JP2002056668A - Drive circuit device for matrix type image display device having display storage function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the reading and writing operations of image information on storage cells of a flat display device including both liquid crystal and EL (electro-luminescence) elements which are arranged in a matrix form and also to attain the transfer of information to a drive circuit while keeping the power saving performance. SOLUTION: The drive circuit device uses a dynamic storage where the storage cells constituted of MOS transistors and MOS capacity elements are arranged in a matrix form, a word line 203 connected in common to the gates of MOS transistors in the row direction and a bit line 204 connected in common to the drains of MOS transistors set in the column direction in place of a conventional static memory device. Furthermore, a 1st sense amplifier circuit 401 placed between the dynamic storage and a pixel drive device and a 2nd sense amplifier circuit for reading and writing independently the information of a display and storage device are provided. As a result, the display storage element information can be read and written and also the information can be transferred to a drive circuit 205.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a matrix type image display device, and more particularly to a drive circuit device provided with a dynamic type storage device for a display storage function.

[0002]

2. Description of the Related Art A flat display device in which liquid crystal and EL (Electro-Luminescence) elements are arranged in a matrix has a display storage circuit for storing information of a luminance level for each pixel, and a signal generated in accordance with the stored information. Conventionally, a display memory device must have a drive circuit to drive the signal line that supplies the voltage, or a general-purpose semiconductor memory device is connected outside the drive device, or a display memory device such as a static memory is driven. It is commonly used to mount it inside equipment.

In particular, a drive circuit device of a matrix type image display device having a display storage function in which a display storage device is mounted inside a drive device is a bus circuit required for an interface with an external semiconductor memory device and a storage information of the external semiconductor memory device. It can reduce the bus charge / discharge current required for reading and writing data, making it ideal for driving circuit devices for matrix-type image display devices for mobile devices.

On the other hand, as the definition and colorization of flat display devices for portable equipment have increased and the number of color display colors has been gradually increased, a large-capacity display memory has also been stored in a drive circuit device of a matrix type image display device for portable equipment. If a monochrome black and white flat display device is simply made into a color, three times as many display storage elements as three RGB colors are required, but the driving circuit of a matrix type image display device is required. When a large-scale static memory is mounted on a device, the chip size is inevitably increased and the chip cost is increased.To avoid this, design and manufacture display storage devices and drive circuit devices using advanced microfabrication technology. It is possible to do so, but this would increase the manufacturing cost, which is not desirable.

[0005]

SUMMARY OF THE INVENTION In a drive circuit device of a matrix type image display device having a display storage function, it is possible to mount a large-scale display storage element, while increasing the chip size of the drive circuit device and increasing the degree of fineness. Compact and large-capacity display storage used in drive circuit devices of matrix type image display devices that can respond to high definition and colorization of flat display devices or increase the number of color display colors without the need for processing technology It also aims to maintain the desired power savings for the drive circuit of a matrix-type image display device for mobile devices.

[0006]

SUMMARY OF THE INVENTION When a drive circuit device is mounted with a large-capacity storage device corresponding to higher definition and colorization of a flat display device for portable equipment or an increase in the number of color display colors, a conventional device is used. Instead of the static memory device, storage cells composed of MOS transistors and MOS capacitors are arranged in rows and columns, and word lines and columns commonly connected to the gates of the MOS transistors in the row direction are arranged. And a bit line commonly connected to the drain of the MOS transistor in the direction.

When a dynamic memory device is used, it is necessary to amplify the memory information stored in the dynamic memory cell once. Therefore, the arbitration problem of the read / write of the display memory element information and the access of the information transfer to the drive circuit is solved. In order to solve this problem, it is necessary to provide a first sense amplifier circuit provided between the dynamic memory device and the pixel drive device and a second sense amplifier for reading and writing information in the display memory device independently. This reduces the number of data latches for access arbitration, thereby realizing a storage device circuit desirable for a drive circuit device of a matrix type image display device for portable equipment.

[0008]

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

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows main functional components constituting a drive circuit device of a matrix type image display device having a display storage function. 101 is an entire drive circuit device of a matrix type image display device having a display storage function. The main functional components are a signal line drive circuit (102), a digital-to-analog converter (103), a display data storage device (104), and a data register (10
5), X-address register (106), Y-address register (10
7), and a control circuit (108) that controls them.

When a dynamic storage device is used instead of a static storage device as a display storage device of a drive circuit device of a matrix type image display device as in the present invention, storage information stored in a dynamic storage cell is used. Since it is necessary to amplify once with a sense amplifier, two types of data latches for reading and writing are required in addition to the data latch for display to arbitrate display and read / write access.

FIG. 2 shows main functional components constituting a display memory device (104) using a dynamic memory cell as a conventional example. Reference numeral 201 denotes a memory cell (202) of the dynamic memory device. Memory blocks arranged in rows and columns.203 is a memory cell of a dynamic memory device arranged in the row direction.
The word line 204 is commonly connected to the gate of the MOS transistor.
A bit line commonly connected to the drain of a MOS transistor. Each word line (203) is a dynamic storage device.
(104) connected to a word line drive circuit (205) for driving a word line corresponding to a row address specified from the outside,
A sense amplifier (207) is provided in each bit line (204) in the column direction.Image data stored in the storage cell (202) is converted into a signal line driving circuit (10) through a digital-to-analog converter (103).
2) a first data latch (206) for transfer to the display data storage device (104) and a second data latch (2) necessary for reading and writing the contents of the storage cell (202) from outside the display independently of display. Two
08), and is selectively connected to an external data bus by a column selection circuit (209) according to given column address information.

FIG. 3 is a circuit diagram showing one row of a display storage device (104) using a dynamic storage cell composed of memory blocks in which conventional storage cells (202) are arranged in a matrix. Here, 301 is an input / output port for reading and writing the contents of the storage cell (202) from outside the display data storage device independently of display, and 302 is a signal for transmitting image data stored in the storage cell (202). Output ports for transferring to the line drive circuit.303 and 304 are complementary signals for activating the sense amplifier, and 305 is a transfer signal for transferring the contents of the memory cell (202) to the first data latch. , 306 are transfer signals for transferring the contents of the memory cell (202) to the second data latch.

In the conventional example described above, the display storage device (104) using the dynamic storage device includes, as constituent elements, a memory block in which storage cells (202) are arranged in a matrix and a sense amplifier provided in a column direction. 207) and a first data latch (206) for transferring image data to the signal line driving circuit, and a second data latch (208) necessary for reading and writing the contents of the storage cells independently of display. Is required.

FIG. 4 shows main functional components constituting one embodiment of the present invention. 201 is a memory block in which storage cells (202) of a dynamic storage device are arranged in a matrix.
203 is a word line commonly connected to the gate of the MOS transistor of the memory cell of the dynamic memory device arranged in the row direction, and 204 is commonly connected to the drain of the MOS transistor of the memory cell of the dynamic memory device. Each word line (203) is connected to a word line drive circuit (205) that drives a word line corresponding to a row address specified from outside the dynamic memory device (104). (204) has a first sense which is also used as a data latch for transferring the image data stored in the storage cell (202) to the signal line drive circuit (102) via the digital-to-analog converter (103). An amplifier (401) and a second sense amplifier (402) that is also used as a data latch necessary for reading and writing the contents of the storage cell (202) from outside the display data storage device (104) independently of display are provided. , Columns By 択回 path (209) is selectively connected to an external data bus in accordance with the column address information provided.

5 is a circuit diagram showing a row of a display storage device (104) using a dynamic storage cell according to an embodiment of the present invention, wherein 501 is a storage cell (104). 20
A transfer gate for transferring the contents of (2) to the first sense amplifier, 502 is a transfer gate for transferring the contents of the memory cell (202) to the second sense amplifier.503 and 504 are for the first sense amplifier. Complementary signals for activation, 505 and 50
6 is a complementary signal for activating the second sense amplifier.

By using the present invention, it is possible to reduce the number of circuits required for the display storage device (104) using dynamic storage cells, as compared with the conventional example requiring two types of data latches for the sense amplifier. It is possible to realize a display storage device using a dynamic storage device which is desirable for a drive circuit device of a matrix type image display device for a band device.

6 shows an embodiment (601) of a layout drawing of a storage cell (202) of a dynamic memory device according to the present invention. In order to suppress the accompanying increase in manufacturing cost, the effective thickness of the gate insulating film of the MOS capacitor constituting the memory cell of the dynamic memory device must be the same as that of the memory cell.
Because of the same thickness as the OS transistor, the area reduction effect is only about 1/3 compared to the layout drawing (602) of the static memory (conventional example) which is shown in the same size for comparison. Is not obtained.

In general, a comparison is made between manufacturing techniques having the same minimum line width. The area of a unit cell of a dynamic memory used in a general-purpose semiconductor memory device is about 1 / the area of a unit cell of a static memory. However, in order to realize a dynamic memory with a small cell area, the MOS transistors and MOS transistors that make up the cell are required.
It is necessary to apply different gate materials and gate structures to the capacitive element, and to construct a dynamic memory using such a special material or structure, it is necessary to use a driving circuit for a matrix type image display device. Undesirably increases the manufacturing cost.

On the other hand, as indicated by reference numeral 601 in FIG. 6, the effective thickness of the gate insulating film of the MOS capacitor constituting the memory cell of the dynamic memory device is the same as that of the MOS transistor constituting the memory cell. By using a dynamic memory element with a layout that can be composed of materials,
It is possible to design a dynamic memory cell with low manufacturing cost without using any special manufacturing technology.
Although the area of the unit cell of the dynamic memory used in the present invention can be reduced only to about 1/3 of the area of the unit cell of the static memory designed with the technology of the same minimum line width, the matrix Storage device that can easily mount triple the amount of display storage elements equivalent to the three colors of RGB required for the colorization of the drive circuit of the image display device without increasing the chip size. Is an effective means for miniaturization.

FIG. 7 shows a second embodiment according to the present invention, in which a circuit diagram of a display memory device (104) using dynamic memory cells is shown in which two rows are extracted. While the first sense amplifier required to amplify and transfer the image data stored for each column to the signal line drive circuit is arranged, the contents of the storage cells are displayed and displayed. The second sense amplifier (402), which is also used as a data latch necessary for reading and writing independently, is shared by two columns via (701, 702) which functions as a transfer gate and selection circuit, and the column address is The selection lines (703, 704) are exclusively selected according to the information and connected to the bit lines.
Further, the second sense amplifier is selectively connected to an external data bus according to column address information given by a column selection circuit (209).

In the above embodiment, the means for reducing the number of the second sense amplifiers according to the number of data latches required for reading and writing independently of the display is used. This makes it possible to design the second sense amplifier to the required minimum, thereby realizing a small and large-capacity display storage device which is the object of the present invention. However, the present invention is effective and realizable for sharing of the second sense amplifier other than this configuration. It is possible.

Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and can be freely modified and changed within the scope described in the claims. .

According to the present invention, there is provided a method for transferring display image data stored in a memory cell to a signal line drive circuit, which is necessary for a drive circuit device of a matrix type image display device using a dynamic memory device. The first request and the second request to read and write the contents of the memory cells independently of the display can be reduced, and two types of data latches can be eliminated. As a result, it is possible to reduce the number of circuits required for the display data storage device of the drive circuit device of the portable image display device. Display storage device.

According to the present invention, display image data stored in a memory cell, which is necessary for a drive circuit device of a matrix type image display device using a dynamic memory device, is transferred to a signal line drive circuit. Instead of the two types of data latches required to fulfill the first request to perform and the second request to read and write the contents of the storage cell independently of the display, the image data stored in the storage cell is used. A first sense amplifier that is also used as a data latch to transfer to the signal line drive circuit and a second sense amplifier that is also used as a data latch necessary to read and write the contents of storage cells independently of display In addition, the required circuit can be reduced by providing the second sense amplifier, and the area can be further reduced by sharing the second sense amplifier in the column direction as necessary. With regard to the rise in manufacturing cost, which is a concern due to this, a layout that allows the effective thickness of the gate insulating film of the MOS capacitor constituting the dynamic memory cell to be made of the same gate material as that of the MOS transistor constituting the memory cell will be adopted. By using it, it is possible to design a memory cell of a dynamic memory device with reduced manufacturing cost without using any special manufacturing technology.

[Brief description of the drawings]

FIG. 1 is an example of a drive circuit device of a matrix type image display device with a display storage function according to a conventional example according to the present invention.

FIG. 2 shows an example of a display storage device using a conventional dynamic storage cell.

FIG. 3 is a circuit example of a display storage device using a conventional dynamic storage cell.

FIG. 4 is an embodiment of a drive circuit device of a matrix type image display device with a display storage function according to the present invention.

FIG. 5 is an embodiment of a display storage device using a conventional dynamic storage cell according to the present invention.

FIG. 6 is a first embodiment of a circuit of a display storage device using a conventional dynamic storage cell according to the present invention;

FIG. 7 is a circuit diagram of a conventional display memory device using a dynamic memory cell according to a second embodiment of the present invention;

[Explanation of symbols]

101: Drive circuit device of matrix type image display device with display storage function 102: Signal line drive circuit 103: Digital-to-analog converter 104: Display data storage device 105: Data register 106: X-address register 107: Y-address register 108 … Control circuit 201… memory block of dynamic storage device 202… storage cell 203 of dynamic storage device 203… word line 204 of dynamic storage device… bit line 205 of dynamic storage device… word line drive circuit 206… first Data latch 207 Sense amplifier 208 Second data latch 301 I / O port 302 Output port 303 Sense amplifier activation signal (1) 304 Sense amplifier activation signal (2) 305 Data transfer gate signal (1 ) 306… data transfer gate signal (2) 401… first sense amplifier 401… second sense amplifier 501… One transfer gate 502… Second transfer gate 503… First sense amplifier activation signal (1) 504… First sense amplifier activation signal (2) 505… Second sense amplifier activation signal (1) 506… Second sense amplifier activation signal (2) 601… Layout diagram of dynamic memory cell 602… Layout diagram of static memory cell 701… Second transfer select gate (1) 702… Second transfer select gate (2) 703… Second transfer selection gate control signal (1) 704… Second transfer selection gate control signal (2)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 27/108 G11C 11/34 371H 5F083 21/8242 362G H04N 5/66 H01L 27/10 671C 681G F term ( Reference) 2H093 NA16 NC15 NC21 NC26 NC34 NC35 ND49 NE02 5B024 AA01 AA07 BA02 BA03 BA05 BA09 CA07 CA13 CA18 5C006 AA16 AA22 AC21 AF43 AF83 BB16 BC06 BF04 BF25 FA41 5C058 AA05 AB01 BA01 BA25 BA26 BB11 5A080 EB11 A03 EB11 A30 AE11 5F083 AD02 AD11 LA03

Claims (16)

[Claims] A plurality of matrix type image display signal line drive circuits, storage cells each comprising a MOS transistor and a MOS type capacitance element are arranged in a matrix and commonly connected to the gates of the MOS transistors in a row direction. And a bit line connected in common to the drain of the MOS transistor in the column direction. A matrix type image display device with a display storage function, comprising: a first sense amplifier provided between the pixel drive device and a second sense amplifier for independently reading and writing information in the display storage device. Drive circuit device. 2. The driving circuit device according to claim 1, wherein said MOS transistor and said MOS type capacitance element are formed of the same conductor. 3. The MOS transistor according to claim 1, wherein said MOS transistor and said MOS type capacitance element are formed of the same conductor.
A drive circuit device for a matrix-type image display device with a display storage function, wherein a conductive layer of each MOS gate is formed simultaneously in a manufacturing process. 4. The MOS transistor according to claim 1, wherein the MOS transistor and the MOS capacitor are formed of the same conductor.
A drive circuit device for a matrix-type image display device with a display storage function, characterized in that the oxide films of the respective MOS gates are simultaneously formed in the same thickness in the manufacturing process. 5. A memory cell comprising a plurality of matrix type image display signal line drive circuits, MOS transistors and MOS type capacitance elements, arranged in rows and columns, and commonly connected to the gates of said MOS transistors in a row direction. And a bit line connected in common to the drain of the MOS transistor in the column direction. A first sense amplifier provided between the pixel driver and the pixel driver is connected to one end of the bit line via a first transfer gate, and the other end of the bit line is connected via a second transfer gate. A drive circuit device for a matrix-type image display device with a display storage function, wherein the drive circuit device is connected to a second sense amplifier. 6. A driving circuit device for a matrix type image display device with a display storage function according to claim 5, wherein said MOS transistor and said MOS type capacitance element are formed of the same conductor. 7. The MOS transistor according to claim 5, wherein the MOS transistor and the MOS type capacitance element are formed of the same conductor.
A drive circuit device for a matrix-type image display device with a display storage function, wherein a conductive layer of each MOS gate is formed simultaneously in a manufacturing process. 8. The MOS transistor according to claim 5, wherein said MOS transistor and said MOS type capacitance element are formed of the same conductor.
A drive circuit device for a matrix-type image display device with a display storage function, characterized in that the oxide films of the respective MOS gates are simultaneously formed in the same thickness in the manufacturing process. 9. A memory cell comprising a plurality of matrix type image display signal line drive circuits, MOS transistors and MOS type capacitance elements, arranged in a matrix and commonly connected to the gates of said MOS transistors in a row direction. And a bit line connected in common to the drain of the MOS transistor in the column direction. A first sense amplifier provided between the pixel driver and the pixel driver is connected to one end of the bit line via a first transfer gate, and the other end of the bit line is connected via a second transfer gate. A second sense amplifier connected to the second sense amplifier, wherein the second sense amplifier is commonly connected to two or more columns of bit lines. The drive circuit unit of the box-type image display apparatus. 10. A drive circuit device for a matrix type image display device with a display storage function according to claim 9, wherein said MOS transistor and said MOS type capacitance element are formed of the same conductor. 11. The MOS transistor according to claim 9, wherein said MOS transistor and said MOS type capacitance element are formed of the same conductor, and the conductor layers of the respective MOS gates are formed simultaneously in a manufacturing process. Drive circuit device for matrix type image display device with display storage function. 12. The MOS transistor according to claim 9, wherein said MOS transistor and said MOS type capacitance element are formed of the same conductor, and the oxide films of the respective MOS gates are formed to have the same thickness simultaneously in the manufacturing process. A drive circuit device for a matrix-type image display device having a display storage function, characterized by that: 13. N and M are any positive integers equal to or greater than 1;
A memory cell composed of a matrix type image display signal line drive circuit, a MOS transistor and a MOS type capacitance element is arranged in a matrix, and a word line and a column commonly connected to the gate of the MOS transistor in a row direction are arranged. And a bit line commonly connected to the drain of the MOS transistor in a direction, and a first transfer gate is provided between the dynamic storage device and a bit line of a pixel driving device. Matrix type image display device with display storage function provided with N first sense amplifiers through the second transfer gate between the other end of the bit line and the other end of the bit line Wherein the integer M is equal to or smaller than the integer N, wherein the integer M is equal to or smaller than the integer N. 14. A driving circuit device for a matrix type image display device with a display storage function according to claim 13, wherein said MOS transistor and said MOS type capacitance element are formed of the same conductor. 15. The MOS transistor according to claim 13, wherein said MOS transistor and said MOS capacitor are formed of the same conductor, and the conductor layers of the respective MOS gates are formed simultaneously in a manufacturing process. Drive circuit device for matrix type image display device with display storage function. 16. The MOS transistor according to claim 13, wherein said MOS transistor and said MOS type capacitance element are formed of the same conductor, and the oxide films of the respective MOS gates are formed to have the same thickness simultaneously in the manufacturing process. A drive circuit device for a matrix-type image display device having a display storage function, characterized by that: