JPS631208Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device for illuminating the focus plate of a telescope in a surveying instrument such as a level or theodolite.

Conventionally, as this type of illumination device, a cylindrical body is attached to the tip of a telescope of a surveying instrument, and illumination light is incident perpendicularly to the optical axis of the telescope from a light source provided on the outer periphery of the cylindrical body through an aperture. 2. Description of the Related Art A device is known in which a reflecting mirror rotatably provided on an axis reflects illumination light along an optical axis to illuminate a reticle.

However, in such conventional illumination devices, the light intensity loss of the reflected light with respect to the incident light on the reflector is not deviated from, and the brightness of the focusing plate can be adjusted by rotating the reflector in the direction of reflection, that is, by rotating the reflector. Because this is done by tilting the direction in which the reticle is irradiated with light relative to the optical axis of the telescope, the brightness on the reticle is not uniform, and the rotation angle of the reflector that can illuminate the reticle is only 2. Therefore, it is extremely difficult to finely adjust the brightness within such a very small rotational adjustment range.

In order to solve the above-mentioned conventional problems, this invention
It is possible to directly illuminate the focus plate while adjusting the light intensity without requiring a reflector, and it is possible to effectively utilize the illumination light from the light source without loss of light intensity and illuminate with uniform brightness. We propose a focus plate illumination device that can be easily finely adjusted.

Hereinafter, an embodiment of this invention shown in the drawings will be described. A small light source 4 such as a light emitting diode attached to a support member 3 on the optical axis 0 in front of the focusing plate 2 of the telescope 1 directs its light emission direction to the focal point. It is installed facing plate 2.

A light amount adjustment plate 5 is installed near the light source 4 and in front of it in the irradiation direction. This light amount adjustment plate 5
is configured to be rotatable around an axis perpendicular to the optical axis by an adjustment knob 6 on the outside of the telescope 1, and by changing the rotation angle, the amount of shielding of the illumination light beam from the light source 4 is changed. However, the brightness of the focus plate 2 can be adjusted by changing the amount of light passing through it.

Therefore, when the light amount adjusting plate 5 is at an angle parallel to the optical axis 0, the brightness of the focusing plate 2 becomes maximum.
It is minimum when the angle is perpendicular to the optical axis 0,
The brightness can be adjusted within a 90° range.

The light source 4 is connected to a power supply battery 7 provided outside or inside the telescope 1, and is turned on or off by a changeover switch 8.

In the first embodiment shown in FIG.
This figure shows the case where the light source 4 and the light amount adjusting plate 5 are installed between the objective lens 9 and the focusing plate 2.
is located.

The second embodiment shown in FIG. 3 shows a case where the light source 4 is installed outside the telescope 1, and the light source 4 and the light amount adjusting plate 5 are connected to a cylindrical body 10 that is detachably fitted to the tip of the telescope 1. It is configured such that it can be easily removed from the telescope 1 together with the battery 7 and changeover switch 8, which are integrated into the barrel 10, when there is no need to illuminate the focusing plate 2.

When surveying with the above configuration at night or in a dimly lit place such as inside a tunnel, turn on the changeover switch 8 to cause the light source 4 to emit light, and while looking through the telescope 1, turn the light amount adjustment plate 5 as appropriate using the adjustment knob 6. , the brightness is adjusted by adjusting the amount of shielding of the illumination light flux to the focus plate 2. In this case, since the rotation adjustment of the light amount adjustment plate 5 is performed within an angular range of 90 degrees, fine adjustment of brightness is easy.Moreover, the illumination light flux is always directed toward the focusing plate, so that the light amount adjustment plate 5 is tilted. Since the focusing plate 2 is illuminated by passing through both edges, the brightness of the focusing plate 2 becomes uniform without unevenness.

Note that the light source 4 is a small one such as a light emitting diode, and the light intensity adjustment plate only needs to be large enough to cover it, so even if these are always installed on the optical axis of the telescope 1, it can still be used as a telescope. There are no problems.

As described above, according to this invention, the light source is installed on the optical axis of the telescope with its emitted light direction directed toward the focus plate, so the illumination light from the light source can directly illuminate the focus plate, reducing the amount of light. There is no loss, and even if the amount of electricity stored in the power supply battery decreases and the light emission from the light source is considerably weakened, a sufficient amount of light can be obtained for illumination, and the battery can be used for a long period of time.

In addition, since the light source is always directed toward the focus plate, the brightness of the focus plate can be made uniform, and the light amount adjustment plate is rotatably provided in front of the light source in the light emission direction. The light amount adjustment range is wide, making it easy to finely adjust the brightness.

[Brief explanation of the drawing]

Fig. 1 is a schematic vertical sectional view of the first embodiment of this invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig.
The figure is a schematic vertical sectional view of the second embodiment of this invention, and the fourth embodiment.
The figure is a BB sectional view in FIG. 3. 1...Telescope, 2...Focal plate, 4...Light source, 5
...Light adjustment board.

Claims (1)

[Scope of utility model registration request] A focal point of a telescope in a surveying instrument, characterized in that a light source is installed on the optical axis of the telescope with its emission direction directed toward a focusing plate, and a rotatably adjustable light amount adjusting plate is provided in front of the light source in its emission direction. Board lighting device.