Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
FOLDABLE PORTABLE TELEPHONE
FIELD OF THE INVENTION
The present invention relates to foldable portable
telephones comprising a main body case and a lid case
openably connected thereto.
BACKGROUND OF THE INVENTION
Foldable portable telephones comprise a main body
case and a lid case which are foldable into a compact
form for carrying and which are opened for communicating
speech to expose a manual key arrangement provided on the
inner surface of the main body case and a display screen
provided on the inner surface of the lid case for
manipulating keys or displaying telephone numbers, etc.
Such a foldable portable telephone is not only convenient
to carry but also free of the likelihood that some keys
will be inadvertently depressed when the telephone is
carried as placed in a bag or the like since the manual
keys are then covered with the lid case.
However, conventional foldable portable telephones
have the problem that when a call is received by the
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telephone, the user is unable to immediately read the
telephone number of the caller and other information
given on the display screen by the incoming call because
the display screen does not appear unless the lid case is
opened.
SUMMARY OF THE INVENTION
An object of the present invention is to.provide a
foldable portable telephone which enables the user to
view the information given by the caller upon receiving a
call .
The present invention fulfills the above object by
utilizing the inherent construction of a liquid crystal
display device, i.e., the construction of a transparent
or semitransparent image display screen which comprises a
liquid crystal material and which enables the viewer to
observe images on the display screen from both the front
side and the rear side thereof.
The present invention provides a foldable portable
telephone comprising a main body case and a lid case
openably connected thereto. The main body case is
provided with a manual key arrangement on the inner
surface thereof, and the lid case has a liquid crystal
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display device incorporated therein and comprising a
transparent or semitransparent image display screen. The
lid case has an inner surface including an inner display
surface opposed to a first display region of the screen
of the display device. The lid case has a rear surface
including an outer display surface opposed to a second
display region of the screen of the display device. The
display device displays in the first display region of
the screen thereof images with a display pattern
appearing normal when observed through the inner display
surface and displays in the second display region images
with a display pattern appearing normal when observed
through the outer display surface. For example, a
display pattern providing some of the images displayed in
the first display region of the screen of the device is
displayed as reversed in the second display region of the
screen.
For example when a call is received by the foldable
portable telephone of the invention, the images of the
telephone number, name, etc. of the caller is presented
in the first display region of the screen of the display
device by the same processing as in the prior art. On
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the other hand, for example, some of the images shown in
the first display region are displayed in the second
display region of the screen with the display pattern
thereof as reversed in line symmetric relationship.
When the lid case is in its open state, therefore,
the images of the telephone number, name, etc. of the
caller presented in the first display region of the
display device can be observed normally on the front side
of the device , i.e., through the inner display surface
of the lid case . Further when the lid case is in its
closed state, the images of the telephone number, etc. of
the caller displayed as reversed in the second display
region of the device can be observed normally on the rear
side of the device, i.e., through the outer display
surface of the lid case.
According to an embodiment of the invention, the
liquid crystal display device is provided with a first
light guide plate over a surface of the screen opposite
to the inner display surface of the first display region
thereof, and with a second light guide plate over a
surface of the screen opposite to the outer display
surface of the second display region thereof, and the
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display device is provided with a light source for
emitting light toward each of the light guide plates.
With this embodiment, light is emitted from the light
source and guided through the first and second light
5 guide plates to irradiate the first and second display
regions of the display screen so that the images
displayed in these regions can be clearly observed
through the inner display surface and the outer display
surface.
Thus upon receiving a call, the foldable portable
telephone of the present invention enables the user to
view information such as the telephone number of the
caller without opening the lid case.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1(a) is a perspective view showing a foldable
portable telephone embodying the invention as it is
opened;
FIG. 1(b) is a perspective view showing the
telephone as it is closed;
FIG. 2 is a side elevation showing the interior
construction of the telephone;
FIG. 3 is a view in section showing the construction
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of a liquid crystal display device;
FIG. 4 includes diagrams showing a plurality of
pixels forming an image display pattern as reversed;
FIG. 5 is a flow chart showing an operation in
response to an incoming call; and
FIG. 6 is a diagram showing a procedure for
processing of an image display pattern for reversal.
DETAILED DESCRIPTION OF EMBODIMENT
An embodiment of the present invention will be
described below in detail with reference to the drawings.
FIGS. 1(a) and 1(b) show a foldable portable telephone
embodying the present invention and comprising a main
body case 1 and a lid case 2 connected to the case 1 by a
hinge mechanism 3. The telephone can be opened to a
state wherein the lid case 2 is open as shown in FIG.
1(a) and closed to a state wherein the lid case 2 is
closed as shown in FIG. 1(b).
The main body case 1 has an inner surface provided
with a manual key arrangement 11. The lid case 2 has a
liquid crystal display device incorporated therein, an
inner surface including an inner display surface 21 for
observing therethrough a major portion of image display
A~
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of the liquid crystal display device, and a rear surface
including an outer display surface 22 for observing
therethrough part of the remaining portion of the image
display of the device. The lid case 2 has an antenna 23
projecting therefrom.
With reference to FIG. 2, arranged in the interior
of the main body case 1 are a control circuit board 6,
radio circuit board 61, cell 62 serving as a power source
for these circuit boards, and a microphone 12. On the
other hand, the liquid crystal display device 4 is
disposed inside the lid case 2 as described above. The
image display screen of the device 4 is divided into a
first display region A occupying an upper major portion
of the screen and a second display region B corresponding
to the remaining lower portion of the screen. Disposed
on the inner side of the lid case 2 is a protective glass
panel 5 covering the first display region A of the device
4, while a protective glass panel 51 is provided on the
rear side of the lid case 2 to cover the second display
region B of the device. Thus, the inner protective glass
panel 5 provides the inner display surface 21, and the
rear protective glass panel 51 provides the outer display
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surface 22.
The liquid crystal display device 4 further has a
first light guide plate 48 covering a surface portion
thereof opposite to the inner display surface 21 of the
first display region A, and a second light guide plate 49
covering a surface portion thereof opposite to the outer
display surface 22 of the second display region B. LEDs
9, 91 are arranged above and below the display device 4
for emitting light toward the respective light guide
plates 48, 49. Further arranged inside the lid case 2
are a liquid crystal display driver 8 and a speaker 24.
The liquid crystal display device 4 has the same
construction as in the prior art. With reference to FIG.
3, the device 4 comprises a liquid crystal material 41, X
electrodes 42 and Y electrodes arranged with a
predetermined pitch respectively on opposite sides of the
liquid crystal material 41, and two polarizers 46, 47
disposed respectively on the outer sides of the electrode
arrangements, with a glass plate 44 or 45 interposed
between each polarizer and the corresponding electrode
arrangement. The two polariziers 46, 47 are used in
combination with their polarization directions positioned
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orthogonally to each other, and the molecules of the
liquid crystal material 41 are twisted through 90 degrees
as positioned between the two polarizers 46, 47. With no
voltage impressed across the X electrode 42 and the Y
electrode 43, light is propagated as twisted through 90
degrees along the twist of the liquid crystal molecules
and therefore passes through the polarizers 46, 47.
However, voltage applied eliminates the twist of the
liquid crystal molecules, with the result that light
fails to pass through the polarizers 46, 47. Utilizing
these phenomena, the device 4 displays images on the
display screen provided by the liquid crystal material 41.
With the liquid crystal display device 4, therefore,
the image display screen provided by the liquid crystal
material 41 is transparent, and the images displayed on
the screen can be observed from both the front side and
rear side thereof.
Further with the display device 4, the intersection
of a pair of X electrode 42 and Y electrode serves as one
pixel, and one character can be formed by a plurality of
pixels as seen in FIG. 4(a). For example, in the case
where the character "a" is to be displayed on the screen
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which is to be observed from the front side thereof, a
usual display pattern is produced as shown in FIG. 4(a).
On the other hand, when the display device 4 is reversed
by turning upside down to observe the device 4 from the
5 rear side thereof, as shown in FIG. 4(b), the display
pattern is reversed in symmetric relationship about a
horizontal line, whereby the character "a" can be
observed normally even when the device 4 is reversed by
turning upside down.
10 Accordingly with the foldable portable telephone of
the present invention, all the required images are
displayed in the first display region A of the display
device 4 as in the prior art, and the display pattern of
some of the images, for example, of the telephone number
of the caller, is displayed in the second display region
B of the device 4.
Thus, when the lid case 2 is open as shown in FIG.
1(a), all the information is available from the images on
the inner display surface 21. Alternatively when the lid
case 2 is closed shown in FIG. 1(b), a portion of the
information, such as the telephone number of the caller,
is available from the images on the outer display surface
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22. When the images displayed in the second display
region of the device 4 are those obtained by reversal
processing and observed through the outer display surface
22, the images appear normal.
FIG. 5 shows the operation to be performed when a
call is received by the foldable portable telephone.
When the call is received in step S1, step S2 prepares a
usual display pattern representing information which
indicates the telephone number of the caller and the
reception of the call, and the portion of image display
pattern for the images to be displayed in the second
display region of the device is processed for reversal in
step S3.
Subsequently in step S4, the data for forming the
display patterns for the first display region and the
second display region is transferred to the liquid
crystal display driver 8. As a result, images are
presented in the first and second display regions of the
display device 4 in step S5.
The images shown in the first display region A of
the device 4 can be observed normally through the inner
display surface 21 with the lid case 2 opened. The
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images presented in the second display region B of the
device 4 can be observed normally through the outer
display surface 22 with the lid case 2 closed.
FIG. 6 shows two methods of reversing the image
display pattern for the second display region B which
pattern is included in the image display pattern produced
by the liquid crystal display device 4. One of the
methods resorts to the processing by the control circuit
board 6, and the other method is practiced by processing
by the liquid crystal display driver 8.
When the reversal processing is performed by the
control circuit board 6, a display pattern of all the
information to be displayed upon receiving a call is
produced first in the control circuit for the first
display region A of the display device as seen in FIG.
6(a). Next, the portion of display pattern representing
part of the information, for example, the display pattern
of the telephone number of the caller, is reversed within
the control circuit as shown in FIG. 6(b) to additionally
prepare a display pattern for the second display region B.
The data forming the display patterns for the overall
display region is thereafter transferred to the liquid
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crystal display driver 8. Consequently, as shown in FIG.
6(d), all the information is displayed in the usual state
in the first display region A of the device 4, and the
telephone number is displayed as reversed in the second
display region B of the device.
When reversal processing is performed by the liquid
crystal display driver 8, on the other hand, the display
pattern of FIG. 6(a) is similarly produced in the control
circuit of the control circuit board 6, and the portion
of display pattern for part of the information, for
example, the display pattern of the telephone number of
the caller, is additionally prepared for the second
display region B as shown in FIG. 6(c). The data forming
the display patterns for the overall display region is
thereafter transferred to the liquid crystal display
driver 8. The driver 8 reverses the data forming only
the display pattern for the second display region B, and
then drives the display device 4. Consequently, as shown
in FIG. 6(d), all the information is displayed in the
usual state in the first display region A of the device 4,
and the telephone number is displayed as reversed in the
second display region B of the device.
r.,
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The images displayed in the first display region of
the device 4 can be observed normally through the inner
display surface 21 by opening the lid case 2, and the
images displayed in the second display region can be
observed normally through the outer display surface 22,
with the lid case 2 closed. When a call is received,
therefore, the outer display surface 22 on the closed lid
case 2 indicates the telephone number of the caller to
the user, and the user can thereafter recognize all
information including the name of the caller by opening
the lid case 2.
Upon receiving a call, the foldable portable
telephone of the invention enables the user to view the
telephone number of the caller, etc. without opening the
lid case as described above, and is therefore convenient.
Further the invention wherein the single liquid crystal
display device 4 is used to provide the inner display
surface 21 and the outer display surface 22 results in a
lower cost and a smaller space than the use of two liquid
crystal display devices for providing an inner display
screen and an outer display screen.
The telephone of the present invention is not
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limited to the foregoing embodiment in construction but
can be modified variously by one skilled in the art
without departing from the spirit of the invention as set
forth in the appended claims. The control circuit board
5 6 or liquid crystal display driver 8 is operated for
producing a reversed image display pattern for
presentation on the openable lid case as described above,
whereas it is also possible to modify the wiring between
the driver 8 and the display device 4 so that the display
10 can be reversed for the second display region.
Although the image display pattern to be shown in
the second display region of the liquid crystal display
device is reversed according to the procedure of FIG. 5
(step S3), it is alternatively possible to produce the
15 image display pattern first which is to be observed
normally through the outer display surface 22 and to
subsequently reverse the image display pattern to be
shown in the first display region.
With the construction shown in FIGS. 1(a), 1(b) and
2, the liquid crystal display device is turned upside
down and reversed by opening the lid case 2 so that the
image display pattern for the second display region is
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reversed in symmetric relationship about a horizontal
line, whereas if the display device 4 is adapted to be
turned laterally and reversed by opening the lid case 2,
the image display pattern for the second display region
may be reversed in symmetric relationship about a
vertical line.
