JP2806329B2 - Focusing adjustment device for telescopes for space vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescope device mounted on a spacecraft, and more particularly, to a light control device of a telescope for a spacecraft for performing light control.

[0002]

2. Description of the Related Art For a telescope device mounted on a space vehicle such as an artificial satellite, it is necessary to adjust the focal length of the telescope in orbit or to stabilize the telescope regardless of environmental changes.

Conventionally, for such a purpose, as shown in Japanese Patent Application Laid-Open No. 2-294607, the condensing portion is moved along the Z axis (axial direction of the cylinder) by a piezoelectric element mounted around the lens barrel. ). FIG. 3 is a view schematically showing this conventional example, in which a mounting plate 10A is provided inside a lens barrel 10, and a rod-shaped elastic body 3, a piezoelectric element 4, and a protrusion 2A are arranged between the mounting plate 10A and the light collecting section 2. . In the above-mentioned publication, four adjustment means using such a piezoelectric element are arranged to perform desired adjustment.

[0004]

A first problem of the prior art is that when the temperature of the lens barrel fluctuates, the amount of movement of the light condensing part fluctuates. This is because expansion or contraction occurs in the lens barrel due to temperature fluctuations in the lens barrel.

A second problem is that in order to suppress the temperature fluctuation of the lens barrel, the lens barrel is made of a material having a small coefficient of thermal expansion.
Further, it is necessary to uniformly perform temperature control with high accuracy as a whole, but it is difficult to perform temperature control with required accuracy. The reason is that a material with a small coefficient of thermal expansion usually has a small thermal conductivity, and when a heater is attached to a lens barrel made of such a material and temperature control is performed, a temperature difference occurs in the lens barrel and thermal distortion causes a focus. This is because the position becomes unstable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a focusing device for a telescope for a spacecraft which eliminates non-uniform thermal distortion generated when controlling the temperature of the barrel of the conventional telescope for a spacecraft.

Another object of the present invention is to eliminate a driving element such as a piezoelectric element used in a conventional light-condensing adjusting device, and to improve mechanical strength, reliability and operability of a lens barrel. It is an object of the present invention to provide a focusing device for a telescope for a spacecraft capable of performing the above-mentioned operations.

[0008]

According to the present invention, a material having a large thermal expansion coefficient and a high thermal conductivity is adopted for the lens barrel, and a heater is attached to the lens barrel to control the temperature of the lens barrel. A focusing control device for a spacecraft telescope is obtained.

In the present invention, the focusing section is moved along the Z axis by thermal expansion to stabilize and adjust the focal length of the telescope. Further, since a material having a high thermal conductivity is adopted for the lens barrel, the temperature can be easily made uniform and the temperature can be easily controlled.

More specifically, in the light-gathering control device according to the present invention, an aluminum material or the like having a large thermal expansion coefficient and a large thermal conductivity is used in the center of the lens barrel, and the other parts of the lens barrel are used in other parts of the lens barrel. A titanium material having a small coefficient of thermal expansion and a small thermal conductivity is used. At the center of the lens barrel, heat is directly or indirectly easily radiated to outer space, and at the same time, a sheet-like heater and a temperature sensor are attached, and the temperature is controlled by a heater control device. Since the center of the lens barrel has high heat conduction, it can be uniformly controlled at an arbitrary temperature. Therefore, by controlling the temperature at an appropriate value in consideration of the thermal expansion of the aluminum material, the light-collecting unit can be moved to an appropriate position.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a side sectional view of an example of an embodiment of the present invention. In the figure, the telescope barrel is made of a material having low thermal conductivity and low thermal expansion coefficient,
Center part 10 of lens barrel manufactured with high thermal conductivity and high thermal expansion coefficient
, And a lens barrel base 50 made of the same material as the lens barrel tip 40. A heater 20 for temperature control is added to the lens barrel center portion 10, and power is supplied to the heater 20 from the control unit 80. The light collector 30 is fixed to the lens barrel tip 40, and can move in the Z-axis direction together with the tip 40. At least one temperature sensor 90 is attached to the center portion 10 of the lens barrel.
And the temperature is controlled based on this.

The center portion 10 of the lens barrel is subjected to a surface treatment such as painting having a high emissivity so as to easily radiate heat to the outer space or the periphery of the lens barrel.

Next, the operation of the embodiment of the present invention will be described. To move the light collector 30 in the + Z direction, the heater 20 is energized to increase the temperature of the lens barrel 10. Conversely, in order to move the focusing unit 30 in the −Z direction, the power supply to the heater 20 is turned off, and the temperature of the central part 10 of the lens barrel is lowered by radiation radiation from the surface of the lens barrel 10 to outer space or surroundings. Shrink. The temperature control of the lens barrel central part 10 is performed by the lens barrel central part 10.
And a heater control unit 80 that controls power supplied to the heater 20 based on an output signal of the temperature sensor.

Next, a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the lens barrel 10 is entirely made of a material having a high thermal conductivity and a high thermal expansion coefficient, and expands or contracts as a whole lens barrel. In this example, a lens barrel cover 60 that covers the lens barrel is provided. Lens barrel cover 60
In order to easily release heat from the lens barrel, the outer surface is subjected to a surface treatment that has a high emissivity and hardly absorbs sunlight, and is maintained at a low temperature. The inner surface of the lens barrel cover 60 is subjected to a surface treatment having a high emissivity in order to increase the radiation coupling with the lens barrel 10. The mounting plate 70 is provided for fixing the lens barrel 10 and the lens barrel cover 60.

[0015]

A first effect of the present invention is that precise temperature control of a lens barrel made of a low thermal conductivity material required for a conventional spacecraft telescope is not required. The reason for this is that, by manufacturing the lens barrel with a material having a high thermal conductivity, it is possible to easily control temperature uniformity and the like.

A second effect is that a light-concentration adjusting device which conventionally requires a complicated structure can be realized with a simple structure, and the weight of optical equipment can be reduced. The reason for this is that by changing the temperature of the telescope barrel, the light-collecting unit is moved in the Z-axis direction, thereby realizing the light-collecting adjustment function.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a conventional light condensing adjustment device of a spacecraft telescope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Center part of lens barrel 20 Heater 30 Condensing part 40 Tip part of lens barrel 50 Root part of lens barrel 60 Lens barrel cover 70 Mounting plate 80 Temperature controller 90 Temperature sensor

Claims (6)

(57) [Claims] 1. A method for controlling a thermal expansion of a telescope for a spacecraft by controlling a focal length of the telescope by controlling a temperature of a lens barrel of the telescope.
A focusing control device for a spacecraft telescope that expands and contracts the lens barrel in the optical axis direction. 2. The optical system according to claim 1, wherein the lens barrel is made of a combination of a first metal having a high coefficient of thermal expansion and a second metal having a small coefficient of thermal expansion.
Attach a heater to the first metal and control the temperature with this heater
2. The light condensing control device for a telescope for a spacecraft according to claim 1, wherein: 3. The light condensing control device for a spacecraft telescope according to claim 2, wherein a temperature sensor is attached to the first metal, and power is supplied to the heater according to a detection result of the temperature sensor. 4. The light-gathering control device for a telescope for a spacecraft according to claim 1, wherein a cover is arranged around the lens barrel. 5. The focusing device for a spacecraft telescope according to claim 2, wherein said first metal is aluminum and said second metal is titanium. 6. The light-gathering control device for a spacecraft telescope according to claim 1, wherein the surface of the lens barrel is covered with a substance having a high emissivity.