GB2334112A

GB2334112A - Microscope stage control

Info

Publication number: GB2334112A
Application number: GB9901741A
Authority: GB
Inventors: Peter John Reilly
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-01-27
Filing date: 1999-01-27
Publication date: 1999-08-11
Also published as: GB9901741D0; GB9801636D0

Abstract

A microscope stage control system for a microscope 10, has a control unit 30 which generates, in response to forces manually applied to the top of the control unit, corresponding X, Y, and optionally Z (focus) signals, and drive circuitry 20 couples those signals to motors 17 coupled to the microscope stage 14 to cause X and Y movement and focussing adjustment. The control unit 30 maybe a flat pad with a pair of transducers (preferably FSRs (force sensitive resistors)) mounted below it at the sides for X control, a similar pair of transducers mounted at top and bottom for Y control, and a third pair of transducers mounted adjacent to a radial arm underneath the plate for Z control. The drive unit 20 may contain 3 parallel channels, each with a respective settable reversing switch (21, Fig 4) and settable gain control.

Description

b1icr^oscope Control The present invention relates to microscopes. and more specifically to controlling the position of microscope stages.

A microscope normally consists broadly of a stage on which a slide is mounted, an optical enlargement system above the stage, and a lighting source beneath the stage. The slide often carries a specimen which extends over a considerable area. It is often necessary to scan over most or all of the specimen, which may for example be a medical cell sample (ie a large patch of cells which need to be inspected). The microscope stage is therefore provided with mechanical movement controls which are manually operable to move the stage in the X and Y directions.

Such an arrangement is highly satisfactory for occasional use. However, in some situations the operator is required to use the microscope on a substantially continuous basis, for example in medical mass screening programmes. With such long-term and near-continuous use, there is a substantial risk of inconvenience and discomfort at best and more severe conditions such as repetitive strain injury at worst.

The general object of the present invention is to provide a microscope stage control system which alleviates this problem.

Accordingly the invention provides a microscope stage control system comprising control means generating, in response to manually applied forces, corresponding X and Y signals, and drive circuitry coupling those signals to a pair of motors coupled to the stage to give X and Y movement thereof.

Preferably the control means are also responsive to a manually applied turning force to generate a focus control signal and the drive circuitry couples that signal to a focus motor also coupled to the stage to adjust the focussing of the microscope.

Further features of the invention will become apparent from the following description of a microscope and stage control system therefor embodying the invention, given by way of example and with reference to the drawings, in which: Fig. 1 is a general view of the microscope and control system; Fig. 2 is à more detailed view of the control unit; Fig. 3A is a more detailed diagrammatic vertical sectional view of the control unit; Fig. 3B is a more detailed diagrammatic and partial horizontal sectional view of the control unit; and Fig. 4 is a simplified block diagram of the drive circuitry.

Referring to Fig. 1, the system consists a microscope 10, drive circuitry 20, and a control unit 30. The microscope 10 comprises a base 11 and column 12, with an optical system 13 mounted on the top of the column 12, a stage assembly 14 mounted part-way up the column 12, and a light source 15 mounted on the base 11. The stage assembly consists of a stage support arm 1S carrying a stage 16 which is movably mounted thereon. A set of 3 motors 17 is mounted on the support arm 18 such that the 3 motors move the stage 16 in the X, Y, and Z (focus) directions respectively. The X and Y drive motors are preferably coupled to the stage via a pair of vertical concentric shafts coupled to the motors and the stage 16 via bevel gears.

The control unit 30 is a flat pad which operates somewhat like a joystick.

The pad consists of a rectangular base 31 having a rectangular plate 32 mounted on it. The plate 32 is mounted on a shaft 33 (Fig. 3A) which is loosely attached to the base 31, so that the plate and shaft can rock on and rotate slightly about the base. Resilient mounting means 33 around the shaft 32 hold the plate 32 in a rest position in which it is horizontal and aligned with the base 31. The plate 32 can be moved from the rest position manually; the mounting means 33 provide resistance against such movement of the plate and return it to the rest position after displacement. The mounting means 33 may comprise a spring andi or resilient material.

The control unit contains two opposite pairs of transducer stations 35 arranged as shown in Fig. 2. As shown in Fig. 3A, each transducer station consists of a column 36 mounted on the base 31, a stud 37 mounted on the underside of the plate 32, and an electrical transducer element 38 mounted between the column and the stud. The elements 38 are preferably FSRs (force sensitive resistors), the resistance of which varies with the compressive force applied across them. A resilient element (not shown) may be included between the column and the stud if desired.

The control unit also contains a further pair of transducer stations 33, as shown in Fig. 3B. These transducer stations are similar to the stations 35 but are mounted horizontally instead of vertically. An arm 40 mounted on the shaft 33 extends between these two transducer stations. Each of the stations 39 consists of a column element 41 mounted on the base 31, a stud 42 mounted on the arm 40, and an electrical transducer element 43 mounted between the column and the stud. The elements 43 are preferably FSRs (force sensitive resistors) like the elements 38.

The two pairs of transducer stations 35 in the control unit 30 form X and Y sensors respectively, and the third pair of transducer stations 39 form a Z or focus sensor. The drive unit 20 contains 3 parallel channels, one for each of these 3 pairs of sensors. For each channel, there is a respective reversing switch 21, which can be manually set to transmit the signal from the sensor direct or to invert it. For each channel, the reversing switch 2 1 feeds a variable gain amplifier and driver circuit 22, the gain of which is manually settable by means of a potentiometer (not shown). The driver circuits 22 are coupled to the X, Y, and Z (focus) motors 17 of the microscope 10. (Obviously the drive unit 20 also contains conventional circuitry such as a power supply unit, drive circuitry for driving the sensor elements 38 and 43, & c.' The mounting of the plate 32 on the base 31 of control unit 30, ie the shaft 32 and resilient mounting means 33, is arranged so that slight displacements of the plate 32 do not generate any signals in the transducer stations.

This ensures that the system is stable, ie that movement of the stage 16 only occurs in response to movements of the plate 32 exceeding a certain threshold.

In use, the operator rests their hand on the control unit 30, which is placed at any convenient position, generally on the bench or work surface which supports the microscope 10 and to one or other side of the microscope. To adjust the stage, the operator simply rocks the plate 32 from side to side, from front to back, or around its axis. The operator's hand can be kept more or less flat and open for this. Further, the operator can rest their hand on the control unit continuously, as the control unit is not responsive to downward pressure. The operator can also rest their forearm on the bench or work surface.

The reversing switches 21 in the drive unit 20 allow the drive signals therefrom to be reversed if necessary, so that the unit (together with the control unit 30) can be used in conjunction with different microscopes in which the drive directions of some or all the motors 17 are different. The gain controls (potentiometers) of the variable gain amplifiers 22 in the drive unit allow the unit (with the control unit) to be used in conjunction with different microscopes in which the responses of some or all of the motors 17 are different; these variable gain controls also allow individual operators to adjust the response speed of the system to suit their individual requirements.

A joy-stick type unit may be used as the control unit. Also, the Z control may drive the optical system 13 rather than the stage assembly 14.

In summary, there is provided a microscope stage control system for a microscope 10. A control unit 30 generates, in response to forces manually applied to the top of the control unit, corresponding X, Y, and Z (focus) signals, and drive circuitry 20 couples those signals to motors 17 coupled to the microscope stage 1 4 to cause X and Y movement and focussing adjustment. The control unit 30 is a flat pad with a pair of transducers 35 (preferably FSRs (force sensitive resistors)) mounted below it at the sides for X control, a similar pair of transducers 35 mounted at top and bottom for Y control, and a third pair of transducers 39 mounted adjacent to a radial arm underneath the plate for Z control. The drive unit 20 contains 3 parallel channels, each with a respective settable reversing switch and settable gain control.

Claims

Claims A A microscope stage control system comprising control means generating, in response to manually applied forces, corresponding X and Y signals, and drive circuitry coupling those signals to a pair of motors coupled to the stage to give X and Y movement thereof.
2 A microscope stage control system according to claim I wherein the control means are also responsive to a manually applied turning force to generate a focus control signal and the drive circuitry couples that signal to a focus motor also coupled to the stage to adjust the focussing of the microscope.
3 A microscope stage control system according to either previous claim wherein the control means includes, for each signal (X, Y, and focus if used), a settable reversing switch.
4 A microscope stage control system according to any previous claim wherein the control means includes, for each signal (X, Y, and focus if used), a settable gain control.
5 A microscope stage control system according to any previous claim wherein the control means includes a substantially flat control unit to which the manually applied forces are applied.
6 A microscope stage control system substantially as herein described and illustrated.
7 Any novel and inventive feature or combination of features specifically disclosed herein within the meaning of Article 4H of the International Convention (Paris Convention).