CA1058905A - Controlling energy to flash lamp response to toner image density - Google Patents
Controlling energy to flash lamp response to toner image densityInfo
- Publication number
- CA1058905A CA1058905A CA251,387A CA251387A CA1058905A CA 1058905 A CA1058905 A CA 1058905A CA 251387 A CA251387 A CA 251387A CA 1058905 A CA1058905 A CA 1058905A
- Authority
- CA
- Canada
- Prior art keywords
- copy sheets
- flash lamp
- energy storage
- density
- signals
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Fixing For Electrophotography (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An area coverage sensing apparatus for sensing toner image density on copy sheets. A first array of fiber optic elements connected to a light source transmits illumination to copy sheet. A second array of fiber optic elements re-ceives the reflected illumination from the copy sheets and transmits the reflected illumination spacially concentrated to a remote location. A photodiode at the remote location con-verts the spatially concentrated optical information into electrical signals proportional thereto for subsequent input.
An area coverage sensing apparatus for sensing toner image density on copy sheets. A first array of fiber optic elements connected to a light source transmits illumination to copy sheet. A second array of fiber optic elements re-ceives the reflected illumination from the copy sheets and transmits the reflected illumination spacially concentrated to a remote location. A photodiode at the remote location con-verts the spatially concentrated optical information into electrical signals proportional thereto for subsequent input.
Description
s The invention relates generally to an area coverage sensing apparatus and in particular -to energy control for flash lamp devices by sensing the density of toner images on copy sheets produced by a copier/duplicator system.
In the xerographic process used for copier/duplicator systems, a plate, generally comprising a conductive backing upon which is placed a photoconductive insulating surface, is uniformly charged and the photocnductive surface then exposed to a light image of an original to be reproduced.
`; ~he photoconductive surface is caused to become conductive under the influence of the light image so as to selectively dissipate the electrostatic charge found thereon to produce what is developed by means of a variety of pigmented resin materials specifically made for thij purpose w~ich are known ~ ;, in the xerograp~ic art as l'toners". The toner material is electrostatically attracted to the latent image areas on the plate in proportion to the charge concentration found thereon.
Areas of high charge concentration become areas of high toner density while correspondingly low charge image areas become proportionally less dense~ The developed image is transferred to a final support material, typically paper, and fixed thereto to form a permanent record or copy of the original.
Many forms of image fixing techniques are known in the prior art, the most prevalent of which are vapor fixing, heat fixing, pressure fixing or combination thereof as de-scribed in U. S. Patent ~o. 3,539,161. Each of ~hese techni~ues, b~ itself ox in combination sufer from deficiencies which make their use impractical or difficult for ~pecific xerographic applications. In general, it has been difficult to con~truct an entirely satisfactory heat fuser having a
In the xerographic process used for copier/duplicator systems, a plate, generally comprising a conductive backing upon which is placed a photoconductive insulating surface, is uniformly charged and the photocnductive surface then exposed to a light image of an original to be reproduced.
`; ~he photoconductive surface is caused to become conductive under the influence of the light image so as to selectively dissipate the electrostatic charge found thereon to produce what is developed by means of a variety of pigmented resin materials specifically made for thij purpose w~ich are known ~ ;, in the xerograp~ic art as l'toners". The toner material is electrostatically attracted to the latent image areas on the plate in proportion to the charge concentration found thereon.
Areas of high charge concentration become areas of high toner density while correspondingly low charge image areas become proportionally less dense~ The developed image is transferred to a final support material, typically paper, and fixed thereto to form a permanent record or copy of the original.
Many forms of image fixing techniques are known in the prior art, the most prevalent of which are vapor fixing, heat fixing, pressure fixing or combination thereof as de-scribed in U. S. Patent ~o. 3,539,161. Each of ~hese techni~ues, b~ itself ox in combination sufer from deficiencies which make their use impractical or difficult for ~pecific xerographic applications. In general, it has been difficult to con~truct an entirely satisfactory heat fuser having a
-2- :
,~
-~5~ 5 short warm up time, high efflciency, and each of control.
further problem associated with heat fusers has been their tendency to burn or scorch the support material. Pressure fixing methods whether hot or cold have created problem~
with image offsetting~ resolution, degradation and producing consistently a good class of fix. On the other hand, vapor fixing, which typically employs a toxic solvent has proven commercially unfeasible because of the health haæard involved~
Equipment to sufficiently isolate the fuser from the surrounding ambient air must by its very nature be complex and costly.
With the advent of new materials and new xerographic processing techniques, it is now feasible to construct auto-matic xerographic reproducing apparatus capable of producing copies at an extremely rapid rate. Radiant flash fusing is one practical method of image fixing that will lend itself readily to use in a high speed automatic processor as described ~; in U. S. Patent 3,529,129. The main advantage of the flash fuser over the other known methods is that the energy, which is propagated in the form of electromagnetic waves, is in-stanteously available and requires no inter~ening medium for its propagation. As can be seen, such apparatus does not require long warm up periods nor does the energy have to be transferred through a relatively slow conducti~e or convective heat transfer mechanism.
Although an extremely rapid transfer of energy between the source and the receiving body is afforded by the flash fusing process, a major problem with flash fusing a~ applied to the xerographic fixing art, has been designing apparatus which can operate at one power level adequate to fuse all pos~ible copy prints under varying conditions. This :
,~
-~5~ 5 short warm up time, high efflciency, and each of control.
further problem associated with heat fusers has been their tendency to burn or scorch the support material. Pressure fixing methods whether hot or cold have created problem~
with image offsetting~ resolution, degradation and producing consistently a good class of fix. On the other hand, vapor fixing, which typically employs a toxic solvent has proven commercially unfeasible because of the health haæard involved~
Equipment to sufficiently isolate the fuser from the surrounding ambient air must by its very nature be complex and costly.
With the advent of new materials and new xerographic processing techniques, it is now feasible to construct auto-matic xerographic reproducing apparatus capable of producing copies at an extremely rapid rate. Radiant flash fusing is one practical method of image fixing that will lend itself readily to use in a high speed automatic processor as described ~; in U. S. Patent 3,529,129. The main advantage of the flash fuser over the other known methods is that the energy, which is propagated in the form of electromagnetic waves, is in-stanteously available and requires no inter~ening medium for its propagation. As can be seen, such apparatus does not require long warm up periods nor does the energy have to be transferred through a relatively slow conducti~e or convective heat transfer mechanism.
Although an extremely rapid transfer of energy between the source and the receiving body is afforded by the flash fusing process, a major problem with flash fusing a~ applied to the xerographic fixing art, has been designing apparatus which can operate at one power level adequate to fuse all pos~ible copy prints under varying conditions. This :
-3-~s~
has led to several problems including a vast over cons~nption o power and poor negative latitude.
With the present invention the density of toner images on an individual copy sheet is sensed via its reflectivity which is then used to regulate the power supply of a flash lamp system. -In accordance with one aspect of this invention there is provided an improved interface system for controlling ~
~; energy to a flash li~mp in response to toner image density on - ~;
copy sheets comprising: means for advancing copy sheets bearing toner images along a predetermined path, flash lamp means posi- ; ;
tioned in the path Eor processing said copy sheets, area cover- --:~. , ,:, aye sensing means for sensing the densitv of the toner images ;
on said copy sheets advanced and producing spatially concentra-~ , .
ted optical signals thereof and converting the optical signals into electrical signals proportional thereof, said area coverage sensing means including first fiber optic means for transmitting ~ ;~
.: . . : - :.. .
illumination to a predetermined location in the copy sheet path `
and second fiber optic means for receiving illumination reflect-ed from said copy sheets and transmitting reflected illumination -' to a remote location, first circuit means for receiving and conditioning said electrical signals, variable energy storage ~ ;
means including at least one chargeable capacitor for driving said flash lamp means, and second circuit means coupled to said ~, energy storage means for receiving the conditioned signals and ~`
j controlling the input to said energy storage means for driving said flash lamp means in response to the density of toner images ' on said copy sheets. ~;
In accordance with another aspect of this inven-- 30 tion there is provided a method of controlling the energy to a flash lamp in xesponse to toner image density on copy sheets comprising the steps of optically sensing the density of toner _4_ ~:i :: ' -:
.. . .
images on copy sheets advanced along a path, converting the optically sensed information .into electrical signals proportional thereto, and transmitting the signals to uni directional switch-ing means coupled to a variable energy storage device to control the input to said energy storage device for driving the flash lamp in response to the densi.ty of toner images on said copy sheets.
For a better understanding of the invention as well as further features thereof, reference is had to the following .
description of the invention to be read in conjunction with the drawings wherein:
Figure 1 illustrates xerographic reproducing apparatus incorporating a flash fusing system in accordance with the invention;
Figure 2 i5 a block diagram of the flash fusing system of the invention; .~
Figure 3 is a schematic view of the copy reflect- - -ivity sensing apparatus:
~ "' ' '' `"
' .
, -- , , ' ' :
, :
-4a-Figure 4 is a circuit fQr the sensor and signal conditioner shown by a block in Figure ~;
Figure 5 is a circuit for the energy storage power supply shown by a block in Figure 2.
For a general understanding of the illustrated copier/reproduction machine, in which the invention may be incorporated, reference is had to Figure 1 in which the various system components for the machine are schematically illustrated.
As in all electrostatic systems such as a xerographic machine of the type illustrated, a light image of a document to be reproduced is projected onto the sensitized surface of a xerographic plate to form an electrostatic latent image thereon. Thereafter, the latent image is developed with an .. . .
oppositely charged develop m g material to form a xerographic ~ -powder image, corresponding to the latent image on the plate surface. The powder image is then alectrostatically transferred ~ .' ~ ! ' ~, to a upport surface to which it is fused in this case by an ., .i~ .
~- improved flash fusing system whereby the powder images are caused permanently to be affixed to the support surface as .
will be described more fully hereinafter.
In the illustrated machine, an original D to be ., .
copied i8 placed upon a transparent support platen P ~ixedly arranged in an illumination assembly generally indicated by the re~erence numeral 10, arranged at the left end of the machine. The image rays are projected by means of an optical ~ystem for exposing the photosensitive surface of a xerographic plate in t7ne form o~ a flexible photoconductive belt 12 which can be any ~uitable xerographic material such as selenium or an insulating surface.
, .
l -5-. ~ ' .
. .
The photoconductive belt 12 is mounted upon the frame of the machine and is adapted to move in the direction of the arrow at a constant rate. Duxing this movement of the belt, the light image of the origina! on the platen i~ flashed upon the xerographic surface of the belt. The flash exposure of the belt surface to the light image discharges the photo-conductive layer in the areas struck by light, whereby there remains on the belt a latent electrostatic image in image configuration corresponding to the light image projected from the original on the supporting platen. Aq the belt surface continues its movement, the electrostatic image passes ~hrough a developing station B in which there is positioned a developer assembly generally indicated by the re~erence numeral 14. The developer a~sembly 14 deposits developing material to the upper part of the be:Lt where the material is directed to cascade down over the upwardly moving inclined belt in order to provide development of the electrostatic image. As ~he developing material iS cascaded over the xero-graphic plate, toner particles in the development material are deposited on the belt surface to form powder images.
The developed electrostatic image is transported by the belt to a transfer station C where a sheet of copy paper is moved at a speed in synchronism with the moving belt in order to accomplish transfer of the developed image. There is provided at this station a sheet transport mechanism generally indicated at 16 adapted to transport sheets of paper from a paper handling mechanism generally indicated by the reference numeral 18 to the developed image on the belt at the station C.
After the sheet is stripped from the belt 12, it is conveyed to an improved flash fuser system generally indicated ~5~ 5 by the reference numeral 20 where the developed and transferred xerographic powder image on the sheet material is permanently affixed thereto accordin~ to the present invention a3 will ~e explained hereinafter. A~ter fusing, the finished copy is di~charged from the apparatus by a belt conveyor 21 to a suitable point for collection externally of the apparatus.
Suitable drive means may be arranged to drive the selenium belt 12 in conjunction with timed flash exposure of an original to be copied, to effect conveying and cascade of toner material, to separate and feed sheets of paper and to transport the same across the transfer station C and to convey the sheet of paper through the ~lash fuser in timed sequence to produce copies of the original~
It is believed that the foregoing description is sufficient for the purpose of this application to show the general operation of an electrostatic copier using an ill~ination system constructed in accordance with the in-vention. For further details ~oncerning the specific con-struction of the electrostatic copier, reference is made to U. S. Patent ~o. 3,661,452 issued May 3, 1972 in ~he name of Hewes et al.
, . .
As best depicted in the block diagram of Figure 2, the mass of toner images I on individual copy sheets S is sensed via its reflectivity and an input produced by sensor and ~ignal conditioner 50 is made to an ener~y storage power supply 52 w~ich supplies an input to one or more flash lamps 40 of the system 20 to produce the desired power level at optimum energy or ~lashing the lamps. Power ~upply 52 receives another i~put from D.C. voltage sources 54.
-7~
~' .
~l~5&~35 Referring now to Figure 3 there is shown the sens ing apparatus for sensing the density o~ toner on a copy sheet to be fused and producing spatially concentrated optical signals and converting the optical signals into electrical signals proportional thereto for input as will be discussed more fully hereinafter. As the lead edge of the copy sheet 5 bearing llose toner images I comes into view of the sensing apparatus light originating from a light source 60 is conducted towards the copy sheet S via an array of fiber optic elements 62 such that a uniform line source of illumination is provided across the sheet S. A second array of fiber opti~ elements 64 receives the reflected illumination which is transmitted to a localized area 65 and coupled into a photosensor 70.
Shown in Figure 4 is a circuit for the signal sensor and signal conditioner 50. Photosensor 70 is a photo-diode whose current is proportional to the incident illumination.
The output of photosensor 70 is amplified by amplifier 75 and :.
integrated by inkegrator 76 providing an output voltage 80 for controlling the output of the energy storage power supply 52.
t should ~e understood that the ouput voltage 80 from inte-grator 76 must be reset a~ter each copy sheet S is ~used by any suitable circuit.
~ he operation of the system can be best understood by referring to the diagramatic circuit shown in Figure 5. The output 80 from sensor and conditioner 50 is fed into voltage sensor 101 which inhibits transistor switch driver 102. The transistor switch 102 is al80 inhibited by an input from the minimum current sen~or 105. The peak current sensor 103 provides an enable voltage to driver 102. The driver 102 provides base drive to transistor switches 107 which switches ' .
5~
curr~nt through the primary winding of transformex 110. The phasing of primary with respect to the secondary is such that when the primary is conducting the secondary is not conducting and vice versa. The energy from the primary winding is coupled to the secondary winding when said switch is turned off. The secondary energy is rectified and stored in capacitor C.
Discharging the capacitor which reduces the load impedance of the secondary to virtua~ly zero allows the primary to conduct in the normal manner since the primary is not coupled to the secondaxy load when said switch is on.
The voltage of capacitor C is sensed by and divided down by resistors Rl and R2 and inputed into voltage sensor 101. The energy stored on capacitor C is delivered as the input voltage to flash lamps 40 for Eusing the images I on ,;
copy sheets S. This input voltage supplied to the flash fusing lamps 40 results in optimum energy to fuse the toner , imayes onto the copy sheets.
;, Above is described a new and improved area sensing apparatus which senses the density of toner images and produces electrical control signals for input to a flash lamp power supply. It will be appreciated ~hat the sensing apparatus of the invention produces a spatially concentrated illumination reflected from copy sheets at a remote location for subsequent input and control to a copier/duplicator system.
While the invention has been described with reference to the structure di closed herein it is not confined to the details set forth in thi~ application but is intended to cover such modifications or changes as may come with the purpose of t,he improvement~ or the scope of the fo~lowing claims.
~: ~g_
has led to several problems including a vast over cons~nption o power and poor negative latitude.
With the present invention the density of toner images on an individual copy sheet is sensed via its reflectivity which is then used to regulate the power supply of a flash lamp system. -In accordance with one aspect of this invention there is provided an improved interface system for controlling ~
~; energy to a flash li~mp in response to toner image density on - ~;
copy sheets comprising: means for advancing copy sheets bearing toner images along a predetermined path, flash lamp means posi- ; ;
tioned in the path Eor processing said copy sheets, area cover- --:~. , ,:, aye sensing means for sensing the densitv of the toner images ;
on said copy sheets advanced and producing spatially concentra-~ , .
ted optical signals thereof and converting the optical signals into electrical signals proportional thereof, said area coverage sensing means including first fiber optic means for transmitting ~ ;~
.: . . : - :.. .
illumination to a predetermined location in the copy sheet path `
and second fiber optic means for receiving illumination reflect-ed from said copy sheets and transmitting reflected illumination -' to a remote location, first circuit means for receiving and conditioning said electrical signals, variable energy storage ~ ;
means including at least one chargeable capacitor for driving said flash lamp means, and second circuit means coupled to said ~, energy storage means for receiving the conditioned signals and ~`
j controlling the input to said energy storage means for driving said flash lamp means in response to the density of toner images ' on said copy sheets. ~;
In accordance with another aspect of this inven-- 30 tion there is provided a method of controlling the energy to a flash lamp in xesponse to toner image density on copy sheets comprising the steps of optically sensing the density of toner _4_ ~:i :: ' -:
.. . .
images on copy sheets advanced along a path, converting the optically sensed information .into electrical signals proportional thereto, and transmitting the signals to uni directional switch-ing means coupled to a variable energy storage device to control the input to said energy storage device for driving the flash lamp in response to the densi.ty of toner images on said copy sheets.
For a better understanding of the invention as well as further features thereof, reference is had to the following .
description of the invention to be read in conjunction with the drawings wherein:
Figure 1 illustrates xerographic reproducing apparatus incorporating a flash fusing system in accordance with the invention;
Figure 2 i5 a block diagram of the flash fusing system of the invention; .~
Figure 3 is a schematic view of the copy reflect- - -ivity sensing apparatus:
~ "' ' '' `"
' .
, -- , , ' ' :
, :
-4a-Figure 4 is a circuit fQr the sensor and signal conditioner shown by a block in Figure ~;
Figure 5 is a circuit for the energy storage power supply shown by a block in Figure 2.
For a general understanding of the illustrated copier/reproduction machine, in which the invention may be incorporated, reference is had to Figure 1 in which the various system components for the machine are schematically illustrated.
As in all electrostatic systems such as a xerographic machine of the type illustrated, a light image of a document to be reproduced is projected onto the sensitized surface of a xerographic plate to form an electrostatic latent image thereon. Thereafter, the latent image is developed with an .. . .
oppositely charged develop m g material to form a xerographic ~ -powder image, corresponding to the latent image on the plate surface. The powder image is then alectrostatically transferred ~ .' ~ ! ' ~, to a upport surface to which it is fused in this case by an ., .i~ .
~- improved flash fusing system whereby the powder images are caused permanently to be affixed to the support surface as .
will be described more fully hereinafter.
In the illustrated machine, an original D to be ., .
copied i8 placed upon a transparent support platen P ~ixedly arranged in an illumination assembly generally indicated by the re~erence numeral 10, arranged at the left end of the machine. The image rays are projected by means of an optical ~ystem for exposing the photosensitive surface of a xerographic plate in t7ne form o~ a flexible photoconductive belt 12 which can be any ~uitable xerographic material such as selenium or an insulating surface.
, .
l -5-. ~ ' .
. .
The photoconductive belt 12 is mounted upon the frame of the machine and is adapted to move in the direction of the arrow at a constant rate. Duxing this movement of the belt, the light image of the origina! on the platen i~ flashed upon the xerographic surface of the belt. The flash exposure of the belt surface to the light image discharges the photo-conductive layer in the areas struck by light, whereby there remains on the belt a latent electrostatic image in image configuration corresponding to the light image projected from the original on the supporting platen. Aq the belt surface continues its movement, the electrostatic image passes ~hrough a developing station B in which there is positioned a developer assembly generally indicated by the re~erence numeral 14. The developer a~sembly 14 deposits developing material to the upper part of the be:Lt where the material is directed to cascade down over the upwardly moving inclined belt in order to provide development of the electrostatic image. As ~he developing material iS cascaded over the xero-graphic plate, toner particles in the development material are deposited on the belt surface to form powder images.
The developed electrostatic image is transported by the belt to a transfer station C where a sheet of copy paper is moved at a speed in synchronism with the moving belt in order to accomplish transfer of the developed image. There is provided at this station a sheet transport mechanism generally indicated at 16 adapted to transport sheets of paper from a paper handling mechanism generally indicated by the reference numeral 18 to the developed image on the belt at the station C.
After the sheet is stripped from the belt 12, it is conveyed to an improved flash fuser system generally indicated ~5~ 5 by the reference numeral 20 where the developed and transferred xerographic powder image on the sheet material is permanently affixed thereto accordin~ to the present invention a3 will ~e explained hereinafter. A~ter fusing, the finished copy is di~charged from the apparatus by a belt conveyor 21 to a suitable point for collection externally of the apparatus.
Suitable drive means may be arranged to drive the selenium belt 12 in conjunction with timed flash exposure of an original to be copied, to effect conveying and cascade of toner material, to separate and feed sheets of paper and to transport the same across the transfer station C and to convey the sheet of paper through the ~lash fuser in timed sequence to produce copies of the original~
It is believed that the foregoing description is sufficient for the purpose of this application to show the general operation of an electrostatic copier using an ill~ination system constructed in accordance with the in-vention. For further details ~oncerning the specific con-struction of the electrostatic copier, reference is made to U. S. Patent ~o. 3,661,452 issued May 3, 1972 in ~he name of Hewes et al.
, . .
As best depicted in the block diagram of Figure 2, the mass of toner images I on individual copy sheets S is sensed via its reflectivity and an input produced by sensor and ~ignal conditioner 50 is made to an ener~y storage power supply 52 w~ich supplies an input to one or more flash lamps 40 of the system 20 to produce the desired power level at optimum energy or ~lashing the lamps. Power ~upply 52 receives another i~put from D.C. voltage sources 54.
-7~
~' .
~l~5&~35 Referring now to Figure 3 there is shown the sens ing apparatus for sensing the density o~ toner on a copy sheet to be fused and producing spatially concentrated optical signals and converting the optical signals into electrical signals proportional thereto for input as will be discussed more fully hereinafter. As the lead edge of the copy sheet 5 bearing llose toner images I comes into view of the sensing apparatus light originating from a light source 60 is conducted towards the copy sheet S via an array of fiber optic elements 62 such that a uniform line source of illumination is provided across the sheet S. A second array of fiber opti~ elements 64 receives the reflected illumination which is transmitted to a localized area 65 and coupled into a photosensor 70.
Shown in Figure 4 is a circuit for the signal sensor and signal conditioner 50. Photosensor 70 is a photo-diode whose current is proportional to the incident illumination.
The output of photosensor 70 is amplified by amplifier 75 and :.
integrated by inkegrator 76 providing an output voltage 80 for controlling the output of the energy storage power supply 52.
t should ~e understood that the ouput voltage 80 from inte-grator 76 must be reset a~ter each copy sheet S is ~used by any suitable circuit.
~ he operation of the system can be best understood by referring to the diagramatic circuit shown in Figure 5. The output 80 from sensor and conditioner 50 is fed into voltage sensor 101 which inhibits transistor switch driver 102. The transistor switch 102 is al80 inhibited by an input from the minimum current sen~or 105. The peak current sensor 103 provides an enable voltage to driver 102. The driver 102 provides base drive to transistor switches 107 which switches ' .
5~
curr~nt through the primary winding of transformex 110. The phasing of primary with respect to the secondary is such that when the primary is conducting the secondary is not conducting and vice versa. The energy from the primary winding is coupled to the secondary winding when said switch is turned off. The secondary energy is rectified and stored in capacitor C.
Discharging the capacitor which reduces the load impedance of the secondary to virtua~ly zero allows the primary to conduct in the normal manner since the primary is not coupled to the secondaxy load when said switch is on.
The voltage of capacitor C is sensed by and divided down by resistors Rl and R2 and inputed into voltage sensor 101. The energy stored on capacitor C is delivered as the input voltage to flash lamps 40 for Eusing the images I on ,;
copy sheets S. This input voltage supplied to the flash fusing lamps 40 results in optimum energy to fuse the toner , imayes onto the copy sheets.
;, Above is described a new and improved area sensing apparatus which senses the density of toner images and produces electrical control signals for input to a flash lamp power supply. It will be appreciated ~hat the sensing apparatus of the invention produces a spatially concentrated illumination reflected from copy sheets at a remote location for subsequent input and control to a copier/duplicator system.
While the invention has been described with reference to the structure di closed herein it is not confined to the details set forth in thi~ application but is intended to cover such modifications or changes as may come with the purpose of t,he improvement~ or the scope of the fo~lowing claims.
~: ~g_
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An improved interface system for controlling energy to a flash lamp in response to toner image density on copy sheets comprising: means for advancing copy sheets bearing toner images along a predetermined path, flash lamp means positioned in the path for processing said copy sheets, area coverage sensing means for sensing the density of the toner images on said copy sheets advanced and producing spatially concentrated optical signals thereof and converting the optical signals into electrical signals proportional thereof, said area coverage sensing means including first fiber optic means for transmitting illumination to a predetermined location in the copy sheet path and second fiber optic means for receiving illumination reflected from said copy sheets and transmitting reflected illumination to a remote location, first circuit means for receiving and conditioning said electrical signals, variable energy storage means including at least one chargeable capacitor for driving said flash lamp means, and second circuit means coupled to said energy storage means for receiving the conditioned signals and controlling the input to said energy storage means for driving said flash lamp means in response to the density of toner images on said copy sheets.
2. A method of controlling the energy to a flash lamp in response to toner image density on copy sheets com-prising the steps of optically sensing the density of toner images on copy sheets advanced along a path, converting the optically sensed information into electrical signals pro-portional thereto, and transmitting the signals to uni-directional switching means coupled to a variable energy storage device to control the input to said energy storage device for driving the flash lamp in response to the density of toner images on said copy sheets.
3. A method according to claim 2 wherein the signals received in the switching means coupled to said variable energy storage device are compared to the voltage across the flash lamp and output signals generated to control said voltage by turning said switching means on and off.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US58594575A | 1975-06-11 | 1975-06-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1058905A true CA1058905A (en) | 1979-07-24 |
Family
ID=24343647
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA251,387A Expired CA1058905A (en) | 1975-06-11 | 1976-04-29 | Controlling energy to flash lamp response to toner image density |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1058905A (en) |
-
1976
- 1976-04-29 CA CA251,387A patent/CA1058905A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3834807A (en) | Copier with leading edge image control | |
| US3603680A (en) | Ultrasonic paper detection | |
| US3547533A (en) | Microfilm reproduction machine | |
| US4551008A (en) | Image annotator for use with printing and coping machines | |
| US4341463A (en) | Image reproducing apparatus | |
| US3860338A (en) | Adjustable fadeout control | |
| US3881085A (en) | Fuser control circuit for copying apparatus | |
| GB1404218A (en) | Electrophotographic apparatus using a photosensitive member with electrically insulating layer | |
| JPS6048750B2 (en) | electrostatic copying machine | |
| US3838921A (en) | Photoelectrostatic copying apparatus | |
| US3751155A (en) | Pre-development exposure assembly | |
| US4248519A (en) | Charge control system for xerographic machines | |
| US3687538A (en) | Apparatus for exposing latent image margins in electrophotographic copying apparatus | |
| US4001541A (en) | Flash fusing system with energy control | |
| CA1095121A (en) | Flash lamp modulator system | |
| US4039770A (en) | Interface system to control flash lamp | |
| US4090108A (en) | Interface system to control flash lamp | |
| US3584195A (en) | Heat fixing apparatus | |
| CA1058905A (en) | Controlling energy to flash lamp response to toner image density | |
| US4110026A (en) | Discharger apparatus for photoconductors | |
| JPS5473046A (en) | Electrophotographic apparatus | |
| US3432232A (en) | Illumination system | |
| JPS6012631B2 (en) | Copier flash fixing device | |
| US3935424A (en) | Flash fusing apparatus | |
| CA1063666A (en) | Cylindrical high efficiency flash fusing apparatus |