JPH09311281A - Visual field changeover mechanism for infrared ray video device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce impact force for a lens system by providing a slide adjusting means for decelerating the slide of a direction separating from ground and accelerating the slide of the direction approaching to the ground at the time of switching visual field in relation to a driving means. SOLUTION: A torsion coil spring 50 is attached to the output shaft 20 of a motor as the slide adjusting means. A parallel movement load is made nearly equal to the case of θ=0 deg., because the gravitational acceleration component of the mass of a lens assembly 2 acting in the direction where a movement is prevented in the case of switching the visual field from the wide visual field to the narrow visual field, namely, the motor shaft conversion torque Tm of mgsinθ is negated by the torque Tx of the torsion coil spring 50. The increase of the rotational speed of the motor is eliminated so that it is negated by the gravitational acceleration component of the mass of the lens assembly (parallel movement load) 2 acting in the direction where the movement is accelerated in the case of switching the visual field from the narrow visual field to the wide visual field, namely, the motor shaft conversion torque Tm of mgsinθ is cancelled by the torque Tx of the spring 50, so that the parallel movement load is made nearly equal to the case of θ=0 deg..

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a wide field of view and a narrow field of view.
The present invention relates to a visual field switching mechanism for switching a visual field from a wide visual field to a narrow visual field or from a narrow visual field to a wide visual field in an infrared image device having a visual field.

In an infrared imager used for detecting an aircraft or the like having a temperature higher than room temperature in an outdoor space, generally, the visual field to be detected can be switched between a wide visual field and a narrow visual field in two steps. It is being appreciated.

As a visual field switching mechanism of an infrared imager,
A mechanism is generally used in which a wide-field lens and a narrow-field lens are translated in a plane perpendicular to the optical axis of incident light to switch the field of view.

At this time, it is required that the switching speed is high and that the impact force applied to the lens and the impact force applied to the drive unit are small. Depending on the installation conditions of the device, it may be necessary to use it with the switching direction inclined to the ground, and under such conditions the impact force applied to the lens etc. is small and high-speed switching of the field of view is achieved. Is required to do so.

[0005]

2. Description of the Related Art Conventionally, in a visual field switching mechanism of an infrared imager, a visual field switching mechanism has been generally adopted in which the viewing angle of a lens is switched on an incident optical axis of radiated infrared rays from a target object to an infrared detector. ing.

FIG. 1 shows a front view of a conventional visual field switching mechanism. Reference numeral 2 is a lens assembly in which a wide-field lens 6 and a narrow-field lens 8 are attached to a lens holder 4, and the lens assembly can slide along a slider rail 10 attached at a predetermined angle θ with respect to the ground.

A sliding member 12 which slides integrally with the lens assembly 2 is fixed to the lens holder 4. One end of a slider link 14 is rotatably attached to the sliding member 12 by a shaft 16, and the other end of the slider link 14 is rotatably attached to a tip of a rotary crank 18 by a shaft 22. .

The base end of the rotary crank 18 is fixed to an output shaft 20 of a motor (not shown). Slider rail 1
Stoppers 24 and 26 for restricting the rotational movement of the rotary crank 18 are fixed to 0. The motor is regulated to rotate normally and reversely within a range of 180 °.

However, when the wide-field lens 6 rotates the motor (not shown) from the solid line position on the incident optical axis A to rotate the rotary crank 18 by 180 ° in the direction of arrow P, it is integrated with the lens holder 4. The sliding member 12, which is fixed to, moves in the direction of the arrow B, and the wide-field lens 6 deviates from the incident optical axis A as shown by the chain double-dashed line. Instead, the narrow-field lens 8 is placed on the incident optical axis A. Will match.

On the contrary, from the narrow-field lens 8 to the wide-field lens 6
When switching to, the motor is reversely rotated to rotate the rotary crank 18 in the counterclockwise direction. As a result, the lens assembly 2 slides along the slider rail 10, and the wide-field lens 6 is switched to a position that coincides with the incident optical axis A.

In this case, since the switching direction is inclined by θ ° with respect to the ground, when switching from the wide field of view to the narrow field of view,
Assuming that the mass of the lens assembly 2 is m and the gravitational acceleration motion is g, a force equivalent to mgcos (90−θ) = mgsin θ acts in a direction in which the movement of the lens assembly 2 is hindered.

Assuming that a drive motor having the same capacity as in the case of θ = 0 ° is used, the amount of increased load (mgsin θ
The switching speed becomes slower by the motor shaft converted torque of the force.
In order to obtain the same switching speed as in the case of θ = 0 °, it is necessary to increase the motor capacity in accordance with the increased amount of load, which causes an increase in the size, mass and cost of the visual field switching mechanism.

On the other hand, when switching from the narrow field of view to the wide field of view, the force of mg sin θ acts in the direction of accelerating the movement, so assuming that the drive motor of the same capacity as in the case of θ = 0 ° is used, the load is reduced. The switching speed becomes faster by the amount.

The fact that the switching speed is high does not pose a problem, but the torque in the direction of acceleration is increased by the torque equivalent to the motor shaft equivalent torque of mgsin θ, so that the motor rotation speed is increased. As a result, the rotation speed of the rotary crank 18 increases, and the impact force when the rotary crank 18 collides with the stopper 24 increases.

The rotary crank 1 responds to an increase in impact force.
8. The strength of the stopper 24 has to be increased, and since the impact force on the motor is also large, it is necessary to increase the strength of the motor shaft.

As a result, the size and the mass of the rotary crank 18 and the stopper 24 increase, and the size, the mass and the cost increase as the motor capacity increases. Also, the impact force on the lens itself is increased.

[0017]

As described above, in the field-of-view switching mechanism of the conventional infrared imaging apparatus, when used in a condition in which the switching direction is inclined with respect to the ground, the load increases depending on the switching direction. Therefore, there is a problem that the switching speed is not constant and the impact force on the lens assembly increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make the load uniform when switching from a wide field of view to a narrow field of view or switching from a narrow field of view to a wide field of view. (EN) Provided is a field-of-view switching mechanism of an infrared imaging device in which the switching speed is made uniform and high speed and the impact force on the lens system is reduced.

[0019]

According to the present invention, a slider rail mounted so that the sliding direction is inclined at a predetermined angle with respect to the ground, a wide-field lens and a narrow-field lens are provided, and the wide-field lens is used for incident light. 1 that roughly matches the optical axis of
A lens assembly slidable along the slider rail in a plane perpendicular to the optical axis of the incident light between a position and a second position where the narrow-field lens substantially coincides with the optical axis of the incident light;
A field-of-view switching mechanism of an infrared imaging device comprising a driving means for driving the lens assembly between the first position and the second position, wherein when the field-of-view is switched by the driving means, the slide in the direction away from the ground is decelerated. There is provided a visual field switching mechanism for an infrared imaging device, characterized in that slide adjusting means for accelerating the slide in the direction approaching is provided in association with the driving means.

For example, the driving means comprises a slider crank mechanism having one end rotatably connected to the slider rail and the other end fixed to the output shaft of the motor. The slide adjusting means is composed of a torsion coil spring attached to the output shaft of the motor.

Instead of the torsion coil spring, a compression coil spring interposed between the slider rail and the lens assembly may be used as the slide adjusting means. Instead of the compression coil spring, the slide adjusting means may be configured by a tension coil spring stretched between the slider rail and the lens assembly.

Instead of the slider crank mechanism, a rack / pinion mechanism, a ball screw mechanism, an electromagnet suction mechanism or the like can be adopted as the driving means. Even when such a driving means is adopted, the same torsion coil spring, compression coil spring, or tension coil spring as described above can be adopted as the slide adjusting means.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description of the embodiment,
The substantially same components as those of the conventional example shown in FIG.

Referring to FIG. 2, there is shown a system configuration diagram of the infrared imager. The infrared energy 28 from the background passes through the infrared lens 6 or 8, is reflected by the horizontal scanning mirror 34, and is collected by the infrared lens 36 on the multi-element infrared detector 38.

The infrared detector 38 converts the optical signal into an electrical signal, the amplifier 40 amplifies the electrical signal, and the video circuit 42 visualizes it to display the infrared image on the CRT monitor 44.

A wide-field lens 6 and a narrow-field lens 8 are switched by the field switching mechanism 32 as needed. When it is desired to switch the visual field, a wide or narrow visual field command is given to the drive circuit 46 to drive the visual field switching mechanism 32 to switch between the wide visual field lens 6 and the narrow visual field lens 8.

Next, a first embodiment of the present invention will be described with reference to FIGS. The visual field switching mechanism of this embodiment is similar to the conventional mechanism shown in FIG. The biggest difference is that the torsion coil spring 50 is attached to the output shaft 20 of the motor 48.

That is, one end of the torsion coil spring 50 is fixed to the output shaft 20 of the motor 48, and the other end is fixed to a spring holder 52 integrally fixed to the slider rail 10. 6A and 6B are detailed views of the torsion coil spring portion. FIG. 6A is a plan view, FIG. 6B is a front view, and FIG. 6C is a side view.

As the torque of the torsion coil spring 50,
Lens assembly (parallel movement load) in the state shown in FIG.
It is necessary to give a torque in the Tx direction (clockwise direction) sufficient to cancel the gravitational acceleration component of the mass of 2, that is, the motor shaft conversion torque Tm of mgsin θ. Therefore, such a spring is designed and attached to the output shaft 20. The torque value of the torsion coil spring 50 is approximately equal to Tm at both the C position and the B position.

When the field of view is switched from C to B, that is, when the field of view is switched from the wide field of view to the narrow field of view, the gravitational acceleration component of the mass of the lens assembly 2 acting in the direction in which the movement is impeded, that is, mgsinθ torque converted to the motor axis. Since Tm is canceled by the torque Tx of the torsion coil spring 50, the parallel movement load is almost the same as in the case of θ = 0 °. Therefore, the visual field switching speed can be made approximately the same as in the case of θ = 0 °, and it is not necessary to increase the capacity of the motor.

When the field of view is switched from B to C, that is, when the field of view is switched from the narrow field of view to the wide field of view, the gravitational acceleration component of the mass of the lens assembly (translation load) 2 acting in the direction of accelerating the movement, that is, mgsin
Since the torque Tm converted into the motor shaft of θ is canceled by the torque Tx of the torsion coil spring 50, the rotation speed of the motor does not increase, and the parallel movement load becomes almost equal to that in the case of θ = 0 °.

Therefore, the visual field switching speed can be made substantially the same as in the case of θ = 0 °, and the rotary crank 18 is stopped by the stopper 24.
There is no increase in the impact force when the vehicle collides with. The required spring force of the torsion coil spring 50 can be calculated, but in the end, the torsion force is the same when switching from a wide field of view to a narrow field of view or from a narrow field of view to a wide field of view by experiments. It is desirable to select a coil spring.

Referring to FIG. 7, there is shown a front view of the second preferred embodiment of the present invention. In this embodiment, a compression coil spring 58 is interposed between a spring holder 54 fixed to the lens assembly 2 and a spring holder 56 fixed to the slider rail 10, instead of the torsion coil spring of the first embodiment.

The spring force of the compression coil spring 58 is a force Fx that cancels the gravitational acceleration component mgsin θ of the mass of the lens assembly (parallel movement load) 2 in the state shown in the figure.
Need to give. Design and install such a spring. The spring force of the compression coil spring 58 is approximately equal to mgsin θ at both the C position and the B position.

When the field of view is switched from C to B, the gravitational acceleration component of the mass of the lens assembly 2 acting in the direction of impeding the movement is canceled by the compression coil spring force Fx. On the other hand, when the field of view is switched from B to C, the gravitational acceleration component of the mass of the lens assembly 2 acting in the direction of accelerating the movement is canceled by the compression coil spring force Fx.

Referring to FIG. 8, there is shown a front view of the third preferred embodiment of the present invention. In the present embodiment, the lens assembly 2 is replaced with the compression coil spring of the second embodiment described above.
An extension coil spring 64 is stretched between a spring holder 60 fixed to the slider holder 10 and a spring holder 62 fixed to the slider rail 10.

As the spring force of the tension coil spring 64, it is necessary to give a force Fx for canceling out the gravitational acceleration component of the mass of the lens assembly (parallel movement load) 2, that is, mgsin θ, in the state shown in the figure. Also according to this embodiment, it is possible to achieve the same effects as those of the above-described first and second embodiments.

Referring to FIG. 9A, there is shown a front view of the fourth embodiment of the present invention. The present embodiment differs from the first embodiment shown in FIG. 3 in that the view switching mechanism is changed to a rack / pinion mechanism.

That is, the rack 66 is integrally fixed to the lens assembly 2, and the rack 66 is attached to the output shaft 20 of the motor 48 attached to the slider rail 10.
A pinion 68 that meshes with is fixed. Rack 66
Stoppers 70 and 72 are provided at both ends of the.

As best shown in the plan view of FIG. 9B, the output shaft 20 of the motor 48 has a torsion coil spring 5
0 is attached. That is, one end of the torsion coil spring 50 is fixed to the output shaft 50 of the motor 48, and the other end is fixed to the spring holder 52 integrally fixed to the slider rail 10.

When the pinion 68 is rotated by the motor 48,
The rack 66 meshed with the pinion 68 is linearly moved,
The lens assembly 2 is switched from the wide field of view to the narrow field of view or from the narrow field of view to the wide field of view according to the rotation direction of the motor 48.

In this embodiment, the output shaft 20 of the motor 48 is
Since the torsion coil spring 50 is attached to the, the effect thereof is similar to the effect of the first embodiment shown in FIGS. 3 to 6.

Referring to FIG. 10, there is shown a front view of the fifth embodiment of the present invention. The present embodiment differs from the second embodiment shown in FIG. 7 in that the view switching mechanism is changed to a rack / pinion. Also in this embodiment, the same effect as that of the second embodiment can be obtained.

Referring to FIG. 11, there is shown a front view of the sixth embodiment of the present invention. The present embodiment differs from the third embodiment shown in FIG. 8 in that the view switching mechanism is changed to a rack / pinion. Also in this embodiment, the same effect as that of the third embodiment can be obtained.

Referring to FIG. 12, there is shown a front view of the seventh embodiment of the present invention. This embodiment is different from the second embodiment shown in FIG. 7 in that the visual field switching mechanism is changed to a ball screw drive.

A pair of support members 7 are attached to the slider rail 10.
4, 76 are fixed, and these support members 74, 7 are fixed.
A ball screw 82 is rotatably supported on the shaft 6 via bearings 84 and 86, respectively. The ball screw 82 is the motor 7
8 are connected to the output shaft 80.

On the other hand, the lens assembly 2 is provided with a nut 88 screwed into the ball screw 82 and a collision member 90. The slider rail 10 has this collision member 90.
7 that stops the lens assembly 2 due to collision with
0 and 72 are fixed.

When the motor 78 is driven, the ball screw 82 is rotated, and the nut 88 screwed onto the ball screw 82 makes a linear motion. As a result, the lens assembly 2 is switched from the wide field of view to the narrow field of view or from the narrow field of view to the wide field of view.

As the spring force of the compression coil spring 58, a force Fx sufficient to cancel out the gravitational acceleration component of the mass of the lens assembly (parallel movement load) 2, that is, mgsin θ, is required in the state shown in the figure. Therefore, such springs are designed and installed. Also in the case of this embodiment, the same effect as that of the second embodiment shown in FIG. 7 is obtained.

Referring to FIG. 13, there is shown a front view of the eighth embodiment of the present invention. This embodiment is different from the third embodiment shown in FIG. 8 in that the visual field switching mechanism is changed to a ball screw drive. The present embodiment also has the same effect as the third embodiment shown in FIG.

Referring to FIG. 14A, there is shown a front view of the ninth embodiment of the present invention. The present embodiment differs from the first embodiment shown in FIGS. 3 to 6 in that the visual field switching mechanism is changed to an electromagnet suction mechanism.

The electromagnet attracting mechanism 94 includes a pair of electromagnets 96 and 98 attached to a fixed member, and the guide 1
Connecting rod 102 that moves linearly along 00 is electromagnet 96,
It is located between 98. Pin 104 is connecting rod 102
And are formed integrally with it.

A shaft 108 is fixed to the slider rail 10, and an arm 106 is rotatably mounted around the shaft 108. Slide member 11
0 is integrally fixed to the lens assembly 2, and the slide member 110 is provided with a pin 112 protruding therefrom.

Both ends 114 and 116 of the arm 106 are each formed in a U shape.
14 and 116 are engaged with the pins 104 and 112, respectively.

As shown in FIG. 14B, the shaft 10
A torsion coil spring 50 is attached to 8. That is, one end of the torsion coil spring 50 is connected to the shaft 108.
And the other end is fixed to the arm 106.

To hold the lens assembly 2 in the C position, a voltage is applied to the electromagnet 98 and the electromagnet 96 is turned off. As a result, the connecting rod 102 is attracted to the electromagnet 98, the lens assembly 2 is held at the C position, and the wide-field lens 6 is aligned with the incident optical axis.

When the field of view is switched from C to B, that is, when the field of view is switched from the wide-field lens 6 to the narrow-field lens 8, the gravitational acceleration of the mass of the lens assembly (parallel movement load) 2 acting in the direction in which the movement is impeded. In order to cancel out the component, that is, the torque Ts of mgsin θ converted into the shaft 108 by the torque Tx of the torsion coil spring 50,
The load is almost the same as in the case of 0 °.

Therefore, the visual field switching speed is also substantially the same as in the case of θ = 0 °, and the lens assembly 2 causes the stopper 70,
There is no need to increase the impact force when the vehicle collides with 72, and there is no need to take measures against the increase in strength and increase the capacity of the electromagnets 96 and 98.

Referring to FIG. 15, there is shown a front view of the tenth embodiment of the present invention. The present embodiment differs from the second embodiment shown in FIG. 7 in that the visual field switching mechanism is changed to an electromagnet suction mechanism 94.

The electromagnet suction mechanism 94 is the ninth magnet shown in FIG.
It is substantially the same as the electromagnet suction mechanism 94 of the embodiment. This embodiment also has the same effect as that of the second embodiment shown in FIG. Referring to FIG. 16, there is shown a front view of the eleventh embodiment of the present invention. The present embodiment differs from the third embodiment shown in FIG. 8 in that the visual field switching mechanism is changed to an electromagnet suction mechanism 94. This embodiment also has the same effect as the third embodiment shown in FIG.

Referring to FIG. 17, there is shown a front view of the twelfth embodiment of the present invention. This embodiment differs from the eleventh embodiment shown in FIG. 16 in that the arm 128 is connected to the connecting rod 12.
The tension coil spring 138 extends beyond 0 and the fixing member 1
It is stretched between 39 and the end portion 134 of the arm 128.

That is, the connecting rod 120 is a pair of guides 1.
Guided by 22, 124, it moves linearly between the electromagnets 96, 98. A pin 126 is provided on the connecting rod 120 in a protruding manner. A shaft 130 is integrally fixed to the slider rail 10, and an arm 128 is attached rotatably around the shaft 130. The slot 132 formed in the arm 128 engages the pin 126 and the U-shaped end 136 engages the pin 112. Electromagnet suction mechanism 1
18 has a structure different from that of the electromagnet suction mechanism 94 shown in FIG.

The spring force of the tension coil spring 138 is as follows.
In the state shown in the figure, the force F is sufficient to cancel the gravitational acceleration component mgsinθ of the mass of the lens assembly (parallel movement load) 2.
x needs to be provided at the end 134 of the arm 128. Therefore, such springs are designed and installed. Also in the case of the present embodiment, there are the same effects as those of the eleventh embodiment shown in FIG.

Referring to FIG. 18A, there is shown a front view of the thirteenth embodiment of the present invention. This embodiment is different from the ninth embodiment shown in FIG. 14 in that the electromagnet suction mechanism 140 has a single electromagnet 98.

As the torque of the torsion coil spring 50,
In the state shown in the figure, the applied voltage of the electromagnet 98 is cut off, and the gravitational acceleration component mgsin θ of the mass of the lens assembly 2 is further supplied to the lens assembly 2 within a specified time T (field switching time).
It is necessary to give the shaft 108 conversion torque of a value obtained by adding a force sufficient to move from C to B in the Tx direction. Therefore, such springs are designed and installed.

As the attractive force of the electromagnet 98, the lens assembly 2 moves from B to C within a prescribed time T (field switching time) in accordance with the conversion force at the position of the electromagnet 98 of the torque Tx of the torsion coil spring 50 at the C position. A value obtained by adding as much force as possible (force equivalent to the time required to move from C to B by the torque of the torsion coil spring 50) is necessary.

The operation when switching the field of view from C to B is as follows. At the position C, since the voltage is applied to the electromagnet 98, the electromagnet 98 is turned off first.
Then, since the attractive force of the electromagnet 98 becomes zero, the torque of the torsion coil spring 50 causes the arm 106 to rotate counterclockwise around the shaft 108. This causes the lens assembly 2 to translate from C to B.

The operation when switching the field of view from B to C is as follows. A voltage is applied to the electromagnet 98. Then, a suction force is generated in the electromagnet 98, and the connecting rod 102 is attracted to the electromagnet 98. As a result, the arm 106 rotates clockwise, and the lens assembly 2 translates from B to C.

According to this embodiment, the torsion coil spring 5
Since the torque of 0 and the attraction force of the electromagnet 98 are set as described above, the load at the time of switching in both directions is made uniform, and the impact force when the lens assembly 2 collides with the stoppers 70, 72 can be reduced. Furthermore, since only one electromagnet 98 is required, the device can be downsized and the cost can be reduced.

Referring to FIG. 19, there is shown a front view of the fourteenth embodiment of the present invention. This embodiment is different from the tenth embodiment shown in FIG. 15 in that one electromagnet 98 of the electromagnet suction mechanism 140 is provided.

As for the spring force of the compression coil spring 58, the voltage applied to the electromagnet 98 is cut off in the state shown in the figure, and the gravitational acceleration component mgsin θ of the mass of the lens assembly 2 causes the lens assembly 2 to fall within the specified time T (field switching time). To C
You need a value that adds the force to move from B to B. Therefore, such springs are designed and installed.

As the attractive force of the electromagnet 98, the lens assembly 2 moves from B to C within a prescribed time T (field switching time) in accordance with the conversion force of the spring force Fx of the compression coil spring 58 at the C position at the electromagnet 98 position. A value obtained by adding as much force as possible (force equivalent to the time required to move from C to B by the spring force Fx of the compression coil spring 58) is required.
Therefore, the attraction force of the electromagnet 98 is set to such a value.

Referring to FIG. 20, there is shown a front view of the fifteenth embodiment of the present invention. This embodiment is different from the eleventh embodiment shown in FIG. 16 in that the electromagnet suction mechanism 140 has a single electromagnet 98.

As the spring force of the tension coil spring 64, the voltage applied to the electromagnet 98 is cut off in the illustrated state, and the gravitational acceleration component mgsin θ of the mass of the lens assembly 2 causes the lens assembly 2 to fall within the specified time T (field switching time). To C
You need a value that adds the force to move from B to B. Therefore, such springs are designed and installed.

As the attraction force of the electromagnet 98, the lens assembly 2 moves from B to C within a prescribed time T (field switching time) in accordance with the conversion force of the spring force Fx of the tension coil spring 64 at the C position at the electromagnet 98 position. A value obtained by adding as much force as possible (force equivalent to the time required to move from C to B by the spring force Fx of the tension coil spring 64) is required.
Therefore, the attraction force of the electromagnet 98 is set to such a value.

Referring to FIG. 21, there is shown a front view of the sixteenth embodiment of the present invention. This embodiment is different from the twelfth embodiment shown in FIG. 17 in that the electromagnet 98 of the electromagnet suction mechanism 142 is integrated.

The spring force of the tension coil spring 138 is as follows.
In the state shown in the figure, the applied voltage of the electromagnet 98 is cut off, and the lens assembly 2 converts the gravity force component mgsin θ of the mass of the lens assembly 2 at the end portion 134 of the arm 128 into C within the specified time T (field switching time). A value obtained by adding the converted force at the end portion 134 of the arm 128 of the force capable of moving from B to B is required. Therefore, such springs are designed and installed.

As the attraction force of the electromagnet 98, the lens assembly 2 moves from B to C within a prescribed time T (field switching time) in accordance with the conversion force of the spring force Fx of the tension coil spring 138 at the C position at the electromagnet 98 position. A value obtained by adding as much force as possible (force equivalent to the time required to move from C to B by the spring force Fx of the tension coil spring 138) is required. Therefore, the attraction force of the electromagnet 98 is set to such a value.

Referring to FIG. 22, there is shown a front view of the seventeenth embodiment of the present invention. In contrast to the sixteenth embodiment shown in FIG. 21, a tension coil spring 146 is provided on the connecting rod 120.

That is, the tension coil spring 146 is stretched between the end portion 120a of the connecting rod 120 and the fixing member 121. This embodiment operates in a similar manner to the 16th embodiment shown in FIG. 21 and has the same effect.

Referring to FIG. 23, there is shown a front view of the eighteenth embodiment of the present invention. This embodiment differs from the seventeenth embodiment shown in FIG. 22 in that a compression coil spring 152 is provided instead of the tension coil spring.

That is, the compression coil spring 152 is interposed between the end portion 120a of the connecting rod 120 and the fixing member 150. As the spring force of the compression coil spring 152, the voltage applied to the electromagnet 98 is cut off in the illustrated state, and the lens assembly 2 converts the gravitational acceleration component mgsin θ of the mass of the lens assembly 2 into the connecting force of the connecting rod 120 within a predetermined time T ( A value obtained by adding the converted force in the connecting rod 120 of the force capable of moving from C to B is required for the field of view switching time). Therefore, such springs are designed and installed.

As the attraction force of the electromagnet 98, the spring force Fx of the compression coil spring 152 at the position C is converted into the force at the position of the electromagnet 98, and the lens assembly 2 moves from B to C within the specified time T (field switching time). A value obtained by adding as much force as possible (force equivalent to the time required to move from C to B by the spring force Fx of the compression coil spring 152) is required. Therefore, the attraction force of the electromagnet 98 is set to such a value.

[0084]

Since the present invention is configured as described above in detail, when the field of view switching mechanism of the infrared imaging apparatus is used in a state in which the switching direction is inclined with respect to the ground, when switching between a wide field of view and a narrow field of view. The mechanical load and the visual field switching speed can be made uniform, and the impact force applied to the lens can be alleviated.

[Brief description of drawings]

FIG. 1 is a front view of a conventional example.

FIG. 2 is a block diagram of an infrared image device.

FIG. 3 is a front view of the first embodiment of the present invention.

FIG. 4 is a plan view of the first embodiment.

FIG. 5 is a perspective view of the first embodiment.

FIG. 6 is a detailed view of a torsion coil spring portion.

FIG. 7 is a front view of a second embodiment of the present invention.

FIG. 8 is a front view of a third embodiment of the present invention.

FIG. 9 is a front view of a fourth embodiment of the present invention.

FIG. 10 is a front view of a fifth embodiment of the present invention.

FIG. 11 is a front view of a sixth embodiment of the present invention.

FIG. 12 is a front view of a seventh embodiment of the present invention.

FIG. 13 is a front view of an eighth embodiment of the present invention.

FIG. 14 is a front view of a ninth embodiment of the present invention.

FIG. 15 is a front view of the tenth embodiment of the present invention.

FIG. 16 is a front view of the eleventh embodiment of the present invention.

FIG. 17 is a front view of the twelfth embodiment of the present invention.

FIG. 18 is a front view of a thirteenth embodiment of the present invention.

FIG. 19 is a front view of a fourteenth embodiment of the present invention.

FIG. 20 is a front view of the fifteenth embodiment of the present invention.

FIG. 21 is a front view of the sixteenth embodiment of the present invention.

FIG. 22 is a front view of the seventeenth embodiment of the present invention.

FIG. 23 is a front view of the eighteenth embodiment of the present invention.

[Explanation of symbols]

 2 lens assembly 4 lens holder 6 wide-field lens 8 narrow-field lens 10 slider rail 14 slider link 18 rotating crank 50 torsion coil spring

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hironori Ishizuka 4-1-1 Kamiotanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (72) Inventor Takayuki Tsuboi 4-chome, Ueodaanaka, Nakahara-ku, Kawasaki, Kanagawa 1-1 No. 1 within Fujitsu Limited (72) Inventor Tsutomu Maruyama 4-1-1 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Within Fujitsu Limited

Claims (15)

[Claims] 1. A slider rail mounted so that a sliding direction is inclined at a predetermined angle with respect to the ground, a wide-field lens and a narrow-field lens, and the wide-field lens substantially coincides with an optical axis of incident light. A lens assembly slidable along the slider rail in a plane perpendicular to the optical axis of the incident light between a position and a second position where the narrow-field lens substantially coincides with the optical axis of the incident light; The first
A field-of-view switching mechanism of an infrared imaging device including a driving unit that drives between a position and a second position, wherein when the field-of-view is switched by the driving unit, a slide in a direction away from the ground is decelerated and a slide in a direction approaching the ground is accelerated. A field-of-view switching mechanism for an infrared image device, characterized in that slide adjusting means is provided in association with the driving means. 2. The driving means comprises a crank mechanism having one end fixed to the output shaft of the motor and the other end rotatably connected to the lens assembly, and the slide adjusting means is attached to the output shaft of the motor. The field-of-view switching mechanism of the infrared imaging device according to claim 1, wherein the field switching mechanism comprises a twisted coil spring. 3. The driving means comprises a crank mechanism having one end fixed to an output shaft of a motor and the other end rotatably connected to the lens assembly, and the slide adjusting means comprises the slider rail and the lens assembly. The field-of-view switching mechanism of the infrared imaging device according to claim 1, comprising a compression coil spring that is interposed between the compression coil spring and the lens assembly and extends in the sliding direction of the lens assembly. 4. The driving means comprises a crank mechanism having one end fixed to an output shaft of a motor and the other end rotatably connected to the lens assembly, and the slide adjusting means comprises the slider rail and the lens assembly. The field-of-view switching mechanism of the infrared imaging device according to claim 1, wherein the field switching mechanism comprises a tension coil spring stretched between the slider rail and the slider rail and extending in a sliding direction of the slider rail. 5. The driving means comprises a rack fixed to the lens assembly, and a pinion meshing with the rack fixed to the output shaft of a motor mounted on the slider rail, and the slide adjusting means is the slide adjusting means. 2. The field-of-view switching mechanism of the infrared imaging device according to claim 1, wherein the field-of-view switching mechanism is composed of a torsion coil spring attached to the output shaft of the motor. 6. The drive means comprises a rack fixed to the lens assembly, and a pinion meshing with the rack fixed to an output shaft of a motor attached to the slider rail, and the slide adjusting means is provided with the slide adjusting means. 2. The field-of-view switching mechanism of the infrared imaging device according to claim 1, comprising a compression coil spring interposed between the slider rail and the lens assembly and extending in the sliding direction of the slider rail. 7. The drive means comprises a rack fixed to the lens assembly, and a pinion meshing with the rack fixed to an output shaft of a motor mounted on the slider rail, and the slide adjusting means includes the slide adjusting means. A field-of-view switching mechanism for an infrared imaging device, comprising a tension coil spring stretched between a slider rail and the lens assembly and extending in a sliding direction of the lens assembly. 8. The drive means is constituted by a ball screw mechanism including a ball screw attached to the slider rail and a nut screwed to the ball screw fixed to the lens assembly, and the slide adjusting means is the slider rail. 2. The field-of-view switching mechanism of the infrared imaging device according to claim 1, further comprising a compression coil spring interposed between the lens assembly and the lens assembly and extending in a sliding direction of the lens assembly. 9. The driving means comprises a ball screw mechanism including a ball screw attached to the slider rail and a nut screwed to the ball screw fixed to the lens assembly, and the slide adjusting means includes the slider rail. The field-of-view switching mechanism of the infrared imaging device according to claim 1, comprising a tension coil spring stretched between the lens assembly and the lens assembly and extending in a sliding direction of the lens assembly. 10. The driving means comprises at least one electromagnet, a connecting rod extending in the sliding direction of the lens assembly, which is arranged to be selectively attracted / released by the electromagnet, and one end of which is connected to the lens assembly. The slide adjusting means comprises an electromagnet attracting mechanism including an arm rotatably mounted around a fixed shaft so that the other end is engaged with the connecting rod, and the slide adjusting means is a screw mounted on the fixed shaft. The field-of-view switching mechanism of the infrared imaging device according to claim 1, wherein the field-of-view switching mechanism comprises a coil spring. 11. The driving means comprises at least one electromagnet, a connecting rod extending in the sliding direction of the lens assembly, which is arranged to be selectively attracted / released by the electromagnet, and one end of the driving means is connected to the lens assembly. The slide adjusting means comprises an electromagnet attracting mechanism including an arm rotatably mounted around a fixed shaft so that the other end engages with the connecting rod, and the slide adjusting means includes the slider rail and the lens assembly. 2. The visual field switching mechanism for an infrared imaging device according to claim 1, wherein the visual field switching mechanism comprises a compression coil spring that is interposed between the lens assembly and extends in the sliding direction of the lens assembly. 12. The driving means comprises at least one electromagnet, a connecting rod extending in the sliding direction of the lens assembly, which is arranged to be selectively attracted / released by the electromagnet, and one end of which is connected to the lens assembly. The slide adjusting means comprises an electromagnet attracting mechanism including an arm rotatably mounted around a fixed shaft so that the other end engages with the connecting rod, and the slide adjusting means includes the slider rail and the lens assembly. The field-of-view switching mechanism of the infrared imaging device according to claim 1, comprising a tension coil spring extending in the sliding direction of the lens assembly stretched between the two. 13. The driving means includes at least one electromagnet, a connecting rod extending in the sliding direction of the lens assembly, the connecting rod being arranged to be selectively attracted / released by the electromagnet, and one end of which is connected to the lens assembly. The slide adjusting means is comprised of an arm attached to be rotatable about a fixed shaft so that the intermediate portion engages with the connecting rod, and the slide adjusting means has the other end of the arm and a fixing member. The field-of-view switching mechanism of the infrared imaging device according to claim 1, characterized in that the field switching mechanism comprises an extension coil spring stretched between and. 14. The driving means includes at least one electromagnet, a connecting rod extending in a sliding direction of the lens assembly, the connecting rod being arranged to be selectively attracted / released by the electromagnet, and one end of which is connected to the lens assembly. The slide adjusting means includes one end of the connecting rod and a fixing member, the arm being rotatably mounted around a fixed shaft so that the other end engages with the connecting rod. 2. The field-of-view switching mechanism of the infrared imaging device according to claim 1, further comprising a tension coil spring that urges the connecting rod stretched between and between the electromagnet and the electromagnet. 15. The driving means includes at least one electromagnet, a connecting rod extending in the sliding direction of the lens assembly, the connecting rod being arranged to be selectively attracted / released by the electromagnet, and one end of which is connected to the lens assembly. The slide adjusting means is comprised of an arm attached to the other end so as to be rotatable around a fixed shaft so as to engage with the connecting rod at the other end, and the slide adjusting means includes one end of the connecting rod and a fixing member. 2. The field-of-view switching mechanism of the infrared imaging device according to claim 1, further comprising a compression coil spring for urging the connecting rod interposed between the compression coil spring and the electromagnet so as to separate the connecting rod from the electromagnet.