JPH0728095A - Image pickup display device - Google Patents

Abstract

PURPOSE:To provide an image pickup display device integrated with an image pickup part and a display part on the same screen. CONSTITUTION:Two sheets of transparent substrates 13, 14 are arranged in parallel and pixel electrodes 8a, 8b are respectively disposed in a matrix form on the opposite surfaces of the transparent substrates 13, 14. A liquid crystal layer 8c is held in the spacing between the transparent substrates 13 and 14 to constitute the display section 7. The one transparent substrate 13 is provided thereon with photodiodes 2 in a matrix form to constitute the image pickup part 1. The photodiodes 2 of the image pickup section 1 and MOS transistor 3 which are their switching elements are arranged in such position where the light transmitted through the liquid crystal layer 8c of the display section 7 is not shut off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup display device.
More specifically, the present invention relates to an image pickup display device used in a two-way communication terminal device such as a videophone.

[0002]

2. Description of the Related Art A videophone is composed of an image pickup device for converting a subject image into an electric image signal and a display device for converting an electric image signal into an optical signal for display. The user of the videophone has a conversation while looking at the face of the other party displayed on the screen of the display device, and at the same time, the face of the user is photographed by the image pickup device and converted into an electric signal and then sent to the other party.

Photoelectric conversion elements used in image pickup devices include
An image pickup tube using a cadmium selenide film, an amorphous silicon film, or the like as an electron beam target, an image pickup device combining a MOS transistor, a photodiode, or a phototransistor, or an image pickup device using a charge-coupled device is used. An electron beam cathode tube is mainly used for the electro-optical element of the display device.

[0004]

In the conventional image pickup display device used for two-way communication such as a videophone, the image pickup unit is provided next to the display screen or as another independent device, and is looking at the display screen. The recipient will be photographed from an oblique direction. Therefore, the other person's face reflected on the display screen (TV) has a different line of sight, and even if they talk to each other, they feel uncomfortable compared to when they talk face-to-face awkwardly. is there.

Further, the image pickup device and the display device have to be separately manufactured and assembled or separated into separate devices, which causes a problem of high manufacturing cost.

The present invention solves such a problem and integrates the image pickup device and the display device, so that when the device is used for a videophone or the like, it is possible to talk with the other person without feeling uncomfortable and the same. It is an object of the present invention to provide an image pickup display device which can be manufactured at low cost by the manufacturing line.

[0007]

In an image pickup display device according to the present invention, two transparent substrates are arranged in parallel with a certain gap, and photoelectric conversion is performed on one transparent substrate to convert an optical signal into an electric signal. The elements are provided in a matrix, and the electro-optical element that emits an optical signal is provided in a matrix on the other transparent substrate or between the two transparent substrates, and the photoelectric conversion element and the electro-optical element emit light to each other. It is arranged so that it will not be blocked.

[0008]

According to the present invention, since the image pickup unit which is the image pickup device of the conventional videophone and the display unit which is the display unit are integrated, it is possible to take an image from the direction of the line of sight and display it on the display screen of the other party. You can talk to the other person without feeling discomfort.

Further, since the image pickup section and the display section are independently provided on different transparent substrates, the image pickup display apparatus can be obtained only by adding the manufacturing steps of the image pickup section to the manufacturing steps of the conventional display apparatus. The manufacturing cost can be kept low.

Further, since the image pickup section can be provided in the non-display area of each pixel of the display section, the effective display area of the display section is not narrowed by the photoelectric conversion element of the image pickup section.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an image pickup display device of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view conceptually showing the circuit structure of an image pickup section of an embodiment of the image pickup display apparatus of the present invention, and FIG. 2 shows the circuit structure of the display section of an embodiment of the image pickup display apparatus of the present invention. 3 is a conceptual explanatory view, FIG. 3 is an explanatory plan view showing a configuration of an image pickup section of an embodiment of the image pickup display apparatus of the present invention, and FIG. It is a cross-sectional explanatory view showing the configuration of FIG.

In the image pickup display device of this embodiment, the display portion is composed of a liquid crystal display panel in which a liquid crystal layer is sandwiched between two transparent substrates. That is, on the liquid crystal layer side of one transparent substrate, the switching elements are arranged in a matrix together with the pixel electrodes of the liquid crystal display device. On the liquid crystal layer side of the other transparent substrate corresponding to the non-display area such as the switching element of the pixel electrode, photoelectric conversion elements such as photodiodes are arranged in a matrix to form an image pickup section.

The image pickup section of the image pickup display apparatus according to the present invention is as follows (see FIG.
(As shown in FIG. 2), the photodiodes 2 are photoelectric conversion elements and the MOS transistors 3 are switching elements for signal transmission, which are arranged in a matrix. The photodiode 2 generates electromotive force by absorbing light. For the MOS transistor 3, for example, a TFT or the like is used. Then, when a voltage is selectively applied to the i-th gate line 4 by the vertical scanning circuit and a voltage is selectively applied to the j-th data line 5 by the horizontal scanning circuit, the position of the matrix (i, j) is changed. The electromotive force of the photodiode 2 is output from the signal output terminal 6. Therefore, by sequentially applying the voltage to the gate line 4 and the data line 5, the image of the subject formed on the image pickup unit by the lens can be taken out as an electric signal. Although an example using a photodiode as a photoelectric conversion element is shown in the embodiment, the photoelectric conversion element is not limited to this in the present invention, and may be an image pickup element such as a phototransistor or a charge-coupled element. Good.

On the other hand, the display portion of the image pickup display device according to the present invention is, as shown in FIG. 2, for example, a normal liquid crystal display device, and an electro-optical element 8 comprising pixel electrodes and liquid crystal layers arranged in a matrix. TFT that is a switching element
It is composed of 9 and 9. Further, 10 is a parallel capacitor for holding the voltage applied to the pixel electrode of the liquid crystal display device. Then, the gate line drive circuit drives the i-th gate line 11
When a voltage is selectively applied to the data line driving circuit and the voltage is selectively applied to the j-th data line 12 by the data line driving circuit, the light transmittance of the liquid crystal layer of the pixel at the position of the matrix (i, j) is Change. Therefore, by sequentially applying the signal voltage to the gate line 11 and the data line 12, the pixels in the matrix can be arbitrarily turned on and an image can be displayed.

In the present embodiment, the number of rows and the number of columns of the matrix of the image pickup section and the matrix of the display section are the same, and the photoelectric conversion element and the electro-optical element are paired.
It is also preferable to arrange the photodiode 2 and the MOS transistor 3 of the image pickup unit so as not to overlap the display region of the display unit.

Next, a specific structure of the above-described embodiment of the image pickup display apparatus of the present invention will be described with reference to FIGS. 3 and 4.

FIG. 3 is a plan view showing the structure of the photodiode, MOS transistor, etc. provided on the transparent substrate which is the image pickup section in the above-mentioned embodiment.

As shown in FIG. 3, the image pickup section is provided on one transparent substrate together with one pixel electrode 8a of the liquid crystal display device constituting the display section, and the photodiode is provided at a location where the pixel electrode 8a is not present. 2 and a MOS transistor 3 which is a charge transfer element. The photodiode 2 is composed of electrodes 2a and 2b and a light receiving region (not shown in FIG. 3) held between the electrodes. This light receiving region is made of a pn junction such as amorphous silicon or polysilicon. Further, the electrode 2b on the back surface side is connected to the drain region 3g of the MOS transistor 3, and the charge generated in the photodiode 2 is sent to the data line 5 by the MOS transistor 3. Reference numeral 4 is a gate line, and the pixel electrode 8a is grounded by a wiring (not shown).

Further, in front of the photodiode 2, a transparent film made of, for example, glass or the like having an opening is provided, and a lens 15 made of, for example, glass is provided in the opening, so that each part of the subject can be seen. It is preferable to collect the above light and irradiate it to the photodiode 2. This lens is provided only on the image pickup section by providing a frame with a glass lens only on the photodiode part or a glass plate with a lens effect by partially changing the refractive index on the display surface. be able to.

Next, FIG. 4 shows a cross-sectional view of the transparent substrate, which is the image pickup section, taken along the line IV-IV in FIG. FIG. 4 also shows a cross-sectional view of the other transparent substrate that holds the liquid crystal layer.

As shown in FIG. 4, one of the transparent substrates 13 and 14 made of two pieces of glass and the like holding the liquid crystal layer 8c is placed on the surface of the transparent substrate 13 on the opposite side to the electro-optical display unit 7. The image pickup section 1 is provided by providing the photodiode 2 and the MOS transistor 3 which is the charge transfer element thereof together with the pixel electrode 8a forming the element 8, and the other side of the transparent substrate 14 on the opposite side surface of the liquid crystal display device. The pixel electrode 8b and the TFT 9 which is a switching element thereof are provided to form the display unit 7.

The photodiode 2 has electrodes 2a and 2b.
It is composed of a light receiving region 2c made of a semiconductor material such as amorphous silicon or polysilicon having a pn junction sandwiched between, and the generated charges are sequentially transferred to the signal processing unit via the MOS transistor 3. In front of the photodiode 2, the lens 15 as described above is preferably arranged in the opening of the transparent film 15a.

Since the surface area of the photodiode 2 is set smaller than the surface area of the lens 15 and is arranged almost at the center of the lens surface, only the light which is vertically incident on the lens 15 is the light receiving area of the photodiode 2. 2c is selectively irradiated. That is, the light from each part of the subject is received by the light receiving regions 2 of the photodiodes 2 of different pixels.
Since the light is irradiated on c, an image of the subject is formed on the photodiodes 2 arranged in a matrix.

In FIG. 4, the MOS transistor 3
And TFT 9 are gate electrodes 3a and 9a, gate insulating films 3b and 9b, semiconductor layers 3c and 9c, source regions 3d and 9d, drain regions 3e and 9e, and source electrode 3, respectively.
f, 9f, drain electrodes 3g, 9g, etching stoppers 3h, 9h, and protective films 3j, 9j.

As shown in FIG. 4, since the photodiode 2 of the image pickup section 1 and its MOS transistor 3 are provided in such a position as not to block the light transmitted through the liquid crystal layer 8c of the display section 7, The effective display area of the unit can be increased, and a bright display screen can be obtained.

Further, by disposing a color filter in front of the liquid crystal layer 8c and the lens 15, it is possible to obtain an image pickup display device capable of displaying in color and picking up an image.

[0028]

When the image pickup display apparatus of the present invention is used in a videophone, the image pickup section and the display section are integrated, so that the line of sight of the other person displayed on the display screen does not feel unnatural and the conversation is natural. You can

Further, the image pickup section and the display section can be manufactured on the same manufacturing line, and the manufacturing cost can be kept low.

[Brief description of drawings]

FIG. 1 is an explanatory diagram conceptually showing the circuit configuration of an image pickup section of an embodiment of an image pickup display apparatus of the present invention.

FIG. 2 is an explanatory diagram conceptually showing the circuit configuration of the display section of the embodiment of the image pickup display apparatus of the present invention.

FIG. 3 is an explanatory plan view showing a configuration of an image pickup section of an embodiment of the image pickup display device of the present invention.

FIG. 4 is a cross-sectional explanatory view showing a configuration of an image pickup section and a display section of an example of the image pickup display apparatus of the present invention.

[Explanation of symbols]

 2 Photodiode 2a Electrode 2b Electrode 2c Light receiving area 8 Electro-optical element 8a Pixel electrode 8b Pixel electrode 8c Liquid crystal layer 13 Transparent substrate 14 Transparent substrate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiro Hata 21 No. 21, Mizozaki-cho, Saiin, Ukyo-ku, Kyoto City ROHM Co., Ltd.

Claims (1)

[Claims] 1. Two transparent substrates are arranged in parallel with a constant gap, photoelectric conversion elements for converting an optical signal into an electric signal are provided in a matrix on one transparent substrate, and the other transparent substrate. An image pickup display device comprising electro-optical elements that emit optical signals arranged in a matrix on or between the two transparent substrates, and the photoelectric conversion elements and the electro-optical elements are arranged so as not to block light from each other.