Head control apparatus

A head contorl apparatus is disclosed for a printing machine. The apparatus includes a frame with a thermal head connected to the frame. A tape roller guide is connected to the frame. The guide and the head are disposed on opposite sides of an intended tape pathway, The guide and head are both movable between first and second positions with the guide and head in the first positions being spaced apart a first distance sized to freely position a tape within the intended pathway. The guide and the head in the second positions are disposed to be closely adjacent with a tape within the pathway being urged against the head. The drive for the image source type is disconnected when the guide and head are separated.

BACKGROUND OF THE INVENTION 
I. Field of the Invention 
This invention relates generally to printing or typing equipment involving 
the use of a direct thermal printing process or thermal transfer process 
to transfer a dry film impression onto an image carrying tape. More 
particularly, this invention pertains to an apparatus for controlling a 
thermal head associated with the printing machine. 
II. Background of the Invention 
In the field of commercial art, there is a significant need for a simple 
means for transferring prefabricated letters or characters to a "paste-up" 
sheet for later photographing and printing. The earliest technology 
involving letter transfers was that of dry rub-on transfer sheets which 
had a series of characters preprinted thereon. These materials, however, 
are limited by the number of characters available on the sheet and must be 
very carefully aligned to produce acceptable images. Machines were later 
developed which printed such letters on a continuous adhesive tape. The 
first such machines employed print disks having raised characters and used 
impact printing to transfer pigment to a carrier tape. Some machines were 
keyboard driven while others were manual "spin and print" machines. See, 
for example, U.S. Pat. Nos. 3,912,064, 4,243,333, 4,462,708 and 4,579,056. 
The impact printing machines mentioned above had many advantages over the 
rub-on letters, but still suffered from certain limitations. Specifically, 
these machines were necessarily complicated, heavy, and relatively slow 
since the printing effect was accomplished by using physical force against 
the type face with the print media and pigment ribbon in between. Such 
machines were also restricted to pigment transfer of some form. In 
addition, an expensive type disk had to be molded for every point size, 
type style and language, leading to enormous costs in creating a suitable 
library. Certain foreign languages which are written either "backwards" or 
vertically would require very specialized type disks. Speed was further 
limited because the type disks had to physically move to a new location to 
print each successive character. Finally, the resulting output was 
generally not considered smear proof and would have to be further coated 
if used in areas where frequent contact with the print surface was 
anticipated. 
Thermal transfer printing, such as that known in inexpensive portable 
typewriters (Canon Typestar 5.TM., etc.), employed a new technology which 
used a heat generating print head to melt a wax-like pigment from a 
carrier ribbon to a receiving tape. By using digital technology, 
characters could be formed of a series of pixels and no print disk was 
required. A related technology is direct thermal printing where an image 
is created on a thermally sensitive receiving paper directly by the head 
without the use of an intermediate carrier ribbon. 
The key element in a direct thermal or thermal transfer system is the head, 
its alignment mechanism and the feeding device which precisely moves the 
receiving tape in synchronization with the activation of pixel elements on 
the head. In the above-mentioned typewriter devices, the pixel density is 
so low that only draft quality print is created and, thus misalignment of 
the head is not particularly serious. In the graphic arts, however, a much 
higher degree of accuracy for head alignment, paper feed and pixel density 
is required. This combination of circumstances creates special problems 
not previously encountered. 
In thermal transfer, the pigment carrying tape is typically quite thin and 
fragile and, thus its surface must be well protected from mishandling by 
the user. Prior art devices such as the above-mentioned typewriter have 
employed cartridges, but they did not fully protect the ribbon from 
damage. The present invention solves this problem of damage to the tape 
and ribbon, as well as maintaining same in precise alignment. 
An additional problem encountered in direct thermal and thermal transfer is 
the alignment of the head which is routinely exposed to the user. If the 
head is rigidly mounted so as to be accurately positioned, the mount may 
be damaged by the user. If the head is on a movable mount, it may not 
always return to its proper position. The present invention solves this 
problem by creating a mount which is both flexible, to resist damage, and 
designed to accurately return to its proper position. In addition to head 
alignment, the drive rollers which advance the tape must maintain accurate 
alignment despite the need for their retractability. The present invention 
likewise solves this problem. 
In a printing apparatus, it is desirable to provide a mechanism to control 
the thermal head so that the head and its associated guide roller may be 
spaced apart to easily receive a tape and brought together in proper 
alignment when a tape is properly positioned between the roller and the 
head. Such an arrangement will facilitate installation of the tape. With 
respect to thermal heads, such control apparatus must include means to 
insure that the head is properly aligned when in its operable position to 
insure that any printed message is not distorted. Also, such apparatus 
should include means to permit the head to endure a user inflicted blow 
without misalignment of the head. 
SUMMARY OF THE INVENTION 
According to a preferred embodiment of the present invention, a head 
control apparatus is provided for a printing machine for printing an image 
on an image receiving tape. The head control apparatus includes a frame 
and a transfer head connected to the frame. A guide is also connected to 
the frame. The head and the guide are disposed on opposite sides of a 
pathway through which a receiving tape is intended to be disposed. The 
guide and head are disposed on opposite sides of an intended position of 
the image receiving tape. The guide and the head are movable between first 
and second positions. When in the first positions, the guide and head are 
spaced apart a distance sufficient to freely position the tape within the 
passageway without interference by the guide and head. When in the second 
positions, the guide and head are disposed for the guide and head to be 
urged together with the tape held between the head and guide.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
1. General Description. 
Referring to the several figures in which like elements are identically 
numbered throughout, the preferred embodiment of the present invention 
will now be described. With reference to FIG. 1, a printing machine 20 is 
shown together with an associate tape cartridge 22. The printing machine 
20 includes a key board portion 24 having a plurality of operator 
engageable keys 25 and control keys 26. The printing machine 20 further 
includes a user readable screen 27 to enable an operator to view a message 
as it is being keyed as well as other messages which may be presented by 
the machine 20 such as prompts and the like. 
In using the machine 20, an operator selects a desired mode of operation 
and inputs a message through keys 25 in order to produce a tape having the 
desired message imprinted on the tape. The machine includes electronics 
(not shown) for accepting the keyed inputs and processing the inputs to 
generate a desired output. The desired output affects such devices as a 
thermal head, a tape advance motor, and a tape termination blade all of 
which will be described. It will be appreciated that the electronics and 
keyboard mechanism as well as display screen 27 do not form any part of 
this invention per se and are shown and discussed solely for purposes of 
background and illustration to enable a reader to understand the 
interaction of the novel cartridge 22 and novel head control apparatus in 
a preferred embodiment. 
With reference to FIG. 2, the cartridge receiving area of the printing 
machine 20 is shown with tape cartridge 22 removed thereby exposing 
machine plate 48 on which cartridge 22 rests in operation. With cartridge 
22 removed, a head control apparatus 28 is shown disposed beneath plate 
48. Apparatus 28 is secured to the underside of plate 48 by a plurality of 
screws 30. 
Various elements of apparatus 28 protrude through openings in plate 48. 
These exposed elements include a first guide roller 32, a second guide 
roller 34, a thermal head 36, a cartridge lock 38, a tape free end 
detector 40, a scissor cutter 380, a cartridge detection pin 134 and a 
take-up spool drive sprocket 37. As shown in FIG. 2, first roller 32 and 
head 36 oppose one another. In the view of FIG. 2, roller 32 and head 36 
are shown in their first positions (as shall be more fully described) with 
roller 32 and head 36 spaced apart to define a pathway 42 therebetween. 
Pathway 42 is intended to receive a tape. To facilitate understanding of 
the apparatus, detailed discussion of the head control apparatus 28 will 
now be deferred pending a more complete description of tape cartridge 22. 
As will be described, rollers 32, 34 act to guide a tape as well as 
advance a tape. 
2. Detailed Description of Tape Cartridge 22. 
With primary reference to FIGS. 3 and 4, tape cartridge 22 is shown as 
including a generally rectangular shaped housing 50 defined by a flat 
lower plate 52 and a flat upper plate 54 joined by left and right side 
walls 56 and 58, respectively (as shown in the view of FIG. 3) and end 
walls 57 and 59. Side walls 56, 58 and end walls 57, 59 together with 
plates 52 and 54 cooperate to define a housing interior in which is 
disposed a first tape system 60 and a second tape system 62. Top and 
bottom plates 54, 52 are joined with pins 53 of the top plate 54 received 
within aligned hollow posts 55 of the bottom plate 52 (as shown in FIGS. 2 
and 11). 
First tape system 60 includes a first tape spool 64 rotatably mounted on a 
cylindrical hub 65. The first tape system 60 also include a take-up spool 
66 rotatably mounted within housing 50. An image source tape 68 is 
originally carried on first spool 64 and extends therefrom to take-up 
spool 66. Source tape 68 is entrained around a plurality of alignment pins 
70. Each of pins 70 is surrounded by a rotatably mounted cylindrical 
collar 72. 
Cartridge 22 is provided with a wall 74 partially surrounding an opening 
105 sized to receive thermal head 36. (In FIG. 3, head 36, first roller 
32, second roller 34 and tape free end detector 40 are shown in phantom 
lines to indicate their positions when the cartridge 22 is mounted on the 
machine 20. Rollers 32, 34 and head 36 are shown in their first 
positions.) Wall 74 extends from lower plate 52 toward upper plate 54 and 
terminates at arcuate ends 78 and 80. Ends 78 and 80 are disposed to 
receive image source tape 68 and retain a portion 68' of the tape 68 in 
predetermined alignment for the portion 68' to be received within pathway 
42 when cartridge 22 is inserted on the machine 20. So inserted, as shown 
in the phantom lines of FIG. 3, head 36 opposes portion 68' with a 
printing substance carrying face of the tape 68 facing away from transfer 
head 36. 
First tape system 60 includes a brake 82 comprising a felt pad 84 
resiliently urged against spool 64 by a spring 83 having one end mounted 
on end wall 59. 
Take-up spool 66 includes a hub 86 exposed through upper plate 54 (as shown 
in FIG. 1) so that hub 86 may be manually engaged by an operator and the 
take-up spool 66 may be advanced manually if desired. The bottom of 
take-up spool 66 includes a female sprocket 88 disposed to be received on 
a male sprocket 37 of the head control apparatus 28 as will be described. 
Bottom plate 52 defines an opening 45 on an output side of pathway 42 which 
is sized to receive scissor cutter 380. Within housing 50, opening 45 is 
surrounded by walls 90 having openings 91 which act as a housing outlet 
for second tape system 62 as will now be described. 
Second tape system 62 includes cylinder 94 for receiving a spool 96 of an 
image receiving tape 98. A plurality of pins 100 guide a free end 102 of 
tape 98 to housing outlet 91. A wall 101 spaced from arcuate end 78 of 
wall 74 aligns a portion 98' of tape 98 in face-to-face alignment with 
image source tape portion 68' within pathway 42. Plastic disks 140 are 
disposed on opposite sides of spool 66 and protect edges of tape 98 during 
operation of the cartridge 22. The discs 140 reduce friction and helps to 
prevent the adhesive of the tape 98 sticking to the housing. 
Second tape system 92 includes a roller 108 for biasing tape 98 against 
roller 34. Roller 108 is provided with axially extending hubs 110 which 
are received within elongated slots 112. With hubs 110 received within 
slots 112, roller 108 is slidable toward and away from roller 34 while 
retaining the axis of rotation of roller 108 parallel to the axis of 
rotation of roller 34. A spring 114 entrained around a post 116 is 
provided with one end 114' urged against side wall 58 and a free end 114" 
received within a circumferential slot 109 (FIG. 12) in roller 108 with 
free end 114" urging roller 108 toward roller 34. A brake 118 is provided 
in the form of a spring entrained around a post 120 with one end 122 
acting against side wall 56 and a free end 124 urged against spool 96. 
Hollow cylindrical posts 117, 121 formed on upper plate 54 are received on 
pins 116, 120 and retain springs 114 and 118 in proper alignment as shown 
in FIGS. 11 and 12. 
Bottom plate 52 is provided with a generally circular opening 126 which is 
axially aligned with cylinder 94. Opening 126 is provided with opposing 
side ledges 127 which cooperate with cartridge lock 38 to lock the 
cartridge 22 onto machine 20 as will be described. 
The bottom plate 52 defines a first guide opening 104 and a second guide 
opening 106 sized to receive the roller guides 32 and 34, respectively, of 
the head control apparatus 28. An opening 105 is formed through plate 52 
and sized to receive head 36. Openings 104, 106 and 105 are dimensioned to 
permit relative movement of guides 32, 34 and head 36 as will be 
described. Lower plate 52 is also provided with an opening 128 sized to 
receive tape free end detector 40 when cartridge 22 is mounted on machine 
20 in a predetermined alignment. 
Lower plate 52 is provided with offset notches 130 sized to receive offset 
posts 132 (shown in FIG. 2) projecting from the machine 20. With cartridge 
22 aligned with machine 20 such that notches 130 are aligned with posts 
132, cartridge 22 is in proper alignment with the machine and may be 
placed in its proper position such that guide rollers 32, 34 are received 
within openings 104, 106, respectively, and head 36 is received within 
opening 76 with tape portions 68', 98' received within pathway 42. 
Further, with cartridge 22 properly aligned and in position, tape free end 
detector 40 is received within opening 128 and male sprocket 37 is 
operably received within female sprocket 88. Additionally, scissor cutter 
380 is received within opening 45. With bottom plate 52 of a cartridge 22 
urged against the top surface of the machine plate 48, detection pin 134 
will be depressed as described. Also, cartridge lock 38 may be turned 
90.degree. clockwise from the position shown in FIG. 2 such that its 
rounded edges 38' are received overlying side ledges 127 to thereby 
capture bottom plate 52 between the machine plate 48 and cartridge lock 
38. 
The upper plate 54 is provided with a plurality of vent openings 136 shown 
in FIG. 1. Vent openings 136 are disposed above the intended position of 
head 36. Additionally, a slot 137 is formed in upper plate 54 projecting 
radially away from cylinder 94. Slot 137 enables a user to determine the 
amount of tape left on spool 66. A notch 138 formed in apparatus 20 
adjacent the intended position of cartridge 22 enables the operator to 
grasp cartridge 22. 
The foregoing description of cartridge 22 is a description of a first 
preferred embodiment. In the first preferred embodiment, the cartridge 
includes both first tape system 60 and second tape system 62. Second tape 
98 is a tape intended to receive an image by means of a printing substance 
transferred from image source tape 68 to image receiving tape 98. This 
process is known as thermal transfer printing. The tranfer occurs by 
reason of thermal head 36 being selectively heated and thereby melting a 
point on the source tape 68 onto the receiving surface of tape 98. The 
head is a thermal head having a plurality of individually controlled 
pixels disposed in an array perpendicular to the direction of travel of 
the tapes. In a preferred embodiment, head 36 will have 96 pixels disposed 
in a density of 240 pixels per inch. The circuitry of the machine 20 can 
individually heat each of the pixels so that any possible permutation of 
the 96 pixel array may be heated to transfer the image of the permutation 
to the receiving tape 98 by melting the permutation from the source tape 
68 to receiving tape 98. It will be appreciated that thermal heads such as 
head 36 and circuitry for controlling the heads form no part of this 
invention per se and are described to facilitate an understanding of the 
novel tape cartridge 22 and head control apparatus 28. 
In addition to the first preferred embodiment of melting an image from the 
source tape 68 to the receiving tape 98, the present invention is suitable 
for use where the image receiving tape 98 receives the image by directly 
"burning" an image from the head 36 to the receiving tape 98. This process 
is known as direct thermal printing. In this embodiment, the spool 64 of 
image source tape 68 is not needed and is simply eliminated from the 
cartidge 22. 
3. Detailed Description of Head Control Apparatus 28. 
a. Frame 200 and Movable Carriage 210 
Head control apparatus 28 includes a hollow box-shaped frame 200 including 
a flat top plate 202 and a flat bottom plate 204 which are spaced apart by 
left and right side walls 206, 208 (as shown in the view of FIG. 12). 
Frame 200 is secured to machine 20 by attaching top plate 202 to the under 
surface of machine plate 48 by screws 30. Frame top plate 202 is 
maintained in spaced relation from machine plate 48 by spacers 142 (shown 
in FIG. 11). 
Disposed within the interior of the box-shaped frame 200 is a carriage 210 
shown best in FIG. 11. Carriage 210 includes an upper carriage plate 212 
which slidably abuts an interior surface of frame top plate 202. Carriage 
210 further includes a lower plate 214 which slidably abuts an interior 
surface of frame bottom plate 204. A spacer bar 216 (shown broken away in 
FIG. 11) is secured to upper plate 212 and extends to lower plate 214. 
Lower plate 214 is secured to spacer bar 216 by means of screw 218. 
A motor mount plate 220 is secured to carriage 210 by means of a first 
motor mount support bar 222 extending from carriage upper plate 212 to 
motor mount plate 220 and a second motor mount support bar 224 also 
extending from carriage upper plate 212 to a second end of motor mount 
plate 220. A third motor mount support bar 226 extends from the motor 
mount plate 220 coaxially with second support bar 224 and is secured to 
carriage lower plate 214 by means of screw 228 (shown in FIGS. 9 and 10). 
Spacer bar 216, motor mount plate 220 and motor mount support bars 222, 224 
and 226 maintain upper plate 212 in spaced relation from lower plate 214 
with carriage 210 slidably received within the interior of frame 200. 
Carriage 210 is slidable within frame 200 in the direction of arrow A shown 
in FIG. 11. To guide carriage 210 and to limit its slidable stroke, upper 
plate 212 is provided with an elongated slot 230 which receives a pivot 
pin 232 which extends inwardly into frame 200 from frame top plate 202. 
Slot 230 and pin 232 are shown best in FIG. 6. Lock control shaft 234 
extends vertically (in the view of FIG. 11) through frame 202 and machine 
plate 48 and is journalled for rotation about its axis within top frame 
plate 202 and bottom frame plate 204. As shown in FIG. 6, upper carriage 
plate 212 is provided with a slot 236 sized to receive control shaft 234. 
Slot 236 and shaft 234, together with slot 230 and pin 232, cooperate to 
restrain the sliding movement of carriage 210 in the direction of arrow A 
and to limit the stroke of the carriage between a first location with the 
right hand ends of the slots 230, 236 abutting pin 232 and shaft 234, 
respectively (as shown in FIG. 6) and a second position with a left hand 
end of slot 230 abutting pin 232 (references to left and right taken in 
the view of FIG. 6). 
b. Motor 240 and Gear Train 
A motor 240 is mounted on motor mount plate 220 and is provided with a 
driving gear 244 carried on an end of the motor shaft 246. Motor 240 is a 
rotary digital actuator which, on receipt of a signal, rotates in discreet 
angular displacements. As shown best in FIGS. 9 and 10, bottom frame plate 
204 includes an opening 238 sized to accommodate unrestricted movement of 
motor 240 and screw 228 which extend beneath the bottom of lower carriage 
plate 214. A slot 242 in bottom frame plate 204 accommodates reciprocal 
movement of screw 218 as the carriage 210 moves between its first and 
second locations. Motor 240 is secured to motor mount plate 220 for 
movement therewith as the carriage 210 moves between the first and second 
locations 
Shown best in FIGS. 7, 11 and 12, the carriage 210 includes a gear train 
which is mounted on the carriage 210 for movement therewith. The gear 
train includes the motor driving gear 244. The carriage gear train further 
includes integrally connected first intermediate transfer gear 248 and 
second intermediate transfer gear 250 which are mounted for simultaneous 
rotation on a common fixed shaft 252 which extends between upper and lower 
carriage plates 212, 214. First intermediate transfer gear 248 is disposed 
to mesh with driving gear 244. 
A first rotary shaft 254 is journalled through the carriage upper plate 212 
and carriage lower plate 214 and extends through frame top plate 202 and 
machine plate 48. First roller 32 is connected to first rotary shaft 254 
for rotation therewith. A first roller gear 256 is connected to first 
rotary shaft 254 to cause rotation of shaft 254 as gear 256 is rotated 
about its axis. 
A second rotary shaft 258 is journalled through the carriage upper plate 
212 and carriage lower plate 214 and extends through frame top plate 202 
and machine plate 48. Second roller 34 is secured to shaft 258 for 
rotation therewith. Shaft 258 carries a driven gear 260 which is enmeshed 
with second intermediate transfer gear 250. An integrally connected drive 
gear 262 is carried on shaft 258 to rotate as gear 260 is driven by gear 
250. Gear 262 is aligned in a common plane with first roller gear 256. 
An idler gear 264 is mounted on a fixed shaft 266 between gears 262 and 
256. Gear 264 is enmeshed with both of gears 262 and 256 for gear 264 to 
drive first roller gear 256 as second roller gear 262 is driven. In the 
view of FIG. 7, portions of gears 248 and 260 are broken away to 
illustrate meshing of gear pairs 250, 260 and 262, 264. 
As shown in FIGS. 5, 6-8 and 11, male sprocket 37 is mounted on a rotary 
shaft 268 which is journalled between frame top plate 202 and frame bottom 
plate 204. Shaft 268 carries a driven gear 270 which is mounted on shaft 
268 for rotation therewith. Gear 270 is aligned in a common plane with 
gear 260. As shown best in FIGS. 7 and 8, gears 260 and 270 are disposed 
such that when carriage 210 is in the first location (as depicted in FIG. 
7), gear 260 and gear 270 are disengaged. When carriage 210 is shifted to 
the second position (as depicted in FIG. 8), gear 260 and gear 270 are 
enmeshed for gear 260 to drive gear 270. 
Having described the gear train, it can be seen that as motor shaft 246 
rotates in a clockwise direction (when viewed in FIG. 7), gear 244 rotates 
in a clockwise direction, urging gears 248 and 250 to rotate in a 
counterclockwise direction. Gear 250 urges gear 260 to rotate in the 
clockwise direction with the corresponding rotation of gear 262 in a 
clockwise direction. Gear 262 urges gear 264 to rotate in the 
counter-clockwise direction, which in turn urges gear 256 to rotate in the 
clockwise direction. When the carriage 210 is shifted to the second 
location (as depicted in FIG. 8), gear 260 urges gear 270 to rotate in the 
counter-clockwise direction. 
As a result of the gearing arrangement, the gear train, upon actuation of 
motor 240, causes first and second rollers 32, 34 to rotate in the 
clockwise direction, when viewed in FIG. 2. When the carriage 210 is in 
the second position (the position of FIG. 8), the gear train urges the 
male sprocket 37 to rotate in the counter-clockwise direction when viewed 
in FIG. 2. 
As the carriage 210 moves between its first and second locations, rollers 
32, 34 move between first and second predetermined positions. In the view 
of FIG. 2, the rollers 32, 34 are shown in the first positions with the 
rollers spaced away from the intended position of the tape portions 68', 
98'. When the carriage 210 is moved to its second location, the roller 32 
is moved toward head 36 and roller 34 is moved toward cassette roller 108. 
FIG. 11 shows the carriage 210 in the second location with roller 32 
against head 36. Roller shafts 254, 258 extend through openings formed in 
frame top plate 202 and machine plate 48. The openings are elongated to 
accommodate movement of the shafts 254, 258 between their first and second 
positions. 
Roller 32 and head 36 are disposed so that when in the second position the 
center line of roller 32 is accurately aligned with the pixel array of 
head 36. Small deviations from accurate alignment will result in failure 
of the head 36 to properly transfer an image onto the tape 98. 
c. Carriage Movement Control 
To effect movement of the carriage 210 between its first and second 
locations, an over-center locking mechanism 272 is provided which is best 
shown in FIGS. 5, 9, 10 and 11. Over-center locking mechanism 272 includes 
a flat cane-shaped linkage 274 having a straight end 275 pivotally mounted 
to carriage upper plate 214 by means of a pivot pin 276. A curved end 277 
of linkage 274 is sized to extend and curve around lock control shaft 234. 
A linkage arm 278 is secured to control shaft 234 for rotation therewith. 
Linkage arm 278 includes a pivot pin 280 which pivotally connects link arm 
278 to cane-shaped linkage 274 on a pivot axis spaced away from the axis 
of shaft 234. 
With the structure thus described, carriage 210 is moved to the first 
location (as shown in FIG. 9) by turning shaft 234 in a clockwise 
direction (when viewed in FIG. 9) with the result that linkage 274 is 
pivoted away from the center of shaft 234 urging carriage 210 to move to 
the right (when viewed in FIG. 9). When shaft 234 is rotated in a 
clockwise direction, pivot pin 280 carries the cane-shaped linkage 274 
around shaft 234, as viewed in FIG. 10, with the result that carriage 210 
is moved to the left and assumes its second location. 
A spring 282 is provided for urging the carriage 210 to its first location. 
Spring 282 includes a first end which is secured to a pin 284 which is 
rigidly connected to the frame bottom plate 204. A second end of spring 
282 is connected to a pin 286 which is rigidly connected to the carriage 
lower plate 214 and extends through opening 238. 
d. Carriage Lock Mechanism 
To insure that carriage 210 will be in the first position when a cartridge 
is not mounted on the machine, a lock mechanism is provided which is best 
shown with reference to FIGS. 9 through 11. The lock mechanism includes a 
lever arm 288 having a first end 288a hingedly mounted on a fulcrum 289 
carried on frame bottom plate 204 by a pin 290. A free end 288b of pivot 
arm 288 is connected to detection pin 134 which extends through machine 
plate 48. A central portion of pivot arm 288 is provided with a first 
opening 292 which slidably receives control shaft 234. A spring 294 is 
mounted between arm 288 and a free end 296 of shaft 234. Spring 294 urges 
arm 288 away from free end 296. 
Linkage arm 278 is provided with a stop pin 298. Pivot arm 288 is provided 
with a slot 300 disposed to receive stop pin 298 when carriage 210 is in 
its first location (as depicted in FIG. 9). Accordingly, when a cartridge 
22 is inserted on the machine in proper alignment, the cartridge 22 moves 
detection pin 134 downwardly (in the view of FIG. 11). Downward movement 
of pin 134 moves lever arm 288 against the urging of spring 294 to free 
pin 298. With pin 298 free of slot 300, an operator may rotate lock 
control shaft 234 with carriage 210 correspondingly moving to the second 
location (depicted in FIG. 10). 
e. Take-up Spool Slip Clutch 
Shown most clearly in FIG. 11, shaft 268 is provided with a slip clutch 
mechanism 302 to permit gear 270 to rotate without rotation of shaft 268. 
A first hub 306 is mounted on shaft 268 for rotation therewith. A second 
hub 305 and gear 270 is loosely received on shaft 268 for relative 
rotation between shaft 268 and gear 270 and hub 305. A felt disc 303 is 
disposed between second hub 305 and gear 270. A spring 304 is disposed 
between first hub 306 and second hub 305 urging hub 305 to rub disc 303 
against gear 270. Gear 270 is moved against a snap ring 307 disposed 
between gear 270 and a bearing 309 for shaft 268. Spring 304 is selected 
to urge second hub 305 against gear 270 to rotate shaft 268 until 
resistance of the shaft against further rotation is sufficient to overcome 
the urging of spring 304. At this point, spring 304 yields to permit 
relative rotation of shaft 268 and gear 270. A second spring 308 extends 
above top plate 202 between bearing 309 and male sprocket 37. Second 
spring 308 permits the male sprocket 37 to be moved downwardly when a 
cartridge 22 is placed on the machine 20 in the event that the female 
sprocket 88 is not properly aligned with the male sprocket 37. With the 
male sprocket 37 moved downwardly, the male sprocket 37 will come into 
alignment with the female sprocket 88 and spring 308 will urge the male 
sprocket 37 into engagement with the female sprocket 88. 
f. Head Alignment 
Head control apparatus 28 includes a head alignment mechanism for 
accurately aligning head 36 with roller 32. The alignment mechanism is 
best shown in FIG. 12 and includes a mounting bracket 330. Mounting 
bracket 330 is generally L-shaped. Head 3 is secured to a first end of 
mounting bracket 330 by means of a screw 332. The first end of the 
mounting bracket 330 includes an indent 334 which projects away from the 
surface of the mounting bracket 330 on a side thereof opposing head 36. 
Head 36 is provided with a recess sized to receive indent 34. The indent 
34 and its associated recess on head 36 together with screw 332 maintain 
head 36 in accurate fixed alignment with mounting bracket 330. 
A second end of mounting bracket 330 is provided with upwardly and 
downwardly projecting pivot plates 336 and 338, respectively (as shown in 
the view of FIG. 12). Pivot plates 336, 338 have aligned pivot edges 340, 
342, respectively facing in the direction of head 36. Upper and lower 
pivot plates 336, 338 are received in upper and lower slots 344, 346, 
respectively formed in frame top plate 202 and frame bottom plate 204, 
respectively. In the preferred embodiment, plates 202 and 204 are formed 
of plastic material and the mounting bracket 330 is metallic. 
Shown in FIGS. 6-8 and 12, pivot plates 336, 338 are maintained within 
slots 344, 346 by means of a leaf spring 350 which is carried on the 
interior surface of frame side wall 208. The leaf spring 350 has an 
arcuate central portion 352 which is a narrow strip of metal (as shown in 
FIGS. 6-8). The surfaces of the central portion 352 opposing the bracket 
330 are parallel to axis X--X. 
As shown in FIG. 12, mounting bracket 330 is provided with a recess 354 
centrally disposed between upper pivot plate 336 and lower pivot plate 
338. Recess 354 is sized to receive spring body 352 against a face 356 of 
recess 354. With spring central portion 352 received within recess 354 as 
described, spring central portion 352 urges the pivot edges 340, 342 of 
pivot plates 336, 338 into slots 344, 346. Additionally, in response to a 
downward force imparted on head 36 (indicated by the arrow B), spring 
central portion 352 permits lower plate 338 to pivot out of slot 346 as 
indicated by the arrow C. With lower plate 338 pivoting out of slot 346, 
the pivot axis of the motion occurs at upper pivot edge 340. When the 
downward force is removed, deformation of spring central portion 352 away 
from its alignment with axis X--X urges spring central portion 352 back to 
alignment with consequential urging of lower plate 338 into slot 346. 
Head 36 and the first end of the mounting bracket 330 extend through an 
opening 358 formed in the frame top plate 202. A ledge 360 formed on 
mounting bracket 330 opposes an inner surface of frame top plate 202 
adjacent opening 358. As spring body 352 is urging mounting bracket 330 to 
restore head 336 in its proper position, ledge 360 abuts frame top plate 
202 when head 36 is properly positioned. 
A spring 362 extends between mounting bracket 330 and lock control shaft 
234 (shown in FIGS. 7 and 8). Spring 362 urges mounting bracket 330 to 
pivot about axis X--X to move head 36 to its second position with the head 
36 resiliently urged against first roller 32. 
To move head 36 against the urging of spring 362 to the head's first 
position, an alignment bracket 364 is provided. Alignment bracket 364 is 
best shown with reference to FIGS. 7, 8 and 12. Bracket 364 is pivotably 
secured to frame top plate 202 by means of pivot pin 232. Alignment 
bracket 364 is provided with a contact element 368 disposed opposing a 
surface of ledge 360 on a side of mounting bracket 330 facing the 
direction of urging of spring 362. Contact element 368 is disposed to 
contact ledge 360 and urge mounting bracket 330 to pivot about axis X--X 
against the urging of spring 362 as alignment bracket 364 pivots about pin 
366 in a counterclockwise direction (when viewed in FIG. 7). 
An engagement element in the form of a cam 370 is fixed to upper carriage 
plate 212 for movement therewith. The cam 370 is disposed opposing a cam 
follower side edge 372 of alignment bracket 364 to abut the side edge 372 
and urge alignment bracket 364 to pivot in a counterclockwise direction 
(in the view of FIG. 7) as the carriage is moved to its first location 
(i.e. to the left in the view of FIG. 7). As previously mentioned, upper 
carriage plate 212 has an elongated slot 230 sized to freely receive pin 
232. Slot 230 is provided with a longitudinal dimension sufficient to 
permit carriage 210 to move between its first and second locations with 
pin 232 remaining in a fixed position relative to the frame 200 and with 
slot 230 and pin 232 sliding relative to one another. 
g. Tape Termination Apparatus 
A termination blade mechanism 46 is provided for terminating a tape after 
it has received an image from head 36. The termination mechanism 46 
includes a scissor cutter 380 mounted on the exterior surface of frame 
side wall 206. Cutter 380 includes a stationary blade 382 and a 
cooperating cutting blade 384 pivotably mounted to frame side wall 206. A 
motor 386 is carried on frame 200 and has a shaft 388 with a driving gear 
390. Driving gear 390 is operably connected by means of a gear train to 
the cutting blade 384 to advance and retract the cutting blade away from 
stationary blade 382. 
The gear train includes first and second gears 392, 394, respectively which 
are mounted on a common fixed shaft 396 with first gear 392 emmeshed with 
driving gear 390. A blade actuating gear 398 is mounted by means of a 
central shaft 400 to the frame 200 with gear 398 emmeshed with gear 394. 
Blade actuating gear 398 has a pin 402 eccentrically mounted thereon. 
Cutting blade 384 includes a linkage 404 having an elongated slot 406 
disposed to receive pin 402. As gear 398 rotates about its central axis, 
pin 402 reciprocally slides within slot 406 causing linkage 404 to rock 
with consequential movement of cutting blade 384 toward and away from 
stationary blade 382. 
A Hall effect transistor 408 is mounted on frame 200 to detect the presence 
of target 407 mounted on blade actuating gear 398. Hall effect transistors 
408 are known in the art and form no part of this invention per se. Use of 
Hall effect transistors to detect targets such as target 407 is known. 
With the transistor 408 and the target 407 on the blade actuating gear 
398, the positioning of the cutting blade 384 relative to the stationary 
blade 382 can be determined. The transistor 408 and motor 386 are 
connected through conductors (not shown) to the circuitry of the printing 
machine 220. 
4. Operation of Apparatus. 
With the structure of the printing machine 20 and the novel tape cartridge 
22 and head control apparatus 28 described, a description of the operation 
of the apparatus will now be provided. With reference to FIG. 2, the head 
control apparatus 28 is shown in the idle position when a tape cartridge 
22 is not inserted onto machine plate 48. In the idle position, cartridge 
lock 38 is pivoted to a position with its longitudinal direction aligned 
with the longitudinal direction of plate 48 as shown in FIG. 2. So 
aligned, rounded edges 38' are disposed at the top and bottom of cartridge 
lock 38 as shown in FIG. 2. With cartridge lock 38 so positioned, 
over-center locking mechanism 272 is pivoted to the position shown in FIG. 
9 with carriage 210 disposed to the left (when viewed in FIG. 9) with the 
carriage 210 assuming its first location. With the carriage 210 in its 
first location, cam 370 has acted against cam follower side edge 372 of 
alignment bracket 364 causing contacting element 368 to act against ledge 
360 of mounting bracket 330 and urge mounting bracket 330 against the 
urging of spring 362. With mounting bracket 330 urged to its first 
position, head 36 is moved to its first position and spaced away from the 
intended tape pathway 42. Interaction of spring 362, contact element 368 
and mounting bracket 330 in the first position are shown in FIG. 7. Also, 
with carriage 210 moved to the left and in its first location, guide 
rollers 32 and 34 (which are connected to carriage 210 for movement 
therewith) are moved to their first positions with roller 32 spaced from 
intended pathway 42. Finally, with the carriage 210 in its first location 
as shown in FIG. 9, stop pin 298 is aligned with slot 300 whereby urging 
of spring 294 causes pivot arm 288 to pivot upwardly (when viewed in FIG. 
11) with detection pin 134 extending above machine plate 48. 
When it is desired to use machine 20, a tape cartridge 22 is positioned on 
machine plate 48 with post 132 received within notches 130. With cartridge 
22 properly aligned on plate 48, cartridge 22 is pushed by the operator to 
urge pin 134 downwardly (when viewed in FIG. 11) and pivot arm 288 away 
from stop pin 298 as shown in FIG. 11. With cartridge 22 held down tightly 
against surface 48, cartridge lock 38 is engaged by an operator and 
rotated 90.degree. clockwise (when viewed in FIG. 2) whereby rounded edges 
38' capture ledges 127 of cartridge 22 between the rounded edges 38' and 
machine plate 48. 
With cartridge 22 locked onto machine plate 48, the apparatus may now be 
used by an operator to produce a tape with a desired printed image. As 
shown in FIG. 3, when a cartridge 22 is being positioned on machine 20 and 
an operator has not yet turned lock 38 from the position shown in FIG. 2, 
rollers 32, 34 and head 36 are in their first positions. The first roller 
32 and head 36 are spaced apart a distance sufficient to permit tape 
portions 98' and 68' to be received within the intended tape pathway 42 
without obstruction. Further, with roller 34 in its first position, the 
cartridge may be installed without obstruction of roller 34 against the 
tape 98 and cartridge roller 108. 
During installation of the cartridge 22 onto machine plate 48, an operator 
may inadvertently urge the bottom plate 52 of cartridge 22 downwardly onto 
head 36. In this event, head 36 moves downwardly in the direction of arrow 
B of FIG. 12 with the result that the entire mounting bracket 330 pivots 
at upper plate 336 with lower plate 338 moving in the direction of arrow 
C. When the operator re-adjusts cartridge 22 such that it is properly 
aligned, head 36 is aligned with cartridge opening 105. When so aligned, 
spring body portion 352 urges mounting bracket 330 to pivot back to its 
original position with ledge 360 acting against frame upper plate 202 to 
positively stop head 36 in its intended aligned position. 
As the operator rotates cartridge lock 38 to its intended locked position, 
over-center locking mechanism 272 pivots to the position shown in FIG. 10 
and thereby urges carriage 210 to the right whereby the carriage 210 
assumes its second location. As carriage 210 moves to its second location, 
guide rollers 32 and 34 move to their first positions. Simultaneously, 
movement of carriage 210 to the right (as shown in FIG. 8) causes cam 270 
to move away from cam follower surface 372 of aligning bracket 364. In the 
absence of the urging of the cam 370, spring 362 urges mounting bracket 
330 and head 36 to its first position. With the cartridge 22 installed and 
with the rollers 32, 34 and head 36 in their first positions, tape 
portions 68', 98' are snuggly received between roller 32 and head 36 and 
with head 36 resiliently urging the tape portions against the roller in 
proper alignment. In the event the cartridge 22 is being used without a 
source tape 68 and, instead, is being used for direct thermal printing, 
only an image receiving tape 98 will be disposed between head 36 and 
roller 32. With roller 34 in its first position, cartridge roller 108, in 
response to the action of spring 114, resiliently urges tape 98 against 
roller 34. Finally, with the tape cartridge 22 installed, tape 98 is 
received within tape free end detector 40 and stationary blade 382 and 
cutting blade 384 are spaced apart to receive the free end 102 of tape 98 
between the blades. 
With the tape cartridge 22 installed as described, the machine is ready for 
use by an operator. The operator selects a desired printing mode and 
enters an input through keys 25. The input may be a command for the 
apparatus to print a letter. In the event the command is given, the 
particular letter is known by the electronics of machine 20 to represent a 
controlled arrangement of dots generated by energizing pixels on head 36 
as a tape 98 advances past head 36. When the command to print a letter is 
given, step motor 240 turns shaft 246. Accordingly, rollers 32, 34 advance 
the tape 98 past head 36 with the head pixels being variously energized to 
imprint the letter onto tape 98. After a letter is printed, step motor 240 
operates rollers 32, 34 to advance tape 98 a predetermined amount to a 
point to begin printing of a next inputted letter. Simultaneous with the 
advancement of tape 98, step motor 240 advances take-up spool 66 so that a 
fresh portion of tape 68 is opposing the pixels of head 36. 
In a preferred embodiment, roller 32 is sized to have a slightly larger 
diameter than roller 34. Since rollers 32 and 34 are rotated at the same 
rotations per minute, roller 32 is attempting to advance tape 98 faster 
than roller 34 can feed tape 98. This action maintains a taut tape between 
rollers 32, 34. The incremental distance of feed is controlled by roller 
34. Roller 32 maintains the tape 98 in a taut condition. 
If during operation, tape 98 runs out, the terminal end of tape 98 is 
sensed by free end detector 40 which sends a signal to the machine 20 
electronics by conductors 420. The machine can then cease operation or 
signal an operator. It will be appreciated that detectors such as detector 
40 are commercially available. A very important purpose of detector 40 is 
to provide safety to an operator and protect the equipment of machine 20. 
Namely, the electronics of machine 20 will prevent the machine from 
operating when no tape is detected. This implies no cartridge is mounted 
on the machine. Accordingly, using the detection of an absence of a tape, 
the machine 20 will prevent operation of scissor cutter 380 without a 
cartridge 22 on the machine thereby providing protection to an operator. 
Also, in the event head 36 and rollers 32, 34 are in their first positions 
with head 36 spaced from roller 32, the head's pixels would become damaged 
if they were energized without being urged against a roller to dissipate 
the generated heat. By not operating after detector 40 notes the absence 
of a tape 98, this circumstance is avoided. 
As the message is being printed, rollers 32 and 34 advance tape 98. The 
resilient biasing of head 36 against roller 32 and cartridge roller 108 
against roller 34, insure uniform pressure on the advancing tape 98. In 
the event the cartridge is being used for direct thermal printing, first 
tape system 64 is not present and the imaging process occurs by reason of 
direct burning by the pixel array of head 36 onto tape 98. 
After a desired completed image has been produced onto tape 98, step motor 
240 receives a signal to advance the tape out of outlet 91. With the tape 
98 so advanced, motor 386 receives a signal through conductors (not shown) 
to rotate driving gear 398 and consequently move cutting blade 384 toward 
stationary blade 382 to terminate the tape. After termination has 
occurred, motor 240 operates to automatically rotate and advance the 
cutting blade 384 away from the stationary blade 382. As the cutting blade 
approaches its position fully displaced from the stationary blade 382, 
first target 407 passes Hall effect transistor which detects the position 
of target 407 and through conductors (not shown) sends this information to 
the electronic controls of machine 20. Upon detection of first target 407, 
motor 386 receives a signal to discontinue rotation. 
With the operation completed and the desired tape produced, an operator 
rotates cartridge lock 38 90.degree. counterclockwise to the position 
shown in FIG. 2. With this rotation, rollers 32 and 34 and head 36 are 
automatically moved to their first position with the rollers and head 
spaced away from the cartridge tapes. Also, as lock control mechanism 
rotates lock control shaft 234, lock pin 298 comes into alignment with 
slot 300 whereby spring 294 urges hinge arm 288 upwardly (in the view of 
FIG. 11) with pin 134 slightly lifting cartridge 22. At this position, the 
cartridge can be removed by the operator with the spaced apart positioning 
of the rollers 32, 34 and head 36 permitting quick removal of the tape 
without damage to the tape within the cartridge 22. 
From the foregoing detailed description of the present invention, it has 
been shown how the object of the invention have been attained in a 
preferred manner. However, modifications and equivalents of the disclosed 
concepts such as readily occur to those skilled in the art are intended to 
be included in the scope of this invention. Thus, the scope of the 
invention is intended to be limited only by the scope of the claims as 
are, or may hereafter be, appended hereto.