Observation and guide beam apparatus for day and night use

An observation and guide beam apparatus, referred to as a spotter scope, has in addition to a laser guide beam generator an optical daytime channel for daytime spotting or viewing and a day- and nighttime channel for both night and day observations. These channels are harmonized relative to the laser guide beam by the same automatic axial harmonizing device. Further, the day and night channel includes a heat imaging device that is internally harmonized on a long term basis. The scope also has an ocular arm. This combination is especially suitable for use in a weapons system using remote controlled flying bodies, for example. The scope can use any available type of detector or detector technology.

FIELD OF THE INVENTION 
The invention relates to an observation and guide beam apparatus for day 
and night use by a so-called "spotter". Such apparatus includes a night 
viewing system, a day viewing system, and a guide beam projector, as well 
as an arm supporting an eyepiece or ocular. For simplicity's sake the 
apparatus will be referred to as a "spotter scope" herein. 
DESCRIPTION OF THE PRIOR ART 
Different versions of spotter scopes are known in the art. One known 
spotter scope includes means for an automatic auto-collimation and 
harmonization. Portable spotter scopes, however, can so far not be 
provided with automatic harmonizing means since prior art harmonizing 
means are too complicated and too expensive for portable spotter scopes. 
Additionally, conventional harmonizing devices for three axes have the 
disadvantage that for each harmonizing operation all three axes require a 
follow-up adjustment. 
It is also known from U.K. Patent Application No. 2,148,663 that the 
harmonizing of a heat imaging device including a cathode ray tube, 
relative to a daylight channel, is difficult with complicated means, and 
impossible with simple means. Therefore, the so-called "1:1-solution" has 
been employed in connection with the harmonizing of a heat imaging device 
with a daylight channel. However, even this "1:1-solution" has its 
disadvantages that cannot be disregarded. For example, the image 
reproduction or display is possible only with light emitting diodes, a 
secondary image can be obtained only with the aid of an additional 
television system. 
Another disadvantage results when the heat imaging system is attached to 
the daylight system because this provides an additional optical 
intersection, so to speak, having two windows. Another drawback is seen in 
that three separate protection covers are necessary, and in that the arm 
carrying the imaging mirrors is unfavorable for a long duration axial 
harmonizing. Thus, this prior art approach of the so-called "1:1-solution" 
is not suitable for a subsequent installation in existing equipment. 
Incidentally, German Patent Publication (DE-OS) No. 3,338,496 describes an 
example of the so-called "1:1-solution". 
German Patent (DE-PS) No. 3,232,092 discloses other day and nighttime 
spotter scopes in which a daylight periscope is combined with a heat 
imaging device and with a cathode ray tube which displays the heat image. 
In this system the imaging scale is again on a 1:1 ratio. 
OBJECTS OF THE INVENTION 
In view of the foregoing it is the aim of the invention to achieve the 
following objects singly or in combination: 
to construct a spotter scope of the type mentioned above which is suitable 
for all weapons systems employing remote controlled flying bodies, and for 
all spotter requirements; 
to construct such a spotter scope in such a way that the required 
auto-collimation and harmonizing is achievable in a simple manner; and 
to construct such a spotter scope that all types of detectors, or rather 
detector technologies, may be employed. 
SUMMARY OF THE INVENTION 
The spotter scope according to the invention is characterzied by a 
day-night viewing system which is internally harmonized on a long term 
duration, and which cooperates with an automatic axial harmonizing device 
for providing the harmonization relative to a guide beam projector. The 
spotter scope is further characterized by a daylight viewing system which 
uses the same automatic axial harmonizing apparatus for its harmonization 
relative to the guide beam projector, such as a laser beam generator.

DETAILED DESCRIPTION OF PREFERRED EXAMPLE EMBODIMENTS AND OF THE BEST MODE 
OF THE INVENTION 
The spotter scope 100 shown in FIGS. 1, 2, and 3 comprises a daylight and 
night viewing system 10 which is internally harmonized on a long term 
basis. The system 10 comprises a heat imaging device 34 capable of daytime 
or nighttime viewing. The spotter scope 100 further includes a daylight 
viewing system 13 which is harmonized relative to the optical axis of a 
guide beam projector 12 by an automatic axial harmonizing device 11. The 
daylight and night viewing system 10 cooperates with the same axial 
harmonizing device 11 for achieving the required axial harmonization 
relative to the guide beam projector 12. The heat imaging device 34 of the 
system 10 is preferably internally harmonized. The entire spotter scope or 
unit 100 is housed in an insert which is connectable to a weapons system 
101 by conventional means not shown. Such conventional means would, for 
example, include mechanical guide prisms for securing the unit 100 to the 
weapons system 101. The connection may also be accomplished by a 
conventional snap-in mechanism. 
Referring to FIG. 3, the daylight and nighttime viewing system 10 comprises 
a first optical axis 10a forming part of the so-called night viewing 
channel 10b. A second optical axis 13a forms part of the daylight channel 
13b of the daylight viewing system 13. The two optical axes 10a and 13a 
extend in parallel to each other. The axis 10a of the nighttime channel is 
determined by the objective lens 10c and by the line marker 10d. The 
optical axis 13a of the day channel is determined by the objective lens 
13c and the line marker 13d. The line markers 10d and 13d are located in 
the focal plane. The parallelism between the axis 10a of the night viewing 
channel 10b and the axis 13a of the daylight channel 13b may be adjusted 
by an adjustment means comprising, for example, a plurality of optical 
wedges 11a. These optical wedges 11a are part of the above mentioned 
automatic axial harmonizing device 11. Both, the nighttime channel 10b and 
the daytime channel 13b are located in a common housing. Therefore, it is 
possible to achieve an optimal long term harmonization of both optical 
axes 10a and 13a. A cathode ray tube 16 provides the image display with 
the aid of a mirror 17 which may be switched from a display position in 
the daylight channel 13b into an inoperative position (shown as phantom 
lines 17' in FIG. 3) and vice versa. As mentioned, the system 10 includes 
the heat imaging device 34 of conventional construction. It is merely 
required that the heat imaging device 34 is compatible with a television 
display system. The heat imaging device 34 does not need to rely on any 
particular type of detector technology. The line marker 10d in the heat 
imaging device 34 can be constructed directly as a target marker or it may 
be merely a marker for the position of a target marker which is 
electronically produced. 
Referring further to FIG. 2, the guide beam projector 12 may be a laser 
generator inserted in an insert tubular member 12' of the unit 100 and has 
an optical axis 12a. The tubular member 12' reaches into the common 
housing of the unit 100. The wavelength of the laser generator 12 should 
be about one micrometer to assure that a simple and automatic axial 
harmonization with the daylight channel 13b is possible. For this purpose 
the harmonizing device 11 in the daylight channel 13b comprises a detector 
array 11b for determining the position of the laser beam generated by the 
laser or guide beam generator 12. Incidentally, the ocular arm or operator 
unit 14 is also shown in FIGS. 1 and 2 and is used for both channels. 
FIG. 4 show harmonizing means for achieving a long term harmonizing in the 
spotter scope or unit 100. The optical axis 13a of the daylight channel 
13b is harmonized relative to the optical axis 10a of the heat imaging 
device 34 by the above mentioned optical wedges 11a which may be of the 
rotatable type or which may be replaced by a plane plate or similar 
adjusting elements. As shown, these elements are located in the daylight 
channel 13b. The optical axis 10a of the nighttime channel 10b is used as 
the reference axis and hence axis 10a is not adjustable. The degree of 
size of the misadjustment is determined by an auto-collimation as shown in 
FIG. 5. The line marker 10d provides a rated measure for the adjustment 
markers 22 of the reticle 21. The unit 100 has a hinged cover 20 which is 
simultaneously a protection device for the optical means as well as an 
optical device in the form of a plane mirror 18 which is used for the 
harmonizing. A simple adjustment screw 20a permits an adjustment of the 
cover 20 and thus of the plane mirror 18 relative to the optical axis 13a 
to thereby provide the required zero auto-collimation or zero adjustment. 
FIG. 6 illustrates an embodiment in which the mirror 18 in the cover 20 has 
been replaced by a triple prism 19 for the harmonizing of the laser beam 
axis 12a with the optical axis 13a of the daylight channel. This triple 
prism 19 assures a proper harmonizing of the axes 13a and 12a by 
deflecting the laser beam into the daylight channel 13b. Thus, it is 
possible to perform the harmonizing when the cover is closed without any 
external adjustments. 
In FIG. 7 the harmonizing is to be accomplished directly or immediately 
prior to the firing of the weapons system. For this purpose it is 
necessary that the cover 20 is in its open position as shown in FIG. 7. In 
this embodiment the plane mirror 18 and the triple prism 19 is tiltable 
independently of the cover 20 into the position shown in FIG. 7. Thus, the 
mirror 18 has a hinging mechanism independently of the hinge for the cover 
20. 
The electrical power supply means 23 shown in FIG. 1 may also be arranged 
entirely or partially in the weapons carrier 101 such as a tank or the 
like. 
FIGS. 8 and 9 illustrate the present spotter scope incorporated in a turret 
of the weapons system, for example, a tank or the like. In FIG. 8 the 
spotter or operator rotates with the entire unit. In FIG. 9 the spotter or 
operator remains stationary while the unit is rotatable for an all around 
azimuth viewing. FIGS. 8 and 9 are otherwise self-explanatory having 
regard to the labels used in these Figs. 
The invention has provided a spotter scope which is equally suited for an 
installation as shown in FIGS. 8 and 9 or for a portable unit. A separate 
drive 102, for example, including an electrical motor and a respective 
gear, rotates the aiming mirror in its dome which can be closed by the 
above described cover 20. 
Although the invention has been described with reference to specific 
example embodiments, it will be appreciated, that it is intended to cover 
all modifications and equivalents within the scope of the appended claims.