KR20110001902A - Display device - Google Patents

Abstract

PURPOSE: A display device is provided to implement low power consumption of a multicolor display by reducing power consumption. CONSTITUTION: A driving IC part(10) outputs a driving signal and compensated video data. A panel portion(20) reads the driving signal and the compensated video data. The panel displays a certain color. A display switch controller outputs a single color mode signal.

Description

Display device

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a display device that realizes multicolor display by using color display and a desired single color display. In particular, the present invention provides low power consumption by preventing video data from being transmitted in a panel when a desired single color display is performed. The present invention relates to a display device capable of realizing this.

The long life of battery operation time of mobile devices such as mobile phones and cameras is very important in terms of extending the use period and effectively utilizing energy. In general, a display panel (display device) is used for such a portable device, and inevitably, the power consumption of the display panel needs to be reduced.

In particular, there is an OLED display as a display device having various good features required for a portable device such as a thin film, contrast, and video characteristics.

Fig. 14 is an explanatory diagram showing a display method of a conventional OLED display device. Fig. 14A shows a drive circuit for a data line, and Fig. 14B shows a drive waveform when a normal color display is performed.

In Fig. 14, each pixel is composed of three sub pixels R, G, and B. The data line driver is controlled by the Mux signals corresponding to R, G, and B, and video data corresponding to R, G, and B is input to each data line. In addition, the subpixels R, G, and B are displayed in accordance with the signal of each data line at an appropriate timing by the gate line signal.

In order to realize low power consumption in an OLED display device having such a configuration, the following are generally known as control methods (long life of batteries).

1) The luminance of emitted light is lowered after displaying for a certain time.

2) The display stops after the display for a certain time.

3) The ambient light is detected to set the appropriate luminance.

4) The maximum current consumption is set, and when exceeded, the brightness is automatically lowered to reset the brightness.

5) Change the power supply voltage for each light color and set the power supply value (VDD or CV) while ensuring an appropriate margin.

6) In the test screen, display data is inverted.

7) All displays shall be black and white.

8) Reduce the amplitude of the control signal (level shift (L / S) is built into the panel, and low amplitude driving is performed until the value of L / S).

9) Operate the drive circuit concisely.

10) The subpixel is used for four colors (RGBW), and the driving by the W component is increased.

11) Achieves high efficiency of OLED materials.

12) The light extraction efficiency can be improved by optimizing the OLED device structure or by optimizing the optical material and structure.

However, the OLED display according to the prior art has the following problems.

That is, recently, display devices used for portable devices require lower power consumption and improved video characteristics.

In a conventional display device, a video signal is inputted from an external driving IC and controlled so as to have a luminance corresponding to the signal. Therefore, the increase in power consumption of the external driving IC is caused by an increase in load between the external driving IC and the display panel or an increase in driving frequency.

On the other hand, there is a technique of inserting single video data such as a black image to achieve the improvement of video characteristics. However, in the conventional display device, even in the case of a single display such as a black image, the color signal is inputted and displayed as a video signal from an external driving IC. Therefore, it is urgent to achieve a low power consumption in consideration of displaying a combination of normal color display and a desired single color display in combination.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to provide a display device capable of realizing multi-color display low power consumption using a combination of normal color display and a desired single color display.

The display device according to the present invention for achieving the above object is a drive for performing correction operation for display on the video data to generate the corrected video data, and output the drive signal required for display and the corrected video data. An IC unit and the drive signal generated by the driver IC unit and the corrected video data are read, and the corrected video data corresponding to the data line is supplied to each data line connected to a plurality of sub-pixels. A display device having a panel portion for performing a desired color display, the display device comprising: a display switching control unit for outputting a single color display mode signal when switching from color display to single color display, wherein the driving IC unit outputs the single color display mode signal; If received, the correction operation and the video after correction When the data output process is stopped or in a standby state, and when the monochromatic mode signal is received, it is desired that the panel supply a specific voltage necessary for performing the monochromatic display to the data line instead of the corrected video data. To display a single color.

According to the display device according to the present invention, when switching to the mode for the desired single color display, the panel has a configuration that does not need to transmit video data. Thus, the power consumption in the driving IC unit is reduced. A display device capable of realizing low power consumption of multicolor display using color display and a desired single color display in combination can be obtained.

1 is a view showing an example of black image display applied to a general display device;
2 is a diagram illustrating an example of black image display applied to a general display device;
3 is an overall configuration diagram of an OLED display according to Embodiment 1 of the present invention.
4 is an overall configuration diagram of an OLED display according to Embodiment 1 of the present invention.
5 is an explanatory diagram of a display method when a mode of an OLED display device according to Embodiment 1 of the present invention is switched;
6 is an explanatory diagram of a display method when black data is displayed in one screen mode of an OLED display according to Embodiment 1 of the present invention;
7 is an explanatory diagram of a display method of an OLED display device according to a second embodiment of the present invention;
8 is a diagram showing another configuration example of a light emitting stop circuit applicable to an OLED display device according to Embodiment 2 of the present invention.
9 is an explanatory diagram of a display method of an OLED display device according to Embodiment 3 of the present invention.
10 is an overall configuration diagram of an OLED display according to Embodiment 3 of the present invention.
11 is an explanatory diagram of a display method of an OLED display device according to Embodiment 4 of the present invention.
12 is a diagram showing an example of colors that can be displayed by the display device according to Embodiment 4 of the present invention.
13 is an overall configuration diagram of an OLED display according to Embodiment 4 of the present invention.
14 is an explanatory diagram of a display method of a conventional OLED display device;

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of the display apparatus which concerns on this invention is described with reference to drawings.

In the present invention, the display device is capable of displaying a desired single color without transmitting a single video signal from an external driver IC, achieving excellent display performance for video characteristics, and realizing low power consumption.

Before describing the detailed embodiment, the outline of the functions and effects of the display device in the present invention will first be described.

1 and 2 illustrate an example of black image display applied to a general display device. FIG. 1A illustrates a state in which black lines are inserted into upper and lower portions to change aspect ratios of a screen. 1B has shown the state which displayed the background color switching from white to black. Moreover, FIG. 2 shows a state in which a black image is inserted every frame as one of the improvement of the moving picture characteristic.

The present invention is effective when the monochromatic data to be written is at least one vertical line unit or more, and is a technique capable of achieving low power consumption for the display as shown in Figs. 1 and 2. For example, as shown in Fig. 2, when the black image is inserted to improve the video characteristic, the operating frequency necessarily increases, and power consumption increases. On the other hand, by applying the display device in the present invention, the power consumption can be reduced.

In the present invention, the display device performs any one of the following four functions, or a combination of functions 1, 2, and 4, or a combination of functions 1, 3, and 4, thereby enabling low power consumption.

In addition, in the following description, there is no normal color display, and the thing of the mode which performs the desired single color display in order to implement | achieve the low power consumption which is the characteristic of this invention is called "multi-color mode."

Function 1: New addition of a signal indicating whether or not the same data transmission (one line, one pixel, etc.), that is, an MCM (Multi Color Mode) signal corresponding to a multi-color mode selection signal.

Function 2: Add multi-color data transmission circuits to data lines in the panel.

Function 3: Added the function to stop light emission for pixel circuit and vertical driving circuit.

Function 4: While the video signal does not need to be transmitted, the function to stop operation of the internal circuit of the driver IC is added.

Having the above-described function, the display device of the present invention can realize driving capable of suppressing the operating power of the driving IC in the case of displaying one or more lines of single color. In addition, by changing the number or potential of the input video signal, multicolor display such as black, white, gray, and monochrome can be realized while suppressing the operation of the driving IC.

In particular, it is effective to reduce the power consumption of the display device consisting of LCD and OLED when driving black image insertion to improve the video characteristics. Therefore, the display device of this invention is demonstrated concretely by following Embodiment 1-4.

In addition, description of the following specific example is demonstrated centering on the case where OLED display apparatus is used as an example of a display apparatus. However, the present invention is also applicable to display devices other than OLEDs.

Embodiment 1

In the first embodiment, a display device that realizes low power consumption by a combination of the above-described functions 1, 2, and 4 will be described in detail.

3 is an overall configuration diagram of an OLED display according to Embodiment 1 of the present invention, and is composed of a driving IC 10 and a panel 20. The configuration IC 10 includes a gamma correction circuit 11, a memory 12, a logic circuit 13, a driver 14, and a DAC 15. In addition, the internal structure of the panel 20 is mentioned later using FIGS. On the other hand, although the MCM signal corresponding to the selection signal of the multi-color mode is not shown, it is output from the display switching controller.

The power consumption of the OLED display device is divided into the power consumption in the driver IC 10 part and the power consumption in the panel 20 part, and it is effective to lower the power of both sides. In the panel 20 which performs OLED display, a video signal is normally input from the drive IC 10, and light is emitted according to the signal. Therefore, the reduction of the number of pixels contributing to light emission and the reduction of the number of video signals input from the driving IC 10 are effective for lowering power consumption.

Therefore, the invention according to the first embodiment proposes an OLED display device that adds a switching function to a multi-color mode and realizes low power consumption, for example, when a black image is inserted as a display mode. More specifically, in the first embodiment, in the sense that low power consumption is achieved by multi-color display, the following two points are used.

Point 1: Writing black data (i.e., data in which the OLED does not emit light) to the data line of each sub-pixel by MCM signal meaning multi-color display.

Point 2: To stop the circuit operation (operation processing, video signal output processing, etc.) in the driving IC for all sub-pixels displaying black data by the MCM signal, which means multi-color display.

By inserting the black image in this way, it is possible to achieve low power consumption while improving the moving picture characteristics. On the other hand, the potential supplied to the panel 20, which will be described later, is set to an appropriate value so that a single color display other than black is possible (see Embodiment 3), and full color display is also possible (see Embodiment 4).

 The driver IC 10 stops the calculation performed between the logic circuit 13 and the memory 12 when the MCM signal, which means black data transfer, is generated. In addition, the driver IC 10 sends a drive signal (CLK, X, Y drive signal, Mux signal, MCM signal) or video signal (video data) necessary for the MCM from the driver 14 or the DAC 15 to the panel 20. send.

In the logic circuit 13, arithmetic processing is performed on the video data R, G, and B for various corrections. On the other hand, in the MCM, calculation of the input RGB data is stopped, and the amount of calculation is almost zero. In addition, the data between the memory 12 also has no input.

The driver 14 also outputs a signal for writing video data of three colors. However, in the MCM, only signals necessary for writing black data are output to the pixels of the panel 20.

In addition, the video data of three colors is output from the DAC 15. However, in the MCM, it is set to a state in which power consumption is strongly suppressed (for example, a standby state). In the case where the pixels on the panel 20 side are not RGB but also RGBW, the low power consumption is achieved by setting them to the stopped or standby state in the same manner.

FIG. 4 is an explanatory view of a display method of an OLED display according to Embodiment 1 of the present invention, where FIG. 4A shows a driving circuit of a data line, and FIG. 4B shows respective waveforms during MCM. The specific configuration is the same as that of the conventional OLED display shown in FIG. 4 illustrates the case of displaying black data. That is, the circuit (black data transfer circuit) which transfers black data to the data line in a panel by the function 2 mentioned above is illustrated.

A circuit composed of the MCM signal of FIG. 4, a transistor which is a multi-color-SW (MSW), and a power supply line connected to each of the subpixels R, G, and B corresponds to a black data transfer circuit. Since the conduction type of the OLED driving TFT in the pixel is a p-channel transistor, the black data is at the VDD potential of "H".

This black data is determined either by "H" or "L" by the pixel circuit configuration. The MCM signal is activated when the pixel data of all one vertical line is black (not emitting). In the case of Fig. 4, it is activated by "L" from the point of logic operation, but it may be activated by "H" in the circuit structure.

Next, the specific operation of the circuit shown in FIG. 4 will be described. At the time of MCM (that is, when the MCM signal is "L"), it operates as follows.

Operation 1: The Mux signal is fixed to " H " to stop the operation of the RGB data line driving transistor (corresponding to the data line driver in Fig. 4).

Operation 2: On the other hand, MSW is turned on, and " H " data is input from the VDD line to the RGB data line.

Operation 3: When the gate line is activated, " H " data is transmitted to each of the sub pixels R, G, and B. As a result, the driving transistor of the pixel is turned OFF, light emission is stopped, and black data is displayed.

On the other hand, the video data of RGB in the operation | movement at the time of MCM mentioned above is "Dont't care", and it is not necessary to drive by a drive IC. As a result, the power consumption of the driver IC can be reduced, resulting in lower power consumption.

Next, the case where normal color display and the display by the "multi-color mode" of this invention mix is demonstrated based on drawing. 5 is an explanatory diagram of a display method at the time of mode switching of the OLED display according to the first embodiment of the present invention. More specifically, when all pixel data of only the gate line n is a "multi-color mode" displaying black data, the front and rear gate lines n-1 and n + 1 are modes of displaying normal video data. The waveform of each signal is shown. When the MCM signal is activated ("L"), the Mux signal and each data line R, G, and B become "H".

On the other hand, generation of the MCM signal is not limited to one vertical line. Even when the plurality of vertical lines or one screen is black data, the switching operation can be applied similarly to FIG. 5.

FIG. 6 is an explanatory diagram of a display method when black data is displayed on all one screen of an OLED display according to Embodiment 1 of the present invention. FIG. In this case, the MCM signal is set to output the data corresponding to one screen of data. On the other hand, if the MCM signal is generated for each vertical line, the MCM signal operates as many as the vertical lines. Therefore, from the viewpoint of low power consumption, it is preferable to generate the MCM signal only once for one screen of data.

The timing of generation of the MCM signal can be set at a timing synchronized with the basic clock (CKV) of the vertical scanning system (V system) for each line, and the start signal (VST) of the vertical scanning system driving circuit for each screen. The timing is synchronized with ().

As mentioned above, according to Embodiment 1, it has a function to switch from normal color display to display by a "multi-color mode" based on the MCM signal which generate | occur | produces at the timing to perform monochrome display.

When displaying the "multi-color mode" by this function, it is not necessary to transfer video data from the driver IC to the panel. As a result, the processing operation in the driver IC can be made small or in a standby state, and the power consumption of the driver IC can be reduced, and the power consumption can be reduced when displaying a mixture of specific monochrome colors.

Recently, a driving method for inserting " black data " for each screen or in the form of a band has been developed for the purpose of improving the video characteristics for TV. On the other hand, switching to the "multi-color mode" according to the present invention can be suppressed for each line, so that delicate power consumption management can be performed.

In the case where the black data is used abundantly for such a purpose, the invention according to the present embodiment is particularly effective, and the moving picture characteristics can be improved and the power consumption can be reduced. In the display device which tends to be high resolution and large in size, the output load of the DAC circuit becomes large, but the effect of the present invention becomes larger as the load becomes larger.

Embodiment 2

In the second embodiment, a display device that realizes low power consumption by the combination of the functions 1, 3, and 4 described above will be described in detail.

7 is an explanatory view of a display method of an OLED display according to a second embodiment of the present invention. The display device according to the second embodiment is characterized in that the light emitting stop circuit is provided in the pixel circuit and the vertical driving circuit.

In order to realize this "light emitting stop circuit", it is essential to provide the following two structures in circuit design.

Essential configuration 1: The pixel circuit is designed to receive a signal (light emission stop signal) and stop light emission.

Essential configuration 2: The vertical scan driving circuit has a function of driving a light emission stop signal.

First, the essential structure 1 is demonstrated. The pixel circuit of FIG. 7 includes a selection transistor Tr1, a driving transistor Tr2, and a light emission stopping transistor Tr3. The light emission stop transistor Tr3 receives the light emission stop signal and stops light emission. In FIG. 7, the light emitting stop transistor Tr3 is disposed in series in a path through which the light emitting current id flows. In such a configuration, when the light emission stop transistor Tr3 is turned off in response to a light emission stop signal from the outside, light emission can be stopped and black data can be displayed.

Fig. 8 is a diagram showing another example of the configuration of the light emitting stop circuit applicable to the OLED display according to the second embodiment. In FIG. 8, the light emission stop transistor Tr3 is arrange | positioned in the position which turns off the drive transistor Tr2 by making the gate potential of the drive transistor Tr2 into "H". In addition, such a control method may be applied to a pixel circuit for compensating the threshold voltage value of the TFT.

Next, the essential structure 2 is demonstrated. In the configuration of FIG. 7, when the MCM signal is activated to write black data, the operation of the gate driving circuit (corresponding to the gate driver of FIG. 7) is stopped, and the emission stop signal driving circuit (the emission OFF driver of FIG. 7) is stopped. Enable). The light emission stop transistor Tr3 is turned OFF by the light emission stop signal driver circuit transmitting the "H" signal.

On the other hand, the light emission stop signal driving circuit is activated by at least the signal from the shift register and the MCM signal for writing black data.

As described above, according to Embodiment 2, in order to switch from the normal color display to the display in the "multi-color mode" based on the MCM signal generated at the timing at which the monochrome display is to be performed, It is. With such a configuration, black data can be displayed by stopping light emission, and the same effect as in the first embodiment can be obtained.

Embodiment 3

In Embodiment 1 and 2, the case where black data is displayed as a single color display was demonstrated. On the other hand, in the third embodiment, a case is described in which a shade is enabled by a desired gradation from white to black by setting the voltage value applied in the "multi-color mode" to an appropriate value.

9 is an explanatory view of a display method of an OLED display according to Embodiment 3 of the present invention. The display device according to the third embodiment is characterized in that the source potential of the MSW is connected to a potential (Vmcm) different from that of VDD.

In Embodiment 1, the source potential of MSW is connected to the VDD potential, and the display is limited to black data only in the "multi-color mode". On the other hand, in the third embodiment, the potential Vmcm formed differently from VDD is used. In the "multi-color mode", each gray scale can be displayed from white data to dyed black data. In each gradation from white to black, when one line wants to display the same data, it is possible to reduce the power consumption by applying the present invention.

10 is an overall configuration diagram of an OLED display according to Embodiment 3 of the present invention. Compared with the structure of FIG. 3 explained in Embodiment 1, the structure of FIG. 10 differs in that the potential generator 16 is further provided in the drive IC 10 in the third embodiment.

This potential generator 16 is connected to the MCM signal similarly to the logic circuit 13 and the DAC 15. Furthermore, the potential generator 16 is also connected to a VMCM signal corresponding to the potential of the desired single color display. As a result, the potential generator 16 receives the MCM signal and the VMCM signal, so that the potential Vmcm corresponding to the desired shade of color can be supplied to the panel 20 in the "multi-color mode". do.

As described above, according to the third embodiment, it is further provided with a potential generator for generating a potential corresponding to the desired shade of color when displaying in the "multi-color mode". Thereby, while the same effect as Embodiment 1, 2 is acquired, it becomes possible to set single color to any desired gradation color from white to black in "multi-color mode."

Embodiment 4

In Embodiment 3, the case where the color tone of the desired gradation is performed from white to black in the "multi-color mode" has been described. On the other hand, the fourth embodiment describes a case in which desired full color display is enabled by individually setting the voltage values applied in the "multi-color mode" to R, G, and B when setting them to appropriate values.

11 is an explanatory diagram of a display method of an OLED display according to a fourth embodiment of the present invention. The display device according to the fourth embodiment is characterized in that the source potential of each MSW corresponding to R, G, and B is individually connected to three kinds of potentials Vmcmr, Vmcmg, and Vmcmb different from VDD.

In Embodiment 3, the potential (Vmcm) formed in common for each sub-pixel of R, G, and B is used, and each gray scale display from white data to dyed black data is possible in the "multi color mode". Let it go. On the contrary, in the fourth embodiment, the potentials Vmcmr, Vmcmg, and Vmcmb that are formed differently from VDD and individually formed for each of the sub-pixels of R, G, and B are used. It is possible to display in full color simple color (raster).

As a result, when there is a display of the same color, the display of simple color (raster) of black, pure color (red, green, blue) and mixed color full color from the external IC is suppressed from the white while suppressing power consumption of the external IC. Display data can be transmitted.

12 is a diagram showing an example of colors that can be displayed in the display device according to Embodiment 4 of the present invention. In other words, by contributing an appropriate combination of potentials to Vmcmr, Vmcmg, and Vmcmb, it indicates that a desired color can be displayed in the full color. In this manner, although it is a single color, full color display is also possible.

13 is an overall configuration diagram of an OLED display according to the fourth embodiment. Compared with the configuration of FIG. 10 described in Embodiment 3, the configuration of FIG. 13 to Embodiment 4 includes a potential generator 16a capable of generating individual potentials corresponding to each subpixel of R, G, and B. (16) The points provided instead of them are different.

This potential generator 16a is connected to the MCM signal similarly to the logic circuit 13 and the DAC 15. Furthermore, the potential generator 16a is also connected to three kinds of VMCM signals (VMCMR signal, VMCMG signal, VMCMB signal) corresponding to the potential of the desired display color of each sub-pixel. As a result, the potential generator 16a receives the MCM signal and the three kinds of VMCM signals, and in the "multi-color mode", the potentials Vmcmr, Vmcmg, and Vmcmb corresponding to the desired raster display color are supplied to the panel 920. It becomes possible to supply with respect to.

As mentioned above, according to Embodiment 4, when displaying by a "multi-color mode", it becomes the structure further provided with the potential generator which produces the electric potential corresponding to a desired raster display color. As a result, the same effects as those in the third embodiment can be obtained, and the display color can be set to any of the full color display colors in the "multi-color mode". For example, it can provide an option to change the background color to the user's favor with low power consumption in the frame or text mode.

10: drive IC (drive IC section) 11: gamma correction circuit
12 memory 13 logic circuit
14 driver 15 DAC
16,16a: potential generator 20: panel (panel portion)

Claims (8)

A drive IC unit for performing correction operation for display on the video data to generate corrected video data, and outputting a drive signal for display and the corrected video data; and the drive signal generated by the drive IC unit. And a panel unit for reading the corrected video data, supplying the corrected video data corresponding to the data line to each data line connected to a plurality of sub-pixels, and displaying a desired color. ,
And a display switching control unit for outputting a single color display mode signal when switching from color display to single color display.
When the driving IC unit receives the monochromatic display mode signal, the driver IC unit stops or executes the correction operation processing and the video data output processing after the correction.
And when the monochromatic mode signal is received, the panel unit displays the desired monochromatic color by supplying the data line with a specific voltage necessary to perform the monochromatic display instead of the corrected video data. Device. The method of claim 1,
And the panel unit displays black when the single color display mode signal is received, by supplying a potential supplied from a DC power supply line to the data line as the specific voltage. The method of claim 1,
When the panel unit receives the single color display mode signal, the panel unit turns off the voltage supplied to each display element of the plurality of subpixels instead of supplying the specific voltage to the data line. And a light emission stop circuit for stopping the light emission of the element and displaying black color. The method of claim 1,
The driving IC unit further includes a potential generator for generating a specific potential corresponding to a desired single color display,
When the monochromatic display mode signal is received, the specific voltage generated by the potential generator is supplied to the panel portion instead of the video data necessary for performing the desired color display.
And the panel unit displays the desired monochromatic color by supplying the specific voltage read from the driver IC unit to the data line when the monochromatic display mode signal is received. The method of claim 1,
And the display switching control unit outputs the single color display mode signal in one vertical line unit or one screen unit. The method of claim 5, wherein
The display switching control unit outputs the single color display mode signal in one screen unit,
And the panel unit repeats the normal color display and the desired single color display on a screen basis in accordance with the state of the single color display mode signal. The monochromatic display as claimed in claim 1, wherein the driving IC unit generates a mux signal as one of the driving signals for driving control of a data line driver connected to a data line corresponding to each sub-pixel in the panel unit. Generates and outputs a mux signal that turns off the data line driver according to the mode signal.
The panel portion further has a single color display cutoff switch between each of the data lines connected to each subpixel and the potential supply line to supply the specific voltage.
And turning on the switch for switching the single color display in accordance with the single color display mode signal to display the desired single color by supplying the specific voltage from the potential supply line to the data line. The method of claim 1,
And the display device is an LEC display device or an OLED display device.

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