JPS636740Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to an information display device for a camera or the like, which displays all the information necessary for photographing in one block as one block. In photography, information related to exposure includes exposure time, aperture value, information on AE lock and exposure compensation that can be operated under special shooting conditions or according to the shooting intention, whether automatic exposure or manual exposure, and if manual exposure, whether it is appropriate. There is a lot of information such as selected mode information such as underexposure, overexposure, or flash photography, and whether there is enough battery capacity to operate the exposure control circuit normally, and this information is up to the photographer. It is desirable to be able to confirm this while looking through the window viewfinder. Furthermore, this photographic information is generally placed outside the screen in the viewfinder so as not to interfere with the composition intended by the photographer. It is desirable to display all of this information in one place due to the diopter, but due to constraints such as mechanical interlocking mechanisms or space constraints, it may be necessary to display this information on the right side and upper part of the screen, or on the left side and lower side. It had to be displayed in two or three locations, and there was a difference in diopter between each piece of information, making it difficult to see a lot of information at once. Alternatively, when displaying information in one place, it was limited to time, aperture value, etc., and other displays were omitted. In this case, if the photographer performs operations such as AE lock or exposure compensation and forgets to return them after taking a picture, there is no warning message and there is a risk of taking a picture with an incorrect exposure. It was hot. An object of the present invention is to provide a display device that can rationally display information such as AE lock, exposure compensation, and battery status with a simple circuit configuration. In order to achieve the above object, the display device according to the present invention can be used to display exposure time, aperture display, etc. of a camera, etc.
Each display digit of the mode display is composed of 7 segments or a dot matrix and integrated to display numbers, letters,
In a digital display device that displays symbols, etc., a semiconductor switching element array controlled by a scan signal that drives each display digit is used as a switch whose one end is commonly grounded to set shooting information such as film sensitivity value and lens aperture value. By connecting to the corresponding switch of the group, turning on one of the switching element arrays while driving a certain display digit, and inputting one of the photographic information to the arithmetic unit, multiple display digits are synchronized with the multiple display digit signal. By inputting photographic information into the arithmetic unit in a time-division manner, display and input timings are determined using the same signal, and signals on the display segment side are sent correspondingly with this time-division signal, and the segment signal is controlled at a blinking frequency. In addition, the display digit signal is configured to drive the display digits at a predetermined constant cycle without being affected by this blinking signal. According to the above structure, the object of the present invention can be completely achieved. The apparatus according to the present invention will be described in more detail below with reference to the drawings and the like. FIG. 1 is a block diagram showing an embodiment of an exposure calculation circuit according to the present invention. The information input section INP contains mode information MS indicating whether the shooting mode is shutter priority Tp, aperture priority Ap, or manual M, shutter time setting T or setting aperture A, film sensitivity S, and information on the attached lens such as aperture F value F and maximum aperture. This input section receives input signals such as the narrowing down amount C from , lens type signal New, and strobe charge completion signal STB.The signals sent from INP in a time-sharing manner are converted into binary codes by code conversion section CNV. It is converted and sent to the information storage unit IM. The information storage unit IM stores each input in the latch memory using the control signal from the calculation control unit CNT, and stores the stored information.
It is sent to the calculation unit OPE by the control signal of CNT. The mode decoder MDC decodes BULB, SYNC, and NC LOCK from IM, Tp mode, Ap mode, M mode, strobe mode STB, and setting time T. In the case of NC LOCK, (NC
If LOCK) = 1, the release signal from the control input CINP is prohibited, and if STB・(NC LOCK) = 1, the shutter time T = 1/90 sec with SYNC
is equivalent to The photometry unit BTL converts the logarithmically compressed photometry values into AD converters and converts the photometry data using the control signal from the CNT.
Send to OPE. AD conversion is also controlled by the control signal of SCNT and the AE lock signal of control input unit CINP. The calculation unit OPE calculates the data from IN and BTL and the calculation results inside the calculation unit based on the control signal from the CNT, and displays the display unit DSP and the coincidence detection unit.
Send data to COM. Also, the flag of the calculation process is
Send it to CNT and use it as control signal data. The counter and match detection unit COM is the calculation unit OPE.
A match signal between the calculated aperture data from OPE and the count value of the aperture control pulse Pn inputted through the aperture control correction unit APJ, and a match signal between the calculated time data from OPE and the time counter are sent to the shutter sequence control unit SCNT. The control input section CINP sends the release, shutter charge (film advance), self-timer, and trigger signals to the SCNT, and the AE lock signal to the BTL to hold the photometric value BTLV, and also sends the DSP and CNT.
It is also used for display and arithmetic control (when STB = 1). The release, check, and AE lock (fixing the photometric value) signals are controlled by the power supply hold section.
This becomes the PH input and the power-on signal for the circuit system. The aperture control pulse Pn is a pulse generated in response to the movement of the aperture control lever, and serves as an input to APJ. The power hold section PH receives the above signals from CINP and the charging completion signal from the external strobe.
The power is turned on by the STB, and the power is maintained or turned off by the signal from the SCNT. The aperture control correction unit APJ sends the aperture control pulse Pn from CINP to the coincidence detection unit COM in accordance with the coded aperture adjustment input. The shutter sequence control section SCNT is a control input section.
The control input from CINP and the signal from the power supply check unit BCH activate the release magnet RsMg to start aperture, enter a series of shutter sequences such as mirror up, and the match signal from COM activates the aperture control magnet and shutter. Control the control magnet. Also, SCNT is COM, OPE,
Sends signals to CNT, BTL, and DSP to inform them of the sequence status and control each part. The power supply check section BCH checks the circuit voltage,
Serves as a control signal for DSP and SCNT. The display DSP displays time and time using display data from OPE.
Displays aperture and exposure warnings and modes using mode data from MDC. Also, the mode display blinks with the AE lock signal to indicate AE lock. The display blinks, turns off, etc. based on the signal from the BCH to notify the battery status. The calculation control unit CNT receives the mode and
Aperture and time calculations are controlled by calculation flags from OPE. Also, the calculated value is fixed by the signal from SCNT. Although the lens type signal New was mentioned earlier in the INP information input section, two types of lenses are planned to be used in this embodiment. The lens indicated by the signal New is a lens designed so that the aperture can be automatically controlled using aperture control data, and the amount of movement of the lens aperture pin drive lever and the amount of aperture from the actual aperture are in a predetermined relationship. It is a lens unified to Since the aperture of lenses other than this lens cannot be automatically adjusted based on the aperture control data, automatic switching to another arithmetic control method is performed. Now, in a camera having the arithmetic circuit shown in the block diagram, either Tp, Ap, or Mp selected by the mode select section of the INP section is output, and Tv or Av set by operating the setting dial.
Or suppose both are output. When a lens is installed whose aperture cannot be accurately controlled using the calculated aperture control data Cvse, or in other words, the amount of movement of the lens aperture pin drive lever does not have a certain relationship with the actual amount of aperture from opening. The aperture preset value Cvms of the lens is calculated as the set aperture regardless of the setting value of Tv or Av.When the signal is 1, and when using a strobe, the aperture data SBvs from the strobe is calculated.
In the signal STB that detects the strobe mode, the aperture is controlled independently of Tp and Ap. In addition, in strobe mode, the shutter time must be longer than the synchronization time (for example, 1/90sec), and the exposure memory AEL must be Tp or Ap.
(Automatic Exposure Lock means that the exposure is fixed by fixing the metering value.) Shutter time is reduced to 1/9 when not being operated.
Automatically set to 0sec, when in AEL, time is calculated according to the aperture signal from the strobe, and when in manual M, aperture is set in Cvms so that exposure compensation can be performed in strobe mode, and time is
Set with TV. In such a configuration, the power supply check section BCH
sends a preliminary warning signal B2 warning that the battery capacity has decreased and a non-operation warning signal B1 that indicates that the battery capacity has further decreased and normal operation of the camera cannot be guaranteed to the display unit DSP and shutter sequence control unit SCNT. It gives a warning and checks the power supply in a time-divided manner. Figure 2 shows an example of the circuit of the power supply check section BCH. In the figure, COMP is a comparator that inputs the reference voltage Vref and a voltage Vdet obtained by dividing the circuit voltage, and when Vdet>Vref, its output CHE becomes HIGH. F1 and F2 are “DATA”
It is a type flip-flop, and outputs the D input CHE at the rising edge of the clock, CK1 or CK2. In is the initialization signal when the power is turned on.
This is the initial reset signal for F1 and F2. N3 to N12 are clock signals from the counter and create time division signals. Nd5, Nd6, and Nd7 are time-division signals for the display system, which will be described later, and Nd5=N6・
N5・N4, Nd6=N6・N5・4, Nd7=N6・
These are N5 and N4, which are signals obtained by decoding the clock from the counter. The release latch is a signal that becomes HIGH when the photographer presses down the release switch and enters the shutter sequence control state.
Keep Bcnt low. RL1 and RL2 are dummy load resistors for battery check. In such a configuration, Bcnt = 7・8・9・10・11・12 ・Release latch ...The logic is (1), and if the frequency of each clock signal is as shown in Figure 8, Bcnt is as shown in Figure 9. like
It becomes a pulse signal of 4 ms width with a period of 250 ms and sends Bcnt to the display unit DSP, and when Bcnt=1, display is prohibited, the display current is turned off, and the dummy load resistor RL1 is turned on. The F1 clock CK1 is CK1 = Bcnt・Nd5・N3 = Bcnt・N6・5・N4・N3 ...(2) The timing is shown in the time chart in Figure 10, and the circuit voltage when RL1 is conducting is of
Check with COMP, and at the rising edge of CK1, output F1 and replace the data of low battery warning signal in 1. 1 controls the display section DSP and the shutter sequence control section SCNT. The logic for RL2 to conduct is Bcnt・(Nd6○・Nd7) =Bcnt・N6・N5...(3) F2 clock CK2 is given by the following equation (4). CK2=Bcnt・Nd7・N3=Bcnt・N6・N5・N4・N3...(4) The timing is shown in the time chart of FIG. 10. In other words, check the circuit voltage with COMP when RL1 and RL2 are conducting, and at the timing when CK2 rises, CHE = 1, that is, Vdet>
If Vref, the output signal B2 of F2 becomes 1, indicating that the battery capacity is sufficiently large, and if CHE=0, B2=0, which becomes a warning signal. When Bcnt=0, dummy resistors RL1 and RL2 are turned off, and clocks CK1CK2 to F1 and F2 are LOW.
The circuit voltage state detected when Bcnt=1 is maintained. The display CSP becomes active when Bcnt=0.
If B2=1, the display system lights up, B2=0, 1=0
If so, it will blink, and if 1=1, it will be a signal to turn off the light. 1 is the shutter sequence control section
This becomes the SCNT release control signal, and if 1=1, the release is prohibited and the shutter sequence is disabled. FIG. 11 shows the detection state of the circuit voltage. In the figure, In is the initialization signal when the power is turned on, and when a reset signal is given to F1 and F2, 1=
1, B2 = 0, the counter is reset to Bcnt = 1, and the battery check of the sample cycle T _p begins. T _p shows an example when the battery capacity is large, and during the period t ₁ , the circuit voltage is checked with the load RL1 conducting, and Vdet>
Vref, so the output CHE of the comparator COMP is
CHE=1 and F1's output signal 1 becomes 1=0 at F1's clock CK1. Load RL1 in period t ₂ ,
RL2 becomes conductive. As the load becomes heavier, the circuit voltage decreases, but since Vdet > Vref, the CMP output CHE
=1, and the output signal B2 of F2 becomes B2=1 when the clock CK2 is applied to F2. During the period _t3 , Bcnt = 0, turning off RL1 and RL2, the battery check cycle is completed, the display DSP becomes active, 1 = 0, B2 = 1
The display lights up in response to the battery detection signal. Sample cycle T _n is an example in which the battery capacity becomes low and becomes a preliminary warning area. During the period t ₀ , Bcnt = 0 and the display is active.
The display lights up or flashes depending on the battery detection signal in the sample cycle of T _n -1. FIG. 11 shows an example in which the light is on. During period t ₁ , Bcnt = 1, the display is turned off, the battery check cycle begins, and the dummy load is applied.
Make RL1 conductive. Check the circuit voltage status at this time using clock CK1.
=1 is sent to the output of F1, and the output signal 1 becomes 0.
During the period _t2 , the dummy load RL2 becomes conductive and the circuit voltage decreases, Vdet<Vref, and CHE=0. Send CHE=0 to the output of F2 with clock CK2 B2
=0. Bcnt=0 in period t ₃ and dummy load
RL1RL2 turns off, the battery check cycle ends, and the display DSP becomes active.
The display blinks in response to the battery detection signal of B1=0 and B2=0. Sample cycle T _o is an example in which the battery capacity has decreased and entered the non-operation warning region. As before, t ₀
During the period, the display blinks or turns off depending on the battery detection signal in the sample cycle of T _o -1. At t ₁ , Bcnt = 1 and the display is turned off,
Turn on RL1 and check the circuit voltage status.
CK1 sends CHE=0 to the output of F1 and becomes 1=1. RL2 turns on at t ₂ , and CHE=0 at CK2.
Send to the output of F2 and B2 becomes 0. At _t3 , Bcnt=0, RL1 and RL2 are turned off, and the display becomes active, but since the battery detection signal 1=1 and B2=0, the display turns off. Also, 1 at this time is sent to the shutter sequence control unit SCNT to prohibit the release signal. In the above explanation, the _dummy load is
The warning signal B2 was obtained by making RL2 conductive in addition to RL1, but instead of making RL2 conductive, the same result can be obtained by changing the voltage division ratio of the power supply voltage to obtain the comparison voltage Vdet to the comparator COMP as shown in Figure 12. be. In other words, when Bcnt = 1, the display is turned off and a dummy load is applied.
RL1 is made conductive, and during period t ₁ , Vdet=R2/R1+R2V _B is applied as a comparison voltage to COMP to detect 1, and during period t ₂ , switching element T _r is made conductive and comparison voltage is applied to COMP. Vdet= as voltage
Apply R2R3/R1+R2R3V _B , detect B2, set RL1 of at period t ₃ , set the display to active, and set 1, B2
Display accordingly. The same effect can be obtained by switching the reference voltage Vref to COMP instead of changing the voltage division ratio. Alternatively, it is also possible to detect more power supply voltage states by sequentially switching Vdet or Vref while Bcnt=1. Figure 3 shows an example of the circuit of the display section DSP. In the figure, the counter divides the reference clock O ₀ =32.768 KHz to obtain N0 to N14 as shown in FIG.
The decoder receives clocks N4, N5 from the counter,
Decode N6 and Nd0=6・5・4 Nd1=
N6・5・N4…Nd6＝N6・N5・4 Nd7＝
Obtain N6, N5, and N4. The display consists of a 7-segment, 7-digit LED, etc., and each digit is composed of elements a, b,...g, and DP (decimal point) as shown in Figure 5, and the exposure time is indicated by 4 digits from _t1 to _t4 . Display the aperture value in two digits f ₁ and f ₂ ,
Displays the mode using digits. Elements a, b, c...DP of each digit light up according to data D0, D1...D7 in a ROM (read-only memory). FIG. 6 shows the relationship between display data and display.
D7 is a decimal point signal, and if D7=1, DP lights up. ROM data is address
It is selected by AD0 to AD7, and the lower addresses of AD0 to AD2 are input clocks N4 to N6 of the decoder, and each digit of the display corresponds to the address input of the lower 3 bits. As for the upper addresses AD3 to AD7, the time display code shown in FIG. 19, the aperture value display code, and the mode display codes d ₂ to d ₆ shown in FIG. 4 are time-divisionally input into the upper addresses. In other words, at the exposure time display timing Nd0○, Nd1○, Nd2○, Nd3 = 6, the enable signal EN _t is given to the memory DT _v in which the time display code is stored, and the time display code becomes the upper address input to the ROM. , at the aperture value display timing Nd4○・Nd5=N6・5, the enable signal EN _f is applied to the memory DA _v in which the aperture value display code is stored, and the aperture value display code is displayed.
The upper address is input to the ROM, and the enable signal ENm is given to the mode display code at the mode display timing Nd6 = N6・N5・4.
This is the upper address input to the ROM. In the mode display code, EA is an exposure compensation signal, and when exposure compensation is performed, EA becomes 1 and the decimal point of the mode display lights up.
STB is a signal that becomes STB=1 when the strobe is charged. M is the manual mode, and UNDER and OVER are the determination of the photographing conditions at the exposure time Tv and aperture value Av set in the manual mode. The relationship between display functions and mode display codes is shown in FIG. 4, and the relationship between mode display data and mode display is shown in FIG. Figure 7 shows the display code (the upper two digits of the address in octal notation) that becomes the upper address input of the ROM, the lower address input (the lower one digit of the address in octal notation), and the memory content of the ROM that becomes the data output. shows the relationship between As an example, we will explain the display timing when exposure time is 1/60sec, aperture value is 5.6 in auto mode, and exposure compensation is being applied. In the above example, the display code is as shown in Figure 13, and when the counter is 6 = 1, the time display code becomes the upper address input of the ROM, and N6.5
When = 1, the aperture value display code becomes the upper address input of the ROM, and when it is N6, N5, and 4, the mode display code becomes the upper address of the ROM, and the ROM
The address input is input as shown in FIG. 13 by the counter values of N6, N5, and N4. FIG. 14 shows a time chart of the display. In other words, at the timing of 6・5・4=1, the ROM is addressed by (100) ₈ and (175) ₈ is used as data output to light up the display element shown in Figure 5 and set the time.

[Table] BULB is displayed in the pattern “buLb”, NC-
LOCK is displayed in a “Lo” pattern. The mode display is as shown in FIG. Also, the scan signal of this display digit is the information input INP (see Figure 1).
It is also used as an input selection scan signal for the information input INP to the code conversion section CNV mode decoding section.
It is also used to send data to MDC in time division. That is, as shown in Fig. 15, for example, the switching element array S1 is turned on at the display timing of ₁ digit t, and the strobe information and mode information are sent to the common bus Q1.
~Q6 signal line, and at the display timing of _t2 digits, switching element array S2 is turned on and lens preset aperture information is placed on the common bus Q1~Q6 signal line. Similarly, information is input in a time-division manner using t ₃ , t _{4 .} . . and display digit signals. The switching element array is, for example, an N-channel array as shown in FIG.
It is a MOSFET, and the source is connected to the switch that sets the information, and the drain is the corresponding common bus.
It is connected to Q1 to Q6, and its gate is connected to the display digit scan signal, so that when the display digit becomes high active, the switching element becomes conductive. In synchronization with this display digit scan signal, a strobe signal is sent to the corresponding latch memory of the information storage section to store the input information. As shown in FIG. 17, when a switch array is used in this manner, an input code pattern with only the necessary number of bits is required, and a scan signal pattern is not required, making it possible to design an effective pattern within a limited area like a camera. Further, the sliding switch does not need to be insulated from the switch support member and can be used as a body ground. FIG. 18 shows a circuit constructed using a conventional method using a diode matrix. In this case, an input code pattern for a scan signal is required, which requires an extra pattern compared to a switch array. An extra pattern is required for each piece of input information, and an increase in the amount of input information is disadvantageous in terms of pattern design within a limited area such as a camera. The sliding switch also needs to be insulated from the switch support member. Further, in such a diode matrix system, the voltage drop across the diode becomes a non-negligible value when used with a low voltage power supply of 2 to 3 V, and there is a risk that an incorrect input code may be read. In the above explanation, in the circuit example shown in Figure 3, the ROM
The explanation has been made assuming that the chip select signal is simply active when it is 0, but by controlling this, the time display and aperture value display mode display blink, and an exposure warning, aperture warning, AE lock, battery warning, etc. are performed. Also, the display is turned off when the battery check cycle Bcnt=1. In the circuit example shown in Figure 3, SF is an out-of-photometry warning signal that becomes 1 when the photometry value is outside the photometry range, and the time display and aperture value display are set to 4.
Flash at Hz. CQ5 and CQ6 are display warning flags, and these are stored in memory at the predetermined calculation step a13.
When AFK=1, the aperture display blinks at 4Hz and TFK
When =1, the time display blinks at 4Hz to display an exposure warning. AEL fixes the exposure value by memorizing and fixing the metering value through the photographer's operation.
This is the AE lock signal, and when AEL=1, the mode display blinks at 4Hz to indicate that AE lock is being operated. B2,1 is a signal from the power supply check unit BCH mentioned above, and when B2=0, the display blinks at 1 Hz as a preliminary battery warning. When 1=1, it means that the battery capacity is low, and all the displays are turned off to give a warning. That is, in Figure 3, Dcnt=・B1・(B2○・1Hz) ……(5) TFK=CQ6+SF ……(6) AFK=CQ5+SF ……(7) Tcnt=○・4Hz ……(8) Fcnt=○・4Hz ……(9) Mcnt=○・4Hz ……(10) Tct=Dcnt・Tcnt・6 ……(11) Fct=Dcnt・Fcnt・(Nd4○・Nd5) ……(12) Mct=Dcnt・Mcnt・Nd6 ……(13) = ○・○・ ……(14) It is a logical configuration and decodes the display code.
When the chip select signal of the ROM is at low level, display data is sent to the display element. The condition for = 0 is when either Tct, Fct or Mct is 1, but since Tct is 6,
Tct=0 except when time display code storage memory DT _v is active, and Fct is Nd4○・Nd5
Except when the aperture value display code storage memory DA _v is active, Fct=0, and Mct is Nd6.
Since Mct=0 except when the mode display code storage memory is active, Tct, Fct,
Two or more Mcts cannot be at a high level at the same time. Therefore, when Tct=0, the time display turns off,
When Fct=0, the aperture value display is turned off, and when Mct=0, the mode display is turned off. Yotsute Dcnt
When = 0, the display will turn off, and Dcnt = 0
From equation (5), the condition is = 0, that is, Bcnt = 1
In this battery check cycle, as described above, the display is turned off, the dummy load resistor is energized, and the battery check is performed under a certain load condition. This light-off time is 250ms as explained in Figure 9.
Each time, the period is 4ms, and it appears to the photographer as if the light is lit continuously. When B1=0, that is, 1=1, when the battery capacity decreases, B1=1, B2=0, that is, when the battery reserve warning occurs, Dcnt=0 at a cycle of 1 Hz, and the display blinks at 1 Hz. In this way, the display lights up,
By blinking and turning off the light at 1Hz, the photographer can also know the battery status when checking exposure. When the battery is normal, the condition for the time display to turn off is when Tcnt = 0 from equation (11),
From formula (8), 4Hz when = 0, that is, TFK = 1
Flashes in cycles. Similarly, the aperture value display blinks at a 4Hz cycle when AFK=1, giving an exposure warning. According to equation (13), the condition for the mode display to turn off when Dcnt = 1 is when Mcnt = 0, and Mcnt is
From formula (10), when = 0, that is, AEL = 1, 4Hz
The photographer can confirm AE lock by seeing the mode display blinking at a 4Hz cycle. As explained above, according to the present invention, the basic display is 4 digits for time, 2 digits for aperture display, and 1 digit for mode display, and can be used to display time or aperture by using a 7-digit display element with a 7-segment display element or a 7-digit dot display element in a matrix configuration. By blinking, it is used as an exposure warning display; by blinking the mode display or lighting the decimal point, it is used as a warning display for AE lock or exposure compensation; and by making the entire display blink at a lower frequency than the warning display or by turning it off. By using this as a battery warning, a large amount of photographic information can be displayed in an easy-to-understand and concise manner, and an information concentrated display system that eliminates diopter differences is constructed by combining the information into one block. Furthermore, in the present invention, the signal for blinking is not sent to the scan signal side of the display digits, but is sent to the decoder side for driving the common display elements a, b, c..., so that the scan signals t ₁ , t ₂ of the display digits are used. …
can be used as a control signal for input selection of the information input INP. The display device according to the present invention uses a semiconductor switching element array controlled by a scan signal that drives each display digit to set shooting information such as the film sensitivity value and the aperture value of the lens. It is configured to be connected to a switch. Therefore, one end of the input information switches can be commonly grounded, and the circuit configuration such as wiring can be simplified. Further, the display device according to the present invention is configured so that one of the semiconductor switching element arrays is turned on while a certain display digit is being driven, and one piece of photographic information is input to the arithmetic unit. Therefore, by time-divisionally inputting a plurality of photographic information inputs into the arithmetic unit in synchronization with a plurality of display digit signals, display and input timing can be determined using the same signal, and the circuit configuration can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an exposure calculation circuit according to the present invention. FIG. 2 is a circuit diagram showing an embodiment of the power supply check section BCH in the circuit.
FIG. 3 is a circuit diagram showing an embodiment of the display section DSP. FIG. 4 is an explanatory diagram showing display functions and mode codes. FIG. 5 is an explanatory diagram showing the segment arrangement of display elements. FIG. 6 is an explanatory diagram showing the relationship between display data and display. FIG. 7 is an explanatory diagram showing the contents of the ROM. FIG. 8 is an explanatory diagram showing the relationship between the counter output signal and the clock frequency.
Figure 9 is the BCNT time chart. 1st
Figure 0 is a time chart showing the relationship between RL1, CK1, RL2, and CK2. FIG. 11 is a time chart showing the detection state of the circuit voltage. FIG. 12 is a circuit diagram showing another embodiment in which the power check section BCH is of a power hold type. FIG. 13 is an explanatory diagram showing the correspondence between display codes and ROM addresses.
FIG. 14 is a time chart for explaining the display state. FIG. 15 is a circuit diagram showing an embodiment of the time division input control circuit. FIG. 16 is a circuit diagram showing an embodiment of the switching element array. 17th
The figure is a diagram showing an example of an input pattern and an input circuit. FIG. 18 is a circuit diagram showing an example of the configuration of an input circuit using a conventionally used diode matrix. FIG. 19 is an explanatory diagram showing time display codes and the like. INP...Information input section, CNV...Code conversion section,
IM...Information storage unit, CNT...Arithmetic control unit, OPE
...Arithmetic unit, MDC...Mode decoder, BTL...
...Photometering section, COM...Counter and coincidence detection section,
CINP...Control input section, PH...Power hold section,
APJ...Aperture control correction section, SCNT...Shutter sequence control section, BCH...Power supply check section,
DSP...display section.

Claims (1)

[Scope of utility model registration request] In a digital display device that integrates each display digit for exposure time display, aperture display, mode display, etc. of a camera with 7 segments or dot matrix to display numbers, characters, symbols, etc., the scan that drives each display digit is used. A semiconductor switching element array controlled by a signal is connected to a corresponding switch of a switch group whose one end is commonly grounded for setting shooting information such as film sensitivity value and lens aperture value, and when a certain display digit is being driven, By turning on one of the switching element arrays and inputting one piece of photographic information to the arithmetic unit, multiple pieces of photographic information input can be time-divided into the arithmetic unit in synchronization with the multiple display digit signal, thereby allowing the same signal to be input. The timing of display and input is determined, the signal on the display segment side is sent correspondingly with this time division signal, and the segment signal is controlled at the blinking frequency, and the display digit signal is not affected by this blinking signal. A display device characterized in that it is configured to drive display digits at a predetermined constant cycle.