WO2002065752A1

WO2002065752A1 - Image input device with built-in display function

Info

Publication number: WO2002065752A1
Application number: PCT/JP2002/001073
Authority: WO
Inventors: Ichiro Fujieda
Original assignee: Nec Corporation
Priority date: 2001-02-09
Filing date: 2002-02-08
Publication date: 2002-08-22
Also published as: JP4543560B2; JP2002237923A

Abstract

An image input device comprising a transparent substrate, a plurality of light emitting means arranged on one surface of this transparent substrate, a plurality of photoelectric conversion means arranged on the above one surface of the transparent substrate, and a light switching means disposed on the other surface of the transparent substrate, for selectively reflecting or transmitting light emitted from the light emitting means. The light emitting means emits light toward the above other surface of the transparent substrate, and the photoelectric conversion means detects light incident on the toe above one surface, and allows, when an image is to be input, the light emitting means to emit light toward the above other surface of the transparent substrate and the light switching means to be set to reflect the above light so that the photoelectric conversion means receives a reflection light from the image. When an image is to be displayed, the light switching means is set to transmit the light and allows the light emitting device to emit light toward the above other surface of the transparent substrate as required by the image.

Description

Image input device with built-in display function TECHNICAL FIELD OF THE INVENTION

The present invention relates to an image input device used for electronic devices such as a portable information terminal, a mobile phone, and a personal computer, and more particularly, to an image input device having a built-in image display function. Conventional technology

2. Description of the Related Art Hitherto, an image input device for inputting image information recorded on a flat medium such as a document, a photograph, or the like and having an image display function has been proposed. As an example of such a conventional image input device, FIG. 20 shows a side view of an image input device disclosed in Japanese Patent Application Laid-Open No. Hei 7-236209.

As shown in FIG. 20, the image input device includes a two-dimensional image sensor 110, a planar light source 120 arranged on the two-dimensional image sensor 110, and a planar light source 120. The two-dimensional image sensor 110, which is arranged on the side of the liquid crystal light valve 130 disposed above, the two-dimensional image sensor 110, the planar light source 120, and the liquid crystal light valve 130, is disposed. And a drive circuit 140 for driving the liquid crystal light valve 130.

The two-dimensional image sensor 110 is configured by arranging a large number of photoelectric conversion elements on a transparent substrate. Adjacent photoelectric conversion elements are spaced apart from each other so that a gap is formed between them, and an opening for transmitting light emitted from the planar light source 120 is provided in this gap. Have been.

Image input in this image input device is performed as follows.

First, the original 100 is brought into close contact with the two-dimensional image sensor 110. Next, the planar light source 120 emits light toward the original 100. The light emitted from the planar light source 120 passes through an opening formed in a gap between the photoelectric conversion elements constituting the two-dimensional image sensor 110, and illuminates the original 100. The reflected light from original 100 is the same The light is transmitted through the opening, is received by the photoelectric conversion element constituting the two-dimensional image sensor 110, and is converted into an electric signal.

Each photoelectric conversion element is provided with a switch (usually, this switch is formed by a thin film transistor) for reading out the electric signal to the outside. These switches are controlled to control all the photoelectric conversion elements. Image information is obtained by reading electrical signals.

The drive circuit 140 controls this series of image input operations by transmitting a control signal 150 to the photoelectric conversion element.

On the other hand, the liquid crystal light valve 130 includes two transparent substrates and a liquid crystal layer sandwiched between the two transparent substrates. Many pixels are regularly arranged on the display surface of the liquid crystal light valve 130, and the drive circuit 140 issues a control signal 160 to each pixel. Each pixel displays an image by switching between transmitting and absorbing light emitted from the planar light source 120 according to the control signal 160.

As described above, the conventional image input device shown in FIG. 20 is a flat type, and one surface (the bottom surface of the two-dimensional image sensor 110) is an input surface, and the other surface (a liquid crystal light valve 13). There is a variety of uses because the (top) of is the display surface. For example, place this image input device on a fine image document and display an enlarged image of that image, or place this image input device on an English document and translate the contents into Japanese. It is possible to display after doing.

Further, by using a device having both functions of the liquid crystal light valve 130 and the two-dimensional image sensor 110, input and display can be performed on the same surface. An example of such an image input device is disclosed in the above publication.

FIG. 21 is a side view showing the configuration of this image input device.

The image input device shown in FIG. 21 includes a planar light source 120 b, a two-dimensional image sensor 170 serving also as a liquid crystal light valve disposed on the planar light source 120 b, and a planar light source 1 2 0b and a drive circuit 140b that is disposed on the side surface of the two-dimensional image sensor 170 that also serves as a liquid crystal light valve and drives the two-dimensional image sensor 170 that also serves as a liquid crystal light valve. FIG. 22 is a cross-sectional view showing a cross section of a pixel portion of a two-dimensional image sensor 170 that also serves as a liquid crystal light valve, and a principle of operation thereof.

The two-dimensional image sensor 170 also serves as a liquid crystal light valve. The two-dimensional image sensor 170 is composed of two transparent substrates 170 and 180, and a transparent electrode 17 formed on one surface of each of the transparent substrates 170 and 180. 5, 179, a liquid crystal layer 180 sandwiched between two transparent substrates 174, 180, and formed on the other surface of each of the transparent substrates 174, 180 Polarizing plates 17 3 and 18 1, a transparent protective layer 17 1 formed on the polarizing plate 17 3, and a plurality of lenses 17 regularly arranged on the polarizing plate 17 3 2, a photoelectric conversion material 1 76 in contact with the liquid crystal layer 1 78 on the transparent electrode 1 75 and regularly arranged corresponding to the lens 1 72, and on each photoelectric conversion material 1 6 And an opaque electrode 17 7 The two-dimensional image sensor 170, which also serves as a liquid crystal light valve, has a sensor pixel 182 sandwiched between two liquid crystal light bulb pixels 183, a lens 172, and a photoelectric conversion material 1776. The opaque electrode 177 is arranged inside the sensor pixel 182.

The operation of the image input device shown in FIGS. 21 and 22 is as follows.

In the area of the liquid crystal light valve pixel 183, only one polarized component of the light emitted from the light source 120b is transmitted by the polarizing plate 181 and reaches the liquid crystal layer 178. Here, by controlling the voltage applied to the transparent electrodes 179 and 175 so that this light is transmitted through the polarizing plate 173, the light emitted from the light source 120b is converted to the original. Illuminate 100.

The reflected light from the original 100 reaches the photoelectric conversion material 176 through the lens 172, and is converted into an electric signal by the photoelectric conversion material 176. Thus, an electrical signal corresponding to the light / dark information of the original document 100, that is, an image can be obtained by the large number of lenses 172 and the photoelectric conversion material 176 arranged regularly. The opaque electrode 177 prevents direct light from the planar light source 12 Ob from entering the photoelectric conversion material 176.

The display of an image is realized by controlling the voltage applied to the transparent electrodes 179 and 175 and controlling the transmission of light from the planar light source 12 Ob.

However, the conventional image input devices shown in FIGS. 20 to 22 have the following problems. was there.

First, the thickness of the conventional image input device shown in FIG. 20 is equal to the sum of the components, and further thinning is difficult or impossible.

For example, when the thickness of the two-dimensional image sensor 110 is 0.7 mm, the thickness of the planar light source 120 is l mm, and the thickness of the liquid crystal light pulp 130 is 1.4 mm, The total thickness of the image input device is 3.1 mm, and further reduction in thickness is physically impossible.

Further, in the conventional image input device shown in FIG. 20, since the liquid crystal light pulp 130 and the two-dimensional image sensor 110 are arranged on both sides of the planar light source 120, the planar The light source 120 is configured to emit light in both directions. For this reason, for example, even when an image is displayed, the input light is emitted to the opposite side, which causes a reduction in light use efficiency.

Furthermore, the conventional image input device shown in FIG. 20 has a large number of components, and it is difficult to reduce the manufacturing cost.

Second, when a thin film transistor (TFT) liquid crystal light valve 130 capable of displaying high-quality images is adopted, a large number of TFTs are used in the two-dimensional image sensor 110 as well. Since an array of transparent substrates is required, a total of two transparent substrates that have undergone the TFT manufacturing process are required.

On the other hand, in the image input device shown in FIGS. 21 and 22, the required number of transparent substrates after the TFT manufacturing process is one. As described above, according to the image input devices shown in FIGS. 21 and 22, it is possible to avoid an increase in the manufacturing cost due to the manufacture of the TFT.

However, since the image input device shown in FIG. 22 requires the lens 17 2, the manufacturing cost for forming the lens 17 2 is added, and the manufacturing cost is eventually increased due to the TFT manufacturing. Nevertheless, the production cost is increasing due to the production of the lens 172.

In the image input device shown in FIG. 22, the light component reaching the opaque electrode 177 of the light emitted from the planar light source 120b is used to illuminate the original 100. Absent. For this reason, the image input device shown in FIG. It has the problem of not being able to do so.

Further, the thickness of the image input device shown in FIG. 22 is the thickness of the planar light source 120 b, the thickness of two transparent substrates 174 and 180, and the connection of the lens 172. It is equal to the sum of the distance required for the image and.

In this case, even if the imaging distance can be neglected, for example, the thickness of the planar light source 120b is 1 mm, and the thickness of the two transparent substrates 174 and 180 is 1.4. If it is mm, it is difficult to make the thickness of the image input device thinner than 2.4 mm, which is the sum of them.

Also, Japanese Patent Application Laid-Open No. Hei 7-322210 discloses an image input / output device having image input means, and image display means for enlarging and displaying at least a part of image information input by the image input means. Wherein the reading surface of the image input means and the display surface of the image display means are arranged so as to face each other, and the display surface is positioned on the reading range. is suggesting.

Japanese Patent Publication No. 390885/1995 (Japanese Patent Application Laid-Open No. 10-97385) discloses an image sensor section having a plurality of light receiving elements arranged in a row facing the side of a document to be read. A thin light source that is arranged in close contact with the reading document side of a sensor unit and emits light toward the reading document, wherein the thin light sources are smaller than the light receiving elements for each of the light receiving elements. It has at least one light emitting unit having an area, the light emitting unit has a light shielding layer on the light receiving element side, and is located on the lower surface of the light receiving element between the light receiving element and the original to be read. An image sensor device characterized by being arranged is proposed.

Furthermore, Japanese Patent Publication No. 7-62885 (Japanese Patent Application Laid-Open No. Hei 6-32515) discloses a planar light source and a light source arranged on the planar light source and emitting light emitted from the planar light source. A two-dimensional image sensor having an opening through which light passes, and optical means for guiding light transmitted through the opening so as to irradiate a finger obliquely, and guiding reflected light from the finger to a photoelectric conversion element of the two-dimensional image sensor And a fingerprint image input device characterized by the following.

However, the problems described above remain unresolved in the image input / output devices and other devices proposed in these publications. The present invention has been made in view of the above problems, and has as its object to realize, at low cost, an image input device having a thin display function that can be driven with high light use efficiency and low power consumption. . Disclosure of the invention

In order to achieve the above object, the present invention provides, as a first aspect, a transparent substrate, a plurality of light emitting units arranged on one surface of the transparent substrate, and an array of light emitting units arranged on the one surface of the transparent substrate. An image input device, comprising: a plurality of photoelectric conversion units; and a light switching unit disposed on the other surface of the transparent substrate and selectively reflecting or transmitting light emitted from the light emitting unit. Wherein the light emitting means emits light toward the other surface of the transparent substrate, the photoelectric conversion means detects light incident on the one surface, and when an image is inputted, the light emitting means Light is emitted toward the other surface of the transparent substrate, and the light switching means is set to reflect the light, and the photoelectric conversion means receives reflected light from the image. Image input equipment Provide a replacement.

In the image input device described above, when displaying an image, the light switching unit is set to transmit the light, and the light emitting unit is set to the other one of the transparent substrates according to the image. To emit light toward the surface of.

Further, according to a second aspect of the present invention, a substrate, a plurality of light emitting units arranged on one surface of the substrate, and a plurality of photoelectric conversion units arranged on the one surface of the substrate, An image input device comprising: the light emitting unit emits light in a direction opposite to the other surface of the transparent substrate; the photoelectric conversion unit detects light incident on the one surface; and inputs an image. If so, an image input device is provided in which the light emitting means emits light in a direction opposite to the other surface of the transparent substrate, and the photoelectric conversion means receives reflected light.

In the above image input device, when displaying an image, the light emitting unit emits light toward the other surface of the transparent substrate according to the image.

In the image input device according to the second aspect, for example, each of the light emitting units can be arranged so as to overlap each of the photoelectric conversion units. Further, it is preferable that the image input device according to the first and second aspects further includes a transparent protective layer covering the light emitting means and the photoelectric conversion means.

In the image input devices according to the first and second aspects, the light-emitting unit may include, for example, a light-emitting element that emits light to the outside, and a light-emitting element selection unit that causes a specific light-emitting element to emit light. Can be.

Further, the photoelectric conversion means can be constituted by, for example, a light receiving element for generating an electric signal corresponding to the amount of absorbed light, and a light receiving element selecting means for operating a specific light receiving element. .

In the image input device according to the first and second aspects, the light-emitting means includes, for example, a light-emitting element that emits light to the outside, and a light-emitting element selecting means for causing a specific light-emitting element to emit light. The photoelectric conversion unit includes: a light receiving element that generates an electric signal corresponding to an amount of absorbed light; and a light receiving element selecting unit that operates a specific light receiving element. The light emitting element selecting unit and the light receiving unit A control signal for operating one of the element selecting means may be supplied to the light emitting element selecting means or the light receiving element selecting means via the same control wiring.

In the image input device according to the first and second aspects, the light emitting unit includes: a light emitting element that emits light to the outside; and a light emitting element selecting unit that causes a specific light emitting element to emit light. The converting means comprises: a light receiving element for generating an electric signal corresponding to the amount of absorbed light; and a light receiving element selecting means for operating a specific light receiving element, and provides the light emitting intensity of the light emitting element. A signal and the electric signal generated by the light receiving element may be supplied to the light emitting element selecting means or the light receiving element selecting means via the same signal wiring.

In the image input device according to the first and second aspects, the light emitting unit includes: a light emitting element that emits light to the outside; and a light emitting element selecting unit that causes a specific light emitting element to emit light. The converting means comprises: a light receiving element for generating an electric signal corresponding to the amount of absorbed light; and a light receiving element selecting means for operating a specific light receiving element. The current for charging the light receiving element may be supplied to the light emitting element and the light receiving element via the same power supply wiring. In the image input devices according to the first and second aspects, the light switching means may include, for example, two transparent electrodes facing each other, and a liquid crystal layer sandwiched between the transparent electrodes. it can.

The light emitting element can be composed of, for example, two electrode layers, at least one of which is transparent, and a light emitting layer made of a light emitting material, sandwiched between the electrode layers. Further, the light receiving element can be composed of: two electrode layers, at least one of which is transparent; and a photoelectric conversion layer made of a photoelectric conversion material, sandwiched between the electrode layers.

When the light emitting element and the light receiving element are configured as described above, it is preferable that the transparent electrode layer of the light emitting element and the transparent electrode layer of the light receiving element are formed in the same step. The light emitting element can be composed of, for example, a laminate in which a first electrode, a first insulating layer, an inorganic electroluminescent material, a second insulating layer, and a second electrode are laminated in this order.

The light receiving element includes: a first electrode region; a first semiconductor region into which impurities are introduced; a second semiconductor region into which impurities are introduced at a lower concentration than the first semiconductor region; The third semiconductor region made of the same material as the semiconductor region may be sequentially joined to the third semiconductor region.

In the image input device of the second aspect, a crystalline silicon substrate can be used as the substrate, and the photoelectric conversion unit has a light receiving element that generates an electric signal corresponding to an amount of absorbed light. Can be configured. In this case, the light receiving element has a structure in which a region into which p-type silicon is introduced by introducing a first impurity into a region into which n-type silicon is introduced by introducing a second impurity into the crystalline silicon substrate. It can be configured as having.

The above-described image input device according to the present invention can be applied to mobile phones and other various devices.

Therefore, the present invention provides a first housing incorporating the image input device of the first and second aspects, a second housing rotatably connected to the first housing, Wherein the first casing and the second casing are foldable so as to overlap each other, and the light switching means of the image input device includes the first casing. And the second Provided is a device that is disposed so as to face the second housing when the housing is folded.

Further, the present invention provides a first housing incorporating an image input device, a second housing rotatably connected to the first housing, and being foldable so as to overlap with the first housing. And the first housing and the second housing so as to face the first housing when the first housing and the second housing are mutually folded. A light diffuser having a light diffusing function, disposed between the transparent substrate, the image input device comprising: a plurality of light emitting means arranged on one surface of a transparent substrate; and the transparent substrate And a plurality of photoelectric conversion units arranged on the one surface of the transparent substrate, wherein the light emitting unit emits light toward the other surface of the transparent substrate, and the photoelectric conversion unit emits light incident on the one surface. Is detected, and when an image is input, the light emitting means is connected to the other side of the transparent substrate. Emit light towards the surface, and the light switching means is by Uni set to reflect the light, the photoelectric conversion means to provide a device is intended for receiving light reflected from the image.

The image input device in the above-described device corresponds to the image input device of the above-described first embodiment in which the light switching unit is removed.

Further, the present invention provides a first housing incorporating an image input device, a second housing rotatably connected to the first housing, and being foldable so as to overlap with the first housing. And the first housing and the second housing are arranged to be sandwiched between the first housing and the second housing when the first housing and the second housing are folded together. A third housing, wherein the image input device comprises: a plurality of light emitting units arranged on one surface of a transparent substrate; and a plurality of light emitting units arranged on the one surface of the transparent substrate. Photoelectric conversion means, wherein the light emitting means emits light toward the other surface of the transparent substrate, and the photoelectric conversion means detects light incident on the one surface and inputs an image. In this case, the light emitting unit emits light toward the other surface of the transparent substrate. And the light switching means is set to reflect the light, and the photoelectric conversion means receives reflected light from the image. Opposing surfaces provide equipment with the added ability to diffuse light. The image input device in the above-described device corresponds to the image input device of the first embodiment described above, from which the light switching unit is removed.

For example, a microphone can be built in the third housing.

Further, the present invention is an apparatus having a housing incorporating the image input device according to the first and second aspects, wherein the image input device irradiates a finger with light emitted by the light emitting unit, Provided is a device for inputting a fingerprint as an image by receiving reflected light from the finger in the photoelectric conversion means.

As the above-mentioned device, for example, a mobile phone can be selected. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of an image input device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the cross section of the image input device according to the first embodiment of the present invention and the operation principle thereof.

FIG. 3 is a plan view (FIG. 3 (A)) showing an arrangement state of pixels in the image input device according to the first embodiment of the present invention, and a circuit diagram of each pixel (FIG. 3 (B)).

FIG. 4 is a circuit diagram of a pixel (FIG. 3A) in the image input device according to the first embodiment of the present invention, and a plan view (FIG. 3B) showing a layout of the pixel.

FIG. 5 is a sectional view showing a section of a pixel in the image input device according to the first embodiment of the present invention.

FIG. 6 is a plan view (FIG. 6) showing a manufacturing process of the image input device according to the first embodiment of the present invention.

6 (A)) and a sectional view (FIG. 6 (B)). '

FIG. 7 is a plan view (FIG. 7) showing a manufacturing process of the image input device according to the first embodiment of the present invention.

7 (A)) and a sectional view (FIG. 7 (B)).

FIG. 8 is a cross-sectional view illustrating a manufacturing process of the image input device according to the first embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating a manufacturing process of the image input device according to the first embodiment of the present invention.

FIG. 10 is a plan view (FIG. 10 (A)) and a cross-sectional view (FIG. 10 (B)) showing a manufacturing process of the image input device according to the first embodiment of the present invention. FIG. 11 is a plan view (FIG. 11 (A)) and a cross-sectional view (FIG. 11 (B)) showing a manufacturing process of the image input device according to the first embodiment of the present invention.

FIG. 12 is a plan view (FIG. 12 (A)) and a cross-sectional view (FIG. 12 (B)) showing a manufacturing process of the image input device according to the first embodiment of the present invention.

FIG. 13 shows a mobile phone (FIG. 13 (A) and FIG. 13 (C)) equipped with the image input device according to the first embodiment of the present invention and a portable information terminal (FIG. 13 (A)). FIG.

FIG. 14 is a plan view (FIG. 14 (A)) showing an arrangement state of pixels in a modified example of the image input device according to the first embodiment of the present invention, and a circuit diagram of each pixel (FIG. B)).

FIG. 15 is a plan view showing a pixel layout in a modified example of the image input device according to the first embodiment of the present invention.

FIG. 16 is a perspective view of an image input device according to the second embodiment of the present invention.

FIG. 17 is a cross-sectional view showing a cross-section of an image input device according to a second embodiment of the present invention and its operation principle.

FIG. 18 is a plan view (FIG. 18 (A)) showing a layout of a pixel in the image input device according to the second embodiment of the present invention, and a circuit diagram (FIG. 18 (B)) of the pixel. is there. FIG. 19 is a sectional view showing a section of a pixel in the image input device according to the second embodiment of the present invention.

FIG. 20 is a side view showing the configuration of a conventional image input device.

FIG. 21 is a side view showing the configuration of another conventional image input device.

FIG. 22 is a cross-sectional view of the conventional image input device shown in FIG. Detailed Description of the Preferred Embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)

FIG. 1 is a perspective view of the image input device according to the first embodiment of the present invention, and FIG. 2 is a sectional view of the image input device shown in FIG. FIG. 3 is a plan view (FIG. 3A) showing an arrangement state of pixels in the image input device according to the present embodiment, and a circuit diagram (FIG. (B)). FIG. 4 is a circuit diagram of a pixel in the image input device according to the first embodiment of the present invention (FIG. 3A) and a plan view showing a layout of the pixel (FIG. 3B). The image input device according to the present embodiment includes a transparent substrate 10, a plurality of light emitting elements 20 regularly arranged on one surface 10 a of the transparent substrate 10, and one of the transparent substrates 10. A plurality of light receiving elements 30 regularly arranged with the light emitting elements 20 on the surface 10 a; a vertical driving circuit 40 and a horizontal driving circuit 41 for driving the light emitting elements 20 and the light receiving elements 30; A protection layer 60 formed on one surface 10 a of the transparent substrate 10 so as to cover the light emitting element 20 and the light receiving element 30, and to protect the light emitting element 20 and the light receiving element 30; And light switching means 70 formed on the other surface 1 Ob of the transparent substrate 10. As shown in FIG. 1, the light emitting elements 20 and the light receiving elements 30 are alternately arranged in a matrix in both the X direction and the Y direction.

The light switching means 70 selectively reflects or transmits light emitted from the light emitting element 20 and transmitted through the transparent substrate 10.

As shown in FIG. 2, the light emitting element 20 is configured to emit light only in a direction from one surface 10a to the other surface 10b. The light receiving element 30 is configured to detect only light from the other surface 10 b of the transparent substrate 10. As schematically shown in FIG. 3A, each light receiving element 30 is provided with an opening 56 for transmitting light incident from the direction of the other surface 10 b of the transparent substrate 10. ing.

Further, as shown in FIG. 2, the light switching means 70 is formed on one surface of a transparent substrate 74, a transparent electrode 71 formed on the surface 10 b of the transparent substrate 10, and a transparent substrate 74. A transparent electrode 73, and a liquid crystal layer 72 sandwiched between the two transparent electrodes 71 and 73.

By changing the voltage applied between the two transparent electrodes 71 and 73, it is possible to switch between a state where the liquid crystal layer 72 transmits light and a state where the liquid crystal layer 72 diffuses light.

As a material of the liquid crystal layer 72, for example, a chiral nematic liquid crystal can be used. This type of liquid crystal maintains a helical structure when no voltage is applied, so that light incident on the liquid crystal is scattered. On the other hand, when voltage is applied, Since the helical structure is stretched into an almost linear structure, light can pass through the liquid crystal.

Next, the overall operation of the image input apparatus according to the present embodiment will be described with reference to FIGS. The operation of each component will be described later together with the detailed configuration of each component.

First, when inputting an image, as shown in FIG. 2, an input target 80 such as a manuscript is placed in close contact with the protective layer 60.

Next, all the light emitting elements 20 are turned on by the vertical drive circuit 40 and the horizontal drive circuit 41. At this time, the light switching means 70 is set so as to diffuse and reflect the light. Therefore, the light emitted from the light emitting element 20 in the direction of the surface 10b of the transparent substrate 10 is transmitted through the transparent substrate 10 and is diffusely reflected by the light switching means 70.

The diffusely reflected light passes through the transparent substrate 10 again, reaches the surface 10a of the transparent substrate 10 and eventually reaches the light receiving element 30.

The light that reaches the light receiving element 30 passes through a gap formed between the light receiving element 30 and the light emitting element 20 or an opening 56 provided in the light receiving element 30, and passes through the protective layer 60. The input target 80 that is in close contact with the object is illuminated and reflected by the input target 80.

The light reflected by the input object 80 is received by the light receiving element 30 and is converted into an electric signal according to the intensity of the reflected light.

The vertical drive circuit 40 and the horizontal drive circuit 41 read electric signals reflecting the intensity of the reflected light from all the light receiving elements 30. Thereby, the light / dark information of the input target 80, that is, the image is input to the image input device.

When displaying an image, the light switching means 70 is set to transmit light. Next, the light emitting element 20 corresponding to the image to be displayed is turned on via the vertical drive circuit 40 and the horizontal drive circuit 41. Light from the light emitting element 20 passes through the transparent substrate 10 and the light switching means 70 and reaches an observer (not shown). Thus, the image of the input object 80 is provided to the observer.

Hereinafter, the configuration, operation, and manufacturing method of the components of the image input device according to the present embodiment will be described.

FIG. 3 is a plan view (FIG. 3A) showing an arrangement state of pixels in the image input device according to the present embodiment, and a circuit diagram of each pixel (FIG. 3B). Here, the display resolution is 20 Opp i (pi xe l / inch, that is, the number of pixels per inch when the light emitting elements of red, green, and blue are regarded as one pixel), the resolution of image input 400 dp i (do t / i nch, that is, the number of light receiving elements per inch). In Fig. 3 (A), one red (R) element, one green (G) element, and two blue (B) light emitting elements are arranged in a square, and each light emitting element is in a one-to-one relationship. One pixel is configured by arranging light receiving elements.

Further, as shown in FIG. 3 (B), circuits and wirings for driving these light emitting elements and light receiving elements are formed. The pixel arrangement pitch is 127 m in both the X and Y directions. In the driving circuit for the light emitting element and the light receiving element, some wirings (data line 87, gate line 85, power supply line 86) are shared by the light emitting element and the light receiving element. This is because, as shown in FIG. 4B, the area occupied by the wiring is reduced so that the areas of the light receiving element and the light emitting element are set large.

As shown in the circuit diagram of FIG. 3 (B), the source electrode of the first thin film transistor (TFT) Tr 1 is connected to the data line 87, the gate electrode is connected to the power supply line 86, and the drain electrode is connected to the input end of the light receiving element PD. It is connected. The first thin film transistor (TFT) Tr 1 transfers the charge stored in the light receiving element PD to an external circuit.

The input terminal of the light receiving element PD is connected to the drain electrode of the first thin film transistor Tr1, and the output terminal is connected to the power supply line 86.

The source electrode of the second thin film transistor Tr2 is connected to the data line 87, the gate electrode is connected to the gate line 85, and the drain electrode is connected to the gate electrode of the third thin film transistor Tr3.

The drain electrode of the third thin film transistor Tr3 is connected to the power supply line 86, the gate electrode is connected to the drain electrode and capacitance of the second thin film transistor Tr2, and the source electrode is connected to the input terminal of the light emitting element LED.

The input terminal of the light emitting element LED is connected to the source electrode of the third thin film transistor Tr3, and the output terminal is connected to the ground line 88. The third thin film transistor Tr3 supplies a current to the light emitting element LED.

Between the connection point between the drain electrode of the second thin film transistor Tr2 and the gate electrode of the third thin film transistor Tr3, and the connection point between the output terminal of the light receiving element PD and the power supply line 86 Is connected to a capacitance C for holding the gate electrode of the third thin film transistor Tr3 at a constant potential. .

The second thin film transistor Tr2 charges the capacitance C to a desired voltage corresponding to the video signal.

As shown in FIG. 1, a TFT circuit for driving the light emitting element and the light receiving element is provided in the periphery of the pixel. Note that these TFT circuits are configured using polycrystalline silicon (po1y-Si) TFTs, and it is particularly desirable to include CMOS circuits using both n-type TFTs and p-type TFTs.

Hereinafter, the display operation of the image input device according to the present embodiment will be described with reference to FIG.

First, a control signal is supplied to the gate line 85 shown in FIG. 3B, and the second thin film transistors Tr2 of all the pixels sharing the gate line 85 are turned on. In synchronization with this, when a video signal to be displayed is applied to each data line 87, the video signal is stored in each capacitance C.

In this way, when the video signals are stored in the capacitances C of all the pixels selected by the gate line 85, the desired currents corresponding to the respective video signals are supplied to the light emitting element LEDs of these pixels. Is done. As a result, as shown in FIG. 2, light is emitted from the light emitting element 20 in the direction of the surface 10 b of the transparent substrate 10.

By repeating the above operation for all the gate lines 85, a desired image can be displayed.

Next, the operation of image input will be described.

First, a control signal is supplied to the gate line 85 shown in FIG. 3B to make the first thin film transistor Tr1 and the second thin film transistor Tr2 of all the pixels sharing the gate line 85 conductive. By setting all the data lines 87 to a low potential, the light emitting element P is completely charged, and the third thin film transistor Tr3 is turned on to turn on the light emitting element LED.

Immediately after these operations are completed, the potential of the gate line 85 is set to low level, and all the first thin film transistors Tr1 and the second thin film transistors Tr2 are turned off. At this time, the capacitance of the gate electrode of the third thin film transistor Tr 3 is generated by the capacitance C. Since the position is fixed, all light emitting diode LEDs continue to emit light at the same constant intensity.

Therefore, according to the above-described process, uniform illumination light reaches the original 80 and other input objects 80, and reflected light corresponding to the brightness information of the input object 80 is generated.

On the other hand, the light receiving element PD is separated from the data line 87 by the first thin film transistor Tr1, and its potential changes as the reflected light enters the light receiving element PD. After a certain time called the accumulation time, the data line 87 is connected to the detection circuit in the horizontal drive circuit 41, and a control signal is supplied to the gate line 85 to make the first thin film transistor Tr1 conductive.

At this time, electric charge corresponding to the amount of electric charge discharged during the accumulation time flows into the light receiving element PD. By detecting this charge amount for all the light receiving elements P D by the detection circuit, light / dark information of the input target 80, that is, image information can be obtained.

In the above case, all the light emitting element LEDs are turned on uniformly, but the operation of turning on a light emitting element of only one color and recording a reflection image of that color is repeated for three colors. A color image can also be input.

Next, an element structure for realizing the above-described image display operation and image input operation will be described.

In FIG. 3 (A), if the color of the light emitting element is ignored, it can be seen that the repeating unit of the pixel layout is the circuit shown in FIG. 4 (A). Figure 4 (B) shows the layout of the circuit components included in this basic unit.

FIG. 5 is a cross-sectional view showing a cross section of main components of a pixel portion such as a thin film transistor (TFT), a light emitting element, and a light receiving element. The numbers assigned to the wiring in the layout of FIG. 4 (B) correspond to the materials shown in FIG. Further, the wiring, the light receiving element PD, the light emitting element LED, and other components shown in FIG. 4B are arranged as much as possible to correspond to the circuit diagram shown in FIG. 4A.

Here, as the light emitting element 20, a device using an organic electroluminescence (E1 ectrol luminescence) (EL) material will be described as an example. As shown in FIG. 5, the light emitting element 20 includes a transparent electrode 53, an electrode 55, and a light emitting material layer 5 formed of an organic EL material sandwiched between the transparent electrode 53 and the electrode 55. 4 and have. When a potential difference is provided between the transparent electrode 53 and the electrode 55, a current flows through the luminescent material layer 54 in a region sandwiched between these electrodes 53, 55, and from this region, the transparent electrode 53, Light is emitted through the second interlayer insulating film 50, the first interlayer insulating film 48, the via layer 43, and the transparent substrate 10.

On the other hand, the light receiving element 30 will be described here with reference to an example of a photodiode having a ρ-i one-shot configuration.

The light-receiving element 30 is composed of an electrode 49, which is a material of source and drain electrodes of a thin film transistor (TFT), a transparent electrode 53, and a photoelectric conversion formed by being sandwiched between these electrodes 49, 53. Material 51 is provided. Between the transparent electrode 53 and the photoelectric conversion material 51, an extremely thin p-type silicon force-by-layer (p-SiC) layer is inserted as a blocking contact layer 52.

Hydrogenated amorphous silicon (a-Si: H), which is a photoelectric conversion material 51, is weak n-type when formed by ordinary plasma-enhanced chemical vapor deposition (PCVD), but intentionally contains impurities. Since it has not been introduced, it is called intrinsic semiconductor, that is, i-type. Since the interface between the i-type a-Si: H and the electrode formed of a metal material is a Schottky junction, this photodiode is called a p-i-Schottky type.

Suppose that an n-type a-Si: H layer with a high concentration of phosphorus (P) introduced between the metal electrode and the i-type a-Si: H is used to form a p-i-n structure. The photodiode may be used. This has the advantage that the leakage current is smaller than that of the Schottky type. At the center of the light receiving element 30, an opening 56 is provided as shown in FIG.

Both the light emitting element 20 and the light receiving element 30 have a diode structure, and their lower electrodes are connected to the source / drain regions 45 of the corresponding thin film transistors (TFT).

Here, as the thin film transistor (TFT), a general top gate type polycrystalline silicon (Po1y-Si) TFT is adopted. As shown in FIGS. 4 (B) and 5, in the present embodiment, the wiring material 47 for the gate electrode and the wiring material 49 for the source drain electrode and the power supply line are connected between the wiring material 47 for the gate electrode and the wiring material 49 for the power supply line. The capacitance C is formed by sandwiching one interlayer insulating film 48. Next, a method of manufacturing the components of the image input device according to the present embodiment will be described with reference to FIGS. The manufacturing process is roughly divided into a pre-process for forming a thin film transistor (TFT) and a light-receiving device, and a post-process for forming a light-emitting device using an organic EL material. FIGS. 6, 7, 10 to 12 include a plan view (A) and a cross-sectional view (B) of the structure at the time of performing each step.

Various thin film transistors can be employed in the manufacturing process of the thin film transistor (TFT) and the light receiving element as a pre-process. In this embodiment, a top gate type polycrystalline silicon (po 1 y-Si) TFT will be described as an example. First, a layer made of tungsten silicide (WSi) or another high melting point material is formed on a glass or other transparent substrate 10 by a sputtering method. This high melting point material layer is patterned by photolithography to form a light shielding layer 42 on the transparent substrate 10 as shown in FIG. 6 (B). When the light shielding layer 42 is formed from tungsten silicide (WSi), the thickness of the light shielding layer 42 is set in the range of 100 to 200 nm.

Then, oxygen and silicon-containing gas (e.g., silane (S i H ₄₎₎ by a CVD method to deposit onto a substrate and then decomposed in a plasma, silicon dioxide (S i 0 ₂₎ or Ranaru barrier layer 43 Form on one side. The barrier layer 43 prevents an impurity element contained in the transparent substrate 10 from diffusing into a layer above the transparent substrate 10 during a subsequent process. The thickness of the layer 43 is 300 to 500 nm. Next, an amorphous silicon (aSi) layer, which is a precursor of the po1ySi layer, is formed on the parier layer 43 by a plasma CVD method, a low pressure CVD method, or a sputtering method to a thickness of 100 nm. Formed to the extent. The amorphous silicon (a-Si) layer is irradiated with a very short pulse light of several tens of nanoseconds from an excimer laser to instantaneously melt the amorphous silicon (a-Si) layer so that the amorphous silicon (aSi) layer becomes polysilicon.

(po 1 yS i) layer. It is known that when the irradiation energy density at this time is set to around 40 OmJ / cm ² , a po 1 yS i TFT with good characteristics can be obtained.

This po 1 ySi layer is patterned by photolithography to form a thin film semiconductor 44. Next, formed in the same manner a thickness 5 0 nm approximately silicon dioxide (S i 0 ₂₎ film and a thickness of 2 0 0 nm extent of tungsten Siri Sai de (WS i) layer, the follower Torisogura Fi method A gate insulating film 46 and a gate electrode 47 are formed by patterning a tungsten silicide (WS i) layer.

Next, high concentration phosphorus (P) or boron (B) is selectively introduced into the region of the thin film semiconductor 44 by an ion doping method.

Thereafter, the transparent substrate 10 is heated to a temperature of about 500 degrees Celsius to activate the introduced impurity elements. At this time, the concentration of the impurity element, the heating time, the temperature, and other process conditions are important, and these process conditions are determined so that an ohmic contact with a wiring material to be formed later can be obtained.

Thus, the source / drain regions 45 of the thin film semiconductor 44 are formed. The region into which the impurity element has not been introduced becomes the channel region 44 a of the thin film semiconductor 44.

Thereafter, a first interlayer insulating film 4 8 made of silicon dioxide (S i 0 ₂₎ on the entire surface by plasma CVD method.

Through the above steps, the structure shown in the plan view of FIG. 6 (FIG. 6A) and the cross-sectional view of FIG. 6B is formed. Here, in the plan view of FIG. 6A, the tungsten silicide (W Si) layer and the insulating film at the lowermost layer of the thin film semiconductor 44 are not shown. It can be confirmed that the material of the gate electrode 47 is arranged in the semiconductor region of the three thin film semiconductors 44 and the gate electrode, and in the region that will later become the lower electrode of the capacitance C. Next, as shown in FIG. 7 (B), a contact hole is opened in the first interlayer insulating film 48, and the source / drain electrode 49 and the wiring are made of chromium (Cr) or another low-resistance metal material. Form.

Thus, the structure shown in the plan view of FIG. 7A and the cross-sectional view of FIG. 7B is formed. It can be confirmed that the data line, the power supply line, and the lower electrode of the light receiving element are formed of the material of the source / drain electrodes 49.

An opening 56 is formed in the lower electrode of the light receiving element.

Next, as shown in FIG. 8, after forming a second interlayer insulating film 50 on the entire surface, a contact hole is formed in the second interlayer insulating film 50 by lithography and etching. I do.

Further, as shown in FIG. 9, a hydrogenated amorphous Si layer 51 and a SiC layer 52 are continuously formed on the entire surface by a plasma CVD method.

Next, as shown in FIG. 10, these two layers 51 and 52 are patterned by lithography and etching, and further, an indium tin oxide (ITO) is sputtered over the entire surface. (ITO) is patterned by lithography and etching.

At this stage, it can be confirmed that the transparent electrode 53 is formed in a region to be the lower electrode (anode) of the light emitting element 20 while the light receiving element 30 is formed.

That is, by performing this series of steps once, the transparent electrodes 53 of the light receiving element 30 and the light emitting element 20 are simultaneously formed. Here, the indium tin oxide (ITO) used as the transparent electrode 53 has a sheet resistance of about 20 Ω / b and a thickness of about 1 O Onm.

Through the above steps, the previous steps of manufacturing the thin film semiconductor and the light receiving element are completed. In the subsequent manufacturing process, first, as shown in FIG. 11B, a light emitting material layer 54 made of an organic EL material is formed so as to cover the transparent electrode 53.

The light-emitting material layer 54 has a two-layer structure including a light-emitting layer and a hole injection / transport layer, a three-layer structure including an electron injection / transport layer, or a structure in which a thin insulating film is disposed at an interface with a metal electrode. Can be adopted.

As a method for manufacturing the light emitting material layer 54, a spin coating method, a vacuum evaporation method, or an ink jet printing method can be used. In accordance with each manufacturing method, a polymer or low molecular organic EL material is used. Selection, base structure, method of manufacturing upper electrode, and other manufacturing conditions are determined.

In this embodiment, the light-emitting material layer 54 has a two-layer structure of a light-emitting layer and a hole transport layer. As a material of the hole injection / transport layer, for example, a triarylamine derivative, an oxaziazole derivative or A porphyrin derivative can be selected. As a material for the light emitting layer, for example, a metal complex of 8-hydroxyquinoline and its derivative, a tetraphenylbutadiene derivative or a distyrylaryl derivative is selected. be able to. The light emitting layer and the hole transport layer are formed by laminating each with a thickness of about 50 nm by a vacuum evaporation method.

In FIG. 11B, the light emitting material layer 54 is patterned so as to cover almost the transparent electrode 53, but the light emitting material layer 54 is a layer made of an insulating material. However, patterning is not necessarily required, and the transparent substrate 10 can be formed so as to cover the entire surface. However, when the image input device according to the present embodiment is applied to a color display, at least three kinds of light emitting material layers and their separation are required, so that the light emitting material layer 54 needs to be patterned.

Next, a material having a low work function, such as an aluminum-lithium alloy, is vacuum-deposited as a cathode of the light-emitting element 20 to a thickness of about 200 nm through a metal shadow mask. Thus, an electrode 55 is formed as shown in FIG. 12 (B). Here, the GND line 55 shown in the circuit diagram of FIG. 4A is also formed of the same material as the electrode 55.

Further, the entire surface of the device is covered with a protective layer 60. Thus, the image input device according to the present embodiment is formed.

Since the image input device according to the present embodiment is thin and has high light use efficiency, it is advantageous for mounting on a portable device such as a mobile phone. FIG. 13A is a perspective view of a mobile phone equipped with the image input device according to the present embodiment.

The image input device according to the present embodiment is mounted on a foldable mobile phone. The foldable mobile phone includes a first housing 81 in which keys and other input means are arranged, and a second housing 82 including an antenna and other components. The first and second housings 82 are connected at their ends via a hinge mechanism 83 so as to be mutually rotatable.

The image input device according to the present embodiment is incorporated in the second housing 82. That is, in the image input device according to the present embodiment, when the foldable mobile phone is folded, the protection layer 60, that is, the input surface 90 of the image input device according to the present embodiment faces the outside, and the light switching means 7 It is mounted on a foldable mobile phone such that the zero transparent electrode 74, that is, the display surface 91 faces inward.

The image input device according to the present embodiment is mounted on a foldable mobile phone as described above. Thus, the following functions can be realized.

For example, when a mobile phone is folded, a finger is brought into close contact with the input surface 90 to input a fingerprint image into the image input device, and the phone is used only when it is confirmed that the mobile phone is a valid owner. Can be possible.

Alternatively, when various services are provided through a mobile phone, a fingerprint can be used for personal authentication when the service provider charges.

In addition, fingerprints of mobile phone users can be used as various payment means.

In the mobile phone shown in FIG. 13A, since the input surface 90 and the display surface 91 are separate, it is not necessary to bring a finger into close contact with the display surface 91. Therefore, it is possible to avoid the problem that the image quality of the image display on the display surface 91 is deteriorated by the residual fingerprint.

FIG. 13B is a perspective view of a double-page spread portable information terminal equipped with the image input device according to the present embodiment.

The portable information terminal shown in FIG. 13B includes a first housing 81, a second housing 82, and a third housing 84, and the first housing 81 The second case 82 and the second case 82 are connected to each other at their ends via a hinge mechanism (not shown) so as to be rotatable with each other, and the first case 81 and the third case 82 are connected to each other. The housing 84 is connected at its ends via a hinge mechanism (not shown) so as to be mutually rotatable.

The image input device according to the present embodiment is incorporated in the second housing 82 without the light switching means 70. That is, when the portable information terminal is folded, the protective layer 60 of the image input device according to the present embodiment faces outward, and the transparent electrode 7 4 Is incorporated in the second housing 82 so that it faces inward.

The third housing 84 is formed of a light diffusion sheet 7OA having the same function as the light switching means 70. As the light diffusion sheet 7OA, for example, a plastic sheet having an uneven shape on the surface and having a thickness of 1 mm or less can be used. When folding the second case 82 and the third case 84 with respect to the first case 81, the second case 82 and the third case 84 Of the first housing 8 1 It is folded immediately so that the second housing 82 is positioned on the third housing 84 directly above.

The operation of the portable information terminal shown in Fig. 13 (B) is as follows.

For image input, the original is closely attached to the protective layer 60 of the image input device in a state where the second housing 82 and the third housing 84 are folded with respect to the first housing 81. Let me do it. At this time, the light diffusion sheet 7 OA is disposed in close contact with the lower part of the transparent substrate 10 of the image input device incorporated in the second housing 82, and is similar to the light switching means 70. Performs functions.

When displaying an image, the second housing 82 is opened with respect to the first housing 81. Thus, an image can be displayed through the transparent substrate 10.

By opening the second housing 82 with respect to the first housing 81 and also opening the third housing 84 with respect to the first housing 81, the first housing 8 is opened. It is possible to use a keyboard or display screen arranged on the surface of one.

Thus, according to the portable information terminal shown in FIG. 13B, the advantage of the image input device according to the present embodiment, which can be reduced in thickness to almost the thickness of the transparent substrate 10, can be fully utilized.

Note that, in the portable information terminal shown in FIG. 13B, the third housing 84 and the second housing 82 are located on two sides of the first housing 81 opposite to each other. Although they are arranged, for example, the third housing 84 can be arranged on a side orthogonal to the side of the first housing 81 in which the second housing 82 is arranged. is there.

FIG. 13C is a perspective view showing a three-fold type mobile phone equipped with the image input device according to the present embodiment.

The mobile phone shown in FIG. 13C has a first housing 81 in which keys and other input means are arranged, a second housing 82 including an antenna and other components, and a third housing. The first housing 81 and the second housing 82 are connected to each other at their ends via a hinge mechanism 83a so as to be mutually rotatable. The first housing 81 and the third housing 84 are connected at their ends via a hinge mechanism 83b so as to be mutually rotatable.

The image input device according to the present embodiment includes a second housing 8 excluding the light switching means 70. Built in two. That is, when the mobile phone is folded, the protective layer 60 of the image input device according to the present embodiment, that is, the input surface 90 faces the outside, and the image switching device 70 is transparent. The electrode 74, that is, the display surface 91, faces the inside, and is incorporated in the second housing 82.

In addition, a light diffusion surface 70 B having the same function as the light switching means 70 is formed on the outer surface of the third housing 84. The third housing 84 has a built-in microphone.

When folding the second case 82 and the third case 84 with respect to the first case 81, the second case 82 and the third case 84 The second case 82 is folded so that the second case 82 is located directly above the first case 81 and the second case 82 is located above the third case 84.

The operation of the mobile phone shown in Fig. 13 (C) is as follows.

Image input is performed on the protective layer 60 of the image input device, that is, on the input surface 9 in a state where the second housing 82 and the third housing 84 are folded with respect to the first housing 81. This is done by placing the original on top of 0. At this time, the light-diffusing surface 70 B of the third housing 84 is disposed in close contact with the transparent substrate 10 of the image input device incorporated in the second housing 82. It has the same function as the light switching means 70.

By opening the second housing 82 with respect to the first housing 81 and also opening the third housing 84 with respect to the first housing 81, the first housing 8 is opened. It is possible to use a keyboard arranged on the surface of one.

Further, by opening the third casing 84, the microphone is located near the mouth of the user of the mobile phone, so that voice input can be performed easily.

As described above, according to the mobile phone shown in FIG. 13C, the advantage of the image input device according to the present embodiment, which can be reduced in thickness to almost the thickness of the transparent substrate 10, can be fully utilized.

Note that, in the mobile phone shown in FIG. 13C, the third housing 84 and the second housing 82 are arranged on two mutually facing sides of the first housing 81. But, for example, It is also possible to arrange the third housing 84 on a side orthogonal to the side of the first housing 81 in which the second housing 82 is arranged.

In the first embodiment described above, an example has been described in which the pixel layout shown in FIGS. 3A and 3B realizes a 200 ppi color display and a 400 di image input. The resolution and pixel rate of image display and image input are not limited to this example, and various combinations of resolutions can be realized by changing the pixel layout.

For example, FIG. 14A shows another example of the pixel layout. In this pixel layout, one red (R) element, one green (G) element, and one blue (B) light emitting element are arranged in the vertical direction, and three light receiving elements are arranged for each light emitting element. One pixel is configured by arranging the elements. The circuit configuration of the pixel layout shown in Fig. 14 (A) is shown in Fig. 14 (B).

With the pixel layout shown in FIG. 14A, it is possible to realize a color display of 200 ppi and an image input of 600 dpi.

Further, as described below, in the image input device according to the first embodiment described above, replacement of components, change of material type, change of circuit mounting form, and other various changes are possible.

For example, in the first embodiment, a light emitting diode made of an organic EL material has been described as an example of a light emitting element. However, an EL light emitting element made of an inorganic material can be used.

An EL light-emitting element composed of an inorganic material has, for example, a structure in which a first electrode, a first insulating layer, an inorganic EL material, a second insulating layer, and a second electrode are laminated in this order. can do. By forming one of the first and second electrodes from a transparent material, light emitted from the inorganic EL material can be extracted to the outside. For example, I TO of the first electrode has a thickness 0.2 m, the first and second insulating layers may be made of T a ₂ 0 ₅ with a thickness of 0.3 to 0.5 m, an inorganic EL material Can be formed by sputtering ZnS: Tb with a thickness of 0.5 μm.

Further, in the above-described first embodiment, an example in which the photodiode having the p-i-Schottky configuration is used as the light receiving element has been described. However, as described above, the photodiode having the P-i-n configuration has been described. Echoes can also be used.

Alternatively, a photoconductive light-receiving element made of n-type hydrogenated amorphous silicon (a-Si: H) can be used. This light-receiving element has two n-type a-Si: H regions in which P is introduced at a high concentration, and an i-type a-Si: H region sandwiched between those n-type a-Si: H regions. Area.

FIG. 15 shows a layout of a pixel using such a photoconductive light receiving element. In this pixel, the light receiving element is formed by successively overlapping the regions of i-type a-Si: H and n-type aSi: H, and using the material 49b of the source and drain electrodes on them. It is configured such that two electrodes formed in a comb shape face each other. At this time, the n-type a-Si: H in the region not covered by the electrode has been removed.

In the pixel shown in FIG. 15, the i-type a-Si: H and n-type a-Si: H regions after such patterning are shown as the photoelectric conversion layer 51b.

Further, although not shown in FIG. 15 because it is complicated, a light-shielding layer 42 is arranged below the photoelectric conversion layer 5 lb, and light does not directly enter the photoelectric conversion layer 51 b through the transparent substrate 10. It has been like that. When the adopted TFT is an inverted staggered aSi TFT in which the gate electrode is disposed below the channel material a-Si: H, the material of the gate electrode can be used instead of the light shielding layer 42 .

The operation of the pixel using the photoconductive light-receiving element described above is as follows.

When light that has entered through the transparent substrate 10 from below the transparent substrate 10 and light that has entered from above the transparent substrate 10 enter the i-type aSi: H in the region sandwiched by the comb-shaped electrodes, A current corresponding to the number of electron-hole pairs generated by this light is generated, and this current flows between these two electrodes. For this reason, an electric signal corresponding to the light amount is obtained.

Here, when the inverted staggered a-Si TFT is adopted, such a light receiving element can be formed simultaneously with the TFT in the process of manufacturing the TFT as follows.

To simultaneously form a-Si: H of the channel material of the TFT and a_Si: H of the photoelectric conversion material of the light-receiving element, and to subsequently connect the source / drain regions of the TFT to the electrodes in an atomic fashion. The n-type a-S i: H and the n-type a_S i: H of the light receiving element are simultaneously formed. Next, finally, the source / K-rain electrode of the TFT and the comb-shaped electrode of the light receiving element are formed at the same time. At this time, the n-type aSi: H existing between the source electrode and the drain electrode of the TFT and the n-type a-Si: H existing between two opposing comb-shaped electrodes of the light receiving element are as follows. Are removed simultaneously in the step of patterning the electrodes.

In the first embodiment, an example of a top gate type po 1 y-Si TFT has been described, but FIG. 3 (B) shows an example using a bottom gate type P 0 1 y-Si TFT. The circuit shown can also be configured.

Alternatively, the circuit shown in FIG. 3B can be formed using an inverted staggered a-Si TFT or a forward staggered a-Si TFT generally applied to a liquid crystal display.

However, since the mobility of the a-Si TFT is about 1/100 of that of the po-y-Si TFT, the resistance should be sufficiently low especially when used as a TFT that supplies current to light-emitting elements. It is necessary. In order to lower the resistance, for example, the width of the TFT is set to be large, or the thickness of the gate insulating film is reduced.

Further, in the first embodiment, the configuration in which the vertical drive circuit 40 and the horizontal drive circuit 41 are formed on the transparent substrate 10 using the po1ySi TFT has been described. It is not limited to this.

For example, a TAB (Tape Automated Bonding) connection and a COG (Chip On G 1 ass) connection are used to perform the same functions as those commonly used in the manufacturing process of liquid crystal displays. This may be realized by an integrated circuit formed of a semiconductor, and the integrated circuit may be fixed on the transparent substrate 10 and electrically connected.

Further, in the first embodiment, the configuration in which the light-emitting materials of three colors (RGB) are arranged in parallel is adopted. However, by combining a color filter and a white light-emitting material, By combining the material and the color conversion material, it is possible to realize the power display.

(Second embodiment)

In the first embodiment described above, light is emitted from the light emitting element 20 using the organic EL material toward the bottom surface 10 b of the transparent substrate 10. It is also possible to change the arrangement of the other electrode so that light is emitted above the transparent substrate 10. In this case, since the light emitted from the light emitting element 20 does not need to pass through the transparent substrate 10, the substrate corresponding to the transparent substrate 10 does not need to be transparent.

The image input device according to the second embodiment has the above configuration, FIG. 16 is a perspective view of the image input device according to the second embodiment, and FIG. FIG. 3 is a cross-sectional view of the image input device. FIG. 18 shows a layout of a pixel unit (FIG. 18 (A)) and a circuit diagram of the pixel unit (FIG. 18 (B)) in the image input device according to the second embodiment. 19 is a sectional view of a pixel portion.

As shown in FIGS. 16 and 17, the image input device according to the second embodiment includes a substrate 10 and a plurality of light receiving elements 3 O b arranged on one surface 10 a of the substrate 10. A plurality of light emitting elements 20 b arranged on each of the light receiving elements 30 b, a vertical driving circuit 4 O b and a horizontal driving circuit for driving the light emitting element 2 O b and the light receiving element 3 O b 4 1 b and the light emitting element 20 b and the light receiving element 30 b formed on one surface 10 a of the transparent substrate 10 so as to cover the light emitting element 20 b and the light receiving element 30 b. And a protective layer 60 b for protection.

In FIGS. 16 and 17, the same components as those in the first embodiment are denoted by the same reference numerals. In addition, for components that are made of the same material but have different shapes, the same numbers are added with “b”.

As shown in FIG. 16, the light emitting elements 20b and the light receiving elements 30b are arranged in a matrix.

The light emitting element 2 Ob is configured to emit light upward from the surface 10 a of the transparent substrate 10, and the light receiving element 3 Ob is incident on the surface 10 a of the transparent substrate 10 It is configured to detect light.

The reason why the light emitting element 20b is arranged above the light receiving element 30b is as follows. The first reason is to increase the area of the light emitting element 20b as compared with the case where the light emitting element 20b and the light receiving element 30b are juxtaposed. By increasing the area of the light-emitting element 20b, the voltage applied to the light-emitting element 20b in order to realize the display with the desired brightness is increased when the light-emitting element 20b and the light-receiving element 30b are juxtaposed. Lower than Can be.

The second reason is that the area of the light receiving element 3 Ob, and therefore the capacitance thereof, can be increased, and the dynamic range of the light receiving element 3 Ob can be set wide. By thus arranging the light emitting element 20b on top of the light receiving element 30b, there is an advantage that the degree of freedom in designing these elements is increased.

On the other hand, as shown in Fig. 19, the step to be covered by the lower electrode 55b of the light-receiving element 30b becomes large, so it is necessary to determine the conditions of the manufacturing process so that the step in the wiring does not break. It is.

Instead of arranging the light emitting element 20 b on top of the light receiving element 30 b, the light emitting element 20 b and the light receiving element 30 b are arranged in parallel as in the first embodiment. It is also possible. In particular, when the resolution requirement is low, the two elements 20b and 30b are juxtaposed to give priority to the ease of the manufacturing process over the design freedom of the light receiving element 30Ob and the light emitting element 20b. It is desirable that the configuration be such.

The manufacturing process of the image input device according to the second embodiment is based on the point that the transparent electrode of the light emitting element 20b and the other electrode are exchanged, and the light receiving element 30b and the light emitting element 20 This is the same as the manufacturing process of the image input device according to the first embodiment, except that the transparent electrode cannot be formed simultaneously with the same material in b.

That is, as shown in the cross-sectional view of FIG. 19, on the transparent substrate 10, the TFT, the light receiving element 30 b, and the light emitting element 20 b are formed in this order.

Even in the configuration in which the light emitting element 20b and the light receiving element 30b are juxtaposed, the order of forming them is the same. This is because if an organic thin film is formed before forming the a-Si film, which is a photoelectric conversion material of the light receiving element 30b, the temperature will be around 250 ° C in the process of forming the a-Si film. This causes a problem that the organic thin film sublimates.

The operation of the image input device according to the second embodiment is as follows.

The operation of displaying an image is exactly the same as that of the first embodiment, except that light is emitted in the direction of the protective layer 60b.

When inputting an image, as shown in Fig. 17, the light emitted from the light emitting element 2 Ob directly illuminates the input target 80, and the reflected light is covered by the light emitting element 20b. No light is detected in the area of the light receiving element 30b. This allows the input object 80 Information, ie, an image, is input. That is, in the second embodiment, display and input are performed on the same surface 10 a of the transparent substrate 10.

For example, when inputting a fingerprint, the area where the finger is to be placed can be displayed by illuminating the light emitting element 2 Ob corresponding to the area where the finger is to be placed. As a result, the position of the finger can be determined accurately, and the stability of fingerprint image input can be increased, and the accuracy of personal authentication can be improved.

As in the first embodiment, in the second embodiment, as described below, the replacement of the constituent elements and the change of the material type or dimensions are possible.

For example, a bottom gate type p 01 y-S i TFT can be used instead of a top gate type p 01 y-S i TFT.

Further, the substrate 10 in the present embodiment does not need to be transparent, and for example, a crystalline Si substrate can be used. In this case, the drive circuits 40b and 4lb and the transistor-to-capacitance of the pixel portion can be formed as a normal integrated circuit on the crystal S1 substrate.

Further, as the light receiving element 3 Ob, a photodiode having a pn junction formed on a substrate can be used as in the case of a normal MOS image sensor. Industrial applicability

Hereinafter, the effects that can be obtained by the present invention will be described with reference to the above-described first and second embodiments.

The first effect is that the thickness of the entire image input device can be significantly reduced as compared with the conventional image input device.

In the image input device according to the first embodiment of the present invention, as shown in FIG. 2, the thickness of the transparent substrate 10 is set to 0.7 mm, and the thickness of the transparent substrate 74 is set to 0.7 mm. be able to. The total thickness of each of the transparent electrode 71, the liquid crystal layer 72, and the transparent electrode 73 is at most 5 m, and the height of the light emitting element 20 and the light receiving element 30 formed on the surface 10a of the transparent substrate 10 Is at most 50 m.

For this reason, the thickness of the image input device according to the first embodiment can be about 1.4 mm at the maximum. This is less than half the thickness of the conventional image input device shown in FIG. Is the thickness.

Further, the image input device according to the first embodiment is 1 mm or thinner than the conventional image input device shown in FIG.

Further, in the image input device according to the second embodiment of the present invention, as shown in FIG. 17, the thickness of the substrate 10 is about 0.7 mm, and the surface 10 of the transparent substrate 10 is The height of the light emitting element 20 and the light receiving element 30 formed on a is 50 m at the maximum. As described above, the image input device according to the second embodiment is much thinner than the conventional image input device shown in FIGS. 20 and 21, and furthermore, the image input device according to the second embodiment. It can be formed thinner than the device.

As described above, the image input device according to the present invention has an effect that it can be configured to be thin. This is a great advantage when the image input device according to the present invention is incorporated in a mobile phone or other portable terminal device. Become.

The second effect is that the number of substrates on which TFTs are mounted can be reduced as compared with a conventional image input device.

In the image input device according to the first and second embodiments of the present invention, the number of substrates on which TFTs are mounted is halved compared to the conventional image input device shown in FIG. For this reason, compared with the conventional image input device, the number of manufacturing steps of the image input device according to the present invention, and hence the manufacturing time, can be reduced, which directly leads to a reduction in manufacturing cost.

Furthermore, as compared with the conventional image input device shown in FIG. 21, the image input device according to the present invention does not require a lens, thereby reducing the number of manufacturing steps and manufacturing time, and consequently manufacturing. Cost can be reduced.

The third effect is that the light use efficiency can be improved.

Compared to the conventional image input device shown in FIG. 21 which emits light in both directions, in the image input device according to the first and second embodiments of the present invention, the light emitted from the light emitting element is one. Since the light is emitted only in the direction, the light use efficiency can be increased. Further, as compared with the conventional image input device shown in FIG. 21, the image input devices according to the first and second embodiments of the present invention provide a light emitting device that emits light emitted from the light emitting element when displaying an image. Since almost 100% can be used for display, light use efficiency is high, and Thus, power consumption can be reduced.

As described above, the image input device according to the present invention can be formed thinner, can reduce power consumption, and can reduce the number of manufacturing steps and the manufacturing time, and thus the manufacturing time, as compared with the conventional image input device. Cost can be reduced. Therefore, the image input device according to the present invention is particularly useful for mounting on a portable device such as a mobile phone.

Claims

The scope of the claims

1. Transparent substrate,

A plurality of light emitting means arranged on one surface of the transparent substrate,

A plurality of photoelectric conversion means arranged on the one surface of the transparent substrate; and a light arranged on the other surface of the transparent substrate, for selectively reflecting or transmitting light emitted from the light emitting means. Switching means;

An image input device comprising:

The light emitting means emits light toward the other surface of the transparent substrate,

The photoelectric conversion means detects light incident on the one surface,

When inputting an image, the light emitting unit is caused to emit light toward the other surface of the transparent substrate, and the light switching unit is set to reflect the light, and the photoelectric conversion unit is configured to output the image. An image input device that receives reflected light from a computer.

2. When displaying an image, the light switching unit is set to transmit the light, and emits the light toward the other surface of the transparent substrate according to the image. 2. The image input device according to claim 1, wherein the image input device is a device.

3. substrate and

A plurality of light emitting means arranged on one surface of the substrate,

A plurality of photoelectric conversion means arranged on the one surface of the substrate,

An image input device comprising:

The light emitting unit emits light in a direction opposite to the other surface of the transparent substrate, and the photoelectric conversion unit detects light incident on the one surface,

When inputting an image, the light emitting means emits light in a direction opposite to the other surface of the transparent substrate, and the photoelectric conversion means receives reflected light.

4. When displaying an image, according to the image, the light-emitting means is 4. The image input according to claim 3, wherein light is emitted toward the other surface of the plate.

5. The image input device according to claim 3, wherein each of the light emitting means is arranged so as to overlap with each of the photoelectric conversion means.

6. The image input device according to claim 1, further comprising a transparent protective layer covering the light emitting unit and the photoelectric conversion unit.

7. The light emitting means,

A light-emitting element that emits light to the outside,

Light emitting element selecting means for causing a specific light emitting element to emit light,

7. The image input device according to claim 1, wherein the image input device comprises:

8. The photoelectric conversion unit includes:

A light-receiving element that generates an electric signal corresponding to the amount of light absorbed,

Light receiving element selecting means for operating a specific light receiving element,

9. The light emitting means,

A light-emitting element that emits light to the outside,

Consisting of

The photoelectric conversion means,

Consisting of A control signal for operating one of the light emitting element selecting means and the light receiving element selecting means is supplied to the light emitting element selecting stage or the light receiving element selecting means via the same control wiring. The image input device according to any one of claims 1 to 6, wherein

1 0. The light emitting means,

A light-emitting element that emits light to the outside,

Consisting of

The photoelectric conversion means,

Consisting of

A signal giving the light emission intensity of the light emitting element and the electric signal generated by the light receiving element are supplied to the light emitting element selecting means or the light receiving element selecting means via the same signal wiring. Image input according to any one of claims 1 to 6

1 1. The light emitting means is:

A light-emitting element that emits light to the outside,

Consisting of

The photoelectric conversion means,

Consisting of

The current flowing through the light emitting element and the current charging the light receiving element are supplied to the light emitting element and the light receiving element via the same power supply wiring. An image input device according to the item.

1 2. The light switching means,

Two transparent electrodes facing each other,

A liquid crystal layer sandwiched between the transparent electrodes,

The image input device according to any one of claims 1 to 11, wherein the image input device comprises:

1 3. The light emitting element

Two electrode layers at least one of which is transparent,

A light-emitting layer made of a light-emitting material, sandwiched between the electrode layers;

The image input device according to any one of claims 7, 9, 10, and 11, wherein the image input device comprises:

1 4. The light receiving element is

Two electrode layers at least one of which is transparent,

A photoelectric conversion layer sandwiched between the electrode layers, and made of a photoelectric conversion material;

The image input device according to any one of claims 8 to 11, wherein the image input device comprises:

1 5. The light emitting element

Two electrode layers at least one of which is transparent,

Consisting of

The light receiving element,

Two electrode layers at least one of which is transparent,

Consisting of

12. The image input device according to claim 9, wherein the transparent electrode layer of the light emitting element and the transparent electrode layer of the light receiving element are formed in the same step.

1 6. The light-emitting element is formed of a laminate in which a first electrode, a first insulating layer, an inorganic electorescence material, a second insulating layer, and a second electrode are laminated in this order. The image input device according to any one of claims 7, 9, 10, and 11, wherein:

1 7. The light receiving element

A first electrode area;

A first semiconductor region into which impurities are introduced,

A second semiconductor region in which impurities are introduced at a lower concentration than the first semiconductor region, a third semiconductor region made of the same material as the first semiconductor region,

The image input device according to any one of claims 8 to 11, wherein the image input device has a structure in which are sequentially joined.

1 8. The substrate is a crystalline silicon substrate,

The photoelectric conversion unit has a light receiving element that generates an electric signal corresponding to the amount of absorbed light,

The light receiving element has a structure in which a region formed by introducing a first impurity into the crystalline silicon substrate and formed into p-type silicon is joined to a region formed by introducing a second impurity and formed into n-type silicon. Image input according to any one of claims 3 to 17, characterized in that

1 9. a first housing incorporating the image input device according to any one of claims 1, 2 and 6 to 18;

A second housing rotatably connected to the first housing,

An apparatus comprising:

The first housing and the second housing can be folded so as to overlap each other,

The light switching unit of the image input device folds the first housing and the second housing. The device which is arranged so as to face the second housing in the open state.

20. A first housing containing an image input device;

A second housing rotatably connected to the first housing and foldable so as to overlap with the first housing,

Arranged between the first housing and the second housing so as to face the first housing when the first housing and the second housing are folded together. A light diffuser having a light diffusion function,

An apparatus comprising:

The image input device,

A plurality of photoelectric conversion means arranged on the one surface of the transparent substrate,

The photoelectric conversion means detects light incident on the one surface,

When inputting an image, the light emitting unit is caused to emit light toward the other surface of the transparent substrate, and the light switching unit is set to reflect the light. Equipment that receives light reflected from the

2 1. A first housing containing an image input device,

A third housing arranged so as to be sandwiched between the first housing and the second housing when the first housing and the second housing are folded together. A device comprising a body and

The image input device,

A plurality of photoelectric conversion means arranged on the one surface of the transparent substrate, The light emitting means emits light toward the other surface of the transparent substrate,

The photoelectric conversion means detects light incident on the one surface,

When inputting an image, the light emitting unit is caused to emit light toward the other surface of the transparent substrate, and the light switching unit is set to reflect the light. To receive the reflected light from the

A device to which a function of diffusing light is added to a surface of the third housing facing the first housing.

22. The device according to claim 21, wherein the third housing has a built-in microphone.

2 3. An apparatus having a housing incorporating the image input device according to any one of claims 1 to 18,

The image input device is a device that irradiates a finger with light emitted by the light emitting unit and receives reflected light from the finger by the photoelectric conversion unit to input a fingerprint as an image.

24. The device according to any one of claims 19 to 23, wherein the device is a mobile phone.