KR100732856B1 - Folder type light emitting display and driving method thereof - Google Patents

Abstract

SUMMARY OF THE INVENTION An object of the present invention is to provide a folding light emitting display device and a method of driving the same so that the screen of the flat panel display device is turned on when natural light is detected and natural light is sensed, so that it is light and easy to design.

According to the present invention, an upper folder having an image display device for displaying an image, a lower folder connected to the upper folder and a hinge, and formed on a surface where the upper folder and the lower folder are in contact with each other are one of the upper folder and the lower folder. An optical sensing unit configured to sense light according to opening and closing of the upper folder and the lower folder, and output a detection signal according to the amount of light; a light emission time and non-emission of the image display device in response to the detection signal Foldable light emitting display device including a control unit for adjusting the ratio of time, a power supply unit for outputting the power to drive the image display device, and a switching unit to block the output of the power supply unit if the detection signal is greater than a predetermined size and its driving To provide a way.

Hinge, light sensing, switching, display

Description

Foldable light emitting display device and its driving method {FOLDER TYPE LIGHT EMITTING DISPLAY AND DRIVING METHOD THEREOF}

1 is a view showing a mobile phone using a foldable light emitting display device that automatically performs the on-off operation according to the prior art.

2 is a block diagram illustrating a structure of a foldable light emitting display device according to the present invention.

3 is a diagram illustrating a mobile phone employing the foldable light emitting display device shown in FIG. 2.

4 is a structural diagram illustrating a structure of a pixel unit employed in a foldable light emitting display device according to the present invention.

5 is a circuit diagram illustrating a first embodiment of a pixel employed in a foldable light emitting display device according to the present invention.

6 is a structural diagram showing an example of a control unit employed in the light emitting display device according to the present invention.

Fig. 7 is a circuit diagram showing a circuit for generating light emission control signals employed in the scan driver of the light emitting display device of the present invention.

8 is a diagram illustrating systems employing a foldable light emitting display device according to the present invention.

*** Explanation of symbols on main parts of drawings ***

1: upper folder 2: lower folder

3: hinge 100: image display device

200: light detecting unit 300: power supply unit

400: current-voltage converter 500: filter

SW: Switch ST: Switching Transistor

The present invention relates to a foldable light emitting display device and a driving method thereof. More specifically, the present invention relates to a foldable light emitting display that detects natural light and automatically turns on a light emitting display device according to a detected signal when the folded light emitting display device is unfolded. A display device and a driving method thereof.

 BACKGROUND ART A thin, lightweight flat panel display is used as a display device of a portable information terminal such as a personal computer, a cellular phone, a PDA, or a monitor of various information devices. Such flat panel displays include LCDs using liquid crystal panels, organic light emitting displays using organic light emitting diodes, and PDPs using plasma panels.

In such a flat panel display, a plurality of pixels are arranged on a substrate to form a display area, and a scan line and a data line are connected to each pixel to selectively apply a data signal to the pixel for display.

Among the current flat panel display devices, the light emitting display device has a response speed of about 30,000 times faster than the LCD device, and thus, it is easy to implement a video, emits light by itself, and has a high brightness and wide viewing angle. I am getting it.

 The light emitting display includes an organic light emitting display using an organic light emitting element and an inorganic light emitting display using an inorganic light emitting element. The organic light emitting diode is also referred to as an organic light emitting diode (OLED), and includes an anode, a cathode, and an organic light emitting layer disposed therebetween to emit light by a combination of electrons and holes. The inorganic light emitting device is also referred to as a light emitting diode (LED) and, unlike an organic light emitting diode, includes an inorganic light emitting layer, for example, a light emitting layer made of a PN bonded semiconductor.

 The mobile phone has a flat panel display and a button for displaying a screen, and has a constant length so that the handset and the handset of the mobile phone can be used in close proximity to the user's ear and mouth.

If the mobile phone is configured to be too long, it is inconvenient for the user to carry and has an upper folder including a handset and a lower folder including a handset so that the upper folder and the lower folder are coupled to the hinge so that the upper folder and the lower folder are combined. Foldable cell phones to open and close have emerged.

Such a folding mobile phone is provided with a flat panel display device on the side where the upper folder and the lower folder contact each other so that the flat panel display device is turned on or off depending on the state in which the upper and lower folders are opened and closed. Make it easier.

And, because of the convenience of folding, folding is applied to digital cameras, camcorders and the like, not limited to mobile phones.

The folding device should be provided with a device for automatically adjusting the on and off of the flat panel display by recognizing the opening and closing of the upper folder and the lower folder for ease of use.

1 is a view showing a mobile phone using a foldable light emitting display device that automatically performs the on-off operation according to the prior art. Referring to FIG. 1, the cellular phone includes an upper folder 10 and a lower folder 20. In addition, the magnetic material 30 is installed in the upper folder 10 to recognize whether the upper folder 10 and the lower folder 20 are opened or closed, and the magnetic material 30 when the magnetic material 30 approaches the lower folder 20. Magnetic force sensor 40 to detect the magnetic force of the) was installed. When the magnetic force sensor 40 detects the magnetic force from the magnetic body 30, the magnetic force sensor 40 cuts off the power of the flat panel display.

However, using the magnetic force sensor 30 to turn on and off the power of the flat panel display requires a magnetic body 20 having a sufficiently strong magnetic force corresponding to the magnetic force sensor 30 and the magnetic body 20. There is a problem that the weight and volume of the product is increased. In addition, the magnetic force of the magnetic body 20 is weakened over time, if the product is used for a long time there is a risk of malfunction due to the weakening of the magnetic force.

In addition, the magnetic body 30 and the magnetic force sensor 40 has to be correctly positioned at the symmetrical point to the correct operation has a problem that a lot of difficulties in the design and circuit design.

Therefore, the present invention was created to solve the problems of the prior art, an object of the present invention is to detect the natural light and when the natural light is detected, the screen of the flat panel display device is turned on and light and easy to fold light emitting design A display device and a driving method thereof are provided.

In order to achieve the above object, a first aspect of the present invention provides an upper folder including an image display device for displaying an image, a lower folder connected through a hinge with the upper folder, and a surface in contact with the upper folder and the lower folder. Is formed in one folder of the upper folder and the lower folder, the light sensing unit for detecting light in accordance with the opening and closing of the upper folder and the lower folder to output a detection signal according to the amount of light, in response to the detection signal A control unit for controlling the ratio of the light emission time and the non-emission time of the image display device, a power supply for outputting power for driving the image display device, and switching to block the output of the power supply unit if the detection signal is greater than a predetermined size It is to provide a folding light emitting display device including a portion.

According to a second aspect of the present invention, in the image display device including an upper folder and a lower folder coupled by a hinge, detecting a light according to opening and closing of the upper folder and the lower folder, and outputting a control signal and the control. According to a signal, a driving power of the image display device is cut off, and a method of driving a foldable light emitting display device comprising the step of adjusting a ratio between a light emission time and a non-light emission time of the image display device.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

2 is a block diagram illustrating a structure of a foldable light emitting display device according to the present invention. Referring to FIG. 2, the foldable light emitting display device includes an image display device 100, a light sensing unit 200, a power supply unit 300, a current-voltage conversion unit 400, a voltage limiting unit 500, and a filter ( 600), the switching transistor ST and the switch SW.

The image display apparatus 100 displays various images to provide various information to the user.

The photo detector 200 uses a photodiode as a means for outputting a plurality of control signals by sensing the light transmitted from the outside. When light enters the photodiode, current flows from the anode to the cathode, and the amount of current flowing varies according to the amount of light.

The power supply unit 300 outputs driving power of the image display apparatus 100 so that the image display apparatus 100 is driven. In addition, when the voltage is transmitted to the anode and the cathode of the photodiode by the power supply unit 300 and the light is irradiated to the photodiode, the current can flow by the photodiode, and is formed between the power supply unit 600 and the photodiode. The line resistance causes a voltage drop, causing current to flow.

The current-voltage converter 400 may use an amplifier as a means for receiving a current and outputting a voltage. The current-voltage converter 400 receives a current formed by the light sensing unit 200 and outputs a voltage corresponding to the magnitude of the current.
The voltage limiter 500 limits the maximum and minimum values of the voltage waveform output from the current-voltage converter 400 to shape the waveform.

The filter 600 is a means for passing a signal having a frequency band in a predetermined range and not passing a signal having a frequency band in the other range. The filter 600 is implemented as a low pass filter that does not pass high frequency components. . Therefore, the filter 600 blocks the high frequency components included in the voltage output from the voltage limiter 500.

The switching transistor ST is a means for generating a switching signal of the switch SW through a switching operation. The switching transistor ST receives a signal output from the filter 600 as a control signal and generates a switching signal. The switching transistor ST uses a Bipolar Junction Transistor (BJT). The switching transistor ST has a base connected to the output of the filter, a collector connected to a first power supply through a resistor, and an emitter connected to ground. The output terminal is connected to the collector. Therefore, the switching transistor ST is turned on or off according to the output signal of the filter input to the base. When the switching transistor ST is turned on, the ground voltage is applied to the output terminal of the switching transistor ST to provide a low signal. When the switching transistor ST is turned off and the switching transistor ST is turned off, the voltage of the first power supply is output to the output terminal by the resistor to output a high signal.

The switch SW is connected between the image display unit 100 and the power supply unit 300 to switch the connection between the image display unit 100 and the power supply unit 300 according to the output signal of the output terminal of the switching transistor ST to supply the power supply unit 300. ) To be supplied power or to cut off the power. That is, the switch SW receives a low signal or a high signal output from the switching transistor ST to perform a switching operation.

3 is a diagram illustrating a mobile phone employing the foldable light emitting display device shown in FIG. 2. Referring to FIG. 3, the mobile phone includes an upper folder 1 and a lower folder 2, and an image display device 100 is formed in the upper folder 1, and the lower folder 2 controls the mobile phone. A driving device for driving a mobile phone is formed including an operation button. The driving device may include an optical sensing unit 200, a power supply unit 300, a current-voltage conversion unit 400, a filter 500, a switching transistor ST, a switching unit SW, and the like.

In addition, the upper folder 1 and the lower folder 2 are coupled through the hinge 3, and light is input or blocked to the light sensing unit 200 by opening and closing the upper folder 1 and the lower folder 2. .

4 is a structural diagram illustrating a structure of a pixel unit employed in a foldable light emitting display device according to the present invention. Referring to FIG. 4, the image display unit 100 includes a pixel unit 110, a data driver 120, a scan driver 130, and a controller 140.

 In the pixel unit 110, a plurality of scan lines S1, S2,... Sn-1, Sn for transmitting scan signals in a row direction are arranged, and a plurality of data lines D1, D2 for transferring data signals in a column direction. ... Dm-1, Dm) are arranged and include a plurality of pixels 111 connected to the scan line and the data line to emit light. The pixel 111 includes a light emitting element and a pixel circuit. When the current flows from the first electrode to the second electrode, the light emitting element emits light according to the intensity of the current, and the pixel circuit is connected to the scan line and the data line to scan. By transmitting the data signal to the pixel circuit selected by the signal, the pixel circuit generates a current corresponding to the data signal so that the current flows through the light emitting element.

The data driver 120 is a means for transmitting a data signal to the pixel unit 110. The data driver 120 receives the video data, generates a data signal, transfers the data signal to the pixel unit 110, and receives the data signal. To generate a current corresponding to.

The scan driver 130 is a means for transmitting a scan signal and a light emission control signal to the pixel unit 110. The scan driver 130 sequentially transmits a scan signal and a light emission control signal to the pixels 111 positioned in each row. The pixel 111 to which the scan signal is transmitted generates a current by receiving a data signal and emits light by transferring a current to the light emitting device by a light emission control signal.

The controller 140 transmits the data driver 120, the data control signal DCS, the digital data signals D and DATA, and the scan control signal SCS to the scan driver 130. The scan driver 130 transmits the data signal and the scan signal, and controls the pixel unit 110 to emit light.

5 is a circuit diagram illustrating a first embodiment of a pixel employed in a foldable light emitting display device according to the present invention. Referring to FIG. 5, a pixel includes a pixel circuit including a light emitting device OLED, a first transistor M1, a second transistor M2, a third transistor M3, and a capacitor Cst. The scanning line Sn, the emission control line En, the data line Dm, and the power supply line ELVdd are connected to the pixel circuit. The scanning line Sn and the emission control line En are formed in the row direction, and the data line Dm and the power supply line ELVdd are formed in the column direction.

The first transistor M1 has a source connected to the power line ELVdd, a drain connected to the light emitting device OLED, and a gate connected to the first node A. Then, a current for emitting light is supplied to the light emitting device OLED by a signal input to the gate. The amount of current flowing from the source to the drain of the first transistor M1 is controlled by the data signal transmitted to the first node A through the second transistor M2.

The second transistor M2 has a source connected to the data line Dm, a drain connected to the first node A, a gate connected to the scan line Sn, and selectively receiving a data signal by the scan signal. To A).

The capacitor Cst has a first electrode connected to the source of the second transistor M2, and a second electrode connected to the first node A, between the source and the gate of the first transistor M1 by a data signal. Keep the voltage at

The third transistor M3 has a source connected to the drain of the first transistor M1, a drain connected to the light emitting device OLED, and a gate connected to the light emission control line En so as to be transferred through the light emission control line En. The current generated by the first transistor M1 is selectively transmitted to the light emitting device OLED in response to the light emission control signal.

Due to such a configuration, when the first transistor M1 is turned on by the scan signal applied to the gate of the second transistor M2, the capacitor Cst is charged with a voltage corresponding to the data signal, and the capacitor ( The voltage charged in Cst is applied to the gate electrode of the first transistor M1 so that the first transistor M1 flows a current corresponding to the data signal and is selectively emitted by the third transistor M3. Receives current and emits light.

At this time, the current flowing to the light emitting device OLED by the first transistor M1 is represented by Equation 1 below.

Where I _OLED is the current flowing through the light emitting device, Vgs is the voltage between the source and gate of the first transistor M1, Vth is the threshold voltage of the first transistor M1, ELVdd is the voltage of the first power supply, and Vdata is the data signal. The voltage β denotes a gain factor of the second transistor M2.

6 is a structural diagram showing an example of a control unit employed in the light emitting display device according to the present invention. Referring to FIG. 6, the controller 140 includes an A / D converter 141, a counter 142, and a conversion processor 142.

The A / D converter 141 converts the analog sense signal transmitted from the light sensing unit 200 into a digital sense signal in response to the ambient light and outputs the digital sense signal.

The counter 142 counts a predetermined number for a predetermined time by the vertical synchronization signal Vsync supplied from the outside and outputs a counting signal Cs corresponding thereto.

For example, in the case of the counter 142 referring to a binary value of 4 bits, the counter 142 is initialized to '0000' when the vertical synchronization signal Vsync is input, and then shifts the clock CLK signal in sequence. Count up to '1111'. When the vertical synchronization signal Vsync is input to the counter 142 again, it is initialized again. Accordingly, the counter 142 sequentially counts the numbers '0000' to '1111' during one frame period.

The conversion processor 143 compares the counting signal Cs output from the counter 142 with the detection signal output from the A / D converter 141 and outputs a second start pulse corresponding thereto. Referring to the operation of the conversion processor 143, for example, the detection signal output from the A / D converter 141 may be divided into four stages according to the brightness of the ambient light. The control signal having a value of '1000' is output at a stage where ambient light is the darkest, and the control signal having a value of '0110' is output at a stage where ambient light is somewhat dark. In addition, a control signal having a value of '0100' is output in a stage where ambient light is somewhat bright, and a control signal having a value of '0010' in a stage where ambient light is the brightest.

When the ambient light is the darkest, the counting signal is compared with the control signal of '1000'. The counting signal outputs a high start pulse when the counting signal is smaller than '1000', and the counting signal is low when the counting signal is larger than '1000'. Outputs the start pulse of the state. When the ambient light is somewhat dark, the counting signal is compared with the control signal of '0110', and the start pulse of the high state is output when the counting signal is smaller than '0110', and low when the counting signal is larger than '0110'. Outputs the start pulse of the state. When the ambient light is a little brighter, the counting signal is compared with the control signal of '0100'. The counting signal outputs a high start pulse when the counting signal is smaller than '0100', and the counting signal is low when the counting signal is larger than '0100'. Outputs the start pulse of the state. When the ambient light is the brightest, the counting signal is compared with the control signal with the value of '0010', and the start pulse of the high state is output in the section where the counting signal is smaller than '0010', and the low level when the counting signal is greater than '0010'. Outputs the start pulse of the state. The conversion processing unit 143 may operate in this manner to adjust the width of the start pulse according to the ambient light.

When the ambient light is very dark, the light emitting display device may not be used.

Fig. 7 is a circuit diagram showing a circuit for generating light emission control signals employed in the scan driver of the light emitting display device of the present invention. Referring to FIG. 7, the emission control signal generation circuit is a means for sequentially outputting the emission control signals E1, E2,... En and includes a plurality of flip-flops, and the signal output from the upper flip-flop The lower flip-flop is input and the lower flip-flop shifts and outputs the signal output from the upper flip-flop.

In more detail, the emission control signal circuit 60 includes a first flip-flop 61, a second flip-flop 62, a third flip-flop 63, and a fourth flip-flop 64.

The first flip-flop 61 receives the second start pulse SP2 signal and outputs the first output signal elsr0, and the first output signal elsr0 is input to the second flip-flop 62 and the second The flip-flop 62 outputs the second output signal elsr1. The first output signal elsr0 is outputted as the first light emission signal e0 through the first buffer 71 in which two inverters are connected in series.

The second output signal elsr1 output from the second flip-flop 62 is input to the third flip-flop 63, and the third flip-flop 63 outputs the third output signal elsr2. In addition, the second output signal elsr is output as the second emission signal e1 through the second buffer 72 in which two inverters are connected in series.

The third output signal elsr2 output from the third flip-flop 63 is input to the fourth flip-flop 64, and the fourth flip-flop 64 outputs the fourth output signal elsr3. The third output signal elsr2 is output as the third emission signal e2 through the third buffer 73 in which two NOT gates are connected in series.

The fourth output signal elsr3 passes through the fourth buffer 74 in which two NOT gates are connected in series, outputs the fourth emission signal e3, and is input to the pixel.

It can be seen that the emission control signal having the same width as the second start pulse is generated according to the input second start pulse through the operation of the generation circuit of the emission control signal described above. Therefore, the brightness of the light emitting display device can be controlled by adjusting the width of the second start pulse according to the ambient light.

8 is a diagram illustrating systems employing a foldable light emitting display device according to the present invention. FIG. 8A shows a notebook, FIG. 8B shows a digital camera and FIG. 8C shows a camcorder. Referring to FIGS. 8A to 8C, portable telephones, digital cameras, camcorders, and the like are provided with image display apparatuses for expressing images, and various types of information are displayed on the image display apparatuses for ease of use. The image display device is connected through a hinge, and when not in use, the image display device is folded and when used, the image display device is expanded. When an image display apparatus is used, light enters the image display apparatus and light is input to the photodiode installed in the image display apparatus so that current flows through the photodiode to operate the image display apparatus.

While preferred embodiments of the present invention have been described using specific terms, such descriptions are for illustrative purposes only and it is understood that various changes and modifications may be made without departing from the spirit and scope of the following claims. You must lose.

According to the light emitting display device and the driving method thereof according to the present invention, it is easy to design by detecting the natural light and turning the power of the light emitting display device on and off according to the detected data so that the power of the light emitting display device is turned on and off without a separate mechanical switch. Provided is a folding light emitting display device. Therefore, the present invention can be applied to a system employing various folding light emitting display devices.

Claims (12)

An upper folder having an image display device for displaying an image; A lower folder connected to the upper folder and a hinge; The upper and lower folders are formed in contact with each other, and are formed in one of the upper and lower folders. The light is sensed according to the opening and closing of the upper and lower folders to output a detection signal according to the amount of light. A light sensing unit; A controller configured to adjust a ratio between a light emission time and a non-light emission time of the image display device in response to the detection signal; A power supply unit for outputting power to drive the image display device; And And a switching unit to block the output of the power supply unit if the detection signal is greater than or equal to a predetermined size. The method of claim 1, The switching unit may include a switching signal generation unit configured to output an off signal when the detection signal is greater than or equal to the predetermined magnitude and output an on signal when the detection signal is smaller than or equal to the predetermined magnitude; And And a switch to block an output of the power supply unit according to the output signal of the switching signal generator. The method of claim 1, The image display device A pixel portion including a data line, a scan line, a light emission control line, and a plurality of pixels connected to the data line, the scan line, and the light emission control line to emit light; A data driver connected to the data line to transmit a data signal to the pixel unit; And And a scan driver connected to the scan line and the light emission control line to transmit a scan signal and a light emission control signal to the pixel unit. The method of claim 1, The photodetector photodiode for generating a current by sensing the light; A current-voltage converter converting the current formed by the photodiode into a voltage; And And a voltage limiter configured to shape a waveform of the voltage converted by the current-to-DC voltage converter. The method of claim 4, wherein The current-voltage converter is a folding light emitting display device comprising an amplifier. The method of claim 4, wherein And a voltage of the voltage outputted from the voltage limiting unit to block high frequency components through a filter. The method of claim 2, The control unit, An analog-to-digital converter receiving the sensed signal and converting the detected signal into a digital sensed signal; A counter for counting a predetermined number during a time of one frame and generating a counting signal corresponding thereto; And And a conversion processor for comparing the digital sensing signal with the counting signal and outputting a second start pulse corresponding thereto. The method of claim 4, wherein The switching unit includes a transistor configured to perform an on-off operation in response to an output signal of the current-voltage converter, wherein the transistor outputs one of the off signal and the on signal by an on-off operation. Device. The method of claim 3, wherein the pixel, Light emitting device for emitting light according to the flow of current; A first transistor for generating said current by a voltage applied to a gate; A second transistor configured to transfer a data signal to a gate of the first transistor by the scan signal; A capacitor configured to store a voltage corresponding to a difference between a first power supply and the data signal; And And a third transistor configured to transfer the current generated by the first transistor to the light emitting device by the light emission control signal. delete The method of claim 1, And a display screen of a mobile phone, a digital camera, a notebook, or a camcorder corresponding to the upper folder, and an operation unit of the mobile phone, a digital camera, a notebook, or a camcorder corresponding to the lower folder. Outputting a control signal by sensing light according to opening and closing of the upper folder and the lower folder in an image display device including an upper folder and a lower folder coupled by a hinge; And And cutting off the driving power of the image display device in response to the control signal, and adjusting a ratio between the light emission time and the non-light emission time of the image display device.

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