JPH04367808A - Photographing device with incorporated extender - Google Patents

Abstract

PURPOSE:To obtain the photographing device with the incorporated extender which continuousluy extends the focal length range of a zoom lens by using the incorporated extender which has variable refracting power. CONSTITUTION:The photographing device is provided with a relay system 2a including a master lens 1a having a zoom part and the incorporated extender which is a variable refracting power lens, a zoom position detecting means 1d which detects a zoom position, a zoom driving means 1c for zooming, a zoom control means 1b which controls the driving of the zoom driving means by referring to the signal from the zoom position detecting means, an extender driving means 2c which varies the refracting power of the incoroporated extender, a storage means 2d stored with the relation berween the zoom position and the refracting power of the incorporated extender, and an extender control means 2b which controls the driving of the extender driving means.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a photographing device having a built-in extender that is attached to a part of a relay lens (relay system) of a zoom lens and displaces the focal length range (variable magnification range) of the entire system. The present invention relates to a photographing device having a built-in extender suitable for a 35 mm film photographic camera, a video camera, etc., which can continuously change the focal length range.

0002

[Prior Art] Conventionally, a front converter is a method in which the focal length range of the entire zoom lens system is shifted to a long focal length side or a short focal length side, and a teleconverter lens or wide converter lens is attached to the front of the lens system. There are various methods and various proposals have been made.

Although the front converter system has a simple configuration and can easily change the focal length range, there is a problem in that the converter lens itself is large and when attached to a zoom lens, the entire lens system becomes large.

In contrast to this front converter system, an extender lens is removably attached to a part of the relay lens that is fixed during zooming, which constitutes the zoom lens, and the focal length range of the entire system is shifted, for example, to the long focal length side. There is a built-in extender method that allows the
This has been proposed in Publication No. 5818 and the like.

[0005]

In the built-in extender system, the extender lens itself can be made relatively compact, and even when attached to a zoom lens, the overall lens system does not become large.

However, there are problems in that the focal length changes discontinuously and a retraction space for the extender lens must be provided in a part of the lens system or camera body when the extender lens is not installed in the optical path. there were.

In the present invention, the extender lens is composed of a variable refractive power lens, and the refractive power of the extender lens (hereinafter also referred to as "built-in extender") is changed only when necessary with the extender lens always attached to the relay system. Expansion of focal length range (displacement) by changing
An object of the present invention is to provide a photographing device having a built-in extender, which eliminates the need for a space for retracting the extender lens from the optical path by continuously performing the steps, and reduces the size of the entire lens system.

[0008]

[Means for Solving the Problems] A photographing device having a built-in extender of the present invention uses a relay system to form a subject image on a predetermined plane using a light beam from a master lens having a zoom section. The system has a built-in extender including a variable refractive power lens, a zoom position detection means for detecting the zoom position of the zoom section, a zoom drive means for zooming the zoom section, and a zoom drive means for driving the zoom drive means. A zoom control means for controlling by referring to a signal from the zoom position detection means, an extender driving means for changing the refractive power of the built-in extender, and a relationship between the zoom position of the zoom section and the refractive power of the built-in extender. The zoom position detection means, the zoom control means, and an extender control means for controlling the drive of the extender drive means with reference to signals from the zoom position detection means, the zoom control means, and the storage means. There is.

In particular, in the present invention, the extender control means controls the extender drive means to change the refractive power of the built-in extender based on a signal from the zoom position detection means indicating that the zoom section has reached the telephoto end. and at this time, sends a signal to drive the zoom unit so that the focal length of the entire system at the telephoto end and the focal length of the entire system after changing the refractive power of the built-in extender substantially match. zooming by the zoom driving means and changing the refractive power of the built-in extender by the extender driving means from a predetermined zoom position, thereby changing the focal length of the entire system. It is a feature.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram of the paraxial refractive power arrangement of a zoom lens according to the present invention, and FIG. 2 is a block diagram of essential parts showing the operation of the photographing apparatus according to the present invention.

In FIG. 1, L1 is a focus lens group;
L2 is a variable power lens group that performs zooming, L3 is a correction lens group that corrects image plane fluctuations due to zooming, L4a is a relay system,
L4b is a built-in extender consisting of a variable refractive power lens, and is attached to a part of the relay system 4a. A zoom unit LZ is configured by the variable power lens group L2 and the correction lens group L3. The focus lens group L1 and the zoom section LZ constitute a master lens LM.

First, a method of zooming and expanding (displacing) the focal length range of the zoom lens shown in FIG. 1 will be explained.

FIG. 1(A) shows the zoom position at the wide-angle end;
B) shows a state in which the lens groups L2 and L3 are moved from the zoom position in FIG. 1A as indicated by arrows to perform zooming to the telephoto end zoom position.

During zooming from FIG. 1(A) to FIG. 1(B), the refractive power of the built-in extender L4b is constant. In this embodiment, for example, a parallel plane plate without refractive power is used.

In FIG. 1(C), the refractive power of the built-in extender L4b is changed to a predetermined value from the telephoto end zoom position in FIG. 1(B), and the zoom part LZ is moved as shown by the arrow to change the telephoto end zoom position ( This shows the case where the focal length is approximately the same as that in FIG. 1(B), and the imaging plane is at a constant position.

FIG. 1(D) shows the case where zooming is performed from the zoom position of FIG. 1(C) to the super-telephoto end by moving the zoom unit LZ as shown by the arrow.

In this embodiment, the zoom lens group L2 and the correction lens group L3 are moved along the optical axis as shown by the arrows from the zoom position at the wide-angle end in FIG. 1(A) to the normal zoom position at the telephoto end in FIG. 1(B). is zooming.

When the telephoto end in FIG. 1(B) is reached, the refractive power of the built-in extender L4b is changed and the zoom part LZ is moved. At this time, the focal length remains unchanged before and after the change (as shown in FIG. 1(B)). (same as the telephoto end), and the imaging plane remains unchanged. Then, the zoom unit LZ is moved from the zoom position shown in FIG. 1(C) to perform zooming to the super-telephoto end shown in FIG. 1(D).

In this way, in this embodiment, FIG. 1(A)
In addition to normal zooming from FIG. 1(C) to FIG.
Zooming is performed continuously from 1 to 1D to expand the focal length range.

In this embodiment, the refractive power of the built-in extender is gradually changed from the zoom position during zooming from the wide-angle end in FIG. 1(A) to the telephoto end in FIG. 1(B). Zooming may be performed by simultaneously obtaining the effects of zooming by moving L2 and correction lens group L3 and changing the focal length by changing the refractive power of the built-in extender.

In addition, the variable refractive power lens in this embodiment has transparency, homogeneity, and mechanical properties as proposed in, for example, Japanese Patent Laid-Open No. 61-200522 and Japanese Patent Laid-Open No. 2-124518. silicone rubber (d
Line refractive index Nd = 1.406 to 1.509, Abbe number ν
d=52.5 to 34.7) to change the curvature of each lens surface to change the refractive power.

Next, the operation of the photographing apparatus according to the present invention will be explained using FIG.

In FIG. 2, 1 is a front lens section, and 2 is a rear lens section. The front lens section 1 includes a master lens 1a having a zoom section, a zoom position detection means 1d for detecting the zoom position of the zoom section, a zoom drive means for driving the zoom section and performing zooming, and a drive control for the zoom drive means 1c. It has a zoom control means 1b that performs the zoom control with reference to signals from a zoom position detection means 1d and an extender control means 2b which will be described later.

The rear lens section 2 includes a relay system 2a having a built-in extender made of a variable refractive power lens, an extender drive means 2c for changing the refractive power of the built-in extender, and an extender drive means 2c that is connected to a zoom position detection means 1d or zoom control. Extender control means 2b that performs drive control with reference to signals from means 1b, storage means 2d, etc. to be described later, and storage means consisting of a ROM or the like that stores relational data between the zoom position of master lens 1a and the refractive power of the built-in extender. 2d.

In this embodiment, the zoom position of the zoom section of the master lens 1a is detected by the zoom position detection means 1d. At this time, when the master lens 1a reaches a predetermined zoom position (for example, the telephoto end in FIG. 1(B)),
The zoom position is detected by the zoom position detection means 1d, and a signal to that effect is transmitted to the extender control means 2b.

The extender control means 2b changes the refractive power of the built-in extender to a preset value based on the data stored in the storage means 2d based on the signal from the zoom position detection means 1d, and zooms. move each lens group in the section. At this time, the focal length of the entire system is made to substantially match the focal length at the telephoto end (FIG. 1(B)), and the imaging position is also made to match the imaging position at the telephoto end. (Corresponding to FIG. 1(C).) When the drive by the extender control means 2b is completed, the zoom drive means 1b receives a signal to that effect and moves the zoom part of the master lens 1a to perform zooming to the super telephoto end. (Figure 1(D)). This expands the focal length range by performing normal zooming operations and zooming from the telephoto end zoom position to the super telephoto end zoom position.

Next, the operation of the extender control means 2b, which is one of the features of the present invention, will be explained using the flowchart of FIG.

First, turn on the power of the photographing device (step 1)
). It is confirmed whether the zoom section of the master lens has moved from the wide-angle side to the telephoto end (the zoom position in FIG. 1(B)) (step 2). If it is other than the telephoto end, return to step 2.

When the zoom section reaches the telephoto end, it is checked whether the refractive power of the built-in extender is OFF (step 3). If it is OFF, the refractive power of the built-in extender is turned ON and the refractive power set in advance is applied.
Move the zoom section to the appropriate position. Then, the zoom unit is moved to perform zooming toward the super telephoto side (zooming from FIG. 1(C) to FIG. 1(D)). Then, a predetermined zoom is performed, and then the zoom unit is returned to the telephoto end, and it is determined whether or not it has reached the appropriate position (the zoom position in FIG. 1C) (step 5).

If the refractive power of the built-in extender is not OFF in step 3, that is, it is ON, the process proceeds to step 5. In step 5, when the zoom unit reaches the appropriate position from the super telephoto side (zoom position in Figure 1 (C)), turn off the refractive power of the built-in extender, release the refractive power, and move the zoom unit to the telephoto end (Figure 1 (C)). (B) (step 6).

If the zoom section is not at the proper position in step 5, the process returns to step 5 and this confirmation is repeated. In step 6, normal zooming is performed and the process returns to step 2.

[0032]

According to the present invention, a built-in extender including a variable refractive power lens is provided as a part of the relay system, and the refractive power and zoom section of the built-in extender are moved to appropriately set the position on the optical axis. To achieve a photographic device having a built-in extender capable of continuously zooming from the telephoto end to the super telephoto end, effectively expanding the focal length range, and downsizing the entire lens system. Can be done.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the paraxial refractive power arrangement of the zoom lens according to the present invention.

[Fig. 2] A block diagram of main parts showing the operation of the photographing device according to the present invention.

FIG. 3 is a flowchart diagram showing the operation of the extender control means according to the present invention.

[Explanation of symbols]

L1 Focus lens group L2 variable magnification lens group L3 correction lens group L4a Relay system L4b built-in extender LZ zoom section LM master lens 1 Front lens part 1a Master lens 1b Zoom control means 1c Zoom drive means 1d Zoom position detection means 2 Rear lens part 2a Relay system 2b Extender control means 2c Extender drive means 2d Storage means

Claims (3)

[Claims] 1. When a relay system forms a subject image on a predetermined plane using a light beam from a master lens having a zoom section, the relay system has a built-in extender including a variable refractive power lens, A zoom position detection means for detecting a zoom position of the zoom section, a zoom drive means for zooming the zoom section, and a zoom control for controlling the drive of the zoom drive means with reference to a signal from the zoom position detection means. means for changing the refractive power of the built-in extender; storage means for storing the relationship between the zoom position of the zoom unit and the refractive power of the built-in extender; 1. A photographing device having a built-in extender, comprising: a detection means, the zoom control means, and an extender control means for controlling the extender by referring to a signal from the storage means. 2. The extender control means controls the extender drive means to change the refractive power of the built-in extender based on a signal from the zoom position detection means indicating that the zoom section has reached a telephoto end. At this time, a signal is sent to the zoom control means to drive the zoom unit so that the focal length of the entire system at the telephoto end and the focal length of the entire system after changing the refractive power of the built-in extender substantially match. 2. A photographing device having a built-in extender according to claim 1. 3. A focal length of the entire system is changed by simultaneously performing zooming by the zoom driving means and changing the refractive power of the built-in extender by the extender driving means from a predetermined zoom position. An imaging device with a built-in extender as described in item 1.