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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a video camera and, more particularly, to
a video camera provided with a recorder for recording a signal obtained by
photography.
2. Description of the Related Art
A camera-integrated type video tape recorder (VTR) is known as one example
of a video camera provided with such a recorder. In recent years, such a
camera-integrated type VTR has been being reduced in size and weight to a
remarkable extent, so that this kind of apparatus has become more and more
popular.
As is known to those skilled in the art of this kind of video camera, the
easiness with which such a camera-integrated type VTR is handled is
determined by how to dispose a photographic optical system of a camera
part or an electronic viewfinder (EVF) in relation to the mechanism of a
VTR part (recorder part).
In a typical conventional arrangement, the photographic optical system is
disposed on the front face of a VTR casing, while the EVF is disposed on
the top face of the VTR casing. This arrangement can be considered very
superior in that since the EVF is positioned on the top of the VTR casing,
an operator can look into the EVF during photography without the need to
raise the VTR casing up to a high position.
A camera-integrated type VTR which has recently been provided as a
manufactured product adopts an arrangement in which the photographic
optical system and the EVF are disposed on one side of the recorder
casing.
This kind of camera-integrated type VTR can be considered superior in that
the entire apparatus can be made extremely compact.
However, the former arrangement is not preferable in terms of the pursuit
of the compactness of the camera-integrated type VTR. In this arrangement,
since the photographic optical system is disposed to project from the
front face of the VTR casing, the entire length of the camera-integrated
type VTR is greater than the length of the VTR casing by the projecting
length of the photographic optical system.
According to the latter arrangement, it is possible to realize a compact
camera-integrated type VTR which has an extremely small size as viewed
from either side thereof. However, since the photographic optical system
and the EVF are disposed side by side in the lateral direction relative to
the VTR casing, the entire thickness of the apparatus increases. If this
arrangement is adapted to a portable camera-integrated type VTR which is
often carried in a bag, the portability itself will be impaired because of
the thickness. For example, if a camera-integrated type VTR having such
thickness is to be accommodated in a suitcase, a suitcase having a
sufficient width must be employed.
This kind of camera-integrated type VTR is designed in such a manner that
the photographic optical system and the EVF are disposed on one side. If a
grip is to be provided on the opposite side, various operating keys must
be disposed on the top or rear face of the apparatus. As a result, not
only is the freedom of arrangement of the operating keys limited but also
there is no sufficient room to dispose them. The grip may be provided on
the photographic optical system or the EVF. However, this arrangement has
the disadvantages that the sensation of grip holding is impaired and that
the center of balance of the camera-integrated type VTR is away from a
holding position. A user will have to perform photography while bearing
the burden of supporting the weight of the camera-integrated type VTR
which is biased from the center of balance.
The reductions in the size and weight of the conventional camera-integrated
type VTR are only intended for a reduction in the size of the external
appearance and a mere reduction in the weight of the entire apparatus. In
other words, the reductions in the size and weight of the conventional
camera-integrated type VTR do not take account of elimination of
disturbances such as the influence of noise on a microphone used with a
video camera and the influence of heat on an image sensor in the video
camera.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to solve the
above-described problems.
Another object of the present invention is to provide a video camera having
an arrangement which satisfies conditions such as compactness, thinness
and operability.
To achieve the above-described objects, according to one aspect of the
present invention, there is provided an arrangement in which a
photographic optical system and a viewfinder are disposed above a recorder
casing for recording a signal obtained by photography.
In addition, the photographic optical system and the viewfinder are
disposed so as not to overlap each other in a direction parallel to the
optical axis of the photographic optical system and so that the optical
path of the photographic optical system and the optical path of the
viewfinder overlap each other as viewed on an extended line of the optical
axis of the photographic optical system.
According to another aspect of the present invention, there is provided an
arrangement in which a photographic optical system is disposed between
sound inputting means for inputting sound information and a driving part
for controlling the position of a lens in the photographic optical system.
In addition, the aforesaid arrangement also includes a recorder mechanism
part, and the photographic optical system is disposed above the recorder
mechanism part and the driving part is disposed above the photographic
optical system.
The above and other objects, features and advantages of the present
invention will become apparent from the following detailed description of
a preferred embodiment of the present invention, taken in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a right side view diagrammatically showing the structure of a
camera-integrated type VTR according to an embodiment of the present
invention;
FIG. 2 is a front elevational view diagrammatically showing the structure
of the camera-integrated type VTR according to the embodiment of the
present invention;
FIG. 3 is a top side view diagrammatically showing the structure of the
camera-integrated type VTR according to the embodiment of the present
invention;
FIG. 4 is a left side view diagrammatically showing the structure of the
camera-integrated type VTR according to the embodiment of the present
invention;
FIG. 5 is a perspective view diagrammatically showing the structure of the
camera-integrated type VTR according to the embodiment of the present
invention;
FIG. 6 is an exploded, perspective view diagrammatically showing the
internal structure of the embodiment of the present invention;
FIG. 7 is a perspective view diagrammatically showing the assembled state
of the units shown in FIG. 6; and
FIG. 8 is a cross-sectional view diagrammatically showing the structure of
the camera-integrated type VTR according to the embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the present invention will be described below in
detail with reference to the accompanying drawings.
FIGS. 1 to 5 are diagrammatic views showing the structure of a
camera-integrated type VTR according to the embodiment of the present
invention. FIGS. 1 to 5 are a right side view, a front elevational view, a
top side view, a left side view and a perspective view, respectively, and
throughout the figures, the same reference numerals are used to denote
common constituent elements.
Referring to FIG. 1, an optical-system accommodating part 1 accommodates a
photographic optical system which contains a number of lens elements
aligned behind a lens opening portion 2. The photographic optical system
in the present embodiment employs a so-called rear focusing lens unit,
i.e., a lens unit arranged not to move a lens element nearest to a subject
when the focal length is to be varied or when focus adjustment is to be
performed. As is well known, such a rear focusing lens unit has the
advantage that the length along the optical axis can be reduced, although
the position of a driven lens needs to be controlled in a complicated way.
Since the details of the rear focusing lens unit are known, detailed
description is omitted herein.
The optical-system accommodating part 1 is disposed on a subject side of
the body of the camera-integrated type VTR, as shown in FIG. 1, and has a
cylindrical portion, such as that shown in FIG. 3, in which the aforesaid
lens unit is accommodated. An elongate portion 3 is formed integrally with
the cylindrical portion, and a supporting portion (not shown) for turnably
supporting an EVF unit 4 is provided on the right side face of the
elongate portion 3 in such a manner that the EVF unit 4 is turnable about
a portion thereof nearer to the optical-system accommodating part 1. More
specifically, an eyepiece part 5 of the EVF unit 4 can be moved in the
direction indicated by the arrow a of FIG. 1, thereby facilitating
so-called low-angle photography.
The EVF unit 4 includes a small monitor, such as a CRT or a liquid-crystal
display, and an optical system for conducting a picture displayed on the
small monitor into the eyepiece part 5. During the state of normal
photography shown in FIG. 1, the optical system within the EVF unit 4 and
the photographic optical system are disposed so that their optical paths
overlap each other as viewed from a point on an extended line of the
optical axis of the photographic optical system, that is to say, both
optical paths are positioned in overlapping relation to each other as
viewed from the front side of the body. In such an arrangement, not only
is it possible to effectively utilize space on the top of a VTR casing 6
but also it is possible to reduce parallax to an extremely small extent
since the optical path of the optical system in the EVF unit 4 and the
optical path of the photographic optical system are positioned extremely
close to each other. As will be described later, since the EVF unit 4 is
provided on the top of the VTR casing 6, if an operator holds the
camera-integrated type VTR with the eye applied to the eyepiece part 5,
the operator can perform photography with the arm which is holding it kept
closed. Accordingly, the operator can hold the VTR body securely and
stably during photography.
The VTR casing 6 includes mechanisms such as a rotary head drum and a
cassette accommodating/holding part, an electrical circuit, and others. As
is apparent from FIGS. 1 to 5, in the present embodiment, the
optical-system accommodating part 1 and the EVF unit 4 are disposed on the
top of the VTR casing 6 so that the thickness of the entire
camera-integrated type VTR can be reduced to the required minimum
thickness of the VTR casing 6.
A zoom switch 7 for varying the focal length is disposed on the left side
face of the elongate portion 3 so as to effectively utilize space on the
top of the VTR casing 6. More specifically, as will be described later,
the camera-integrated type VTR according to the present embodiment is
designed in such a manner that the operator can hold the left side face of
the VTR casing 6, and it is, therefore, preferable to dispose the zoom
switch 7 at a position which the fingers of the operator can reach with
the left side face held. For this reason, the zoom switch 7 is disposed
within space which is defined on the rear side of the optical-system
accommodating part 1 by reducing the axial length thereof. The disposition
of the zoom switch 7 at that position realizes the effective use of the
space. In the present embodiment, the optical-system accommodating part 1
and the VTR casing 6 are integrally formed.
A remote controller 27 also serves to constitute part of a grip which aids
the operator in holding the camera-integrated type VTR, as will be
described later. As shown in FIGS. 2, 4 and 5, the remote controller 27 is
disposed on the left side face of the VTR casing 6. The remote controller
27 has engagement portions 8a and 8b, and is secured to engagement
portions 9a and 9b provided on the left side face of the VTR casing 6 by
means of the respective engagement portions 8a and 8b. The remote
controller 27 is arranged for turning motion through approximately
120.degree. about an axis defined by the engagement portions 8a and 8b.
The remote controller 27 has an operating portion 10 disposed on a reverse
side thereof as shown in FIG. 5. The operator can cause the
camera-integrated type VTR to perform all kinds of operations associated
with reproduction, while operating the operating portion 10, for example,
to perform normal reproduction, special reproduction, tape fast forward
feed, stop, cueing search, or sound switching, by operating a
corresponding one of the operating keys disposed in the operating portion
10. Of course, it is also possible to cause the camera-integrated type VTR
to perform an operation for photography, such as start/stop of recording,
variation of the focal length, insertion of a date or a title, or fading.
The front portion of the remote controller 27 is provided with an
infrared-light emitting part 11 for outputting infrared light indicative
of information about the operation of each operating key disposed in the
operating portion 10. Infrared light emitted from the infrared-light
emitting part 11 is received by an infrared-light receiving part 12
provided on the front left side of the VTR casing 6, and the received
infrared light is conducted to the system controller of the apparatus
body.
During photography, the remote controller 27 is attached with the operating
portion 10 hidden as shown in FIG. 2, and functions as part of the grip.
If only the VTR part of the apparatus is to be operated, the remote
controller 27 is made to rotate through 120.degree. so that the operating
portion 10 is exposed as shown in FIG. 5. The right side face of the VTR
shown in FIG. 1 is provided with projections 14a, 14b and 14c in addition
to operating keyboards 13a, 13b and 13c to be operated during photography.
Accordingly, if the camera-integrated type VTR is placed on a flat surface
with the right side face down, the projections 14a, 14b and 14c play the
roles of feet and the camera-integrated type VTR can be stably laid there
by support on three points.
Accordingly, if the camera-integrated type VTR is laid as shown in FIG. 5,
it can be extremely stably laid by three-point support provided by the
projections 14a, 14b and 14c. In addition, in the shown state, since the
operating keys for reproduction are positioned on the apparatus with an
inclination of approximately 60.degree. as shown in FIG. 5, the operator
can operate the apparatus as if he/she were operating an exclusive video
deck for reproduction.
A tape cassette 15 is loaded in a predetermined position within the VTR
casing 6 by a cassette holder 16. When the cassette holder 16 is popped
up, the tape cassette 15 can be ejected from the apparatus. In the
arrangement adopted in the present embodiment, since the optical-system
accommodating part 1 and the EVF unit 4 are disposed on the top of the VTR
casing 6, the cassette 15 is ejected downward from the VTR casing 6.
According to such an arrangement, although the optical-system
accommodating part 1 is disposed on the top of the VTR casing 6, the
cassette 15 can be inserted or ejected without the need to pop up the
cassette holder 16 to a large extent. Accordingly, the aforesaid
embodiment provides an arrangement which makes it possible to effectively
reduce the thickness of the entire apparatus without increasing the size
of the entire mechanism.
A cover 17 serves to cover an ejection portion for the cassette 15, and is
arranged for turning motion about a support portion provided on the bottom
of the VTR casing 6. During photography, the cover 17 is locked in the
state shown in each of FIGS. 2 and 4 by a lock mechanism which is not
shown. Although not illustrated, the loading of the cassette 15 is
completed when the cover 17 is in the locked state. The lock of the cover
17 can be released by means of a lock release lever 18.
Hand-strap hooks 19 and 20 are provided at the opposite end portions of the
cover 17, and a hand strap 21 is secured between the hand-strap hooks 19
and 20. During photography, the operator applies a lower portion of the
palm to the locked cover 17 and inserts the hand through the space between
the hand strap 21 and the cover 17 until the middle portion of the palm
comes into contact with the remote controller 27. In this manner, the
operator can firmly hold the entire camera-integrated type VTR. The size
of each of the aforesaid elements is determined so that the operator can
operate the zoom switch 7 by using the index finger and the middle finger.
A microphone 23 and a cover 24 for an input-output terminal assembly 57 are
provided on the front face of the VTR casing 6 according to the present
embodiment, while a battery 25 is attached to the rear face of the same,
whereby all faces of the VTR casing 6 are utilized extremely effectively.
As described above, according to the present embodiment, since the
photographic optical system and the electronic viewfinder are disposed
above the recorder casing for recording a signal obtained by photography,
the thickness of the entire video camera is reduced to a remarkable extent
and hence the compactness is improved. Since the electronic viewfinder is
disposed on the top of the video camera, the user can hold the VTR casing
with ease. In addition, since the optical axis of the electronic
viewfinder and that of the photographic optical system are positioned
close to each other, it is possible to reduce parallax during photography.
Since the photographic optical system is disposed above the recorder casing
and a recording medium is ejected downward from the recorder casing, the
thickness of the entire video camera can be reduced to a remarkable extent
because a holding mechanism for the recording medium can be simplified.
An operating part for actuating a mechanism for varying the magnification
of the photographic optical system is disposed at the rear of the
photographic optical system disposed above the recorder casing, and a grip
is disposed on one side of the recorder casing. Accordingly, since space
on the top of the recorder casing is utilized extremely effectively, an
arrangement favorable for making this kind of video camera compact can be
achieved.
FIG. 6 is an exploded, perspective view diagrammatically showing the
internal structure of the embodiment of the present invention, and FIG. 7
is a perspective view diagrammatically showing the assembled state of the
units shown in FIG. 6.
A photographic optical system 31 includes actuators such as an IG meter 32,
a power zooming motor 33 and a focusing motor 34. The photographic optical
system 31 is fixedly held by holding portions 40 provided on a recorder
holder 37, by the fixing of mounting portions 36 formed on the
photographic optical system 31 to the respective holding portions 40 by
means of screws. Since each of the actuators incessantly operates during
photography, it is preferable to adopt a layout which can minimize the
level of operating noise generated from the actuators and picked up by a
microphone 23. For this reason, in the present embodiment, since the
actuators are disposed on the top of the photographic optical system 31,
the distance between the microphone 23 and each of the actuators is made
large so that the microphone 23 is prevented from easily picking up the
operating noise. From the viewpoint of design, it is preferable to lower
the position of the optical axis of the photographic optical system, since
the entire apparatus can be made apparently small and stable even if the
external size is the same. For this reason, in the present embodiment, the
actuators are disposed above the photographic optical system 31, and the
photographic optical system 31 and a recorder mechanism part 38 are
disposed close to each other.
An infrared-light receiving unit 58 and a tally LED 59 are disposed on the
front face of the apparatus. Accordingly, if a photographer is to
photograph himself/herself by using the remote controller 27, infrared
light emitted from the remote controller 27 can be directly received at
the same time that a lens opening portion is aimed at the photographer,
and the photographer can confirm whether the infrared light has been
received, through the tally LED 59. In addition, as shown in FIG. 5, an
arrangement is adopted in which the infrared light emitted from the
infrared-light emitting part 11 of the remote controller 27 can be
received by the infrared-light receiving part 12 (the infrared-light
receiving unit 58 shown in FIG. 7) even during the operation of the VTR
through the remote controller 27. Accordingly, it is possible to achieve a
compact and reasonable layout which can provide improved operability.
A first circuit board 51 has a power supply circuit which is not shown. A
second circuit board 54 has a servo system control circuit and an
audio/video signal processing circuit, neither of which is shown. A third
circuit board 56 has the audio/video input-output terminal assembly 57,
the infrared-light receiving unit 58, the tally LED 59, and a microphone
amplifier circuit which is not shown. Electrical circuits for the VTR part
are formed on the three circuit boards 51, 54 and 56, and the circuit
boards 51, 54 and 56 are disposed so as to cover three sides of the
recorder mechanism part 38, respectively. In this arrangement, the
electrical connection between the circuit boards 51 and 54 and that
between the circuit boards 54 and 56 can be achieved, respectively, by
circuit board connectors 52 and 55 each of which has small size, light
weight and low cost and which can be easily assembled. Accordingly, since
it is not necessary to use a wiring material which would have
conventionally been needed, it is possible to effectively reduce the size,
weight and cost of the apparatus and it is also possible to improve
reliability. In addition, all faces of the VTR part can be effectively
utilized in determining the arrangement of various constituent elements
such as operating keyboards.
Since the audio/video input-output terminal assembly 57 is disposed on the
front face of the apparatus, AV cables 28 can be easily connected to the
audio/video input-output terminal assembly 57 whether the
camera-integrated type VTR is laid vertically or horizontally as shown in
FIG. 5.
The microphone 23 is connected to a connector 60 on the third circuit board
56, and a microphone jack 29 is also disposed on the third circuit board
56. Since elements associated with the microphone amplifier circuit are
disposed close to each other in this manner, the circuit is not
susceptible to electrical noise and easy connection can be achieved.
Accordingly, this arrangement contributes to an improvement in performance
and reliability.
Since the first circuit board 51 is disposed on the rear side where the
battery 25 is attached, the distance between the battery 25 and the power
supply circuit is reduced to realize efficient supply of electrical power.
If a lithium battery is mounted on the first circuit board 51, it is
possible to realize a backup power supply for a memory which serves the
function "auto date" or "digital title" which is a feature of the
apparatus. It is, therefore, possible to achieve the advantage of
realizing a power supply system having a simplified construction and an
improved efficiency.
An element 41 is a charge-coupled device (CCD), and the CCD 41 and a fourth
circuit board 43 which will be described later are connected to each other
by a flexible printed circuit board (FPC) 42. The fourth circuit board 43
has elements such as a clock, a sync generator and a sample-and-hold
circuit which are associated with the CCD 41 in a video camera part. The
fourth circuit board 43 and a fifth circuit board 45 which will be
described later are connected to each other by an FPC 44. The fifth
circuit board 45 has circuits such as a camera signal processing circuit,
a microcomputer for automatic focusing (AF) and a circuit for "digital
title". The above-described arrangement constitutes an electrical circuit
for the video camera part.
In general, the CCD 41 has the disadvantage that the uniformity of image
quality is impaired by dark current under high-temperature conditions. The
dark current in the CCD 41 is a main cause of the deterioration of image
quality. However, the current trend in the art is to develop a
miniaturized camera-integrated type VTR in which circuit boards which
generate heat are closely spaced from each other. In such a
camera-integrated type VTR, the CCD 41 is easily heated due to a
temperature rise which is caused by the close arrangement of the circuit
boards. In the present embodiment, the distance between each of the
circuit boards, which generate heat, accommodated in the casing 6 and the
CCD 41 accommodated in the optical-system accommodating part 1 is made
large, and as shown in FIG. 8, it is possible to isolate the CCD 41 from
the heat of the circuit boards by utilizing as a shield a top plate of the
recorder holder 37 which is an internal mechanical part. In actual
measurement, it has been observed that a temperature rise on the CCD 41
can be suppressed by approximately 20.degree. C. when compared to the
conventional camera-integrated type VTR. Accordingly, the above-described
arrangement greatly contributes to an improvement in image quality.
A multi-layer circuit board made of a ceramic material is used as the
fourth circuit board 43 to reduce the size thereof. In a conventional
example, since the mechanical strength of ceramics is comparatively low, a
fixing method such as normal screwing is not adopted. Instead, after a
metallic terminal has been fixed to a ceramic board by soldering, the
ceramic board is fixed in position by screwing the metallic terminal.
However, in the present embodiment, a holder 39 is made of an elastic
material, and the fourth circuit board 43 is held by the elasticity of the
holder 39. Accordingly, it is possible to reduce the size, weight and cost
of the apparatus.
A CRT unit 48 mounted on an EVF circuit board 49 is accommodated in a case
to constitute the EVF unit 4 (refer to FIG. 1). The EVF circuit board 49
and the fifth circuit board 45 in the casing 6 are connected to each other
by an FPC 50 inserted through a turning shaft (not shown) of the EVF unit
4.
As described above, according to the present embodiment, since the
photographic optical system is disposed between sound inputting means for
inputting sound information and a driving part for controlling the
position of a lens in the photographic optical system, it is possible to
achieve a camera-integrated type VTR having a compact arrangement.
Further, it is possible to prevent the operating noise of the driving part
from being inputted into the sound inputting means. In addition, since the
photographic optical system is disposed above the recorder mechanism part
and the driving part is disposed above the photographic optical system, it
is possible to reduce the thickness of the apparatus.
In addition, first sound inputting means for inputting sound information
and connecting means to which second sound inputting means different from
the first sound inputting means is to be connected are provided on one
circuit board from among a plurality of circuit boards which are provided
in surrounding relation to the recorder mechanism part. Accordingly, it is
possible to achieve a compact arrangement which is not susceptible to
electrical noise and contributes to an improvement in performance and
reliability.
In addition, since a shielding part is provided for isolating an image
sensor part from a plurality of circuit boards which are provided in
surrounding relation to the recorder mechanism part, not only is it
possible to achieve a compact arrangement but also it is possible to
eliminate thermal influence on the image sensor part, thereby improving
image quality.
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