JP2001228473A - Electronic view finder using reflection type liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the artificiality of display by turning a liquid crystal screen and a light emitting surface of tally display into the same surface nearly in a tally display part of a reflection type liquid crystal display device used for an electronic view finder. SOLUTION: In the electronic view finder using the reflection type liquid crystal display device mounting a reflection type liquid crystal display element in an upper part of a circuit board, and having a front light in the upper part of the reflection type liquid crystal display element, in order to provide the tally display part on the reflection type liquid crystal display element, a light emitting element is mounted closely to the reflection type liquid crystal display element of a circuit board, and the electronic view finder using the reflection type liquid crystal display device having a structure to guide the light from the light emitting element to the tally display part by using a light transmission sheet is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic viewfinder using a reflection type liquid crystal display device.

[0002]

2. Description of the Related Art An electronic viewfinder using a liquid crystal display element is used as a display device of an integrated video camera. The electronic viewfinder is used to check the shooting status of the video camera. In addition, the electronic viewfinder can also display a shooting mode status display, a battery life display, a recording status display, and the like (referred to as a tally display in this specification). is there.
The image may be displayed in a liquid crystal display device, or may be displayed around a liquid crystal display unit by turning on or off a light emitting element such as a light emitting diode.

The liquid crystal display device for an electronic viewfinder according to the prior art uses a transmissive TFT liquid crystal display element, and a light emitting diode or the like is arranged around a liquid crystal display portion to turn on and off the liquid crystal display device. The display could be easily made through the hole of the light shielding plate provided on the outer periphery of the portion.

[0004] Since the resolution of the TFT liquid crystal display element is low due to its structure, an electronic viewfinder using a reflection type liquid crystal display element using a ferroelectric liquid crystal capable of increasing the resolution has begun to be used. Since the substrate is a reflection type using a silicon substrate, a front light is used instead of a backlight.

FIG. 1 is an exploded perspective view of a reflection type liquid crystal display device of an electronic viewfinder according to the present invention. FIG. 2 is a front sectional view of a reflection type liquid crystal display device according to the present invention. A reflective liquid crystal display element 2 and a light emitting element 3 are mounted on an upper surface of a circuit board 1, and a base 4 surrounding the reflective liquid crystal display element 2 is fixed. The base 4 has three guide pins 4
a, 4b, and 4c are provided, and the housing 5 is positioned and fixed by the guide pins. A potting resin (not shown) is filled around the reflective liquid crystal display element 2 inside the base 4. The portion of the housing 5a located above the light emitting element 3 is a concave portion, and when viewed from the inside of the housing 5, the polarizing plate 6, the diffusion plate 7, the light guide plate 8, and the reflection plate (reflection frame).
9 are incorporated. The light guide plate 8 has a structure that is built up on the circuit board 1. Although not shown, there is also a structure in which a concave portion for accommodating the light emitting element 3 is provided at an end of the light guide plate 8 and the light guide plate 8 is directly erected on the circuit board 1. 5c of the housing 5 located on the upper part of the reflective liquid crystal display element 2 is a hollow part, and the upper part is open. Reference numeral 5b denotes a slope of the housing, which serves as a mounting table for the transflective reflection sheet 10.

Reference numeral 12 denotes a light-shielding plate, which is a plate or sheet made of resin or the like. The light shielding plate 12 has an opening 12a corresponding to the display area 2a of the reflective liquid crystal display element 2.
And a hole 1 for inserting and fixing the transflective reflection sheet 10
2b and a notch 12c for arranging the light guide plate 8. The non-display area 2b other than the display area 2a of the reflective liquid crystal display element 2 is configured to be completely covered by the light shielding plate. Therefore, the incident light enters only from the opening 12a and enters only the display area of the reflective liquid crystal display element 2. As a result, light leakage and irregular light from the non-display area are eliminated, and the image can be easily viewed.

[0007]

By arranging a light emitting diode or the like around the TFT liquid crystal display and turning it on and off, it is possible to easily display an image through a hole of a light shielding plate provided on the outer periphery of the liquid crystal display. Was. In the above-mentioned reflection type liquid crystal display device, since the non-display area other than the display area of the reflection type liquid crystal display element is completely covered by the light shielding plate, a light emitting diode or the like is arranged between the liquid crystal display element and the light shielding plate. Is difficult. If it is forcibly arranged, a large step is formed between the light emitting diode and the like and the liquid crystal display unit, resulting in an unnatural display.

[0008]

SUMMARY OF THE INVENTION In an electronic viewfinder using a reflection type liquid crystal display device having a reflection type liquid crystal display device mounted on a circuit board and a front light provided on the reflection type liquid crystal display device, a reflection type liquid crystal display device is provided. In order to provide a tally display section on the liquid crystal display element, a light emitting element is mounted near the reflection type liquid crystal display element of the circuit board, and light from the light emitting element is guided to the tally display section using a light guide sheet. An electronic viewfinder using a reflective liquid crystal display device having a structure.

The light guide sheet is a rectangular transparent sheet. One end in the longitudinal direction faces the light emitting element, and the other end faces the tally display section. The light guide sheet has a portion facing the light emitting element and a section facing the tally display section. An electronic viewfinder using a reflection type liquid crystal display device in which a reflection layer is formed only on the back surface.

[0010]

FIG. 3 is a front sectional view of a reflection type liquid crystal display device showing one embodiment of the present invention, and FIG. 4 is a side sectional view. 5 is an enlarged view near the transparent sheet of FIG. 3, and FIG. 6 is an enlarged view near the transparent sheet of FIG. FIG.
3A is a top view (A) and a front view (B) of the transparent sheet.

A reflection type liquid crystal display element 22 and light emitting elements 23 and 31 are mounted on an upper surface of a circuit board 21, and a base 24 surrounding the periphery of the reflection type liquid crystal display element is fixed. Base 24
Are provided with guide pins (not shown), and the housing 25 is positioned and fixed by the guide pins. Base 24
Is filled with a potting resin (not shown) around the reflective liquid crystal display element 22. The portion of the housing 25a located above the light emitting element 23 is a concave portion,
As viewed from the inside of the housing 25, a polarizing plate 26, a diffusion plate 27, a light guide plate 28, and a reflection plate (reflection frame) 29 are incorporated.
A window 25b is formed in the upper part of the housing 25, and the liquid crystal display and the like are observed from the window 25b. The light guide plate 28 is structured to be built up on the circuit board 21. Although not shown, there is also a structure in which a concave portion for accommodating the light emitting element 23 is provided at the end of the light guide plate 28 and the light guide plate 28 is directly erected on the circuit board 21. Housing 2 located above reflective liquid crystal display element 22
Reference numeral 25c denotes a hollow portion, and the semi-transmissive reflective sheet 30 is arranged obliquely as in the above-described reflective liquid crystal display device.

Reference numeral 32 denotes a light-shielding plate, which is a plate-like member made of resin or the like. The light shielding plate 32 is a reflection type liquid crystal display element 2.
An opening 32a corresponding to the second display area, and a light guide section (tally display section) 32b for guiding the light guided by the light guide sheet 32 to the upper portion of the light shielding plate. The light shielding plate 32 is formed with a slit 32c for inserting a light guide sheet 33 for guiding light from the upper part of the light emitting element 31 to the lower part of the light guide part 32b. The display area of the reflection type liquid crystal display element 22 and the non-display area other than the light guide section 32b are completely covered by the light shielding plate 32.

The light guide sheet 33 guides light from the light emitting element 31 and guides the light to the light guide portion 32b of the light shielding plate. A rectangular sheet formed of a transparent material having a high light transmittance such as polycarbonate, and one end in the longitudinal direction faces the light emitting element 31 and the other end faces the tally display section 32b. Layer 33 only on the back surface of the portion facing the tally display portion 32b and the portion facing the
a and 33b are formed. If a reflection layer is provided on the entire surface of the light guide sheet 33 other than the light guide section and the light output section, light output from the light output section will be extremely reduced, so that the portion facing the light emitting element 31 (light input section) and the section facing the tally display section The reflection layer is formed only on the back surface of the (light emitting portion). According to this structure, the light incident on the reflective liquid crystal display element 22 is transmitted through the opening 32a as in the prior art.
And only the display area of the reflective liquid crystal display element 22. As a result, light leakage and irregular light from the non-display area are eliminated, and the image can be easily viewed.

[0014]

According to the present invention, the light emitting element is mounted near the reflection type liquid crystal display element of the circuit board, and the light from the light emitting element is guided to the tally display section using the light guide sheet. Even in a configuration in which a non-display area other than the display area of the reflective liquid crystal display element is completely covered by the light-shielding plate, a light-emitting portion (light-emitting portion) can be arranged between the liquid crystal display element and the light-shielding plate. The liquid crystal display surface and the light emission surface of the tally display are almost the same, and the unnaturalness is eliminated. When the light guide sheet is incorporated in the light shielding plate as in the embodiment, the tally display portion can be formed without changing the thickness of the reflection type liquid crystal display device.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a reflective liquid crystal display device of an electronic viewfinder according to the present invention.

FIG. 2 is a front sectional view of a reflection type liquid crystal display device of the present invention.

FIG. 3 is a front sectional view of a reflective liquid crystal display device according to an embodiment of the present invention.

FIG. 4 is a side sectional view

FIG. 5 is an enlarged view of the vicinity of the transparent sheet of FIG. 3;

FIG. 6 is an enlarged view of the vicinity of the transparent sheet of FIG. 4;

FIG. 7 is a top view (A) and a front view (B) of a transparent sheet.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 circuit board 2 reflective liquid crystal display element 2 a display area 2 b non-display area 3 light emitting element 4 base 4 a guide pin 4 b guide pin 4 c guide pin 5 housing 5 a housing recess 5 b housing slope 5 c housing cavity Unit 6 Polarizing plate 7 Diffusion plate 8 Light guide plate 9 Reflection plate 10 Transflective reflection sheet 12 Light shielding plate 12a Opening 12b Hole 12c Notch 21 Circuit board 22 Reflective liquid crystal display element 22a Display area 2b Non-display area 23 Light emitting element Reference Signs List 24 base 25 housing 25a housing window 26 polarizing plate 27 diffusion plate 28 light guide plate 29 reflector 30 transflective reflection sheet 31 light emitting element 32 light shielding plate 32a opening 32b light guide 32c slit 33 light guide sheet 33a Reflective layer 33b Reflective layer

Continued on the front page F term (reference) 2H088 EA13 EA20 EA22 EA25 2H091 FA14X FA14Z FA15X FA23X FA41X FA45Z GA11 LA16 MA10 5C022 AA11 AC03 AC15

Claims (2)

[Claims] 1. An electronic view finder using a reflection type liquid crystal display device having a reflection type liquid crystal display device mounted on a circuit board and a front light provided above the reflection type liquid crystal display device. In order to provide a tally display section, a light emitting element is mounted in proximity to the reflection type liquid crystal display element of the circuit board, and light from the light emitting element is guided to the tally display section using a light guide sheet. Viewfinder using a reflective liquid crystal display device. 2. The light guide sheet is a rectangular transparent sheet, and one end in the longitudinal direction faces the light emitting element, and the other end faces the tally display section, and faces the light emitting element and the tally display section. 2. The electronic viewfinder according to claim 1, wherein a reflection layer is formed only on the rear surface of the portion.