JPS6246184Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a camera, and more particularly to a display device for a camera having a display device inside and outside the viewfinder screen.

Conventionally, the display brightness of the display device outside the viewfinder screen is adjusted according to the brightness of the external light, and when it is bright, it is adjusted to bright.
2. Description of the Related Art Display devices are known that are controlled to become darker when it is dark, thereby making the display easier to see.

On the other hand, even when a display device is installed within the viewfinder screen, the display brightness can be adjusted using external light, but unlike conventional devices, the display brightness is adjusted based on the brightness detected by the photometry circuit that measures the brightness of the entire screen. When you adjust the display brightness, the position of the display device within the screen and
A problem arises in that the display brightness is adjusted based on the brightness of the entire screen, regardless of the relationship with the brightness state at the installation position.

The present invention has been developed in view of the above-mentioned issues, and since the brightness adjustment for the display elements outside the viewfinder screen is performed using the output of a photometry circuit that performs average photometry, the brightness adjustment for the display elements inside the viewfinder screen is The purpose is to perform so-called two-bottom photometry output that photometers the luminous flux at a position corresponding to the position of the display element within the screen, and to adjust the brightness of the display elements inside and outside the viewfinder screen in an easy-to-see state.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figure 1 shows an example showing the positions of the photometry display and distance measurement display shown on the finder screen, where 1 is the finder screen, 2 and 3 are the photometry displays during spot photometry, and 4 and 5 are the photometry displays during average photometry. photometric display, 6,
7 is a distance measurement display of the distance measurement system. FIG. 2 shows an example of the arrangement of photometric sensors arranged inside the camera, where 100 is an imaging lens, 107 is a focusing glass, 101 is a quick return mirror,
The center part is a half mirror 104,
A total reflection mirror 104 is attached to the quick return mirror, and the light beam incident through the imaging lens 100 and the quick return mirror 101 is converted to SN1.
This is to guide the distance measurement sensor. For example, the distance measuring sensor SN1 includes an optical system, and includes a half mirror 105 that receives the light beam from the imaging lens 100, and a half mirror 105 that receives the light beam from the imaging lens 100.
A total reflection mirror 106 that receives the light beam reflected by the half mirror 105 and totally reflects the light beam is arranged in parallel with the imaging lens 10.
They may be placed before and after a position conjugate with the zero focal plane. 103 is a pentagonal roof prism, 108 is an eyepiece, and the average photometry sensor of SN2 is placed at a slightly shifted position between these. Fig. 3 is an example of a block diagram for displaying the distance measuring device and the average photometry device of the present invention, and SN1 and SN2 are the distance measuring devices arranged inside the camera shown in Fig. 2. sensor and average photometry sensor. 10 is a photometry processing circuit;
It is used to amplify the signal received by the average photometry sensor and photoelectrically converted. 11 is a distance measurement system processing circuit; one is for outputting a distance measurement signal by processing the signal received by the distance measurement sensor SN1; Calculate the difference in output between adjacent pixels in each light-receiving element row arranged at The total sum of the light-receiving element rows behind the position conjugate to the plane is subtracted, and this is used as the ranging signal. (Actually, it is compared with a reference voltage using a comparator as described later). The other is integrating the photoelectric conversion signal received by the ranging sensor SN1,
Performs signal processing such as amplification and outputs for photometry. At this time, when the distance measurement sensor SN1 is used for both distance measurement and spot photometry, it is switched through a switching circuit or the like. SW9-1 and SW9-2 receive photometry signals from the average photometry sensor SN2 for average photometry and its photometry processing circuit 10, or from the distance measurement sensor SN1 for spot photometry and its distance measurement system processing circuit. A switch is used to change whether or not to receive an optical signal, and a switch is used to switch the display to average photometry or spot photometry in conjunction with this switch. Reference numeral 12 is a photometric calculation processing circuit, for example, when priority is given to shutter speed, the shutter speed information is
It inputs Tv, film sensitivity information Sv, photometry signal, etc., outputs the aperture apex value, compares it with the set aperture value, etc., and outputs an exposure signal. 13 and 14 are for brightness modulation. The analog photometry signal from the photometry processing circuit 10 or the distance measurement system processing circuit 11 is converted into a digital signal by the A/D converter.
These signals are transmitted to 15 brightness modulation circuits and 1
They are connected to be input to the distance measuring system brightness modulation circuits of No. 6, respectively. The distance measurement system brightness modulation circuit 16 receives a signal obtained by converting the distance measurement signal from the distance measurement system processing circuit 11 and the photometry signal from the photometry processing circuit 10 into digital signals by the A/D converter 13, performs brightness modulation, and performs distance measurement. System display 19
is connected to provide a ranging signal for display. The position of this distance measuring system display 19 on the finder screen is indicated by 6 and 7 in FIG. The brightness modulation circuit 15 determines whether the photometry signal is average photometry;
It receives the output signal of the photometry calculation circuit which receives the photometry signal switched by switch SW9-1 to determine whether it is spot photometry, and the output signal of the A/D converter which receives the switched photometry signal and converts it into a digital signal. It is connected so as to modulate the brightness and give a signal for display to the average photometry display 17 or the spot photometry display 18. The switch SW9-2 is connected to the power supply voltage V _DD , and in conjunction with the switch SW9-1 is connected to either one of the display devices 17 and 18 to connect the power supply to the display device and enable display. . The average photometry display 17 is 4,5 in FIG.
And the spot photometry display 18 is also 2, 3,
Their locations are shown. 30 is a line that transmits the output of the photometry processing circuit 10, 31 is a line that outputs a spot photometry signal among the outputs of the distance measurement system processing circuit 11, and 32 is a line that transmits the output of the distance measurement system processing circuit 11.
Of the outputs, the ranging signal is sent to the ranging system brightness modulation circuit 16.
33 is the line to send to the switch SW9-
1 is a line for transmitting the photometric signal switched to the A/D converter 14 and the photometric calculation processing circuit 12, and 34 is a line for transmitting the display output of the photometry calculation processing circuit 12 to the brightness modulation circuit 15. It is. Note that among these lines, lines that extend over a plurality of lines are indicated by thick arrows. FIG. 4 is an embodiment of a more specific circuit diagram of the brightness modulation circuit 15 or the ranging system brightness modulation circuit 16 shown in FIG.
50 and 51 are display instruction inputs given from the photometry calculation processing circuit 12 or distance measurement system processing circuit 11 shown in FIG. 3; 52 and 53 are NAND gates;
A display instruction input is given through 51, and its output is sent to the display output terminal 5 through resistors 54 and 55, respectively.
6 and 57 respectively. 52 to 55 constitute a display drive circuit. 58 is a brightness modulation oscillator, the output of which is given to the brightness modulation frequency divider 19, and the output is output from output terminals T ₁ , T ₂ , T ₃ at frequency division ratios of 1/2, 1/4, and 1/8. , respectively, are output. 60 is an AND gate for generating 1/8 duty, and output terminals T ₁ , T ₂ ,
T ₃ is also on the input side for generating 1/4 duty of 61.
Output terminals T ₂ and T ₃ are connected to the input side of the AND gate. 63 is a decoder which receives the output of the A/D converter from line 62 as an input (the output of A/D converter 13 or 14 shown in FIG. 3).
The output is given to output terminals T ₄ , T ₅ , T ₆ , and T ₇ . The decoder 63 selects the output terminals _T4 to _T7 from dark to bright in accordance with the intensity of the measured light and outputs a "high" level. Output terminal
T ₄ , T ₅ , T ₆ , T ₇ are AND gates 64, 65, 66
and the input side of the OR gate 67, respectively, and the AND
The gate 64 is connected to receive the output of the AND gate 60, the AND gate 65 is connected to receive the output of the AND gate 71, and the AND gate 66 is connected to receive the output from the output terminal _T3 of the brightness modulation frequency divider 59. . The outputs of the AND gates 64 to 66 for selection are given as inputs to the OR gate 67 for selection,
The output of OR gate 67 is NAND gate 52, 55
is connected so that it can be given as an input. FIG. 5 shows an example of a circuit for displaying three points in response to the distance measurement signal from the distance measurement processing circuit shown in FIG. 3 or the exposure signal from the photometry calculation processing circuit.
0 is a comparison signal output circuit that provides an output for photometry calculation or distance measurement detection, and 81 is a reference voltage generation circuit for setting. When distance measurement display is desired, as described above with reference to FIG. 2, the comparison signal output circuit 80 outputs a positive voltage when the front pin is located, and a negative voltage when the rear pin is located. The setting reference voltage circuit 81 generates reference voltages of +V (>0) and -V (<0), which are divided by resistors, for example. If a photometric display is desired and priority is given to fringing, the setting reference voltage circuit 81 receives and calculates the shutter time information, film sensitivity information, and photometric signal, and calculates and outputs the apex value V _A of the fringing. The comparison signal output circuit 80 outputs an electric signal (mark information) Vr according to the set pattern of the mark. Comparators 83 and 84 input the +V output from the setting reference voltage circuit 81 to the inverting input side of the comparator 83, and similarly input -V to the non-inverting input side of the comparator 84. The output of the comparison signal output circuit 80 is connected to be applied to the non-inverting input side of the comparator 83 and the inverting input side input of the comparator 84. In the case of a distance measurement system, the comparators 83 and 84 compare the distance measurement detection signal output from the comparison signal output circuit 80 and the output from the setting reference voltage circuit 81, and input the display instruction for distance measurement to the next stage. to the circuit. In the case of a photometry system, if the fringe is given priority, the apex value of the frit output from the comparison signal output circuit 80 is compared with the frit information from the setting reference voltage circuit 81 to determine the photometry instruction. Give the input to the next stage circuit. As the next stage circuit, the output of comparator 83 is input to NAND gate 52, and the output of comparator 84 is input to NAND gate 52.
5, and both outputs of comparators 83 and 84 are
It is connected to be given as an input to NOR gate 85. The output of NOR gate 85 is NAND
The NAND gates 52, 53, and 86 are given as inputs to the gate 86, and the NAND gates 52, 53, and 86 are OR gates as a distance brightness modulation circuit or a brightness modulation circuit, which is surrounded by the dotted line in FIG.
It is connected to receive the output of the gate 67, and here 82 represents a brightness modulation circuit surrounded by a dotted line in FIG. The outputs of the NAND gates 52, 86, 55 are connected via resistors 54, 87, 55 to display output terminals 56, 88, 57, respectively. In the case of a distance measurement system, a comparison signal output circuit 80, a setting reference voltage circuit 81, a comparator 83,
84 constitutes a circuit that outputs a distance measurement signal from the distance measurement system processing circuit 11 shown in FIG.
3 and 84 constitute a circuit between the photometry calculation processing circuit 12 shown in FIG. 3 and the spot photometry circuit of the photometry processing circuit 10 or distance measurement system processing circuit 11. Of course, it includes an average photometry sensor SN1 and a distance measurement sensor SN2. 52 to 55 and 85 to 87 constitute a display drive circuit.

Next, the operation of the circuit configured as described above will be explained, mainly for normal average photometry. In FIG. 2, the brightness of the subject is imaged on a focusing glass 107 by an imaging lens 100, and then focused on a pendaconal prism 1.
Through 03, average brightness can be obtained with the average photometry sensor of SN2. At the same time, a half mirror 102, a total reflection mirror 104, a half mirror 10
5. Distance measurement sensor using total reflection mirror 106
With SN1, the brightness and image formation state of the central part of the subject can be obtained. The average brightness, center brightness, and image forming state are led to the circuit shown in FIG. The brightness and central distance measurement results are output on line 32. In the case of brightness signals, these outputs are obtained by amplifying photoelectric conversion signals from the average photometry sensor SN2 and the distance measurement sensor SN1 in the photometry processing circuit 10 and the distance measurement system processing circuit 11. In the case of central distance measurement, as mentioned above, calculate the sum of the differences in the outputs of adjacent pixels of the light receiving element rows placed before and after the position conjugate to the focal plane, and subtract the sums of each light receiving element row from each other. You can obtain the output of the center distance measurement results. Now, during average metering, switch SW9-1 and
SW9-2 is in the position shown in the diagram, that is, switch SW9
-1 is connected to the average photometry sensor SN1 side, and switch SW9-2 is connected to the average photometry display 17 side, so the line 30 is connected to the photometry line 33.
The photometric information of the average photometry is transmitted. As a result, the photometry calculation processing circuit 12 calculates the above-mentioned information, shutter speed information (not shown), and film sensitivity information, and outputs a signal indicating over/appropriate/underexposure on the line 34. It is modulated by the average brightness of the line 30 by the A/D converter 13 and displayed as front focus/in focus/rear focus on the distance measurement system display 19, that is, the distance measurement display 6 and 7 in FIG. . Similarly, the average photometric information on line 34 is modulated by the signal on line 30 from switch SW9-1 through the brightness modulation circuit 15, that is, the average brightness of the signal on line 30 from A/D converter 14,
9-2 indicator, i.e. average photometry indicator 17;
That is, the photometric displays 4 and 5 shown in FIG. 1 display over/appropriate/underexposure. In these cases, when the display is located at the edge of the viewfinder screen, etc., its visibility is strongly affected by the brightness of the entire screen, so by performing brightness modulation using the average photometric value in this way, the brightness is always easy to see. This is how it is displayed.

Next, in the case of spot metering, the switch SW9-1 and SW9-2 are switched by an operation section (not shown), and the switch SW9-1 is used for the distance measurement sensor SN.
The switch SW9-2 is connected to the spot photometry display 18 side. The input of the photometry arithmetic processing circuit 12 and the A/D converter 14 for photometry display modulation, that is, the line 33, is switched by the switch SW9-1 to be connected to the line 31, and the distance measurement section by the distance measurement sensor SN1, that is, the spot. The brightness is input. The output of the photometric calculation processing circuit 12 is sent to the A/D converter 14 by the brightness modulation circuit 15.
is modulated by the conversion value, that is, the central brightness,
Spot metering display 1 by switch SW9-2
8, that is, the overexposure/adequate/underexposure is displayed on the photometric displays 2 and 3 of FIG. 1 at an easy-to-read brightness that matches the central brightness to the same brightness. The distance measurement display also operates in exactly the same manner as described above, and the distance measurement system display 19, that is, the distance measurement displays 6 and 7 in FIG. displayed for easy viewing.

Next, the brightness modulation circuit 15 and the ranging system brightness modulation circuit 1
6 is shown in FIG. 4, and its operation will be explained. The signal from the aforementioned A/D converter is applied as an input to a decoder 63 by a line 62 and is applied to the output terminal T ₄ of the decoder 63 when its input is low, i.e. when it is very dark, and when its input is high. That is, when it is very bright, a "high" level output is output to the output terminal _T7 of the decoder 63. As a result, when it is very dark, the output terminal of the decoder 63
By outputting "high" level to _T4 and "low" level to output terminals _T5 , _T6 , _T7, the outputs of AND gates 65 and 66 become "low" level,
The AND gate 64 obtains an output 1/8 duty pulse from the _T1 output terminal of the brightness frequency divider 59, and outputs the 1/8 duty pulse to the OR gate 67. This allows input terminal 50 or 5
Since the NAND gates 52 and 53 are opened by the 1/8 duty pulse for the display instruction input 1, the display device, for example, a light emitting diode, is dimly illuminated through the resistors 54 and 55 only at that time. That is, when a 1/8 duty pulse is output to the OR gate 67 and the pulse is at a "high" level, if either the display instruction input of the input terminal 50 or 51 is at a "high" level, the output of the NAND gates 54 and 55 is All the inputs of either one are at "high" level, so the output is at "low" level, so resistor 54 or 5
The display dims through the resistor 5. Similarly, when it is very bright, a "high" level is output to the output terminal _T7 of the decoder 63, the other output terminals become "low" level, and the decoder 6 is output to the OR gate 67.
Since the output “high” level of 3 is input,
Since this output is duty cycle 1, it is always at a "high" level, and the output of the NAND gate 52 or 53 whose inputs are all at a "high" level is at a "low" level, which makes the display brighter. Let it shine. In the case of intermediate brightness, only the output terminal T ₅ or T ₆ of the decoder 63 becomes "high" level, and the AND gate 65 or 66 passes the pulse of 1/4 duty or 1/2 duty from the frequency divider 59 for brightness modulation. By inputting it to the OR gate 67, a pulse of 1/4 duty or 1/2 duty is output from the OR gate 67 to the NAND gate 67.
2.53 to similarly illuminate the display at a medium level of brightness.

Next, the operation of FIG. 5 will be explained. This is an example of a case where three displays are shown instead of two in Fig. 4. In the case of a rangefinder system, the rangefinder sensor SN1 is placed before and after the focal plane as shown in Fig. 2. As mentioned above, it is assumed that the comparison signal output circuit 80 outputs a positive voltage when the front pin is applied, and a negative voltage when the rear pin is applied, as described above. The setting reference voltage circuit 81 provides a positive reference voltage of +V to the comparator 83 and a negative reference voltage of -V to the comparator 84. Now, if a voltage higher than +V is output from the comparison signal output circuit 80 in the state of the front pin, the output of the comparator 83 is "high".
The output of the level comparator 84 becomes a "low" level and is input to the NAND gates 52 and 53, and the duty pulse corresponding to the brightness is output from the brightness modulation circuit 82 and given as the other input. , the output of the NAND gate 52 becomes "low" level continuously or intermittently, and lights up an indicator light such as a light emitting diode (not shown) connected to the output terminal 56 via the resistor 54 as a distance measurement indicator. Since the output of the NAND gate 53 is always at a "high" level, the display does not light up, and the NOR gate 85
Since one “high” level signal is input to the , its output becomes “low” level. This "low" level signal is input to the NAND gate 86, so its output becomes "high" level and the display does not light up. When the rear pin is selected, comparison signal output circuit 8
0 outputs a signal below -V, so the output of the comparator 84 is "high" level, and the output of the comparator 83 is "low" level, so the display output terminal 56
Since a "high" level is output to and 88 and a "low" level is output to the display output terminal 57, only the display element such as a light emitting diode connected to the display output terminal 57 via the resistor 55 lights up. . When the comparison signal output circuit 80 outputs a signal within the focus tolerance range, that is, a voltage between +V and -V, the comparator 8
Since the outputs of 3 and 84 are both “low” level,
The outputs of the NAND gates 52 and 53 become "high" level. The display elements connected to display output terminals 56 and 57 do not light up. However, since all "low" level signals are input to the NOR gate 85, its output becomes "high" level and the NAND gate 86
Since the duty pulse from the brightness modulation circuit 82 is also input, the output of the NAND gate 86 becomes "low" in response to the "high" level of the duty pulse.
level, so only the display element such as a light emitting diode connected to the display output terminal 88 via the resistor 87 lights up. This makes it possible to display front focus/focus/rear focus in distance measurement display. When displaying exposure, the comparison signal output circuit 81 outputs frit information according to the fringe level set in the same way.
Vr is applied as a voltage to comparison circuits 83 and 84, and the setting reference voltage circuit 8 is connected to the average photometry sensor SN2 and the photometry processing circuit 10 or the distance measurement sensor SN1 and the distance measurement system processing circuit 11 shown in FIG. It takes in the photometric information, shutter speed information, and film sensitivity information given from , and outputs the apex value of the frit as a voltage V _A . Compared by comparator, Vr>V
If it is _A , the comparator 83 will be at a "high" level and the comparator 84 will be at a "low" level, so the NAND gate 5
The output of 3,86 is “high” level NAND gate 5
Since the output of No. 2 becomes a "low" level in response to the "high" level of the duty pulse of the brightness modulation circuit 82, only the display element connected to the display output terminal 56 lights up. If Vr<V _A , the output of comparator 83 is “low” level, and the output of comparator 84 is “high”
level, so only the output of the NAND gate 53 is the “high” level of the duty pulse of the brightness modulation circuit 82.
Since it becomes a "low" level depending on the level, only the indicator light connected to the display output terminal 57 lights up.
If Vr = V _A , the outputs of both comparators 83 and 84 will be at "low" level, the outputs of NAND gates 52 and 53 will be at "high" level, and both inputs of the NOR gate are at "low" level, so the output becomes a “high” level and is input to the NAND gate 86,
On the other side of the NAND gate is a brightness modulation circuit 82.
Since the duty pulse is input and a "high" level is input continuously or intermittently, the NAND gate 86 outputs a "low" level continuously or intermittently, so that only the display element connected to the display output terminal 88 lights up. to display the appropriate exposure.
This will display over/appropriate/underexposure.

The present invention is not limited to this, but as a modification of the above embodiment, the duty cycle and current of the modulation pulse can be changed depending on the position of the display section, and the display element is not limited to a light emitting diode, but can be a light emitting element. can be modulated by a similar circuit, and it goes without saying that even in the case of a passive element (for example, a liquid crystal), an easy-to-read display can be obtained regardless of the subject illuminance by using a similar configuration for lighting the auxiliary illumination.
Note that the display is not limited to the one mentioned above, and the same can be said of other warning displays and status displays such as the number of frames.

By configuring and operating the present invention as described above, it is possible to easily obtain an easy-to-read display by modulating the brightness depending on the position of the display section, and it also saves power, and it is relatively easy to use in combination with photometry of a distance measurement system. It is possible to construct an easy-to-use camera that performs spot photometry, partial photometry, etc.

[Brief explanation of the drawing]

Fig. 1 is a drawing of an embodiment showing the positions of the photometry display and distance measurement display shown on the finder screen, Fig. 2 is a drawing showing the arrangement of photometry sensors etc. arranged inside the camera, and Fig. 3 4 is a block diagram of an embodiment for displaying a display using the distance measuring device and the average photometry device of the present invention, and FIG. A specific circuit diagram as an example of the circuit shown in FIG. 5 shows three types of displays in response to the output of the distance measurement signal from the distance measurement processing circuit shown in FIG. 3 or the exposure signal from the photometry calculation circuit. FIG. 2 is a specific circuit diagram as an example, commonly showing a circuit in the case of the above. 1... Finder screen, 2, 3... Photometry display, 4, 5... Photometry display, 6, 7... Distance measurement display, 10... Photometry processing circuit, 11... Distance measurement system processing circuit, 12...Photometry calculation processing circuit, 13, 14...
...A/D converter, 15...Brightness modulation circuit, 16...
...Distance measurement system brightness modulation circuit, 17...Average photometry display, 18...Spot photometry display, 19...Distance measurement system display, SW9-1, SW9-2...Switch, SN1...For distance measurement Sensor, SN2...Sensor for average photometry.

Claims (1)

[Scope of utility model claims] a first light receiving unit that measures a luminous flux from a part of the subject and outputs a luminance signal based on the measured luminous flux;
a second light receiving section that measures luminous flux from a wider range of objects than the luminous flux measured by the first light receiving section and outputs a luminance signal based on the measured luminous flux; A first display means provided at a position corresponding to the measurement luminous flux area in the first light receiving section, and a second display means provided outside the viewfinder screen.
a display section in the viewfinder having a display means;
The display brightness of the first display means is set to be higher as the field brightness is higher based on the output of the first light receiving section, and the display brightness of the second display means is set based on the output of the second light receiving section. A display device for a camera, comprising a display brightness control circuit that increases the brightness as the field brightness increases.