JPS58174929A - Blurring detector for camera - Google Patents

Abstract

PURPOSE:To perform always stable photographing, by storing object information in a memory according to an initial memory signal, comparing the same with a fresh object signal and displaying the detection of a blurring when the number of dissidence is the threshold value or above. CONSTITUTION:A photoelectric conversion sensor 1 consisting of (n) bits receives the image of an object according to a shutter operation and outputs the signal (a) corresponding to the optical axis of the object. The signal (a) is stored in a memory part 3 according to an initial memory signal (m). The old object information d1 thereof is inputted to a comparing counter part, by which the information is compared with the fresh object signal d2 inputted directly from the sensor 1 according to a timing signal. The case when both inputs d1, d2 are dissident is counted. when the count value thereof exceeds a preset specified value, a display element 7 displays an alarm for the detection of the blurring with a display driving part 6. Always stable photographing is thus accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a pre-detection device for a camera that detects blur that occurs when taking pictures with a camera.

[Technical background of the invention]

When photographing with a camera, so-called blurring may occur when the shutter is opened and closed, that is, when the subject'f or the camera moves during exposure. Such blurring is blurring caused by the movement of the object that enters the lens on the film. Some conventional cameras are equipped with a device that warns of camera shake if the light and sound from the subject is measured and the opening/closing of the shutter is slow.

[Point d during the back flying technique south] However, it is necessary to measure the actual blurring that has occurred before determining whether or not it is within the allowable range. cannot be ejected with conventional cameras. Therefore, when blurring occurs, it is only noticed after the film is loaded, which often spoils important photo shoots.

[Purpose of the invention]

This invention was made in view of the above-mentioned circumstances, and detects the amount of pretension using a relatively simple circuit, and if the amount of predation is outside the permissible range for photographing, it displays a warning and always An object of the present invention is to provide a pre-detection device for a camera that allows stable photography.

[A essential point of the invention]

That is, in the present invention, tear-off photographic object information is stored in an analog memory or the like in accordance with the gJ period memory decoding. Then, the new subject information after a certain period of time and the above-mentioned open subject information are compared by a comparing means such as an operational amplifier in accordance with a certain timing signal.

If the result of this comparison is greater than or equal to a preset value corresponding to the amount of preset force, a predetection display is performed.

[Implementation sequence of the invention]

An actual WA example of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a pre-detection device according to the present invention, which is a photoelectric conversion sensor consisting of an IFi photodiode and the like. The photoelectric conversion sensor 2 converts the reflected light of the object (A or B) input from the lens 2 into an electric signal a and outputs it in accordance with the shutter operation of the camera. The photoelectric f conversion sensor 1 is composed of n bits as shown in FIG. 2, and outputs an electric signal a corresponding to the optical axis of the subject (A or B). This 'Electricity 1Δ No.a' is COD (charge coupled) according to the initial memory signal.
The data is stored in the memory unit 3, which is an analog memory such as device). The electrical signal output from this memory section 3 is open subject information (equivalent to subject A VC if kept).
It is input to the comparison and counting section 4 as at. An electrical signal from the photoelectric conversion sensor 1 is directly input to the specific absorption counting unit 4 as new photographic object information (for example, corresponding to the photographic subject B) dm. In the comparison and counting section 4, the above new and old subject information d, d
, are compared using a comparator. This comparison operation is controlled by a timing signal output from the control section 5 at regular intervals. Further, in the comparison/counting section 4, the comparison result of the comparator,
If the new and old object information d, , d are inconsistent, the number of discrepancies is counted. If this counting result is significantly larger than a preset specified value, an output signal is input to the display drive unit 6. The specified value is, for example, a numerical value corresponding to the amount of preform within an allowable range in photography.

The display drive section 6 outputs an output signal b''IIe-IIe-a drive signal e for driving a display element 7 such as a human-powered light emitting diode. This display element 7 displays a pre-detection warning.

Such a pre-detection device is physically constructed as shown in FIG. That is, the electrical signal a output from the n-bit photoelectric conversion sensor 1 is transmitted through the MOS 1-. 9 input to a switch circuit 10 such as a transistor. At the same time, the electrical signal a is passed through a comparator 11. such as an operational amplifier. ~lln is input to one of each input terminal. The switch circuit 10 transfers the electrical signal a to the memory section 3, which is an analog memory such as a COD, in response to the input of the initial memory signal m.

The good electrical signal a stored in the memory section 3 is inputted to the other input terminal of each of the comparators 111 to 11n (D) as open subject information d1.In the comparators 11. to 11m, open subject information d, And the new photographic object information d, which is input directly from the photoelectric sensor 1 using the electric signal a, is transferred to the timing signal t.
Synchronize and compare. This comparison result, that is, comparator 1
Each comparison output signal C of 11 to Iln is input to the counting circuit 12. This stitch count circuit 12 calculates the number of stitches from the valley comparison output signal C, and outputs a count output signal g when the count result exceeds the prescribed value (f of the third factor) as described above. This output signal g is input to one input terminal of the AND circuit 13.

The other input terminal of the AND circuit 13 receives a shutter signal 8 (OFF) when the shutter of the camera is closed. The output signal of the AND circuit 13 is input to the display driving section 6. This display drive section 6 outputs a drive signal for driving a display element 7 such as a light emitting diode.

The operation of this configuration will be explained. As shown in Figure 4, when you operate the camera's shutter button,
The shutter opens and a 7-ray signal 5 (ON) is output.

In synchronization with this shutter signal 8 (ON), the initial memory signal m is input to the switch circuit 10 for a certain period of time, turning the switch circuit '70 on. Therefore, the electrical signal a (corresponding to the subject A in FIG. 1) from the photoelectric sensor I is stored in the memory section 3 via the switch circuit 10. This electric signal & is the front plate object information d at the moment when the film starts to be opened and the film is exposed. Then, at the same time as the exposure, the photoelectric conversion sensor 1 sends the latest electric signal all the new liquid photographic object information d! outputs. In this case, the initial memory signal m falls and the switch circuit 10 is off, so #subject 1f report d!
is a direct comparator 11. ~11n is input to one input terminal. The ratio I21S111zlln compares the old subject information II dt and the new subject information d from the memory section 3 in synchronization with the timing signal t (which is a sampling signal) input at regular intervals, and calculates the comparison result. Output C. For example, as shown in FIG. 1, when subject B moves relative to subject A, new liquid subject information d-, which is information about subject A, is generated. The information will be different from that. Therefore, comparator 11. Among the valley comparison results C of ~Iln, some comparison results C output inconsistent signals.

Each comparison result C corresponds to n bits of the optical TF conversion sensor 1. The counting circuit I2 counts the number of bits of the comparison result C, that is, the number of mismatches, and outputs a count output signal g'k if the count result exceeds a certain specified value f. That is, if the output signal a of the photoelectric f conversion sensor l changes in a certain number of pits, a shake is detected.

By the way, the counting circuit 12 is, for example, a clip 70-7'' (
(not shown), and the output signal g output from the clip 70 is input to the AND circuit 13 in response to the set input of the count output signal g'.

The AND circuit 13 outputs the output signal g and the shutter signal 5 (
Displays the output signal according to both inputs (OFF) IIIA
input to the moving part 6. The display driver 6 outputs a drive signal corresponding to the output signal of the AND circuit 13 to drive the display element 7.

In this way, immediately after the shutter is operated, the optical operator of the subject input from the lens is recorded in the memory section 3 in the form of an analog signal as subject information d. Then, the latest subject information d, which changes at regular intervals, is compared with the open subject information (1). By detecting this comparison result, if the subject's position relative to the camera moves after the shutter operation, It is possible to detect a discrepancy in the mouth subject information d,,d, and as a result, the occurrence of blur can be detected.Furthermore, the above comparison result is a specified value (number of bits) corresponding to the amount of blur in a preset punch capacity range. A blur detection display is performed only when the blur exceeds the allowable range.In the past, if the blur that exceeds the allowable range actually occurs after the film is developed, the photographer can immediately take another red photo. , normal photography can always be achieved.

FIG. 5 shows new and old subject information d, d in the above embodiment.
! A comparator for comparing 11. This shows another configuration for the portion of ~11n. That is, the open subject information d and Fi from the memory section 3 are input to the input terminal of the buffer amplifier 21 of the voltage follower. The output terminal of this buffer amplifier 21 has a constant voltage (fit) as shown in FIG.
The resistors 22a, 22b and the resistors 23a, 23b are connected directly to nine circuits. Output terminal 2 of this circuit
4a and 24b are set to [dl+
αJ, ra, −α” are output respectively. In this case, α
is α= I-R・・・・・・・・・・・・ Song...
Curve: concave curve (1), however: constant current freezing 22a, 22b valley current value R: resistor 23
It is determined by the valley resistance value of a and 23b. Then, "d, +α" is input to the input terminal (G) of the conoparator 26a of the window comparator 25,
rd, -α” is input to the input terminal (to) of the comparator 26b. Input terminals (c) of both comparators 26a and 26b.

In (-)-), the new subject t#information d output from the light '1ILf conversion sensor 1 is input to the common VC person. The valley output terminals of the comparators 26a and 16b are respectively connected to the NAND l! of the window comparator 25. l! Enter in 27.

This NAND circuit zyo output signal is
, d, the comparison result is C'.

With this type of circuit, the output signal a (dB and d) of sensor 1 will change depending on the brightness of the light around the camera, reducing the occurrence of errors in detecting camera shake. can do.

That is, the change (by ¥α) in the output signal a due to the brightness of light that occurs depending on the time of the shutter operation is adjusted to g4 within the allowable range of the comparison operation. Specifically, by decreasing α when the shutter time is short and increasing α when the shutter time is long, the error in detecting blur can be reduced. α is set by the above equation (1), and the electrician can adjust the value of α to a predetermined value through externally adjustable rounding.

〔Effect of the invention〕

As described in detail above, according to the present invention, when the position of the subject moves relative to the camera after the shutter operation of the camera, the blur can be reliably detected using a relatively simple circuit.

Furthermore, if the detected blur is outside the permissible range for photographing, a warning can be displayed to the photographer. Therefore, the photographer can always take stable photographs.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram showing the configuration of a shake detection device according to an embodiment of the present invention, FIG. 2 is a partial configuration diagram thereof, and FIG. 3 is a block diagram showing the configuration of a shake detection device according to an embodiment of the present invention. FIG. 4 is a specific circuit diagram of such a pre-detection device, and FIG. 5 is a partial circuit diagram of a pre-detection device according to another embodiment of the present invention.

Claims (1)

[Claims] a photoelectric conversion means for converting light from a subject into an electrical signal according to the operation of a shutter; a storage means for storing the electrical signal from the photoelectric conversion means as teardown object information according to an initial memory m; a comparing means for comparing the broken object information from the recording means and the new object information directly transferred from the photoelectric conversion means in synchronization with a certain timing signal; A pre-detection device for a special effects camera, comprising display means for performing a detection display.