Detection device and method to locate film

A detection apparatus for locating a film position detects the position with a simple structure. The apparatus uses a plurality of position detection holes for each picture frame in a film. The holes are repeatedly formed in the film in a certain arrangement and correspond to detection bodies located in the camera. The device includes a signal output circuit generating signals indicative of the proper or improper positioning of the film based on alignment between the holes and the detection bodies.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a method and an apparatus to detect the position 
of film in a photographic device, such as a camera or the like. The method 
and device sense position detection holes in the film. 
2. Description of Related Art 
Japanese Unexamined Patent Application, Sho 57-74735 discloses a device to 
detect a film's position. This device uses signal detection holes formed 
on a film, which are distinct and different from holes used for feeding 
the film. The device detects the passing of the signal detection holes as 
the film is fed using an optical sensor or electrical switch facing the 
film supply passage in the camera. 
Japanese Unexamined Patent Application Sho 57-202524 discloses a device to 
determine the position of each picture frame in a film. The device 
includes detection pins, which can be inserted into holes in the film, to 
determine the position of the film. When the detection pins are inserted 
into the holes, the device detects the feeding of a frame of film, by 
actuating a switch that is in interlocking cooperation with the pin. 
Several problems exist in each of the above apparatuses. In Japanese 
Unexamined Patent Application Sho 57-74735, the signals from the sensor or 
switch are inverted several times as the film is fed. Therefore, it is 
necessary to provide the device with a circuit that can generate a signal 
corresponding to a starting or ending edge of the film that is different 
from the signal for a picture frame. The structure of the detection 
circuit becomes complicated with this type of signal generation. 
In Japanese Unexamined Patent Application Sho 57-202524, the output signal 
is inverted when the film supply signal quantity equals the picture frame 
signal quantity. The relationship between the signals from the switches 
and for the film position is clear and the structure of the detection 
circuit is relatively simple. However, problems arise when additional 
through holes are provided for other purposes. These through holes may 
detect the recording start position data for the film and be positioned 
between the position determining holes. Therefore, it is necessary to take 
precautions not to have additional holes detected by the picture frame 
detection switch. This leads to a complicated circuit and associated 
detection device. 
SUMMARY OF THE INVENTION 
An object of the invention is to provide a film position detection 
apparatus and method having a relatively simple structure for use in a 
camera. The apparatus permits additional through holes to be used in the 
film without impairing the detection of a film frame. 
The detection apparatus includes a plurality of detection bodies positioned 
to move orthogonally to a film supply passage. A film having a plurality 
of position detection holes formed in alignment with a picture frame is 
loaded into the camera and fed to the position detection device. A picture 
frame of the film is aligned with detection holes when a single picture 
frame is positioned at a specific position in the film supply passage. The 
detection bodies are biased toward the film supply passage and into the 
position detection holes. Signal output devices generate signals when the 
detection bodies are inserted into the position detection holes. 
The invention achieves another object of detecting the differences in the 
spacing between the position detecting holes for a single frame and 
adjacent frames in the film. The device also indicates a proper alignment 
of the film and designated exposure area of the camera. This and other 
objects will become evident from the following description of the 
invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
FIG. 1 shows the structure of the camera including a detection apparatus 
according to first embodiment. The camera main body 1 includes a cartridge 
chamber 2 and a spool chamber 3. A cartridge PT is mounted in the 
cartridge chamber 2. The film F is unwound from the chamber 2 and 
subsequently wound onto rolling spool 3a in spool chamber 3. The film F 
passes through exposure part or area 4 after being unwound from chamber 2 
and before being wound onto spool 3a by an appropriate motive source or 
driving assembly (not shown). 
As shown in FIG. 2, the film F includes two position detection holes H11, 
H12 aligned with the picture frame FR. Holes H11, H12 are spaced apart a 
distance S0 parallel to the film supply direction show by arrow A. S1 
defines the distance between the position detection holes H11 of two 
adjoining picture frames FR and represents the picture frame FR pitch. 
Additionally, length S2, between adjoining picture frame position 
detection holes H12, H11, is greater than the length S0. 
Detection apparatus 5 is positioned in the camera main body 1, between the 
film exposure area 4 and the spool chamber 3. The detection apparatus 5 
includes base 50, a pair of detection bodies 51, 52 connected to the base 
50, and a spring or biasing element, here coil spring 53, and a conduction 
plate 54. 
The base 50 can move orthogonal to the film supply passage when the film F 
is inserted through the recessed part 1a of the main body 1. The coil 
spring 53 biases the base 50 orthogonally toward the film supply passage. 
The conduction plate 54 is fastened to a pressure plate 6 located on the 
opposite side from the base 50, divided by the film supply passage. 
The base 50 is preferably constructed from an insulative material, such as 
plastic, ceramics or the like. The detection bodies 51, 52 are formed from 
an electrically conductive material, such as steel, copper or the like. 
The coil spring 53 may be formed from any appropriate elastic material. 
Further, the spring does not necessarily have to be a coil spring, as any 
appropriate biasing structure may be used. 
The detection bodies 51, 52 are aligned parallel to each other in the film 
supply direction A. The bodies 51, 52 are spaced apart a distance equal to 
the distance S0 between the detection holes H11, H12. A face of the 
detection bodies 51, 52 is formed substantially in a square shape, 
facilitating the insertion of the detection bodies 51, 52 into the 
position detection holes H11, H12. 
As seen in FIGS. 3 and 4, the detection bodies 51, 52 include terminals 
510, 520. The terminals 510, 520 are connected to an end of the detection 
bodies 51, 52 and project out of the recessed part 1a through hole 1b. The 
terminals 510, 520 are connected to a control apparatus (not shown), via 
an appropriate electrical connection, such as a flexible printed circuit 
board (FPCB) or the like. 
Additionally, pressure plate 6 is provided to define film exposure area 4. 
The pressure plate 6 includes an external rail 70 and an internal rail 71. 
The rails 70, 71 guide and position the edges of film F, as the film F 
moves in the film supply direction A. This prevents the film F from moving 
perpendicularly to the film supply direction and ensures the alignment of 
the detection bodies 51, 52 and the position detection holes H11, H12. 
In operation, when the film F is advanced, a picture frame FR is moved and 
aligned with the film exposure area 4. The film F is aligned at the film 
exposure area 4 so as to form a rectangularly shaped picture taking 
surface or luminous flux, as seen in FIG. 4(a). In this position, the 
detection bodies 51, 52 are positioned to overlie the position detection 
holes H11, H12. 
The base 50, biased by the coil spring 53, urges the detection bodies 51, 
52 into the position detection holes H11, H12. The detection bodies 51, 52 
contact the conduction plate 54. This completes an electrical connection 
between the terminal 510 of detection body 51 and between the terminal 520 
of detection body 52 through the conductor plate 54. Thus, an electrical 
signal can pass through terminals 510,520. 
When the film F is moved in direction A, as seen in FIGS. 4(b) and 4(c), at 
least one of the detection bodies 51, 52 is caused to ride up onto the 
film F. This breaks the electrical connection between the detection bodies 
51, 52 and the conduction plate 54, which in turn breaks the connection 
and signal through the terminals 510, 520. 
When the next picture frame FR reaches a position aligned with the film 
exposure area 4, as in FIG. 4(a), the detection bodies 51, 52 are 
reinserted to the corresponding position detection holes H11, H12. The 
electrical connection between the terminals 510, 520 is again completed 
and a signal can pass through the terminals 510, 520. Therefore, when an 
electrical connection occurs through the terminals 510, 520, the picture 
frame FR of the film F is in an aligned position with the film exposure 
area 4. 
If the bodies 51, 52 are not inserted into position detection holes H11, H1 
after the film F has been advanced, the film F may not have moved a 
sufficient distance to align a new picture frame FR with the film exposure 
area 4. Alternatively, the film F may have moved too much so that the new 
picture frame FR is not aligned with the film exposure area 4. 
Therefore, the invention also determines whether the film F has moved 
enough to properly advance to a picture film frame positioned state by 
determining if an electrical connection between bodies 51, 52 and the 
conduction plate 54 is made. 
The terminals 510, 520 are preferably positioned and extend from the same 
side of the supply passage of the film F. This permits a relatively simple 
wiring scheme for the camera and detection device. The positioning of the 
terminals 510, 520 on the same side makes it unnecessary to wire the 
detection device from both sides, circling and crossing the film supply 
passage. Therefore, an easy and uncomplicated camera assembly is achieved. 
A picture frame FR is detected when the detection bodies 51, 52 are 
inserted into the corresponding detection holes H11, H12. As shown by the 
broken dotted line of FIG. 2, even if other similarly shaped through holes 
are provided on the film, such as through holes Hx, that are positioned in 
approximately the same area of the position detection holes H11, H12 but 
not spaced apart a length S0, both of the detection bodies 51, 52 can not 
be inadvertently inserted into the through holes Hx. The electrical 
connection cannot be completed and an indication of proper film-frame 
position state will not occur because the distance between through holes 
Hx, or the distance between through holes Hx and one of the position 
detection holes H11, H12, does not equal the distance S0 between the 
position detection holes H11, H12. Therefore, the detection bodies 51, 52 
do not make and complete the electrical connection. Using this 
relationship between the holes, the proper alignment of a picture frame FR 
is readily determined. 
FIG. 5 shows a second embodiment of the invention, which is similar to the 
first embodiment and where similar parts are indicated by similar 
reference characters. 
In the second embodiment, base 55 and detection bodies 56, 57 are shown 
constructed in an integral fashion, contrary to the first embodiment, 
where the base 50 and detection bodies 51, 52 are constructed separately. 
Either integral or separate components may be used in this embodiment and 
also in the first embodiment. The base 55 and detection bodies 56, 57 can 
be constructed from either an electrically insulative or conductive 
material. 
The base 55 is orthogonally biased toward the film supply passage side by a 
spring or biasing element, here coil spring 53. The detection bodies 56, 
57 can be simultaneously inserted into position detection holes H11, H12 
in the film F, in a manner similar to the first embodiment. 
On one side of the base 55, opposite the detection bodies 56, 57, an 
elongated member or rod 58 is provided. The rod 58 extends away from the 
film exposure area 4 and through hole 1c formed in the recessed part 1a. 
The rod 58 is connectable to one of a pair of armatures 59a, 59b. 
Armatures 59a, 59b are connected to a control apparatus (not shown), via 
appropriate electrical connection such as flexible printed circuit board 
(FPCB). 
As shown in FIG. 5(a), detection bodies 56, 57 are normally biased by coil 
spring 53 to be inserted into position detection holes H11, H12, when the 
detection holes H11, H12 are aligned with the detection bodies 56, 57. The 
rod 58 is then retracted into the recessed part 1a and the pair of 
armatures 59a, 59b separate and an electrical connection between the 
armatures is broken. 
When film F is fed in the film supply direction A (FIG. 2) at least one of 
the detection bodies 56, 57 rides up onto the film F, as seen in FIGS. 
5(b) and 5(c). This causes the rod 58 to be projected up through the 
recessed part 1a and through hole 1c. Armature 59a is then pushed upwardly 
(in FIG. 5(b)) to contact the armature 59b. An electrical connection is 
then made between armatures 59a, 59b and a signal indicating a film frame 
non-position state is generated. 
Similar to the first embodiment, it is possible to determine whether the 
picture frame FR of the film F is aligned with the film exposure area 4, 
or whether the film F has not been fed by an equivalent amount equal to 
one picture frame FR, by detecting a connection between the armatures 59a, 
59b. 
In the second embodiment, armatures 59a, 59b are on the same side of the 
supply passage for the film F. This permits a relatively simple wiring 
scheme in the camera and detection device. The positioning of the 
armatures 59a, 59b on the same side makes it unnecessary to wire the 
device from both sides, circling and crossing the film supply passage. 
Therefore, an easy and uncomplicated assembly of the camera can be 
achieved. 
Furthermore, armatures 59a, 59b do not have to be separately positioned for 
each detection bodies 56, 57. The armatures 59a, 59b can be formed from 
one piece. Thus, the structure is relatively simple with few movable 
parts. The determination and signaling can be conducted with relative 
ease. 
In each of the embodiments described above, the detection bodies 51, 52 or 
the detection bodies 56, 57 are spaced in the direction of film supply 
equal to 50, the space between position detection holes H11, H12. As shown 
in FIG. 6, if one of the detection bodies 56, 57 is displaced toward the 
film supply direction, the electrical connection is not made, and the 
aligned position signal for the film cannot be generated. Therefore, if 
the detection bodies 56, 57 are not aligned with the position detection 
holes H11, H12, a signal cannot be produced representative of a film's 
proper aligned position. 
Additionally, the position detection holes H11, H12 are preferably arranged 
parallel to the film supply direction A. However, as shown in FIG. 7, the 
position detection holes H11, H12 can be positioned offset from each other 
as long as they are parallel or generally parallel to the film supply 
direction A. If the detection holes H11, H12 are offset, the detection 
bodies 51, 52 or 56, 57 must be similarly offset to cooperate with and be 
insertable into the holes. 
The number of the position detection holes is not limited to two. Any 
number of position detection holes is possible as long as they correspond 
to detection holes in the film F. When the plurality of position detection 
holes and the detection bodies become aligned, the signal from the signal 
output device is changed to indicate detection of an aligned picture frame 
FR. Therefore, the change in the signal from the device is indicative of 
an aligned film position. 
The detection circuit for the picture frame FR is also simplified. It 
avoids problems and limitations when additional through holes are added in 
the film F. By positioning the detection through holes H11, H12, spaced 
apart a present distance S0 between them, the detection device can 
determine if the film F has been moved so the distance S0 is detected. If 
the distance S0 is not detected, the film F has either not moved enough to 
align a new picture frame FR with the film exposure area 4 or the film F 
has moved too far beyond aligning a new picture frame FR with the film 
exposure area 4. 
While this invention has been described in conjunction with specific 
embodiments thereof, it is evident that many alternatives, modifications 
and variations will be apparent to those skilled in the art. Accordingly, 
the preferred embodiments of the invention as set forth herein are 
intended to be illustrative, not limiting. Various changes may be made 
without departing from the spirit and scope of the invention as defined in 
the following claims.