GB2117325A - Apparatus for making projection slides without using photographic means - Google Patents

Abstract

Apparatus for transferring information from a master record such as a printed circuit board to a photographic projector slide without the aid of photography includes a stylus (17) arranged to scan the master record along X and Y axes, a scriber (10) or like device for scribing on a slide (12) located remote from the master record and linkage means (5 to 9) coupling X-Y axis slideways (1, 2) associated with the stylus (17) with X-Y axis slideways (3, 4) associated with the scriber (10) whereby information scanned from the master record is transferred to the slide (12) but on a reduced scale. Means are provided for altering the scale of the image inscribed on the slide (12) from that of the master record scanned by the stylus 17. <IMAGE>

Description

SPECIFICATION Apparatus for making projection slides without using photographic means This invention relates to apparatus for transferring information from a master record onto a photographic projector slide and to a method of preparing slides for use in a photographic projector in a manner that maintains the required quality and overcomes the defects of the photographic systems currently used with film or slide projectors as aids to assembling printed circuit boards incorporated in electronic equipment.

Hitherto a popular means of assembling printed circuit boards has been to project a film frame or slide on to the board to indicate the location and orientation of groups of components. For those assemblers of circuit boards requiring frequent design changes the preparation of artwork and the photographing of it to make a film frame has proved too slow, and alternative means of indicating the required information using microprocessors have been developed to indicate location of components despite the better clarity of definition and the ability to display printed instructions with film based systems. Another known method is to use slides with holes drilled in them to indicate the information needed.

It is an object of this invention to provide a means of making slides to use in a slide projector that locates slides in an accurate position within the projector mechanism, and in turn which enables the slides to be provided with information accurately located on the slide in relation to its datum faces. This has proved difficult in the past because of difficulties in accurately locating small pieces of film in a slide holder with reference to datum faces.

According to one aspect of the invention there is provided apparatus for transferring information from a master record on to a photographic projector slide located remote from the master record and on a reduced scale but without the use of photography, including a stylus arranged to scan the master record along X and Y axes, means for inscribing on the surface of the slide, driving means for said stylus to allow the stylus to scan the master record and means linking the stylus with the inscribing means to transfer the movement of the stylus to said inscribing means to reproduce on said slide a reduced image of the information scanned from said master record.

The invention will now be described by way of example only with particular reference to the accompanying drawings wherein: Figure 1 is a general arrangement of the mechanism of the slide making apparatus, in orthographic projection; Figure 2 illustrates details of the scale changing mechanism of the apparatus shown in Figure 1; Figure 3 illustrates an alternative scale changing mechanism; and Figure 4 illustrates a further alternative scale changing mechanism, and shows the way of calculating the scale ratio.

The apparatus of the present invention includes means for providing a slide for projection, by copying information from a master on to the slide at a reduced scale without using photography. The invention includes means for the scribing or engraving of a surface coating on a glass or plastics plate slide of a size to fit the projector. The surface coating can be, by way of example a photographic emulsion, or an impervious paint or a chemical treatment or sputtered aluminium or a metal surface applied by other means, which can be removed by a scriber, an engraving tool, or a material suitable for part removal by spark erosion or by chemical means to produce clear areas in an otherwise light impervious surface. Such a slide is shown at 12 in Figure 1 mounted under a stylus 10 which can be actuated to produce the clear areas required on the surface of the slide.

A copying stylus 17 is located on an arm 19 attached to a Y-axis motion plate 2, of an upper X-Y axis slideway, which in turn is attached to the X-axis motion plate 1 of the upper X-Y axis slideway. A table top on a mainframe (not shown) to which the upper X-Y axis slideways mechanism is attached, is located in the gap between plate 2 and the horizontal part 1 9a of arm 19. Stylus 1 7 can be made to scan the area of the table whilst its motion is parallel to the top of the table, and thus scans the material such as a printed circuit board to be copied (not shown) which is placed in position on the top surface of the table.

A lower X-Y axis motion mechanism with surfaces running parallel to the upper X-Y axis mechanism is mounted at the lower extremities of the main frame, item 4 representing the Y-axis moving part and item 3 the X-axis moving plate.

An extension arm to the X-axis moving plate 3 carries a solenoid or other operating means 20 to actuate a hinged stylus rod 11 to bring the stylus 10 attached thereto into contact with slide 1 2 and to produce the clear areas on the surface of the slide by scribing, when the stylus 10 is moved.

The solenoid or other operating means 20 is brought into operation by the operator pressing lever 1 8 when stylus 1 7 indicates as it is moved that scribing should commence.

A projector lamp 14 directs light through condenser lenses 1 5 and through the slide 12 as scribing proceeds and thence through object lens 16 on to screen 1 3. As the scribing arm is very thin the operator can check the scribing accuracy as work proceeds by means of viewing screen 13 which is preferably located on the table top (not shown).

In this way, a slide is made ready for immediate projection by transferring the information from the printed circuit board or the artwork from which the printed circuit board is produced.

Now described is the means of providing the driving motion from copying stylus 17 and its upper X-Y axis mechanism to the lower X-Y axis mechanism and its scribing stylus 10.

A plate 8 carrying a spherical bearing or universal joint 5 is mounted rigidly on or hinged to the main frame (not shown) between the upper and lower X-Y axis slideways, and a scale rod 9 passing through the bearing or joint 5 can be made to swivel in both X and Y axes. In the embodiment shown in Figures 1 and 2 the scale rod 9 has its upper end fixed in a spherical bearing or universal joint 6 mounted on plate 2 of the upperX-Y axis mechanism, and is free to slide through bearing 5 but is restrained from sideways movement at its pivotal point.Similarly it passes with a sliding fit through the spherical bearing or universal joint 7 mounted on X axis plate 3 in such a way that it causes any motion of arm 1 9 carrying stylus 17 to be copied faithfully on a much reduced scale by stylus 10 attached through arm 11 to the lower X-axis plate 3. The normal scale reduction may be of the order of eighteen to one, but depends on the relative position of plate 8 and joint 5 to the centres of the two bearing or joints 6 and 7.

A desirable feature of the present invention is the ability to change the scale. It is well known that the greater the area of the projection slide actually in use for any given image size the greater will be the brightness on projection. This is achieved by making the information on the slide to the maximum scale permitted by the circumstances of the circuit. To achieve this feature, plate 8 is hinged to the main frame and the position of the centre of bearing 5 can be moved along the line joining the centres of bearings 6 and 7. The scale depends on the ratio between the distance from their centres of joints 5 and 6 and the distance between the centres of joints 5 and 7. Although the detail of this part of the invention is not shown it is partly illustrated by the double ended arrow and scale shown in Figure 1 adjacent to item 8. A lever attached to the end of plate 8 remote from the hinge end is moved against a calibrated scale to determine the scale ratio of the size of the material being copied to the size of the scribed information on the slide.

Figure 3 shows a further embodiment of the scale rod and its mechanism in which scale rod 9 is fixed in spherical bearing or universal joint 5 and slides through both bearings or joints 6 and 7.

Figure 4 shows an another embodiment of the scale rod and its mechanism in which the scale rod is fixed in bearing 5 and has sliding extensions at each end which respectively engage in spherical bearings or universal joints 6 and 7.

Claims (13)

1. Apparatus for transferring information from a master record on to a photographic projector slide located remote from the master record and on a reduced scale but without the use of photography, including a stylus arranged to scan the master record along X and Y axes, means for inscribing on the surface of the slide, driving means for said stylus to allow the stylus to scan the master record and means linking the stylus with the inscribing means to transfer the movement of the stylus to said inscribing means to reproduce on said slide a reduced image of the information scanned from said master record.

2. Apparatus as claimed in claim 1 wherein the slide is located below and spaced from a planar surface containing the master record.

3. Apparatus as claimed in claim 1 and 2 wherein the stylus is located at one extremity of an arm connected to an upper X-Y axis slideway to allow the stylus to scan the master record along said axes, and in a direction parallel to said planar surface, said inscribing means being located at one extremity of an arm connected to a lower X-Y axis motion mechanism having surfaces parallel to said planar surface, to allow the inscribing means to move over the surface of the slide, when said driving means is actuated.

4. Apparatus as claimed in any preceding claim wherein a light source is located on one side of said slide with means for directing light through the slide on to a screen located on the opposite surface of the slide.

5. Apparatus as claimed in claims 2 and 4 wherein the screen is located on said planar surface containing the master record.

6. Apparatus as claimed in claim 3 wherein said means linking the stylus with the inscribing means extends between the upper X-Y slideway and the lowerX-Y axis motion mechanism.

7. Apparatus as claimed in claim 6 wherein said upper X-Y slideway includes X and Y-axis motion plates and said lower X-Y axis motion mechanism including X and Y axis moving parts, and said means linking the stylus with the inscribing means including a fixed plate located between the upper and lower X-Y axis slideways, a rod extending vertically between the upper and lower slideways and passing through means located on said fixed plate such as to allow said rod to swivel about both X and Y axes.

8. Apparatus as claimed in claim 7 wherein said rod has the upper end thereof fixed in a spherical bearing or universal joint mounted on a plate of the upper X-Y axis slideway, and passing through bearings or universal joints located in the fixed plate and a plate of the lower X-Y axis slideway, such that any motion of the arm of the upper X-Y axis slideway is transmitted on a reduced scale to the arm associated with the said inscribing means.

9. Apparatus as claimed in claim 7 wherein said rod has the upper end thereof passing through a spherical bearing or universal joint mounted on a plate of the upper X-Y axis slideway, and a part intermediate the lower end thereof fixed to a spherical joint or universal bearing located in the fixed plate, with the lower end passing through a spherical bearing or universal joint connected to a plate of the lower X-Y axis slideway.

1 0. Apparatus as claimed in claim 7 wherein said rod is fixed at its lower end in a bearing secured to said fixed plate, the upper and lower ends of the rod having extensions engaging in bearings connected to plates of the upper and lower X-Y axis slideways respectively.

1 Apparatus as claimed in any preceding claim wherein means are provided for altering the scale of the image inscribed on the slide from that of the master record scanned by said stylus.

12. Apparatus as claimed in claim 3 wherein the upper and lower X-Y axis slideways are mounted in a main frame to which said planar surface is attached, a plate member hinged to said main frame, an extensible rod pivoted on a fixed fulcrum formed by a bearing mounted on said plate member, whereby the fixed position is movable along the length of the rod to alter the scale of the apparatus in respect of the information transferred from said master record to said slide.

13. Apparatus for transferring information from a master record to a slide and substantially as hereinbefore described with reference to the accompanying drawings.