CN102375199B - Camera module - Google Patents

Abstract

A camera module includes a first lens array, a second lens array, a liquid crystal shutter arranged between the first lens array and the second lens array, a controller, an image sensor and an image processor. The first lens array includes a plurality of first lenses. The second lens array includes a plurality of second lenses, and the plurality of second lenses are optically aligned with the plurality of first lenses respectively. The liquid crystal shutter has a plurality of light holes, and the light holes are optically aligned with the plurality of first lenses respectively. The controller is used for controlling each light hole of the liquid crystal shutter to be opened once in a shooting cycle. The image sensor is used to obtain a sub-image corresponding to each light hole when each light hole is opened in a shooting period. The image processor is used for synthesizing the sub-images corresponding to each aperture into an image by adopting super-resolution image restoration technology.

Description

camera module

technical field

The invention relates to a camera module.

Background technique

With the development of multimedia technology, people have higher and higher requirements for camera modules in portable electronic devices, for example, higher and higher resolution requirements. In order to improve the resolution of the camera module, it is often necessary to add optical lenses, etc., resulting in an increase in the total optical length (Optical Total Track Length) of the camera module, which in turn leads to an increase in the thickness of the portable electronic device. However, this is contrary to people's requirements for portable electronic devices to be thin, light and small.

Contents of the invention

In view of this, it is necessary to provide a camera module with high resolution and small thickness.

A camera module includes a first lens array, a second lens array, a liquid crystal shutter arranged between the first lens array and the second lens array, a controller, an image sensor and an image processor. The first lens array includes a plurality of first lenses. The second lens array includes a plurality of second lenses, and the plurality of second lenses are optically aligned with the plurality of first lenses respectively. The liquid crystal shutter has a plurality of light holes, and the light holes are optically aligned with the plurality of first lenses respectively. The controller is used for controlling each light hole of the liquid crystal shutter to be opened once in a shooting cycle. The image sensor is used to obtain a sub-image corresponding to each light hole when each light hole is opened in a shooting period. The image processor is used for synthesizing the sub-images corresponding to each aperture into an image by adopting super-resolution image restoration technology.

Compared with the prior art, the present invention uses the first lens array, the second lens array and the liquid crystal shutter to obtain sub-images with lower resolution, and then uses super-resolution image restoration technology to synthesize each sub-image into a high-resolution image. Since the resolution of the sub-image is lower, the total optical length of the camera module forming the sub-image can be shortened, so the thickness of the camera module can be reduced.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a camera module according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a compound lens in the camera module of FIG. 1 .

Fig. 3 is a plan view of the composite lens of Fig. 2 .

FIG. 4 is a schematic diagram of the connection between the upper electrode and the lower electrode of the liquid crystal shutter and the controller in the camera module of FIG. 1 .

Description of main component symbols

Camera Module 100

Composite lens 10

Image sensor 20

circuit board 30

image processor 40

Controller 50

Solder Ball 22

Frame 101

Second lens 102

Upper substrate 103

Second lens array 104

First lens 105, 105a, 105b, 105c, 105d

LCD shutter 106

First lens array 107

Alignment mark 108

Lower substrate 109

Upper polarizer 1061

Upper shading layer 1062

Stop electrode 1063

Liquid crystal layer 1064

Lower electrode 1065

Lower shading layer 1066

Lower polarizer 1067

Clear hole 1068

Upper light hole 10624

Lower pass light hole 10664

Alignment hole 10622

Conductive area 10631, 10651

Connecting part 10633

Pin 10635, 10653

Detailed ways

The technical solution will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Referring to FIG. 1 , a preferred embodiment of the present invention provides a camera module 100 . The camera module 100 includes a composite lens 10 , a controller 50 , an image sensor 20 , an image processor 40 and a circuit board 30 . The image sensor 20 is soldered on the circuit board 30 through solder balls 22 . The image processor 40 is provided on the circuit board 30 . The image sensor 20 is electrically connected to the controller 50 and the image processor 40 respectively.

2 and 3, the composite lens 10 includes a frame 101, an upper substrate 103, a lower substrate 109, a first lens array 107 formed on the upper substrate 103, a second lens array 104 formed on the lower substrate 109, and an interposed The liquid crystal shutter 106 between the upper substrate 103 and the lower substrate 109 .

The mirror frame 101 is approximately square in cross section. The mirror frame 101 includes four interconnected side walls. The side walls of the mirror frame 101 form a substantially rectangular parallelepiped storage space for accommodating the upper substrate 103 , the lower substrate 109 , the first lens array 107 , the second lens array 104 and the liquid crystal shutter 106 . A light hole is opened at the bottom of the mirror frame 101, and the light hole communicates with the receiving space.

The bottom of the upper substrate 103 is provided with a first groove, and the top of the lower substrate 109 is provided with a second groove. The accommodation cavity of the liquid crystal shutter 106 .

In this embodiment, the first lens array 107 includes four first lenses 105a, 105b, 105c, and 105d (hereinafter collectively referred to as 105 when there is no need to distinguish them), and the four first lenses 105 are arrayed in two rows and two columns. arranged. The centers of the first lenses 105 in each row are aligned with each other, and the centers of the first lenses 105 in each column are also aligned with each other. The orthographic projection areas of the four first lenses 105 along their respective optical axes are substantially equal. The second lens array 104 includes four second lenses 102 arranged in an array of two rows and two columns. The centers of the second lenses 102 in each row are aligned with each other, and the centers of the second lenses 102 in each column are also aligned with each other. The orthographic areas of the four second lenses 102 along their respective optical axes are substantially equal. The four first lenses 105 correspond to the four second lenses 102 one by one, and the optical axis of each first lens 105 coincides with the corresponding second lens 102 . The area of the orthographic projection of each first lens 105 along its optical axis is approximately equal to the area of the orthographic projection of each second lens 102 along its optical axis.

In this embodiment, the upper substrate 103 and the first lens array 107 , the lower substrate 109 and the second lens array 104 are respectively integrally formed. It can be understood that the upper substrate 103 and the first lens array 107 can also be formed independently, and the lower substrate 109 and the second lens array 104 can also be formed independently.

The liquid crystal shutter 106 has four light holes 1068 arranged in an array. The four light holes 1068 are in one-to-one correspondence with the four first lenses 105 and the four second lenses 102 . The liquid crystal shutter 106 can selectively open or close each light hole 1068 to determine whether to allow light to pass through the first lens 105 and the second lens 102 . Each light through hole 1068 is substantially circular. The area of each light through hole 1068 is approximately equal to the area of the orthographic projection of the first lens 105 along its optical axis.

From the upper substrate 103 to the lower substrate 109, the liquid crystal shutter 106 sequentially includes an upper polarizer 1061, an upper light-shielding layer 1062, an upper electrode 1063, a liquid crystal layer 1064, a lower electrode 1065, a lower light-shielding layer 1066, and a lower polarizer 1067.

Please also refer to FIG. 3 , the upper light-shielding layer 1062 can be made of light-shielding materials such as chromium. The upper light-shielding layer 1062 defines four substantially circular upper light holes 10624 . The four upper light holes 10624 correspond to the four first lenses 105 and the four second lenses 102 respectively. The area of each upper light hole 10624 is approximately equal to the area of the orthographic projection of the first lens 105 along its optical axis.

The upper electrode 1063 is a common electrode (Common Electrode), and the upper electrode 1063 includes four substantially circular conductive regions 10631, a connection portion 10633 connecting the four conductive regions 10631, and a pin 10635 connected to the connection portion 10633. The upper electrode 1063 is electrically connected to the controller 50 . The upper electrode 1063 is a transparent electrode, and its material can be a transparent conductive material such as an indium tin oxide conductive film (Indium Tin Oxide, ITO) or a carbon nanotube film. The four conductive regions 10631 are in one-to-one correspondence with the four first lenses 105 . The area of each conductive region 10631 is approximately equal to the area of the orthographic projection of the first lens 105 along its optical axis.

The liquid crystal layer 1064 adopts a liquid crystal material with a relatively fast response time, for example, a liquid crystal material with a response time of several milliseconds. In this embodiment, the liquid crystal layer 1064 is a ferroelectric liquid crystal material (Ferroelectric Liquid Crystal).

The lower electrode 1065 includes four substantially circular conductive regions 10651 and four pins 10653 respectively connected to the conductive regions 10651 . The pins 10653 of the lower electrode 1065 are electrically connected with the controller 50 . The lower electrode 1065 is a transparent electrode, and its material can be transparent conductive materials such as indium tin oxide conductive film (Indium Tin Oxide, ITO) or carbon nanotube film. The four conductive regions 10651 correspond to the four first lenses 105 and the four second lenses 102 respectively. The area of each conductive region 10651 is roughly equal to the area of the orthographic projection of the second lens 102 along its optical axis.

The lower light-shielding layer 1065 can be made of light-shielding materials such as chrome. The lower light-shielding layer 1065 defines four substantially circular lower light holes 10664 . The four lower light holes 10664 correspond to the four first lenses 105 and the four second lenses 102 respectively. The area of each lower light hole 10664 is approximately equal to the area of the second lens 102 along its optical axis orthographically projected. The four upper light holes 10624 and the four lower light holes 10664 are coaxially arranged respectively, and one upper light hole 10624 and one corresponding lower light hole 10664 together form a light hole 1068 .

Further, an alignment mark 108 may be provided at the central position of the upper substrate 103, and in this embodiment, the alignment mark 108 is a "cross"-shaped alignment mark. Correspondingly, an alignment mark (not shown) is also provided at the central position of the lower substrate 109, and an alignment hole 10622 is opened at the central positions of the upper light-shielding layer 1062 and the lower light-shielding layer 1066, so that the upper substrate 103 and When the lower substrates 109 are assembled together, precise alignment can be achieved through the alignment marks 108 .

The controller 50 is used to control each light hole 1068 of the liquid crystal shutter 106 to open once in a shooting cycle. The controller 50 changes the alignment of the liquid crystal molecules in the liquid crystal layer 1064 by controlling the voltage applied between the upper electrode 1063 and the lower electrode 1065 , thereby independently controlling the opening and closing of each light hole 1068 . In this embodiment, the controller 50 controls each light through hole 1068 to be opened sequentially, and only one light through hole 1068 is opened at a time. Moreover, when each light hole 1068 is opened, the controller 50 synchronously controls the image sensor 20 to acquire a sub-image corresponding to the light hole 1068 .

The image sensor 20 is used to obtain a sub-image corresponding to each light hole 1068 when each light hole 1068 is opened within a shooting period.

The image processor 40 is used for synthesizing the sub-images corresponding to the light holes 1068 within one shooting period into one image by using Super-Resolution Image Reconstruction technology.

In use, the controller 50 changes the arrangement of liquid crystal molecules in the liquid crystal layer 1064 by controlling the voltage between the upper electrode 1063 and the lower electrode 1065 , thereby sequentially opening the light holes 1068 of the liquid crystal shutter 106 . When each light aperture 1068 is opened, the controller 50 synchronously controls the image sensor 20 to acquire a sub-image. to obtain a high-resolution image that is higher than the resolution of each sub-image.

More specifically, at time T1, the controller 50 only opens the light aperture 1068 corresponding to the first lens 105a, and the controller 50 synchronously controls the image sensor 20 to obtain the light formed by the first lens 105a and the corresponding second lens 102. at time T2, the controller 50 only opens the light aperture 1068 corresponding to the first lens 105b, and the controller 50 synchronously controls the image sensor 20 to acquire images obtained by the first lens 105b and the corresponding second lens 102 The formed sub-image P2; at time T3, the controller 50 only opens the light aperture 1068 corresponding to the first lens 105c, and the controller 50 synchronously controls the image sensor 20 to acquire images obtained by the first lens 105c and the corresponding second lens 102 to form the sub-image P3; at time T4, the controller 50 only opens the light aperture 1068 corresponding to the first lens 105d, and the controller 50 synchronously controls the image sensor 20 to obtain images captured by the first lens 105d and the corresponding second lens 105d. The sub-image P4 formed by the lens 102 . Finally, the image processor 40 synthesizes the four sub-images P1-P4 by using super-resolution image restoration technology to obtain a high-resolution image P.

Compared with the prior art, the present invention uses the first lens array 107, the second lens array 104, and the liquid crystal shutter 106 to obtain sub-images with lower resolution, and then uses super-resolution image restoration technology to synthesize each sub-image into a high-resolution image. of the image. Since the resolution of the sub-image is lower, the total optical length of the camera module 100 for forming the sub-image can be shortened, so the thickness of the camera module 100 can be reduced.

It can be understood that, in other embodiments, the first lens array 107 may include m rows and n columns of first lenses 105 (m and n are positive integers). Correspondingly, the second lens array 104 includes m rows and n columns of second lenses 102 , and the liquid crystal shutter 106 has m×n light holes 1068 .

It can be understood that in the liquid crystal shutter 106, the order of the upper polarizer 1061, the upper light-shielding layer 1062 and the upper electrode 1063 can be changed freely, and the order of the lower electrode 1065, the lower light-shielding layer 1066 and the lower polarizer 1067 can be changed freely.

When shooting two connected sub-images in an array shooting, there may be overlapping of images in the boundary area of the two sub-images, resulting in blurred edges of the two sub-images, which is called image distortion (Aliasing). It can be understood that, under the condition that Aliasing is not generated, the controller 50 can open two or more light holes 1068 at the same time, and the image sensor 20 can acquire two or more images at the same time. sub-images, thereby shortening the continuous shooting time of sub-images.

In addition, those skilled in the art can also make other changes within the spirit of the present invention. Of course, these changes made according to the spirit of the present invention should be included within the scope of protection claimed by the present invention.

Claims (8)

1. A camera module, characterized in that it comprises: a first lens array, the first lens array includes a plurality of first lenses; a second lens array, the second lens array includes a plurality of second lenses, and the plurality of second lenses are optically aligned with the plurality of first lenses respectively; A liquid crystal shutter arranged between the first lens array and the second lens array, the liquid crystal shutter has a plurality of light holes, and the plurality of light holes are optically aligned with the plurality of first lenses respectively, automatically From the first lens array to the second lens array, the liquid crystal shutter sequentially includes an upper polarizer, an upper light-shielding layer, an upper electrode, a liquid crystal layer, a lower electrode, a lower light-shielding layer, and a lower polarizer. The upper light-shielding layer is provided with A plurality of upper light holes, the lower light-shielding layer is provided with a plurality of lower light holes, the plurality of upper light holes correspond to the plurality of first lenses respectively, and the plurality of lower light holes are respectively connected to the plurality of first lenses. There is a one-to-one correspondence between the first lenses, and each upper light hole and the corresponding lower light hole together form the light hole of the liquid crystal shutter; The controller is used to control each light hole of the liquid crystal shutter to open once in a shooting period; The image sensor is used to obtain a sub-image corresponding to each light hole when each light hole is opened in one shooting period; and The image processor is used for synthesizing the sub-images corresponding to the light holes within one shooting period into one image by using super-resolution image restoration technology. 2. The camera module according to claim 1, wherein the camera module further comprises an upper substrate and a lower substrate, the first lens array is formed on the upper substrate, and the second lens array is formed on the the lower substrate, and the liquid crystal shutter is arranged between the upper substrate and the lower substrate. 3. The camera module according to claim 2, wherein a receiving cavity is formed between the upper substrate and the lower substrate, and the liquid crystal shutter is disposed in the receiving cavity. 4. The camera module as claimed in claim 1, wherein the upper electrode and the lower electrode are both transparent electrodes. 5. The camera module according to claim 1, wherein the material of the liquid crystal layer is ferroelectric liquid crystal. 6 . The camera module as claimed in claim 1 , wherein, within one shooting cycle, the controller opens the plurality of light holes sequentially, and only opens one light hole at a time. 6 . 7 . The camera module according to claim 6 , wherein when a light hole is opened, the controller synchronously controls the image sensor to acquire a sub-image corresponding to the light hole. 8 . The camera module according to claim 1 , wherein, within one shooting period, the controller simultaneously opens two or more light holes.