JPS6158021B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device in the viewfinder of a camera, and more particularly to a device for guiding exposure information displayed by a plurality of exposure information display elements located outside the viewfinder optical path into the viewfinder. .

In recent years, with electronic control of cameras, the method of displaying exposure information in the viewfinder is also shifting to digital display. That is, in this digital display device, a plurality of exposure information display elements corresponding to individual exposure information are placed outside the viewfinder optical path, and the optical images of these elements are brought into the viewfinder optical path by the light guide member. The structure is such that it can be introduced.

By the way, in the above-mentioned digital display type in-finder display device, the number of display elements increases as exposure information increases, but when using a large number of display elements aligned in one direction, the following problems arise. There is. In other words, since conventional light guide members only have the function of changing the optical path of the principal ray of each element in a plane perpendicular to the alignment direction of the element group, eyepoint Only these elements can be clearly observed. In other words, the chief rays of the elements in the center of the alignment direction can enter the eyepoint, but as the number of elements increases, the chief rays of the elements closer to both ends of the alignment direction do not pass through the eyepoint. becomes difficult. For this reason, in the conventional method, when reading exposure information, it is necessary to move the eyepoint in the alignment direction of the element group for observation.

In order to solve this problem, conventionally, a transparent plate having an image forming optical part such as a microprism on one side is placed between the incident surface of the light guide member and the display element to direct the light from the display element. Attempts are being made to spread it (see Japanese Patent Laid-Open No. 53-65725). However, with this structure, the light from the display element is diffused to make the light incident on the eyepiece more uniform, which results in a large loss of light. The amount will have to be increased. Therefore, such measures have the disadvantage that the power consumed by the display element increases and the battery life is shortened.

The present invention takes into account the actual situation of the conventional in-viewfinder display device as described above, and provides an in-viewfinder device for a camera that allows all display elements to be observed uniformly and clearly from an eye point, and in which the loss of light amount of the display elements is small. This paper proposes a display device.

To summarize the present invention, the present invention includes a plurality of information display elements disposed outside the viewfinder optical path, and introduces emitted light beams of information displayed by these elements into the viewfinder optical path by a light guide member. In the in-finder display device, the light guide member includes:
a condenser lens section that is provided facing the information display element and converts the emitted light beams into parallel light beams; an optical path converter section that changes the optical path of the parallel light beams toward a viewfinder optical path; A display device in the viewfinder of a camera, comprising a converging part that converges the optical path of a light ray passing through a plurality of through holes formed in a display scale means provided in a plane substantially parallel to the alignment direction and near an eye point. It is in.

Embodiments of the invention will now be described in detail with reference to the drawings.

FIG. 1 shows an enlarged cross-section of the main part of a single-lens reflex camera to which the present invention is applied, and the screen 1
That is, a penta prism 5 held by a penta support member 4 is mounted on a penta frame 3 to which a focusing glass and a viewfinder field mask 2 are attached. Outside the penta support member 4, there are a plurality of exposure information display elements 6a, 6 arranged in a direction perpendicular to the plane of the paper of FIG.
b...6n is attached. A window 7 is bored in the pentagonal support member 4, and the window 7 changes the optical path of the incident light from the elements 6a, 6b, . A guide member 8 is attached. The light guide member 8 is made of, for example, transparent acrylic resin and is molded into a block shape as shown in the third figure. 6a, 6
b……Condenser lens group 8 compatible with 6n
b is integrally formed. The light guide member 8 also includes an introducing means (optical path converter) that changes the optical path of the incident light from the element group in a plane parallel to the plane of the paper in FIG. 2 and causes it to enter the finder optical path. In the illustrated embodiment, this introduction means includes a first reflective surface 8 that reflects the incident light in a substantially perpendicular direction.
c, and a second reflective surface 8d that reflects the reflected light from the reflective surface 8c into the finer optical path of the pentagonal prism 5 so that the final reflected light is directed toward the vicinity of the eye point.

On the other hand, the light guide member 8 includes a light projection surface 8e facing the entrance surface 5a of the pentagonal prism 5. According to the illustrated embodiment, the light projection surface 8e is constituted by a cylindrical surface having a central axis Z (shown in the second figure) in a plane parallel to the alignment direction of the elements 6a, 6b, . . . , 6n. Therefore, each element 6a, 6b...
Principal rays a, b...n from ...6n are converged toward eyepoint I in a plane parallel to the alignment direction of the element group, as shown in the second diagram. The shape of the light projecting surface 8e according to the present invention, that is, the converging means is not limited to a cylindrical surface, but may have a wedge shape 8f shown in FIG. You can still achieve your goal. In the figure, reference numeral 9 denotes a scale plate on which exposure information values are displayed on a portion extending into the viewfinder optical path, and the chief rays a, b, etc. of each element 6a, 6b, 6n, etc.
n is magnified by each condenser lens 8 and enters the pentagonal prism 5 through the hole 10 corresponding to these information values.

As is clear from the above description, in the camera viewfinder display device of the present invention, not only the light beam of the exposure information display element is introduced into the viewfinder optical path, but also the chief ray of each element is directed near the eye point. Even if the number of elements is increased, the light from all the elements can be uniformly and clearly observed from the eyepoint. This eliminates the inconvenience of moving the eye point to read exposure information and the need to increase the amount of light emitted from the element, as in the past.

In the illustrated embodiment, the exposure information display element group is arranged such that the direction of light emitted from the element group is directed downward; however, the present invention is not limited to this. The light emitting device may be installed horizontally so that the light emission direction is directed toward the viewfinder optical path. In this case, there is no need to provide the one reflective surface 8c.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the display device in the viewfinder according to the present invention, FIG. 2 is a developed view taken along a plane including each principal ray of the display device, and FIG. 3 is a light guide member used in the display device. FIG. 4 is an explanatory view of a modified example of the light guide member. 6a, 6b,...6n...Exposure information display element, 8...Light guide member, 8c, 8d...Reflection surface, 8e...Light projection surface, a, b,......n...Principal ray , I...Eye point.

Claims (1)

[Claims] 1. An in-finder display device comprising a plurality of information display elements disposed outside the finder optical path, and in which a light beam of information displayed by these elements is introduced into the finder optical path by a light guide member, The light guide member includes a condenser lens part that is provided facing the information display element and converts the emitted light beams into parallel light beams, and an optical path converter part that changes the optical path of the parallel light beams toward the inside of the finder optical path. , a converging part that converges the optical path of the light ray passing through a plurality of through holes formed in the attached display scale means in a plane substantially parallel to the alignment direction of the display elements, to near the eye point. A display device in the camera's viewfinder.