JPH0425812A - Lens device for television camera - Google Patents

Abstract

PURPOSE:To omit a mechanism which drives a master lens and to make the constitution of the whole device simple and compact by providing at least a normal photographic lens and a macrophotographic lens on an extender lens insertion position in an exchangeable state. CONSTITUTION:When normal photographing is performed after a tracking adjustment is made by moving the master lens 3 in the optical axis directions, a 1st lens 10a is made to face the axis A. When the image formation magnifica tion is varied, a 2nd lens 10b and a 3rd lens 10c are made to face the optical axis A by the displacement of a zoom lens group 2 and the rotation of a turret plate 10 and the photographic magnification of an object is set to double or three times. For macrophotographing, a 4th lens 10d which is displaced by a distance alpha by rotating the turret plate 10 is made to face the axis A and the lens group 2 and a focus lens group 1 are operated. Even when normal photographing is performed again, the lens 10a is only made to face the axis A and the lens 3 need not be adjusted, thereby simplifying the constitution.

Description

[Detailed Description of the Invention] [Industrial Field of Application J] The present invention relates to a lens device for a television camera, and particularly to a lens device that can be switched between a normal shooting state with tracking adjustment and a macro shooting state. The present invention relates to a lens device that enables

[Prior art 1] In a lens device for a television camera (hereinafter abbreviated as TV camera), by adjusting the position of the master lens group of the photographing lens system in the optical axis direction,
To form a sharp image of a subject on a light receiving surface of an imaging means. It is now possible to perform so-called tracking adjustment.

Furthermore, there is also known an apparatus in which close-up photography, that is, macro photography, can be performed by moving the master lens group in the optical axis direction.

[Problem to be Solved by the Invention 1] However, if the master lens group is moved in the optical axis direction during macro photography as in the prior art described above,
When performing normal photography in which tracking has been adjusted, the master lens must be returned to its original tracking position. For this reason, the following problems arise.

That is, first, positioning of the master lens during tracking adjustment is performed with extremely high precision, and if the master lens adjusted with high precision is moved in the optical axis direction during macro photography, In order to return the master lens to its original position with good return accuracy, a complicated positioning mechanism must be provided, which increases the size of the entire lens device and complicates its configuration. There are also problems. Furthermore, when automating the movement control of the master lens, such as when operating the lens device by remote control, a drive mechanism for the master lens must be installed, and from this point of view, the lens device Or make it larger.

In particular, the master lens is located close to the connection to the camera body, and due to its relationship with the focal plane position, it is necessary to attach components to improve the drive mechanism and positioning accuracy of this master lens. It is difficult to secure space.

The present invention has been made in view of the above points, and its purpose is to switch between normal photography and macro photography with tracking adjusted without moving the master lens. An object of the present invention is to provide a imaging device for a telephoto camera that can perform the following functions.

[Means for Solving the Problem] In order to achieve the above-mentioned object, the present invention provides an extension lens for at least a normal photography lens and a macro photography lens whose imaging position is different from that of the normal photography lens. Its feature is that it is configured to be replaceably installed in the insertion position.

L effect j By adopting such a configuration, by placing the tracking-adjusted lens for normal photography on the optical axis, when performing normal photography, the light-receiving surface of the imaging means, which is the object image, can be It is possible to form a sharp image, and it is also possible to perform normal photography. Here, this tracking adjustment is performed initially, and is performed extremely strictly and carefully.

On the other hand, when performing macro photography, a macro photography lens is placed on the optical axis in place of the normal photography lens. This moves the focal position of the lens device to a position where macro photography is possible.

In this way, since there is no need to move the master lens in the optical axis direction during macro photography, even if you repeatedly switch between the normal photography state and the macro photography state, the tracking position can be adjusted precisely. There is no risk of it becoming damaged. Furthermore, when automatically controlling the lens device, such as when operating a TV camera by remote control, there is no need to provide a mechanism for controlling the movement of the master lens in the optical axis direction. Moreover, when a normal photographic lens and a macro photographic lens are incorporated into the extender lens exchange mechanism, there is no need to provide a driving mechanism. Moreover, when automatic control is performed in this manner, since an extender drive mechanism is naturally provided, the entire dividing lens device without a master lens drive mechanism can be miniaturized.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

First, FIG. 1 shows the overall configuration of a lens device.

In the figure, 1 is a focus lens group, 2 is a zoom lens group, 3 is a master lens group, and 4 is a focus lens group.
is an Extentaresis replacement turret.

The concrete structure of the extentaresis replacement turret 4 is as shown in FIG. That is, four lenses 1. Oa, 10b.

], Oc, 10d, of these four lenses, the first lens 10a and the fourth lens 10d
are both 1x lenses, the second lens 1υb is 2x lenses,
The third lens 10c is a 3x lens. The turret plate 10 is rotatably driven by a motor 11, and when rotated by the motor 11, one of the lenses 10a, 10b, 10 is rotated.
c, a click groove 13a that is engaged with the positioning click hole 12 in order to position the lens device 10d at a position facing the optical axis A of the lens device;

13b, 13c, and 13d are formed on the outer periphery of the turret plate 10.

The fourth lens 10a and the fourth lens 10d are formed as the same 1x lens, or are they aligned with the optical axis A of the lens device?
The positions are shifted in the direction. That is, as is clear from FIG. The fourth lens 10d is mounted at a position displaced by a distance α toward the subject with respect to Oa.

Therefore, the lens 1.0a is the optical axis A of the entire lens device.
The truck adjustment is done while facing upwards. This tracking adjustment is done with master lens 3.
This is performed by appropriately moving the optical axis in the optical axis direction. Therefore, when the tracking adjustment is performed, the focal position F in this lens device will be accurately located on the imaging plane 5. Thereby, adjustment is made so that the subject image can be sharply formed on the light receiving surface of the imaging means during normal photographing. Furthermore, when the fourth lens 10d faces the optical axis A, the focal position F' of the lens device shifts to the front side of the imaging plane 5, making macro photography possible.

This embodiment is configured as described above, and when performing normal photography with tracking adjustment, the lens lOa is used, and when changing the imaging magnification, the zoom lens group is used. 2 in the optical axis direction or by rotating the turret plate 10, the second lens 10b'
l'' By directing the third lens 10c toward the optical axis A, the photographing magnification of the subject can be increased to 2x, 3x, etc. Therefore, the master lens 3 is placed accurately at the tracking position. The subject image is transferred to the imaging plane 5.
It is possible to form a sharp image on top.

On the other hand, when performing macro photography, the turret plate 10 is rotated by the motor 1, so that the fourth lens 10d faces on the optical axis A, and in this state, the fourth lens 10d is placed along with the zoom lens group 2, and the focus lens Operate group 1. With this, it is possible to perform the necessary focus movement when performing macro photography.

In order to perform normal photography after macro photography, for example, it is not necessary to move the first lens 10a to face the optical axis A, or to move the master lens 3 in this case. Therefore, there is no need to move the master lens 3 after the tracking adjustment is performed, and there is no fear that the tracking position will shift. Moreover, since there is no need to provide a mechanism for moving the master lens 3 in the optical axis direction, the lens device itself can be made smaller and more compact.

In addition, in the above-mentioned embodiments, the configuration is shown that uses the Extenterence Exchange System of type 191~, or even if this Extenterence Exchange System is of a sliding type, it may be different depending on the shooting conditions. Accordingly, it is also possible to have an exchangeable configuration. In addition, the types of lenses provided on the extender are not limited to four types,
In short, it is best to have two 1x lenses shifted in the optical axis direction of the lens device, but it is also possible to use three, five, etc. types of lenses, and it is also possible to use other types of lenses. The magnification can also be set appropriately. moreover,
The extender may be interposed between the zoom lens group and the master lens group, or may be arranged at a position closer to the image formation side than the master lens group.

[Effects of the Invention] As explained above, the present invention has a configuration in which at least a normal photography lens and a macro photography lens whose imaging position is different from that of the normal photography lens can be exchanged to the extender lens insertion position. As a result, you can now switch shooting conditions without moving the master lens.
Even if the shooting state is repeatedly switched, the lens does not shift from the state in which the tracking adjustment was made during normal shooting, and there is no need to provide a mechanism to drive the master lens, so the entire lens device It is possible to simplify and make the configuration of the system more compact.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic configuration diagram of a lens device, and FIG. 2 is an external view of an extender. 1: Focus lens group, 2: Zoom lens group, 3: Master lens group, 4: Extended lens group, 10 Rotating plate,
10a: 2nd lenth, ], Ob 2nd lenth, 10c
: 3rd lens, 10d: 4th lens.

Claims (1)

[Claims] A lens device for a television camera, in which at least a lens for normal photography and a lens for macro photography whose imaging position is different from that of the normal photography lens are replaceably attached to an extender lens insertion position.