JPH1184426A - Liquid crystal display device with built-in image sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive liquid crystal display panel having a sensitive sensor part by arranging a peripheral drive circuit in parallel to one side of a liquid crystal display part and arranging the sensor part in parallel to the outer side. SOLUTION: This display panel is provided with a sensor part 103 consisting of a photoelectric conversion element, a liquid crystal display part 101 consisting of a thin film transistor and a peripheral drive circuit 104 for driving the liquid crystal display part 101. Then, the peripheral drive circuit 104 is arranged in parallel to one side of the liquid crystal display part and the sensor part 103 is arranged in parallel to the other one side. That is, by such a constitution, the sensor part 103 is provided on a place without the peripheral drive circuit 104 and a lead-out terminal part 105 is provided on the opposite side holding the liquid crystal display part 101. By such a manner, an excellent image is read without being affected by noise, heat generation from the peripheral drive circuit 104 and static electricity, etc., easy to occur on the lead-out terminal part 105.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated liquid crystal display panel having an image sensor function, and more particularly to an arrangement of an image sensor unit.

[0002]

2. Description of the Related Art There is known a liquid crystal panel in which a voltage is applied to a liquid crystal layer from a pixel electrode to orient a liquid crystal to form an image on a display unit. The configuration of a conventional liquid crystal panel will be briefly described below. An element substrate in which a display portion and a peripheral circuit formed of a thin film transistor are formed on an insulating substrate and an opposing substrate are spaced from each other by a spacer, and are bonded by a sealant. And it has a structure having liquid crystal between the element substrate and the counter substrate. The liquid crystal is sandwiched between a pair of substrates and is surrounded by a seal portion. The seal portion of the panel is arranged so as to surround the display portion or the display portion and the peripheral drive circuit in a ring shape.

[0003] In the above conventional configuration, the element substrate is
Refers to a substrate provided with an active matrix circuit and a peripheral circuit. Further, the opposing substrate is a substrate provided so as to oppose the element substrate, in which an opposing electrode, a color filter, and the like are formed.

Further, in the above-described conventional structure, a sealing resin having ultraviolet curability or thermosetting is used as a sealing material.

On the other hand, as an image sensor, a photocopier, a digital still camera, a video camera, a facsimile, etc., is widely used as an optical sensor for converting an image into an electric signal, and an optical sensor module is incorporated therein. It has a device configuration.

When such a liquid crystal panel and an image sensor are manufactured on the same substrate, the arrangement of the panel and the image sensor becomes an important problem.

In particular, the sensor section of the image sensor is made up of sensitive elements, and the heat dissipation of the glass substrate is poor. As a result, the sensitivity of the sensor tends to decrease.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display panel having a display unit and an image sensor on the same substrate and an inexpensive liquid crystal display panel having a sensor unit with good sensitivity. .

[0009]

According to the structure of the present invention disclosed in this specification, a pair of substrates using two substrates is provided, and a sensor unit including a photoelectric conversion element is provided on one of the substrates.
A liquid crystal display section comprising a thin film transistor; and a peripheral drive circuit section for driving the display section, wherein a peripheral drive circuit section is arranged in parallel with at least one side of the liquid crystal display section. A liquid crystal display device having a built-in image sensor, wherein the sensor unit is arranged parallel to another side.

In another aspect of the present invention, there is provided a pair of substrates using two substrates, one of which has a sensor unit composed of a photoelectric conversion element, a liquid crystal display unit composed of a thin film transistor, and A peripheral drive circuit section for driving the display section, wherein the display section and the sensor section are connected to an external wiring through a lead-out wiring terminal section of the display section and the sensor section. A liquid crystal display device having a built-in image sensor, wherein the image sensor is provided.

In another aspect of the present invention, there is provided a pair of substrates using two substrates, and a sensor unit composed of a photoelectric conversion element, a liquid crystal display unit composed of a thin film transistor, and the like on one substrate. An image sensor, comprising: a peripheral drive circuit section for driving the display section, wherein a longitudinal symmetry axis of the display section coincides with a longitudinal symmetry axis of the sensor section. Is a liquid crystal display device incorporating the same.

According to another aspect of the present invention, there is provided a liquid crystal display comprising a pair of substrates using two substrates, two sensor units each comprising a photoelectric conversion element and a thin film transistor on one of the substrates. And a peripheral drive circuit unit for driving the display unit, wherein the two sensor units are arranged at positions symmetrical with respect to a longitudinal symmetry axis of the display unit. It is a built-in liquid crystal display device.

In the present invention, a liquid crystal display device having a built-in image sensor refers to a liquid crystal display device having a display portion and a sensor portion formed on the same substrate, and the position of the sensor portion will be described in detail below. To place. First, when an image is output to the display unit, the peripheral drive circuit unit generates heat. mainly,
It has been found from experiments by the inventors that the location where heat is concentrated is near the center point of the peripheral drive circuit section.

Therefore, at least the peripheral driving circuit 104
In the vicinity of the central point of FIG.
(D). Also, noise and static electricity are generated from the lead-out wiring portion 105 and affect the sensor portion (including the peripheral circuit of the sensor portion) 103. Therefore, as shown in FIGS.
It is desirable that the lead wiring portion 105 be spaced apart from the wiring portion 105.

In the area sensor, the sensor section 103 is provided on the side where the peripheral drive circuit section 104 is not provided. In the case of a single area sensor, as shown in FIGS. 1A and 1B, it is desirable to arrange the sensor in the upper central portion of the display unit 101 in order to mainly capture the image of the user. FIG. 1C shows an example in which a single area sensor is provided on the side of the display unit so that a space is not taken in the short side direction of the substrate, and the short side of the substrate is made as small as possible.

Also, as shown in FIG. 1D, two double area sensors are arranged at symmetrical positions with respect to the axis of symmetry of the display unit 101 in order to mainly take in a three-dimensional image of the user. Is desirable.

Further, when a linear sensor is used as another configuration, as shown in FIGS.
The linear sensor unit 107 is installed on the side without the “04”. Further, the linear sensor unit 107 is installed horizontally or vertically with respect to the display unit 101. With such an arrangement, the moving mechanism can be facilitated.

With the above configuration, the peripheral driving circuit,
It is possible to obtain an inexpensive liquid crystal display panel having a sensor unit with good sensitivity and not affected by the lead wiring terminal (noise or heat).

[0019]

【Example】

[Embodiment 1] FIG. 1A shows an arrangement in an element substrate.
In the present embodiment, as shown in FIG.
Is provided at a position where the peripheral drive circuit 104 is not provided, and the lead terminal portion 105 is provided on the opposite side of the display portion 101. This makes it possible to read a good image without being affected by noise and heat generated from the peripheral drive circuit 104 and by static electricity and the like which are likely to be generated in the lead terminal 105. In addition, since the substrate is separated from the substrate at the time of dividing the substrate in the manufacturing process, the substrate is not affected by stress.

FIG. 1B shows another arrangement.
As shown by, the lead terminal portion 105 may be provided in parallel with the peripheral drive circuit 104 on the side of the display portion.

In another arrangement, the single area sensor 103 is provided on the side of the display unit 101 so that the short side of the substrate is made as small as possible so that no space is taken in the short side direction of the substrate. FIG. 1 (C).

As an example of an electric device having a sensor unit and a display unit on the same substrate, a notebook personal computer using a liquid crystal panel having an area sensor 603 disposed at the upper center of the display unit 601 is shown in FIG. FIG. 6B shows a television mobile phone as another application example.

Embodiment 2 FIG. 1 shows an arrangement in an element substrate.
(D). In this embodiment, as shown in FIG. 1D, the sensor unit 103 is provided at a location far from the center of the peripheral drive circuit, and is provided symmetrically to the left and right. By providing two sensors on the left and right sides, a user image can be captured three-dimensionally. In the present embodiment, the peripheral driving circuit 10
4, but the location where the peripheral drive circuit generates heat is in the center, so that the area sensor unit 103 includes:
No effect. FIG. 6C illustrates a notebook computer to which a liquid crystal panel in which two area sensors are arranged above a display portion is used.

[Embodiment 3] A method of manufacturing the element substrates of Embodiments 1 and 2 will be described with reference to FIGS. First, FIG.
As shown in FIG.
0 is formed. As the transparent substrate 100, a glass substrate or a quartz substrate can be used. As the base film 110, a 200-nm-thick silicon oxide film was formed by a plasma CVD method.

Next, an amorphous silicon film is formed to a thickness of 30 to 100 nm, preferably 30 nm by a plasma CVD method, and the polycrystalline silicon film 60 is irradiated with an excimer laser beam.
Was formed. This crystallization step is particularly performed in CMOS-TFT
This is an important step in increasing the mobility of 400. Note that as a method for crystallizing the amorphous silicon film, a thermal crystallization method called SPC, an RTA method of irradiating infrared rays, a method using thermal crystallization and laser annealing, or the like can be used (FIG. 3A). ).

Next, the polycrystalline silicon film 60 is patterned to form island-shaped semiconductor layers 301, 201, 401, and 402 constituting source, drain, and channel formation regions of the TFTs 200, 300, and 400. Next, a gate insulating film 120 covering these semiconductor layers 301, 201, 401, and 402 is formed. The gate insulating film 120 is formed to a thickness of 120 nm by a plasma CVD method using silane (SiH ₄ ) and N ₂ O as source gases.

Next, the aluminum film 61 is formed to a thickness of 300 to 500 nm by the sputtering method.
Formed. In order to suppress generation of hillocks and whiskers, scandium (Sc), titanium (Ti), and yttrium (Y) are contained in the aluminum film 61 in an amount of 0.04 to 1.
0% by weight (FIG. 3B).

Next, on the surface of the aluminum film 61, an anodic oxide film having a dense film quality (not shown) is formed. In order to form an anodic oxide film, an aluminum film 61 is used as an anode and platinum is used as a cathode in an ethylene glycol solution containing 3% tartaric acid, and a current may be passed between the electrodes. The thickness of the anodic oxide film is controlled by the applied voltage. In this embodiment, the thickness of the anodic oxide film is set to 10 to 30 nm.

Next, a resist mask 62 is formed, and the aluminum film 61 is patterned to form an electrode pattern 20.
2, 302, 403 and 404 are formed. (FIG. 3
(C)).

Then, anodic oxidation is performed again, and FIG.
, The electrode patterns 202, 302, 403,
A porous anodic oxide film 203, 303,
405 and 406 are formed respectively. In this case, the anodic oxidation step is performed by the electrode patterns 202, 302, 403, and 40.
4 may be used as an anode and platinum may be used as a cathode, and a current may be passed between the electrodes in an oxalic acid aqueous solution having a concentration of 3%. The thickness of the anodic oxide films 203, 303, 405, 406 can be controlled by the voltage application time. Anodic oxide films 203, 303,
Reference numerals 405 and 406 are used to form a low-concentration impurity region in the semiconductor layer in a self-aligned manner (FIG. 4A).

After the resist mask 62 is removed by a dedicated stripper, an anodic oxidation step is performed again, and the anodic oxide films 204, 304, 407,
408 are respectively formed. The electrode patterns 202, 302 that have not been anodized in the above anodic oxidation step,
403, 404 are substantially gate electrodes 205, 30
5, 409 and 410 function. The anodic oxide films 204, 304, 407, which are formed around these gate electrodes 205, 305, 409, 410 and have a fine film quality,
Reference numeral 408 functions to electrically and physically protect the gate electrode. Further, the offset structure can be formed in a self-aligned manner by these anodic oxide films (FIG. 4).
(B)).

When the state shown in FIG. 4B is obtained, the semiconductor is doped with P ions in order to impart N-type conductivity. In this embodiment, an ion doping method is used. The conditions are a dose of 1 × 10 ¹⁵ / cm ² and an acceleration voltage of 80 kv. As a result, the gate electrode and the anodic oxide film function as a mask, and the semiconductor layers 201, 301, 401, 402
N-type impurity regions 206, 306, 411,
412 are formed in a self-aligned manner (FIG. 4C).

Next, the porous anodic oxide films 203, 30
After removing 3, 405 and 406, P ions are doped again by the ion doping method. The doping conditions are a dose of 5 × 10 ¹³ / cm ² and an acceleration voltage of 70 kv. As a result, the regions 207, 307, 413, and 414 into which the P ions have been implanted become the N-type high-concentration impurity regions in both of the two doping steps. Implanted regions 208, 30
8, 415 and 416 are N-type low concentration impurity regions.
In addition, regions 209, 309, 417, and 418 in which P ions are not implanted in both of the two doping steps are channel formation regions. (FIG. 4 (D))

An offset structure is formed in a self-aligned manner in a lower region of the dense anodic oxide film in a region between the source region and the drain region.

Next, as shown in FIG.
-To invert the N-type impurity region of the semiconductor layer 402 of the TFT 400 to the P-type, set another semiconductor layer to a resist mask 6
Cover with 3. In this state, B ions imparting P-type conductivity are implanted by ion doping. Condition is dose 2
× 10 ¹⁵ / cm ² and acceleration voltage 65 kV. As a result,
The conductivity types of the N-type impurity regions 414 and 416 are inverted,
Type impurity regions 419 and 420. Then, laser annealing is performed to activate the doped P ions and B ions (FIG. 5A).

Then, a first interlayer insulating film 130 is formed, and a contact hole reaching the N-type high-concentration impurity regions 207, 307, 413 and the P-type impurity region 419 is formed. Thereafter, a metal film is formed and patterned, and the wirings 210, 211, 310, 311, 421, and 4 are formed.
22, 423 are formed. Note that the TFT 400 is CMO
In order to form an S structure, the N-type high-concentration impurity region 414 and the P-type impurity region 419 are connected by a wiring 422.

In this embodiment, the first interlayer insulating film 130 is formed of a 500 nm thick silicon nitride film. As the first interlayer insulating film 130, a silicon oxide film or a silicon nitride film can be used in addition to the silicon nitride film. Further, a multilayer film of these insulating films may be used.

The wirings 210, 211, 310, 31
In this embodiment, a stacked film including a titanium film, an aluminum film, and a titanium film is formed as a metal film serving as a starting film of 1, 421, 422, and 423 by a sputtering method. These film thicknesses are 100 nm, 300 nm, and 100 nm, respectively.

Through the above CMOS process, the pixel TF
T200, light receiving unit TFT300, CMOS-TFT40
0 are completed at the same time (FIG. 5B).

Next, a second interlayer insulating film 140 that covers the TFTs 200, 300, and 400 is formed. As the second interlayer insulating film 140, a resin film capable of offsetting unevenness of a lower layer to obtain a flat surface is preferable. As such a resin film, polyimide, polyamide, polyimide amide, or acrylic can be used. Also, the second interlayer insulating film 1
The surface layer 40 may be a resin film for obtaining a flat surface, and the lower layer may be a single layer or a multilayer of an inorganic insulating material such as silicon oxide, silicon nitride, or silicon oxynitride. In this embodiment, a polyimide film is formed as the second interlayer insulating film 140 to a thickness of 1.5 μm.

Next, the light receiving portion T is formed on the second interlayer insulating film 140.
After forming a contact hole reaching the FT wiring 310, a conductive film is formed. In this embodiment, a 200-nm-thick titanium film is formed as a conductive film by a sputtering method.

Next, the conductive film is patterned and the display portion T
An FT light-shielding film 221 and a lower electrode 321 connected to the light-receiving unit TFT are formed. Titanium and chromium can be used as this conductive film.

Next, it functions as the photoelectric conversion layer 322.
An amorphous silicon film to which hydrogen is added (hereinafter referred to as an a-Si: H film) is formed over the entire surface of the substrate. Then, patterning is performed so that the a-Si: H film remains only in the light receiving portion, and the photoelectric conversion layer 322 is formed.

Then, a third interlayer insulating film 150 is formed. It is preferable to form a resin film of polyimide, polyamide, polyimide amide, acrylic, or the like as an insulating film included in the third interlayer insulating film 150 because a flat surface can be obtained. Alternatively, the third interlayer insulating film 150
The surface layer may be a resin film as described above, and the lower layer may be a single layer or a multilayer film of an inorganic insulating material such as silicon oxide, silicon nitride, or silicon oxynitride. In this embodiment, the insulating film has a thickness of 0.1 mm.
A 5 μm polyimide film was formed on the entire surface of the substrate.

The maximum process temperature of the present invention is set to a temperature lower than the heat-resistant temperature of polyimide of 320 ° C.

After a polyimide film is formed, patterning is performed. By this patterning, the polyimide film on the photoelectric conversion layer 322 is removed, and the remaining polyimide film is used as the third interlayer insulating film 150.

Further, a wiring 21 is formed on the third and second interlayer insulating films.
A contact hole reaching 1 is formed. Next, a transparent conductive film is formed over the entire surface of the substrate, and is patterned to form a pixel TF.
The pixel electrode 223 connected to T and the transparent electrode 323 of the photoelectric conversion element are formed. ITO or SnO ₂ is used for the transparent conductive film.
Can be used. In this embodiment, an ITO film having a thickness of 120 nm is formed as a transparent conductive film.

Through the above steps, an element substrate as shown in FIG. 5C is completed. In this embodiment, since the control circuit for performing control for displaying the read image data is provided on the same substrate, the apparatus does not become large even if it has multiple functions.

[0049]

According to the present invention, it is possible to obtain an inexpensive liquid crystal display panel having a sensor unit with good sensitivity, which is not affected by the peripheral drive circuit and the lead wiring (noise and heat). Further, in the present invention, since the image sensor is provided on the same substrate as the pixel matrix and the peripheral driver circuit, a display device having a display function and an imaging function can be reduced in size and weight, and the sensor unit and the display unit can be simultaneously formed. Since the display device is formed, a display device can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a panel layout diagram of an area sensor.

Fig. 2 Panel layout of linear sensor

FIG. 3 is a manufacturing process diagram of a TFT.

FIG. 4 is a manufacturing process diagram of a TFT.

FIG. 5 is a manufacturing process diagram of a TFT.

FIG. 6 is an application example of the present invention.

[Explanation of symbols]

 101 display unit 103 area sensor unit 104 peripheral driving circuit 105 lead terminal unit 107 linear sensor unit

Claims (4)

[Claims] 1. A pair of substrates using two substrates, a sensor unit including a photoelectric conversion element, a liquid crystal display unit including a thin film transistor, and a periphery for driving the display unit on one of the substrates. A driving circuit section, wherein a peripheral driving circuit section is arranged in parallel with at least one side of the liquid crystal display section, and the sensor section is arranged in parallel with another side of the liquid crystal display section. A liquid crystal display device having a built-in image sensor. 2. A pair of substrates using two substrates, wherein a sensor unit composed of a photoelectric conversion element, a liquid crystal display unit composed of a thin film transistor, and a periphery for driving the display unit are provided on one of the substrates. A driving circuit unit, wherein the display unit is disposed between the sensor unit and a lead wiring terminal unit of the display unit that connects the display unit and the sensor unit with external wiring. Liquid crystal display device incorporating an image sensor. 3. A pair of substrates using two substrates, wherein a sensor unit composed of a photoelectric conversion element, a liquid crystal display unit composed of a thin film transistor, and a periphery for driving the display unit are provided on one of the substrates. A liquid crystal display device having a built-in image sensor, comprising: a driving circuit unit; and a symmetric axis in a longitudinal direction of the display unit coincides with a symmetric axis in a longitudinal direction of the sensor unit. 4. A pair of substrates using two substrates, one sensor substrate including two photoelectric conversion elements, a liquid crystal display unit including thin film transistors, and a driving unit for driving the display unit. A liquid crystal display device having a built-in image sensor, wherein the two sensor units are disposed at positions symmetrical with respect to a longitudinal symmetry axis of the display unit.