WO1996013931A1

WO1996013931A1 - Video and photographic imaging camera

Info

Publication number: WO1996013931A1
Application number: PCT/US1995/013645
Authority: WO
Inventors: Sayu Chen
Original assignee: Sayu Chen
Priority date: 1994-11-01
Filing date: 1995-10-04
Publication date: 1996-05-09
Also published as: JP2001523402A

Abstract

Dual video and still-film camera embodying video recorder camera technology in two popular types of still-film camera: single-lens reflex (SLR) (3) and compact (18). The most advanced digital image-sensing semiconductor chip (charge-coupled device or CCD) (4, 22) and circuit board (8, 24), as well as other functional video camera components, are combined with the conventional apparatus of the still-film camera to support the video and still-film modes of photography in a single camera casing. By means of a manual switch (9, 25) or, as an alternate embodiment, an electrical switch, the user can extend the digital image sensor (4, 22) into the light-image line of sight in order to activate video operation or can retract the image sensor in order to allow still-film operation unimpeded by the video apparatus. In a third configuration - SLR reflex-type dual camera - the digital image-sensing semiconductor chip (charge-coupled device or CCD) is mounted in a fixed position within a vertical focal chamber (34) projecting upward from the main chamber behind the camera lens (6). Replacing the conventional SLR prism viewfinder, the focal chamber houses the CCD (4), a fixed focusing lens (37), a glass focusing screen (36), and a hinged focal mirror (14). These are positioned in a vertical or stack position at mathematically-calculated distances from each other to maximize image resolution during the time of video operation.

Description

Video and Photographic Imaging Camera

Background — Field of Invention

The field of this invention relates to video cameras and to still-film cameras of the single-lens reflex (SLR) type and compact types, specifically to the combination of video and still-film apparatuses in a single camera to allow switching between video and still-film operation at will, and more specifically to the incorporation of a digital image sensor and circuit board in this dual-purpose camera in order to support video photography in a still-film type of camera environment.

Background — Description of Prior Art

Digital image sensors are currently being used in several diverse applications and particularly in the camera field. The two notable applications are video recorder cameras, including the more recently invented "camcorder" type, and still digital cameras.

In both of these applications, the image sensor, located at a focal point within the camera behind the lens, converts the light image to a digital signal which is processed for color and then recorded on magnetic tape. This signal in turn can be captured or played back as a video image on a CRT-type screen or as a still computer image ultimately reproducible on film negative and positive paper print.

Almost all image sensors currently being manufactured and used in today's video and digital camera applications are one of two types of solid-state semi-conductors: the charge-coupled device (CCD) or the metal-oxide semiconductor (MOS). The CCD appears to be the chip of choice for most manufacturers. Up to the present moment in time, the high-resolution image sensors being manufactured have been too expensive to consider for application in a type of camera that would combine video and still-film operation. However, available manufacturing and marketing data indicates that shortly these limitations will no longer apply.

The object of this invention, therefore, is to modify the conventional still- film camera (SLR and compact types) by combining the still-film apparatus with the video apparatus, principally the image sensor and circuit board but also the other means for video recording, such as tape deck, video eyepiece, video head drum, sound recorder and playback mechanism, and controls. In addition to porting the necessary video apparatus to a still-camera fabrication, only a few simple and economic modifications, mechanical and electrical, have to be effected in order to make a very portable and easily-controlled dual camera.

Summary of Invention — Objects and Advantages

The objects and advantages of the invention are these:

1. Dual operation.. The camera user can carry and use a single camera, lightweight and easily manipulated, to take both video and still-film pictures, whereas heretofore two cameras would have had to be carried if one intended to use both types of camera for the same photography session.

2. Equipment Backup. If in the middle of a photography session involving an unrepeatable event (a wedding, for example), the dual camera runs out of either video tape or film, the user can switch to the other media in order to capture something of the remaining event.

3. Instantaneous Switching in Operation. With the dual camera, the user can instantaneously capture a film image with one press of a button and no noticeable interruption of video recording operation.

4. Shared Viewfinder. In the configuration of the SLR-type camera with a fixed position CCD — the reflex dual camera — a single, electronic viewfinder is used for both still-film and video operation. These objects and advantages will be obtained by the invention of a combi¬ nation video and still-film camera which incorporates the most advanced image sensing technology (CCD) and a simple control allowing the user to easily switch from video to still-film operation or the reverse.

Description of the Drawings

To more fully understand the invention, consider the detailed description which follows in conjunction with the attached drawings and reference numerals, wherein

FIG. 1 (overview) is a perspective view of the two camera types — still-film and video — being combined in this invention, which is the third camera type, a dual video and still-film camera.

FIGS. 2-6 (figure summary) comprise various views of the invention incorporating a single-lens reflex (SLR) type of still-camera apparatus.

FIG. 2 (assembled SLR) is a perspective view of the fully assembled invention incorporating a single-lens reflex (SLR) type of still-camera apparatus.

FIG. 3 (preferred SLR) is a partially exploded view of the SLR type showing the principal apparatus for switching from still-film to video operation in the preferred, vertical-plane embodiment.

FIG. 4 (alternate SLR) is a partially exploded view of the SLR type showing the principal apparatus for switching from still-film to video operation in an alternate or horizontal-plane embodiment.

FIG. 5 (sensor extended) is an exploded view of the principal parts of the SLR type as activated when the image sensor (CCD) is extended into the light image line of sight for video operation.

FIG. 6 (sensor retracted) is an exploded view of the principal parts of the SLR type as activated when the image sensor (CCD) is retracted to allow still-film operation.

FIGS. 7-11 (figure summary) comprise various views of the invention incorporating a compact type of still-camera apparatus. FIG. 7 (assembled compact) is a perspective view of the fully assembled invention incorporating a compact type of still-camera apparatus.

FIG. 8 (preferred compact) is a partially exploded view of the compact type showing the principal apparatus for switching from still-film to video operation in the preferred, vertical-plane embodiment.

FIG. 9 (alternate compact) is a partially exploded view of the compact type showing the principal apparatus for switching from still-film to video operation in an alternate or horizontal-plane embodiment.

FIG. 10 (sensor extended) is an exploded view of the principal parts of the compact type as activated when the image sensor (CCD) is extended into the light image line of sight for video operation.

FIG. 11 (sensor retracted) is an exploded view of the principal parts of the compact type as activated when the image sensor (CCD) is retracted to allow still- film operation.

FIGS. 12-15 (figure summary) comprise various views of the invention incorporating an SLR-type of still-camera apparatus and combining it with an focal chamber — a reflex-type dual camera.

FIG. 12 (assembled SLR, reflex-type configuration) is a perspective view of the fully assembled invention incorporating a single-lens reflex (SLR) type of still-camera apparatus but with a focal chamber projecting upward from the main chamber of the camera holding an optical apparatus which allows the CCD to remain in a fixed position during video and still-film operation — the reflex dual camera.

FIG. 13 (SLR reflex-type configuration) is a partially exploded view of the SLR reflex-type showing the principal optical apparatus inside the vertical focal chamber together with the image path through the focusing elements of the chamber to the CCD.

FIG. 14 (video operation) is an exploded view of the principal elements of the SLR reflex-type with the focal mirror immobilized in the downward position, and the film plane shutter is closed, in order to capture and reflect the image up through the focal chamber to the CCD for video recording.

FIG. 15 (film operation) is an exploded view of the principal elements of the SLR reflex-type when the focal mirror is activated, i.e. rotated upward, in order to allow the image to pass through the now-open film plane shutter and register on the film while not noticeably interrupting video recording.

Reference Numerals in Drawings

1 single-lens reflex (SLR) camera 20 compact-type lens

2 video recorder 21 electrical contact points

3 SLR-type dual camera 22 image sensor (CCD type)

4 image sensor (CCD type) 23 video components casing

5 video eyepiece 24 image-sensor circuit board

6 SLR-type lens 25 switching worm gear and knob

7 electrical contact points 26 alternate video components casing

8 image-sensor circuit board 27 auxiliary components casing

9 switching worm gear and knob 28 focal plane chamber opening

10 video components casing 29 spacer backing for image sensor

11 alternate video components 30 film casing 31 lens shutter

12 auxiliary components casing 32 aperture diaphragm

13 refracting viewfinder prism 33 SLR reflex-type dual camera

14 mirror with focal chamber

15 film 34 focal chamber

16 focal plane shutter 35 image path

17 aperture diaphragm 36 focusing screen

18 compact-type dual camera 37 focusing lens

19 video eyepiece 38 electronic viewfinder Detailed Description of the Invention

Because the invention can be embodied in either of two types of popular still-film cameras — single-lens reflex (SLR) or compact — this detailed description of the invention will discuss the two types separately.

la. Structure: Dual Camera With SLR-type Still-film Embodiment

As illustrated in Fig. 1, the combination of still-film 1 and video camera 2 apparatuses in a dual-purpose camera 3 is dependent mainly on the incorporation of a digital image sensing or CCD semiconductor device 4 in the dual camera, with, of course, a camera casing (Fig. 2) large enough to contain these and other necessary film and video components. Looking at Fig. 3, note that in the SLR-type still-film embodiment a video eyepiece 5 is required for when the video mode is active. Note also that the SLR-type lens 6 and other SLR camera still-film components will be conventional and not ported over from other technologies.

Illustrated in Fig. 3, the preferred embodiment of the video apparatus is a video components casing 10 extended vertically below the still-film casing 3. Fig. 4 shows an alternate embodiment, with the video components casing 11 extended in a horizontal plane and a small auxiliary components casing 12 extended vertically.

Figs. 3 and 4 illustrate the principal innovation of the invention, a movable image sensor (CCD type) 4 and image-sensor circuit board 8. In these figures, the movement is managed by a switching worm gear and knob control 9. However, a feasible alternative not shown here is a motor-driven movement initiated by a button or lever control manipulated by the user.

lb. Operation: Dual Camera With SLR-type Still-film Embodiment

Operation of this SLR-type embodiment of the dual video and still-film camera begins with the user's decision on which mode to use. If the user elects the video mode (Fig. 5), he or she turns the switching worm gear and knob 9 to a fixed-click position in order to extend the image sensor 4 into the path of the light image. Now an electrical contact point 7 on the leading edge of the image- sensor circuit board 8 meets a corresponding contact point on the camera body, thereby completing a circuit connection to the camera's electronic micro- controller. The micro controller in turn automatically immobilizes three still- film camera parts: the focal plane shutter 16, the mirror 14, and the aperture diaphragm 17 (if the aperture diaphragm is controlled automatically). The focal plane shutter is immobilized in the closed position during video operation in order to protect the film 15 from exposure to light, and the mirror is immobilized in the down position so that it cannot collide with the CCD in the active position. The aperture diaphragm is immobilized initially at a default opening set by the factory. However, the micro controller allows the manual diaphragm control, if there is one, to override the automatic, in case the user wishes to select an alternate /-stop or aperture opening.

If the user elects the still-film mode (Fig. 6), he or she turns the switching worm gear and knob 9 in the opposite direction to a fixed-click position in order to retract the image sensor 4 completely outside the path of the light image. Now the electrical contact points 7 separate to break the circuit connection which had immobilized the focal plane shutter 16 , the mirror 14, and the aperture diaphragm 17 As before, the user can manually adjust the aperture diaphragm (if this version of the camera has manual diaphragm control) or can accept the automatic setting. The shutter is freed to open when the user presses or turns the shutter release control. The mirror is freed to move to the up position when the user has completed viewing the image by means of the refracting viewfinder prism 13 and has pressed or turned the shutter release control, thereby allowing the light image to travel through the camera to strike the film.

2a. Structure: Dual Camera With Compact-type Still-film Embodiment

When the invention is embodied in a dual camera incorporating the compact-type of still-film apparatus 18, as with the SLR type there must be a camera casing (Fig. 7) large enough to contain the necessary still-film and video components when the video mode is active. Looking at Fig. 8, note that the compact-type lens 20 and other compact camera still-film components will be conventional and not ported over from other technologies. For the compact-type still-film embodiment, a video eyepiece 19 is a construction alternative or manufacturing option. Because the viewfinder of the compact-type apparatus yields a direct view of the image and does not require the refracting prism of the SLR-type, the video eyepiece is not needed for video operation unless the still- film viewfinder cannot produce the proper focus corresponding to the lens during video operation. Illustrated in Fig. 8, the preferred embodiment of the video apparatus is a video components casing 23 extended vertically below the still-film casing 2. Fig. 9 shows an alternate embodiment, with the video components casing 26 extended in a horizontal plane and a small auxiliary components casing 27 extended vertically.

Figs. 8 and 9 illustrate the principal innovation of the invention but accommodated to the compact-type of still-film apparatus, a movable image sensor (CCD type) 22 and image-sensor circuit board 24. In these figures, the movement is managed by a switching worm gear and knob control 25. However, a feasible alternative not shown here is a motor-driven movement initiated by a button or lever control manipulated by the user.

2b. Operation: Dual Camera With Compact-type Still-film Embodiment

Operation of this compact-type embodiment of the dual video and still- film camera begins with the user's decision on which mode to use. If the user elects the video mode (Fig, 10), he or she turns the switching worm gear and knob 25 to a fixed-dick position in order to extend the image sensor 22 into the path of the light image. Now an electrical contact point 21 on the leading edge of the image-sensor circuit board 24 meets a corresponding contact point on the camera body and completes a circuit connection to the camera electronic micro controller. The micro controller in turn automatically immobilizes the lens shutter 31 and the aperture diaphragm 32 (if this camera embodiment utilizes an aperture diaphragm). The shutter is fully opened and immobilized so that during video operation the light image is unimpeded from striking the image sensor or CCD. The aperture diaphragm is immobilized initially at a default opening set by the factory. However, the micro controller allows the manual diaphragm control, if there is one, to override the automatic, in case the user wishes to select an alternate /-stop or aperture opening.

If the user elects the still-film mode (Fig. 11), he or she turns the switching worm gear and knob 25 in the opposite direction to a fixed-click position in order to retract the image sensor 22 completely outside the path of the light image. Now the electrical contact points 21 separate to break the circuit connection which had immobilized the lens shutter 31 and aperture diaphragm 32 (if this camera embodiment utilizes an aperture diaphragm). The shutter is now freed to open when the user presses or turns the shutter release control. If this camera embodiment utilizes an aperture diaphragm and offers both automatic and manual diaphragm control, the user, before releasing the shutter, can manually adjust the aperture diaphragm or can accept the automatic diaphragm setting.

3a. Structure: Dual Camera With Alternative SLR-type Still-film Embodiment

As illustrated in Fig. 12, this combination of still-film and video camera apparatuses in an SLR-type dual-purpose camera — reflex dual camera — 33 differs from SLR embodiments described in the original patent application mainly by the facts (i) of the addition of a focal chamber 34 projecting upward in the center of the camera case above the main camera chamber and (ii) a single, electronic viewfinder 35. The camera casing is large enough to house the necessary film components (lower case) and video components 10 above. The SLR-type lens 6 and other SLR camera still-film components will be conventional types.

Illustrated in Fig. 13, the vertical focal chamber 34 holds an optical apparatus to capture and focus the image for registration by the image sensor or CCD 4. With the mirror 14 in the down position, the image is reflected up through the focusing screen 36, then through the focusing lens to the CCD 4.

Fig. 14 is an exploded view of the focal chamber optical apparatus 34 as activated during video operation. At this time the mirror 14 is automatically rotated downward to catch the image and the film plane shutter 16 is closed to prevent film 15 exposure.

Fig. 15 is an exploded view of the focal chamber optical apparatus 34 as momentarily (a few milliseconds) deactivated during video operation. At this time the mirror 14 is automatically rotated upward and the film plane shutter 16 is opened to allow the image passage through to the film 15 .

3b. Operation: Dual Camera With SLR Reflex-type Focal Chamber

Operation of this alternative SLR-type embodiment of the dual video and still-film camera — the SLR reflex-type dual camera — begins with the user's decision on which mode to use, video or film. If the user elects the video mode, (Fig. 14), he or she starts and operates the camera as any other video recorder. Most significantly, the camera's micro controller immobilizes the focal mirror 14 in the downward position to catch the image and at the same time automatically immobilizes the focal plane shutter 16 and the aperture diaphragm 17 (if the aperture diaphragm is controlled automatically). The focal plane shutter is immobilized in the closed position during video operation in order to protect the film 15 from exposure to light, and the mirror is immobilized in the downward position in order to reflect the image upward through the focal chamber apparatus 34 to the CCD 4. The aperture diaphragm is immobilized initially at a default opening set by the factory. However, the micro controller allows the manual diaphragm control, if there is one, to override the automatic, in case the user wishes to select an alternate /-stop or aperture opening.

If the user elects the still-film mode (Fig. 15) — either during video operation or not — he or she presses the camera shutter button, and the micro controller automatically breaks the circuit connection which had immobilized the focal plane shutter 16 , the mirror 14, and the aperture diaphragm 17 The mirror swings upward to the horizontal position, the focal plane shutter opens, and the image registers on the film 15. With the user release of shutter and mirror, video recording, if operative, continues. Before film operation, the user can manually adjust the aperture diaphragm (if this version of the camera has manual diaphragm control) or can accept the automatic setting.

Conclusion

Whether embodied in a single-lens reflex (SLR) type, compact type of still- film apparatus, or reflex (SLR) type, the invention incorporates an advanced digital image-sensing technology in a dual video and still-film camera in such a way that the user can easily switch between the video and still-film modes with the assurance that the inactive mode will not interrupt and impair the active mode. The invention overcomes the inconvenience of carrying two cameras (a video recorder and a still film camera) or the frustration of finding oneself at a photography site only to discover that one was carrying the wrong type of camera for the purpose at hand. Easily carried and easy to use, the dual video and still- film camera fills a unique need in the worlds of popular and professional photography.

Claims

1. A camera combining user-selected apparatus for still-film photography and user-selected apparatus for video photography, comprising

a. an electronic image sensor with circuit board which elements can be extended into and retracted from the light-image line of sight as necessary for video or still-film operation,

b. an electrical contact as signaling means for the camera micro controller to enable or disable certain elements, such as mirror, shutter, an aperture diaphragm, maintaining them in fixed positions needed for still-film or video operation,

c. a conventional still-film photographing apparatus, with elements including film spool, film track, film controls, view finder, lens, flash device, and shutter and aperture diaphragm controls, and

d. a conventional video photographing apparatus, with elements including tape deck and spools, video eyepiece, video head drum, sound recorder, and playback mechanism, and controls.

2. The camera of claim 1 wherein the still-film components are either of the single-lens reflex (SLR) type or of the compact type.

3. The camera of claim 2 wherein the compact type of still-film apparatus uses a rigid, thin spacer bonded to the back of the image sensor and sized to the focal plane chamber opening as a light-protecting means to avoid film exposure during video operation.

4. The camera of claim 2 wherein the single-lens reflex (SLR) type employs a configuration of camera elements which is alternative to, but does not replace, that described in dependent claims a. through d. of claim 1, comprising

a. a fixed position, rather than retractable, electronic image sensor together with a focusing lens and focusing screen, these elements installed above the standard reflecting mirror in a vertical focal chamber replacing the conventional prism viewfinder, b. an electronic viewfinder shared by both film and video operation rather than being reserved for video operation alone,

c. a conventional still-film photographing apparatus, as described in dependent claim c. of claim 1, with the exclusion of a view finder dedicated exclusively to film operation, and

d. a conventional video photographing apparatus, as described in dependent claim d. of claim 1, noting the electronic-type viewfinder used for both video and film operation.

AMENDED CLAIMS

[received by the International Bureau on 28 March 1996 (28.03.96); original claim 4 cancelled; remaining claims unchanged (1 page)]

b. an electrical contact as signaling means for the camera micro controller to enable or disable certain elements, such as mirror, shutter, an aperture diaphragm, mamtaining them in fixed positions needed for still-film or video operation,

STATEMENT UNDER ARTICLE 19

Explanations of the claims amendments to the international application, as submitted to the W-PO/ISA under Article 19 are as follows:

1. Claim 1 is unchanged.

2. Claim 2 in unchanged.

3. Claim 3 is unchanged.

4. Claim 4 is dropped because this claim embodied an alternative configuration of the invention which had been stated originally in the U.S. domestic application but later was withdrawn and is not any longer a part of the invention for which patent protection is sought.