Patent ID: 8279211
Filing Date: 2012-10-02
Classification: G09G

Abstract:
1. A light emitting device, comprising: a pixel array, which is constituted of a plurality of pixels, connected to each of a plurality of signal lines, and each comprising a light emitting element, and a pixel drive circuit having a drive transistor for controlling current supplied to the light emitting element with one end of a current path of the drive transistor connected to one terminal of the light emitting element, the pixel drive circuit further having a holding capacity for storing charge by a voltage impressed on a current control terminal of the drive transistor; a voltage impressing circuit for outputting a reference voltage; a plurality of voltage measurement circuits equipped respectively for connecting to each of the plurality of signal lines; a switching circuit for switching connection of one end of each signal line, between the voltage impressing circuit and each voltage measurement circuit; a property parameter acquisition circuit for acquiring property parameters that relate to electrical properties of each pixel; a signal correction circuit for outputting a corrected gradation signal by correcting supplied image data based on the acquired property parameters; and a drive signal impressing circuit for generating a drive signal based on the corrected gradation signal and impressing the drive signal on the one end of each signal line; wherein the reference voltage has an electric potential in which an electric potential difference between the one end and the other end of the current path of the drive transistor is a value that exceeds a threshold voltage of the drive transistor; wherein the switching circuit connects the one end of each signal line to the voltage impressing circuit and interrupts the connection between the one end of each signal line and the voltage impressing circuit after impressing the reference voltage for a predetermined time on the one end of each signal line by the voltage impressing circuit, and connects the one end of each signal line to each voltage measurement circuit after a predetermined settling time has elapsed; wherein each voltage measurement circuit acquires a voltage of the one end of each signal line as a measured voltage when connected with the one end of each signal line by the switching circuit; wherein the settling time is set to respective values of a first settling time group and a second settling time; wherein the first settling time group is constituted of a plurality of different time values, each of which is larger than a ratio (C/β wherein the property parameter acquisition circuit acquires the threshold voltage of the drive transistor for each pixel and the current amplification factor of the pixel drive circuit as a first property parameter in the property parameters based on voltage values of a plurality of measured voltages acquired by the voltage measurement circuits for the first settling time group; and the property parameter acquisition circuit acquires an irregularity parameter that indicates an irregularity of the current amplification factor as a second property parameter in the property parameters based on a value of the threshold voltage acquired for each pixel and values of measured voltages acquired by the voltage measurement circuits for the second settling time.