Incremental printing of symbolic information – Light or beam marking apparatus or processes – Scan of light
Reexamination Certificate
1999-09-09
2001-05-01
Le, N. (Department: 2861)
Incremental printing of symbolic information
Light or beam marking apparatus or processes
Scan of light
C347S241000, C347S256000, C347S257000
Reexamination Certificate
active
06226028
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to an optical printer head, and more particularly to an optical printer head adapted to carry out absorption and transmission of light emitted from a light source through a filter and reflection of the light through a lens, to thereby irradiate it on a photosensitive medium while focusing it thereon, resulting in forming a desired image on the photosensitive medium.
A conventional optical printer adapted to form a desired image on a record medium such as a photosensitive film or the like typically includes a fluorescent luminous tube which is used as a light source. The optical printer is so constructed that light emitted from the fluorescent luminous tube is guided through red, green or blue filters arranged so as to be selectively changeable with each other, to thereby obtain light of the three primary colors, which is then irradiated for writing on a record medium such as a color film or the like, resulting in a full-color image being formed on the record medium.
Now, such a conventional optical printer head will be described with reference to
FIGS. 7
to
9
, wherein
FIG. 7
is an exploded perspective view of the optical printer head and
FIGS. 8 and 9
each are a side elevation view in section of the optical printer head. The printer head generally designated at reference numeral
100
includes a fluorescent luminous tube
101
including a plurality of luminous dots for emitting linear light and acting as a light source. Also, it includes a filter holder
102
for holding red, green and blue color filters R, G and B thereon. The thus-constructed fluorescent luminous tube
101
and filter holder
102
are housed or received in a housing
103
. Also, the optical printer head
100
includes a selfoc lens array
104
arranged above the housing
103
for forming incident light into an erected real image at an equi-magnification.
The housing
103
, as shown in
FIG. 8
, is formed with an inner space in which the fluorescent luminous tube
101
and filter holder
102
are arranged. The housing
103
is mounted thereon with a bottom plate
106
to close an opening
105
of the space while receiving the fluorescent luminous tube
101
and filter holder
102
in the space. The housing
103
and bottom plate
106
cooperate with each other to provide a box-like base
107
. The filter holder
102
is formed thereon with elongated filter holding holes
108
in a manner to extend in a direction perpendicular to a sub-scanning direction indicated at an arrow A in
FIG. 8
in which the optical printer head
100
is moved. The color filters R, G and B are held in the filter holding holes
108
, respectively.
The fluorescent luminous tube
101
includes a glass plate
101
a.
The filter holder
102
is slid along an upper surface of the glass plate
101
a
and a wall surface of the opening
105
in the direction A or sub-scanning direction, resulting in selective change-over among red, green and blue colors being carried out. The selfoc lens array
104
is formed by constructing a plurality of selfoc lenses into a single module.
However, the optical printer head
100
thus constructed, as shown in
FIG. 9
, causes an end of the upper surface of the glass plate
101
a
of the fluorescent luminous tube
101
to tend to be caught in the filter holding holes
108
in which the color filters R, G and B are held, when the filter holder
102
is slid in the sub-scanning direction A in
FIG. 8
to carry out selective change-over among the color filters R, G and B.
When the filter holder
102
is slid under such circumstances, the filter holder
012
made of a resin material is shaved off to produce shavings or dust. When the thus-produced dust adheres to a surface of the color filters R, G and B, light emitted from the fluorescent luminous tube
101
is kept from satisfactorily permeating through the filters, to thereby fail to permit light to appropriately form an image on a photosensitive film W, leading to a deterioration in quality of the image.
Also, replacement of the fluorescent luminous tube
101
of which a life expired requires to detach the bottom plate
106
from the housing
103
, to thereby cause the color filters R, G and B to be exposed to an ambient atmosphere. Such exposure causes dust in an ambient atmosphere to adhere to the color filters R, G and B, resulting in the image quality being further deteriorated.
Referring now to
FIG. 10
, another conventional optical printer head is illustrated, which is generally designated at reference numeral
110
. In
FIG. 10
, reference characters like those in
FIGS. 7
to
9
designate corresponding parts. The optical printer head
110
includes a selfoc lens array
104
arranged in a through-hole
111
a
formed via a central portion of a body
111
. The body
111
is provided on a lower portion thereof with a flat section
111
b,
which cooperates with a frame
112
to constitute a housing
113
. The selfoc lens array
104
is arranged in a manner to extend through the though-hole
111
a
into the housing
113
. The housing
113
has the selfoc lens array
104
and a filter holder
102
received therein while keeping a distal end or outgoing surface
104
a
of the selfoc lens array
104
and one surface of the filter holder
102
facing each other.
The housing
113
is formed with an opening
114
, on which a bottom plate
106
is mounted, to thereby provide a box-like base
115
. The bottom plate
106
is so arranged that an inner surface
106
a
thereof is opposite to the other surface
102
b
of the filter holder
102
. The bottom plate
106
is formed with a hole
106
b
in correspondence to the distal end
104
a
of the selfoc lens array
104
. The body
111
is provided at an upper portion thereof with a flange
111
c
formed therein with a hollow section
111
d.
The hollow section
111
d
has a flat surface
111
e,
which is mounted thereon with a fluorescent luminous tube
101
while keeping a glass plate
101
a
abutted thereagainst.
In the thus-constructed optical printer head
110
, the filter holder
102
is slid to select any desired one of color filters R, G and B to drive the fluorescent luminous tube
101
. In
FIG. 10
, the color filter G is selected by way of example. Driving of the fluorescent luminous tube
101
permits it to emit light, which is guided through the hollow section
111
d,
to thereby be collected on an incident surface
104
b
of the selfoc lens array
104
. The light thus collected is then discharged through the outgoing surface
104
a
of the selfoc lens array
104
and partially absorbed by the color filter G. Light permeating through the color filter G is guided through the hole
106
b
of the bottom plate
106
to a photosensitive plate W, to thereby form an image thereon.
Unfortunately, the optical printer head
110
thus constructed causes the outgoing surface
104
a
of the selfoc lens array
104
to tend to be caught in filter holding holes
108
in which the color filters R, G and B are held, when the filter holder
102
is slid in a sub-scanning direction A to carry out selective change-over among the color filters R, G and B.
When the filter holder
102
is slid in such a state, the filter holder
102
made of a resin material is shaved off to produce shavings or dust. When the thus-produced dust adheres to a surface of the color filters R, G and B, light emitted from the fluorescent luminous tube
101
is kept from satisfactorily permeating through the filters, to thereby fail to permit light to appropriately form an image on the photosensitive film W, leading to a deterioration in quality of the image as in the optical printer head
100
described above with reference to
FIGS. 7
to
9
.
In addition, when it is desired to clear the outgoing surface
104
a
of the selfoc lens array
104
for maintenance, it is required to detach the bottom plate from the housing
113
, to thereby cause the color filters R, G and B to be exposed to an ambient atmosphere. This causes dust in an ambient atmosphere to adhere to the color filters R, G and B
Kato Hideo
Kimura Yuuichi
Nakahara Toshiaki
Yuge Tomohiko
Futaba Denshi Kogyo Kabushiki Kaisha
Le N.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Pham Hai C.
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