CN201247340Y - Image auto-focus device - Google Patents

Abstract

The utility model relates to an image automatic focusing device. The existing automatic focusing device has a complex structure and requires high processing precision. In the utility model, the stator coil is fixedly embedded in the stator coil installation groove on the inner wall of the casing. The sleeve-shaped front and rear end covers are fixedly connected with the two end faces of the shell. The through holes in the front end cover and the rear end cover are imaging channels. The sleeve part of the front end cover and the rear end cover protrudes into the casing, a part of the sleeve rotor is threadedly connected with the tail of the front end cover, and a part is threaded with the tail of the rear end cover. A focusing lens is fixedly arranged in the sleeve rotor, and the tail of the front end cover and the tail of the rear end cover are separately arranged, and the space in the middle is the movement space of the focusing lens. After electrification, the stator generates a rotating magnetic field, and the sleeve rotor can rotate forward and reverse, driving the focusing lens to move left and right, thereby adjusting the focal length of the lens. The utility model has a simple structure and reduces the requirements on the processing accuracy and assembly accuracy of each link of the focusing device, thereby reducing the cost of the device.

Description

An image auto-focus device

technical field

The utility model belongs to the field of optical-mechanical-electrical integration, and in particular relates to an image automatic focusing device based on digital technology.

Background technique

The focusing method of changing the focal length is to change the focal length of the lens by moving the axial position of a lens or a group of lenses in the lens, so that the image distance can be kept constant when the object distance changes. It is one of the most commonly employed focusing methods. The focusing process of this focusing method can be completed manually or automatically by controlling the motor to drive the lens.

The existing autofocus device is composed of a lens assembly, a motor, a driving mechanism, a detection sensor, etc. The motion transmission between the motor and the lens assembly is realized through an external driving mechanism, and the driving mechanism is generally a rack and pinion pair, a rotating screw pair, etc. . The discrete structure of detection sensor, motor, lens assembly and driving mechanism will complicate the structure of the system, increase the cost, and increase the processing and assembly precision requirements of each link of the focusing device. Due to the addition of detection sensors, an intermediate detection and data processing process is formed, which inevitably introduces errors and affects the focusing accuracy of the system.

Contents of the invention

The purpose of the utility model is to provide an image auto-focusing device based on digital technology to address the shortcomings of existing auto-focusing devices. The utility model adopts the principle of relative positioning of the focus lens under closed-loop control, adopts an integrated transmission mechanism, and can remove the intermediate detection link in the existing focusing device, thereby improving the focusing accuracy and reducing the manufacturing and assembly accuracy requirements of each link in the focusing device.

The specific structure of the device of the utility model includes a cylindrical shell, and a stator coil installation slot is opened along the circumference of the inner side wall of the shell, and the stator coil is fixedly embedded in the stator coil installation slot. The front end cover and the rear end cover are respectively fixedly connected with the two end faces of the casing. The front end cover and the rear end cover are sleeve-shaped, and their longitudinal sections are T-shaped; through holes are respectively opened along the centerlines of the front end cover and the rear end cover, and the positions of the through holes of the front end cover and the through holes of the rear end cover are Correspondingly, an imaging channel is formed. The sleeve part of the front end cover and the rear end cover extends into the shell, and the outer wall of the sleeve is threaded. The sleeve parts of the front end cover and the rear end cover are respectively socketed with the sleeve rotor; the sleeve rotor is a magnetic steel cylinder with internal tapping threads, a part of the sleeve rotor is threaded with the tail of the front end cover, and a part is connected with the rear Threaded connection at the end of the end cap. A focusing lens is fixedly arranged in the sleeve rotor, and the tail of the front end cover and the tail of the rear end cover are separately arranged, and the space between them is the movement space of the focusing lens. A front lens is fixedly arranged on the head of the front end cover, a rear lens is fixedly arranged on the tail of the rear end cover, and a planar photoelectric sensor is fixedly arranged on the head of the rear end cover. The front lens, focusing lens, rear lens, and planar photoelectric sensor are sequentially arranged parallel to the axis of the focusing device and perpendicular to the axis of the focusing device.

In the utility model, the stator with a coil embedded in the outer casing generates a rotating magnetic field after being energized. Under the action of the rotating magnetic field of the stator, the sleeve rotor can rotate forward and reverse, driving the focusing lens to move left and right, thereby adjusting the focal length of the lens; the circuit board completes the image clear Degree identification, focus control and stator rotating magnetic field generation and other functions.

The device of the utility model can realize the direct automatic focusing of the image without the intermediate detection link; the integrated transmission mechanism can avoid the focusing error caused by the intermediate link, and the structure is simple; the focusing process adopts the relative position adjustment method, which reduces the The processing accuracy and assembly accuracy requirements of the link, thereby reducing the cost of the device.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

As shown in FIG. 1 , the image auto-focusing device includes a cylindrical casing 1 , and a stator coil installation groove is opened along the circumference of the inner wall of the casing 1 , and the stator coil 2 is fixedly embedded in the stator coil installation groove. The front end cover 11 and the rear end cover 8 are respectively fixedly connected with the two end faces of the housing 1 by screws. The front end cover 11 and the rear end cover 8 are sleeve-shaped, and their longitudinal sections are T-shaped. Through holes are respectively opened along the centerlines of the front end cover 11 and the rear end cover 8 , and the positions of the through holes of the front end cover 11 and the through holes of the rear end cover 8 correspond to form an imaging channel 4 . The sleeve part of the front end cover 11 and the rear end cover 8 stretches into the shell 1, and its outer wall is threaded. The sleeve parts of the front end cover 11 and the rear end cover 8 are respectively socketed with the sleeve rotor 3 . The sleeve rotor 3 is a magnetic steel cylinder with internal tapping threads. A part of the sleeve rotor 3 is threaded with the tail of the front end cover 11 , and a part is threaded with the tail of the rear end cover 8 . A focus lens 10 is fixed inside the sleeve rotor 3 , and the tail of the front end cover 11 and the tail of the rear end cover 8 are separately arranged, and the space in between is the movement space 5 of the focus lens 10 . The head of the front end cover 11 is fixedly provided with a front lens 12 , the tail of the rear end cover 8 is fixedly provided with a rear lens 9 , and the head of the rear end cover 8 is fixedly provided with a planar photoelectric sensor 6 . The front lens 12, the focusing lens 10, the rear lens 9, and the planar photoelectric sensor 6 are sequentially arranged parallel to and perpendicular to the axis of the focusing device. The planar photoelectric sensor 6 is connected with the circuit board 7 arranged on the head of the rear end cover 8 . The planar photoelectric sensor 6 and the circuit board 7 adopt existing mature technology.

When focusing, the coil stator 2 is energized through the circuit board 7, and a rotating magnetic field is generated after energization. Under the action of the rotating magnetic field, the sleeve rotor 3 can rotate forward and reverse, driving the focusing lens 10 to move left and right, thereby adjusting the focal length of the lens.

Claims (1)

1. An image automatic focusing device, comprising a cylindrical shell, characterized in that: a stator coil installation groove is opened along the circumference of the inner wall of the shell, the stator coil is fixedly embedded in the stator coil installation groove, the front end cover and the rear end cover respectively fixedly connected with the two end faces of the housing; The front end cover and the rear end cover are sleeve-shaped, and their longitudinal sections are T-shaped; through holes are respectively opened along the centerlines of the front end cover and the rear end cover, and the positions of the through holes of the front end cover and the through holes of the rear end cover are Correspondingly, an imaging channel is formed, and the tail of the front end cover and the tail of the rear end cover are separately arranged, and the space in the middle is the movement space of the focusing lens; The sleeve parts of the front end cover and the rear end cover extend into the casing, and the outer wall is tapped with threads; the sleeve parts of the front end cover and the rear end cover are respectively socketed with the sleeve rotor; The sleeve rotor is a magnetic steel cylinder with internal tapping threads, a part of the sleeve rotor is threadedly connected to the tail of the front end cover, and a part is threaded to the tail of the rear end cover, and a focusing lens is fixed inside the sleeve rotor; The head of the front end cover is fixedly provided with a front lens, the rear part of the rear end cover is fixedly provided with a rear lens, and the head of the rear end cover is fixedly provided with a planar photoelectric sensor; The axial direction of the device is arranged in parallel and perpendicular to the axial direction of the focusing device.

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