Liquid crystal display device provided with an image capturing function

1. A liquid crystal display device comprising:

a plurality of pixels;

a plurality of optical sensors corresponding to each of the plurality of pixels, each optical sensor having a sensitivity R and each optical sensor being configured to convert an accepted light into an electric signal;

a plurality of charge storage units corresponding to each of the plurality of optical sensors, each charge storage unit having a capacitance C and each charge storage unit being configured to store a charge in response to the electric signal converted by the optical sensor while the optical sensor has an initial voltage V applied;

a plurality of retention units corresponding to each of the plurality of charge storage units, each retention unit being configured to retain a plurality of binary data, said binary data indicating whether an amount of charge stored in the charge storage unit is equal to or above a threshold voltage Vth;

an image capturing control unit configured to generate a plurality of pixel data in a plurality of tone levels, based on the binary data outputted from each of the retention units of the plurality of adjacent pixels by image capturing for N times, wherein at least one value of sensitivity R, capacitance C, initial voltage V, and threshold voltage Vth in each of the pixels is set to a different value from a relevant value of other adjacent pixels; and

wherein, in terms of p×q adjacent pixels of the plurality of adjacent pixels, an exposure time T(n) for an n-th (n=1, 2, . . . , N) image capturing by a specified pixel is calculated based on an average dark current I 0 , a reversal exposure time Tw in terms of a white standard subject for the specified pixel, a reversal exposure time Tb in terms of a black standard subject for the specified pixel, and with equations expressed as

1

T

⁡

(

n

)

=

1

Tw

-

n

⁢

⁢

Δ

,

Δ

=

(

1

Tw

-

1

Tb

)

/

N

,

and

a parameter k, to determine an amount of variation of sensitivity for each of the plurality of pixels, is set in a range defined as 1≦k≦N−p×q+1 and, based on a standard value of sensitivity R 1 set in the specified pixel, a plurality of respective values of sensitivity R 2 to R p×q set in other pixels are calculated by equations expressed as

R

m

+

1

=

R

1

+

m

⁢

⁢

δ

⁢

⁢

R

,

δ

⁢

⁢

R

R

1

=

Δ

·

T

⁡

(

k

)

·

1

1

-

I

0

⁢

T

⁡

(

k

)

C

1

⁡

(

V

1

-

Vth

1

)

(where m=1, 2, . . . , p×q−1).

2. The liquid crystal display device according to claim 1 ,

wherein, in terms of p×q adjacent pixels of the plurality of adjacent pixels, exposure time T(n) for an n-th (n=1, 2, . . . , N) image capturing by a specified pixel is calculated based on an average dark current I 0 , a reversal exposure time Tw in terms of a white standard subject for the specified pixel, a reversal exposure time Tb in terms of a black standard subject for the specified pixel, and with equations expressed as

1

T

⁡

(

n

)

=

1

Tw

-

n

⁢

⁢

Δ

,

Δ

=

(

1

Tw

-

1

Tb

)

/

N

,

and

a parameter k, to determine an amount of variation of sensitivity for each of the plurality of pixels, is set in a range defined as 1≦k≦N−p×q+1, and, based on a standard value of capacitance C 1 set in the specified pixel, a plurality of respective values of capacitance C 2 to C p×q set in other pixels are calculated by equations expressed as

C

m

+

1

=

C

1

-

m

⁢

⁢

δ

⁢

⁢

C

,

δ

⁢

⁢

C

C

1

=

Δ

·

T

⁡

(

k

)

(where m=1, 2, . . . , p×q−1).

3. The liquid crystal display device according to claim 1 ,

wherein, in terms of p×q adjacent pixels of the plurality of adjacent pixels, exposure time T(n) for an n-th (n=1, 2, . . . , N) image capturing by a specified pixel is calculated based on an average dark current I 0 , a reversal exposure time Tw in terms of a white standard subject for the specified pixel, a reversal exposure time Tb in terms of a black standard subject for the specified pixel, and with equations expressed as

1

T

⁡

(

n

)

=

1

Tw

-

n

⁢

⁢

Δ

,

Δ

=

(

1

Tw

-

1

Tb

)

/

N

,

and

a parameter k, to determine an amount of variation of sensitivity for each of the plurality of pixels, is set in a range defined as 1≦k≦N−p×q+1, and, based on a standard value of initial voltage V 1 set in the specified pixel, a plurality of respective values of initial voltage V 2 to V p×q set in other pixels are calculated by equations expressed as

V

m

+

1

=

V

1

-

m

⁢

⁢

δ

⁢

⁢

V

,

δ

⁢

⁢

V

V

1

-

V

⁢

⁢

th

1

=

Δ

·

T

⁡

(

k

)

(where m=1, 2, . . . , p×q−1).

4. The liquid crystal display device according to claim 1 ,

wherein, in terms of p×q adjacent pixels of the plurality of adjacent pixels, exposure time T(n) for an n-th (n=1, 2, . . . , N) image capturing by a specified pixel is calculated based on an average dark current I 0 , a reversal exposure time Tw in terms of a white standard subject for the specified pixel, a reversal exposure time Tb in terms of a black standard subject for the specified pixel, and with equations expressed as

1

T

⁡

(

n

)

=

1

Tw

-

n

⁢

⁢

Δ

,

Δ

=

(

1

Tw

-

1

Tb

)

/

N

,

and

a parameter k, to determine an amount of variation of sensitivity for each of the plurality of pixels, is set in a range defined as 1≦k≦N−p×q+1, and, based on a standard value of threshold voltage Vth 1 set to the specified pixel, a plurality of respective values of threshold voltage Vth 2 to Vth p×q set in other pixels are calculated by equations expressed as

Vth

m

+

1

=

Vth

1

+

m

⁢

⁢

δ

⁢

⁢

Vth

,

δ

⁢

⁢

Vth

V

1

-

V

⁢

⁢

th

1

=

Δ

·

T

⁡

(

k

)

(where m=1, 2, . . . , p×q−1).