JPS58123580A - Information mark display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides, for example, in a finder optical path of a cine camera, etc.
The present invention relates to an information mark display device in which a special relief type grid line structure is arranged, and a display pattern from this grid line structure can be observed along with a finder screen as necessary.

Mizu Applicant has already applied a reflective coating to a relief-type focused image hologram, embedded this relief structure with a medium having the same refractive index as the relief component, and placed it near the focus surface of a cine camera. proposed an information mark display device that reproduces information. However, this display device requires a process of applying a coating and then bonding it in order to create the information mark display body.
There was also a problem that the display body was expensive.

An object of the present invention is to provide an information mark display device that is simpler and cheaper to implement, and its gist is to provide an information mark display device that is simpler and cheaper to implement. Forms information patterns based on the results of minute slopes,
The sloped surface is configured such that illumination light entering the substrate from a light source disposed on the side of the substrate is totally reflected by the input plane, further totally reflected by the sloped surface, and exits from the exit plane of the substrate. The feature is that the angle of inclination with respect to the plane of use is determined.

The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 shows a cross-sectional view of the focus plate of the finder of a cine camera, in which the focus plate l having a split image rangefinder is arranged almost perpendicularly to the finder optical axis C from the input side of the finder light beam, and Information mark display bodies 2 having pattern information on their surfaces are arranged adjacent to each other. A prism 4 is glued to a position off the optical axis C of the exit plane 3 of the information mark display body 2, and a tungsten lamp,
Illumination light from a light source 5 such as an LED is made to enter the information mark display body 2 via this prism 4. In addition, a plurality of draft-shaped notches 7 are carved in a grid pattern in a direction substantially perpendicular to the direction of the light source 5 on the finder light flux use plane 6 of the information mark display body 2. A set of notches 7 represents an information pattern. Each cut 7
As shown in an enlarged view in FIG. 2, the information mark display body 2 has a surface 8 substantially perpendicular to the plane of use 6 and an inclined surface 9 having an inclination angle α with respect to the plane of incidence 6. There is. The irradiation light g that enters the information mark display body 2 from the light source 5 via the prism 4 travels through the information mark display body 2 while repeating total reflection, passes through the notch 7 in the middle, and enters the information mark display body 2. It is totally reflected by the incident plane 6 just before it and directed toward the inclined surface 9. It is further totally reflected by the inclined surface 9 and is emitted from the exit plane 3 of the information mark display 2 in a substantially vertical direction to the observer looking through the finder window. It has a length of 11'77, reaching the eyes. The light emitted from the information mark display body 2 does not necessarily have to be perpendicular to the exit plane 3, but may be at an angle that is incident on the observer's eyes. If it is a general finder optical system, the exit angle may be about 20 degrees.

Here, in order for two series of total reflections to occur, the plane of incidence 6
It is necessary that both the conditions for total reflection of the illumination light at the slope surface 9 and the conditions for the total reflection of this total reflection light to be satisfied at the inclined surface 9 are satisfied. Therefore, the inclination angle of the inclined surface 9 of the notch 7 is α, the incident angle of the illumination light ρ to the incident plane 6 is β, and the information mark display body 2
In order to satisfy the former condition, n = 180'-2α>sin-' (1/
n) e * (1) To satisfy the latter condition, α>S! n −' (1/ n) I @ 11
11t It is required that the inequality of fist (2) is satisfied.

Therefore, from both equations, sin '(1/n)(α(90' - (1/
2) ・sin −' (1/n)・shu・(3) It must be. If the information mark display body 2 is made of an acrylic material, n=1.492, then equation (3) becomes: 42° α 696 . . . (4).

In addition, in FIG. 2, α=600 is shown.

By the way, when we consider the influence of the notch 7 on the finder light flux, we find that the information mark display 2
Cut 7 of the finder light flux from the subject that has reached
The incident light beam L1 is refracted by the inclined surface 9 and the exit plane 9 of the information mark display body 2, and as a whole is refracted by an angle θ with respect to the finder optical axis C. This angle θ has a refractive index n of the information mark display body 2 of 1.492,
If the inclination angle α of the inclined surface 9 is 60°, it will be approximately 38.2°. For this reason, there is a possibility that the notch 7 may be seen as a black line in a finder in a normal state. Therefore, in order to prevent this, it is desirable to make the grid structure so fine that it cannot be resolved by the eye. If this is done, the part of the notch 7 will simply appear dim on average, and no particular dark line structure will be recognized. Expressing this mathematically, the interval between the notches 7 is Pw, and the width of the notches 7 is Pd.
In this case, the part of the notch 7 in the subject image seen through the finder will appear shadowed at a ratio of Pd/Pw. In a normal single-lens reflex camera, it is desirable to keep the width Pd at about 10 pm or less, and in the case of a cinera camera, it is desirable to keep the width Pd at about 10 pm or less.

Furthermore, if fine notches 7 like this are periodically present,
The finder light beam becomes subject to diffraction effects. Let us consider the influence of this diffraction effect on the luminous flux approximately as follows. When the finder light beam consisting of a plane wave is perpendicularly incident on the information mark display body 2, the light beam L2 that has entered the required plane 6 without the notch 7 will travel straight, but the light beam Ll that has entered the notch 7 is Since it is refracted as described above, the amplitude distribution of the wavefront immediately after passing through the information mark display body 2 is as follows.
If the vertical axis is the amplitude of the transmitted light and the horizontal axis is the in-plane distance trend 1 of the information mark display body 2, an approximation can be made as shown in FIG. Here, by changing the ratio of Pd/Pw and calculating the 0th, 1st, and -1st order diffraction effects for the wavelength of input = 0.5b, the 5th
The result will be as shown in the figure.

Note that the N-order diffraction efficiency η on the vertical axis is the ratio of the amount of N-th diffracted light to the amount of incident light, and reflection loss and absorption loss are not considered. The 0th order diffracted light is light that is transmitted in the same direction as the incident direction, and this is the correct finder image.
I will do it. At least the O-order diffraction efficiency is required to be 70% or more, and from Figure 5, Pd/Pw < O, l
6 is required.

FIG. 6 is a front view of the information mark display body 2, and a plurality of rows of notches 7 are provided only in the pattern 10 to be displayed provided on the use plane 6 of the information mark display body 2. :(
It is provided in a direction perpendicular to the illumination light ρ from 5. Therefore, the illumination light ρ from the light source 5 enters the information mark display body 2 via the prism 4, and further hits each notch 7 in the display pattern 10 and is totally reflected and enters the observer's eyes. will appear to shine brightly.

FIG. 7 shows a case where there are two display patterns, in which two light sources 5a, 5b and two prisms 4a, 4b are arranged at the corners of the information mark display body 2, respectively. , notch 7 in two display patterns 10a and 10b
The grid line directions are arranged to be orthogonal to the traveling directions of the illumination lights ρa and ρb from the respective lights 7g 5 a and 5b. Therefore, the illumination light Na from the light sources 5a and 5b,
By selectively or simultaneously irradiating ρb, the desired display pattern 10a or 10b or both can be displayed.

As explained above, the information mark display device according to the present invention illuminates the grid line structure consisting of a plurality of cherry-shaped notches provided in the desired plane of the finder light beam of the information mark display body, which is an optically transparent body. By simply irradiating light, display patterns can be projected on both sides of the finder extremely easily and inexpensively.

[Brief explanation of drawings]

The drawings show an embodiment of the information mark display device according to the present invention, and FIG. 1 is a sectional view thereof, FIG. 2 is an explanatory diagram of the cut structure, FIG. 3 is an explanatory diagram of the optical path of the finder light beam, and FIG. 4 is an explanatory diagram of the optical path of the finder light beam. , FIG. 5 is an explanatory diagram of the diffraction of the finder light beam, and FIGS. 6 and 7 are front views of the information mark display body. 1 is a focusing plate, 2 is an information mark display body, 3 is an exit plane, 4.4a, 4b are prisms, 5.5a, 5b are light sources, 6 is a use plane, 7 is a notch, 8 is a vertical plane, 9 is an inclined surface, and 10110a and 10b are display patterns. Patent applicant Canon Co., Ltd. JP-A-58-123580 (4) Figure 4 Keiji Nuka. 1. Fig. 5 1 L-101"-w I&-1

Claims (1)

[Claims] 1. An information pattern is formed by a collection of a large number of fine inclined surfaces on the desired plane of a substrate made of a transparent flat plate, and light is incident into the substrate from a light source arranged on the side of the substrate. The illumination light is totally reflected by the incident plane, and further totally reflected by the inclined surface, resulting in
(An information mark display device characterized in that the tilt angle of the slope with respect to the plane of incidence is determined so that the light is emitted from the plane of incidence of the plate. 2. Let α be the tilt angle of the slope, and n be the refractive index of the substrate. When, sin' (1/n) <α<9o'-(1'/2)
・Claim 1 that satisfies 5 in-breath (1/n)
Information mark display device as described in Section. 3. When the interval between the inclined surfaces is Pw, and the width in the plane direction of the plate of the inclined surface is Pd, Pd/Pw ≦0. 16. The information mark display device according to claim 1.