Temperature control method for distributing power to a plurality of heating elements

• US 4,920,252 A
• Filed: 11/14/1988
• Issued: 04/24/1990
• Est. Priority Date: 02/05/1988
• Status: Expired due to Term

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Yoshino, Tatsuo
• Primary Examiner(s): Paschall, M. H.
• Application Number:
  US07/270,589
• Time in Patent Office: 526 Days
• Field of Search: 219/494, 219/485, 219/497, 219/501, 219/505, 219/507, 219/509, 219/330, 219/483, 219/486, 219/331, 219/491, 307/117, 307/38-41, 323/235, 323/236, 323/319
• US Class Current: 219/497
• CPC Class Codes: G05D 23/1934 each space being provided with one sensor acting on one or more control means

Abstract

A temperature control method is provided which is capable of carrying out a more efficient temperature control through an impartial starting of a plurality of temperature control objects such as the respective heating elements in the liquid tank portion and the drying portion of a developing device for photosensitive material. According to the method of the present invention, a required actuating time is allocated for each of the heating elements within one cycle of a predetermined length of time. As a result, it is possible to supply the required energy for each of the heating elements in a well-balanced manner.

Claims

1. In a temperature control method using a heating means and a temperature detecting means for each of a plurality of objects which are temperature controlled according to sequential, predetermined intervals of time designated as heater switching control cycles, said method comprising the steps of:

(a) controlling the heating of each of said heating means, for each cycle of said heater switching control cycles, by measuring and storing a temperature of each of said objects using said temperature detecting means, and in response thereto, allocating a specific length of actuating time and a specific cycle portion for controlling a heating means of each respective object, such that a total energy requirement for activating a subset of said heating means at any given time during said each cycle is maintained within a range of a predetermined rated capacity; and

(b) actuating each of said heating means according to said specific length of actuating time and said specific cycle portion.

2. A temperature control method according to claim 1, wherein said heating means of at least one of the temperature control objects is given an allocated actuating time based on a proportional plus integral plus derivative (PID) control operation.

3. A temperature control method according to claim 1 or claim 2, wherein said heater switching control cycles are set based on the detection of a zero crossing of an AC power supply signal.

4. In a temperature control method for a developing device for carrying out a wet processing of a photosensitive material, said developing device including a heating means and a temperature detecting means for each of a plurality of liquid tanks of a liquid tank portion and a drying portion, said method for effecting temperature control according to sequential, predetermined intervals of time designated as heater switching control cycles, and comprising the steps of:

(a) controlling the heating of said heating means for each of said liquid tanks and said drying portion, for each cycle of said heater switching control cycles, by measuring and storing a temperature of each of said liquid tanks and drying portion using said temperature detecting means, and in response thereto, allocating a specific length of actuating time and a specific cycle portion for controlling a heating means of each respective said liquid tanks and drying portion, such that a total energy requirement for activating a subset of said heating means at any given time during said each cycle is maintained within a range of a predetermined rated capacity; and

(b) actuating each of said heating means according to said specific length of actuating time and said specific cycle portion.

5. A temperature control method according to claim 4, wherein said heating means of at least one of said liquid tanks or drying portion is given an allocated actuating time based on a proportional plus integral plus derivative (PID) control operation.

6. A temperature control method according to claim 4 or claim 5, wherein said heater switching control cycles are set based on the detection of a zero crossing of an AC power supply signal.