant current source (212) may supply a constant current to the light-emitting element connected to the first pad (140) in the first switching mode for the common cathode structure. The constant current generated by the first constant current source (211) and the constant current generated by the second constant current source (212) may be the same, but are not limited thereto.

[0109] A first selection switch (213) may be provided to select a first constant current source (211). A second selection switch (214) may be provided to select a second constant current source (212). The first constant current source (211) may be selected by turning on the first selection switch (213) in response to a first control signal (S41). The second constant current source (212) may be selected by turning on the second selection switch (214) in response to a second control signal (S42).

[0110] The first selection switch (213) may be connected in series with the first constant current source (211). The first selection switch (213) may be connected between the first light-emitting control switch (221) and the first constant current source (211). The second selection switch (214) may be connected in series with the second constant current source (212). The second selection switch (214) may be connected between the second constant current source (212) and the second light-emitting control switch (222).

[0111] As illustrated in FIG. 9, in the first switching mode, the first pad (140) can be connected to the first node (N1) by the first mode switching switch (120), and the second pad (150) can be connected to the second node (N2) by the second mode switching switch (130). In addition, the first constant current source (211) can be selected as the first selection switch (213) is turned on. Accordingly, a display device having a common anode structure in which the light-emitting circuit (110) is connected to the cathode (162) of the light-emitting element (160) through the first pad (140) and to the second power line (172) through the second pad (150) can be configured. In a display device having a common anode structure, the first light-emitting control switch (221) and the second light-emitting control switch (222) are turned on during the on period for each frame, so that the light-emitting element (160) connected to the first pad (140) can emit light by the constant current generated from the first constant current source (211).

[0112] As illustrated in FIG. 10, in the second switching mode, the first pad (140) can be connected to the second node (N2) by the first mode switching switch (120), and the second pad (150) can be connected to the first node (N1) by the second mode switching switch (130). In addition, the second constant current source (212) can be selected as the second selection switch (214) is turned on. Accordingly, a display device having a common cathode structure in which the light emitting circuit (110) is connected to the anode (161) of the light emitting element (160) through the first pad (140) and to the first power line (171) through the second pad (150) can be configured. In a display device having a common cathode structure, the first light-emitting control switch (221) and the second light-emitting control switch (222) are turned on during the on period for each frame, so that the light-emitting element (160) connected to the first pad (140) can emit light by the constant current generated from the second constant current source (212).

[0113] Therefore, according to the third embodiment, even if a plurality of light-emitting elements arranged on a substrate are connected with a common anode structure or a common cathode structure, the driving IC (103) can be universally applied to the common anode structure and the common cathode structure by switching the connection of the light-emitting circuits to match the structure.

[0114] Fig. 11 is a circuit diagram illustrating a driving IC according to the fourth embodiment. Fig. 11 may be a diagram that embodies the circuit diagram of Fig. 10.

[0115] Referring to FIG. 11, the driving IC (104) according to the fourth embodiment may include a first constant current source (211), a second constant current source (212), a first selection switch (213), a second selection switch (214), a first light-emitting control switch (221), a second light-emitting control switch (222), etc.

[0116] The first light-emitting control switch (221) may include a PMOS transistor (T1), and the second light-emitting control switch (222) may include an NMOS transistor (T2), but the opposite may also be possible. In this case, the first light-emitting control switch (221) may be turned on in response to a first control signal (S31) having a low level, and the second light-emitting control switch (222) may be turned on in response to a second control signal (S32) having a high level.

[0117] The first constant current source (211) may include an NMOS transistor (T3), and the second constant current source (212) may include a PMOS transistor (T4). The first constant current source (211) may generate a constant current corresponding to a first reference voltage (VA), and the second constant current source (212) may generate a constant current corresponding to a second reference voltage (VB). As the first reference voltage (VA) increases, the constant current generated from the first constant current source (211) may also increase. As the second reference voltage (VB) increases, the constant current generated from the second constant current source (212) may also increase. The first reference voltage (VA) and the second reference voltage (VB) may be provided from a reference voltage generator (not shown).

[0118] The first selection switch (213) may include a PMOS transistor (T5), and the second selection switch (214) may include an NMS transistor (T6), but the opposite may also be possible. The first selection switch (213) and the second selection switch (214) may be complementarily turned on in response to the same control signal (S41).

[0119] As illustrated in Fig. 12, in a display device having a common anode structure, in response to a control signal (S41) having a low level, the first selection switch (213) may be turned on and the first constant current source (211) may be selected, but the second selection switch (214) may be turned off and the second constant current source (212) may not be selected.

[0120] As illustrated in Fig. 13, in a display device having a common cathode structure, in response to a control signal (S41) having a high level, the first selection switch (213) is turned off so that the first constant current source (211) is not selected, but the second selection switch (214) is turned on so that the second constant current source (212) can be selected.

[0121] Fig. 14 is a circuit diagram illustrating a driving IC according to the fifth embodiment.

[0122] Referring to FIG. 14, the driving IC (105) according to the fifth embodiment may include a first constant current source (211), a second constant current source (212), a first light-emitting control switch (215), a second light-emitting control switch (216), etc.

[0123] The first constant current source (211) and the second constant current source (212) can be connected between the first node (N1) and the second node (N2). The first constant current source (211) and the second constant current source (212) can be connected in parallel with each other.

[0124] The first light emitting control switch (215) may be connected in series with the first constant current source (211). The first light emitting control switch (215) may be connected between the first constant current source (211) and the second node (N2). The second light emitting control switch (216) may be connected in series with the second constant current source (212). The second light emitting control switch (216) may be connected between the first node (N1) and the second constant current source (212).

[0125] The first light-emitting control switch (215) may be a selection switch for selecting the first constant current source (211). The first light-emitting control switch (215) may be a control switch for controlling the supply time (or duration) of the constant current, i.e., the light-emitting current, supplied to the light-emitting element connected to the first pad (140) for each frame.

[0126] The second light emission control switch (216) may be a selection switch for selecting the second constant current source (212). The second light emission control switch (216) may be a control switch for controlling the supply time (or duration) of the constant current, i.e., the light emission current, supplied to the light emission element connected to the first pad (140) for each frame.

[0127] The first light-emitting control switch (215) may include an NMOS transistor (T7), and the second light-emitting control switch (216) may include a PMOS transistor (T8), but the opposite may also be possible.

[0128] As illustrated in Fig. 15, in the first switching mode, the first pad (140) can be connected to the first node (N1) by the first mode switching switch (120), and the second pad (150) can be connected to the second node (N2) by the second mode switching switch (130). In addition, the first constant current source (211) can be selected as the first light-emitting control switch (215) is turned on. Accordingly, a display device having a common anode structure in which the light-emitting circuit (110) is connected to the cathode (162) of the light-emitting element (160) through the first pad (140) and to the second power line (172) through the second pad (150) can be configured. In the display device having the common anode structure, the supply time of the constant current of the first constant current source (211), i.e., the light-emitting current, can be controlled by the first light-emitting control switch (215). For example, the first light-emitting control switch (215) can be kept turned on during the on-period (or light-emitting period) of one frame determined using digital data and a program signal. Accordingly, light-emitting current is supplied to the light-emitting element (160) connected to the first pad (140), so that light emission of the light-emitting element (160) can be maintained during the on-period of one frame. This operation is repeated for each frame, so that an image can be displayed.

[0129] As illustrated in Fig. 16, in the second switching mode, the first pad (140) can be connected to the second node (N2) by the first mode switching switch (120), and the second pad (150) can be connected to the first node (N1) by the second mode switching switch (130). In addition, the second constant current source (212) can be selected as the second light-emitting control switch (216) is turned on. Accordingly, a display device having a common cathode structure in which the light-emitting circuit (110) is connected to the anode (161) of the light-emitting element (160) through the first pad (140) and to the first power line (171) through the second pad (150) can be configured. In the display device having the common cathode structure, the supply time of the constant current of the second constant current source (212), i.e., the light-emitting current, can be controlled by the second light-emitting control switch (216). In each frame, the first light-emitting control switch (215) is kept turned on during the entire period, so that light-emitting current is supplied to the light-emitting element (160) connected to the first pad (140), so that light-emitting of the light-emitting element is maintained during the entire period of each frame, so that an image can be displayed.

[0130] Therefore, according to the fifth embodiment, even if a plurality of light-emitting elements arranged on a substrate are connected with a common anode structure or a common cathode structure, the driving IC (105) can be universally applied to a common anode structure and a common cathode structure by switching the connection of the light-emitting circuits to match the structure.

[0131] In addition, according to the fifth embodiment, since each of the first light-emitting control switch (215) and the second light-emitting control switch (216) performs both a selection function and a light-emitting maintenance function, the circuit structure can be simplified and the area can be reduced. In addition, since the first light-emitting control switch (215) and the second light-emitting control switch (216) of the fourth embodiment are omitted in the fifth embodiment, the IR drop due to each of the first light-emitting control switch (215) and the second light-emitting control switch (216) of the fourth embodiment does not occur, so that malfunction due to signal delay or poor picture quality can be prevented.

[0132] Fig. 17 is a circuit diagram illustrating a driving IC according to the sixth embodiment.

[0133] The sixth embodiment is identical to the fourth embodiment (Fig. 11) except for the third power line (173), the measurement line (175), and the plurality of control switches (231, 232, 241, 242). In the sixth embodiment, the same components as in the fourth embodiment (Fig. 11) are given the same drawing reference numerals, and detailed descriptions are omitted.

[0134] Referring to FIG. 17, the driving IC (106) according to the sixth embodiment may include a first constant current source (211), a second constant current source (212), a first selection switch (213), a second selection switch (214), a first light-emitting control switch (221), a second light-emitting control switch (222), a plurality of control switches (231, 232, 241, 242), etc.

[0135] The first control switch (231) can be connected between the first node (N1) and the first light-emitting control switch (221), and the second control switch (232) can be connected between the third power line (173) and the first light-emitting control switch (221).

[0136] A third power supply voltage (PVDD) may be supplied to a third power supply line (173). The third power supply voltage (PVDD) is a high-potential voltage and may be similar to the first power supply voltage (EVDD). For example, the third power supply voltage (PVDD) may be lower than the first power supply voltage (EVDD) but higher than the second power supply voltage (EVSS), but is not limited thereto.

[0137] The first control switch (231) and the second control switch (232) may include PMOS transistors (T11, T12), but the opposite may also be possible.

[0138] The third control switch (241) can be connected between the second light-emitting control switch (222) and the second node (N2), and the fourth control switch (242) can be connected between the second light-emitting control switch (222) and the measurement line (175).

[0139] In an embodiment, a constant current, i.e., a luminous current, of a first constant current source (211) or a second constant current source (212) can be measured through a measurement line (175). In an embodiment, a non-luminous current can be measured through a measurement line (175). The non-luminous current can be a current generated by a third power supply voltage (PVDD).

[0140] The third control switch (241) and the fourth control switch (242) may include NMOS transistors (T13, T14), but the opposite may also be possible.

[0141] In an embodiment, it can be operated in a luminous current measurement mode when luminous and a non-luminous current measurement mode when not luminous.

[0142] In the luminescence current measurement mode during luminescence, the first control switch (231) and the fourth control switch (242) may be turned on, and the second control switch (232) and the third control switch (241) may be turned off. In this case, the constant current of the first constant current source (211) or the second constant current source (212), i.e., the luminescence current, may be supplied to the luminescence element connected to the first pad (140) to emit light, while being measured through the measurement line (175).

[0143] In the non-luminescent current measurement mode in the non-luminescent state, the second control switch (232) and the fourth control switch (242) may be turned on, and the first control switch (231) and the third control switch (241) may be turned off. In this case, the luminescent current of the first constant current source (211) or the second constant current source (212) is not supplied to the luminescent element connected to the first pad (140), so that the luminescent element does not emit light. A non-luminescent current may be generated from the first constant current source (211) or the second constant current source (212) by the third power supply voltage (PVDD). The non-luminescent current may be measured through the measurement line (175).

[0144] As illustrated in FIG. 18, a display device having a common anode structure can be configured in response to the operation of the first mode switching switch (120) and the second mode switching switch (130) in the first switching mode.

[0145] As illustrated in FIG. 19, a display device having a common cathode structure can be configured in response to the operation of the first mode switching switch (120) and the second mode switching switch (130) in the second switching mode.

[0146] Fig. 20 is a circuit diagram illustrating a driving IC according to the seventh embodiment.

[0147] The seventh embodiment is similar to the sixth embodiment (Fig. 17) except for the first light-emitting control switch (215) and the second light-emitting control switch (216). In the seventh embodiment, the same components as in the sixth embodiment (Fig. 17) are given the same drawing reference numerals, and detailed descriptions are omitted.

[0148] Referring to FIG. 20, a driving IC (107) according to the seventh embodiment may include a first constant current source (211), a second constant current source (212), a first light-emitting control switch (215), a second light-emitting control switch (216), a plurality of control switches (231, 232, 241, 242), etc.

[0149] The first light-emitting control switch (215) and the second light-emitting control switch (216) are the same as the first light-emitting control switch (215) and the second light-emitting switch in the fifth embodiment (Fig. 14), so detailed descriptions are omitted.

[0150] As illustrated in Fig. 21, a display device having a common anode structure can be configured in response to the operation of the first mode switching switch (120) and the second mode switching switch (130) in the first switching mode.

[0151] As illustrated in FIG. 22, a display device having a common cathode structure can be configured in response to the operation of the first mode switching switch (120) and the second mode switching switch (130) in the second switching mode.

[0152] Fig. 23 is a circuit diagram illustrating a driving IC according to the eighth embodiment.

[0153] The eighth embodiment is identical to the seventh embodiment (Fig. 20) except for the OR gate (251) and the AND gate (252). In the eighth embodiment, the same components as in the seventh embodiment (Fig. 20) are given the same drawing reference numerals, and detailed descriptions are omitted. The OR gate (251) and the AND gate (252) can also be applied to the fifth embodiment (Fig. 14).

[0154] Referring to FIG. 23, a driving IC (108) according to the eighth embodiment may include a first constant current source (211), a second constant current source (212), a first light-emitting control switch (215), a second light-emitting control switch (216), a plurality of control switches (231, 232, 241, 242), an OR gate (251), an AND gate (252), etc.

[0155] The OR gate (251) may be connected to the gate of the first light-emitting control switch (215), and the AND gate (252) may be connected to the gate of the second light-emitting control switch (216). In this case, the turn-on / off of the first light-emitting control switch (215) may be controlled by the first output signal of the OR gate (251), and the turn-on / off of the second light-emitting control switch (216) may be controlled by the second output signal of the AND gate (252).

[0156] The OR gate (251) can perform an OR gate operation on the first control signal (S51) and the second control signal (S81) and output a first output signal to the gate of the first light-emitting control switch (215). The AND gate (252) can perform an AND gate operation on the first control signal (S51) and the third control signal (S82) and output a second output signal to the gate of the second light-emitting control switch (216).

[0157] When the first light-emitting control switch (215) is a PMOS transistor (T5), the first light-emitting control switch (215) can be turned on in response to a first output signal having a low level. When the first control signal (S51) and the second control signal (S81) each have a low level, the OR gate (251) can output a first output signal having a low level to the gate of the first light-emitting control switch (215).

[0158] When the second light emission control switch (216) is an NMOS transistor (T6), the second light emission control switch (216) can be turned on in response to a second output signal having a high level. When the first control signal (S51) and the third control signal (S82) each have a high level, the AND gate (252) can output a second output signal having a high level to the gate of the second light emission control switch (216).

[0159] The above detailed description should not be construed as limiting in any respect and should be considered illustrative only. The scope of the embodiments should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalency range of the embodiments are intended to be included within the scope of the embodiments.

Claims

1. A light-emitting circuit connected between the first node and the second node; A first mode switching switch that selectively connects the first pad to the first node or the second node depending on the switching mode; and A second mode switching switch selectively connecting a second pad to the first node or the second node according to the switching mode; The above first pad is electrically connected to one of the anode and cathode of the light emitting element according to the above switching mode, The second pad is connected to one of the first power line and the second power line depending on the switching mode, The first power line has a first power voltage greater than a second power voltage of the second power line, Drive IC.

2. In paragraph 1, The above switching mode includes a first switching mode for a common anode structure and a second switching mode for a common cathode structure, In the first switching mode, the first pad is connected to the first node by the first mode switching switch, and the second pad is connected to the second node by the second mode switching switch. The first pad is connected to the cathode of the light emitting element and the second pad is connected to the second power line. Drive IC.

3. In paragraph 2, In the second switching mode, the first pad is connected to the second node by the first mode switching switch, and the second pad is connected to the first node by the second mode switching switch. The first pad is connected to the anode of the light emitting element and the second pad is connected to the first power line. Drive IC.

4. In paragraph 1, The above light emitting circuit, A constant current source between the first node and the second node; A first light-emitting control switch between the first node and the constant current source; a second light-emitting control switch between the constant current source and the second node; Drive IC.

5. In paragraph 1, The above light emitting circuit, A first constant current source between the first node and the second node; A first constant current switch connected in series with the first constant current source; A first light emitting control switch between the first node and the first constant current switch; A second constant current source connected in parallel with the first constant current source between the first node and the second node; A second constant current switch connected in series with the second constant current source; and a second light emitting control switch between the second constant current switch and the second node; Drive IC.

6. In paragraph 5, The first constant current switch and the second constant current switch include transistors of the same type and are individually turned on in response to a first control signal and a second control signal. Drive IC.

7. In paragraph 5, The first constant current switch and the second constant current switch include different types of transistors and are complementarily turned on in response to the same control signal. Drive IC.

8. In paragraph 1, The above light emitting circuit, A first constant current source between the first node and the second node; A first light-emitting control switch connected in series with the first constant current source; A second constant current source connected in parallel with the first constant current source between the first node and the second node; and A second light-emitting control switch connected in series with the second constant current source; Drive IC.

9. In paragraph 8, The above first light-emitting control switch includes a PMOS transistor, The above second light-emitting control switch includes an NMOS transistor, An OR gate connected to the gate of the PMOS transistor; and Further comprising an AND gate connected to the gate of the NMOS transistor; Drive IC.

10. In paragraph 1, further comprising a measuring line connected to the above light emitting circuit; Drive IC.

11. In paragraph 1, The first mode switching switch and the second mode switching switch include transmission gates or pass transistors. Drive IC.

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