JP2008039953A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device whose sensitivity of the sensor is improved by making an output derived from the optical sensor unaffected by peripheral circuits, in installing the optical sensor on a panel substrate. <P>SOLUTION: The liquid crystal display device is equipped with a liquid crystal display panel comprising a liquid crystal layer formed between a TFT substrate 2 and a CF substrate 10 having a common electrode 12, a color filter, and a black matrix 11 and a light detecting part LS having the TFT optical sensor. The light detecting part LS, a power supply line L to supply power to the light detecting part LS, and an output line L<SB>o</SB>to derive the output from the light detecting part LS are installed on the TFT substrate 2. A removal section S from which the common electrode 12 and the black matrix 11 are removed is formed on a section of the CF substrate 10 directly above the output line L<SB>o</SB>arranged on the active matrix substrate 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device in which an optical sensor for detecting external light is incorporated in a liquid crystal display panel.

In recent years, flat display panels have been used not only in information communication equipment but also in general electronic equipment, and among them, liquid crystal display panels are most frequently used. This liquid crystal display panel is provided with a backlight or a sidelight (hereinafter collectively referred to as “backlight etc.”) because the display image is difficult to see in the dark because the liquid crystal is a non-luminous material. A light or the like is turned on when the outside light is dark to irradiate a display image. However, manual operation requires the backlight to be turned on / off each time the light is dark or dark, which is cumbersome, and the backlight is turned on even when it is bright. Therefore, in such a case, wasteful power is consumed, so that the battery such as a mobile phone may be consumed quickly.

Therefore, in order to eliminate such inconvenience, an optical sensor is incorporated in the liquid crystal display panel,
A technology has been developed in which the light sensor detects the contrast of external light and controls on / off of a backlight or the like based on the detection result (see, for example, Patent Documents 1 to 3 below).

For example, a liquid crystal display device described in Patent Document 1 below uses a thin film transistor (TFT) as an optical sensor, and the TFT optical sensor is manufactured at the same time as a TFT used as a switching element of a liquid crystal display panel. In addition, the liquid crystal display device described in the following Patent Document 2 includes an external light illuminance detection sensor and a backlight illuminance detection sensor, and the external light illuminance detection sensor is provided in a protruding portion formed by stacking a pair of glass substrates. The backlight illuminance detection sensor is provided outside the seal frame. Further, in the liquid crystal display device described in Patent Document 3 below, an optical sensor is disposed at a location away from the peripheral drive circuit portion and external terminals of the liquid crystal, and high frequency noise and heat generated from these drive circuits and the like are provided. This prevents the sensor from being affected.
JP 2002-131719 A (claims, paragraphs [0010] to [0013], FIG. 1) JP 2000-122575 A (paragraphs [0013] to [0016], FIG. 4) JP 11-84426 A (paragraphs [0019] to [0022], FIGS. 1 and 2) JP-A-1-143257 (Claims, FIG. 3) Japanese Patent Laid-Open No. 5-95100 (paragraph [0010], FIG. 1)

The TFT photosensor has a small leakage current (in the gate-off region when light is not irradiated).
Dark current) flows, and when light is radiated, the leakage current (with a magnitude corresponding to the light intensity (brightness)) (
(Also referred to as a leakage current). Since this TFT photosensor detects the brightness of external light using this leak current, the leak current is extremely weak, so the output from the photosensor is affected by external noise and the like. It is easy.

For this reason, when the optical sensor as described above is incorporated in a liquid crystal display panel, a peripheral drive circuit for driving liquid crystal and external terminals are disposed on one substrate (active matrix substrate). The optical sensor may be affected by heat generated from the light and high-frequency signals. In this regard, in the liquid crystal display device of Patent Document 3, the optical sensor is disposed in a location away from the peripheral circuit and the terminal portion that generate high-frequency signals and heat generation so as not to be affected by such noise. Yes. However, since at least a power supply line and an output line connected to the drain electrode of the TFT photosensor are drawn out from the photosensor, and these leadout wirings are routed around the display portion. If the line is exposed to external noise, it will affect the light detection sensitivity. For example, when a rectangular VCOM voltage is applied to the common electrode of the counter substrate of the liquid crystal display panel, a parasitic capacitance is generated between the common electrode and the output line, and the output signal is affected by the parasitic capacitance. There is a risk of receiving. In addition, since this type of optical sensor is easily affected by external noise, a technique for shielding an external noise by providing an electrostatic shielding film on a panel substrate is known (see, for example, Patent Documents 4 and 5 above). ). However, the sensors described in these documents are provided with a conductive film and an insulating film for electrostatic shielding between the substrate and the gate wiring. When such a conductive film is provided, a special manufacturing process is provided. Will increase the overall cost.

Accordingly, the present invention has been made to eliminate such inconveniences, and the object of the present invention is to influence the output derived from the optical sensor from the influence of peripheral circuits when the optical sensor is incorporated into a panel substrate. It is an object of the present invention to provide a liquid crystal display device with improved sensor sensitivity so as not to be affected.

Another object of the present invention is to provide a liquid crystal display device which can easily achieve the above object without increasing the manufacturing process of the liquid crystal display panel.

The above object of the present invention can be achieved by the following configurations. That is, the invention of the liquid crystal display device according to claim 1 is a liquid crystal display in which a liquid crystal layer is formed between an active matrix substrate on which various wirings are formed and a color filter substrate having a common electrode, a color filter, and a black matrix. A power source for supplying power to the light detection unit and the light detection unit on the active matrix substrate, comprising: a panel; a light detection unit having a light sensor; and an illumination unit controlled by an output of the light detection unit. In a liquid crystal display device provided with an output line for deriving an output from the line and the light detection unit,
The color filter substrate is characterized in that a removal region from which the common electrode and the black matrix are removed is formed immediately above the output line disposed on the active matrix substrate.

The invention of a liquid crystal display device according to claim 2 is a liquid crystal display panel in which a liquid crystal layer is formed between an active matrix substrate on which various wirings are formed and a color filter substrate having a common electrode, a color filter, and a black matrix. A light detection unit having a light sensor, and illumination means controlled by the output of the light detection unit, on the active matrix substrate,
In the liquid crystal display device provided with the light detection unit, a power supply line for supplying power to the light detection unit, and an output line for deriving an output from the light detection unit,
In the color filter substrate, the black matrix is formed of a non-conductive resin material, and a removal region in which the common electrode is removed is formed immediately above the output line disposed on the active matrix substrate. It is characterized by being.

According to a third aspect of the present invention, in the liquid crystal display device according to the first or second aspect, the removal region is formed by one or a plurality of window openings positioned immediately above the output line. It is characterized by being.

According to a fourth aspect of the present invention, in the liquid crystal display device according to the first or second aspect, the optical sensor comprises a thin film transistor, and is formed simultaneously with the thin film transistor as a switching element in the manufacturing process of the liquid crystal display panel. It is characterized by being.

According to a fifth aspect of the present invention, in the liquid crystal display device according to the fourth aspect, the output line is formed of the same material as a source electrode or a drain electrode of a thin film transistor as the photosensor. And

According to a sixth aspect of the present invention, in the liquid crystal display device according to the first or second aspect, a constant DC voltage is applied to the power line, and a predetermined rectangular wave voltage is applied to the common electrode. It is characterized by.

By providing the above configuration, the present invention has the following excellent effects. That is, according to the first aspect of the present invention, since the common electrode and the black matrix are removed from the color filter substrate immediately above the output line disposed on the active matrix substrate, the output line as in the prior art is removed. The parasitic capacitance formed between the output line and the common electrode when the liquid crystal display panel is driven is reduced as compared with the case where the common electrode or the like is present immediately above. As a result, the adverse effect on the output signal from the light detection unit flowing in the output line, for example, the disturbance of the output waveform is reduced, and highly sensitive light detection is possible.

According to the invention of claim 2, in the color filter substrate, the black matrix is formed of a non-conductive material and the common electrode directly above the output line disposed on the active matrix substrate is removed. Therefore, the parasitic capacitance formed between the output line and the common electrode during driving of the liquid crystal display panel is reduced as compared with the conventional technique in which a common electrode or the like exists directly above the output line. . As a result, adverse effects on the output signal from the light detection unit flowing in the output line,
For example, the output waveform is less disturbed, and highly sensitive light detection is possible. Further, by forming the black matrix from a non-conductive material, the black matrix can be easily formed, and the wiring on the active matrix substrate is hidden by the black matrix so that it cannot be seen, and the display quality is improved.

According to the invention of claim 3, if the removal region is formed by one window opening, the removal region is widened and the parasitic capacitance between the common electrode and the output line is further reduced. By making one, the opening can be easily formed. Further, if the removal region is formed by a plurality of window openings, a bridge region in which the common electrode is not removed is formed between the window openings, so that the electrical connection of the common electrode is improved.

In addition, according to the invention of claim 4, since it is possible to simultaneously form a thin film transistor (TFT) that uses a thin film transistor as a switching element of a liquid crystal display panel, it is necessary to particularly increase the number of manufacturing steps in order to form the optical sensor. Disappears.

According to the invention of claim 5, since the output line and the power supply line can be formed simultaneously with the photosensor comprising the thin film transistor, it is not necessary to particularly increase the number of manufacturing steps for forming the output line and the power supply line.

According to the invention of claim 6, VC is obtained by connecting the power line to a constant DC voltage source.
A stable output voltage that is not affected by the OM voltage can be obtained.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. The embodiments described below are examples of liquid crystal display devices for embodying the technical idea of the present invention. Therefore, the present invention is not intended to be specified in this embodiment, and the present invention can be equally applied to various modifications without departing from the technical idea shown in the claims. Is.

1 is a plan view schematically showing a TFT substrate as seen through a color filter substrate of a liquid crystal display panel according to Embodiment 1 of the present invention, and FIG. 2 schematically shows the color filter substrate of FIG. It is a back view.
As shown in FIG. 1, a liquid crystal display panel 1 includes a pair of active matrix substrates (hereinafter referred to as TFT substrates) 2 and a color filter substrate (hereinafter referred to as CF substrates) made of rectangular transparent materials arranged opposite to each other, such as glass plates. (Referred to as a substrate) 10 and the TFT substrate 2 is formed so that a protruding portion 2A having a predetermined space is formed when the TFT substrate 2 is disposed opposite to the CF substrate 10.
A material having a size larger than 0 is used, and a sealing material (not shown) is attached to the outer periphery of the TFT substrate 2 and the CF substrate 10, and liquid crystal and spacers are enclosed inside.

Various wirings and the like are formed on the opposing surfaces of the TFT substrate 2 and the CF substrate 10. Among them, the CF substrate 10 is surrounded by a black matrix 11 (see FIG. 5) made of metal chromium or the like provided in a matrix in accordance with the pixel area in the display area DA of the TFT substrate 2, and the black matrix 11. For example, a color filter (not shown) made of, for example, red (R), green (G), and blue (B) provided in the region, and an electrode on the TFT substrate 2 side are electrically connected to the CF substrate 1
A common electrode 12 (see FIG. 5) is provided so as to cover the 0 facing surface. The common electrode 12 is made of a transparent material such as indium oxide or tin oxide. Although the specific configurations of the color filter, the black matrix 11 and the common electrode 12 are not shown in the drawing, these are the light detection unit LS formed on the TFT substrate 2 and various lead lines L and L ₀ derived from the light detection unit LS. It is extended to the place facing. TFT substrate 2
A backlight (not shown) as an illuminating means is provided on the back surface of the lens. This backlight is controlled by the output of the light detection unit LS.

The TFT substrate 2 has short sides 2a and 2b and long sides 2c and 2d which are opposed to each other, and one short side 2b side is an overhang portion 2A. A semiconductor for a source driver and a gate driver is provided in the overhang portion 2A. The chip Dr is mounted, and the light detection unit LS is disposed on the other short side 2a side.

The TFT substrate 2 has a plurality of gate lines GW _{1 to} GW _n (n = 2) arranged at predetermined intervals in the row direction (lateral direction) in FIG. 3, 4,
And a plurality of source lines SW _{1 to} SW _m (m = 2, 3, 4,...) Insulated from these gate lines and arranged in the column direction (vertical direction). The source lines SW _{1 to} SW _m and the gate lines GW _{1 to} GW _n are wired in a matrix, and the gate lines GW _{1 to} G that intersect with each other.
In each region surrounded by W _n and source lines SW _{1 to} SW _m , switching elements (not shown) that are turned on by scanning signals from the gate lines GW _{1 to} GW _n and source lines SW _{1 to} SW m
A pixel electrode 6 (see FIG. 4) to which a video signal from _m is supplied via a switching element is formed.

Each region surrounded by the gate lines GW _{1 to} GW _n and the source lines SW _{1 to} SW _m constitutes a so-called pixel, and an area in which these pixels are formed becomes a display region DA, that is, an image display unit. ing. For example, a thin film transistor (TFT) is used as the switching element.

Each of the gate lines GW _{1 to} GW _n and each of the source lines SW _{1 to} SW _m is extended outside the display area DA and is routed to an outer peripheral area outside the display area to be a source driver and a gate driver semiconductor chip. Connected to Dr. Further, the TFT substrate 2 has a light detection portion L on one long side 2d side.
The lead-out lines L ₀ and L derived from the S optical sensor are connected to terminals T ₁ and T ₂ to which an external control circuit is connected.

Next, the structure of the light detection unit and the lead-out wiring will be described with reference to FIGS. 3 shows the light detection unit, FIG. 3A is an equivalent circuit diagram, and FIG. 3B is a VCOM applied to the common electrode.
FIG. 4 is a cross-sectional view of the light detection unit, and FIG. 5 is a cross-sectional view of FIG.
It is -A sectional drawing.

Light detecting section LS as shown in FIG. 3, has a configuration in which the capacitor C is connected in parallel between the drain electrode D _L and the source electrode S _L of the TFT ambient light photosensor. In the light detection unit LS, the source electrode S _L and one terminal of the capacitor C are connected to the reference voltage source V _S via the switch element SW, and the drain electrode _DL and the other terminal of the capacitor C are connected to the DC reference voltage source. Connected to Vref. As shown in FIG. 4, the light detection unit LS includes a gate electrode G _L of the TFT optical sensor and one terminal C ₁ of the capacitor C formed on the TFT substrate 2 and is covered with silicon nitride so as to cover the surface thereof. A gate insulating film 3 made of silicon oxide or the like is laminated. T
On the gate electrode G _L of the FT photosensor is a semiconductor layer 4 is formed made of amorphous silicon or polycrystalline silicon through a gate insulating film 3, and then aluminum and metal such as molybdenum on the gate insulating film 3 A source electrode S _L and a drain electrode D _L of a TFT photosensor consisting of
One end thereof is provided in contact with the semiconductor layer 4. Of these, the source electrode S _L of the TFT ambient light photosensor is extended to form the other terminal C ₂ of the capacitor C. Furthermore, TF
A protective insulating film 5 made of, for example, an inorganic insulating material is laminated so as to cover the surfaces of the T photosensor and the capacitor C, and a pixel electrode 6 made of a transparent material is further formed thereon. The light detection unit LS is formed simultaneously with the TFT as a switching element for driving the liquid crystal in the manufacturing process of the liquid crystal display panel. This eliminates the need to increase the number of manufacturing steps in particular in order to provide the light detection unit LS. Further, a plurality of TFT photosensors may be used instead of one, and these may be provided in a row along the short side 2a. By arranging a plurality of TFT photosensors in a row in this way, even if the user inadvertently blocks some TFT photosensors with a finger or the like, all the TFT photosensors are simultaneously Since it is rarely blocked, light detection is possible with a TFT light sensor that is not shielded.

The from the light sensing section LS has a drain electrode D connected to the power line _L L and the source electrode S output line L ₀ connected to _L are drawn respectively as lead wiring (see FIG. 1). Note that a lead line connected to the gate electrode _GL is also drawn from the light detection unit LS, but this lead line is connected to a circuit for driving the liquid crystal display panel, and is not shown.

Sectional structure in the vicinity of the output line L ₀ is as shown in FIG. 5, the output line L ₀ on the gate insulating film 3 provided on the TFT substrate 2 is provided, the output line L ₀ is the protective insulating film 5 It is the structure covered with. The power line L may have the same configuration, these output lines L ₀ and the power supply line L is formed with a source electrode material and a drain electrode materials of the TFT ambient light photosensor. This eliminates the need to particularly increase the number of manufacturing processes in order to provide the output line L ₀ and the power supply line L.

The CF substrate 10 has a black matrix 11, a color filter and a common (common) electrode 12 formed in the display area DA. Among the black matrix 11, the color filter and the common electrode 12, the black matrix 11 and the common electrode 12 are provided. It is extended to a point facing the lead wiring L, L ₀ derived from the optical detection unit LS and the light detecting portion LS is disposed on the TFT substrate 2. The extended black matrix 11 and the common electrode 12 have a removal region S formed by removing a portion directly above the output line L ₀ provided on the TFT substrate 2. That is, as shown in FIG. 5, the output line L is formed on the gate insulation 3 of the TFT substrate 2.
_In the CF substrate 10 on which ₀ is disposed and opposed to the TFT substrate 2, the common electrode 12 and the black matrix 11 immediately above the output line L ₀ are removed to form a gap 13.

The range of the removal region S from which the common electrode 12 and the black matrix 11 are removed is as shown in FIG.
As shown, when the width a, the length is b, an area of a × b is larger same or slightly the area covering the output line L _0. In this way, the common electrode 1 directly above the output line L ₀
2 and the black matrix 11 are removed, the capacitance formed between the output line L ₀ and the common electrode 12 becomes extremely small to a negligible level, and the output flowing through the output line caused by the VCOM voltage applied to the common electrode 12 The influence on the signal can be reduced. That is, the liquid crystal display panel 1 of the present embodiment has a parasitic capacitance C _VCOM between the output line L ₀ and the common electrode 12 when driven.
As a result, there is an adverse effect on the output signal flowing through the output line L ₀ , for example, disturbance of the output waveform, as compared with the case where a common electrode is present directly above the output line L ₀ as in the prior art. It becomes less and light detection with high sensitivity becomes possible.

Next, the operation of the light detection unit LS will be described with reference to FIG.
DC reference voltage source drain from Vref electrode D _L to a constant DC voltage (e.g., 0V) is applied with a common electrode 12, a rectangular wave having a predetermined amplitude as shown in (1) shown in FIG. 3 (b) from consisting VCOM voltage advance by applying, after applying a constant reverse bias voltage (e.g. -10 V) to the gate electrode _{G L} of the TFT ambient light photosensor, a switching element SW predetermined time (e.g., FIG. 3 (b) (2 ) Reference) In the ON state, the reference voltage Vs is applied to the capacitor C, and the capacitor C is charged with the difference voltage Va between the DC voltage from the DC reference voltage source Vref and the reference voltage Vs. In this state, when the TFT light sensor is exposed to external light, a leakage current flows through the TFT light sensor, and a part of the charging voltage of the capacitor C is discharged. The amount of discharge increases with time according to the ambient brightness. Therefore, the charging voltage of the capacitor C obtained by subtracting the discharged voltage, that is, the output voltage Vs ′ is, as shown in (3) of FIG. This is the voltage after the voltage drops after drawing a discharge curve. The output voltage Vs ′ is read by an output reading unit (not shown), and the backlight is controlled.

According to this first embodiment, by a black matrix 11 composed of the common electrode 12 and the conductive material directly over the output line L ₀ is removed, the common electrode 12 as shown in FIG. 3 (a) (or the common parasitic capacitance C _VCOM generated between the black matrix 11) which is electrically connected to the electrode 12 and the output line L ₀ that eliminates influence the very small output signal of the capacitor C.

Further, the voltage supplied from the DC reference voltage source Vref is changed to a constant DC voltage (for example, 0V
), A stable output voltage Vs ′ that is not affected by the VCOM voltage can be obtained. When the voltage applied from the DC reference voltage source Vref is replaced with a constant DC voltage, for example, a VCOM voltage composed of a rectangular wave (see FIG. 3B), the output voltage is
As shown in (4) of FIG. 3B, the voltage drops in synchronization with the VCOM voltage, lacks stability, and makes it difficult for the reading unit to read.

6 is a plan view schematically showing a TFT substrate seen through a color filter substrate of a liquid crystal display panel according to Embodiment 2 of the present invention, and FIG. 7 schematically shows the color filter substrate of FIG. It is a back view. This liquid crystal display device 1A differs from the liquid crystal display device 1 of the first embodiment in the removal regions (S _{1 to} S ₃ ) of the common electrode 12 and the black matrix 11 in the CF substrate 10A. Therefore, the same reference numerals are given to the same components as those in the first embodiment, and the duplicate description will be omitted, and only different components will be described.

The removal region of the common electrode 12 and the black matrix 11 in the CF substrate 10A is shown in FIG.
As shown in FIG. 7, a plurality of window openings S _{1 to} S ₃ having a predetermined area are formed.

With this configuration, the liquid crystal display device 1A of the second embodiment can achieve the same effects as those shown in the liquid crystal display device 1 of the first embodiment, and in addition, the removal region has a plurality of window openings S ₁ to S ₁ .
By forming in S ₃ , a bridge region that does not remove the common electrode 12 and the black matrix 11 is formed between the window openings S _{1 to} S ₃ , so that the electrical connection of the common electrode 12 is improved. .

8 is a plan view schematically showing a TFT substrate seen through a color filter substrate of a liquid crystal display panel according to Embodiment 3 of the present invention, and FIG. 9 is a cross-sectional view taken along line BB in FIG. . This liquid crystal display device 1B is different from the liquid crystal display devices 1 of the first and second embodiments in the material of the black matrix in the CF substrate 10B. Therefore, the same reference numerals are given to the configurations common to the first and second embodiments, and the duplicate description will be omitted, and only different configurations will be described.

A black matrix 11a made of a non-conductive synthetic resin, a color filter, and a common electrode 12 made of a conductive member are formed on the opposite surface of the CF substrate of the liquid crystal display device 1B according to the third embodiment. the common electrode 12, in the same manner as in example 1 or example 2, removal area consisting of a gap 13a in the area just above the output line L ₀ is formed. Note that no removal region is formed in the black matrix 11a. The black matrix 11a in the CF substrate 10B is formed of a non-conductive synthetic resin material. As the non-conductive synthetic resin material, for example, a black resist obtained by adding a small amount of carbon to a UV curable transparent resin is used. use.

With this configuration, the liquid crystal display device 1B of the third embodiment is the same as the liquid crystal display device 1 of the first and second embodiments,
In addition to having the same effect as 1A, it is necessary to form a gap in the black matrix 11 as in the first and second embodiments by forming the black matrix 11a of the CF substrate 10B from a non-conductive resin material. Therefore, the formation thereof is facilitated, and various wirings on the TFT substrate 2 are all hidden by the black matrix 11a and cannot be seen, so that the display quality is improved.

FIG. 1 is a plan view schematically showing a TFT substrate seen through a color filter substrate of a liquid crystal display panel according to Embodiment 1 of the present invention. FIG. 2 is a back view schematically showing the color filter substrate of FIG. FIG. 3 shows a light detection unit, FIG. 3A is an equivalent circuit diagram, and FIG. 3B is a waveform diagram for explaining the relationship between the VCOM voltage applied to the common electrode and the sensor output. FIG. 4 is a cross-sectional view of the light detection unit. FIG. 5 is a cross-sectional view taken along the line AA in FIG. FIG. 6 is a plan view schematically showing a TFT substrate seen through a color filter substrate of a liquid crystal display panel according to Embodiment 2 of the present invention. FIG. 7 is a back view schematically showing the color filter substrate of FIG. FIG. 8 is a plan view schematically showing a TFT substrate seen through a color filter substrate of a liquid crystal display panel according to Embodiment 3 of the present invention. FIG. 9 is a sectional view taken along line BB in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A, 1B Liquid crystal display device 2 TFT substrate 2A Overhang | projection part 3 Gate insulating film 5 Protective insulating film 10, 10A, 10B CF board | substrate 11, 11a Black matrix 12 Common electrode LS Photodetection part L Power supply line (drawer wiring)
L ₀ output line (drawer wiring)
S, S _{1 to} S ₃ removal region (window opening)

Claims (6)

A liquid crystal display panel in which a liquid crystal layer is formed between an active matrix substrate on which various wirings are formed and a color filter substrate having a common electrode, a color filter, and a black matrix, a light detection unit having a light sensor, and the light detection Illuminating means controlled by the output of the unit, and on the active matrix substrate, the light detection unit, a power line for supplying power to the light detection unit, and an output line for deriving an output from the light detection unit In the provided liquid crystal display device,
2. The liquid crystal display device according to claim 1, wherein the color filter substrate is formed with a removal region from which the common electrode and the black matrix are removed immediately above the output line disposed on the active matrix substrate. A liquid crystal display panel in which a liquid crystal layer is formed between an active matrix substrate on which various wirings are formed and a color filter substrate having a common electrode, a color filter, and a black matrix, a light detection unit having a light sensor, and the light detection Illuminating means controlled by the output of the unit, and on the active matrix substrate, the light detection unit, a power line for supplying power to the light detection unit, and an output line for deriving an output from the light detection unit In the provided liquid crystal display device,
In the color filter substrate, the black matrix is formed of a non-conductive resin material, and a removal region in which the common electrode is removed is formed immediately above the output line disposed on the active matrix substrate. A liquid crystal display device. 3. The liquid crystal display device according to claim 1, wherein the removal region is formed by one or a plurality of window openings positioned immediately above the output line. 4. 3. The liquid crystal display device according to claim 1, wherein the photosensor includes a thin film transistor, and is formed simultaneously with the thin film transistor as a switching element in a manufacturing process of the liquid crystal display panel. The liquid crystal display device according to claim 4, wherein the output line and the power line are formed of the same material as a source electrode or a drain electrode of a thin film transistor serving as the photosensor. 3. The liquid crystal display device according to claim 1, wherein a constant DC voltage is applied to the power supply line, and a predetermined rectangular wave voltage is applied to the common electrode.

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