Liquid crystal cells – elements and systems – Particular structure – Holder – support – frame – or housing
Reexamination Certificate
2002-07-26
2004-10-19
Kim, Robert H. (Department: 2871)
Liquid crystal cells, elements and systems
Particular structure
Holder, support, frame, or housing
C349S063000, C362S035000
Reexamination Certificate
active
06806920
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2001-230502, filed Jul. 30, 2001; and No. 2001-380619, filed Dec. 13, 2001, the entire contents of both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a liquid crystal display (LCD) apparatus, and more particularly to a reflection type liquid crystal display apparatus having a front light.
2. Description of the Related Art
Jpn. Pat. Appln. KOKAI Publication No. 2000-284706, for instance, discloses a conventional LCD apparatus, which is a reflection type LCD apparatus having a front light as an auxiliary light source on a front face side of a reflection liquid crystal (LC) panel.
This reflection type LCD apparatus has a structure as shown in
FIG. 10. A
reflection type LC panel
11
is constructed such that a liquid crystal layer is interposed between a pair of substrates each having a thickness of 1 mm or less. One of the substrates has an integrally attached polarizing plate
12
on a front face side thereof. A flexible printed wiring board
13
is connected to the LC panel
11
. The wiring board
13
supplies the LC panel
11
with electric signals and electric energy for driving the LC panel
11
. The LC panel
11
is supplied with electric signals and electric energy from the printed wiring board
13
, thereby displaying a desired image on a surface portion thereof.
A front light unit
15
comprises a light guide body
16
and a light source
17
provided on a side face of the light guide body
16
. The light guide body
16
has a front surface provided with prism surface, and a back surface coated with an antireflective material. A flexible printed wiring board
18
is connected to the light source
17
. The light source
17
is supplied with electric energy from the wiring board
18
and thus emits light. The light guide body
16
of front light unit
15
is fixed by one through four adhesive double-coated tapes
20
disposed on peripheral portions of the polarizing plate
12
of LC panel
11
.
The LC panel
11
, to which the front light unit
15
is integrally attached, is stored in a cell case
21
. The LC panel
11
is integrally attached to the cell case
21
by one through four adhesive double-coated tapes
22
disposed within the cell case
21
, and thus a module of these structural elements is formed. Claws
23
formed on the back face of the cell case
21
are used for fixation to a mobile phone or a portable information terminal (not shown).
In the LCD apparatus with the above structure, however, the light guide body
16
has to be directly held by a worker when the front light unit
15
is to be fixed to the surface portion of the LC panel
11
by the adhesive double-coated tapes
20
. A problem may occur when the worker touches the light guide body
16
, and the productivity of front light unit
15
may deteriorate.
Besides, there are gaps between the front light unit
15
and LC panel
11
at regions not surrounded by the double-coated tapes
20
. Dust may easily enter through such gaps. If dust has entered, it is difficult to separate the front light unit
15
and LC panel
11
which are directly adhered. Consequently, dust may not be removed and the productivity of the LCD apparatus may deteriorate.
As shown in
FIGS. 11 and 12
, the light source
17
of front light unit
15
comprises a light guide stick
25
disposed at one end of the light guide body
16
, and a holder
26
which holds the light guide stick
25
and light guide body
16
as one piece. Light-emitting diodes (LEDs)
27
are disposed on both sides of the light guide stick
25
and mounted at both side portions of the printed wiring board
18
fixed on an outside face of the holder
26
by means of an adhesive double-coated tape
28
. Light emanating from light emission faces
27
a
of LEDs
27
enters end faces of the light guide stick
25
, which are opposed to the light emission faces
27
a
. Then, light emitted from the light guide stick
25
enters one end face of the light guide body
16
. Thus, the light guide body
16
emits light.
The light guide stick
25
is simply held by the holder
26
and is not fixed. As a result, the positional relationship between the light guide stick
25
and light guide body
16
tends to vary, and the efficiency of light incidence from the light guide stick
25
to the light guide body
16
may deteriorate.
In addition, the double-coated tape
28
and holder
26
are interposed between the printed wiring board
18
, on which the LEDs
27
are mounted, and the light guide stick
25
. Thus, there is a difference a in dimension between the center axis of the light emission face
27
a
of each LED
27
and the center axis of the end face of the light guide stick
25
. Consequently, the efficiency of light incidence from the LEDs
27
to the light guide stick
25
decreases and the loss in light increases.
Furthermore, the location of each LED
27
on the printed wiring board
18
is not exactly determined and is variable. It is thus necessary to provide relatively large gaps b and c between the light emission faces
27
a
of LEDs
27
, on the one hand, and the end faces of the light guide stick
25
, on the other. However, if the gaps b and c are great, the efficiency of light incidence from the LEDs
27
to the light guide stick
25
decreases and the loss in light increases.
As has been described above, with the conventional LCD apparatus, the productivity of the front light unit
15
may decrease, and the efficiency of light incidence from the LEDs
27
to the light guide body
16
may decrease. Owing to such problems of the front light unit
15
, the productivity of the LCD apparatus may decrease.
BRIEF SUMMARY OF THE INVENTION
The present invention has been made to solve the above problems, and its object is to provide a liquid crystal display apparatus wherein a problem will hardly occur in a front light unit, contributing to an increase in productivity.
According to an aspect of the invention, there is provided a liquid crystal display apparatus including:
a liquid crystal panel in which a liquid crystal layer is interposed between a pair of substrates;
a front light unit that illuminates the liquid crystal panel; and
a cell case that cooperates with the front light unit to sandwich the liquid crystal panel,
wherein the front light unit comprises a light source section, a plate-shaped light guide body that guides light from the light source section to the liquid crystal panel, and a frame-shaped protection member mounted on a peripheral portion of the light guide body and engaged with the cell case, integrally holding the liquid crystal panel and the light guide body.
According to this LCD apparatus, the frame-shaped protection member is attached to the peripheral portion of the light guide body, and the liquid crystal panel is disposed between the protection member and the cell case. In this state, the protection member is engaged with the cell case, whereby the liquid crystal panel and the light guide body are integrally held. Thus, at the time of fabrication, a manufacturing worker can handle the front light unit by holding the protection member, without directly touching the light guide body. Therefore, problems hardly occur with the front light unit, and the productivity increases.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
REFERENCES:
patent: 4453200 (1984-06-01), Trcka et al.
patent: 5889623 (1999-03-01), Ueda et al.
patent: 6055029 (2000-04-01), Kurihara et al.
patent: 6204898 (2001-03-01), Maeda
patent: 6352350 (2002-03-01), Ma
patent: 6474823 (2002-11-01), Agata et al.
patent:
Hayashi Shunichiro
Yamanaka Satoru
Caley Michael H.
Kim Robert H.
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