KR20120055162A - Camera module - Google Patents

Abstract

PURPOSE: A camera module is provided to obtain a final image with a weak flicker phenomenon by setting a high brightness level. CONSTITUTION: An image sensor(20) generates a final image by sensing optical energy corresponding to input exposure time. A flicker sensing unit senses a flicker. If the flicker occurs, an image signal processing unit(30) outputs a fourth exposure time in which the weight of a central region of a preview image is equal to the weight of an edge region of the preview image.

Description

Camera module {Camera module}

The present invention relates to a camera module.

In general, a camera having an automatic shutter speed adjustment function increases the speed of the camera's shutter speed as the illumination level increases, and operates up to 30 fps (frame per sec).

For example, a 1, 500Lux fluorescent light that is directly lit by a 50-HZ commercial AC power source will cause a change in illuminance at 1 / 100-second intervals. Under these circumstances, the shutter speed of the camera will be up to 30fps, or 1 / 120s. It is operated until.

By the way, when the subject is photographed by a camera under the illumination of the fluorescent lamp which is turned on by a commercial AC power supply directly, to the difference of the frequency (two times of the commercial AC power supply frequency) of the illumination intensity change (light quantity change) of the fluorescent lamp and the camera shutter speed Accordingly, there is a problem that a change in temporal contrast, that is, flicker occurs, in the video signal of the photographing output.

For example, when photographing a subject by a camera under a fluorescent lamp having a commercial AC power supply frequency of 50 Hz, the shutter speed of the camera is increased as the illuminance level of the fluorescent lamp is increased to operate up to 30 fps.

Therefore, since the shutter speed of the camera has a maximum of 1/120 second while the period of illumination intensity change of the fluorescent lamp is at a maximum of 1/120 seconds, the exposure timing of each field is shifted with respect to the illumination intensity change of the fluorescent lamp, and the exposure amount of each pixel It is changed for each field.

As a result, since the exposure timing of the shutter speed according to the illuminance change period, such as a fluorescent lamp, does not coincide, there is a problem in that the flicker section is repeatedly generated at a predetermined period.

The present invention provides a camera module capable of preventing the flicker phenomenon that occurs when the illuminance change cycle and the shutter speed exposure timing do not coincide.

According to an aspect of the present invention, a lens unit, an image sensor for detecting the light energy incident through the lens unit to generate a preview image image, and detects the light energy corresponding to the input exposure time to generate a final image image And determining whether flicker has occurred in the preview image image. If the flicker does not occur, the first image sensor has a first exposure time or a first weight value different from each other in the weights of the center region and the edge region of the preview image image. A camera module including an image signal processor outputting a second exposure time and outputting a fourth exposure time equal to a weight of the center region and the edge region of the preview image image to the first image sensor when the flicker occurs; This is provided.

According to an embodiment of the present invention, when the flicker occurs, the final image is generated at the same exposure time as the weights of the center region and the edge region of the preview image image, so that the difference in the amount of light does not occur in the final image image. Video images can be obtained.

In addition, when the flicker occurs, the luminance level is set as high as the set reference luminance level, thereby obtaining a final image image in which the flicker is weakened by the high luminance.

1 is a schematic configuration diagram of a camera module according to an embodiment of the present invention.
2 is a schematic structural diagram of an image signal processor according to an exemplary embodiment of the present invention.
3 is an exemplary view of a flicker pattern according to an embodiment of the present invention.
4A and 4B illustrate exemplary exposure time adjustments of the exposure time adjusting unit when no flicker occurs, and FIG. 4C illustrates exposure time adjustment units of the exposure time adjusting unit when the flicker occurs.
5A is an exemplary diagram of a preview image image in which a flicker phenomenon occurs according to an embodiment of the present invention, and FIG. 5B is an exemplary diagram of a final image image according to an embodiment of the present invention.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Now, a camera module according to an embodiment of the present invention will be described in detail with reference to the drawings. The same or corresponding components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.

1 is a schematic configuration diagram of a camera module according to an embodiment of the present invention.

As shown in FIG. 1, the camera module includes a lens unit 10, an image sensor 20, and an image signal processor 30.

The lens unit 10 includes at least one lens, and receives light energy and condenses the incident light energy and outputs the light energy to the image sensor 20.

The image sensor 20 includes a plurality of pixels that sense the light energy passing through the lens unit 10, and converts the light energy detected by the plurality of pixels into an electrical signal and outputs the electrical signal to the image signal processor 30. .

Before the exposure time is input from the image signal processor 30, the image sensor 20 generates a preview image and outputs the image to the image signal processor 30. When the exposure time is input from the image signal processor 30, the image sensor ( 20 outputs a final image image of sensing light energy to the image signal processor 30 according to the input exposure time.

2 is a schematic configuration diagram of an image signal processor according to an exemplary embodiment of the present invention, FIG. 3 is an exemplary diagram of a flicker pattern according to an exemplary embodiment of the present invention, and FIGS. 4A and 4B are examples in which no flicker occurs. 4C is an exemplary view of adjusting the exposure time of the exposure time adjusting unit, and FIG. 4C is an exemplary view of adjusting the exposure time of the exposure time adjusting unit when flicker occurs, and FIG. 5A is an exemplary view of a preview image image in which the flicker occurs according to an embodiment of the present invention. 5B is an exemplary view of a final image image according to an embodiment of the present invention.

As illustrated in FIG. 2, the image signal processor 30 may include a flicker detector 31 that detects whether a flicker phenomenon occurs in the preview image image input from the image sensor 20, and the flicker detector 31. ), The exposure level adjusting unit 32 adjusts the exposure time of the image sensor 20 according to whether the flicker is detected, and when the flicker is detected, the luminance level is compared with the exposure time adjusted by the exposure time adjusting unit 32. And an exposure target adjuster 33 that readjusts the exposure time to be as high as the level.

When the flicker phenomenon occurs, as shown in FIG. 3, a pattern in which a part or the whole is waved in the horizontal direction appears in the preview image image input from the image sensor 20, and the flicker detector 31 has the flicker of FIG. 3. The pattern is saved.

When the preview image image is input from the image sensor 20, the flicker detector 31 compares whether a flicker pattern stored in advance is generated in the preview image image.

If the flicker pattern does not appear in the preview image, the flicker detection unit 31 outputs a first control signal indicating that the flicker does not occur to the exposure time adjusting unit 32. When the flicker pattern appears in the preview image, the flicker phenomenon is displayed. The second control signal indicative of the occurrence is output to the exposure time adjustment unit 32.

When the first control signal indicating that the flicker does not occur from the flicker detector 31 is input to the exposure time adjusting unit 32, the exposure time adjusting unit 32 has a weight (a weight) in the center region of the preview image image to improve the sensitivity as shown in FIG. 4A. A first exposure time giving a weight) is set, and a second exposure time giving a weight to an edge area of the preview image image is set and output to the image sensor 20 as shown in FIG. 4B.

Then, the image sensor 20 outputs the first final image image or the second final image image generated by sensing the light energy corresponding to the first exposure time or the second exposure time to the image signal processor 30.

In this case, the first final image image photographed according to the first exposure time is an image image in which the center region is bright and the edge region has a relatively dark light quantity difference compared to the center region.

In addition, the second final image image photographed according to the second exposure time is an image image in which a central area has a relatively dark light quantity difference compared to the edge region.

In general, the flicker phenomenon appears more clearly as the amount of light difference occurs.

Accordingly, when the exposure time adjusting unit 32 receives the second control signal indicating that the flicker occurs in the flicker detecting unit 31, the weights of the center region and the edge region of the preview image image are the same as illustrated in FIG. 4C. The third exposure time is set and output to the exposure target adjustment unit 33.

The exposure target adjustment unit 33 adjusts the luminance level (Y-level), and the R, G, and B levels are approximately 20 to 30 degrees higher than the third exposure time, thereby increasing the luminance level (Y-level) of the third exposure time. The third exposure time is readjusted to the fourth exposure time so as to be set as high as the set reference luminance level and output to the image sensor 20.

Then, the image sensor 20 outputs the third final image image generated by sensing the light energy corresponding to the fourth exposure time to the image signal processor 30.

As shown in FIG. 5B, the final image image according to the fourth exposure time input through the image sensor 20 is an image image in which the light amount difference between the center region and the edge region having the same brightness as a whole does not occur. Since the difference in light quantity does not occur in the final image image photographed according to the fourth exposure time, the third final image image of FIG. 5B having a weaker flicker than that of FIG. 5A may be obtained.

In addition, in the present invention, when the flicker occurs, the luminance level is set as high as the reference luminance level (the level at which the R, G, and B levels are increased by about 20 to 30), whereby the third final factor that can weaken the flicker due to the high luminance is achieved. Video images can be obtained.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

10: lens unit
20: image sensor
30: image signal processor
31: flicker detector
32: exposure time adjustment unit
33: exposure target adjustment unit

Claims (7)

Lens,
An image sensor which detects the light energy incident through the lens unit to generate a preview image image, and detects the light energy corresponding to the input exposure time to generate a final image image;
It is determined whether flicker has occurred in the preview image image, and when the flicker does not occur, the first image sensor has a first exposure time or a second weight value different from the center and edge regions of the preview image image. And an image signal processor configured to output an exposure time and output, when the flicker occurs, a fourth exposure time equal to the weight of the center region and the edge region of the preview image image to the first image sensor. The method of claim 1,
The first exposure time is a camera module, the weight of the center area is set higher than the weight of the edge area, and the second exposure time of the camera module, the weight of the center area is set lower than the weight of the edge area. The method of claim 1,
The image signal processor,
A flicker detector for detecting whether the flicker has occurred;
Outputting the first exposure time or the second exposure time to the image sensor when the flicker is not detected; and a third weight having the same weight as that of the center region and the edge region of the preview image image when the flicker is detected. An exposure time adjusting unit for setting and outputting an exposure time; and
And an exposure target adjuster configured to readjust the third exposure time to the fourth exposure time such that the brightness level is increased by a reference brightness level compared to the third exposure time output from the exposure time adjuster. The method of claim 3,
And the flicker detector detects whether a pre-stored flicker pattern has occurred in the preview image image. The method of claim 3,
And when the flicker is detected, the image sensor detects the light energy corresponding to the fourth exposure time to generate the final image image. The method of claim 3,
And the reference luminance level is a luminance level at which R, G, and B levels of the third exposure time are increased by a set range. The method of claim 3,
The flicker detection unit is a camera module that stores a flicker pattern having a pattern shape in which part or the whole wave in the horizontal direction in the preview image image.

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