JPS6131323Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a display device for various types of photographic information in a camera or exposure system, etc., which uses a digital circuit to accumulate photographic information in a digitally controlled camera or exposure system, etc. This invention relates to a display device for encoding and digitally displaying the code in a viewfinder or the like.

In recent years, with the development of electronic technology, many cameras using digital control methods have been proposed for exposure control. These cameras also use a digital method to display various photographic information, and even if exposure control is performed in an analog manner, there are many advantages to using a digital display for convenient camera operation. Many display devices are now using digital displays. Digital exposure control and display devices have the characteristic of digital circuits that even devices that perform fairly complex operations can be made extremely compact by configuring the circuits using LSI, etc., and can be incorporated into cameras, etc. It is suitable for In addition, its operation is much more accurate than analog control, making it particularly suitable for complex control devices such as ultra-high-end cameras. In this type of camera, each shooting information is displayed in the viewfinder, and it is desirable to display it digitally using numbers, symbols, etc. to make it easier to confirm. Therefore, it is preferable to use a digital display device. It must be placed near the camera's viewfinder system. In order to transmit more information signals to such a display device than the camera's exposure control device, conventionally multiple transmission lines corresponding to each signal have been used. The advantage of this method is that it requires less space inside the camera, and the disadvantage is that the arrangement of the exposure control system, display system, etc. inside the camera is restricted.

The present invention provides a display device that eliminates the drawbacks of the conventional devices as described above. That is, according to the display device of the present invention, registers for digitizing and storing various photographic information and means for converting the stored data in these registers into time-series signals are configured as one LSI, and each of the signals is obtained from the output of this LSI. A display device that creates a digital signal corresponding to information, decodes it, and displays it as a numerical value in the viewfinder, etc.
An LSI is placed near the finder optical system, and a single transmission line connects these two LSIs to form a display device.

The present invention will be explained in detail below with reference to the drawings. FIG. 1 is a perspective view of an embodiment in which a display device according to the present invention is applied to a single-lens reflex camera, FIG. 2 is a display device, and FIG. 3 is a layout diagram of a viewfinder optical system.
FIG. 4 is a surface view of the finder. Reference numeral 1 denotes an LSI chip constituting the control system, which is placed, for example, on the internal bottom surface of the camera as shown in the figure. 2 is the terminal of 1,
3 is a connection line from terminal 2, which transmits signals to each electric member other than 1. 4 is the substrate of 1, 5 is the mirror,
6 is a focusing plate, 7 is a condenser lens, 9 is a pentaprism, and 8 is a prism provided on the bottom of the pentaprism, which allows illumination light to enter the display device 11. 10 is an eyepiece lens, and 12 is a camera body. Note that 13 in FIG. 2 is an LSI of a display circuit constituting the display device, and is constructed integrally with the display board 11. In FIG. 4, reference numeral 14 indicates a finder mask, and 15 indicates an information display board within the finder. In the figure,
11 display devices are arranged on one side of the prism 8,
The numbers, symbols, etc. displayed by this are reflected by the prism 8 and pentaprism 9 and are reflected by the eyepiece lens 1.
The light is emitted from 0 and displayed outside the viewfinder field frame as shown in FIG.

FIG. 5 is a circuit diagram showing an embodiment of the display device according to the present invention, and FIG. 6 is a curve diagram showing an example of a timing chart for explaining the operation of the device shown in FIG. In the figure, is a display output circuit that forms part of a camera control system (not shown), and is a block diagram of a circuit that forms part of LSI 1 in FIG. 4 is a block diagram showing an LSI 13 and a group of display elements that constitute the 11 display sections in FIG. 3. FIG. R ₁ to R ₈ in are each 4
The shutter speed and aperture value among the photographic information are stored in a bit shift register as a 4-bit binary code. _A1 to _A8 are and gates,
OR is an OR gate, RC is an octal ring counter, PC is a quaternary ripple counter, and CP is a clock pulse input terminal. That is, each output of R ₁ to R ₈ and
The 8 outputs from the RC are ANDed with _A1 to _A8 , and the output is transmitted to the display section via an OR through a single transmission line. The SP in the 3-bit shift register processes the time-series signal sent from the 3-bit shift register in synchronization with the clock pulse CP to obtain a parallel output. SD1 converts the contents of the 4-bit register in the segment decoder into numerical and symbolic control signals for display in 7 segments. The output of SD1 is a 7 segment driver SD2
input to display section E via. DD1 is a digital decoder that generates a digit shift signal using the signal from the quaternary ripple counter PC and the signal from the octal ring counter RC. DD2 is a DD with a digital driver.
The number of digits on the display section E is controlled by the signal from 1.

Next, the operation of the apparatus shown in FIG. 5 will be explained. A digitally coded information signal from the camera control system (not shown in the figure) is sent to shift register _R1 .
Enter ~ _R8 . The format of the input information signal is, for example, a binary code, a gray code, etc., and the contents of the signal include numbers from 0 to 9, a 1/ signal, and a decimal point.
When the clock pulse CP shown in Figure 6 1 is input from the clock pulse oscillator to the quaternary ripple counter PC, the output of the PC is output as shown in Figure 2 synchronized with the falling edge of CP.
The pulse is output, and this is the octal ring counter.
Input to RC. Strobe pulses St ₁ to _{St 8} are sequentially outputted to each output of the RC with phase differences shown in FIGS. 3 to 10 in synchronization with the falling edge of the pulse from the PC. Assuming that the code "0110" with the number "6" is written in the register _R8 , the AND gate _A1 is turned on for a time to generate four clock pulses by the strobe pulse _St1 in _FIG . Content “0110” is read. Then by St ₂ of R.C.
_A2 turns on and reads out, for example, the decimal point "1010" written in _R7 . In this way, the strobe pulses from the ring counter RC are sent sequentially from St ₁ to St ₈ every time the ripple counter PC generates a pulse.
The data codes stored in the registers _R8 to _R1 are sequentially read out by sequentially turning on the AND circuits _A1 to _A8 . These are output from the output circuit as time-series digital signals through the OR circuit OR, and are sequentially transmitted to the circuit through one transmission line. In the circuit shown in FIG.
The content of _R8 “0110” is transmitted, and the last data is 0.
is input, the digital decoder DD
1 outputs a signal as shown in FIG. 6, and the contents of the least significant digit _R8 become ready to be displayed. At this time, the content of the signal _R8 inputted to SD1 is "0110", which is converted into a 7-segment display signal by SD1, inputted to display section E, and displayed as a numerical symbol. That is, when the above signal is input to the driver SD2, the content " ₆ " of the least significant digit R8 is displayed on the display section E as its output. The above operations are performed serially, and each time the pulses shown in Fig. 6 11 to 18 are sequentially output from DD1, the displayed digit is advanced, and the digital code written in registers R ₁ to _{R 8} is displayed. It is displayed in section E as a numerical value or symbol.

In each of the above embodiments, the display device of the present invention is applied to a camera, but the display device of the present invention can also be applied to a stand-alone exposure meter that obtains an appropriate exposure value through digital control, or to an external display device attached externally to the camera. It is possible.

As described above, in the display device according to the present invention, a plurality of pieces of digitally encoded photographic information are sequentially transmitted to the display device in chronological order through a single transmission path, and the LSI chip for exposure control and the display Since the number of signal transmission paths between the LSI chips and the LSI chips used is extremely small, and the space required for these wirings can be reduced, each part can be arranged without being restricted by the arrangement of the two LSI chips in the equipment. Since this allows the space within the device to be fully utilized, it is effective in reducing the size and weight of the device, and is suitable for high-end compact cameras that use a digital control method.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the arrangement of various parts when the display device according to the present invention is implemented in a single-lens reflex camera, Fig. 2 is a diagram showing an example of the configuration of the display device in Fig. 1, and Fig. 3 is a sectional view showing the arrangement of the display device of the present invention in a finder optical system, FIG. 4 is a surface view of the finder, FIG. 5 is a circuit system diagram showing an embodiment of the display device of the present invention, and FIG. 5 is a curve diagram showing an example of a timing chart for explaining the operation of the device shown in FIG. 5. FIG. ...control section of display device, ...display section of display device, PC...quaternary ripple counter, RC...8
Numerical ring counter, _R1 to _R8 ...Shift register, _A1 to _A8 ...AND gate circuit, OR...Or gate circuit, SP...3-bit shift register, SD1...Segment decoder, DD1...
Digital decoder, SD2...Segment driver, DD2...Digital driver, E...
7 segment display section.

Claims (1)

[Claims for Utility Model Registration] In a camera display device that displays exposure information consisting of a plurality of digits, encoding of a plurality of predetermined bit configurations each representing each digit of the plurality of digits. a plurality of storage circuits each storing a signal; a first circuit that receives clock pulses and generates an output each time a number of clock pulses equal to the number of bits of the coded signal is input; a first control circuit section consisting of a transfer circuit that selects a memory circuit and serially sends out a coded signal of the selected memory circuit; A numeric display for displaying the plurality of digits arranged therein, a conversion circuit for inputting the coded signal serially sent from the transfer circuit and outputting the serial input signal in parallel, and a first control circuit of the first control circuit section. a second control circuit section comprising a second circuit that sequentially switches and selects display digits of the display in response to a circuit output and transmits the parallel output of the conversion circuit to the selected display digit; and the first control circuit. A first signal line connecting the transfer circuit of the section and a conversion circuit of the second control circuit section, and a second signal line connecting the first circuit and the second circuit. Display device.