Hyundai Electronics Industries Co. Ltd.

Hynix Semiconductor Inc.

Suk-Joong Lee

Gyu-Tae Hwang

Oh-Bong Kwon

Hyun-Eun Kim

Sang-Yeon Kim

Disclosed is an apparatus for converting an analog image data into a digital image data in a CMOS image sensor including a pixel array having M (row line)&#xd7;N (column line) color pixels, wherein the color pixels include a first color pixel for sensing a first color, a second color pixel for sensing a second color and a third pixel for sensing a third color. The apparatus includes an analog reference voltage generating unit for generating different analog reference voltages according to the analog image data of the color pixels, wherein the different analog reference voltage has different value and different decline rate, a selecting unit, in response to a select control signal, for selecting one of the corresponding analog reference voltages according to the color pixels, and a comparing unit for comparing the analog reference voltage and the analog image data to generate the digital image data corresponding to the color pixels, whereby a conversion operation of the analog image data into the digital image data is differently carried out according to the color characteristic.

Apparatus for converting analog image data into digital image data in CMOS image sensor

A method for automatically controlling an exposure time in image sensor having a pixel array includes the steps of producing total pixel value of the green pixels from the pixel array, producing a mean value of the green pixels dividing the total pixel value of the green pixels by the number of the green pixels, producing a deviation value, wherein the deviation value is an absolute value of a difference between the mean value and a predetermined reference value, comparing the deviation value with a predetermined boundary value, in case where the deviation value is smaller than the predetermined boundary value, capturing a next image according to a current exposure time, and in case where the deviation value is larger than the predetermined boundary value, calculating an exposure control rate and determining whether an automatic exposure control mode is enabled, and in case where the automatic exposure control mode is disabled, capturing the next image according to the current exposure time, and in case where the automatic exposure control mode is enabled, capturing the next image according a next exposure time, wherein the next exposure time is calculated multiplying the current exposure time by the exposure control rate.

Apparatus and method for automatically controlling exposure time using a mean value of green pixels

A method for automatically controlling an exposure time in a CMOS image sensor includes the steps of a) estimating green pixel values and counting green pixels according to respective predetermined ranges, b) calculating a first total count value and a first maximum count value of green pixels having pixel values greater than a predetermined reference range and a second total count value and a second maximum count value of the green pixels having pixel values smaller than the reference ranges, c) comparing the first total count value with the second total count value, d) comparing a third total count value of the green pixels having a pixel value within the predetermined reference range with the first maximum count value if the first total count value is greater than the second total count value, and comparing the third total count value with the second maximum count value if the second total count value is greater than the first total count value, e) capturing a next image according to a current exposure time control signal if the third total count value is greater, and calculating an exposure control rate and an exposure time control signal and capturing the next image according to the next exposure time control signal if the third total count value is smaller, and f) repeating the steps a) to e) until the final completion of capturing image.

Apparatus and method for automatically controlling exposure time in CMOS image sensor

A method for detecting and correcting a defective pixel in an image sensor including an M(row line)&times;N(column line) unit pixels, M and N being positive integers, includes a first step of electrically scanning photoelectric charges generated from unit pixels of a first row line for a first integration time and storing a first data corresponding to the photoelectric charges, a second step of electrically scanning photoelectric charges generated from the unit pixels of the first row line for a second integration time and storing a second data corresponding to the photoelectric charges, a third step of comparing the first data and the second data one another, if the first data is different from the second data, an error signal is generated and then a corresponding address of the unit pixel is stored as a defective pixel address, a fourth step of repeating the first to the third step to an Mth line by increasing an address by one, and a fifth step of comparing an address of a unit pixel to be read with the defective pixel address, if the address of the unit pixel is equal to the defective pixel address, a correction operation is performed to generated a corrected data.

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Ichon-shi, South Korea

Suk-Joong Lee