JPH11274551A - Led device, driving method thereof, light source, picture forming apparatus, picture reader and display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise the light emitting intensity and reduce the crosstalk by storing charges corresponding to data signals in a storage capacitor to drive an LED element to emit a light by the stored charges. SOLUTION: When a reset signal applied to Pd2 is reset, a reset diode 5 turns on to flow a current in a storage capacitor 2, the potential on Pm goes to a reset potential while a high current flows in a driving transistor 3 and an LED element 4 lights at a high brightness. When the reset signal applied to Pd2 goes to a non-reset state, the reset diode 5 turns off and a select signal applied to Pc goes to a select state to raise the potential on Pc , resulting in that the potential difference between Pm and Pc and the current flowing in the driving transistor 3 settle to values conformed with data signals and light emission intensity of the LED element 4 settles to a value conformed with the data signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a light emitting device used for electronic equipment such as a copying machine, a printer, a computer system, and a television system.

[0002]

2. Description of the Related Art Conventionally, a light emitting device in which a large number of pixels each composed of a minute light emitting portion are arranged one-dimensionally or two-dimensionally and the light emission of each pixel can be individually controlled has been used in an image forming apparatus such as a copying machine or a printer. It is used as a writing head or the like inside a forming apparatus, or as a display device of a computer system, a television system, or the like. Here, the prior art and its problems will be described using an example of a write head of an image forming apparatus. FIG. 42 shows a schematic configuration diagram of an example of an image forming apparatus using a conventional electrophotographic method.

In FIG. 42, reference numeral 91 denotes a rotating drum type electrophotographic photosensitive member as an image carrier, 92 denotes a charging device, 93 denotes a developing device, 94 denotes a transfer device, 95 denotes a fixing device, and 96 denotes a cleaning device. The mechanism of operation of the image forming apparatus of this figure is as follows.

The photosensitive member 91 is uniformly charged by a charging device 92. Exposure L corresponding to a time-series electric digital image signal of desired image information is performed on the belt surface of the photoconductor 92, and an electrostatic latent image corresponding to the desired image information is formed on the peripheral surface of the photoconductor 91. It is formed. The electrostatic latent image is developed as a toner image by a developing device 93 using a developing toner. On the other hand, a transfer material P
Is supplied at a predetermined timing to a press-contact nip (transfer portion) T between the photoreceptor 91 and the contact transfer means contacted with a predetermined pressing force, and a predetermined transfer bias voltage is applied. Thus, the toner image is transferred to the transfer material P. The transfer material P to which the toner image has been transferred is separated from the surface of the photoreceptor 91, introduced into a fixing device 95 such as a heat fixing system, and fixed to the toner image, and discharged out of the device as an image formed product (print). Is done. After the transfer of the toner image to the transfer material P, the surface of the photoreceptor 91 is cleaned by removing the adhered contaminants such as residual toner by the cleaning device 96, and is repeatedly provided for the operation.

Here, as an exposure system for writing a latent image on the photosensitive member 91, a laser beam system, an LED (light emitting diode) array system, or the like is mainly used.

In the laser beam method, a latent image is formed by scanning a laser beam emitted from a laser device such as a semiconductor or a gas laser on a photoreceptor 91 via a polygon mirror or a lens while controlling the intensity thereof. However, there is a problem that optical components such as a polygon mirror and a lens become obstacles, and it is difficult to reduce the size and cost of the apparatus.

In the LED array system, the light emission intensity of the light emitting portions of the LED chips arranged in large numbers on a substrate is controlled by a data signal, and an image is formed by projecting the light on a photoreceptor by a rod lens array. Since it is more suitable for downsizing and price reduction than the laser beam method, it has been widely used. FIG. 43 shows a configuration of such an LED array type printer head.

In FIG. 43, an LED array type printer head has a plurality of LED array chips 112 arranged in a line on a substrate 111, and each of these LED arrays is connected to a circuit comprising a plurality of driver ICs 113 for driving and a bonding wire. The LED printer heads are connected with each other at 114 and arranged one-dimensionally. Accordingly, the LED array of the LED printer head emits light in response to a predetermined drive signal, and the emitted light irradiates the surface of the photoconductor via the rod lens array 115 to form a latent image.

In such an LED array system, since the substrate is expensive and an array cannot be formed with one substrate, it is necessary to arrange the cut chips. At this time, if the steps and intervals between the chips are not strictly managed, the quality of the image is degraded. There is a problem that this causes a cost increase.

On the other hand, in recent years, an organic thin-film light-emitting element (hereinafter, referred to as an “organic LED element”) which can be formed as a thin film on a large-area substrate and can be driven in a direct current has been developed. It has been proposed to use, as a printer head, an organic LED device in which light-emitting portions composed of organic LED elements are arranged one-dimensionally.

FIG. 44 is a plan view schematically showing an example of such an organic LED device. In this example, a device including nine pixels is shown.

In FIG. 44, reference numeral 120 denotes a translucent substrate;
Reference numeral 129 denotes an organic LED element that constitutes a light emitting unit of each of the pixels 1 to 9. BLK _{1 to} BLK ₃ are common wirings connected to the anodes of the organic LED elements of each pixel, and MTX _{1 to} MTX ₃ are matrix wirings connected to the cathodes of the organic LED elements of each pixel. 50 denotes matrix wirings MTX _{1 to} MT
Data signal circuit for supplying a data signal to X ₃ (DAT
A), 60 is a selection signal circuit for supplying a selection signal to the common line BLK ₁ ~BLK ₃ (SEL).

FIG. 45 is a schematic diagram showing a section taken along the line AA ′ in FIG. In the drawing, reference numeral 131 denotes a cathode of the organic LED element 121, and MTX ₁ is connected to a lead line thereof. The cathode 131 is composed of Li, Al, Mg, Mg-Ag, A
It is composed of a thin film such as l-Li, In or the like. Reference numeral 132 denotes an organic light emitting layer of the organic LED element 121, which includes, for example, an electron transport layer made of an organic electron transport material such as an aluminum quinolinol complex and a hole transport layer made of an organic hole transport material such as triphenylamine. It is formed by lamination. BLK ₁ is both an anode of the organic LED and a common wiring, and is formed of indium tin oxide (ITO) or the like.

FIG. 46 is a diagram showing an overall equivalent circuit of the above-described organic LED device. Organic LE for pixels 1-3
The anode side of each of the D elements 121 to 123 has a common wiring BLK _1.
It is connected to the. Similarly, the organic LED element 124
- 126 is the BLK _2, 127 to 129 are respectively connected to the BLK _3.

On the other hand, the cathodes of the organic LED elements 121 to 123 are respectively different matrix wirings MTX _{1 to} MTX _3.
It is connected to the. Similarly, 124-126, 127-
129 are connected to different matrix wirings, and as a result, the organic LED elements 121, 124, 127
Are commonly used as MTX ₁ , the cathodes 122, 125 and 128 are used as MTX ₂ and the cathodes 123, 126 and 129 are used as MTX _1.
They are connected in common respectively to the TX _3.

The common lines BLK _{1 to} BLK ₃ are drawn out and connected to a selection signal circuit 60 such as a shift register. The matrix wirings MTX _{1 to} MT
X ₃ is connected to a data signal circuit 50 having a signal source operating on each.

FIG. 47 is a diagram showing an example of the drive timing of the organic LED device as described above. In the figure, sel ₁ to
sel ₃ is a selection signal applied to the common lines BLK _{1 to} BLK ₃ , and data _{1 to} data ₃ are matrix lines MT
Data signals applied to X _{1 to} MTX ₃ , L _{121 to} L ₁₂₁
Reference numeral ₁₂₉ denotes the luminance of the organic LED elements 121 to ₁₂₉ .

The selection signal sel ₁ applied to the common line BLK ₁ at time t ₁ becomes a high potential state is on. se
l ₂ and sel ₃ remain in the low potential state which is off.
On the other hand, the data signal data ₁ to Data _3, which is applied to the matrix wiring MTX ₁ ~MTX ₃ becomes the low potential state. Therefore, the organic L connected to the common wiring BLK ₁
A forward voltage is applied to the ED elements 121 to 123, and light emission starts.

After the lapse of the period τ ₁ , at time t _{1 ′} , the selection signal s
el ₁ is a low potential state, which is the off, data ₁ ~d
Data ₃ also becomes a high potential state. Therefore, no forward voltage is applied to the organic LED elements 121 to 123, and the light emission ends.

Next, at time t ₂ , only the selection signal sel ₂ applied to the common line BLK ₂ is turned on to a high potential state, and data _{1 to} data ₃ are also turned to a low potential state.
A forward potential is applied to the organic LED elements 124 to 126, and light emission starts. After the period τ _{2 has} elapsed, at time t _{2 ′} , sel ₂ is in a low potential state, and data _{1 to} data ₃ are in a high potential state,
The light emission of the organic LED elements 124 to 126 ends.

Similarly, only the organic LED elements 127 to 129 emit light during a period τ _{3 from} time t _{3 to} t _{3 ′} . In this way, the pixels belonging to each block emit light while slightly shifting the timing.

Such an organic LED device uses a vacuum process such as vapor deposition or sputtering on a light-transmitting substrate such as glass to form a metal or ITO as an electrode, or an organic electron transporting material or an organic light emitting layer. It is obtained by forming a film of an organic hole transporting material or the like and patterning the film using a technique such as photolithography. If a sufficiently large substrate is used, the entire organic LED device can be made from a single substrate,
It is not necessary to arrange the chips cut out like an LED array. Therefore, if this organic LED device is used as a printer head, a small, high-definition, and low-cost image forming device that does not require a polygon mirror or the like as in the laser beam system and has no problem of step difference between chips as in the LED array system. A device can be obtained.

[0023]

However, the above-mentioned organic LED device has a problem that a sufficient light emission intensity cannot be obtained as compared with the LED array.

The first reason is a problem of the organic LED element itself.
LEDs made of inorganic materials such as aAs and AlInGaP
This is because, compared to the organic LED element, the organic LED element has problems such as low luminous efficiency, high DC forward voltage and large heat generation, and significant deterioration due to self-heating, which prevents a sufficient current from flowing.

In recent years, research on this point has progressed, and the development of new organic electron transporting materials, organic hole transporting materials, organic light emitting materials, etc., and the improvement of the film structure of organic LED elements have led to
It is improving rapidly.

Furthermore, the second reason is that it is caused by the circuit configuration or driving method of the organic LED device.

In the configuration as shown in FIG.
Each organic LED element emits light only while the selection signal applied to the common wiring connected to its electrode is on, and does not emit light while the selection signal is off. For this reason, organic LED
When the number of pixels constituting the device increases and the number of blocks increases, the light emission duty of each pixel decreases. Was.

Further, in order to prevent crosstalk, the pixels connected to the common line whose selection signal is off must not emit light. To ensure this, a reverse voltage is applied to the organic LED element connected to the common line whose selection signal is off. However, organic LE
Applying an excessively large reverse voltage to the D element is not desirable because it leads to deterioration, and as a result, a sufficient reverse voltage cannot be applied, so that crosstalk cannot be completely prevented.

The present invention has been made in view of the above problems, and an LED device having a high light emission duty of a pixel, a high light emission intensity on a time average within a predetermined time, and a small crosstalk, particularly an organic LED. An object of the present invention is to provide an image forming apparatus, a display apparatus, and an image reading apparatus which realize a device and have high image quality and low power consumption.

[0030]

According to the present invention, first, an LED element having a light emitting layer sandwiched between an anode and a cathode on a substrate, a storage capacitor for accumulating electric charge, and a resistance varying according to an applied voltage are provided. A non-linear two-terminal element, comprising: storing an electric charge corresponding to a data signal in the storage capacitor via the non-linear two-terminal element; and operating the LED element by the stored electric charge. An object of the present invention is to provide a method for driving an LED device, which emits light.

Secondly, the present invention provides an LED device for implementing the above-mentioned driving method, in which an LED element having a light emitting layer sandwiched between an anode and a cathode, a storage capacitor, and a light emitting element are applied. A non-linear two-terminal element whose resistance changes according to a voltage, wherein the LED element emits light by electric charges stored in the storage capacitor via the non-linear two-terminal element in response to a data signal. .

Furthermore, the present invention thirdly provides the above-mentioned LE of the present invention.
The D device has n × m pixels (where n and m are 2 or more) as one pixel, and divides the plurality of pixels into m blocks composed of n pixels adjacent to each other. , The pixels of each block are commonly wired for each block by m common wirings, one pixel is selected from each block, and commonly wired between different blocks by n matrix wirings. An LED device is provided.

In the present invention, a storage capacitor is connected to the LED element, the charge is temporarily stored in the storage capacitor, and the LED element emits light by the stored charge.
Since the accumulation of electric charge in the storage capacitor is controlled by a non-linear two-terminal element whose resistance changes according to the applied voltage, in an arbitrary pixel of a device having a plurality of pixels, the electric charge is stored in the storage capacitor of another pixel. During the period during which is stored, the light emission of the LED element can be continued by the charge stored in the storage capacitor of the pixel, and a sufficient amount of light energy for forming an image can be obtained as the total light energy for one scanning time. For this reason, even when the organic LED element is used, there is obtained an advantage that the element is hardly deteriorated and the energy use efficiency is high.

In the present invention, it is preferable that the current flowing between the source and drain electrodes is controlled by a transistor whose current is controlled by the amount of charge stored in the storage capacitor.
By controlling the current flowing through the ED element, the required amount of stored charge can be reduced, so that the size of the nonlinear two-terminal element and the storage capacitor can be reduced, and the area of the LED element can be increased accordingly, Greater light emission can be obtained.

In the LED device of the present invention, an LED device in which pixels are arranged one-dimensionally and an LED device in which n rows × m columns are arranged two-dimensionally are formed. An image display device, an image reading device, and a display device are configured.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, each component of the present invention will be described in detail.

[Embodiment 1] FIG. 1 shows an equivalent circuit of an LED device according to a first embodiment of the present invention. In the figure, 1 is a writing diode, 2 is a storage capacitor, 3 is a driving transistor which is a thin film transistor, and 4 is an LED which is a light emitting portion.
The element 5 is a reset diode, and the write diode 1 and the reset diode 5 correspond to the nonlinear two-terminal element according to the present invention. P _c is the storage capacitor 2
P _m is an electrode connected to the second side of the storage capacitor, P _d1 is an electrode connected to the cathode of the writing diode 1, P _d2 is an electrode connected to the anode of the reset diode, and P _led is an LED. The electrode connected to the cathode of the element 4 is shown.

In this embodiment, _Pc is a selection signal, _Pd1 is a data signal, _Pd2 is a reset signal, _Pm
A potential corresponding to the data signal appears due to charging and discharging of the storage capacitor 2. P _led is a fixed potential.

FIG. 2 is a diagram showing an example of voltage-current characteristics of a diode. The diode has high resistance when the voltage is applied in the reverse direction or the voltage applied in the forward direction does not exceed the rising voltage, but the voltage applied in the forward direction exceeds the rising voltage And the resistance is rapidly reduced.

In all the embodiments described below, the write diode, the reset diode, or the MIM
The (Metal Insulator Metal) element may be a single element, or may be a single unit composed of a circuit in which a plurality of elements are connected in series or parallel with their forward directions aligned. It is sufficient that the element has the property of a non-linear element whose resistance changes according to the applied voltage, and is appropriately selected depending on the convenience of adjusting the operating voltage, securing the operating current, and the like. The same applies to the storage capacitor and the drive transistor, and these can be replaced by a circuit unit having an equivalent function.

In the drive transistor 3 of this embodiment, the channel formed in the gate portion is an n-channel type field effect transistor using electrons as charge transport carriers. Further, when the potential of the gate electrode of the transistor is lower than or equal to the potential of the source electrode, no current flows between the source electrode and the drain electrode, and when the potential of the gate electrode is higher than the potential of the source electrode, It operates in an enhancement mode in which current flows through the device.

FIG. 3 is a diagram showing the drive timing of the LED device of the present embodiment, and shows the selection signal se applied to _Pc .
1, data signal data applied to P _d1 , reset signal res applied to P _d2 , potential of P _m , LED element 4
And the luminance L. Hereinafter, the operation of the LED device of the present embodiment will be described.

At time t ₁ , when the reset signal res applied to P _d2 enters the reset state (high potential state), P _d2
Potential rises. A forward voltage is applied to the reset diode 5, and the reset diode 5 becomes conductive. Therefore, a current flows into the storage capacitor 2. Potential of this for P _m is reset to reset potential (V _reset). The gate electrode of the P _m is the driving transistor 3, since P _c are respectively connected to the source electrode of the driving transistor 3, a current flows to the driving transistor 3 in accordance with the potential difference between the P _m and P _c, the high reset state At this time, a large current flows through the drive transistor 3 because of the potential, and the LED element 4 emits light with high luminance.

At time t ₂ , when the reset signal res applied to P _d2 goes into the non-reset state (low potential state), P
The potential of _d2 drops. Since a voltage higher than the rising forward voltage is not applied to the reset diode 5, the reset diode 5 is turned off. At the same time, the selection signal sel applied to _Pc is in the selected state (high potential state), and the potential of _Pc rises. As a result, increases the potential of the P _m which separates the storage capacitor 2, the write diode 1 takes forward voltage, becomes conductive. Therefore, the potential is settled to a potential corresponding to the data signal data applied to P _d1 . Accordingly, restless to the value current is also corresponding to the data signal (data) flows to the potential difference and the driving transistor 3 P _m and P _c, the light emission luminance of the LED element 4 is also settled to a value corresponding to the data signal data.

At time t ₃ , the selection signal s applied to P _c
el is the potential of the P _m becomes a non-selected state (low potential) is lowered. However, since not change the potential difference P _m and P _c, the current flowing through the driving transistor 3 is hardly changed, the emission luminance of the LED element 4 is also hardly changed.

While the selection signal sel applied to P _c is in a non-selection state (low potential state), a forward voltage higher than the rising voltage is not applied to the write diode 1.
Has a non-conducting state, the potential of the even P _m and the data signal data applied to the P _d1 is changed are preserved,
The current flowing through the drive transistor 3 continues to flow as it is, and the light emission of the LED element 4 continues.

The time t ₄ and later, the above-described operation is repeated.

FIG. 4 shows the LE of the first embodiment of the present invention.
FIG. 14 is a diagram illustrating another example of the drive timing of the D device. This example is different from the driving of FIG. 3 in that the data signal data for determining the luminance of the LED element 4 is given as a time modulation signal.

[Embodiment 2] FIG. 5 shows an equivalent circuit of an LED device according to a second embodiment of the present invention. In the figure, 1 is a write diode, 2 storage capacitor, the driving transistor 3, the LED element 4, 6 are reset diode, P _c is connected to the first side of the storage capacitor 2 electrode, P _m is the storage capacitor Electrodes hanging on the second side of the
P _d1 is an electrode connected to the anode of the writing diode 1;
_d2 is an electrode connected to the cathode of the reset diode 5, P
_led indicates an electrode connected to the cathode of the LED element 4. In this embodiment, a selection signal is applied to P _c , a data signal is applied to P _d1 , a reset signal is applied to P _d2 , and a potential corresponding to the data signal appears in P _m by charging and discharging of the storage capacitor 2. . P _led is a fixed potential. Also in the present embodiment, the driving transistor 3 is an n-channel field effect transistor and operates in the enhancement mode.

FIG. 6 shows the drive timing of the LED device of this embodiment. In this figure, similarly to FIG. 3, the selection signal sel applied to P _c , the data signal data applied to P _d1 ,
Reset signal res applied to P _d2 , potential of P _m , L
5 shows the luminance L of the ED element 4. Hereinafter, the operation of the LED device of the present embodiment will be described.

At time t ₁ , when the reset signal res applied to P _d2 enters the reset state (low potential state), the potential of P _d2 falls. A forward voltage is applied to the reset diode 5, and the reset diode 5 becomes conductive. Therefore, current flows from the storage capacitor 2, the potential of the P _m reset potential (V
_reset ). At this time, since the reset potential is low, no current flows through the drive transistor 3 and the LED element 4 does not emit light.

[0052] In time t _2, the when the reset signal res applied to P _d2 becomes non reset state (high potential state) P _d2
Potential rises. The reset diode 5 is not applied with a forward voltage higher than the rising voltage, and becomes non-conductive. At the same time, the selection signal sel applied to P _c is in the selected state (low potential state), and the potential of P _c falls. As a result, lowers the potential of the P _m which separates the storage capacitor 2, the write diode 1 takes forward voltage, becomes conductive. Therefore, current flows into the storage capacitor 2 in accordance with the data signal data applied to P _d1 , and P
The potential of _m is the data signal d applied to P _d1 during the selection period.
It calms down to the potential corresponding to the data. The gate electrode of the P _m is the driving transistor 3, since P _c are respectively connected to the source electrode of the driving transistor 3, P _m and P at this time
_A current flows through the driving transistor 3 according to the potential difference of _c ,
The LED element 4 emits light.

At time t ₃ , the selection signal s applied to P _c
el is the potential of the P _m becomes a non-selected state (high potential state) increases. However, since not change the potential difference P _m and P _c, the current flowing through the driving transistor 3 is hardly changed, the emission luminance of the LED element 4 is also hardly changed.

While the selection signal sel applied to P _c is in a non-selection state (high potential state), the write diode 1 is in a non-conductive state without applying a forward voltage higher than the rising voltage. Data signal d applied to P _d1
ata also changes, since the potential of the P _m is maintained as it is, the current flowing through the driving transistor 3 continues to flow as it is, thus LED element 4 is directly sustained emission.

[0055] time t ₄ and later, the above-described operation is repeated.

FIG. 7 is a diagram showing another drive timing of the LED device of FIG. The driving timing in this figure differs from that in FIG. 6 in that the data signal data is given as a time-modulated signal.

[0057] In this embodiment, when the driving transistor 3 is transistor operating in en lotus placement mode n-channel type, as compared with the first embodiment, from the extreme potential of the P _m at reset is P _c The point is that unnecessary high current does not flow to the LED element 4 because it does not increase.
In the case where the LED element 4 is an organic LED element, flowing an excessive current is a factor that accelerates the deterioration, and the present embodiment is more advantageous in this point. In addition, if a high current flows through the organic LED element at the time of reset, regardless of the data signal, and the light is emitted, complete black cannot be expressed and the problem that the contrast is lowered occurs. Therefore, the present embodiment is also preferable in that respect. .

[0058] Also, when the driving transistor 3 is transistor operating in depletion mode n-channel type, as compared with the previous embodiments, can be set so that the potential of P _m is sufficiently lower than the potential of the P _c at reset Therefore, a similar advantage can be obtained.

[0059] Conversely, when the driving transistor 3 of the transistor to operate in an enhancement mode and depletion-mode p-channel type, towards the circuit configuration of the first embodiment, potential P _c of P _m at reset Is not extremely lower than the potential of P _m
Can be set to be sufficiently higher than the potential of _Pc , so that unnecessary high current does not flow, which is advantageous.

Third Embodiment FIG. 8 shows a third embodiment of the present invention, which is equivalent to an LED device in which a plurality of pixels are arranged two-dimensionally with the LED device of the second embodiment as one pixel. It is a figure showing a circuit. An LED device configured by arranging pixels two-dimensionally as in the present embodiment is often used as a display device of a computer, a mobile terminal, a car navigation system, or the like.

This embodiment is an LED device composed of four pixels 1 to 4 and the anodes of the write diodes 11 and 21 of the pixels 1 and 2 are both connected to the data signal line Y ₁ . The anodes of the write diodes 31 and 41 of the pixels 3 and 4 are both connected to the data signal line Y _2.
It is connected to the.

On the other hand, the first sides of the respective storage capacitors 12 and 22 of the pixels ₁ and ₂ are connected to different selection signal lines X ₁ and X ₂ , respectively. Similarly, the first sides of the respective storage capacitors 32 and 42 of the pixels 3 and 4 are also connected to the selection signal lines X ₁ and X ₂ , respectively.

The cathodes of the reset diodes 15 and 25 of the pixels 1 and 2 are connected to different selection signal lines X ₀ and X ₁ , respectively, and the cathodes of the reset diodes 35 and 45 of the pixels 3 and 4 are also connected. , Respectively, are connected to different selection signal lines X ₀ , X ₁ .

The data signal lines Y ₁ and Y ₂ are connected to a data signal circuit (DATA) 50 having a signal source which operates respectively.
It is connected to the. Each signal source may function as a voltage source that generates a voltage signal, or may function as a current source that generates a current signal. On the other hand, the selection signal source X ₀ to X ₂ is connected to the selection circuit (SEL) 60.

FIG. 9 is a diagram showing the drive timing of the LED device shown in FIG.
Luminances L14 to L44 of the ED elements _14, 24, 34, ₄₄ ;
The selection signal sel ₀ applied to the selection signal lines X _{0 to} X ₂
To sel ₂ and the data signals data ₁ and data ₂ applied to the data signal lines Y ₁ and Y ₂ .

[0066] At time t _1, a low potential state of the selection signal sel ₀ applied to the selected signal lines X ₀ is on, X _1, X ₂
When sel ₁ and sel ₂ are turned off, the reset diodes 15 and 35 of the pixels 1 and 3 connected to the selection signal line X ₀ are turned on, and the current flows from the storage capacitors 12 and 32. Flows out, and the potentials of the second sides P _m1 and P _m3 of the storage capacitors 12 and 32 are reset to the reset potential.

[0067] In time t _2, the low potential selection signals sel ₁ applied to the selected signal line X ₁ is ON, X _0, X ₂
Is in a high potential state in which sel ₀ and sel ₂ are turned off. Then, the pixel 1 connected to the selected signal lines X _0,
The reset diodes 15 and 35 of No. 3 are turned off. At the same time, the write diodes 11 and 31 of the pixels 1 and 3 become conductive, and the storage capacitors 12 and 32 respond to the data signals data ₁ and data ₂ applied to the data signal lines Y ₁ and Y ₂ at that time. And the potentials of the second sides P _m1 and P _m3 of the storage capacitors 12 and 32 become data signals data ₁ and data _{2, respectively.}
Settles to the potential according to. Then, according to this potential, a current flows through the driving transistors 13 and 33, and the LED element 1
4 and 34 emit light at a luminance corresponding to the data signals data ₁ and data ₂ .

Further, the reset diodes 25 and 45 of the pixels 2 and 4 connected to the selection signal line X ₁ are turned on, current flows out of the storage capacitors 22 and 42, and the second side of the storage capacitors 22 and 42. P _m2 , p _m4
Is reset to the reset potential.

[0069] At time t _3, a low potential state of the selection signal sel ₂ applied to the selected signal line X ₂ is on, X _0, X ₁
Sel _0, sel ₁ to be applied when a high potential state which is off, each of the reset diode 25, 45 of the pixels 2, 4 connected to the selected signal line X ₁ is turned off to. At the same time, the write diodes 21 and 41 of the pixels 2 and 4 are all turned on, and the storage capacitors 22 and 42 are connected to the data signals data ₁ and data ₂ applied to the data signal lines Y ₁ and Y ₂ at that time. Accordingly, current flows into the second side P of the storage capacitors 22, 42.
_m2, the potential of the P _m4 settles the potential corresponding to the data signals data _1, data _2. Then, according to this potential, a current flows through the drive transistors 23 and 43, and the LED element 2
4 and 44 emit light with luminance according to the data signals data ₁ and data ₂ .

As described above, pixels 1, 3 and pixel 2,
4 emits light at a luminance corresponding to the data signal while slightly shifting the timing.

[Embodiment 4] FIG. 10 shows an LED device according to a fourth embodiment of the present invention.
FIG. 2 is a diagram illustrating an equivalent circuit of the entire device configured by arranging the device D in one dimension.

This embodiment is composed of six pixels, pixels 1 to 6, and has a write diode 1 for each of pixels 1 to 3.
The anodes of ₁ , 21 and 31 are all connected to the data signal line BLK1, and the respective write diodes 4 of the pixels 4 to 6 are connected.
The anode of 1,51,61 are both connected to the data signal line BLK _2. On the other hand, the first side of each of the storage capacitors 12, 22 and 32 of the pixel 1-3 is connected to a different selection signal line MTX ₁ ~MTX ₃ respectively. The storage capacitors 42, 5 of the pixels 4 to 6 respectively.
2 and 62 also have different selection signal lines MT.
X _{1 to} MTX ₃ .

Further, the cathodes of the reset diodes 15, 25, and 35 of the pixels 1 to 3 are connected to different selection signal lines MTX ₃ , MTX ₁ , and MTX ₂ , respectively. Diode 4
5, 55 and 65 also have different selection signal lines M, respectively.
It is connected to TX ₃ , MTX ₁ , MTX ₂ .

The selection signal lines MTX _{1 to} MTX ₃ are connected to a selection circuit (SEL) 60 such as a shift register. On the other hand, the data signal lines BLK ₁ , BLK ₂
Are connected to a data signal circuit (DATA) 50 having a signal source that operates respectively. Each signal source may function as a voltage source that generates a voltage signal, or may function as a current source that generates a current signal source.

FIG. 11 is a diagram showing the drive timing of the LED device of FIG. 10 described above. The luminances L _{14 to} L of the LED elements _14, 24, 34, 54, 64 forming the light emitting portions of the respective pixels 1 to 6 are shown. ₆₄ , the selection signals sel _{1 to} sel ₃ applied to the selection signal lines MTX _{1 to} MTX ₃ and the data signal line BLK
₁ , data signals data ₁ , da applied to BLK ₂
It represents a ta _2.

[0076] At time t _1, a low potential state of the selection signal sel ₃ applied to the selected signal line MTX ₃ is ON, MTX
₁ , when sel ₁ and sel ₂ applied to MTX ₂ are in a high potential state in which the reset diodes 15 and 4 are connected to the selection signal line MTX ₃ , respectively.
5 becomes conductive, current flows out of the storage capacitors 12 and 42, and the potentials of the second sides P _m1 and P _m4 of the storage capacitors 12 and 42 are reset to the reset potential.

[0077] In time t _2, the low potential selection signals sel ₁ applied to the selected signal line MTX ₁ is on, MTX
₂ , when sel ₂ and sel ₃ applied to MTX ₃ are in a high potential state in which the reset diodes 15 and 4 are connected to the selection signal line MTX ₃ , respectively.
5 becomes non-conductive. At the same time, the write diodes 11 and 41 of the pixels 1 and 4 are turned on, and the storage capacitors 12 and 42 are connected to the data signal lines BL at that time.
Data signal data applied to K ₁ and BLK _2
1 and data ₂ , a current flows in, and the potentials of the second sides P _m1 and P _m4 of the storage capacitors 12 and 42 become the data signal d.
The potential settles to a potential corresponding to data ₁ and data ₂ . Then, according to this potential, a current flows through the drive transistors 13 and 43, and the LED elements 14 and 44 cause the data signals data
₁ and emit light with a luminance corresponding to data ₂ .

Further, the reset diodes 25 and 55 of the pixels 2 and 5 connected to the selection signal line MTX ₁ are turned on, current flows out of the storage capacitors 22 and 52, and the second side of the storage capacitors 22 and 52 is turned on. P _m2 , P
The potential of _m5 is reset to the reset potential.

[0079] At time t _3, a low potential state of the selection signal sel ₂ applied to the selected signal line MTX ₂ is on, MTX
_{1. When} sel ₁ and sel ₃ applied to MTX ₃ are in a high potential state in which they are off, the reset diodes 25 and 55 of the pixels 2 and 5 are turned off. At the same time, the respective write diodes 21 of the pixels 2 and 5
51 becomes conductive, and the storage capacitors 22 and 52 flow currents in accordance with the data signals data ₁ and data ₂ applied to the data signal lines BLK ₁ and BLK ₂ at that time. The other side _Pm2 , P
potential of _m5 settles the potential corresponding to the data signals data _1, data _2. Then, according to this potential, a current flows through the driving transistors 23 and 53 and the LED elements 24 and 54
Emits light at a luminance corresponding to the data signals data ₁ and data ₂ .

Further, the reset diodes 35 and 65 of the pixels 3 and 6 connected to the selection signal MTX ₂ are turned on, current flows out of the storage capacitors 32 and 62, and the second side P of the storage capacitors 32 and 62 is turned off. _m3 , P _m6
Is reset to the reset potential.

[0081] At time t _4, the low potential state of the selection signal sel ₃ applied to the selected signal line MTX ₃ is ON, MTX
₁ , when sel ₁ and sel ₂ applied to MTX ₂ are in a high potential state in which they are on, reset diodes 35 and 6 of pixels 3 and 6 connected to selection signal line MTX ₂ respectively.
5 becomes non-conductive. At the same time, the write diodes 31 and 61 of the pixels 3 and 6 are turned on, and the storage capacitors 32 and 62 are connected to the data signal line BL at that time.
Data signal data applied to K ₁ and BLK _2
1 and data ₂ , a current flows in, and the potentials of the second sides P _m3 and P _m6 of the storage capacitors 32 and 62 become the data signal d.
The potential settles to a potential corresponding to data ₁ and data ₂ . In accordance with this potential, current flows through the drive transistors 33 and 63, and the LED elements 34 and 64 cause the data signals data
₁ and emit light with a luminance corresponding to data ₂ .

Further, the reset diodes 15 and 45 of the pixels 1 and 4 connected to the selection signal line MTX ₃ are turned on, current flows from the storage capacitors 12 and 42, and the second side of the storage capacitors 12 and 42 P _m1 , P
The potential of _m4 is reset to the reset potential.

As described above, the pixels 1 and 4, the pixels 2 and 5, and the pixels 3 and 6 emit light at a luminance corresponding to the data signal while slightly shifting the timing.

[Fifth Embodiment] FIG. 12 is a diagram showing an equivalent circuit of an LED device according to a fifth embodiment of the present invention. In the figure, 1
Is a write diode, 2 is a storage capacitor, 3 is a drive transistor, 4 is an LED element as a light emitting unit, and 5 is a reset transistor. In the present embodiment, P _c
First connected to the side electrode, P _m is electrode connected to the second side of the storage capacitor 2, P _d is connected to the cathode of the anode and the reset diode 5 write diode 1 electrode of the storage capacitor 2, P _{of led} the LED The electrode connected to the cathode of the element 4 is shown. In the present embodiment, a data signal is applied to P _c , and a selection / reset signal is applied to P _d , and a potential corresponding to the data signal appears at P _m by charging and discharging of the storage capacitor 2. P _led is a fixed potential.

The driving transistor 3 of this embodiment is also an n-channel field effect transistor and operates in the enhancement mode.

In the present embodiment, the cathode of the write diode 1 and the anode of the reset diode 5 are connected, and the anode of the write diode 1 and the cathode of the reset diode 5 are connected to each other. Provided from terminal. By doing this,
The number of terminals belonging to one pixel can be reduced by one, and when configuring an LED device in which pixels are arranged one-dimensionally or two-dimensionally, there is an advantage that wiring complexity is reduced.

FIG. 13 shows the drive timing of the LED device of this embodiment. In this figure, the data signal data applied to the P _c, select and reset signal applied to P _d s
and el, represents the potential of the P _m, the LED element 4 constituting the light emitting portion and a luminance L.

[0088] At time t _1, when the selection reset signal sel applied to P _d is the reset state (low potential state), the potential of the P _d is lowered. As a result, a forward voltage higher than the rising voltage is applied to the reset diode 5, and the reset diode 5 is turned on. Therefore, current flows out of the storage capacitor 2. At this time, the data signal appearing at P _c is fixed at a potential lower than the reset potential by the rising voltage of the reset diode 5. Therefore, the potential of the P _m is reset to reset potential (V _reset).

[0089] At time t _2, P · When selecting the reset signal sel applied to P _d is selected (high potential state) _d
Potential rises. As a result, a forward voltage equal to or higher than the rising voltage is applied to the write diode 1, and the write diode 1 is turned on. Therefore, a current flows into the storage capacitor 2 in accordance with the data signal data appearing on _Pc .

At time t ₃ , when the selection / reset signal applied to P _c is in a non-selection state (middle potential state), the voltage applied to the write diode 1 becomes lower than the rising voltage, and the write diode 1 is turned off. . At this time, the reset diode 5 is also off. The potential of the P _m becomes a potential corresponding to the data signal data appearing on the P _c during the selection period. In accordance with the potential of the P _m, a current flows through the driving transistor 3, LED element 4 is a data signal d
It emits light at a luminance corresponding to “ata”. During selection signal applied to P _d is deselected (medium potential state), since the write diode 1, any such voltage of the reset diode 5 is not respectively reached the forward threshold voltage and a non-conductive state I have. Therefore, even if the data signal appearing at P _c changes, the potential difference between P _m and P _c is maintained as it is, so that the current flowing through the drive transistor 3 continues to flow and the LED element 4 also continues to emit light.

After time t ₄ , the above operation is repeated.

[Embodiment 6] FIG. 14 shows an LED device according to a sixth embodiment of the present invention, in which a plurality of pixels are arranged two-dimensionally using the LED device of the fifth embodiment as one pixel. 3 is a diagram showing an equivalent circuit of FIG.

In this embodiment, four pixels 1 to 4 are provided. The anodes of the write diodes 11 and 21 of the pixels 1 and 2 and the reset diode 15 are provided.
The cathode 25 is connected both to the selection reset signal line Y _1,
Write diodes 31 and 41 of pixels 3 and 4 respectively
The anode and the cathode of the reset diode 35, 45 are connected together to the selected reset signal line Y _2.

On the other hand, the first sides of the respective storage capacitors 12 and 22 of the pixels ₁ and ₂ are connected to different data signal lines X ₁ and X ₂ , respectively. The first sides of the respective storage capacitors 32 and 42 of the pixels 3 and 4 are also connected to different data signal lines X ₃ and X ₄ , respectively.

The data signal lines X ₁ and X ₂ are connected to a data signal circuit (DATA) 50 having a signal source which operates respectively.
It is connected to the. Each signal source may function as a voltage source that generates a voltage signal, or may function as a current signal source that generates a current signal. Select / reset signal line Y
₁ and Y ₂ are connected to a selection / reset circuit (SEL) 60.

FIG. 15 is a diagram showing the drive timing of the LED device of FIG. In this figure, the luminance L ₁₄ of the LED elements _14, 24, 34, and 44 of the light emitting section of each of the pixels 1 to 4 is shown.
L ₄₄ , select signals sel ₁ and sel ₂ applied to select / reset signal lines Y ₁ and Y ₂ , and data signal lines X ₁ and X ₂
, And data signals data ₁ and data ₂ applied to.

At time t ₁ , when the selection / reset signal sel ₁ applied to the selection / reset signal line Y ₁ goes to a low potential state, which is a reset state, the selection / reset signal line Y ₁
, The reset diodes 15 and 25 of the pixels 1 and 2 respectively become conductive, and the storage capacitors 12 and 2
Current flows out of the storage capacitor 2 and the potentials on the second sides P _m1 and P _m2 of the storage capacitors 12 and 22 are reset to the reset potential.

[0098] In time t _2, the the selection and reset signals sel ₁ applied to the selected reset signal line Y ₁ is a high potential state, which is the selected state, the pixel 1 connected to the selected reset signal line Y ₁ Each reset diode 1
5 and 25 become non-conductive. At the same time, each of the writing diodes 11 and 21 of the pixels 1 and 2 connected to the selected reset signal line Y ₁ is turned on, the storage capacitor 12, 22 is applied to the data signal lines X _1, X ₂ at which time A current flows according to the data signals data ₁ and data _2, and the potentials of the second sides P _m1 and P _m2 of the storage capacitors 12 and 22 are changed to the data signals data ₁ and data _2.
Settles to the potential according to. Then, according to this potential, a current flows through the drive transistors 13 and 23, and the LED element 1
Lights 4 and 24 emit light at a luminance corresponding to the data signals data ₁ and data ₂ .

At time t ₃ , sel ₁ applied to the select / reset signal line Y ₁ is in the middle potential state in which the sel ₁ is in the non-selected state,
_When sel ₂ applied to the pixel ₂ goes to a low potential state, which is a reset state, the reset diodes 35 and 45 of the pixels 3 and 4 connected to the selection / reset signal line Y ₂ become conductive and the storage capacitors 32 and 42 The current flows out and the second sides P _m3 , P _m4 of the storage capacitors 32, 42
Is reset to the reset potential.

At time t ₄ , when the selection / reset signal sel ₂ applied to the selection / reset signal line Y ₁ changes to the high potential state of the selected state, the pixels 3 and 4 connected to the selection / reset signal line Y ₂ Each reset diode 3
5 and 45 become non-conductive. At the same time, each of the writing diodes 31 and 41 of the pixels 3, 4 connected to the selected reset signal line Y ₂ is conductive, the storage capacitor 32, 42 is applied to the data signal lines X _1, X ₂ at which time A current flows according to the data signals data ₁ and data _2, and the potentials of the second sides P _m3 and P _m4 of the storage capacitors 32 and 42 are changed to data signals data ₁ and data _2.
Settles to the potential according to. Then, according to this potential, a current flows through the driving transistors 33 and 43, and the LED element 3
4 and 44 emit light with luminance according to the data signals data ₁ and data ₂ .

In this way, pixels 1, 2 and 3,
4 emits light at a luminance corresponding to the data signal while slightly shifting the timing.

LEs arranged two-dimensionally as in this embodiment
In addition to the D device, it is also possible to configure an LED device in which the LED device of the fifth embodiment is one pixel and a plurality of pixels are arranged one-dimensionally like the LED device shown in FIG.

[Seventh Embodiment] FIG. 16 is a diagram showing an equivalent circuit of an LED device according to a seventh embodiment of the present invention. In the figure, 2 is a storage capacitor, 3 is a driving transistor, 4 is an LED element which is a light emitting unit, and 6 is an MIM element which is a nonlinear element having bidirectional diode characteristics. In the present embodiment, P _c is an electrode connected to the storage capacitor 2,
P _m is an electrode connected to the second side of the storage capacitor 2;
_d denotes an electrode connected to the MIM element 6, and P _led denotes an electrode connected to the cathode of the LED element 4. In the present embodiment, a data signal is applied to P _c , a selection / reset signal is applied to P _d , and a potential corresponding to the data signal appears in P _m by charging and discharging of the storage capacitor 2. P _led
Is a fixed potential.

The drive transistor 3 of the present embodiment is also an n-channel field effect transistor and operates in the enhancement mode.

In this embodiment, the role of the write diode 1 and the reset diode 5 in the LED device of the fifth embodiment is performed by the MIM element 6 which is one nonlinear two-terminal element. . The MIM element is an element formed by sandwiching a thin insulating layer between two layers of metal or a transparent conductive layer, and has bidirectional diode characteristics. FIG. 17 shows an example of the voltage-current characteristics of the MIM element.

The MIM element exhibits a high resistance when it is in a specific range in which the applied voltage is lower than the forward rising voltage and higher than the reverse rising voltage. Has the property of decreasing. In the present embodiment, by using such an MIM element, there is an advantage that the number of elements belonging to one pixel can be reduced by one, and the complexity of the pixel can be reduced.

FIG. 18 shows the drive timing of the LED device of this embodiment. This figure shows the data signal data applied to the P _c, select and reset signal applied to P _d se
and l, represents the potential of the P _m, the luminance L of the LED element 4 is a light-emitting portion.

[0108] At time t _1, when the selection and reset signal applied to P _d is the reset state (low potential), P _d
Potential drops. Therefore, a reverse voltage equal to or higher than the reverse rise voltage is applied to the MIM element 6, and the MIM element 6 is turned on, and the current flows out of the storage capacitor 2. At this time, the data signal data applied to P _c becomes MIM from the reset potential.
Because it is fixed in the opposite direction rising voltage potential lower element, the potential of the P _m is reset to reset potential (V _reset).

[0109] In time t _2, the the selection and reset signals sel applied to P _d is in the selected state (high potential state) P _d
Potential rises. The data signal data applied to P _c is superimposed on this, and a forward voltage equal to or higher than the forward rising voltage is applied to the MIM element 6, and the MIM element 6 is turned on. Therefore, a current flows into the storage capacitor 2 according to the data signal data applied to _Pc .

[0110] At time t _3, the selection reset signal sel applied to P _d becomes unselected state (medium potential state),
Since the voltage applied to the MIM element 6 does not reach either the forward rising voltage or the backward rising voltage,
It becomes non-conductive. The potential of the P _m becomes a potential corresponding to the applied data signal data to P _c during the selection period. In accordance with the potential of the P _m, the current to the driving transistor 3 flows, LED element 4 emits light with a luminance corresponding to the data signal data.

[0111] The selection is applied to the P _d · reset signal se
While 1 is in a non-selected state (middle potential state), even if the data signal data applied to P _c is superimposed, the voltage applied to the MIM element 6 is either a forward rising voltage or a reverse rising voltage. Since it does not reach, it is in a non-conductive state. For this reason, even if the data signal data appearing on P _c changes, the potential difference between P _m and P _c is maintained as it is, so that the current flowing through the drive transistor 3 continues to flow, and the LED element 4 also emits light as it is. continue.

[Eighth Embodiment] FIG. 19 shows an LED according to an eighth embodiment of the present invention in which the LED device of the seventh embodiment is arranged as one pixel and a plurality of pixels are two-dimensionally arranged.
It is a figure showing an equivalent circuit of a device.

[0113] LED device of the present embodiment is composed of four pixels of the pixel 1-4, the respective MIM elements 16 and 26 are both selected reset signal line Y ₁ of the pixel 1, pixel 3,4 Select each of the MIM elements 36 and 46
It is connected to a reset signal line Y _2. On the other hand, pixel 1,
Each first side of the storage capacitor 12, 22 of the two are connected to different data signal lines X _1, X _2, respectively. The first sides of the storage capacitors 32 and 42 of the pixels 3 and 4 are also connected to the data signal lines X ₁ and X ₁ , respectively.
It is connected to X _2.

The data signal lines X ₁ and X ₂ are connected to a data signal circuit (DATA) 50 having a signal source operating respectively.
It is connected to the. Each signal source may function as a voltage source that generates a voltage signal, or may function as a current source that generates a current signal. Select / reset signal line Y ₁ ,
Y ₂ is connected to a select / reset circuit (SEL) 60.

FIG. 20 is a diagram showing the drive timing of the LED device of FIG. This figure shows the luminance L of the LED elements 14, 24, 34, and 44, which are the light emitting units of the pixels 1-4.
₁₄ and ~L _44, the selection reset signal sel _1, sel ₂ applied to the selected reset signal line Y _1, Y _2, the data signal line X _1, a data signal line is applied to the X ₂ data
₁ and data ₂ .

At time t ₁ , when the selection / reset signal sel ₁ applied to the selection / reset signal line Y ₁ goes to the low potential state of the reset state, the selection / reset signal line Y ₁
MIM elements 16 and 2 of pixels 1 and 2 connected to
6 is in the reverse conduction state, and the storage capacitors 12 and 22
, And the potentials of the second sides P _m1 and P _m2 of the storage capacitors 12 and 22 are reset to the reset potential.

[0117] In time t _2, the the selection and reset signals sel ₁ applied to the selected reset signal line Y ₁ is a high potential state, which is the selected state, the pixel 1 connected to the selected reset signal line Y ₁ The respective MIM elements 16 and 26 become forward conductive, and the storage capacitors 12 and 22 flow currents according to the data signals data ₁ and data ₂ applied to the data signal lines X ₁ and X ₂ at that time. ,
The potentials of the second sides P _m1 and P _m2 of the storage capacitors 12 and 22 settle down to potentials corresponding to the data signals data ₁ and data ₂ . Then, according to this potential, the driving transistor 1
3 and 23 current flows in, LED elements 14 and 24 emits light at a luminance corresponding to the data signals data _1, data _2.

[0118] At time t _3, the potential state in sel ₁ applied to the selected reset signal line Y ₁ is a non-selected state, Y
Sel ₂ applied to the ₂ becomes a low potential state in the reset state. Each MIM elements 36 and 46 of the selection and reset signal lines Y ₂ to lead pixels 3, 4 becomes reverse conduction state, a current flows from the storage capacitor 32 and 42, a second side P of the storage capacitor 32, 42 The potentials of _m3 and _Pm4 are reset to the reset potential.

At time t ₄ , when the selection / reset signal sel ₂ applied to the selection / reset signal line Y ₂ is set to the high potential state, which is the selected state, the pixels 3 and 4 connected to the selection / reset signal line Y ₂ are turned off. The respective MIM elements 36 and 46 become forward conductive, and the storage capacitors 32 and 42 flow currents according to the data signals data ₁ and data ₂ appearing on the data signal lines X ₁ and X ₂ at that time, The potentials of the second sides P _m3 and P _m4 of the storage capacitors 32 and 42 settle down to potentials according to the data signals data ₁ and data ₂ . Then, according to this potential, the driving transistor 33,
43 current flows in, LED elements 34 and 44 emits light at a luminance corresponding to the data signals data _1, data _2.

In this way, pixels 1, 2 and 3,
4 emits light at a luminance corresponding to the data signal while slightly shifting the timing.

LEs arranged two-dimensionally as in this embodiment
In addition to the D device, it is also possible to configure an LED device in which a plurality of pixels are arranged one-dimensionally like the LED device shown in FIG. 10 by using the LED device of the seventh embodiment as one pixel.

[Ninth Embodiment] FIG. 21 is a diagram showing an equivalent circuit of an LED device according to a ninth embodiment of the present invention. In the figure, 1 is a write diode, 2 is a storage capacitor, 4
The LED element is a light emitting portion, 5 is a reset diode, P _c is an electrode connected to the first side of the storage capacitor 2, P _m is connected to the second side of the storage capacitor 2 electrode, P _d1 write diode An electrode connected to the anode of
P _d2 is an electrode connected to the cathode of the reset diode, P
_led indicates an electrode connected to the cathode of the LED element 4. In the present embodiment, a selection signal is applied to P _c , a data signal is applied to P _d1 , and a reset signal is applied to P _d2 , and a potential corresponding to the data signal appears at P _m by charging and discharging of the storage capacitor 2. P _led is a fixed potential.

The feature of the present embodiment is that, unlike the LED device shown in FIG.
The charge corresponding to the data signal stored in
The point is to flow to the ED element 4. Therefore, the configuration of the pixel can be extremely simplified.

FIG. 22 shows the drive timing of the LED device of this embodiment. This figure shows the selection signal s applied to P _c
el, data signal data applied to P _d1 , and P _d2
And the reset signal res applied to, the potential of the P _m, L
5 shows the luminance L of the ED element 4.

At time t ₁ , when the reset signal res applied to P _d2 enters the reset state (low potential state), P _d2
Potential drops. A forward voltage is applied to the reset diode 5, and the reset diode 5 becomes conductive. Therefore, the storage capacitor 2
Current flows from the potential of P _m are reset potential (V
_reset ).

At time t ₂ , when the reset signal res applied to P _d2 goes into the non-reset state (high potential state), P
The potential of _d2 rises. The reset diode 5 is not applied with a forward voltage higher than the rising voltage, and becomes non-conductive. At the same time, the selection signal sel applied to P _c
Is in the selected state (low potential state), the potential of _Pc falls. As a result, even lowered potential of P _m which separates the storage capacitor 2, a current flows into the storage capacitor 2 in accordance with the data signal data applied to the p _d.

At time t ₃ , the selection signal s applied to P _c
el potential and becomes the P _m unselected state (high potential state) rises, the voltage across the write diode 1 becomes less rising voltage, a non-conductive state. P during the selection period
_The charge accumulated according to the data signal data applied to _d1 flows out through the LED element 4, and the LED element 4 emits light at a luminance according to the data signal data or during a light emission time according to the data signal data. I do. While the selection signal sel applied to P _c is in a non-selection state (high potential state), the write diode 1 is in a non-conduction state, so that even if the data signal data applied to P _d1 changes, since the potential of the P _m is held as it is, light emission of the LED element 4 is not affected.

After time t ₄ , the above operation is repeated.

In the present embodiment, the reset diode 5 is arranged so that its anode is connected to the second side of the storage capacitor 2 and the anode of the LED element 4, and the reset state is set to a low potential from the cathode. The reset is performed by applying a reset signal that is in a state. Therefore, at the time of reset, the potential of the anode of the LED element 4 is always lower than that at the time of operation. Therefore, there is an advantage that unnecessary high current does not flow through the LED element 4 at the time of reset.

[Tenth Embodiment] FIG.
The embodiment is an equivalent circuit of an LED device in which a plurality of pixels are arranged two-dimensionally with the LED device of the ninth embodiment as one pixel.

[0131] LED device of the present embodiment is composed of four pixels of the pixel 1-4, the anode both data signal lines Y ₁ each write diodes 11 and 21 of the pixels 1 and 2,
Write diodes 31 and 41 of pixels 3 and 4 respectively
Of the anode are both connected to the data signal line Y _2.

On the other hand, the first sides of the respective storage capacitors 12 and 22 of the pixels ₁ and ₂ are connected to different selection signal lines X ₁ and X ₂ , respectively. The first sides of the respective storage capacitors 32 and 42 of the pixels 3 and 4 are also connected to the selection signal lines X ₁ and X ₂ , respectively.

The cathodes of the reset diodes 15 and 25 of the pixels 1 and 2 are connected to different selection signal lines X ₀ and X ₁ , respectively. The cathodes of the reset diodes 35 and 45 of the pixels 3 and 4 are also connected to the selection signal lines X ₀ and X ₁ , respectively.

The data signal lines Y ₁ and Y ₂ are connected to a data signal circuit (DATA) 50 having operating signal sources. Each signal source may function as a voltage source that generates a voltage signal, or may function as a current source that generates a current signal. Selection signal lines X ₀ to X ₂ is connected to the selection circuit (SEL) 60.

FIG. 24 is a diagram showing the drive timing of the LED device of FIG. This figure shows the L of each of the pixels 1-4.
Luminances L14 to L44 of the ED elements _14, 24, 34, ₄₄ ;
The selection signals sel ₀ to sel ₀ applied to the selection signal lines X _{0 to} X ₂
sel ₂ and data signals data ₁ and data ₂ applied to the data signal lines Y ₁ and Y ₂ .

[0136] At time t _1, a low potential state of the selection signal sel ₀ applied to the selected signal X ₀ is on, the high potential state sel _1, sel ₂ applied to X _1, X ₂ are off comes to, each of the reset diode 15, 35 of the pixels 1, 3 connected to the selected signal lines X ₀ becomes conductive, a current flows from the storage capacitor 12 and 32, a second side P _m1 of the storage capacitor 12, 32, The potential of P _m3 is reset to the reset potential.

[0137] In time t _2, the low potential selection signals sel ₁ applied to the selected signal line X ₁ is ON, X _0, X ₂
When the sel ₀ and sel ₂ applied to the pixel are in a high potential state in which they are off, the reset diodes 15 and 35 of the pixels 1 and 3 connected to the selection signal line X ₀ are turned off. At the same time, the respective writing diodes 11 and 31 of the pixels 1 and 3 become conductive, and the storage capacitor 1
Currents ₂ and 32 flow currents according to the data signals data ₁ and data ₂ applied to the data signal lines Y ₁ and Y ₂ at that time.

Further, the reset diodes 25 and 45 of the pixels 2 and 4 connected to the selection signal line X ₁ are turned on, and current flows out of the storage capacitors 22 and 42, and the second side of the storage capacitors 22 and 42. P _m2 , P _m4
Is reset to the reset potential.

[0139] At time t _3, a low potential state of the selection signal sel ₂ applied to the selected signal line X ₂ is on, X _0, X ₁
Is in a high potential state in which sel ₀ and sel ₁ are turned off, the second sides P _m1 and P m2 of the respective storage capacitors 12 and 32 of the pixels 1 and 3 connected to the selection signal line X _1.
The potential of _m3 rises, and the data signal lines Y ₁ , Y
_The charges accumulated in response to the data signals data ₁ and data ₂ applied to ₂ flow out through the LED elements 14 and 34, and the LED elements 14 and 34
₁ and emits light at a luminance according to data ₂ or during a light emission time according to the data signal. At the same time, the selection signal X ₁
, The reset diodes 25 and 45 of the pixels 2 and 4 are turned off.

The writing diodes 21 and 41 of the pixels 2 and 4 are turned on, and the storage capacitors 22 and 42 are connected to the data signals data ₁ and data applied to the data signal lines Y ₁ and Y ₂ at that time. Current flows according to ₂ .

At time t ₄ , when sel ₀ to sel ₂ applied to the selection signal lines X _{0 to} X ₂ are in a high potential state in which they are off, the accumulation of each of the pixels 2 and 4 connected to the selection signal line X ₂ The potentials on the second sides P _m2 , P _m4 of the capacitors 22, 42 rise, and the electric charges accumulated according to the data signals data ₁ , data ₂ applied to the data signal lines Y ₁ , Y ₂ during the selection period. Flows out through the LED elements 24 and 44, and the LED elements 24 and 44 output data signals data ₁ and d.
In the luminance corresponding to ata _2, or between the light-emitting time corresponding to the data signal, to emit light.

As described above, the pixels 1 and 3 and the pixels 2 and 4 emit light at a luminance corresponding to the data signal while slightly shifting the timing.

[Embodiment 11] FIG. 25 shows a first embodiment of the present invention.
It is a figure showing the equivalent circuit of the LED device of one embodiment.
In the figure, 1 is a write diode, 2 is a storage capacitor,
4 is a LED element which is a light emitting portion, P _c is connected to the first side of the storage capacitor 2 electrode, P _m is connected to the second side of the storage capacitor 2 electrode, P _d to the anode of the write diode 1 The lead electrode, P _led, is an electrode leading to the cathode of the LED element 4. In the present embodiment, a selection signal is applied to P _c , and a data signal is applied to P _d , and a potential corresponding to the data signal appears in P _m by charging and discharging of the storage capacitor 2. P _led is a fixed potential.

In the LED device of the present embodiment, FIG.
It does not have the drive transistor 3 like the LED device of the above, and further does not have the reset diode 5. The charge accumulated in response to the data signal during the selection period may be completely discharged until the next selection period, or may have some remaining discharge, compared to the required characteristics. If it is acceptable, there is an advantage that the configuration of the pixel can be further simplified.

The configuration of the pixel can be further simplified, and a configuration without the storage capacitor 2 can be considered. The reason is that the LED element has an equivalent capacitance component. However, in this case, the value of the capacitance is uniquely determined by the size of the LED element, and it is difficult to secure a capacitance for accumulating charges required for sufficient light emission. Alternatively, if an attempt is made to accumulate charges necessary for sufficient light emission, the voltage applied to the LED element must be increased, and the reliability is not preferable.

Furthermore, since the equivalent capacitance component of the LED element itself cannot be driven separately from the function as the light emitting diode, for example, as shown in this embodiment, the P _{led connected to} the cathode of the LED element 4 Is maintained at a fixed potential, and P is connected to the first side of the storage capacitor 2.
It cannot be said that the selection signal is applied only to _c to drive.

This limits the degree of freedom in design in that the potential of the selection signal and the potential of the data signal cannot be set freely, and complicates the element manufacturing process described below.

That is, when the storage capacitor 2 is not provided,
The storage capacitor 2 cannot be driven by applying a selection signal to the electrode _{Pc connected} to the first side. After all, the selection signal is applied to P _{led connected} to the cathode of the LED element 4, and the data signal is written to P _{d connected to} the anode of the writing diode 1.
Or a configuration to be applied to, or a configuration for applying a selection signal to the data signal is applied to the P _{of led} to P _d, inevitably either. In any case, since the signal applied to the cathode of the LED element 4 differs for each pixel,
It becomes necessary to perform fine patterning on the cathode of the element 4.

Since the anode of the LED element 4 is originally required to be patterned for each pixel because of the connection to the cathode of the writing diode 1 which is unique to each pixel, LE
Both the cathode and the anode of the D element 4 require fine patterning.

In the case of the organic LED element, the organic LED element has a structure in which an organic light emitting layer is sandwiched between an anode and a cathode on a substrate. Since the organic light emitting layer is weak to heat and solvents, it is relatively easy to pattern the electrode (anode or cathode) below the organic light emitting layer, but pattern the electrode (cathode or anode) above the organic light emitting layer. It is difficult. That is, it is difficult to finely pattern both the cathode and the anode of the organic LED element, and the manufacturing process is complicated.

As described above, the configuration having no storage capacitor is simple, but has an undesirable aspect.

FIG. 26 shows the drive timing of the LED device shown in FIG. This figure shows the selection signal sel applied to P _c
When represents a data signal data applied to P _d, the potential of the P _m, the brightness L of the LED element 4 is a light-emitting portion.

At time t ₁ , the selection signal s applied to P _c
When el changes to the selected state (low potential state), the potential of _Pc decreases. As a result, even lowered potential of P _m which separates the storage capacitor 2, the write diode 1 so as to overlap with the data signal data applied to the P _d takes forward voltage than the rising voltage, it becomes conductive. Therefore, current flows into the storage capacitor 2 in accordance with the data signal data applied to P _d.

At time t ₂ , the selection signal s applied to P _c
el is the potential of the P _m becomes a non-selected state (high potential state) rises, the voltage across the write diode 1 becomes less rising voltage, a non-conductive state. P during the selection period
_The charge accumulated according to the data signal data applied to _d flows out through the LED element 4, and the LED element 4 emits light at a luminance according to the data signal data or during a light emission time according to the data signal. I do.

While the selection signal sel applied to P _c is in a non-selection state (high potential state), the write diode 1 is in a non-conductive state, so that the data signal data applied to P _d changes. also, since the potential of the P _m is maintained as it is, light emission of the LED element 4 is not affected.

[0156] t ₃ or later, the above-described operation is repeated.

[Embodiment 12] FIG. 27 shows a twelfth embodiment of the present invention.
The LED device according to the eleventh embodiment is different from the LED device according to the eleventh embodiment.
FIG. 3 is a diagram illustrating an equivalent circuit of a device in which a plurality of pixels are arranged two-dimensionally in a two-dimensional manner with the ED device as one pixel.

[0158] The present embodiment is configured by four pixels of the pixel 1-4, the anode of each write diodes 11 and 21 of the pixels 1 and 2 are both connected to the data signal lines Y _1, pixel 3,4 Each writing diode 3
Anode 1 and 41 are both connected to the data signal line Y _2.

On the other hand, the first sides of the respective storage capacitors 12 and 22 of the pixels ₁ and ₂ are connected to different selection signal lines X ₁ and X ₂ , respectively. The first sides of the respective storage capacitors 32 and 42 of the pixels 3 and 4 are also connected to different selection signal lines X ₁ and X ₂ , respectively.

The data signal lines Y ₁ and Y ₂ are connected to a data signal line (DATA) 50 having a signal source which operates respectively. Each signal source may function as a voltage source that generates a voltage signal, or may function as a current source that generates a current signal source. The selection signal lines X ₁ and X ₂ are connected to a selection circuit (SEL) 60.

FIG. 28 is a diagram showing the drive timing of the LED device of FIG. This figure includes a luminance L ₁₄ ~L ₄₄ of the LED elements 14, 24, 34, 44 of the pixel 1-4, selection signals sel _1, sel applied to the selected signal lines X _1, X _2
2 and data signal lines data ₁ and data ₂ applied to the data signal lines Y ₁ and Y ₂ , respectively.

At time t ₁ , when the selection signal sel ₁ applied to the selection signal line X ₁ changes to a low potential state in which it is on and X ₂ applied to a high potential state in which sel ₂ is off, the selection signal line The potential of P _m1 and P _m3 on the second side of the respective storage capacitors 12 and 32 of the pixels 1 and 3 connected to X ₁ drops, and the forward voltage applied to the writing diodes 11 and 31 of the pixels 1 and 3 becomes a rising voltage. As described above, the conduction state is established, and the storage capacitors 12 and 32 are connected to the data signals data ₁ and data ₂ applied to the data signal lines Y ₁ and Y ₂ at that time.
A current flows in according to data ₂ .

[0163] In time t _2, the low potential selection signal sel ₂ applied to the selected signal line X ₂ is on, the sel ₁ applied to X ₁ becomes a high potential state is OFF, the selection signal line storage capacitor 1 pixel 1, 3 connected to X ₁
The potentials of the second sides P _m1 and P _m3 of the pixels 2 and 32 increase, and the forward voltages applied to the respective write diodes 11 and 31 of the pixels 1 and 3 become lower than the rising voltage, and the pixels become non-conductive. As a result, during the selection period, the data signal lines Y ₁ , Y ₂
The electric charges accumulated in response to the data signals data ₁ and data ₂ applied to the memory device flow out through the LED elements 14 and 34, and the LED elements 14 and 34 cause the data signals data ₁ and
Light is emitted at a luminance according to data ₂ or during a light emission time according to the data signal. At the same time, the potentials of P _m2 and P _m4 of the pixels 2 and 4 connected to the selection signal X ₂ drop, and the respective writing diodes 21 and 41 of the pixels 2 and 4 become conductive, and the storage capacitors 22 and 42 change at that time. , The data signal d applied to the data signal lines Y ₁ and Y ₂
A current flows according to data ₁ and data ₂ .

At time t ₃ , when the selection signal sel ₂ applied to the selection signal line X ₂ is turned off to a high potential state, the potentials of P _m2 and P _m4 of the pixels 2 and 4 connected to the selection signal line X ₂ are changed. Rise, the forward voltage applied to each of the write diodes 21 and 41 of the pixels 2 and 4 becomes equal to or lower than the rising voltage and becomes non-conductive. During the selection period, the data signal line Y
₁ , data signals data ₁ , data applied to Y _2
2 flows out through the LED elements 24 and 44, and the LED elements 24 and 44 output the data signal da.
Light is emitted at a luminance according to ta ₁ and data ₂ or during a light emission time according to the data signal.

As described above, the pixels 1, 3 and the pixels 2, 4 emit light at a luminance corresponding to the data signal while slightly shifting the timing.

[Thirteenth Embodiment] FIG. 29 is a view showing a first embodiment of the present invention.
It is a figure showing the equivalent circuit of the LED device of a 3rd embodiment.
In the figure, 1 is a write diode, and 4 is a light emitting unit LE.
D element, 5 is a reset diode, and 7 is a storage diode that functions as a storage capacitor. In the present embodiment, P _c is an electrode connected to the anode of the storage diode 7,
P _m is an electrode connected to the cathode of the storage diode 7, P _d1 is an electrode connected to the anode of the writing diode 1, P _d2 is an electrode connected to the cathode of the reset diode 5, and P _led is L.
The electrode connected to the cathode of the ED element 4 is shown. In this embodiment, P _c is a selection signal, P _d1 is a data signal,
A reset signal is applied to P _d2, and a potential corresponding to the data signal appears at P _m by charging and discharging of the storage diode 7. P _led is a fixed potential.

Generally, a diode has an equivalent capacitance component because charge is accumulated at a junction thereof. The feature of this embodiment lies in that an equivalent capacitance component of a diode is used as a storage capacitor. In particular, in the present embodiment, since the potentials of the data signal, the selection signal, and the reset signal are set so that the reverse voltage is always applied to the storage diode 7, signal charges are lost through the storage diode 7 or unnecessary. Such a charge does not flow in and can function as a storage capacitor. Specifically, for example, when the forward rise voltage of the write diode 1, the reset diode 5, and the storage diode 7 is 0.8 V and the forward rise voltage of the LED element 4 is 5 V, P _d1
The potential of the data signal to be applied to is 0.8V to 3.8V,
The potential applied to P _d2 is set to 4.2 in the reset state.
V, 9.2 V in the non-reset state, the potential of the selection signal applied to the P _c, 0V in the selected state, 5V in the non-selected state, the potential of the P _{of led} 0V (fixed) can be set so as It is. Actually, these setting values may be appropriately optimized.

FIG. 30 shows the drive timing of the LED device of this embodiment. This figure shows the selection signal s applied to P _c
el, data signal data applied to P _d1 , and P _d2
And the reset signal res applied to represent the potential of the P _m, the luminance L of the LED element 4 is a light-emitting portion.

[0169] At time t _1, the potential of the P _d2 when the reset signal applied to the P _d2 is in the reset state (low potential) is lowered. A forward voltage is applied to the reset diode 5,
It becomes conductive. Therefore, a current flows from the storage diode 7, the potential of the P _m is reset to reset potential (V _reset).

At time t ₂ , when the reset signal applied to P _d2 is in the non-reset state (high potential state), the potential of P _d2 rises. The reset diode 5 is not applied with a forward voltage higher than the rising voltage, and becomes non-conductive. At the same time, when the selection signal applied to _Pc is in the selected state (low potential state), the potential of _Pc falls. As a result,
Also lowered potential of P _m which separates the storage diode 2, the write diode 1 so as to overlap with the data signal data applied to the P _d1 takes forward voltage than the rising voltage, becomes conductive. Therefore, a current flows into the storage diode 7 according to the data signal applied to P _d1 .

At time t ₃ , when the selection signal applied to P _c changes to the non-selection state (high potential state), the potential of P _m rises, the voltage applied to the write diode 1 becomes lower than the rising voltage, and the non-conduction state is established. Becomes The charge accumulated in response to the data signal applied to P _d1 during the selection period is LE
It flows out through the D element 4 and the LED element 4 outputs the data signal d.
Light is emitted at a luminance corresponding to the data or during a light emission time according to the data signal.

While the selection signal applied to P _c is in a non-selection state (high potential state), the write diode 1 is in a non-conductive state, so that the data signal d applied to P _d1 is
Since ata is the potential of the even P _m varies is kept as it is, light emission of the LED element 4 is not affected.

[0173] time t ₄ and later, the above-described operation is repeated.

[Embodiment 14] FIG. 31 shows a fourteenth embodiment of the present invention.
The LED device according to the thirteenth embodiment,
FIG. 3 is a diagram illustrating an equivalent circuit of an LED device in which a plurality of pixels are two-dimensionally arranged with an ED device as one pixel.

The present embodiment is composed of four pixels, pixels 1 to 4, and has a write diode 1 for each of pixels 1 and 2.
The anode of 1,21 are both connected to the data signal lines Y _1, anode for each write diodes 31 and 41 of the pixel 3 and 4 are both connected to the data signal line Y _2.

On the other hand, the anode sides of the storage diodes 17 and 27 of the pixels 1 and ₂ are connected to different selection signal lines X ₁ and X ₂ , respectively, and the anodes of the storage diodes 37 and 47 of the pixels 3 and 4 are connected. The other side is also connected to different selection signal lines X ₁ and X ₂ , respectively.

The cathodes of the reset diodes 15 and 25 of the pixels 1 and 2 are connected to different selection signal lines X ₀ and X ₁ , respectively, and the cathodes of the reset diodes 35 and 45 of the pixels 3 and 4 are also connected. , Respectively, are connected to different selection signal lines X ₀ , X ₁ .

The data signal lines Y ₁ and Y ₂ are connected to a data signal circuit (DATA) 50 having a signal source which operates respectively.
It is connected to the. Each signal source may function as a voltage source that generates a voltage signal, or may function as a current source that generates a current signal. The selection signal lines X ₀ to X ₂ is connected to the selection circuit (SEL) 60.

FIG. 32 is a diagram showing the drive timing of the LED device of this embodiment. This figure shows the luminances L _{14 to} L ₄₄ of the LED elements _14, 24, 34, ₄₄ of each of the pixels 1 to 4.
If the selection signal sel applied to the selected signal lines X ₀ to X _{2
0 to} sel ₂ and data signals data ₁ and data ₂ applied to the data signal lines Y ₁ and Y ₂ , respectively.

[0180] At time t _1, a low potential state of the selection signal sel ₀ applied to the selected signal lines X ₀ is on, X _1, X ₂
When the sel ₁ and sel ₂ applied to the pixel are in a high potential state in which they are off, the reset diodes 15 and 35 of the pixels 1 and 3 connected to the selection signal line X ₀ become conductive, and the current flows from the storage diodes 17 and 37. Flows out, and the potentials of P _m1 and P _m3 on the cathode side of the storage diodes 17 and 37 are reset to the reset potential.

[0181] In time t _2, the low potential selection signals sel ₁ applied to the selected signal line X ₁ is ON, X _0, X ₂
When the sel ₀ and sel ₂ applied to the pixel are in a high potential state in which they are off, the reset diodes 15 and 35 of the pixels 1 and 3 connected to the selection signal line X ₀ are turned off. At the same time, P _m1 on the cathode side of the respective storage diodes 17 and 37 of the pixels 1 and 3 connected to the selection signal line X ₁ ,
The potential of P _m3 falls, the write diodes 11 and 31 of the pixels 1 and 3 become conductive, and the data signals data ₁ and d applied to the data signal lines Y ₁ and Y ₂ at that time.
flowing a current to the storage diode 17 and 37 in accordance with the ata _2.

[0182] Further, each of the reset diode 25, 45 of the pixels 2, 4 connected to the selected signal line X ₁ becomes conductive, a current flows from the storage diode 27 and 47, the cathode side P _{m @ 2} of the storage diode 27, 47 , P _m4 are reset to the reset potential.

[0183] At time t _3, a low potential state of the selection signal sel ₂ applied to the selected signal line X ₂ is on, X _0, X ₁
When sel ₀ and sel ₁ applied to the pixel are in a high potential state in which they are off, the cathode sides P _m1 and P _m3 of the storage diodes 17 and 37 of the pixels 1 and 3 connected to the selection signal line X _1.
Of the data signal lines Y ₁ and Y ₂ during the selection period.
The electric charges accumulated in response to the data signals data ₁ and data ₂ applied to the memory device flow out through the LED elements 14 and 34, and the LED elements 14 and 34 cause the data signals data ₁ and
Light is emitted at a luminance according to data ₂ or during a light emission time according to the data signal. At the same time, the reset diodes 2 of the pixels 2 and 4 connected to the selection signal line X ₁
5 and 45 become non-conductive.

[0184] The pixel 2 connected to the selected signal lines X _2,
4 are connected on the cathode side of the respective storage diodes 27 and 37.
_{m @ 2,} P potential of _m4 is lowered, each of the writing diodes 21 and 41 of the pixel 2 and 4 becomes conductive, the data signal lines Y ₁ storage diode 27 and 47 at that time, Y ₂
A current flows in accordance with the data signals data ₁ and data ₂ applied to the memory cell.

At time t ₄ , when sel ₀ to sel ₂ applied to the selection signal lines X _{0 to} X ₂ are in a high potential state in which they are off, the accumulation of each of the pixels 2 and 4 connected to the selection signal line X ₂ The potentials of the cathodes P _m2 and P _m4 of the diodes 27 and 47 rise, and the charges accumulated according to the data signals data ₁ and data ₂ applied to the data signal lines Y ₁ and Y ₂ during the selection period are: Flowing out through the LED elements 24, 44,
The LED elements 34 and 44 receive data signals data ₁ and data
Light is emitted at a luminance according to a ₂ or during a light emission time according to the data signal.

As described above, the pixels 1 and 3 and the pixels 2 and 4 emit light at a luminance corresponding to the data signal while slightly shifting the timing.

[Embodiment 15] In the thirteenth and fourteenth embodiments of the present invention, the potentials of the data signal, the selection signal, and the reset signal are set so that a reverse voltage is always applied to the storage diode. Thus, the signal charge is not lost through the storage diode or unnecessary charge does not flow in, so that the storage diode functions as a storage capacitor.However, even when a forward voltage is applied to the storage diode, If the forward rise voltage of the storage diode is large and the forward voltage applied to the storage diode can be suppressed to a range not exceeding the rise voltage, the storage diode can function as a storage capacitor. First of the present invention
The fifth embodiment is an example using such a storage diode.

FIG. 33 shows an LED according to a fifteenth embodiment of the present invention.
2 shows an equivalent circuit of the device. In the figure, 1 is a write diode, 4 is an LED element as a light emitting unit, 5 is a reset diode, and 7 is a storage diode that functions as a storage capacitor. Also, P _c is an electrode connected to the cathode of the storage diode 7, P _m is electrode connected to the anode of the storage diode 7, P _d1 is connected to the anode of the write diode 1 electrode, P _d2 Electrodes connected to the cathode of the reset diode 5, P _led indicates an electrode connected to the cathode of the LED element 4. In the present embodiment, P _c is a selection signal, P _d1
Is applied with a data signal, _Pd2 is applied with a reset signal,
A potential corresponding to the data signal appears at P _m by charging and discharging of the storage diode 7. P _led is a fixed potential.

The operation and the drive timing of the LED device of the present embodiment are similar to those of the LED device of the thirteenth embodiment, and the description is omitted. Further, an LED device in which such pixels are arranged two-dimensionally or one-dimensionally can be similarly configured, and the description thereof will be omitted.

[Embodiment 16] When a storage diode is formed by combining a plurality of diodes in series and in a reverse direction, even if a forward voltage is applied to one diode, a reverse voltage is applied to the other diode. Unless a high voltage such as a reverse breakdown voltage is applied, no signal charge is lost or unnecessary charge does not flow through the diode, and the diode can function as a storage capacitor in a wider operation range. FIG. 34 shows such an example.

FIG. 34 shows an LED according to a sixteenth embodiment of the present invention.
It is an equivalent circuit of the device. In the figure, 1 is a writing diode, 4 is an LED element as a light emitting unit, 5 is a reset diode, and 7a and 7b are storage diodes as storage capacitors. Further, an electrode connected to the cathode of the P _c accumulation diode 7b, electrodes connected to the anode of the P _m accumulation diodes 7a, electrode contiguous P _d1 to the anode of the write diode 1, P _d2 is an electrode connected to the cathode of the reset diode 5 Show. In the present embodiment, a selection signal is applied to P _c , a data signal is applied to P _d1 , and a reset signal is applied to P _d2 , and a potential corresponding to the data signal is applied to P _m by charging and discharging of the storage diodes 7a and 7b. appear. P _led is a fixed potential.

The operation and the drive timing of the LED device of the present embodiment are similar to those of the LED device of the thirteenth embodiment, and the description is omitted. Further, an LED device in which such pixels are arranged two-dimensionally or one-dimensionally can be similarly configured, and the description thereof will be omitted.

[Embodiment 17] FIG. 35 is a sectional view schematically showing the structure of an example of an organic LED element used as an LED element in the present invention. In the figure, reference numeral 100 denotes a light-transmitting insulating substrate, and 101 denotes ITO by a vacuum deposition method.
An anode formed by depositing 15 μm, an organic hole transport layer 102 formed by depositing an organic hole transport material such as an aromatic tertiary amine represented by the following formula (I) by 0.05 μm;
Reference numeral 103 denotes an organic electron transporting layer formed by depositing an organic electron transporting material such as an organometallic complex represented by the following formula (II) at a thickness of 0.05 μm. 104 denotes a metal having a low work function such as Mg or its alloy. This is a cathode formed by depositing .15 μm. In the present embodiment, it is assumed that the alloy is deposited by a binary simultaneous evaporation method using Mg and Ag.

[0194]

Embedded image

The organic LED device used in the present invention is not limited to the above-mentioned LED device. For example, in addition to ITO, metals such as Au, Ag, Pd, and Pt, metal oxides, and conductive polymers can be used for the anode.

Examples of the hole transporting material include, besides the aromatic tertiary amine represented by the above formula (I), aromatic amine compounds, hydrazone compounds, silazane compounds, and polymers such as polyvinyl carbazole and polysilazane. Any material having a hole transporting property can be used. Further, inorganic materials such as silicon and diamond doped with impurities may be used.

As the electron transporting material, other than the organic metal complex represented by the formula (II), any other organic metal complex, aromatic compound such as tetraphenylbutadiene, or the like may be used as long as it has electron transporting properties. . Alternatively, these materials may be doped with various fluorescent materials.

In addition to the layered structure of the hole transport layer and the electron transport layer, a single polymer layer such as polyphenylenevinylene may be provided, or various organic molecules may be dispersed in these polymer layers. Alternatively, a layer in which various functional side chains are added to the polymer main chain may be provided.

As the cathode, in addition to the alloy of Mg and Ag, an alloy of Al and Li, Sn, Mg, In, Al, C
Metals having a low work function such as a can be used.

Further, the film constitution of the organic LED element is not limited to the above constitution, but may be composed of a single organic layer, a light emitting layer between the hole transport layer and the electron transport layer, or a combination of the anode and the hole transport layer. Various film configurations can be considered, such as inserting a hole injection layer between them, or inserting an electron injection layer between the cathode and the electron transport layer.
It is also conceivable that the overall layer configuration is reversed and a layer configuration such as a cathode, an electron transport layer, a hole transport layer, and an anode is formed on the substrate.

This configuration is particularly necessary when a non-light-transmitting substrate such as a ceramic, metal, or silicon single crystal substrate is used instead of a light-transmitting substrate.

The method for producing each film is not limited to the above-mentioned method, but various film-forming methods such as a coating method and a Langmuir-Blodgett method can be used.

FIG. 36 is a sectional view schematically showing the structure of an example of a thin film transistor used as a driving transistor in the present invention. In the figure, 100 is a translucent insulating substrate, 301 is a gate electrode formed by depositing Al / Cr by vacuum deposition, 302 is an insulating layer formed by depositing silicon nitride by plasma CVD, 30
3 is an intrinsic semiconductor layer formed by depositing amorphous silicon, 304 is an n ⁺ semiconductor layer which is an ohmic contact layer formed by doping silicon with phosphorus,
305 is a source / drain electrode formed by depositing Al.

The thin film transistor used in the present invention may have a configuration other than the above. For example, instead of using amorphous silicon as it is, annealing may be performed by heating the substrate or annealing by laser irradiation. If a step of forming polycrystalline silicon thin film by forming polycrystalline silicon into polycrystalline silicon is adopted, a drive circuit capable of operating at higher speed can be obtained.

In addition, instead of a so-called field effect thin film transistor, another type of transistor such as a bipolar transistor can be used instead. When a silicon single crystal substrate is used as the substrate, such other types of transistors can be easily manufactured. Further, another thin film semiconductor such as cadmium selenide can be used. further,
It is also possible to use a conductive polymer such as polythienylenevinylene.

The thin film transistor is not limited to the n-channel field effect thin film transistor described in the above embodiment. A channel formed in the gate portion may be a p-channel field effect transistor using holes as charge transport carriers. Further, any of the enhancement mode and the depression mode can be used.

FIG. 37 is a sectional view schematically showing an example of the structure of a diode used as a write diode, a reset diode, and a storage diode in the present invention. In the figure, reference numeral 100 denotes a light-transmitting insulating substrate; 311, an anode formed by depositing Al / Cr by a vacuum deposition method;
Reference numeral 12 denotes an insulating layer formed by depositing silicon nitride by plasma CVD, 313 denotes an intrinsic semiconductor layer formed by depositing amorphous silicon, and 314 denotes an ohmic contact formed by doping silicon with phosphorus. The n ⁺ semiconductor layer 315 as a layer is a cathode formed by depositing Al.

The structure of the diode used in the present invention is not limited to the above. For example, a diode using polycrystalline silicon or single crystal silicon other than amorphous silicon may be used. Instead of a diode having a MIS structure using a Schottky junction between a metal and a semiconductor, a diode using a PN junction of a p-type semiconductor and an n-type semiconductor may be used.

FIG. 38 shows the MI used in the present invention.
It is sectional drawing which shows the structure of an example of M element typically. In the figure, reference numeral 100 denotes a light-transmitting insulating substrate; 401, a first electrode formed by depositing Ta by a vacuum deposition method; 402, an insulating layer formed by oxidizing the Ta surface of the first electrode 401;
03 is a second electrode formed by depositing Cr.

The configuration of the MIM element is not limited to the above configuration. For example, instead of using a metal anodic oxide layer as an insulating layer, an insulator such as silicon nitride is formed by a plasma CVD method or the like. May be.

The storage capacitor used in the present invention is:
The element may be formed in such a way as to be understood, but may be a parasitic capacitance which is parasitic on each element such as a wiring, a driving transistor, and a reset diode. Further, it may be an equivalent capacitance component of a diode that functions as a storage capacitor.

[Embodiment 18] According to the present invention, there can be obtained an LED device having a large light emission intensity and a small crosstalk, in particular, an organic LED device. Therefore, good characteristics can be obtained by using the LED device in various devices.

FIG. 39 is a diagram showing a display device and a computer system using the LED device of the present invention. In the figure, 501 is a display, 502 is L of the present invention.
An ED device, 503 is a keyboard, and 504 is a computer. The system includes, as an LED device 502,
By using an LED device in which a large number of pixels are arranged two-dimensionally and emitting light in accordance with the signal of each pixel,
Display information. The system uses the organic LE of the present invention.
By using the D device, low power consumption and high image quality can be obtained.

FIG. 40 is a diagram showing an electrophotographic image forming apparatus using the LED device of the present invention. In the figure, the same members as those in the apparatus of FIG. 42 described above are denoted by the same reference numerals, and description thereof will be omitted. In the figure, 97 is a printer head, 98 is an LED device of the present invention, and 99 is a rod lens array.

The feature of the image forming apparatus of the present invention is that the photosensitive member 9
1 of the present invention as an exposure apparatus for writing a latent image in
That is, a printer head 97 in which an ED device 98 and a rod lens array 99 are combined is used. The organic LED device according to the present invention has higher emission intensity and lower crosstalk than conventional organic LED devices, so that higher-speed and higher-quality printing can be performed.
The laser system or the LED array system can be used, and the size and cost of the device can be reduced.

FIG. 41 is a schematic diagram showing an example of an image reading apparatus using the LED device of the present invention. This device is
Using the LED device 411 of the present invention in which a plurality of pixels of different emission colors are arranged, each pixel is switched according to a signal to emit light, illuminate the surface of the original 414, and the reflected light is sensed by the rod lens array 412. The image information is projected onto the document 413 to obtain image information on the surface of the document 414. In this device, low power consumption and high image quality can be obtained by using the organic LED device of the present invention.

[0219]

As described above, according to the present invention,
LED with higher emission intensity and reduced crosstalk
It is possible to provide an image forming apparatus, a display apparatus, and an image reading apparatus with high image quality and low power consumption. Conventionally, the organic LED device can be suitably used for an image forming apparatus or the like which has insufficient light emission intensity, and can be reduced in size and cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing an equivalent circuit of an LED device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing voltage-current characteristics of a diode used in the present invention.

FIG. 3 is a diagram illustrating drive timing of the LED device according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating another drive timing of the LED device according to the first embodiment of the present invention.

FIG. 5 is a diagram showing an equivalent circuit of the LED device according to Embodiment 2 of the present invention.

FIG. 6 is a diagram illustrating driving timings of the LED device according to the second embodiment of the present invention.

FIG. 7 is a diagram illustrating another driving timing of the LED device according to the second embodiment of the present invention.

FIG. 8 is a diagram showing an equivalent circuit of the LED device according to Embodiment 3 of the present invention.

FIG. 9 is a diagram illustrating a drive timing of the LED device according to the third embodiment of the present invention.

FIG. 10 is a diagram illustrating an equivalent circuit of an LED device according to Embodiment 4 of the present invention.

FIG. 11 is a diagram illustrating a drive timing of an LED device according to a fourth embodiment of the present invention.

FIG. 12 is a diagram showing an equivalent circuit of an LED device according to Embodiment 5 of the present invention.

FIG. 13 is a diagram showing the drive timing of the LED device according to the fifth embodiment of the present invention.

FIG. 14 is a diagram showing an equivalent circuit of an LED device according to Embodiment 6 of the present invention.

FIG. 15 is a diagram illustrating drive timing of an LED device according to Embodiment 6 of the present invention.

FIG. 16 is a diagram showing an equivalent circuit of an LED device according to Embodiment 7 of the present invention.

FIG. 17 is a diagram showing voltage-current characteristics of the MIM element according to the present invention.

FIG. 18 is a diagram showing the drive timing of the LED device according to the seventh embodiment of the present invention.

FIG. 19 is a diagram showing an equivalent circuit of the LED device according to Embodiment 8 of the present invention.

FIG. 20 is a diagram illustrating drive timing of the LED device according to the eighth embodiment of the present invention.

FIG. 21 is a diagram showing an equivalent circuit of an LED device according to Embodiment 9 of the present invention.

FIG. 22 is a diagram illustrating drive timing of the LED device according to the ninth embodiment of the present invention.

FIG. 23 is a diagram showing an equivalent circuit of the LED device according to Embodiment 10 of the present invention.

FIG. 24 is a diagram illustrating drive timing of the LED device according to the tenth embodiment of the present invention.

FIG. 25 is a diagram showing an equivalent circuit of the LED device according to Embodiment 11 of the present invention.

FIG. 26 is a diagram illustrating drive timing of the LED device according to Embodiment 11 of the present invention.

FIG. 27 is a diagram showing an equivalent circuit of the LED device according to Embodiment 12 of the present invention.

FIG. 28 is a diagram illustrating drive timing of the LED device according to Embodiment 12 of the present invention.

FIG. 29 is a diagram showing an equivalent circuit of the LED device according to Embodiment 13 of the present invention.

FIG. 30 is a diagram illustrating drive timing of the LED device according to Embodiment 13 of the present invention.

FIG. 31 is a diagram showing an equivalent circuit of the LED device according to Embodiment 14 of the present invention.

FIG. 32 is a diagram illustrating drive timing of the LED device according to Embodiment 14 of the present invention.

FIG. 33 is a diagram showing an equivalent circuit of the LED device according to Embodiment 15 of the present invention.

FIG. 34 is a diagram showing an equivalent circuit of the LED device according to Embodiment 16 of the present invention.

FIG. 35 is a schematic sectional view of an example of an organic LED element used in the present invention.

FIG. 36 is a schematic cross-sectional view of an example of a thin film transistor used in the present invention.

FIG. 37 is a schematic sectional view of an example of a diode used in the present invention.

FIG. 38 is a schematic sectional view of an example of the MIM element used in the present invention.

FIG. 39 is a schematic diagram showing a computer system using the LED device of the present invention.

FIG. 40 is a schematic view of an example of the image forming apparatus of the present invention.

FIG. 41 is a schematic view of an example of the image reading apparatus of the present invention.

FIG. 42 is a schematic configuration diagram illustrating an example of a conventional image forming apparatus.

FIG. 43 illustrates an LED used in a conventional image forming apparatus.
FIG. 2 is a diagram illustrating an array type printer head.

FIG. 44 is a schematic plan view of an example of a conventional organic LED device.

FIG. 45 is a schematic sectional view of the organic LED device of FIG. 44.

FIG. 46 is an equivalent circuit diagram of the organic LED device of FIG. 44.

FIG. 47 is a diagram illustrating drive timing of the organic LED device of FIG. 44.

[Explanation of symbols]

1, 11, 21, 31, 41 Writing diode 2, 12, 22, 32, 42 Storage capacitor 3, 13, 23, 33, 43 Driving transistor 4, 14, 24, 34, 44 LED element 5, 15, 25, 35, 45 Reset diode 6, 16, 26, 36, 46 MIM element 7, 7a, 7b, 17, 27, 37, 47 Storage diode 50 Data signal circuit (DATA) 60 Selection signal circuit (SEL) 91 Electrophotographic photosensitive member 92 Charging device 93 Developing device 94 Transfer device 95 Fixing device 96 Cleaning device 97 Printer head 98 LED device 99 Rod lens array 100 Insulating substrate 101 Anode 102 Organic hole transport layer 103 Organic electron transport layer 104 Cathode 111 Substrate 112 LED chip array 113 Driving driver IC 114 Welding wire 115 rod lens array 120 substrate 121 to 129 the organic LED element 131 cathode 132 organic light-emitting layer 133 insulating layer 301 gate electrode 302 insulating layer 303 intrinsic semiconductor layer 304 n ⁺ semiconductor layer 305 source and drain electrode 401 first electrode 402 insulated Layer 403 Second electrode 411 LED device 412 Rod lens array 413 Sensor 414 Document 501 Display 502 LED device 503 Keyboard 504 Computer

Claims (18)

[Claims] 1. An LED device comprising: an LED element having a light-emitting layer sandwiched between an anode and a cathode; a storage capacitor for accumulating electric charges; and a non-linear two-terminal element having a resistance that changes according to an applied voltage. LE. A driving method, wherein an electric charge corresponding to a data signal is stored in said storage capacitor via said non-linear two-terminal element, and said LED element emits light by said stored electric charge.
D device driving method. 2. The method according to claim 1, wherein the LED element is an organic LED element having an organic light emitting layer. 3. The LED device includes a transistor in which a current flowing between a source electrode and a drain electrode is controlled by an amount of charge stored in the storage capacitor, and a current that causes the LED element to emit light through the transistor. The method for driving an LED device according to claim 1, wherein the driving is controlled. 4. The method according to claim 3, wherein said transistor is a thin film transistor. 5. An LED device having a light-emitting layer sandwiched between an anode and a cathode, a storage capacitor, and a non-linear two-terminal device having a resistance that changes according to an applied voltage. And the charge stored in the storage capacitor via the nonlinear two-terminal element,
An LED device characterized by causing an ED element to emit light. 6. The LED device according to claim 5, wherein said LED element is an organic LED element having an organic light emitting layer. 7. A transistor in which a current flowing between a source electrode and a drain electrode is controlled by an amount of charge stored in the storage capacitor, and a current for causing the LED element to emit light is controlled via the transistor. The LED device according to claim 5. 8. The LED device according to claim 7, wherein said transistor is a thin film transistor. 9. The LED device according to claim 5, wherein said nonlinear two-terminal element is a diode. 10. The nonlinear two-terminal element is an MIM type nonlinear element having bidirectional diode characteristics.
8. The LED device according to any one of 8 above. 11. The LED device according to claim 5, wherein a diode is used as the storage capacitor. 12. The LE according to claim 5, wherein
The D device has n × m pixels (where n and m are 2 or more) as one pixel, and divides the plurality of pixels into m blocks composed of n pixels adjacent to each other. , The pixels of each block are commonly wired for each block by m common wirings, one pixel is selected from each block, and commonly wired between different blocks by n matrix wirings. LED device. 13. The LED device according to claim 12, wherein the pixels are arranged one-dimensionally. 14. The LED device according to claim 12, wherein the pixels are arranged two-dimensionally in n rows × m columns. 15. L according to any one of claims 12 to 14,
A light source characterized by using an ED device. 16. A photoconductor, a charging device for uniformly charging the photoconductor, an exposure device for forming an electrostatic latent image on the photoconductor, and a toner for forming an electrostatic latent image formed on the photoconductor. And a fixing device for fixing the toner image transferred to the transfer material to the transfer material, and a transfer device for transferring the toner image on the photoconductor to a transfer material. And a writing head for the exposure apparatus.
An image forming apparatus using the light source described above. 17. An LED device in which a plurality of pixels having different emission colors are arranged, a lot lens array for irradiating light emitted from the LED device onto a document surface and condensing reflected light, and An image reading apparatus, comprising: a sensor for sensing the reflected light; and using the LED device according to any one of claims 12 to 14 as the LED device. 18. L according to claim 12, wherein
A display device using an ED device.