Digital camera which produces a single image based on two exposures

• US 6,903,770 B1
• Filed: 07/27/1999
• Issued: 06/07/2005
• Est. Priority Date: 07/27/1998
• Status: Expired due to Fees

• Current Assignee: Xacti Corporation (Office Support KK)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Kobayashi, Akio, Okada, Hidefumi
• Primary Examiner(s): Ho, Tuan
• Assistant Examiner(s): VILLECCO, JOHN M
• Application Number:
  US09/361,610
• Time in Patent Office: 2,142 Days
• Field of Search: 348/216.1, 348/218.1, 348/220.1, 348/294, 348/296, 348/299, 348/303, 348/311, 348/312, 348/314, 348/316, 348/322, 250/208.1
• US Class Current: 348/296
• CPC Class Codes: H01L 27/1462 Coatings
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14806 Structural or functional details thereof
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors
• CPC Class Codes: H04N 25/7795 Circuitry for generating timing or clock signals

Abstract

A digital camera includes a CCD imager having an interline transfer scheme. A first charge produced due to first exposure is read from light receiving elements positioned vertically intermittently. A second charge produced due to second exposure is also read from the same light receiving elements to vertical transfer regions. Here, the first charge is vertically moved simultaneously with or prior to reading out the second charge. The moving distance, at this time, is equal to or greater than a distance that the light receiving elements continue in the vertical direction. As a result of this, the second charge will not be mixed with the first charge. The first and second charges are subjected to a compositing process to display a composite image on an LCD.

Claims

1. A digital camera, comprising:

an imager including a vertical transfer register having a plurality of transfer areas, a horizontal transfer register connected to an output terminal of said vertical transfer register, and a plurality of light-receiving elements respectively assigned to said plurality of transfer areas;

a timing generator connected to said imager, and for applying timing signals to said imager, wherein said timing signals include a first exposure signal for carrying out a first exposure of a first time period, a second exposure signal for carrying out after said first exposure a second exposure of a second time period, which is shorter than said first time period, a first reading signal for reading-out from first light-receiving elements intermittently present in a vertical direction out of said plurality of light-receiving elements to said vertical transfer register first electric charges generated by said first exposure, a second reading signal for reading-out from second light-receiving elements respectively assigned to vacant transfer areas in which no electric charge is present out of said plurality of light-receiving elements to said vertical transfer register second electric charges generated by said second exposure, a vertical transfer signal for transferring the electric charges read-out to said vertical transfer register in a vertical direction, and a horizontal transfer signal for transferring in a horizontal direction the electric charges that reaches said horizontal transfer register by a transfer in accordance with said vertical transfer signal, and wherein said second light receiving elements are intermittently present in the vertical direction, and said first electric charges read out by said first reading signal and said second electric charges read out by said second reading signal are alternately arranged on said vertical transfer register; and

a processor for generating one screen of a first image signal based on said first electric charges and said second electric charges output from said imager;

an instruction key for inputting an imaging instruction; and

a shutter member arranged at a front surface of said imager, and for cutting-off an irradiation of light into said imager;

wherein

said timing signal further includes a third exposure signal output in response to an operation of said instruction key, and for carrying out a third exposure of a third time period, a third reading signal for reading out from said plurality of light-receiving elements to said vertical transfer register third electric charges generated by said third exposure, a second vertical transfer signal for transferring in a vertical direction said third electric charges on said vertical transfer register, a second horizontal transfer signal for transferring in a horizontal direction said third electric charges applied to said horizontal transfer register, a fourth exposure signal for carrying out a fourth exposure after said third exposure, a driving signal output after a fourth time period, which is different from said third time period, has passed since a time of starting said fourth exposure, and for driving said shutter member, a fourth reading signal for reading out fourth electric charges generated by said fourth exposure from said plurality of light-receiving elements to said vertical transfer register after a completion of a vertical transfer of said third electric charges, a third vertical transfer signal for transferring in a vertical direction said fourth electric charges on said vertical transfer register, and a third horizontal transfer signal for transferring in a horizontal direction said fourth electric charges applied to said horizontal transfer register, and said processor generating one screen of a second image signal based on said third electric charges and fourth electric charges output from said imager.

2. A digital camera according to claim 1, further comprising a recorder for recording said second image signal into a recording medium in a compressed state.

3. A digital camera, comprising:

an imager including a vertical transfer register having a plurality of transfer areas, a horizontal transfer register connected to an output terminal of said vertical transfer register, and a plurality of light-receiving elements respectively assigned to said plurality of transfer areas;

an exposure controller for controlling an exposure of said imager by using an electric shutter system;

a reader for reading out from a portion of said plurality of light-receiving elements to said vertical transfer register electric charges generated by an exposure of said exposure controller;

a vertical transferor for transferring in a vertical direction the electric charges read-out to said vertical transfer register by said reader;

a horizontal transferor for transferring in a horizontal direction the electric charges that reach said horizontal transfer register by a transfer of said vertical transferor, wherein said exposure controller carries out a first exposure of a first time period, and carries out after said first exposure a second exposure of a second time period, which is shorter than said first time period, said reader reads out from first light-receiving elements intermittently present in a vertical direction out of said plurality of light-receiving elements to said vertical transfer register first electric charges generated by said first exposure, and reads out from second light-receiving elements respectively assigned to vacant transfer areas in which no electric charge is present out of said plurality of light-receiving elements to said vertical transfer register second electric charges generated by said second exposure, and wherein said second light-receiving elements are intermittently present in the vertical direction, and said first electric charges and said second electric charges read out by said reader are alternately arranged on said vertical transfer register; and

a generator for generating one screen of a first image signal based on said first electric charges and said second electric charges output from said imager;

an instruction key for inputting an imaging instruction;

a shutter member arranged at a front surface of said imager, and for cutting-off an irradiation of light into said imager; and

a driver for driving said shutter member, wherein said exposure controller carries out a third exposure of a third time period in response to an operation of said instruction key, and starts a fourth exposure after said third exposure, said reader reads out from said plurality of light-receiving elements to said vertical transfer register third electric charges generated by said third exposure, and reads out fourth electric charges generated by said fourth exposure from said plurality of light-receiving elements to said vertical transfer register after a completion of a vertical transfer of said third electric charges, said driver drives said shutter member when a fourth time period, which is different from said third period, has passed since a time of staring said fourth exposure, and said generator generates one screen of a second image signal based on said third electric charges and said fourth electric charges output from said imager.

4. A digital camera according to claim 3, further comprising a recorder for recording said second image signal into a recording medium in a compressed state.