Patent Application
20090159786
The present invention contains subject matter related to Japanese Patent Application JP 2008-260906 and JP 2007-327953 both filed in the Japan Patent Office on Oct. 7, 2008, and on Dec. 19, 2007, the entire contents of which being incorporated herein by reference.
1. Field of the Invention
In general, the present invention relates to a display apparatus and an illumination apparatus. In particular, the present invention relates to a display apparatus which has a display panel employing a plurality of pixels laid out on the surface of a pixel area on the display panel, includes a plurality of photo sensor devices also arranged in the pixel area to serve as devices each used for receiving light propagating in a direction parallel to the direction from the front-surface side of the display panel to the rear-surface side of the display panel and functions as an apparatus for displaying an image in the pixel area on the front-surface side. In addition, the present invention also relates to an illumination apparatus having an illumination section for radiating illumination light in a normal direction perpendicular to the display panel.
2. Description of the Related Art
A display apparatus such as a liquid-crystal display apparatus or an EL (Electro Luminescence) display apparatus offers merits such as being thin, being light and a low power consumption. For more information on such a display apparatus, the reader is suggested to refer to Japanese Patent Laid-open No. 2007-249241 and Japanese Patent Laid-open No. 2007-227117.
Such a display apparatus like a liquid-crystal display apparatus employs a liquid-crystal panel, which includes a liquid-crystal layer sealed between 2 substrates forming a substrate pair, as a display panel. The liquid-crystal panel is for example a transmission-type panel which modulates illumination light radiated thereto by an illumination apparatus provided on the rear-surface side of the liquid-crystal panel before passing on the modulated illumination light. A typical example of the illumination apparatus is a backlight. The modulated illumination light passed on by the liquid-crystal panel appears on the front surface of the liquid-crystal panel as the display of an image.
The liquid-crystal panel for example has a TFT (Thin Film Transistor) array substrate on which a plurality of TFTs each functioning as a pixel switching device are created to implement a driving method such as an active matrix method. In addition, the liquid-crystal panel also employs a facing substrate exposed to the TFT array substrate. A liquid crystal layer is provided between the facing substrate and the TFT array substrate, being sandwiched by the facing substrate and the TFT array substrate. In the liquid-crystal panel adopting the active matrix method, when a TFT serving as a pixel switching device for switching a pixel supplies an electric potential to a pixel electrode of the pixel, a voltage applied to the liquid-crystal layer changes, controlling the transmissivity of light passing through the pixel. As a result, the light is modulated.
There has been also proposed a typical liquid-crystal panel which includes photo sensor devices embedded in a pixel area of the liquid-crystal panel to serve as photo sensor devices each used for obtaining data of received incoming light by receiving the incoming light in addition to the TFTs each functioning a pixel switching device as described above.
By making use of each of the embedded photo sensor devices as an imaging sensor device for example, it is possible to implement the function of a biometric authentication apparatus. For more information on the imaging sensor device and the function of the biometric authentication apparatus, the reader is suggested to refer to documents such as Japanese Patent No. 3742846.
In addition, the liquid-crystal panel may make use of each of the embedded photo sensor devices as a position-sensor device in order to implement a user interface. For more information on the position-sensor device and the user interface, the reader is suggested to refer to documents such as Japanese Patent Laid-open No. 2007-128497. For this reason, the liquid-crystal panel is referred to as an I/O (Integrated-Optical) touch panel.
In the case of a liquid-crystal panel of this type, it is no longer necessary to separately provide a touch panel adopting a resistive film method or an electrostatic capacitance method on the front surface of the liquid-crystal panel. Thus, it is possible to easily reduce the size and/or thickness of a liquid-crystal display apparatus employing the liquid-crystal panel. In addition, in the case of a liquid-crystal panel provided with a separately constructed touch panel adopting a resistive film method or an electrostatic capacitance method, there may be raised problems that the amount of light passing through the pixel area of the liquid-crystal panel decreases or there are interference between the light passing through the pixel area and light hitting the touch panel. With a liquid-crystal panel including photo sensor devices embedded in the pixel area of the liquid-crystal panel, on the other hand, these problems can be solved.
In the case of a liquid-crystal panel including photo sensor devices embedded in a pixel area of the liquid-crystal panel, incoming visible light reflected by a detection subject such as a finger touching the front surface of the liquid-crystal panel is received by the photo sensor devices. Later on, on the basis of received-light data generated by the photo sensor devices from the received incoming visible light, a location touched by the subject of detection can be identified. Then, the liquid-crystal display apparatus itself or another electronic instrument connected to the liquid-crystal display apparatus carries out an operation corresponding to the touched location on the liquid-crystal panel. As an alternative, on the basis of the received-light data generated by the photo sensor devices, a biometric authentication can be carried out on the subject of detection.
As is obvious from the above description, an electrical signal representing received-light data generated by the photo sensor devices embedded in the display panel may include noises in some cases due to the influence of visible light included in external light. In addition, if a black display is implemented on the pixel area of the liquid-crystal panel, it is difficult for the photo sensor devices provided on the TFT array substrate to receive visible light radiated by a subject of detection. It is thus hard in some cases to detect the position of the subject of detection with a high degree of precision.
In order to solve the problems described above, there has been proposed a technology of making use of an illumination apparatus having an invisible light source for radiating invisible light other than visible light. A typical example of the invisible light is the infrared light. For more information on this technology, the reader is suggested to refer to documents such as Japanese Patent Laid-open No. 2004-318819.
Since an electrical signal representing received-light data generated by the photo sensor devices includes many noises, however, it is difficult to generate the signal representing the received-light data with a sufficiently high S/N ratio in some cases. It is thus hard in some cases to carry out a process to detect the position of a detection subject and/or a biometric authentication process with a high degree of precision.
In order to solve the problems described above, the present embodiment provides a display apparatus capable of increasing the S/N ratio of an electrical signal representing received-light data so as to allow a process to detect the position of a detection subject and/or a biometric authentication process to be carried out with a high degree of precision and provides an illumination apparatus having functions similar to those of an illumination section employed in the display apparatus.
A display apparatus provided by the present embodiment employs a display panel including a plurality of pixels laid out on the surface of a pixel area of the display panel and an illumination section for generating illumination light in a normal direction perpendicular to the display panel. The illumination section has a light source for radiating original light and a light guiding board which is exposed to a surface of the display panel. The original light generated by the light source hits an incidence surface of the light guiding board and the original light hitting the incidence surface is guided to a radiation surface of the light guiding board to be radiated from the radiation surface as the illumination light. The display panel also includes a plurality of photo sensor devices also arranged in the pixel area to serve as devices each used for receiving incoming light propagating in a direction parallel to the direction from the front-surface side of the display panel to the rear-surface side of the display panel and functions as a panel for displaying an image in the pixel area on the front-surface side.
The light source includes an invisible light source for generating an invisible light beam as the original light cited above. The light guiding board includes an invisible light beam reflection section for reflecting the invisible light beam generated by the invisible light source in a direction parallel to the direction from the rear-surface side of the display panel to the front-surface side of the display panel. The invisible light beam reflection section is provided at a location corresponding to an area included in the pixel area in which the photo sensor devices are created. The invisible light beam reflected by the invisible-light beam reflection section is radiated from the radiation surface of the light guiding board as the illumination light.
It is preferable to configure the invisible light source to generate an infrared light beam as the invisible light beam.
It is preferable to configure the display apparatus to further employ a biometric authentication section for authenticating a biological subject located on the front-surface side of the display panel. In this case, the biological subject reflects the illumination light, which has been generated by the illumination section, in the direction parallel to the direction from the front-surface side of the display panel to the rear-surface side of the display panel. The photo sensor devices receive the reflected illumination light as the incoming light and generate received-light data from the reflected illumination light. The biometric authentication section authenticates the biological object on the basis of the received-light data.
It is preferable to configure the photo sensor devices to generate the received-light data by receiving the reflected light reflected from the illumination light reflected by blood flowing in the biological subject.
It is preferable to configure the display panel to employ: a first substrate provided on the rear-surface side; a second substrate exposed to the first substrate and separated away from the first substrate by a gap; and a liquid-crystal layer provided in the gap sandwiched by the first and second substrates to serve as a layer including uniformly oriented liquid-crystal molecules.
It is preferable to configure the display apparatus to employ the illumination section which is provided on the rear-surface side of the display panel.
It is preferable to provide a configuration in which a transmission-type liquid-crystal panel which is liquid-crystal panel of the transmission type is used as the display panel. The illumination section includes a visible light source for generating a visible light beam, and the light guiding board guides the visible light beam, which is radiated by the visible light source to the incidence surface, and the invisible light beam, which is radiated by the invisible light source to the incidence surface, to the radiation surface as the illumination light to the transmission-type liquid-crystal panel functioning as the transmission-type liquid-crystal panel in order to display an image in the pixel area of the display panel.
It is preferable to configure the invisible light beam reflection section to have an invisible light beam reflection layer including an invisible light beam reflection pigment for reflecting the invisible light beam generated by the invisible light source.
It is preferable to configure the invisible light beam reflection section to include a plurality of aforementioned invisible light beam reflection layers created at a location corresponding to an area included in the pixel area, in which the photo sensor devices are created, by separating the invisible light beam reflection layers from each other.
It is preferable to configure the invisible light beam reflection section to employ a diffraction lattice section for diffracting the invisible light beam and a reflection section for reflecting the invisible light beam diffracted by the diffraction lattice section.
It is preferable to configure the invisible light beam reflection section to include a plurality of aforementioned diffraction lattice sections created at a location corresponding to an area included in the pixel area, in which the photo sensor devices are created, by separating the diffraction lattice sections from each other.
It is preferable to provide the illumination section on the front-surface side of the display panel.
It is preferable to configure the invisible light beam reflection section to include a prism surface for reflecting the invisible light beam generated by the invisible light source in the direction parallel to the direction from the rear-surface side of the display panel to the front-surface side of the display panel.
It is preferable to configure the invisible light beam reflection section to have an invisible light beam reflection layer including an invisible light beam reflection pigment for reflecting the invisible light beam.
It is preferable to configure the invisible light beam reflection section to include a plurality of aforementioned invisible light beam reflection layers created at a location corresponding to an area included in the pixel area, in which the photo sensor devices are created, by separating the invisible light beam reflection layers from each other.
It is preferable to make use of a liquid-crystal panel of the reflection type as the display panel.
It is preferable to make use of an EL panel as the display panel.
An illumination apparatus employing an illumination section for generating illumination light in a normal direction perpendicular to a display panel provided with a plurality of pixels, which are laid out on the surface of a pixel area, and provided with a plurality of photo sensor devices, which are also arranged in the pixel area to serve as devices each used for generating received-light data by receiving incoming light propagating in a direction parallel to the direction from the front-surface side of the display panel to the rear-surface side of the display panel, to serve as a panel for displaying an image on the front-surface side.
The illumination section has a light source for radiating original light and a light guiding board which is exposed to a surface of the display panel so as to direct the original light generated by the light source to hit an incidence surface of the light guiding board and guide the original light hitting the incidence surface to a radiation surface of the light guiding board to be radiated from the radiation surface as the illumination light.
The light source includes an invisible light source for generating an invisible light beam as the original light. The light guiding board includes an invisible light beam reflection section for reflecting the invisible light beam generated by the invisible light source in a direction parallel to the direction from the rear-surface side of the display panel to the front-surface side of the display panel. The invisible light beam reflection section is provided at a location corresponding to an area included in the pixel area in which the photo sensor devices are created. The invisible light beam reflected by the invisible-light beam reflection section is radiated from the radiation surface of the light guiding board as the illumination light.
In accordance with the present embodiment, the invisible light beam reflection section employed in the light guiding board reflects the invisible light beam generated by the invisible light source in a direction parallel to the direction from the rear-surface side of the display panel to the front-surface side of the display panel. The invisible light beam reflection section is provided at a location corresponding to an area included in the pixel area in which the photo sensor devices are created. The invisible light beam reflected by the invisible-light beam reflection section is radiated from the radiation surface as the illumination light.
In accordance with the present embodiment, a display apparatus is made capable of increasing the S/N ratio of an electrical signal representing received-light data so as to allow a process to detect the position of a detection subject and/or a biometric authentication process to be carried out with a high degree of precision and an illumination apparatus is provided to serve as an apparatus having functions similar to those of an illumination section employed in the display apparatus.
Typical embodiments of the present invention are explained by referring to diagrams as follows.
As shown in the cross-sectional diagram of
The liquid-crystal panel 200 adopts an active-matrix method. As shown in the cross-sectional diagram of
In the liquid-crystal panel 200, the TFT array substrate 201 and the facing substrate 202 are separated away from each other by a gap in which the liquid-crystal layer 203 is provided in a state of being sandwiched by the TFT array substrate 201 and the facing substrate 202.
The liquid-crystal panel 200 is a panel of the transmission type. As shown in the cross-sectional diagram of
The liquid-crystal panel 200 includes a pixel area PA for displaying an image. In the pixel area PA, a plurality of pixels not shown in the cross-sectional diagram of
In addition, as will be described later in detail, in the liquid-crystal panel 200 of this embodiment, a plurality of photo sensor devices not shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
To put it concretely, outside the liquid-crystal panel 200, the backlight 300 is provided on a side close to the TFT array substrate 201 instead of being provided on a side close to the facing substrate 202 which composes the liquid-crystal panel 200 in conjunction with the TFT array substrate 201. The backlight 300 radiates the illumination light beam R to a surface of the TFT array substrate 201. The surface of the TFT array substrate 201 to which the illumination light beam R is radiated is the surface on the side opposite to the side of the other surface of the TFT array substrate 201. The other surface of the TFT array substrate 201 is a surface facing the facing substrate 202. That is to say, the backlight 300 generates the illumination light beam R in a direction parallel to the direction from the side of the TFT array substrate 201 to the side of the facing substrate 202. To put it more accurately, the backlight 300 generates the illumination light beam R in the normal direction z perpendicular to the surfaces of the liquid-crystal panel 200.
As shown in the cross-sectional diagram of
The control section 401 employed in the data processing block 400 is configured to control operations carried out by the liquid-crystal panel 200 and the backlight 300. To be more specific, the control section 401 supplies control signals to the liquid-crystal panel 200 in order to control operations carried out by a plurality of pixel switching devices provided in the liquid-crystal panel 200. It is to be noted that the pixel switching devices themselves are not shown in the cross-sectional diagram of
On top of that, the control section 401 supplies control signals to the liquid-crystal panel 200 in order to control operations carried out by a plurality of photo sensor devices provided in the liquid-crystal panel 200. Each of the photo sensor devices serves as a position sensor device. It is to be noted that the photo sensor devices themselves are not shown in the cross-sectional diagram of
The biometric authentication section 402 employed in the data processing block 400 is configured to carry out an imaging process of creating an image of a detection subject F coming into contact with the pixel area PA or approaching the pixel area PA on the front-surface side of the liquid-crystal panel 200 and carry out a biometric authentication process from an image obtained as a result of the imaging process. As described earlier, a finger of a human being is a typical subject of detection. In accordance with this embodiment, on the basis of received-light data collected from the photo sensor devices provided in the liquid-crystal panel 200 as devices also not shown in the cross-sectional diagram of
Next, the entire configuration of the liquid-crystal panel 200 is explained.
As shown in the top-view diagram of
As shown in the top-view diagram of
In the liquid-crystal panel 200, the peripheral area CA is placed at a location surrounding the pixel area PA as shown in the top-view diagram of
The pixel switching devices each provided in the pixel area PA for a pixel P are driven by the display vertical driving circuit 11 and the display horizontal driving circuit 12 in an operation to display an image in the pixel area PA. In the mean time, the photo sensor devices each provided in the pixel area PA for a pixel P are driven by the sensor vertical driving circuit 13 and the sensor horizontal driving circuit 14 in an operation to collect received-light data. As described above, neither the pixel switching devices nor the photo sensor devices are shown in the top-view diagram of
To put it concretely, the display vertical driving circuit 11 is extended in the vertical direction y as shown in the top-view diagram of
The display horizontal driving circuit 12 is extended in the horizontal direction x as shown in the top-view diagram of
The sensor vertical driving circuit 13 is also extended in the vertical direction y as shown in the top-view diagram of
The sensor horizontal driving circuit 14 is also extended in the horizontal direction x as shown in the top-view diagram of
As shown in the cross-sectional diagram of
In the liquid-crystal panel 200, each of the TFT array substrate 201 and the facing substrate 202 is a substrate made of a semiconductor material which passes on light. For example, each of the TFT array substrate 201 and the facing substrate 202 is made of glass. The TFT array substrate 201 and the facing substrate 202 face each other and are separated away from each other by a spacer which is not shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
Components of the display area TA are described as follows.
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
To put it concretely, the gate electrode 45 of the pixel switching device 31 is created from for example a metallic material such as the molybdenum.
On the other hand, the gate insulation film 46g of the pixel switching device 31 is created from an insulation material such as a silicon-oxide film.
The semiconductor layer 48 of the pixel switching device 31 is created from for example low-temperature poly-silicon. In addition, on the semiconductor layer 48, a channel area 48C is created at a location corresponding to the gate electrode 45 whereas an electrode pair consisting of source-drain electrodes 48A and 48B is created on both sides of the channel area 48C as shown in the cross-sectional diagram of
In the pixel switching device 31, each of the source electrode 53 and the drain electrode 54 is created by making use of a conductive material such as the aluminum.
As shown in the cross-sectional diagram of
In the sensor area RA, on the other hand, a light blocking section 21S and a photo sensor device 32a are created as shown in the cross-sectional diagram of
As the black matrix layer 21K is created on the specific surface of the facing substrate 202 in the display area TA, the light blocking section 21S is created on the specific surface of the facing substrate 202. In the same way as the color filter layer 21, the black matrix layer 21K blocks light. The light blocking section 21S is provided with a light receiving area SA. The light coming from the front-surface side of the liquid-crystal panel 200 passes through the light receiving area SA. In the same way as the flattening film 22 in the display area TA, the flattening film 22 is also created beneath the light blocking section 21S on the specific surface of the facing substrate 202 to cover the light blocking section 21S whereas the facing electrode 23 is created below the flattening film 22.
Much like the pixel switching devices 31, the photo sensor device 32a is created on the particular surface of the TFT array substrate 201. As described before, the particular surface of the TFT array substrate 201 is a surface exposed to the facing substrate 202 as shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
To put it concretely, in the photo sensor device 32a, the control electrode 43 is created from for example a metallic material such as the molybdenum whereas the insulation film 46s is created from an insulation material such as a silicon-oxide film and the semiconductor layer 47 is created from for example poly-silicon. The semiconductor layer 47 includes a p layer 47p, an n layer 47n and a high-resistance 47i which is placed between the p layer 47p and the n layer 47n. Each of the anode electrode 51 and the cathode electrode 52 is created by making use of a conductive material such as the aluminum.
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
As shown in the perspective-view diagram of
The visible light source 301a is for example a white-color LED configured to generate a visible light beam provided with the white color. As shown in the perspective-view diagram of
The infrared light source 301b is for example an infrared color LED configured to generate an infrared light beam. As shown in the perspective-view diagram of
As shown in the cross-sectional diagram of
To put it in detail, in this embodiment, the light guiding board 302 guides both the visible light beam generated by the visible light source 301a to hit the light incidence surface IS and the infrared light beam generated by the infrared light source 301b also to hit the light incidence surface IS. The guided visible light beam and the guided infrared light beam are radiated from the radiation surface PS1 to the liquid-crystal panel 200 as the illumination light beam R. As a result of the radiation of the visible light beam, an image is displayed in the pixel area PA of the liquid-crystal panel 200 of the transmission type as described before.
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
In this embodiment, the optical film 303 has a light spreading sheet 303a and a prism sheet 303b. In the light guiding board 302, the light spreading sheet 303a is created on the radiation surface PS1 and the prism sheet 303b is created on the light spreading sheet 303a. In the light guiding board 302, the light spreading sheet 303a spreads the illumination light beam radiated by the radiation surface PS1 of the light guiding board 302 whereas the prism sheet 303b converges the illumination light beam, which has been spread by the light spreading sheet 303a, in a normal direction z perpendicular to the radiation surface PS1. Thus, the optical film 303 radiates the illumination light beam generated by the radiation surface PS1 of the light guiding board 302 to the rear surface of the liquid-crystal panel 200 as a planar illumination light beam R.
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
The infrared light beam reflection layers 305 reflect only the infrared light beams in a direction parallel to the direction from the rear-surface side of the liquid-crystal panel 200 to the front-surface side of the liquid-crystal panel 200. Provided at locations corresponding to the locations of the photo sensor devices 32a in the pixel area PA, the infrared light beam reflection layers 305 reflect only the infrared light beams to the radiation surface PS1 to be radiated from the radiation surface PS1 as the illumination light beam R.
As shown in the perspective-view diagram of
In this embodiment, each of the infrared light beam reflection layers 305 is created to include an infrared light beam reflection pigment for reflecting an infrared light beam. For example, the infrared light beam reflection layers 305 are created by carrying out a printing process to print printing liquid including infrared light beam reflection pigments and binder resin on locations on the bottom surface PS2 provided on the side opposite to the radiation surface PS1 in the light guiding board 302.
For example, the infrared light beam reflection pigment used in the infrared light beam reflection layer 305 is a product made by Kawamura Chemical Corporation as a product having a commercial name of AB820 Black.
As shown in the diagram of
In addition, it is preferable to make use of resin capable of transmitting light as the binder resin for creating the infrared light beam reflection layer 305. Typical resin capable of transmitting light is the resin of the acryl group. For example, as the binder resin used for creating the infrared light beam reflection layer 305, it is possible to make use of the acryl resin MG10 made by Sumitomo Chemical Corporation. The infrared light beam reflection layers 305 are created by carrying out a printing process to print mixture liquid mixing infrared light beam reflection pigments with the binder resin. To put it concretely, the infrared light beam reflection pigments are mixed with the binder resin in the mixture liquid to be used as ink liquid at a pigment mixture concentration in the range 0.01 to 5% which are values each representing a ratio of the weight of the infrared light beam reflection pigments to the weight of the binding resin. After the pigment mixture concentration of the ink liquid is adjusted to a value in the range, dots of the ink liquid are printed on a light transmissible substrate by carrying out a screen printing process. For example, the area of the dot is set at a value in the range 10 to 500 μm2. In addition, the density of the dots is set at such a design value that the uniformity and strength of infrared planar light sources on the upper surface of the backlight 300 are made optimal. The design value of the density of the dots is found by carrying out optical simulation.
In addition, it is desirable to set the thickness of the infrared light beam reflection layer 305 at a value at least equal to 0.8 μm.
It is to be noted that it is also desirable to provide visible-light reflection layers to serve as layers for reflecting only visible light beams as a plurality of dots in the same way as the infrared light beam reflection layers 305.
The following description explains a biometric authentication process carried out by the liquid-crystal display apparatus 100 on the basis received-light data obtained by receiving light which is reflected by a detection subject F such as a finger of the user when the detection subject F is brought into contact with the pixel area PA of the liquid-crystal panel 200 or approaches the pixel area PA.
When the detection subject F such a finger of the user is brought into contact with the pixel area PA of the liquid-crystal panel 200 or approaches the pixel area PA, as shown in the cross-sectional diagram of
To put it concretely, first of all, light D1 generated by the light source 301 in the backlight 300 is guided by the light guiding board 302 to the infrared light beam reflection layer 305 as shown in the cross-sectional diagram of
In this embodiment, the light D1 generated by the light source 301 and guided by the light guiding board 302 include a visible light beam VR and an infrared light beam IR as described above.
The light D1 generated by the light source 301 propagates to the infrared light beam reflection layer 305 provided on the rear surface of the light guiding board 302.
Each of
As shown in the side-view diagram of
If the visible light beam VR included in the light D1 hits an infrared-light-beam reflection pigment particle PG of the infrared light beam reflection layer 305, the visible light beam VR is not reflected by the infrared-light-beam reflection pigment particle PG. Instead, the visible light beam VR is absorbed by the infrared-light-beam reflection pigment particle PG.
If the infrared light beam IR included in the light D1 hits an infrared-light-beam reflection pigment particle PG of the infrared light beam reflection layer 305, the infrared light beam IR is reflected by the infrared-light-beam reflection pigment particle PG. In this case, the infrared light beam IR is reflected by the infrared-light-beam reflection pigment particle PG, being conceivably scattered in a variety of directions as shown in the side-view diagram of
As shown in the side-view diagram of
That is to say, the visible light beam VR included in the light D1 passes through the transparent binder resin TJ of the infrared light beam reflection layer 305 and is reflected by the light reflecting surface of the light reflection film 304. By the same token, the infrared light beam IR included in the light D1 passes through the transparent binder resin TJ of the infrared light beam reflection layer 305 and is reflected by the light reflecting surface of the light reflection film 304. In addition, some other infrared light beams IR included in the light D1 and some other visible light beams VR also included in the light D1 are conceivably reflected by the boundary surface of the infrared light beam reflection layer 305.
Since some visible light beams VR included in the light D1 generated by the light source 301 are absorbed by the light guiding board 302, the number of visible light beams VR included in the light D1 decreases as shown in the cross-sectional diagram of
It is to be noted that an area for reflecting infrared light does not need to reflect visible light. In an area of dots for reflecting infrared light, however, it is necessary to separately print dots for reflecting visible light. The dots for reflecting visible light are shown in none of the figures. The layout of the dots for reflecting visible light is designed by setting each of the size of the dot and the density of such dots at such a design value according to the visible-light absorption characteristic exhibited by the infrared-light reflection material that the visible light is reflected uniformly in order to prevent the luminance of the visible light from decreasing.
The number of visible light beams VR included in the light D1 decreases to result in light D2 including more infrared light beams IR than visible light beams VR as shown in the cross-sectional diagram of
The illumination light beam R generated by the backlight 300 passes through the liquid-crystal panel 200 and is then radiated to the detection subject F to be reflected by the detection subject F as reflected light H. As described above, since the infrared light beam reflection layer 305 reflects only infrared light beams IR, the illumination light beam R generated by the backlight 300 includes more infrared light beams IR than visible light beams VR. Thus, the reflected light H which is reflected by the detection subject F also includes more infrared light beams IR than visible light beams VR. In the case of this embodiment, a finger of a person is used as the detection subject F and blood flowing in a vein of the finger reflects the illumination light beam R, radiating the reflected light H as a result of the reflection to be used in a biometric authentication process which is based on many infrared light beams IR included in the reflected light H.
The reflected light H radiated by the detection subject F passes through the light receiving area SA provided in the sensor area RA of the liquid-crystal panel 200 and propagates to the light receiving surface JSa of the photo sensor device 32a located at a position corresponding to the position of the light receiving area SA. Then, the photo sensor device 32a receives the reflected light H arriving at the light receiving surface JSa.
The reflected light H directed to the light receiving surface JSa of the photo sensor device 32a and received by the photo sensor device 32a is subjected to a photo electrical conversion process of converting the reflected light H into an electrical signal having a strength according to the quantity of the reflected light H. The photo sensor device 32a thus generates an electrical signal with the strength thereof representing received-light data. Later on, a peripheral circuit reads out the received-light data.
Then, as described before, the biometric authentication section 402 makes use of the received-light data read out from the photo sensor device 32a to carry out an imaging process to create an image of the detection subject F positioned in the pixel area PA including a sensor area RA for every pixel P on the front-surface side of the liquid-crystal panel 200. Subsequently, the biometric authentication section 402 carries out a biometric authentication process on the image created as a result of the imaging process.
As described above, in this embodiment, the infrared light beam reflection layer 305 of the light guiding board 302 reflects the infrared light beam IR in a direction parallel to the direction from the rear-surface side of the liquid-crystal panel 200 to the front-surface side of the liquid-crystal panel 200. Each of the infrared light beam reflection layers 305 is provided at a position corresponding to a sensor area RA included in the pixel area PA as a sensor area in which one of a plurality of photo sensor devices 32a is created. Thus, illumination light beam R is radiated from the radiation surface PS1 of the light guiding board 302 as light including more infrared light beams IR reflected by the infrared light beam reflection layers 305 and the light reflection film 304 than visible light beams VR reflected only by the light reflection film 304. As a result, the photo sensor device 32a receives the reflected light H also including more infrared light beams IR than visible light beams VR because the reflected light H is no more than the illumination light beam R reflected by the detection subject F. The photo sensor device 32a then generates an electrical signal with the strength thereof representing received-light data from the reflected light H including more infrared light beams IR than visible light beams VR. Thus, this embodiment is capable of improving the S/N ratio of the received-light data. As a result, this embodiment is capable of carrying out a biometric authentication process based on infrared light beams IR with a high degree of precision.
If a biometric authentication process is carried out on the basis of received-light data generated from visible light beams VR included in the light H reflected by blood flowing in a finger used as the detection subject F, it is difficult to carry out the biometric authentication process with a high degree of precision in some cases. This is because the blood reflects the illumination light beam R including more infrared light beams IR than visible light beams VR as described above. In the case of this embodiment, however, the biometric authentication process is carried out on the basis of received-light data generated from infrared light beams IR included in the light H reflected by blood flowing in such a finger. Thus, the embodiment is capable of exhibiting the effect described above more remarkably than the effect of a case in which a biometric authentication process is carried out on the basis of received-light data generated from visible light beams VR included in the light H reflected by blood flowing in such a finger.
Next, a second embodiment of the present invention is explained.
As is obvious from comparison of the cross-sectional diagram of
In the backlight 300b, the diffraction lattice sections 305KK are provided on the bottom surface PS2 on the side opposite to the radiation surface PS1 in the light guiding board 302 as shown in the cross-sectional diagram of
In this embodiment, each of the diffraction lattice sections 305KK is configured to radiate only an infrared light beam generated by the infrared light source 301b of the light source 301 to the light reflection film 304. Much like the infrared light beam reflection layers 305 employed in the first embodiment, each of the diffraction lattice sections 305KK is provided at a position corresponding to a sensor area RA included in the pixel area PA as a sensor area in which one of a plurality of photo sensor devices 32a is created.
A plurality of aforementioned diffraction lattice sections 305KK are provided as shown in the perspective-view diagram of
As shown in the perspective-view diagram of
In order for the light guiding board 302 to radiate only light having a specific wavelength to the light reflection film 304, the diffraction lattice section 305KK is created so that the pitch d of the lattice pattern satisfies a relation for example expressed by Eq. (1) given below. It is to be noted that, in Eq. (1), notation d denotes the pitch d of the lattice pattern, notation θ denotes the incidence angle of a light beam arriving at the diffraction lattice section 305KK and notation λ denotes the wavelength of the light beam.
2 d sin θ=λ (1)
For example, in this embodiment, the diffraction lattice section 305KK is created with the width L of the line pattern LP set at 0.4 μm, the width of the space SP between two line patterns LP adjacent to each other set at 0.6 μm and the h of the line pattern LP set at 1 μm.
For example, the diffraction lattice section 305KK is created on the bottom surface PS2 of the light guiding board 302 so as to integrate the diffraction lattice section 305KK with the light guiding board 302. To put it concretely, the diffraction lattice section 305KK is created on the bottom surface PS2 of the light guiding board 302 so as to integrate the diffraction lattice section 305KK with the light guiding board 302 by, first of all, injecting a creation material such as the acryl resin into a mold and, then, cooling the injected material in order to make the material hard.
The following description explains operations which are carried out in this second embodiment to implement the biometric authentication process on the basis of received-light data obtained from the reflected light H which is reflected by the detection subject F such a finger of the user when the detection subject F is brought into contact with the pixel area PA of the liquid-crystal panel 200 or approaches the pixel area PA.
When the detection subject F such a finger of the user is brought into contact with the pixel area PA of the liquid-crystal panel 200 or approaches the pixel area PA, as shown in the cross-sectional diagram of
To put it concretely, first of all, light D1 generated by the light source 301 in the backlight 300 is guided by the light guiding board 302 as shown in the cross-sectional diagram of
The light D1 generated by the light source 301 include a visible light beam VR and an infrared light beam IR as described above.
The diffraction lattice section 305KK is configured to reflect only an infrared light beam IR. Thus, the infrared diffraction lattice section 305KK provided on the rear surface (that is, the bottom surface PS2) of the light guiding board 302 radiates only the infrared light beam IR, which is included in the D1 generated by the light source 301 and guided by the light guiding board 302 to hit the diffraction lattice section 305KK, to the light reflection film 304 as light D2.
The light D2 radiated by the diffraction lattice section 305KK is reflected by the light reflection film 304 to be radiated from the radiation surface PS1 of the light guiding board 302 to the optical film 303. In the optical film 303, the light spreading sheet 303a spreads the light D2 radiated by the diffraction lattice section 305KK, reflected by the light reflection film 304 and radiated from the radiation surface PS1 of the light guiding board 302, whereas the prism sheet 303b converges the light D2, which has been spread by the light guarding board 302, in a normal direction z perpendicular to the radiation surface PS1. Thus, the optical film 303 eventually radiates the illumination light D2 generated by the radiation surface PS1 of the light guiding board 302 to the rear surface of the liquid-crystal panel 200 as planar light R.
The illumination light beam R radiated by the prism sheet 303b of the backlight 300b passes through the liquid-crystal panel 200 and is then radiated to the detection subject F to be reflected by the detection subject F as reflected light H. As described above, since the diffraction lattice section 305KK reflects only infrared light beams IR, the illumination light beam R radiated by the prism sheet 303b of the backlight 300b includes more infrared light beams IR than visible light beams VR. Thus, the reflected light H which is reflected by the detection subject F also includes more infrared light beams IR than visible light beams VR. In the case of this second embodiment, in the same way as the first embodiment, a finger of a person is used as the detection subject F and blood flowing in a vein of the finger reflects the illumination light beam R, radiating the reflected light H as a result of the reflection to be used in a biometric authentication process based on many infrared light beams IR included in the reflected light H.
The reflected light H radiated by the detection subject F passes through the light receiving area SA provided in the sensor area RA of the liquid-crystal panel 200 and propagates to the light receiving surface JSa of the photo sensor device 32a located at a position corresponding to the position of the light receiving area SA. Then, the photo sensor device 32a receives the reflected light H arriving at the light receiving surface JSa.
The reflected light H directed to the light receiving surface JSa of the photo sensor device 32a and received by the photo sensor device 32a is subjected to a photo electrical conversion process of converting the reflected light H into an electrical signal having a strength according to the quantity of the reflected light H. The photo sensor device 32a generates the electrical signal having a strength representing received-light data. Later on, the data processing block 400 serving as a peripheral circuit reads out the received-light data from the photo sensor device 32a.
Then, as described before, the biometric authentication section 402 employed in the data processing block 400 makes use of the received-light data read out from the photo sensor device 32a to carry out an imaging process to create an image of the detection subject F positioned in the pixel area PA including a sensor area RA for every pixel P on the front-surface side of the liquid-crystal panel 200. Subsequently, the biometric authentication section 402 carries out a biometric authentication process on the image created as a result of the imaging process.
As described above, in this embodiment, the diffraction lattice section 305KK of the light guiding board 302 radiates only the infrared light beam IR to the light reflection film 304 which then reflects the radiated infrared light beam IR and a visible light beam VR in a direction parallel to the direction from the rear-surface side of the liquid-crystal panel 200 to the front-surface side of the liquid-crystal panel 200. Each of the diffraction lattice sections 305KK is provided at a position corresponding to a sensor area RA included in the pixel area PA as a sensor area in which one of a plurality of photo sensor devices 32a is created. Thus, illumination light beam R is radiated from the radiation surface PS1 of the light guiding board 302 as light including more infrared light beams IR reflected by the diffraction lattice sections 305KK and the light reflection film 304 than visible light beams VR reflected only by the light reflection film 304. As a result, the photo sensor device 32a receives the reflected light H also including more infrared light beams IR than visible light beams VR. The photo sensor device 32a then generates received-light data from the reflected light H including more infrared light beams IR than visible light beams VR. Thus, this embodiment is capable of improving the S/N ratio of the electrical signal with the strength thereof representing the received-light data. As a result, this embodiment is capable of carrying out a biometric authentication process based on infrared light beams IR with a high degree of precision.
Next, a third embodiment of the present invention is explained.
The third embodiment is different from the first one in that the third embodiment employs a front-light 500 as shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
To put it concretely, the front-light 500 is provided outside the liquid-crystal panel 200 at a position closer to the facing substrate 202 employed in the liquid-crystal panel 200 than the TFT array substrate 201 also employed in the liquid-crystal panel 200. The front-light 500 generates illumination light RF from its surface on a side opposite to the side facing the liquid-crystal panel 200. That is to say, the front-light 500 generates illumination light RF in a direction parallel to the direction from the side of the TFT array substrate 201 to the side of the facing substrate 202. A direction parallel to a direction from the side of the TFT array substrate 201 to the side of the facing substrate 202 is referred to as a normal direction z perpendicular to the surfaces of the liquid-crystal panel 200.
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
As shown in the perspective-view diagram of
The infrared light source 501b is for example an infrared color LED configured to generate an infrared light beam. As shown in the perspective-view diagram of
As shown in the cross-sectional diagram of
In this embodiment, an infrared light beam generated by the infrared light source 501b hits the light incidence surface IS of the light guiding board 502 and the light guiding board 502 guides the light beam hitting the light incidence surface IS so that the light is generated from the radiation surface PS1 of the light guiding board 502 as the illumination light RF cited above.
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
To put it in detail, each of the infrared light beam reflection layers 505 reflects only an infrared light beam generated by the infrared light source 501b employed in the light source 501 in a direction parallel to a direction from the rear-surface side of the liquid-crystal panel 200 to the front-surface side of the liquid-crystal panel 200. Provided at locations corresponding to the locations of the photo sensor devices 32a in the pixel area PA, the infrared light beam reflection layers 505 reflect only the infrared light beams to the radiation surface PS1 to be radiated from the radiation surface PS1 as the illumination light RF.
As shown in the perspective-view diagram of
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
In this embodiment, as shown in the perspective-view diagram of
The visible light source 301a is for example a white-color LED configured to generate a visible light beam provided with the white color. As shown in the perspective-view diagram of
As shown in the cross-sectional diagram of
To put it in detail, in this embodiment, the light guiding board 302 guides the visible light beam generated by the visible light source 301a to hit the light incidence surface IS. The guided visible light beam is radiated from the radiation surface PS1 to the liquid-crystal panel 200 as the illumination light beam R. As a result, an image is displayed in the pixel area PA of the liquid-crystal panel 200 of the transmission type as described before.
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
The following description explains a biometric authentication process carried out by the liquid-crystal display apparatus 100c on the basis received-light data obtained by receiving light which is reflected by a detection subject F such as a finger of the user when the detection subject F is brought into contact with the pixel area PA of the liquid-crystal panel 200 or approaches the pixel area PA.
When the detection subject F such a finger of the user is brought into contact with the pixel area PA of the liquid-crystal panel 200 or approaches the pixel area PA, as shown in the cross-sectional diagram of
To put it concretely, first of all, light D1 generated by the light source 501 is guided by the light guiding board 502 as shown in the cross-sectional diagram of
In this embodiment, the light D1 generated by the light source 501 and guided by the light guiding board 502 includes an infrared light beam IR as described above.
The infrared light beam reflection layer 505 is configured to reflect only an infrared light beam IR rather than reflecting a visible light beam VR. Thus, an infrared light beam IR included in the light D1 generated by the light source 501 and guided by the light guiding board 502 to hit the infrared light beam reflection layer 505 provided on the rear surface of the light guiding board 502 is selectively reflected by the infrared light beam reflection layer 505 to the radiation surface PS1 of the light guiding board 502. That is to say, the infrared light beam reflection layer 505 reflects only an infrared light beam IR included in the light D1 to the radiation surface PS1 of the light guiding board 502.
The light D2 reflected by the infrared light beam reflection layer 505 to the radiation surface PS1 of the light guiding board 502 is radiated from the radiation surface PS1 as the illumination light RF.
The illumination light RF generated by the front-light 500 is radiated to the detection subject F to be reflected by the detection subject F as reflected light HF. As described above, since the infrared light beam reflection layer 505 reflects only infrared light beams IR, the illumination light RF generated by the front-light 500 includes mainly infrared light beams IR. Thus, the reflected light HF reflected by the detection subject F also includes mainly infrared light beams IR. In the case of this embodiment, a finger of a person is used as the detection subject F and blood flowing in a vein of the finger reflects the illumination light RF, radiating the reflected light HF as a result of the reflection to be used in a biometric authentication process based on many infrared light beams IR included in the reflected light HF.
The reflected light HF radiated by the detection subject F passes through the light receiving area SA provided in the sensor area RA of the liquid-crystal panel 200 and propagates to the light receiving surface JSa of the photo sensor device 32a located at a position corresponding to the position of the light receiving area SA. Then, the photo sensor device 32a receives the reflected light HF arriving at the light receiving surface JSa. As shown in the cross-sectional diagram of
The reflected light HF directed to the light receiving surface JSa of the photo sensor device 32a and received by the photo sensor device 32a is subjected to a photo electrical conversion process of converting the reflected light HF into an electrical signal having a strength according to the quantity of the reflected light HF. The photo sensor device 32a generates the electrical signal with the strength thereof representing received-light data. Later on, the a peripheral circuit reads out the received-light data.
Then, as described before, the biometric authentication section 402 makes use of the received-light data read out from the photo sensor device 32a to carry out an imaging process to create an image of the detection subject F positioned in the pixel area PA on the front-surface side of the liquid-crystal panel 200. Subsequently, the biometric authentication section 402 carries out a biometric authentication process on the image created as a result of the imaging process.
As described above, in this embodiment, the infrared light beam reflection layer 505 of the light guiding board 502 reflects the infrared light beam IR in a direction parallel to the direction from the rear-surface side of the liquid-crystal panel 200 to the front-surface side of the liquid-crystal panel 200. Each of the infrared light beam reflection layers 505 is provided at a position corresponding to a sensor area RA included in the pixel area PA as a sensor area in which one of a plurality of photo sensor devices 32a is created. Thus, illumination light RF is radiated from the radiation surface PS1 of the light guiding board 502 as light including mainly infrared light beams IR reflected by the infrared light beam reflection layers 505. As a result, the photo sensor device 32a receives the reflected light HF also including mainly infrared light beams IR. The photo sensor device 32a then generates received-light data from the reflected light HF including many infrared light beams IR. Thus, in the same way as the first embodiment, the third embodiment is capable of improving the S/N ratio of an electrical signal with the strength thereof representing the received-light data. As a result, this embodiment is capable of carrying out a biometric authentication process based on infrared light beams IR with a high degree of precision.
Next, a fourth embodiment of the present invention is explained.
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
The prism surface 505P is created by adjusting the angle of inclined surfaces of the prism surface 505P so that the prism surface 505P reflects an infrared light beam in a direction parallel to the direction from the rear-surface side of the liquid-crystal panel 200 to the front-surface side of the liquid-crystal panel 200. To put it concretely, the angle of the inclined surfaces of the prism surface 505P is adjusted in accordance with the incidence angle of the infrared light beam arriving at the light guiding board 502d. For example, in a process of creating the light guiding board 502d, the prism surface 505P is also created so as to provide the light guiding board 502d with the prism surface 505P. Each of the prism surfaces 505P is provided at a position corresponding to a sensor area RA included in the pixel area PA as a sensor area in which one of a plurality of photo sensor devices 32a is created. The prism surface 505P reflects an infrared light beam and the reflected infrared light beam is radiated by the radiation surface PS1 as illumination light RF.
As shown in the cross-sectional diagram of
The following description explains a biometric authentication process on the basis received-light data obtained by receiving light which is reflected by a detection subject F such as a finger of the user when the detection subject F is brought into contact with the pixel area PA of the liquid-crystal panel 200 or approaches the pixel area PA.
When the detection subject F such a finger of the user is brought into contact with the pixel area PA of the liquid-crystal panel 200 or approaches the pixel area PA, as shown in the cross-sectional diagram of
To put it concretely, first of all, light D1 generated by the light source 501 in the front-light 500d is guided by the light guiding board 502d to propagate to the prism surface 505P as shown in the cross-sectional diagram of
The illumination light RF generated by the front-light 500d is radiated to the detection subject F to be reflected by the detection subject F as reflected light HF in the same way as the first embodiment. The reflected light HF radiated by the detection subject F passes through the light receiving area SA provided in the sensor area RA of the liquid-crystal panel 200 and propagates to the light receiving surface JSa of the photo sensor device 32a located at a position corresponding to the position of the light receiving area SA. Then, the photo sensor device 32a receives the reflected light HF arriving at the light receiving surface JSa.
The reflected light HF directed to the light receiving surface JSa of the photo sensor device 32a and received by the photo sensor device 32a is subjected to a photo electrical conversion process of converting the reflected light HF into an electrical signal having a strength according to the quantity of the reflected light HF. The photo sensor device 32a generates the electrical signal with the strength thereof representing received-light data. Later on, a peripheral circuit reads out the received-light data.
Then, in the same way as the first embodiment described before, the biometric authentication section 402 employed in the data processing block 400 makes use of the received-light data read out from the photo sensor device 32a to carry out an imaging process to create an image of the detection subject F positioned in the pixel area PA including a sensor area RA for every pixel P on the front-surface side of the liquid-crystal panel 200. Subsequently, the biometric authentication section 402 carries out a biometric authentication process on the image created as a result of the imaging process.
As described above, in the fourth embodiment, the prism surface 505P of the light guiding board 502d reflects the infrared light beam IR in a direction parallel to the direction from the rear-surface side of the liquid-crystal panel 200 to the front-surface side of the liquid-crystal panel 200. Each of the prism surfaces 505P is provided at a position corresponding to a sensor area RA included in the pixel area PA as a sensor area in which one of a plurality of photo sensor devices 32a is created. The illumination light RF is radiated from the radiation surface PS1 of the light guiding board 502 as light including mainly infrared light beams IR reflected by the prism surfaces 505P. Thus, the photo sensor device 32a receives the reflected light HF also including mainly infrared light beams IR. The photo sensor device 32a then generates received-light data from the reflected light HF including many infrared light beams IR. Thus, the fourth embodiment is capable of improving the S/N ratio of an electrical signal with the strength thereof representing the received-light data in the same way as the third embodiment. As a result, much like the third embodiment, the fourth embodiment is capable of carrying out a biometric authentication process based on infrared light beams IR with a high degree of precision.
Next, a fifth embodiment of the present invention is explained.
As is obvious from comparison of the diagram of
As shown in the cross-sectional diagram of
The pixel electrode 62H employed in the liquid-crystal panel 200e is not a transmission-type electrode for passing through light like the pixel electrode 62 employed in the third embodiment, but a reflection-type electrode for reflecting light. The pixel electrode 62H is created by for example making use of silver. That is to say, the liquid-crystal panel 200e is not a panel of the transmission type, but a panel of the reflection type. In the liquid-crystal panel 200e of the reflection type, the pixel electrode 62H of the reflection type is configured to reflect light entering the liquid-crystal panel 200e from the front-surface side in order to display an image. Except for the difference between the pixel electrode 62H employed in the liquid-crystal panel 200e and the pixel electrode 62 employed in the liquid-crystal panel 200, the configuration of the liquid-crystal panel 200e is identical with the configuration of the liquid-crystal panel 200.
A biometric authentication process carried out by the liquid-crystal display apparatus 100e on the basis received-light data obtained by receiving light which is reflected by a detection subject F such as a finger of the user when the detection subject F is brought into contact with the pixel area PA of the liquid-crystal panel 200e or approaches the pixel area PA is identical with the biometric authentication process according to the third embodiment.
That is to say, as shown in the cross-sectional diagram of
The illumination light RF generated by the front-light 500 is radiated to the detection subject F to be reflected by the detection subject F as reflected light HF. As described above, since the infrared light beam reflection layer 505 reflects only infrared light beams IR, the illumination light RF generated by the front-light 500 includes mainly infrared light beams IR. Thus, the reflected light HF reflected by the detection subject F also includes mainly infrared light beams IR. In the case of the fifth embodiment, a finger of a person is used as the detection subject F and blood flowing in a vein of the finger reflects the illumination light RF, radiating the reflected light HF as a result of the reflection to be used in a biometric authentication process based on many infrared light beams IR included in the reflected light HF.
The reflected light HF radiated by the detection subject F passes through the light receiving area SA provided in the sensor area RA of the liquid-crystal panel 200e and propagates to the light receiving surface JSa of the photo sensor device 32a located at a position corresponding to the position of the light receiving area SA. Then, the photo sensor device 32a receives the reflected light HF arriving at the light receiving surface JSa.
The reflected light HF directed to the light receiving surface JSa of the photo sensor device 32a and received by the photo sensor device 32a is subjected to a photo electrical conversion process of converting the reflected light HF into an electrical signal having a strength according to the quantity of the reflected light HF. The photo sensor device 32a generates the electrical signal with the strength thereof representing received-light data. Later on, a peripheral circuit reads out the received-light data.
Then, in the same way as the third embodiment described before, the biometric authentication section 402 employed in the data processing block 400 makes use of the received-light data read out from the photo sensor device 32a to carry out an imaging process to create an image of the detection subject F positioned in the pixel area PA on the front-surface side of the liquid-crystal panel 200e. Subsequently, the biometric authentication section 402 carries out a biometric authentication process on the image created as a result of the imaging process.
As described above, in the same way as the third embodiment, in the fifth embodiment, the photo sensor device 32a employed in the liquid-crystal panel 200e receives the reflected light HF also including mainly infrared light beams IR. The photo sensor device 32a then generates received-light data from the reflected light HF including many infrared light beams IR. Thus, the fifth embodiment is capable of improving the S/N ratio of an electrical signal with the strength thereof representing the received-light data in the same way as the third embodiment. As a result, much like the third embodiment, the fifth embodiment is capable of carrying out a biometric authentication process based on infrared light beams IR with a high degree of precision.
Next, a sixth embodiment of the present invention is explained.
As shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
The substrate 201S of the EL panel 200E is for example made of an insulation material such as the glass.
The electric-field light emitting devices 31E in a pixel P are created in the display area TA. The electric-field light emitting devices 31E emit light to display an image. The electric-field light emitting devices 31E is created by sequentially piling up components not shown in the cross-sectional diagram of
In the sixth embodiment, the field-effect light emitting device 31E includes a red-color field-effect light emitting device 31ER, a green-color field-effect light emitting device 31EG and a blue-color field-effect light emitting device 31EB as shown in the cross-sectional diagram of
As shown in the cross-sectional diagram of
A biometric authentication process carried out by the EL display apparatus 100E on the basis received-light data obtained by receiving light which is reflected by the detection subject F such as a finger of the user when the detection subject F is brought into contact with the pixel area PA of the EL panel 200E or approaches the pixel area PA is identical with the biometric authentication process according to the third embodiment.
As shown in the cross-sectional diagram of
The illumination light RF generated by the front-light 500 is radiated to the detection subject F to be reflected by the detection subject F. As described above, since the infrared light beam reflection layer 505 reflects only infrared light beams IR, the illumination light RF generated by the front-light 500 includes mainly infrared light beams IR. Thus, the reflected light HF reflected by the detection subject F also includes mainly infrared light beams IR. In the case of the sixth embodiment, a finger of a person is used as the detection subject F and blood flowing in a vein of the finger reflects the illumination light RF.
The reflected light HF radiated by the detection subject F propagates to the light receiving surface JSa of the photo sensor device 32a in the sensor area RA of the EL panel 200E. Then, the photo sensor device 32a receives the reflected light HF arriving at the light receiving surface JSa.
The reflected light HF is subjected to a photo electrical conversion process of converting the reflected light HF into an electrical signal having a strength according to the quantity of the reflected light HF. The photo sensor device 32a generates the electrical signal with the strength thereof representing received-light data. Later on, the data processing block 400 serving as a peripheral circuit reads out the received-light data from the photo sensor device 32a.
Then, in the same way as the third embodiment described before, the biometric authentication section 402 makes use of the received-light data read out from the photo sensor device 32a to carry out an imaging process to create an image of the detection subject F positioned in the pixel area PA on the front-surface side of the EL panel 200E. Subsequently, the biometric authentication section 402 carries out a biometric authentication process on the image created as a result of the imaging process.
As described above, in the same way as the third embodiment, in the sixth embodiment, the photo sensor device 32a employed in the EL panel 200E receives the reflected light HF also including mainly infrared light beams IR because the reflected light HF is no more than the illumination light RF reflected by the detection subject F. The photo sensor device 32a then generates received-light data from the reflected light HF. Thus, the sixth embodiment is capable of improving the S/N ratio of an electrical signal with the strength thereof representing the received-light data in the same way as the third embodiment. As a result, much like the third embodiment, the sixth embodiment is capable of carrying out a biometric authentication process with a high degree of precision.
It is to be noted that the scope of the present invention is by no means limited to the embodiments described above. That is to say, the embodiments can be changed to result in a variety of modified versions.
For example, in the embodiments described above, a thin-film transistor of the bottom-gate type is employed as the pixel switching device 31. However, the pixel switching device 31 does not have to be a thin-film transistor of the bottom-gate type.
As shown in the cross-sectional diagram of
In addition, in the embodiments described above, a plurality of photo sensor devices 32a are provided to correspond to the same plurality of pixels P respectively. However, the scope of the present invention is by no means limited to this scheme. For example, one photo sensor device 32a can also be provided to correspond to a plurality of pixels P or, conversely, a plurality of photo sensor devices 32a can also be provided to correspond to one pixel P. On top of that, it is also possible to provide a configuration in which a plurality of photo sensor devices 32a are provided to correspond to the same plurality of pixels P respectively in a partial area of the pixel area PA.
In addition, in the embodiments described above, the received-light data generated by the photo sensor device 32a is used in the execution of a biometric authentication process. However, the scope of the present invention is by no means limited to this scheme. For example, the received-light data generated by the photo sensor device 32a can also be used in the execution of a process to determine the position of a detection subject F. On top of that, the received-light data generated by the photo sensor device 32a can be used in a variety of applications.
In addition, in the embodiments described above, a photodiode of the PIN type is used as the photo sensor device 32a. However, the scope of the present invention is by no means limited to this scheme. For example, as the photo sensor device 32a, it is also possible to make use of a photodiode having a PDN structure in which an i layer is doped with impurities. Even if a photodiode having a PDN structure is used, it is possible to obtain the same effects as the photodiode of the PIN type. On top of that, a photo transistor can be provided as a photo sensor device 32a.
On top of that, in the embodiments described above, the red-color filter layer 21R, the green-color filter layer 21G and the blue-color filter layer 21B are each created to have a strip shape and arranged in the horizontal direction x. In the same array of the red-color filter layer 21R, the green-color filter layer 21G and the blue-color filter layer 21B, the light receiving area SA is created at a location adjacent to the red-color filter layer 21R. However, the scope of the present invention is by no means limited to this scheme. For example, it is also possible to provide a configuration in which the red-color filter layer 21R, the green-color filter layer 21G, the blue-color filter layer 21B and the light receiving area SA are combined in a set, being arranged to form a matrix consisting or two rows and two columns.
In addition, in the embodiments described above, illumination light including an infrared light beam as an invisible light beam is radiated. However, the scope of the present invention is by no means limited to this scheme. For example, the illumination light may also an ultraviolet light beam as an invisible light beam.
On top of that, it should be understood by those skilled in the art that a variety of modifications, combinations, sub-combinations and alterations may occur, depending on design requirements and other factors as far as they are within the scope of the appended claims or the equivalents thereof.
In addition, the display apparatus such as the liquid-crystal display apparatus 100, 100b, 100c, 100d or 100e according to the embodiments of the present invention can each be used as a display unit of a variety of electronic instruments.
Each of
On top of that, the display apparatus such as the EL display apparatus 100E according to the sixth embodiment of the present invention can be used as a display unit of a variety of electronic instruments in the same way as the liquid-crystal display apparatus 100, 100b, 100c, 100d or 100e.
In addition, it is possible to apply the present invention to liquid-crystal display panels adopting a variety of methods such as IPS (In-Plane-Switching) and FFS (Field Fringe Switching) methods. On top of that, the display apparatus according to the present invention can be used as other display units such as an electronic-paper unit.
It is to be noted that each of the liquid-crystal display apparatus 100, 100b, 100c, 100d and 100e employed in the embodiments described above corresponds to a display apparatus provided by an embodiment of the present invention. In addition, the EL display apparatus 100E in the sixth embodiment described above corresponds to also a display apparatus provided by an embodiment of the present invention.
On top of that, each of the liquid-crystal panels 200, 200c and 200e employed in the embodiments described above corresponds to a display panel provided by an embodiment of the present invention. In addition, the EL panel 200E in the sixth embodiment described above corresponds to an EL panel provided by an embodiment of the present invention.
On top of that, the TFT array substrate 201 employed in the embodiments described above corresponds to the first substrate provided by an embodiment of the present invention whereas the facing substrate 202 employed in the embodiments described above corresponds to the second substrate provided by an embodiment of the present invention. In addition, the liquid-crystal layer 203 employed in the embodiments described above corresponds to a liquid-crystal layer provided by an embodiment of the present invention.
On top of that, each of the backlights 300, 300b and 300c employed in the embodiments described above corresponds to an illumination unit/apparatus provided by an embodiment of the present invention. In addition, the light source 301 employed in the embodiments described above corresponds to a light source provided by an embodiment of the present invention whereas the light guiding board 302 employed in the embodiments described above corresponds to a light guiding board provided by an embodiment of the present invention.
On top of that, the visible light source 301a employed in the embodiments described above corresponds to a visible light source provided by an embodiment of the present invention. In addition, the infrared light source 301b employed in the embodiments described above corresponds to an invisible light source provided by an embodiment of the present invention.
On top of that, the light reflection film 304 employed in the embodiments described above corresponds to a light reflection section provided by an embodiment of the present invention or, strictly speaking, an invisible light reflection section provided by an embodiment of the present invention.
In addition, the infrared light beam reflection layer 305 employed in the embodiments described above corresponds to an invisible light beam reflection layer/section provided by an embodiment of the present invention. On top of that, the diffraction lattice section 305KK in the second embodiment described above corresponds to a light diffraction lattice section provided by an embodiment of the present invention or an invisible light beam reflection section provided by an embodiment of the present invention.
In addition, the biometric authentication section 402 employed in the embodiments described above corresponds to a biometric authentication section provided by an embodiment of the present invention.
On top of that, each of the front-lights 500 and 500d employed in the embodiments described above corresponds to an illumination unit/apparatus provided by an embodiment of the present invention. In addition, the light source 501 employed in the embodiments described above corresponds to a light source provided by an embodiment of the present invention whereas each of the light guiding boards 502 and 502d employed in the embodiments described above corresponds to a light guiding board provided by an embodiment of the present invention.
On top of that, the infrared light source 501b employed in the embodiments described above corresponds to an invisible light source provided by an embodiment of the present invention.
In addition, the infrared light beam reflection layer 505 employed in the embodiments described above corresponds to an invisible light beam reflection layer/section provided by an embodiment of the present invention. On top of that, the prism surface 505P in the fourth embodiment described above corresponds to a prism surface provided by an embodiment of the present invention or an invisible light beam reflection section provided by an embodiment of the present invention.
In addition, the pixel area PA employed in the embodiments described above corresponds to a pixel area provided by an embodiment of the present invention whereas the pixel P employed in the embodiments described above corresponds to a pixel provided by an embodiment of the present invention. On top of that, the photo sensor device 32a employed in the embodiments described above corresponds to a photo sensor device provided by an embodiment of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-327953 | Dec 2007 | JP | national |
| 2008-260906 | Oct 2008 | JP | national |
