Information
-
Patent Grant
-
6404454
-
Patent Number
6,404,454
-
Date Filed
Friday, February 4, 200024 years ago
-
Date Issued
Tuesday, June 11, 200222 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 347 232
- 347 241
- 347 242
- 347 257
- 347 256
- 347 134
- 430 245
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International Classifications
-
Abstract
An optical printer performs optical writing on a film and includes a print head with a luminous source and a plurality of filters selectively set to the luminous source by moving toward a predetermined direction with respect to the luminous source, and a moving unit for allowing the print head to be reciprocated in the predetermined direction. A transfer unit is disposed the print head to allow the filters to be moved by a regular amount, i.e., a predetermined pitch(“c” to “e”), thereby setting a desired filter to the luminous source. The transfer unit is operated to by the regular amount from one end side of the moving region of the print head. Further, a reset unit is disposed to the print head and is operated when the print head is moved more than the moving region from one end side ad of the moving region of the print head, forcing the moved filter to return to the original position. Furthermore, one end side of the moving region of the print head is provided with an accelerating region for accelerating the print head at a regular speed.
Description
FIELDS OF THE INVENTION
The present invention generally relates to an optical printer for example, a fixed, a portable printer and the like, for optical writing on a recording medium; and more particularly to an optical printer and a print head therefor, wherein a plurality of filters are selectively alternated or changed with respect to a common luminous source.
BACKGROUND OF THE INVENTION
As is well known, a print head in a typical optical printer includes a luminous source in which a plurality of fine luminous dots are juxtaposed along a line, the luminous source moving from a main scanning direction juxtaposing to the luminous dots to a sub-scanning direction perpendicular to the main scanning direction so as to irradiate dot-type lights on a recording medium, forming a desired image thereon. A variety of luminous elements such as a fluorescent luminous tube or LED and the like are utilized as the luminous source.
There is schematically shown in
FIG. 14
a structure of a print head incorporated in a conventional optical printer, for example, a portable color printer and the like and there is shown in
FIG. 15
a partial structure of the print head, with some parts omitted therefrom.
As shown in
FIG. 14
, a print head
100
is made to reciprocate in a sub-scanning direction, e.g., with respect to a film
102
acting as a recording medium placed at a predetermined position. That is, as shown in
FIG. 15
, the print head
100
is guided by a pair of guide shafts
104
which are positioned parallel to the sub-scanning direction and is connected to a pulse motor
106
through a wire
108
to be driven, thereby allowing the print head
100
to reciprocate in the sub-scanning direction. Further, the print head
100
includes a luminous element
110
acting as a luminous source, the luminous element
110
having a plurality of luminous dots that are positioned parallel to the main scanning direction. Light emitted from the luminous element
110
passes through three filters R,G,B as described hereinafter and is imaged through a reflective optical element(mirror)
112
, a single optical system(lens)
114
, and a reflective optical element (mirror)
116
to the film
102
.
As shown in
FIG. 14
, each of the red filter R, the green filter G and the blue filter B is disposed on an irradiating side of the luminous element
110
to be alternated or changed as desired. As shown in
FIG. 15
, the three filters R,G,B are mounted on a common filter holder
118
in such a way that longer sides thereof are parallel to the main scanning direction and shorter sides are parallel to the sub-scanning direction. The filter holder
118
is provided with a projection
120
for manipulating the filter holder
118
, the projection
120
projecting in the sub-scanning direction. Also, the projection
120
is maintained between a guide bearing
122
and a position determining bearing
124
. The position determining bearing
124
is biased by a spring
126
and engaged with any one of three cut-off portions
128
formed on the projection
120
. The filter holder
118
is compressed by a spring
130
toward a predetermined direction in the sub-scanning direction. An abutment
132
is disposed at a predetermined distance from the projection
120
and a reset plate
134
is disposed at an opposite side therefrom in such a manner that the print head
100
is sandwiched therebetween. That is, when the projection
120
of the filter holder
118
comes in contact with the abutment
132
as a result of the print head
100
moving, the filter holder
118
also moves, allowing the filters R,G,B to be alternated or changed as desired. Further, when the print head
100
is moved in an opposite direction as described above, resulting in the reset plate
134
shifting a shaft
136
of the position determining bearing
124
, the engagement of the filter holder
118
is released by the position determining bearing
124
and the spring
130
allows the filter holder
118
to move toward a direction of the abutment
132
.
A writing operation on the film
102
using the above-described structure will be described using FIG.
16
. There is shown in
FIG. 16
a moving chart of the print head
100
. As shown, reference numeral “a” indicates a filter reset position, a region between reference numerals “b” and “c” is referred to as an accelerating region, a region between reference numerals “c” and “d” is an exposure region, and a region between reference numerals “d” and “f” is a change-over region of the filters R,G,B. Further, Δ marks in the drawing is referred to as a position of the luminous source
110
, i.e., a luminous dot row. In the above-described print head
100
, a full-color image is formed on the film
102
by color-separating an image into three images of primary colors of R,G,B and superposing the three images.
As shown in
FIG. 16
, the reset plate
134
moves the shaft
136
of the position determining bearing
124
when the print head
100
is moved to the “a” position, which, in turn, results in the filter holder
118
moving to right by the elastic force of the spring to be reset at an initial position. At this position, the filter R is set at a light irradiating position (referred to as Δ mark) of the luminous element
110
.
The printer head
100
, as shown in
FIG. 16
, accelerates at a regular speed through the accelerating region, i.e., between “b” and “c” along the sub-scanning direction and moves to the exposure region, i.e., between “c” and “d”. In synch with this operation, the luminous element
110
is driven with an image signal of red R, forming the image in red R on the film.
Furthermore, at the completion of the forming of the image in red R on the film, the projection
120
of the filter holder
118
comes in contact with the abutment
132
at the changing-over region, allowing the filter holder
118
to move and the filter to change-over from red R to green G.
Next, the print head
100
moves to the “b” position. At this position, since the reset plate
134
and the shaft
136
of the position determining bearing
124
are not in contact with each other, the filters are not reset. The print head, as shown in
FIG. 16
, is accelerated at the regular speed through the accelerating region along the subscanning direction and moves to the exposure region. In synch with this operation, the luminous element
110
is driven with an image signal of green G, forming an image in green G on the film. At the completion of the forming of the image in green on the film, the projection
120
of the filter holder
118
comes in contact with the abutment
132
at the change-over region, i.e., between “e” and “f”, allowing the filter holder
118
to move and causing the filter to change-over from green G to blue B.
Again, the print head
100
moves to “b” position. At this position, since the reset plate
134
and the shaft
136
of the position determining bearing
124
are not in contact with each other, the filters are not reset. Further, the print head
100
, as shown in
FIG. 16
, is accelerated at the regular speed through the accelerating region and moves to the exposure region. In synch with this operation, the eluminous element
110
is driven with an image signal of blue B, forming an image in blue B on the film.
Next, the print head
100
moves to the “a” position as shown in
FIG. 16
, the reset plate
134
and the shaft
136
of the filter holder
124
come in contact with each other and the filter is reset as red R.
As described above, in the conventional optical printer, the print head
100
is movable in the sub-scanning direction with respect to the film
102
placed at a desired position. Further, the print head
100
is constructed in such a way that the change-overs among the filters R,G,B being movable in the sub-scanning direction, are accomplished only by the movement thereof.
However, in the conventional optical printer as described, the change-over from green G to blue B takes place when the print head
100
moves and comes in contact with the abutment
132
shown at the right side in FIG.
15
and the resetting to red R takes place when the print head
100
moves and comes in contact with the reset plate
134
shown at the left side in FIG.
15
. In other words, there are formed on, both right and left, change-over regions, the change-over resulting from the print head
100
moving. The existence of change-over regions in two opposite direction runs counter to the down-sizing of the optical printer.
In addition, during the change-over from green G to blue B, since an independent change-over region, i.e., between “d” and “e” and “e” and “f” in
FIG. 16
exists at each of the pitches of the filters of green G and blue B, the print head must move accordingly. Further, the description above is referred to a situation where only three filters of R,G,B are used. However, if three or more filters are required to change-over, the print head
100
must move accordingly, except for one pitch of one filter.
Further, even though the amount of movement of the print head
100
is controlled by recognizing a pulse number of the pulse motor
106
, the amount of movement thereof required is different, as shown in
FIG. 16
, when it moves from right to left and vice versa, thereby making the control thereof difficult and complicated.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an optical printer and a print head therefor capable of small-sizing of an apparatus by reducing a moving amount of the print head and simplifying a control according to the movement of the print head.
In accordance with one aspect of the present invention, there is provided an optical printer for optical writing on a recording medium and having a print head with a luminous source and a plurality of filters selectively set to a luminous section of the luminous source by moving toward a predetermined direction with respect to the luminous source, and a moving means for allowing the print head to be reciprocated in the predetermined direction, the optical printer comprising: a transfer means disposed the print head and for allowing the filters to be moved to the predetermined direction by a regular amount, thereby setting a desired filter to the luminous source; an abutting means disposed to one end side of the moving region of the print head and is abutted to the transfer means when the print head is moved to one end side of the moving region, thereby allowing the transfer means to operate in the regular amount; and a reset means disposed to the print head and operated at the same side as the abutting means for resetting the filter to its initial position when the print head is moved more than the moving region.
In a preferred embodiment of the present invention, the optical printer further may include an accelerating region for accelerating the print head at a regular speed to the other end side of the moving region by being disposed to the same side as the abutting portion.
In a preferred embodiment of the present invention, each of the filters may have a predetermined pitch in the predetermined direction and is maintained in a filter holder resiliently supported to be moved toward the predetermined direction with respect to the luminous source, the transfer means may include a transferring portion detachably engaged to the filter holder and for moving the filter holder by the predetermined pitch of the filters against the elastic force by the regular amount to be abutted to the abutment, and an engagement engaged with the filter holder moved by the transferring portion against the elastic force, thereby positioning a desired filter to correspond to a position set to the luminous source, and the reset means may be positioned at the same side as the abutting portion and may release simultaneously the filter holder from the engagement and the engagement of the transferring portion with the filter holder when the print head is moved more than the moving region.
In accordance with the other aspect of the present invention, there is provided a print head of an optical printer for optical writing on a recording medium during moving toward a predetermined direction by a moving means, the print head comprising: a base having a luminous source and movably disposed in the predetermined direction by the moving means; a filter holder having a predetermined pitch toward the predetermined direction to thereby maintain a plurality of filters therein and resiliently supported to the base to allow the filters to be moved toward the predetermined direction on the luminous source; a transfer means abutted to one portion of the optical printer when the base is moved to one end side of the moving region by the moving means and engaged to allow the filter to be moved by the predetermined pitch toward the predetermined direction by the regular amount against the elastic force so that a desired filter is set to the luminous source; and a reset means for releasing the engagement with the filter holder in the transfer means when the base is moved more than the moving region from one end side of the moving region.
In a preferred embodiment of the present invention, the transfer means may include a transferring portion detachably engaged to the filter holder and for moving the filter holder to be moved by the predetermined pitch of the filters against the elastic force of the filter by the regular amount to be abutted to a portion of the optical printer, and an engagement engaged with the filter holder moved by the transferring portion against the elastic force, thereby positioning the desired filter to correspond to a position set to the luminous source, and the reset means may simultaneously release the filter holder from the engagement and the engagement of the transferring portion with the filter holder when the base is moved more than the moving region from one end side of the moving region.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:
FIGS. 1A and 1B
illustrate a plan view and a cross sectional view showing an optical printer in accordance with a first preferred embodiment of the present invention, respectively;
FIG. 2
shows a sectional view schematically showing a print head incorporated in the optical printer of
FIG. 1
;
FIG. 3
is a plan view schematically showing a change-over mechanism in the first embodiment of the present invention;
FIG. 4
is a perspective view of the change-over mechanism of
FIG. 3
;
FIG. 5
is a perspective view partially showing the change-over mechanism of
FIG. 3
;
FIGS. 6
to
8
each are plan views showing operation of the change-over mechanism of
FIG. 3
;
FIG. 9
is a chart showing movement of the print head in the first embodiment of the present invention;
FIGS. 10A and 10B
are a plan view showing a change-over mechanism in accordance with a second embodiment of the present invention and an exploded view showing essential parts thereof;
FIGS. 11A
to
11
C each are plan views showing operation of the change-over mechanism in accordance with the second embodiment of the present invention;
FIG. 12
is a plan view schematic showing a change-over mechanism in accordance with a third embodiment of the present invention;
FIGS. 13A
to
13
C each are plan views showing operation of the change-over mechanism in accordance with the third embodiment of the present invention;
FIG. 14
is a sectional view schematic showing a print head incorporated in a conventional optical printer;
FIG. 15
is a partial plan view showing a conventional print head, with some essential parts omitted therefrom; and
FIG. 16
is a chart showing movement of the conventional print head.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first preferred embodiment of the present invention will now be described hereinafter with reference to the drawings.
FIGS. 1A and 1B
are a plan view and a cross-sectional view of an optical printer in accordance with a first embodiment of the present invention, respectively, and
FIG. 2
is a schematic view showing an optical system of a print head of the optical printer in FIG.
1
.
The optical printer, as shown in
FIGS. 1A and 1B
, allows the print head
1
to be reciprocated in a predetermined direction by a moving means
3
on a film
2
acting as a recording medium placed at a desired position therefrom. The moving means
3
is provided with a pair of guide shafts
4
which are positioned parallel to a sub-scanning direction. Further, the moving means
3
has a pair of pulleys
5
, the pulleys being placed at two opposite end sides of one of the guide shafts, respectively, and being connected to each other through a wire
6
wound therearound. One of the pulleys
5
is rotated by a pulse motor
7
, the rotation of the pulley
5
being transferred to the other pulley
5
through the wire
6
. The print head
1
is guided by the guide shafts
4
and a portion thereof is fixed to the wire
6
. That is, when the pulse motor
7
is driven to circulate the wire
6
between the pulleys
5
, the print head
1
moves along the sub-scanning direction by being guided by the guide shafts.
The print head
1
capable of being moved along the sub-scanning direction by the moving means
3
is guided by the guide shafts
4
and has a base
8
fixed to the wire
6
, the base being provided with each of the optical elements. The optical elements, as shown in
FIG. 2
, includes a luminous source
9
, filters
10
, a reflective optical element
11
, and an equal magnification lens
12
.
In this embodiment, it is preferred that the luminous source
9
may employ a fluorescent luminous tube. The tube has a substrate
15
constructed of a glass material having a light-permeability and an insulating property and a substantial rectangular envelope
17
formed by attaching a box-like container
16
on the substrate
15
, an inside of the envelope
17
being evacuated to a high vacuum. A plurality of luminous dots
18
acting as a luminous portion which are arranged at regular intervals in two lines along a main scanning direction are formed on the substrate
15
inside the envelope
17
. The luminous dots
18
include anode conductors formed at the substrate
15
and a phosphor layer deposited on each of the anode conductors, the phosphor layer being formed of ZnO:Zn phosphor material. Further, not shown, a line-shaped cathode acting as an electron source along the main scanning direction is disposed below the luminous dots
18
. The anode conductors of each of the luminous dots
18
are independently taken out of the envelope
17
and is independently driven by a driving signal applied thereto.
The filters
10
in three primary luminous colors of red R, green G, and blue B, each being arranged lengthwise along the luminous dots
18
on the substrate
15
in the main scanning direction and maintained at the same pitch in a sub-scanning direction with respect to a filter holder
20
.
Further, the filter holder
20
for holding the respective filters is slidably mounted in the sub-scanning direction with respect to the base
8
.
The reflective optical elements
11
, in this case, mirrors, are disposed at the base
8
to thereby allow light from the luminous dots
18
of the luminous source
9
to be focused only on the film
2
, not on the base
8
. The reflective optical elements
11
are disposed at two positions in such a manner that the light from the luminous dots
18
is introduced into the sub-scanning direction and then introduced only onto the film
2
, not on the base
8
, i.e., toward an upper portion in FIG.
2
.
The equal magnification optical system
12
, also known as a lens, is disposed at the base
8
so as to be placed between the reflective optical elements
11
. The optical system
12
comprises a plurality of substantially cylindrical lenses, i.e., SELFOC lenses(Registered trademark) corresponding to each of the luminous dots
18
in the embodiment, the lenses being formed into a module.
The light emitted from the luminous dots
18
of the luminous source
9
permeates any one of the R, G, and B filters
10
by the respective optical elements as described above and is irradiated only onto the film
2
, not on the base
8
, i.e., excluding the print head
1
, through one portion of the reflective optical element
11
, the equal magnification optical system
12
, and the other reflective optical element
11
. This results in a line-shaped image being written on the film
2
in the main scanning direction. Further, the print head
1
is moved by the moving means
3
in the sub-scanning direction to thereby permit a planer image to be formed on the film
2
.
The filter holder
20
is moved in the sub-scanning direction to selectively change-over the filters R,G,B to thereby expose the respective colors. The fluorescent luminous tube is driven by a corresponding signal produced by the changing-over of the filters
10
, permitting color images to be formed on the film
2
.
Hereinafter, a change-over mechanism for changing-over the filters
10
will be described.
FIG. 3
is a schematic plan view showing the change-over mechanism in accordance with the first embodiment of the present invention,
FIG. 4
is a perspective view of the change-over mechanism, and
FIG. 5
is a perspective view partially showing the change-over mechanism.
The change-over mechanism of the filters
10
capable of moving the filter holder
20
in the sub-scanning direction as described above includes a transfer means
25
and a reset means
26
located at a side of the print head
1
as shown in FIG.
3
. Further, since the change-over mechanism in the first embodiment operates only when the print head
1
is moved by the moving means
3
as described above, it further includes an abutment
27
related to the transfer means
25
and the reset means
26
with respect to a chassis(not shown) side of the optical printer having the moving means
3
.
First, the transfer means
25
and the reset means
26
will be described.
As shown in
FIG. 4
, the base
8
of the print head
1
is a two-layered structure including an upper layer
8
b
and a lower layer
8
a
, the lower layer being provided with the luminous source
9
and the filter holder
20
as described above and the upper layer being provided with the reflective optical elements(mirror)
11
and the equal magnification optical system(lens)
12
as described above. Further, the lower layer
8
a
is provided with the filter holder
20
slidably disposed in the sub-scanning direction between the upper and the lower layers. The filter holder
20
is always resiliently supported in one direction(A direction in
FIGS. 3 and 4
) of the sub-scanning direction by one end
30
a
of a twist coil spring
30
. Further, the upper layer
8
b
is provided with a through-hole
21
of a lengthwise slit shape in the main scanning direction for passing through the light emitted from the luminous source
9
(the luminous dots
18
) for permeating the filters
10
toward the reflective optical elements
11
.
The transfer means
25
is disposed to be related to the filter holder
20
and the upper layer
8
b.
The filter holder
20
resiliently supported by the twist coil spring
30
in one direction(A direction in
FIGS. 3 and 4
) side of the sub-scanning direction is provided with a ratchet
31
extended into the other direction(B direction in
FIGS. 3 and 4
) side of the sub-scanning direction opposite to the resiliently supported direction. The ratchet
31
is provided with two pawls
31
a
formed at the same pitch and direction as the respective filters
10
.
The lower layer
8
a
is provided with an engagement
32
. The engagement
32
has an engaging pawl
32
a
for engaging with each of the pawls
31
a
of the ratchet
31
. The engagement
32
is swingably disposed through a shaft
33
against the lower layer
8
a
. The swing of the engagement
32
is elastically supported by the other end
30
b
of the twist coil spring
30
, allowing the engaging pawl
32
a
to be engaged with each of the pawls
31
a
of the ratchet
3
l.
The engaging pawl
32
a
of the engagement
32
becomes engaged with each of the pawls
31
a
as the filter holder
20
slides against the elastic force of the twist coil spring
30
and moves near to the engagement
32
. At this time, the engagement
32
climbs over the pawl
31
a
engaged therewith to thereby swing against the elastic force of the twist coil spring
30
(see FIG.
6
). Likewise, when the filter holder
20
is slid to thereby permit the ratchet
31
to be further adjacent thereto, the engagement
32
climbs over the next pawl
31
a
to thereby be engaged therewith (see FIG.
7
).
Further, when the engagement
32
is not engaged with each of the pawls
31
a
, as shown in
FIGS. 3 and 4
, the engagement
32
and the ratchet
31
are separated farthest from each other (an initial position). In other words, there exists a total of three conditions of engagements including, i.e., the initial position and the above-described two conditions where the engaging pawl
32
a
is engaged with the two pawls
31
a
, respectively, (see
FIGS. 6 and 7
) as the ratchet
31
(the filter holder
20
) moves closer to the engaging pawl
32
a
. The three conditions corresponds to the positions at which the three filters
10
of R,G,B are aligned to the through-holes
21
, respectively. In this embodiment, the filter
10
corresponding to the through-hole
21
at the initial position is a red filter, and the filters
10
of green G and blue B correspond to the through-holes
21
according to the order of the engagement.
As described above, an engaging portion
34
of the transfer means
25
includes the ratchet
31
and the engagement
32
, the ratchet
31
being slidably positioned to the filter holder
20
which is resiliently supported and the engagement
32
forcing each of the R,G,B of the filters
10
of filter holder
20
which is slid in relation to the ratchet
31
to correspond to the respective through-holes
21
.
On the other hand, an engaging pin
35
fixed in the same direction(A direction in
FIGS. 3 and 4
) as the filter holder
20
is resiliently supported, i.e., in the sub-scanning direction. A pawl
35
a
, as shown in
FIG. 5
, is disposed to an upper surface of the engaging pin
35
. The upper surface of the engaging pin
35
having the pawl
35
a
is projected upward from the upper layer
8
b
. Further, the upper layer
8
b
moves with the engaging pin
35
projected upward from the upper layer
8
b
by the sliding of the filter holder
20
.
Further, the upper layer
8
b
is disposed to a longitudinal transfer arm
36
. The transfer arm
36
is pivoted to about lengthwise center portion thereof through a shaft
37
to thereby be swung in the sub-scanning direction. The swing of the transfer arm
36
is resiliently supported by a twist coil spring
38
wound around the shaft
37
, one end
36
a
thereof being swung toward one direction(A direction in
FIGS. 3 and 4
) of the sub-scanning direction, while the other end
36
b
thereof being swung toward the other direction (B direction in
FIGS. 3 and 4
) thereof. However, the other end
36
b
is in contact with a projection
39
placed to the base
8
as shown in
FIG. 3
so that the swing of the transfer arm
36
by the elastic force of the twist coil spring
38
is restricted to a predetermined range.
One end
36
a
of the transfer arm
36
is placed on the pawl
35
a
of the engaging pin
35
. A couple of transferring pawls
36
c
engaged with the pawl
35
a
, as shown in
FIG. 5
, are disposed to a bottom surface of one end
36
a
of the transfer arm
36
, allowing them to have the same direction and pitch as the respective filters
10
.
Further, each of the transferring pawls
36
c
of the transfer arm
36
and the pawl
35
a
of the engaging pin
35
are engaged with each other when one end
36
a
of the transfer arm
36
is swung toward the other direction(B direction in
FIG. 5
) of the sub-scanning direction against the elastic force of the twist coil spring
38
. That is, when the transferring pawls
36
c
are engaged with the pawls
35
a
by the swing toward the other direction of the sub-scanning direction in one end
36
a
of the transfer arm
36
, the engaging pin
35
is pushed to the other direction of the sub-scanning direction to thereby allow the filter holder
20
to move in the same direction. The moved filter holder
20
is engaged at a position corresponding to moving at one pitch of the filter
10
by the operation of the above-described engaging portion
34
(see FIG.
6
).
Further, when each of the transferring pawls
36
c
and the pawls
35
are swung to be returned toward one direction(A direction in
FIG. 5
) of the sub-scanning direction by the elastic force of the twist coil spring
38
, it does not become engaged at a common slant portion of each other. In this case, since one end
36
a
of the transfer arm
36
is formed to be twisted upward, the transferring pawls
36
c climb over the pawls
35
a
. That is, the transfer arm
36
returns to a predetermined position where the other end
36
b
comes in contact with the projection
39
as shown in
FIG. 3
after the filter holder
20
is moved corresponding to one pitch of the filter
10
.
In the engagement of the respective transferring pawls
36
c
with the pawls
35
a
, as indicated with two dotted lines in
FIG. 5
, the condition in which the transferring pawls
36
c
partially placed in one direction(A direction in
FIG. 5
) of the sub-scanning direction are engaged with the pawls
35
a
is the initial position as shown in
FIGS. 3 and 4
at which the engaging pawls
32
a
of the engagement
32
are not engaged with each of the pawls
31
a
of the ratchet
31
and the filter
10
of red R corresponds to the through-hole
21
in this embodiment.
Further, when the transfer arm
36
returns to the predetermined position after one end
36
a
of the transfer arm is swung toward the B direction in
FIG. 5
by engaging the transferring pawls
36
c
partially placed toward one direction(A direction in
FIG. 5
) of the sub-scanning direction with the pawls
35
a
, the filter holder
20
is moved corresponding to one pitch of the filter
10
by the operation of the engaging portion
34
as described above(see FIG.
6
), thereby allowing the filter
10
of green G to correspond to the through-hole
21
. Further, under this condition, since the engaging pin
35
is moved by one pitch of the filter
10
by the movement of the filter holder
20
, the transferring pawls
36
c
partially placed to the other direction(B direction in
FIG. 5
) of the sub-scanning direction are engaged with the pawls
35
a.
Next, the transferring pawls
36
c
partially placed on the other direction(B direction in
FIG. 5
) of the sub-scanning direction become engaged with the pawls
35
a
so that when the transfer arm
36
returns to the predetermined position after one end
36
a
of the transfer arm
36
is swung toward the B direction in
FIG. 5
, the filter holder
20
is further moved by one pitch of the filter
10
by the operation of the engaging portion
34
(see FIG.
7
), allowing the filter
10
of blue B to correspond to the through-hole
21
. Further, under this condition, since the engaging pin
35
is further moved by one pitch of the filter
10
by the movement of the filter holder
20
, the transferring pawls
36
c
partially placed on the other direction(B direction in
FIG. 5
) of the sub-scanning direction moves away by one pitch of the filter
10
from the pawls
35
a.
As described above, the transfer arm
36
permits the filter holder
20
to move by one pitch of the filter
10
as a result of the reciprocating swing operation in a regular amount. In order to perform the operation, a transferring portion
40
in the transfer means
25
includes the engaging pin
35
and the transfer arm
36
.
The reset means
26
is disposed with the above-described engagement
32
and the upper layer
8
b
connected to one end
36
a
of the transfer arm
36
.
As shown in
FIGS. 3 and 4
, the engagement
32
is provided with an operating lever
32
b
which extends toward the other direction(B direction in
FIGS. 3 and 4
) of the sub-scanning direction from the base
8
. When the operating lever
32
b
is pressed toward one direction(A direction in
FIGS. 3 and 4
) of the sub-scanning direction, the engagement
32
is swung against the elastic force of the twist coil spring
30
to thereby release the pawl
31
a
of the ratchet
31
from the engaging pawl
32
a
. The filter holder
20
then slides in the sub-scanning direction(A direction in
FIGS. 3 and 4
) by the elastic force of the twist coil spring
30
, returning to the initial position.
The operating surface
41
coming in contact with a bottom surface of one end
36
a
of the transfer arm
36
is disposed to the upper layer
8
b
side below the bottom surface of one end
36
a
thereof. The operating surface
41
has a flat surface
41
a
at a portion where one end
36
a
of the transfer arm
36
corresponds to the regular swing region in which the filter holder
20
is moved by one pitch of the filter
10
as described above. Further, the operating surface
41
has a slant surface
41
b
inclined upward toward the other direction(B direction in
FIGS. 3 and 4
) of the sub-scanning direction from the flat surface
41
a
to allow one end
36
a
of the transfer arm
36
to be further swung to the other direction (B direction in
FIGS. 3 and 4
) of the sub-scanning direction from the regular swing region. Each of the transferring pawls
36
c
of the transfer arm
36
is not engaged with the pawls
35
a
of the engaging pin
35
placed below thereof because the pawls
36
c
and
35
are raised up together.
Since the operation of the operating lever
32
b
of the engagement
32
and the operation of the slant surface
41
b
of the operating surface
41
are generated together, the filter holder
20
is released and returns to the initial position. At the same time, the pawls
35
in the engaging pin
35
moving by this releasing operation release the engagement with the transferring pawls
36
a
, returning to the initial position without preventing the movement of the filter holder
20
.
Next, the abutment
27
will be described hereinafter.
The abutment
27
is disposed to an abutting base
45
fixed to one end side of the reciprocated moving region of the print head
1
in the other direction(B direction in
FIG. 3
) of the sub-scanning direction as shown in
FIG. 3
with respect to a chassis (not shown) of the optical printer having the above-described moving mechanism
3
.
In the abutting base
45
, a transferring abutment
46
is disposed toward one direction(A direction in
FIG. 3
) of the sub-scanning direction facing to the print head
1
. The transferring abutment
46
has a bar-shaped form and is disposed to be extended into the moving region side of the print head
1
. A tip
46
a
of the transferring abutment
46
is abutted to the other end
36
b
of the transfer arm
36
consisting of the transferring portion
40
of the transfer means
25
. When the print head
1
moves toward the other direction (B direction in
FIG. 3
) of the sub-scanning direction and reaches one end side of the reciprocating region of the print head
1
, the tip
46
a
of the transferring abutment
46
gets abutted to the other end
36
b
of the transfer arm
36
. The transferring abutment
46
forces the transfer arm
36
to be swung by a fixed amount by moving the print head
1
. In addition, the transferring abutment
46
carries out the above-described operation in which one end
36
a
of the transfer arm
36
is raised upward by the slant surface
41
b
when the print head
1
moves a larger distance than the fixed amount by which the transfer arm is swung toward the other direction(B direction in
FIG. 3
) of the sub-scanning direction. As a consequence, the filter holder moves by one pitch of the filter
10
.
Further, a reset abutment
47
is disposed toward one direction(A direction in
FIG. 3
) of the sub-scanning direction in the abutting base
45
facing the print head
1
. A tip
47
a
of the reset abutment
47
is abutted to the operating lever
32
b
of the engagement
32
acting as the reset means
26
when the print head
1
moves toward the other direction (B direction in
FIG. 3
) of the sub-scanning direction to reach one end side of the reciprocating region. To be more specific, the tip
47
a
is not abutted to the lever
32
b
when the transferring abutment
46
is swinging the transfer arm
36
by the fixed amount, while the tip
47
a
is abutted to the lever
32
b
when the print head
1
moves a larger distance than the fixed amount by which the transfer arm is swung toward the other direction(B direction in
FIG. 3
) of the sub-scanning direction to the above-described operation, in which one end
36
a
of the transfer arm
36
is raised upward by the slant surface
41
b.
Accordingly, the transferring abutment
46
swings the transfer arm
36
by the fixed amount by moving toward one end side of the reciprocating region of the print head
1
, forcing the filter holder
20
to move by one pitch of the filter
10
(see FIGS.
6
and
7
). Further, when the print head
1
is moved a larger distance than the fixed amount toward one end side of the reciprocating region of the print head
1
, the transferring abutment
46
and the reset abutment
47
operate the reset means
26
to allow the filter holder
20
to be placed at the initial position as shown in
FIG. 3
, allowing the filter
10
to be changed-over to red R (see FIG.
8
).
Further, the disposal of the abutting means
27
should not be restricted to situation where it is disposed to the abutting base
45
. It is preferred that as a part of the optical printer, the abutting means may be disposed with the transferring abutment
46
and the reset abutment
47
.
The exposure operation of the optical printer and the change-over operation of the filter in accordance with the first embodiment of the present invention will be described hereinafter with reference to a moving chart of the print head of FIG.
9
.
An ordinate row designated as a reference sign “a” in
FIG. 9
is referred to a reset position of the filter
10
, reference signs “b” to “c” are referred to as an accelerating region of the print head, reference signs “c” to “d” are referred to as a start region and an end region of the exposure, and reference signs “c” to “e” are referred to as a change-over region of the filters
10
of R, G, B. Further, Δ mark in the drawings is referred to as a position of a luminous dot row acting as the luminous source. A full-color latent image is formed by color-separating an image into images in three primary colors of R,G,B and superposing the images on the top of each other.
Firstly, the filter
10
performs an exposure for changing-over into red R. In this case, as shown in
FIG. 9
, the print head
1
moves to the “a” position. The “a” position is referred to the initial position of the filter holder
20
in which the filter
10
is changed-over to the red R by allowing the transferring abutment
46
and the reset abutment
47
to operate the reset means
26
. The print head
1
moves from the “a” position toward one direction(A direction) of the sub-scanning direction, accelerates through the accelerating region of “b” to “c” at a predetermined speed, and then moves to the exposure region of “c” to “d”. In synch with the operation, the luminous source
9
is driven by the image signal of red R to thereby form an image in red R on the film
2
.
Next, the filter
10
performs the exposure for changing-over into green G. In this case, after such exposure through the above-described red filter R is completed, the print head
1
moves toward the “d” to “e” position in the other direction(B direction) of the sub-scanning direction. In the change-over region of “c” to “e”, the transferring abutment
46
permits the print head
1
to move so that the transfer arm
36
is swung by the fixed amount to thereby allow the filter holder
20
to move one pitch of the filter
10
. This results in the filter
10
, as shown in
FIG. 6
, changing-over into green G. Thereafter, the print head
1
moves from the “e” position toward one direction(A direction) of the sub-scanning direction(A direction), accelerates through the accelerating region of “b”, to “c” at the predetermined speed, and then moves to the exposure region of “c” to “d”. In synch with this operation, the luminous source
9
is driven by the image signal of green G to thereby form an image in green G on the film
2
.
Thereafter, the filter
10
performs the exposure for changing-over into blue B. In this case, after such exposure through the above-described green filter G is completed, the print head
1
moves toward the “d” to “e” position in the other direction(B direction) of the sub-scanning direction. In the change-over region of “c” to “e”, the transferring abutment
46
permits the print head
1
to move so that the transfer arm
36
is swung by the fixed amount to thereby allow the filter holder
20
to move by one pitch of the filter
10
. This results in that, at the “e” position, the filter
10
, as shown in
FIG. 7
, is changed-over into blue B. Thereafter, the print head
1
moves from the “e” position toward one direction(A direction) side of the sub-scanning direction, accelerates through the accelerating region of “b” to “c” at the predetermined speed, and then moves to the exposure region of “c” to “d”. In synch with this operation, the luminous source
9
is driven by the image signal of blue B to thereby form an image in blue B on the film
2
.
Subsequently, the print head
1
moves to the “a” position in the other direction(B direction) of the sub-scanning direction so that, as shown in
FIG. 8
, the filter
10
is changed-over again into red R as a result of the transfer abutment
46
and the reset abutment
47
driving the reset means
26
.
Therefore, according to the optical printer in the first embodiment, all of the change-overs with respect to each of the filters
10
including the reset operation into red R as well as moving through the accelerating region by the print head
1
are carried out at one end side in the moving region of the print head
1
, resulting in the accelerating region being set within the change-over region of the filter
10
, reducing the total amount of the print head movement, which will, in turn, allow the down-sizing of the apparatus possible.
More particularly, when the filter
10
is changed-over into G and B by the transfer means
25
, the filter holder
20
moves by one pitch by the regular movement between “c” and “e” of the print head
1
as shown in FIG.
9
. This makes it unnecessary for the change-over region to be independently disposed at all of the pitches of the conventional filters G, B and allows a common change-over region to be formed, reducing the total amount of the print head movement, which will, in turn, allow to down-sizing of the apparatus possible.
To be more specific, the moving chart of
FIG. 9
shows that the exposure region, the accelerating region, the moving by one pitch of the filter, and the amount of moving required to the reset operation by the print head
1
are identical when compared to the conventional moving chart of FIG.
16
. However, as is well known from
FIG. 9
of the first embodiment of the present invention, the total amount of the print head movement in the first embodiment, when compared to the total amount of the print head movement in
FIG. 16
, is reduced by movements corresponding the accelerating region and one pitch of the filter.
Further, the amount of movement of the print head
1
is controlled by recognizing a pulse number of the pulse motor
7
. Such an amount, as shown in
FIG. 9
, except for the time of the reset during the movement of the print head
1
in the sub-scanning direction from a right side to a left side or vice versa, is always the same, allowing the pulse motor
7
to be easily controlled.
Hereinafter, the second embodiment of the present invention will be described with reference to the drawings.
The transferring portion
40
of the transfer means
25
in the change-over mechanism of the filter and the operation surface
41
of the reset means
26
incorporated in the transferring portion
40
of the second embodiment are constructed differently from those of the first embodiment described above. Therefore, the parts in the second embodiment having the same construction as those in the first embodiment will not be further discussed herein and they will be affixed with the same reference numerals as the first embodiment. Rather, the following description is only directed to the parts of the second embodiment which are of different elemental construction.
FIG. 10A
show a schematic plan view of a change-over mechanism of the second embodiment of the present invention,
FIG. 10B
illustrates a detailed enlarged view of the change-over mechanism thereof, and
FIGS. 11A
to
11
C are operating diagrams of the change-over mechanism thereof.
First, the transfer means
25
of the transferring portion
40
in accordance with the second embodiment will be described.
An engaging pin
50
projected on the upper layer
8
b
is fixed and points toward an end of one direction(A direction in
FIG. 10
) of the sub-scanning direction oriented into the resilient supported direction of the filter holder
20
. Further, the upper layer
8
b
is provided with a cutout
51
to thereby allow it to be moved together with the engaging pin
50
projected on the upper layer
8
b
by the sliding of the filter holder
20
.
Further, a transfer arm
52
is disposed to the upper layer
8
b
. A substantial center portion of the transfer arm
52
is pivoted about the shaft
37
to thereby be swung toward the sub-scanning direction. One end
52
a
of the transfer arm
52
is resiliently supported to thereby be swung in one direction (A direction in
FIG. 10
) of the sub-scanning direction by a spring(not shown), while the other end
52
b
of the transfer arm
52
is resiliently supported to be swung toward the other direction(B direction in
FIG. 10
) of the sub-scanning direction by the spring, but the swing of the transfer arm
52
depending on the elastic force of the spring is restricted to a predetermined range by the other end
52
b
coming in contact with the projection
39
which is placed on the base
8
.
One end
52
a
of the transfer arm
52
is a flexible and is J-shaped when viewed on a plane. A tip thereof is arc shaped being oriented in the other direction(B direction in
FIG. 10
) of the sub-scanning direction. A transferring pawl
52
c
projected outward is formed at the tip thereof.
A base end of a follower arm
53
is swingably pivoted to the shaft
37
for pivoting the transfer arm
52
. The follower arm
53
is placed on one end
52
a of the transfer arm
52
. Further, an engaging pin
50
is inserted into a tip
53
a
of the follower arm
53
so as to be supported thereto. The engaging pin
50
moves in the sub-scanning direction by the moving of the filter holder
20
so that the engaging pin
50
is inserted through a lengthwise hole
53
b
into the tip
53
a
of the follower arm
53
without hindering the movement of the engaging pin
50
and its own swing to thereby be supported thereto.
Further, the follower arm
53
is provided with two pawls
53
c
to be engaged with a transferring pawl
52
c
placed to the tip of the transfer arm
52
. The pawls
53
c
are formed at the follower arm
53
to be oriented in the same direction and pitch along tip's arc shape of one end
52
a
of the transfer arm
52
with respect to each of the filters
10
.
The transferring pawl
52
c
of the transfer arm
52
and each of the pawls
53
c
of the follower arm
53
are engaged with each other when one end
52
a
of the transfer arm
52
is swung toward the other direction(B direction in
FIG. 10
) of the sub-scanning direction against the elastic force of a spring. That is, when the engaging pin
50
inserted and supported at the tip of the follower arm
53
is pressed toward the other direction of the sub-scanning direction by engaging the transferring pawl
52
c
with the pawl
53
c
as a result of the swing toward the other side of the sub-scanning direction in one end
52
a
of the transfer arm
52
, the filter holder
20
moves in the same direction. At this time, the moved filter holder
20
is engaged by the operation of the engaging portion
34
at a position moved by one pitch of the filter
10
(see FIG.
11
A).
Further, when one end
52
a
of the transfer arm
52
is swung to be returned by the elastic force of the spring toward one direction(A direction) side of the sub-scanning direction, one end
52
a
having the transferring pawl
52
c
in the transfer arm
52
is twisted to the shaft
37
side so that the transferring pawl
52
c
climbs over each of the pawls
53
c
. That is, the transfer arm
52
returns to a predetermined position where the other end
52
b
comes in contact with the projection
39
as shown in
FIG. 10A
after the filter holder
20
is moved by one pitch of the filter
10
.
Further, as shown in
FIGS. 10A and 10B
, the transferring pawl
52
c
is engaged with the pawls
53
c
which are adjacent at the other direction(B direction in
FIG. 10
) side of the sub-scanning direction, while the engaging pawls
32
a
of the engagement
32
and each of the pawls
31
a
of the ratchet
31
in the engaging portion
34
are not engaged with each other to thereby be in the initial position. In this embodiment, the filter
10
of red R corresponds to the through-hole
21
.
Further, when the transfer arm
52
is returned to the predetermined position after one end
52
a
of the transfer arm is swung toward the B direction as a result of the transferring pawl
52
c
being engaged with the pawls
53
c
which are adjacent to the other direction (B direction in
FIG. 10
) side of the sub-scanning direction, the filter holder
20
, as shown in
FIG. 11A
, is moved by one pitch of the filter
10
by the operation of the above-described engaging portion
34
and is engaged therewith, thereby corresponding the filter
10
of green G to the through-hole
21
. Further, under this condition, the engaging pin to is further moved by one pitch of the filter
10
as a result of the movement of the filter holder
20
and the follower arm
53
is swung, following up with the movement of the engaging pin
50
so that the transferring pawl
52
c
is separated by one pitch of the filter
10
from the pawl
53
c
which is adjacent to one direction (A direction) side of the sub-scanning direction.
Subsequently, when the transfer arm
52
returns to the predetermined position after one end
52
a
of the transfer arm is swung toward the B direction by the transferring pawl
52
c
being engaged with the pawl
53
c
which is adjacent to one direction(A direction in
FIG. 10
) side of the sub-scanning direction, the filter holder
20
, as shown in
FIG. 11B
, is further moved by one pitch of the filter
10
by the operation of the above-described engaging portion
34
and engaged therewith, thereby corresponding the filter
10
of blue B to the through-hole
21
. Further, under this condition, the engaging pin
50
is further moved by one pitch of the filter
10
as a result of the movement of the filter holder
20
and the follower arm
53
is swung, following up to the movement of the engaging pin
50
so that the transferring pawl
52
c
is placed to be separated by one pitch of the filter
10
from the pawl
53
c
which is adjacent to one direction(A direction) side of the sub-scanning direction.
As described above, the filter holder
20
is moved by one pitch of filter
10
by the regular reciprocating operation of the transfer arm
52
. The transferring portion
40
in the transfer means
25
includes the engaging pin
50
for performing this operation, the transfer arm
52
, and the follower arm
53
.
Hereinafter, the reset means
26
in accordance with the third embodiment of the present invention will be described.
The reset means
26
is disposed in connection with the above-described engagement
32
and the upper layer
8
b
provided with one end
52
a
of the transfer arm
52
.
The reset means
26
having the engagement
32
is provided with the operating lever
32
b
, which is identical to that of the first embodiment of the present invention. The engagement
32
is swung against the elastic force of the twist coil spring
30
by the operating lever
32
b
so as to release the engagement of the pawl
31
a
of the ratchet
31
with the engaging pawl
32
a
, resulting in returning of the filter holder
20
to the initial position.
An operating surface
54
coming in contact with the tip of one end
52
a
is disposed on the upper layer
8
b
within the swingable region of a fixed amount. The operating surface
54
faces the tip before the swing of the tip of one end
52
a
. When one end
52
a
of the transfer arm
52
is within the swingable region of the fixed amount so as to allow the filter holder
20
to be swung by one pitch of the filter
10
as described above, the operating surface
54
is placed to be not in contact with the tip of one end
52
a
. Further, when one end
52
a
of the transfer arm
52
is swung from the swingable region toward the other direction(B direction in
FIG. 10
) side of the sub-scanning direction, the operating surface
54
comes in contact with the tip of one end
52
a
. Further, one end
52
a
of the transfer arm
52
further swung from the swingable region toward the other direction(B direction in
FIG. 10
) side of the sub-scanning direction becomes twisted so that the operating surface
54
becomes provided with a properly inclined surface to allow the transferring pawl
52
c
placed to the tip to become separated from each of the pawls
53
c
of the follower arm
53
.
As shown in
FIG. 11C
, the filter holder
20
is released to be returned to the initial position by the operation of the operating lever
32
b
of the engagement
32
and that of the operating surface
54
. At the same time, the pawls
53
c
are not engaged with the transferring pawl
52
c
in the follower arm
53
which is swung by the above release operation, thereby returning to the initial position without preventing the movement of the filter holder
20
.
The abutment
27
includes, as in the first embodiment, the transferring abutment
46
and the reset abutment
47
. The transfer arm
52
is swung by a fixed amount by the movement of the transferring abutment
46
to one end side of the print head
1
within the reciprocating region thereof, as shown in
FIGS. 11A and 11B
, allowing the filter holder
20
to move by one pitch of the filter
10
. Further, when the print head
1
is moved more than the moving region in one end side of the reciprocating region of the print head
1
, the reset means
26
is operated, as shown in
FIG. 11C
, forcing the filter holder
20
to be placed at the initial position, as shown in
FIGS. 10A and 10B
, i.e., the filter
10
is changed-over into red R.
Further, the exposure operation of the optical printer and the change-over of the filter in accordance with the second embodiment are similar to those of the first embodiment which were fully described using the moving chart of FIG.
9
.
Therefore, according to the optical printer of the second embodiment, every change-over operations of each of the filters
10
including the reset operation to red R are performed at one end side (A side) of the moving region of the print head
1
and the accelerating region of the print head
1
is commonly set in the above change-over region to thereby reduce the total amount of movement of the print head
1
, allowing the apparatus to be down-sized.
Further, similar to the first embodiment, the change-over to green G and blue B of the filters
10
have also a common change-over region where the filter holder
20
moves by one pitch of the filter
10
by the regular movement of the print head
1
depending on the operation of the transfer means
25
to thereby further reduce the total amount of movement of the print head
1
, making it possible to down-size the apparatus.
Further, the control of the pulse motor
7
may be also similar to the first embodiment, leading to simplification of the device.
Hereinafter, the third embodiment of the present invention will be described with reference to the drawings.
First, the filter holder
20
is resiliently supported by a tension coil spring
60
in the other direction(B direction in
FIG. 12
) side of the sub-scanning direction. The filter holder
20
is provided with a ratchet
61
which extends toward the other direction(B direction) side of the sub-scanning direction, i.e., the resiliently supported direction. The ratchet
61
is provided with two pawls
61
a
(upper side) and two pawls
61
b
(lower side), respectively, which are formed in the same direction and pitch as each of the filters
10
at a top end edge and a bottom end edge of the main scanning direction in FIG.
12
.
The lower layer
8
a
is provided with an engagement
62
. An engaging pawl
62
a
engaged with each of the pawls
61
b which is placed to a bottom side of the ratchet
61
is formed on the engagement
62
. The engagement
62
is swingably disposed through a shaft
33
with respect to the lower layer
8
a
. The swing of the engagement
62
is resiliently supported by the tension coil spring
60
for resiliently supporting the filter holder
20
to thereby allow the engaging pawl
62
a
to engage with each of the pawls
61
b
of the ratchet
61
.
When the filter holder
20
is slid against the elastic force of the tension coil spring
60
, the engaging pawl
62
a
of the engagement
62
becomes engaged with each of the pawl
61
b
of the ratchet
61
. At this time, it is preferred that the engagement
62
may climb over the pawls
61
b
engaging therewith, thereby swinging against the elastic force of the tension coil spring
60
(see FIG.
13
A). Further, when the filter holder
20
is further slid, the engagement
62
climbs over the following pawl
61
b
to thereby be engaged therewith(see FIG.
13
B).
Further, as shown in
FIG. 12
, when the engaging pawl
62
a
is not engaged with each of the pawls
61
b
, the engagement
62
and the ratchet
61
are placed at the initial position at which the engagement
62
and the ratchet
61
are nearest to each other. Accordingly, the ratchet
61
(the filter holder
20
) moves away from the engagement
62
on the basis of the initial position to allow the engaging pawl
62
a
to be engaged with each of the pawls
61
b
, respectively, to thereby generate three conditions including the above described two conditions (see FIGS.
13
A and
13
B). These three conditions are provided with a position allowing each of the three filters
10
of R,G,B to correspond to the through-hole
21
, respectively. In this embodiment, the filter
10
corresponding to the through-hole
21
in the initial position is red R, the filters
10
of green G and blue B correspond to the through-hole
21
in order of the engaging condition as the ratchet
51
moves away from the engagement
62
.
As described above, the engaging portion
34
includes the ratchet
61
placed to the slidable filter holder
20
which is resiliently supported and the engagement
62
allowing the filters
10
of R,G,B of the filter holder
20
slid with respect to the operation of the ratchet
61
to correspond to the through-hole
21
, respectively.
Further, a transfer arm
63
is disposed toward the upper layer
8
b
. One end
63
a
of the transfer arm
63
is oriented to the filter holder
20
side, while the other end
63
b
thereof is projected from an end of the other direction (B direction in
FIG. 12
) side of the sub-scanning direction of the base
8
so that the transfer arm
63
is slidably disposed to the sub-scanning direction. The transfer arm
63
is resiliently supported to be slid toward the other direction (B direction in
FIG. 12
) side of the sub-scanning direction by a compress coil spring
64
. The sliding of the transfer arm
63
is restricted to the other direction (B direction) of the sub-scanning direction at a predetermined position where the other end
63
b
thereof projects from the other direction (B direction) side of the sub-scanning direction by length L in FIG.
12
.
One end
63
a
of the transfer arm
63
is a flexible in the main scanning direction and the transferring pawl
63
c
engaged with each of the pawls
61
a
of the ratchet
61
is disposed to a tip thereof. When the transfer arm
63
is slid against the elastic force of the compress coil spring
64
to one direction(A direction in
FIG. 2
) of the sub-scanning direction, the transferring pawls
63
c
of the transfer arm
63
and each of the pawls
61
a
become engaged with each other.
That is, the filter holder
20
moves in one direction(A direction) of the sub-scanning direction by the engagement of the transferring pawls
63
c
with the pawls
61
a
sliding toward one direction(A direction) side of the sub-scanning direction of the transfer arm
63
. At this time, the moved filter holder
20
, as shown in
FIG. 13A
, is engaged at a position where the filter
10
is moved by one pitch by the operation of the above-described engaging portion
34
.
Further, when the transfer arm
63
slides toward the other direction(B direction in
FIG. 12
) side of the sub-scanning direction by the elastic force of the compress coil spring
64
, the transferring pawl
63
c
and each of the pawls
61
a
are not engaged at a common slant portion thereof. In this case, one end
63
a
of the transfer arm
63
is twisted upward so that the transferring pawls
63
c
climb over the pawls
61
a
. That is, the transfer arm
63
is returned to a predetermined position where the other end
63
b
is projected by the length L from the other direction(B direction) side of the sub-scanning direction of the base
8
as shown in
FIG. 12
after the filter holder
20
is moved by one pitch of the filter
10
.
In the engagement of the transferring pawls
63
c
with each of the pawls
61
a
, as shown in
FIG. 12
, when the transferring pawls
63
c
placed in adjacent to one direction(A direction in
FIG. 12
) side of the sub-scanning direction are engaged with the pawls
61
a
, it is at an initial position where the engaging pawls
62
a
of the engagement
62
are not engaged with each of the pawls
61
a
of the ratchet
61
and the filter
10
of red R corresponds to the through-hole
21
in this embodiment.
Further, after the transfer arm
63
is slid toward the A direction by engaging the transferring pawl
63
c
placed adjacent to the other direction(A direction in
FIG. 12
) side of the sub-scanning direction with the pawls
61
a
, the transfer arm
63
returns to the above-described predetermined position, the filter holder
20
moves by one pitch of the filter
10
and becomes engaged by the operation of the engaging portion
34
as shown in
FIG. 13A
to thereby allow the filter
10
of green G to correspond to the through-hole
21
. Further, under this condition, since the filter holder
20
is moved by one pitch of the filter
10
, the transferring pawls
63
c
placed adjacent to the other direction(B direction) side of the sub-scanning direction become engaged with the pawls
61
a.
Next, the transferring pawls
63
c
placed adjacent to the other direction(B direction in
FIG. 12
) side of the sub-scanning direction are engaged with the pawls
61
a
so that, the transfer arm
63
returns to the above-described predetermined position after the transfer arm
63
is slid toward the A direction, and the filter holder
20
, as shown in
FIG. 13B
, moves by one pitch of the filer
10
and become engaged by the operation of the above-described engaging portion
34
, allowing the filter
10
of blue B to correspond to the through hole
21
. Further, under this condition, since the filter holder
20
is further moved by one pitch of the filter
10
, the transferring pawls
63
c
placed adjacent to the other direction(B direction) side of the sub-scanning direction are placed away by one pitch of the filter
10
from the pawls
61
a.
As described above, the transfer arm
63
permits the filter holder
20
to move by one pitch of the filter
10
by the regular amount of the reciprocating operation. In order to perform the operation, the transferring portion
40
in the transfer means
25
includes the pawls
61
a
of the ratchet
61
and the transfer arm
63
.
The reset means
26
in accordance with the third embodiment will be described hereinafter.
The reset means
26
is disposed by the above-described engagement
62
and the upper layer
8
b
connected with one end
63
a
of the transfer arm
63
.
The reset means
26
having the engagement
62
is so constructed to be provided with an operating lever
62
b
which is swung against the elastic force of the tension coil spring
60
, releasing the engaging condition of each of the pawls
61
b
of the ratchet
61
with the engaging pawl
62
a
, thereby returning the filter holder
20
to the initial position.
A releasing lever
63
d
is disposed to one end
63
a
of the transfer arm
63
. The releasing lever
63
d
extends from a center portion of one end
63
a
having a flexible property to form about L-shaped configuration so that the tip thereof is oriented toward one direction(A direction in
FIG. 12
) of the sub-scanning direction.
Further, an operating surface
65
coming in contact with the tip of the releasing lever
63
d
placed to one end
63
a
is disposed on the upper layer
8
b
within the slidable region of one end
63
a
of the transfer arm
63
. The operating surface
65
faces the tip prior to the tip of the releasing lever
63
d
is slid. When the transfer arm
63
is placed in the slidable region where the filter holder
20
is allowed to move a regular amount, i.e., one pitch of the filter
10
as described above, the operating surface
65
is placed at a position where it is not in contact with the tip of the releasing lever
63
d
. When the transfer arm
63
is slid from the regular sliding region toward the other direction(B direction in
FIG. 12
) of the subscanning direction, the operating surface
65
comes in contact with the tip of the releasing lever
63
d
. Further, one end
63
a
of the transfer arm
63
further slid from the regular slidable region toward the other direction(B direction) of the sub-scanning direction is twisted by the operating surface
65
so that the transferring pawls
63
c
placed to the tip thereof become distanced from each of the pawls
61
a
of the ratchet
61
, thereby forming a properly inclined surface.
Since the operating lever
62
b
of the engagement
62
and the operating surface
65
are operated together, the filter holder
20
is released to be returned to the initial position as shown in FIG.
13
C. At the same time, the transferring pawls
63
c
are not engaged with each of the pawls
61
a
, thereby allowing the filter holder to return to the initial position without the filter holder
20
moving.
Next, the abutment
27
in accordance with the third embodiment of the present invention will be described.
The abutment
27
is disposed to the abutting base
45
(similar to the first embodiment, see
FIG. 3
) fixed to one end side of the reciprocating region of the print head
1
in the other direction(B direction in
FIG. 12
) side of the sub-scanning direction with respect to a chassis (not shown) of the optical printer having the moving mechanism
3
for moving the print head
1
.
In the abutting base
45
, a transferring abutment
66
is so constructed to allow a surface of one direction(A direction in
FIG. 3
) side of the sub-scanning direction to face the print head
1
, forming the transferring abutment and the reset abutment of the first and the second embodiments.
The transferring abutment
66
is abutted to the other end
63
b
of the transfer arm
63
consisting of the transferring portion
40
of the transfer means
25
. When the print head
1
moves toward the other direction (B direction in
FIG. 12
) side of the sub-scanning direction and reaches to one end side of the reciprocating region of the print head
1
, the transferring abutment
66
becomes abutted to the other end
63
b
of the transfer arm
63
. The transferring abutment
66
allows the transfer arm
63
to slide by a fixed amount during the movement of the print head
1
. This results in the filter holder
20
moving by one pitch of the filter
10
. Further, when the print head
1
moves more toward the other direction (B direction) side of the sub-scanning direction than that of the transfer arm
63
is slid, the transferring abutment
66
operates to allow one end
63
a
of the transfer arm
63
to be raised upward by the releasing lever
63
d
and the operating surface
65
.
Further, when the print head
1
moves toward the other direction (B direction in
FIG. 12
) side of the sub-scanning direction, reaching one end side of the reciprocating region, the transferring abutment
66
becomes abutted to the operating lever
62
b
of the engagement
62
. To be more specific, the transferring abutment
66
becomes abutted, not during the regular sliding of the transfer arm
63
, but when the print head
1
moves more toward the other direction(B direction) side of the sub-scanning direction than the regular sliding region of the transfer arm
63
, raising upward one end
63
a
of the transfer arm
63
by the releasing lever
63
d
and the operating surface
65
.
As a result, the transferring abutment
66
operates to allow the transfer arm
63
to be regularly swung by the movement of the print head
1
to one end side of the reciprocating region as shown in
FIGS. 13A and 13B
, moving the filter holder
20
by one pitch of the filter
10
. Further, when the print head
1
moves further toward one end side of the reciprocating region thereof, the transferring abutment
66
, as shown in
FIG. 13
c
, functions to operate the reset means
26
, moving the filter holder
20
to the initial position where the filter
10
is changed-over to red R.
Further, the exposure operation and the change-over operation of the optical printer in the third embodiment is performed in the same manner as the operation as shown in the moving chart of
FIG. 9
in accordance with the first embodiment.
According to the optical printer in the third embodiment, in the same manner as the first embodiment, all of the changing-over of each of the filters
10
including the reset operation to red R are performed at one end side (A side) of the moving region of the print head
1
. At the same time, the accelerating region of the print head
1
is set commonly within the change-over region so that the total amount of movement of the print head
1
is reduced, leading to down-sizing of the apparatus.
Further, since the change-over of the filter
10
to G,B is also similar to the first embodiment, the filter holder
20
is moved by one pitch of the filter
10
by the regular movement of the print head
1
at the common change-over region, allowing the total amount of movement of the print head
1
to be further reduced, making it possible further down-size the apparatus.
Further, the control of the pulse motor
7
can be also simplified as in the first embodiment.
Particularly, the optical printer in the third embodiment is so constructed that the transfer means
25
and the reset means
26
are concentrated at one side of the filter holder
20
, e.g., the other direction side of the sub-scanning direction, allowing an easy assembling the parts and the like.
Further, the transfer means
25
and the reset means
26
of the third embodiment in the optical printer operate only in the sub-scanning direction and do not allow vertical movements thereof, making it possible to further thin, and hence down-size, the print head
1
.
Incidentally, although the accelerating regions in the first to third embodiments are disposed within the change-over region, allowing all of the change-overs of each of the filter
10
including the reset region, i.e., toward one end side (A side) of the moving region of the print head
1
, to be performed therein, the accelerating region can also be set at the other end side (B side) of the moving region of the print head
1
. In both cases, the total amount of movement is reduced by one pitch of the filter
10
in comparison with the prior art, allowing further down-sizing of the apparatus possible.
Further, although the accelerating region is set at the other end side (B side) of the moving region of the print head
1
, the amount of moving required for reciprocating the print head
1
between one end side and the other end side thereof is all the same except for the reset operation, thereby simplifying the control of the pulse motor
7
.
The optical printer in accordance with the present invention includes a transfer means for moving a plurality of filters moving toward a predetermined direction by a regular amount in such a way that it sets a desired filter to a luminous source, the transfer means being located at and operates from one end side of the moving region of the print head and moving toward a particular direction by the regular amount, and the reset means for returning the filter to the original position in one end side of the moving region.
That is, in the change-over of the filters, a desired filter is set to the luminous source by the regular moving of the transfer means by a fixed amount(by one pitch). Such an operation is accomplished by the transfer means moving toward one end side of the print head. As a result, since, in changing-over the plurality of filters, the change-over region of the moving print head corresponds to a regular amount of movement of the transfer means, i.e., by one pitch of filter, and this is common to all of the filters, the total amount of movement of the print head
1
is reduced, leading to a down-sizing of the apparatus.
Further, the filter is changed-over at each pitch by the regular amount of movement of the transfer means, and this is accomplished by the print head moving. As a result, the change-over region of the print head moved in order to change-over the plurality of filters corresponds to one pitch of the filter, and this common to all of the filters, so that the change-over thereof is all the same except for when movement each of the filters is reset, leading to simplifying of the moving control of the print head.
Furthermore, although the accelerating regions in the present invention are disposed within the change-over region, allowing all of the change-overs of each of the filter
10
including the reset region, i.e., toward one end side (A side) of the moving region of the print head
1
, to be performed therein, the accelerating region can also be set at the other end side (B side) of the moving region of the print head
1
. In both cases, the total amount of movement is reduced by one pitch of the filter
10
in comparison with the prior art, allowing further down-sizing of the apparatus possible.
While the present invention has been described with respect to the particular embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
Claims
- 1. An optical printer for optical writing on a recording medium, the optical printer comprising:a print head including a luminous source and a plurality of filters for being selectively aligned with the luminous source by moving parallel to a predetermined direction; a head moving unit for allowing the print head to be reciprocated parallel to the predetermined direction, the print head moving in a print head moving region; a transfer unit disposed in the print head and for moving the filters along the predetermined direction by a preset distance, thereby placing a desired filter in front of the luminous source; an abutting unit disposed close to one end side of the print head moving region, the abutting unit being coupled with the transfer unit when the print head is moved to one end side of the print head moving region, thereby allowing the transfer unit to move the filters along the predetermined direction by the preset distance; and a reset unit disposed in the print head for resetting the filters to their initial positions when the print head is moved beyond said one end side of the print head moving region, wherein the print head moving region includes a print head accelerating region located close to said one end side for accelerating the print head toward the other end side of the print head moving region until the print head gains a predetermined speed.
- 2. The optical printer according to claim 1, wherein the filters are disposed to have a predetermined pitch therebetween along the predetermined direction and is maintained on a filter holder being urged to move along the opposite direction of the predetermined direction by a resilient force,the transfer unit includes a transferring portion detachably engaged to the filter holder and for moving the filter holder by the predetermined pitch against the resilient force when coupled with the abutting unit, and an engagement engaged with the filter holder moved by the transferring portion, thereby positioning the desired filter in front of the luminous source, and the reset unit releases the filter holder from the engagement and the transferring portion when the print head is moved beyond the print head moving region.
- 3. The optical printer according to claim 1, wherein the print head accelerating region is set within the change-over region of the filter.
- 4. A print head for use in an optical printer for optical writing on a recording medium while the print head moves along a predetermined direction by a head moving unit, the print head comprising:a base having a luminous source and being moved parallel to the predetermined direction by the head moving unit; a filter holder having a plurality of filters with a predetermined pitch therebetween along the predetermined direction, the filter holder being urged by a resilient force to move along the predetermined direction; a transfer unit coupled with a portion of the optical printer to move the filter holder against the resilient force by the predetermined pitch along the opposite direction of the predetermined direction when the base is moved to one end side of a print head moving region by the moving unit and hold the filter holder thereat, thereby positioning a desired filter in front of the luminous source; and a reset unit for releasing the filter holder from the transfer unit when the base is moved beyond said one end side of the print head moving region, thereby restoring the filter holder at its initial position, wherein the transfer unit includes a transferring portion detachably engaged to the filter holder and for moving the filter holder by the predetermined pitch against the resilient force when coupled with the portion of the optical printer, and an engagement engaged with the filter holder moved by the transferring portion, thereby positioning the desired filter in front of the luminous source, and the reset unit releases the filter holder from the engagement and the transferring portion when the base is moved beyond said one end side of the print head moving region.
- 5. An optical printer comprising:an optical head having a light source and a set of color filters including a first filter and more than one different second filters; a head moving unit for moving the optical head in a head moving region, the head moving region including an exposure region where the optical head moves at a speed, a filter change-over region and a head acceleration region where the optical head is accelerated to gain the speed, and one of the change-over region and the head acceleration region substantially overlaps with the other spatially; and a filter change-over unit for aligning one of the second filters in front of the light source at the filter change-over region.
- 6. The optical printer according to claim 5, wherein the head moving region further includes a reset region located at the opposite side of the exposure region with respect to the filter change-over region, andthe optical printer further comprising a reset unit for aligning the first filter in front of the light source at the reset region.
- 7. The optical printer according to claim 6, wherein the head accelerating region a part of the filter change-over region.
- 8. The optical printer according to claim 5, wherein the head accelerating region is a part of the filter change-over region.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-028507 |
Feb 1999 |
JP |
|
US Referenced Citations (4)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0512924 |
Nov 1992 |
EP |
3142413 |
Jun 1991 |
JP |