JP5866173B2 - Waterproof push-in camera head - Google Patents

Description

  The present invention relates to a waterproof push-in camera head suitable for use in various pipe inspections such as a water pipe, a sewer pipe, and a gas pipe.

  As an in-pipe inspection camera device that inspects water pipes, sewer pipes, gas pipes, etc., a camera head is attached to the tip of a hard cable (push-in cable), and the camera head is inserted into the pipe to be inspected with a hard cable. There is a waterproof push-in camera head that captures the inside of a tube with a head and can be moved back and forth with respect to the inside of the inspection target tube (see Patent Document 1). This waterproof push-in camera head has an illumination cover around the imaging lens, and a sensor unit and a posture control mechanism that keeps the vertical direction of the imaging surface constant on the optical axis of the imaging lens.

JP 2008-28722 A

  The waterproof push-in camera head configured as described above has no problem in the resolution of the captured image in normal use, but when used in a high water pressure (eg, about 1 MPa) pipe, Deterioration was observed.

  As a result of investigating the cause, an illumination cover (a plastic protective cover that protects the light source around the lens) that is integrally provided around the imaging lens is deformed by exposure to the high water pressure. As a result, it has been found that the distance (flange focal length; flange back) from the lens mounting reference surface to the focal point (imaging surface) is shifted.

  An object of the present invention is to solve the above-mentioned problems and to provide a waterproof push-in camera head that does not deteriorate in resolution even if the inside of the inspection target pipe has a high water pressure.

  An embodiment of the present invention is a waterproof type having an illumination cover around an imaging lens, and having a sensor unit and a posture control mechanism that controls the imaging surface of the sensor unit on the optical axis of the imaging lens. In the push-in camera head, a damper mechanism is provided in which the sensor unit is coupled to the attitude control mechanism in a direction around the optical axis so as to be slidable in the optical axis direction.

  According to the embodiment of the present invention, it is possible to provide a waterproof push-in camera head that does not deteriorate in resolution even when the inside of the inspection target pipe has a high water pressure.

1 is a side sectional view showing a configuration of a camera head according to an embodiment of the present invention. The front view which shows the structure of the said camera head. The rear view which shows the structure of the said camera head. FIG. 3 is an assembly diagram of a damper mechanism provided in the camera head. The assembly drawing of the damper mechanism. The assembly drawing of the damper mechanism. The assembly drawing of the damper mechanism. The assembly drawing of the damper mechanism. The perspective view which shows the structure of the weight body provided in the said camera head.

Embodiments of the present invention will be described below with reference to the drawings.
The structure of a waterproof push-in camera head according to an embodiment of the present invention is shown in FIGS. 1 is a side sectional view of the camera head, FIG. 2 is a front view of the camera head, FIG. 3 is a rear view of the camera head, and FIGS. 4 to 8 are damper mechanisms provided in the camera head and components around it. FIG. 9 is a perspective view showing a configuration of a weight body provided in the posture control mechanism.

The structure of a waterproof push-in camera head according to an embodiment of the present invention is shown in a side cross section in FIG.
The waterproof push-in camera head 1 is attached to the tip of a push-in cable (hard cable) HC, is pushed into the inspection target tube by operating the push-in cable HC, and is pulled out from the inspection target tube after the inspection.

  As shown in FIG. 1, the waterproof push-in camera head 1 includes a cylindrical camera housing 11 and a camera cover 12 constituting a camera head body (camera head frame) 10, and a front portion (camera cover 12) of the camera head body 10. The lens unit 13 provided in the opening), the illumination cover 15 provided integrally with the lens unit 13 via the lens holder 14 around the lens unit 13, and the rear part of the camera head body 10 (of the camera housing 11). A terminal plate (terminal plate) 11A provided in the opening) constitutes an outer casing whose inside is hermetically sealed. In the drawing, or1 to 0r4 are waterproof O-rings for forming a secret room in the camera head main body 10, respectively.

  As shown in FIG. 2, the front opening of the camera cover 12, the lens unit 13, and the illumination cover 15 are provided concentrically around the optical axis O1 of the imaging lens 13A, and the lens unit 13 is a lens holder. The lens unit 13 is fitted to the inner peripheral portion of the plastic lighting cover 15 via 14 and the outer peripheral portion of the lighting cover 15 is attached to the front opening of the camera cover 12 by tightening the cover presser 16 by screwing. The illumination cover 15 is fixed to the front part of the camera cover 12 to make the inside of the camera head main body 10 airtight. As shown in FIG. 3, the camera housing 11, the camera cover 12, and the terminal plate 11A are also provided concentrically around the optical axis O1. The terminal board 11A is provided with a video terminal T1, a power supply terminal T2, and a ground (GND) terminal T3 which are cable connection connectors for connecting to the push-in cable HC.

  The lens unit 13 includes an imaging lens 13A of an imaging unit that images the inside of the inspection target tube, a lens case 13B that constitutes the imaging lens 13A, and a lens cover (lens glass) 13C that protects the imaging lens 13A. 14 is held on the inner peripheral surface of the illumination cover 15 via 14.

  Inside the camera head body 10 constituting the confidential room, there are an illumination unit that illuminates the inside of the inspection target tube via the illumination cover 15, a sensor unit in which the imaging surface of the imaging element is arranged on the optical axis O1 of the lens unit 13, and a sensor A bearing mechanism for coupling the unit to the lens unit 13 so as to be rotatable around the optical axis O1, a posture control mechanism for directing the vertical direction of the sensor unit in a fixed direction around the axis, and a posture control of the lens unit 13. A damper mechanism or the like is provided that transmits the rotation in the direction around the axis so as to be slidable in the direction of the optical axis O1 with respect to the mechanism.

  The illumination unit includes an illumination substrate 19 having a plurality of LED light sources 18 arranged around the lens unit 13, and is attached to a camera holder 17 that is rotated and transmitted in the direction around the optical axis O1 by an attitude control mechanism.

  The sensor unit is composed of a sensor substrate 25 on which an image sensor (area image sensor) 24 is mounted, and is attached to a camera holder 17 that is rotated and transmitted in the direction around the optical axis O1 by an attitude control mechanism in the same manner as the illumination unit.

  The bearing mechanism inserts a ball bearing 20 between a cylindrical bearing portion 14 a provided at the rear end of the lens holder 14 and a cylindrical shaft support portion 17 a provided at the tip of the camera holder 17, thereby The lens holder 14 is configured to be rotatable in the direction around the axis O1. By this bearing mechanism, an optical system (lens) is provided between the lens unit 13 held by the lens holder 14 and the imaging device 24 held by the camera holder 17 and mounted on the sensor substrate 25 via the inside of the shaft support portion 17a. Unit 13) is formed, and the sensor substrate 25 held by the camera holder 17 is supported at the center of the optical axis O1 while keeping the distance (optical path) between the lens unit 13 and the imaging surface 24a of the imaging device 24 constant. Are supported so as to be rotatable around the optical axis O1.

The posture control mechanism includes a slip ring 37 that connects the push-in cable HC to the sensor unit and the illumination unit, and a semicircular weight body 35 that is pivotally attached to a rotation shaft 37 s of the slip ring 37.

  When the waterproof push-in camera head 1 is used in an inspection target tube having a high water pressure (for example, about 1 MPa), the plastic lighting cover 15 is deformed by the high water pressure (the lighting cover 15 is distorted). In other words, even if the lens unit 13 is displaced along the optical axis O1 in the direction of the sensor unit along with the deformation (distortion), a predetermined focal length between the lens unit and the sensor unit constituting the imaging unit is set. (Flange back) is maintained so that the lens unit and the sensor unit constituting the imaging unit act as a damper that presses the attitude control mechanism with a certain restoring width in the direction of the optical axis O1 so as to be displaceable. . Incidentally, the flange back is 17.526 mm in the case of the C mount and 12.5 mm in the case of the CS mount. If the flange back deviates from this value (distance), so-called defocusing occurs in the captured image. The lens cover (lens glass) 13C of the lens unit 13 is not distorted with respect to the high water pressure.

  This damper mechanism is provided with the optical axis O1 as an axis and interposed between the imaging unit and the attitude control mechanism, and includes a camera spacer 21, a rotation transmission plate (camera bracket) 31, and an elastic sheet. The gap pad 33 is configured. This damper mechanism, its peripheral components and assembly structure are shown in FIGS.

  As shown in FIG. 4, the camera holder 17 has a disc shape, and an illumination substrate 19 on which a plurality of LED light sources 18 are mounted is attached to the front surface, and a sensor substrate 25 is attached to the back surface via an insulating sheet. Thus, a module (sensor module) serving as a sensor unit is configured. Further, the camera holder 17 is provided with a pair of cutout grooves 17b that engage with slide bars 32 of a rotation transmission plate 31 to be described later at both radial ends that are horizontal during posture control. Note that Pa and Pb in the figure are test signal terminals that are connected to the sensor substrate 25 and whose leading ends are led out to the outside.

As shown in FIG. 5, the rotation transmission plate (camera bracket) 31 is provided on a semicircular weight body 35 pivotally attached to the rotation shaft 37s of the slip ring 37, around the optical axis O1 about the optical axis O1. It is fixed to the screw with a screw. A rotation shaft 37 s of the slip ring 37 has a cylindrical shape, and a hollow portion in the cylinder serves as a wiring passage 37 h of the slip ring 37.

Rotation transmitting plate 31 has an opening 31a for wiring to contact the wiring passage 37h, as a buffer surface 31b opposite the surface abutting against the mounting surface to the weight body 35, the cushioning surface 31b, an opening 31a A plurality of sheet-like gap pads 33 having elasticity are attached so as to surround. The gap pad 33 is made of an elastic material having a high thermal conductivity, and functions as a buffer member and a heat conductive sheet that guides heat generated by the circuit operation of the heat conductive sensor substrate 25 to the outside. The mounting arrangement of the gap pad 33 is shown in FIG. Here, three sheet-like gap pads 33 are attached in a U-shape to the buffer surface 31b so as to surround the opening 31a. Further, the rotation transmission plate 31 is a component for mounting the lens unit and sensor unit constituting the imaging unit so as to be slidable in the direction of the optical axis O1 with respect to the attitude control mechanism. In addition, a pair of slide bars (thrust pieces) 32 extending in parallel with the optical axis O1 is provided. The slide bar 32 has a locking piece (stopper) 32 s that maintains engagement with the camera spacer 21 and the camera holder 17 and restricts the sliding amount of the camera holder 17 at the tip.

  As shown in FIG. 7, the camera spacer 21 to which the rotation by the rotation transmission plate 31 is transmitted by the posture control has a wiring opening 21a communicating with the wiring passage 37h. A semi-cylindrical wall portion 22 that forms a fixed gap with the rotation transmission plate 31 is provided, and the wall portions are notched at both ends in the radial direction that are horizontal during posture control. A pair of cutout grooves 22 a that engage with the slide bar 32 are provided. This notch groove 22a engages with the slide bar 32 of the rotation transmitting plate 31, and allows the camera spacer 21 to slide in the direction of the optical axis O1 with the slide bar 32 as a guide and transmits the rotation of the rotary shaft 37s. .

  The slide bar 32 of the rotation transmission plate 31 is slidably engaged with the cutout groove 17b of the camera holder 17 and the cutout groove 17b of the camera holder 17 with the camera spacer 21 interposed therebetween. When 32s is locked in the notch groove 17b of the camera holder 17, the elastic sheet-like gap pad 33 attached to the buffer surface 31b of the rotation transmission plate 31 is opposed to the camera spacer 21 by its elastic action. Abutting on the surface part to be pressed.

FIG. 8 shows the overall configuration of the damper mechanism after assembly.
The damper mechanism is inserted between the lens unit and sensor unit pair constituting the imaging unit and the posture control mechanism, so that the damper mechanism postures the lens unit and sensor unit pair constituting the imaging unit. It acts as a damper that has a certain restoring width in the direction of the optical axis O1 and presses the control mechanism so as to be displaceable.

  As a result, the waterproof push-in camera head 1 is exposed to high water pressure and the illumination cover 15 is deformed (distortion occurs in the illumination cover 15). With this deformation (distortion), the lens unit 13 is moved backward (the sensor unit's The damper mechanism temporarily absorbs the displacement of the lens unit 13 due to the distortion of the illumination cover 15 even when the illumination cover 15 is displaced, and the focal point (imaging surface) from the lens mounting reference plane with the deformation of the illumination cover 15. Can be obtained, and a high-resolution in-pipe image that does not deteriorate in resolution can be obtained even if the inside of the inspection target pipe has a high water pressure.

In the actual machine, as shown in FIG. 9, a desiccant 36 is stuck on the upper surface of the weight body 35 that is pivotally attached to the rotating shaft 37s of the slip ring 37, and the airtight chamber in the camera head body 10 is fixed. Keep it at low humidity. In addition, the code | symbol 35h in a figure is an attachment hole in which the rotating shaft 37s of the slip ring 37 is inserted.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. For example, in the above-described embodiment, the damper mechanism is configured by the camera spacer 21, the rotation transmission plate (camera bracket) 31, and the elastic sheet-like gap pad 33, but instead of the sheet-like gap pad 33. It is also possible to use a coil spring having a predetermined elasticity. Further, the arrangement of the LED light source 18, the shape of the illumination substrate 19, the sensor substrate 25, the posture control mechanism, and the like are not limited to the above-described embodiments, and various changes can be made without departing from the gist of the present invention. is there.

DESCRIPTION OF SYMBOLS 1 ... Waterproof-type pushing camera head, 10 ... Camera head main body, 11 ... Camera housing, 12 ... Camera cover, 13 ... Lens unit, 14 ... Lens holder, 15 ... Illumination cover, 16 ... Cover press, 17 ... Camera holder, 18 DESCRIPTION OF SYMBOLS ... LED light source, 19 ... Board for illumination, 20 ... Ball bearing, 21 ... Camera spacer, 22 ... Semi-cylindrical wall part, 24 ... (Area image sensor), 24a ... Imaging surface, 25 ... Sensor substrate, 31 ... Rotation transmitting plate (camera bracket) 32 ... slide bar, sheet-like gap pad with 33 ... resilient, 35 ... weight body, 37 ... slip ring, 37s ... rotary shaft.

Claims (4)

A waterproof push-in camera head that includes a camera head body and a camera cable having rigidity connected to a rear portion of the camera body, and that photographs the inside of the inspection target tube by operating the camera cable forward and backward,
A lens unit provided at the front of the camera head body and having an imaging lens;
A plurality of light sources provided at a plurality of locations around the imaging lens;
An illumination cover that holds the lens unit on an inner peripheral surface, covers the plurality of light sources, and transmits light emitted from the light sources;
An image sensor mounted on the sensor substrate, a sensor unit arranged an imaging surface of the imaging element on the optical axis of the imaging lens,
A bearing mechanism in which the sensor unit is coupled to the lens unit so as to be rotatable in a direction around the optical axis;
An attitude control mechanism for directing the sensor unit in a fixed direction around the optical axis;
It is attached to the sensor unit side of the attitude control mechanism, and even if the lens unit is displaced in the direction of the sensor unit along the optical axis as the lighting cover is deformed, it is between the lens unit and the sensor unit. A damper mechanism that presses the lens unit and the sensor unit to be displaceable with a certain restoring width in the optical axis direction against the attitude control mechanism so as to maintain a preset focal length of
A waterproof indentation camera head characterized by comprising: The damper mechanism is
A rotation transmission plate pivotally attached to a rotation shaft of a slip ring provided to connect the camera cable of the posture control mechanism and the sensor unit ;
A spacer having a flat surface that is slidably engaged with the rotation transmission plate in the optical axis direction and covers a surface portion of the sensor substrate opposite to the surface on which the imaging element is mounted;
An elastic sheet-like gap pad provided in contact with the flat surface of the spacer on the surface of the rotation transmission plate facing the flat surface of the spacer;
The waterproof push-in camera head according to claim 1, comprising:   The rotation transmission plate has a slide bar extending in a rotation axis direction and having a locking piece at an extended end at a plurality of locations on a peripheral portion, and the spacer has a guide groove that engages with the slide bar. The waterproof push-in camera according to claim 2, wherein the spacer is coupled to the rotation transmission plate so as to be movable in the axial direction of the rotation transmission plate by engagement of the slide bar and the guide groove. head.   The gap pad functions as a heat conduction sheet between the spacer and the rotation transmission plate, and forms a heat conduction path that guides heat generated by circuit operation of the sensor substrate to the outside. The waterproof push-in camera head according to claim 2.

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