JPH0581889B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a data imprinting device, and more particularly to a camera equipped with a data imprinting device that imprints characters, numbers, symbols, etc. onto the film surface by flashing a plurality of imprinting elements in conjunction with the film feeding operation. It is. Conventional cameras with data imprinting devices include those in which a data plate on which numbers, symbols, etc. to be imprinted are formed are manually set and imprinted onto the film surface at the same time as the photograph is taken using light emitted from a small light source; There are also known methods in which a 7-segment liquid crystal display is used instead of a 7-segment liquid crystal display and images are made using a transmitted light method, and 7-segment light-emitting diodes are used to form numbers and the like and the images are made by emitting light. With all of these types of data imprinting devices, data is imprinted while the film is still, so the number of numbers, symbols, etc. that can be imprinted is limited by the size of the data board, the number of liquid crystal panels, and the number of light emitting diodes. The types were limited to numbers and very limited symbols. On the other hand, an apparatus has been proposed, for example, in Japanese Utility Model Publication No. 1245/1983, which flashes a point light source in conjunction with the film feeding operation, thereby imprinting data symbols on the film. In such a device, for example, 5× with a character width of 1 mm
When attempting to imprint seven-dot characters on a film, it is necessary to generate a pulse every time the film moves by 0.2 mm, but it has been difficult to detect such an amount of movement. In addition, the film feeding speed of the electric winding type cameras used these days varies greatly depending on the type of film, the power supply status of the feeding circuit, the temperature, etc. (hereinafter referred to as LED), etc., when the film feeding speed is fast, the letters spread out horizontally as shown in Figure 8b, and when the film feeding speed is slow, the characters appear as shown in Figure 8c. The drawback was that the letters ended up looking a lot different. Also, it takes a certain amount of time for the film feeding speed to reach a constant speed from when the motor starts, and the speed changes rapidly during this time, so if you blink an LED at a certain time interval, the speed shown in Figure 8d will change. The dot spacing changes as shown. FIG. 9 shows changes in the film feeding speed from the time the motor is started. For example, the film feeding speed changes depending on the magnitude of the motor load torque as shown in the figure. The present invention was made in view of the above circumstances,
A data imprinting light source is provided which energizes the motor and drives the film feeding mechanism with the driving force of the motor to feed the film and also provides data imprinting light onto the film feeding path.
A data imprinting device for a camera that imprints data onto the film while the film is being fed includes a light emitting circuit that emits the light source to start data imprinting, and a light emitting circuit that detects the speed of the motor and feeds the film by energizing the motor. a determination circuit that determines whether a change in motor speed since the start of film feeding has fallen within a predetermined range; and a determination circuit that determines whether a change in motor speed since the start of film feeding has fallen within the predetermined range. A light projection start control circuit is provided, which holds the light projection circuit inoperative until the end of the film feeding operation, and activates the light projection circuit when it is determined that the speed change of the motor falls within the predetermined range. To provide a data imprinting device for a camera that appropriately imprints data when imprinting data on a camera. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a camera to which the present invention is applied, with the back cover open. A is a camera, 5 is a light emitting unit held on the back cover B, and seven light emitting units are arranged in a line perpendicular to the running direction of the film 9.
It is composed of an LED, and the light emitted by the LED is focused on the film by a lens 8 placed on the front, and by blinking while the film is being fed, a data image is projected onto the film screen. Reference numeral 11 denotes a film feeding motor, which drives the winding shaft of the camera via a transmission gear train 12. FIG. 2 is a block diagram of the data imprinting circuit. In the figure, 1 is a data input means for setting data such as numbers and characters to be imprinted using a key switch or the like. 2 is a means of storing the data, 3
is a decoder that converts data into a 5×7 dot pattern. Reference numeral 4 denotes a register group into which converted data is imprinted and sequentially read out in response to a timing signal TCK. 5 is the aforementioned light emitting unit, and 10 is a control circuit for the aforementioned motor 11, which drives the motor at a constant voltage, detects the current I _M flowing through the motor, and when the current value becomes constant, outputs an imprinting start signal.
START is issued and the speed V _C at that time is output to the timing generation circuit 13. 13 is designed to generate an imprint timing signal TCK in response to V _C upon receiving the start signal START. The TCK signal is input to the LED lighting circuit 6, which lights the LED every time the TCK signal rises.
is turned on, and its lighting time can be changed by film sensitivity input means 7. Each time one lighting is completed, the CLK terminal of the shift register group 4 becomes high level, and the shift register group 4 sequentially shifts data. FIG. 3 shows the shift register group 4 in FIG.
This shows an embodiment of the LED lighting circuit 6 and the film sensitivity input means 7. 6 and 7 constitute a monostable multivibrator, and when the TCK terminal becomes high, the capacitor 602 and the resistors 701 to 703
The transistor 601 is turned on for a certain period of time determined by one of the following. 40
1 to 407 are shift registers in which data is set when the DSET terminal is made high, and the data is sequentially output at each rising edge of the input to each CK terminal. FIG. 4 shows an embodiment of the shift register shown in 401 to 407 above. 408-415 are D flip-flops whose operations are shown in Table 1. When the DSET terminal is high, each data from _Dio to _Dip is set to each flip-flop.

[Table] ↓ Falling edge of clock

Claims (1)

[Scope of Claims] 1. A data imprinting light source that energizes the motor and drives the film feeding mechanism with the driving force of the motor to feed the film, and also provides data imprinting light to the film feeding path. A data imprinting device for a camera that imprints data onto a film while the film is being fed, includes a light emitting circuit that emits the light source and starts data imprinting, and a light emitter circuit that detects the speed of the motor and energizes the motor. a determination circuit for determining whether a change in motor speed from the start of film feeding has fallen within a predetermined range; The light emitting start control circuit holds the light emitting circuit inoperative until a determination is made, and activates the light emitting circuit when it is determined that the speed change of the motor falls within the predetermined range. Camera data imprinting device.