Profile sewing machine capable of projecting stitching reference image in accordance with profile of workpiece edgeline

A sewing machine capable of performing a profile sewing in which a stitch is provided at a position spaced away from an edgeline of a workpiece by a predetermined constant distance to provide a predetermined margin. The sewing machine is provided with memory means which stores therein the needle position data. This data is transmitted to a sewing needle swinging mechanism so as to move the sewing needle to a position inwardly spaced away from the edgeline to provide the margin. The sewing machine is also provided with image forming means connected to the memory means for providing a visualized image of a stitching reference line on one of a surface of the bed and the workpiece fabric on the bed in accordance with the needle position data. The stitching reference serves as a guide line along which the edgeline is placed.

BACKGROUND OF THE INVENTION 
The present invention relates to a profile sewing machine for profile 
stitching to a workpiece in parallelism with an edgeline thereof. More 
particularly, the invention relates to such profile sewing machine in 
which a stitching reference line can be visualized on a bed or the 
workpiece on the bed by a projector etc., the reference line serving as a 
guide line for sewing a predetermined inward position of the workpiece in 
parallelism with the edgeline of the workpiece. 
Profile sewing has been conventionally carried out in which swing needle 
location is positioned at a predetermined inward position of the workpiece 
fabric relative to the edgeline thereof, so that a seam or stitching line 
is oriented in parallel with the edgeline. For facilitating the profile 
sewing, one conventional profile sewing machine has been proposed in which 
the sewing needle can be automatically moved laterally at the 
predetermined inward position of the workpiece fabric in such a manner 
that the needle location is automatically changed to maintain parallelism 
with the edgeline of the workpiece fabric in accordance with a result of 
detection to a position of the edgeline. 
Such profile sewing machine is described in, for example, Japanese Patent 
Application Kokai No. 62-68483. The profile sewing machine includes a 
needle bar, a needle bar swinging mechanism, a workpiece fabric detector 
and control means. The needle bar has a lower end securing a sewing 
needle, and is movable in a vertical direction as well as a lateral 
direction with respect to feeding direction of the workpiece fabric. The 
needle bar swinging mechanism is adapted for swinging the needle bar in 
the lateral direction within a predetermined stroke range. The workpiece 
fabric detector is adapted to detect the edgeline of the workpiece fabric. 
And the control means is adapted for controlling the movement of the 
needle bar swinging mechanism in order to provide a needle location at a 
proper inward distance from the workpiece edgeline. 
With the structure, the sewing needle can follow the workpiece fabric in 
the lateral direction even if the latter is laterally deviated during the 
profile sewing operation. Therefore, maintainable is a constant distance 
between the workpiece edgeline and the needle location, to thereby provide 
a constant or uniform stitch margin (the distance between the edgeline and 
the exact needle location or exact stitched line will be referred 
hereinafter as the term "margin"). 
Further, prior to the profile sewing, the sewing needle can be 
automatically moved toward the seam or stitching position when the 
workpiece fabric is mounted on the bed. However, in such conventional 
sewing machine, if the deviation of the workpiece fabric exceeds a 
predetermined level during the profile sewing, the sewing needle cannot 
follow the deviation, to thereby render the automatic profile sewing 
inoperative. In such case, the sewing operation is temporarily suspended 
or the sewing speed is lowered, and then, the workpiece fabric is manually 
moved so as to correct the lateral position of the sewing needle or the 
needle location in response to the lateral movement of the workpiece. When 
correction work is carried out for correcting the position of the 
workpiece fabric, it would be rather difficult for an operator to make 
judgment as to the laterally deviating direction of the sewing needle. As 
a result, a long time period may be required for the positional 
correction. 
Then, improvement is made on such conventional profile sewing machine in an 
invention disclosed in Japanese Patent Application Kokai No. 1-115469. The 
improved sewing machine is provided with instruction means for instructing 
direction in which the sewing needle is to be moved in order to correct 
the deviation or for instructing the deviating direction of the sewing 
needle. The improved sewing machine includes, in addition to the 
mechanical and electrical components equipped in the conventional sewing 
machine described in the above described JP 62-68483, a detection means 
and the instruction means. The detection means detects the deviating 
direction of the sewing needle with respect to a center position of a 
swingable range of the needle, and the instruction means instructs the 
deviating direction of the sewing needle or correcting direction of the 
needle in accordance with a result of the detection by the detection 
means. The instruction means includes a plurality of display lamps 
arranged on a main body of the sewing machine, which lamps indicate the 
deviating direction or deviation-correcting direction. Further, a front 
ruler is conventionally used for guiding travel of the workpiece fabric so 
as to obtain uniform stitching margin, and the ruler is also available in 
the profile sewing machine. 
However, when correcting the needle location in accordance with the 
deviation of the workpiece fabric during profile sewing operation, the 
improved sewing machine still has a problem in that it would be difficult 
for an operator to make judgment as to a proper correcting position from 
the deviated position. In the sewing machine described in the above 
described JP 1-115469, since the deviating direction and the 
deviation-correcting direction are displayed by the lamps arranged on the 
main body, the operator, who draws her particular attention to the sewing 
needle and the workpiece edge, must also turn her eyes upon these lamps in 
sewing operation in order to note the deviating direction and the 
deviation correcting direction. 
Further, in the method using the front ruler, the ruler must be provided at 
a precise position, otherwise sufficient profile sewing cannot be 
attained. Particularly, if the workpiece has a continuous curving 
edgeline, it would be extremely difficult to determine the suitable 
setting position of the ruler. 
For the purpose of information, a commonly assigned U.S. patent application 
Ser. No. 07/602,699 has been filed on Oct. 24, 1990. Further, sewing 
machines of relevant field have been described in U.S. Pat. Nos. 
4,248,168, 4,664,048, 4,823,716, 4,827,858 and 4,869,189. 
SUMMARY OF THE INVENTION 
It is therefore, an object of the present invention to overcome the 
above-described drawbacks and to provide an improved profile sewing 
machine in which correction to a position of the workpiece can be easily 
achieved without turning operator's eye upon a location other than the 
exact stitching position even during the profile sewing operation. 
This and other object of the invention will be attained by providing a 
visualized projection image indicative of a reference stitching line on a 
bed or on a workpiece fabric thereon, which reference stitching line 
serves as a guide line for sewing a predetermined inward position of the 
workpiece fabric in parallelism with the edgeline thereof, to thereby 
obtain a constant stitching margin. 
That is, according to the present invention, there is provided a sewing 
machine including a bed, a sewing needle vertically reciprocable for 
stitching to a workpiece fabric at a position inward from an edgeline and 
in parallelism therewith to provide a margin, sewing needle swinging 
mechanism for swinging the sewing needle within a maximum swingable range 
in a direction across a feeding direction of the workpiece fabric, the 
swingable range defining a swingable center between one and another 
swinging end stroke positions, sewing margin setting means for setting the 
margin, and detection means for detecting the edgeline of the workpiece 
fabric, and the improvement comprises control means connected to the 
sewing needle swinging mechanism, the sewing margin setting means and the 
detection means, the control means comprising means for computing needle 
position data on a basis of first data indicative of the edgeline position 
sent from the detector and second data provided by the sewing margin 
setting means, and memory means which stores therein the needle position 
data, the needle position data being transmitted to the sewing needle 
swinging mechanism so as to move the sewing needle to a position inwardly 
spaced away from the edgeline to provide the margin, and image forming 
means connected to the control means for providing a visualized image of a 
stitching reference line on one of a surface of the bed and the workpiece 
fabric on the bed in accordance with the needle position data, the 
stitching reference serving as a guide line along which the edgeline is 
placed. 
For the profile sewing, the workpiece fabric can be set on a proper 
position on the bed with reference to the stitching reference line 
visually projected on the surface of the bed. Further, during the profile 
sewing operation, if the workpiece fabric is displaced from its proper 
position, the position of the workpiece fabric can be easily correctable 
with reference to the stitching reference line provided on the bed or on 
the workpiece fabric. During the sewing, the operator gazes at the sewing 
needle and the edgeline of the workpiece fabric. In this case, the 
operator can also recognize the reference stitching line, since the line 
is also directly projected on the workpiece fabric or on the bed 
positioned immediately adjacent the sewing needle. Therefore, the operator 
simply looks at this position without turning his or her eyes upon another 
portion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Described will be a profile sewing machine capable of projecting a visible 
projection image indicative of a guide line for stitching along a 
workpiece edgeline with a predetermined distance therefrom according to 
one embodiment of the present invention with reference to accompanying 
drawings. The described embodiment pertains to a profile sewing machine in 
which a sewing needle is automatically moved to a needle location at a 
position inwardly of the workpiece edgeline in accordance with a result of 
detecting the edgeline position of the workpiece fabric. However, the 
embodiment will also be available for an ordinary sewing machine wherein 
no fabric edge detection means is provided. 
FUNDAMENTAL CONSTRUCTION OF THE SEWING MACHINE 
In FIG. 1, a profile sewing machine is illustrated. The machine has a 
machine frame 16 provided with a bed 10, an upstanding support 12 and an 
upper arm 14. The bed 10 is of flat configuration and is provided with a 
throat plate 62. The upstanding support 12 extends from one side of the 
bed 10, and the upper arm 14 horizontally extends from the upstanding 
support 12 in substantially parallel with the bed 10. In the upper arm 14, 
a pattern indicating board 22 is attached in which various stitching 
patterns are illustrated those being stitchable by the sewing machine. 
Further, a selection switch 24 is also provided in the upper arm 14 so as 
to select one of the intended stitching patterns. The upper arm 14 has a 
head 18 at which an energization switch 20 is provided so as to control 
energization and deenergization of a sewing machine motor 48 shown in FIG. 
4. 
The upstanding support 12 is provided with a profile sewing switch 26 
manipulated for the profile sewing, a sewing margin setting means 28 for 
setting intended sewing margin, a control means 30 for controlling 
swingable range of the sewing needle, and a feed amount control means 32. 
Incidentally, the profile sewing is made along a linear stitching in the 
case of the profile sewing machine. Accordingly, the control means 30 and 
32 are manipulated if a pattern sewing other than the linear stitching is 
to be performed so as to control needle swinging amount and feed amount. 
As shown in FIG. 2, within the interior of the head portion 18, a U-shaped 
bracket 34 is stationarily fixed, and a needle bar support frame 38 is 
pivotally supported to the bracket 34 through a vertical rod 36. That is, 
the needle bar support frame 38 is pivotable about an axis of the vertical 
rod 36. More specifically, the needle bar support frame 38 includes a 
first pair of arms 40, 40 extending in one direction and coupled to the 
vertical rod 36, and a second pair of arms 42, 42 for slidably supporting 
a needle bar 44 whose lower end is provided with a sewing needle 46. The 
needle bar 44 vertically extends through the second pair of arms 42 and 42 
and is vertically movable relative to the second pair of arms 42, 42. The 
needle bar 44 is coupled to the sewing machine motor 48 through a link 
mechanism (not shown), and is reciprocally movable by the rotation of the 
motor 48. 
The needle bar support frame 38 is connected to a needle swing control 
motor 50 (FIG. 4) through a link mechanism (not shown). By the rotation of 
the motor 50, the needle bar support frame 38 is pivotably movable about 
the axis of the vertical rod 36, so that the sewing needle 46 is movable 
on the bed along an arcuate locus whose center is coincident with the axis 
of the vertical rod 36, the locus being substantially transverse with 
respect to the running direction of the workpiece fabric. The swingable 
range or stroke of the sewing needle 46 is about 7 mm in the illustrated 
embodiment. 
WORKPIECE FABRIC DETECTOR 54 
At a lower portion of the bracket 34, a workpiece fabric detector 54 is 
provided. The detector 54 includes a light emitting element 56 which emits 
infrared rays having predetermined wavelength range, and a light receiving 
element 58 for receiving the infrared rays emitted from the light emitting 
element 56 and reflected from a reflection surface 74. The detector 54 
also includes an optical filter 60 to permit only the infrared rays having 
the predetermined wavelength range to pass therethrough. The filter 60 is 
positioned in the vicinity of the light receiving element 58. The detector 
54 further includes a signal processing circuit (not shown). The infrared 
rays emitted from the light emitting element 56 is reflected on the 
reflection surface 74 and the reflected light is received in the light 
receiving element 58, to thereby detect a position of the edgeline of the 
workpiece fabric 70. 
As shown in FIG. 2, on an upper surface of the bed 10, a throat plate 62 is 
openably and closeably provided, and a plurality of slots are formed in 
the throat plate 62. Further, feed dogs 64 are upwardly protrudably 
provided in the corresponding slots. These feed dogs 64 are connected to 
the sewing machine motor 48 by means of a link mechanism (not shown), so 
that the workpiece fabric feeding motions are performed in timed relation 
to the vertically reciprocating motion of the sewing needle 46 in 
conjunction with a pressure foot (not shown). Further, as shown in FIG. 4, 
these feed dogs 64 are connected to a feed control motor 65, and 
therefore, these feed dogs undergo controlled workpiece fabric feeding. As 
shown in FIG. 2, the workpiece fabric is fed in a direction indicated by 
an arrow A. Thus, the feed dogs 64 and the pressure foot perform 
controlled workpiece fabric feeding operation for feeding the workpiece 
fabric 70 on the bed in a frontward and rearward directions with respect 
to an operator. 
As shown in FIGS. 2 and 6, the throat plate 62 is formed with an arcuate 
needle slot 72 at a position in conformance with the arcuate moving locus 
of the sewing needle 46, the arcuate locus being given by the swinging 
motion of the needle bar support frame 38. Further, along the arcuate 
needle slot 72 and at a position adjacent thereto, the above described 
reflection surface 74 is provided on the throat plate 62. The reflection 
surface 74 extends in the transverse direction of the running direction of 
the workpiece fabric 70. The reflection surface 74 is of an arcuate recess 
whose radius center is positioned at a central point between the light 
emitting element 56 and the light receiving element 58. The infrared rays 
emitted from the light emitting element 56 is reflected at the arcuate 
surface, and is directed toward the light receiving element 58. 
PROJECTOR 
A projector 52 is provided on the fabric edge detector 54 provided at the 
lower portion of the bracket 34. The projector 52 is adapted for 
projecting, on the surface of the bed 10 or on the workpiece fabric 70 on 
the bed 10, a visualized image of a stitching reference line or a guide 
line at a position indicating the edgeline positioned upstream of the 
sewing needle with respect to the feeding direction A. The projector 52 
fundamentally includes a light source 66, a liquid crystal panel 68 and a 
focusing lens 76 as shown in FIG. 3. The light source 66 is provided by a 
discharge lamp of a metal halides type. The liquid crystal panel 68 is 
adapted to visualize the inward stitching reference in profiling with the 
edgeline of the workpiece fabric in accordance with data of the sewing 
needle position read from a memory of a RAM 96 (described later and shown 
in FIG. 4). The focusing lens 76 is adapted to optically providing the 
visualized image of the stitching reference by making use of the light 
transmitted through the liquid crystal panel 68. In the liquid crystal 
panel 68, a plurality of minute size of shutters (not shown) are arranged. 
These shutters are openably and closably provided by a drive circuit (not 
shown) so as to provide the visible image of the stitching reference. 
Therefore, by transmitting the light from the light source 66 through the 
liquid crystal panel 68 and the focusing lens 76, the visualized stitching 
reference is projected on the surface of the bed 10, or the workpiece 
fabric 70 on the bed 10 those being positioned at a focal point of the 
focusing lens 76. Incidentally, instead of the liquid crystal panel 68, a 
laser beam and a slide film are also available for forming the stitching 
reference. 
ELECTRICAL CONTROL CIRCUIT ARRANGEMENT 
An electrical control circuit arrangement for controlling various 
components and segments in the profile sewing machine of this embodiment 
is shown in FIG. 4. The control arrangement includes a control unit 
primarily including a computer 90 for controlling the sewing machine. The 
computer 90 includes a central processing unit (CPU) 92. The ROM 94 as a 
memory means, and a readable and rewritable RAM 96, those being connected 
to one another by a bus 98. The bus 98 is connected, through an input 
interface 100, the above described sewing machine energization switch 20, 
the stitch pattern selection switch 24, the profile sewing switch 26, the 
sewing margin setting means 28, the control means 30 for controlling the 
swingable range of the sewing needle, the feed amount control means 32, 
and the fabric edge detector 54. The bus 98 is also connected, through the 
interface 100, a timing pulse generator 102, and a clock pulse generator 
104. Details of the pulse generators 102 and 104 are described in JP 
62-68483, and therefore, further description is negligible. 
The bus 98 is connected, through an output interface 108, the above 
described sewing machine motor 48, the needle swing control motor 50, the 
feed control motor 65 and the projector 52. In the RAM 96, a needle 
position data memory 110 is provided, in which stored are data of the 
needle position at a predetermined distance from the edgeline of the 
workpiece fabric 70 and extending in parallelism with the edgeline or in 
profiling therewith at a position inward of the edgeline. Further, in the 
ROM 94, sewing machine control program is stored which program contains 
the sewing needle swinging control routine shown in a flowchart of FIG. 5. 
In accordance with the program, the CPU 92 controls the motors 48, 50, 65 
and the projector 52. 
CONTROL ROUTINE IN PROFILE SEWING OPERATION 
Next, the profile sewing operation, particularly the sewing needle position 
control routine for the profile sewing in accordance with the above 
described embodiment will be described with reference to the flowchart 
shown in FIG. 5. In Step S1, judgment is made as to whether or not an 
intended sewing operation is the profile sewing. This judgment is made in 
accordance with a signal from the profile sewing switch 26 manipulated by 
the operator. To be more specific, if the sewing operation other than the 
profile sewing is intended, the profile sewing switch 26 is rendered OFF, 
so that the judgment falls NO to proceed into Step S2, to thereby render 
the projector 52 OFF. Then, the routine proceeds into Step S3 where 
executed is the sewing operation other than the profile sewing such as 
pattern stitching. 
On the other hand, if the profile sewing operation is selected by the 
manipulation to the profile sewing switch 26, the judgment in Step S1 
falls YES to proceed into Step S4. In Step S4, judgment is made as to 
whether or not the sewing needle 46 is positioned above he bed 10. This 
Step S4 is required, since the sewing needle 46 must be disengaged from 
the workpiece fabric 70 in order to laterally shift the position of the 
sewing needle 46 for the control to the profile sewing. If the sewing 
needle 46 is positioned above the bed 10, sewing needle position data Dp 
(FIG. 6) is computed, and the sewing needle 46 is laterally shifted. The 
judgment in Step S4 is made by the generation of the pulse generated from 
the timing pulse generator 102 or the clock pulse generator 104. 
If the profile sewing has not yet been started, the judgment in Step S4 
falls YES as far as the clock pulse generator 104 generates the clock 
pulse. On the other hand, if the profile sewing has already been started, 
the judgment in Step S4 falls YES as far as the timing pulse generator 102 
generates the timing pulse. Then, the routine proceeds into Step S5 where 
read are workpiece fabric edgeline position data Dd (FIG. 6) and the 
stitching margin data Dw (FIG. 6). If neither the clock pulse nor the 
timing pulse are generated , the judgment in Step S4 falls NO, and the 
routine goes back to a main routine. 
Incidentally, the timing pulse generator 102 generates the timing pulse TP 
only when the sewing machine motor is energized. In response to every 
reciprocating motion of the sewing needle 46, one timing pulse signal is 
generated. Each time the timing pulse is supplied, the feed data and the 
needle swing data are supplied to the CPU 92. 
As best shown in FIG. 6, the edgeline detector 54 has a lateral detectable 
range Dc defined by the right and left edges. The workpiece fabric 
edgeline position data Dd is represented by a distance between the right 
edge of the detectable range Dc and the edgeline of the workpiece fabric 
70. This position data Dd is provided on a basis of the detection signal 
from the edge detector 54. The stitch margin data Dw represents a size of 
the stitching margin, and is set by the manipulation to the stitch margin 
setting means 28. (In FIG. 6, the stitching line is represented by 
characters ST). After these data Dd and Dw are read, the routine proceeds 
into Step S6 where the sewing needle position data Dp is computed. The 
result of the computation is stored in the needle position data memory 
110. In accordance with the present embodiment, the position of the sewing 
needle 46 is derived by the workpiece fabric edgeline position data Dd, 
the stitching margin data Dw, detectable range Dc of the edge detector 54, 
and data Da representing a distance between the left edge of the 
detectable range Dc and a left edge of the swingable rang of the sewing 
needle 46. That is, provided that a left edge of the maximum swingable 
range X of the sewing needle 46 is regarded as a reference position, the 
sewing needle position data Dp is represented by the following equation: 
Dp=Dc-Da-Dd-Dw 
In this equation, the data Da and Dc are constant values and are 
provisionally stored in the memory of the ROM 94. 
After the computation of the position data Dp, the routine proceeds into 
Step S7, where a drive signal is transmitted to the needle swing control 
motor 50 on a basis of the sewing needle position data Dp. Upon rotation 
of the needle swing control motor 50, the sewing needle 46 is shifted 
rightwardly from its left edge position of the maximum swingable range X 
by a distance represented by the needle position data Dp. That is, the 
sewing needle 46 is brought to an intended needle location whose position 
is inwardly spaced away from the edgeline of the workpiece by the intended 
stitching margin. Consequently, the profile sewing can be made in 
parallelism with the edgeline of the workpiece fabric 70. 
Then, in Step S8, the workpiece fabric edgeline position data Dd read in 
the Step S5 is computed in the CPU 92, and in Step S9, the projector 52 is 
rendered ON through the output interface 108 in accordance with the result 
of the computation. Therefore, a proper edgeline position of the workpiece 
fabric 70 can be provided on the bed 10 or on the workpiece fabric 70 on 
the bed by the reference line or guide line as a visualized projection 
image which provides the proper margin set by the operator. The projected 
reference line 80 may be positioned by a distance corresponding to a 
margin length measured from a swingable center line C of the sewing needle 
46. For example, in FIG. 7, if the sewing needle 46 is positioned on the 
swingable center C, the edgeline 70' of the workpiece 70 can be positioned 
coincident with the reference line 80. However, in FIG. 7, the sewing 
needle 46 is displaced leftwardly relative to the swingable center C, and 
the edgeline 70' of the workpiece fabric 70 is positioned slightly 
leftwardly with respect to the reference line 80. Still however, the 
reference line 80 can serve as a guide line for providing a proper margin. 
Thus, the stitching reference line 80 can be utilized as a guide line for 
the operator, so that the workpiece fabric 70 can be positioned at the 
most suitable location on the bed 10 with reference to the stitching guide 
line 80 as far as the sewing needle is positioned within its swingable 
range. 
Furthermore, as shown in FIG. 8, a two dimensional projection image can be 
provided on the bed 10 or on the workpiece fabric. The two dimensional 
image is divided into two sections 80a and 80b by colors different from 
each other in which the stitching reference line 80 divides the image into 
the two sections 80a, 80b. With using the projection image, the operator 
can note the displacing direction of the sewing needle 47 relative to the 
swingable center C. 
Moreover in another modification, a stitching reference has a predetermined 
width as shown in FIG. 9, in which a reference line 80 divides the width 
into halves. The width corresponds to the maximum swingable range X (FIG. 
6) of the sewing needle 46. In other words, as far as the edgeline 70' of 
the workpiece fabric 70 is positioned on one of the sections 80c and 80d, 
the profile sewing can be carried out. For example, if the edgeline 70' is 
positioned on the section 80c, the operator can perform profile sewing 
operation with reference to the reference line 80, while assuming that the 
sewing needle 46 is positioned rightwardly with respect to its swingable 
center line C. However, if the edgeline 70' is positioned out of the 
sections 80c or 80d, it can be understood that the sewing needle 46 is 
positioned at an unwanted swinging position, or the sewing needle cannot 
be any more swung within the arcuate needle slot 72. 
INDICATION FOR THE CORRECTION TO ACTUAL STITCHING POSITION 
In the present embodiment, in addition to the visualization of the 
stitching reference in conformance with the edgeline of the workpiece 
fabric, can be displayed, by steps beginning from Step S10, the direction 
for correcting the displacement of the workpiece fabric if the latter is 
deviated from the profile stitching position. That is, in these steps 
shown in FIG. 5, needle location is investigated, and if the sewing needle 
46 is positioned at rightmost or leftmost stroke end, (in the described 
embodiment, if the sewing needle 46 is positioned within 1 mm from the 
rightmost or leftmost stroke end), the needle position and position 
correcting direction are projected by the projector 52. 
Firstly, in Step S10, determination is made as to whether or not the sewing 
needle 46 is positioned within 1 mm from the leftmost end of the maximum 
swingable range on a basis of the needle position data Dp. If it is the 
case, the determination falls Yes, and the routine goes into Step S11. In 
Step S11, the correcting direction is projected by the projector 52 as 
shown in FIG. 7, where an arrow image 82 directing toward the right is 
displayed on the bed or on the workpiece fabric. Therefore, the operator 
can note that the sewing needle is excessively displaced leftwardly, and 
the correcting direction is determined as to be rightwardly. 
Incidentally, during the profile sewing, the sewing operation is 
temporarily stopped, and the workpiece fabric 70 is manually moved for the 
correction. Alternatively, the sewing speed is lowered for controlling the 
position of the workpiece fabric without temporary stop of the profile 
sewing operation. Further, prior to the profile sewing operation, by 
moving the fabric 70 in accordance with the arrow display 82, the sewing 
needle 46 can stitch the workpiece at a position approximately at the 
swingable center line C. 
On the other hand, if the sewing needle 46 is positioned away by more than 
1 mm from the leftmost stroke end, the judgment in Step S10 falls No, so 
that the routine proceeds into Step S12. In the Step S12, judgment is made 
as to whether or not the sewing needle 46 is positioned within 1 mm from 
the rightmost end stroke. This judgment is based on an equivalent judgment 
as to whether or not the sewing needle 46 is positioned within a range of 
6 mm to 7 mm from the leftmost stroke end. If the judgment falls Yes, the 
routine goes to Step S13 where, as shown in FIG. 7, a leftwardly directing 
arrow image 84 is provided on the bed 10. Therefore, the operator can 
notify that the sewing needle 46 is excessively displaced rightwardly so 
that the correcting direction is revealed to be left. 
Further, if the sewing needle 46 is far spaced away from the rightmost 
stroke end by more than 1 mm, the judgment in Step S12 falls No, so that 
the routine returns back to the main routine. In the latter case, the 
sewing needle 46 is not largely displaced, and it is unnecessary to 
perform positional correction. Therefore, the operator can continue the 
profile sewing operation. 
In the above described embodiment, the profile sewing operation is made on 
the premise of the linearly orienting edgeline of the workpiece. However, 
even if a curved or arcuate edgeline is provided, a curved or arcuate 
stitching reference line 80 can be provided from the projector 52. This 
can be done by storing a data of radius of curvature or pattern data of a 
paper pattern into the control device, and by supplying the data to the 
projector 52. 
Further, in the above described embodiment, the profile sewing machine 
provided with the fabric edgeline detector 54 is used for embodying the 
invention. However, the present invention is also available for a sewing 
machine having an automatic profiling mechanism for automatically 
following the sewing needle along the workpiece edgeline, or for an 
ordinary sewing machine having no workpiece edgeline detector. In other 
words, the present invention can be established by incorporating the above 
described memory means which stores therein data of the needle position 
positioned inward of the edgeline by a given distance and the projector 
for projecting the stitching reference or guide line in accordance with 
the needle position data read out from the memory. Furthermore, the 
present invention can also be reduced to practice by the employment of the 
projector 52 on the sewing machine other than the linearly stitching 
profile sewing machine such as a zigzag stitch sewing machine or an 
embroidery sewing machine in which the workpiece fabric is abruptly moved 
on a horizontal plane while the sewing needle is vertically reciprocated.