United States Patent
`
`[19]
`
`[11] Patent Number:
`
`4,838,713
`
`[45] Date of Patent:
`Kunimitsu et al.
`Jun. 13, 1989
`
`[54] THERMAL TRANSFER PRINTER HEAD
`POSITION HOMING MECHANISM
`
`[75]
`
`Inventors: Michio Kunimitsu, Yawata; Hiroshi
`Tomita, Tsuzuki; Akio Akao; Hiroshi
`Kano, both of Osaka, all of Japan
`
`[73] Assignee:
`
`Sanyo Electric Ltd., Osaka, Japan
`
`[21] Appl. No.: 897,382
`
`[22] Filed:
`
`Aug. 18, 1986
`
`Foreign Application Priority Data
`[30]
`Aug. 20, 1985 [JP]
`Japan ......................... .. 60-l26653[U]
`Dec. 16, 1985 [JP]
`Japan ........................... 60-193974[U]
`
`Int. Cl.4 .............................................. .. B4lJ 3/20
`[51]
`[52] U.S. Cl. .............................. .. 400/120; 346/76 PH
`[58] Field of Search ............................... 400/120, 356;
`346/76 PH
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`8/1985 lsogai .............
`
`3,848,720 11/1974 Carlsen ................................ 400/120
`4,458,253
`7/1984 Goff, Jr. et al.
`..
`4,536,772
`. 400/120
`1/1986 Negita et al.
`4,563,692
`. . .. .. 400/120
`4,625,218 11/1986 Watanabe . ... . .
`.. 400/120
`4,657,417 4/1987 Kikuchi et al.
`4,705,414 ll/1987 Guy et al.
`........................... 400/120
`FOREIGN PATENT DOCUMENTS
`
`184685 10/1984 Japan ................................. .. 400/120
`155485
`8/1985 Japan ................................. .. 400/120
`
`Primary Examt'ner—-David A. Wiecking
`Attorney, Agent, or Fz'rm——James D. Hall; Thomas J.
`Dodd; Todd A. Dawson
`
`ABSTRACT
`[57]
`The thermal transfer printer of the present invention is
`provided with a cam follower mounted on a thermal
`transfer head in one body and an eccentric cam, which
`is controlled within a semicircle so as to be positioned at
`either a first position for releasing it from the cam fol-
`lower to press the thermal transfer head to a platen or a
`second position for pressing it to release the thermal
`transfer head from the platen, as a construction for
`pressing the thermal transfer head to the platen and
`releasing the thermal transfer head from the platen,
`whereby the mechanism for pressing the thermal trans-
`fer head to the platen and releasing the thermal transfer
`head from the platen itself can be remarkably small-
`sized and is simple in action due to its remarkably small
`working quantity, the printer can be small-sized as a
`whole and improved in reliability of operation as well as
`durability. Furthermore, the thermal transfer printer
`can be stably carried out the subsequent controls after
`initial powering, since the positional relation between
`the thermal transfer head and the platen is controlled so
`as to be initially set to the predetermined relation with-
`out delay when it is initially powered.
`
`58-140266
`
`8/1983 Japan ................................. .. 400/236
`
`6 Claims, 16 Drawing Sheets
`
`Esselte Exhibit 1007
`Page 1
`
`Esselte Exhibit 1007
`Page 1
`
`

`
`U.S. Patent
`
`Jun. 13,1989
`
`Sheet 1 of 16
`
`4,838,713
`
`' Esselte Exhibit 1007
`Page 2
`
`Esselte Exhibit 1007
`Page 2
`
`

`
`U.S. Patent
`
`Jun. 13,1989
`
`Sheet2 of 16
`
`4,838,713
`
`\.‘ii............i...N.:.................:.....E....=.....................~:...
`
`Esselte Exhibit 1007
`Page 3
`
`Esselte Exhibit 1007
`Page 3
`
`

`
`‘E....~.....=.....~=.~.E‘...............:....:..‘..................:‘..=......."0.
`
`U
`In
`0::
`
`Esselte Exhibit 1007
`Page 4
`
`US. Patent
`
`Jun. 13, 1989
`
`Sheet 3 of 16
`
`0Q
`
`
`
`om~wwo_oo_._
`
`8
`
`Na
`
`N_.
`
`mam
`
`Esselte Exhibit 1007
`Page 4
`
`
`

`
`US. Patent
`
`Jun. 13,1989
`
`Sheet 4 of 16
`
`4,838,713
`
`Esselte Exhibit 1007
`Page 5
`
`Esselte Exhibit 1007
`Page 5
`
`

`
`US. Patent
`
`Jun. 13,1989
`
`Sheet 5 of 16
`
` 4,838,713
`
`Hlllllllllll
`A1 5
`5...
`
`-
`
`" «
`figK‘ &‘{n{ w’:
`—7 ll“'32.: A.
`n‘\n\\\\\\‘\‘¢
`
`Fig.5
`
`Esselte Exhibit 1007
`Page 6
`
`Esselte Exhibit 1007
`Page 6
`
`

`
`US. Patent
`
`Jun. 13,1989
`
`Sheet 6 of 16
`
`4,838,713
`
`Esselte Exhibit 1007
`Page 7
`
`Esselte Exhibit 1007
`Page 7
`
`

`
`U.S. Patent
`
`Jun. 13,1989
`
`Sheet 7 of 16-
`
`4,838,713
`
`Fig.7’
`
`Esselte Exhibit 1007
`Page 8
`
`Esselte Exhibit 1007
`Page 8
`
`

`
`U.S. Patent
`
`Jun.13, 1989
`
`Sheet 3 of 16
`
`4,838,713
`
`‘Fig.8
`
`65646l2
`
`E-sselte Ex '
`
`' 1007
`age 9
`
`Esselte Exhibit 1007
`Page 9
`
`

`
`U.S. Patent
`
`Jun. 13,1989
`
`Sheet 9 of 16
`
`4,838,713
`
`Fig.9
`
`9
`
`KEY BOARD
`
`CONTROL
`
`9
`
`UNIT
`
`INTERFACE
`
`ISI SENSOR
`
`60
`
`2nd SENSOR
`
`9
`
`3rd SENSOR
`
`I02
`
`COLOR
`SENSOR
`
`CAM POSITION
`SENSOR
`
`LIGHT
`SOURCE
`
`“I
`
`Tl
`
`H 0
`
`DRIVING SYSTEM
`FOR PLAT EN
`
`0‘) U
`
`DRIVING SYSTEM
`FOR PAPER
`CARRER ROLLER
`
`I8D
`
`DRIVING MOTOR
`FOR INK SHEET
`CARRIER ROLLER
`
`DRIVING MOTOR
`FOR EOCENTRIC
`CAM
`
`30
`
`93
`
`Esselte Exhibit 1007
`Page 10
`
`Esselte Exhibit 1007
`Page 10
`
`

`
`U.S. Patent
`
`Jun. 13, 1989
`
`Sheet 10 of 16
`
`4,838,713
`
`Fig .
`
`I 0
`
`INITIAL POSITION
`SETTING OF CAM
`
`S
`
`CAM POSITI
`SENSOR = “I "
`?
`
`TURN CAM CLOCKWISE
`BY 6 I
`
`CAM POSITIO
`SENSOR = “ I "
`7
`
`
`
`TURN CAM
`
`COUNTER CLOCKWISE
`
`CAM POSITION
`SENSOR =~‘ I ”
`?
`
`STOP CAM
`
`TURN CAM CLOCKWISE
`
`
`
`
`
`
`
`
`
`sENsoR=“o”
`
`YES
`
`7 '
`
`TURN CAM CLOCKWISE
`
`S9
`
`av e2
`
`Esselte Exhibit 1007
`Page 11
`
`Esselte Exhibit 1007
`Page 11
`
`

`
`. US. Patent
`
`Jun. 13,1989
`
`Sheet 11 of 16
`
`4,838,713
`
`Figll |(c1)
`
`ls? POSITION
`
`7
`
`2nd POSITION
`
`9S
`
`683
`st
`
`Fig.l|(b)
`
`688
`
`SI
`
`s7
`
`_
`Is? POSITION
`
`33
`
`32
`
`’
`
`Fig .I I (c)
`
`I sf PO§.lT|ON
`
`I/
`
`37
`
`2nd POSITION
`
`S8
`
`S9
`
`%
`
`2nd POSITION
`
`83
`
`3
`S4
`
`’.
`
`SI
`
`89
`
`S
`
`68
`
`S5,S6,S7,S8
`
`Esselte Exhibit 1007
`Page 12
`
`Esselte Exhibit 1007
`Page 12
`
`

`
`US. Patent
`
`Jun. 13,1989
`
`Sheet 12 of 16
`
`4,838,713
`
`Fig. I2
`
`PRESSlNG OF HEAD
`
`TURN CAM
`COUNTERCLOCKW ISE
`
`
`
`Sll
`
`
`
`
`
`
`S12
` CAM POSIIION
`SENSOR = "I
`
`
`
`- YES
`
`TURN CAM
`
`COUNTERCLOCKWISE
`
`SI3
`
`S I4
`
`AM POSITLON
`SENSOR ="o
`?
`
`YES
`
`TURN CAM COUNTER-
`CLOCKWISE BY 92
`
`Sl5
`
`END
`
`Esselte Exhibit 1007
`Page 13
`
`Esselte Exhibit 1007
`Page 13
`
`

`
`U.S. Patent
`
`Jun. 13, 1989
`
`Sheet 13 of 16
`
`4,838,713
`
`Fig.1?)
`
`
`
`DETACHING OF HEAD
`
`
`
`
`TURN CAM CLOCKWISE
`
`S2|
`
`S22
`
`CAM POSITION
`SENSOR= "1"
`
`YES
`
`TURN CAM CLOCKWISE
`
`S23
`
`S24
`
`CAM POSITIHON
`SENSOR= "o
`?
`
`YES
`
`TURN CAM
`CLOCKWISE BY 92
`
` 825
`
`END
`
`Esselte Exhibit 1007
`Page 14
`
`Esselte Exhibit 1007
`Page 14
`
`

`
`A,U.S. Patent
`
`Jun. 13,1989
`
`Sheet 14 of 16
`
`4,838,713
`
`Fig. I4
`
`INITIAL POSITION
`SETTING OF PAPER
`
`SET CAM AT
`Isf POSITION
`
`S3l
`
`
`
`
`
`INDICATE "PAPER OUT"
`
`YES
`
`3rd SENSOR
`
`___ ulu ,?
`
`Yes
`
`835
`
`S37
`
`CARRY PAPER AND INK SHEET
`TO PRINTING POSITION
`
`Esselte Exhibit 1007
`Page 15
`
`YES
`
`S33
`
`2nd SENSOR
`= nlu
`
`
`
`
`
`D 534
`
`PAPER CARRYING
`
`SWlTC?H=ON
`YES
`
`CARRY PAPER AND
`
`INK SHEET
`
`Esselte Exhibit 1007
`Page 15
`
`

`
`U.S. Patent
`
`Jun. 13, 1989
`
`Sheet 15 of 16
`
`4,838,713
`
`FTg.l5
`
`POSITION ADJUSTNENT
`OF INK SHEET
`
`SET CAM AT
`2nd
`POSITION
`
`34‘
`
`CARRY WK SHEET
`BACKWARDLY BY LENGTH
`OF PAPER CARRIED
`
`342
`
`843
`
`344
`
`345
`
`848
`
`TURN ON LIGHT SOURCE
`
`DRIVE MOTOR
`
`STEP BY I
`
`
`
`
`S 45
`
`PREDETERMINED
`COLOR ?
`
`NO
`
`BY I
`
`STEP
`
` omvE MOTOR
` S47
`
`PREDETERMINED
`
`COLOR ’?
`
`
`YES
`
`TURN OFF LIGHT SOURCE
`
`END
`
`Esselte Exhibit 1007
`Page 16
`
`Esselte Exhibit 1007
`Page 16
`
`

`
`US. Patent
`
`Jun. 13, 1989
`
`Sheet 16 of 16
`
`4,838,713
`
`Fig.
`
`I 6
`
`
`
`BACKWARD WIN DING
`OF PAPER
`
`SET CAM AT
`2nd POSFHON
`
`S5!
`
`
`
`
`
`CARRY RAPER BACKW%RDLY S52
`BY PREDETERMWEDLENGTH
`
`2nd SENSOR
`
`/I
`
` 3rd SENSOR
`=1?
`\\//
`
`
`
`Esselte Exhibit 1007
`Page 17
`
`Esselte Exhibit 1007
`Page 17
`
`

`
`1
`
`4,838,713
`
`THERMAL TRANSFER PRINTER HEAD
`POSITION HOMING MECHANISM
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`This invention relates to a thermal transfer printer for
`color printing and, in particular, to a thermal transfer
`printer for color printing on a recording paper by using
`an ink sheet having sequential segments of ink of three
`primary colors or four colors including black.
`2. Description of the Prior Art
`A thermal transfer printer used as an output printer in
`the computer system, word-processor, and the like is
`readily capable of color printing the application of ink
`of several different colors to the same page of the same
`printing medium. Thus, such a printer can be used for
`outputting such data as displayed by the so-called com-
`puter graphics or to produce multi-color images.
`A thermal transfer printer capable of color printing as
`described above has been disclosed in, for example, the
`Japanese Patent, Laid-open No. 58-140266 (1983).
`In the thermal transfer printer such as above, gener-
`ally, an ink sheet having sequential segments of ink in
`four colors including three primary colors (yellow,
`magenta, and cyan) and black and a recording paper are
`put one upon another and carried to a contact position
`between a thermal transfer head and the platen so that
`all colors of ink are thermally transferred to the record-
`ing paper in succession. Each time that printing in one
`color is completed, the recording paper is reversed,
`then brought forward and again printed in the succeed-
`ing color on the same page as that previously printed,
`the repeat of such process providing multi-color print-
`ing.
`However, with a thermal transfer printer of this type,
`it is necessary to press a thermal transfer head to a
`platen or release the thermal transfer head from the
`platen very frequently in comparison with a usual
`printer. In such prior art printers, the head is pressed to
`the platen when a recording paper is first set on the
`printer to carry out the initial position setting of the
`recording paper relative to the thermal transfer head
`and then a predetermined color of an ink sheet is set to
`a printing position or when the recording paper is car-
`ried in the backward direction after completing the
`printing with an ink of one color.
`However, with the above described conventional
`example,
`the mechanism comprises a first lever for
`pressing the thermal transfer head to the platen by a
`biasing force of a spring and a second lever for releasing
`the thermal transfer head from the platen by the action
`of an electro-magnetic solenoid. Accordingly, with
`such the conventional construction,
`the construction
`itself is complicated and the size and weight of each
`lever and the like is large, so that it is difficult to reduce
`the size of the printer as a whole and the printer has
`problems with respect to reliability and durability.
`In addition, since the positional relation between the
`thermal transfer head and the platen is unstable directly
`after the printer is switched on, various kinds of prob-
`lem occur in the subsequent controls. Accordingly, it is
`desired to instantly control the positional relation be-
`tween the thermal transfer head and the platen to the
`predetermined initial condition when the printer is ini-
`tially powered and carry out the subsequent controls
`with this initial condition as a basic state for control.
`
`5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`65
`
`2
`This is accomplished by the provision of mechanisms
`for pressing the thermal transfer head to the platen and
`releasing the thermal transfer head from the platen with
`a very simple structure of reduced size and weight,
`being more economical to produce and of a high reli-
`ability and durability.
`SUMMARY OF THE INVENTION
`
`The present invention is intended to overcome the
`problem described above and it is a primary object of
`the present
`invention to provide a thermal
`transfer
`printer with a mechanism for pressing a thermal transfer
`head to a platen and separating the thermal transfer
`head from the platen which can reliably operate with a
`simple structure and a reduced size and which has de-
`sired duability. This is achieved by the provision of a
`mechanism whereby the thermal
`transfer head is
`pressed to the platen and released from the platen by the
`rotation of an eccentric cam.
`It is another object of the present invention to pro-
`vide a thermal transfer printer capable of reliably carry-
`ing out the subsequent controls by importing the con-
`trol function of initially setting the positional relation
`between the thermal transfer head and the platen di-
`rectly after being powered to the predetermined rela-
`tion without delay.
`The thermal transfer printer of the invention is pro-
`vided with a thermal transfer head on which a series of
`heating elements arranged in parallel to an axial direc-
`tion of a platen, supported so as to be brought into
`contact with said platen or released from said platen,
`and a biasing member for biasing said thermal transfer
`head to be pressed to said platen, characterized by com-
`prising an eccentric cam rotationally controlled so as to
`be positioned at either a first position, at which said
`thermal transfer head is pressed to said platen, or a
`second position, at which said thermal transfer head is
`released from said platen; and a cam follower being
`mounted on and rotating together with said thermal
`transfer head, which is released from a cam surface to
`press said thermal transfer head to said platen by the ‘
`biasing force of said biasing member when said eccen-
`tric cam is positioned at the first position and pressed by
`the cam surface to release said thermal transfer head
`from said platen when said eccentric cam is position at
`the second position.
`The above and further objects and features of the
`invention will more fully be apparent from the follow-
`ing detailed description with accompanying drawings.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a perspective view showing the appearance
`of a thermal transfer printer of this invention;
`FIGS. 2 and 3 are sectional side views showing the
`mechanical structure thereof;
`FIG. 4 is a fragmentary perspective of a structure of
`carrying system for the ink sheet;
`FIG. 5 is an plan view thereof;
`FIG. 6 is a fragmentary perspective view of a struc-
`ture of a thermal transfer head and nearby parts, the
`major part being an eccentric cam for pressing and
`releasing the thermal transfer head to and from the
`platen;
`FIGS. 7 and 8 are side views thereof;
`FIG. 9 is a block diagram showing a structure of a
`control system of the thermal transfer printer of this
`invention;
`
`Esselte Exhibit 1007
`Page 18
`
`Esselte Exhibit 1007
`Page 18
`
`

`
`4,838,713
`
`3
`FIG. 10 is a flow chart showing the sequence for
`initialization of positioning of cam by a control unit;
`FIGS. 11a—c is a model view showing a position of
`cam for explanation of the above sequence;
`FIG. 12 is a flow chart showing the control sequence 5
`in pressing the thermal transfer head of the platen by
`means of the control unit;
`FIG. 13 is a flow chart showing the control sequence
`in releasing the thermal transfer head from the platen by
`means of the control unit;
`FIG. 14 is a flow chart showing the control sequence
`for initialization of position of the recording paper by
`means of the control unit;
`FIG. 15 is a flow chart showing the control sequence
`for adjustment of position of the ink sheet by means of 15
`the control unit; and
`FIG. 16 is a flow chart showing the control sequence
`for backward carrying of the recording paper by means
`of the control unit after completing the printing with
`one color.
`
`10
`
`20
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`
`A description of this invention will be made with
`reference to the drawings showing the preferred em- 25
`bodiment of this invention.
`
`35
`
`FIG. 1 is a perspective view showing the appearance
`of a thermal transfer printer of this invention. Mechani-
`cal structural elements of the thermal transfer printer of
`this invention are contained in a roughly box-like casing 30
`120. The printer is provided with a main switch 122
`disposed on the upper rear end of the casing 120, an
`indication part 123 having various indicators, a key
`board 92 having various instruction keys disposed on
`the front right side, and a cover 121 for covering the
`central portions of the upper front sides throughout. An
`outlet 125 for the printed recording paper is provided in
`the upper surface of cover 121.
`FIGS. 2 and 3 are sectional side views of a mechani-
`cal structure of the thermal transfer printer of this in-
`vention, showing a condition in which the thermal
`transfer head 5 and the platen 6 are pressed to each
`other and the other condition in which an upper part
`including the platen 6 is opened.
`The main component members of this thermal trans-
`fer printer are fixed to a pair of stationary side plates 80
`and 80 suitably fixed to the interior of the casing 120
`upright on the right and left sides to be parallel with
`each other and also to a pair of movable side plates 82
`and 82 lying above the stationary side plates 80 and 80
`to be parallel with each other along the front-to-back
`direction (the direction of carrying the ink sheet 2 and
`the recording paper 13 as will be described later), being
`pivotally fixed to the stationary side plates 80 and 80.
`Between the stationary side walls 80 and 80 and near
`the rear ends thereof (the right side on every drawings),
`is provided a supply roll 1 having the ink sheet 2 wound
`therearound; at the central parts of the stationary plates
`80 and 80, a bracket 60 having the thermal transfer head
`5 fixed thereto; at the front upper parts (the left side on
`every drawing), a take-up roll 11 for the ink sheet 2; in
`a position between the bracket 60 and the take-up roll
`11, an ink sheet carrier roller 8 for carrying the ink sheet
`2; and at the lower central parts of the stationary plates
`80 and 80, a cam supporting shaft 70 being fixed an
`eccentric cam 68 whose rotational center lies on a pivot
`of a segment. Further provided are: a guide shaft 3 for
`the ink sheet 2 and a first head guide shaft 4 between the
`
`45
`
`50
`
`55
`
`65
`
`4
`ink sheet supply roll 1 and the platen 6; a second head
`guide shaft 7 between the platen 6 and the ink sheet
`carrier roller 8; and a guide shaft 10 between the ink
`sheet carrier roller 8 and the take-up roll 11.
`The ink sheet carrier 8 is driven by an electric driving
`motor 30 as will be described later (see FIGS. 4 and 5).
`The rotational speed of roller 8 for carrying ink sheet 2
`is synchronized with the carrying speed for the record-
`ing paper 13 as will be described later.
`The movable side plates 82 and 82 are pivotally sup-
`ported at one end thereof at an axis 81 of rotation pro-
`vided on the front upper parts of the aforesaid station-
`ary side plates 80 and 80. This permits the platen 6 and
`the thermal transfer head 5 to be pressed to each other
`with the other ends thereof turned backward in the
`normal state of operation. In other words, the movable
`side plates 82 and 82, when put into a state of use, are
`provided with: a recording paper roll 12 having the
`recording paper 13 wound therearound, disposed near
`the rear ends of the side plates (near the other ends of
`the casing 120); a slit-like sheet-inserting passage 15
`formed by guide plates 105 and 106 depending almost
`vertically from the guide shaft 14 in the middle portion
`of a space interposed between the movable side plates
`82 and 82; an upwardly directed recording paper dis-
`charging passage 20 formed by the second paper carrier
`roller 18 and the second pressing roller 19 facing each
`other so that the discharge passage is roughly parallel
`with the recording paper inserting passage 15; a platen
`6 in the form of a roller further serving as a first record-
`ing paper carrier roller disposed between the lower end
`parts of the inserting passage 15 and of the discharging
`passage 20, as well as a first pressing roller 17; and
`another pressing roller 9 disposed slighly behind the
`axis of rotation 81 lying on the front side.
`A pressing position of the first pressing roller 17
`against the platen 6, serving as the first carrier roller,
`lies on the upstream side along the carrying direction
`for the recording paper above a contact position pro-
`duced when the thermal transfer head 5 is pressed to the
`platen 6 (also a position of a line of heating elements of
`the thermal transfer head 5). Therefore, an acting posi-
`tion of carrying force exerted by the platen 6 as the first
`recording paper carrier roller upon the recording paper
`lies on the upstream side along the carrying direction
`for the recording paper 13 above the pressing position
`of the thermal transfer head 5 to the platen 6.
`The upper end of the inserting passage 15 and that of
`the discharging passage 20 lead to an inlet opening 15a
`for the recording paper 13 undergoing change of run-
`ning direction thereof at the guide shaft 14 and to an
`outlet 20a for discharging the recording paper 13
`toward a discharging opening 125 of the cover 121 of
`the casing 120, repectively.
`A positional relation between parts to be arranged
`when the printer is in use (a state as shown in FIG. 2) is
`fixed so that the pressing roller 9 and the ink sheet car-
`rier roller 8 on the side of the stationary side plates 80
`and 80 are pressed to each other at the sairie time that
`the platen 6, as the first recording paper carrier roller,
`and the thermal transfer head 5 are pressed to each
`other.
`
`A first sensor 1(1) is provided in a position relatively
`near the upper end (near insertion opening 15a) of the
`inserting passage 15; a third sensor 102, in a relatively
`lower position (near the platen 6) between the first
`sensor and the platen 6 in the insertion passage 15, and
`a second sensor 101, in a position relatively near the
`
`Esselte Exhibit 1007
`Page 19
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`Esselte Exhibit 1007
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`

`
`4,838,713
`
`5
`upper part (near discharging outlet 20a) of the discharg-
`ing passage 20. The first and the second sensors 100 and
`101 are photosensors for detecting whether the record-
`ing paper is present or not, and the third sensor 102 is a
`photosensor for detecting a mark indicating a printing
`start position impressed on the recording paper 13.
`The printing start position mark is used as a basis for
`setting a position from which printing with each color
`of the ink sheet 2 on the recording paper 13 is started.
`A color sensor 111 is fixed to the movable side plates
`82 and 82 at a position to intermediate platen 6 and ink
`sheet supply roll 1. Further, a light source 110 for the
`color sensor 111 is fixed at the position of the plate
`brackets 60 and 60 opposite the color sensor 111 and
`interposed by the carrying passage for the ink sheet 2.
`When the movable side plates 82 and 82 are turned
`counterclockwise around shaft 81 with the cover 121
`
`removed as shown in FIG. 3 to be put into an open
`state, the ink sheet supply roll 1 and the ink sheet 2 are
`exposed to a wide open space above the casing 120 and
`the ink sheet supply roll 1 is readily inserted or re-
`placed.
`When the movable side plates 82 and 82 are turned as
`described above, the platen 6 is displaced from its posi-
`tion adjacent the thermal transfer head 5. However,
`clockwise rotation of the thermal transfer head 5 by the
`spring 67 around shaft 63 is prevented by the contact of
`lower branch parts 62 and 62 of the plate brackets 60
`and 60 with cam supporting shaft 70. Accordingly,
`there is no possibility that the thermal transfer head 5
`may obstruct the movenent of side plates 82 and 82.
`FIGS. 4 and 5 are a fragmentary perspective view
`and a plan view, respectively, of a main parts compos-
`ing a carrying system for the ink sheet 2.
`The electric driving motor 30 used in this printer is a
`pulse motor capable of rotating in either direction and
`mounted with a spur gear 31 at the output shaft. The
`spur gear 31 meshes with another spur gear 32 fixed to
`a shaft 85 pivoted by the stationary side plates 80 and
`80. The shaft 8S in mounted with spur gears 34 and 33
`disposed in succession from a position near the spur
`gear 32 and a part thereof closer to the front end is
`formed of a larger diameter to work as an ink sheet
`carrier roller 8.
`A cogged belt 37 having teeth corrugated on its inner
`periphery is extended between the spur gear 33 and an
`idler gear 35 idly mounted on a shaft 35S fixed to the
`side plate 80 and spaced from the shaft 8S at an appro-
`priate distance. Another similar cogged belt 38 is ex-
`tended between the spur gear 34 and an idler gear 36
`idly mounted on a shaft 36S fixed to the side plate 80
`and spaced from the shaft 8S at an appropriate distance.
`The idler gear 35 is connected to an idler gear 41 idly
`mounted on the shaft common thereto through a spring
`clutch 39. Another idler gear 36 is connected to an idler
`gear 42 idly mounted on the shaft common thereto
`through a spring clutch 40.
`The spring clutch 39 transmits rotation of the idler
`gear 35 to the idler gear 41 only when the idler gear 35
`turns counterclockwise on FIG. 4. The spring clutch 40 -
`transmits rotation of the idler gear 36 to the idler gear
`’ 42 only when the idler gear 36 turns clockwise on FIG.
`4.
`
`The idler gears 41 and 42 mesh with idler gears 43
`and 44 idly fitted onto shafts 49 and 50 fixed to station-
`ary side plates 80 and spaced at appropriate distances
`from shafts 35S and 36S, respectively.
`
`6
`The idler gears 43 and 44 are provided with spring
`clutches 51 and 52 on the root sides of shafts 49 and 50,
`respectively. The spring clutch 51 operates for inter-
`cepting rotation of the idler gear 43 in the counterclock-
`wise direction on FIG. 4 whereas another spring clutch
`52 operates intercepting rotation of the idler gear 44 in
`the clockwise direction.
`
`l0
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`60
`
`65
`
`Friction rings 45 and 46 as well as holding reels 47
`and 48 for the ink sheet take-up roll 11 and for the ink
`sheet supply roll 1, respectively, are idly fitted on the
`front end sides of the idler gears 43 and 44 on the end
`parts of the shafts 49 and 50, respectively. Both reels 47
`and 48 press the friction rings 45 and 46 toward the idler
`gears 43 and 44 by means of coiled springs 47S and 48S
`provided for both reels, respectively.
`Performance of the driving system thus constructed
`for the carrying of the ink sheet 2 is fully described in
`our co-pending Application Ser. No. 897,193, and will
`not be described here.
`The structure around thermal transfer head 5 of the
`printer of this invention, particularly, a structure for
`adapting the printing head 5 to be pressed or to be re-
`leased from the platen 6 will be described with refer-
`ence to FIGS. 6, 7 and 8. FIG. 6 is a fragmentary per-
`spective view of the structure around the thermal trans-
`fer head 5; FIG. 7 is a side view showing a state in
`which the platen 6 and the thermal transfer head 5 are
`tightly pressed together with an eccentric cam 68 set in
`a first position; and FIG. 8 is a side view showing a state
`in which th platen 6 is released from the thermal trans-
`fer head 5 with the eccentric cam 68 set in a second
`position.
`A pair of plate brackets 60 and 60 disposed right and
`left for supporting the thermal transfer head 5 are each
`formed of an upper branch part 61 positioned above and
`a lower branch part 62 positioned below which extend
`so to be distant from each other at the front end and to
`provide a V-shape. Both plate brackets 60 and 60 are
`pivoted rotatably about a shaft 63 positioned near the
`stationary side plates 80 and 80 so as to be parallel with
`each other between the side plates 80 and 80. Further,
`both plate brackets 60 and 60 are made in one body with
`each other in order that the thermal transfer head 5, first
`head guide shaft 4, and second head guide shaft 7 are
`fixed to both upper branch parts 61 and 61 and a cam
`pressing shaft 65 provided with a cam pressing roller 64
`as a cam follower is fixed to the lower branch parts 62
`and 62.
`Both plate brackets 60 and 60 are biased rearwardly
`upwardly (clockwise on the drawings) at the front end
`portion thereof to turn around the shaft 63 by tensions
`of the springs 67 and 67 as biasing members stretched
`between the front end of each of lower branch parts 62
`and 62 and a shaft 66 fixed to both stationary side plates
`80 and 80.
`Positions of parts fixed between the plate brackets 60
`and 60 are set in such manner that, when the platen 6
`and the thermal transfer head 5 are pressed to each
`other, the first and the second head guide shafts 4, 7 are
`disposed before and behind the platen 6, respectively.
`The position of pressing roller 64 on the cam pressing
`shaft 65 is set to face the cam surface of the eccentric
`cam 68 fixed to the aforesaid cam supporting shaft 70.
`A sensor shutter 69 is also fixed to cam supporting
`shaft 70. A cam position sensor 71, which comprises a
`photo-interrupter being turning on and off by rotational
`position of the sensor shutter 69 when the eccentric cam
`68 and the sensor shutter 69 rotate together with the
`
`Esselte Exhibit 1007
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`Page 20
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`4,838,713
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`rotation of the cam supporting shaft 70, is disposed on
`the sides of the stationary side plates 80 and 80. The cam
`position sensor 71 outputs: a signal “0" when the sensor
`shutter 69 is out of engagement with this sensor 71 on
`account of a positional relation that the eccentric cam
`68 is in a second position where the cam surface thereof
`is directed downward to press the cam pressing roller
`64 downward, that is, in the direction opposite to that of
`biasing force of the spring 67 (the thermal transfer head
`5 is released from the platen 6) and is at a first position
`where the plate brackets 60 and 60 are urged upwardly
`by the springs 67 and 67 (the thermal transfer head 5 is
`in pressing to the platen 6) while the eccentric cam 68 is
`adapted to be out of contact with cam pressing roller 64
`with the cam surface of the eccentric cam 68 turned
`upwardly; and a signal “1” when the sensor shutter 69 is
`in engagement with the cam position sensor 71 due to
`other positional relations than the above-described one.
`Accordingly, as shown in, for example, FIG. 7, when
`a positional relation that the eccentric cam 68 is at the
`first position and the platen 6 is pressed to the thermal
`transfer head 5 is changed to a position where the cam
`surface of the eccentric cam 68 is brought into contact
`with the cam pressing roller 64 being turned on the cam
`supporting shaft 70 and the eccentric cam 68 reaches
`the second position with the cam pressing shaft 65 de-
`pressed lower, the plate brackets 60 and 60 are turned
`downward together at the front ends thereof in opposi-
`tion to stretching force of the spring 67. Thus, as shown
`in FIG. 8, the thermal
`ransfer head 5 is released from
`the platen 6.
`The plate brackets 60 and 60 are also provided with a
`light source 110 for the color sensor 111 for sensing the
`colors of ink of the ink sheet 2.
`
`FIG. 9 is a block diagram showing structure of a
`control circuit of the thermal transfer printer of this
`invention.
`
`In the drawing, the reference numeral 90 designates a
`microcomputer system as a control unit including CPU
`as a control center, ROM containing programs for vari-
`ous kinds of control and RAM for memorizing various
`kinds of information. The control unit 90 receives vari-
`ous kinds of key signals from the key board 92. Further,
`the control unit 90, while receiving signals from the
`aforesaid first sensor 100, second sensor 101, third sen-
`sor 102, color sensor 111, and cam position sensor 71,
`provides control signals to a light source 110 for the
`color sensor 111, driving system 6D for the platen 6 as
`the first recording paper carrier roller, driving system
`18D for the second recording paper carrier roller 18,
`driving motor 30 for the ink sheet driving system, and
`driving motor 93 for driving the eccentric cam through
`an interface 91.
`Next, control operation conducted by the control
`unit 90, that is, a performance of the thermal transfer
`printer of this invention will be described.
`In the thermal transfer printer of this invention, the
`eccentric cam 68 is initially set in the second position
`where the cam surface thereof presses the cam pressing
`roller 64 immediately after the power source is thrown
`in. In other words, in the printer of this invention, im-
`mediately after the power source is turned on,
`the
`platen 6 and the thermal transfer head 5 are always set
`in positions so as to be distant from each other. The
`sequence for initial position setting of the eccentric cam
`68 by means of the control unit 90 will be described
`with reference to the flow chart in FIG. 10 and illustra-
`tive drawings in FIG. 11
`
`8
`First, with the power source turned on, the control
`unit 90 distinguishes signals outputted from the cam
`position sensor 71 (step S1). As a result, if the output
`from the cam position sensor 71 is “1”, it informs that
`the cam surface of the eccentric cam 68 lies between the
`first and the second positions as shown by the black
`round mark ('0 ) 68S in FIG. 11. In this case, the control
`unit 90 performs control to drive the eccentric cam
`driving motor 93 so as to move the cam surface of the
`eccentric cam 68 toward the second position (lower in
`the clockwise direction on the drawings) (step S7).
`When output from the cam position sensor 71 changes
`into “0” from “1”, the control unit 90 moves the cam
`surface of the eccentric cam 68 from the previous posi-
`tion further toward the second position by a predeter-
`mined degree 92 of angle (for example 30°) (steps S8
`and S9). In this way, the eccentric cam 68 is set in the
`second position.
`On the other hand, in the case when the output of the
`cam position sens