CERTIFICATE OF INCORPORATION

                                       OF

                             DETECTION SYSTEMS, INC.

                          [as amended through 8/12/99]

                        Under Section 402 of the Business

                             Corporation Law of the

                                State of New York

                  FIRST:  The name of the corporation is:

                             DETECTION SYSTEMS, INC.

                  SECOND:  The purposes for which it is formed are as follows:

                           To design, develop, manufacture, assemble, fabricate,
                           import, lease, market,  purchase or otherwise acquire
                           and  generally  to  trade  and deal in and  with,  as
                           principal  or  agent,   at  wholesale,   retail,   on
                           commission or otherwise,  materials,  components  and
                           devices  of  a  mechanical,  electrical,  optical  or
                           chemical nature for use in detection systems,  signal
                           systems and other systems.

                           To acquire by purchase, assignment, grant, license or
                           otherwise,  to  apply  for,  secure,  lease or in any
                           manner obtain,  to develop,  hold, own, use, exploit,
                           operate, enjoy and introduce, to sell, assign, lease,
                           mortgage,  pledge,  grant  licenses and rights of all
                           kinds in respect  of, or  otherwise  dispose  of, and
                           generally to deal in and with and turn to account for
                           any or all purposes,  either for itself or as nominee
                           or agent for others:

                              (1) Any  and  all  inventions, devices, processes,
                                  discoveries and formulae, and improvements and
                                  modifications thereof and rights and interests
                                  therein;

                              (2) Any and all letters patent or applications for
                                  letters patent of the United States of America
                                  or of any  other  country, state,  locality or
                                  authority, and

                              (3) any and all rights, interests  and  privileges
                                  connected  therewith  or  incidental  or
                                  appertaining thereto;

                              (4) Any and all copyrights granted  by the  United
                                  States of America or any other country, state,
                                  locality or authority, and any and all rights,
                                  interests and privileges  connected  therewith
                                  or incidental or appertaining thereto.

                           To purchase or otherwise  acquire,  hold,  own, sell,
                           lease or otherwise dispose of real property, improved
                           or  unimproved,  and personal  property,  tangible or
                           intangible,  including,  without  limitation,  goods,
                           wares and  merchandise of every  description  and the
                           securities and obligations of any issuer,  whether or
                           not incorporated.

                  To do all and everything  necessary,  suitable,  or proper for
the accomplishment of any of the purposes,  the attainment of any of the objects
or the furtherance of any of the powers  hereinbefore set forth, either alone or
connection  with  other  corporations,   firms  or  individuals  and  either  as
principals,  or  agents  and to do  every  other  act or acts,  thing or  things
incidental or appurtenant to or growing out of or connection  with the aforesaid
objects, purposes or powers or any of them.

                  The  foregoing  enumeration  of specific  powers  shall not be
deemed to limit or restrict in any manner the general powers of the corporation,
and the enjoyment and exercise thereof, as conferred by the laws of the State of
New York upon  corporations  organized  under  the  provisions  of the  Business
Corporation Law.

                  THIRD:  The office  of the corporation within the State of New
York is to be located in the City of Rochester, County of Monroe.

                  FOURTH:  The aggregate  number of shares which the Corporation
shall have authority to issue is twenty-four million (24,000,000) common shares,
with par value of Five Cents ($.05) per share.

                  FIFTH: No holder of shares of the Corporation of any class now
or hereafter  authorized,  shall have any  preferential  or preemptive  right to
subscribe for,  purchase or receive any shares of the  corporation of any class,
now or hereafter authorized,  or any options or warrants for such shares, or any
rights to subscribe to or purchase such shares,  or any  securities  convertible
into or exchangeable for such shares,  which may at any time be issued,  sold or
offered for sale by the Corporation.

                  SIXTH:  The Secretary of State is designated  the agent of the
Corporation  upon whom process against the  Corporation may be served.  The post
office  address to which the Secretary of State shall mail a copy of any process
against the  Corporation so served upon him is 130 Perinton  Parkway,  Fairport,
New York 14450.

                  SEVENTH:  The  Corporation  may not lend money to or guarantee
the obligation of a director of the  Corporation  unless (1) the particular loan
or guarantee is approved by the  shareholders  in accordance with the provisions
of Section 714 of the  Business  Corporation  Law or (2) the Board of  Directors
determines  that the loan or  guarantee  benefits  the  Corporation  and  either
approves the specific loan or guarantee or a general plan authorizing  loans and
guarantees.