GB2318644A

GB2318644A - Film transport of an APS camera

Info

Publication number: GB2318644A
Application number: GB9718951A
Authority: GB
Inventors: Byung-Su Kim
Original assignee: Samsung Aerospace Industries Ltd
Current assignee: Hanwha Aerospace Co Ltd
Priority date: 1996-09-20
Filing date: 1997-09-05
Publication date: 1998-04-29
Anticipated expiration: 2017-09-05
Also published as: FR2753809A1; KR19980022103A; FR2753809B1; GB2318644B; DE19740899A1; GB9718951D0; KR100205981B1

Abstract

An apparatus for film transport of an APS camera has a film perforation sensing unit 10 for sensing a perforation formed in a film, and for outputting a signal according to a sensed perforation; a controller 20 for measuring a time period until the next perforation is detected after a perforation is detected during the film transport when a winding error occurs or a battery is changed after film transport, for comparing the time period with a determined value, and for generating a signal to stop the film transport at a position at which the next perforation detection is finished after a perforation is detected when the time is less than or equal to the determined value; a film transport unit 30 for moving a film according to said control signal. If a winding error occurs or a battery is changed, the apparatus can expose an object at a frame next to the exposed frame or a frame after one frame is skipped.

Description

2318644 APPARATUS AND METHOD FOR FILM TRANSPORT OF AN APS CAMERA

FIELD OF THE INVENTION

The present invention relates to an apparatus and method for transporting film in an APS (Advanced Photo System) camera. More particularly, the present invention relates to an apparatus and method for moving film in an APS camera which senses a perforation formed in the film, compares output signals from photosensors used to sense the perforations, and operates to move the film.

BACKGROUND OF THE INVENTION

Generally, a camera uses 35mm film, as shown in Fig. 1, on which perforations are formed on both sides. One frame of the film has eight perforations on each side, and the loading and transporting operation of the film is controlled according to the number of perforations detected.

In a conventional camera, when a release button is operated by a user, a frame of film is exposed to an object. After exposure, the film is transported within the camera and perforations are detected by perforation sensors and counted by a counter. When the counter counts a total of eight perforations, the controller determines the film transport is complete and stops the film transport in order for the next frame to be available for exposure.

However, since the film frame is determined by the number of perforations counted, exposed images may overlap if an error occurs during the film transport operation. Moreover, when an external malfunction stops the film transport, the motor is overloaded. Therefore, because the controller determines that the film is completely exposed, the controller operates to rewind the film even though the film is not completely exposed.

In an APS camera with various functions in accordance with a user's demand, a film other than a 35mm type is used. As shown in Fig. 2, a film for an APS camera has only two perforations which are formed on one side of the film.

The first perforation is formed at a start position to indicate the start position of the frame and the second perforation is formed at an end position to indicate the end position of the frame. It would be desirable to provide an improved APS camera which avoids the problems described above.

SUMMARY OF THE INVENTION

In view of the discussion described above, it is an object of the present invention to provide an apparatus and method for transporting film in an APS camera to a correct position.

In order to achieve the above object, the present invention comprises film perforation sensing means for sensing a perforation formed in a film, and for outputting a signal according to a sensed perforation. The invention also comprises control means for measuring a time period until the next perforation is detected after a perforation is detected during film transport when a winding error occurs or a battery is changed after film transport, for comparing the time period with a determined value, and for generating a control signal to stop the film transport at a position at which the next perforation detection is finished after a perforation is detected when the time is less than or equal to the determined value. Finally, the invention comprises film transport means for moving a film according to said control signal.

2 In another aspect of the invention, a method is provided for controlling the film transport operation of an APS camera. The method comprises the steps of judging whether or not a winding error occurs or a battery is changed; measuring a time period until the next perforation is detected after a perforation is detected during the film transport, when a winding error occurs or a battery is changed during film transport; comparing the time period with a determined value; and generating a control signal to stop the film transport at a position at which the detection of the next perforation is finished after a perforation is detected, when the time is less than or equal to the determined value.

In order to achieve the above object, another embodiment of the present invention comprises film perforation sensing means for sensing a perforation formed in a film, and for outputting a signal according to a sensed perforation. The invention also comprises control means for measuring a time period at which a perforation is not detected after a winding error occurs or a battery is changed during film transport and a time period at which a perforation is not detected after a first counted time, and defining the times as the first counted time and the second counted time respectively, for comparing the first counted time with the second counted time, and for generating a control signal to stop the film transport at a position at which second perforation detection is finished when the first counted time is more than or equal to the second counted time. Finally, the invention comprises film transport means for moving a film according to said control signal.

In another aspect of the invention, a method is provided for controlling the film transport operation of an APS camera. The method comprises the steps of measuring a time period at which a perforation is not detected after a winding error occurs or a battery is changed during film transport; defining the time as the first counted time; measuring a time period at which a perforation is not detected after a 3 first counted time; defining the time as the second counted time; comparing the first counted time with the second counted time; and generating a control signal to stop the film transport at a position at which a perforation detection is finished when the first counted time is more than or equal to the second counted time.

BRIEF DESCRIPTION OF THE DRAWINGS

The above object and feature of the present invention will be apparent from the following description of the preferred embodiment with reference to the accompanying drawings.

Fig. 1 is a schematic of a 35mm film of the prior art,

Fig. 2 is a schematic of a film used in an APS camera, Fig. 3 is a block diagram of an apparatus for transporting the film according to the present invention, Fig. 4 is a detailed circuit diagram showing a film perforation sensing unit for sensing perforations of a film, Fig. 5 shows a film perforation sensing unit according to the present invention, Fig. 6 shows an output signal of a film perforation sensing unit according to a first embodiment of the present invention, Fig. 7 is a flow chart illustrating a method for transporting film of an APS camera according to the embodiment of the present invention, Fig. 8 shows an output signal of a film perforation sensing part according to the second embodiment of the present invention, Fig. 9 is a flow chart illustrating a method for moving film according to the second embodiment of the present invention.

4 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described in detail with reference to the accompanying drawings.

Fig. 3 is a block diagram of an apparatus for transporting film according to the present invention. As shown in Fig. 3, an apparatus for transporting film in an APS camera in accordance with the present invention includes a film perforation sensing unit 10, a controller 20, and a film transport unit 30.

As shown in Fig. 5, the above film perforation sensing unit 10 has a first sensing part 11 and a second sensing part 13, which are spaced apart at a predetermined distance according to the formed film perforations.

As shown in Fig. 4, the film perforation sensing unit 10 consists of a first sensing part 11 and a second sensing part 13. The first 11 and second 13 sensing parts comprise a photocouper 111 having an LED ("Light Emitting Diode") D1 and a phototransistor T1, and a signal generating part 113 having a transistor T2 and resistors R2 and R3. The second sensing part 13 comprises a photocouper 131 having an LED D2 and a phototransistor T3, and a signal generating part 133 having a transistor T4 and resistors R5 and R6.

The signal generating parts 113 and 133 generate an electric signal on the basis of a signal received from the photocoupers 111 and 131, respectively. When the LED D1 emits light through a perforation, the phototransistor T1 receives light through the perforation. Therefore, the phototransistor T1 turns on, and then the transistor T2 turns on subsequently.

However, if the LED D1 emits light onto the film's surface, the phototransistor T1 does not receive light because light is reflected by the film surface. Thus the phototransistor T1 and transistor T2 do not turn on.

Because the transistor T2 turns on when a perforation is sensed by the photocouper 111, the signal generating part 113 outputs an L signal. However if the transistor T2 is not sensed by the photocouper 111, the signal generating part 113 outputs an H signal.

The controller 20 is connected to the output terminal of the film perforation sensing unit 10, and controls the transporting operation of the film in accordance with the signal from the film perforation sensing unit 10.

The film transport unit 30 is connected to the output terminal of the controller 20, and transports the film.

The operation of the invention device is as follows:

Referring to Fig. 7, when a release button is operated and a frame is exposed, the controller 20 drives to wind the film. The film transport unit 30 further operates to move the film in the direction which makes the film wind. (S1 10) At that time, the film perforation sensing unit 10 senses a perforation, then outputs a pulse signal to the controller 20 in response to light passed through the film perforation. (S120) In the above, when the film is transported, the pulse signal which is outputted from the film perforation sensing unit 10 changes state. Namely, when the film perforation sensing unit 10 emits light through a perforation, the film perforation sensing unit 10 receives light via the perforation.

However, when the film perforation sensing unit 10 emits light onto the film surface where a perforation is not formed, the film perforation sensing unit 10 does not receive light because light is reflected by the film surface.

Therefore, the output signal from the film perforation sensing unit 10 changes the signal state according to whether the film perforation sensing unit 10 receives light or not.

6 That is, if the photodiode D1 emits light through a perforation, the phototransistor T1 turns on and then the transistor T2 also turns on. Thus, a low level signal L is supplied to the controller 20.

However, if light from the photo diode D1 is not emitted through a perforation but emitted onto the film surface, the photo transistor T1 and the transistor T2 do not turn on. Thus, a high level signal H is supplied to the controller 20.

After a film frame is exposed, the controller 20 transports the film to move the exposed frame, and then the controller 20 judges whether or not a winding error has occurred in accordance with the signal outputted from the film perforation sensing unit 10. Also, the controller 20 judges whether or not the battery which operates the camera has been changed. (S1 30) For example, when the film perforation sensing part 10 does not output any signals or the output signals are not changed while the controller 10 operates to transport the film, the controller 20 judges if a winding error has occurred in which the film does not transport normally. Also, if power is restarted again, the controller judges whether the user changed the battery.

When a winding error occurs or a battery is changed, the controller 20 controls the transport of the film in accordance with an output signal from the film perforation sensing unit 10.

In the present invention, the controller 20 controls the film transport in accordance with an outputted signal from the first sensing part 11. However, the second sensing part 13 can also be used.

When the winding error occurs or the battery is changed, the controller 20 counts a time period at which a N status has been maintained after an L signal is outputted from the film perforation sensing unit 10. After the controller 20 has 7 counted the time period, the controller 20 defines the time period as the first time T1. (S 140 and S 150) Next, in order to judge whether or not transport of the exposed frame is completed, the controller 20 compares the first time T1 with the determined maximum value. (S160) The determined maximum value is already predetermined for a time period during which the perforation is not detected in period bl, as shown in Fig. 6.

If the first time T1 is less than or equal to the determined maximum value, the controller 20 stops the film transport of an exposed frame.

In other words, when the first time T1 is less than or equal to the determined maximum value, the controller 20 stops when an L signal outputted from the film perforation sensing unit 10 is changed to an H signal, after the film perforation sensing unit 10 outputs an L signal.

However, if the first time T1 is more than the determined maximum value, the controller 20 is returned to step.( S140) Hence, the controller 20 counts a time period until an L signal is outputted from the film perforation sensing unit 10 according to a perforation sensed after an H signal is outputted.

After the controller 20 has counted the time period, the controller 20 defines the time period as the first time T1, again. (S140 and S1 50) Next, the controller 20 compares the first time T1 with the above determined maximum value. (S160) If the first time T1 is less than or equal to the determined maximum value, the controller 20 stops the film transport at an unexposed frame. Thus, the controller 20 stops the control signal to be outputted to the film transport unit 30.

8 Therefore, as shown in Fig. 6, when a winding error occurs or a battery is changed during the first period All of film transport, the film transport operation stops at a position 11.

However, when the winding error occurs or the battery is changed during the second period Bl of the film transport, the film transport operation stops at a position Ill. Hence, the film's frame is placed at the beginning position of the next frame after a frame is skipped.

However, if the film transport operation is executed normally without a winding error occurring or the battery being changed, the controller 20 judges whether or not the film perforation sensing unit 10 outputs an L signal according to sensing the next perforation and the L signal is changed to the H signal.

That is, in the position 11, the controller 20 stops to output a control signal to the film transport unit 30.

Therefore, when the film transport operation is executed normally, the frame of the film is placed at the beginning position of the frame next to the exposed frame and a subject is exposed.

When a winding error occurs or a battery is changed during the film transport, only one frame can not be used, but the other frame can be used normally.

Preferred second embodiments of the present invention will now be discussed in detail with reference to the accompanying drawings.

Fig. 8 shows an output signal of a film perforation sensing unit according to the second embodiment of the present invention, Fig. 9 is a flow chart illustrating a method for moving the film according to the second embodiment of the present invention.

9 An apparatus for film transport of the second embodiment of the present invention is the same as the first embodiment of the present invention.

As shown in the Fig. 9, after a film frame is exposed, the controller 20 outputs a control signal to the film transport unit 30 to transport the exposed frame of the film.

As the film perforation sensing unit 10 outputs an H signal, the controller 20 counts a time period at which the H state is maintained. (S310 and S320) After, the controller 20 judges whether or not a winding error has occurred or a battery has been changed. (S330) If a winding error occurs or the battery is changed, the controller 20 counts the time period at which a H state has been maintained after the winding error occurs or a battery is changed. After counting the time period, the controller 20 defines the time period as the first counted time. (S340) After the controller 20 counts the first counted time, the controller 20 counts the time the film perforation sensing unit 10 outputs a H signal after the first counted time, and the controller 20 defines this time period as the second counted time. (S350) That is, the controller 20 separately counts the time period during the film perforation sensing unit 10 outputs an H signal, after and before sensing perforation, after the winding error occurs or the battery is changed.

After the controller 20 counts the first counted time and the second counted time, the controller 20 compares the first counted time with the second counted time. (S360) If the controller 20 judges that the first counted time is more than the second counted time, the controller 20 judges that the film transported normally.

Therefore, the controller 20 stops the film transport operation at a position 12 at which an L signal is changed to an H signal after a L signal is outputted from the film perforation sensing unit 10. (S370) For example, in Fig. 8, when the film is normally transported, the first counted time is the total value of Ta2 + Tb2 and the second counted time is the value of Tc2. Therefore, because the total value of Ta2 + Tb2 is more than or equal to Tc2 the film transport operation stops at the position at which an L signal is changed to an H signal after a L signal is outputted from the film perforation sensing unit 10.

However, when the first counted time is less than the second counted time the controller 20 defines the second counted time as the first counted time, and the controller 20 counts a time period until the film perforation sensing unit 10 outputs H signal. Thus, the controller 20 defines this time period as the new second counted time, and the controller 20 controls the film transport operation until the first time is more than the second time.(S380) When the first counted time is more than the second counted time, the controller 20 stops the film transport operation at the position 12 at which a L signal outputted from the film perforation sensing unit 10 is changed to an H signal. As shown in Fig. 8, in the case where the winding error occurs or a battery is changed during the first block A2, the controller 20 defines the first counted time and the second counted time as Ta2 + Tb2 and Tc2, respectively.

Therefore, because the first counted time is more than or equal to the second counted time, the controller 20 stops the film transport operation at the position 12 at which the next L signal outputted from the film sensing unit 10 is changed to an H signal.

In the case where a winding error occurs or a battery is changed during the second block B2, the first counted time is less than the second counted time because the first counted time is Tb2 and the second counted time is Tc2 of the third block C2. At that time, the second block B2 is less than the third block C2.

Thus, the controller 20 defines the second counted time as the new first counted time Tc2, and then the controller 20 defines as the second counted time the time period at which the film perforation sensing unit 10 next outputs an H signal. However, the first counted time is less than the second time because the first counted time becomes Tc2 and the second counted time becomes Td2.

Therefore, the controller 20 defines the second counted time Td2 as the first counted time, and the controller 20 counts a time period until the film perforation sensing unit 10 outputs another H signal, and then the controller 20 defines that time period as the second counted time.

Consequently, because the first counted time and the second counted time are to be Td2 and Te2 respectively, the first counted time is more than the second counted time. Therefore, the controller 20 stops the film transport operation at a position 112 at which the output signal from the film sensing unit 10 is changed to an H signal.

Also, in the case where a winding error occurs or a battery is changed during the third period C2, the first counted time is less than the second counted time because the first counted time is to be Tc2 and the second counted time is Td2.

Therefore, the controller 20 defines as the first counted time the second counted time Td2, and then defines as the second counted time the time until the film sensing unit 10 outputs another H signal.

Consequently, since the first counted time is Td2, and the second counted time is Te2, the first counted time is more than the second counted time.

12 Therefore, the controller 20 stops the film transport operation at the position 112 at which the output signal from the film perforation sensing unit 10 is changed to an H signal.

Also, in case the winding error occurs or a battery is changed during the fourth block D2, the first counted time is more than the second counted time because the first counted time is Td2 and the second counted time is Te2. Thus, the controller 20 stops the film transport operation at the position 112 at which the output signal from the film perforation sensing unit 10 is changed to an H signal.

According to the preferred embodiments of the present invention related to an APS camera, although a winding error occurs or battery is changed, an object is exposed at a frame next to the exposed frame or at a frame after one frame is skipped. Hence, in the present invention, because all frames of the film are able to be exposed, a film can be used very effectively. While it has been shown and described what is at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can by readily made therein without departing from the scope and spirit of the invention as defined by the appended claims.

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Claims

WHAT IS CLAIMED IS:

1. An apparatus for film transport of an APS camera, comprising: film perforation sensing means for sensing a perforation formed in a film, and for outputting a signal according to a sensed perforation; control means for measuring a time period until the next perforation is detected after a perforation is detected during the film transport when a winding error occurs or a battery is changed after film transport, for comparing the time period with a determined value, and for generating a control signal to stop the film transport at a position at which the next perforation detection is finished after a perforation is detected when the time is less than or equal to the determined value; and film transport means for moving a film according to said control signal.

2. The apparatus of claim 1, wherein said control means comprise means for generating a control signal to stop the film transport at a position at which the next perforation detection is finished when the winding error does not occur or the battery is not changed.

3. An apparatus for film transport of an APS camera, comprising: film perforation sensing means for sensing a perforation formed in a film, and for outputting a signal according to a sensed perforation; control means for measuring a time period at which a perforation is not detected after a winding error occurs or a battery is changed during film transport and a time period at which a perforation is not detected after a first counted time, and defining the times as the first counted time and the second counted time respectively, for comparing the first counted time with the second counted time, for generating a control signal to stop the film transport at a position at which second perforation detection is finished when the first counted time is more than or equal to the second counted time; and 14 film transport means for moving a film according to said control signal.

4. The apparatus of claim 3, wherein said control means comprise means for defining the second counted time as the first counted time when the first counted time is less than the second counted time, for measuring a time period at which a perforation is not detected, for defining the time as the second counted time, and for generating a control signal to stop film transport at a position at which a perforation detection is finished when the first counted time is more than the second counted time.

5. A method for controlling the movement of a film in an APS camera comprising the steps of: judging whether or not a winding error occurs or a battery is changed; measuring a time period until a next perforation is detected after a perforation is detected during a film transport, when a winding error occurs or a battery is changed during film transport; comparing the time period with a determined value; and generating a control signal to stop the film transport at a position at which the next perforation detection is finished after a perforation is detected when the time is less than or equal to the determined value.

6. The method according to claim 5, wherein the method for controlling the movement of the film in an APS camera further comprises the steps of: generating a control signal to stop film transport at a position at which the next perforation detection is finished when the winding error does not occur or the battery in not changed.

7. A method for controlling the moving operation of a film of an APS camera comprising the steps of:

measuring a time period at which a perforation is not detected after a winding error occurs or a battery is changed during film transport; defining the time as the first counted time; measuring a time period at which a perforation is not detected after a first counted time; defining the time as the second counted time; comparing the first counted time with the second counted time., and generating a control signal to stop the film transport at a position at which a perforation detection is finished when the first counted time is more than or equal to the second counted time.

8. The method according to claim 7, wherein the method for comparing the first counted time with the second counted time further comprises the steps of: defining the second counted time as the first counted time when the first counted time is less than the second counted time; measuring a time period at which a perforation is not detected, and defining the time as the second counted time; and generating a control signal to stop film transport at a position at which a perforation detection is finished when the first counted time is more than the second counted time.

9. A film transport apparatus for an APS camera substantially as hereinbefore described with reference to any of Figures 3 to 9 of the accompanying drawings.

10. A method of controlling the movement of a film in an APS camera substantially as hereinbefore described with reference to any of Figures 3 to 9 of the accompanying drawings.

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