JP4831456B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus, and more particularly to an image reading apparatus in which an image reading sensor is disposed on the front surface (view side) of an image display panel and has an image display function and an image reading function.

  In recent years, portable electronic devices such as mobile phones, personal digital assistants (PDAs), notebook personal computers (notebook personal computers), digital cameras, and the like have become widespread. Such electronic devices can easily communicate by voice, e-mail, etc., take images, edit various information, and carry a large amount of information. In addition, some mobile phones and the like are equipped with electronic money and credit card functions, as well as commuter pass functions for public transportation, and are expected to become more popular in the future.

  However, in the portable electronic device, although the convenience is improved as described above, there is also a problem that there is a high risk that personal information or confidential information is leaked or stolen and misused. ing. For this reason, in order to prevent the leakage and theft of various types of information and restrict access to the information, it is important to install a personal authentication function that identifies and authenticates the user in the electronic device. Yes.

  Conventionally, as a personal authentication technique, in addition to a simple method by inputting a personal identification number or the like, in recent years, a more sophisticated and rigorous method has been used in which an individual is identified using biometric data unique to the human body including fingerprints and irises of the eye Methods have been researched and developed, and some have already been put into practical use. For example, in a personal authentication technique using a fingerprint, it is roughly classified into a semiconductor type that reads a fingerprint image (subject image) by detecting a capacitance based on a potential difference generated between a finger (subject) and a detection sensor ( Brightness information using a capacitance reading type fingerprint reader or photosensor (specifically, CCD or CMOS sensor) that captures a fingerprint image via an optical system such as a prism or mirror and is arranged in a matrix. An optical (optical image reading type) fingerprint reading device and the like are known.

  Here, in the semiconductor fingerprint reading apparatus described above, a finger is placed, and a reading detection unit (sensor array) that reads the fingerprint image can be formed extremely thin and light using semiconductor manufacturing technology. It has the advantage of being able to. On the other hand, in an optical fingerprint reader, an optical system is interposed between a finger and a photo sensor, which is not suitable for thinning and weight reduction. There is an advantage that the fingerprint reader is not damaged by static electricity, the user himself does not feel discomfort associated with electrostatic discharge, and the fingerprint reading response speed is relatively fast.

  However, not only the detection sensor applied to the semiconductor fingerprint reader described above, but also a CCD or CMOS sensor applied to the optical fingerprint reader is formed on a semiconductor substrate as is well known. Therefore, all of the fingerprint readers (detection sensors and photosensors) in the prior art are opaque. Therefore, in a portable electronic device that is required to be smaller and thinner and lighter, such a fingerprint reader is directly superimposed on a functional unit (for example, an image display panel) that is originally provided in the electronic device (lamination). Could not be provided.

Hereinafter, as a personal authentication function in the prior art, a portable electronic device equipped with a fingerprint reader will be described with a specific example.
FIG. 22 is a schematic configuration diagram showing an example of a portable electronic device (mobile phone) equipped with a fingerprint reading device in the prior art.

  The apparatus configuration shown in FIGS. 22A and 22B is, for example, an image display panel (image display unit) that is originally provided in a mobile phone (electronic device) 10P or 10Q as described in Patent Document 1 or the like. ) Fingerprint reading sensors (fingerprint reading devices) 12P and 12Q are provided at different positions independent of 11P and 11Q (above the image display panel in the figure). In the figure, 13P and 13Q are operation keys (operation buttons) for operating various functions of the mobile phones 10P and 10Q. Here, in addition to the positions shown in FIG. 22, the fingerprint reading sensors 12P and 12Q are also known, for example, arranged below the operation keys 13P and 13Q.

In addition, as another example of the configuration of an electronic device equipped with a fingerprint reading sensor (personal authentication function), for example, as described in Patent Literature 2, Patent Literature 3, and the like, an image originally possessed by the electronic device A display panel in which a fingerprint reading sensor is integrated and mounted is also known.
For example, Patent Document 2 describes a configuration in which a prism is provided on a liquid crystal display panel (image display panel) having a backlight so that a fingerprint image (subject image) is guided to a photosensor (fingerprint reading sensor). In addition, Patent Document 3 describes a configuration in which a photodiode is incorporated in each display pixel of a liquid crystal display panel together with a pixel transistor (TFT).

JP 2002-279212 A (FIGS. 1 and 5 pages 2 to 3) JP 2001-351099 A (FIG. 1, page 3) JP 2002-33823 A (FIG. 1, page 4)

However, the conventional technology as described above has the following problems.
In other words, in the configuration described in Patent Document 1 and the like described above, the scale of the electronic device increases, and it is not possible to sufficiently meet the demands for downsizing, weight reduction, and thinning of the portable electronic device. There was a problem.

Therefore, in order to avoid such problems, it is conceivable to reduce the size of the fingerprint reading sensor. However, in personal authentication by fingerprint, it is necessary to extract several or more feature points from the fingerprint image, Among sensor structures for which various reading mechanisms have been devised, the finger is placed on the sensor panel and stationary compared to a fingerprint reading sensor that reads the fingerprint image by rotating the sensor unit or sliding the finger. In consideration of the fact that the method of reading a fingerprint image (denoted as “planar type” for convenience) has a relatively high reading accuracy and a simple device structure, etc. When is applied, it is necessary that the detection surface (the detection area of the sensor panel) has a size sufficient for at least the size of the fingertip.
Therefore, when the fingerprint reading sensor is downsized in order to provide a personal authentication function in an existing housing of an electronic device, there is a problem that it is difficult to read a fingerprint image well and authentication accuracy is lowered. .

  Further, in the configuration in which an optical member such as a prism is provided on the image display panel and the subject image is guided to the fingerprint reading sensor provided on the side surface as in the configuration described in Patent Document 2, the subject image The optical member such as a prism for guiding the image to the fingerprint reading sensor is relatively thick, and some optical components (mirrors), fingerprint reading sensors, etc. are installed in the image display panel installation area (front of the image display panel). ), And it is difficult to make the electronic device sufficiently small and thin.

  Further, in the configuration in which the photodiode is formed in the display pixel as in the configuration described in Patent Document 3 and the like, the existing image display panel, the fingerprint reading sensor (device), and the design assets thereof Etc. cannot be applied as they are, and the number of elements formed on the substrate increases, the circuit configuration becomes complicated, and in addition, microfabrication is required, leading to a decrease in product yield and manufacturing costs. Has the problem of rising.

  Therefore, in view of the above-described problems, the present invention is capable of reading user-specific information (such as a fingerprint image) well and realizing proper personal authentication while realizing an original good image display of the image display unit. In addition, an object of the present invention is to provide an image reading apparatus capable of reducing the size and thickness of the apparatus and reducing the cost.

The invention described in claim 1 includes an image display function for displaying desired image information in a specific image area, and an image reading function for reading an image of a desired subject placed in the specific image area. In the image reading apparatus, each of the plurality of display pixels that emit light of a gradation corresponding to the image information to the visual field side has a first direction and a first direction orthogonal to the first direction on the first substrate . Yes display pixel array which are regularly arranged in two directions in a matrix, a black matrix having a light shielding property formed in a lattice pattern between each of the display pixels, and an image display unit having a transparent and, each of the plurality of read pixels for reading the image of the subject, on the second substrate are two-dimensionally arranged along row and column directions, a staggered structure at least in the row direction or the column direction image with a reading pixel array having Comprising a reading unit, a, to the field side of the image display means, said image reading means, the row direction is parallel to the first direction, the column direction is parallel to the second direction The image reading area defined by the read pixel array is set so as to overlap with the image display area defined by the display pixel array.

According to a second aspect of the invention, in the image reading apparatus according to claim 1, wherein the image reading means, said plurality of read pixels are arranged alternately in the column direction the row direction are arranged a staggered structure It is arranged so that it may have.
According to a third aspect of the invention, in the image reading apparatus according to claim 1, wherein the image reading means, said plurality of read pixels, the row direction are arranged alternately arranged in the column direction a zigzag structure It is arranged so that it may have.

Invention of claim 4, in the image reading apparatus according to claim 1, wherein the image reading means, said plurality of read pixels are arranged alternately in the column direction the row direction are arranged a staggered structure the a, and, and characterized in that it is arranged to have the row direction are arranged alternately arranged in the row direction the staggered structure.
According to a fifth aspect of the present invention, in the image reading device according to the third or fourth aspect, the image reading means includes the plurality of read pixels arranged so as to have a staggered arrangement structure in the column direction. It is characterized in that the element structures are symmetrical in the left and right columns.

Invention according to claim 6, in the image reading apparatus according to claim 2 or 5, wherein said image reading means, the linear wiring patterns of the plurality of reading pixels in at least the columns are arranged in the column direction It is connected by the signal line which has.
Invention of claim 7, in the image reading apparatus according to claim 3, wherein the image reading means, a signal line having a linear wiring patterns of the plurality of reading pixels in at least each row are arranged in the row direction It is connected by this.

Invention of claim 8, wherein, in the image reading apparatus according to any one of claims 2 to 7, of the plurality of reading pixels in the image reading unit, staggered arrangement structure arranged in the row direction, the row the first reading every other pixel in the direction, only half of the column direction of the arrangement interval between the read pixel, has a structure in which by shifting the read pixel in the column direction, are arranged in the column direction staggered sequence structure, one read pixel every other of said column direction, by 1/2 of the column direction of the arrangement interval between the read pixel, and characterized by having a structure in which by shifting the read pixel in the row direction To do.

  According to a ninth aspect of the present invention, in the image reading apparatus according to any one of the first to eighth aspects, the image reading means is radiated from the image display means, passes through the image reading means, and the image reading area. Light reflected by the subject placed on a detection surface provided on the light is received by the reading pixel, and the subject image is read.

The invention of claim 10, wherein, in the image reading apparatus according to claim 1, wherein the read pixel is on the second substrate having transparency, permeability formed across a channel region of a semiconductor layer A drain electrode and a source electrode made of an electrode material, a first gate electrode made of a transmissive electrode material formed above the channel region through a transmissive insulating film, and the channel region A second gate electrode made of a light-shielding electrode material formed through a transparent insulating film below and a transparent insulating film formed above the first gate electrode. And a photosensor having a double-gate thin film transistor structure having the detection surface on which the subject is placed.

According to an eleventh aspect of the present invention, in the image reading device according to the tenth aspect, the image reading means has a signal having a linear wiring pattern in which at least the plurality of read pixels in each column are arranged in the column direction. A signal line connected by a line and having a linear wiring pattern arranged in the column direction in the image reading means is the drain electrode of the photosensor constituting the plurality of read pixels in each column. The signal lines connect the source electrodes to each other and the source electrodes.

According to a twelfth aspect of the present invention, in the image reading device according to the tenth aspect, the image reading means has a linear wiring pattern in which at least the plurality of read pixels in each column are arranged in the row direction. A signal line having a linear wiring pattern arranged in the row direction in the image reading means is connected by a line, and the first of the photosensors constituting the plurality of read pixels in each column. Each of the gate electrodes and the second gate electrode are signal lines that individually connect each other.

According to a thirteenth aspect of the present invention, in the image reading device according to the first to twelfth aspects, the image reading device is set to have a two-dimensional spread so that the image reading region is included in the image display region. It is characterized by that.

According to a fourteenth aspect of the present invention, in the image reading apparatus according to the first to thirteenth aspects, the image display means constitutes at least a surface light source and emits light in a specific one-surface direction, and the light emitting means. And a transmission type liquid crystal display panel in which liquid crystal pixels are two-dimensionally arranged.
According to a fifteenth aspect of the present invention, in the image reading device according to the first to thirteenth aspects, the image display means includes at least a self-luminous display panel in which the display pixels including light emitting elements are two-dimensionally arranged. It is characterized by that.

An image reading apparatus according to the present invention has an image display function and an image reading function, and an image of a subject (fingerprint image) so as to overlap with an image display area (image display area) for displaying desired image information. in the image reading apparatus in which the image reading area (image reading region) is set reading, a matrix in a second direction, each of the plurality of display pixels of liquid crystal pixels is orthogonal to the first direction and the first direction And an image display unit (image) comprising: a pixel array (display pixel array) that is regularly arranged and defines the image display area; and a black matrix having a light shielding property formed in a lattice shape between the display pixels. a display unit), each of the plurality of photo having permeability such as a double gate type photosensor sensor (read pixel) are arranged two-dimensionally along the row and column directions, at least the row direction or column direction An image reading means having a array of sensor array to have a staggered arrangement structure (read pixel array), and provided to, the field side of the image display section, an image reading means, the row direction first direction and become parallel, are configured so that the stacked so the column direction is parallel to the second direction.

  Here, as the staggered arrangement of the photosensors applied to the sensor array, in the row direction, for example, a structure in which the photosensors are alternately arranged in the column direction and arranged in the row direction can be applied. In the direction, for example, it is possible to apply a structure that is alternately arranged in the row direction and arranged in the column direction.

According to this, as compared with a normal matrix arrangement structure in which photosensors are regularly arranged in the row direction and the column direction, the photosensors are linearly arranged in the row direction or the column direction to which the staggered arrangement structure is applied. The number of can be reduced.
Accordingly, the black matrix regularly arranged in the pixel array of the image display unit arranged on the back side of the sensor array (image reading unit) is arranged in at least one direction of the row direction or the column direction. Since the number of photosensors can be reduced, moire fringes caused by light interference between the regular lattice structure in the black matrix of the pixel array and the regular arrangement structure of the photosensors in the sensor array can be reduced. Generation | occurrence | production can be suppressed and degradation of the display quality of the image information displayed on the image display part (pixel array) can be improved.

  In this case, in the image reading unit (sensor array), the photosensors arranged in at least one of the row direction or the column direction are shifted so as to have a staggered arrangement structure, thereby being arranged in the sensor array as a whole. Since the number of photosensors to be reduced does not decrease, a subject image (fingerprint image) can be read with appropriate reading accuracy and a sufficient reading area.

  Further, according to the image reading apparatus of the present invention, only the photosensors arranged in any one of the row direction and the column direction of the image reading unit (sensor array) are shifted so as to have a staggered arrangement structure. In the configuration described above, only one of the signal lines (drain line and source line or top gate line and bottom gate line) connecting the photosensors in each row direction or each column direction is bent so as to meander. Therefore, it is possible to suppress as much as possible the complexity of the design and manufacturing process, the decrease in yield, and the increase in resistance and capacitance components parasitic on the wiring.

  On the other hand, in the configuration in which the photosensors arranged in the row direction and the column direction of the image reading unit (sensor array) are shifted so as to have a staggered arrangement structure, the photosensors have a staggered arrangement structure in the column direction. By forming the arranged photosensors so that the element structures are symmetrical in the left and right columns of the column, at least a signal line (drain line and source line) that connects the photosensors in each column direction. ) Can be connected by a signal line having a linear wiring pattern, which complicates the wiring pattern (such as meandering) and wiring length, complicates the design and manufacturing process, decreases the yield, and parasitics on the wiring. Increase in resistance component and capacitance component can be suppressed as much as possible.

  Furthermore, the image reading apparatus according to the present invention has a configuration in which an image reading unit (sensor array) manufactured separately is planarly stacked (stacked) on the visual field side of the image display unit (pixel array). Since it can be applied, the manufacturing technology and design assets in the existing image display unit (liquid crystal display device) and image reading unit (fingerprint reading sensor) can be used as they are, and the product yield and manufacturing cost increase For example, by applying a double gate type photo sensor as a photo sensor, the image reading unit can be formed relatively thin, so that the increase in the size and thickness of the apparatus is suppressed as much as possible. can do.

  In addition, in the image reading apparatus according to the present invention, as a configuration of the image display unit, a well-known transmissive liquid crystal display panel having a backlight can be applied well, and a self-luminous type such as an organic EL element can be used. A display panel in which display pixels are two-dimensionally arranged can also be applied. According to the former, the existing liquid crystal display panel can be applied as it is, and according to the latter, since the display panel can be significantly thinned, the image reading device and the image reading device are mounted. The device can be further reduced in size and thickness.

Hereinafter, embodiments of an image reading apparatus according to the present invention will be described in detail.
<Overall configuration>
First, the overall configuration of the image reading apparatus according to the present invention will be briefly described.
FIG. 1 is an overall configuration diagram showing an embodiment of an image reading apparatus according to the present invention. Here, FIG. 1A is a schematic perspective view illustrating the overall configuration of the image reading apparatus according to the present embodiment, and FIG. 1B is a schematic cross-sectional view illustrating the overall configuration of the image reading apparatus.

  As shown in FIGS. 1A and 1B, the image reading apparatus according to the present embodiment is roughly divided into a transmissive image display unit such as a liquid crystal display device (image display means, transmissive liquid crystal display panel). 200, a transmissive image reading unit (image reading unit) 100 disposed on the visual field side of the image display unit 200, and the back side of the image display unit 200 (opposite side of the visual field side; in FIG. 1B) A backlight 300 (light emitting means) disposed on the lower side, and at least an image reading area (detection area; image reading area) of a subject defined by the sensor array 140 of the image reading unit 100 is an image display unit. The sensor array (reading pixels) of the image reading unit 100 is set so as to overlap an image display area (image display area) defined by the 200 pixel array (display pixel array) 250. Photo sensors arranged in ray) 140 (read pixel) has a present invention unique array structure.

  Here, in FIGS. 1A and 1B, for the sake of illustration, the image display unit 200 and the image reading unit 100 and the image display unit 200 and the backlight 300 are separated from each other. However, these configurations may have a laminated structure in close contact with each other, or a laminated structure in which an optical member such as a diffusion film or a polarizing plate is interposed between the components. You may have.

  Further, for example, as shown in FIG. 1, the backlight 300 applied to the present embodiment includes a light guide plate 310 made of an acrylic plate or the like disposed on the back side of the image display unit 200, and the light guide plate 310. A configuration provided with a light source 320 made of a cold cathode ray tube, a light emitting diode (LED) or the like provided on one side end face side of the light plate 310 can be applied, but is not particularly limited, for example, A planar light source in which self-luminous elements such as organic electroluminescent elements (organic EL elements) and light emitting diodes are two-dimensionally arranged may be applied.

  As shown schematically in FIG. 1B, the image display unit 200 applied to the present embodiment is one side of the light guide plate from which light is radiated in the backlight 300 described above (radiation surface side; the visual field side). A transparent insulating substrate (first substrate) 210 such as a glass substrate disposed on the substrate, a transparent counter substrate 220 disposed so as to face one surface side (viewing side) of the insulating substrate 210, and insulation Each of the conductive substrate 210 and the counter substrate 220 includes an electrode layer and a wiring layer provided on the opposing surface side, and a liquid crystal encapsulating layer 240 made of liquid crystal sealed between the electrode layers. A plurality of arranged liquid crystal pixels (display pixels), a pixel transistor (described later in detail) provided for each liquid crystal pixel, and a black matrix (details) made of a light-shielding metal material provided between the liquid crystal pixels. Ku has a configuration with a later-described).

  Here, the plurality of liquid crystal pixels arranged in the image display area constitute a pixel array 250. A display drive driver (a gate driver and a source driver described later) 230 for controlling an image information display operation in the pixel array 250 is provided on the insulating substrate 210 on which the counter substrate 220 is not disposed. .

  In addition, an image reading unit 100 applied to the present embodiment schematically includes a transparent insulating substrate (second glass substrate) such as a glass substrate disposed on the visual field side of the image display unit 200 described above, as shown in FIG. Substrate) 110, a sensor array 140 comprising a plurality of photosensors (reading pixels) at least two-dimensionally arranged in the image reading area, and an image information reading operation on the insulating substrate 110 on the sensor array 140 And a scanning driver 120 and a reading driver 130 for controlling the above.

  In the present embodiment, the light emitted from the backlight 300 passes through the insulating substrate 210 and the counter substrate 220 constituting the pixel array 250 of the image display unit 200, and passes through the image reading unit 100. The desired image information can be displayed in the image display area (image display function), and the light reflected and irradiated on the subject placed in the image reading area of the image reading unit 100 can be displayed. A subject image can be read by detecting by each photo sensor of the sensor array 140 (image reading function).

Each configuration will be specifically described below.
<Image display section>
FIG. 2 is a main part configuration diagram showing an example of the configuration of an image display unit applied to the image reading apparatus according to the present embodiment, and FIG. 3 is a black matrix applied to the image display unit according to the present embodiment. It is a schematic block diagram which shows an example. Here, a case where a display pixel structure and a driver structure corresponding to a known active matrix type driving method are described as an image display unit applied to the present embodiment will be described.

  As shown in FIG. 2, an image display unit (liquid crystal display device) 200 according to this embodiment is roughly divided into a transmissive liquid crystal pixel array (display pixel array) in which a large number of liquid crystal pixels (display pixels) Px are two-dimensionally arranged. ) 250P, a scanning line SL that extends by connecting the liquid crystal pixels Px of each row of the liquid crystal pixel array 250P in the row direction, a data line DL that extends by connecting each liquid crystal pixel Px in the column direction, and each scan A gate driver (scan driver) 231 connected to the line SL and a source driver (data driver) 232 connected to each data line DL are configured. Here, the gate driver 231 and the source driver 232 constitute the display drive driver 230 shown in FIG.

  In FIG. 2, the vertical control signal is a control signal for sequentially generating and outputting a scanning signal for setting the liquid crystal pixel Px group of each row to the selected state in the gate driver 231, and the horizontal control signal is In the source driver 232, a control signal for generating and applying a display signal voltage for performing gradation display based on display data to each liquid crystal pixel Px set in a selected state by the gate driver 231. All of these control signals are generated and supplied by, for example, an LCD controller (timing control means) (not shown).

  As shown schematically in FIG. 2, the liquid crystal pixel array 250P includes a matrix in which liquid crystal pixels Px are connected in the vicinity of intersections of a plurality of scanning lines SL and a plurality of data lines DL arranged orthogonal to each other. It has the structure arranged in the shape. Here, as is well known, each liquid crystal pixel Px includes a pixel transistor TFT having a gate terminal connected to the scanning line SL and a source terminal connected to the data line DL, and one end side ( A pixel electrode), and a common signal voltage Vcom is applied to the other end side (common electrode). And a storage capacitor Cs to which a common voltage Vcs (for example, a common signal voltage Vcom) is applied to the other end side (counter electrode) via the common line CL.

  Further, in the liquid crystal pixel array 250P according to the present embodiment, for example, as shown in FIGS. 3A and 3B, it corresponds to three colors of red (R), green (G), and blue (B). Liquid crystal pixels Px composed of pixel regions Pr, Pg, and Pb each having a filter are arranged in a matrix, and between the pixel regions Pr, Pg, and Pb of each color, the color mixture between adjacent colors and the light in the inter-pixel region For the purpose of preventing transmission and incidence of light, a known black matrix BM made of a light-shielding metal material or the like is formed. Here, the case where the stripe arrangement is applied so as to correspond to the pixel region having a vertically long shape as the arrangement structure of the black matrix is shown, but the arrangement is not limited to this and is regularly arranged. Other known structures may be applied.

  In FIG. 3, as one configuration example of the liquid crystal pixel Px, for example, the pixel pitch (that is, the vertical direction and the horizontal direction of the region defining the liquid crystal pixel) is set to 222 μm in each of the x and y directions, and In the region of the liquid crystal pixel Px (222 μm □), there is shown a case where each color of RGB is in the x direction and each has a vertically long pixel region (222 μm long × 74 μm wide) Pr, Pg, Pb. Is not limited to this shape and size.

  For example, as shown in FIG. 2, the gate driver 231 corresponds to the scanning line SL of each row on the basis of vertical control signals (start signal, reference clock signal, etc.) supplied from an LCD controller or the like not shown schematically. Shift register circuit unit 231s for sequentially outputting the shift signal to be output, and an output buffer for amplifying the shift signal sequentially output from the shift register circuit unit 231s to a predetermined signal level and outputting the amplified signal to each scanning line SL Part 231b.

  For example, as shown in FIG. 2, the source driver 232 is configured to display each data line on the basis of horizontal control signals (start signal, reference clock signal, output enable signal, etc.) output from an LCD controller or the like that is schematically omitted. A shift register circuit unit 232s that sequentially outputs shift signals corresponding to DL, and a timing based on the shift signal sequentially output from the shift register circuit unit 232s, for example, red (R), green (G), blue (B ) A sample-and-hold circuit unit 232h that captures and holds display data (analog RGB) composed of analog signals of each color in units of one row, and a signal voltage corresponding to the display data held by the sample-and-hold circuit unit 232h Output buffer that amplifies to signal level and outputs to each data line DL as display signal voltage Is configured to include a section 232b, the.

  The LCD controller (not shown) generates the horizontal control signal and the vertical control signal based on various timing signals such as a horizontal synchronization signal, a vertical synchronization signal, and a system clock supplied to the image display unit 200. This is supplied to the gate driver 231 and the source driver 232.

  In the drive control method in the image display unit 200 having such a configuration, first, display data for one row of the liquid crystal pixel array 250P is sequentially captured and held by the source driver 232 based on a horizontal control signal. On the other hand, based on the vertical control signal, the gate driver 231 sequentially applies a scanning signal to each scanning line SL arranged in the liquid crystal pixel array 250P to set the liquid crystal pixels Px group in each row to a selected state. Then, in synchronization with the selection timing of the liquid crystal pixel Px group in the row corresponding to the held display data, the source driver 232 applies the display signal voltage corresponding to the held display data to each of the data lines DL via each data line DL. By simultaneously applying to the display pixels Px, the liquid crystal molecules filled in the liquid crystal pixels Px set in the selected state are controlled to an alignment state according to the display data.

  By repeating such a series of operations for each row for one screen, gradation display based on the display data is performed. At this time, the backlight 300 is turned on to emit radiated light to the liquid crystal. By transmitting to the visual field side of the pixel array 250P, desired image information is displayed and visually recognized by the user.

<Image reading unit>
FIG. 4 is a main part configuration diagram showing a configuration example of an image reading unit applied to the image reading apparatus according to the present embodiment.
As shown in FIG. 4, the image reading unit (fingerprint reading sensor) 100 according to the present embodiment is roughly divided into a large number of photosensors (reading pixels; a double gate type photosensor described later) PS, for example, n rows × A transmission type photosensor array (sensor array, read pixel array) 140P arranged in a matrix of m columns (n and m are arbitrary natural numbers) and a top gate terminal TG of each photosensor PS are connected in the row direction. The extending top gate line Lt, the bottom gate line Lb extending by connecting the bottom gate terminal BG of each photosensor PS in the row direction, and the drain extending by connecting the drain terminal D of each photosensor PS in the column direction A source line (common line) that commonly connects a line (data line) Ld and a source terminal S to a predetermined low potential voltage (for example, ground potential) Vss. Ls, a top gate driver 120T connected to each top gate line Lt, a bottom gate driver 120B connected to each bottom gate line Lb, and a drain driver 130D connected to each drain line Ld. Configured. Here, the top gate driver 120T and the bottom gate driver 120B correspond to the scan driver 120 shown in FIG. 1, and the drain driver 130D corresponds to the readout driver 130.

  Note that the top gate control signal shown in FIG. 4 is selectively output as signals φT1, φT2,... ΦTi,. The bottom gate control signal is a control signal for generating φTn, and the bottom gate driver 120B selectively outputs signals φB1, φB2,... φBi,. The drain control signal is a control signal for generating φBn. The drain control signal applies a precharge voltage Vpg, which will be described later, to each photosensor PS in the drain driver 130D, and a data voltage corresponding to the carrier accumulated in each photosensor PS. This is a control signal for controlling the reading of Vrd. All of these control signals are generated and supplied by, for example, a system controller (timing control means) (not shown).

  In the photosensor array 140P shown in FIG. 4, a plurality of photosensors PS are linearly arranged in the row and column directions in order to simplify the description of the configuration and drive control operation of the photosensor PS described later. However, as described later, according to the present invention, the arrangement structure of the photosensors PS in the photosensor array 140P is not a normal matrix arrangement but has a unique structure. It is characterized by that. The arrangement structure of the photosensors in the photosensor array will be described later in detail.

(Photo sensor PS)
FIG. 5 is a schematic cross-sectional view showing the element structure of a photosensor applicable to the image reading unit according to the present embodiment. Here, FIG. 5A is a schematic plan view showing a configuration example of the photosensor according to the present embodiment, and FIG. 5B is a schematic cross-sectional view of the photosensor in the BB cross section. In FIG. 5A, for convenience of illustration, the insulating film of each layer is omitted, only the main structure of the photosensor is shown, and further, it is seen through the transparent top gate electrode and the top gate line. Each structure of the lower layer (drain, source electrode and semiconductor layer) is indicated by a solid line. In order to clarify the structure of the photosensor, the drain, the source electrode, and the semiconductor layer were hatched.

A photosensor PS applicable to the above-described image reading unit 100 (photosensor array 140P) is schematically shown in FIGS. 5 (a) and 5 (b) in which electrons are emitted by incidence of excitation light (here, visible light). A semiconductor layer (channel region) 11 made of amorphous silicon or the like in which hole pairs are generated, and impurity layers (ohmic contact layers) 17 and 18 made of n ⁺ silicon on both ends of the semiconductor layer 11, respectively. A drain electrode 12 (drain terminal D) and a source electrode 13 (source terminal S) which are made of a conductive material selected from chrome, chromium alloy, aluminum, aluminum alloy and the like and are opaque to visible light; and the semiconductor layer 11 Above (above the drawing) via a block insulating film (stopper film) 14 and an upper gate insulating film 15, a tin oxide film or an ITO film (indium-stannic acid) A top gate electrode TGx (first gate electrode; top gate terminal TG) that is transparent to visible light, and a lower gate below the semiconductor layer 11 (downward in the drawing). A bottom gate electrode BGx (second light-shielding) which is formed through an insulating film 16 and is made of a conductive material selected from chromium, chromium alloy, aluminum, aluminum alloy or the like and is opaque to light (has a light shielding property). Gate electrode; bottom gate terminal BG).

  That is, the photosensor PS applied to the sensor array 110 according to the present embodiment has a so-called double gate type thin film transistor structure (double gate type photosensor), and applies semiconductor manufacturing technology as shown in FIG. Thus, a thin film is formed on the insulating substrate 110. A protective insulating film (passivation film) 19 is formed on the entire surface of the insulating substrate 110 including the photosensor PS, and a subject is placed with the upper surface of the protective insulating film 19 as a detection surface DTC. Thus, it is configured to suppress direct electrical and physicochemical damage to the photosensor PS.

  In the photosensor PS shown in FIG. 5, the top gate insulating film 15, the block insulating film 14, the insulating film constituting the bottom gate insulating film 16, and the protective insulating film 19 provided on the top gate electrode TGx are as follows. , Both of which are made of a material having high transmittance for visible light that excites the semiconductor layer 11, for example, silicon nitride, silicon oxide, or the like, thereby providing a light source (not shown) provided on the insulating substrate 110 side. Omitted; the radiated light from the backlight 300) provided on the back side of the image display unit 200 described above is transmitted upward in the drawing, and the subject placed on the detection surface DTC provided on the upper surface of the protective insulating film 19 It has a structure that detects only light that is reflected by the (finger) and incident on the photosensor PS (specifically, the semiconductor layer 11) from above.

(Top gate driver 120T / Bottom gate driver 120B)
FIG. 6 is a schematic block diagram illustrating a configuration example of a top gate driver or a bottom gate driver applicable to the image reading unit according to the present embodiment. Here, since the top gate driver 120T and the bottom gate driver 120B have substantially the same configuration, in the following description, the configuration will be described mainly using the top gate driver as an example.

  For example, as shown in FIG. 6, the top gate driver 120T (or the bottom gate driver 120B) is supplied as a top gate control signal (or bottom gate control signal) from a system controller or the like that is schematically omitted. Based on the signal STtb, the reference clock signal CKtb, the output enable signal OEtb, etc., the start signal STtb is sequentially shifted to the next stage at the timing based on the reference clock signal CKtb, and at the timing based on the output enable signal OEtb etc. The shift register circuit unit 121 that outputs the shift signals SG1, SG2,... SGn corresponding to the gate line Lt (or the bottom gate line Lb), and the shift signals SG1, SG2 sequentially output from the shift register circuit unit 121 , ... SGn No. reset pulse φTi amplifies the level (or read pulse FaiBi) as, each top gate line Lt (or bottom gate line Lb) is configured to have an output buffer 122 for output to the.

(Drain driver 130D)
FIG. 7 is a schematic block diagram illustrating a configuration example of a drain driver applicable to the image reading unit according to the present embodiment.
For example, as shown in FIG. 7, the drain driver 130D is started based on a start signal STd, a reference clock signal CKd, an output enable signal OEd, and the like that are supplied as a drain control signal from a system controller or the like not shown. While sequentially shifting the signal STd to the next stage at the timing based on the reference clock signal CKd, the shift signals SD1, SD corresponding to the drain lines Ld at the timing based on the output enable signal OEd or the like.
S2,... SDm output as a shift register circuit portion 131 and a timing (precharge period described later) based on a precharge signal φpg supplied as a drain control signal, a predetermined precharge pulse ( The precharge circuit unit 135 that simultaneously applies the precharge voltage Vpg) and a timing (reading period described later) based on a sampling signal φsr supplied as a drain control signal to each photosensor PS via each drain line Ld. A sampling circuit unit 134 that reads and holds the drain voltage VD (data voltage Vrd) corresponding to the accumulated carrier in parallel, and the drain line voltage VD read (held) by the sampling circuit unit 134 is predetermined. Source follower circuit that amplifies to the signal level of 33 and the timing based on the shift signals SD1, SD2,... SDm sequentially output from the shift register circuit unit 131, the data voltage output from the source follower circuit unit 1D3 is extracted in time series and converted into a serial signal. And a parallel-serial conversion circuit unit 132 that converts and outputs the data as a read data signal Vdata.

(Drive control method)
Next, a driving control method for the above-described image reading unit (photosensor array) will be briefly described with reference to the drawings.
FIG. 8 is a timing chart showing an example of a drive control method in the image reading unit (photo sensor array) according to the present embodiment. FIG. 9 is a conceptual diagram showing a fingerprint image reading operation when the image reading unit according to this embodiment is applied to a fingerprint reading sensor. Here, in FIG. 9, for convenience of illustration, a part of hatching that represents a cross-sectional portion of the photosensor array 140 </ b> P is omitted.

For example, as shown in FIG. 8, the drive control method for the photosensor array 140P described above includes a reset period Trst, a charge accumulation period Ta, a precharge period Tprch, and a readout period Tread in a predetermined processing operation period (processing cycle). This is realized by setting.
As shown in FIG. 8, first, in the reset period Trst, the top of the photo sensor PS in the i-th row (i is an arbitrary natural number of 1 ≦ i ≦ n) by the top gate driver 120T via the top gate line Lt. A reset pulse (for example, a high level of top gate voltage (= reset pulse voltage) Vtg = + 15 V) φTi is applied to the gate terminal TG to release carriers (here, holes) accumulated in the semiconductor layer 11. Perform a reset operation (initialization operation).

  Next, in the charge accumulation period Ta, the top gate driver 120T applies a low level (for example, top gate voltage Vtg = −15V) bias voltage φTi to the top gate terminal TG, thereby ending the reset operation. The accumulation operation (carrier accumulation operation) is started.

  Here, in the charge accumulation period Ta, as shown in FIG. 9, below the transparent insulating substrate 110 on which the photosensor PS shown in FIG. 5 is formed (in the image reading apparatus according to the present embodiment, an image is displayed). The light Lx emitted from the backlight 300 arranged on the back side of the display unit 200 passes through the image reading unit 100 (the image display unit 200) and adheres to the detection surface DTC on the upper surface of the photosensor array 140P. Then, the finger (subject) FG placed thereon is irradiated, and the reflected light Ly of the light Lx passes through the top gate electrode TGx made of a transparent electrode layer and enters the semiconductor layer 11. Thereby, electron-hole pairs are generated in the incident effective region (carrier generation region) of the semiconductor layer 11 according to the amount of light incident on the semiconductor layer 11 during the charge accumulation period Ta, and the semiconductor layer 11 and the block insulating film 14 Holes are accumulated in the vicinity of the interface (around the channel region).

  In the precharge period Tprch, the drain driver 130D precharges the drain terminal D via the drain line Ld based on the precharge signal φpg supplied as a drain control signal in parallel with the charge accumulation period Ta. A pulse (for example, precharge voltage Vpg = + 5 V) is applied, and a precharge operation for holding the charge in the drain electrode 12 is executed.

  Next, in the read period Tread, after the precharge period Tprch has elapsed, a read pulse (for example, a bottom gate voltage (= read pulse voltage)) is applied to the bottom gate terminal BG via the bottom gate line Lb by the bottom gate driver 120B. By applying (Vbg = + 10V high level) φBi, a drain voltage VD (data voltage Vrd; voltage signal) corresponding to the carriers (holes) accumulated in the channel region in the charge accumulation period Ta is applied to the drain line Ld. A read operation is performed by the drain driver 130D.

  Here, the change tendency of the drain voltage VD (data voltage Vrd) during the application period (readout period) of the read pulse φBi is such that the voltage is steep when there are many carriers accumulated in the charge accumulation period Ta (bright state). On the other hand, when the number of accumulated carriers is small (dark state), it tends to decrease gradually. For example, the data voltage Vrd after a predetermined time has elapsed after the start of the read period Tread is detected. Accordingly, it is possible to detect the amount of light incident on the photosensor PS, that is, lightness data (lightness / darkness information) corresponding to the light / dark pattern of the subject.

  Then, a series of brightness data detection operations for such a specific row (i-th row) is regarded as one cycle, and it is equivalent to each row (i = 1, 2,... N) of the photosensor array 140P described above. By repeating the above operation process, the photo sensor array 140P to which the photo sensor PS having a double gate type thin film transistor structure is applied operates as a monochrome type image reading unit that reads a two-dimensional image (fingerprint image) of a subject as lightness data. Can be made.

<First Embodiment>
Next, a first embodiment of a sensor array applied to the image reading unit having the above-described configuration will be described with reference to the drawings.
FIG. 10 is a schematic diagram showing a first embodiment of the sensor array of the image reading unit applied to the image reading apparatus according to the present invention, and FIG. 11 is for comparison with the sensor array according to the present embodiment. FIG. 2 is a schematic view showing a sensor array having a normal matrix arrangement structure. FIG. 12 is a schematic view showing another example of the first embodiment of the sensor array of the image reading unit applied to the image reading apparatus according to the present invention.

  In the sensor array 140A according to the present embodiment, a plurality of photosensors (double gate photosensors) PS having the above-described configuration are, for example, the same in the row and column directions, as shown in FIG. Photosensor array having a normal matrix arrangement structure (see FIG. 4) arranged in a straight line with an element pitch PTp (interval between photosensors PS; the same as row pitch PTc and column pitch PTr). With respect to 140P, as shown in FIG. 10, every other column, the photosensors PS of the column are arranged in the column direction (y direction corresponding to the vertical direction in the figure), and the element pitch PTp (or the row pitch). It has an array structure shifted (shifted) by half the dimension of PTc) (PTp / 2 or PTc / 2).

Specifically, in the normal matrix arrangement structure shown in FIG. 11, the element pitch PTp between the photosensors in the row and column directions (x direction and y direction) (or the row pitch PTc and the column pitch PTr). Is 60 μm, for example, in the sensor array 140 according to this embodiment, the inter-element pitch PTp and the inter-column pitch PTr between the photosensors in the column direction (y direction) in each column are the same as in FIG. In addition, for example, only even-numbered photosensors PS are arranged in the column direction (y direction) with respect to the arrangement position of the photosensors PSp in the normal matrix arrangement structure shown in FIG. The elements are arranged at a shifted position by a half of the element pitch PTp = 60 μm (half pitch = 30 μm).
That is, the photosensors PS of each row are shifted up and down alternately by a half pitch (= 30 μm; corresponding to a half pitch of the pitch between rows) in the column direction (y direction) between the odd and even columns. Has a staggered arrangement structure.

  Further, in the sensor array 140B according to another configuration example of the present embodiment, a plurality of photosensors (double gate type photosensors) PS having the configuration as described above are provided every other row as shown in FIG. The photosensor PS of the row in the row direction (x direction corresponding to the left-right direction in the figure) is half the dimension (PTp / 2 or PTr / 2) of the element pitch PTp (or column pitch PTr). Only have a shifted array structure.

  Specifically, the inter-element pitch PTp and the inter-row pitch PTc between the photosensors in the row direction (x direction) in each row are set to 60 μm as in FIG. However, only the half of the inter-element pitch PTp = 60 μm (half pitch = 30 μm) is shifted in the row direction (x direction) with respect to the arrangement position of the photosensors PSp in the normal matrix arrangement structure shown in FIG. The photosensors PS of each column are arranged at half-pitch in the row direction (x direction) between the odd-numbered rows and the even-numbered rows (= 30 μm; corresponding to the half-pitch of the pitch between columns). It has a staggered arrangement structure that is shifted and arranged alternately on the left and right.

Next, the effect of the sensor array (image reading unit) having the photosensor array structure as described above will be examined in detail.
In the configuration in which the transmissive image reading unit is arranged on the visual field side of the image display unit as shown in FIG. 1, first, as shown in FIG. Consider a configuration in which a matrix BM is provided in a grid pattern and photosensors PS having a light-shielding region are arranged in a normal matrix as shown in FIG. 11 in the sensor array 140 of the image reading unit 100.

  In such a configuration, both the pixel array 250 of the image display unit 200 and the sensor array 140 of the image reading unit 100 have a configuration formed on an insulating substrate such as a glass substrate. An insulating substrate is interposed between the pixel array 250 on which image information is displayed and the sensor array 140 on which a subject image is read, and a gap is necessarily generated between the two. Become.

  Therefore, when the image reading unit 100 (sensor array 140) is stacked on the image display unit 200 (pixel array 250), the regular lattice structure in the black matrix BM of the pixel array 250 and the photosensor PS in the sensor array 140 are arranged. Periodic striped patterns, so-called moire fringes, may occur due to light interference with the regular array structure. This improves the quality (display quality) of the image information displayed on the image display unit. ) Was found to be significantly reduced.

  Here, the degree of occurrence of the moire fringes varies greatly depending on the alignment accuracy when the image reading unit 100 (sensor array 140) is stacked on the image display unit 200 (pixel array 250), and in particular, the rotation direction. Therefore, in order to suppress the occurrence of moire fringes, it is necessary to increase the alignment accuracy between the two. For this reason, a high alignment system is required in the manufacturing process, which requires a high-precision manufacturing apparatus and a complicated process, resulting in a problem that the manufacturing cost increases and the yield decreases. Yes.

  Therefore, the inventor of the present application is concerned with the generation of moire fringes as described above in the configuration in which the image reading unit 100 (sensor array 140) is stacked on the image display unit 200 (pixel array 250) as shown in FIG. As a result of various verifications, the degree of occurrence of moire fringes varies greatly depending on the arrangement direction of the photosensors PS of the sensor array 140 with respect to the extending direction of the black matrix BM provided in the pixel array 250 and the number of the arrangements. I found out. According to this, the intensity of moire fringes increases as the number (arrangement number) of the photosensors PS linearly arranged in the extending direction of the black matrix BM (that is, the x direction or the y direction) increases. It has been found that the strength decreases as the number of the particles decreases, and there is a certain dependence.

  On the other hand, in the image reading unit 100, image reading accuracy is set in advance according to the subject. For example, when reading the above-described fingerprint image, the number of pixels that can identify at least several feature points with high accuracy is required, and thus the number of photosensors PS arranged in the sensor array 140 is greatly reduced. I can't do it.

  Based on such verification results and functional requirements, in the present invention, among the photosensors PSp regularly arranged in a matrix as shown in FIG. The photosensors PS arranged in a straight line in the x direction are arranged by shifting the photosensors PS in the corresponding column in the y direction by a half pitch of the inter-element pitch PTp (or the inter-row pitch PTc). Is set to substantially reduce the number of.

  Alternatively, among the photosensors PSp regularly arranged in a matrix as shown in FIG. 11, as shown in FIG. 12, every other row, the photosensors PS in the row are inter-element pitches in the x direction. By shifting the arrangement by a half pitch of PTp (or inter-column pitch PTr), the number of photosensors PS arranged linearly in the y direction is set to be substantially reduced.

  Thus, the number of photosensors PS arranged in the x direction (row direction) is halved (1/2) in the array structure shown in FIG. 10 compared to the normal matrix array structure shown in FIG. In the arrangement structure shown in FIG. 12, the number of photosensors PS arranged on the straight line in the y direction (column direction) can be halved (1/2).

  Therefore, since the number of photosensors arranged in at least one specific direction among the extending directions of the black matrix of the regularly arranged pixel array can be reduced, the occurrence of moire fringes can be suppressed. It is possible to reduce the display quality of the image information displayed on the image display unit (pixel array).

<Second Embodiment>
Next, a second embodiment of the sensor array applied to the image reading unit according to the present invention will be described with reference to the drawings.
FIG. 13 is a schematic diagram showing a second embodiment of the sensor array of the image reading unit applied to the image reading apparatus according to the present invention, and FIG. 14 is an arrangement of photosensors in the sensor array according to the present embodiment. It is a conceptual diagram for demonstrating a structure.

  In the sensor array 140C according to the present embodiment, as shown in FIG. 11, a plurality of photosensors PSp have the same element pitch PTp (row pitch PTc and column pitch PTr) in the row and column directions, respectively. In contrast to the photosensor array 140P having a normal matrix arrangement structure (see FIG. 4) arranged in a straight line, as shown in FIG. 13, every other column in the row direction, as shown in FIG. Is shifted in the column direction (y direction) by half the dimension (PTp / 2 or PTc / 2) of the inter-element pitch PTp (or inter-row pitch PTc), and one row in the column direction. In other words, the photosensor PS of the row in the row direction (x direction) is half the dimension (PTp / 2 or PTr) of the element pitch PTp (or column pitch PTr). 2) it has the sequence structure with shifted.

  Specifically, as shown in FIG. 14A, in the normal matrix arrangement structure shown in FIG. 11, for example, as shown in FIG. In the (y direction), it is arranged at a position shifted by half (half pitch = 30 μm) of the inter-element pitch PTs (for example, 60 μm), has a staggered arrangement structure in the row direction, and FIG. ), For example, only odd-numbered photosensors PSp each having a staggered arrangement structure are arranged at positions shifted in the row direction (x direction) by half (30 μm) of the inter-element pitch PTs. Thus, it also has a staggered arrangement in the column direction.

  Therefore, even in a sensor array having such an arrangement structure, the photosensors regularly arranged in a matrix form are arranged every other column, and the photosensors in the column are arranged in an element pitch (or pitch between rows) in the y direction. And by shifting the photosensors in the corresponding row in the x direction by a half pitch of the inter-element pitch (or inter-column pitch) every other row, In two directions, the x direction and the y direction, the number of photosensors arranged in a straight line can be reduced (halved), so that the generation of moire fringes is greatly suppressed and the moire fringes are not visually recognized. As a result, deterioration of display quality of image information displayed on the image display unit (pixel array) can be remarkably suppressed.

<Third Embodiment>
Next, a third embodiment of the sensor array applied to the image reading unit according to the present invention will be described with reference to the drawings.
First, the signal line connection structure applied to the sensor arrays according to the first and second embodiments described above will be discussed.

  FIG. 15 is a schematic diagram illustrating an example of a connection structure of signal lines applied to the sensor array of the image reading unit according to the first embodiment, and FIG. 16 is a diagram of the image reading unit according to the second embodiment. FIG. 17 is a schematic diagram illustrating an example of a signal line connection structure applied to the sensor array, and FIG. 17 is a detailed diagram for explaining the signal line connection structure illustrated in FIG. 16. Here, FIG. 17A is a schematic diagram in which only the connection structure between the photosensor, the drain line, and the source line in the sensor array according to the second embodiment is extracted, and FIG. It is the schematic which extracted only the connection structure of the photosensor in the sensor array which concerns on 2 embodiment, and a top gate line and a bottom gate line.

  As described above, in the first embodiment, as shown in FIGS. 10 and 12, among the photosensors PSp regularly arranged in a matrix, every other column or every other row. Alternatively, the photosensors PS in the rows have a staggered arrangement structure in either the direction of each row or each column by shifting the photosensors PSp in the y direction or the x direction by a half pitch of the inter-element pitch. ing.

  Therefore, when a double gate type photosensor having a wiring structure as shown in FIG. 5A is applied as the photosensor PS, in the arrangement structure of the photosensor PS as shown in FIG. As shown in a), since they are arranged in a straight line in the column direction, the drain terminal D and the source terminal S of the photosensor PS are connected to each other by a straight drain line Ld and a source line Ls, respectively. Since the wiring structure (that is, the same wiring structure as in the normal matrix array structure as shown in FIGS. 4 and 11) is arranged in a staggered manner in the row direction, the top of the photosensor PS The gate terminal TG and the bottom gate terminal BG are respectively connected by a top gate line Lt and a bottom gate line Lb that are bent so as to meander. It will have a wiring structure.

  In addition, in the photosensor array structure as shown in FIG. 12, as shown in FIG. 15B, the drain terminals D and the source terminals S of the photosensor PS are arranged in a staggered manner in the column direction. , Each having a wiring structure interconnected by meandering drain line Ld and source line Ls, while being arranged linearly in the column direction, the top gate terminal of photosensor PS The TG and the bottom gate terminal BG are respectively the same in the wiring structure connected by the linear top gate line Lt and the bottom gate line Lb (that is, in the normal matrix arrangement structure as shown in FIGS. 4 and 11). Wiring structure).

  Therefore, in the first embodiment, in order to suppress moire fringes, the arrangement of the photosensors PS in either the x direction or the y direction of the sensor arrays 140A and 140B is shifted by a half pitch in a staggered arrangement structure. In such a case, the drain line Ld and the source line Ls, or only one of the top gate line Lt and the bottom gate line Lb may be bent so as to meander, and the design and manufacturing process may be complicated. A decrease in yield and an increase in resistance component and capacitance component parasitic on the wiring can be suppressed as much as possible.

  On the other hand, in the second embodiment, as shown in FIG. 13, among the photosensors PSp regularly arranged in a matrix, every other column and every other row, By arranging the photosensors PSp in the rows by shifting the photosensors PSp in the y direction and the x direction by a half pitch of the inter-element pitch, the photosensors PS have a staggered arrangement structure in the two directions of each row and each column.

  Therefore, when a double gate type photosensor having a wiring structure as shown in FIG. 5A is applied as the photosensor, the drain terminal D and the source terminal S of the photosensor PS arranged in a staggered manner in the column direction are: As shown in FIG. 16 and FIG. 17A, each has a wiring structure interconnected by a drain line Ld and a source line Ls that are bent so as to meander, and is also a photo that is staggered in the row direction. The top gate terminal TG and the bottom gate terminal BG of the sensor PS are also connected by a top gate line Lt and a bottom gate line Lb that are bent so as to meander as shown in FIGS. 16 and 17B. Will have.

  As described above, the drain line Ld and the source line Ls, and the top gate line Lt and the bottom gate line Lb (that is, all the signal lines provided in the sensor array 140C) are bent so as to meander. In the wiring structure, the wiring pattern becomes complicated, the design and manufacturing process is complicated and increased, the yield is reduced, and the wiring length is increased and the resistance and capacitance components parasitic on the wiring. Therefore, there is a possibility that the drive control operation in the image reading unit is greatly affected (operation delay, malfunction, etc.).

  FIG. 18 is a schematic diagram showing an example of a connection structure of signal lines applied to the sensor array of the third embodiment of the sensor array of the image reading unit applied to the image reading apparatus according to the present invention. FIG. 19 is a detailed view for explaining the signal line connection structure shown in FIG. Here, FIG. 19A is a schematic diagram in which only the connection structure between the photosensor, the drain line, and the source line in the sensor array according to the present embodiment is extracted, and FIG. 19B is the present embodiment. It is the schematic which extracted only the connection structure of the photosensor in the sensor array which concerns on, and a top gate line and a bottom gate line.

  Therefore, in the sensor array 140C according to the present embodiment, in view of the examination contents as described above, as shown in FIGS. 18A and 19A, the photosensors PS arranged in the sensor array 140C are arranged. Among them, the drain terminals D of the photosensors PS arranged in adjacent columns are connected by a common linear drain line Ld, and similarly, the source terminals S are mutually connected by a common linear source line Ls. It has a connected configuration.

  That is, as shown in FIG. 18B, when attention is paid to the photosensors PS in each column (for example, the first column) arranged with a staggered arrangement structure, the left column of the column (first column) The element structures of the photosensor PS of the right column and the photosensor PS of the right column are formed so as to be bilaterally symmetric (inverted horizontally). Are connected to one common linear drain line Ld.

  When attention is paid to adjacent columns (for example, the photosensor PS in the right column of the first column and the photosensor PS in the left column of the second column), the photosensors in the right column of one column (first column) The element structures of the photosensors PS in the left column of the PS and the other column (second column) are formed so as to be symmetrical with each other. For example, the right column of the one column and the other column The source terminals S (source electrodes 13) of the photosensors PS in the left column are connected to one common linear source line Ls.

  With such a signal line connection structure in the column direction, at least the drain line and the source line can be formed to have a linear wiring pattern, so that the wiring pattern is complicated (meandering etc.) as described above. Further, it is possible to eliminate the complexity of the design and manufacturing process, the decrease in yield, the influence on the image reading operation due to the parasitic resistance and the parasitic capacitance due to the wiring length.

  Further, in the sensor array 140C according to the present embodiment, as shown in FIGS. 18A and 19B, for example, in each row among the photosensors PS arranged in the sensor array 140C, a staggered arrangement structure is used. The bottom gate terminals BG of the photosensors PS that are arranged to be connected to each other may be connected by a bottom gate line Lb having a wiring pattern having the shortest distance.

  That is, as shown in FIG. 19B, when attention is paid to the photosensors PS in each row (for example, the first row) arranged with the staggered arrangement structure, the photo in the upper row of the row (first row). The bottom gate terminals BG (bottom gate electrodes BGx) of the sensor PS and the lower photosensor PS are connected to a bottom gate line Lb having a path and a wiring pattern that have the shortest distance.

  With such a signal line connection structure in the column direction, at least the wiring length of the bottom gate line can be made shorter than the meandering distance caused by the staggered arrangement structure of the photosensors. It is possible to suppress the influence on the image reading operation due to the resistance component and the capacitance component.

  In the present embodiment, as shown in the second embodiment described above, the photosensors PS in each row and each column have a staggered arrangement structure in the two directions of the sensor array 140C in the row direction and the column direction. The signal line connection structure has been verified for the configuration arranged in the same manner, but the same technical idea is applied in either the row direction or the column direction as shown in the first embodiment. The photo sensor may be applied to a configuration in which the photo sensors are arranged in a staggered arrangement.

  That is, when the photosensor PS has a staggered arrangement only in the row direction (in the case of a configuration corresponding to FIG. 10), the photosensor PS in the upper row of each row is similar to the case shown in FIG. A configuration in which the bottom gate terminals BG (bottom gate electrodes BGx) of the lower photosensor PS are connected to each other by a bottom gate line Lb having a path and a wiring pattern having the shortest distance can be applied. The wiring length of the gate line can be made shorter than the meandering distance due to the staggered arrangement structure of the photosensors.

  Further, when the photosensor PS has a staggered arrangement only in the column direction (in the case of a configuration corresponding to FIG. 12), each column is similar to the case shown in FIGS. 18B and 19A. The left column photosensor PS and the right column photosensor PS are formed so as to be symmetrical (inverted horizontally). For example, the drain terminals D (drains) of the left column and right column photosensors PS are formed. The electrodes 12) are connected to each other by one common linear drain line Ld, and the source terminals S (source electrodes 13) of the photosensors PS in the right column and the left column in adjacent columns are connected to each other. The common linear source line Ls can be applied, whereby at least the drain line and the source line can be formed to have a linear wiring pattern.

(Relationship between image reading area and image display area)
Next, the relationship between the image reading area (detection area) in the image reading unit according to the present embodiment and the image display area in the image display unit will be described with reference to the drawings.
FIG. 20 is a conceptual diagram showing a relationship between an image reading area (image reading area) in the image reading unit according to the present embodiment and an image display area (image display area) in the image display unit. In FIG. 20, hatching is performed for the sake of convenience in order to clarify the image reading area.

  As shown in FIG. 1, the image reading apparatus according to the present embodiment includes an image display unit 200 having a transmissive pixel array 250 on the radiation surface side of a single backlight 300, and a transmissive sensor array. The image reading unit 100 having 140 is sequentially stacked. Here, the image display unit 200 has an image display area defined by the pixel array 250, and the image reading unit 100 further transmits the light emitted through the image display area to the visual field side. And an image reading area (detection area) ARf defined by the sensor array 140.

  Regarding the relationship between the image reading area in the image reading unit 100 and the image display area in the image display unit 200, for example, as shown in FIG. 20A, the image reading area ARf and the image display area ARi are substantially the same. May be set so as to overlap in a plane, and as shown in FIG. 20B, the image reading area ARf is part of the area included in the image display area ARi. May be set so as to overlap in a planar manner (that is, the image reading area ARf is smaller than the image display area ARi).

  In the configuration shown in FIG. 20B, the image reading area ARf is set only in the substantially central region of the image display area ARi (display pixel array 250), and the image reading area overlaps the image display area ARi in a plane. The photosensor PS is not formed in the area other than ARf (that is, the peripheral area of the image reading area ARf). In the image reading area ARf and other areas, the image reading unit 100 (sensor array 140) is interposed. Thus, the transmittance of light emitted toward the field of view is different. For this reason, there is a possibility that the surface luminance that is visually recognized when displaying the image information varies and the display image quality is deteriorated.

  Therefore, in the configuration in which the image reading area ARf is set to be smaller than the image display area ARi, for example, all the regions (the periphery of the image reading area ARf) corresponding to the image display area ARi other than the image reading area ARf. As in the image reading area ARf, dummy photosensors (dummy pixels) and signal lines (for example, dummy wirings corresponding to the above-described top gate line Lt, bottom gate line Lb, drain line Ld, and source line Ls) ), The surface luminance can be made uniform over the entire area of the image display area ARi, and deterioration of display image quality can be suppressed.

  Therefore, according to such an image reading apparatus, a transmission made of a double gate type photosensor or the like is provided on the front surface of an image display unit having a pixel array including known display pixels such as liquid crystal pixels, organic EL elements, and light emitting diodes. An image reading unit having a sensor array of a type is arranged, and an image display unit (image display area) is set so that the image display area of the image display unit and the image reading area of the image reading unit overlap in a plane The image information displayed on the screen can be viewed with a good luminance gradation from the visual field side through a transparent image reading unit (image reading area), and the subject image (fingerprint image, etc.) can be read with appropriate accuracy. And it can be read with a sufficient reading area.

  In addition, it is possible to apply a configuration in which image reading units (sensor arrays) manufactured separately are stacked in a planar manner on the visual field side of the image display unit (pixel array). Manufacturing technology and design assets in the display unit (liquid crystal display device) and image reading unit (fingerprint reading sensor) can be used as they are, and the decrease in product yield and the increase in manufacturing cost can be suppressed. Since a relatively thin fingerprint reading sensor (image reading unit) can be arranged on the front surface of a display panel (image display unit) already provided in a housing of a type electronic device, There is no increase in size or thickness.

  In particular, when a double gate type photosensor having a thin film transistor structure formed on a transparent insulating substrate using a semiconductor manufacturing technique is applied as an image reading unit (sensor array) disposed on the visual field side of the image display unit Since the configuration of the image reading unit including the sensor array can be significantly reduced compared to the optical image reading unit (fingerprint reading sensor) as shown in the prior art, the image reading apparatus The mounted electronic device can be reduced in size and thickness.

<Another configuration example of the image reading apparatus>
Next, another embodiment of the image reading apparatus according to the present invention will be described.
FIG. 21 is an overall configuration diagram showing another embodiment of the image reading apparatus according to the present invention. Here, FIG. 21A is a schematic perspective view illustrating the overall configuration of the image reading apparatus according to the present embodiment, and FIG. 21B is a schematic cross-sectional view illustrating the overall configuration of the image reading apparatus. In addition, about the structure equivalent to the whole structure shown to embodiment mentioned above, the same or equivalent code | symbol is attached | subjected and the description is simplified or abbreviate | omitted.

  In the above-described embodiment (see FIG. 1), the image display unit 200 applied to the image reading apparatus according to the present invention includes a transmissive liquid crystal pixel array (liquid crystal display panel) 250, and Although the configuration in which the surface light source type backlight 300 is arranged on the back side is shown, the present invention is not limited to this. For example, as shown in FIGS. A self-luminous image display unit 400 including a pixel array 430 in which display pixels including light-emitting elements such as organic EL elements and light-emitting diodes are two-dimensionally arranged on the main substrate 410 may be applied.

  Here, for example, when a display pixel including an organic EL element as a light emitting element is applied, each pixel region is formed on one surface side of the main substrate 410 as shown in FIGS. A display drive in which an image display area is defined by a pixel array 430 in which a plurality of display pixels in which an organic EL layer and an electrode layer (not shown) are formed corresponding to the two-dimensional array is arranged and arranged on the main substrate 410. Based on the control signal from the driver 420, the display driving operation is controlled.

  According to the image reading unit provided with such a self-luminous image display unit, the image display operation of desired image information and the transmission type arranged on the visual field side by the radiated light from the image display unit. Since the subject image reading operation in the image reading unit can be realized, the configuration of the image reading apparatus is omitted by omitting the above-described backlight, the control circuit for controlling the light emission drive of the backlight, the power supply circuit, and the like. It can be made smaller, lighter, and thinner, and power consumption can be reduced.

  In each of the embodiments described above, the case where a double gate type photosensor is applied as the photosensor applied to the image reading unit has been described. However, the present invention is not limited to this, and in short, the sensor. The array is composed of a transmissive photosensor, and the image information displayed on the image display unit can be viewed with good luminance gradation from the visual field side through the image reading unit equipped with the photosensor. Needless to say, other element structures may be used.

1 is an overall configuration diagram showing an embodiment of an image reading apparatus according to the present invention. It is a principal part block diagram which shows one structural example of the image display part applied to the image reading apparatus which concerns on this embodiment. It is a schematic block diagram which shows an example of the black matrix applied to the image display part which concerns on this embodiment. It is a principal part block diagram which shows the example of 1 structure of the image reading part applied to the image reading apparatus which concerns on this embodiment. It is a schematic sectional drawing which shows the element structure of the photosensor applicable to the image reading part which concerns on this embodiment. It is a schematic block diagram which shows the example of 1 structure of the top gate driver or bottom gate driver applicable to the image reading part which concerns on this embodiment. It is a schematic block diagram which shows the example of 1 structure of the drain driver applicable to the image reading part which concerns on this embodiment. 6 is a timing chart illustrating an example of a drive control method in the image reading unit (photo sensor array) according to the present embodiment. It is a conceptual diagram which shows the reading operation | movement of a fingerprint image at the time of applying the image reading part which concerns on this embodiment to a fingerprint reading sensor. It is the schematic which shows 1st Embodiment of the sensor array of the image reading part applied to the image reading apparatus which concerns on this invention. It is the schematic which shows the sensor array which has a normal matrix arrangement | sequence structure for the comparison with the sensor array which concerns on this embodiment. It is the schematic which shows the other example of 1st Embodiment of the sensor array of the image reading part applied to the image reading apparatus which concerns on this invention. It is the schematic which shows 2nd Embodiment of the sensor array of the image reading part applied to the image reading apparatus which concerns on this invention. It is a conceptual diagram for demonstrating the arrangement structure of the photosensor in the sensor array which concerns on this embodiment. It is the schematic which shows an example of the connection structure of the signal wire | line applied to the sensor array of the image reading part which concerns on 1st Embodiment. It is the schematic which shows an example of the connection structure of the signal wire | line applied to the sensor array of the image reading part which concerns on 2nd Embodiment. FIG. 17 is a detailed diagram for explaining a connection structure of signal lines illustrated in FIG. 16. It is 3rd Embodiment of the sensor array of the image reading part applied to the image reading apparatus which concerns on this invention. FIG. 19 is a detailed diagram for explaining a connection structure of signal lines illustrated in FIG. 18. It is a conceptual diagram which shows the relationship between the image reading area in the image reading part which concerns on this embodiment, and the image display area in an image display part. It is a whole lineblock diagram showing other embodiments of an image reading device concerning the present invention. It is a schematic block diagram which shows an example of the portable electronic device (cellular phone) carrying the fingerprint reader in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image reading part 110 Insulating board | substrate 120 Scan driver 130 Reading driver 140 Sensor array 200 Image display part 210 Insulating board | substrate 220 Opposite board | substrate 230 Display drive driver 250 Pixel array 300 Backlight PS Photo sensor Px Liquid crystal pixel PTp Inter-element pitch PTc Between lines Pitch PTr Inter-pitch pitch

Claims (15)

An image reading apparatus comprising: an image display function for displaying desired image information in a specific image area; and an image reading function for reading an image of a desired subject placed in the specific image area.
Each of the plurality of display pixels that emit light of gradation according to the image information to the field of view is matrixed on the first substrate in a first direction and a second direction orthogonal to the first direction. a display pixel array which are regularly arranged in Jo, an image display means and a black matrix having a light shielding property formed in a lattice pattern between the display pixels,
It has permeability, each of the plurality of read pixels for reading the image of the subject, on the second substrate, arranged along row and column directions two-dimensionally, at least the row direction or the column direction in a staggered sequence An image reading means comprising a read pixel array having the above structure;
Comprising
The field side of the image display means, said image reading means, the row direction is parallel to the first direction, together with the column direction are stacked in parallel with the second direction, An image reading apparatus, wherein an image reading area defined by the reading pixel array is set so as to overlap the image display area defined by the display pixel array in a plane. Wherein the image reading means, said plurality of read pixels, according to claim 1, characterized in that it is arranged to have a staggered structure arranged in the row direction are arranged alternately in the column direction Image reading device. Wherein the image reading means, said plurality of read pixels, according to claim 1, characterized in that said are arranged as the row direction are arranged alternately with a staggered structure arranged in the column direction Image reading device. Wherein the image reading means, said plurality of read pixels, are arranged alternately in the column direction have a staggered structure arranged in the row direction, and the row direction are arranged alternately in the row direction The image reading apparatus according to claim 1, wherein the image reading apparatus is arranged so as to have a staggered arrangement structure.   In the image reading means, the plurality of reading pixels arranged so as to have a staggered arrangement structure in the column direction are formed so that the element structures are symmetrical in the left column and the right column of the column. The image reading apparatus according to claim 3 or 4, The image reading means, said plurality of at least each column reading pixel of claim 2 or 5, wherein it is connected by a signal line having a linear wiring pattern disposed on the column Image reading device. The image reading unit, the image reading apparatus according to claim 3, characterized in that it is connected by a signal line having a linear wiring patterns of the plurality of reading pixels in at least each row are arranged in the row direction . Of the plurality of reading pixels in the image reading unit, staggered arrangement structure arranged in the row direction, the first reading every other pixel of the row direction, only half of the column direction of the arrangement interval between the read pixel has a structure in which by shifting the read pixel in the column direction, staggered structure arranged in the column direction, the first reading every other pixel of the column, the arrangement of the column direction between the read pixel by half the interval, the image reading apparatus according to any one of claims 2 to 7, characterized in that it has a structure in which by shifting the read pixel in the row direction.   The image reading means emits light emitted from the image display means, transmitted through the image reading means, and reflected by the subject placed on a detection surface provided on the image reading area by the reading pixels. The image reading device according to claim 1, wherein the image reading device receives light and reads the subject image. The reading pixel includes a drain electrode and a source electrode made of a transparent electrode material formed on a second substrate having transparency with a channel region made of a semiconductor layer interposed therebetween, and an upper side of the channel region. A first gate electrode made of a transparent electrode material formed through a transparent insulating film, and a light shielding property formed through a transparent insulating film below the channel region. A double gate type comprising: a second gate electrode made of an electrode material having the electrode; and a detection surface formed on the first gate electrode through a transparent insulating film on which the subject is placed. The image reading apparatus according to claim 1 , wherein the image reading apparatus has a thin film transistor structure. The image reading means is connected by a signal line having a linear wiring pattern in which at least the plurality of reading pixels in each column are arranged in the column direction,
The signal lines having a linear wiring pattern arranged in the column direction in the image reading means are the drain electrodes of the photosensors constituting the plurality of reading pixels in each column, and the source electrodes. The image reading apparatus according to claim 10, wherein the image reading apparatuses are signal lines that individually connect each other. The image reading means is connected by a signal line having a linear wiring pattern in which at least the plurality of reading pixels in each column are arranged in the row direction,
A signal line having a linear wiring pattern arranged in the row direction in the image reading means includes the first gate electrodes of the photosensors constituting the plurality of reading pixels in each column, and The image reading apparatus according to claim 10, wherein the second gate electrodes are signal lines that individually connect each other.   13. The image reading apparatus according to claim 1, wherein the image reading apparatus is set to have a two-dimensional spread so that the image reading area is included in the image display area. The image display means constitutes at least a surface light source, emits light in a specific one-surface direction, and is disposed on the one surface side of the light-emitting means, and a transmissive liquid crystal display in which liquid crystal pixels are arranged two-dimensionally the image reading apparatus according to claim 1 to 13 further characterized in that comprises a panel. The image display means, at least, the image reading apparatus of claims 1 to 13, wherein it has a display panel of the self-emission type of the display pixels including a light emitting element are arranged two-dimensionally.

Images