U.S. patent number 3,746,443 [Application Number 05/184,226] was granted by the patent office on 1973-07-17 for magnetically controlled machine programmer.
Invention is credited to Lionel Russell Hickey.
United States Patent |
3,746,443 |
Hickey |
July 17, 1973 |
MAGNETICALLY CONTROLLED MACHINE PROGRAMMER
Abstract
A machine programmer is provided for controlling work performed
on a work piece which moves through separate work stations wherein
a shift register selectively energizes and deenergizes the work
stations in response to movement of the work. The shift register
includes a multisectioned cylinder divided into individual
light-tight sectors, each having a slot along the periphery of the
cylinder through which light can pass, and is rotatably driven by
an endless photoconductive member. Each sector has a switching
circuit which includes a lamp and a photosensitive device. When it
is desired to make electrophotographic copies of an original, the
lamp is turned on by an input signal from an electromagnet adjacent
the cylinder which is energized in accordance with the number of
copies to be made. As each sector moves along a circular path past
the electromagnet, a reed switch is operated to turn on the lamp,
whose light by means of a photosensitive device maintains the
circuit, and hence the lamp itself, in activated condition. As the
cylinder is rotated the light in each lighted sector activates a
series of photosensitive devices spaced around the cylinder to
energize circuits connected to electrophotographic stations along
the path of the photoconductive element in response to movement of
the photoconductive element to make copies of the original.
Inventors: |
Hickey; Lionel Russell
(Rochester, NY) |
Family
ID: |
26692448 |
Appl.
No.: |
05/184,226 |
Filed: |
September 27, 1971 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
19644 |
Mar 16, 1970 |
|
|
|
|
Current U.S.
Class: |
399/76 |
Current CPC
Class: |
G05B
19/063 (20130101); G03G 21/145 (20130101); G05B
19/124 (20130101) |
Current International
Class: |
G05B
19/12 (20060101); G05B 19/06 (20060101); G05B
19/04 (20060101); G03G 21/14 (20060101); G03g
015/00 () |
Field of
Search: |
;355/14,16,3 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Greiner; Robert P.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of Ser. No. 19,644 entitled,
"MAGNETICALLY CONTROLLED MACHINE PROGRAMMER" filed Mar. 16, 1970 in
the name of Hickey.
Reference is made to copending U.S. application Ser. No. 19,999,
"Machine Programmer" by Lionel R. Hickey and Ellsworth J. McCune,
filed on even date herewith.
Claims
We claim:
1. In electrophotographic apparatus having an elongated
electrosensitive member defining a plurality of selectable image
areas and movable along an endless first path, the combination
comprising:
a. a plurality of electrophotographic work stations located along
said path including an actuable exposure station operative when
actuated for exposing a selected image area of said member to a
light image to form a latent electrostatic image, a development
station for applying toner to such electrostatic images on said
member to form toner images, and an actuable transfer station
operative when actuated for transferring a toner image on a
selected image area of said member to a receiving medium;
b. means defining a second predetermined path; and
c. means movable along said second path for sequentially actuating
and de-actuating said exposure and transfer stations in accordance
with a predetermined sequence in timed relation to movement of said
member past said stations to effect sequential operation of said
exposure and transfer stations with respect to a selected image
area during movement around said endless path, said sequential
means being effective to simultaneously produce at least two of
such predetermined sequences of work station actuations to form at
least two latent electrostatic images in selected image areas
respectively prior to completing the transfer of the toner image
corresponding to the first of such two formed latent electrostatic
images to a receiving medium, said sequential means includes an
element movable along said second predetermined path; an actuable
first source of energy positioned along said second path; an
actuable second source of energy on said element; means for
activating said first energy source; first energy sensor means on
said element responsive to said first energy source upon movement
of said element along said second path past said first energy
source to activate said second energy source; and second energy
sensor means disposed along said second path and spaced from said
first energy source and coupled to at least one particular work
station for causing said particular work station to perform a work
operation on said member in response to energy from said second
energy source upon movement of said element past said second energy
sensor means.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a machine programmer for controlling
operations on a work piece in response to movement of the work
piece and more particularly to a machine programmer which includes
a shift register for controlling electrophotographic operations on
a photoconductive member in response to movement of the
photoconductive member through an endless path.
2. Description of the Prior Art
In many machine control applications it is necessary to perform a
series of predetermined functions on selective elements as they
pass through various work stations along a path. Such machine
control problems in general require some type of shift register or
control device which permits the insertion of action information at
the start of a register cycle for those elements requiring action
and provides a shifting of this action information through the
register as the work element passes through the separate work
stations. It is necessary that multiple sections of the register
can receive action information when desired and that each section
of the register will shift at the same time as the work element
moves from one work station to the next. Thus, it is of utmost
importance that the shift register shifts each time the work piece
advances from one station to the next station and that this shift
occurs simultaneously.
One area in which this type of machine control is necessary is in a
continuous electrophotographic process wherein an endless
photoconductive member, such as a drum or an endless web moves
continuously through a series of electrophotographic stations to
form a toner image from an original, which toner image is
transferred to a receiver sheet to make a copy of the original.
Typically, the photoconductive member first is advanced past a
charging station which places a generally uniform electrostatic
charge on the photoconductive member, such as by corona discharge.
Next it passes an exposure station where it is exposed to a pattern
of radiation corresponding to an original to be copied. This
discharges a photoconductive member in the exposed areas to form an
electrostatic latent image. This image is toned at a developing
station to form a toner image. As the photoconductive member
continues along its endless path the toner image can be utilized in
any one of several ways but is commonly transferred to a receiver
sheet at a transfer station to form a copy of the original. At a
subsequent station any residual toner particles remaining on the
photoconductive member are cleaned therefrom so that the
photoconductive member may be recycled through the stations just
described.
With such electrophotographic apparatus, it is clear that the
operation of each station along the path of the photoconductive
member must be perfectly synchronized with the movement of the
photoconductive member so that each work function is performed at
the proper time in order to made a satisfactory print. It can be
seen that if any one function is advanced or retarded slightly with
respect to the movement of the photoconductive member the resulting
image may be imperfect.
Control of an electrophotographic endless web is disclosed in U.S.
Pat. No. 3,134,090 to Blakely which issued May 19, 1964 and is
entitled "Proportional Space Recording Devices." This device is
directed to the formation and projection of letters having varying
dimensions onto a photoconductive member so that they are
proportionally spaced. In U.S. Pat. No. 3,294,050 to Corley et al.
which issued Dec. 27, 1966 and is entitled "Pattern Mechanism for a
Tufting Machine and a Process for Producing a Patterned Tufted
Fabric," is disclosed a control device having a plurality of
photoelectric cells within a drum wherein light is intermittently
interrupted to control a mechanism associated with the drum. U.S.
Pat. No. 3,225,207 to Connors et al. which issued Dec. 21, 1965 and
is entitled "Radiation Responsive Selectively Programmed
Controller," discloses a rotating disc having shutters which are
opened or closed to admit or block light from photocells behind the
shutters. The disc is rotated to control machine operations and is
electrically pulsed from the machine. A light is provided adjacent
the photocell to maintain the circuit in activated condition once
the photocell has been triggered by light passing through the
shutters in the rotating disc. It can be seen that although the
prior art provides a number of devices for controlling machine
operations no machine programmer is disclosed wherein the control
itself is moved in response to movement of the work piece.
SUMMARY OF THE INVENTION
In accordance with this invention a machine programmer is provided
which includes a shift register into which is fed information as to
the number of times one or more operations are to be performed on a
work piece. Output signals are derived from the shift register
which is moved in response to movement of the work piece along a
path past one or more work stations where the operations are
performed. The input signal is derived from a first electromagnetic
energy source associated with the shift register. The shift
register includes an element having at least one signal circuit for
producing an output signal. This circuit includes a first energy
sensor for enabling the signal circuit in response to a signal from
the first electromagnetic energy source and a second source of
electromagnetic energy which retains the signal circuit in enabled
condition and provides an output signal. At least one second energy
sensor is electrically connected to a work station provides a
signal thereto in response to the output signal upon movement of
the shift register past the second sensor. Means is provided to
disable the signal circuit upon movement of the shift register and
work piece through a complete cycle.
More particularly the shift register comprises a rotatable cylinder
divided into a plurality of light-tight sectors, each of which has
a slit in the periphery thereof through which light can pass and
which contains a signal circuit which includes an output signal
lamp that is enabled in response to electromagnetic energy as an
input signal from an information center as to the number of
operations to be performed on the work piece. Upon rotation of the
cylinder in response to movement of the work piece, each sector
will move past an electromagnet, which when energized will operate
a reed switch in the signal circuit which enables the signal
circuit to illuminate the output signal lamp. The light energy from
this signal lamp shines on a photocell in the circuit to maintain
the circuit in enabled condition after this now lighted sector
rotates away from the electromagnet. Other photocells are spaced
about the periphery of the cylinder and are sequentially energized
by the output signal lamp as the lighted sector moves therepast.
Each of these photocells are connected to circuits at the work
stations to control operations on the work stations to control
operations on the work piece in response to its movement. At the
end of a complete revolution of each sector a permanent magnet
disables the circuit by operating a second reed switch therein to
turn off the signal lamp so that further work operations will not
be performed upon the work piece unless the input lamp enables the
circuit again. The electromagnet provides a signal to the cylinder
sectors until the number of sectors lighted corresponds to the
number of times the information center indicates that work is to be
done on the work piece.
In one embodiment of the present invention, the work piece
comprises an endless photoconductive member, such as an endless
belt or drum which moves past a plurality of electrophotographic
stations, such as a charging station, an exposure station, a
developing station, a transfer station and a cleaning station. The
shift register is mechanically connected to the belt whereby the
shift register turns one complete revolution for each complete
cycle of the photoconductive member so that all electrophotographic
operations on the photoconductive web occur in proper timed
sequence. Each sector of the shift register corresponds to a print
sector of the photoconductive member. As used herein, the term
"print sector" is that portion of the photoconductive member
required for making a single print.
When it is desired to make a number of electrophotographic prints
from an original, the operator places this information into an
information center as by means of a keyboard connected to a print
control circuit. The print control circuit responds by providing a
signal to a drive means for the endless photoconductive member and
also by energizing an electromagnet to provide an input signal to
the shift register. As the photoconductive member begins to move
through a cycle the shift register will move in response thereto so
that one of the sectors is brought into a position to be enabled by
the electromagnet operating a reed switch to cause the output
signal light to be turned on. As the lighted sector rotates the
output light therein shines onto the first of several radiation
receptors or photosensitive cells spaced about the periphery of the
shift register. The first photocell provides a signal to the
charging station to begin charging of the corresponding print
sector of the photoconductive member. As the photoconductive member
continues to move this print sector is charged as it moves through
the charging station until the lighted shift register reaches a
second photosensitive cell positioned along the periphery of the
shift register, which second photosensitive cell provides a second
signal to turn off the charging station. Continued movement of the
photoconductive member results in continued rotation of the shift
register as the charged print sector is moved into an exposure
station which is triggered by another photosensitive cell now
receiving light from the lighted shift register sector. This causes
an exposure device, such as an electronic flash, to imagewise
expose the charged print sector at precisely the time when the
print sector is centered in the exposure station.
Similarly, at the developing station a development electrode is
turned on and off, respectively, by two spaced photosensitive
devices which are responsive to movement of the lighted sector past
them in order to develop a toner image. At an appropriate time
photocells are energized by the lighted sector to turn on a paper
feeding device which causes a receiver sheet to be brought into
position at a transfer station. The lighted sector also energizes a
second photocell to discontinue paper feeding after one sheet of
paper has been fed. When the print sector reaches the transfer
station another photocell can be energized as by the shift register
to energize a transfer electrode to cause the toner image to be
transferred from the photoconductive member to the receiver. The
cleaning station normally is not controlled by the shift register
since cleaning can be a continuous operation which is not dependent
upon the position of the print sector in its cycle.
If more than one print is to be made, additional sectors of the
shift registers are sequentially lighted by the electromagnet in
response to a signal from the information center. These lighted
sectors energize the various stations described in the proper
sequence to perform electrophotographic operations on subsequent
print sectors of the photoconductive member. As each shift register
sector completes a cycle, its circuit is disabled, as by
momentarily closing a second reed switch by means of a permanent
magnet to turn off the output signal light which once turned off,
will remain off, since the photosensitive cell in the circuit is no
longer energized. The sector remains off unless a signal from the
print control circuit via the electromagnet indicates that
additional copies are needed whereupon it is enabled again and
becomes lighted to cause another series of electrophotographic
operations to be performed on the photoconductive member as a
corresponding print sector moves through the various
electrophotographic stations.
Additional advantages of this invention will become apparent from
the description which follow, taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic side elevation of an electrophotographic
device incorporating the shift register of this invention;
FIG. 2 is a diagrammatic enlarged view of the shift register of
FIG. 1;
FIG. 3 is an offset section taken along lines 3--3 of FIG. 2
showing further details of the shift register;
FIG. 4 is a circuit diagram of the circuit associated with each
sector of the shift register; and
FIG. 5 is a circuit diagram of an amplifier circuit which forms
part of the circuit for controlling each electro-photographic
station.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A typical electrophotographic apparatus E is shown in FIG. 1 which
is controlled by a shift register R. The latter controls the
sequence and timing of electrophotographic operations on a
photoconductive member such as endless photoconductive web 2 which
is mounted for movement along a path defined by the rollers 3 and 4
as shown. The web is driven by a drive means, such as motor 5
connected to a roller 3, as shown. Electrophotographic device E
includes a charging station 6, an exposure station 8, a developing
station 10, a paper feeding station 12 for feeding sheets of paper
from a paper supply 13 to a transfer station 14, the finished
prints being collected in a receptacle 16. Of course, it will be
understood that after transfer the receiver sheets could pass
through a fusing station (not shown), before being fed to
receptacle 16. After transfer the photoconductive web 2 passes a
cleaning station 18. The cycle then is repeated. It will be
understood that the sequence of operations described above is by
way of example only and that additional operations can be
controlled by the shift register as required or that some of the
operations described may be performed by other means if
desired.
The shift register R includes a rotatable segmented and slotted
cylinder 20 which is driven by suitable means, such as belt 22
extending from a pulley around roller 3 so that movement of the
shift register is in direct response to movement of photoconductive
web 2. When it is desired to make one or more prints a start button
on an information center (not shown) is depressed and information
as to the number of prints to be made is fed to print control
circuit 24. The print control circuit energizes motor 5 so that
photoconductive web begins moving through a cycle. Also, it
energizes an initiator device such as an electromagnet 25 to enable
the sectors of cylinder 20 as they rotate past electromagnet 25.
Cylinder 20 may be divided into any number of sectors but is
illustrated as being divided into 5 sectors, 26, 27, 28, 29, and
30.
Cylinder 20 includes a bottom wall 32 and a peripheral side wall 34
having a plurality of slots 36, one slot being provided for each
sector of the shift register, as best seen in FIGS. 2 and 3. Light
can shine through this slit to effect operation of the various
electrophotographic stations in a manner to be described. A center
hub 38 extends away from the cylinder from bottom wall 32 as shown
in FIG. 3 which has a flange 39 and a central opening 40 to provide
a bearing surface about which cylinder 20 rotates on bearing 42.
Hub 38 and flange 39 form a pulley about which belt 22 extends so
that cylinder 20 is rotatably driven in response to movement of
photoconductive web 2. A circular or disc-shaped circuit-board 44
is mounted within cylinder 20 and is centered as it is positioned
therein by means of a stub shaft 45 which extends from bearing 42
and produces through a hole in the circuitboard when the
circuitboard is in place. The circuitboard is spaced from bottom 32
by means of a plurality of spacers 46 and is held in position by
fastening means 48 extending into the spacers, as shown. The
individual sectors are formed by a divider 50 having a circular
center portion 51 which has a plurality of radial flanges 52
extending to sidewall 34, as shown. A circular cover 54 fits over
divider 50 and engages sidewall 34 to complete cylinder 12 and to
form the separate light-tight sectors.
Conveniently, cylinder 20 is mounted within a circular sleeve 56
having a plurality of slots 58 spaced therearound. As cylinder 20
is rotated the slots 36 therein are sequentially aligned with slots
58 in sleeve 56. Adjacent each of slots 58 is a photosensitive
device which is connected to a circuit associated with one of the
electrophotographic stations. When a slot 36 of an enabled sector
is aligned with a slot 58 of sleeve 56 the light within the sector
shines through the aligned slots onto the photosensitive device
adjacent the slots to provide a control signal to an
electrophotographic station to control an electrophotographic
operation on the corresponding print sector of web 2. Slots 58 and
the corresponding photosensitive devices are so spaced about the
periphery of cylinder 20 that a signal is provided to an
electrophotographic station at precisely the appropriate time with
respect to the position of the corresponding print sector so that
each step occurs in proper sequence and in proper time relation to
the position of each print sector of the web.
In the present embodiment, the input signal from print control
circuit 24 is to electromagnet 25 which is energized so that a reed
switch 60, which is part of enabling circuit 63 of FIG. 4 and will
saturate the base of transistor 64 which is negative with respect
to the emitter. This will drive transistor 64 to saturation and
light 72 will turn on and illuminate sector 26 and photocell or
phototransistor 62. The emitter of transistor 64 is connected to
ground through a diode 66 and lamp 72 is connected to ground
through resistor 68 as shown. Another resistor 70 is connected
between the base of transistor 64 and ground.
Power to enabling circuit 63 of FIG. 4 is provided by means of
brushes 74, 75, and 76 (FIG. 3) which are mounted on blocks 77
attached to bearing 42. Conveniently, brushes 74 are connected to
ground; brushes 75 are connected to an arming circuit at a
potential, such as -12 volts to heat the filament of light 72 so
that when reed switch 60 is closed light 72 will immediately be
illuminated without requiring a warmup period. Brushes 76 are also
connected to a potential source, such as a -12 volts, and provide
the power to light lamp 72. Conveniently, the brushes engage slip
rings 78, 79 and 80 on the bottom of circuitboard 44 and are
connected to the other parts of the enabling circuit of FIG. 4 by
means of a printed circuit (not shown) on circuitboard 44. Thus,
brushes 74 are connected to ground at input 81; brushes 75 are
connected to input 84 and brushes 76 are connected to input 82. The
use of input 82 is optional and is used only when it is desirable
to have light 72 remain on continuously for more than one cycle for
a particular machine operation. In practice, the optional
connection between input 82 and brushes 76 can be made through a
normally open switch (not shown). Once light 72 has been turned on
the circuit effectively locks the light on in that the light level
from lamp 72 is sufficient to keep phototransistor 62
saturated.
However, light 72 is turned off at the end of one complete
revolution by a permanent magnet 85, shown in FIGS. 2, 3 and 4.
This magnet is positioned within sleeve 56 so that a second reed
switch 86 connected between ground 81 and the base of transistor
64, is closed as it moves thereacross. Thus, transistor 64 becomes
unsaturated and light 72 is turned off. Conveniently, bottom 32 of
cylinder 20 is provided with an opening 108 immediately below the
end 88 of reed switch 86 so that the magnetic field from magnet 85
is not blocked at that position.
After electromagnet 25 enables a sector, the sector rotates in a
clockwise direction, as viewed in FIG. 2. As it rotates it becomes
aligned with a slot 58 adjacent a photocell 90 in charging station
circuit 91 at precisely the same time that a print sector of
photoconductive web 2 enters charging station 6. This enables
circuit 91 which causes a corona discharge device or other charging
device to be turned on as photoconductive web 2 moves thereunder.
At precisely the time that the end of the print sector of
photoconductive web 2 reaches the end of charging station 6 the
lighted sector of shift register R has rotated to a position where
light 72 shines through the slot 58 adjacent photocell 92 in
charging station circuit to disable the circuit to discontinue
charging.
As the photoconductive web 2 continues to move the now charged
print sector enters exposure station 8. At the point in the cycle
where the print sector is centered in the exposure station the
lighted sector of shift register R is in a position so that the
light shines through a slot 58 adjacent photocell 94 of exposure
station circuit 95 to cause exposure of the charged print sector to
a pattern of radiation, as by an electronic flash. The charged
print sector is discharged in the exposed areas and remains charged
in the unexposed areas to provide an electrostatic image.
When the print sector reaches developing station 10, the lighted
sector is in a position so that the light shines upon photocell 97
of developing station circuit 98 to activate the developing
station. This may consist of agitation and movement developer fluid
and of energizing a development electrode to facilitate development
of the electrostatic image to form a toner image. Just as the toner
image leaves developing station 10, the shift register is rotated
to a position so that photocell 99 is energized to disable
developing station circuit 98 to turn the developing station
off.
As the toner image moves toward transfer station 14, the lighted
sector energizes photocell 101 at the appropriate time to cause
paper feeding circuit 102 to feed a sheet of receiver paper by
means of paper feeding station 12 from paper supply 13 to transfer
station 14. The paper feeding operation is discontinued upon
energization of photocell 103. As the toned image enters transfer
station 14 photocell 105 is energized to enable transfer station
circuit 106 to effect operation of transfer station 14, such as to
energize a transfer electrode to facilitate transfer of the toner
image from photoconductive web 2 to the receiver sheet. After the
print sector of web 2 leaves transfer station 14 shift register R
has reached a position where photocell 107 is energized to cause
transfer station circuit 106 to disable transfer station 14.
As photoconductive web 2 continues to move the print sector passes
through cleaning station 18 where any residual toner particles
thereon removed. Cleaning station 18 need not be operated in
accordance with movement of shift register R since cleaning can be
a continuous operation rather than being performed just when a
print sector is in the cleaning station.
As the web continues to move cylinder 20 continues to rotate so
that a sector reaches a position such as the position of sector 30
where the reed switch 86 passes over permanent magnet 85 to turn
off lamp 72, as described above.
It will be understood that if more than one print is to be made
successive sectors are lighted by electromagnet 25 as each sector
moves past it so that different electrophotographic operations are
performed on different print sectors of photoconductive web 2 at
the same time. The number of sectors which are lit correspond in
number to the number of prints desired. For example, if three
prints are desired, three sectors are lighted. On the other hand,
if seven prints are desired, each sector is lighted once and the
first two sectors are lighted twice. The print control circuit 24
includes means (not shown) to sense the number of sectors lighted
and when the proper number of sectors have been lighted
electromagnet 25 is turned off so that no further sectors are
lighted.
Each of the circuits for controlling electrophotographic operations
include an amplifier circuit which generates a signal in response
to energization of the photocell or phototransistor associated with
it by lamp 72. FIG. 5 is exemplary of this circuit and shows such a
circuit associated with photocell 90. This photocell is connected
through a resistor 110 and a lead 111 to ground and is connected to
the base of a transistor 112 by means of a second resistor 114.
When no light falls upon photocell 90, there is a reverse bias
across it and across transistor 112. However, when phototransistor
90 is illuminated by light 72 transistors 112 and 116 become
saturated. The amplifier circuit also includes a resistor 120
connected between transistors 112 and 116 and a negative power
source through lead 122, as shown. Thus, when no light falls upon
photocell 90 the output potential at lead 118 is near the negative
input potential at input lead 122, whereas when photocell 90 is
illuminated the output potential at lead 118 is near ground.
From the foregoing, the advantages of this invention are readily
apparent. A machine programmer has been provided which includes a
shift register that operates in response to movement of a work
piece wherein the shift register controls different operations to
be performed on the work piece as the work piece moves from station
to station. In an electrophotographic application the movement of
an endless photoconductive member such as endless web causes a
circular shift register having a plurality of light-tight sectors
to rotate through one complete revolution in response to movement
of print sector of the photoconductive member through a complete
cycle. The shift register sectors can be energized or lighted by an
initiator signal, such as an electrogmagnet. One sector is lighted
for each print which is desired. As the shift register rotates,
each lighted sector sequentially energizes photocells to provide
signals to respective work stations along the path of the
photoconductive member to perform electrophotographic operation on
the print sectors in exact time sequence with the passage of the
print sectors through each electrophotographic station.
The invention has been described in detail with particular
reference to a preferred embodiment thereof, but it will be
understood that variations and modifications can be effected within
the spirit and scope of the invention.
* * * * *