JPH09322030A - Camera head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the camera head with a small size in which an image pickup range over an entire circumference of a camera installed point is obtained without turning the camera main body. SOLUTION: The camera head is formed cylindrically and has a case 1 fitted to a camera lens of a camera main body 7. The case 1 of the camera head is turnable around an image pickup direction (referred to as camera axis) of the camera main body 7. A turnable mirror 2 is provided in the inside of the case 1 to reflect an external light made incident from an image pickup window toward the camera axis, in other words, to deflect the image pickup direction laterally with respect to the camera axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera head applicable to, for example, a surveillance camera or an inspection device using the camera.

[0002]

2. Description of the Related Art FIG. 3 is a view showing the structure of a conventionally known surveillance camera, and FIG.
FIG. 3B is a side view. As shown in FIGS. 3A and 3B, the camera body 10 includes a drive base 13 via a stepping motor 11 and a drive gear 12.
Mounted on The drive base 13 also contains a stepping motor 14 and a drive gear 15. The camera body 10 is rotationally driven in a plurality of directions by the stepping motor 11 and the drive gear 12, and the stepping motor 14 and the drive gear 15. This makes it possible to change the shooting direction of the camera body 10 to an appropriate direction.

[0003]

The above-mentioned conventional surveillance camera has the following drawbacks. That is, in the above-mentioned surveillance camera, it is difficult to reduce the size of the entire apparatus because the camera body has a structure in which it is rotationally driven by a drive stand or the like.

An object of the present invention is to provide a camera head which can obtain a photographing range around the entire camera installation point without rotating the camera body and can downsize the apparatus.

[0005]

In order to solve the above problems and achieve the object, a camera head of the present invention comprises a rotatable mirror and a housing which houses this mirror and is rotatable about the camera axis. It consists of

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 is a view showing the schematic arrangement of a surveillance camera to which a camera head according to a first embodiment of the present invention is attached. The housing 1 of the camera head has a cylindrical shape and is attached to a camera lens portion (not shown) of the camera body 7. The housing 1 of the camera head is rotatable around the shooting direction of the camera body 7 (this is called the camera axis). The X axis shown in FIG. 1 represents the camera axis.

Inside the housing 1, a mirror 2, a stepping motor 3 and a shift gear train 4 are housed.
A drive gear 5 and a stepping motor 6 are provided outside the housing 1.

FIG. 2 is a partial sectional view showing the detailed structure of the camera head. The mirror 2 is provided to reflect the external light incident from the window 7 in the X-axis direction (camera axis direction), in other words, to deflect the photographing direction laterally with respect to the central axis (X-axis) of the camera body 7. And can be rotated.

The stepping motor 3 and the shift gear train 4 are provided to rotate the mirror 2 and change its directivity angle. The speed change gear train 4 improves the accuracy of the rotation angle of the stepping motor 3, and at the same time, the motor 3
It is composed of a plurality of gears for transmitting the rotational force of the to the mirror 2.

The stepping motor 6 and the drive gear 5 drive the rotating portion of the housing 1 separated by the bearing 8 about the X axis (camera axis) with respect to the fixed portion. By rotating and driving the rotating portion of the housing 1 having the mirror 2, the window 7, etc., the photographing direction can be continuously changed.

Bearings 8 for smoothly rotating the rotating portion of the housing 1 are mounted on the radial shaft and the thrust shaft so that smooth rotation can be obtained even if the camera body 7 is installed in any direction. (Three places here).

The window 7 is provided on a part of the outer surface of the housing 1,
The size is such that a photographing range described later can be obtained at a minimum. The connection between the housing 1 of the camera head and the camera body 7 is
It is screwed with a screw for mounting camera accessories on the front of the camera lens. Therefore, the case 1
One end of the is threaded according to official standards.

Referring back to FIG. The camera head of this embodiment operates as follows. First, the Y axis gives the center position of the photographing screen when the angle formed by the X axis (camera axis) and the perpendicular to the mirror surface of the mirror 2 is set to 45 degrees.

When the stepping motor 3 is operated, the output shaft angle of the motor 3 is changed to a gear train (gear ratio; 1 :).
N) The speed is reduced by 4. When the angular resolution of the stepping motor 3 is Δθ degrees, the mirror 2 is Δθ /
Driven with an angular accuracy of N degrees, the shooting direction changes. With respect to the change amount c or d in the shooting direction, a double angle change can be obtained based on the double angle theorem with respect to the operation angle of the mirror 2. This defines the Y1 axis and the Y2 axis. In the same figure, when the Y axis, the Y1 axis, or the Y2 axis is set as the center of the photographing screen, the individual photographing ranges (three areas) obtained by the camera angle of view b are shown by hatching.

The photographing range a in the direction orthogonal to the X axis (camera axis) is expressed by the following equation. a = b + 2 · θ / N [deg] where, b: camera angle of view θ: output shaft angle of the stepping motor N: gear ratio of the gear shift gear Next, the shooting range around the central axis (X axis) of the camera body 7 Is continuously rotated by the drive gear 5 directly connected to the output shaft of the stepping motor 6 with the connecting portion with the camera body 7 being fixed as a whole of the housing 1 housing the mirror 2. ) It is possible to obtain the shooting range.

The diameter of the housing 1 for accommodating the individual parts constituting the camera head as described above is approximately the same size as the camera lens (however, because of its structural strength, it is about 1.5 times the diameter of the camera lens). ), And the length of the housing 1 can be 2-3 times as long as the camera lens.

Therefore, in the case of using the above-mentioned drive stand, the volume of the entire apparatus is 4,800 cm 3 (when the camera weight is up to 3 kg), whereas
According to the present embodiment, the volume of the entire apparatus can be reduced to about 1,000 cm3 (1/4 or less) (where the lens diameter is φ60 (6 cm)).

(Summary of Embodiments) The structure and operational effects of the camera head shown in the above-described embodiments are summarized as follows. [1] The camera head shown in the embodiment includes a rotatable mirror 2 and a housing 1 that houses the mirror 2 and is rotatable about the camera axis.

In the above camera head, the entire housing 1 containing the mirror 2 is continuously rotated with the joint portion with the camera body 7 being fixed, so that a photographing range of 360 degrees or more (entire circumference) can be obtained. Becomes And the housing 1
The diameter of can be made almost the same as that of the camera lens, and the length of the housing 1 can be made two to three times as long as that of the camera lens. Therefore, there is an advantage that the entire device can be downsized. [2] The camera head shown in the embodiment has the above-mentioned [1].
And the stepping motor 3 and the rotation angle accuracy of the stepping motor 3 are improved, and the rotational force of the stepping motor 3 is applied to the mirror 2
And a gear change gear train 4 for transmission to the gear.

In the above camera head, the above [1]
In addition to the same effects and advantages, the imaging range [deg] defined by the directional angle range of the mirror 2 can be specified as follows.

Shooting range a = b + 2θ / N [deg] where: b: camera angle of view θ: output shaft angle of stepping motor 3 N: gear ratio of shift gear train 4 [3] shown in the embodiment. The housing 1 of the camera head comprises a rotating part and a fixed part which are slidably coupled to each other via a plurality of bearings 8. The bearings 8 are mounted on the radial shaft and the thrust shaft, respectively. .

In the above camera head, the above [1]
In addition to the same effects and advantages, the rotating portion and the fixed portion of the housing 1 can slide smoothly regardless of the orientation of the camera body 7.

[0023]

According to the present invention, the mirror incorporated in the cylindrical housing which can be coupled to the tip of the camera lens is driven, and the housing is rotated around the central axis of the camera body 7. Due to the structure, it is possible to obtain a 360 ° or more omnidirectional shooting range centered on the camera installation point.
It is possible to provide a camera head capable of downsizing the entire apparatus as compared with the conventional method using a drive base.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a surveillance camera to which a camera head according to a first embodiment of the present invention is attached.

FIG. 2 is a partial cross-sectional view showing the detailed structure of the camera head according to the first embodiment of the invention.

FIG. 3 is a diagram showing a configuration of a surveillance camera according to a conventional example.

[Explanation of symbols]

 1 ... Camera head housing 2 ... Mirror 3, 6 ... Stepping motor 4 ... Shift gear row 5 ... Drive gear 7 ... Camera body

Claims (1)

[Claims] 1. A camera head comprising: a rotatable mirror; and a housing that houses the mirror and is rotatable about a camera axis.