JPH0581816U - Telescope for surveying instrument - Google Patents

Abstract

(57) [Summary] [Purpose] In a telescope for surveying instruments, to prevent the attachment of water droplets that cause clouding that would interfere with surveying. [Structure] The objective lens holder 2 includes an objective lens 21,
22 and 23 are held, parallel plate glass 24 is attached, and sealed with sealing materials 25 and 26, and the objective lens 2
Nitrogen gas 24 is enclosed in a hermetically sealed space between the glass plates 24, 24 and 24, and the objective lens holder 2 is fixed to the telescope lens barrel 2 by a pressing cylinder 13. With this configuration, the inner surface 23 of the objective lens 23
No clouding occurs in a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a surveying instrument telescope, and more particularly to a surveying instrument telescope that has a drip-proof function and can be used in environments with high humidity and severe temperature differences.

[0002]

[Prior art]

 The telescope of a conventional surveying instrument has, for example, a structure as shown in FIG. In this telescope, three objective lenses 121, 122, 123 of two groups are held by an objective lens holder 102, and the objective lens holder 102 is fixed to the telescope lens barrel 101 by a pressing barrel 112.

In recent years, such a surveying instrument has been increasingly used in a high humidity environment such as surveying a tunnel in tunnel construction for laying a water pipe.

[0004]

[Problems to be solved by the device]

 In the high humidity environment, especially when there is a large temperature difference between the inside and outside of the surveying instrument such as in winter, the objective lens of the telescope of the surveying instrument may become cloudy, which may interfere with the surveying. The inventor of the present invention has found that, among other things, the cloudiness generated on the inner surface 123a of the objective lens 123 hinders surveying.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a telescope for a surveying instrument having a drip-proof function.

[0006]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, a telescope for a surveying instrument of the present invention comprises an objective lens holder (2) holding an objective lens (21, 22, 23) and a telescope lens barrel (1) holding the holder. In the telescope for a surveying instrument having the objective lens holder, the objective lens holder holds the objective lens airtightly on the front end side, and attaches the transparent member (24) airtightly on the rear end side. And a dry gas (29) enclosed in the closed space, and is connected to the telescope lens barrel.

[0007]

[Action]

 Like the telescope for a surveying instrument of the present invention, the space formed by the objective lens barrel, the objective lens, and the transparent member is sealed, and if a desiccant is enclosed in the sealed space, the most water drops will be attached. Water droplets do not adhere to areas where fogging is likely to occur, that is, inside the objective lens provided in the telescope barrel.

[0008]

【Example】

 FIG. 1 shows an embodiment of the present invention. In the telescope for a surveying instrument of the embodiment, a focusing lens holder 3 is movably arranged inside a telescope lens barrel 1, and further, an objective lens holder 3, a Porro prism holder 4, a focusing screen adjusting mechanism 5, and an eyepiece holder. 6 and 6 are connected.

The telescope lens barrel 1 is formed with a long groove 11 extending in the optical axis direction, and a focusing knob 12 is fitted outside the long groove. The focusing knob 12 has a spiral groove formed inside. Further, this telescope lens barrel 1 has a male screw formed at its tip end and is screwed with a holding cylinder 13 for fixing the objective lens holder 2. The objective lens holder 2 holds three objective lenses 21, 22 and 23 in two groups in a lens barrel, and seals the contact portion between the lens barrel and the objective lens 21 with a sealing material 25. A parallel flat plate glass 24 is attached to the other end side, and a contact portion between the lens barrel and the parallel flat plate glass 24 is hermetically sealed by a seal member 26. Further, two gas holes 27 are formed in the lens barrel 2, and the gas holes 27 are sealed with a lid 28 with a male screw after enclosing nitrogen gas 29. In such an objective lens holder 2, the parallel plate glass 24 is fitted in the telescope lens barrel 1 so that the parallel plate glass 24 is located between the objective lens and the focusing lens, and the pressing barrel 13 and the telescope lens barrel 1 are screwed together. It is fixed by. The parallel flat plate glass 24 has a pattern engraved on one surface thereof. The parallel flat plate glass 24 has a center P of the pattern substantially coincident with the optical axis O of the telescope and an object lens. It is fixed to the objective lens holder 2 at a position such that the virtual image of the point P is formed at the intersection Q of the optical axis O and the vertical axis V of the surveying instrument body.

The focusing lens holder 3 holds the focusing lenses 31 and 32, and is movably arranged in the telescope barrel 1. The moving pin 33 is screwed into the focusing lens holder through the long groove 11. The Porro prism holder 4 holds the Porro prisms 41 and 42 and is fixed to the telescope lens barrel 1. The focusing screen adjusting mechanism 5 includes a lens barrel 53 that holds the focusing screens 51 and 52, a fixing member 54 that movably fixes the lens barrel 53, and the lens barrel 53 that is screwed to the fixing member 54. It is composed of a screw 55 that moves in a direction orthogonal to the optical axis O, and a cover 56 of this screw. Further, the eyepiece lens holder 6 holds two pieces of three pieces of eyepiece lenses 61, 62, 63, and the eyepiece lens holder 6 is held by a holding ring 64 so that the diopter can be adjusted.

In the telescope of such an embodiment, the objective lens holder 2 is assembled as follows. First, the three objective lenses 21, 22, and 23 are fixed to the objective lens holder 2, and the outermost lens 21 and the objective lens holder 2 are sealed with the seal material 25. Further, the parallel flat plate glass 24 is attached to the side opposite to the objective lens, and similarly sealed with a sealant 26, and the objective lens holder 2, the objective lens 21, and the parallel flat plate glass 24 form a closed space. Next, dry the nitrogen gas 29 from the other gas hole 27 while removing air from the one gas hole 27, and when the nitrogen gas 29 fills the closed space, the two gas holes 27 are covered with a screw. The objective lens holder 2 is filled with nitrogen gas 29 by closing it with 28 and then applying a sealing material around the lid.

After assembling, the objective lens holder 2 assembled in this manner is fixed by inserting it into the telescope lens barrel 1 and screwing the telescope lens barrel 1 and the pressing barrel 13 together. Further, such a telescope lens barrel 1 is rotatably fixed to the surveying instrument body by fitting a rotary shaft (not shown) of the surveying instrument body into a recess 14 formed in the abdomen.

As described above, in the telescope for a surveying instrument according to the present embodiment, the closed space including the inner side surface of the objective lens 23 is filled with the dry nitrogen gas, so that the closed space including the inner side surface of the objective lens has no moisture. Therefore, it is possible to measure even in an environment where there is a large temperature difference between the inside and outside of the telescope without clouding. Further, if only the objective lens holder 2 is filled with gas as in the present embodiment, the number of parts is small and the number of sealed parts is small. Therefore, it is easy to perform gas leak inspections during assembly and maintenance, and the related resealing and regas filling.

In the present invention, the installation position of the parallel flat plate glass, that is, the transparent member is not limited to the position of this embodiment as long as it is between the objective lens and the focusing lens. However, in order to prevent water droplets from adhering to the parallel plate glass and to prevent fogging, it is desirable to install it in a position away from the external environment, that is, closer to the focusing lens than to the objective lens.

Further, as in the present embodiment, a pattern is formed on the parallel plate glass 24, the center P of this pattern is substantially coincident with the optical axis O of the telescope, and the virtual image of the point P by the objective lens is the optical axis O. By observing the central point P of the pattern of the parallel plate glass 24 from the front of the objective lens, by fixing the parallel plate glass 24 at a position formed at the intersection Q between the vertical axis V of the surveying instrument and the vertical axis V of the surveying instrument body. Moreover, this point P seems to be at the position of the point Q which is the center of the surveying instrument body. Therefore, even if the telescope is slightly inclined in the horizontal plane including the point Q and in the vertical plane, the observation point Q, which is the measurement reference of the surveying instrument body, can be collimated without error.

The conventional surveying instrument has not formed a target for measuring its own position from another surveying instrument. Therefore, when measuring the position of the other surveying instrument from one surveying instrument in a survey using two surveying instruments, there was no choice but to guess the approximate center of the other surveying instrument and measure the other position. , Some error was unavoidable. However, the center P of the pattern of the parallel plate glass 24 of this embodiment can be visually recognized from the outside through the object lens of the telescope. Therefore, this pattern can be used as a target instead of the target to measure the position of your own from the other surveying instrument.

[0017]

[Effect of the device]

 As described above, according to the telescope for a surveying instrument of the present invention, it is possible to prevent the occurrence of fogging due to the attachment of water droplets to the object lens, which may hinder surveying. Therefore, even in an environment where the humidity is high and the temperature difference is large, it is possible to perform the survey without any trouble.

Further, since only the objective lens holder is hermetically sealed and gas is sealed, the number of hermetically sealed parts can be reduced. Therefore, not only sealing and gas filling but also gas leak inspection can be performed easily.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a telescope for a surveying instrument of this embodiment.

FIG. 2 is a sectional view showing a conventional telescope for a surveying instrument.

[Explanation of symbols]

 1 ... Telescope lens barrel 2 ... Objective lens holder 21, 22, 23 ... Objective lens 24 ... Transparent member 25, 26 ... Seal material 27 ... Gas hole 28 ... Screwed lid 29 ... Nitrogen (dry) gas O ... Optical axis

Claims (1)

[Scope of utility model registration request] 1. A telescope for a surveying instrument, comprising: an objective lens holder for holding an objective lens; and a telescope barrel for holding the holder, wherein the objective lens holder hermetically holds the objective lens on a tip side. Then, a transparent member is attached to the rear end side in an airtight manner to form a closed space between the objective lens and the transparent member, and the dry gas is sealed in the closed space. A telescope for a survey instrument, characterized in that the telescope is coupled to the telescope barrel.