Liquid crystal driving system

• US 4,834,503 A
• Filed: 03/16/1988
• Issued: 05/30/1989
• Est. Priority Date: 12/06/1983
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tsujimoto, Shinichi, Kazumi, Jiro
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Lerner, Martin
• Application Number:
  US07/169,072
• Time in Patent Office: 440 Days
• Field of Search: 340/717, 340/764, 340/784, 350/332, 350/334, 350/335, 350/342
• US Class Current: 349/73
• CPC Class Codes: G03B 17/24 with means for separately producing marks on the film, e.g. title, time of exposure
• CPC Class Codes: G03B 2217/243 Optical devices
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G09G 3/18 using liquid crystals

Abstract

In a liquid crystal driving system for driving a plurality of liquid crystal display devices with a single liquid crystal driver, segment signals from the driver are connected in common to the liquid crystal devices. Meanwhile, common signals which are connected to the liquid crystal display devices are in different waveforms from each other.

Claims

1. A display device for a camera, comprising:

(a) a first liquid crystal display unit having a common electrode and segment electrodes for displaying letters or figures or the like in a non-transmissive state by shapes of the segment electrodes with a potential difference generated between said common electrode and said segment electrodes, said first liquid crystal display unit being used for monitoring;

(b) a second liquid crystal display unit having a common electrode and segment electrodes for displaying letters or figures or the like in a transmissive state by shapes of the segment electrodes without generating a potential difference between said common electrode and said segment electrodes, wherein said segment electrodes of said second liquid crystal display unit have a region with an almost same shape as that of said segment electrodes of the first liquid crystal display unit and said second liquid crystal display unit is used for imprinting data on a film;

(c) a display circuit for driving said first and second liquid crystal display units, said display circuit having a driver being connected to said segment electrodes having said regions with the same shape of both said first and second liquid crystal display units so as to supply same segment signals thereto, and said driver being connected to said common electrodes of both said liquid crystal display units so as to supply common signals having phases inversed between the two common electrodes; and

(d) a light source for imprinting data, positioned near said second liquid crystal unit.

2. A display device according to claim 1, wherein:

said first liquid crystal display unit and said second liquid crystal display unit are disposed side-by-side.

3. A display device according to claim 1, wherein:

said first and second liquid crystal display units are disposed within a back lid.

4. A display device according to claim 1, wherein:

said first and second liquid crystal display units are mounted on a same printed circuit board.

5. A display device for a camera, comprising:

(a) a first liquid crystal display unit having a common electrode and segment electrodes for displaying letters or figures or the like in a non-transmissive state by shapes of the segment electrodes with a potential difference created between said common electrode and said segment electrodes;

(b) a second liquid crystal display unit having a common electrode and segment electrodes for displaying letters or figures or the like in a light transmissive state by shapes of the segment electrodes when a potential difference is not generated between said common electrode and said segment electrodes, wherein said segment electrodes of the second liquid crystal display unit have a region with an almost same shape as that of said segment electrodes of the first liquid crystal display unit, and wherein a mask having an opening over a region of said segment electrodes, is formed at said second liquid crystal display unit; and

(c) a display circuit for driving both of said first and second liquid crystal display units, said display circuit having a driver being connected to segment electrodes of both said first and second liquid crystal display units having regions with the same shape so as to supply same segment signals thereto, and said driver is connected to said common electrodes of both said liquid crystal display units so as to supply common signals having respective phases inversed therebetween.

6. A display device according to claim 5, wherein:

said mask is made of a layer of masks having an opening only over a region of said segment electrodes.

7. A display device according to claim 5, wherein:

said mask is disposed between said segment electrodes and said common electrode.