Claims
- 1. A radiation sensing system comprising:
- (A) accumulation type radiation sensing means which produces an electrical indication by accumulating incident radiation over an accumulation time;
- (B) discrimination means for discriminating the value of said electrical indication produced by said sensing means, said discrimination means discriminating that said sensing means is in a first state when an accumulating value indicated by said electrical indication is larger than a first value and said means discriminating that said sensing means is in a second state when said accumulation value is smaller than a second value; and
- (C) control means for controlling the accumulation time of said sensing means, said control means decreasing said accumulating time when said discrimination means discriminates that said sensing means is in said second state, and increasing said accumulation time when said discrimination means discriminates that said sensing means is in said first state, wherein the amount of increase or decrease in said accumulation time is controlled so as to become a half of the previous increase or decrease in said accumulation time set by said control means until the accumulation time reaches a proper value.
- 2. A radiation sensing system comprising:
- (A) accumulation rype radiation sensing means for producing an electrical indication by accumulating incident radiation over an accumulation time;
- (B) control means for controlling the accumulation time of said sensing means, said control means having the following two control modes in order to control said accumulation time to be a proper value;
- (a) a successively approximating mode under which the control means changes said accumulation time by different steps to control said accumulation time to be a proper value;
- (b) a follow-up mode under which the control means changes said accumulation time by a constant step to control said accumulation time to be a proper value; and
- (c) drive means for driving said control means, said drive means driving said control means to control said accumulation time under said successively approximating mode, and after once said accumulation time has reached a proper value, said drive means driving said control means to control said accumulation time under said follow-up mode.
- 3. A system according to claim 2 further comprising initiation means for initiating the operation of said drive means,
- said drive means driving said control means under said successively approximating mode in response to the initiation of said initiation means.
- 4. The system according to claim 3, wherein said control means includes a programmed Read-Only-Memory.
- 5. A system according to claim 3, wherein said initiation means executes the initiation of said drive means by performing the initiation of said system in response to the turning-on of a power source.
- 6. The system according to claim 1 or 2, wherein said control means includes a programmed Read-Only-Memory.
- 7. A radiation sensing system comprising:
- (a) accumulation type radiation sensing means for producing electrical indication by accumulating incident radiation over an accumulation time;
- (B) control means for controlling said accumulation time of said sensing means, said control means having the following two control modes in order to adjust said accumulation time to be a proper value;
- (a) a first mode, under which the control means changes said accumulation time by a constant value to control said accumulation time to be a proper value;
- (b) a second mode under which the control means, at least one time, changes said accumulation time by a value larger than said constant value in said first mode to control said accumulation time to be a proper value; and
- (C) drive means for driving said control means so that firstly, said control means is driven under said second mode and after once said accumulation time has reached a proper value, said control means is driven under said first mode.
Priority Claims (1)
Number |
Date |
Country |
Kind |
56-106341 |
Jul 1981 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 392,757 filed June 28, 1982 now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4329577 |
Asano et al. |
May 1982 |
|
4377742 |
Kawabata et al. |
Mar 1983 |
|
4384199 |
Ogino et al. |
May 1983 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
392757 |
Jun 1982 |
|