JPH06205342A - Liquid crystal display device, view finder having the display device and electronic camera having the view finder - Google Patents

Abstract

PURPOSE:To make the entire system small and to attain high performance by providing a photoelectric conversion section used for a visual line sensing system to the liquid crystal display device. CONSTITUTION:A visual light from a back light 1011 projects an image of a liquid crystal display panel 1012 and the image is made incident into an eyeball 1015 through a display panel convex lens. On the other hand, a ray from an infrared ray source 1014a for sensing a visual line is collected by a condenser lens 1014b, reflected in a cornea face 1016a or a cornea rear face 1016b and made incident in a photoelectric conversion condensing convex lens 1013b. The shape of the convex lens 1013b is decided so that the incident light is formed to the photoelectric conversion section on the liquid crystal display panel 1012.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, a viewfinder having the device, and an electronic camera having the viewfinder, and more particularly to a liquid crystal display device for displaying an image using a liquid crystal material. A liquid crystal display device having means that can be used to detect the line-of-sight position of the
The present invention relates to a viewfinder that can be used for an electronic camera such as a video camera or a still video camera having the device, and an electronic camera having the viewfinder.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device has been used exclusively for displaying an image, and as shown in the schematic configuration diagram of FIG. 2, an image display section which is a liquid crystal display region 502 using liquid crystal. And a drive circuit area 5 in which a circuit for driving the drive circuit is formed in at least a part of the peripheral portion thereof.
It was composed of 01. Recently, liquid crystal display devices have come to be used in various electronic devices such as display screens of notebook computers, monitor parts of devices, and viewfinders of video camcorders. Under such circumstances, there have been remarkable technological advances such as improvement in image quality of liquid crystal display devices, enlargement of screens, and low-cost mass production technology. But,
During this period, the progress was mainly in improving the display performance, and there were few examples in which the liquid crystal display device was provided with additional functions.

On the other hand, at the request of the side using the product, many new functions are beginning to be required for the above-mentioned office equipment and recording equipment. Among them, many methods have been proposed in which a user of the apparatus (hereinafter referred to as an observer) detects which position the user is gazing at and uses the detection signal for controlling the system. For example, Japanese Patent Publication No. 1-241511 discloses a specific method of using this detection signal as a camera focus signal.

An outline of the focusing system will be described with reference to FIG. FIG. 3 is a schematic sectional view schematically showing the configuration of the single-lens reflex camera. Light from a subject (not shown) passes through the objective lens 701 and the main mirror 702 when the image is not captured.
The image is bent and reflected at, and an image is formed on a focusing plate 707 arranged corresponding to the photosensitive member 705 such as a film. The image formed on the focusing plate 707 passes through the optical path inside the penta roof prism 708 and passes through the eyepiece 709 to the observer's eye 71.
It is incident on 5. In FIG. 3, reference numeral 701 denotes an objective lens, which is shown as a single lens for convenience, but it is well known that it is actually composed of a large number of lenses. Reference numeral 702 denotes a main mirror, which is obliquely installed in the photographing optical path or is retreated according to the observation state (when not photographing) and the photographing state. A sub-mirror 703 reflects the light flux transmitted through the main mirror 702 toward the lower side of the camera body and makes it enter the focus detection device 706a. Reference numeral 704a is a shutter, 704b is a diaphragm arranged in the objective lens 701, and 704c is a drive mechanism for moving the objective lens 701 in the optical axis direction for focusing. Reference numeral 705 denotes a photosensitive member, which is a film using silver salt, a solid-state image sensor using a CCD or a MOS transistor, or an image pickup tube such as a vidicon. A focus detection device 706a enables focus detection at a plurality of positions of the line of sight of the photographing. An exposure value detection unit 706b includes an imaging lens and a light receiver capable of divided photometry. The imaging lens is associated with a light receiving device and a focusing plate 707 arranged on the planned imaging surface of the objective lens 1 through an optical path in the penta prism 708. The output of the light receiver is input to the microprocessor mp, and the weighting can be changed so as to have a photometric sensitivity distribution centered on a plurality of center points.

Next, an eyepiece 709 is arranged behind the exit surface of the penta roof prism 708 for changing the optical path of the finder, and is used for the observation of the focusing plate 707 by the observer's eye 715. Reference numeral 710 denotes a light splitter, which uses, for example, a dichroic mirror that reflects infrared light, and is provided in the eyepiece lens 709 here. 711 is a condenser lens, 712
Is a light splitter such as a half mirror, and 713 is an illumination light source such as an LED, and preferably emits infrared light (and near infrared light). The light flux emitted from the infrared illumination light source 713 is emitted as parallel light along the finder optical path by the power of the rear surface (observer side surface) of the condenser lens 711 and the eyepiece lens 709. Reference numeral 714 is a photoelectric converter, which allows the observer to view the eyepiece 7
When the eye 09 is properly viewed, the rear surface of the eyepiece lens 709 and the condenser lens 711 are arranged behind the anterior ocular segment of the observer's eye, specifically, near the pupil. That is, the finder optical system (7
08.709) and the photoelectric converter 714 are arranged conjugate with each other, and the imaging magnification is preferably 1 or less.

With the above construction, the image-forming light flux that has passed through the objective lens 701 is partially transmitted, and is split by the main mirror 702 into a finder light flux and a focus detection light flux. The focus detection light flux passes through the main mirror 702 and then passes through the sub mirror 703.
And is incident on the focus detection position 706a. At the time of shooting, the main mirror 702 is flipped up, the sub-mirror 703 is laminated and folded on the main mirror, and the shutter blade 704a is opened and closed to open the film 70.
5 is exposed for a predetermined time.

On the other hand, the finder luminous flux is focused by a focusing plate 707.
Then, the light enters the penta roof prism 708. However, a Fresnel lens or the like, which is integrated with the focus plate or separate, is 70
It may be disposed in the vicinity of 8. The light flux is focused on the object image on the focusing plate 707 by the diopter eyepiece 709.
It enters the observer's eye 715 while magnifying and projecting.

The optical path of the line-of-sight detection system is as follows. The illumination light emitted from the infrared illumination source 713 passes through the half mirror 712, is collimated to some extent by the lens 711, is reflected by the mirror 710, and enters the finder optical path.
The light splitter 710 is a dichroic mirror that transmits the finder light in the visible range coming from the subject and reflects the illumination light in the infrared range, from the viewpoint of the brightness of the finder and the viewpoint of the illumination efficiency of the line-of-sight detection system. Is also desirable. However, if an infrared light source having a sufficiently high brightness is used, it is possible to design in consideration of a decrease in illumination efficiency and substitute the ND half mirror. The infrared illumination light introduced into the finder optical path passes through the rear surface of the eyepiece lens 709 and illuminates the observer's eyeball. It is one method that the illumination light is made into a substantially parallel light flux when the eyeball enters the eyeball so that the illumination condition is maintained even if the position of the observer's eye changes. This can be realized by adjusting the power arrangement of each part so that the total power of the lens 711 and the power of the rear surface of the eyepiece lens 709 is realized.

The light reflected by the observer follows the opposite path,
Half mirror 712 via mirror 710 and lens 711
And is received by the photoelectric converter 714. It is desirable that a visible cut / infrared transmission filter is inserted in the optical path until the reflected light is separated from the finder optical path and is received by the photoelectric converter. This is because the cornea reflected light due to the visible light of the finder image is cut and only the reflection of the infrared illumination light that is significant as an optical signal is photoelectrically converted. The photocathode is placed at such a position that the near power of the lens 711 and the rear surface of the eyepiece 709 and the vicinity of the front surface of the crystalline lens of the observer's eye, that is, the vicinity of the pupil are imaged. As a result, the first, second, and fourth images of Brukinje are received in the formed state,
The amount of reflected light is not necessarily weak. Since the third image is defocused and the light is diffused, it does not contribute much to the photoelectric conversion signal.

In order to realize such a system when the liquid crystal display device is used as an image display device, the photoelectric conversion device is integrated in a part of the liquid crystal display device, whereby the number of parts and the size of the entire device are increased. It is important to have a gaze detection function without increasing the number of eyes.

[0011]

However, the conventional active type liquid crystal display device uses a TFT for driving the liquid crystal.
Made of amorphous silicon or single crystal silicon,
The film thickness was several hundred Å to 1 μm. On the other hand, in order to perform photoelectric conversion of infrared light efficiently, about several μm is required even for polysilicon and amorphous silicon, and at least 5 μm is required for single crystal silicon. Considering that the light used for line-of-sight detection is an extremely weak signal, it was virtually impossible to integrate the liquid crystal display and the photoelectric conversion unit.

That is, as long as the conventional liquid crystal display device is used, visible light is transmitted through the same substrate and TF is used.
It has both an image display area in which a T (Thin Film Transistor) can be operated and a photoelectric conversion area in which light is sufficiently absorbed and photoelectric conversion is performed for eye gaze detection. was difficult.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in a liquid crystal display device having a pair of substrates and a liquid crystal material enclosed between the pair of substrates, the liquid crystal A liquid crystal display device comprising a semiconductor element for driving a display device and a photoelectric conversion element arranged separately from the semiconductor element, a viewfinder having the liquid crystal display element, and an electron having the viewfinder It is a camera.

As a result, since the liquid crystal display device is provided with the photoelectric conversion portion having excellent photoelectric conversion efficiency, the display function and the line-of-sight detection function can be reduced in space efficiency.

Further, when the viewfinder is used, the display can be focused according to the line of sight, so that the feeling of fatigue can be reduced even when used for a long time.

Further, according to the electronic camera such as a video camera using the viewfinder of the present invention, it is possible to surely focus on a desired portion and perform extremely excellent recording.

Further, the liquid crystal display device of the present invention can be further miniaturized because the photoelectric conversion portion is integrated, and the viewfinder and the electronic camera can be further miniaturized and highly functionalized. it can.

[0018]

The present invention will be described below with reference to preferred specific examples.

FIG. 1 is a schematic plan view of a liquid crystal display device of the present invention, in which 1 is the outer shape of a panel, 2 is a drive circuit area, 3 is a display section, and 4 is a photoelectric conversion area. FIG. 4 is a circuit diagram showing a part of the display unit and the drive circuit of the liquid crystal display device, and includes the horizontal shift register 5 and the vertical shift register 6 which are the drive circuits, the TFT 9 of each pixel, the liquid crystal 10 and the auxiliary capacitance. Have 11. The horizontal shift register 5 driven by an image synchronizing signal (not shown) sends the image signal to the signal lines 7a and 7b, and outputs it from the vertical shift register 6 which is also driven by the synchronizing signal onto the scanning lines 8a and 8b. An image signal is applied to the liquid crystal 10 through the TFT 9 that opens and closes according to the scanning signal. The auxiliary capacitance 11 is provided to prevent the voltage applied to the liquid crystal 10 from being easily affected by fluctuations in the signal line 7a and the scanning line 8a.

FIG. 5 shows a circuit diagram of the photoelectric conversion section, in which the BA with a bipolar amplification type sensor arranged two-dimensionally is shown.
SIS (Base Store-type Image)
Sensor) Area sensor. The detailed operation of this area sensor is, for example, 1989 IEEE.
Solid Circuit Conference Technical Digest P9
6-97. In the above description, a sensor for detecting visible light is provided, but it is easy to obtain a sensor suitable for infrared light as well, if the structure of the sensor is slightly changed as described later. In FIG. 5, the sensor unit 21
Is supplied with a read pulse by the vertical shift register 24 and outputs a photoelectric conversion signal to the read circuits 22 and 25. The output signal is output to the horizontal shift registers 23 and 26.
Are sequentially read. As shown in 25, this circuit has a built-in fixed pattern noise automatic suppression circuit that uses the difference between the noise component N1 of photoelectric conversion and the signal component S1 as the final signal. The reason for having the two read circuits 22 and 25 and the two horizontal shift registers 23 and 26 is as follows.
This is to lower the drive frequency of the horizontal shift register,
If the processing speed is increased by fine processing, two of them are not necessarily required.

FIG. 6 shows a schematic diagram of an optical system in the case where a visual axis detection system is constituted by the liquid crystal display device of the present invention.
Visible light emitted from the backlight 1011 projects an image on the liquid crystal display panel 1012 and passes through a convex lens on the display panel.
It enters the eyeball 1015. On the other hand, the infrared light source 1014a for line-of-sight detection is condensed by the condenser lens 1014b, reflected by the corneal surface 1016a or the corneal rear surface 1016b, and incident on the photoelectric conversion condenser lens 1013b. The shape of the convex lens 1013b is determined so that the incident light forms an image on the photoelectric conversion portion on the surface of the liquid crystal display panel 1012.

As described above, according to the present invention, by providing the liquid crystal display device with the photoelectric conversion unit that can be used in the visual axis detection system, it is possible to achieve miniaturization and high performance of the entire system.

The liquid crystal display device of the present invention will be described in detail below with reference to specific examples.

<Embodiment 1> FIG. 7A shows a schematic cross-sectional view of a display section 122 integrated on a silicon substrate, its drive circuit 121, and a photoelectric conversion section 120. In this embodiment, polysilicon is used as an active layer of a TFT of a pixel, a driving circuit is composed of CMOS, and a bipolar amplification type sensor is used as a photoelectric conversion part.

The photoelectric conversion section 120 is composed of a bipolar transistor composed of an epitaxial layer 104 serving as a collector, a base region 106 and an sitter region 116, and a read capacitor composed of capacitive coupling between the polysilicon 107a and the base region 106. The epitaxial layer 104 is 5 to 20 in order to efficiently photoelectrically convert infrared light.
A thickness of μm is suitable. Further, the buried layer 103 lowers the collector resistance and, at the same time, suppresses the diffusion current from the substrate generated when the silicon substrate 101 is of the same type as the epitaxial layer, thereby reducing the dark current. The drive circuit 121 is a CMOS and is an NMO formed in the P well 105.
S, a PMOS formed in the epitaxial layer 104. The display portion is composed of an n-type or p-type polysilicon channel TFT. The thickness of the polysilicon channel 112 can be several hundred Å to several thousand Å, but it is determined to be an appropriate thickness in consideration of the leak current of the TFT and the resistance of the source / drain. In the hollow portion 102, a part of the silicon substrate 101 and the epitaxial layer 104 is formed by, for example, KOH (potassium hydroxide) tetramethyl-ammonium-hydroxide (TMA).
H) It is formed by wet etching with an aqueous solution such as 2.38 wt%. In this way, the display portion was made transparent by removing the silicon layer opaque to visible light.

A manufacturing process for realizing the structure of the present invention will be described with reference to the schematic sectional views of FIGS. 7 (b) to 7 (d). First, after forming the buried layer 103 on the silicon substrate 101, the Si epitaxial layer 104 is formed with a thickness of 5 to 20 μm.
m. Next, on the surface of the epitaxial layer, SiO ₂
And after growing and patterning the silicon nitride film, L
The LOCOS oxide film 108 is formed by the OCOS method. This oxide film serves as a drive circuit, element isolation of the photoelectric conversion section, and a hollow etching stopper of the display section. After that, the P well region 105 and the base region 106 are formed, and the structure shown in FIG. Next, after forming the isolation region 109 with a non-doped polysilicon layer, polysilicon 123 is deposited to form an active layer (FIG. 7C). After that, polysilicon is deposited again and the read capacitor 107 is formed.
a, CMOS gate 107b, TFT gate 113
To form. Then, by ion implantation, the emitter 11
6, the NMOS source / drain 117 and the TFT lease / drain 110, 111 are formed (FIG. 7D).
After that, after depositing the interlayer insulating film 114, an electrode is formed of aluminum to obtain the structure of FIG.

As described above, in the present embodiment, by using the polysilicon process and the LOCOS oxidation technique, the photoelectric conversion section, the drive circuit, and the T circuit are formed on the high quality silicon substrate.
Accumulates FT.

According to this embodiment having such a structure, it becomes possible to integrate the high-sensitivity photoelectric conversion section, the drive circuit and the liquid crystal display section on the same silicon, and the liquid crystal display panel having the visual axis detecting function is inexpensive. Can be downsized.
In particular, in this embodiment, since it is not necessary to form the TFT of the display section on the glass substrate which is expensive and difficult to handle, the cost of the substrate is low and the conventional integrated circuit manufacturing process can be used as it is.

<Embodiment 2> FIG. 8A is a schematic sectional view of a liquid crystal panel for explaining a second embodiment of the present invention. The photoelectric conversion part 220 includes an epitaxial layer 204 serving as a collector, a base region 206, and an emitter region 216.
It is composed of a bipolar transistor composed of the above and a read capacity composed of capacitive coupling between the polysilicon 207a and the base region 206. The drive circuit 221 is a CMOS
And is composed of an NMOS formed in the P well 205 and a PMOS formed in the epitaxial layer 204. The feature of this embodiment is that the active layer of the TFT of the display portion is single crystal silicon. The TFT is on the embedded insulating film 203, and the same process as that of the driving circuit section is performed.
MOS channel region 211, source / drain region 2
10 are formed.

In this embodiment, as in the first embodiment, the silicon substrate of the display portion is made transparent by etching removal (hollowing), and the buried insulating film 203 serves as a stopper during etching.

An example of a manufacturing process for realizing the structure of the present invention will be described with reference to schematic sectional views shown in FIGS. 8 (b) and 8 (c).

First, in order to form the buried insulating film 203, the surface of the epitaxial layer 204 other than the display portion is covered with a thermal oxide film 224 and an oxide film 225 formed by vapor phase growth. Then, using a high-current ion implanter, the oxide ions were adjusted to 4E17 to 2.4E18 at 150 to 300 KeO.
(Piece / cm ² ) is injected. After oxide ion implantation 1100
Annealing is performed at a temperature of ˜1250 ° C. for 2 to 20 hours to form a buried insulating film (oxide film) 203 having a thickness of 2000 to 5000 Å (FIG. 8B).

Next, the channel region 211 of the P well 205TFT of the drive circuit and the base region 206 of the photoelectric conversion unit are formed, and the read capacitor electrode 207a of the photoelectric conversion unit and the gate electrode of the drive circuit are formed by depositing and patterning polysilicon. 207b, the gate electrode 213 of the TFT is formed (FIG. 8C).

By ion implantation, the sitter 216, CM
The source / drain 217 and 218 of the OS and the source / drain 210 of the TFT are formed, an interlayer insulating film 214 is deposited, and then an electrode is formed of aluminum to obtain the structure of FIG.

In this embodiment, since the active region of the TFT is single crystal silicon, it is possible to easily obtain a TFT having a small leak current and a large driving ability. According to the experiment, the leak current is less than 10 (fA) per pixel, T
Since the current driving capability of the FT is 10 times or more that of the polysilicon TFT, it is possible to produce gray scales of 64 gray scales or more in white to black of the liquid crystal display. Further, even if the gate width of the TFT is 3 μm or less, sufficient driving ability can be obtained,
The aperture ratio of the pixels can be increased, and a liquid crystal panel having 300,000 or more pixels can be realized. Further, since the photoelectric conversion unit and the drive circuit also have the same performance as that of the first embodiment,
According to this embodiment, the gaze detection function can be realized for the first time in a high gradation and high definition liquid crystal display panel.

<Embodiment 3> FIG. 9A is a schematic sectional view of a liquid crystal panel for explaining a third embodiment of the present invention. The photoelectric conversion unit 320 includes an epitaxial layer 304 serving as a collector, a base region 306, and an emitter region 316.
And a read capacitor formed by capacitive coupling between the polysilicon 307a and the base region 306. The drive circuit 321 is a CMOS
And is composed of an NMOS formed in the P well 305 and a PMOS formed in the epitaxial layer 304. The feature of this embodiment is that the active layer of the TFT of the display portion is single crystal silicon, and at the same time, the cost is reduced by using an expensive bonded substrate which does not use high current ion implantation. The TFT is on the insulating substrate obtained by bonding, and at the same time, the driving circuit and the photoelectric conversion unit have the epitaxial single crystal silicon 30 from which the thin silicon layer 323 and the insulating layer 330 of the insulating substrate are removed.
Made in 4. Similar to the first and second embodiments, the silicon substrate of the display portion is made transparent by etching removal (hollowing), and the buried insulating film 330 serves as a stopper during etching.

The manufacturing process for realizing the structure of the present invention is the same as that of the second embodiment except for the method of manufacturing the substrate, and therefore the schematic cross-sectional views of FIGS. 9B to 9D are used. The processing of the insulating substrate will be described in detail.

FIG. 9B shows a sectional view of the insulating substrate, in which 323 is a thin film silicon layer, 330 is an insulating layer, and 3 is an insulating layer.
Reference numeral 04 is an epitaxial layer, and 301 is a silicon substrate. In this structure, for example, a first silicon wafer having an epitaxial layer formed on the surface thereof and a second silicon wafer having an insulating film formed on the surface thereof are faced to each other and bonded to each other, and then a second silicon wafer side is formed by a grinder. Can be removed by polishing to form a thin film silicon layer having a desired thickness. Needless to say, the thin film single crystal silicon layer may be present on the insulated silicon substrate, and the manufacturing method is not limited to the above.

Next, of this substrate, the thin film silicon layer on the silicon surface which will be the drive circuit and the photoelectric conversion portion and the insulating layer 3 are formed.
30 is removed (FIG. 9C). After that, the structure of FIG. 9A can be realized through the same manufacturing process as that of the second embodiment.

In FIG. 9 (c), a step of ˜1 μm is formed between the display portion and other portions. For this reason, when the pattern is printed by photolithography, the depth of focus cannot be taken, so that the pattern dimensions may differ above and below the step. As a method of solving this problem, for example, as shown in FIG. 9D, there is a method of backfilling the silicon single crystal only in a region having a low step. For example, a method of performing selective epitaxial growth after covering only the pixel portion with an insulating film, or a single crystal growth method by dual frequency bias sputtering can be used. Also in the case of FIG. 9D, the subsequent manufacturing process is the same as that of the case of FIG. 9C.

According to the present embodiment, the use of the insulating substrate produced by laminating makes it possible to obtain a high gradation by an inexpensive method.
It is possible to provide a liquid crystal display panel with a high-definition gaze detection function.

Similar to the second embodiment, the leak current of the pixel TFT is 10 (fA) or less, and the driving ability is 10 times or more that of the polysilicon TFT.
It is possible to produce four or more gradations.

Furthermore, since a high current ion implantation process which is expensive and easily causes crystal defects is not used, it is possible to provide a liquid crystal display panel having a low manufacturing cost and a higher yield.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a schematic cross-sectional view of a liquid crystal display device with a photoelectric conversion device of the present invention, and FIG. 11 shows a typical method of manufacturing a substrate for manufacturing the device.
Is shown in a schematic sectional view of FIG.

As shown in FIG. 10, 401 is a photoelectric conversion device region, 402 is a p-type single crystal region, 403 is an n-type single crystal region, and 402 and 403 constitute a photodiode. Other structures are the same as those of the first to third embodiments, for example, and the description thereof will be omitted. Reference numeral 404 is a switching transistor portion of the liquid crystal display portion, 408 is a signal line, and 409
Is a scanning line, and 410 is a pixel electrode. 405 is a liquid crystal layer,
407 is a transparent electrode provided with a color filter or the like, 4
Reference numeral 06 is a substrate provided with them. As shown by 400 and 400 ', the TFT semiconductor layer thickness of the liquid crystal display portion is thinner than the semiconductor layer of the photoelectric conversion portion, and both are optimal.

In this embodiment, both the photoelectric conversion section and the liquid crystal display section are composed of a single crystal layer provided on an insulating substrate and have different thicknesses. This is done by etching the area of the liquid crystal display part to a desired thickness (several hundred Å to several thousand Å) in a normal SOI substrate, or only the photoelectric conversion part S is etched.
This is achieved by subjecting the OI substrate to selective epitaxial growth to thicken the single crystal layer.

Furthermore, regarding the method in which the substrate having the above structure can be manufactured without using such a new process, FIG.
Will be explained.

In FIG. 11A, in the normal high-concentration p-type substrate 411, the region where the liquid crystal display region is to be formed is made porous as indicated by 412. this is,
It can be formed by passing an electric current of several A in a water solution obtained by adding alcohol to 49% HF. The region where the porous layer is not formed may be sealed so that the liquid does not enter. The thickness of the porous layer was 20 μm.

Next, as shown in FIG. 11B, an epi shown by 413 is formed to a thickness of 3 μm by LP-CVD on the surface of FIG. 11A. Then, a substrate 415 having an oxide layer 414 formed thereon is prepared separately from the above substrate (see FIG. 11).
(C)), as shown by 416 in FIG. The pieces were stuck together in an N ₂ or O ₂ atmosphere and heat-treated at 1000 ° C. for 1b to adhere them.

Next, the back surface of the substrate on which the epi was formed was cut with a polishing machine or the like as shown by 417 until the porous layer was exposed (FIG. 11 (d)).

Finally, as shown in FIG. 11 (e), when this wafer is put into a HF + H ₂ O ₂ (1: 5) solution, only the porous layer is selectively removed as shown by 418. As a result, a thin region 420 and a thick region 419 of the single crystal Si layer could be formed. By this method, it was possible to easily proceed to the next step without complicated steps.

Incidentally, in the present invention, the photoelectric conversion section is C
It is also possible to use a CD type (charge coupled device), the drive circuit may have a single channel structure or a bipolar MOS mixed mounting structure, and a-Si may be used as the active layer of the TFT or a PMOS structure. It can be modified within the scope of the gist.

<Embodiment 5> A case where the liquid crystal display device of the present invention is used in a video camera will be described.

FIG. 12 is a schematic block diagram for explaining the structure of the video camera.

In FIG. 12, reference numeral 601 denotes an optical system having a lens, a diaphragm, etc., and 602 is an image pickup device such as a CCD.
Light from a subject (not shown) is imaged and / or input to the image sensor 602 through the lens 601 and photoelectrically converted into an electric signal, which is input to the sampling circuit 603. Subsequently, the photoelectric conversion output is output by the automatic gain control 604. It is adjusted and input to the process circuit 605. The process circuit 605 processes the signal based on the photoelectrically converted signal and outputs it as R, G, and B signals. The R, G, and B signals output from the process circuit 605 are the display circuit 606 and the processing circuit 6 for the viewfinder 615.
07 are input respectively. The R, G, and B signals input to the display circuit 606 are adjusted for the liquid crystal display device 614, which is a display element in the viewfinder 615, and input to the liquid crystal display device 614. Further, a signal from the driver 609 is input to the liquid crystal display device 614 to display an image. RY, BY, and Y signals are produced from the R, G, and B signals input to the processing circuit 607, respectively, and output. Each of the R-Y and B-Y signals is input to the FM modulation 608, is FM-modulated, and is input to the decoder 612. In addition, FM
The subcarrier from the control circuit 611 is input to the modulator 608. The Y signal from the processing circuit 607 is also input to the decoder 612. The image sensor 602, the sampling circuit 603, the process circuit 605, the driver 609, and the decoder 612 respectively receive the pulses based on the pulses input from the pulse generator 610 to the control circuit 611, and synchronize and input / output signals. Is adjusted. The signal output from the decoder 612 is output from the terminal 613 as a composite television signal.

When recording the composite television signal, this signal may be output to a normal video recording device.

When the viewfinder of the video camera having such a structure is driven by using the liquid crystal display device described in Embodiments 1 to 4 of the present invention, the observer is in focus and follows the line of sight of the observer. I was able to see the in-focus display for the direction in which I was looking. Moreover, since the subject is always focused in the direction in which he is gazing, the operation is not complicated.

[0058]

As described above, according to the present invention, since the liquid crystal display device is provided with the photoelectric conversion section having excellent photoelectric conversion efficiency, the display function and the line-of-sight detection function can be efficiently reduced in space.

Further, when the viewfinder is used, the display can be focused according to the line of sight, so that the feeling of fatigue can be reduced even when the viewfinder is used for a long time.

Further, according to the electronic camera such as a video camera using the viewfinder of the present invention, it is possible to surely focus the portion to be photographed and to record extremely excellently.

Further, the liquid crystal display device of the present invention can be further miniaturized because the photoelectric conversion portion is integrated, and the viewfinder and the electronic camera can be further miniaturized and highly functionalized. it can.

According to the present invention, the photoelectric conversion element has been described for detecting the line of sight, but it can be used for measuring the brightness around the liquid crystal display device or the brightness of the backlight light source. . In this case, it is not always necessary to provide a plurality of photoelectric conversion elements, and it can be achieved by providing at least one photoelectric conversion element at a required position.

Needless to say, the present invention can be appropriately modified within the scope of the gist of the present invention.

[Brief description of drawings]

FIG. 1 is a schematic plan view for explaining a liquid crystal display device of the present invention.

FIG. 2 is a schematic configuration diagram of a conventional liquid crystal display device.

FIG. 3 is a schematic cross-sectional view illustrating a configuration for line-of-sight detection.

FIG. 4 is a circuit diagram illustrating a display unit and a driving unit of a liquid crystal display device.

FIG. 5 is a circuit diagram of a photoelectric conversion unit.

FIG. 6 is a schematic diagram illustrating an optical system of a line-of-sight detection system.

7A is a schematic cross-sectional view for explaining a substrate of the liquid crystal display device described in Embodiment 1, and FIGS. 7B to 7D are schematic cross-sectional views for explaining a manufacturing process thereof.

8A is a schematic cross-sectional view for explaining a substrate of a liquid crystal display device described in Embodiment 2, and FIGS. 8B and 8C are schematic cross-sectional views for explaining a manufacturing process thereof.

9A is a schematic cross-sectional view for explaining the substrate of the liquid crystal display device described in Embodiment 3, and FIGS. 9B to 9D are schematic cross-sectional views for explaining the manufacturing process thereof.

FIG. 10 is a schematic cross-sectional view of a liquid crystal display device of the present invention.

11A to 11E are schematic cross-sectional views for explaining a method for manufacturing a semiconductor substrate used in the present invention.

FIG. 12 is a schematic configuration diagram for explaining a configuration of an electronic camera.

[Explanation of symbols]

1 Panel Outline 2 Drive Circuit Area 3 Display Area 4 Photoelectric Conversion Area 101 Silicon Substrate 102 Hollow Out Area 103 Buried Layer 104 Epitaxial Layer 105 P-type Well 106 Base Region 107a Readout Capacitance Polysilicon Electrode 107b Polysilicon Gate 108 LOCOS Oxide Film 109 Pixel Separation film 110 Pixel TFT source region 111 Pixel TFT drain region 112 Pixel TFT channel region 113 Pixel TFT gate polysilicon 114 Interlayer insulating film 115a Emitter electrode 115b Driving circuit CMOS source / drain electrode 115c Pixel TFT source / drain electrode 116 Emitter region 117 CMOSn ⁺ Type source / drain region 118 CMOSp ⁺ type source / drain region

Claims (49)

[Claims] 1. A liquid crystal display device comprising a pair of substrates and a liquid crystal material enclosed between the pair of substrates, wherein a semiconductor element for driving the liquid crystal display device and the semiconductor element are arranged separately. And a photoelectric conversion element. 2. One of the pair of substrates is electrically connected to a signal line and a scanning line arranged in a matrix, the semiconductor element provided at an intersection of the signal line and the scanning line, and the semiconductor element. The liquid crystal display device according to claim 1, further comprising a pixel electrode and the photoelectric conversion element, and the other of the pair of substrates has an electrode provided corresponding to the pixel electrode. 3. The liquid crystal display device according to claim 1, wherein the photoelectric conversion element is provided in a first semiconductor region, and the semiconductor element is provided in a second semiconductor region. 4. The liquid crystal display device according to claim 3, wherein the first semiconductor region and the second semiconductor region are formed on the same semiconductor substrate. 5. The semiconductor thickness of the first semiconductor region is thicker than the semiconductor thickness of the second semiconductor region.
Or the liquid crystal display device according to item 4. 6. The liquid crystal display device according to claim 1, further comprising a circuit for driving the semiconductor element. 7. The liquid crystal display device according to claim 6, wherein the circuit is a shift register. 8. The liquid crystal display device according to claim 6, wherein the circuit is provided on a semiconductor substrate on which the semiconductor element is provided. 9. The liquid crystal display device according to claim 1, wherein the semiconductor element is a thin film transistor. 10. The first semiconductor region is a silicon single crystal,
The liquid crystal display device according to claim 3, wherein the second semiconductor region is polysilicon or amorphous silicon. 11. The liquid crystal display device according to claim 3, wherein the first and second semiconductor regions are made of single crystal silicon, and an insulating layer is provided immediately below the semiconductor regions. 12. The liquid crystal display device according to claim 2, wherein the one substrate includes a first semiconductor substrate or a quartz substrate having an insulating film on a surface thereof and a second semiconductor substrate. 13. The liquid crystal display device according to claim 3, further comprising an insulating layer formed by oxygen ion implantation directly below the semiconductor in the first semiconductor region. 14. The liquid crystal display device according to claim 3, further comprising an insulating layer formed by selective oxidation of the substrate surface immediately below the semiconductor in the first semiconductor region. 15. A liquid crystal display device comprising a pair of substrates and a liquid crystal material enclosed between the pair of substrates, wherein a semiconductor element for driving the liquid crystal display device and the semiconductor element are arranged separately. A viewfinder having a liquid crystal display including the photoelectric conversion element, and an eyepiece provided so as to face the liquid crystal display device. 16. One of the pair of substrates is electrically connected to a signal line and a scanning line arranged in a matrix, the semiconductor element provided at an intersection of the signal line and the scanning line, and the semiconductor element. 16. The viewfinder according to claim 15, further comprising a pixel electrode and the photoelectric conversion element, and the other of the pair of substrates has an electrode provided corresponding to the pixel electrode. 17. The view finder according to claim 5, wherein the photoelectric conversion element is provided in the first semiconductor region, and the semiconductor element is provided in the second semiconductor region. 18. The first semiconductor region and the second semiconductor region are formed on the same semiconductor substrate.
Viewfinder described in. 19. The view finder according to claim 17, wherein the thickness of the semiconductor in the first semiconductor region is larger than the thickness of the semiconductor in the second semiconductor region. 20. The view finder according to claim 15, further comprising a circuit for driving the semiconductor device. 21. The viewfinder of claim 20, wherein the circuit is a shift register. 22. The view finder according to claim 20, wherein the circuit is provided on a semiconductor substrate on which the semiconductor element is provided. 23. The viewfinder according to claim 15, wherein the semiconductor element is a thin film transistor. 24. The first semiconductor region is a silicon single crystal,
18. The view finder of claim 17, wherein the second semiconductor region is polysilicon or amorphous silicon. 25. The view finder according to claim 26, wherein the first and second semiconductor regions are made of single crystal silicon, and an insulating layer is provided immediately below the second semiconductor region. 26. The viewfinder according to claim 16, wherein the one substrate has a first semiconductor substrate or a quartz substrate having an insulating film on a surface thereof and a second semiconductor substrate. 27. The view finder according to claim 17, further comprising an insulating layer formed by ion implantation of oxygen directly below the semiconductor in the first semiconductor region. 28. The view finder according to claim 17, further comprising an insulating layer formed by selective oxidation of a substrate surface immediately below the semiconductor in the first semiconductor region. 29. The viewfinder according to claim 15, further comprising an optical system for making light incident on the photoelectric conversion element, separately from the eyepiece lens. 30. The viewfinder according to claim 29, further comprising a light emitting source of the light. 31. In a liquid crystal display device having a pair of substrates and a liquid crystal material enclosed between the pair of substrates, a semiconductor element for driving the liquid crystal display device and the semiconductor element are provided separately. An electronic device including a liquid crystal display device having a photoelectric conversion element, a viewfinder having an eyepiece lens provided facing the liquid crystal display device, and an image sensor for reading an image displayed on the liquid crystal display device. camera. 32. One of the pair of substrates is electrically connected to a signal line and a scanning line arranged in a matrix, the semiconductor element provided at an intersection of the signal line and the scanning line, and the semiconductor element. 32. The electronic camera according to claim 31, further comprising a pixel electrode and the photoelectric conversion element, and the other of the pair of substrates has an electrode provided corresponding to the pixel electrode. 33. The electronic camera according to claim 1, wherein the photoelectric conversion element is provided in the first semiconductor region, and the semiconductor element is provided in the second semiconductor region. 34. The first semiconductor region and the second semiconductor region are formed on the same semiconductor substrate.
The electronic camera described in. 35. The electronic camera according to claim 33, wherein the thickness of the semiconductor in the first semiconductor region is larger than the thickness of the semiconductor in the second semiconductor region. 36. The electronic camera according to claim 31, further comprising a circuit for driving the semiconductor element. 37. The electronic camera of claim 36, wherein the circuit is a shift register. 38. The electronic camera according to claim 36, wherein the circuit is provided on a semiconductor substrate on which the semiconductor element is provided. 39. The electronic camera according to claim 31, wherein the semiconductor element is a thin film transistor. 40. The first semiconductor region is a silicon single crystal,
The electronic camera according to claim 33, wherein the second semiconductor region is polysilicon or amorphous silicon. 41. The electronic camera according to claim 33, wherein the first and second semiconductor regions are made of single crystal silicon, and an insulating layer is provided immediately below the second semiconductor region. 42. The electronic camera according to claim 32, wherein the one substrate has a first semiconductor substrate or a quartz substrate having an insulating film on a surface thereof and a second semiconductor substrate. 43. The electronic camera according to claim 33, further comprising an insulating layer formed by ion implantation of oxygen directly below the semiconductor in the first semiconductor region. 44. The electronic camera according to claim 33, further comprising an insulating layer formed by selective oxidation of a substrate surface immediately below the semiconductor in the first semiconductor region. 45. The electronic camera according to claim 31, wherein the viewfinder has an optical system for making light incident on the photoelectric conversion element, separately from the eyepiece lens. 46. The electronic camera of claim 45, wherein the viewfinder further comprises a light source for the light. 47. The electronic camera according to claim 45, wherein the light is light reflected by an observing eye. 48. An optical system is further provided for forming an image of information input to the image pickup device on the image pickup device, and focusing of the optical system is performed by optical information input to the photoelectric conversion device. The electronic camera according to claim 31, which is formed. 49. The light received by the photoelectric conversion unit includes information for determining the line-of-sight direction of an eyeball of a person observing the display device, and means for measuring the line-of-sight direction by an electric signal output from the photoelectric conversion unit. 32. The electronic camera according to claim 31, further comprising: