CN107566763B - Large-size image sensor and image correction method thereof - Google Patents
Large-size image sensor and image correction method thereof Download PDFInfo
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- CN107566763B CN107566763B CN201710084628.8A CN201710084628A CN107566763B CN 107566763 B CN107566763 B CN 107566763B CN 201710084628 A CN201710084628 A CN 201710084628A CN 107566763 B CN107566763 B CN 107566763B
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Abstract
The invention provides an image sensor and an image correction method thereof, wherein the whole pixel array of an image sensor chip is divided into a plurality of sub-arrays, the fitting values of the sub-arrays under different light intensities are obtained by testing before the packaging of the image sensor chip is finished, so as to be written into an internal storage unit of the image sensor chip, and when the image sensor chip is used for outputting images after the image sensor chip is shipped, the corresponding fitting values can be automatically called from the internal storage unit to correct the output of the sub-arrays, so as to output the corrected images, thereby improving the image uniformity of the image sensor.
Description
Technical Field
The invention relates to the technical field of image sensors, in particular to a large-size image sensor and an image correction method thereof.
Background
An image sensor or a photosensitive element is a device for converting an optical image into an electronic signal, and is widely used in digital cameras and other electronic optical devices. With the development of modern industry and the increase of human demand, the pixels of the image sensor are increasingly enlarged, and after the pixels reach the order of tens of millions or even tens of millions, the whole image sensor reaches a huge size of centimeter or even decimeter, i.e. a large-size image sensor, and the proportion difference of the pixels of the large-size image sensor and the normal-size image sensor on the wafer is very large, as shown in fig. 1, and the proportion difference of the pixels of the 5-million-pixel large-size image sensor (50Mega sensor) and the 5-million-pixel normal-size image sensor (5Mega sensor) on the wafer is shown in fig. 1.
The current large-size image sensor generally has the problem of poor image uniformity, mainly due to the following reasons:
1. the pixels and physical size of the large-sized image sensor are greatly increased compared with the normal-sized image sensor, so that the uniformity of the image of the large-sized image sensor is poor;
2. from the perspective of semiconductor manufacturing processes, due to limitations in semiconductor processing capabilities, pixels within a wafer vary from center to edge within the wafer, and also vary in pixel between wafers of different wafers to varying degrees. For an image sensor chip with normal million-level pixels, because the chip size is small, the influence of the pixel difference inside a single chip on the image uniformity is not very large, but for a large-size image sensor, when the size of the large-size image sensor is increased to tens of millions of pixels, the pixel difference inside the chip is large to the extent that the pixel difference cannot be ignored, and further the image uniformity is deteriorated.
Disclosure of Invention
The invention aims to provide a large-size image sensor and an image correction method thereof, which can improve the image uniformity inside a large-size image sensor chip.
In order to solve the above problem, the present invention provides an image correction method for an image sensor, comprising the following steps:
dividing the whole pixel array of each image sensor chip into a plurality of sub-arrays;
irradiating the image sensor chip with uniform light with different light intensities, and recording the output intensity of each subarray under each light intensity;
calculating the deviation value of the output intensity of each subarray under each light intensity to obtain the fitting value of each subarray under each light intensity;
and finally, before the image sensor chip is packaged and delivered from the factory, writing the fitting values into an internal storage unit of the image sensor chip, and automatically calling corresponding fitting values from the internal storage unit to correct the output of each subarray when the image sensor chip is set to be used for outputting images after the image sensor chip is delivered from the factory so as to output the corrected images.
Furthermore, the whole pixel array of each image sensor chip is divided into (n +1) × (m +1) equal parts to be divided into a plurality of sub-arrays with the same size, wherein n is larger than or equal to 1, and m is larger than or equal to 1.
Further, the optical size of the image sensor chip is 1/2 inches or more.
Further, the wavelength of the uniform light is 400nm to 1000 nm.
Further, after calculating the deviation value of the output intensity of each sub-array under each light intensity, taking the center of the whole pixel array as a reference, taking the deviation value of each sub-array under each light intensity as a fitting curve, and recording the value of the corresponding point of each sub-array in the fitting curve, thereby obtaining the fitting value of each sub-array under each light intensity.
Further, the internal storage unit is a one-time programmable memory OTP or a flash memory flash.
The invention also provides a large-size image sensor which is provided with a pixel array and an internal storage unit, wherein the whole pixel array is set to be composed of a plurality of sub-arrays, and fitting values of the sub-arrays under different light intensities, which are measured before the image sensor chip is packaged and leaves a factory, are stored in the internal storage unit; when the image sensor outputs an image, the image sensor can automatically call corresponding fitting values from the internal storage unit to correct the output of each sub-array so as to output the corrected image.
Further, the pixel array is configured to be composed of (n +1) × (m +1) sub-arrays of the same size, where n ≧ 1 and m ≧ 1.
Further, the optical size of the image sensor chip is 1/2 inches or more.
Further, the internal storage unit is a one-time programmable memory OTP or a flash memory flash.
Compared with the prior art, the image sensor and the image correction method thereof divide the whole pixel array of the image sensor chip into a plurality of sub-arrays, test is carried out before the image sensor chip is packaged and delivered from a factory to obtain the fitting value of each sub-array under different light intensities so as to write the fitting value into the internal storage unit of the image sensor chip, and when the image sensor chip is used for outputting images after being delivered from the factory, the corresponding fitting value can be automatically called from the internal storage unit to correct the output of each sub-array so as to output the corrected images, so that the image uniformity of the image sensor is improved. The technical scheme of the invention is particularly suitable for 1/2-inch large-size image sensors.
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FIG. 1 is a diagram illustrating the difference between the ratio of pixels on a wafer between a conventional 50Mega large-size image sensor and a conventional 5Mega normal-size image sensor;
FIG. 2 is a flow chart of an image correction method of an image sensor according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a pixel array according to an embodiment of the present invention;
FIG. 4 is a graph of the output intensity of each subarray at different light intensities in accordance with an embodiment of the present invention;
FIG. 5 is a graph of the output intensity of the pixel array at different intensities before and after calibration of the image sensor in accordance with one embodiment of the present invention.
Detailed Description
The present invention will be described in more detail with reference to the accompanying drawings, which are included to illustrate embodiments of the present invention.
Referring to fig. 2, the present invention provides an image correction method of an image sensor, including the following steps:
s1, dividing the whole pixel array of each image sensor chip into a plurality of sub-arrays;
s2, irradiating the image sensor chip by using uniform light with different light intensities, and recording the output intensity of each subarray under each light intensity;
s3, calculating the deviation value of the output intensity of each subarray under each light intensity to obtain the fitting value of each subarray under each light intensity;
and S4, writing the fitting values into an internal storage unit of the image sensor chip before the image sensor chip is packaged and shipped, and automatically calling corresponding fitting values from the internal storage unit to correct the output of each subarray when the image sensor chip is set to be used for outputting images after the image sensor chip is shipped, so as to output the corrected images.
In step S1, the optical size of each image sensor chip may be 1/2 inches or more. The pixel array of the image sensor chips in the same batch can be divided according to the same dividing mode, the pixel array of each image sensor chip can be divided into a plurality of sub-arrays with the same size, and also can be divided into a plurality of sub-arrays with the size in gradient arrangement according to a certain size gradient. In the present embodiment, for each image sensor chip, the entire pixel array is divided in the (n +1) × (m +1) grid, thereby forming sub-arrays arranged in the (n +1) × (m +1) matrix, as shown in fig. 3. Wherein n and m are integers equal to or greater than 1, i.e. n is greater than or equal to 1, m is greater than or equal to 1, and the minimum of n and m can be 1, or can be other integers, for example, n and m can be different multiples of 2.
In step S2, the wavelength range of the selected uniform light may be 400nm to 1000nm, i.e. visible light or infrared light. The uniform light with different light intensities for testing can cover all light intensity values with the wavelength range of 400 nm-1000 nm, namely the light intensity values are continuously changed; however, in order to save the test time and cost, the uniform light with different intensities for testing can be tested from some wavelength ranges of 400nm to 1000nm, such as 400nm to 435nm, 435nm to 455nm, 460nm to 490nm, 492nm to 560nm, 577nm to 610nm, 622nm to 650nm, 700nm to 760nm, 770nm to 850nm, 900nm to 1000nm, or some wavelengths, such as 400nm, 435nm, 460nm, 520nm, 555nm, 560nm, 610nm, 650nm, 750nm, 760nm, 780nm, 900nm, 1000nm, etc. The output intensities La 00-Lanm, … … Lx 00-Lxnm of the respective subarrays at each light intensity were recorded as shown in FIG. 4.
In step S3, after obtaining the output intensities of the sub-arrays under the irradiation of all different light intensities, calculating a deviation value of the output intensity of each sub-array under each light intensity, taking the center of the entire pixel array as a reference, making a fitting curve of the deviation values of the different light intensities corresponding to each sub-array, and recording the values of the corresponding points of each sub-array in the fitting curve, thereby obtaining the fitting value of each sub-array under each light intensity.
Introducing an on-chip OTP (one time program) or flash (flash memory) storage technology into the image sensor chip in advance, and completing steps S1 to S3 before the image sensor chip is packaged and shipped, so that in step S4, the fitting value of each sub-array obtained in step S3 is written into an internal storage unit (OTP/flash), and it is set that the image sensor chip can automatically retrieve a corresponding fitting value from the internal storage unit when used for outputting an image after shipped, and the fitting value of each sub-array is substituted into the current output of each sub-array to correct the output of each sub-array, so that the image sensor can output a corrected image after shipped.
As shown in fig. 5, the curve before correction is a wavy curve, which illustrates that the output intensities of the sub-arrays of an image sensor without the improvement of the present invention are different and have poor uniformity, i.e. the image uniformity of the image sensor before correction is poor, and the curve after correction is a straight line, i.e. the output intensities of the sub-arrays of the image sensor improved according to the present invention are completely the same and have uniform uniformity. Therefore, the correction method of the image sensor of the invention can greatly improve the image uniformity of the image sensor and is suitable for manufacturing and image correction of large-size image sensors with the size of 1/2 inches or more.
Therefore, according to the image correction method of the image sensor, the whole pixel array of the image sensor chip is divided into the plurality of sub-arrays, the fitting values of the sub-arrays under different light intensities are obtained through testing before the image sensor chip is packaged and leaves factory, and are written into the internal storage unit of the image sensor chip, so that when the image sensor chip is used for outputting images after leaving factory, the corresponding fitting values can be automatically called from the internal storage unit to correct the output of the sub-arrays, and the corrected images are finally output, and therefore the image uniformity of the image sensor is improved.
The invention also provides an image sensor which is provided with a pixel array and an internal storage unit, wherein the whole pixel array is set to be composed of a plurality of sub-arrays, and fitting values of the sub-arrays under different light intensities, which are measured before the image sensor chip is packaged and leaves a factory, are stored in the internal storage unit; when the image sensor outputs an image, the image sensor can automatically call corresponding fitting values from the internal storage unit to correct the output of each sub-array so as to output the corrected image.
The optical size of the image sensor chip can be 1/2 inches or more, the pixel array can be configured to be composed of (n +1) × (m +1) sub-arrays with the same size, wherein n is equal to or greater than 1, m is equal to or greater than 1, and the internal storage unit can be one-time programmable memory OTP or flash memory flash.
Therefore, in the image sensor, the fitting values of each subarray under different light intensities are pre-stored in the internal storage unit, and the fitting values are obtained and written in by testing before the chip is packaged and leaves factory, so that the corresponding fitting values can be automatically called from the internal storage unit to correct the output of each subarray in the using process of the image sensor, and the uniformity of the output image is high.
It will be apparent to those skilled in the art that various changes and modifications may be made in the invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (10)
1. An image correction method of an image sensor, the image correction method is used for correcting the problems of pixel difference inside a chip of the image sensor and image uniformity deterioration caused by the physical size of the image sensor, and the image correction method comprises the following steps:
dividing the whole pixel array of each image sensor chip into a plurality of sub-arrays according to grids;
irradiating the image sensor chip with uniform light with different light intensities, and recording the output intensity of each subarray under each light intensity;
calculating the deviation value of the output intensity of each subarray under each light intensity to obtain the fitting value of each subarray under each light intensity;
and finally, before the image sensor chip is packaged and delivered from the factory, writing the fitting values into an internal storage unit of the image sensor chip, and automatically calling corresponding fitting values from the internal storage unit to correct the output of each subarray when the image sensor chip is set to be used for outputting images after the image sensor chip is delivered from the factory so as to output the corrected images.
2. The image correction method of image sensor according to claim 1, wherein the whole pixel array of each image sensor chip is divided into sub-arrays of the same size by dividing (n +1) × (m +1) equally, wherein n ≧ 1 and m ≧ 1.
3. The image correction method of an image sensor according to claim 1, wherein an optical size of the image sensor chip is 1/2 inches or more.
4. The image correction method of an image sensor according to claim 1, wherein the wavelength of the uniform light is 400nm to 1000 nm.
5. The image correction method of an image sensor as claimed in claim 1, wherein after calculating the deviation value of the output intensity of each sub-array at each light intensity, the deviation value of each sub-array at each light intensity is taken as a fitting curve with respect to the center of the entire pixel array, and the values of the corresponding points of each sub-array in the fitting curve are recorded, thereby obtaining the fitting value of each sub-array at each light intensity.
6. The image correction method of an image sensor according to claim 1, wherein the internal storage unit is a one-time programmable memory OTP or a flash memory flash.
7. An image sensor is provided with a pixel array and an internal storage unit, and is characterized in that the whole pixel array is divided into a plurality of sub-arrays according to grids, fitting values of the sub-arrays under different light intensities, which are measured before the chip of the image sensor is packaged and leaves factory, are stored in the internal storage unit, and the fitting values are used for correcting the problems of image uniformity deterioration caused by pixel difference inside the chip of the image sensor and the physical size of the image sensor; when the image sensor outputs an image, the image sensor can automatically call corresponding fitting values from the internal storage unit to correct the output of each sub-array so as to output the corrected image.
8. The image sensor of claim 7, wherein the pixel array is configured to consist of (n +1) × (m +1) sub-arrays of equal size, where n ≧ 1 and m ≧ 1.
9. The image sensor of claim 7, wherein the image sensor chip has an optical size of 1/2 inches or more.
10. The image sensor of claim 7, wherein the internal memory unit is a one-time programmable memory (OTP) or a flash memory (flash).
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1501111A (en) * | 2002-11-13 | 2004-06-02 | ��ʽ���������Ƽ� | Camera accessory |
| CN101510962A (en) * | 2008-12-31 | 2009-08-19 | 昆山锐芯微电子有限公司 | Method and apparatus for correcting lens shadow |
| CN103024300A (en) * | 2012-12-25 | 2013-04-03 | 华为技术有限公司 | Device and method for high dynamic range image display |
| CN104680489A (en) * | 2015-02-11 | 2015-06-03 | 深圳怡化电脑股份有限公司 | Image correcting method and system |
| CN106169178A (en) * | 2016-06-30 | 2016-11-30 | 北京大学 | A kind of method improving camera lens vignetting |
-
2017
- 2017-02-16 CN CN201710084628.8A patent/CN107566763B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1501111A (en) * | 2002-11-13 | 2004-06-02 | ��ʽ���������Ƽ� | Camera accessory |
| CN101510962A (en) * | 2008-12-31 | 2009-08-19 | 昆山锐芯微电子有限公司 | Method and apparatus for correcting lens shadow |
| CN103024300A (en) * | 2012-12-25 | 2013-04-03 | 华为技术有限公司 | Device and method for high dynamic range image display |
| CN104680489A (en) * | 2015-02-11 | 2015-06-03 | 深圳怡化电脑股份有限公司 | Image correcting method and system |
| CN106169178A (en) * | 2016-06-30 | 2016-11-30 | 北京大学 | A kind of method improving camera lens vignetting |
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