JPS6255127B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a device for visually displaying the driving direction of an objective lens by processing a signal obtained by a focus detection device. The light that has passed through the objective lens is received at a position equivalent to the focal plane, and the current position of the objective lens determines whether the focus is on an object in front of the subject or an object behind it. Various photoelectric focus detection devices have been proposed that generate signals indicating the state of focus. The present invention relates to a display device that processes the output of the focus detection circuit of the type described above and can intuitively indicate the operating direction of the objective lens of a camera. Although not for the purpose of focus adjustment, various displays are performed within the viewfinder for the purpose of, for example, exposure adjustment. Among such displays, for example, there are displays using three LEDs to indicate overexposure, underexposure, appropriateness, etc., and displays that indicate directions in conjunction with characters and symbols. Direction, etc. can also be displayed by such a display. An object of the present invention is to provide a sensory display device suitable for manually adjusting the position of an objective lens using the output of the photoelectric focus detection device as described above. In order to achieve the above object, a device for displaying the direction in which an objective lens is driven according to the present invention includes a display section formed so that each light emitting position of three or more light emitting elements is arranged in a ring shape and can be observed; a focus detection circuit that generates an output indicating whether the current objective lens is in front or rear focus with respect to the subject; a clock generation circuit; the output of the clock generation circuit is connected to an input terminal; The shift register is connected to a shift direction indicating terminal and has parallel output terminals respectively connected to the light emitting elements. According to the above configuration, if the rotation direction of the light emission position is made to correspond to the rotation direction of the distance ring of the lens, the user can adjust the focus of the objective lens by turning the distance ring of the objective lens in that direction. Therefore, there is no room for error in lens operation. If we simply repurpose the conventional exposure-related display,
Although the user is forced to make many decisions, according to the configuration of the present invention, the display directly indicates the rotation operation direction of the lens. The apparatus according to the present invention will be explained in more detail below with reference to the drawings and the like. FIG. 1 is a schematic diagram showing an example of a display according to the invention. In the figure, 1 indicates a viewfinder field of a single-lens reflex camera, and 2 indicates a display portion. FIG. 2 shows an enlarged view of the structure of the display portion. This display part uses four LEDs, and the display part shown in A has light emitting parts arranged in a concentric ring shape. Part B is for restricting the height direction.
The light emitting parts are arranged flat. FIG. 3 is a circuit diagram showing a first embodiment of the drive circuit. In this embodiment, four LEDs are sequentially turned on by an output from a circuit (hereinafter referred to as a module) that photoelectrically detects a focus and generates an output. Module 3 has two output terminals. Table 1 is the output truth table of module 3.

[Table] The circuit shown in Figure 3 is for the front pin, that is,
When N ₁ =0 N ₂ =1, the LED of display section 2
LED ₁ , LED ₂ , LED ₃ , and LED ₄ are turned on in this order, turning clockwise in FIG. 2, and turning counterclockwise when the rear pin is set, that is, when N ₁ =1 N ₂ =0.
N ₁ N ₂ are both 1, meaning all LEDs are in focus
It is designed to light up. In this state, the direction of left and right rotation is made to coincide with the direction in which the distance ring of the objective lens should be rotated for focusing. The output of the oscillator 4 is counted down by a counter 5. This is to ensure that the speed of movement of the LED light is appropriate. The output of this counter is connected to the clock terminal of a shift register 6 which is shiftable in both directions. In this example, MC14194 is used. This shift register 6 is a 4-bit shift register, and when the signals input to the mode control input terminals S ₀ and S ₁ are 0 and 1, the output terminals are set to Q ₀ , Q ₁ , . . . in accordance with the clock. Let L be the order of Q ₃ .
Conversely, when S ₀ and S ₁ are 1 and 0, Q ₀ Q ₃ Q ₂ Q ₁ Q ₀ ...
Let it be L as follows. When S ₀ S ₁ is 1, 1, all output terminals are set to L at the same time. The outputs of the shift registers 6 are sent to the display unit 2 via buffers 7, respectively.
connected to the LED. FIG. 4 shows an output time chart of the shift register during clockwise rotation. According to the circuit with such a configuration, module 3
When the front pin signal from (0, 1) is supplied, the light spot on the display section 2 rotates clockwise. The lens rotates counterclockwise when focusing on the rear, and all LEDs light up when in focus. Next, a second embodiment will be described with reference to FIGS. 3, 5, and 6. In the second embodiment circuit, the buffer 7 shown in FIG. 3 is replaced with a gate circuit shown in FIG. 5. FIG. 6 shows the output waveform of the gate circuit 9 when rotating clockwise. In other words, in this embodiment, LED ₁ is lit, followed by LED ₂ , and when LED ₁ goes out, LED ₃ is lit, and so on, so that two LEDs are lit one after the other at the same time. This enables rotating lighting that is different from the first embodiment. As described above in detail, according to the present invention, rotational display is possible by controlling the clock using the module output. Although a clock is required in such digital processing, other clocks for exposure control and the like provided in the camera can be used without providing a dedicated clock. The rotational display described above is particularly convenient when manually operating the objective lens using the modular output display as described above. This is because it is only necessary to operate in the rotation instruction direction while looking through the viewfinder without making any judgment. Various modifications can be made to the embodiments described in detail above within the scope of the present invention. Although an example using four LEDs has been described in detail, it is possible to display rotation by emitting light from three LEDs, and the rotation can be further simplified. Next, even if the light emitting elements are not necessarily arranged in an annular manner, an annular light emitting position can be determined by using a suitable optical system, such as a light guide. Further, the display section can be positioned above, below, to the left, to the right of the field of view, or within the field of view.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the arrangement of a display section of a device according to the present invention, FIG. 2 is a schematic diagram showing an example of a display pattern, FIG. 3 is a circuit diagram showing the first embodiment, and FIG. 4 is an operation diagram. FIG. FIG. 5 is a circuit diagram showing a portion of the second embodiment, and FIG. 6 is an operation waveform diagram of the second embodiment. 1...Finder field of view, 2...Display section, 3...
Module, 4...Oscillator, 5...Counter, 6
...Shift register, 7...Buffer, 9...Gate circuit.

Claims (1)

[Claims] 1. A display section formed so that each light emitting position of three or more light emitting elements is arranged in a ring shape and can be observed;
a focus detection circuit that generates an output indicating whether the current objective lens is in front or rear focus with respect to the subject; a clock generation circuit; the output of the clock generation circuit is connected to an input terminal; A device for indicating the direction in which an objective lens is driven, comprising a shift register connected to a shift direction indicating terminal and having parallel output terminals respectively connected to the light emitting elements. 2. The device for displaying the direction in which the objective lens is driven according to claim 1, wherein the display section is formed of four LEDs. 3. The device for displaying the direction in which the objective lens is driven according to claim 1, wherein the display section is provided adjacent to the viewfinder field of view. 4. The device for displaying the direction in which the objective lens is driven according to claim 1, wherein the shift direction instruction terminal of the shift register is a mode control input terminal.