JP4671494B2 - Driving method of information device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information device having a function of inputting information with a pen or the like. In particular, the present invention relates to an information device that performs a pen input operation on a screen of a display device. The display device particularly relates to an EL display device using an EL element. The present invention also relates to a portable information device having this information device.
[0002]
Note that in this specification, an EL element refers to an element that utilizes both light emission from singlet excitons (fluorescence) and light emission from triplet excitons (phosphorescence).
[0003]
[Prior art]
In portable information devices, demand for pen-type portable information devices is increasing from the viewpoints of miniaturization and operability. The pen input method is a method of inputting information by using a dedicated or arbitrary pen or the like and bringing the pen tip into contact with or close to the display screen.
[0004]
That is, information corresponding to the position indicated by the pen tip on the display screen is input. The display screen also serves as a pen input screen. In this pen input method, it is necessary to specify the position indicated by the pen on the pen input screen. Examples of the pen input method include a resistance film type and an optical type.
[0005]
First, the resistance film type will be described.
[0006]
FIG. 7 is a schematic diagram showing the structure of a resistance film type pen input device. Note that the pen input device 7711 is formed above the display device 7708. A display device 7708 includes a display portion 7709 and a peripheral circuit 7710.
[0007]
In the pen input device 7711, the movable electrode 7701 and the fixed electrode 7702 are connected in parallel to each other at an interval of about 100 to 300 μm by a bonding material 7703 with the dot spacer 7704 interposed therebetween. Here, the movable electrode 7701 and the fixed electrode 7702 are formed of a light-transmitting conductive material so that an image displayed on the display portion 7709 of the display device 7708 can be seen via the pen input device 7711. Yes. In general, an indium tin oxide (ITO) film is used as the light-transmitting conductive material.
[0008]
In the resistance film type, the movable electrode 7701 and the fixed electrode 7702 are in contact with each other at the position (input point A in FIG. 7) indicated by the input pen 7705 on the pen input device 7711. At this time, the position of the input point A is read as the ratio of the resistors R1 and R2 from the two position detection electrodes 7706 and 7707.
[0009]
Specifically, FIG. 8 shows an example in which the position is read. A pressure is applied from the movable electrode 801 side at the input point A by the input pen 807 and brought into contact with the fixed electrode 802. Here, a voltage is applied between the two electrodes 803 and 804 of the movable electrode 801 to generate a potential gradient inside the movable electrode 801. The potential V of the input point A at this time _A By measuring the resistance R from the electrodes 803 and 804 to the input point A _x1 And R _x2 Can know. Here, if the film quality of the movable electrode 801 is uniform, the resistance value R _x1 And R _x2 Is proportional to the distance from each of the electrodes 803 and 804 to the input point A.
[0010]
Similarly, this time, a voltage is applied between the two electrodes 805 and 806 of the fixed electrode 802, and a potential gradient is generated inside the fixed electrode 802. The potential V of the input point A at this time _A , The resistance value R from the electrode 805 and the electrode 806 to the input point A _y1 And R _y2 Can know. Here, if the film quality of the fixed electrode 802 is uniform, the resistance value R _y1 And R _y2 Is proportional to the distance from each of the electrodes 805 and 806 to the point A. Thus, the position of the input point A can be known.
[0011]
Note that the method of measuring the potential of the input point A for measuring the position of the input point A is not limited to the above configuration, and various methods can be used.
[0012]
Next, an optical pen input device will be described. FIG. 9A shows a schematic top view of this type of pen input device.
[0013]
When the pen tip of the input pen 901 touches the input unit 902, the touched position is detected. This position detection operation will be described.
[0014]
Around the input unit 902, x-1 light emitting diodes (hereinafter referred to as LEDs) 2 are arranged on the right side. ₁ ~ 2 _x And x-1 phototransistors (hereinafter referred to as PT) 3 on the left side. ₁ ~ 3 _x LED2 ₁ ~ 2 _x And is embedded in the frame 4.
[0015]
On the other hand, on the lower side, y-1 LEDs 5 ₁ ~ 5 _y Are arranged on the upper side, and y-1 PT6 ₁ ~ 6 _y But LED5 ₁ ~ 5 _y And is embedded in the frame 4.
[0016]
And LED2 ₁ ~ 2 _x And PT3 ₁ ~ 3 _x Form x-1 horizontal touch input lines, LED5 ₁ ~ 5 _y And PT6 ₁ ~ 6 _y Form y-1 vertical touch input lines.
[0017]
Here, the touch input line is a path through which light emitted from the LED is input to the PT in a pair of LEDs and PT facing each other.
[0018]
3 ₁ ~ 3 _x And 6 ₁ ~ 6 _y As described above, PT is used, but not limited to PT, any photoelectric conversion element that converts light into an electric signal can be used freely.
[0019]
LED2 ₁ ~ 2 _x And 5 ₁ ~ 5 _y Radiated from each, PT3 ₁ ~ 3 _x And 6 ₁ ~ 6 _y In order to improve the directivity of light incident on each of the two, circular slits 7 are formed in front of the frame 4 in which each element is embedded.
[0020]
FIG. 9B is a cross-sectional view taken along line aa ′ in FIG. A display device 910 is formed below the pen input device. The display device 910 includes a display unit 911 and a peripheral circuit 912. Unlike the resistive film type, an image displayed on the display portion 911 can be directly viewed.
[0021]
Reference is again made to FIG.
[0022]
In the pen input device having the above-described configuration, the horizontal light touch input line and the vertical touch input line are simultaneously made to emit light and receive light sequentially from the end of each pair of opposing LED and PT (hereinafter referred to as scanning). ).
[0023]
Here, the input pen 901 points to one point in the input unit 902. Assume that the input point A in FIG. At this time, two touch input lines 2 corresponding to the input point A _n ~ 3 _n And 5 _m ~ 6 _m The position A where the input pen 901 touches is recognized.
[0024]
[Problems to be solved by the invention]
In the resistive film type, it is necessary to mechanically deform the movable electrode every time information is input. For this reason, the movable electrode may be fatigued and destroyed by repeated deformation. This is a problem in terms of durability.
[0025]
In addition, even if it does not lead to destruction, if a minute crack of micrometer order is formed in the process of repeated deformation or production, the conductivity of the ITO film will not be uniform, so the position of the pen input A problem occurs in the accuracy of detection.
[0026]
In addition, the image of the display device is read through the two electrodes of the movable electrode and the fixed electrode. At this time, since the transmittance of the transparent electrode is not 100%, there arises a problem of visibility of the screen such that the light from the display device is attenuated and the luminance of the image is lowered. Therefore, it is necessary to increase the light emission of the display device in order to increase the luminance of the image, and there is a problem of an increase in power consumption of the device.
[0027]
In addition, when stress is applied from the outside and the distance between the two electrodes of the movable electrode and the fixed electrode becomes 40 μm or less, there is a problem that Newton rings appear due to the interference effect of reflected light between the two electrodes.
[0028]
Furthermore, since the capacitor structure has two electrodes arranged in parallel, there is a problem that consumption is large when using a battery power source. This is a serious problem in portable information devices where low power consumption is desired.
[0029]
On the other hand, in the optical pen input device, it is not necessary to repeatedly deform the thin film as in the resistive film type, and there is no problem of mechanical durability. Further, the display device is not seen through the transparent electrode, and there are few problems in terms of visibility of the screen.
[0030]
However, when the light emitted from the light emitting element is not received straight by the pair of light receiving elements, it may not be recognized even if it indicates the position of the input pen or the like.
[0031]
In addition, since it is necessary to form a row of light emitting elements and light receiving elements, slits, and the like on the display device, there is a problem that miniaturization is difficult.
[0032]
[Means for Solving the Problems]
Therefore, in the information device having the pen input function of the present invention, both an EL (electroluminescence) element and a photoelectric conversion element are arranged in the pixel of the display device, and information is input by a pen that emits light from the pen tip.
[0033]
The EL element is a self-luminous element and is mainly used in an EL display device. The EL display device is also referred to as an organic EL display device (OELD) or an organic light emitting diode (OLED).
[0034]
The EL element has a structure in which an EL layer is sandwiched between a pair of electrodes (anode and cathode). The EL layer usually has a laminated structure. A typical example is a stacked structure of “hole transport layer / light emitting layer / electron transport layer” proposed by Tang et al. Of Kodak Eastman Company. This structure is known to have extremely high luminous efficiency.
[0035]
In addition, the “hole injection layer / hole transport layer / light emitting layer / electron transport layer” layered on the electrode or “hole injection layer / hole transport layer / light emitting layer / electron transport layer” / "Electron injection layer" may be laminated. Further, the light emitting layer may be doped with a fluorescent dye or the like.
[0036]
In this specification, all layers provided between a pair of electrodes are referred to as EL layers. Therefore, the above-described hole injection layer, hole transport layer, light emitting layer, electron transport layer, electron injection layer, and the like are all included in the EL layer. A predetermined voltage is applied from the pair of electrodes to the EL layer having the above structure. Thereby, recombination of carriers occurs in the light emitting layer to emit light.
[0037]
A photodiode or the like can be used as the photoelectric conversion element. In this specification, the photodiode includes a cathode electrode, an anode electrode, and a photoelectric conversion layer between the cathode electrode and the anode electrode.
[0038]
Note that the photodiode is not limited to this configuration, and may have a PIN structure in which a photoelectric conversion layer including an i-type (intrinsic) semiconductor layer is provided between a p-type semiconductor layer and an n-type semiconductor layer. Alternatively, a PN photodiode including a p-type semiconductor layer and an n-type semiconductor layer may be used.
[0039]
Moreover, you may use the thing which has the photoelectric converting layer etc. which are comprised from organic substance as a photoelectric conversion element.
[0040]
In a photodiode, when a reverse bias voltage is applied between the cathode electrode and the anode electrode (referred to as between the electrodes of the photodiode) and then irradiated with light, the voltage between the electrodes decreases due to the carriers generated by the light. To do. At this time, the higher the intensity of the irradiated light, the greater the amount by which this voltage decreases. Using this, the light is detected as an electrical signal by comparing the voltage when the photodiode is irradiated with light and the voltage when the photodiode is not irradiated.
[0041]
The EL elements and the photodiodes are formed in a matrix on the same substrate, and the respective operations of the EL elements and the photodiodes are controlled using thin film transistors (TFTs) that are also provided in the matrix.
[0042]
As a result, an information device that displays a clear image without impairing the luminance of the display image, has excellent durability, can be reduced in size, has high accuracy, and has a pen input function with low power consumption can be obtained.
[0043]
The configuration of the information device of the present invention will be described below.
[0044]
According to the present invention,
In an information device having a plurality of pixels,
Have an input pen,
Each of the plurality of pixels has an EL element and a photoelectric conversion element,
The input pen emits a light beam;
An information device is provided in which information is input by the light beam being input to the photoelectric conversion element.
[0045]
The EL device and the photoelectric conversion device may be an information device formed on the same substrate.
[0046]
The photoelectric conversion element may be an information device that is a photodiode.
[0047]
According to the present invention,
In an information device having a plurality of pixels,
EL display source signal line drive circuit, EL display gate signal line drive circuit, a plurality of EL display source signal lines, a plurality of EL display gate signal lines, a plurality of power supply lines, and an input pen Have
The EL display source signal line drive circuit outputs a signal to the plurality of EL display source signal lines,
The EL display gate signal line driving circuit outputs a signal to the plurality of EL display gate signal lines,
Each of the plurality of pixels has an EL display unit and a sensor unit,
The EL display unit and the sensor unit are formed on the same substrate,
The EL display unit includes a switching TFT, an EL driving TFT, and an EL element.
A gate electrode of the switching TFT is connected to one of the plurality of EL display gate signal lines;
One of a source region and a drain region of the switching TFT is connected to one of the plurality of EL display source signal lines, and the other is connected to a gate electrode of the EL driving TFT.
One of the source region and the drain region of the EL driving TFT is connected to one of the plurality of power supply lines, and the other is connected to the EL element.
The sensor unit includes a photodiode,
The input pen emits a light beam;
An information device is provided in which information is input by inputting the light beam to the photodiode.
[0048]
According to the present invention,
In an information device having a plurality of pixels,
Sensor source signal line drive circuit, sensor gate signal pioneer circuit, multiple sensor output wires, multiple sensor gate signal lines, multiple reset gate signal lines, and multiple sensor power lines Have an input pen,
The sensor source signal line drive circuit reads signals from the plurality of sensor output wirings,
The sensor gate signal line driving circuit outputs signals to the plurality of sensor gate signal lines and the plurality of reset gate signal lines,
Each of the plurality of pixels has an EL display unit and a sensor unit,
The EL display unit and the sensor unit are formed on the same substrate,
The sensor unit includes a selection TFT, a buffer TFT, a reset TFT, and a photodiode.
A gate electrode of the selection TFT is connected to one of the plurality of sensor gate signal lines;
One of the source region and the drain region of the selection TFT is connected to one of the plurality of sensor output wirings, and the other is either the source region or the drain region of the buffer TFT. Connected to
The source region and drain region of the buffer TFT that are not connected to the selection TFT are connected to one of the plurality of sensor power lines,
A gate electrode of the buffer TFT is connected to a source region or a drain region of the photodiode and the reset TFT;
The source region or drain region of the reset TFT that is not connected to the buffer TFT is connected to one of the plurality of sensor power lines,
A gate electrode of the reset TFT is connected to one of the plurality of reset gate signal lines;
The EL display unit includes an EL element,
The input pen emits light;
An information device is provided in which information is input by inputting the light beam to the photodiode.
[0049]
According to the present invention,
In an information device having a plurality of pixels,
EL display source signal line drive circuit, EL display gate signal line drive circuit, sensor source signal line drive circuit, sensor gate signal precursor circuit, a plurality of EL display source signal lines, and a plurality of ELs Display gate signal lines, a plurality of power supply lines, a plurality of sensor output lines, a plurality of sensor gate signal lines, a plurality of reset gate signal lines, a plurality of sensor power lines, and an input pen And
The EL display source signal line drive circuit outputs a signal to the plurality of EL display source signal lines,
The EL display gate signal line driving circuit outputs a signal to the plurality of EL display gate signal lines,
The sensor source signal line drive circuit reads signals from the plurality of sensor output wirings,
The sensor gate signal line driving circuit outputs signals to the plurality of sensor gate signal lines and the plurality of reset gate signal lines,
The plurality of pixels include an EL display unit and a sensor unit,
The EL display unit and the sensor unit are formed on the same substrate,
The EL display unit includes a switching TFT, an EL driving TFT, and an EL element.
A gate electrode of the switching TFT is connected to one of the plurality of EL display gate signal lines;
One of a source region and a drain region of the switching TFT is connected to one of the plurality of EL display source signal lines, and the other is connected to a gate electrode of the EL driving TFT.
One of the source region and the drain region of the EL driving TFT is connected to one of the plurality of power supply lines, and the other is connected to the EL element.
The sensor unit includes a selection TFT, a buffer TFT, a reset TFT, and a photodiode.
A gate electrode of the selection TFT is connected to one of the plurality of sensor gate signal lines;
One of the source region and the drain region of the selection TFT is connected to one of the plurality of sensor output wirings, and the other is either the source region or the drain region of the buffer TFT. Connected to
The source region and drain region of the buffer TFT that are not connected to the selection TFT are connected to one of the plurality of sensor power lines,
A gate electrode of the buffer TFT is connected to a source region or a drain region of the photodiode and the reset TFT;
The source region or drain region of the reset TFT that is not connected to the buffer TFT is connected to one of the plurality of sensor power lines,
A gate electrode of the reset TFT is connected to one of the plurality of reset gate signal lines;
The input pen emits a light beam;
An information device is provided in which information is input by inputting the light beam to the photodiode.
[0050]
The light beam may be an information device characterized by being a laser beam.
[0051]
The light beam may be an information device characterized by being ultraviolet light or near ultraviolet light.
[0052]
The EL display source signal line drive circuit and the EL display gate signal drive circuit are formed on the same substrate as the substrate on which the EL display unit and the sensor unit are formed. There may be.
[0053]
The sensor source signal line drive circuit and the sensor gate signal drive circuit are formed on the same substrate as the substrate on which the EL display unit and the sensor unit are formed. Also good.
[0054]
The EL display source signal line drive circuit, the EL display gate signal drive circuit, the sensor source signal line drive circuit, and the sensor gate signal drive circuit form the EL display unit and the sensor unit. The information device may be formed on the same substrate as the other substrate.
[0055]
The photodiode may be an information device including an anode electrode, a cathode electrode, and a photoelectric conversion layer sandwiched between the anode electrode and the cathode electrode.
[0056]
The photoelectric conversion layer may be an information device including an organic material.
[0057]
The photodiode includes an p-type semiconductor layer, an n-type semiconductor layer, and a photoelectric conversion layer sandwiched between the p-type semiconductor layer and the n-type semiconductor layer. Also good.
[0058]
The photoelectric conversion layer may be an information device including an amorphous semiconductor.
[0059]
The light emitted from the EL element is applied to the surface of the subject,
The light applied to the surface of the subject is reflected by the surface of the subject,
The information apparatus may be characterized in that light reflected by the surface of the subject is input to the photoelectric conversion element, whereby information on the surface of the subject is input as an image.
[0060]
The information on the surface of the subject may be biological information.
[0061]
The biological information may be an information device that is a palm print.
[0062]
The biological information may be an information device that is a fingerprint.
[0063]
The information device may be a portable information terminal or a PDA.
[0064]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described.
[0065]
FIG. 1 is a schematic diagram of an information apparatus having a pen input function according to the present invention.
[0066]
In the present embodiment, a method of inputting information by indicating the inside of the display / input unit with an input pen that emits light from the pen tip will be described. Here, each pixel in the display / input unit includes an EL display unit having an EL element and a sensor unit having a photoelectric conversion element. The EL display unit and the sensor unit are arranged around the display unit / input unit, such as an EL display source signal line driving circuit, an EL display gate signal line driving circuit, a sensor source signal line driving circuit, and a sensor. It is driven by a signal from the gate signal line driving circuit.
[0067]
Here, each driving circuit (EL display source signal line driving circuit, EL driving gate signal line driving circuit, sensor source signal line driving circuit, sensor) is formed on the same substrate as the substrate on which the display / input unit is formed. Gate signal line driving circuit).
[0068]
The signal from the EL display source signal line drive circuit is transmitted to the EL display portion of each pixel by the EL display source signal line S, and the signal from the EL display gate signal line drive circuit is transmitted to the EL display gate signal line. G is transmitted to the EL display section of each pixel.
[0069]
The sensor source signal line drive circuit reads the signal of the sensor part of each pixel by the sensor output wiring SS, and the sensor gate signal line drive circuit transmits the signal to the sensor part of each pixel by the sensor gate signal line SG. To do.
[0070]
In FIG. 1, a power supply line for EL elements (power supply line), a sensor power supply line, a reset signal line (reset gate signal line), and the like wired to each pixel are not shown.
[0071]
In the display / input unit, each pixel displays on the EL display unit.
[0072]
At the same time, the pen tip of the input pen emits light and a light beam is emitted, and light is input to a sensor unit (light input region) near the pen tip. Thus, the position pointed to by the input pen is recognized.
[0073]
Next, a specific circuit configuration of the display / input unit will be described.
[0074]
FIG. 2 is a diagram illustrating an example of a circuit configuration of the display / input unit.
[0075]
The display / input unit 2201 includes EL display source signal lines S1 to Sx, EL display gate signal lines G1 to Gy, power supply lines V1 to Vx, sensor output wirings SS1 to SSx, and a sensor gate. It has signal lines SG1 to SGy, reset gate signal lines RG1 to RGy, and a sensor power supply line VB.
[0076]
The display / input unit 2201 has a plurality of pixels 2202. Each of the plurality of pixels 2202 is one of the EL display source signal lines S1 to Sx, one of the EL display gate signal lines G1 to Gy, and one of the power supply lines V1 to Vx. One of the sensor output lines SS1 to SSx, one of the sensor gate signal lines SG1 to SGy, one of the reset gate signal lines RG1 to RGy, and the sensor power line Has VB.
[0077]
The sensor output lines SS1 to SSx are connected to constant current sources 2203-1 to 2203-x, respectively.
[0078]
FIG. 3 shows a detailed configuration of the pixel 2202 in FIG. The EL display source signal line S indicates one of the EL display source signal lines S1 to Sx. The EL display gate signal line G indicates any one of the EL drive gate signal lines G1 to Gy. The power supply line V indicates any one of the power supply lines V1 to Vx. The sensor output wiring SS indicates any one of the sensor output wirings SS1 to SSx. The sensor gate signal line SG indicates any one of the sensor gate signal lines SG1 to SGy.
[0079]
The pixel includes an EL display portion 3311 and a sensor portion 3312.
[0080]
The EL display portion 3311 includes an EL element 3301, a switching TFT 3302, an EL driving TFT 3303, and a capacitor 3304. Note that the capacitor 3304 is not necessarily provided.
[0081]
The gate electrode of the switching TFT 3302 is connected to the EL display gate signal line G, one of the source region and the drain region is connected to the EL display source signal line S, and the other is one electrode of the capacitor 3304. And the gate electrode of the EL driving TFT 3303. The other electrode of the capacitor 3304 is connected to the power supply line V. One of a source region and a drain region of the EL driving TFT 3303 is connected to the power supply line V, and the other is connected to the EL element 3301.
[0082]
The side of the EL element 3301 that is connected to the source region or drain region of the EL driving TFT 3303 is a pixel electrode, and the side that is not connected to the source region or drain region of the EL driving TFT 3303 is a counter electrode.
[0083]
The sensor portion 3312 includes a photodiode 3305, a selection TFT 3306, a buffer TFT 3307, and a reset TFT 3308.
[0084]
As the structure of the photodiode 3305, a Schottky structure in which a photoelectric conversion layer is sandwiched between an anode electrode and a cathode electrode is used in this embodiment.
[0085]
Light incident on the photodiode is absorbed by the photoelectric conversion layer to form carriers. The amount of carriers formed by this light depends on the amount of light absorbed by the photoelectric conversion layer.
[0086]
Here, the photodiode having the above-described configuration is used as the photoelectric conversion element that converts light into an electric signal.
[0087]
Note that a PIN photodiode includes a p-type semiconductor layer, an n-type semiconductor layer, and an i-type (intrinsic) semiconductor layer sandwiched between the p-type semiconductor layer and the n-type semiconductor layer. Here, the i-type semiconductor layer is also referred to as a photoelectric conversion layer.
[0088]
Further, by using an amorphous semiconductor such as an amorphous silicon film (amorphous silicon film) as a photoelectric conversion layer included in these photodiodes, the light absorption rate in the photoelectric conversion layer can be increased.
[0089]
Moreover, you may use the thing which has the photoelectric converting layer etc. which are comprised from organic substance as a photoelectric conversion element.
[0090]
The gate electrode of the selection TFT 3306 is connected to the sensor gate signal line SG, one of the source region and the drain region is connected to the sensor output wiring SS, and the other is the source region or the drain region of the buffer TFT 3307. And connected. The side of the source region and drain region of the buffer TFT 3307 that is not connected to the selection TFT 3306 is connected to the sensor power supply line VB. The gate electrode of the reset TFT 3308 is connected to the reset gate signal line RG. One of the source region and the drain region is connected to the sensor power supply line VB, and the other is connected to the gate electrode of the buffer TFT 3307 and the photodiode 3305. It is connected to the.
[0091]
The sensor power supply line VB is kept at a constant potential (reference potential). The sensor output wiring SS is connected to a constant current source.
[0092]
Note that the EL display source signal line drive circuit, the sensor source signal line drive circuit, the EL display gate signal line drive circuit, and the sensor gate signal line drive circuit may be circuits having known configurations.
[0093]
An operation method of the display / pixel unit having the above structure will be described with reference to circuit diagrams of FIGS. 2 and 3 and timing charts of FIGS. 17 and 18.
[0094]
First, an operation method of the EL display unit will be described with reference to FIGS. 2 and 3 and FIG.
[0095]
Here, a method of inputting an analog signal to the source signal lines S1 to Sx and performing display (hereinafter referred to as an analog method) will be described.
[0096]
Here, although the switching TFT 3302 and the EL driving TFT 3303 are n-channel TFTs, the switching TFT 3302 and the EL driving TFT 3303 may be either an n-channel TFT or a p-channel TFT, respectively. However, when the anode of the EL element 3301 is a pixel electrode, the EL driving TFT 3303 is preferably a p-channel TFT. Conversely, when the cathode of the EL element 3301 is a pixel electrode, the EL driving TFT 3303 is used. The TFT 3303 is preferably an n-channel TFT.
[0097]
First, all the switching TFTs 3302 connected to the EL display gate signal line G1 are turned on by a signal input to the EL display gate signal line G1.
[0098]
A period in which a certain EL display gate signal line is selected is referred to as one line period, and in particular, a period in which the EL display gate signal line G1 is selected is referred to as a first line period L1. During the line period L1, analog signals are sequentially input to the EL display source signal lines S1 to Sx. The analog signal voltage input to the EL display source signal line is applied to the capacitor 3304 and the gate electrode of the EL driving TFT 3303. The EL driving TFT 3303 causes a source-drain current corresponding to the analog signal voltage applied to the gate electrode to flow from the power supply line V to the EL element 3301. The EL element 3301 emits light with a luminance corresponding to the current.
[0099]
Next, the EL display gate signal line G2 is selected, and all the switching TFTs 3302 connected to the EL display gate signal line G2 are turned on. Thus, the second line period L2 starts. Thereafter, signal voltages are sequentially input to the EL display source signal lines S1 to Sx. This signal voltage is applied to the gate electrode of the EL driving TFT 3303, and a source-drain current corresponding to the analog signal voltage applied to the gate electrode is supplied from the power supply line V to the EL element 3301. The EL element 3301 emits light with a luminance corresponding to the current.
[0100]
The above operation is repeated for all the EL display gate signal lines G1 to Gy, and one frame period F1 ends. Thereafter, the second frame period F2 starts. By repeating this operation, an image is displayed.
[0101]
Next, an operation method of the sensor unit will be described with reference to FIGS. 2, 3, and 18.
[0102]
Here, the reset TFT 3308 is an n-channel TFT, the buffer TFT 3307 is a p-channel TFT, and the selection TFT 3306 is an n-channel TFT. However, the reset TFT 3308, the buffer TFT 3307, and the selection TFT 3306 are each n Either a channel TFT or a p-channel TFT may be used. Note that it is desirable that the polarities of the reset TFT 3308 and the buffer TFT 3307 are reversed.
[0103]
First, all reset TFTs 3308 connected to the reset gate signal line RG1 are in a conductive state by a signal of the reset gate signal line RG1. At this time, the reset gate signal line is selected. Note that all of the glue setting TFTs 3308 connected to the other reset gate signal lines RG2 to RGy are in a non-conductive state. At this time, the potential of the sensor power supply line VB is applied to the gate electrode of the buffer TFT 3307 via the reset TFT 3308. Thus, the source region of the buffer TFT 3307 is maintained at a potential obtained by subtracting the potential difference between the source region and the gate region of the buffer TFT 3307 from the potential (reference potential) of the sensor power supply line VB. Thus, a reverse bias voltage is applied between the electrodes of the photodiode 3305.
[0104]
At this time, all the selection TFTs 3306 connected to the sensor gate signal line SG1 are in a non-conductive state by the signal of the sensor gate signal line SG1. In this specification, a period in which the reset gate signal line is selected is referred to as a reset period RS.
[0105]
Next, the signal of the reset gate signal line RG1 changes, and all the reset TFTs 3308 connected to the reset gate signal line RG1 are turned off. At this time, the reset gate signal line is not selected. Then, when the photodiode 3305 is irradiated with light, a current flows between the electrodes of the photodiode 3305, and the reverse bias voltage between the electrodes applied during the reset period is lowered. Thereafter, all the selection TFTs 3306 connected to the sensor gate signal line SG1 are turned on by a signal input to the sensor gate signal line SG1.
[0106]
A period until the reset gate signal line is in a non-selected state and a selection TFT corresponding to a pixel on the same line is selected is referred to as a sampling period ST. In particular, a period until the reset gate signal line RG1 is deselected and the selection gate signal line SG1 is selected is referred to as a first sampling period ST1.
[0107]
In the sampling period ST1, the reverse bias voltage between the electrodes of the photodiode 3305 decreases with time. The degree to which the reverse bias voltage decreases depends on the intensity of light irradiated on the photoelectric conversion layer of the photodiode 3305. Here, the electrode not connected to the gate electrode of the buffer TFT 3307 of the photodiode 3305 is kept at a constant potential. Thus, the potential of the photodiode 3305 connected to the gate electrode of the buffer TFT 3307 is lowered.
[0108]
This decrease in potential lowers the potential of the gate electrode of the buffer TFT 3307.
[0109]
Here, since the source region of the buffer TFT 3307 is connected to the constant current sources 2203-1 to 2203-x via the drain and source of the selection TFT 3306, the buffer TFT 3307 functions as a source follower. . Therefore, the gate-source voltage of the buffer TFT 3307 is always kept equal. Therefore, when the potential of the gate electrode of the buffer TFT 3307 changes due to the change in potential between the electrodes of the photodiode 3305, the potential of the source region of the buffer TFT 3307 also changes by the same potential. After the sampling period ST1, the sensor gate signal line SG1 is selected, and the change in the potential of the source region is output to the sensor output lines SS1 to SSx.
[0110]
Thereafter, the sensor gate signal line SG1 is in a non-selected state.
[0111]
On the other hand, when the reset gate signal line RG1 is not selected, the reset gate signal line RG2 is selected. All reset TFTs 3308 connected to the reset gate signal line RG2 are turned on, and the reset period RS of the second line starts. Thereafter, the reset gate signal line RG2 is in a non-selected state, and the sampling period ST2 of the second line starts. Note that the first sampling period ST1 and the second sampling period ST2 have the same length, although the starting time is different.
[0112]
Similarly, in the second sampling period ST2, the reverse bias voltage between the electrodes of the photodiode decreases in the sensor portion of each pixel according to the intensity of the input light. After the second sampling period ST2, all the selection TFTs 3306 connected to the sensor gate signal line SG2 are turned on by the signal of the sensor gate signal line SG2, and the potential change between the electrodes of the photodiode 3305 is as follows. Are input to the gate electrode of the buffer TFT 3307, change in the potential of the source region of the buffer TFT 3307, and output to the sensor output wirings SS 1 to SSx.
[0113]
Thereafter, the sensor gate signal line SG2 is not selected.
[0114]
The above operation is repeated for all the sensor gate signal lines SG1 to SGy, and the information of the signals input to the sensor units 3312 of all the pixels of the display unit / input unit 2201 is read.
[0115]
In this way, the EL display unit displays an image. At the same time, the sensor unit can detect light emitted from the pen tip of the input pen and specify the position indicated by the pen tip of the input pen.
[0116]
【Example】
Examples of the present invention will be described below.
[0117]
[Example 1]
In this example, a case where an information device having the structure described in Embodiment Mode is actually manufactured will be described.
[0118]
In this embodiment, a cross-sectional view of the information device of the present invention will be described with reference to FIG.
[0119]
Reference numeral 601 denotes a switching TFT, 602 denotes an EL drive TFT, 603 denotes a reset TFT, 604 denotes a buffer TFT, and 605 denotes a selection TFT.
[0120]
Reference numeral 606 denotes an anode electrode, 607 denotes a photoelectric conversion layer, and 608 denotes a cathode electrode. A photodiode 621 is formed by the anode electrode 606, the photoelectric conversion layer 607, and the cathode electrode 608. Reference numeral 614 denotes a sensor wiring, which electrically connects the cathode electrode 608 and an external power source. Further, the anode electrode 606 of the photodiode 621 and the drain region of the reset TFT 603 are electrically connected.
[0121]
Here, the anode electrode 606 of the photodiode 621 is formed of a light-transmitting material.
[0122]
Reference numeral 609 denotes a pixel electrode (anode), 610 denotes an EL layer, and 611 denotes a counter electrode (cathode). An EL element 622 is formed by the pixel electrode (anode) 609, the EL layer 610, and the counter electrode (cathode) 611. Reference numeral 612 denotes a bank that divides an EL layer 610 between adjacent pixels.
[0123]
Here, the pixel electrode 609 of the EL element 622 is formed using a light-transmitting material.
[0124]
In the information device having the configuration illustrated in FIG. 15, the EL element 622 emits light in the direction of the substrate 630.
[0125]
Reference numeral 624 denotes an input pen, and light emitted from the pen tip light emitting unit 623 of the input pen 624 enters the photodiode 621. In this embodiment, input by the input pen 624 is performed from the side of the substrate 630 where the TFT is not formed. The pen input side corresponds to the light emission side of the EL element 622, and information is input while visually recognizing the image displayed by the EL element 622.
[0126]
Note that light emitted from the pen tip light emitting unit 623 of the input pen 624 preferably has high directivity. Therefore, it is preferable to use an input pen 624 that emits laser light from the pen tip light emitting unit 623.
[0127]
In addition, it is preferable to use light having a short wavelength, that is, light having high energy, as light emitted from the pen tip light emitting unit 623 of the input pen 624. For example, it is preferable to use ultraviolet or near ultraviolet light. Note that in this specification, near-ultraviolet light includes purple and blue visible light. Therefore, it is preferable to use an input pen 624 having an ultraviolet light-emitting diode, a near-ultraviolet light-emitting diode, or the like and having a structure in which light from the light-emitting diode is irradiated from the pen-tip light emitting unit 623.
[0128]
By using light having such high energy, a signal input to a photoelectric conversion element such as a photodiode by the input pen 624 and converted into an electric signal can be made larger than a noise signal such as external light. it can. Therefore, a more reliable pen input operation can be performed.
[0129]
In this embodiment, the switching TFT 601, the reset TFT 603, and the selection TFT 605 are all n-channel TFTs. The EL driving TFT 602 and the buffer TFT 604 are p-channel TFTs. The present invention is not limited to this configuration. Therefore, the switching TFT 601, the EL driving TFT 602, the buffer TFT 604, the selection TFT 605, and the reset TFT 603 may be either an n-channel TFT or a p-channel TFT.
[0130]
However, when the source region or the drain region of the EL driving TFT 602 is electrically connected to the anode 609 of the EL element 622 as in this embodiment, the EL driving TFT 602 is preferably a p-channel TFT. Conversely, in the case where the source region or the drain region of the EL driving TFT 602 is electrically connected to the cathode of the EL element 622, the EL driving TFT 602 is preferably an n-channel TFT.
[0131]
Further, when the anode electrode 606 of the photodiode 621 is electrically connected to the reset TFT 603 as in this embodiment, the reset TFT 603 is an n-channel TFT and the buffer TFT 604 is a p-channel TFT. Is desirable. Conversely, when the cathode electrode of the photodiode 621 is connected to the reset TFT 603 and the sensor wiring 616 is connected to the anode electrode, the reset TFT 303 is a p-channel TFT and the buffer TFT 304 is an n-channel TFT. Is desirable.
[0132]
[Example 2]
In this embodiment, an example in which the light emitting direction of the EL element is different in the information device having the structure described in Embodiment 1 will be described with reference to FIGS.
[0133]
FIG. 16 shows a cross-sectional view of the information device of this embodiment. Reference numeral 701 denotes a switching TFT, 702 denotes an EL drive TFT, 703 denotes a reset TFT, 704 denotes a buffer TFT, and 705 denotes a selection TFT.
[0134]
Reference numeral 706 denotes a cathode electrode, 707 denotes a photoelectric conversion layer, and 708 denotes an anode electrode. A photodiode 721 is formed by the cathode electrode 706, the photoelectric conversion layer 707, and the anode electrode 708. Reference numeral 714 denotes a sensor wiring, which electrically connects the anode electrode 708 and an external power source. Further, the cathode electrode 706 of the photodiode 721 and the drain region of the reset TFT 703 are electrically connected.
[0135]
Here, the anode electrode 708 of the photodiode 721 is formed of a light-transmitting material.
[0136]
Reference numeral 709 denotes a pixel electrode (cathode), 710 denotes an EL layer, and 712 denotes a counter electrode (anode). An EL element 722 is formed by the pixel electrode (cathode) 709, the EL layer 710, and the counter electrode (anode) 712. Reference numeral 713 denotes a bank that divides the EL layer 710 between adjacent pixels.
[0137]
Here, the counter electrode 712 of the EL element 722 is formed using a light-transmitting material.
[0138]
In the information device having the structure illustrated in FIG. 16, the EL element 722 emits light in a direction opposite to the substrate 730.
[0139]
Reference numeral 724 denotes an input pen. Light emitted from the pen tip light emitting unit 723 of the input pen 724 enters the photodiode 721. In this embodiment, information is input by the input pen 724 from the side of the substrate 730 where the TFT is formed. The pen input side corresponds to the light emission side of the EL element 722 and inputs information while visually recognizing an image displayed by the EL element 722.
[0140]
Note that light emitted from the pen tip light emitting unit 723 of the input pen 724 is preferably highly directional. Therefore, it is preferable to use an input pen 724 that emits laser light from the pen tip light emitting unit 723.
[0141]
In addition, it is preferable to use light having a short wavelength, that is, light having high energy, as light emitted from the pen tip light emitting unit 623 of the input pen 624. For example, it is preferable to use ultraviolet or near ultraviolet light. Note that in this specification, near-ultraviolet light includes purple and blue visible light. Therefore, it is preferable to use an input pen 624 having an ultraviolet light-emitting diode, a near-ultraviolet light-emitting diode, or the like and having a structure in which light from the light-emitting diode is irradiated from the pen-tip light emitting unit 623.
[0142]
By using light having such high energy, a signal input to a photoelectric conversion element such as a photodiode by the input pen 624 and converted into an electric signal can be made larger than a noise signal such as external light. it can. Therefore, a more reliable pen input operation can be performed.
[0143]
In this embodiment, the switching TFT 701, the EL driving TFT 702, the buffer TFT 704, and the selection TFT 705 are all n-channel TFTs. The reset TFT 703 is a p-channel TFT. The present invention is not limited to this configuration. Therefore, the switching TFT 701, the EL driving TFT 702, the buffer TFT 704, the selection TFT 705, and the reset TFT 703 may be either an n-channel TFT or a p-channel TFT.
[0144]
However, when the source region or drain region of the EL driving TFT 702 is electrically connected to the cathode 709 of the EL element 722 as in this embodiment, the EL driving TFT 702 is preferably an n-channel TFT. Conversely, in the case where the source region or the drain region of the EL driving TFT 702 is electrically connected to the anode 712 of the EL element 722, the EL driving TFT 702 is preferably a p-channel TFT.
[0145]
Further, when the cathode electrode 706 of the photodiode 721 is electrically connected to the reset TFT 703 as in this embodiment, the reset TFT 703 is a p-channel TFT and the buffer TFT 704 is an n-channel TFT. Is desirable. Conversely, when the anode electrode of the photodiode 721 is connected to the reset TFT 703 and the sensor wiring 714 is connected to the cathode electrode, the reset TFT 703 is an n-channel TFT and the buffer TFT 704 is a p-channel TFT. Is desirable.
[0146]
[Example 3]
In this example, an operation method of the display / input unit, which is different from that described in the embodiment, will be described. Note that the configuration of the pixel unit / input unit is the same as that shown in the embodiment, and the description thereof is omitted with reference to FIGS. Further, the operation method of the sensor unit of the present example is also the same as that shown in the embodiment, and FIG. 18 is referred to. FIG. 5 shows a timing chart showing the operation method of the EL display unit of this embodiment.
[0147]
First, one frame period (F) is divided into N subframe periods (SF1 to SFN). As the number of gradations increases, the number of subframe periods in one frame period also increases. Note that when the sensor unit of the area sensor displays an image, one frame period (F) indicates a period during which the EL display unit of all the pixels of the display unit / input unit displays one image.
[0148]
In this embodiment, it is preferable to provide 60 or more frame periods per second. By setting the number of images displayed per second to 60 or more, it is possible to visually suppress flickering of images such as flicker.
[0149]
The subframe period is divided into an address period (Ta) and a sustain period (Ts). The address period is a period during which a digital video signal is input to all pixels during one subframe period. The digital video signal is a digital signal having image information. The sustain period (also referred to as a lighting period) indicates a period during which display is performed by causing an EL element to emit light or not to emit light by a digital video signal input to a pixel in an address period. The digital video signal means a digital signal having image information.
[0150]
Address periods (Ta) included in SF1 to SFN are Ta1 to TaN, respectively. The sustain periods (Ts) of SF1 to SFN are Ts1 to TsN, respectively.
[0151]
The potential of the power supply lines (V1 to Vx) is kept at a predetermined potential (power supply potential).
[0152]
First, in the address period Ta, the potential of the counter electrode of the EL element 3301 is kept at the same level as the power supply potential.
[0153]
Next, all the switching TFTs 3302 connected to the EL display gate signal line G1 are turned on by a signal input to the EL display gate signal line G1. Next, a digital video signal is input to the EL display source signal lines (S1 to Sx). The digital video signal has information of “0” or “1”, and the digital video signals of “0” and “1” are signals having one voltage of Hi and one of Lo.
[0154]
The digital video signal input to the EL display source signal lines (S1 to Sx) is input to the gate electrode of the EL driving TFT 3303 through the switching TFT 3302 in a conductive state.
[0155]
Next, all the switching TFTs 3302 connected to the EL display gate signal line G1 are turned off and connected to the EL display gate signal line G2 by the gate signal input to the EL display gate signal line G2. All the switching TFTs 3302 are turned on. Next, a digital video signal is input to the EL display source signal lines (S1 to Sx). The digital video signal input to the EL display source signal lines (S1 to Sx) is input to the gate electrode of the EL driving TFT 3303 via the conductive switching TFT 3302.
[0156]
The above-described operation is repeated up to the EL display gate signal line Gy, the digital video signal is input to the gate electrodes of the EL driving TFTs 3303 of all the pixels, and the address period ends.
[0157]
At the same time as the address period Ta ends, the sustain period Ts is reached. In the sustain period, all the switching TFTs 3302 are turned off. In the sustain period, the potentials of the counter electrodes of all the EL elements 3301 are high enough to have a potential difference from the power supply potential so that the EL elements 3301 emit light when the power supply potential is applied to the pixel electrodes.
[0158]
In this embodiment, when the digital video signal has information of “0”, the EL driving TFT 3303 is turned off. Therefore, the pixel electrode of the EL element 3301 is kept at the potential of the counter electrode. As a result, the EL element 3301 does not emit light in a pixel to which a digital video signal having information “0” is input.
[0159]
On the other hand, when the digital video signal has information of “1”, the EL driving TFT 3303 becomes conductive. Therefore, the power supply potential is applied to the pixel electrode of the EL element 3301. As a result, the EL element 3301 included in the pixel to which the digital video signal having the information “1” is input emits light.
[0160]
In this manner, the EL element enters a light emitting state or a non-light emitting state depending on information included in the digital video signal input to the pixel, and the pixel performs display.
[0161]
Simultaneously with the end of the sustain period, one subframe period ends. Then, the next subframe period appears, the address period starts again, and when the digital video signal is input to all pixels, the sustain period starts again. Note that the order in which the subframe periods SF1 to SFN appear is arbitrary.
[0162]
Thereafter, display is performed by repeating the same operation in the remaining subframe periods. When all N subframe periods have ended, one image is displayed and one frame period ends. When one frame period ends, the subframe period of the next frame period appears, and the above-described operation is repeated.
[0163]
In the present invention, the lengths of the address periods (Ta1 to TaN) included in each of the N subframe periods are the same. The ratio of the lengths of the N sustain periods Ts1,..., TsN is Ts1: Ts2: Ts3: ...: Ts (N-1): TsN = 2. ⁰ : 2 ^-1 : 2 ^-2 : ...: 2 ^-(N-2) : 2 ^-(N-1) It is represented by
[0164]
The gradation of each pixel is determined by which sub-frame period is emitted in one frame period. For example, when N = 8, assuming that the luminance of a pixel when light is emitted during the entire sustain period is 100%, when the pixel emits light at Ts1 and Ts2, 75% luminance can be expressed. Ts3, Ts5, and Ts8 When is selected, a luminance of 16% can be expressed.
[0165]
A method of displaying an image by causing the EL element of the pixel to emit light as described above is called a digital method.
[0166]
Next, an operation method of the sensor unit will be described with reference to FIGS. 2, 3, and 18.
[0167]
Here, the reset TFT 3308 is an n-channel TFT, the buffer TFT 3307 is a p-channel TFT, and the selection TFT 3306 is an n-channel TFT. However, the reset TFT 3308, the buffer TFT 3307, and the selection TFT 3306 are each n Either a channel TFT or a p-channel TFT may be used. Note that it is desirable that the polarities of the reset TFT 3308 and the buffer TFT 3307 are reversed.
[0168]
First, all reset TFTs 3308 connected to the reset gate signal line RG1 are in a conductive state by a signal of the reset gate signal line RG1. At this time, the reset gate signal line is selected. Note that all of the glue setting TFTs 3308 connected to the other reset gate signal lines RG2 to RGy are in a non-conductive state. At this time, the potential of the sensor power supply line VB is applied to the gate electrode of the buffer TFT 3307 via the reset TFT 3308. Thus, the source region of the buffer TFT 3307 is maintained at a potential obtained by subtracting the potential difference between the source region and the gate region of the buffer TFT 3307 from the potential (reference potential) of the sensor power supply line VB. Thus, a reverse bias voltage is applied between the electrodes of the photodiode 3305.
[0169]
At this time, all the selection TFTs 3306 connected to the sensor gate signal line SG1 are in a non-conductive state by the signal of the sensor gate signal line SG1. In this specification, a period in which the reset gate signal line is selected is referred to as a reset period RS.
[0170]
Next, the signal of the reset gate signal line RG1 changes, and all the reset TFTs 3308 connected to the reset gate signal line RG1 are turned off. At this time, the reset gate signal line is not selected. Then, when the photodiode 3305 is irradiated with light, a current flows between the electrodes of the photodiode 3305, and the reverse bias voltage between the electrodes applied during the reset period is lowered. Thereafter, all the selection TFTs 3306 connected to the sensor gate signal line SG1 are turned on by a signal input to the sensor gate signal line SG1.
[0171]
A period until the reset gate signal line is in a non-selected state and a selection TFT corresponding to a pixel on the same line is selected is referred to as a sampling period ST. In particular, a period until the reset gate signal line RG1 is deselected and the selection gate signal line SG1 is selected is referred to as a first sampling period ST1.
[0172]
In the sampling period ST1, the reverse bias voltage between the electrodes of the photodiode 3305 decreases with time. The degree to which the reverse bias voltage decreases depends on the intensity of light irradiated on the photoelectric conversion layer of the photodiode 3305. Here, the electrode not connected to the gate electrode of the buffer TFT 3307 of the photodiode 3305 is kept at a constant potential. Thus, the potential of the photodiode 3305 connected to the gate electrode of the buffer TFT 3307 is lowered.
[0173]
This decrease in potential lowers the potential of the gate electrode of the buffer TFT 3307.
[0174]
Here, since the source region of the buffer TFT 3307 is connected to the constant current sources 2203-1 to 2203-x via the drain and source of the selection TFT 3306, the buffer TFT 3307 functions as a source follower. . Therefore, the gate-source voltage of the buffer TFT 3307 is always kept equal. Therefore, when the potential of the gate electrode of the buffer TFT 3307 changes due to the change in potential between the electrodes of the photodiode 3305, the potential of the source region of the buffer TFT 3307 also changes by the same potential. After the sampling period ST1, the sensor gate signal line SG1 is selected, and the change in the potential of the source region is output to the sensor output lines SS1 to SSx.
[0175]
Thereafter, the sensor gate signal line SG1 is in a non-selected state.
[0176]
On the other hand, when the reset gate signal line RG1 is not selected, the reset gate signal line RG2 is selected. All reset TFTs 3308 connected to the reset gate signal line RG2 are turned on, and the reset period RS of the second line starts. Thereafter, the reset gate signal line RG2 is in a non-selected state, and the sampling period ST2 of the second line starts. Note that the first sampling period ST1 and the second sampling period ST2 have the same length, although the starting time is different.
[0177]
Similarly, in the second sampling period ST2, the reverse bias voltage between the electrodes of the photodiode decreases in the sensor portion of each pixel according to the intensity of the input light. After the second sampling period ST2, all the selection TFTs 3306 connected to the sensor gate signal line SG2 are turned on by the signal of the sensor gate signal line SG2, and the potential change between the electrodes of the photodiode 3305 is as follows. Are input to the gate electrode of the buffer TFT 3307, change in the potential of the source region of the buffer TFT 3307, and output to the sensor output wirings SS 1 to SSx.
[0178]
Thereafter, the sensor gate signal line SG2 is not selected.
[0179]
The above operation is repeated for all the sensor gate signal lines SG1 to SGy, and the information of the signals input to the sensor units 3312 of all the pixels of the display unit / input unit 2201 is read.
[0180]
In this way, the position of the pen tip of the input pen can be specified.
[0181]
Note that this embodiment can be freely combined with Embodiments 1 and 2.
[0182]
[Example 4]
The information device of the present invention can be used not only for inputting information with an input pen but also as an image sensor.
[0183]
FIG. 20 is a schematic diagram when the information device of the present invention is used as an image sensor.
[0184]
Since the circuit configuration of the display unit / input unit of the information device is the same as that of the embodiment, the description is omitted here. Further, in the schematic diagram of FIG. 20, the same parts as those of FIG.
[0185]
Further, as a method for driving the display / input unit, a method similar to the method described in the embodiment mode or Example 3 can be used, and thus description thereof is omitted here.
[0186]
An object to be read (read target object: 625) is brought close to the pen input side of the display unit / input unit of the information apparatus of the present invention. Here, the EL element 622 of each pixel is caused to emit light by a method similar to that described in the embodiment mode, Example 3, or the like. Using the light emitted from the EL element 622, the reading target object 625 is irradiated with light. That is, the EL element 622 of each pixel is used as an illumination device for reading information of the reading target object 625.
[0187]
Therefore, when the information device of the present invention is used as an image sensor, it is desirable that the light emission luminances of the EL elements of each pixel are all the same.
[0188]
That is, in the case where the EL element of each pixel is driven by an analog method as shown in the embodiment mode, the analog signal input from the EL source signal line is made equal to all the pixels.
[0189]
On the other hand, when the EL element of each pixel is driven by the digital method as shown in the third embodiment, all the pixels emit light for the same length of time within one frame period. In order to emit light continuously as much as possible, it is desirable that the EL elements of all the pixels be set to emit light in all the sustain periods within one frame period.
[0190]
Thus, the light irradiated on the reading target object 625 is reflected on the surface of the reading target object 625 and is input to the photodiode 621 of the sensor unit of each pixel. This input light is converted into an electrical signal, read by a sensor drive circuit (sensor source signal line drive circuit, sensor gate signal line drive circuit), and information on the surface of the target object 625 to be read is converted into an image. can get.
[0191]
Here, in this embodiment, the description has been given using the information device having the configuration shown in the first embodiment. However, in the second embodiment, the information device having the configuration shown in FIG. It is also possible to read information on the surface of the reading target object by bringing the reading target object closer from the side of the substrate on which the TFT is formed.
[0192]
In addition, a present Example can be implemented combining freely with Example 1- Example 3.
[0193]
[Example 5]
A method for manufacturing the display portion / input portion of the information device of the present invention will be described with reference to FIGS.
[0194]
First, in FIG. 10A, in this embodiment, a substrate 200 made of glass such as barium borosilicate glass represented by Corning # 7059 glass or # 1737 glass or aluminoborosilicate glass is used. The substrate 200 is not limited as long as it has a light transmitting property, and a quartz substrate may be used, or a glass substrate, a ceramic substrate, or the like may be used. Further, a plastic substrate having heat resistance that can withstand the processing temperature of this embodiment may be used.
[0195]
As the substrate 200, a stainless steel substrate may be used. However, since the stainless steel substrate is not transparent, it is effective only when the light emitted from the EL element is emitted to the opposite side of the substrate 200.
[0196]
Next, an insulating film made of silicon oxide is formed over the substrate 200 so as to cover the substrate 200. As the insulating film, a silicon oxide film, a silicon nitride film, or a silicon oxynitride film can be used. For example, SiH by plasma CVD method _Four , NH _Three , N ₂ A silicon oxynitride film made of O is 250 to 800 nm (preferably 300 to 500 nm), similarly SiH _Four , N ₂ A silicon oxynitride nitride film formed from O may be stacked to a thickness of 250 to 800 nm (preferably 300 to 500 nm). Here, the insulating film made of silicon oxide has a single-layer structure and has a thickness of 0.5 to 1.5 μm. Note that the material of the insulating film is not limited to silicon oxide.
[0197]
Next, the planarization insulating film 201 is formed by polishing the insulating film by a CMP method. The CMP method can be performed by a known method. In polishing an oxide film, a solid-liquid dispersion slurry in which an abrasive having a diameter of 100 to 1000 nm is generally dispersed in an aqueous solution containing a reagent such as a PH adjuster is used. In this embodiment, a silica slurry (PH = 10 to 11) in which 20 wt% of fumed silica particles obtained by thermally decomposing silicon chloride gas is used in an aqueous solution to which potassium hydroxide is added.
[0198]
After the planarization insulating film 201 is formed, semiconductor layers 202 to 206 are formed over the planarization insulating film 201. The semiconductor layers 202 to 206 are formed by forming a semiconductor film having an amorphous structure by a known means (sputtering method, LPCVD method, plasma CVD method, or the like), and then known crystallization treatment (laser crystallization method, heat A crystalline semiconductor film obtained by performing a crystallization method or a thermal crystallization method using a catalyst such as nickel) is formed by patterning into a desired shape. The semiconductor layers 202 to 206 are formed to a thickness of 25 to 80 nm (preferably 30 to 60 nm). The material of the crystalline semiconductor film is not limited, but is preferably silicon or silicon germanium (Si _X Ge _1-X (X = 0.0001 to 0.02)) It may be formed of an alloy or the like. In this example, a 55 nm amorphous silicon film was formed by plasma CVD, and then a solution containing nickel was held on the amorphous silicon film. This amorphous silicon film is dehydrogenated (500 ° C., 1 hour), then thermally crystallized (550 ° C., 4 hours), and further laser annealed to improve crystallization. Thus, a crystalline silicon film was formed. Then, the semiconductor layers 202 to 206 were formed by patterning the crystalline silicon film using a photolithography method.
[0199]
Further, after forming the semiconductor layers 202 to 206, a small amount of impurity element (boron or phosphorus) may be doped in order to control the threshold value of the TFT.
[0200]
When a crystalline semiconductor film is formed by laser crystallization, a pulse oscillation type or continuous emission type excimer laser, YAG laser, YVO _Four A laser can be used. When these lasers are used, it is preferable to use a method in which laser light emitted from a laser oscillator is linearly collected by an optical system and irradiated onto a semiconductor film. Crystallization conditions are appropriately selected by the practitioner. When an excimer laser is used, the pulse oscillation frequency is 300 Hz and the laser energy density is 100 to 400 mJ / cm. ² (Typically 200-300mJ / cm ² ). When a YAG laser is used, the second harmonic is used and the pulse oscillation frequency is set to 30 to 300 kHz, and the laser energy density is set to 300 to 600 mJ / cm. ² (Typically 350-500mJ / cm ² ) Then, if the laser beam condensed linearly with a width of 100 to 1000 μm, for example 400 μm, is irradiated over the entire surface of the substrate, the superposition ratio (overlap ratio) of the linear laser light at this time is 50 to 98%. Good.
[0201]
Next, a gate insulating film 209 that covers the semiconductor layers 202 to 206 is formed. The gate insulating film 209 is formed of an insulating film containing silicon with a thickness of 40 to 150 nm by using a plasma CVD method or a sputtering method. In this embodiment, a silicon oxynitride film (composition ratio: Si = 32%, O = 59%, N = 7%, H = 2%) with a thickness of 110 nm is formed by plasma CVD. Needless to say, the gate insulating film is not limited to the silicon oxynitride film, and another insulating film containing silicon may be used as a single layer or a stacked structure.
[0202]
When a silicon oxide film is used, TEOS (Tetraethyl Orthosilicate) and O ₂ The reaction pressure is 40 Pa, the substrate temperature is 300 to 400 ° C., and the high frequency (13.56 MHz) power density is 0.5 to 0.8 W / cm. ² And can be formed by discharging. The silicon oxide film thus manufactured can obtain good characteristics as a gate insulating film by thermal annealing at 400 to 500 ° C. thereafter.
[0203]
Next, as illustrated in FIG. 10A, a first conductive film 210 a with a thickness of 20 to 100 nm and a second conductive film 210 b with a thickness of 100 to 400 nm are stacked over the gate insulating film 209. In this example, a first conductive film 210a made of a TaN film with a thickness of 30 nm and a second conductive film 210b made of a W film with a thickness of 370 nm were stacked. The TaN film was formed by sputtering, and was sputtered in a nitrogen-containing atmosphere using a Ta target. The W film was formed by sputtering using a W target. In addition, tungsten hexafluoride (WF ₆ It can also be formed by a thermal CVD method using In any case, it is necessary to reduce the resistance in order to use it as a gate electrode, and it is desirable that the resistivity of the W film be 20 μΩcm or less. The resistivity of the W film can be reduced by increasing the crystal grains. However, if the W film contains a large amount of impurity elements such as oxygen, crystallization is hindered and the resistance is increased. Therefore, in this embodiment, a sputtering method using a target of high purity W (purity 99.9999%) is used, and a W film is formed with sufficient consideration so that impurities are not mixed in the gas phase during film formation. By forming, a resistivity of 9 to 20 μΩcm could be realized.
[0204]
In this embodiment, the first conductive film 210a is TaN and the second conductive film 210b is W. However, there is no particular limitation, and all of them are Ta, W, Ti, Mo, Al, Cu, Cr, Nd. You may form with the element selected from these, or the alloy material or compound material which has the said element as a main component. Alternatively, a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus may be used. Further, an AgPdCu alloy may be used. In addition, the first conductive film is formed using a tantalum (Ta) film, the second conductive film is formed using a W film, the first conductive film is formed using a titanium nitride (TiN) film, and the second conductive film is formed. The first conductive film is formed of a tantalum nitride (TaN) film, the second conductive film is formed of an Al film, and the first conductive film is formed of a tantalum nitride (TaN) film. The second conductive film may be a combination of Cu films.
[0205]
Next, a resist mask 211 is formed by photolithography, and a first etching process for forming electrodes and wirings is performed (FIG. 10B). The first etching process is performed under the first and second etching conditions. In this embodiment, an ICP (Inductively Coupled Plasma) etching method is used as the first etching condition, and CF is used as an etching gas. _Four And Cl ₂ And O ₂ The gas flow ratio was 25/25/10 (sccm), and 500 W RF (13.56 MHz) power was applied to the coil-type electrode at a pressure of 1 Pa to generate plasma and perform etching. . Here, a dry etching apparatus (Model E645- □ ICP) using ICP manufactured by Matsushita Electric Industrial Co., Ltd. was used. 150 W RF (13.56 MHz) power is also applied to the substrate side (sample stage), and a substantially negative self-bias voltage is applied. The W film is etched under this first etching condition so that the end portion of the first conductive layer is tapered. Under the first etching conditions, the etching rate with respect to W is 200.39 nm / min, the etching rate with respect to TaN is 80.32 nm / min, and the selection ratio of W with respect to TaN is about 2.5. Further, the taper angle of W is about 26 ° under this first etching condition.
[0206]
In the first etching process, by making the shape of the mask 211 made of resist suitable, the ends of the first conductive layer and the second conductive layer are tapered due to the effect of the bias voltage applied to the substrate side. It becomes a shape. The angle of the tapered portion may be 15 to 45 °. Thus, the first shape conductive layers 212 to 216 (the first conductive layers 212 a to 216 a and the second conductive layers 212 b to 216 b) composed of the first conductive layer and the second conductive layer by the first etching treatment. Form. Reference numeral 217 denotes a gate insulating film. A region which is not covered with the first shape conductive layers 212 to 216 is etched and thinned by about 20 to 50 nm.
[0207]
Next, a second etching process is performed without removing the resist mask (FIG. 10C). Here, CF is used as an etching gas. _Four And Cl ₂ And O ₂ The gas flow ratio was 25/25/10 (sccm), and 500 W RF (13.56 MHz) power was applied to the coil-type electrode at a pressure of 1 Pa to generate plasma and perform etching. . 20 W of RF (13.56 MHz) power is also applied to the substrate side (sample stage), and a substantially negative self-bias voltage is applied. In the second etching process, the etching rate with respect to W is 124.62 nm / min, the etching rate with respect to TaN is 20.67 nm / min, and the selection ratio of W with respect to TaN is 6.05. Therefore, the W film is selectively etched. By this second etching, the taper angle of W became 70 °. The second conductive layers 218b to 222b are formed by this second etching process. On the other hand, the first conductive layers 218a to 222a are hardly etched, and the first conductive layers 218a to 222a are formed. Reference numeral 223 denotes a gate insulating film. A region which is not covered with the second shape conductive layers 218 to 222 is etched and thinned by about 20 to 50 nm.
[0208]
An electrode formed of the first conductive layer 218a and the second conductive layer 218b serves as an n-channel buffer TFT formed in a later step, and the first conductive layer 219a and the second conductive layer 219b. The electrodes formed in the above are n-channel type selection TFTs formed in a later step. Similarly, an electrode formed using the first conductive layer 220a and the second conductive layer 220b serves as a p-channel reset TFT formed in a later step, and the first conductive layer 221a and the second conductive layer 220b are formed. The electrode formed with the conductive layer 221b becomes an n-channel switching TFT formed in a later step, and the electrode formed with the first conductive layer 222a and the second conductive layer 222b A p-channel EL driving TFT is formed in the process.
[0209]
Next, a first doping process is performed to obtain the state of FIG. Doping is performed using the second conductive layers 218b to 222b as masks against the impurity elements so that the impurity elements are added to the semiconductor layers below the tapered portions of the first conductive layers 218a to 222a. In this embodiment, P (phosphorus) is used as the impurity element, and the dose amount is 3.5 × 10. ¹² atoms / cm ^Three Plasma doping was performed at an acceleration voltage of 90 keV. In this way, low concentration impurity regions 224a to 228a that do not overlap with the first conductive layer and low concentration impurity regions 224b to 228b that overlap with the first conductive layer are formed in a self-aligned manner. The concentration of phosphorus (P) added to the low concentration impurity regions 224b to 228b is 1 × 10 ¹⁷ ~ 1x10 ¹⁸ atoms / cm ^Three And has a gradual concentration gradient according to the film thickness of the tapered portions of the first conductive layers 218a to 222a. Note that in the semiconductor layer overlapping the tapered portions of the first conductive layers 218a to 222a, although the impurity concentration is slightly decreased from the end portions of the tapered portions of the first conductive layers 218a to 222a to the inside, The concentration is similar.
[0210]
Then, a resist mask 231 is formed, second doping treatment is performed, and an impurity element imparting n-type conductivity is added to the semiconductor layer (FIG. 11B). The doping process may be performed by ion doping or ion implantation. The condition of the ion doping method is a dose of 1 × 10 ¹³ ~ 5x10 ¹⁵ atoms / cm ^Three The acceleration voltage is set to 60 to 100 keV. In this embodiment, the dose amount is 1.5 × 10. ¹⁵ atoms / cm ^Three The acceleration voltage was 80 keV. As an impurity element imparting n-type, an element belonging to Group 15, typically phosphorus (P) or arsenic (As), is used here, but phosphorus (P) is used. In this case, the conductive layers 218 to 222 serve as masks for the impurity element imparting n-type, and the high concentration impurity regions 232a to 236a, the low concentration impurity regions 232b to 236b that do not overlap with the first conductive layer, and the first Low-concentration impurity regions 232c to 236c overlapping with the conductive layers are formed. The high concentration impurity regions 232a to 236a have 1 × 10 ²⁰ ~ 1x10 ^{twenty one} atoms / cm ^Three An impurity element imparting n-type is added in a concentration range of.
[0211]
Note that the semiconductor film in which the p-channel semiconductor film is formed does not need to be doped with n-type impurities by the second doping treatment illustrated in FIG. It may be formed so as to completely cover the surface so that n-type impurities are not doped. Conversely, the mask 231 may not be provided over the semiconductor layers 204 and 206, and the polarity of the semiconductor layer may be reversed to p-type in the third doping process.
[0212]
Next, after removing the resist mask 231, a new resist mask 239 is formed and a third doping process is performed. By this third doping treatment, an impurity region 240a in which an impurity element imparting a conductivity type (p-type) opposite to the one conductivity type (n-type) is added to the semiconductor layer that becomes the active layer of the p-channel TFT. To 240c and 241a to 241c are formed (FIG. 11C). The first conductive layers 220b and 222b are used as masks against the impurity element, and an impurity element imparting p-type is added to form an impurity region in a self-aligning manner. In this embodiment, the impurity regions 240a to 240c and 241a to 241c are diborane (B ₂ H ₆ ) Using an ion doping method. In the third doping process, the semiconductor layer forming the n-channel TFT is covered with a mask 239 made of resist. In the first doping process and the second doping process, phosphorus is added to the impurity regions 240a, 240b, and 240c at different concentrations, respectively, and the concentration of the impurity element imparting p-type is increased in any of the regions. 2 × 10 ²⁰ ~ 2x10 ^{twenty one} atoms / cm ^Three By performing the doping treatment so as to become, no problem arises because it functions as the source region and drain region of the p-channel TFT.
[0213]
Next, a step of activating the impurity element added to each semiconductor layer is performed. This activation process is performed in a thermal annealing furnace using a furnace annealing furnace. The thermal annealing may be performed at 400 to 700 ° C., typically 500 to 550 ° C. in a nitrogen atmosphere having an oxygen concentration of 1 PPm or less, preferably 0.1 PPm or less. In this embodiment, 550 ° C. for 4 hours. The activation treatment was performed by heat treatment. In addition to the thermal annealing method, a laser annealing method, a rapid thermal annealing method (RTA method), or the like can be applied.
[0214]
Further, the activation process may be performed after the first interlayer insulating film is formed. However, when the wiring material used for the wiring is weak against heat, after forming an interlayer insulating film (insulating film containing silicon as a main component, for example, a silicon nitride film) to protect the wiring and the like as in this embodiment. It is preferable to perform the activation process.
[0215]
Furthermore, a heat treatment is performed at 300 to 550 ° C. for 1 to 12 hours in an atmosphere containing 3 to 100% hydrogen to perform a step of hydrogenating the semiconductor layer. In this example, heat treatment was performed at 410 ° C. for 1 hour in a nitrogen atmosphere containing about 3% hydrogen. This step is a step in which the dangling bonds of the semiconductor film are terminated with hydrogen by thermally excited hydrogen. As another means of hydrogenation, plasma hydrogenation (using hydrogen excited by plasma) can also be used.
[0216]
Alternatively, a hydrogenation step may be performed after the passivation film is formed.
[0217]
Through the above steps, impurity regions are formed in the respective semiconductor layers.
[0218]
Next, the resist mask 239 is removed, and a third etching process is performed. In this embodiment, the gate insulating film is etched using the conductive layers 218 to 222 as a mask.
[0219]
Through the third etching process, gate insulating films 243c to 247c are formed below the second conductive layers 243b to 247b (FIG. 12A).
[0220]
Next, a passivation film 291 is formed so as to cover the substrate 200 (FIG. 12B). As the passivation film 291, a silicon oxide film, a silicon nitride film, or a silicon oxynitride film can be used. For example, SiH by plasma CVD method _Four , NH _Three , N ₂ A silicon oxynitride film made from O is 250 to 800 nm (preferably 300 to 500 nm), similarly SiH _Four , N ₂ A silicon oxynitride oxynitride film formed from O may be stacked to a thickness of 250 to 800 nm (preferably 300 to 500 nm). In this embodiment, the passivation film 291 made of nitrogen oxide has a single layer structure and is formed with a thickness of 0.5 to 1.5 μm.
[0221]
Next, a first interlayer insulating film 249 is formed. A plasma CVD method or a sputtering method is used to form an insulating film containing silicon with a thickness of 100 to 200 nm. In this embodiment, a silicon oxynitride film having a thickness of 150 nm is formed by a plasma CVD method. Needless to say, the first interlayer insulating film 249 is not limited to a silicon oxynitride film, and another insulating film containing silicon may be used as a single layer or a stacked structure. Next, patterning for forming contact holes reaching the impurity regions 232a, 233a, 235a, 238, 240a, 241a, and 242 is performed.
[0222]
Next, source wirings 251 to 255 and drain wirings 257 to 261 are formed (FIG. 12C). In this embodiment, it is desirable to use a material having excellent reflectivity such as a film containing Al or Ag as a main component or a laminated film thereof as a material for the wiring.
[0223]
Next, as shown in FIG. 13A, a second passivation film 268 is formed with a thickness of 50 to 500 nm (typically 200 to 300 nm). In this embodiment, a silicon nitride oxide film having a thickness of 300 nm is used as the second passivation film 268. This may be replaced by a silicon nitride film. Prior to the formation of the silicon nitride oxide film, H ₂ , NH _Three It is effective to perform plasma treatment using a gas containing isohydrogen.
[0224]
Next, a second interlayer insulating film 269 made of an organic resin is formed. As the organic resin, polyimide, polyamide, acrylic, BCB (benzocyclobutene), or the like can be used. In particular, since the second interlayer insulating film 269 has a strong meaning of flattening, acrylic having excellent flatness is preferable. In this embodiment, the acrylic film is formed with a film thickness that can sufficiently flatten the step formed by the TFT. The thickness is preferably 1 to 5 μm (more preferably 2 to 4 μm).
[0225]
Next, a contact hole reaching the drain wiring 259 is formed in the second interlayer insulating film 269 and the second passivation film 268, and a cathode electrode 270 of the photodiode is formed so as to be in contact with the drain wiring 259. In this embodiment, an aluminum film formed by sputtering is used as the cathode electrode 270, but other metals such as titanium, tantalum, tungsten, and copper can be used. Alternatively, a laminated film made of titanium, aluminum, or titanium may be used.
[0226]
Next, an amorphous silicon film containing hydrogen is formed over the entire surface of the substrate and then patterned to form a photoelectric conversion layer 271. Next, a transparent conductive film is formed on the entire surface of the substrate. In this embodiment, ITO having a thickness of 200 nm is formed as a transparent conductive film by a sputtering method. The transparent conductive film is patterned to form the anode electrode 272. (Fig. 13B)
[0227]
Next, as shown in FIG. 14A, a third interlayer insulating film 273 is formed. A flat surface can be obtained by using a resin such as polyimide, polyamide, polyimide amide, or acrylic as the third interlayer insulating film 273. In this example, a polyimide film having a thickness of 0.7 μm was formed on the entire surface of the substrate as the third interlayer insulating film 273.
[0228]
Next, a contact hole reaching the drain wiring 261 is formed in the third interlayer insulating film 273, the second interlayer insulating film 269, and the second passivation film 268, and the pixel electrode 275 is formed. In addition, a contact hole reaching the anode electrode 272 is formed in the third interlayer insulating film 273, and a sensor wiring 274 is formed. In this embodiment, an aluminum alloy film (aluminum film containing 1 wt% titanium) is formed to a thickness of 300 nm, and patterning is performed to simultaneously form the sensor wiring 274 and the pixel electrode 275.
[0229]
Next, as shown in FIG. 14B, a bank 276 made of a resin material is formed. The bank 276 may be formed by patterning an acrylic film or a polyimide film having a thickness of 1 to 2 μm. The bank 276 may be formed along the source wiring 254 or may be formed along the gate wiring (not shown). Note that a pigment or the like may be mixed in the resin material forming the bank 276, and the bank 276 may be used as a shielding film.
[0230]
Next, the light emitting layer 277 is formed. Specifically, the organic EL material to be the light emitting layer 277 is dissolved and applied in a solvent such as chloroform, dichloromethane, xylene, toluene, tetrahydrofuran, etc., and then the heat treatment is performed to volatilize the solvent. Thus, a film (light emitting layer) made of an organic EL material is formed.
[0231]
Although only one pixel is shown in this embodiment, when an information device that performs color display is manufactured, a light emitting layer that emits red light, a light emitting layer that emits green light, and a light emitting layer that emits blue light at the same time. Is formed. In this embodiment, cyanopolyphenylene vinylene is formed as a light emitting layer that emits red light, polyphenylene vinylene is formed as a light emitting layer that emits green light, and polyalkylphenylene is formed as a light emitting layer that emits blue light to a thickness of 50 nm. In addition, 1,2-dichloromethane is used as a solvent, and is volatilized by performing heat treatment for 1 to 5 minutes on a hot plate at 80 to 150 ° C.
[0232]
In this embodiment, the EL layer has a single-layer structure composed of a light emitting layer, but a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and the like may be provided in addition. As described above, various examples of combinations have already been reported, and any of the configurations may be used.
[0233]
After the light emitting layer 277 is formed, an anode 279 made of a transparent conductive film is formed as a counter electrode with a thickness of 120 nm. In this embodiment, a transparent conductive film in which 10 to 20 wt% zinc oxide is added to indium oxide is used. As a film forming method, it is preferable that the light emitting layer 277 is formed by vapor deposition at room temperature so as not to deteriorate.
[0234]
After the anode 279 is formed, a fourth interlayer insulating film 280 is formed as shown in FIG. A flat surface can be obtained by using a resin such as polyimide, polyamide, polyimide amide, or acrylic as the fourth interlayer insulating film 280. In this example, a polyimide film having a thickness of 0.7 μm was formed on the entire surface of the substrate as the fourth interlayer insulating film 280.
[0235]
Thus, a sensor substrate having a structure as shown in FIG. 14B is completed. It should be noted that, after the bank 276 is formed, the process from the formation of the fourth interlayer insulating film 280 to a continuous process using the multi-chamber type (or in-line type) thin film forming apparatus without releasing into the atmosphere is possible. It is valid.
[0236]
As described above, the buffer TFT 304, the selection TFT 305, the reset TFT 303, the photodiode 306, the switching TFT 301, the EL driving TFT 302, and the EL element 269 can be formed over the same substrate.
[0237]
Note that the TFTs constituting each driving circuit (EL display source signal line driving circuit, EL display gate signal line driving circuit, sensor source signal line driving circuit, sensor gate signal line driving circuit) are also manufactured by the above manufacturing process. It can be similarly produced. Thus, each drive circuit can be formed on the same substrate as the display / input unit.
[0238]
Note that this embodiment can be freely combined with Embodiments 1 to 4.
[0239]
[Example 6]
In this embodiment, an example in which an information device is manufactured using the present invention will be described with reference to FIGS.
[0240]
6A is a top view of an information device formed by sealing a TFT substrate with a sealing material, and FIG. 6B is a cross-sectional view taken along line AA ′ in FIG. FIG. 6C is a cross-sectional view taken along the line BB ′ in FIG.
[0241]
Display / input unit 4002 provided on the same substrate 4001, source signal line drive circuits 4003a and 400b for sensors and EL elements, and gate signal line drive circuits 4004a and 400b for sensors and EL elements A sealant 4009 is provided so as to surround. In addition, a sealing material 4008 is provided on the display / input unit 4002, the source signal line driver circuits 4003a and 400b for sensors and EL elements, and the gate signal line driver circuits 4004a and 400b for sensors and EL elements. It has been. Therefore, the display / input unit 4002, the sensor and EL element source signal line driver circuits 4003a and 400b, and the sensor and EL element first and second gate signal line driver circuits 4004a and 400b are: The substrate 4001, the sealant 4009, and the sealant 4008 are sealed with a filler 4210.
[0242]
The display / input unit 4002 provided over the substrate 4001, the source signal line driver circuits 4003a and 400b for sensors and EL elements, and the gate signal line driver circuits 4004a and 400b for sensors and EL elements are as follows. And a plurality of TFTs. In FIG. 6B, typically, a reset TFT (TFT for applying a reverse bias voltage to the photodiode) 4201 and an EL drive TFT included in the pixel portion / input portion 4002 formed over the base film 4010. (TFT controlling current to EL element) 4202 and photodiode 4211 are shown.
[0243]
In this embodiment, an n-channel TFT manufactured by a known method is used as the reset TFT 4201, and a p-channel TFT manufactured by a known method is used as the EL driving TFT 4202. The display / input unit 4002 is provided with a storage capacitor (not shown) connected to the gate of the EL driving TFT 4202.
[0244]
A first interlayer insulating film (planarization film) 4311 is formed on the reset TFT 4201 and the EL drive TFT 4202. Next, a second interlayer insulating film (planarization film) 4302 is formed, and a photodiode 4211 is formed thereon. Next, a third interlayer insulating film 4403 is formed, and a pixel electrode (anode) 4203 electrically connected to the drain of the EL driving TFT 4202 is formed thereon. As the pixel electrode 4203, a transparent conductive film having a large work function is used. As the transparent conductive film, a compound of indium oxide and tin oxide, a compound of indium oxide and zinc oxide, zinc oxide, tin oxide, or indium oxide can be used. Moreover, you may use what added the gallium to the said transparent conductive film.
[0245]
An insulating film 4404 is formed over the pixel electrode 4203, and an opening is formed in the insulating film 4404 over the pixel electrode 4203. In this opening, an EL (electroluminescence) layer 4204 is formed on the pixel electrode 4203. A known organic EL material or inorganic EL material can be used for the EL layer 4204. The organic EL material includes a low molecular (monomer) material and a high molecular (polymer) material, either of which may be used.
[0246]
As a method for forming the EL layer 4204, a known vapor deposition technique or coating technique may be used. The EL layer may have a stacked structure or a single layer structure by freely combining a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, or an electron injection layer.
[0247]
Over the EL layer 4204, a cathode 4205 made of a light-shielding conductive film (typically a conductive film containing aluminum, copper, or silver as its main component or a stacked film of these with another conductive film) is formed. . In addition, it is preferable to remove moisture and oxygen present at the interface between the cathode 4205 and the EL layer 4204 as much as possible. Therefore, it is necessary to devise such that the EL layer 4204 is formed in a nitrogen or rare gas atmosphere and the cathode 4205 is formed without being exposed to oxygen or moisture. In this embodiment, the above-described film formation is possible by using a multi-chamber type (cluster tool type) film formation apparatus. The cathode 4205 is given a predetermined voltage.
[0248]
As described above, an EL element 4303 including the pixel electrode (anode) 4203, the EL layer 4204, and the cathode 4205 is formed. A protective film 4209 is formed over the insulating film 4302 so as to cover the EL element 4303. The protective film 4209 is effective in preventing oxygen, moisture, and the like from entering the EL element 4303.
[0249]
Reference numeral 4005 denotes a lead wiring connected to the power supply line, and is electrically connected to the source region of the EL driving TFT 4202. The lead wiring 4005 passes between the sealant 4009 and the substrate 4001 and is electrically connected to the FPC wiring 4301 included in the FPC 4006 through the anisotropic conductive film 4300.
[0250]
As the sealing material 4008, a glass material, a metal material (typically a stainless steel material), a ceramic material, or a plastic material (including a plastic film) can be used. As the plastic material, an FRP (Fiberglass-Reinforced Plastics) plate, a PVF (polyvinyl fluoride) film, a mylar film, a polyester film, or an acrylic resin film can be used. A sheet having a structure in which an aluminum foil is sandwiched between PVF films or mylar films can also be used.
[0251]
However, when the emission direction of light from the EL element is directed toward the cover material, the cover material must be transparent. In that case, a transparent material such as a glass plate, a plastic plate, a polyester film or an acrylic film is used.
[0252]
As the filler 4103, in addition to an inert gas such as nitrogen or argon, an ultraviolet curable resin or a thermosetting resin can be used. PVC (polyvinyl chloride), acrylic, polyimide, epoxy resin, silicon resin, PVB (Polyvinyl butyral) or EVA (ethylene vinyl acetate) can be used. In this example, nitrogen was used as the filler.
[0253]
Further, in order to expose the filler 4210 to a hygroscopic substance (preferably barium oxide) or a substance capable of adsorbing oxygen, a recess 4007 is provided on the surface of the sealing material 4008 on the substrate 4001 side to adsorb the hygroscopic substance or oxygen. A possible substance 4207 is placed. In order to prevent the hygroscopic substance or the substance 4207 capable of adsorbing oxygen from scattering, the concave part cover material 4208 holds the hygroscopic substance or the substance 4207 capable of adsorbing oxygen in the concave part 4007. Note that the concave cover material 4208 has a fine mesh shape, and allows air and moisture to pass therethrough, but does not pass hygroscopic substances or substances 4207 capable of adsorbing oxygen. By providing the hygroscopic substance or the substance 4207 capable of adsorbing oxygen, deterioration of the EL element 4303 can be suppressed.
[0254]
As shown in FIG. 6C, a conductive film 4203a is formed so as to be in contact with the lead wiring 4005 at the same time as the pixel electrode 4203 is formed.
[0255]
The anisotropic conductive film 4300 has a conductive filler 4300a. By thermally pressing the substrate 4001 and the FPC 4006, the conductive film 4203a on the substrate 4001 and the FPC wiring 4301 on the FPC 4006 are electrically connected by the conductive filler 4300a.
[0256]
In addition, a present Example can be implemented freely combining with Example 1- Example 5. FIG.
[0257]
[Example 7]
In this example, an example in which the photoelectric conversion element of the information device of the present invention is manufactured using an organic substance will be described.
[0258]
A photodiode is described as an example of the photoelectric conversion element.
[0259]
An organic substance is used as the photoelectric conversion layer of the photodiode. Specifically, azo pigments, polycyclic compounds such as perylene, phthalocyanine pigments, ionic dyes, and the like can be used. Here, the photoelectric conversion layer is referred to as a charge generation layer.
[0260]
In addition to the charge generation layer, a charge injection barrier layer, a charge transport layer, or the like can be provided.
[0261]
As the charge transport layer, a low molecular compound such as a hydrazone derivative, a stilbenzene derivative or a triphanylamine derivative, or a polymer material such as a polysilane derivative can be used.
[0262]
By providing such a charge transport layer, the light response characteristics of the photodiode can be improved.
[0263]
As the charge injection barrier layer, copolymer nylon or the like can be used.
[0264]
A method for manufacturing such a photodiode having a stacked structure of a charge injection barrier layer, a charge generation layer, and a charge transport layer will be described with reference to FIGS.
[0265]
An anode electrode 991 of an ITO film is formed, and a charge injection barrier layer 992, a charge generation layer 993, a charge transport layer 994, and a cathode electrode 996 are formed in this order.
[0266]
Here, as the charge injection barrier layer 992, a copolymer nylon layer is applied.
[0267]
Thereafter, the charge generation layer 993 is formed by dispersing and applying an azo pigment in a binder resin.
[0268]
Next, the charge transport layer 994 is formed by dispersing and applying the hydrazone derivative in a binder resin.
[0269]
Finally, a cathode electrode 996 is formed from aluminum, and a photodiode 997 is completed.
[0270]
Note that the configuration of the photodiode is not limited to this. The charge injection barrier layer and the charge transport layer are not necessarily set.
[0271]
The anode electrode, the cathode electrode, the charge injection barrier layer, the charge generation layer, the charge transport layer, and the like are not limited to the above materials, and known materials can be used freely.
[0272]
Compared with photodiodes using inorganic substances such as semiconductors, those using organic substances have the advantage that a large-area photodiode can be manufactured, and that they are flexible and have excellent processability.
[0273]
In addition, a present Example can be implemented combining freely with Example 1- Example 6. FIG.
[0274]
[Example 8]
In this embodiment, an electronic device to which the information device of the present invention is applied will be described. As an example to which the information device of the present invention is applied, a personal digital assistant (PDA, mobile phone, electronic book, etc.) and the like can be cited.
[0275]
FIG. 4A is a schematic diagram of a PDA. A display / input unit 1901, an input pen 1902, operation keys 1903, an external connection port 1904, and a power switch 1905 are provided. The information device of the present invention can be used for a display / input unit 1901 of a PDA.
[0276]
FIG. 4B is a schematic diagram of an electronic book. A display / input unit 1911, an input pen 1912, operation keys 1913, and a recording medium 1914 are provided. The information device of the present invention can be used for a display / input unit 1911 of an electronic book.
[0277]
FIG. 21A and FIG. 21B are examples in which the information device of the present invention is applied to a portable information terminal having a function of personal authentication work.
[0278]
Here, the personal authentication work refers to a function that compares information registered in advance with information input thereafter and determines whether these two pieces of information indicate the same person. To do.
[0279]
FIG. 21A illustrates a portable information terminal 2183. This portable information terminal 2183 includes an input pen 2181, a display / input unit 2184, operation keys 2185, an external connection port 2186, a power switch 2187, and the like.
[0280]
Using the method using the display / input unit 2184 as an image sensor shown in the fourth embodiment, the hand 2188 is placed on the display / input unit 2184 to read the palm print.
[0281]
The read palm print can be used as information for identifying an individual (personal information) to perform an authentication operation.
[0282]
The personal information used for the authentication work is not limited to palm prints, and biometric information such as fingerprints can be used freely.
[0283]
These personal information for authentication can be used in any combination.
[0284]
FIG. 21B illustrates a portable information device having the same configuration as that illustrated in FIG. 21A, but a case where the personal authentication operation is performed by a different method will be described.
[0285]
Here, the information of handwriting 2191 input to the display / input unit 2184 by the input pen 2181 is used for the authentication work.
[0286]
In addition, personal information such as handwriting input by pen input and personal information such as palm prints and fingerprints input by an image sensor can be freely combined and applied to a portable information terminal that performs personal authentication work. You can also.
[0287]
The application range of the present invention is extremely wide, and can be applied to electronic devices in various fields. Moreover, the electronic apparatus of a present Example is realizable even if it uses the structure which consists of what combination of Examples 1-7.
【The invention's effect】
Conventional information devices having a resistive film type or optical pen input function have problems such as image visibility, device durability, accuracy, miniaturization, and power consumption.
[0288]
The information device having a pen input function according to the present invention has both an EL element and a photoelectric conversion element arranged in a pixel of a display device, and information is input by inputting light to the photoelectric conversion element with a pen that emits light from a pen tip. I do. As a result, an information device that displays a clear image without impairing the brightness of the display image, has excellent durability, can be miniaturized, and has a highly accurate pen input function can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an information device of the present invention.
FIGS. 2A and 2B are schematic views of an upper surface and a cross section of the photosensor of the present invention. FIGS.
FIG. 3 is a circuit diagram of a pixel portion of a display panel with an image sensor of the information device of the present invention.
FIG. 4 is a diagram of an electronic apparatus to which the information device of the present invention is applied.
FIG. 5 is a timing chart of driving of the information device of the present invention.
6A and 6B are a top view and a cross-sectional view of an information device according to the present invention.
FIG. 7 is a diagram showing the structure of a conventional resistive film pen input device.
FIG. 8 is a diagram showing the structure of a conventional resistive film pen input device.
FIG. 9 is a diagram showing a structure of a conventional optical pen input device.
FIG. 10 is a diagram showing a manufacturing process of an information device of the present invention.
FIG. 11 is a diagram showing a manufacturing process of an information device of the present invention.
FIG. 12 is a diagram showing a manufacturing process of an information device of the present invention.
13 is a diagram showing a manufacturing process of an information device of the present invention. FIG.
14 is a diagram showing a manufacturing process of an information device of the present invention. FIG.
FIG. 15 is a cross-sectional view of an information device of the present invention.
FIG. 16 is a cross-sectional view of an information device according to the present invention.
FIG. 17 is a timing chart of driving of the information device of the present invention.
FIG. 18 is a timing chart of driving of the information device of the present invention.
FIG 19 is a diagram showing a structure of a photoelectric conversion element of an information device of the present invention.
FIG. 20 is a cross-sectional view of the information device of the present invention.
FIG. 21 is a diagram of an electronic device to which the information device of the invention is applied.

Claims (7)

A method for driving an information device having a plurality of pixels each having an EL element and a photoelectric conversion element in a display / input unit ,
Each of the plurality of pixels includes a first transistor and a second transistor,
One of a source and a drain of the first transistor is electrically connected to the first wiring;
The other of the source and drain of the first transistor is electrically connected to the gate of the second transistor;
One of a source and a drain of the second transistor is electrically connected to the second wiring;
The other of the source and drain of the second transistor is electrically connected to the EL element ;
One frame period has a plurality of subframe periods,
Each of the plurality of subframe periods has an address period and a sustain period;
When using the information device as an image sensor , in all the sustain periods of the plurality of subframe periods, the reading target object is irradiated with light by causing all the EL elements of the plurality of pixels to emit light,
The light reflected from the object to be read is input to the photoelectric conversion elements of the plurality of pixels,
A method of driving an information device, wherein information on a surface of the object to be read is obtained by converting light input to the photoelectric conversion element into an electrical signal and reading the electrical signal. Oite to claim 1,
Each of the plurality of pixels includes a third transistor, a fourth transistor, and a fifth transistor,
A gate of the third transistor is electrically connected to the photoelectric conversion element;
The source of the third transistor is electrically connected to the third wiring through the fourth transistor in a conductive state,
The method for driving an information device, wherein the photoelectric conversion element is electrically connected to a fourth wiring through the fifth transistor in a conductive state. In claim 1 or 2 ,
The method for driving an information device, wherein the photoelectric conversion element is a photodiode. In claim 3 ,
The method of driving an information device, wherein the photodiode includes an anode electrode, a cathode electrode, and a photoelectric conversion layer sandwiched between the anode electrode and the cathode electrode. In claim 4 ,
The method for driving an information device, wherein the photoelectric conversion layer is made of an organic material or an amorphous semiconductor. In any one of Claims 1 thru | or 5 ,
A method of driving an information device, wherein the information on the surface of the object to be read is biological information. In claim 6 ,
The method of driving an information device, wherein the biological information is a palm print or a fingerprint.

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