Apparatus for measuring the luminous lifetime of samples

• US 4,563,588 A
• Filed: 12/16/1983
• Issued: 01/07/1986
• Est. Priority Date: 01/08/1983
• Status: Expired due to Fees

• Current Assignee: Horiba Limited
• Original Assignee: Horiba Limited
• Inventors: Tanaka, Masaru
• Primary Examiner(s): Smith, Alfred E.
• Assistant Examiner(s): Lemmo, V.
• Application Number:
  US06/562,119
• Time in Patent Office: 753 Days
• Field of Search: 307/247 R, 307/244, 307/352, 307/353, 307/600, 307/602, 328/129.1, 328/130.1, 328/151, 328/153, 250/255, 250/458.1, 250/459.1, 250/461.1, 250/461.2
• US Class Current: 250/458.1
• CPC Class Codes: G01N 21/6408 with measurement of decay time, time resolved fluorescence
• CPC Class Codes: G01T 1/17 Circuit arrangements not adapted to a particular type of detector pulse-selection circuits H03K, G01R
• CPC Class Codes: G04F 10/10 by measuring electric or magnetic quantities changing in proportion to time
• CPC Class Codes: H03K 5/1508 using a plurality of delay lines

Abstract

An apparatus for measuring the luminous lifetime samples, which eliminates the deviation of the time axis of each channel of a multichannel TAC, deviations resulting from differences the wiring or the time lag of the elements of each channel of the multichannel TAC constituting a principal part of the apparatus. The apparatus operates by adding a respective variable offset voltage to the output of each channel of the TAC and by regulating the offset voltage in every channel without using any delay element so as to eliminate the time axis deviations of the channels.

Claims

1. In an apparatus for measuring the luminous lifetime of samples comprising a multichannel time-to-amplitude converter having N channels numbered 1 through N wherein N is a positive integer, said converter comprising a start pulse input means for receiving a start pulse and a stop pulse input means for receiving a plurality of stop pulses, wherein each of said channels includes a flip-flop having its set input connected to said start pulse input means and having an output connected to a time-to-amplitude converter connected to a sample and hold means;

and wherein said flip-flop of channel 1 has a reset input connected to said stop pulse input means and said channels 2 through N are arranged such that reset inputs of their respective flip-flops are connected to said stop pulse input means through corresponding gate means, each corresponding gate means of channel N having an enabling input connected to and controlled by a corresponding flip-flop of said channel N-1 such that said start pulse sets all of said flip-flops and a first stop pulse resets said first flip-flop and a second stop pulse resets said second flip-flop . . . and N stop pulse resets said N flip-flop, the improvement comprising;

a plurality of voltage adders each connected to a corresponding sample and hold means;

a plurality of variable offset voltage means each connected to a corresponding one of said plurality of adder means wherein each offset voltage may be manually adjusted so as to compensate for errors in a time axis of its corresponding channel.

2. An apparatus as in claim 1, wherein said time-to-amplitude converter channels are arranged to have at least two ranges and wherein each of said offset voltages is arranged to have a different value for each of said ranges.

3. An apparatus as in claim 1, wherein each of said time-to-amplitude converter means comprises a current source controlled by a switching means which charges a capacitor, a voltage across said capacitor feeding said sample and hold circuit.