JP2579608B2 - DX information readable camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Application Field of the Invention) The present invention is capable of reading DX information from a DX code display section of a film and automatically setting the film sensitivity, the number of films, and the like. It is related to improvement of the camera.

(Background of the Invention) In recent years, the automation of cameras has advanced, and it is no longer necessary for the user to manually set shooting information. One of these is the automatic setting of film sensitivity and the number of films by reading the DX code of the film. The camera uses a DX code display on the film cartridge to display the DX code on each bit.
The contact piece is pressed to electrically detect whether the DX code common and each bit are conductive, and read the information. In other words, pull up the DX contacts and set the common
If the terminal voltage when dropped to GND is Hi level, it is insulated from common and if it is Lo level, it is conductive to common.
Thus, the DX information was read from the DX code display section.

As shown in FIG. 7, the DX code display section is composed of 12-bit codes, of which 2 bits are common. Five bits represent film sensitivity information, three bits represent number of shots, and two bits represent film latitude information. As the degree of automation of cameras increases, it becomes necessary to read most of this DX code.

By the way, conventionally, by arranging a plurality of LEDs in a row in a direction orthogonal to the film winding direction and emitting the LEDs in synchronization with the film winding, data such as year, month, day, etc. is printed on the film surface in a dot. Various cameras have been proposed for a camera that captures images in a matrix. In such a camera, since the LED is driven and the data is imprinted during the subsequent film winding performed after the end of each shooting, the data is imprinted on the final shooting frame. The film stretched,
The operation automatically shifts to the rewinding operation without completely imprinting the data on the last photographing frame (imprinting is not completed), and as a result, only a part of the data is imprinted. Sometimes they look unsightly.
For this reason, for example, a detecting means for detecting the specified final photographed frame based on the film prescribed frame number read from the DX code display section and the count content of the photographed frame number counting means, and data imprinting after detection by the detecting means, It has been proposed to provide a control means for limiting at most one frame of the specified final photographed frame so as to stop imprinting data up to the specified final photographed frame or one frame before the frame. JP-A-63-28
4532).

However, when the number of bits of the DX code to be read increases, the current consumption for pulling the DX piece increases, which causes a problem that the circuit for reading becomes complicated.

(Object of the Invention) An object of the present invention is to provide a camera capable of solving the above-mentioned problems and capable of saving current consumption and capable of simplifying the configuration for reading DX information. To provide.

(Features of the Invention) In order to achieve the above object, the present invention provides a DX information reading means, comprising: a plurality of pull-up means arranged corresponding to a plurality of DX contact pieces; A communication is performed, the pull-up means is sequentially selected at a predetermined cycle of the clock, and a pull-up control means for continuously pulling up each of the DX pieces is sequentially selected by the pull-up control means. Output means for performing serial communication of information obtained as a DX information, by using the clock synchronous serial communication already used for camera control, for example, with one cycle width of the clock,
The DX contact pieces are sequentially pulled up to read the DX information, and the sequentially read DX information is serially communicated to the control means.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 6 is a schematic perspective view of a data imprinting mechanism and a film position detecting mechanism applied to the embodiment described below with reference to FIGS. 1 to 5; A film patrone provided with a DX code display unit 12 representing information, 13 is a film, 14 is an aperture,
Reference numeral 15 denotes a film feeding roller fixed to an encoder 17 via a shaft 16, and 18 is disposed at a position facing the film feeding roller 15, and is urged in a direction indicated by an arrow by a spring (not shown) to form a film. 13 is pressed against the film feeding roller 15 side, and 19 is the aperture 14.
For example, an LED array, which is arranged on the spool side deviated from and is driven during the winding operation for each one-frame photographing and prints dot matrix data on the film 13 surface via the imaging lens 20, for example, an LED array 21 This is a DX piece for reading DX information from a DX code display section 12 provided on the side of the patrone 11.

FIG. 1 is a control block diagram of a camera showing one embodiment of the present invention. Reference numeral 1 denotes a microcomputer, which controls the movement of the entire camera. 2, CLK, WRITE-DATA, R while receiving the CSL signal from the microcomputer 1.
A lens control circuit for performing clock synchronous serial communication in response to an EAD-DATA signal. The lens control circuit drives a motor in the lens to control the aperture and sends various kinds of lens information to the microcomputer 1. Reference numeral 3 denotes a liquid crystal display drive circuit, which also performs clock synchronous serial communication while receiving the CSLCD signal, and performs each display according to the microcomputer 1. Reference numeral 4 denotes a DX read circuit, which receives D in synchronization with the CLK signal while receiving the CSDX signal.
Sends X information to microcomputer 1. Reference numeral 5 denotes a switch sense circuit which determines the state of a switch or a dial indicating a camera state to set each photographing condition, and performs clock synchronous serial communication in the same manner as described above while receiving the CSSW signal. The switch dial information requested by the microcomputer 1 is sent. Reference numeral 6 denotes a strobe control circuit for transferring various types of strobe information and dimming level value information by a clock synchronous serial signal while receiving the CSST signal. Dimming is performed at the time of strobe light emission, and light emission is controlled. 7 is
While receiving the CSSPC signal from microcomputer 1, photometric output D
This is a photometric circuit that sends SPC to the microcomputer 1. The microcomputer 1 converts the received photometric output DSPC to A / D
Convert and use as data. Reference numeral 8 denotes a shutter control circuit that controls the running of a shutter first curtain and a rear curtain (not shown) according to a control signal from the microcomputer 1. A feeding / imprinting circuit 9 controls a motor (not shown) in accordance with a control signal from the microcomputer 1 to feed the film, and at the same time, drives the LED array 19 to imprint data. SW1 is a switch linked with a release button of the camera, and when turned on, the microcomputer 1 starts a release sequence.

Next, the DX read circuit 4 will be described in detail with reference to FIG.

In FIG. 2, DFF1 to DFF3 are counters, and IN1 to IN24.
Is an inverter, NAND1 to NAND7 are NAND gates, OR is an OR gate, R1 to R7 are resistors, and DX1 to DX7 are terminals corresponding to the DX contacts 21 in FIG.

The common of the DX code is connected to GND, and the other codes are connected to terminals DX1 to DX7, respectively. While the CSDX signal is at the H level, CLK is counted by the counters DFF1 to DFF3. One of the terminals DX1 to DX7 is selected by the outputs Q1, Q2, Q3 and pulled up. Generated at terminals DX1 to DX7
Hi or Lo level signals are output from inverters IN11 to IN17, respectively.
And then inverted by the next-stage inverters IN18 to IN24 and input to the OR gate OR. The remaining six terminals DX that are not selected are in the pull-down state, so the DX code is at the Lo level regardless of whether it is conducting with the common. , Lo level or Hi level. Therefore, the output of the OR gate OR is connected to the selected terminal DXn
Represents the state of.

FIG. 3 shows the CLK signal, the signals generated at terminals DX1 to DX7, and REA.
The timing of the D-DATA signal is shown.

With the CLK signal, the terminals DX1 to DX7 are sequentially pulled up one by one for one clock time, and the state of the pulled up terminal DXn is included in the READ-DATA signal. The pull-up of the terminal DXn is from the fall of the CLK signal to the next fall, and the microcomputer 1 reads the DX information by latching the data at the rise of the CLK.

FIG. 4 shows another configuration example of the DX read circuit.

The DX code common is pulled down and the inverter IN25
Is input to Other cords are connected to terminals DX1 to DX7, respectively. While the CSDX signal is at the Hi level, the CLK signal is counted, and up to the point where one of the terminals DX1 to DX7 is selected, the same as the above-described example, but the selected terminal DXn is dynamically pulled up by the resistor R8. There is no dynamic Hi level output. If the selected DX code is conductive with the common, READ-DA
The TA signal is at the Hi level and is at the Lo level when not conducting.

Therefore, the DX information can be read by the microcomputer 1 as in the above-described example.

In the DX read circuit 4 having the configuration shown in FIG. 2 or 4, since the terminals DX1 to DX7 are read while sequentially supplying current in synchronization with the clock, a large current does not flow at one time, and the current is wasted. Do not shed. Also, since DX information is read using the clock of the clock synchronous serial communication, it can be shared with other information reading and writing circuits (or software), and the circuit (or software) can be simplified. Become.

Next, the operation of the entire camera will be described with reference to the flowchart of FIG.

[Step 1] When power is supplied to the camera and the camera enters an operation state, first, a switch group (not shown), a switch indicating the operation state of the camera, and a switch set by a user for setting an exposure mode are set via the switch sense circuit 5. Read.

[Step 2] When it is detected by a switch group (not shown) that the film has changed from the unset state to the set state, it is determined that a new film has been set, and the process proceeds to step 3; Go to 5.

[Step 3] When a new film is set, the film is wound up by several frames by the feeding / imprinting circuit 9 (AL:
Auto loading).

[Step 4] The DX reading circuit 4 reads the DX information of the loaded film 13 from the DX code display unit 12,
It obtains film sensitivity information, information on the number of frames specified for the film, and the like.
Thereafter, the process proceeds to step 5.

[Step 5] Information is received from the lens via the lens control circuit 2 and the aperture value data is received.

[Step 6] Information from the strobe is received via the strobe control circuit 6, and information such as whether or not the strobe is used, whether or not charging has been completed, and the strobe shooting mode are received.

[Step 7] The photometric output DSPC is received from the photometric circuit 7, A / D converted, taking into account the film sensitivity information, and calculating based on the exposure mode read from the above-mentioned switch group, and setting the aperture value and shutter speed. Decide.

[Step 8] The liquid crystal display drive circuit 3 is driven to display information such as an aperture value, a shutter speed, and the number of film frames on a liquid crystal display (not shown).

[Step 9] Switch SW1, which is a release switch
When is not pressed, the process returns to the start, and when it is pressed, the process proceeds to the release sequence of step 10 and subsequent steps.

[Step 10] When entering the release sequence, first, the aperture is controlled from the open state to the set aperture value via the lens control circuit 2.

[Step 11] When the flash mode is not set, the process proceeds to step 13, and when the flash mode is set, the process proceeds to step 12.

[Step 12] Since flash photography is performed, data of the dimming level calculated from the film sensitivity information and the like is sent to the flash control circuit 6 to enable dimming control.

[Step 13] The shutter control circuit 8 is driven to control the shutter so as to have the shutter speed obtained by the calculation.

[Step 14] When the release is completed, the feeding and imprinting circuit 9 winds up one frame of the film 13, and at the same time, imprints data such as the year, month, and day on the frame by using the LED array 19. Perform using The aperture is returned to the open state, and the shutter is charged for the next photographing.

[Step 15] Each time one frame is shot, the microcomputer 1 counts the number of shot frames by an internal counter, and determines whether or not the number matches the number of film frames read from the DX code display unit 12. If it is determined that the shooting has been completed up to the last frame, the process proceeds to step S16.

[Step 16] The feeding / imprinting circuit 9 is driven to rewind the film 13. After rewinding, return to start.

According to the present embodiment, the microcomputer 1 performs clock synchronous serial communication with circuits such as a lens and a display.
Since the DX information is read from the DX code display 12 using this format, that is, a buffer and a resistor are provided for pulling up the terminal DX by a predetermined timing, and one cycle width of the clock of the clock synchronous serial communication. With the circuit which pulls up the terminal DX (DX contact piece) one by one in succession, and OR gate which input all terminal DX
Because the output of OR or the common of terminal DX is used as communication data of clock synchronous serial communication, current flows only to one terminal DX at the same time, so that the current consumption of the camera can be saved, Further, the circuit can be the same as the other functions of the camera in the part of the clock synchronous serial communication, so that the circuit (and software) can be simplified.

(Correspondence between the invention and the embodiment) In the embodiment, the microcomputer 1 is used as the control means of the present invention, the DX reading circuit 4 is used as the DX information reading means, and the inverter is used as the inverter.
IN4 to IN10 and resistors R1 to R7 serve as pull-up
FF1 to DFF3, inverters IN1 to IN3, NAND gate NAND1 to
NAND7 is used as pull-up control means, and inverters IN11 to IN2
4, OR gate OR or resistor R8, and inverter IN25 correspond to output means, respectively.

(Effects of the Invention) As described above, according to the present invention, a plurality of pull-up means arranged corresponding to a plurality of DX pieces in a DX information reading means, a control means and a clock synchronous serial A communication is performed, the pull-up means is sequentially selected at a predetermined cycle of the clock, and a pull-up control means for continuously pulling up each of the DX pieces is sequentially selected by the pull-up control means. Output means for performing serial communication of information obtained as a DX information, by using the clock synchronous serial communication already used for camera control, for example, with one cycle width of the clock,
DX contacts are sequentially pulled up to read DX information, and the sequentially read DX information is sent to the control means serially, so current consumption can be saved and the configuration for reading DX information is simplified. Can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing an example of a DX read circuit shown in FIG. 1, FIG. 3 is a timing chart for reading DX information in this embodiment, FIG. 4 is a circuit diagram showing another example of the DX reading circuit shown in FIG. 1, FIG. 5 is a flowchart showing the operation of the whole camera in this embodiment, FIG. 6 is a film DX piece, a data imprinting mechanism and a film FIG. 7 is a perspective view schematically showing a position detecting mechanism, and FIG. 7 is a view for explaining a film cartridge and a DX code provided on a side surface thereof. 1 ... microcomputer, 4 ... DX readout circuit, IN1-IN25 ...
... Inverter, R1-R8 ... Resistance, DFF1-DFF3 ... Counter, NAND1-NAND7 ... Nand gate, OR ... OR gate.

Claims (1)

(57) [Claims] 1. A control means for performing clock-synchronous serial communication with a lens or a peripheral circuit and exchanging and controlling data, and a DX information reading means for reading DX information of a film through a plurality of DX pieces. In the camera capable of reading DX information, a plurality of pull-up means arranged in correspondence with a plurality of DX pieces in the DX information reading means, and perform clock synchronous serial communication with the control means. A pull-up control means for sequentially selecting the pull-up means at a predetermined cycle of the clock and continuously pulling up each of the DX contact pieces; and sequentially selecting the pull-up means by the pull-up control means. An output device for serially communicating obtained information as DX information. A camera capable of reading DX information.