Display device and electronic product having light sensors in plural pixel regions

Abstract

A display device includes: a screen unit; a drive unit; a signal processing unit; and a selector, wherein the screen unit includes rows of scanning lines, columns of signal lines, matrix-state pixel circuits and a light sensor, the drive unit includes a scanner supplying a control signal to the scanning lines and a driver supplying a video signal to the signal lines, the screen unit is sectioned into plural regions each having plural pixel circuits, the pixel circuit emits light in accordance with the video signal, the light sensor is arranged with respect to each region and outputs a luminance signal in accordance with the light emission, the selector supplies plural luminance signals to the signal processing unit by switching the signals, and the signal processing unit corrects the video signal in accordance with the luminance signals and supplies the video signal to the driver.

Description

CROSS REFERENCES TO RELATED APPLICATIONS[0001]The present application is a continuation of application Ser. No. 12 / 588,520, filed Oct. 19, 2009, which in turn claims priority from Japanese Application No.: 2008-286781, filed in the Japan Patent Office on Nov. 7, 2008, the entirety of which being incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a display device displaying images by current-driving a light emitting element arranged at each pixel. The invention also relates to an electronic product using the display device. Particularly, the invention relates to a drive system of a so-called active matrix display device, which controls a current amount flowing in the light emitting element such as an organic EL element by an insulated-gate field effect transistor provided in each pixel circuit.[0004]2. Description of the Related Art[0005]In display devices, for example, in a liquid crystal display, a large...

AI Technical Summary

Benefits of technology

[0018]According to the embodiment of the invention, the signal processing unit corrects the video signal in accordance with the luminance signal outputted from the light sensor as well as supplies the corrected video signal to the driver of the drive unit. According to the configuration, it is possible to compensate luminance deterioration of pixels by the correction of the video signal, as a result, image quality failures such as “burn-in” which have been problems from the past can be prevented.

[0020]Particularly, in the embodiment of the invention, the screen unit is sectioned and the light sensor is arranged with respect to each section. Each section includes a number of pixels in a range in which the corresponding light sensor can detect light emitting luminance. According to the embodiment of the invention, it is not necessary to provide light sensors so as to correspond to respective pixels for detecting light emitting luminance of each pixel, therefore, the necessary number of light sensors can be drastically reduced, as a result, it is possible to simplify a display panel structure as well as to reduce costs for the display panel.

[0021]Furthermore, in a display device according to an embodiment, a selector is arranged between the panel and the signal processing unit (for example, a DSP). The selector supplies luminance signals outputted from plural light sensors arranged so as to correspond to plural regions by switching the signals. It is possible to reduce the number of wirings connecting between plural light sensors and the signal processing unit by interposing the selector. When the signal processing unit includes an IC chip (for example, a FPGA or an ASIC), the number of pins for connecting to the plural light sensors can be reduced. Accordingly, a general-purpose IC chip can be used even when the number of light sensors exceeds the number of pins of the DSP.

[0022]Further, according to the embodiment of the invention, plural light sensors are grouped into blocks by a given number of sensors. The signal processing unit receives luminance signals by each block, and performs correction processing of the video signal based on the luminance signals. In order to process analog luminance signals outputted from the light sensors in the signal processing unit (for example, the DSP), an amplifier for amplifying analog luminance signals or a converter converting analog data of amplified luminance signals into digital data are necessary. According to the embodiment of the invention, the light sensors are grouped into blocks by a given number of sensors, thereby using the amplifier and converter in common by the light sensors which are grouped into blocks, which realizes reduction of the number of components.

Problems solved by technology

In the light emitting element, current / luminance characteristics tend to deteriorate with time.

Accordingly, there is a problem that luminance of each pixel in the organic EL display is reduced with lapse of time.

When the cumulative light emitting time differs in respective pixels in the screen, luminance nonuniformity may occur and an image quality failure called “burn-in” is liable to occur.

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