GB2406390A - Pupil measuring device with horizontal scale - Google Patents

Abstract

A pupil measuring device 14 has a horizontal scale 16, 32 with may be provided on a ruler 20 which may be releasably securable to a spectacle frame 10 by means of low tack adhesive. The ruler 20 may include vertical scales 18, 28 and be made from thin cardboard, plastics material or transparent material. The device 14 may also have a slit (66, fig 5) in a target region.

Description

2406 390 a Optical Measurement This invention relates to a technique for

use in the measurement of parameters relating to the positions of an individual's pupils for subsequent use in the production of a pair of spectacles for the individual. The invention further relates to a device for use in the technique.

When a pair of spectacles is to be manufactured, it is usual for the positions of an individual's pupils to be measured, the position information subsequently being used to ensure that the lenses of the spectacles are correctly located in the spectacle frames so that the optical centres ofthe lenses are located correctly to suit lo the individual. Traditionally, such measurements have been taken by a skilled or trained technician often working in an establishment offering optician's services.

The distance selling of products and services of a range oftypes has become increasingly common, for example through "mail order" companies and with the expansion of the internet. It would be desirable to be able to offer a service of supplying spectacles to order by such means. However, in order to offer such a service, an individual would ideally need to be able to send to the supplier the pupil position information required in the manufacture ofthe spectacles. It is an object of the invention to provide a device and technique whereby such information can be measured and collated accurately in a simple and convenient manner by the individual, either with or without assistance, and which does not require the de; ë individual to be highly skilled or trained.

According to the present invention there is provided a pupil position measuring device comprising a scale associated, in use, with a spectacles frame or the like, the scale extending generally horizontally, in use, so as to allow the horizontal position of an individual's pupils to be measured.

Herein, the term spectacles frame is intended, other than where the context implies otherwise, to cover a spectacles frame into which prescription lenses have been fitted, a frame before such a lens has been fitted, a frame provided with non prescription lens inserts or substitutes, or something which, for the purposes of this invention, can function as if it were a spectacles frame.

The scale may be provided upon a ruler device securable to the spectacles frame. Alternatively, the scale could be printed onto, for example, a lens insert carried by, or to be carried by, a spectacles frame, or onto a label to be secured to such an insert. In a further alternative, a ruler device could be permanency fixed to or integral with a "dummy" spectacles frame.

The pupil position measuring device may also include a scale which extends generally vertically, in use. Such a scale may conveniently be provided in the same manner as the horizontal scale.

Where a ruler device is used, it may conveniendy be formed of a thin cardboard or plastics material and may conveniently be securable to a spectacles ; ë frame using a low tack adhesive, for example in the form of a low tack double sided adhesive strip. However, other techniques for securing the ruler device in position are envisaged. The ruler device could be manufactured from a substantially transparent material or have substantially transparent regions through which the individual's pupils are visible, in use, to allow their positions to be read using the scale(s). Alternatively, the ruler device may be provided with openings through which the individual's pupils are visible, in use. A further alternative is to provide the ruler device with regions which, initially, cover the individuals pupils, the regions being deformed, in use, to just expose the pupils to allow the accurate lo measurement of the pupil positions against the scale(s). The deformation may involve cutting or folding the regions.

In the arrangements defined hereinbefore, the scale(s) is/are substantially stationary relative to the individual's pupils. Arrangements are possible in which the scale(s) can be moved, such movement continuing until a predetermined target region is located immediately in front of the pupil.

Thus, the scale may be provided upon a panel moveable relative to the spectacles frame, in use. Although the panel could take a range of forms, in one preferred arrangement the panel comprises a thin, flexible plastics material securable to the spectacles frame and/or associated lens by the effects of static electricity, surface tension or low tack adhesive. The panel is printed or otherwise provided e. :e se ë ë e.: : .: with the scale(s). At or close to its centre, a target region is provided. In use, the panel is moved relative to the spectacles until the target region is located immediately in front of the individual's pupil. The position of the panel relative to the spectacles frame can be read using the scale(s) and this information, in conjunction with information relating to the dimensions of the spectacles frame, provides an indication of the individual's pupil position.

The panel may be transparent or substantially transparent, in which case the target region may be defined by markings, for example a pair of closely spaced vertical lines printed onto the panel. Alternatively, the panel may be provided with an opening, for example a vertically extending slit, defining the target region. The edges of the slit may be coloured to more clearly indicate the location of the slit.

Where the panel is of a transparent material, the scale(s) may be difficult to read, and so at least parts of the panel on which the scale(s) markings are provided may be provided with, for example, a plain background, for example a plain white I S background, in order to make the scale(s) easier to see.

The invention also relates to a technique for ascertaining information for use in the manufacture of spectacles comprising securing a pupil position measuring device as defined hereinbefore to a pair of spectacles, checking whether the slit is located in front ofthe wearers eyes, repositioning the device, if necessary, until such a position is reached, and reading, using the scales, the position of the panel on the ë :e . . ë ee: : .: spectacles.

The invention will further tee described, byway of example, with reference to the accompanying drawings, in which: Figure 1 is a view illustrating one form of a measurement device; Figure 2 is a view illustrating another device; Figure 3 is a view of another device; Figure 4 is a view illustrating use of the device of Figure 3, Figure 5 illustrates an alternative to the measurement apparatus of Figures 1 to 4; and Figure 6 is a view of another part of a device.

The accompanying drawings illustrate a number of different devices for use in the measurement of an individual's pupil positions. It is thought that the devices will find application in, for example, on-line or internet based services for the supply of prescription spectacles to order or for use in mail-order supplying of spectacles.

However, it will be appreciated that the devices could find other applications and could, if desired, be used in a retail establishment to avoid the necessity to make use of skilled or trained staff to take measurements relating to the location of an individual's pupils for subsequent use in the manufacture of spectacles to order.

Referring firstly to Figure 1 there is shown, somewhat diagrammatically, a spectacles frame 10 onto the lenses 12 of which have been secured labels 14. Each ce :. he -. ë be: : . .: label 14 is provided with horizontally and vertically extending scales 16, 18. The labels 14 are of a transparent material thereby enabling an individual's pupils to be visible through the labels 14. The labels 14 may be secured in position using any suitable technique. It is envisaged that the labels 14 may be of a thin, flexible plastics material and that they be secured in position using the effects of static electricity, surface tension and/or a low tack adhesive. However, the invention is not restricted to such techniques.

In use, an individual wearing the spectacles frame either looks in a mirror and notes the positions of his pupils against the scales 16, l 8 or another person looking at the individual notes the individuals pupil positions using the scales 16, 18.

If the pupil position information is to be used in the manufacture of hior tri- focal spectacles, then several readings may be taken on the vertical scale 18 with the individual positioned with his head tilted at the angles at which he wishes to view through the parts of the lenses of the various focal lengths.

The labels 14 may be positioned as part of the operation of manufacturing the spectacles frame, or may be positioned at a later time. As can be seen from Figure 1, the horizontal scales 16 are preferably arranged to allow the direct measurement ofthe horizontal pupil spacing from the centreline ofthe individuals nose, the scales starting from zero at the centreline. However, arrangements are also possible in which a different datum position is chosen, for example the inner edge ofthe frame.

ce.:. . ë ë ce: : ë:: .

. . ... .. In such arrangements, in order to ascertain the actual pupil position information, the dimensions ofthe spectacles frame in use will also be needed. The vertical scale is, in the arrangement illustrated, centred upon the centreline ofthe lens, but again this could potentially be altered, if desired.

Although the description hereinbefore is of the use of a label 14 secured to the spectacles, the scales 16, 18 could alternatively be printed upon lens inserts mounted in the frames.

Turning next to Figure 2, there is shown a ruler device 20 arranged to be secured to a spectacles frame. The ruler device 20 comprises a strip 22 of, for I O example, a thin cardboard. The strip 22 is shaped to include a pair of openings 24 located such that, when the strip 22 is secured to a spectacles frame, the individuals pupils are visible through the openings 24.

The openings 24 are each shaped to include a projection 26 on which is marked a generally vertically extending scale 28. A similar scale 30 is provided adjacent the openings 24, but this could potentially be omitted, if desired.

The lower part of the strip 22 is provided with markings 32 to allow the vertical dimension of a spectacles frame to be measured.

Beneath each opening 24 is provided a generally horizontally extending scale 34.

In use, the vertical dimension ofthe individual's choice of spectacles frame is ë e:e a: A : . - . . . . . measured using the scale formed by the markings 32. The measured vertical dimension is then halved, to give a measure of the position of centreline of the lenses of the spectacles. The strip 22 is then secured to the spectacles frame with the top of the frame aligned with the calculated half vertical height measurement aligned with the corresponding number on the scales 28. The strip 22 is conveniently affixed in position using short strips of a double sided adhesive material (not shown). However, other techniques for securing the strip 22 in position may be used, and the invention is not restricted to the use of such adhesive strips. The individual, wearing the spectacles frame and looking in a mirror, then measures the positions of his pupils against the horizontal scale 34 to obtain a measurement ofthe individual's pupil positions. As with the arrangement of Figure 1, the scale 34 preferably starts from zero at the centreline, but other configurations are possible.

Although the ruler is described as being of card, it could be manufactured from other materials, for example certain plastics materials. It may be possible to manufacture the ruler of a transparent material in which case it may not be necessary to form openings therein, instead arranging for clear parts of the ruler device to be located in front of the individual's eyes, in use.

Turning next to Figures 3, 4 and 6 there is shown parts of a kit for use by an individual in measuring the positions of his pupils. The kit comprises a number of e. eye.. ë ë : : . :: .

. . ... .. . separate components. Firstly, the kit comprises a length of material 40, for example a stiff paper or cardboard material shaped along the lines illustrated in Figure 3. For convenience, the length of material 40 will be referred to hereafter as a ruler 40.

Secondly, the kit comprises a bridge measurement guide 42 as illustrated in Figure 6.

Referring firstly to Figure 3, the ruler 40 comprises a length of cardboard shaped to define a bridge region 46 in the form of a cut-out arranged to be positioned, in use, over the individual's nose. The ruler 40 further includes a pair of measurement sections 48 provided with scales 50. The scales 50 are intended for use in measuring the horizontal spacing of each of the individual's pupils from a datum position located at the centre of the bridge of the individual's nose.

As illustrated in Figure 4, in use, the ruler 40 is secured to the frame of a pair of spectacles. Typically, the frame used will be the user's existing spectacles or a new spectacles frame into which lenses are to be fitted, but could be a "dummy" frame. The ruler 40 is secured to the spectacles frame using one or more strips of a double-sided, releasable adhesive strip. Although the use of such an adhesive strip is preferred, it will be appreciated that other techniques may be used to releasably secure the ruler 40 to the individual's spectacle frame. The positioning of the ruler on the spectacles frame is such that, when the individual is wearing the spectacles, the bridge region 46 is located centrally over the bridge of the individual's nose.

: : : .: e Once so positioned, the individual looks straight ahead. Initially, his view will be entirely obscured by the presence of the ruler 40. Assuming this to be the case, the user removes his spectacles, complete with the ruler 40 and, using a pair of scissors, deforms the ruler 40 by cutting away the lowermost part of one of the measurement sections 48, following one of the guidelines 54 printed thereon.

Having deformed the ruler 40 in this manner the individual then replaces his spectacles complete with the ruler 40 to ascertain whether, when looking straight ahead, he can now see past the ruler 40. If the ruler 40 is still obscuring the vision of the individual, then the spectacles are removed again and, using the scissors, the measurement section 48 is deformed further by cutting away to the next of the guidelines 54. This operation is repeated until such time as the user is happy that, when looking straight ahead, his view is only just no longer obscured by the presence of the ruler 40. This is the position illustrated in Figure 4.

Once the above operation has been completed in relation to one of the individual's eyes, the operation is repeated by deforming the other of the measurement sections 48.

Once both of the measurement sections 48 have been deformed in this manner, the individual positions himself in front of a mirror and, whilst looking straight ahead into the mirror, notes the position of each pupil relative to the scales 50. The operation of deforming the measurement sections ensures that the scales are :: .2 I: :. e. . . located immediately adjacent the pupils, thereby improving the accuracy with which pupil positions can be measured. It will be appreciated that once this operation has been conducted in relation to both of the individual's eyes, then the readings taken from the scales 50 provide an indication of the horizontal spacing of each pupil from a datum position. With reference to Figure 4, it will be appreciated that for the one exposed pupil, the horizontal position of the pupil relative to the datum position on scale 50 has a value of 22.

Although the techniques described hereinbefore for obtaining an approximate measurement of location of the individuals pupils is thought to work adequately, it will be appreciate that other techniques may be used to achieve the same or a similar result.

Figure 5 illustrates another device for use in measuring the position of an individual's pupils comprising a panel or sheet 60 on which are provided orthogonal, vertical and horizontal scales 62, 64. The sheet 60 is at least partly transparent and is arranged to be releasably secured to or upon the lenses or frame of a pair of spectacles. The sheet 60 could be secured in position, in use, by adhesive, for example in the form of low tack adhesive strips. However, in a preferred arrangement, the sheet 60 is of a suitable plastics material and is securable in position by relying upon the effects of static electricity or a similar effect. The sheet 60 is provided, at or close to its centre, with a target area defined by a vertically en- ': .. .: t. :e ' . . extending slit 66.

In use, the individual positions the frame so that the centre of one ofthe lens holders of the frame is located in the centre of the sheet 60. In this position, the readings on the vertical scale 64 above and below the frame should be the same.

Likewise, the readings on the horizontal scale 62 to the left and right of the frame should be the same. Using approximate pupil position information, for example derived using the technique described hereinbefore, and using information provided by the frame supplier relating to the frame size and bridge width of the frame, an offset value is calculated and the sheet 60 is shifted sideways relative to the frame by the amount of the offset value. The sheet 60 is then secured to the frame in this position.

Once so secured, the individual puts the frame on. Whilst looking straight ahead, the individual should be able to see straight through the slit 66 and should have good, clear vision. If this is not the case, then the individual should be able to tell which way, and by approximately how much, the sheet 60 needs to be moved to bring the slit 66 to a position immediately in front of his pupil. He removes the spectacles, repositions the sheet 14 slightly, in the horizontal direction, and again dies on the spectacles to see if he now has clear forward vision. The process is repeated until the individual does have clear forward vision.

In order to emphasise the position of the slit 66 formed in the sheet 60, the c.':e e. e: se:e dle.e.. ë edges ofthe slit 66 are conveniently marked, for example by being printed with red, green or another contrasting colour ink. As such, if the sheet 60 is secured to the frame at a position close to the ideal position, the presence and location of the marking, and hence the slit 66, will be clear to the individual, giving an indication of in which direction and by how much the sheet 60 needs to be moved to position the sheet 60 in the ideal position.

Once the ideal position has been reached, the positions occupied by the edges of the frame are again noted. The readings above and below the frame should still be equal to one another. The readings on the horizontal scale 64 will usually differ from one another and it is these readings, in conjunction with information relating to the dimensions of the spectacles frame, which will be used by the spectacles manufacturer in correctly locating the lens in the frame in the horizontal direction.

It is thought that, in some circumstances, the scales 62, 64 may be difficult to read. In order to improve the clarity of the scales, the scales 62, 64 may be printed against a substantially blank background. Where the scales are printed in a dark colour, for example black, the background colour is preferably light, for example white, in order to be of good contrast.

In order to assist in ensuring that the individual is looking straight ahead, a target may be supplied, for example a suitably shaped or coloured cardboard letter, which may be secured at the individual's choice to a wall or the like at the . . en.

. . e . . . individual's eye level and on which the individual can focus in testing to ensure that the sheet 60 has been correctly positioned upon his spectacles frame. Depending upon the intended use of the spectacles, the operation of testing that the pupil position has been measured correctly may be repeated at several focal lengths. This can be achieved by the individual moving towards or away from the target.

Having ascertained the horizontal pupil measurement, the vertical position is ascertained by looking into a mirror with the individual wearing the frame bearing the sheet 60 and noting, from the vertical scale 64 the vertical position of his pupil.

This measurement is dependent, in part, upon the angle at which the individuals lo head is tilted forwards, and so it is important to ensure that the individual has his head tilted at a comfortable angle when taking this reading. If the readings are to be used in the manufacture of, for example, bi-focal spectacles, then two or more vertical measurements will need to be taken, one for each focal length of the spectacles. For example, for bi-focal spectacles, the user will tilt his head at the angle at which the spectacles are to be used for near vision and one reading is taken, the user then tilting his head at the angle at which the spectacles are to be used for distant vision and another reading is taken. The vertical position measurements are supplied to the spectacles manufacturer and used in correctly positioning the lenses in the frame.

The operation of double-checking/fine-tuning the measurement of the pupil e eee ë ce e . . . . . . . . location should be carried out one eye at a time. In order to ensure that this takes place correctly, the kit conveniently includes a black eye patch for the individual to wear over his other eye.

Where the ruler illustrated in Figure 2 has been used, then rather than locate the panel of Figure 5 directly on the spectacles, it could be applied to the ruler, positioned with the slit directly aligned with the measured pupil position. The individual then, wearing the spectacles with the ruler and panel attached, undertakes the operations described hereinbefore to check that the panel is correctly positioned in front of his pupils and, if appropriate, to take vertical position measurements, for lo example if hi- or tri-focal spectacles are to be manufactured.

If the panel is transparent, then it may be possible to omit the slit and simply provide the panel with markings, for example closely spaced parallel lines denoting an area which, in use, should be positioned directly in front of the user's pupil.

In addition to the pupil position information, in order to manufacture the spectacles to order, the spectacles manufacturer may also require information relating to the size of the individual's bridge and this can be measured by using the bridge guide device 70 illustrated in Figure 6 which comprises a strip of cardboard having formed therein a plurality of notches 72. The notches 72 are of different sizes. The individual uses the guide 70 by introducing the bridge of his nose in to the notches 72, in turn, and determining which of the notches 72 is the closest fit e ee eee.

ce ee. e e ee e e . . e e ë. e eee eee e upon the bridge of his nose. As shown in Figure 3, the ruler may be preprinted with a series of bridge guide lines. If desired, before using the ruler in the manner described hereinbefore, the ruler may be cut along an appropriate one of the guide lines to fit the ruler to the users bridge size. Additionally, the spectacles manufacturer may require information relating to the width of the spectacles frame to be supplied and the side arm length. Conveniently in order to allow the individual to provide this information, the ruler is provided along an edge thereof with a scale 56 which can be used to measure these dimensions, for example from the individual's existing spectacles.

Once all of these pieces of information have been collated, they can be supplied, together with the individual's spectacles prescription and information relating to the design of spectacles frame the individual wishes to be supplied with either by the internet, by telephone or through a mail-ordering service to a spectacles manufacturer who can manufacture the spectacles to order and supply them, for example, by mail to the individual.

It will be appreciated that although a specific arrangement for measurement of the individual's pupils positions has been described hereinbefore, modifications may be made thereto within the scope of the invention. For example, rather than cutting away parts ofthe measurement sections 48 of the ruler 40, other techniques for deforming the measurement sections 48 may be used. These techniques include e eca ae ace ä a a a e a a ë ë a folding the measurement section 48 along the guidelines 54 rasher then cutting along these lines.

Although in the arrangements illustrated herein, the markings ofthe scales are illustrated in the conventional manner, as the markings are likely to be used by the individual when looking in a mirror, the markings may be printed in reverse, if desired to assist the individual in determining the relevant measurements to be put on to the sheet.

It will be appreciated that although the components described hereinbefore enable readings to be taken by the individual, if desired, readings from the various lo components may be taken by another individual, thereby avoiding the need to take certain measurements whilst looking in a mirror.

Claims (16)

. . . ..e . . . CLAIMS

1. A pupil position measuring device comprising a scale associated, in use, with a spectacles frame or the like, the scale extending generally horizontally, in use, so as to allow the horizontal position of an individual's pupils to be measured.

2. A device according to Claim 1, wherein the scale is provided upon a ruler device securable to the spectacles frame.

3. A device according to Claim 1, wherein the scale is printed onto one of a lens insert carried by, or to be carried by, a spectacles frame, and a label to be secured to such an insert.

4. A device according to Claim 1, where a ruler device is fixed to or integral with a"dummy" spectacles frame.

5. A device according to any ofthe preceding claims, further comprising a scale which extends generally vertically, in use.

6. A device according to any one ofthe preceding claims, wherein where a ruler device is used, it is formed of a thin cardboard or plastics material and is securable to a spectacles frame using a low tack adhesive.

7. A device according to Claim 6, wherein the ruler device is manufactured from a substantially transparent material or has substantially transparent regions through which the individual's pupils are visible, in use, to allow their positions to be read . 1 e using the scale(s).

8. A device according to Claim 6, wherein the ruler device is provided with openings through which the individual's pupils are visible, in use.

9. A device according to Claim 1, wherein the scale is provided upon a panel moveable relative to the spectacles frame, in use.

10. A device according to Claim 9, wherein the panel comprises a thin, flexible plastics material securable to the spectacles frame and/or associated lens by the effects of static electricity, surface tension or low tack adhesive.

11. A device according to Claim 9 or Claim 10, wherein the panel is provided lo with a target region.

12. A device according to Claim 11, wherein the target region is defined by a slit formed in the panel.

13. A device according to Claim 12, wherein the edges of the slit are coloured.

14. A device according to Claim 1 1, wherein the panel is provided with markings deLmmg the target region.

15. A device according to Claim 11, wherein the panel is provided with a background colour which contrasts with the markings den ning the scale.

16. A pupil position measuring device substantially as hereinbefore described with reference to the accompanying drawings.