×

LIGHT EMITTING DEVICE AND A DRIVE CONTROL METHOD FOR DRIVING A LIGHT EMITTING DEVICE

  • US 20100134469A1
  • Filed: 11/27/2009
  • Published: 06/03/2010
  • Est. Priority Date: 11/28/2008
  • Status: Active Grant
First Claim
Patent Images

1. A light emitting device, comprising:

  • a pixel array, which is constituted of a plurality of pixels arranged, 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 the 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 as well as 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 the each voltage measurement circuit; and

    a property parameter acquisition circuit for acquiring the property parameters that relate to the electrical properties of the each pixel;

    a signal correction circuit for outputting a corrected gradation signal by correcting the 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 corrected gradation signal on the one end of the each signal linewherein,the reference voltage has an electric potential in which the 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; and

    the switching circuit connects the one end of each signal line to the voltage impressing circuit and sets the connection between the one end of each signal line and the voltage impressing circuit being interrupted 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 subsequent to a predetermined settling time elapsing ; and

    each voltage measurement circuit acquires the voltage of the one end of each signal line as the measured voltage when being connected with the one end of each signal line by the switching circuit; and

    the settling time is set to each value of a first settling time group and a second settling time;

    the first settling time group is constituted of a plurality of different time values, each of which is larger than the ratio (C/β

    0) where C is total capacity, which is the sum of parasitic capacity that is parasitic on a single signal line, the holding capacity, and light emitting element capacity that is parasitic on the light emitting element, and β

    0 is the reference value of the current amplification factor; and

    the second settling time is constituted of the time value which is shorter than the ratio (C/β

    0); and

    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 the values of the plurality of measured voltages acquired by the voltage measurement circuit for the first settling time group; and

    the property parameter acquisition circuit acquires the irregularity parameter that indicates the irregularity of the current amplification factor as a second property parameter in the property parameters based on value of the threshold voltage acquired for each pixel and the value of the measured voltage acquired by the voltage measurement circuit for the second settling time.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×