Display

Abstract

A display 10 according to one embodiment of the invention includes a display panel having an active matrix substrate and a color filter substrate, a lighting unit for the display panel, ambient light photosensors 321 to 326, a controller that controls luminous intensity of the lighting unit based on outputs from the ambient light photosensors 321 to 326, and a spectral sensitivity adjustor provided at a position on the color filter substrate corresponding to the ambient light photosensors 321 to 326 in order to make the spectral sensitivity of the ambient light photosensors 321 to 326 match human visual sensitivity. The spectral sensitivity adjustor may be a color filter or a polarizing filter. The display thus structured automatically and stably controls on/off of its backlights depending on the brightness of the surroundings with a sensitivity corresponding to human visual sensitivity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of the voltage-current curve of a TFT ambient light photosensor.

FIG. 2 is a circuit diagram of a photodetector unit using the TFT ambient light photosensor.

FIG. 3 shows the voltage-time curve at both ends of a capacitor included in the circuit diagram of FIG. 2 with different brightness levels.

FIG. 4 is a plan view showing a single pixel seen through a color filter substrate included in a semi-transmissive liquid crystal display (LCD).

FIG. 5 is a sectional view along the line A-A of FIG. 4 with the color filter substrate removed.

FIG. 6 is a plan view of the semi-transmissive LCD according to one embodiment of the invention.

FIG. 7 is a sectional view of the photodetector unit.

FIG. 8 shows human visual sensitivity.

FIG. 9 shows the spectral sensitivity of ambient light photosensors according to the embodiment.

FIG. 10 shows the spectral transmittance of R, G, and B color filters included in an LCD panel.

FIG. 11 shows the spectral transmittance of a polarizing filter.

FIG. 12 shows the spectral sensitivity of the ambient light photosensors according to the embodiment that is compensated by the G color filter and the polarizing filter.

FIG. 13A is a plan view of the semi-transmissive LCD including color filter layers according to the embodiment, FIG. 13B is an enlarged view of the color filters on the ambient light photosensors shown in FIG. 13A, and FIGS. 13C to 13G show modifications of FIG. 13B.

FIG. 14 is a circuit diagram showing an example of electrical coupling of a plurality of photodetector units.

FIG. 15 shows a modified example of the circuit diagram of FIG. 14.

FIG. 16 shows a modified example of the semi-transmissive LCD shown in FIG. 6.

FIG. 17 is a block diagram of a backlight control unit.

Claims

1. A display comprising: a display panel having an active matrix substrate and a color filter substrate;a lighting unit for said display panel;a ambient light photosensor;a controller that controls luminous intensity of said lighting unit based on an output from said ambient light photosensor; anda spectral sensitivity adjustor for said ambient light photosensor provided at a position on said color filter substrate corresponding to said ambient light photosensor.

2. The display according to claim 1, wherein said spectral sensitivity adjustor is a color filter layer.

3. The display according to claim 2, wherein said color filter layer is in a combination of colors provided for each pixel within a display area on said display panel.

4. The display according to claim 2, wherein said color filter layer is in one of colors provided for each pixel within a display area on said display panel.

5. The display according to claim 1, wherein said spectral sensitivity adjustor is a polarizing filter layer.

6. The display according to claim 1, wherein said spectral sensitivity adjustor is a combination of a color filter layer and a polarizing filter layer.

7. The display according to claim 6, wherein said color filter layer is in a combination of colors provided for each pixel within a display area on said display panel.

8. The display according to claim 6, wherein said color filter layer is in one of colors provided for each pixel within a display area on said display panel.

9. The display according to claim 1, wherein said ambient light photosensor includes a plurality of thin-film field effect transistors, in each of which a source electrode, a gate electrode, and a drain electrode are coupled in parallel to each other, a capacitor is coupled between said source electrode and said drain electrode, and a switching element is coupled between said source electrode and a predetermined constant voltage source.

10. The display according to claim 1, wherein said lighting unit is a backlight or a side light, and said display is a transmissive liquid crystal display or a semi-transmissive liquid crystal display.

11. The display according to claim 1, wherein said lighting unit is a front light, and said display is a reflective liquid crystal display.