BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to an image forming apparatus and an image forming
method, in particular, using a laminate technique.
2. Description of Related Art
[0002] As one of image forming apparatuses, a sublimation type thermal transfer printer
is known in which color inks of yellow, magenta, and cyan are made to sublimate by
heat of a thermal head to form a color image on a recording medium. On the other hand,
laminate techniques are known in which the surface of a recording medium on which
an image has been formed is coated with a transparent film in order to protect the
image formed on the recording medium against moisture and oil to keep the quality
of the image for a long time. Such techniques are categorized into gross finish in
which a transparent film is transferred to the whole surface in an even pattern; and
mat finish in which a transparent film is transferred to the whole surface in an uneven
pattern. For example, Japanese Patent No.
3861293 discloses a technique concerning mat finish.
[0003] In Japanese Patent No.
3861293, uneven pattern data for the transparent film is sent from a host computer to a printer,
and stored in a laminate memory provided in the printer. The pattern data to be stored
in the laminate memory is not for the whole surface of the recording medium but partial
data. The pattern based on the partial data is repeated in a sub scanning direction
to form an uneven pattern on the whole surface.
SUMMARY OF THE INVENTION
[0004] In the technique of Japanese Patent No.
3861293, because the laminate memory stores therein not data for the whole surface of the
recording medium but partial pattern data as described above, the capacity of the
memory can be reduced in comparison with the case of storing the data for the whole
surface. However, although the capacity can be reduced, a dedicated memory for storing
pattern data for transparent film lamination must be provided in the printer. There
is a problem that the cost can not be reduced due to the provision of the memory.
[0005] An object of the present invention is to provide an image forming apparatus and an
image forming method, wherein there is no necessity of providing a dedicated memory
for storing pattern data for transparent film lamination.
[0006] An image forming apparatus according to the present invention comprises a conveyance
mechanism that conveys a recording medium; a recording head that records an image
in accordance with image data on the recording medium being conveyed by the conveyance
mechanism, and transfers a transparent film on the recording medium on which the image
has been recorded; a data generating unit that generates data concerning a transfer
pattern of the transparent film; and a controller that controls the recording head
so that the transparent film is transferred on the basis of the data generated in
the data generating unit.
[0007] An image forming method according to the present invention in which an image is recorded
on a recording medium in accordance with image data and a transparent film is transferred
onto the recording medium on which the image has been recorded, comprises a data generating
step of generating data concerning a transfer pattern of the transparent film; and
a controlling step of controlling the recording head so that the transparent film
is transferred on the basis of the data generated in the data generating step.
[0008] According to the above features, the data concerning the transfer pattern of a transparent
film is not externally sent and stored in a memory but generated in the data generating
unit. Therefore, there is no necessity of providing a dedicated memory for storing
the data, which is advantageous in cost.
[0009] The data generating unit preferably repeatedly generates data concerning a partial
transfer pattern of the transparent film to be transferred onto the whole surface
of the recording medium.
[0010] In addition, preferably in the data generating step, data concerning a partial transfer
pattern of the transparent film to be transferred onto the whole surface of the recording
medium is repeatedly generated.
[0011] According to the above features, because the data concerning only a partial transfer
pattern is repeatedly generated, the generating process of the transfer pattern data
can be simplified and the time for the process can be shortened.
[0012] The data generating unit preferably repeatedly generates data of one line.
[0013] In addition, preferably in the data generating step, data of one line is repeatedly
generated.
[0014] According to the above features, a simple construction can be realized with the use
of a line buffer for storing data of one line.
[0015] A color controlling unit that controls colors of the image to be recorded on the
recording medium preferably has the function of the data generating unit.
[0016] According to the above feature, because the color controlling unit to be used in
image recording in accordance with image data can be used for lamination, there is
no necessity of adding a new component.
[0017] The data generating unit may include an image processing unit, and the data concerning
the transfer pattern generated by the data generating unit may be processed by the
image processing unit. In addition, the data generating step may include an image
processing step, and the data concerning the transfer pattern generated in the data
generating step may be processed in the image processing step.
[0018] According to the above features, because the data concerning the transfer pattern
can be image-processed, a wide variety of mat prints can be realized. For example,
when the data concerning the transfer pattern is random pattern data, the change in
the unevenness of the random pattern can be made smooth; or a mat print having a three-dimensional
appearance (a feeling of roughness) can be made by enhancing the difference in the
unevenness. The image process may be any known process such as embossment or edge
enhancement. Concretely, it is made by means such as an MTF filter or an unsharp mask.
[0019] The recording head may be a thermal head that transfers inks carried on an ink ribbon
to record an image on the recording medium, and transfers a transparent film carried
on the ink ribbon subsequently to the inks onto the recording medium on which the
image has been formed with the inks.
[0020] The problem that a dedicated memory must be provided for storing pattern data for
transparent film lamination is particularly remarkable in a thermal transfer type
image forming apparatus. According to the above feature, therefore, because the problem
is dissolved, a more practical effect is obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Other and further objects, features and advantages of the invention will appear more
fully from the following description taken in connection with the accompanying drawings
in which:
[0022]
FIG. 1 shows a general construction of a thermal transfer printer according to a first
embodiment of the present invention;
FIG. 2 shows a general construction of an ink ribbon;
FIG. 3 is a block diagram showing an electrical constitution of the thermal transfer
printer;
FIG. 4 is a flowchart of laminate processing;
FIG. 5 is a block diagram showing an electrical constitution of a thermal transfer
printer according to a second embodiment of the present invention; and
FIG. 6 is a flowchart of laminate processing according to the second embodiment of
the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Hereinafter, preferred embodiments of the present invention will be described with
reference to the drawings. As shown in FIG. 1, a thermal transfer printer 100 according
to a first embodiment of the present invention includes a paper holder 140, a paper
conveyance mechanism 110, an ink ribbon conveyance mechanism 150, and a thermal head
130. The thermal transfer printer 100 is connected with a host computer (not shown),
and performs image recording on the basis of image data sent from the host computer.
[0024] The paper holder 140 can hold a rolled long paper 141. The paper 141 held by the
paper holder 140 is conveyed through a paper conveyance path 116 to the paper conveyance
mechanism 110.
[0025] The paper conveyance mechanism 110 includes, in the order from the upstream of the
paper conveyance path 116, a feed roller 111 and a pinch roller 112; a platen roller
113 disposed so as to be opposed to the thermal head 130; and a discharge roller 114
and a pinch roller 115. The paper 141 taken out from the paper holder 140 into the
paper conveyance path 116 is pinched by the feed roller 111 and the pinch roller 112;
passes between the thermal head 130 and the platen roller 113; and is pinched by the
discharge roller 114 and the pinch roller 115. The paper 141 thus conveyed is properly
cut by a not-shown cutter disposed further downstream. The feed roller 111, the platen
roller 113, and the discharge roller 114 are driven to rotate by a paper conveyance
motor 119 (see FIG. 3) such as a stepping motor. When the paper conveyance motor 119
drives the feed roller 111, the platen roller 113, and the discharge roller 114 to
rotate clockwise, the paper 141 is conveyed in the direction of an arrow F. When the
motor 119 drives the rollers to rotate counterclockwise, the paper 141 is conveyed
in the direction of an arrow R.
[0026] The ink ribbon conveyance mechanism 150 includes a feed roller 121, guide rollers
123 and 124, and a take-up roller 122. Both end portions of an ink ribbon 120 are
wound on the feed roller 121 and the take-up roller 122, respectively. The take-up
roller 122 is driven to rotate by an ink ribbon conveyance motor 129 (see FIG. 3)
such as a DC motor. When the take-up roller 122 is rotated clockwise, the ink ribbon
120 is conveyed in the direction of an arrow
f with being taken up on the take-up roller 122.
[0027] As shown in FIG. 2, the ink ribbon 120 includes a long base film 120a; and dye layers
120Y, 120M, and 120C for colors of yellow, magenta, and cyan, and transparent films
120F for lamination, applied on the base film 120a. The dye layers 120Y, 120M, and
120C and the transparent films 120F are repeatedly arranged longitudinally of the
base film 120a in that order. The dye layers 120Y, 120M, and 120C are made of dyes
that sublimate by heat, so that gradation printing in which the printing levels are
changed can be performed by temperature control of the thermal head 130. Thus, a high-quality
color image is formed on the paper 141. In addition, as will be described later in
detail, a transparent film 120F is transferred by heat of the thermal head 130 onto
the paper 141 on which a color image has been formed, and thereby lamination is performed
to protect the surface of the paper 141 from moisture and oil. The transmissivity
of the transparent film 120F may be various.
[0028] The thermal head 130 includes a substrate (not shown) and a plurality of heating
elements (not shown) disposed on the substrate. The thermal head 130 is vertically
moved by a head drive motor 139 (see FIG. 3) to be pressed onto and separated from
the platen roller 113. In an image formation region between the thermal head 130 and
the platen roller 113, each color dye of the ink ribbon 120 is transferred onto the
paper 141 to form a color image.
[0029] On the downstream side of the thermal head 130 in the direction F, a peeling plate
131 is provided to peel off the ink ribbon 120 from the paper 141. The peeling plate
131 comes into contact with the upper surface of the ink ribbon 120 from which dyes
have been transferred onto the paper 141 by the thermal head 130. The peeling plate
131 then separates the ink ribbon 120 from the paper conveyance path 116.
[0030] Next, an electrical constitution of the thermal transfer printer 100 will be described
with reference to FIG. 3. As shown in FIG. 3, the thermal transfer printer 100 includes
frame memories 21Y, 21M, and 21C; a color controlling DSP (digital signal processor)
22; a head signal converting ASIC (application specific integrated circuit) 24; a
CPU (central processing unit) 10 for controlling the operation of each part of the
thermal transfer printer 100; a ROM (read only memory) 11 storing therein a control
program to be executed by the CPU 10 and data to be used in the control program; and
a RAM (random access memory) 12 for temporally storing data in execution of the program.
[0031] The frame memories 21Y, 21M, and 21C store image data of one frame for the respective
colors of yellow, magenta, and cyan, sent from the host computer. Under the control
of the CPU 10, the color controlling DSP 22 performs control such as correction for
data of each color of yellow, magenta, and cyan, sent from the frame memories 21Y,
21M, and 21C. The color controlling DSP 22 includes a random pattern data generating
module 23 that generates random pattern data to be used for transfer of a transparent
film 120F. The random pattern data generating module 23 includes a random number generating
section 23a, a tone data obtaining section 23b, and a transferring section 23c. The
functions of those sections 23a, 23b, and 23c will be described later in detail with
reference to the flow of FIG. 4. The head signal converting ASIC 24 has therein buffers
for two lines, and data for two lines transferred from the color controlling DSP 22
are written in respective line buffers 1 and 2. The CPU 10 reads out the data written
in the line buffers 1 and 2. In addition, by referring to a head voltage table stored
in the ROM 11, the CPU 10 sets a voltage to be supplied to a heat sensitive element
of the thermal head 130. Further, the CPU 10 controls the head signal converting ASIC
24 so that the voltage data is supplied to the thermal head 130 at a predetermined
timing. On the basis of the voltage data thus supplied, the thermal head 130 transfers
onto the paper 141 each of the dye layers 120Y, 120M, and 120C on the ink ribbon 120
to form a color image. Afterward, the thermal head 130 further transfers a transparent
film 120F onto the paper 141 on which the color image has been formed, to perform
lamination.
[0032] Next, laminate processing will be described with reference to FIG. 4. The following
process is performed under the control of the CPU 10.
[0033] First, the random number generating section 23a of the random pattern data generating
module 23 generates a pseudorandom number (S1). By referring to a corresponding table
stored in the ROM 11, the tone data obtaining section 23b obtains tone data corresponding
to the pseudorandom number generated in S1 (S2). Afterward, the transferring section
23c transfers to the head signal converting ASIC 24 the tone data obtained in S2 (S3).
[0034] In this embodiment, the tone data is constituted by four values of "0", "1", "2",
and "3", one of which is determined for each dot. In the order of '0", "1', "2", and
"3", the voltage increases that is to be supplied to the heat sensitive element of
the thermal head 130, so as to increase the thickness of the transparent film 120F
to be transferred. The processes of S1 to S3 are performed for each dot, and tone
data of each dot of one line is sequentially written in one of the line buffers 1
and 2.
[0035] After S3, it is judged whether or not tone data of one line has been transferred
to the head signal converting ASIC 24 (S4). When the tone data of one line has not
yet been transferred (S4: NO), the flow returns to S1 to repeat the processes of S1
to S3 till the tone data of one line is transferred. When the tone data of one line
has been transferred (S4: YES), a transparent film 120F is transferred by using the
tone data written in one of the line buffers 1 and 2 in which the tone data was transferred
in S1 to S3 (S5).
[0036] It is then judged whether or not transfer of N lines corresponding to the whole surface
of the paper 141 is completed (S6). When the transfer of N lines is not yet completed
(S6: NO), the flow returns to S1. In the subsequent processes of S1 to S5, the line
buffer to be used is changed; tone data is transferred to the other line buffer; and
a transparent film 120F is transferred by using the data. When the transfer of N lines
is completed (S6: YES), this laminate process is ended.
[0037] As described above, in the thermal transfer printer 100 of this embodiment, the data
concerning the transfer pattern of a transparent film 120F is not externally sent
and stored in a memory but generated in the random pattern data generating module
23. Therefore, there is no necessity of providing a dedicated memory for storing the
data, which is advantageous in cost.
[0038] Because the data for not the whole but only a part of the surface of the paper 141
(data of one line in this embodiment) is repeatedly generated, the generating process
of the transfer pattern data can be simplified and the time for the process can be
shortened.
[0039] In addition, because data of one line is repeatedly generated, two line buffers provided
in the head signal converting ASIC 24, which are used in image formation by each color
of yellow, magenta, and cyan, can be used for lamination. There is no necessity of
adding a new component, and therefore the construction can be simplified.
[0040] Because the color controlling DSP 22 to be used in image formation by each color
of yellow, magenta, and cyan includes the random pattern data generating module 23,
and therefore the color controlling DSP 22 can be used in lamination, there is no
necessity of adding a new component.
[0041] The image forming apparatus of this embodiment is the thermal transfer printer 100
having the thermal head 130. The problem that a dedicated memory must be provided
for storing pattern data for transparent film lamination is particularly remarkable
in such a thermal transfer type image forming apparatus. In this embodiment, therefore,
because the problem is dissolved, a more practical effect is obtained.
[0042] A second embodiment of the present invention will be described. First, an electrical
constitution of a thermal transfer printer 100 will be described with reference to
FIG. 5. In this embodiment, the same components as in FIG. 3 are denoted by the same
reference numerals as in FIG. 3, respectively, and the description thereof will be
omitted. As shown in FIG. 5, a color controlling DSP 32 includes a random pattern
data generating module 33 that generates random pattern data to be used for transfer
of a transparent film 120F. The random pattern data generating module 33 includes
a random number generating section 33a, a tone data obtaining section 33b, an image
processing section 33c, and a transferring section 33d. The functions of those sections
33a, 33b, 33c, and 33d will be described later in detail with reference to the flowchart
of FIG. 6.
[0043] Next, laminate processing will be described with reference to FIG. 6. The following
process is performed under the control of the CPU 10.
[0044] First, the random number generating section 33a of the random pattern data generating
module 33 generates the same number of pseudorandom numbers as the number of pixels
of one frame (S11). By referring to a corresponding table stored in the ROM 11, the
tone data obtaining section 33b obtains tone data corresponding to the pseudorandom
numbers generated in S11 (S12).
[0045] Further, the image processing section 33c applies image processing to the tone data
of one frame obtained in S12 (S13). As image processing in this step, any of various
known image processes, such as embossment and edge enhancement, may be performed.
Afterward, the transferring section 33d transfers to the head signal converting ASIC
24 tone data of one pixel to which image processing was applied in S13 (S14). The
tone data of one pixel transferred to the head signal converting ASIC 24 is written
in one of two line buffers (the line buffers 1 and 2). When the one line buffer becomes
full, the subsequent tone data is written in the other line buffer. Thus, the tone
data is alternately written in the two line buffers.
[0046] After S14, it is judged whether or not tone data of one line has been transferred
to the head signal converting ASIC 24 (S15). When the tone data of one line has not
yet been transferred (S15: NO), the flow returns to S14 to repeat the process of S14
till the tone data of one line is transferred. When the tone data of one line has
been transferred (S15: YES), a transparent film 120F is transferred by using the tone
data written in one of the line buffers 1 and 2 in which the tone data was transferred
in S14 (S16).
[0047] It is then judged whether or not transfer of N lines corresponding to the whole surface
of the paper 141 is completed (S17). When the transfer of N lines is not yet completed
(S17: NO), the flow returns to S14. In S14, the line buffer for storing data is changed;
tone data is transferred to the other line buffer; and a transparent film 120F is
transferred by using the data. When the transfer of N lines is completed (S17: YES),
this laminate process is ended.
[0048] Also in this embodiment, like the first embodiment, the data concerning the transfer
pattern of a transparent film 120F is not externally sent and stored in a memory but
generated in the random pattern data generating module 33. Therefore, there is no
necessity of providing a dedicated memory for storing the data, which is advantageous
in cost.
[0049] In addition, because the color controlling DSP 32 to be used in image formation by
each color of yellow, magenta, and cyan includes the random pattern data generating
module 33, and therefore the color controlling DSP 32 can be used in lamination, there
is no necessity of adding a new component.
[0050] Further, the tone data generated in the random pattern data generating module 33
is processed with embossment or edge enhancement by the image processing section 33c.
Therefore, a wide variety of mat prints can be realized. When the tone data is random
pattern data as in this embodiment, the change in the unevenness of the random pattern
can be made smooth; or a mat print having a three-dimensional appearance (a feeling
of roughness) can be made by enhancing the difference in the unevenness.
[0051] The above-described embodiments can be variously changed in design. For example,
in the above-described embodiments, the thermal transfer printer 100 records an image
in accordance with image data sent from a host computer (not shown). However, the
present invention is not limited to that. For example, the thermal transfer printer
100 may record an image in accordance with image data read out from a memory card
via a memory card interface.
[0052] In the above-described embodiments, a random pattern is used for the transfer pattern
of a transparent film 120F. However, not such a random pattern but a pattern may be
used in which unevenness is regularly formed at regular intervals (for example, a
checkered pattern). On the other hand, a transparent film 120F may be transferred
not in an uneven pattern but in a uniform thickness. In this case, fixed tone data
may be used. Further, lamination may be performed not over the whole surface but only
part of the surface of the paper 141.
[0053] The thermal transfer printer 100 may have an operation panel operable by an operator
so that a transfer pattern of a transparent film 120F is determined in accordance
with an input through the operation panel.
[0054] In the above-described embodiments, the random pattern data generating module 23
repeatedly generates data of one line. However, the present invention is not limited
to that. The random pattern data generating module 23 may generates data for the whole
surface, a half surface, or the like, of the paper 141. On the other hand, generated
data may be repeatedly used.
[0055] In the above-described embodiments, the color controlling DSP 22 includes the random
pattern data generating module 23. However, the present invention is not limited to
that. In addition, the electrical constitution shown in FIG. 3 is by way of example,
and it can be variously changed.
[0056] Image formation apparatuses according to the present invention are never limited
to thermal transfer printers, and also applicable to inkjet printers and so on. In
addition, the present invention is not limited to such printers, and also applicable
to facsimiles, copying machines, and so on. Further, the paper is not limited to a
wound long paper, and cut papers cut in advance into a predetermined length may be
used.
1. An image forming apparatus
characterized by comprising:
a conveyance mechanism that conveys a recording medium;
a recording head that records an image in accordance with image data on the recording
medium being conveyed by the conveyance mechanism, and transfers a transparent film
on the recording medium on which the image has been recorded;
a data generating unit that generates data concerning a transfer pattern of the transparent
film; and
a controller that controls the recording head so that the transparent film is transferred
on the basis of the data generated in the data generating unit.
2. The image forming apparatus according to claim 1, characterized in that the data generating unit repeatedly generates data concerning a partial transfer
pattern of the transparent film to be transferred onto the whole surface of the recording
medium.
3. The image forming apparatus according to claim 2, characterized in that the data generating unit repeatedly generates data of one line.
4. The image forming apparatus according to any of claims 1 to 3, characterized in that a color controlling unit that controls colors of the image to be recorded on the
recording medium has the function of the data generating unit.
5. The image forming apparatus according to claim 1, characterized in that the data generating unit includes an image processing unit, and
the data concerning the transfer pattern generated by the data generating unit is
processed by the image processing unit.
6. The image forming apparatus according to any of claims 1 to 5, characterized in that the recording head is a thermal head that transfers inks carried on a ink ribbon
to record an image on the recording medium, and transfers a transparent film carried
on the ink ribbon subsequently to the inks onto the recording medium on which the
image has been formed with the inks.
7. An image forming method in which an image is recorded on a recording medium in accordance
with image data and transparent film is transferred onto the recording medium on which
the image has been recorded,
characterized by comprising:
a data generating step of generating data concerning a transfer pattern of the transparent
film; and
a controlling step of controlling a recording head so that the transparent film is
transferred on the basis of the data generated in the data generating step.
8. The image forming method according to claim 7, characterized in that data concerning a partial transfer pattern of the transparent film to be transferred
onto the whole surface of the recording medium is repeatedly generated in the data
generating step.
9. The image forming method according to claim 8, characterized in that data of one line is repeatedly generated in the data generating step.
10. The image forming method according to claim 7, characterized in that the data generating step includes an image processing step, and
the data concerning the transfer pattern generated in the data generating step is
processed in the image processing step.