JP2010283598A - Network camera - Google Patents

Abstract

Displacement of an optical component is prevented and power consumption is reduced by vibration and impact generated when the direction of a pan head is changed.
When the pan drive switch is on (S101), the pan drive motor is driven (S102), or when the tilt drive switch is on (S104), the tilt drive motor is driven (S105), and the filter frame is driven. Turn on the power to the motor.
When the pan drive switch is off (S106), the pan drive motor is stopped (S107), or when the tilt drive switch is off (S110), the tilt drive motor is stopped (S110), and the filter frame drive motor is moved to. Turn off the power.
[Selection] Figure 8

Description

  The present invention relates to a network camera for reducing power consumption of a camera or the like.

  In recent years, network cameras that allow viewing of images at distant locations have become widespread, and are used as surveillance cameras and video conference cameras as main applications. In addition to being able to see images from distant locations, network cameras often have a camera mounted on a pan head in addition to zooming and focusing, and many cameras can be remotely controlled from remote locations.

  In addition, cameras that supply camera power from a network cable and do not need to provide a new power source at the installation site have become widespread. Due to such a background, in recent years, it has become an important issue for network camera devices to save power.

  In Patent Document 1, an optical filter switching means is interposed on the optical path from the objective lens to the image sensor in order to switch between color and monochrome.

JP 2000-162668 A

  In the above-described conventional example, the energized state when the optical filter switching means is not operated is constant. For this reason, it is difficult to achieve both the positional reliability of the optical member against vibration and impact generated when the lens unit is mounted on the pan head and the pan head performs pan and tilt driving, and power saving performance when not driven. In other words, if the optical filter switching means is in a non-energized state, the motor shaft is restricted in rotation only by the cogging torque, so that it is highly possible that the filter rotates due to an impact or the like, and the position of the filter is shifted. Causes deterioration. On the other hand, if the optical filter switching means is in an energized state when the optical filter is not operated, power is always consumed, which causes a problem of increased power consumption.

  Further, not only the optical filter switching means but also the electronic parts constituting the lens unit such as the electric zoom means and the electric focus means may be the same.

  An object of the present invention is to provide a network camera that solves the above-described problems and achieves low power consumption and optical performance stabilization.

  In order to achieve the above object, a network camera according to the present invention includes a pan head that can be electrically panned and / or tilted, and a drive that makes the optical state of an optical element installed on the pan head variable by a motor. A network camera having control means for switching the motors to different energized states when the pan head is driven and when the head is not driven.

  According to the network camera of the present invention, it is possible to achieve both power saving and optical performance maintenance by switching the energization state of the motor that drives the optical element between when the pan head is driven and when it is stopped.

1 is an exploded perspective view of a lens barrel of Embodiment 1. FIG. It is sectional drawing of the principal part. It is a perspective view of a filter switching part. It is explanatory drawing of a camera apparatus. It is explanatory drawing of an operation state. It is explanatory drawing of an operation state. It is a block circuit block diagram. It is a flowchart figure. FIG. 6 is a flowchart of the second embodiment. FIG. 10 is a flowchart of Example 3. It is explanatory drawing of a camera apparatus. It is explanatory drawing of a camera apparatus. FIG. 6 is a block circuit configuration diagram of Embodiment 4. It is a flowchart figure.

  The present invention will be described in detail based on the embodiments shown in the drawings.

  FIG. 1 is an exploded perspective view of the lens barrel of the first embodiment, and FIG. 2 is a cross-sectional view of a main part. A first group barrel 1, a second group barrel 2, a third group barrel 3, and a fourth group barrel 4 are arranged from the object side. An imaging element holding frame 5 is provided behind the fourth group barrel 4, and a diaphragm unit 6 is disposed between the second group barrel 2 and the third group barrel 3.

  The first group barrel 1 includes a lens holding portion, and a first lens group (not shown) is fixedly held by bonding or heat caulking. The second group barrel 2 holds the focus lens group L2, and the focus rack 7 and the focus rack rack spring 8 are attached to the attachment portion 2a. The sleeve portion 2b and the U-groove portion 2c are respectively guided by two first guide bars 9 supported by the first group barrel 1 and the image sensor holding frame 5, and the second group barrel 2 is guided by the first guide bar 9. Movement in directions other than the direction parallel to the optical axis is restricted.

  Further, a focus drive motor 11 comprising a stepping motor is attached to the first group barrel 1 by a screw 10 as a drive source, and a focus rack 7 is screwed to a shaft of the focus drive motor 11. With this configuration, the second lens barrel 2 is moved in the optical axis direction by the drive of the focus drive motor 11 to perform focusing. At this time, the reset position of the second group barrel 2 is defined by the focus sensor 12 attached to the first group barrel 1.

  The third group barrel 3 holds the zoom lens group L3, and the zoom rack 13 and the zoom rack spring 14 are attached to the attachment portion 3a. The sleeve portion 3b and the U-groove portion 3c are guided by the first guide bar 9, and are restricted from moving in directions other than the optical axis. A zoom drive motor 15 comprising a stepping motor is attached to the fourth group barrel 4 with a screw 10, and the zoom rack 13 is screwed onto the shaft of the zoom drive motor 15 to move the third group barrel 3. The zoom sensor 16 fixed to the fourth group lens barrel 4 with a screw 10 detects the position of the third group lens barrel 3, determines the amount of movement of the third group lens barrel 3 based on this signal, and performs zooming.

  The diaphragm unit 6 is fixed to the fourth group lens barrel 4 and moves the built-in diaphragm blades to adjust the aperture diameter on the optical axis and adjust the amount of light incident on the image sensor.

  FIG. 3 is a perspective view of a filter switching unit that is arranged between the fourth group barrel 4 and the image sensor holding frame 5 and switches the infrared cut filter 21, the ND filter 22, and the dummy glass 23 on the optical axis. The filter frame 24 for fixing the filter has three openings, and only the infrared cut filter 21, the infrared cut filter 21, the ND filter 22, and the dummy glass 23 are attached to each opening.

  The filter frame 24 is guided through the sleeve portion so as to be movable in a direction perpendicular to the optical axis by the second guide bar 25 held at both ends by the image sensor holding frame 5. Further, a filter frame rack 26 and a filter frame rack spring 27 are attached to the filter frame 24. The filter frame rack 26 is screwed with a shaft portion of a filter frame drive motor 28 composed of a stepping motor, and is driven in the guide direction by the rotation of the shaft of the filter frame drive motor 28. Then, the filter frame 24 is moved to a predetermined position by a signal from the filter frame sensor 29 that detects the movement of the filter frame 24.

  Accordingly, since the filter frame 24 moves in a direction perpendicular to the optical axis, it is possible to switch a filter or the like located on the optical axis, and thus the wavelength of the light beam incident on the image sensor can be adjusted. For example, when shooting a bright subject in the daytime or the like, the infrared cut filter 21 or the opening to which the infrared cut filter 21 and the ND filter 22 are attached is positioned on the optical axis, so that color reproducibility is good. Get an image. On the other hand, in the case of an object with low illuminance such as at night, the dummy glass 23 is positioned on the optical axis, and it is possible to earn light by passing infrared light. This dummy glass 23 is used to match the optical path length with the insertion of the infrared cut filter 21.

  When the filter frame drive motor 28 is not driven, the rotation of the motor shaft is restricted by cogging torque if the motor is not energized. On the other hand, when the motor is energized, the rotation of the motor shaft is restricted by the energizing torque, and the energizing torque is generally larger than the cogging torque. Therefore, the rotation resistance when vibration and impact are applied is better when energized. It is advantageous. Therefore, the position shift of the filter frame 24 fixed to the motor shaft via the filter frame rack 26 is less likely to occur when the filter frame drive motor 28 is energized than when it is not energized. It is.

  If the filter frame 24 is displaced from a predetermined position, the opening formed by the filter frame 24 may be displaced from the light flux and the light flux entering the image sensor may be kicked. If the light flux is kicked, the peripheral light amount is reduced. Or the problem that an image is missing arises.

  4A is a front view of a specific network camera, and FIG. 4B is a side view. A lens frame 33 is provided on the rotation base 31 via a lens frame support base 32, and a lens unit 34 having the lens barrel described with reference to FIGS. A power source 35 is disposed behind 31. The direction of the lens unit 34 is variable with respect to the rotation base 31 by a remote operation by a remote controller or a network. Further, not only the direction of the camera but also the zooming and focusing of the lens unit 34 and the switching of the optical state of the optical elements of the filter can be electrically driven by a motor by remote control.

  FIGS. 5A and 5B are explanatory views of the operating state as viewed from above by pan driving of the camera. The lens frame support base 32 moves within an arbitrary rotation angle about the pan rotation center O in the direction of the arrow. The rotary base 31 is held freely to rotate. Further, the rotation base 31 has a built-in pan motor, and the lens frame support base 32 can be rotated electrically to change the direction of the lens unit 34.

  FIGS. 6A to 6C are explanatory views of the operating state of the tilt drive of the camera. The lens frame support base 32 is centered on the tilt rotation center O ′, and the lens frame in the direction of the arrow shown in FIG. 33 is rotatably supported. Further, a tilt motor is built in the lens frame support base 32, and the lens unit 34 can be driven by tilting as shown in FIGS. 6 (b) and 6 (c).

  FIG. 7 is a block circuit configuration diagram. A lens unit 34 is provided in the lens frame 33, and a focus lens group L2, a zoom lens group L3, and a filter frame 24 are arranged. The lens frame 33 is provided on the rotation base 31 via the lens frame support base 32.

  The output of the CPU 41 is connected to the focus lens group L 2 via the focus drive motor 11, to the zoom lens group L 3 via the zoom drive motor 15, and to the filter frame 24 via the filter frame drive motor 28. Further, the output of the CPU 41 is connected to the rotation base 31 via a pan driving motor 42 and to the lens frame support base 32 via a tilt driving motor 43. Further, the CPU 41 is connected to outputs of a pan driving switch 44 and a tilt driving switch 45.

  FIG. 8 is a flowchart of the embodiment. When the pan drive switch 44 is turned on in step S101, the drive of the pan drive motor 42 is started in step S102. At the same time, the energization of the filter frame drive motor 28 is turned on in step S103. If the signal of the pan drive switch 44 is off in step S101 and the tilt drive switch 45 is turned on in step S104, the drive of the tilt drive motor 43 is started in step S105 by that signal. Thereafter, energization of the filter frame drive motor 28 is turned on in step S103.

  Next, in response to an off signal of the pan drive switch 44 in step S106, the drive of the pan drive motor 42 is finished in step S107, and the energization of the filter frame drive motor 28 is turned off in step S108, and a series of operations is finished. Similarly, the signal of the pan drive switch 44 is turned on in step S106, and the drive of the tilt drive motor 43 is finished in step S110 by the off signal of the tilt drive switch 45 in step S109, and the process proceeds to step S108.

  That is, the energization of the filter frame drive motor 28 is on only when the camera is panning or tilting, and the energization of the filter frame driving motor 28 is off when the panning or tilting driving ends. It becomes.

  This is because the screw shaft of the filter frame drive motor 28 in the lens unit 34 rotates when the lens unit 34 receives vibration at the time of panning or tilting driving and impact at the time of stopping, and the filter frame 24 is unlikely to be displaced. Turn on the power.

  As described above, in the first embodiment, the energization state of the filter frame drive motor 28 is switched in conjunction with the movement of the camera direction by the electric pan or tilt drive. The energization to the filter frame drive motor 28 is turned on during the pan or tilt drive, and the energization is turned off after the pan or tilt drive is stopped.

  The reason for turning off the energization of the filter frame drive motor 28 when the pan or tilt is not driven is to save the power of the camera. The reason why the energization of the filter frame drive motor 28 is turned on in conjunction with the pan or tilt drive is to reduce the possibility that the filter frame 24 may be displaced due to vibrations and shocks generated during the pan or tilt drive and stop. It is. Therefore, the first embodiment can achieve both the power saving of the camera and the reliability of the position of the filter frame 24.

  FIG. 9 is a flowchart of the second embodiment, and the other parts are the same as those of the first embodiment.

  When the signal of the pan driving switch 44 is turned on in step S201, the driving of the pan driving motor 42 starts in step S202. In step S203, the energization of the focus drive motor 11, the zoom drive motor 15, and the filter frame drive motor 28 is turned on. If the pan drive switch 44 is off and the tilt drive switch 45 is turned on in step S204, the drive of the tilt drive motor 43 starts in step S205, and the process similarly proceeds to step S203.

  Next, when the signal of the pan driving switch 44 is turned off in step S206, the driving of the pan driving motor 42 is finished in step S207 and the pan driving is stopped. When the pan driving is stopped, the energization of the focus driving motor 11, the zoom driving motor 15, and the filter frame driving motor 28 is turned off in step S208, and the series of operations is completed. If the pan drive switch 44 is turned on in step S206 and the tilt drive switch 45 is turned off in step S209, the drive of the tilt drive motor 43 is finished in step S210, and the process proceeds to step S208.

  In the second embodiment, the energization of the focus drive motor 11, the zoom drive motor 15, and the filter frame drive motor 28 is off when the camera is not panned or tilted, and is energized when panning or tilting is driven. When this energization is turned on, displacement of the optical component held by the electronic component constituting the lens unit is prevented by vibration and impact on the lens unit that occurs during panning or tilting driving.

  The second embodiment shows that it is possible to achieve both the power saving of the camera and the positional reliability of the focus lens group L2, the zoom lens group L3, and the filter frame 24.

  FIG. 10 is a flowchart of the third embodiment, and the other parts are the same as those of the first and second embodiments.

  When the signal of the pan driving switch 44 is turned on in step S301, the driving of the pan driving motor 42 starts in step S302. In step S303, energization of the focus drive motor 11, the zoom drive motor 15, and the filter frame drive motor 28 is turned on.

  Next, when the pan driving switch 44 is turned off in step S304, the driving of the pan driving motor 42 is finished in step S305, and the pan driving is stopped. In step S306, the energization of the focus drive motor 11, the zoom drive motor 15, and the filter frame drive motor 105 is turned off, and a series of operations ends.

  Further, when the signal of the pan drive switch 44 is turned off in step S301 and the signal of the tilt drive switch 45 is turned on in step S307, the drive of the tilt drive motor 43 is started in step S308. In step S309, energization of the focus drive motor 11, the zoom drive motor 15, and the filter frame drive motor 28 is turned on.

  Next, when the signal of the tilt drive switch 45 is turned off in step S310, the drive of the tilt drive motor 43 is finished in step S311 and the tilt drive is stopped. In step S312, the energization of the focus drive motor 11 and the zoom drive motor 15 is turned off, and the series of operations ends.

  11 is a cross-sectional view from above schematically showing the lens barrel and filter inside the camera in the third embodiment, and FIG. 12 is a cross-sectional view from the side of the lens barrel and filter inside the camera, which is the same as FIG. The code | symbol has shown the same member.

  In the lens unit 34, a focus lens group L2, a zoom lens group L3, and an infrared cut filter 21 are arranged. The focus lens group L2, the zoom lens group L3, and the infrared cut filter 21 move in directions indicated by a focus lens group movement direction A, a zoom lens group movement direction B, and an infrared cut filter movement direction C, respectively. Accordingly, when the lens is not driven, it is necessary to hold in the directions indicated by the focus lens group moving direction A, the zoom lens group moving direction B, and the infrared cut filter moving direction C, respectively, which are all substantially parallel to the plane shown in FIG. ing.

  In FIG. 11, the lens unit 34 rotates in the pan rotation direction D around the pan rotation center O during pan driving. Therefore, the direction in which vibrations and impacts generated during pan driving and driving stop are applied to the components inside the lens unit 34 is substantially parallel to the plane shown in FIG. In the focus lens group L2, the zoom lens group L3, and the infrared cut filter 21, the direction in which vibration and impact generated when pan driving and driving are stopped coincides with the direction that needs to maintain the positional deviation.

  Therefore, in the third embodiment, the position holding force is increased by turning on the energization of the focus drive motor 11, the zoom drive motor 15, and the filter frame drive motor 28 in conjunction with the pan drive.

  In FIG. 12, the lens unit 34 rotates in the direction indicated by the tilt rotation direction E around the tilt rotation center O ′ during tilt drive. For this reason, the impact that occurs during tilt drive and drive stop occurs in a direction substantially parallel to the focus lens group movement direction A and the zoom lens group movement direction B.

  Accordingly, it is necessary to increase the holding force by energizing the motor so that the focus lens group L2 and the zoom lens group L3 do not move. On the other hand, the moving direction of the infrared cut filter 21 is substantially orthogonal to the plane shown in FIG. 12 and is substantially orthogonal to the direction to which the impact due to the tilt drive is applied. In Example 3, no energization is performed.

  Thus, in the third embodiment, energization of the focus drive motor 11, the zoom drive motor 15, and the filter frame drive motor 28 is turned on in conjunction with the pan drive of the camera. On the other hand, the energization of the focus drive motor 11 and the zoom drive motor 15 is turned on during the tilt drive of the camera.

  In the third embodiment, the types of motors that are energized during pan driving and tilt driving are different. This is because the pan rotation direction D and the tilt rotation direction E are different from each other, so that the positional deviation of the focus lens group L2, the zoom lens group L3, and the filter frame 24 held by each motor is different between the pan driving and the tilt driving. This is because the possibility of occurrence is different. That is, control is performed so that only the motor holding the focus lens group L2, the zoom lens group L3, or the filter frame 24 is energized in a direction in which positional deviation is likely to occur due to pan driving and tilt driving.

  FIG. 13 is a block circuit configuration diagram of the fourth embodiment, and the same reference numerals as those in FIG. 7 denote the same members. The CPU 41 is connected to a pan high speed drive switch 51 and a pan low speed drive switch 52.

  FIG. 14 is a flowchart of the fourth embodiment. When the pan high speed drive switch 51 is turned on in step S401, the pan drive motor 42 starts high speed drive in step S402, and the filter frame drive motor 28 performs high energization in step S403. When the pan high-speed drive switch 51 is turned off in step S404, the pan drive motor 42 finishes the high-speed drive in step S405 according to the signal, and the energization of the filter frame drive motor 28 is turned off and finished in step S406.

  When the pan high speed drive switch 51 is turned off in step S401 and the pan low speed drive switch 52 is turned on in step S407, the pan drive motor 42 starts low speed drive in step S408, and the filter frame is driven in step S409. The motor 28 performs low energization. When the pan low-speed drive switch 52 is turned off in step S410, the pan drive motor 42 ends the low-speed drive in step S411 according to the signal, and the energization of the filter frame drive motor 28 is turned off in step S406.

  The pan high speed drive and the pan low speed drive have different pan drive speeds, and the user can select the speed. The high energization and low energization of the filter frame drive motor 28 are when the current or voltage when the filter frame drive motor 28 is energized is high or low. That is, since the impact resistance varies depending on the pan driving speed, the minimum energized state is set according to the speed.

  In the fourth embodiment, the pan driving speed and the energization state to the filter frame driving motor 28 are two types, respectively, but it is needless to say that it can be further subdivided.

  As described above, in the fourth embodiment, in a camera that can be panned and tilted by a pan head, the motor energization state in the lens unit is turned on and off in conjunction with the panning or tilting drive, and the optical component is displaced. We are trying to achieve both the prevention of optical performance and power saving.

  In each of the above-described embodiments, the energization of the electronic components constituting the lens unit is turned off when pan / tilt is not driven. There is no problem even if the control is to reduce the power. In the embodiment, a camera having both pan and tilt drive functions has been described. However, the present invention can be applied to a case in which only one of them is provided.

  In each embodiment, the optical element constituting the lens unit is a focus lens group, a zoom lens group, and an infrared cut filter, but is not limited thereto.

DESCRIPTION OF SYMBOLS 1 1st group lens barrel 2 2nd group lens barrel 3 3rd group lens barrel 4 4th group lens barrel 5 Image pick-up element holding frame 11 Focus drive motor 15 Zoom drive motor 21 Infrared cut filter 22 ND filter 23 Dummy glass 24 Filter frame 28 Filter frame Drive motor 31 Rotating base 32 Lens frame support 33 Lens frame 34 Lens unit

Claims (5)

  In a network camera having a pan head that can be driven by panning and / or tilting electrically, and a driving means that varies an optical state of an optical element installed on the pan head by a motor. A network camera comprising control means for switching the motors to different energized states when not driven.   The network camera according to claim 1, wherein the motor drives any one of a zoom lens group, a focus lens group, and a filter frame.   The network camera according to claim 2, wherein the motor is a stepping motor.   The network camera according to any one of claims 1 to 3, wherein the control means switches the motor that is energized between pan driving and tilt driving.   The network camera according to any one of claims 1 to 3, wherein the control means switches an energization amount of the motor in accordance with a driving speed of pan and / or tilt drive.

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