US2950661A - Preparation of copies by xerography - Google Patents

Description

Aug. 30, 1960 w. LIMBERGER PREPARATION OF COPIES BY XEROGRAPHY Filed April 19, 1957 QUE III) "11" "I" -n lIll/lIIIlIIllI/IIIIIIIIIIIIIIIIIIIIIIIIII v-v IIIIIIIIIIIIIIIIIIIIII! lNVE/VTOP.

WALTER UMBERGER Patented Aug. 3%, 1960 PREPARATION OF COPIES BY XEROGRAPHY Walter Limberger, Hamburg, Germany, assignor to Lumoprint Zindler K.G., Hamburg, Germany Filed Apr. 19, 1957, Ser. No. 653,813 Claims priority, application Germany Apr. 24, 1956 1 Claim. (Cl. 95- -1.7)

The invention relates to a device for preparing copies by means of xerographic layers, in which a latent electrostatic image produced in the layer by illumination is rendered visible by coating it with powdered pigment parti cles and is fixed by fusing-in of the pigment particles.

In order to obtain satisfactory copies by such a method, it has previously been necessary to carry out the separate steps of the method in different devices in order to enable exact control and supervision of the separate processes. In known devices, an adaptation to existing special conditions is not possible so that these devices are suitable for preparing a large number of similar copies but are'not suitable for preparing copies representing special viewpoints. There is also the disadvantages, in these known devices, that the layer must be conveyed from one part of the device to another part in order to be subjected to the separate steps of the method.

Particularly in producing the latent electrostatic image by illumination one must also take into account that the xerogrophic layer once formed is light-sensitive, so that the transfer of it from the forming device to an image back plate and from this to a powder-distributing device and then to a fusing device can be accomplished only with difficulty.

The invention has the object of providing an enclosed device, constructed in particular as a table apparatus, in which the electrostatic image is produced by illumination and which, in contrast to known devices for preparing copies by means of Xerographic layers, exhibits substantial advantages.

According to the invention, a forming device is arranged to be movable away from the light-beam on an operating support plate provided in a housing enclosing the illuminating device, this plate serving at the same time as an image-support plate; in addition, a fusing device is provided which in a preferred embodiment is likewise arranged to be movable with respect to the support plate.

This construction leads to the substantial advantage that the image-support plate serves as a general operating surface for the whole sequence of steps involved in preparing the copies. On this basis, it is possible to provide a table apparatus with small spatial measurements. Furthermore, the handling of the xerographic layer is substantially simplified, since this layer is present before the forming in the light-tight housing'and is only removed after fixing of the image. In this connection, a mounting of the layer during the whole operation on only one support plate is particularly advantageous, since the xerographic layer must not be touched either after the forming or after being powdered. Touching the Xerographic layer after the forming leads, particularly with high hand moisture, to a considerable alteration of the electrostatic charge and finger-prints are produced. Furthermore, by touching after the powdering, the distribution of the powder on the copy is changed.

The operating plate consists of an electrically conductive material and at the same time forms an electrode of the forming device. Furthermore, the operating plate is I a slot 3 on to a the master.

arranged to be pivotable into an inclined position as a constituent part of a powder-distributing device. If the fusing device is directly connected with the image plate, it will partake of the movements of this plate during the coating of the latent image with powder. In the preferred embodiment hereinafter described, in which the fusing device is movable and is swingable about a post located in front of the operating plate, the fusing device is not subjected to the oscillatory movements of the operating plate in distributing the powder.

In a preferred embodiment, the forming electrode, which preferably consists of several parallel wires, is displaceable across the operating plate, the rest position of the electrode being so chosen that it is located on one side of the operating plate.

The forming device and the heating device are supplied with current only during the short operative period of these parts. The current supply in the preferred embodiment is automatically disconnected by a contact control in dependence upon the movement of these parts by means of an outwardly extending handle, thus insuring that these parts are not connected by potential in their quiescent position. Advantageously, the parts are grounded when at rest. The current supply may additionally be controlled in dependence upon the setting of the closure of a housing cover or a housing door.

Further features and advantages will appear from the description of an embodiment illustrated in the accompanying drawing.

In the drawing:

Fig. 1 shows a section through a device according to the invention; and

Fig. 2 shows a section along the line IIII of Fig. 1.

The housing consists of a base part 2 into which a master image or copy to be reproduced is inserted through master-support plate 4. The mastersupport plate 4 can be constructed as a book-supporting device. In the embodiment shown, it is arranged to be displaceable by being mounted in guides 5, 6, other guides 7, 8 being provided in another, lower position in order to enable further adjustment of its position.

The inlet slot 3 is only so large as is necessary to insert For observation, a window 3' covered by a red glass filter or an equivalent synthetic material is provided above the inlet slot 3. In the base part 2, lamps 9, 10 are located for illuminating the master.

On the base part is located a casing part 11, which is connected with the base 2 by an opening 12 in the Wall part between the base 2 and the casing 11 for passage of the light beam. The casing part 11 contains a mirror 13 on the wall opposite the opening 12. Between the mirror 13 and the master-support plate 4, the objective 14 is arranged which is supported on partitions which close off the part containing the master from the remaining part of the interior of the housing.

Perpendicular to the direction of the reflected light beam determined by the inclination of the mirror 13, the operating plate 15 for the xerographic layer is provided in the structure 11. On this operating plate, the xerographic layer is' formed, illuminated, coated with powder and heated to fuse the powder, so that the operating plate 15 represents the sole operating station for the xerographic layer during the preparation of the copy.

Despite this stationary arrangement of the copy, an alteration of the copying scale is possible, since the objective 14 is arranged on a pivotable support and can be pivoted into the position indicated at 16, and at the same time the master plate 4 can be displaced by being moved, for example, into the guides 7, 8.

The operating plate 15 is pivotally mounted about a pin 17 and is supported by its other end on a cam 18. The operating plate lies in a plane inclined with respect to the vertical, by reason of the provision of the mirror 13. The operating plate is removable through the housing opening, the supporting lugs on plate 15 engaged by the bolts 17 being for this purpose adapted to be. shifted over these.

A hopper 19 for receiving the powder carrying the pigment particles is located over the operating plate 15 inside the casing 11. The lower part of this container runs funnel-shaped to a supply opening 20 in which a distributing device, for example in the form. of a roller rotatable in the opening, is arranged. A hand crank 21 serves to operate the roller. The cam 18 is also connected to this drive whereby the operating plate 15 is oscillated about the pin 17 on actuation of the distributing device 20, so that a good distribution of powder is ensured and excess powder particles are safely collected in the collecting funnel 22. A container 23 for receiving the powder is located under the mouth of this collecting funnel. The container 23 is removable so that the powder collected in it can be returned to the hopper 19, for example through the filling opening 24, in order to be re-used.

The forming electrode 25 is arranged over the operating plate 15 and parallel to it. It consists essentially of a protective capsule which is open towards the operating plate 15 and in which, for example, three wires 26 are stretched. These wires are connected over a supply lead 27 and a switch (not shown) to a suitable current source. The forming electrode 25 can be moved across the operating plate 15 by means of a handle 28 whose shank 29 can also serve as a supply lead for the electrode 25.

The operating plate 15 consists of electrically conductive material and forms the counter-electrode for the forming electrode 25. The operating plate 15 is preferably connected to ground.

In the vicinity of the lower edge of the operating plate, a radiant heating device 31 is pivotally mounted on a shaft 30. This heating device contains essentially a heating screen 32 which can be pivoted over the operating plate 15 by rotation of the shaft by means of the crank handle 33.

v The housing part 11 is accessible through a door 34 whose middle part includes a transparent cover 35, for example of red glass, so that the development of the copies can be observed through this inspection opening. Inside the housing, a red lamp 36 is provided for this purpose;

In operation, the plate 15 is removed from housing 11 through the door 34, in the manner previously described, so that a fresh xerographic layer can be fastened to it. After the plate 15 together with its layer has been returned to the housing, the door 34 is closed.

Next, the forming electrode 25 is displaced across the face of the xerographic layer by means of the handle 28, the Wires 26 of this electrode being simultaneously onergized through closure of the associated switch in a manner known per se. This produces a charge on the photoconductive surface of the xerographic layer.

After a master copy has been placed on its mounting plate 4 and the latter has been operatively received by either the guides 5, 6 or the guides 7, 8, the illuminating device 9, 10 is operated to cause light rays reflected by the master copy to be focused by the objective 14 and the mirror 13 onto the xerographic layer on plate 15,

Following this exposure, the hopper 19 is actuated by means of the crank 21 to distribute the developing powder over the inclined surface of the xerographic layer, this operation also causing the cam 18 to oscillate the layersupporting plate 15 so that excess powder, not held by electrostatic attraction on the layer surface, is caused to run off irrto the receptacle 23. Thereafter, the crank 33 is rotated with simultaneous energization of the heating device 31 to position this device directly in front of the powder-coated face of the xerographic layer whereby the adhering powder particles are fused onto the layer. When this process is completed, the heating device 31 is restored to its normal position and de-energized whereupon the plate 15, carrying the xerographic layer with the fully developed and fixed image thereon, can be removed from the housing by Way of door 34.

In the embodiment illustrated, only the essential parts are shown in order to facilitate comprehension of the principles of the invention. Modifications can be made Within the scope of the invention.

What I claim is:

A xerographic copying device comprising a substantially light-tight housing, a plate in said housing having an inclined upper face provided with means for fixedly supporting a xerographic layer, hinge means mounting said plate for oscillatory movement about a horizontal axis, electrode means in said housing displaceable across said upper face for producing an electrostatic charge on said layer, optical means positioned in said housing for pro- 'ecting onto said upper face an image of a master copy to be reproduced, hopper means positioned in said housing adjacent said plate, said hopper means having an outlet for dispensing an adherent powder onto said upper face after exposure of said layer, thereby developing a visible replica of said master copy, a movable heat source mounted in said housing for displacement into an operative position adjacent said plate, operating means for successively actuating said electrode means, said optical means, said hopper means and said heat source, and vibratory means for oscillating said plate during operation of said hopper means, thereby removing excess powder from said inclined face, said hopper means comprising a funnel having an outlet and a rotatable feed roller adjacent said outlet, said vibratory means including a rotatable earn operatively coupled with said feed roller and bearing upon said plate.

References Cited in the file of this patent UNITED STATES PATENTS 2,027,307 Schacht Jan. 7, 1936 2,588,675 Walkup et al Mar. 11, 1952 2,600,580 Sabel et al June 17, 1952 2,624,652 Carlson Ian. 6, 1953 2,684,901 Sabel et al July 27, 1954 2,684,902 Mayo et al July 27, 1954 2,711,481 Phillips June 21, 1955 2,725,800 Dewhurst Dec. 6, 1955 2,781,704 Mayo et a1 Feb. 19, 1957 2,791,949 Simmons et a1 May 14, 1957 2,831,409 Bixby et al Apr. 22, 1958 FOREIGN PATENTS 201,301 Australia Mar. 19, 1956

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