Description
SPEED DOME CAMERA
Technical Field
[1] The present invention relates to a surveillance camera and, more particularly, to a speed dome surveillance camera for smoothly performing a pan/tilt drive by attaching a sensor that indicates a rotation reference position of a motor.
Background Art
[2] Generally, a surveillance camera is classified into a standard camera, a zoom camera, a dome camera, and a speed dome camera. Disclosure of Invention
Technical Problem
[3] Among them, the dome camera installed in consideration of an interior design has a disadvantage of limiting a photographing range, since the dome camera is fixed to photograph only one point of a corresponding space.
[4] To overcome this disadvantage, the speed dome camera rotated in horizontal / vertical directions has been developed. The speed dome camera is rotated by horizontally 360°(hereinafter referred to as 'pan') and vertically 90°(hereinafter referred to as 'tilt') to photograph all points of the corresponding space.
[5] This speed dome camera performs position control of a surveillance space using a stepping motor, and detects a reference position using a sensor.
[6] Hereinafter, a structure of a speed dome camera in accordance with the prior art disclosed in Korean Patent Laidopen Publication No. 2002-086077 will be described.
[7] Rg. 1 is a perspective view of a speed dome camera structure in accordance with the prior art, and Rg. 2 is a side view of Rg. 1. Referring to Rgs. 1 and 2, the prior art speed dome camera comprises: a main body 2, on which a pan motor 1 is mounted; a pulley 14 axially fixed to the pan motor 1; a timing belt 3, having a relatively smaller amount of backlash than a gear, for connecting the pan motor 1 and the pulley; a pan shaft 4 driven by connecting through the pulley 14; a bearing (not shown) inserted into one end of the pan shaft 4; a pan case 5 rotatably and fixedly supported by the bearing; a tilt case 6 integrally and fixedly supported on the other end of the pan shaft 4; a tilt motor 7 fixed to one side of the tilt case 6; a tilt shaft 9 coupled with the tilt motor 7 in order to vertically rotate a camera 8 provided with a CCD board 15 for photographing an image, rotatably and fixedly supported by the bearing (not shown) inserted into a tilt housing 17 fixed to the tilt case 6, and integrally fixed by a bush 16 spaced apart
from one end of the tilt shaft 9; a bracket 10 engaged with the tilt shaft 9 when the tilt shaft 9 is driven, and to which the camera 8 vertically rotated is fixed; a stopper 13 for limiting a tilting rotation; stoppers 11 and 11a for limiting a panning rotation; and a hooking projection 12 for stopping the stoppers 11 and 1 la when the pan shaft 4 is rotated.
[8] The conventional speed dome camera can be freely rotated horizontally and vertically by the pan/tilt motors, but it limits the pan/tilt rotational angle of the camera through the stopper. When the motor is driven at a position other than its rotational reference position calculated by a controller, the rotational direction of the motor is forcedly (mechanically) restricted by the stopper. As such, the motor may cause malfunction during rotation, and the controller for controlling the rotational direction of the motor may also cause malfunction.
Technical Solution
[9] It is, therefore, an object of the present invention to provide a speed dome camera capable of smoothly driving a pan/tilt motor by precisely calculating a rotational reference position of a motor using an electronic sensor to one end of a pan/tilt shaft in order to indicate the rotational reference position of the motor.
[10] It is another object of the present invention to provide a speed dome camera capable of easily attaching and detaching a PCB to/from an exterior cover of the speed dome camera by composing the PCB of the speed dome camera in an integrally attachable type.
Advantageous Effects
[11] According to an aspect of the present invention, there is provided a speed dome camera provided with a pan/tilt motor comprising: a camera supporter for supporting a camera board; a PCB (Printed Qrcuit Board) supporter installed at one end of the camera supporter; a tilt supporter installed at the other end of the camera supporter; a tilting rotation driver, wherein a tilt driving pulley is installed on the same shaft as the tilt motor, a tilt timing belt is installed to transmit rotational force of the tilt driving pulley to a tilt driven pulley, a bearing is installed to fixedly support the tilt driven pulley on a tilt main supporter, a contact protrusion is formed to set a rotational reference position of the tilt motor, a guide hole is formed at the tilt main supporter to guide a rotational position of the contact protrusion, and a micro-switch is installed at the utmost end part of the guide hole, at which the contact protrusion is started, in order to indicate the reference position of the contact protrusion; a panning rotation driver, wherein a pan driving pulley is installed on the same shaft as the pan motor, a
pan timing belt is installed to transmit rotational force of the pan driving pulley to a pan driven pulley, a bearing is installed to fixedly support the pan driven pulley on a pan supporter, a reference protrusion is formed at one side of the pan driven pulley in order to set a rotational reference position of the pan motor, and a photo coupler is formed at one surface of a periphery surface of the pan driven pulley to detect a position state of the reference protrusion; and a main supporter for entirely supporting the camera and spaced apart from the bearing of the panning rotation driver.
[12] The present invention will be better understood from the following detailed description of the exemplary embodiment thereof taken in conjunction with the accompanying drawings, and its scope will be pointed out in the appended claims.
Description of Drawings
[13] The above and other features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
[14] Rg. 1 is a perspective view of a speed dome camera structure in accordance with the prior art;
[15] Rg. 2 is a side view of Rg. 1;
[16] Rg. 3 is a perspective view of a speed dome camera structure in accordance with the present invention; and
[17] Rg. 4 is a side view of Rg. 3.
Best Mode
[18] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. Like numbers refer to like elements throughout the specification.
[19] Rg. 3 is a perspective view of a speed dome camera structure in accordance with the present invention; and Rg. 4 is a side view of Rg. 3.
[20] As shown in Rgs. 3 and 4, a structure of a speed dome camera in accordance with the present invention is composed of a camera supporter 100, a tilt supporter 100a, a PCB supporter 100b, a camera 105, a tilt main supporter 110, a contact protrusion 111, a guide hole 112, a tilt driving pulley 115a, a tilt driven pulley bearing 113, a micro-
switch 114, a tilt motor 115, a tilt timing belt 116, a tilt driven pulley 117, a pan supporter 120, a reference protrusion 121, a photo coupler 124, a pan motor 125, a pan driving pulley 125a, a pan timing belt 126, a pan driven pulley 127, a main supporter 130, and a main PCB 140.
[21] The micro-switch 114 is one allowing much current to be blocked/flowed compared to a low-capacity switch using a snap mechanism, has a portion (actuator) moved depending upon a movement of a machine or a device and an electrical circuit being changed by the actuator, and is used for a mechanical automatic control. Therefore, when the contact protrusion 111 is reached to the reference position P along the guide hole 112, the micro-switch 114 is pushed to transmit an electrical signal ('on' signal) to a control part (not shown).
[22] The photo coupler 124 consists of a light-emitting part and a light-receiving part, and is referred to as a device for electrically connecting an input side and an output side by converting electricity to light or the light to the electricity. Therefore, when the reference protrusion 121 is reached to a position of the photo coupler 124 as the pan driven pulley 127 is rotated, the light from the light-emitting part in the photo coupler to the light-receiving part is blocked, and the photo coupler 124 outputs an electrical signal ('off signal) to the control part (not shown).
[23] The main supporter 130 may be integrally assembled to the main PCB 140 to form one module (or 'kit').
[24] In addition, for network communication, a network interface PCB (not shown) may be integrally installed at lower ends of the main supporter 130 and the main PCB 140. Of course, if necessary, a user can select the speed dome camera internally provided with the network interface PCB, or optionally select the network interface PCB when the user does not select the speed dome camera provided with no network interface PCB.
[25] Hereinafter, a pan/tilt rotation method of the speed dome camera will be described.
[26] Rrst, describing about a panning (horizontal) rotation, when power is applied to the pan motor 125 to drive it, the driving force through the pan driving pulley 125a and the pan timing belt 126 fixed to the same shaft of the pan motor 125 is transmitted to the pan driven pulley 127, thereby rotating the camera 105 horizontally. At this time, the rotation is performed within a range of 360°.
[27] The reference protrusion 121 is installed to set the rotational reference position during rotation of the camera 105. When the reference protrusion 121 is reached to a position of the photo coupler 124, the photo coupler 124 outputs an 'off signal, and the
control part (not shown) recognizes the rotation of the pan motor 125 at this position to be a reference signal. Therefore, the control part (not shown) can recognize the reference position of the motor on every rotation.
[28] On the other hand, describing about the tilting (vertical) rotation, when power is applied to the tilt motor 115 to drive it, the driving force through the tilt driving pulley 115a and the tilt timing belt 116 fixed to the same shaft as the tilt motor 115 is transmitted to the tilt driven pulley 117, thereby rotating the camera 105 vertically. At this time, the rotation is performed within a range of 90°.
[29] The contact protrusion 111 is installed to set the rotational reference position during rotation of the camera 105. When the contact protrusion 111 is reached to a 'P' position along the guide hole 112, the micro-switch 114 outputs an 'on' signal, and the control part (not shown) recognizes the rotation of the tilt motor 121 at this position to be a reference signal. Therefore, the control part (not shown) can recognize the reference position of the motor on every rotation.
[30] Therefore, in order to rotate the camera in the pan/tilt direction as described hereinabove, since the rotational reference position of each motor is electronically processed, the rotational reference position of the motor can be precisely calculated, thereby smoothly driving the motor. In addition, the camera can be precisely rotated to the position where the user intends to utilize the camera.
[31] As described hereinabove, the speed dome camera in accordance with the present invention employs the electronic sensor (the micro-switch or the photo coupler) to electronically process the rotational reference position of the motor rather than forcedly processing by a physical and mechanical device such as a stopper, thereby providing an effect of eliminating an error in determining the reference position, and an advantage capable of smoothly driving the motor.
[32] While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment, but on the contrary, it is intended to cover various modification within the spirit and the scope of the appended claims.