JPH0274936A - Single-lens reflex camera body for executing display in finder - Google Patents

Abstract

PURPOSE:To efficiently direct the title camera body in the direction of an information light an observation eye and to execute a bright display by assuming the form for reflecting an illuminating light by a main mirror and illuminating an information display body. CONSTITUTION:A luminous flux emitted from a light emission diode is led onto a movable main mirror 4 through a refractive index distribution type lens array 13 and a projection lens 12, reflected thereby, and thereafter, illuminates display parts 5a-5e on a focusing screen. By illuminating selectively one of the display parts 5a-5e by lighting the light emission diode corresponding to a distance measuring visual field, the distance measuring visual field which is selected at present is displayed in red, and other visual field can be displayed in black since a light beam does not go to an eyepiece. A prism for constituting the display parts 5a-5e is roughly orthogonal to the edge line direction of a Fresnel lens 5f, an illuminating light is refracted by an edge line of the Fresnel lens, and it does not occur that said light is confirmed visually as a ghost in the periphery of the display part. In such a way, a bright and easily visible information display can be executed in an observation visual field.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a display device in the finder of a single-lens reflex camera that is capable of displaying photographic information superimposed on a subject image.

[Prior Art] The display in the viewfinder of a single-lens reflex camera is a technology that has been used for a long time, and is usually displayed at the periphery of the photographic field of view.

On the other hand, for example, with advances in automatic focus detection technology, single-lens reflex cameras have been proposed that have multiple distance measurement fields for focus detection, but this type of configuration displays the field of view currently being measured. are required to do so. In that case,
Since the distance measurement field of view is set within the photographing field of view, the display will be performed within the photographing field of view, but if a display member is placed within the field of view, there is a risk that the photographing field of view will be difficult to see due to unused members. , it is difficult to install display members. In addition, JP-A-53-32
No. 048 discloses a configuration in which display can be performed within the photographic field of view.

If the display mark is not sufficiently bright, it may become difficult to see the display, especially when photographing in the daytime when the surrounding area is bright, and this phenomenon is particularly noticeable when the size of the display mark is small.

However, simply increasing the amount of illumination light may have an adverse effect on photoelectric conversion means such as an automatic focus detection device.

[Problems to be Solved by the Invention] An object of the present invention is to display bright and easy-to-see information within the viewing field.

[Means for Solving the Problems] According to the present invention, an information display section is provided at or near the intended image formation plane of the objective lens, and an illumination means is provided for illuminating the information display section via the main mirror.

In order to prevent the illumination light from causing diffuse reflection due to minute dust etc. adhering to the main mirror and entering the photoelectric conversion means, causing erroneous or impossible measurements, the light irradiation area on the main mirror by the illumination means is It is separated from the passage area on the main mirror of the light beam guided to the conversion means.

[Example] Figures 1 to 4 show an example in which the object image observation device according to the present invention is applied to a single-lens reflex camera, and Figure 1 is a cross-sectional view of the single-lens reflex camera. camera body,
2 is a lens barrel that holds the objective lens 3 movably in the direction of its optical axis; 4 is a movable main mirror that separates the object light into a focus detection system and a finder observation system; 5 is a pentaprism 6
, a focusing glass which together with the eyepiece lens 7 constitutes a finder ILI detection system; 8 is a movable mirror that guides a light beam to a focus detection device 9; The main mirror 4 is a mirror partially formed as a half mirror or a mirror having a transparent portion. The focus detection device 9 has a large number of distance measurement fields, as will be described later, and the positions measured within the finder screen correspond to linear areas 101 to 105 (back projection image of pixel rows) in FIG. Note that 106 is the finder screen, 107 a =
1 O7e is a distance measurement visual field display which will be described later.

This distance measurement field of view display is configured as follows. 1st
In the figure, reference numeral 10 indicates five light emitting diodes whose emission peak wavelength is, for example, 635 nm (red), and are arranged in a direction perpendicular to the plane of the paper. 11 is a package that holds this light emitting diode, 12 is a light projecting lens having two reflective surfaces, and 13 is for projecting the image of the light emitting diode 10 near the entrance surface of the light projecting lens 12, ensuring a degree of freedom in the arrangement of components. This is an array (Fig. 2) formed by converging gradient index lenses to achieve this. The light beam emitted from the light emitting diode is guided onto the movable main mirror 4 via the gradient index lens array 13 and the projection lens 12, and after being reflected there, illuminates a display section on the focusing glass 5, which will be described later. This causes the display to turn on. Next, this state will be omitted using FIGS. 3 to 8.

Figures 3 and 4 are expanded views of the optical paths of the finder system and illumination system shown in Figure 1. Figure 3 is a top view, and Figure 4 is a side view. FIG. The light projection lens 12 has three lens parts 12a and 12b.

12c, and as shown in FIG.
7 to 31 are illuminated by these. In addition, in the figure, 37 to 41 are images of the light emitting diode IO formed by the gradient index lens array. As shown in Figure 4, these illumination lights either enter the focusing glass at an angle θ or
As shown in the figure, display sections 5a to 5e made up of a large number of fine prisms are arranged inside this illumination area, and the illumination % is bent in the direction of the tangential lens 7 by refraction by the prisms. Therefore, by selectively illuminating one of the display sections 5a to 5e with the lighting of the light emitting diode corresponding to the distance measurement field, the currently selected distance measurement field is illuminated in red, and the others are illuminated with light or the eyepiece. Since it does not move, it is possible to display it in black. This situation will be explained in more detail using FIG. The figure shows an enlarged cross section of the focusing glass 5 including the display section 5a. It is assumed that a Fresnel lens 5f (FIG. 7) is formed on the light entrance surface of the focusing glass 5, and a light diffusion surface 5g is formed on the light exit surface, and these respectively direct illumination light 22 to the display section located outside. .23, 25.26
(shown in the third figure) also has the function of guiding the lens to the contiguous lens 7 and the function of serving as an image observation surface. In the figure, the illumination light that travels from the bottom to the top is first bent by the Fresnel lens 5f in a plane perpendicular to the plane of the paper toward the eyepiece 7, and is also refracted in the direction of the plane of the paper. 5a and the light diffusing surface 5g.

Of these, the light beam incident on the display section 5a is refracted toward the eyepiece lens 7 due to the action of the prism, and the display section 5a is visually recognized as being colored in accordance with the emission wavelength of the emission diode. On the other hand, the light flux incident on the light diffusing surface is diffused here, but in the configuration of the single-lens reflex camera shown in Fig. 1, the incident angle θ is approximately 27
Since the light beam is determined to correspond to the light beam of the FIO, almost all of the diffused light enters the front upper surface 6a which has been subjected to light absorption treatment, does not enter the eyepiece lens, and is not visually recognized.

Furthermore, if the amount of illumination light is controlled in proportion to the brightness of the object image, for example by the output of a photometric system, it is possible to completely eliminate ghosts caused by diffused light.

Here, if the prisms constituting the display sections 5a to 5e are arranged substantially perpendicular to the ridgeline direction of the Fresnel lens 5f, the illumination light will be refracted by the ridgeline of the Fresnel lens, and will not be visually recognized as a ghost around the display section. .

FIG. 1O shows details of the focus detection device 9 shown in FIG. FIG. 10 shows a perspective view, FIG. 11 shows a vertical cross-sectional shape, and FIG. 12 shows a positional relationship between a pixel column and a light amount distribution of a photoelectric conversion device consisting of a single chip. First, the focus detection device will be explained.

42 is a multi-hole field mask, which has a long side in the horizontal direction in the figure.
It has parallel rectangular apertures and is arranged, for example, in the vicinity of the intended imaging plane of the objective lens 3 in FIG. 43 is a filter that blocks light with a wavelength longer than near-infrared light, and 50 is a split-type field lens, which is arranged slightly offset from the intended image formation plane of the objective lens. The divided field lens 50 is a lens portion 50c that has different optical functions as described later.

50d and 50e, and these parts are formed by changing one or both of the lens thickness and the radius of curvature of the lens surface. In addition, when each lens part is constructed separately, it is also possible to make them from λ materials having different refractive indexes.

51 and 53 form a re-imaging lens unit with a two-hole diaphragm 52 in between, and the convex lens 51 converts the incident light into a state close to parallel light (the optical function is described in Japanese Patent Publication No. 33564/1983), Further, the two-image forming lens 53, which is made by joining two convex lenses 53a and 53b side by side, forms two secondary images of the object image formed by the objective lens. The aforementioned two-hole aperture 5
2 denotes vertically long elliptical openings 52a arranged in the horizontal direction in the drawing.
, 52b.

54 is a concave lens for field curvature correction, and is arranged on a transparent plastic package 56 that houses the photoelectric conversion device 55. In addition, the split field lens 50. The convex lens 51 and the concave lens 54 of the re-imaging lens unit are either vertically shaped or are rotationally symmetrical spherical lens systems.

The light beams passing through the apertures 42b...42f of the multi-hole field mask 42 pass through the split field lens 5o as shown in FIG.
lens portions 50c and 50d.

50e to form a secondary image of the object on each photoelectric conversion device. FIG. 12 shows this situation. 60C, 60d, . . . 60 and 60 are a set of pixel columns consisting of a large number of pixels. Images 61c and -42f of the apertures 42b and -42f of the multi-hole field mask correspond to these pixel columns.
...61fL is projected, and a secondary image of the object is formed inside this. At that time, the mask 42 and the device 55 are adjusted according to the width of each aperture of the multi-hole viewing mask 42, the width of the light-shielding bands 42i...42fL between the apertures, the width of the pixel rows on the photoelectric conversion device 55, and the pitch of the pixel rows. Since the refractive power of the optical system that relays the image, especially each lens part of the split field lens and the re-imaging lens unit, is adjusted, the light-shielding bands 42i...42fL of the multi-hole field mask each emit a predetermined aperture. Part of the light flux is prevented from entering pixel columns other than the pixel column corresponding one-to-one with this aperture. Further, the field mask image is the aperture aperture 52a.

52b and lens portions 53a and 53b, two secondary images of the object therein are formed in each opening of the multi-hole field mask 42 in parallel in the lateral direction, and the secondary images of the object therein are formed in relation to the position of the object image with respect to the intended imaging plane. moves in the directions of arrows A and B. Therefore, since each set of pixel rows detects the relative interval of the light intensity distribution regarding the pair of secondary images based on the photoelectric variation detection power, it is possible to know the focus state of the objective lens for multiple distance measurement positions. can.

It is preferable that the pixel row has a shape that matches the distortion of the visual field mask image, and that the direction of movement of the secondary image and the direction of the pixel row completely match. Further, each pixel column is separated to form a set, but a set may be created by allocating two ranges of one pixel column.

Furthermore, the linear regions 101 to 105 shown in FIG. 9 correspond to the back projection of the set of pixel rows onto the expected imaging plane of the photographing lens using the reimaging lens unit and the field lens.

In the configurations of the display device in the finder and the focus detection device as explained above, the respective effective light beam passage ranges are areas 60 and 61 in FIG. 1, and on the half mirror 4 are shown in FIG. 1O. Shaded area 62.
This is area 63. In this way, these two areas are configured so that they do not overlap with each other. As a result, as shown in FIG. 1, minute dust 64 adheres to the half mirror 4, and even if it is illuminated, its diffusely reflected light will not enter the focus detection device.

[Effects of the Invention] By adopting a configuration in which the illumination light is reflected by the main mirror to illuminate the information display body, the present invention can efficiently direct the information light toward the direction of the viewing eye, and a bright display is possible. becomes.

Furthermore, even if dust or the like adheres to the main mirror, the light scattered by the dust will not enter the photoelectric conversion means, thereby ensuring accurate measurement.

Furthermore, in the embodiment, the information display has two functions: when it is not illuminated, it displays the distance measurement field of view, and when it is illuminated, it stands out brightly in a desired color to indicate what has been selected. Indeed, this contributes to the simplification of the configuration.

[Brief explanation of the drawing]

Figures 1 to 9 show examples of the present invention, Figure 1 is a cross-sectional view of a single-lens reflex camera, Figure 2 is a perspective view of a gradient index lens array, and Figures 3 and 4 are display systems. A developed view of the optical path, Fig. 5 is an explanatory diagram of the illumination optical path, Fig. 6 is a partial cross-sectional perspective view of the focusing glass, Fig. 7 is a plan view of the Fresnel lens, Fig. 8 is a sectional view of the focusing glass, Fig. 9 10 is a perspective view showing the layout of the display device and focus detection device in the camera; FIG. 11 is a sectional view of the focus detection device; FIG. 12 is a plan view of a photoelectric conversion device that is a component of the focus detection device. In the figure, 1 is the camera body, 4 is the main mirror, 5 is a focusing plate with a display, 6 is a pentabulary, 7 is an eyepiece,
8 is a movable mirror, 9 is a focus detection device, IO is a red light,
12 is a light projection lens.

Claims (3)

[Claims] (1) In a single-lens reflex camera equipped with a main mirror that separates the light flux from the subject toward the photoelectric conversion means and the light flux toward the finder system through transmission and reflection, information is placed on or near the intended imaging plane of the objective lens. A display section is provided, and an illumination means is provided for illuminating the information display section through the main mirror, and a light irradiation area on the main mirror by the illumination means is separated from a passage area on the main mirror of the light flux guided to the photoelectric conversion means. A single-lens reflex camera body that displays a viewfinder display. (2) The information display section is composed of a collection of fine light refracting bodies, and the display in the finder according to claim 1, which deflects object light from the eyepiece of the finder system and directs illumination light to the eyepiece. Single-lens reflex camera body. (3) The information display section comprises a plurality of parts, and the illumination means selectively illuminates the parts.
A single-lens reflex camera body that displays the viewfinder display as described in Section 1. (4) A single-lens reflex camera body that performs display within the finder according to claim 1, wherein the information display section is disposed on the optical path of the finder system.